From patchwork Thu Nov 17 22:54:48 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kumar Kartikeya Dwivedi X-Patchwork-Id: 13047426 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 05FC8C4332F for ; Thu, 17 Nov 2022 22:55:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234455AbiKQWzY (ORCPT ); Thu, 17 Nov 2022 17:55:24 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52944 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234802AbiKQWzT (ORCPT ); Thu, 17 Nov 2022 17:55:19 -0500 Received: from mail-pf1-x443.google.com (mail-pf1-x443.google.com [IPv6:2607:f8b0:4864:20::443]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B1D271A3BA for ; Thu, 17 Nov 2022 14:55:18 -0800 (PST) Received: by mail-pf1-x443.google.com with SMTP id k15so3216442pfg.2 for ; Thu, 17 Nov 2022 14:55:18 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=nIaqqP+lrYotcahf/OVYZqQphVsBiOBaqIULMzIdPgs=; b=ggqZnpgYUZO9cE01WaOgfrmyO0kbluzi+CNnY5BJrf61dAoQM45COPHheG2pFqqfId NyLZaC/vpELfaC2PAyp1HVJzPjaeuqrd93ZeoQ4ic18SVEHqNd99U8EOG5xN608/5AD3 5wqL0qcL3ZbByIRWbk/nqC9eV5iM7BUDn/pc4qlopqt3uVg3N4zFmq7h0JjWTWB1rFDS 2re6vsj3bQqOKzuH/IVNnURNVnXiib9aNj1m5BhDgdzn9Erue0X7aSjlgae0AJ4pTlFY iFNmQFJFBl+v3dI3yWlX284lNDo1M8wRpYwoiW2kmG0bYmOWUK7rG5ZBdhbhgiyShrEU Y+eA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=nIaqqP+lrYotcahf/OVYZqQphVsBiOBaqIULMzIdPgs=; b=AImZBfJhTQkO4DDIqlTIPFOmFXJENdb80u8z86qEDBCPwRiaSPOr7ZNXK3Rwno9VZv phjcw6wQ+dACvIyDNzgYCDELhXaOVGV9K6iVjReviPXxRVH8ISUBFMQfDELwhf+2fOpn 5LDRcKwZCBo0xnsy1TqNQjvlCTFL8LvRiPoM8HeCxwFkGhVoxhr5GvkJ9DnhSP81Lfbw 3nPK5sxp+q1BMzLbRJHJarFInKFMTdqYxTiO1TldHadwcaQba4ZVxp5RkMDhTOF6kwKV jLi67pu6DFUpUQm7PAvqMJMwwprXNbeq+1EjbS3LW5blrogHC87Uv2/KTMhHM9us7MBJ DX+Q== X-Gm-Message-State: ANoB5pl08DzbU03/RQux1FmHMe7yT8wTMTbiqKmSEEqpS4/0FF5wmh7c A53oyxh0J8KTEOr8s1k6drk3+9u8LrE= X-Google-Smtp-Source: AA0mqf4stSZTfj2W5LhnGLQLgKIpA5aoXtcidbcpsRItAxfeQDDdD1NkkQygj+2v1gpVl/eM6Tg6Bg== X-Received: by 2002:aa7:8750:0:b0:56c:80e5:c436 with SMTP id g16-20020aa78750000000b0056c80e5c436mr4917877pfo.36.1668725717852; Thu, 17 Nov 2022 14:55:17 -0800 (PST) Received: from localhost ([2409:40f4:8:955c:5484:8048:c08:7b3]) by smtp.gmail.com with ESMTPSA id b8-20020a170903228800b0016c9e5f291bsm2008188plh.111.2022.11.17.14.55.16 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 17 Nov 2022 14:55:17 -0800 (PST) From: Kumar Kartikeya Dwivedi To: bpf@vger.kernel.org Cc: Dan Carpenter , Alexei Starovoitov , Andrii Nakryiko , Daniel Borkmann , Martin KaFai Lau , Dave Marchevsky Subject: [PATCH bpf-next v9 01/23] bpf: Fix early return in map_check_btf Date: Fri, 18 Nov 2022 04:24:48 +0530 Message-Id: <20221117225510.1676785-2-memxor@gmail.com> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20221117225510.1676785-1-memxor@gmail.com> References: <20221117225510.1676785-1-memxor@gmail.com> MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=920; i=memxor@gmail.com; h=from:subject; bh=qOzkLlEqNRMlZc1hevbR7OemmL9Z+xjR14TpehaqFoU=; b=owEBbQKS/ZANAwAIAUzgyIZIvxHKAcsmYgBjdrkaQco8hseIoIn+FXoEPJ9ky0qVqM8ccJD3tXku UeDulmeJAjMEAAEIAB0WIQRLvip+Buz51YI8YRFM4MiGSL8RygUCY3a5GgAKCRBM4MiGSL8RygaGD/ 0ehCtvimH54ZAXmAzCb0+4Xh3gTLue1bCeBrrj4SfbH891UCwVLgktg13D5bqZOaWal6V/cGOC21Ji u8HwNP03cfOYFGxm0IqpfHQiZjAVBsuZi5BHBLjNwEkqVQuWlmItGHOzM4IKos9uo0wT90aNjjVEz8 gwxeUkSbBZr6NsUCW0GGL2nyuag7SuYuPezRWYM10ADDdgc6ajGVKcnAcUKVK+LA+Zb/78iwkudBZu CmyHaAUurdhNiHzPMRTxNKfDDFvUGTf7a5Qqxd65HQQ2yOveYChyuSgmWJRJxwEhGuFjT0AdQZIvmJ w9b7O8tQ9CTouvF8+ub4czxdI4UK/tj+eez+WXSDsIIYeWZPRVzGJTJRmudkqZUaqDNzVNKvsit6IF B8adPoqz0V1SFRdmA7fOPJ2y5BjotYYFsaVS5Wx8gmDck2H6ALWtJezbOGnbtTcsQEm54rkSIzDoiG iYTx4IRHPQbg1k/xVWMNpnPk2Ql+G0u2duYRK3uVuKBjNN5t4lPOn5jcuqr826SZuz3ug+zfpO8jh6 dHdrREvaxLF+ZdqB5zPt0LYhNpelLq9a4Q2vWjRQW+SSW5y8X9AQT7mADy7Ly1ltRsbguh0WqiJjmC KiE9yC4b0Dh5bgmB7+vwyUoSZMNkPji25VUCekmOE9NoEKI+OwPXkgcTMlJw== X-Developer-Key: i=memxor@gmail.com; a=openpgp; fpr=4BBE2A7E06ECF9D5823C61114CE0C88648BF11CA Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net Instead of returning directly with -EOPNOTSUPP for the timer case, we need to free the btf_record before returning to userspace. Fixes: db559117828d ("bpf: Consolidate spin_lock, timer management into btf_record") Reported-by: Dan Carpenter Signed-off-by: Kumar Kartikeya Dwivedi --- kernel/bpf/syscall.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index b078965999e6..8eff51a63af6 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -1010,7 +1010,7 @@ static int map_check_btf(struct bpf_map *map, const struct btf *btf, if (map->map_type != BPF_MAP_TYPE_HASH && map->map_type != BPF_MAP_TYPE_LRU_HASH && map->map_type != BPF_MAP_TYPE_ARRAY) { - return -EOPNOTSUPP; + ret = -EOPNOTSUPP; goto free_map_tab; } break; From patchwork Thu Nov 17 22:54:49 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kumar Kartikeya Dwivedi X-Patchwork-Id: 13047427 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E37EAC4332F for ; Thu, 17 Nov 2022 22:55:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234875AbiKQWz0 (ORCPT ); Thu, 17 Nov 2022 17:55:26 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52978 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234794AbiKQWzY (ORCPT ); Thu, 17 Nov 2022 17:55:24 -0500 Received: from mail-pj1-x1044.google.com (mail-pj1-x1044.google.com [IPv6:2607:f8b0:4864:20::1044]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C8F676339 for ; Thu, 17 Nov 2022 14:55:21 -0800 (PST) Received: by mail-pj1-x1044.google.com with SMTP id o7so2953204pjj.1 for ; Thu, 17 Nov 2022 14:55:21 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=xQWfEZnU96xkexiHPMecwLZhhJHKeuuTJzPTTJL5+18=; b=QPKrhZKSwDbyfpEmbj5zZ+511U3cSlruOLf3EuDvPyj8snc6mMysgIeE/NSoTu2Ap4 37qAScMYmiuHcu2+1JAR3syPLmotQ7VLpbzAtANcERf9wJm8iCS1YVug+YDFYRCmLTBF +jUPdyRoyNqtNWgW+6yFHqOfiE/1BZB6rZeB7e+N/Uxejd2Wix7Et/5c3k/Kr0Ws3MKJ Bg09S29XDWSMym/479DRkC9zj4nCAlZHUSsWcj3FbS0wye2CCkaq1NaIqMMr9oRWLFdy 253RWVbR1YUz8GCcvhlCIq9QbBMgAmtm/rkU9oeZAoda7HLdBHEM8rGY4vkKL+ntVIsv 5L/Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=xQWfEZnU96xkexiHPMecwLZhhJHKeuuTJzPTTJL5+18=; b=bkAUKMNZDCifWHmWWvow6vOXV7qPKhY3pTRdsOx78pMmSuWEBxtMajyi1lOl5SDAHX nKXSEgQyd2PfJJBOBbCW2DxUMncKjWV+WRHAO3kY1PB9jXZNAYoXr3ZIDRvmPQMgM3D6 A2y0fugnUTzqnrwa30ZDtreDGnfTRATnZiTRIc5Txw9iAjJdZgFe9kOcuF2Nx770u5B/ 96Zr8iPIsF/gi/OEIYRucoaYXmjSfJTWIyRvf8ohbxSA61xYmep0/3VIT3BFZB+6yYrn dV6UFmJ/Gxygi/p0f7mk7fwWBSd0tETNSIVcu4SUFvfS+rQb0SypCSvG6ePGA1s+Eb2O O/uw== X-Gm-Message-State: ANoB5plSWHQ5zP8vitnQc8I6nsgNfc170Aw7GtlS8GSk5JrRaBjOYUeN Mpd6ILvSKhUe5tRflLgFT4xWet8JF2I= X-Google-Smtp-Source: AA0mqf7umPW870GywKl1JypWnjUyo2byNx2130CpgqJ8XVupy8iTQmztm7y7wA205wB0fWFWWBXc+w== X-Received: by 2002:a17:90b:106:b0:213:4959:fb98 with SMTP id p6-20020a17090b010600b002134959fb98mr4931712pjz.4.1668725721056; Thu, 17 Nov 2022 14:55:21 -0800 (PST) Received: from localhost ([2409:40f4:8:955c:5484:8048:c08:7b3]) by smtp.gmail.com with ESMTPSA id m13-20020a170902db0d00b00188767268ddsm1980325plx.151.2022.11.17.14.55.20 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 17 Nov 2022 14:55:20 -0800 (PST) From: Kumar Kartikeya Dwivedi To: bpf@vger.kernel.org Cc: Alexei Starovoitov , Andrii Nakryiko , Daniel Borkmann , Martin KaFai Lau , Dave Marchevsky Subject: [PATCH bpf-next v9 02/23] bpf: Do btf_record_free outside map_free callback Date: Fri, 18 Nov 2022 04:24:49 +0530 Message-Id: <20221117225510.1676785-3-memxor@gmail.com> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20221117225510.1676785-1-memxor@gmail.com> References: <20221117225510.1676785-1-memxor@gmail.com> MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=4312; i=memxor@gmail.com; h=from:subject; bh=5PZ4QRQvYOcWzKDR5LxcVFsRltruQteYwu7du7JUqDk=; b=owEBbQKS/ZANAwAIAUzgyIZIvxHKAcsmYgBjdrkaSvKXZ89jWdGw5U7Y5qB+JVaf8OZrycuT+vY5 wHUBAheJAjMEAAEIAB0WIQRLvip+Buz51YI8YRFM4MiGSL8RygUCY3a5GgAKCRBM4MiGSL8RymmxEA DAhXmNuvF9lzb6aw4hCJ89jUp9oTCP07hl9paa1HFUGulpmCdSHi1eCpOxlSABrVSYUHa8l0PhPCjs yGHswCLFp7dpxz3NPupQsgc9+uwDJm9pBGcXberJvmuReNrmucnMfHLXHvjpsPZvc6k6Eo02rEmbto GzPTFTOd7q5Q+g0GFJU+4AqrDnCFxGUmbptkJi+ce6HgxIz5E+YA5fzf9fmaF/r1jVGlUPApzN7j7H bSzIO72G6C7kJNFpxR3TD9+bKgwCiMnJKaU2HAk8gGFdQeHpx1UAVdCPXQVPXXzlK8+mqCj25bzKbJ zqL03AKGcGnYbi5z5BcyxpK5So4g6gsI3Qqfpok456g+eadhekJp7wPcrTQ6itvfthMpL8lzg+f/Lq 18NWdmGB1BWdIfk+7eKs5ijy2BwUNVDxP3L7EbgilRdshIvHonnyOAmyrsXLv3k1Sg3Bd/bmKPIFQt Pcx6QgrFrQEhkg90BvZerHzQLUo9n19r2L7NMp+UzQquWXdyMav44GgxWYv3TIs4EDjByZMRaOITxI HI+IH7xRxTTsCTrmAkBUd/aGr7NIGmRRxe4Fkx81cvdUmaj3t94mT14oxkF2FCRw+jjMayKdH89EUg yUoUyhcc1w30IxQKVmQ8vNRfuCqPRpq4PqbehwlpyYynVKyljVHfR5RetqGA== X-Developer-Key: i=memxor@gmail.com; a=openpgp; fpr=4BBE2A7E06ECF9D5823C61114CE0C88648BF11CA Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net Since the commit being fixed, we now miss freeing btf_record for local storage maps which will have a btf_record populated in case they have bpf_spin_lock element. This was missed because I made the choice of offloading the job to free kptr_off_tab (now btf_record) to the map_free callback when adding support for kptrs. Revisiting the reason for this decision, there is the possibility that the btf_record gets used inside map_free callback (e.g. in case of maps embedding kptrs) to iterate over them and free them, hence doing it before the map_free callback would be leaking special field memory, and do invalid memory access. The btf_record keeps module references which is critical to ensure the dtor call made for referenced kptr is safe to do. If doing it after map_free callback, the map area is already freed, so we cannot access bpf_map structure anymore. To fix this and prevent such lapses in future, move bpf_map_free_record out of the map_free callback, and do it after map_free by remembering the btf_record pointer. There is no need to access bpf_map structure in that case, and we can avoid missing this case when support for new map types is added for other special fields. Since a btf_record and its btf_field_offs are used together, for consistency delay freeing of field_offs as well. While not a problem right now, a lot of code assumes that either both record and field_offs are set or none at once. Note that in case of map of maps (outer maps), inner_map_meta->record is only used during verification, not to free fields in map value, hence we simply keep the bpf_map_free_record call as is in bpf_map_meta_free and never touch map->inner_map_meta in bpf_map_free_deferred. Add a comment making note of these details. Fixes: db559117828d ("bpf: Consolidate spin_lock, timer management into btf_record") Signed-off-by: Kumar Kartikeya Dwivedi --- kernel/bpf/arraymap.c | 1 - kernel/bpf/hashtab.c | 1 - kernel/bpf/syscall.c | 18 ++++++++++++++---- 3 files changed, 14 insertions(+), 6 deletions(-) diff --git a/kernel/bpf/arraymap.c b/kernel/bpf/arraymap.c index 672eb17ac421..484706959556 100644 --- a/kernel/bpf/arraymap.c +++ b/kernel/bpf/arraymap.c @@ -430,7 +430,6 @@ static void array_map_free(struct bpf_map *map) for (i = 0; i < array->map.max_entries; i++) bpf_obj_free_fields(map->record, array_map_elem_ptr(array, i)); } - bpf_map_free_record(map); } if (array->map.map_type == BPF_MAP_TYPE_PERCPU_ARRAY) diff --git a/kernel/bpf/hashtab.c b/kernel/bpf/hashtab.c index 50d254cd0709..5aa2b5525f79 100644 --- a/kernel/bpf/hashtab.c +++ b/kernel/bpf/hashtab.c @@ -1511,7 +1511,6 @@ static void htab_map_free(struct bpf_map *map) prealloc_destroy(htab); } - bpf_map_free_record(map); free_percpu(htab->extra_elems); bpf_map_area_free(htab->buckets); bpf_mem_alloc_destroy(&htab->pcpu_ma); diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index 8eff51a63af6..4c20dcbc6526 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -659,14 +659,24 @@ void bpf_obj_free_fields(const struct btf_record *rec, void *obj) static void bpf_map_free_deferred(struct work_struct *work) { struct bpf_map *map = container_of(work, struct bpf_map, work); + struct btf_field_offs *foffs = map->field_offs; + struct btf_record *rec = map->record; security_bpf_map_free(map); - kfree(map->field_offs); bpf_map_release_memcg(map); - /* implementation dependent freeing, map_free callback also does - * bpf_map_free_record, if needed. - */ + /* implementation dependent freeing */ map->ops->map_free(map); + /* Delay freeing of field_offs and btf_record for maps, as map_free + * callback usually needs access to them. It is better to do it here + * than require each callback to do the free itself manually. + * + * Note that the btf_record stashed in map->inner_map_meta->record was + * already freed using the map_free callback for map in map case which + * eventually calls bpf_map_free_meta, since inner_map_meta is only a + * template bpf_map struct used during verification. + */ + kfree(foffs); + btf_record_free(rec); } static void bpf_map_put_uref(struct bpf_map *map) From patchwork Thu Nov 17 22:54:50 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kumar Kartikeya Dwivedi X-Patchwork-Id: 13047428 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id BBE76C4332F for ; Thu, 17 Nov 2022 22:55:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234710AbiKQWz3 (ORCPT ); Thu, 17 Nov 2022 17:55:29 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53034 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234786AbiKQWz0 (ORCPT ); Thu, 17 Nov 2022 17:55:26 -0500 Received: from mail-pl1-x641.google.com (mail-pl1-x641.google.com [IPv6:2607:f8b0:4864:20::641]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 029546339 for ; Thu, 17 Nov 2022 14:55:26 -0800 (PST) Received: by mail-pl1-x641.google.com with SMTP id p21so2986311plr.7 for ; Thu, 17 Nov 2022 14:55:25 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=wm4NNeNJS0H5WokSXilAlhY0JclfcP6xgh+hPFhMKa4=; b=TECNGCHc6shJxybBV/P2tgtm0vtj0fhNOiAHOHhrWwI2jXe9jVWDJhLOrJtN3W46MO jUy4myEgesWBm/SBi3sVc+YvHar/gSXePYw8JNIAuTZuH0PdP5Fm7I8IjgIKDPvLRjfo s+yDPoyBbnsB6YHibBaQ3UFMrbhvkiCEUI2G3ZmXacWIM+Kqo+8F7+2AzKEXHN8SP0XW YzbVC12zppgFEbaTpqUUBgLVBSqhGF6UtKusCYhAeybQp3c2sWIGr9DQNRE68e/5XaNG WSzI5MHWpWvMa+9+uDPV4YaDi/rE7mLXCIC1BkVx8ThUtEnED49Z4yLGGsMAGQD8b1WU FFwA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=wm4NNeNJS0H5WokSXilAlhY0JclfcP6xgh+hPFhMKa4=; b=QU6pbK6Vc1lara/aWBIRBDnUB5c7y9gmzKHBOnFrLuovDW7LeQFq+d4tOY7eVZI8Vl Tzlwrs1wkpimhhced1/DhoVl99XUhaxTuShqdyiEB25hKeXgBYgIvbnnI0uU5l4a5sA6 NuIBQIeWSb0av2qCRzyJOUQJZe5bBy1fE0gm3BNpDDsipn9v+sTSTWGBH6Sh/9StwewB 5is9AzhhKuaAE0yRT43N7goKsHxLsii9LswnNARXa8SClgR6lpMWG+2qRYK99haGnXCd 8th5aq57EajpBVFLzZ/iaQLGC3msnMHjnonsq0CT7fCM18JIzJb0OwJhx5jJIOlUPLJ7 reCA== X-Gm-Message-State: ANoB5pnbVXxrAxhMLf3HRwltO1cc/1b9FWn6Mw2h5mgC+toD1oMH5u4L mj8+glG/Y+UIszAdjje1td6x3NxVtqE= X-Google-Smtp-Source: AA0mqf5cCYUGb/WtluErlpYfo/lYPvJ06D7BRnm73v0P72jARqo3vPBQTcbUmbgcbHwGXwry2R6Yqw== X-Received: by 2002:a17:903:1109:b0:186:cb27:4e01 with SMTP id n9-20020a170903110900b00186cb274e01mr4705763plh.139.1668725725254; Thu, 17 Nov 2022 14:55:25 -0800 (PST) Received: from localhost ([2409:40f4:8:955c:5484:8048:c08:7b3]) by smtp.gmail.com with ESMTPSA id 205-20020a6217d6000000b0056da073b2b7sm1650629pfx.210.2022.11.17.14.55.23 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 17 Nov 2022 14:55:24 -0800 (PST) From: Kumar Kartikeya Dwivedi To: bpf@vger.kernel.org Cc: Alexei Starovoitov , Andrii Nakryiko , Daniel Borkmann , Martin KaFai Lau , Dave Marchevsky Subject: [PATCH bpf-next v9 03/23] bpf: Free inner_map_meta when btf_record_dup fails Date: Fri, 18 Nov 2022 04:24:50 +0530 Message-Id: <20221117225510.1676785-4-memxor@gmail.com> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20221117225510.1676785-1-memxor@gmail.com> References: <20221117225510.1676785-1-memxor@gmail.com> MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=1211; i=memxor@gmail.com; h=from:subject; bh=MFSSIOz61nwPTf4dvr2OI1CrS/lI0bHuXz3O9ayARiE=; b=owEBbQKS/ZANAwAIAUzgyIZIvxHKAcsmYgBjdrkbn5saVkB7HoV0UppUVjO3d8+04YMSFxUNHz9g 7TAArViJAjMEAAEIAB0WIQRLvip+Buz51YI8YRFM4MiGSL8RygUCY3a5GwAKCRBM4MiGSL8RytBiD/ 9QkE6U8pkHAevfjjsmoLfxDQOuWXSVnhukSYCZ6MTS0u+ehcAlirOwF5HIK7cRkA3zWNvSNAaiKIIF jpITfglp5040S5GScX5GgnIg2ZQv2ASNMotf4RGa7sl7DWebOLLSegBkB3ClTQUqoV8B/Zi19uOaay QOW0liMhDfGpvCbX7tMC3d0zP17bcZbZJ0ef2GKV2c1iFwJTre/JZXWCiiT3+JLpAV6wIkNtVT/FZ6 e69Yfj427xQyj6Yg/ug+NHeC9Hnpz5Z7H9BvR4AEmQlARvyKjYlm5HLPIy0apvfEVqDRaPEK9D3whp +fVFF0TAzA7JuSSqq7/8w8vXSe9p7obpbO3V7O2l9B4fuB/QquUwWt3O3i/vpZMPyqMBfZRvdQ5BRs RYwuPZVmy+rdzG5qmuohp4FGyt5e60HuyIWGfNnMON7WncJz92zZj8FmhTZQga0Q+KxII0CKDbf9lS DgEfPKK5hTJO7cj5jEzXVxspUSBZExE51/3qEE35jvc/j3wvl5MrOtm9m2EPKV/Hr73BOMvz3D9etz 82s2XRuQkFd4W9ROWKS6HJIJvYKE9hJZY9Asrjxa3rqVsSEgZyWBUTSwerkRaHXlITMQJ9f+W/IhBI OfOW5B3ho7P6UW3JALG9Ik+5GNMWEZiCwzd6NwE/pEgTbRLb7E/trBNk1cbQ== X-Developer-Key: i=memxor@gmail.com; a=openpgp; fpr=4BBE2A7E06ECF9D5823C61114CE0C88648BF11CA Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net Whenever btf_record_dup fails, we must free inner_map_meta that was allocated before. This fixes a memory leak (in case of errors) during inner map creation. Fixes: aa3496accc41 ("bpf: Refactor kptr_off_tab into btf_record") Signed-off-by: Kumar Kartikeya Dwivedi --- kernel/bpf/map_in_map.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/kernel/bpf/map_in_map.c b/kernel/bpf/map_in_map.c index 8ca0cca39d49..a423130a8720 100644 --- a/kernel/bpf/map_in_map.c +++ b/kernel/bpf/map_in_map.c @@ -52,12 +52,14 @@ struct bpf_map *bpf_map_meta_alloc(int inner_map_ufd) inner_map_meta->max_entries = inner_map->max_entries; inner_map_meta->record = btf_record_dup(inner_map->record); if (IS_ERR(inner_map_meta->record)) { + struct bpf_map *err_ptr = ERR_CAST(inner_map_meta->record); /* btf_record_dup returns NULL or valid pointer in case of * invalid/empty/valid, but ERR_PTR in case of errors. During * equality NULL or IS_ERR is equivalent. */ + kfree(inner_map_meta); fdput(f); - return ERR_CAST(inner_map_meta->record); + return err_ptr; } if (inner_map->btf) { btf_get(inner_map->btf); From patchwork Thu Nov 17 22:54:51 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kumar Kartikeya Dwivedi X-Patchwork-Id: 13047429 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 360CEC433FE for ; Thu, 17 Nov 2022 22:55:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234794AbiKQWzf (ORCPT ); Thu, 17 Nov 2022 17:55:35 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53078 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234884AbiKQWzc (ORCPT ); Thu, 17 Nov 2022 17:55:32 -0500 Received: from mail-pj1-x1044.google.com (mail-pj1-x1044.google.com [IPv6:2607:f8b0:4864:20::1044]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B02C015829 for ; Thu, 17 Nov 2022 14:55:31 -0800 (PST) Received: by mail-pj1-x1044.google.com with SMTP id e7-20020a17090a77c700b00216928a3917so6699039pjs.4 for ; Thu, 17 Nov 2022 14:55:31 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=4tXOFlrxPDdAO4C616SqFABGb25iFnv7FGs3Eokwgsw=; b=BDYv/f0X6+L65aWH/F2hogFfh/s+OIMhTkTYwIAtL0uH53cZSRv/u9MWd1npzS4qdj CGzAUhhYFsC2uDbbnwbrVjxABWI4TrqHPQvSfjgDjsT4DX9/rzpXpx7FOTdLcEvUU7yp 46Eiy/Y8s53tSvjYCkV62SR+MAFj6hp1PI/s35xsGE9Hwh3Ehj5CWisqB09iaQoE3kYb v/RWv2IkYeycJu2FVjzgRr1ofYmhDabB+af6soa5H/aogKMoyR1doJlVE0NWuz4gZoS3 LgZMZcpoE3eZixxv1+k4PUU61VuhMbRuniCRBGHkEQLXeQ6aTUi9njECHnwmKJfM+a5V CIqw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=4tXOFlrxPDdAO4C616SqFABGb25iFnv7FGs3Eokwgsw=; b=53vCwUDzjY3IO15IqerS8pVaxFKTfKVvrWOXVhbSAbMSj6W1eCOew+b5PCEvAGhIJ2 mPniyYlsbA62IcCQ9VFk1DDKn1l1MuMNyA9dulQjqW9NSlxkF2wr9dWuFWyLLCRkegeQ DxmR07p76hdAf0eHrFl6O+M6dT22tY1vuqHfVTzcsCowxya3xsyfUtitigHVVXWUrko9 OzzwVToZA+8a0Isx8KOM5l9hG83AAZDM5aTeyMds5KVGoE87S1SJXviTHQJFWcwDCc7I Mn1pCwbv4SBPvERrnFb8ZC8ElFau+ASaDq5aHlfV7Ml1mKwt/gQh9TWF1ZW4s/u1vckl blmA== X-Gm-Message-State: ANoB5plB3G/j/PbtYp/vnCpuo3nr4+dpVGjs2+EtAiIcNyyBZ/sR6Phh Qs8PoNaxEJf1Wnv/eIBEE4JITuhz2zM= X-Google-Smtp-Source: AA0mqf7ppHP78R6DoyaSEfdabFN93hGLedM5frzCx5lU0qVbL8x8mv7KVs5D4ri0MCkTZLrnYexjfQ== X-Received: by 2002:a17:902:bd01:b0:188:bed6:3fb8 with SMTP id p1-20020a170902bd0100b00188bed63fb8mr4963505pls.38.1668725730992; Thu, 17 Nov 2022 14:55:30 -0800 (PST) Received: from localhost ([2409:40f4:8:955c:5484:8048:c08:7b3]) by smtp.gmail.com with ESMTPSA id i6-20020a626d06000000b00572275e68f8sm1658620pfc.166.2022.11.17.14.55.27 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 17 Nov 2022 14:55:28 -0800 (PST) From: Kumar Kartikeya Dwivedi To: bpf@vger.kernel.org Cc: Alexei Starovoitov , Andrii Nakryiko , Daniel Borkmann , Martin KaFai Lau , Dave Marchevsky Subject: [PATCH bpf-next v9 04/23] bpf: Populate field_offs for inner_map_meta Date: Fri, 18 Nov 2022 04:24:51 +0530 Message-Id: <20221117225510.1676785-5-memxor@gmail.com> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20221117225510.1676785-1-memxor@gmail.com> References: <20221117225510.1676785-1-memxor@gmail.com> MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=3996; i=memxor@gmail.com; h=from:subject; bh=Cqk0Hx/89vbzoryLz1qsgSw+UY1K0G5tz50Zkumpm18=; b=owEBbQKS/ZANAwAIAUzgyIZIvxHKAcsmYgBjdrkb7cn/1S2dSq5Ou2R0Cg/ljrzysHHZhFc1ctec pCWcA1qJAjMEAAEIAB0WIQRLvip+Buz51YI8YRFM4MiGSL8RygUCY3a5GwAKCRBM4MiGSL8RypAgEA C7dn+S9wJ2v5o+3OVJW5/jKjC7vmbzEl0GsNwrrp6SuvJwgXZI6YV9ewh9TPfxvroo72oPTeX9CZPC YMy8zBXLy8NkEIQk1/APTvmL/8/0xc12obsfHUJchmoTjUDsKD7ylxYEEbK2NJnj7tS1NGWPfoOCu3 iycwJW3WSCgxfujqsBk3EUzUfieS27lk2Q/+Y0lxSEJSq1wzyHNmorAJwjF1FGGEobvugUO/LkwXD5 FmC9E+Zhuzbqhh/NDhwRGh5KnXCG1O52ZEcXjSrz18mDz2wmuBJOX2/iO8kjW6lyu3zZAxzE03ObmF e2sGwIt0mfX54zuPVcBvk303kopSbnMDVNcIzFkFqUOSz2XlxcGBfEBg31qB23At+V0JJ08AE3hQwQ EJ5fi9LpnbsyzADFGM9Hvx/qMrGW8kKlOi9FDnhGkWV0R8nUZQgWrU4HJOvo9m6PvavOapTXDKf/ED RjCkyERAbm/DCvh3Xs7v1umD5yr6IkOHs18vdbcO1LKbSK/ms0PvL665a6waQD+26WfSXTEjIEMMg4 C0wvSWjooPhqoyVUnbuDQRQxKV8wjuKfj1uadw33mouaIAQtm07Gny4qWLAtWznSFlzGM2kGZekTmX JAlmPf/CVfFZssZyTfm8l9YvUdS8gx+/pgqJe/g1GeF0WQ35wTjuPrOEcB4g== X-Developer-Key: i=memxor@gmail.com; a=openpgp; fpr=4BBE2A7E06ECF9D5823C61114CE0C88648BF11CA Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net Far too much code simply assumes that both btf_record and btf_field_offs are set to valid pointers together, or both are unset. They go together hand in hand as btf_record describes the special fields and btf_field_offs is compact representation for runtime copying/zeroing. It is very difficult to make this clear in the code when the only exception to this universal invariant is inner_map_meta which is used as reg->map_ptr in the verifier. This is simply a bug waiting to happen, as in verifier context we cannot easily distinguish if PTR_TO_MAP_VALUE is coming from an inner map, and if we ever end up using field_offs for any reason in the future, we will silently ignore the special fields for inner map case (as NULL is not an error but unset field_offs). Hence, simply copy field_offs from inner map together with btf_record. While at it, refactor code to unwind properly on errors with gotos. Signed-off-by: Kumar Kartikeya Dwivedi --- kernel/bpf/map_in_map.c | 44 ++++++++++++++++++++++++++++++----------- 1 file changed, 32 insertions(+), 12 deletions(-) diff --git a/kernel/bpf/map_in_map.c b/kernel/bpf/map_in_map.c index a423130a8720..fae6a6c33e2d 100644 --- a/kernel/bpf/map_in_map.c +++ b/kernel/bpf/map_in_map.c @@ -12,6 +12,7 @@ struct bpf_map *bpf_map_meta_alloc(int inner_map_ufd) struct bpf_map *inner_map, *inner_map_meta; u32 inner_map_meta_size; struct fd f; + int ret; f = fdget(inner_map_ufd); inner_map = __bpf_map_get(f); @@ -20,18 +21,18 @@ struct bpf_map *bpf_map_meta_alloc(int inner_map_ufd) /* Does not support >1 level map-in-map */ if (inner_map->inner_map_meta) { - fdput(f); - return ERR_PTR(-EINVAL); + ret = -EINVAL; + goto put; } if (!inner_map->ops->map_meta_equal) { - fdput(f); - return ERR_PTR(-ENOTSUPP); + ret = -ENOTSUPP; + goto put; } if (btf_record_has_field(inner_map->record, BPF_SPIN_LOCK)) { - fdput(f); - return ERR_PTR(-ENOTSUPP); + ret = -ENOTSUPP; + goto put; } inner_map_meta_size = sizeof(*inner_map_meta); @@ -41,8 +42,8 @@ struct bpf_map *bpf_map_meta_alloc(int inner_map_ufd) inner_map_meta = kzalloc(inner_map_meta_size, GFP_USER); if (!inner_map_meta) { - fdput(f); - return ERR_PTR(-ENOMEM); + ret = -ENOMEM; + goto put; } inner_map_meta->map_type = inner_map->map_type; @@ -50,16 +51,27 @@ struct bpf_map *bpf_map_meta_alloc(int inner_map_ufd) inner_map_meta->value_size = inner_map->value_size; inner_map_meta->map_flags = inner_map->map_flags; inner_map_meta->max_entries = inner_map->max_entries; + inner_map_meta->record = btf_record_dup(inner_map->record); if (IS_ERR(inner_map_meta->record)) { - struct bpf_map *err_ptr = ERR_CAST(inner_map_meta->record); /* btf_record_dup returns NULL or valid pointer in case of * invalid/empty/valid, but ERR_PTR in case of errors. During * equality NULL or IS_ERR is equivalent. */ - kfree(inner_map_meta); - fdput(f); - return err_ptr; + ret = PTR_ERR(inner_map_meta->record); + goto free; + } + if (inner_map_meta->record) { + struct btf_field_offs *field_offs; + /* If btf_record is !IS_ERR_OR_NULL, then field_offs is always + * valid. + */ + field_offs = kmemdup(inner_map->field_offs, sizeof(*inner_map->field_offs), GFP_KERNEL | __GFP_NOWARN); + if (!field_offs) { + ret = -ENOMEM; + goto free_rec; + } + inner_map_meta->field_offs = field_offs; } if (inner_map->btf) { btf_get(inner_map->btf); @@ -76,10 +88,18 @@ struct bpf_map *bpf_map_meta_alloc(int inner_map_ufd) fdput(f); return inner_map_meta; +free_rec: + btf_record_free(inner_map_meta->record); +free: + kfree(inner_map_meta); +put: + fdput(f); + return ERR_PTR(ret); } void bpf_map_meta_free(struct bpf_map *map_meta) { + kfree(map_meta->field_offs); bpf_map_free_record(map_meta); btf_put(map_meta->btf); kfree(map_meta); From patchwork Thu Nov 17 22:54:52 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kumar Kartikeya Dwivedi X-Patchwork-Id: 13047430 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id BBEF9C433FE for ; Thu, 17 Nov 2022 22:55:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234802AbiKQWzj (ORCPT ); Thu, 17 Nov 2022 17:55:39 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53078 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234954AbiKQWzh (ORCPT ); Thu, 17 Nov 2022 17:55:37 -0500 Received: from mail-pl1-x644.google.com (mail-pl1-x644.google.com [IPv6:2607:f8b0:4864:20::644]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 72CF862CE for ; Thu, 17 Nov 2022 14:55:36 -0800 (PST) Received: by mail-pl1-x644.google.com with SMTP id y10so1802528plp.3 for ; Thu, 17 Nov 2022 14:55:36 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=/dEo1al8fIigkT4udLYOJzh2efBnOQsqXleDSugVnjg=; b=dT4mH/aISJwAAmAGzhZjNFy4ouoCf63hy6duiDZCR1XlVHOFA2D6DmzE55dIBjyXBQ e4BvQKZ7t4z7kBMgO+B7ZKq7MA8TOmBXxE1korCsByO0YjA6y6mIG2+ELj1NMgCSZLsg d7W7UMT8wxkUKCVeZgZxJJSpcomEuwiBaatGO+Ek363x15JOvejuKT6AhUDoLuOi7jZ/ hUo8e2oCAs8kMUmQcjEHjqdPGiDf4NFET8SA5ybklP/zyhsyb2acILhJ6BFGQQaRoKu6 hqCIfexpTEKqI6E/oFPJPnElZATG37uY7wu/ojxQa/31n+wdz3q1ACSzHqf4j7ZaJgPH /gGQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=/dEo1al8fIigkT4udLYOJzh2efBnOQsqXleDSugVnjg=; b=ZM2u0jp+14pOqLqjdp4lH9Bth6Kpt/Ev8iZpqhF0Bnt806vGgMCJcxg/t8elZKkhv0 5xu2MuaRYqi34b1dicjp8KhjtTp5ZXKxTP4qgh59D+FXmO0k3DgVH5udCr4lzEwOIYVe ke3YBpPKC2m97nszszzPcHDB3icq2WrVHN4eeN/kbVRTtODqUiCMaFoC4k055o/GdINg 8Tbjc9yrsUHCO6n9AdmYrxuXNimu+2xGykTGskvak5FKoA2r7PK1Fp2Kf8w9zDvci8ic rlcGzHtlbkDfltryU92CLKLhh8LftQWkN9p5iGSmOWzLRboDvD9Av+rSTkV5r2WgAmjX 4Qxw== X-Gm-Message-State: ANoB5pm3wLvqdbf/yH3bw0mP9eOEocKdZouWIXb0tuEMUrb5w8g+ZYFA RWo0vh4V4JBumDX8/AMlfJ3Rj9HWwe0= X-Google-Smtp-Source: AA0mqf7x/HMmU9y1c/0rMCouwiVCeyEOEvSUJ4MzFqNKn9UX0CreS5jwCy+/qRezEfB6K2f9BMMMAg== X-Received: by 2002:a17:90a:5607:b0:218:7d9e:f8ed with SMTP id r7-20020a17090a560700b002187d9ef8edmr1998465pjf.160.1668725735753; Thu, 17 Nov 2022 14:55:35 -0800 (PST) Received: from localhost ([2409:40f4:8:955c:5484:8048:c08:7b3]) by smtp.gmail.com with ESMTPSA id g28-20020aa79f1c000000b0056da2bf607csm1624238pfr.214.2022.11.17.14.55.33 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 17 Nov 2022 14:55:34 -0800 (PST) From: Kumar Kartikeya Dwivedi To: bpf@vger.kernel.org Cc: Alexei Starovoitov , Andrii Nakryiko , Daniel Borkmann , Martin KaFai Lau , Dave Marchevsky Subject: [PATCH bpf-next v9 05/23] bpf: Introduce allocated objects support Date: Fri, 18 Nov 2022 04:24:52 +0530 Message-Id: <20221117225510.1676785-6-memxor@gmail.com> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20221117225510.1676785-1-memxor@gmail.com> References: <20221117225510.1676785-1-memxor@gmail.com> MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=4893; i=memxor@gmail.com; h=from:subject; bh=bHOSzfm0SbGE8NR+y0cBZt0ThH4SH0n2SmsrPhxvaV8=; b=owEBbQKS/ZANAwAIAUzgyIZIvxHKAcsmYgBjdrkbKMre9cC5HaqcRxm4o8C4RgWVPDo7F/cJZ0b4 oQX18jiJAjMEAAEIAB0WIQRLvip+Buz51YI8YRFM4MiGSL8RygUCY3a5GwAKCRBM4MiGSL8RysrzD/ 4j1CjfwmwzVoHfRmJAAtn3p22t2JFXytPdaEhT0957reUeOVTI8ezvXG65J+q90sV62QAk7TXxmsvn /ZubeevxUN/pdKRF3REgDNrWgegJuRalsvmtwtx5Gf/95oNnblOLxIfElRND/W3Jt4u63z9Isu3RJS zFUEDEkLOe9QUOUCfrCbZrrZNJ4yn5Hqr83EYbvrVlKlccaGCFBa+oFxSaTGh3u+tZn1PsxVKjPk2O yceXO4OuU4n0QENIjVD5bZUQcB55p8/DC/vDNKjH5w/DQT2Cg/Xf8RfOlH8ON6NsMX83TrM7/iU/Wj NKAJryv0+060X84UUgE821cJqL1mY9tuOtB+y/2UYlqeb14VtHhjCnhAvAebL4ILJvOyWMM3AzvcJ8 OKDfWGo6lfNSi1Ea4cDHuTMroYkBCJZJE1cW3G4aKtZWJl03bFfE/v6LSHEiYjcoTP74UNcwUqczOB CZICp3Vv4fyfMLwELzH3dHGRVxt7hNDyPnDYAhhaqFrlrFY7urcyZ8jT4N2W5J1CnZMDpDtLkVq1QO IhKeDqEuJJRju6wJFdiNx0ZVGecezVLYBYf1t3NPjL7FpYiuXtjnR+DPx4dhIClDcKgITkRwgOdqiC riglKinTgqDRO6NB2wJVay0Q8jgN5gsRPMFRsGdzO0ujlol91s75ZJwRiUJw== X-Developer-Key: i=memxor@gmail.com; a=openpgp; fpr=4BBE2A7E06ECF9D5823C61114CE0C88648BF11CA Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net Introduce support for representing pointers to objects allocated by the BPF program, i.e. PTR_TO_BTF_ID that point to a type in program BTF. This is indicated by the presence of MEM_ALLOC type flag in reg->type to avoid having to check btf_is_kernel when trying to match argument types in helpers. Whenever walking such types, any pointers being walked will always yield a SCALAR instead of pointer. In the future we might permit kptr inside such allocated objects (either kernel or program allocated), and it will then form a PTR_TO_BTF_ID of the respective type. For now, such allocated objects will always be referenced in verifier context, hence ref_obj_id == 0 for them is a bug. It is allowed to write to such objects, as long fields that are special are not touched (support for which will be added in subsequent patches). Note that once such a pointer is marked PTR_UNTRUSTED, it is no longer allowed to write to it. No PROBE_MEM handling is therefore done for loads into this type unless PTR_UNTRUSTED is part of the register type, since they can never be in an undefined state, and their lifetime will always be valid. Signed-off-by: Kumar Kartikeya Dwivedi --- include/linux/bpf.h | 11 +++++++++++ kernel/bpf/btf.c | 5 +++++ kernel/bpf/verifier.c | 25 +++++++++++++++++++++++-- 3 files changed, 39 insertions(+), 2 deletions(-) diff --git a/include/linux/bpf.h b/include/linux/bpf.h index e60a5c052473..7440c20c4192 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -525,6 +525,11 @@ enum bpf_type_flag { /* Size is known at compile time. */ MEM_FIXED_SIZE = BIT(10 + BPF_BASE_TYPE_BITS), + /* MEM is of an allocated object of type in program BTF. This is used to + * tag PTR_TO_BTF_ID allocated using bpf_obj_new. + */ + MEM_ALLOC = BIT(11 + BPF_BASE_TYPE_BITS), + __BPF_TYPE_FLAG_MAX, __BPF_TYPE_LAST_FLAG = __BPF_TYPE_FLAG_MAX - 1, }; @@ -2792,4 +2797,10 @@ struct bpf_key { bool has_ref; }; #endif /* CONFIG_KEYS */ + +static inline bool type_is_alloc(u32 type) +{ + return type & MEM_ALLOC; +} + #endif /* _LINUX_BPF_H */ diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c index 875355ff3718..9a596f430558 100644 --- a/kernel/bpf/btf.c +++ b/kernel/bpf/btf.c @@ -6034,6 +6034,11 @@ int btf_struct_access(struct bpf_verifier_log *log, switch (err) { case WALK_PTR: + /* For local types, the destination register cannot + * become a pointer again. + */ + if (type_is_alloc(reg->type)) + return SCALAR_VALUE; /* If we found the pointer or scalar on t+off, * we're done. */ diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 0312d9ce292f..49e08c1c2c61 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -4687,14 +4687,27 @@ static int check_ptr_to_btf_access(struct bpf_verifier_env *env, return -EACCES; } - if (env->ops->btf_struct_access) { + if (env->ops->btf_struct_access && !type_is_alloc(reg->type)) { + if (!btf_is_kernel(reg->btf)) { + verbose(env, "verifier internal error: reg->btf must be kernel btf\n"); + return -EFAULT; + } ret = env->ops->btf_struct_access(&env->log, reg, off, size, atype, &btf_id, &flag); } else { - if (atype != BPF_READ) { + /* Writes are permitted with default btf_struct_access for + * program allocated objects (which always have ref_obj_id > 0), + * but not for untrusted PTR_TO_BTF_ID | MEM_ALLOC. + */ + if (atype != BPF_READ && reg->type != (PTR_TO_BTF_ID | MEM_ALLOC)) { verbose(env, "only read is supported\n"); return -EACCES; } + if (type_is_alloc(reg->type) && !reg->ref_obj_id) { + verbose(env, "verifier internal error: ref_obj_id for allocated object must be non-zero\n"); + return -EFAULT; + } + ret = btf_struct_access(&env->log, reg, off, size, atype, &btf_id, &flag); } @@ -5973,6 +5986,7 @@ int check_func_arg_reg_off(struct bpf_verifier_env *env, * fixed offset. */ case PTR_TO_BTF_ID: + case PTR_TO_BTF_ID | MEM_ALLOC: /* When referenced PTR_TO_BTF_ID is passed to release function, * it's fixed offset must be 0. In the other cases, fixed offset * can be non-zero. @@ -13690,6 +13704,13 @@ static int convert_ctx_accesses(struct bpf_verifier_env *env) break; case PTR_TO_BTF_ID: case PTR_TO_BTF_ID | PTR_UNTRUSTED: + /* PTR_TO_BTF_ID | MEM_ALLOC always has a valid lifetime, unlike + * PTR_TO_BTF_ID, and an active ref_obj_id, but the same cannot + * be said once it is marked PTR_UNTRUSTED, hence we must handle + * any faults for loads into such types. BPF_WRITE is disallowed + * for this case. + */ + case PTR_TO_BTF_ID | MEM_ALLOC | PTR_UNTRUSTED: if (type == BPF_READ) { insn->code = BPF_LDX | BPF_PROBE_MEM | BPF_SIZE((insn)->code); From patchwork Thu Nov 17 22:54:53 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kumar Kartikeya Dwivedi X-Patchwork-Id: 13047431 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A444CC4332F for ; Thu, 17 Nov 2022 22:55:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234847AbiKQWzn (ORCPT ); Thu, 17 Nov 2022 17:55:43 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53198 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234992AbiKQWzl (ORCPT ); Thu, 17 Nov 2022 17:55:41 -0500 Received: from mail-pf1-x441.google.com (mail-pf1-x441.google.com [IPv6:2607:f8b0:4864:20::441]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 383D7186FC for ; Thu, 17 Nov 2022 14:55:40 -0800 (PST) Received: by mail-pf1-x441.google.com with SMTP id c203so3177409pfc.11 for ; Thu, 17 Nov 2022 14:55:40 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=j9L6zs2xpO1suLgtnhOh7GRPwwjzCMBBbuIttorBrF4=; b=LZbcsdFgm41OPNisOQlJnX6vLEv6NbNqWbSN6QGrTI/6x7YATImhYVFHuOrK6mGoYy +4cL+SLI791EtPYDx/SfxtYaD5SSVN5B3ot4U/84iW7O2kYYTcpnngJTuivWY1f0nbvl 0IGzfIUh2pZZxZB/V1lNWoCUmvXPxVReBxQ4W5BwSaf7CbufeIz5Nx6sqdUu4oDDGF3w MztjRLGc+Uu9JNJS1XXQuJ+dFDt2ss9/0pknVxEnIyk3/O2k00SiI0uEKdO+/XDeMq+X mu64lyjerqsek2fC/u2nzDb172gCimdtd93pc2jar6+pXw0RdpMdl/5vRcs7aStXdjJf 5kug== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=j9L6zs2xpO1suLgtnhOh7GRPwwjzCMBBbuIttorBrF4=; b=X7o3afs3J8OJSufb0Tf666tzsVqmU40URSQmo20qgYejowuTEluRws18LQZazr3SQD w+RR+rhtHn6xguze/KHvPW4kxElNzzRGVoU/22baj/EfY1oUgTWeg0uNmUftHjn0dBND +80W4eWjDvHrVb9d75rZKxMt7UNLMHcNyio8rXnKoisVQShME2M1Tx7CXQckap9ZZWTg ouAjDgzXvfm1QePz30aU8ABcAliPQJJkSA8u7OOw2SiJPVpW0dE7n4BinSG9szHGn+JQ 74CiAffYorc7eyal25Cu/hxOW9y9l4Sif5niAy7m99cZbR/KBqWfFx/Ztm18RWlDklR4 iWlQ== X-Gm-Message-State: ANoB5pn3ogqPw7iPIdA/Bti6ur/tP33iqwrZfRhKrJJMmdlFKPxgKRBt viqaG+PMPiloqMpcSo6D35EhoSuCXb8= X-Google-Smtp-Source: AA0mqf4A9zcqbpEiqYgwA6IippVKmz1T1YGU7J3B9RM3L3x8nWjAywCIvXr2YRdarlM/KJquSvMiYw== X-Received: by 2002:a63:134a:0:b0:476:bfca:112d with SMTP id 10-20020a63134a000000b00476bfca112dmr4129979pgt.574.1668725739362; Thu, 17 Nov 2022 14:55:39 -0800 (PST) Received: from localhost ([2409:40f4:8:955c:5484:8048:c08:7b3]) by smtp.gmail.com with ESMTPSA id q11-20020a17090a68cb00b00206023cbcc7sm3993880pjj.15.2022.11.17.14.55.38 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 17 Nov 2022 14:55:38 -0800 (PST) From: Kumar Kartikeya Dwivedi To: bpf@vger.kernel.org Cc: Alexei Starovoitov , Andrii Nakryiko , Daniel Borkmann , Martin KaFai Lau , Dave Marchevsky Subject: [PATCH bpf-next v9 06/23] bpf: Recognize lock and list fields in allocated objects Date: Fri, 18 Nov 2022 04:24:53 +0530 Message-Id: <20221117225510.1676785-7-memxor@gmail.com> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20221117225510.1676785-1-memxor@gmail.com> References: <20221117225510.1676785-1-memxor@gmail.com> MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=14956; i=memxor@gmail.com; h=from:subject; bh=3j2kADy8heWKgTV7xRad/hiMYH5DbNhm6oQjBwn/jpI=; b=owEBbQKS/ZANAwAIAUzgyIZIvxHKAcsmYgBjdrkbI63biJWxTmyvbx6QN1RUAq2GuvFQUs3aOG+B bcI7IfGJAjMEAAEIAB0WIQRLvip+Buz51YI8YRFM4MiGSL8RygUCY3a5GwAKCRBM4MiGSL8RyreoD/ 9kygDPjXzAvZpJfM43LYpk4SHh4RefC8QxkXW3QCAb47axKEqUoFz6kCutJw8B0Aow/CKbOBDJnrQq PHBdBh9QaDWRkqcOjDvBV1tBZfyQHV39+FcNuqP84EZRg5RC5pDUeaSd7xffjsxkYK3F0DyAvwFiEc HUSkduxiCyRW/leRT0xd21ZVTmqsBq9JeYuO5OiBxT3R2GgxzroI6KtFR5XMBODlfckYiRU9GA1IfO JXgq5/0YOariB3WG4jqfvqIwM20yoZEFZzvUET5B/KZxvNdaOIzdFPKytP5M8MudaiG4mZLjsXm7Kb U/C5pmF8A8ibY4TemcZfQYtyg7aVnAwLvQdSLjuf+wDxfY4wO449CIiORouwbzsilWvlefu9AbaUX/ eQfPx8jp5i5oVtTkELQSIh7UCRMajiWbvQz+ek9S3C9i4d+FVeNxxW/aWzZpUTqR9D/3HOO9n4LQOb e4yDBaEJVGN3r3pYw8SxdE1xXT1vSqxQRc/5M4WTjygvQitldSgCpV1Bb9XAfkP1oX7gMCJP581+jH DeWWN0bNlrLc+qSRvA/I0aTLVy9sd/q1ssgDVc36/M4Jq4Lzk3alkELpVL6QS3LdpOk542KtRKH3vq NjZTYbD+PT8ELFHqf2521cHJzXLU3zf6/JwpSEnQ4Zsrz3Epq2iPh9Nu6aAg== X-Developer-Key: i=memxor@gmail.com; a=openpgp; fpr=4BBE2A7E06ECF9D5823C61114CE0C88648BF11CA Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net Allow specifying bpf_spin_lock, bpf_list_head, bpf_list_node fields in a allocated object. Also update btf_struct_access to reject direct access to these special fields. A bpf_list_head allows implementing map-in-map style use cases, where an allocated object with bpf_list_head is linked into a list in a map value. This would require embedding a bpf_list_node, support for which is also included. The bpf_spin_lock is used to protect the bpf_list_head and other data. While we strictly don't require to hold a bpf_spin_lock while touching the bpf_list_head in such objects, as when have access to it, we have complete ownership of the object, the locking constraint is still kept and may be conditionally lifted in the future. Note that the specification of such types can be done just like map values, e.g.: struct bar { struct bpf_list_node node; }; struct foo { struct bpf_spin_lock lock; struct bpf_list_head head __contains(bar, node); struct bpf_list_node node; }; struct map_value { struct bpf_spin_lock lock; struct bpf_list_head head __contains(foo, node); }; To recognize such types in user BTF, we build a btf_struct_metas array of metadata items corresponding to each BTF ID. This is done once during the btf_parse stage to avoid having to do it each time during the verification process's requirement to inspect the metadata. Moreover, the computed metadata needs to be passed to some helpers in future patches which requires allocating them and storing them in the BTF that is pinned by the program itself, so that valid access can be assumed to such data during program runtime. A key thing to note is that once a btf_struct_meta is available for a type, both the btf_record and btf_field_offs should be available. It is critical that btf_field_offs is available in case special fields are present, as we extensively rely on special fields being zeroed out in map values and allocated objects in later patches. The code ensures that by bailing out in case of errors and ensuring both are available together. If the record is not available, the special fields won't be recognized, so not having both is also fine (in terms of being a verification error and not a runtime bug). Signed-off-by: Kumar Kartikeya Dwivedi --- include/linux/bpf.h | 7 ++ include/linux/btf.h | 35 ++++++++ kernel/bpf/btf.c | 197 +++++++++++++++++++++++++++++++++++++++---- kernel/bpf/syscall.c | 4 + 4 files changed, 225 insertions(+), 18 deletions(-) diff --git a/include/linux/bpf.h b/include/linux/bpf.h index 7440c20c4192..eb6ea53fa5a2 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -177,6 +177,7 @@ enum btf_field_type { BPF_KPTR_REF = (1 << 3), BPF_KPTR = BPF_KPTR_UNREF | BPF_KPTR_REF, BPF_LIST_HEAD = (1 << 4), + BPF_LIST_NODE = (1 << 5), }; struct btf_field_kptr { @@ -277,6 +278,8 @@ static inline const char *btf_field_type_name(enum btf_field_type type) return "kptr"; case BPF_LIST_HEAD: return "bpf_list_head"; + case BPF_LIST_NODE: + return "bpf_list_node"; default: WARN_ON_ONCE(1); return "unknown"; @@ -295,6 +298,8 @@ static inline u32 btf_field_type_size(enum btf_field_type type) return sizeof(u64); case BPF_LIST_HEAD: return sizeof(struct bpf_list_head); + case BPF_LIST_NODE: + return sizeof(struct bpf_list_node); default: WARN_ON_ONCE(1); return 0; @@ -313,6 +318,8 @@ static inline u32 btf_field_type_align(enum btf_field_type type) return __alignof__(u64); case BPF_LIST_HEAD: return __alignof__(struct bpf_list_head); + case BPF_LIST_NODE: + return __alignof__(struct bpf_list_node); default: WARN_ON_ONCE(1); return 0; diff --git a/include/linux/btf.h b/include/linux/btf.h index d80345fa566b..a01a8da20021 100644 --- a/include/linux/btf.h +++ b/include/linux/btf.h @@ -6,6 +6,8 @@ #include #include +#include +#include #include #include @@ -78,6 +80,17 @@ struct btf_id_dtor_kfunc { u32 kfunc_btf_id; }; +struct btf_struct_meta { + u32 btf_id; + struct btf_record *record; + struct btf_field_offs *field_offs; +}; + +struct btf_struct_metas { + u32 cnt; + struct btf_struct_meta types[]; +}; + typedef void (*btf_dtor_kfunc_t)(void *); extern const struct file_operations btf_fops; @@ -408,6 +421,23 @@ static inline struct btf_param *btf_params(const struct btf_type *t) return (struct btf_param *)(t + 1); } +static inline int btf_id_cmp_func(const void *a, const void *b) +{ + const int *pa = a, *pb = b; + + return *pa - *pb; +} + +static inline bool btf_id_set_contains(const struct btf_id_set *set, u32 id) +{ + return bsearch(&id, set->ids, set->cnt, sizeof(u32), btf_id_cmp_func) != NULL; +} + +static inline void *btf_id_set8_contains(const struct btf_id_set8 *set, u32 id) +{ + return bsearch(&id, set->pairs, set->cnt, sizeof(set->pairs[0]), btf_id_cmp_func); +} + #ifdef CONFIG_BPF_SYSCALL struct bpf_prog; @@ -423,6 +453,7 @@ int register_btf_kfunc_id_set(enum bpf_prog_type prog_type, s32 btf_find_dtor_kfunc(struct btf *btf, u32 btf_id); int register_btf_id_dtor_kfuncs(const struct btf_id_dtor_kfunc *dtors, u32 add_cnt, struct module *owner); +struct btf_struct_meta *btf_find_struct_meta(const struct btf *btf, u32 btf_id); #else static inline const struct btf_type *btf_type_by_id(const struct btf *btf, u32 type_id) @@ -454,6 +485,10 @@ static inline int register_btf_id_dtor_kfuncs(const struct btf_id_dtor_kfunc *dt { return 0; } +static inline struct btf_struct_meta *btf_find_struct_meta(const struct btf *btf, u32 btf_id) +{ + return NULL; +} #endif static inline bool btf_type_is_struct_ptr(struct btf *btf, const struct btf_type *t) diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c index 9a596f430558..a04e10477567 100644 --- a/kernel/bpf/btf.c +++ b/kernel/bpf/btf.c @@ -237,6 +237,7 @@ struct btf { struct rcu_head rcu; struct btf_kfunc_set_tab *kfunc_set_tab; struct btf_id_dtor_kfunc_tab *dtor_kfunc_tab; + struct btf_struct_metas *struct_meta_tab; /* split BTF support */ struct btf *base_btf; @@ -1642,8 +1643,30 @@ static void btf_free_dtor_kfunc_tab(struct btf *btf) btf->dtor_kfunc_tab = NULL; } +static void btf_struct_metas_free(struct btf_struct_metas *tab) +{ + int i; + + if (!tab) + return; + for (i = 0; i < tab->cnt; i++) { + btf_record_free(tab->types[i].record); + kfree(tab->types[i].field_offs); + } + kfree(tab); +} + +static void btf_free_struct_meta_tab(struct btf *btf) +{ + struct btf_struct_metas *tab = btf->struct_meta_tab; + + btf_struct_metas_free(tab); + btf->struct_meta_tab = NULL; +} + static void btf_free(struct btf *btf) { + btf_free_struct_meta_tab(btf); btf_free_dtor_kfunc_tab(btf); btf_free_kfunc_set_tab(btf); kvfree(btf->types); @@ -3353,6 +3376,12 @@ static int btf_get_field_type(const char *name, u32 field_mask, u32 *seen_mask, goto end; } } + if (field_mask & BPF_LIST_NODE) { + if (!strcmp(name, "bpf_list_node")) { + type = BPF_LIST_NODE; + goto end; + } + } /* Only return BPF_KPTR when all other types with matchable names fail */ if (field_mask & BPF_KPTR) { type = BPF_KPTR_REF; @@ -3396,6 +3425,7 @@ static int btf_find_struct_field(const struct btf *btf, switch (field_type) { case BPF_SPIN_LOCK: case BPF_TIMER: + case BPF_LIST_NODE: ret = btf_find_struct(btf, member_type, off, sz, field_type, idx < info_cnt ? &info[idx] : &tmp); if (ret < 0) @@ -3456,6 +3486,7 @@ static int btf_find_datasec_var(const struct btf *btf, const struct btf_type *t, switch (field_type) { case BPF_SPIN_LOCK: case BPF_TIMER: + case BPF_LIST_NODE: ret = btf_find_struct(btf, var_type, off, sz, field_type, idx < info_cnt ? &info[idx] : &tmp); if (ret < 0) @@ -3671,6 +3702,8 @@ struct btf_record *btf_parse_fields(const struct btf *btf, const struct btf_type if (ret < 0) goto end; break; + case BPF_LIST_NODE: + break; default: ret = -EFAULT; goto end; @@ -5141,6 +5174,119 @@ static int btf_parse_hdr(struct btf_verifier_env *env) return btf_check_sec_info(env, btf_data_size); } +static const char *alloc_obj_fields[] = { + "bpf_spin_lock", + "bpf_list_head", + "bpf_list_node", +}; + +static struct btf_struct_metas * +btf_parse_struct_metas(struct bpf_verifier_log *log, struct btf *btf) +{ + union { + struct btf_id_set set; + struct { + u32 _cnt; + u32 _ids[ARRAY_SIZE(alloc_obj_fields)]; + } _arr; + } aof; + struct btf_struct_metas *tab = NULL; + int i, n, id, ret; + + BUILD_BUG_ON(offsetof(struct btf_id_set, cnt) != 0); + BUILD_BUG_ON(sizeof(struct btf_id_set) != sizeof(u32)); + + memset(&aof, 0, sizeof(aof)); + for (i = 0; i < ARRAY_SIZE(alloc_obj_fields); i++) { + /* Try to find whether this special type exists in user BTF, and + * if so remember its ID so we can easily find it among members + * of structs that we iterate in the next loop. + */ + id = btf_find_by_name_kind(btf, alloc_obj_fields[i], BTF_KIND_STRUCT); + if (id < 0) + continue; + aof.set.ids[aof.set.cnt++] = id; + } + + if (!aof.set.cnt) + return NULL; + sort(&aof.set.ids, aof.set.cnt, sizeof(aof.set.ids[0]), btf_id_cmp_func, NULL); + + n = btf_nr_types(btf); + for (i = 1; i < n; i++) { + struct btf_struct_metas *new_tab; + const struct btf_member *member; + struct btf_field_offs *foffs; + struct btf_struct_meta *type; + struct btf_record *record; + const struct btf_type *t; + int j, tab_cnt; + + t = btf_type_by_id(btf, i); + if (!t) { + ret = -EINVAL; + goto free; + } + if (!__btf_type_is_struct(t)) + continue; + + cond_resched(); + + for_each_member(j, t, member) { + if (btf_id_set_contains(&aof.set, member->type)) + goto parse; + } + continue; + parse: + tab_cnt = tab ? tab->cnt : 0; + new_tab = krealloc(tab, offsetof(struct btf_struct_metas, types[tab_cnt + 1]), + GFP_KERNEL | __GFP_NOWARN); + if (!new_tab) { + ret = -ENOMEM; + goto free; + } + if (!tab) + new_tab->cnt = 0; + tab = new_tab; + + type = &tab->types[tab->cnt]; + type->btf_id = i; + record = btf_parse_fields(btf, t, BPF_SPIN_LOCK | BPF_LIST_HEAD | BPF_LIST_NODE, t->size); + /* The record cannot be unset, treat it as an error if so */ + if (IS_ERR_OR_NULL(record)) { + ret = PTR_ERR_OR_ZERO(record) ?: -EFAULT; + goto free; + } + foffs = btf_parse_field_offs(record); + /* We need the field_offs to be valid for a valid record, + * either both should be set or both should be unset. + */ + if (IS_ERR_OR_NULL(foffs)) { + btf_record_free(record); + ret = -EFAULT; + goto free; + } + type->record = record; + type->field_offs = foffs; + tab->cnt++; + } + return tab; +free: + btf_struct_metas_free(tab); + return ERR_PTR(ret); +} + +struct btf_struct_meta *btf_find_struct_meta(const struct btf *btf, u32 btf_id) +{ + struct btf_struct_metas *tab; + + BUILD_BUG_ON(offsetof(struct btf_struct_meta, btf_id) != 0); + tab = btf->struct_meta_tab; + if (!tab) + return NULL; + return bsearch(&btf_id, tab->types, tab->cnt, sizeof(tab->types[0]), btf_id_cmp_func); +} + static int btf_check_type_tags(struct btf_verifier_env *env, struct btf *btf, int start_id) { @@ -5191,6 +5337,7 @@ static int btf_check_type_tags(struct btf_verifier_env *env, static struct btf *btf_parse(bpfptr_t btf_data, u32 btf_data_size, u32 log_level, char __user *log_ubuf, u32 log_size) { + struct btf_struct_metas *struct_meta_tab; struct btf_verifier_env *env = NULL; struct bpf_verifier_log *log; struct btf *btf = NULL; @@ -5259,15 +5406,24 @@ static struct btf *btf_parse(bpfptr_t btf_data, u32 btf_data_size, if (err) goto errout; + struct_meta_tab = btf_parse_struct_metas(log, btf); + if (IS_ERR(struct_meta_tab)) { + err = PTR_ERR(struct_meta_tab); + goto errout; + } + btf->struct_meta_tab = struct_meta_tab; + if (log->level && bpf_verifier_log_full(log)) { err = -ENOSPC; - goto errout; + goto errout_meta; } btf_verifier_env_free(env); refcount_set(&btf->refcnt, 1); return btf; +errout_meta: + btf_free_struct_meta_tab(btf); errout: btf_verifier_env_free(env); if (btf) @@ -6028,6 +6184,28 @@ int btf_struct_access(struct bpf_verifier_log *log, u32 id = reg->btf_id; int err; + while (type_is_alloc(reg->type)) { + struct btf_struct_meta *meta; + struct btf_record *rec; + int i; + + meta = btf_find_struct_meta(btf, id); + if (!meta) + break; + rec = meta->record; + for (i = 0; i < rec->cnt; i++) { + struct btf_field *field = &rec->fields[i]; + u32 offset = field->offset; + if (off < offset + btf_field_type_size(field->type) && offset < off + size) { + bpf_log(log, + "direct access to %s is disallowed\n", + btf_field_type_name(field->type)); + return -EACCES; + } + } + break; + } + t = btf_type_by_id(btf, id); do { err = btf_struct_walk(log, btf, t, off, size, &id, &tmp_flag); @@ -7269,23 +7447,6 @@ bool btf_is_module(const struct btf *btf) return btf->kernel_btf && strcmp(btf->name, "vmlinux") != 0; } -static int btf_id_cmp_func(const void *a, const void *b) -{ - const int *pa = a, *pb = b; - - return *pa - *pb; -} - -bool btf_id_set_contains(const struct btf_id_set *set, u32 id) -{ - return bsearch(&id, set->ids, set->cnt, sizeof(u32), btf_id_cmp_func) != NULL; -} - -static void *btf_id_set8_contains(const struct btf_id_set8 *set, u32 id) -{ - return bsearch(&id, set->pairs, set->cnt, sizeof(set->pairs[0]), btf_id_cmp_func); -} - enum { BTF_MODULE_F_LIVE = (1 << 0), }; diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index 4c20dcbc6526..56ae97d490f4 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -537,6 +537,7 @@ void btf_record_free(struct btf_record *rec) btf_put(rec->fields[i].kptr.btf); break; case BPF_LIST_HEAD: + case BPF_LIST_NODE: /* Nothing to release for bpf_list_head */ break; default: @@ -582,6 +583,7 @@ struct btf_record *btf_record_dup(const struct btf_record *rec) } break; case BPF_LIST_HEAD: + case BPF_LIST_NODE: /* Nothing to acquire for bpf_list_head */ break; default: @@ -648,6 +650,8 @@ void bpf_obj_free_fields(const struct btf_record *rec, void *obj) continue; bpf_list_head_free(field, field_ptr, obj + rec->spin_lock_off); break; + case BPF_LIST_NODE: + break; default: WARN_ON_ONCE(1); continue; From patchwork Thu Nov 17 22:54:54 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kumar Kartikeya Dwivedi X-Patchwork-Id: 13047432 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 95B45C4332F for ; Thu, 17 Nov 2022 22:55:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234786AbiKQWzs (ORCPT ); Thu, 17 Nov 2022 17:55:48 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53218 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234843AbiKQWzo (ORCPT ); Thu, 17 Nov 2022 17:55:44 -0500 Received: from mail-pj1-x1041.google.com (mail-pj1-x1041.google.com [IPv6:2607:f8b0:4864:20::1041]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D9F0762CE for ; Thu, 17 Nov 2022 14:55:43 -0800 (PST) Received: by mail-pj1-x1041.google.com with SMTP id b1-20020a17090a7ac100b00213fde52d49so3390615pjl.3 for ; Thu, 17 Nov 2022 14:55:43 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=59LPQzxnxExTrnm9z27ZdhRyWEMEvy8zkWsOH6jmk1I=; b=CiEbwjfJhTyyHuW28tXo+HFVt6J9/53Ftsl8aIOzPqrL8QPpPfm67CNSOOlvFNYjeP mmJRRuFDfdpatCB1dZitk8FgpqLX9nOs3SXFFMLce6ceFmjyUnCyTEeHqB7r5f9oX/Kd haRbSiBIN66+wLmPv7yv5WEHaDDlTV2QIcmC7qT+y4vbyKKQUJTjQBatifLj4BoIJl91 EmeHiewR49RNAzk16j0Oxf7Xsdy7Av+0r90FEwCW592kg6Zodql3wiLdgRCTG6yMaMxw y4hiQh/e0T0Ay3ekr2OBvUlWjFpa+G+7l/0gKpGZc6E31wNMD043aSXEVvR9wTxPnKQt wpFA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=59LPQzxnxExTrnm9z27ZdhRyWEMEvy8zkWsOH6jmk1I=; b=cN43JjWp7IG7YLT17He5KNNbl/IVRf6ExT8F+f/h0RlIXXYAYOPdqb6mdvZBD3EFMu LZHLjhUq/Mzrb0KyynJhClDExF+B5kuJd+CD3fDxh7jmXXB/040VJaw3Zv+jqWJ8hwM3 S+FSoBzXyxvEpuxTPN4xN1WzHYB5J0CDxLbyAG+zcsmkxWHWsuNvgOI3YaM54LEwi3Oz MEC6HTiFB2ElYQrkYzAtNZ5aT1/QK4lQodPV8mKLpj/WOI2PGVCYW2Rm1edu/UIJMZ8g dCqTf8/yx8HTCuxv6VSSriokOhpcSgSZiOAiFdYmQLMitKS6BkM39HH6TNpXxgLNBeVP J4vw== X-Gm-Message-State: ANoB5plwrau3HEx8FeFK5PaBggkjKEhsWkIt1qpymsAzhsgI7GTPo57X nT9qgk2B3fjwV6VBOvRarMQZQL1W0po= X-Google-Smtp-Source: AA0mqf58+zZjkH0CyzpyzMpEhKdOeF/cA58fRQRbasaL2bkoFS6iyDzPQclmry6gcUdbbZlGHMoBDA== X-Received: by 2002:a17:902:bd96:b0:181:b55a:f987 with SMTP id q22-20020a170902bd9600b00181b55af987mr4890823pls.67.1668725743129; Thu, 17 Nov 2022 14:55:43 -0800 (PST) Received: from localhost ([2409:40f4:8:955c:5484:8048:c08:7b3]) by smtp.gmail.com with ESMTPSA id iw20-20020a170903045400b00179f370dbe7sm1847384plb.287.2022.11.17.14.55.42 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 17 Nov 2022 14:55:42 -0800 (PST) From: Kumar Kartikeya Dwivedi To: bpf@vger.kernel.org Cc: Alexei Starovoitov , Andrii Nakryiko , Daniel Borkmann , Martin KaFai Lau , Dave Marchevsky Subject: [PATCH bpf-next v9 07/23] bpf: Verify ownership relationships for user BTF types Date: Fri, 18 Nov 2022 04:24:54 +0530 Message-Id: <20221117225510.1676785-8-memxor@gmail.com> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20221117225510.1676785-1-memxor@gmail.com> References: <20221117225510.1676785-1-memxor@gmail.com> MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=5571; i=memxor@gmail.com; h=from:subject; bh=yjHfgHm/5+Ygd2drsc/Tti6WmbVZpvw5QJdLaHTdJrM=; b=owEBbQKS/ZANAwAIAUzgyIZIvxHKAcsmYgBjdrkbBmK1fKl3Ixaf3FLvq3rDvimWbGzprZ//M+bf XUHGe2OJAjMEAAEIAB0WIQRLvip+Buz51YI8YRFM4MiGSL8RygUCY3a5GwAKCRBM4MiGSL8RyvJbD/ 9HqaY4aL9pfovYru3Zm/u0O26mfjgbsbQSNsQqm3RW2hhcUzezEXheX5Zs5DIvfRQGqryYyzeTQeix flKSeG59S2FF0+WSIoK2+aLYmmK0ZBojePNsP3nQpIz4+rFoOeLlZaGijS9OrK6EGqVQhgEvdoMdTH tIl41ktxruvuk1W+eUUXSrQvbYiOc4CbXmAUj+VYHFCOr+g6w+inJEFYaiGImDKDAokNbW/NxuRkKD F6tczFfVuE7OaBuoi4v84PAxW8FY70dgmZyTFbfqt3hMr8nHLjxKn+u1T88KwaV6fmNaLDyzrpJgqM oRfInbft/CPMUSH+HIFgsAiCm/f+QWuQ1f6AIR/VIhU4T5PtXxFzbAY9F3QBASqYGLTLYZsAThGc5f AWlutjPTwImXlmB9vDyB082EcwkeHZOVpixv/nwUURhfqxR4GtLTTWN7kJmxLiuM6P5Loz+G7YMpDv kgOMDQF+Hp5ylwsKyh9Z11lfWUGXoAM8hKgiI9R+X+UvTFM5m53NzIp9nSXW2J34fazq0j9cCV/YTC CaV09sB0rQ/ZipHlNHwBBxa7UTDx6V/YLPN/NVq19Ibeqded72clj+QlHUDIS/VGn/1QdScModa12c lyGUJoNpRVWfW6ScEi6txJK0WcK2OhI6yf/R6eTO8vS4Eep7o8kGsgQCkruA== X-Developer-Key: i=memxor@gmail.com; a=openpgp; fpr=4BBE2A7E06ECF9D5823C61114CE0C88648BF11CA Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net Ensure that there can be no ownership cycles among different types by way of having owning objects that can hold some other type as their element. For instance, a map value can only hold allocated objects, but these are allowed to have another bpf_list_head. To prevent unbounded recursion while freeing resources, elements of bpf_list_head in local kptrs can never have a bpf_list_head which are part of list in a map value. Later patches will verify this by having dedicated BTF selftests. Also, to make runtime destruction easier, once btf_struct_metas is fully populated, we can stash the metadata of the value type directly in the metadata of the list_head fields, as that allows easier access to the value type's layout to destruct it at runtime from the btf_field entry of the list head itself. Signed-off-by: Kumar Kartikeya Dwivedi --- include/linux/bpf.h | 1 + include/linux/btf.h | 1 + kernel/bpf/btf.c | 71 ++++++++++++++++++++++++++++++++++++++++++++ kernel/bpf/syscall.c | 4 +++ 4 files changed, 77 insertions(+) diff --git a/include/linux/bpf.h b/include/linux/bpf.h index eb6ea53fa5a2..323985a39ece 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -191,6 +191,7 @@ struct btf_field_list_head { struct btf *btf; u32 value_btf_id; u32 node_offset; + struct btf_record *value_rec; }; struct btf_field { diff --git a/include/linux/btf.h b/include/linux/btf.h index a01a8da20021..42d8f3730a8d 100644 --- a/include/linux/btf.h +++ b/include/linux/btf.h @@ -178,6 +178,7 @@ int btf_find_spin_lock(const struct btf *btf, const struct btf_type *t); int btf_find_timer(const struct btf *btf, const struct btf_type *t); struct btf_record *btf_parse_fields(const struct btf *btf, const struct btf_type *t, u32 field_mask, u32 value_size); +int btf_check_and_fixup_fields(const struct btf *btf, struct btf_record *rec); struct btf_field_offs *btf_parse_field_offs(struct btf_record *rec); bool btf_type_is_void(const struct btf_type *t); s32 btf_find_by_name_kind(const struct btf *btf, const char *name, u8 kind); diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c index a04e10477567..91aa9c96621f 100644 --- a/kernel/bpf/btf.c +++ b/kernel/bpf/btf.c @@ -3723,6 +3723,67 @@ struct btf_record *btf_parse_fields(const struct btf *btf, const struct btf_type return ERR_PTR(ret); } +int btf_check_and_fixup_fields(const struct btf *btf, struct btf_record *rec) +{ + int i; + + /* There are two owning types, kptr_ref and bpf_list_head. The former + * only supports storing kernel types, which can never store references + * to program allocated local types, atleast not yet. Hence we only need + * to ensure that bpf_list_head ownership does not form cycles. + */ + if (IS_ERR_OR_NULL(rec) || !(rec->field_mask & BPF_LIST_HEAD)) + return 0; + for (i = 0; i < rec->cnt; i++) { + struct btf_struct_meta *meta; + u32 btf_id; + + if (!(rec->fields[i].type & BPF_LIST_HEAD)) + continue; + btf_id = rec->fields[i].list_head.value_btf_id; + meta = btf_find_struct_meta(btf, btf_id); + if (!meta) + return -EFAULT; + rec->fields[i].list_head.value_rec = meta->record; + + if (!(rec->field_mask & BPF_LIST_NODE)) + continue; + + /* We need to ensure ownership acyclicity among all types. The + * proper way to do it would be to topologically sort all BTF + * IDs based on the ownership edges, since there can be multiple + * bpf_list_head in a type. Instead, we use the following + * reasoning: + * + * - A type can only be owned by another type in user BTF if it + * has a bpf_list_node. + * - A type can only _own_ another type in user BTF if it has a + * bpf_list_head. + * + * We ensure that if a type has both bpf_list_head and + * bpf_list_node, its element types cannot be owning types. + * + * To ensure acyclicity: + * + * When A only has bpf_list_head, ownership chain can be: + * A -> B -> C + * Where: + * - B has both bpf_list_head and bpf_list_node. + * - C only has bpf_list_node. + * + * When A has both bpf_list_head and bpf_list_node, some other + * type already owns it in the BTF domain, hence it can not own + * another owning type through any of the bpf_list_head edges. + * A -> B + * Where: + * - B only has bpf_list_node. + */ + if (meta->record->field_mask & BPF_LIST_HEAD) + return -ELOOP; + } + return 0; +} + static int btf_field_offs_cmp(const void *_a, const void *_b, const void *priv) { const u32 a = *(const u32 *)_a; @@ -5413,6 +5474,16 @@ static struct btf *btf_parse(bpfptr_t btf_data, u32 btf_data_size, } btf->struct_meta_tab = struct_meta_tab; + if (struct_meta_tab) { + int i; + + for (i = 0; i < struct_meta_tab->cnt; i++) { + err = btf_check_and_fixup_fields(btf, struct_meta_tab->types[i].record); + if (err < 0) + goto errout_meta; + } + } + if (log->level && bpf_verifier_log_full(log)) { err = -ENOSPC; goto errout_meta; diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index 56ae97d490f4..6140cbc3ed8a 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -1054,6 +1054,10 @@ static int map_check_btf(struct bpf_map *map, const struct btf *btf, } } + ret = btf_check_and_fixup_fields(btf, map->record); + if (ret < 0) + goto free_map_tab; + if (map->ops->map_check_btf) { ret = map->ops->map_check_btf(map, btf, key_type, value_type); if (ret < 0) From patchwork Thu Nov 17 22:54:55 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kumar Kartikeya Dwivedi X-Patchwork-Id: 13047433 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id DF604C43217 for ; Thu, 17 Nov 2022 22:56:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235099AbiKQW4B (ORCPT ); Thu, 17 Nov 2022 17:56:01 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53276 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235000AbiKQWzs (ORCPT ); Thu, 17 Nov 2022 17:55:48 -0500 Received: from mail-pg1-x541.google.com (mail-pg1-x541.google.com [IPv6:2607:f8b0:4864:20::541]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 05806186FC for ; Thu, 17 Nov 2022 14:55:48 -0800 (PST) Received: by mail-pg1-x541.google.com with SMTP id 136so3465277pga.1 for ; Thu, 17 Nov 2022 14:55:48 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=DbEyJK9HHakkaLmZTBG+aVA2e5HoR3xLLcJ7jqCnp4M=; b=PHGxijOIt5+W8su/yKT1fiSwsuZfSCQx4gDDlx9RwLzUXU0PMfBXE1Mq4mGM13gmKm Diqs32ia79k8JRpBKWJ85XFcClbRn/6lDnITprrKJToV48y+sRr6qjJou6/xdjMpMeAj rjm/Lz12rUW+VQ4xnIkSUDjR8xXOOKb+VgLHjkE9FfTH8KzJEC8So5SbqPVgo2Paq20i 13tabbEEz60GOe12IemPet5TyOu96xKQA4UdHf2soOUX/efVjZXaumVIJ4rP4n6acVe6 RDlqlGukNStGN5jOdLYFvKr1HQ+ep+o0N7W4qrWqUYlvpj4olm9s1V7O4nTZvocNYrP4 hbyg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=DbEyJK9HHakkaLmZTBG+aVA2e5HoR3xLLcJ7jqCnp4M=; b=T8iFpghptT8ptwniv6GlQennBe9+q3gm3dFYhkPNN2GVGeC6nt8yD0wHRIO7I3n9O0 lgreF9Oeh+Cpm81weZCB48aqUZBsxv9dELKB+ap8KdDe2G8JSbDBgOqILKCS4r8EQZZ0 hH5BKeSEFw39sNvWMDz7fPlzFZvZpMXwS7kg0sS2sysCRlTVKIt74NOOFsWd5fL5TGgr yO+IWO3XO/nLkLhmzFaYi3iBHJP5+oKOLRzTX54wxGPGcyYWb3B/IVJhzDV+pk+ojBzy q2GNa3nyTRmszba/ENvBo593nLT3+9LuoOHH+EcQFsYLPTUpIEiB59JMotYpe4FqjuhP obyg== X-Gm-Message-State: ANoB5pkV+hlpzOHarKBakC3QBuz9utBQV6+vITN7qGGc/bKKrW2l3wXa gfbaDkWA0PBdkKojJwa2ZgeJn1z2Mqk= X-Google-Smtp-Source: AA0mqf6FlaVmG04nOW2KxrzCl3PP96Q6ukmBFyax0pzay0MRBgY4bizguQJJbP4bkqC3kV8C9Bib8A== X-Received: by 2002:aa7:8608:0:b0:52f:db84:81cf with SMTP id p8-20020aa78608000000b0052fdb8481cfmr5104465pfn.26.1668725747259; Thu, 17 Nov 2022 14:55:47 -0800 (PST) Received: from localhost ([2409:40f4:8:955c:5484:8048:c08:7b3]) by smtp.gmail.com with ESMTPSA id d10-20020a170902654a00b00188fcc4fc00sm243982pln.79.2022.11.17.14.55.45 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 17 Nov 2022 14:55:46 -0800 (PST) From: Kumar Kartikeya Dwivedi To: bpf@vger.kernel.org Cc: Alexei Starovoitov , Andrii Nakryiko , Daniel Borkmann , Martin KaFai Lau , Dave Marchevsky Subject: [PATCH bpf-next v9 08/23] bpf: Allow locking bpf_spin_lock in allocated objects Date: Fri, 18 Nov 2022 04:24:55 +0530 Message-Id: <20221117225510.1676785-9-memxor@gmail.com> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20221117225510.1676785-1-memxor@gmail.com> References: <20221117225510.1676785-1-memxor@gmail.com> MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=8926; i=memxor@gmail.com; h=from:subject; bh=ae8q9s9cDVzghCLBYYIt/0OQIWliZosyXk12KKyNFuE=; b=owEBbQKS/ZANAwAIAUzgyIZIvxHKAcsmYgBjdrkbtufLpx78Y1jeLtm63SLV+2UVK0aVakc7X0u1 XlbMtHmJAjMEAAEIAB0WIQRLvip+Buz51YI8YRFM4MiGSL8RygUCY3a5GwAKCRBM4MiGSL8Ryo9+EA CoXWfBRYL+HF5wKNAOr4XJA51wZ0cxE3bQPboLhp/FI3Edgdrk+aLkIfQBFs7dFZovRfLy0EPTsFt6 +BahZAub9ArFViJHFU60nGPqFtDbhprqOcGf0TTMWcEyhBuCbcbad8EsudyvssoSMCMrgLAWIaXt6J Tdlm7LVruFHvdvvLBocBIMn2r83MRHByluLu1NOR3wjvwzM+4il0yUtOHQ11sBVxXUv/qGkpWgnDEK iMvf4ONDIeyeUn+7mLZdSnNXl0joEM/XRzRdK2YqcdPYlLvAbXdrwPrb9OqzxblfQeWe+Bk/r8/RD7 F6A04Rn+AC1Sh4oKeep3qbr5M2xb3cX4P/bto6HJg0aqFOyIMAsJw6q142QRIuvALvSAatZVPUr39a f75C58u8fOZ3DtYlm1LYMje6rJf4I26iIjk8rdBYz6wssBMA3VLsCmOgyVM4K4p5UGHfzAUofj4n3c sbPa26jQaZ0Iq+wty4OCsEkJ9AJsSAaVEolq8wFtp1/MT9+rLKm3+Xt/3VMfZgsTfgLvZC0jti3vFG iOa/iyPiywpI1PCGJBd5qiOMkYfonObIn1UaXNXPsoq24OIBfWFJYHd5MGmPHrUR8aCxrrzWku9RyV JSfjaR6BT83AxFOgzvqhufLWFv2b25ynvANIgEpnPCB5M//VVU7eozncz7xA== X-Developer-Key: i=memxor@gmail.com; a=openpgp; fpr=4BBE2A7E06ECF9D5823C61114CE0C88648BF11CA Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net Allow locking a bpf_spin_lock in an allocated object, in addition to already supported map value pointers. The handling is similar to that of map values, by just preserving the reg->id of PTR_TO_BTF_ID | MEM_ALLOC as well, and adjusting process_spin_lock to work with them and remember the id in verifier state. Refactor the existing process_spin_lock to work with PTR_TO_BTF_ID | MEM_ALLOC in addition to PTR_TO_MAP_VALUE. We need to update the reg_may_point_to_spin_lock which is used in mark_ptr_or_null_reg to preserve reg->id, that will be used in env->cur_state->active_spin_lock to remember the currently held spin lock. Also update the comment describing bpf_spin_lock implementation details to also talk about PTR_TO_BTF_ID | MEM_ALLOC type. Signed-off-by: Kumar Kartikeya Dwivedi --- kernel/bpf/helpers.c | 2 + kernel/bpf/verifier.c | 89 +++++++++++++++++++++++++++++++------------ 2 files changed, 66 insertions(+), 25 deletions(-) diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c index 7bc71995f17c..5bc0b9f0f306 100644 --- a/kernel/bpf/helpers.c +++ b/kernel/bpf/helpers.c @@ -336,6 +336,7 @@ const struct bpf_func_proto bpf_spin_lock_proto = { .gpl_only = false, .ret_type = RET_VOID, .arg1_type = ARG_PTR_TO_SPIN_LOCK, + .arg1_btf_id = BPF_PTR_POISON, }; static inline void __bpf_spin_unlock_irqrestore(struct bpf_spin_lock *lock) @@ -358,6 +359,7 @@ const struct bpf_func_proto bpf_spin_unlock_proto = { .gpl_only = false, .ret_type = RET_VOID, .arg1_type = ARG_PTR_TO_SPIN_LOCK, + .arg1_btf_id = BPF_PTR_POISON, }; void copy_map_value_locked(struct bpf_map *map, void *dst, void *src, diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 49e08c1c2c61..8eddecfc3a5e 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -453,8 +453,16 @@ static bool reg_type_not_null(enum bpf_reg_type type) static bool reg_may_point_to_spin_lock(const struct bpf_reg_state *reg) { - return reg->type == PTR_TO_MAP_VALUE && - btf_record_has_field(reg->map_ptr->record, BPF_SPIN_LOCK); + struct btf_record *rec = NULL; + + if (reg->type == PTR_TO_MAP_VALUE) { + rec = reg->map_ptr->record; + } else if (reg->type == (PTR_TO_BTF_ID | MEM_ALLOC)) { + struct btf_struct_meta *meta = btf_find_struct_meta(reg->btf, reg->btf_id); + if (meta) + rec = meta->record; + } + return btf_record_has_field(rec, BPF_SPIN_LOCK); } static bool type_is_rdonly_mem(u32 type) @@ -5564,23 +5572,26 @@ int check_kfunc_mem_size_reg(struct bpf_verifier_env *env, struct bpf_reg_state } /* Implementation details: - * bpf_map_lookup returns PTR_TO_MAP_VALUE_OR_NULL + * bpf_map_lookup returns PTR_TO_MAP_VALUE_OR_NULL. + * bpf_obj_new returns PTR_TO_BTF_ID | MEM_ALLOC | PTR_MAYBE_NULL. * Two bpf_map_lookups (even with the same key) will have different reg->id. - * For traditional PTR_TO_MAP_VALUE the verifier clears reg->id after - * value_or_null->value transition, since the verifier only cares about - * the range of access to valid map value pointer and doesn't care about actual - * address of the map element. + * Two separate bpf_obj_new will also have different reg->id. + * For traditional PTR_TO_MAP_VALUE or PTR_TO_BTF_ID | MEM_ALLOC, the verifier + * clears reg->id after value_or_null->value transition, since the verifier only + * cares about the range of access to valid map value pointer and doesn't care + * about actual address of the map element. * For maps with 'struct bpf_spin_lock' inside map value the verifier keeps * reg->id > 0 after value_or_null->value transition. By doing so * two bpf_map_lookups will be considered two different pointers that - * point to different bpf_spin_locks. + * point to different bpf_spin_locks. Likewise for pointers to allocated objects + * returned from bpf_obj_new. * The verifier allows taking only one bpf_spin_lock at a time to avoid * dead-locks. * Since only one bpf_spin_lock is allowed the checks are simpler than * reg_is_refcounted() logic. The verifier needs to remember only * one spin_lock instead of array of acquired_refs. - * cur_state->active_spin_lock remembers which map value element got locked - * and clears it after bpf_spin_unlock. + * cur_state->active_spin_lock remembers which map value element or allocated + * object got locked and clears it after bpf_spin_unlock. */ static int process_spin_lock(struct bpf_verifier_env *env, int regno, bool is_lock) @@ -5588,8 +5599,10 @@ static int process_spin_lock(struct bpf_verifier_env *env, int regno, struct bpf_reg_state *regs = cur_regs(env), *reg = ®s[regno]; struct bpf_verifier_state *cur = env->cur_state; bool is_const = tnum_is_const(reg->var_off); - struct bpf_map *map = reg->map_ptr; + struct btf_record *rec = NULL; u64 val = reg->var_off.value; + struct bpf_map *map = NULL; + struct btf *btf = NULL; if (!is_const) { verbose(env, @@ -5597,19 +5610,32 @@ static int process_spin_lock(struct bpf_verifier_env *env, int regno, regno); return -EINVAL; } - if (!map->btf) { - verbose(env, - "map '%s' has to have BTF in order to use bpf_spin_lock\n", - map->name); - return -EINVAL; + if (reg->type == PTR_TO_MAP_VALUE) { + map = reg->map_ptr; + if (!map->btf) { + verbose(env, + "map '%s' has to have BTF in order to use bpf_spin_lock\n", + map->name); + return -EINVAL; + } + rec = map->record; + } else { + struct btf_struct_meta *meta; + + btf = reg->btf; + meta = btf_find_struct_meta(reg->btf, reg->btf_id); + if (meta) + rec = meta->record; } - if (!btf_record_has_field(map->record, BPF_SPIN_LOCK)) { - verbose(env, "map '%s' has no valid bpf_spin_lock\n", map->name); + + if (!btf_record_has_field(rec, BPF_SPIN_LOCK)) { + verbose(env, "%s '%s' has no valid bpf_spin_lock\n", map ? "map" : "local", + map ? map->name : "kptr"); return -EINVAL; } - if (map->record->spin_lock_off != val + reg->off) { + if (rec->spin_lock_off != val + reg->off) { verbose(env, "off %lld doesn't point to 'struct bpf_spin_lock' that is at %d\n", - val + reg->off, map->record->spin_lock_off); + val + reg->off, rec->spin_lock_off); return -EINVAL; } if (is_lock) { @@ -5815,13 +5841,19 @@ static const struct bpf_reg_types int_ptr_types = { }, }; +static const struct bpf_reg_types spin_lock_types = { + .types = { + PTR_TO_MAP_VALUE, + PTR_TO_BTF_ID | MEM_ALLOC, + } +}; + static const struct bpf_reg_types fullsock_types = { .types = { PTR_TO_SOCKET } }; static const struct bpf_reg_types scalar_types = { .types = { SCALAR_VALUE } }; static const struct bpf_reg_types context_types = { .types = { PTR_TO_CTX } }; static const struct bpf_reg_types ringbuf_mem_types = { .types = { PTR_TO_MEM | MEM_RINGBUF } }; static const struct bpf_reg_types const_map_ptr_types = { .types = { CONST_PTR_TO_MAP } }; static const struct bpf_reg_types btf_ptr_types = { .types = { PTR_TO_BTF_ID } }; -static const struct bpf_reg_types spin_lock_types = { .types = { PTR_TO_MAP_VALUE } }; static const struct bpf_reg_types percpu_btf_ptr_types = { .types = { PTR_TO_BTF_ID | MEM_PERCPU } }; static const struct bpf_reg_types func_ptr_types = { .types = { PTR_TO_FUNC } }; static const struct bpf_reg_types stack_ptr_types = { .types = { PTR_TO_STACK } }; @@ -5946,6 +5978,11 @@ static int check_reg_type(struct bpf_verifier_env *env, u32 regno, return -EACCES; } } + } else if (type_is_alloc(reg->type)) { + if (meta->func_id != BPF_FUNC_spin_lock && meta->func_id != BPF_FUNC_spin_unlock) { + verbose(env, "verifier internal error: unimplemented handling of MEM_ALLOC\n"); + return -EFAULT; + } } return 0; @@ -6062,7 +6099,8 @@ static int check_func_arg(struct bpf_verifier_env *env, u32 arg, goto skip_type_check; /* arg_btf_id and arg_size are in a union. */ - if (base_type(arg_type) == ARG_PTR_TO_BTF_ID) + if (base_type(arg_type) == ARG_PTR_TO_BTF_ID || + base_type(arg_type) == ARG_PTR_TO_SPIN_LOCK) arg_btf_id = fn->arg_btf_id[arg]; err = check_reg_type(env, regno, arg_type, arg_btf_id, meta); @@ -6680,9 +6718,10 @@ static bool check_btf_id_ok(const struct bpf_func_proto *fn) int i; for (i = 0; i < ARRAY_SIZE(fn->arg_type); i++) { - if (base_type(fn->arg_type[i]) == ARG_PTR_TO_BTF_ID && !fn->arg_btf_id[i]) - return false; - + if (base_type(fn->arg_type[i]) == ARG_PTR_TO_BTF_ID) + return !!fn->arg_btf_id[i]; + if (base_type(fn->arg_type[i]) == ARG_PTR_TO_SPIN_LOCK) + return fn->arg_btf_id[i] == BPF_PTR_POISON; if (base_type(fn->arg_type[i]) != ARG_PTR_TO_BTF_ID && fn->arg_btf_id[i] && /* arg_btf_id and arg_size are in a union. */ (base_type(fn->arg_type[i]) != ARG_PTR_TO_MEM || From patchwork Thu Nov 17 22:54:56 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kumar Kartikeya Dwivedi X-Patchwork-Id: 13047434 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 36FBBC4332F for ; Thu, 17 Nov 2022 22:56:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234884AbiKQW4E (ORCPT ); Thu, 17 Nov 2022 17:56:04 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53254 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235058AbiKQWzz (ORCPT ); Thu, 17 Nov 2022 17:55:55 -0500 Received: from mail-pg1-x543.google.com (mail-pg1-x543.google.com [IPv6:2607:f8b0:4864:20::543]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9C10413E28 for ; Thu, 17 Nov 2022 14:55:52 -0800 (PST) Received: by mail-pg1-x543.google.com with SMTP id o13so3426698pgu.7 for ; Thu, 17 Nov 2022 14:55:52 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=+ol7OxizXuiJ4eB7qeHuriIXAY7pywx1ZJI0gazh/20=; b=CEHiUJDt73p8YSq6fZGyoRPpWD6+/OAH+maYcCBLSD+zDeKXxWzvPXxSYeTZi+nldz M9Zj/cFXBvkYReSVnGwWQbbSO4pf16jUiP39xLtdrE0HZ3hb6CpHa5GVqqYcYVFJloHM qZ0N1cCd3l6L0nGfTSu+BhVKFa+CjGtw52U4lC62sAWOK8evWDT3V+bRBnkQ1tDaCFgf w32UvgpbL/dAxWksTqEd25dsg6kgVaXXI2Jx07CpQBqlwksyvsqzRH0HG41FuOdpwHB0 Lz1EClyYiY8EmxdEU54RYM1EYtKuS8p5BFuDtlz8RRh4EZQPrpad/3rfTOSXD/euKo9X Qhow== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=+ol7OxizXuiJ4eB7qeHuriIXAY7pywx1ZJI0gazh/20=; b=Kv71+VImJaEWXGh8iDTODcLvbEDM2hCNU2quyYNBn6BisZeD+orTx2lOogrQYBwoN7 F7TNB/41A69kEeXsd+eV/fNstb9plIsYs2cv4Fsx8tRJH2oJzQk5Q1QSmxAzTReRSlnL eWVhVavvtOCAQU13k9wK1/XqhtdvI6QY6LeiZ9NYHRT0rrpF8RLSFOeM+3z5+/AGzwiq huhjW/YJCHR23SEsmW7qP1PWgWqDHugYS4Y7kKMj74fweiyc1yzSBVDzElQ/tutlbOhW 2l4tSCDTCUac8cHsJti7488GSGg73rUgfsIfIcGFa/vvonaf+wwRCROnlP9A3wmdXuai eTpA== X-Gm-Message-State: ANoB5plZzwSmVnm65hD/5evUo69OQD9/L1egGegsHd/csq+DkF4YgBAO PXfsi9a0RBisbxNDDmbV9E50aD34xtc= X-Google-Smtp-Source: AA0mqf5f3mG9rOJHY3+s6yhaZL4QTLx6FrXHxaPcqIpJdtYh0FoG77WKDH8lnvEBVp2qY0+oEuOpAQ== X-Received: by 2002:a62:3142:0:b0:56d:8d19:f331 with SMTP id x63-20020a623142000000b0056d8d19f331mr5097692pfx.7.1668725751232; Thu, 17 Nov 2022 14:55:51 -0800 (PST) Received: from localhost ([2409:40f4:8:955c:5484:8048:c08:7b3]) by smtp.gmail.com with ESMTPSA id q13-20020aa7960d000000b0057253eb631dsm1694331pfg.46.2022.11.17.14.55.50 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 17 Nov 2022 14:55:50 -0800 (PST) From: Kumar Kartikeya Dwivedi To: bpf@vger.kernel.org Cc: Alexei Starovoitov , Andrii Nakryiko , Daniel Borkmann , Martin KaFai Lau , Dave Marchevsky Subject: [PATCH bpf-next v9 09/23] bpf: Allow locking bpf_spin_lock global variables Date: Fri, 18 Nov 2022 04:24:56 +0530 Message-Id: <20221117225510.1676785-10-memxor@gmail.com> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20221117225510.1676785-1-memxor@gmail.com> References: <20221117225510.1676785-1-memxor@gmail.com> MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=7353; i=memxor@gmail.com; h=from:subject; bh=6Vv4lEhpsQX066e3Wnco5QRfk4WP+T5sUnI+NWbYFw4=; b=owEBbQKS/ZANAwAIAUzgyIZIvxHKAcsmYgBjdrkb8Zv5F6jnmv0dZ31LuaSqMWJy1JocMzVB/Fne /JTeMQSJAjMEAAEIAB0WIQRLvip+Buz51YI8YRFM4MiGSL8RygUCY3a5GwAKCRBM4MiGSL8Rysh9D/ wOaBppX4R8XmSWgw3YACFxggiYoXdJCcqVawKGf4Hykye/n0692eV9B1MClQodDBW3kGLaUzToMFU/ n+ICsuRFl3JE5yoz5Jt8XvJ2qQEaDA+dOiZXTIRY86FmT4DAIpU32GjNwSHbbJZ88FywYHypjPyz4x FHVJTnwfCc7S5tTce5tlUJHHxNfTp/W2m5H85fFy1idQjnXfH+odZAfuGeNlUSSiJlwVEQ15Pwg34N amQrR2iGffJvro3t9h+1RRHdKDR8sCV4THJsLU/cqlBdSN/uVcXfeXrxBWb/h1rB1JbkaqVNCe7ewV j9oWZfuP/fsUEDkKggcAYTwpFrz7XfNOQkfEtiC89c+foewBX+NEZiCfB22FZNLn+8tg0G+YJYGXT5 FjIS83SlfBh+/Jja1nqxJjI3HoArgoBjwJQKTGv7E11H3VN+6VQWHh8cHJyzdCQMZW6zw4yk2uwMYa Ke4hSPrD4hdI0KTCHO+CQzVP9MUY+hKKExViKD/a9Gnv8sWe/eWnXMLwtqBAX0c+R17rfd8mhzbRQz /p83JyQYcBdm9/kjtq6fWMEU6x+iUXXErYp+DtWEZQgDDibNobwNAX85mtUMtG51IUavBF4S2yb/2i nn1xI9TgLoaOFcFifa/198ay86rFSNZAmOBb+tI8G5LqLiumLHeZUy/OGpUA== X-Developer-Key: i=memxor@gmail.com; a=openpgp; fpr=4BBE2A7E06ECF9D5823C61114CE0C88648BF11CA Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net Global variables reside in maps accessible using direct_value_addr callbacks, so giving each load instruction's rewrite a unique reg->id disallows us from holding locks which are global. The reason for preserving reg->id as a unique value for registers that may point to spin lock is that two separate lookups are treated as two separate memory regions, and any possible aliasing is ignored for the purposes of spin lock correctness. This is not great especially for the global variable case, which are served from maps that have max_entries == 1, i.e. they always lead to map values pointing into the same map value. So refactor the active_spin_lock into a 'active_lock' structure which represents the lock identity, and instead of the reg->id, remember two fields, a pointer and the reg->id. The pointer will store reg->map_ptr or reg->btf. It's only necessary to distinguish for the id == 0 case of global variables, but always setting the pointer to a non-NULL value and using the pointer to check whether the lock is held simplifies code in the verifier. This is generic enough to allow it for global variables, map lookups, and allocated objects at the same time. Note that while whether a lock is held can be answered by just comparing active_lock.ptr to NULL, to determine whether the register is pointing to the same held lock requires comparing _both_ ptr and id. Finally, as a result of this refactoring, pseudo load instructions are not given a unique reg->id, as they are doing lookup for the same map value (max_entries is never greater than 1). Essentially, we consider that the tuple of (ptr, id) will always be unique for any kind of argument to bpf_spin_{lock,unlock}. Note that this can be extended in the future to also remember offset used for locking, so that we can introduce multiple bpf_spin_lock fields in the same allocation. Signed-off-by: Kumar Kartikeya Dwivedi --- include/linux/bpf_verifier.h | 16 +++++++++++++- kernel/bpf/verifier.c | 41 ++++++++++++++++++++++++------------ 2 files changed, 43 insertions(+), 14 deletions(-) diff --git a/include/linux/bpf_verifier.h b/include/linux/bpf_verifier.h index 1a32baa78ce2..3770bb1a6f62 100644 --- a/include/linux/bpf_verifier.h +++ b/include/linux/bpf_verifier.h @@ -323,7 +323,21 @@ struct bpf_verifier_state { u32 branches; u32 insn_idx; u32 curframe; - u32 active_spin_lock; + /* For every reg representing a map value of allocated object pointer, + * we consider the tuple of (ptr, id) for them to be unique in verifier + * context and conside them to not alias each other for the purposes of + * tracking lock state. + */ + struct { + /* This can either be reg->map_ptr or reg->btf. If ptr is NULL, + * there's no active lock held, and other fields have no + * meaning. If non-NULL, it indicates that a lock is held and + * id member has the reg->id of the register which can be >= 0. + */ + void *ptr; + /* This will be reg->id */ + u32 id; + } active_lock; bool speculative; /* first and last insn idx of this verifier state */ diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 8eddecfc3a5e..b231abbeaf55 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -1215,7 +1215,8 @@ static int copy_verifier_state(struct bpf_verifier_state *dst_state, } dst_state->speculative = src->speculative; dst_state->curframe = src->curframe; - dst_state->active_spin_lock = src->active_spin_lock; + dst_state->active_lock.ptr = src->active_lock.ptr; + dst_state->active_lock.id = src->active_lock.id; dst_state->branches = src->branches; dst_state->parent = src->parent; dst_state->first_insn_idx = src->first_insn_idx; @@ -5590,7 +5591,7 @@ int check_kfunc_mem_size_reg(struct bpf_verifier_env *env, struct bpf_reg_state * Since only one bpf_spin_lock is allowed the checks are simpler than * reg_is_refcounted() logic. The verifier needs to remember only * one spin_lock instead of array of acquired_refs. - * cur_state->active_spin_lock remembers which map value element or allocated + * cur_state->active_lock remembers which map value element or allocated * object got locked and clears it after bpf_spin_unlock. */ static int process_spin_lock(struct bpf_verifier_env *env, int regno, @@ -5639,22 +5640,35 @@ static int process_spin_lock(struct bpf_verifier_env *env, int regno, return -EINVAL; } if (is_lock) { - if (cur->active_spin_lock) { + if (cur->active_lock.ptr) { verbose(env, "Locking two bpf_spin_locks are not allowed\n"); return -EINVAL; } - cur->active_spin_lock = reg->id; + if (map) + cur->active_lock.ptr = map; + else + cur->active_lock.ptr = btf; + cur->active_lock.id = reg->id; } else { - if (!cur->active_spin_lock) { + void *ptr; + + if (map) + ptr = map; + else + ptr = btf; + + if (!cur->active_lock.ptr) { verbose(env, "bpf_spin_unlock without taking a lock\n"); return -EINVAL; } - if (cur->active_spin_lock != reg->id) { + if (cur->active_lock.ptr != ptr || + cur->active_lock.id != reg->id) { verbose(env, "bpf_spin_unlock of different lock\n"); return -EINVAL; } - cur->active_spin_lock = 0; + cur->active_lock.ptr = NULL; + cur->active_lock.id = 0; } return 0; } @@ -10616,8 +10630,8 @@ static int check_ld_imm(struct bpf_verifier_env *env, struct bpf_insn *insn) insn->src_reg == BPF_PSEUDO_MAP_IDX_VALUE) { dst_reg->type = PTR_TO_MAP_VALUE; dst_reg->off = aux->map_off; - if (btf_record_has_field(map->record, BPF_SPIN_LOCK)) - dst_reg->id = ++env->id_gen; + WARN_ON_ONCE(map->max_entries != 1); + /* We want reg->id to be same (0) as map_value is not distinct */ } else if (insn->src_reg == BPF_PSEUDO_MAP_FD || insn->src_reg == BPF_PSEUDO_MAP_IDX) { dst_reg->type = CONST_PTR_TO_MAP; @@ -10695,7 +10709,7 @@ static int check_ld_abs(struct bpf_verifier_env *env, struct bpf_insn *insn) return err; } - if (env->cur_state->active_spin_lock) { + if (env->cur_state->active_lock.ptr) { verbose(env, "BPF_LD_[ABS|IND] cannot be used inside bpf_spin_lock-ed region\n"); return -EINVAL; } @@ -11961,7 +11975,8 @@ static bool states_equal(struct bpf_verifier_env *env, if (old->speculative && !cur->speculative) return false; - if (old->active_spin_lock != cur->active_spin_lock) + if (old->active_lock.ptr != cur->active_lock.ptr || + old->active_lock.id != cur->active_lock.id) return false; /* for states to be equal callsites have to be the same @@ -12606,7 +12621,7 @@ static int do_check(struct bpf_verifier_env *env) return -EINVAL; } - if (env->cur_state->active_spin_lock && + if (env->cur_state->active_lock.ptr && (insn->src_reg == BPF_PSEUDO_CALL || insn->imm != BPF_FUNC_spin_unlock)) { verbose(env, "function calls are not allowed while holding a lock\n"); @@ -12643,7 +12658,7 @@ static int do_check(struct bpf_verifier_env *env) return -EINVAL; } - if (env->cur_state->active_spin_lock) { + if (env->cur_state->active_lock.ptr) { verbose(env, "bpf_spin_unlock is missing\n"); return -EINVAL; } From patchwork Thu Nov 17 22:54:57 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kumar Kartikeya Dwivedi X-Patchwork-Id: 13047435 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 74014C43217 for ; Thu, 17 Nov 2022 22:56:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234992AbiKQW4G (ORCPT ); Thu, 17 Nov 2022 17:56:06 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53374 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235089AbiKQWz6 (ORCPT ); Thu, 17 Nov 2022 17:55:58 -0500 Received: from mail-pj1-x1041.google.com (mail-pj1-x1041.google.com [IPv6:2607:f8b0:4864:20::1041]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 227BE6454C for ; Thu, 17 Nov 2022 14:55:55 -0800 (PST) Received: by mail-pj1-x1041.google.com with SMTP id u6-20020a17090a5e4600b0021881a8d264so1056865pji.4 for ; Thu, 17 Nov 2022 14:55:55 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=XI0cSLMpOLZbEZfTLKGuck/t/mpojqsult6wbsm/RSE=; b=BLz3MumpGVit8d3jGVSUkxlczr/6dJ09pCifGtXOCYHGWetNHaHG3pkaRSo09RAdoU qPhACvjNK+BOC/+J5P9At6XQjt6Nu3y7amm1fwAcZ4OmZrDtaxJKTMc0S5R1+UcLRarw 71SX3xjeq4V7cYdZsA52BZk0bgjVteZOA62EmZaAv6TmHGebp2dcScUQEvXsPe7fX3mp 19C2ppVHykLO5rnIr1ZIp9SeFn5/fjVq37NnlIV8EhnQqPOboFpDejIRjqWe0HhxFWMz 0O1PzOCMqIhlzlpGqDXuB+/J+WNhwzbQgogyuGPUTvOemKO9aunQ7GSOTl9TLlfZ19jd 6LKg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=XI0cSLMpOLZbEZfTLKGuck/t/mpojqsult6wbsm/RSE=; b=iQiGAlqFrx856ulOQBS3ji9I8399HKMyukSrmPIcgnMY98kMcYclccMiesnkLzoJhc CkSDFdwYjuZrQfSPPhmq8b0tTlUL49GAVTgrm4IA2tTw476U+u0CyYkrrwkG2H9BDDYw zKfeQVMTY7yyejSl8uwFjsinbcQAw4Xg/P+8asr4YsjBmVfs1+ys1DHvt5KZjy8RG9BY 3nxKeHkW9jsCsqY7Mh+X49Kqlz3RamA/EUncEY6/Xz8rPwJCgDtQdLbN6Pj7AZf5At6Q TFXHbOcY76FhPk7wRGf6h2FC6GSd8iQn7y18/2eRr01T1W53SiZxU0K+NWBKKNIlsQq8 uuaw== X-Gm-Message-State: ANoB5plkICF7Yaadb4sQUh5Lv4/k3rH5HE9RsxK2krZxszik36dX27RU 7AzHMgQHQgUX9GzTiwBOyaIMeBwtOlM= X-Google-Smtp-Source: AA0mqf5KxXtXVFD394Hs2dRIiPE4iHqdVdV5ACkhhAsAN7DCsbxyZb+vozzxZQ/dqd3b2rup+fNGYQ== X-Received: by 2002:a17:902:f152:b0:188:5581:c8de with SMTP id d18-20020a170902f15200b001885581c8demr4654998plb.140.1668725754453; Thu, 17 Nov 2022 14:55:54 -0800 (PST) Received: from localhost ([2409:40f4:8:955c:5484:8048:c08:7b3]) by smtp.gmail.com with ESMTPSA id b15-20020a170902d50f00b0018863e1bd3csm1950283plg.134.2022.11.17.14.55.53 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 17 Nov 2022 14:55:54 -0800 (PST) From: Kumar Kartikeya Dwivedi To: bpf@vger.kernel.org Cc: Alexei Starovoitov , Andrii Nakryiko , Daniel Borkmann , Martin KaFai Lau , Dave Marchevsky Subject: [PATCH bpf-next v9 10/23] bpf: Allow locking bpf_spin_lock in inner map values Date: Fri, 18 Nov 2022 04:24:57 +0530 Message-Id: <20221117225510.1676785-11-memxor@gmail.com> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20221117225510.1676785-1-memxor@gmail.com> References: <20221117225510.1676785-1-memxor@gmail.com> MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=1210; i=memxor@gmail.com; h=from:subject; bh=P1undU+At1PLzL1SYYwDyVj3bpoUrN/Ux1z3PCPdpx8=; b=owEBbQKS/ZANAwAIAUzgyIZIvxHKAcsmYgBjdrkbGd5ei57JxekHdh/Q140Pjn7yTFd8i7NCFmoN wsh9V0OJAjMEAAEIAB0WIQRLvip+Buz51YI8YRFM4MiGSL8RygUCY3a5GwAKCRBM4MiGSL8RysreD/ 9EXKsZB3mpmw8EBsET/tFVYFh5E0d5y4kb2NNDa+XKCuq6mwarT93wCe7UEn1UNXykML7TUWp0o9S0 WHkLHPuvEoYftCaoytG+cw8VzQCT413u6EMf8HkRFWweRWpm7plvM2EPxiYjfF6dm4z+uJ+oWSOGl4 mQ8hWINLVPmFDx6cGIAFkKSh4ZvTD3L+e9jDtzzYF20YNA0/D4f3YaV3skfHu0WTkzTlJIDlyX06R7 vhxBTMOnNhpqUSS+sXc1OTFHFUuUAiUob8V9DSYprWtjNDtAOdgf2+BspLivx8kq4KTLwdBQNB0/T1 NIsu6MUQ9SDks4lYxD0kgX6FBrsurClX0qcPGnq4NNvXFXoD7wagm9D7/2KPOKQpaZGYJ1B8wUNNoY CLR/aUVpCGnRsjcQsXRqX2wPLTjNfPlIBBe1WZto9AK+Xxh3CIguzrAyE9UCt6XA3S8c/9T3XYVNLg oPvcmHb6HNK+Agc8jSltZxxS1tPFQ9CAk6munnomv+RGvs1d2q+bqVXn7u0Y2lUBhcgpAAaUgS9DZh X7HiD+tZfCmRL/nmelwqSKyVtdvW7M5E5YdkCBUc2HmdunN07dfnyeuZ2Cu8ygozd4KIq7pbaQHHQI ma/e6dkRU0lsEk1IEjOS0uhJQIXrBkEdrykMxyEvUyQnrxoN1Lmm5XBIUcHw== X-Developer-Key: i=memxor@gmail.com; a=openpgp; fpr=4BBE2A7E06ECF9D5823C61114CE0C88648BF11CA Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net There is no need to restrict users from locking bpf_spin_lock in map values of inner maps. Each inner map lookup gets a unique reg->id assigned to the returned PTR_TO_MAP_VALUE which will be preserved after the NULL check. Distinct lookups into different inner map get unique IDs, and distinct lookups into same inner map also get unique IDs. Hence, lift the restriction by removing the check return -ENOTSUPP in map_in_map.c. Later commits will add comprehensive test cases to ensure that invalid cases are rejected. Signed-off-by: Kumar Kartikeya Dwivedi --- kernel/bpf/map_in_map.c | 5 ----- 1 file changed, 5 deletions(-) diff --git a/kernel/bpf/map_in_map.c b/kernel/bpf/map_in_map.c index fae6a6c33e2d..7cce2047c6ef 100644 --- a/kernel/bpf/map_in_map.c +++ b/kernel/bpf/map_in_map.c @@ -30,11 +30,6 @@ struct bpf_map *bpf_map_meta_alloc(int inner_map_ufd) goto put; } - if (btf_record_has_field(inner_map->record, BPF_SPIN_LOCK)) { - ret = -ENOTSUPP; - goto put; - } - inner_map_meta_size = sizeof(*inner_map_meta); /* In some cases verifier needs to access beyond just base map. */ if (inner_map->ops == &array_map_ops) From patchwork Thu Nov 17 22:54:58 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kumar Kartikeya Dwivedi X-Patchwork-Id: 13047437 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D4F8DC433FE for ; Thu, 17 Nov 2022 22:56:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234955AbiKQW4H (ORCPT ); Thu, 17 Nov 2022 17:56:07 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53240 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235120AbiKQW4C (ORCPT ); Thu, 17 Nov 2022 17:56:02 -0500 Received: from mail-pj1-x1044.google.com (mail-pj1-x1044.google.com [IPv6:2607:f8b0:4864:20::1044]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BA79F12620 for ; Thu, 17 Nov 2022 14:55:59 -0800 (PST) Received: by mail-pj1-x1044.google.com with SMTP id u8-20020a17090a5e4800b002106dcdd4a0so6754183pji.1 for ; Thu, 17 Nov 2022 14:55:59 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=txz4E4ZOze0iPtBRd8YZDAW2T2vLFfwNlBLr810Nooc=; b=Ivyhhh9bKpbX1SVB7Fg7rnk9S/ksL7kVT69n4Knx1qNpsRv1jPY1NqVCNatEYtOaOH Ss3OkH+b3cYKmXfbxzR1KuQ0tZ1aYOlY3Crv1QH+nOEMQ5FjTMwO6qgcYQwX5DZxD9gH qgvXUBParZaoKs71cqoENh0kJpZd0F3+OztM1zCUK2TVH1oX6lvaVhFaNt632pDx1kZl tRp+7As18C3Fcxrujjq6O/i+Owr4TVTSfie2wIWnmGPQVG5KhpBMQkHIOTMpaYAH6etx qZ/Q0yGsz5T/eTYYJZlALXS5lWgP0tTTmRrVo74FXhgpmFJM4PKUI61mVFab01yT3PUF KT/Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=txz4E4ZOze0iPtBRd8YZDAW2T2vLFfwNlBLr810Nooc=; b=t9vpSD4q32NEVDKR6Hy5bQoqcE1XtPjwsWOSc/wN9UjgEZPh0JLEtO06W1UWNdNjtp mg9MmDz/EkpTG+rG2L61IhNBxPxou8ddjPVWDl0+rNk5h7cdCZxh5SU2NKey8EzWvXZl xamOW1RFKifjQxHV+pGjdXDaZ3R565ADOjjdMm5ZHCwj+ij0cgT1+ag5oG2ZjMT72shj yx1WYhcksd3DtQIl5Q1QJLF09NE5bQKBvDW5LF2HdICXOttDuPaB/YgLC3W0C4OwmSxY Mw4zw5ykvH7+ptq0WMRxhRfjv04RhLdklxxwNoS0TmtkqkLOj4+6apcWICVzK8RIeqmW mx4A== X-Gm-Message-State: ANoB5pmGGkzmURHCLnuvErYCllQP+C31UBjK+kIB9C5NYpKm5GWlaXUl mfI59D5ERT0bLc/xFGLSUUHwuMRRPHU= X-Google-Smtp-Source: AA0mqf7Lo/hiv6vpBb767tLM7XJOMZmHJNT9x0VukqxWbQqJ9EqPmZwTIujp9/FOv23mDOGTKSCJ/A== X-Received: by 2002:a17:90a:d805:b0:213:a95:88bd with SMTP id a5-20020a17090ad80500b002130a9588bdmr10711995pjv.98.1668725758435; Thu, 17 Nov 2022 14:55:58 -0800 (PST) Received: from localhost ([2409:40f4:8:955c:5484:8048:c08:7b3]) by smtp.gmail.com with ESMTPSA id a8-20020a1709027e4800b00186abb95bfdsm1975051pln.25.2022.11.17.14.55.56 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 17 Nov 2022 14:55:57 -0800 (PST) From: Kumar Kartikeya Dwivedi To: bpf@vger.kernel.org Cc: Alexei Starovoitov , Andrii Nakryiko , Daniel Borkmann , Martin KaFai Lau , Dave Marchevsky Subject: [PATCH bpf-next v9 11/23] bpf: Rewrite kfunc argument handling Date: Fri, 18 Nov 2022 04:24:58 +0530 Message-Id: <20221117225510.1676785-12-memxor@gmail.com> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20221117225510.1676785-1-memxor@gmail.com> References: <20221117225510.1676785-1-memxor@gmail.com> MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=44919; i=memxor@gmail.com; h=from:subject; bh=PNoCYEHQKhjO0rgwWPpJgDjelMG2IMQAIi7UtGmPbpE=; b=owEBbQKS/ZANAwAIAUzgyIZIvxHKAcsmYgBjdrkbAX1J2V0ukOpGw14ErP2znh5Uiln7OpsBRYzQ w7pkvgaJAjMEAAEIAB0WIQRLvip+Buz51YI8YRFM4MiGSL8RygUCY3a5GwAKCRBM4MiGSL8Rym3JEA CdK0Nzlra7oWEMpp6IKCZ88BJShcDMntfui9r+Xf0hLWwIZWtgw2nXFo4GYQDcCD7510uC5UWFQ+UD vEquQf53z/p81LkjjH/HBxjV3lXnGkcSGPx673PDNnmbhEDFrUgumBhKOUOjJI1nYI180ei24nYKN/ fr7/GLz5FDP2ez616eRZiMWY4pbOI7PnGw3sVdVzY8RFQTjgaw78F39s152ZCelAfoNHQ3TSjzwfVl dRiMEYLf0WBHxdmBDSjvpFHxTYypE6JYamnNhr+dccfESPcGbH/9dRSseG1teSSGvDus1RvZlbZsSY cgaxMHLjyExFT5drmcyWVyRkvsvO+1sn3dI91c26NquZT8OeDxgNe0i7hNBcn4X78RbqlCeyGU6E3J sw2naJTMq1Qaaw8wGIy1AhfPfolINiQGr7skHQeqtEIikBmizqqwrDc/zmW6XP2+rfwo6QjeCUgWmM DbB5GGj6gNEjk4PAELuSyXCXs1+DVGfsbaBY9vGgw50RHe12ok4eqxHUVi+wYS9w63pxqKajhEYylT svuxIb4qe8dZp7er4G8IL2XCvZ4aemTA4kja2prlFUz5ipuHDOFO1+qwtgQg6wGbjP9ReRJfp7AEIT FSBBrzndJ+AqDxa8dRuPewVT7/IrquUfPiaMTohcLUMhiEIu9w9Lsa4l0LNg== X-Developer-Key: i=memxor@gmail.com; a=openpgp; fpr=4BBE2A7E06ECF9D5823C61114CE0C88648BF11CA Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net As we continue to add more features, argument types, kfunc flags, and different extensions to kfuncs, the code to verify the correctness of the kfunc prototype wrt the passed in registers has become ad-hoc and ugly to read. To make life easier, and make a very clear split between different stages of argument processing, move all the code into verifier.c and refactor into easier to read helpers and functions. This also makes sharing code within the verifier easier with kfunc argument processing. This will be more and more useful in later patches as we are now moving to implement very core BPF helpers as kfuncs, to keep them experimental before baking into UAPI. Remove all kfunc related bits now from btf_check_func_arg_match, as users have been converted away to refactored kfunc argument handling. Signed-off-by: Kumar Kartikeya Dwivedi --- include/linux/bpf.h | 11 - include/linux/bpf_verifier.h | 2 - include/linux/btf.h | 31 +- kernel/bpf/btf.c | 380 +----------- kernel/bpf/verifier.c | 545 +++++++++++++++++- .../bpf/prog_tests/kfunc_dynptr_param.c | 2 +- tools/testing/selftests/bpf/verifier/calls.c | 2 +- .../selftests/bpf/verifier/ref_tracking.c | 4 +- 8 files changed, 573 insertions(+), 404 deletions(-) diff --git a/include/linux/bpf.h b/include/linux/bpf.h index 323985a39ece..0a74df731eb8 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -2109,22 +2109,11 @@ int btf_distill_func_proto(struct bpf_verifier_log *log, const char *func_name, struct btf_func_model *m); -struct bpf_kfunc_arg_meta { - u64 r0_size; - bool r0_rdonly; - int ref_obj_id; - u32 flags; -}; - struct bpf_reg_state; int btf_check_subprog_arg_match(struct bpf_verifier_env *env, int subprog, struct bpf_reg_state *regs); int btf_check_subprog_call(struct bpf_verifier_env *env, int subprog, struct bpf_reg_state *regs); -int btf_check_kfunc_arg_match(struct bpf_verifier_env *env, - const struct btf *btf, u32 func_id, - struct bpf_reg_state *regs, - struct bpf_kfunc_arg_meta *meta); int btf_prepare_func_args(struct bpf_verifier_env *env, int subprog, struct bpf_reg_state *reg); int btf_check_type_match(struct bpf_verifier_log *log, const struct bpf_prog *prog, diff --git a/include/linux/bpf_verifier.h b/include/linux/bpf_verifier.h index 3770bb1a6f62..bc786457f51d 100644 --- a/include/linux/bpf_verifier.h +++ b/include/linux/bpf_verifier.h @@ -603,8 +603,6 @@ int check_ptr_off_reg(struct bpf_verifier_env *env, int check_func_arg_reg_off(struct bpf_verifier_env *env, const struct bpf_reg_state *reg, int regno, enum bpf_arg_type arg_type); -int check_kfunc_mem_size_reg(struct bpf_verifier_env *env, struct bpf_reg_state *reg, - u32 regno); int check_mem_reg(struct bpf_verifier_env *env, struct bpf_reg_state *reg, u32 regno, u32 mem_size); bool is_dynptr_reg_valid_init(struct bpf_verifier_env *env, diff --git a/include/linux/btf.h b/include/linux/btf.h index 42d8f3730a8d..d5b26380a60f 100644 --- a/include/linux/btf.h +++ b/include/linux/btf.h @@ -338,6 +338,16 @@ static inline bool btf_type_is_struct(const struct btf_type *t) return kind == BTF_KIND_STRUCT || kind == BTF_KIND_UNION; } +static inline bool __btf_type_is_struct(const struct btf_type *t) +{ + return BTF_INFO_KIND(t->info) == BTF_KIND_STRUCT; +} + +static inline bool btf_type_is_array(const struct btf_type *t) +{ + return BTF_INFO_KIND(t->info) == BTF_KIND_ARRAY; +} + static inline u16 btf_type_vlen(const struct btf_type *t) { return BTF_INFO_VLEN(t->info); @@ -439,9 +449,10 @@ static inline void *btf_id_set8_contains(const struct btf_id_set8 *set, u32 id) return bsearch(&id, set->pairs, set->cnt, sizeof(set->pairs[0]), btf_id_cmp_func); } -#ifdef CONFIG_BPF_SYSCALL struct bpf_prog; +struct bpf_verifier_log; +#ifdef CONFIG_BPF_SYSCALL const struct btf_type *btf_type_by_id(const struct btf *btf, u32 type_id); const char *btf_name_by_offset(const struct btf *btf, u32 offset); struct btf *btf_parse_vmlinux(void); @@ -455,6 +466,12 @@ s32 btf_find_dtor_kfunc(struct btf *btf, u32 btf_id); int register_btf_id_dtor_kfuncs(const struct btf_id_dtor_kfunc *dtors, u32 add_cnt, struct module *owner); struct btf_struct_meta *btf_find_struct_meta(const struct btf *btf, u32 btf_id); +const struct btf_member * +btf_get_prog_ctx_type(struct bpf_verifier_log *log, const struct btf *btf, + const struct btf_type *t, enum bpf_prog_type prog_type, + int arg); +bool btf_types_are_same(const struct btf *btf1, u32 id1, + const struct btf *btf2, u32 id2); #else static inline const struct btf_type *btf_type_by_id(const struct btf *btf, u32 type_id) @@ -490,6 +507,18 @@ static inline struct btf_struct_meta *btf_find_struct_meta(const struct btf *btf { return NULL; } +static inline const struct btf_member * +btf_get_prog_ctx_type(struct bpf_verifier_log *log, const struct btf *btf, + const struct btf_type *t, enum bpf_prog_type prog_type, + int arg) +{ + return NULL; +} +static inline bool btf_types_are_same(const struct btf *btf1, u32 id1, + const struct btf *btf2, u32 id2) +{ + return false; +} #endif static inline bool btf_type_is_struct_ptr(struct btf *btf, const struct btf_type *t) diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c index 91aa9c96621f..4dcda4ae48c1 100644 --- a/kernel/bpf/btf.c +++ b/kernel/bpf/btf.c @@ -478,16 +478,6 @@ static bool btf_type_nosize_or_null(const struct btf_type *t) return !t || btf_type_nosize(t); } -static bool __btf_type_is_struct(const struct btf_type *t) -{ - return BTF_INFO_KIND(t->info) == BTF_KIND_STRUCT; -} - -static bool btf_type_is_array(const struct btf_type *t) -{ - return BTF_INFO_KIND(t->info) == BTF_KIND_ARRAY; -} - static bool btf_type_is_datasec(const struct btf_type *t) { return BTF_INFO_KIND(t->info) == BTF_KIND_DATASEC; @@ -5536,7 +5526,7 @@ static u8 bpf_ctx_convert_map[] = { #undef BPF_MAP_TYPE #undef BPF_LINK_TYPE -static const struct btf_member * +const struct btf_member * btf_get_prog_ctx_type(struct bpf_verifier_log *log, const struct btf *btf, const struct btf_type *t, enum bpf_prog_type prog_type, int arg) @@ -6322,8 +6312,8 @@ int btf_struct_access(struct bpf_verifier_log *log, * end up with two different module BTFs, but IDs point to the common type in * vmlinux BTF. */ -static bool btf_types_are_same(const struct btf *btf1, u32 id1, - const struct btf *btf2, u32 id2) +bool btf_types_are_same(const struct btf *btf1, u32 id1, + const struct btf *btf2, u32 id2) { if (id1 != id2) return false; @@ -6605,122 +6595,19 @@ int btf_check_type_match(struct bpf_verifier_log *log, const struct bpf_prog *pr return btf_check_func_type_match(log, btf1, t1, btf2, t2); } -static u32 *reg2btf_ids[__BPF_REG_TYPE_MAX] = { -#ifdef CONFIG_NET - [PTR_TO_SOCKET] = &btf_sock_ids[BTF_SOCK_TYPE_SOCK], - [PTR_TO_SOCK_COMMON] = &btf_sock_ids[BTF_SOCK_TYPE_SOCK_COMMON], - [PTR_TO_TCP_SOCK] = &btf_sock_ids[BTF_SOCK_TYPE_TCP], -#endif -}; - -/* Returns true if struct is composed of scalars, 4 levels of nesting allowed */ -static bool __btf_type_is_scalar_struct(struct bpf_verifier_log *log, - const struct btf *btf, - const struct btf_type *t, int rec) -{ - const struct btf_type *member_type; - const struct btf_member *member; - u32 i; - - if (!btf_type_is_struct(t)) - return false; - - for_each_member(i, t, member) { - const struct btf_array *array; - - member_type = btf_type_skip_modifiers(btf, member->type, NULL); - if (btf_type_is_struct(member_type)) { - if (rec >= 3) { - bpf_log(log, "max struct nesting depth exceeded\n"); - return false; - } - if (!__btf_type_is_scalar_struct(log, btf, member_type, rec + 1)) - return false; - continue; - } - if (btf_type_is_array(member_type)) { - array = btf_type_array(member_type); - if (!array->nelems) - return false; - member_type = btf_type_skip_modifiers(btf, array->type, NULL); - if (!btf_type_is_scalar(member_type)) - return false; - continue; - } - if (!btf_type_is_scalar(member_type)) - return false; - } - return true; -} - -static bool is_kfunc_arg_mem_size(const struct btf *btf, - const struct btf_param *arg, - const struct bpf_reg_state *reg) -{ - int len, sfx_len = sizeof("__sz") - 1; - const struct btf_type *t; - const char *param_name; - - t = btf_type_skip_modifiers(btf, arg->type, NULL); - if (!btf_type_is_scalar(t) || reg->type != SCALAR_VALUE) - return false; - - /* In the future, this can be ported to use BTF tagging */ - param_name = btf_name_by_offset(btf, arg->name_off); - if (str_is_empty(param_name)) - return false; - len = strlen(param_name); - if (len < sfx_len) - return false; - param_name += len - sfx_len; - if (strncmp(param_name, "__sz", sfx_len)) - return false; - - return true; -} - -static bool btf_is_kfunc_arg_mem_size(const struct btf *btf, - const struct btf_param *arg, - const struct bpf_reg_state *reg, - const char *name) -{ - int len, target_len = strlen(name); - const struct btf_type *t; - const char *param_name; - - t = btf_type_skip_modifiers(btf, arg->type, NULL); - if (!btf_type_is_scalar(t) || reg->type != SCALAR_VALUE) - return false; - - param_name = btf_name_by_offset(btf, arg->name_off); - if (str_is_empty(param_name)) - return false; - len = strlen(param_name); - if (len != target_len) - return false; - if (strcmp(param_name, name)) - return false; - - return true; -} - static int btf_check_func_arg_match(struct bpf_verifier_env *env, const struct btf *btf, u32 func_id, struct bpf_reg_state *regs, bool ptr_to_mem_ok, - struct bpf_kfunc_arg_meta *kfunc_meta, bool processing_call) { enum bpf_prog_type prog_type = resolve_prog_type(env->prog); - bool rel = false, kptr_get = false, trusted_args = false; - bool sleepable = false; struct bpf_verifier_log *log = &env->log; - u32 i, nargs, ref_id, ref_obj_id = 0; - bool is_kfunc = btf_is_kernel(btf); const char *func_name, *ref_tname; const struct btf_type *t, *ref_t; const struct btf_param *args; - int ref_regno = 0, ret; + u32 i, nargs, ref_id; + int ret; t = btf_type_by_id(btf, func_id); if (!t || !btf_type_is_func(t)) { @@ -6746,14 +6633,6 @@ static int btf_check_func_arg_match(struct bpf_verifier_env *env, return -EINVAL; } - if (is_kfunc && kfunc_meta) { - /* Only kfunc can be release func */ - rel = kfunc_meta->flags & KF_RELEASE; - kptr_get = kfunc_meta->flags & KF_KPTR_GET; - trusted_args = kfunc_meta->flags & KF_TRUSTED_ARGS; - sleepable = kfunc_meta->flags & KF_SLEEPABLE; - } - /* check that BTF function arguments match actual types that the * verifier sees. */ @@ -6761,42 +6640,9 @@ static int btf_check_func_arg_match(struct bpf_verifier_env *env, enum bpf_arg_type arg_type = ARG_DONTCARE; u32 regno = i + 1; struct bpf_reg_state *reg = ®s[regno]; - bool obj_ptr = false; t = btf_type_skip_modifiers(btf, args[i].type, NULL); if (btf_type_is_scalar(t)) { - if (is_kfunc && kfunc_meta) { - bool is_buf_size = false; - - /* check for any const scalar parameter of name "rdonly_buf_size" - * or "rdwr_buf_size" - */ - if (btf_is_kfunc_arg_mem_size(btf, &args[i], reg, - "rdonly_buf_size")) { - kfunc_meta->r0_rdonly = true; - is_buf_size = true; - } else if (btf_is_kfunc_arg_mem_size(btf, &args[i], reg, - "rdwr_buf_size")) - is_buf_size = true; - - if (is_buf_size) { - if (kfunc_meta->r0_size) { - bpf_log(log, "2 or more rdonly/rdwr_buf_size parameters for kfunc"); - return -EINVAL; - } - - if (!tnum_is_const(reg->var_off)) { - bpf_log(log, "R%d is not a const\n", regno); - return -EINVAL; - } - - kfunc_meta->r0_size = reg->var_off.value; - ret = mark_chain_precision(env, regno); - if (ret) - return ret; - } - } - if (reg->type == SCALAR_VALUE) continue; bpf_log(log, "R%d is not a scalar\n", regno); @@ -6809,88 +6655,14 @@ static int btf_check_func_arg_match(struct bpf_verifier_env *env, return -EINVAL; } - /* These register types have special constraints wrt ref_obj_id - * and offset checks. The rest of trusted args don't. - */ - obj_ptr = reg->type == PTR_TO_CTX || reg->type == PTR_TO_BTF_ID || - reg2btf_ids[base_type(reg->type)]; - - /* Check if argument must be a referenced pointer, args + i has - * been verified to be a pointer (after skipping modifiers). - * PTR_TO_CTX is ok without having non-zero ref_obj_id. - */ - if (is_kfunc && trusted_args && (obj_ptr && reg->type != PTR_TO_CTX) && !reg->ref_obj_id) { - bpf_log(log, "R%d must be referenced\n", regno); - return -EINVAL; - } - ref_t = btf_type_skip_modifiers(btf, t->type, &ref_id); ref_tname = btf_name_by_offset(btf, ref_t->name_off); - /* Trusted args have the same offset checks as release arguments */ - if ((trusted_args && obj_ptr) || (rel && reg->ref_obj_id)) - arg_type |= OBJ_RELEASE; ret = check_func_arg_reg_off(env, reg, regno, arg_type); if (ret < 0) return ret; - if (is_kfunc && reg->ref_obj_id) { - /* Ensure only one argument is referenced PTR_TO_BTF_ID */ - if (ref_obj_id) { - bpf_log(log, "verifier internal error: more than one arg with ref_obj_id R%d %u %u\n", - regno, reg->ref_obj_id, ref_obj_id); - return -EFAULT; - } - ref_regno = regno; - ref_obj_id = reg->ref_obj_id; - } - - /* kptr_get is only true for kfunc */ - if (i == 0 && kptr_get) { - struct btf_field *kptr_field; - - if (reg->type != PTR_TO_MAP_VALUE) { - bpf_log(log, "arg#0 expected pointer to map value\n"); - return -EINVAL; - } - - /* check_func_arg_reg_off allows var_off for - * PTR_TO_MAP_VALUE, but we need fixed offset to find - * off_desc. - */ - if (!tnum_is_const(reg->var_off)) { - bpf_log(log, "arg#0 must have constant offset\n"); - return -EINVAL; - } - - kptr_field = btf_record_find(reg->map_ptr->record, reg->off + reg->var_off.value, BPF_KPTR); - if (!kptr_field || kptr_field->type != BPF_KPTR_REF) { - bpf_log(log, "arg#0 no referenced kptr at map value offset=%llu\n", - reg->off + reg->var_off.value); - return -EINVAL; - } - - if (!btf_type_is_ptr(ref_t)) { - bpf_log(log, "arg#0 BTF type must be a double pointer\n"); - return -EINVAL; - } - - ref_t = btf_type_skip_modifiers(btf, ref_t->type, &ref_id); - ref_tname = btf_name_by_offset(btf, ref_t->name_off); - - if (!btf_type_is_struct(ref_t)) { - bpf_log(log, "kernel function %s args#%d pointer type %s %s is not supported\n", - func_name, i, btf_type_str(ref_t), ref_tname); - return -EINVAL; - } - if (!btf_struct_ids_match(log, btf, ref_id, 0, kptr_field->kptr.btf, - kptr_field->kptr.btf_id, true)) { - bpf_log(log, "kernel function %s args#%d expected pointer to %s %s\n", - func_name, i, btf_type_str(ref_t), ref_tname); - return -EINVAL; - } - /* rest of the arguments can be anything, like normal kfunc */ - } else if (btf_get_prog_ctx_type(log, btf, t, prog_type, i)) { + if (btf_get_prog_ctx_type(log, btf, t, prog_type, i)) { /* If function expects ctx type in BTF check that caller * is passing PTR_TO_CTX. */ @@ -6900,109 +6672,10 @@ static int btf_check_func_arg_match(struct bpf_verifier_env *env, i, btf_type_str(t)); return -EINVAL; } - } else if (is_kfunc && (reg->type == PTR_TO_BTF_ID || - (reg2btf_ids[base_type(reg->type)] && !type_flag(reg->type)))) { - const struct btf_type *reg_ref_t; - const struct btf *reg_btf; - const char *reg_ref_tname; - u32 reg_ref_id; - - if (!btf_type_is_struct(ref_t)) { - bpf_log(log, "kernel function %s args#%d pointer type %s %s is not supported\n", - func_name, i, btf_type_str(ref_t), - ref_tname); - return -EINVAL; - } - - if (reg->type == PTR_TO_BTF_ID) { - reg_btf = reg->btf; - reg_ref_id = reg->btf_id; - } else { - reg_btf = btf_vmlinux; - reg_ref_id = *reg2btf_ids[base_type(reg->type)]; - } - - reg_ref_t = btf_type_skip_modifiers(reg_btf, reg_ref_id, - ®_ref_id); - reg_ref_tname = btf_name_by_offset(reg_btf, - reg_ref_t->name_off); - if (!btf_struct_ids_match(log, reg_btf, reg_ref_id, - reg->off, btf, ref_id, - trusted_args || (rel && reg->ref_obj_id))) { - bpf_log(log, "kernel function %s args#%d expected pointer to %s %s but R%d has a pointer to %s %s\n", - func_name, i, - btf_type_str(ref_t), ref_tname, - regno, btf_type_str(reg_ref_t), - reg_ref_tname); - return -EINVAL; - } } else if (ptr_to_mem_ok && processing_call) { const struct btf_type *resolve_ret; u32 type_size; - if (is_kfunc) { - bool arg_mem_size = i + 1 < nargs && is_kfunc_arg_mem_size(btf, &args[i + 1], ®s[regno + 1]); - bool arg_dynptr = btf_type_is_struct(ref_t) && - !strcmp(ref_tname, - stringify_struct(bpf_dynptr_kern)); - - /* Permit pointer to mem, but only when argument - * type is pointer to scalar, or struct composed - * (recursively) of scalars. - * When arg_mem_size is true, the pointer can be - * void *. - * Also permit initialized local dynamic pointers. - */ - if (!btf_type_is_scalar(ref_t) && - !__btf_type_is_scalar_struct(log, btf, ref_t, 0) && - !arg_dynptr && - (arg_mem_size ? !btf_type_is_void(ref_t) : 1)) { - bpf_log(log, - "arg#%d pointer type %s %s must point to %sscalar, or struct with scalar\n", - i, btf_type_str(ref_t), ref_tname, arg_mem_size ? "void, " : ""); - return -EINVAL; - } - - if (arg_dynptr) { - if (reg->type != PTR_TO_STACK) { - bpf_log(log, "arg#%d pointer type %s %s not to stack\n", - i, btf_type_str(ref_t), - ref_tname); - return -EINVAL; - } - - if (!is_dynptr_reg_valid_init(env, reg)) { - bpf_log(log, - "arg#%d pointer type %s %s must be valid and initialized\n", - i, btf_type_str(ref_t), - ref_tname); - return -EINVAL; - } - - if (!is_dynptr_type_expected(env, reg, - ARG_PTR_TO_DYNPTR | DYNPTR_TYPE_LOCAL)) { - bpf_log(log, - "arg#%d pointer type %s %s points to unsupported dynamic pointer type\n", - i, btf_type_str(ref_t), - ref_tname); - return -EINVAL; - } - - continue; - } - - /* Check for mem, len pair */ - if (arg_mem_size) { - if (check_kfunc_mem_size_reg(env, ®s[regno + 1], regno + 1)) { - bpf_log(log, "arg#%d arg#%d memory, len pair leads to invalid memory access\n", - i, i + 1); - return -EINVAL; - } - i++; - continue; - } - } - resolve_ret = btf_resolve_size(btf, ref_t, &type_size); if (IS_ERR(resolve_ret)) { bpf_log(log, @@ -7015,36 +6688,13 @@ static int btf_check_func_arg_match(struct bpf_verifier_env *env, if (check_mem_reg(env, reg, regno, type_size)) return -EINVAL; } else { - bpf_log(log, "reg type unsupported for arg#%d %sfunction %s#%d\n", i, - is_kfunc ? "kernel " : "", func_name, func_id); + bpf_log(log, "reg type unsupported for arg#%d function %s#%d\n", i, + func_name, func_id); return -EINVAL; } } - /* Either both are set, or neither */ - WARN_ON_ONCE((ref_obj_id && !ref_regno) || (!ref_obj_id && ref_regno)); - /* We already made sure ref_obj_id is set only for one argument. We do - * allow (!rel && ref_obj_id), so that passing such referenced - * PTR_TO_BTF_ID to other kfuncs works. Note that rel is only true when - * is_kfunc is true. - */ - if (rel && !ref_obj_id) { - bpf_log(log, "release kernel function %s expects refcounted PTR_TO_BTF_ID\n", - func_name); - return -EINVAL; - } - - if (sleepable && !env->prog->aux->sleepable) { - bpf_log(log, "kernel function %s is sleepable but the program is not\n", - func_name); - return -EINVAL; - } - - if (kfunc_meta && ref_obj_id) - kfunc_meta->ref_obj_id = ref_obj_id; - - /* returns argument register number > 0 in case of reference release kfunc */ - return rel ? ref_regno : 0; + return 0; } /* Compare BTF of a function declaration with given bpf_reg_state. @@ -7074,7 +6724,7 @@ int btf_check_subprog_arg_match(struct bpf_verifier_env *env, int subprog, return -EINVAL; is_global = prog->aux->func_info_aux[subprog].linkage == BTF_FUNC_GLOBAL; - err = btf_check_func_arg_match(env, btf, btf_id, regs, is_global, NULL, false); + err = btf_check_func_arg_match(env, btf, btf_id, regs, is_global, false); /* Compiler optimizations can remove arguments from static functions * or mismatched type can be passed into a global function. @@ -7117,7 +6767,7 @@ int btf_check_subprog_call(struct bpf_verifier_env *env, int subprog, return -EINVAL; is_global = prog->aux->func_info_aux[subprog].linkage == BTF_FUNC_GLOBAL; - err = btf_check_func_arg_match(env, btf, btf_id, regs, is_global, NULL, true); + err = btf_check_func_arg_match(env, btf, btf_id, regs, is_global, true); /* Compiler optimizations can remove arguments from static functions * or mismatched type can be passed into a global function. @@ -7128,14 +6778,6 @@ int btf_check_subprog_call(struct bpf_verifier_env *env, int subprog, return err; } -int btf_check_kfunc_arg_match(struct bpf_verifier_env *env, - const struct btf *btf, u32 func_id, - struct bpf_reg_state *regs, - struct bpf_kfunc_arg_meta *meta) -{ - return btf_check_func_arg_match(env, btf, func_id, regs, true, meta, true); -} - /* Convert BTF of a function into bpf_reg_state if possible * Returns: * EFAULT - there is a verifier bug. Abort verification. diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index b231abbeaf55..d85ecc673631 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -5544,8 +5544,8 @@ int check_mem_reg(struct bpf_verifier_env *env, struct bpf_reg_state *reg, return err; } -int check_kfunc_mem_size_reg(struct bpf_verifier_env *env, struct bpf_reg_state *reg, - u32 regno) +static int check_kfunc_mem_size_reg(struct bpf_verifier_env *env, struct bpf_reg_state *reg, + u32 regno) { struct bpf_reg_state *mem_reg = &cur_regs(env)[regno - 1]; bool may_be_null = type_may_be_null(mem_reg->type); @@ -7862,19 +7862,517 @@ static void mark_btf_func_reg_size(struct bpf_verifier_env *env, u32 regno, } } +struct bpf_kfunc_call_arg_meta { + /* In parameters */ + struct btf *btf; + u32 func_id; + u32 kfunc_flags; + const struct btf_type *func_proto; + const char *func_name; + /* Out parameters */ + u32 ref_obj_id; + u8 release_regno; + bool r0_rdonly; + u64 r0_size; +}; + +static bool is_kfunc_acquire(struct bpf_kfunc_call_arg_meta *meta) +{ + return meta->kfunc_flags & KF_ACQUIRE; +} + +static bool is_kfunc_ret_null(struct bpf_kfunc_call_arg_meta *meta) +{ + return meta->kfunc_flags & KF_RET_NULL; +} + +static bool is_kfunc_release(struct bpf_kfunc_call_arg_meta *meta) +{ + return meta->kfunc_flags & KF_RELEASE; +} + +static bool is_kfunc_trusted_args(struct bpf_kfunc_call_arg_meta *meta) +{ + return meta->kfunc_flags & KF_TRUSTED_ARGS; +} + +static bool is_kfunc_sleepable(struct bpf_kfunc_call_arg_meta *meta) +{ + return meta->kfunc_flags & KF_SLEEPABLE; +} + +static bool is_kfunc_destructive(struct bpf_kfunc_call_arg_meta *meta) +{ + return meta->kfunc_flags & KF_DESTRUCTIVE; +} + +static bool is_kfunc_arg_kptr_get(struct bpf_kfunc_call_arg_meta *meta, int arg) +{ + return arg == 0 && (meta->kfunc_flags & KF_KPTR_GET); +} + +static bool is_kfunc_arg_mem_size(const struct btf *btf, + const struct btf_param *arg, + const struct bpf_reg_state *reg) +{ + int len, sfx_len = sizeof("__sz") - 1; + const struct btf_type *t; + const char *param_name; + + t = btf_type_skip_modifiers(btf, arg->type, NULL); + if (!btf_type_is_scalar(t) || reg->type != SCALAR_VALUE) + return false; + + /* In the future, this can be ported to use BTF tagging */ + param_name = btf_name_by_offset(btf, arg->name_off); + if (str_is_empty(param_name)) + return false; + len = strlen(param_name); + if (len < sfx_len) + return false; + param_name += len - sfx_len; + if (strncmp(param_name, "__sz", sfx_len)) + return false; + + return true; +} + +static bool is_kfunc_arg_scalar_with_name(const struct btf *btf, + const struct btf_param *arg, + const char *name) +{ + int len, target_len = strlen(name); + const char *param_name; + + param_name = btf_name_by_offset(btf, arg->name_off); + if (str_is_empty(param_name)) + return false; + len = strlen(param_name); + if (len != target_len) + return false; + if (strcmp(param_name, name)) + return false; + + return true; +} + +enum { + KF_ARG_DYNPTR_ID, +}; + +BTF_ID_LIST(kf_arg_btf_ids) +BTF_ID(struct, bpf_dynptr_kern) + +static bool is_kfunc_arg_dynptr(const struct btf *btf, + const struct btf_param *arg) +{ + const struct btf_type *t; + u32 res_id; + + t = btf_type_skip_modifiers(btf, arg->type, NULL); + if (!t) + return false; + if (!btf_type_is_ptr(t)) + return false; + t = btf_type_skip_modifiers(btf, t->type, &res_id); + if (!t) + return false; + return btf_types_are_same(btf, res_id, btf_vmlinux, kf_arg_btf_ids[KF_ARG_DYNPTR_ID]); +} + +/* Returns true if struct is composed of scalars, 4 levels of nesting allowed */ +static bool __btf_type_is_scalar_struct(struct bpf_verifier_env *env, + const struct btf *btf, + const struct btf_type *t, int rec) +{ + const struct btf_type *member_type; + const struct btf_member *member; + u32 i; + + if (!btf_type_is_struct(t)) + return false; + + for_each_member(i, t, member) { + const struct btf_array *array; + + member_type = btf_type_skip_modifiers(btf, member->type, NULL); + if (btf_type_is_struct(member_type)) { + if (rec >= 3) { + verbose(env, "max struct nesting depth exceeded\n"); + return false; + } + if (!__btf_type_is_scalar_struct(env, btf, member_type, rec + 1)) + return false; + continue; + } + if (btf_type_is_array(member_type)) { + array = btf_array(member_type); + if (!array->nelems) + return false; + member_type = btf_type_skip_modifiers(btf, array->type, NULL); + if (!btf_type_is_scalar(member_type)) + return false; + continue; + } + if (!btf_type_is_scalar(member_type)) + return false; + } + return true; +} + + +static u32 *reg2btf_ids[__BPF_REG_TYPE_MAX] = { +#ifdef CONFIG_NET + [PTR_TO_SOCKET] = &btf_sock_ids[BTF_SOCK_TYPE_SOCK], + [PTR_TO_SOCK_COMMON] = &btf_sock_ids[BTF_SOCK_TYPE_SOCK_COMMON], + [PTR_TO_TCP_SOCK] = &btf_sock_ids[BTF_SOCK_TYPE_TCP], +#endif +}; + +enum kfunc_ptr_arg_type { + KF_ARG_PTR_TO_CTX, + KF_ARG_PTR_TO_KPTR, /* PTR_TO_KPTR but type specific */ + KF_ARG_PTR_TO_DYNPTR, + KF_ARG_PTR_TO_BTF_ID, /* Also covers reg2btf_ids conversions */ + KF_ARG_PTR_TO_MEM, + KF_ARG_PTR_TO_MEM_SIZE, /* Size derived from next argument, skip it */ +}; + +static enum kfunc_ptr_arg_type +get_kfunc_ptr_arg_type(struct bpf_verifier_env *env, + struct bpf_kfunc_call_arg_meta *meta, + const struct btf_type *t, const struct btf_type *ref_t, + const char *ref_tname, const struct btf_param *args, + int argno, int nargs) +{ + u32 regno = argno + 1; + struct bpf_reg_state *regs = cur_regs(env); + struct bpf_reg_state *reg = ®s[regno]; + bool arg_mem_size = false; + + /* In this function, we verify the kfunc's BTF as per the argument type, + * leaving the rest of the verification with respect to the register + * type to our caller. When a set of conditions hold in the BTF type of + * arguments, we resolve it to a known kfunc_ptr_arg_type. + */ + if (btf_get_prog_ctx_type(&env->log, meta->btf, t, resolve_prog_type(env->prog), argno)) + return KF_ARG_PTR_TO_CTX; + + if (is_kfunc_arg_kptr_get(meta, argno)) { + if (!btf_type_is_ptr(ref_t)) { + verbose(env, "arg#0 BTF type must be a double pointer for kptr_get kfunc\n"); + return -EINVAL; + } + ref_t = btf_type_by_id(meta->btf, ref_t->type); + ref_tname = btf_name_by_offset(meta->btf, ref_t->name_off); + if (!btf_type_is_struct(ref_t)) { + verbose(env, "kernel function %s args#0 pointer type %s %s is not supported\n", + meta->func_name, btf_type_str(ref_t), ref_tname); + return -EINVAL; + } + return KF_ARG_PTR_TO_KPTR; + } + + if (is_kfunc_arg_dynptr(meta->btf, &args[argno])) + return KF_ARG_PTR_TO_DYNPTR; + + if ((base_type(reg->type) == PTR_TO_BTF_ID || reg2btf_ids[base_type(reg->type)])) { + if (!btf_type_is_struct(ref_t)) { + verbose(env, "kernel function %s args#%d pointer type %s %s is not supported\n", + meta->func_name, argno, btf_type_str(ref_t), ref_tname); + return -EINVAL; + } + return KF_ARG_PTR_TO_BTF_ID; + } + + if (argno + 1 < nargs && is_kfunc_arg_mem_size(meta->btf, &args[argno + 1], ®s[regno + 1])) + arg_mem_size = true; + + /* This is the catch all argument type of register types supported by + * check_helper_mem_access. However, we only allow when argument type is + * pointer to scalar, or struct composed (recursively) of scalars. When + * arg_mem_size is true, the pointer can be void *. + */ + if (!btf_type_is_scalar(ref_t) && !__btf_type_is_scalar_struct(env, meta->btf, ref_t, 0) && + (arg_mem_size ? !btf_type_is_void(ref_t) : 1)) { + verbose(env, "arg#%d pointer type %s %s must point to %sscalar, or struct with scalar\n", + argno, btf_type_str(ref_t), ref_tname, arg_mem_size ? "void, " : ""); + return -EINVAL; + } + return arg_mem_size ? KF_ARG_PTR_TO_MEM_SIZE : KF_ARG_PTR_TO_MEM; +} + +static int process_kf_arg_ptr_to_btf_id(struct bpf_verifier_env *env, + struct bpf_reg_state *reg, + const struct btf_type *ref_t, + const char *ref_tname, u32 ref_id, + struct bpf_kfunc_call_arg_meta *meta, + int argno) +{ + const struct btf_type *reg_ref_t; + bool strict_type_match = false; + const struct btf *reg_btf; + const char *reg_ref_tname; + u32 reg_ref_id; + + if (reg->type == PTR_TO_BTF_ID) { + reg_btf = reg->btf; + reg_ref_id = reg->btf_id; + } else { + reg_btf = btf_vmlinux; + reg_ref_id = *reg2btf_ids[base_type(reg->type)]; + } + + if (is_kfunc_trusted_args(meta) || (is_kfunc_release(meta) && reg->ref_obj_id)) + strict_type_match = true; + + reg_ref_t = btf_type_skip_modifiers(reg_btf, reg_ref_id, ®_ref_id); + reg_ref_tname = btf_name_by_offset(reg_btf, reg_ref_t->name_off); + if (!btf_struct_ids_match(&env->log, reg_btf, reg_ref_id, reg->off, meta->btf, ref_id, strict_type_match)) { + verbose(env, "kernel function %s args#%d expected pointer to %s %s but R%d has a pointer to %s %s\n", + meta->func_name, argno, btf_type_str(ref_t), ref_tname, argno + 1, + btf_type_str(reg_ref_t), reg_ref_tname); + return -EINVAL; + } + return 0; +} + +static int process_kf_arg_ptr_to_kptr_strong(struct bpf_verifier_env *env, + struct bpf_reg_state *reg, + const struct btf_type *ref_t, + const char *ref_tname, + struct bpf_kfunc_call_arg_meta *meta, + int argno) +{ + struct btf_field *kptr_field; + + /* check_func_arg_reg_off allows var_off for + * PTR_TO_MAP_VALUE, but we need fixed offset to find + * off_desc. + */ + if (!tnum_is_const(reg->var_off)) { + verbose(env, "arg#0 must have constant offset\n"); + return -EINVAL; + } + + kptr_field = btf_record_find(reg->map_ptr->record, reg->off + reg->var_off.value, BPF_KPTR); + if (!kptr_field || kptr_field->type != BPF_KPTR_REF) { + verbose(env, "arg#0 no referenced kptr at map value offset=%llu\n", + reg->off + reg->var_off.value); + return -EINVAL; + } + + if (!btf_struct_ids_match(&env->log, meta->btf, ref_t->type, 0, kptr_field->kptr.btf, + kptr_field->kptr.btf_id, true)) { + verbose(env, "kernel function %s args#%d expected pointer to %s %s\n", + meta->func_name, argno, btf_type_str(ref_t), ref_tname); + return -EINVAL; + } + return 0; +} + +static int check_kfunc_args(struct bpf_verifier_env *env, struct bpf_kfunc_call_arg_meta *meta) +{ + const char *func_name = meta->func_name, *ref_tname; + const struct btf *btf = meta->btf; + const struct btf_param *args; + u32 i, nargs; + int ret; + + args = (const struct btf_param *)(meta->func_proto + 1); + nargs = btf_type_vlen(meta->func_proto); + if (nargs > MAX_BPF_FUNC_REG_ARGS) { + verbose(env, "Function %s has %d > %d args\n", func_name, nargs, + MAX_BPF_FUNC_REG_ARGS); + return -EINVAL; + } + + /* Check that BTF function arguments match actual types that the + * verifier sees. + */ + for (i = 0; i < nargs; i++) { + struct bpf_reg_state *regs = cur_regs(env), *reg = ®s[i + 1]; + const struct btf_type *t, *ref_t, *resolve_ret; + enum bpf_arg_type arg_type = ARG_DONTCARE; + u32 regno = i + 1, ref_id, type_size; + bool is_ret_buf_sz = false; + int kf_arg_type; + + t = btf_type_skip_modifiers(btf, args[i].type, NULL); + if (btf_type_is_scalar(t)) { + if (reg->type != SCALAR_VALUE) { + verbose(env, "R%d is not a scalar\n", regno); + return -EINVAL; + } + if (is_kfunc_arg_scalar_with_name(btf, &args[i], "rdonly_buf_size")) { + meta->r0_rdonly = true; + is_ret_buf_sz = true; + } else if (is_kfunc_arg_scalar_with_name(btf, &args[i], "rdwr_buf_size")) { + is_ret_buf_sz = true; + } + + if (is_ret_buf_sz) { + if (meta->r0_size) { + verbose(env, "2 or more rdonly/rdwr_buf_size parameters for kfunc"); + return -EINVAL; + } + + if (!tnum_is_const(reg->var_off)) { + verbose(env, "R%d is not a const\n", regno); + return -EINVAL; + } + + meta->r0_size = reg->var_off.value; + ret = mark_chain_precision(env, regno); + if (ret) + return ret; + } + continue; + } + + if (!btf_type_is_ptr(t)) { + verbose(env, "Unrecognized arg#%d type %s\n", i, btf_type_str(t)); + return -EINVAL; + } + + if (reg->ref_obj_id) { + if (is_kfunc_release(meta) && meta->ref_obj_id) { + verbose(env, "verifier internal error: more than one arg with ref_obj_id R%d %u %u\n", + regno, reg->ref_obj_id, + meta->ref_obj_id); + return -EFAULT; + } + meta->ref_obj_id = reg->ref_obj_id; + if (is_kfunc_release(meta)) + meta->release_regno = regno; + } + + ref_t = btf_type_skip_modifiers(btf, t->type, &ref_id); + ref_tname = btf_name_by_offset(btf, ref_t->name_off); + + kf_arg_type = get_kfunc_ptr_arg_type(env, meta, t, ref_t, ref_tname, args, i, nargs); + if (kf_arg_type < 0) + return kf_arg_type; + + switch (kf_arg_type) { + case KF_ARG_PTR_TO_BTF_ID: + if (!is_kfunc_trusted_args(meta)) + break; + if (!reg->ref_obj_id) { + verbose(env, "R%d must be referenced\n", regno); + return -EINVAL; + } + fallthrough; + case KF_ARG_PTR_TO_CTX: + /* Trusted arguments have the same offset checks as release arguments */ + arg_type |= OBJ_RELEASE; + break; + case KF_ARG_PTR_TO_KPTR: + case KF_ARG_PTR_TO_DYNPTR: + case KF_ARG_PTR_TO_MEM: + case KF_ARG_PTR_TO_MEM_SIZE: + /* Trusted by default */ + break; + default: + WARN_ON_ONCE(1); + return -EFAULT; + } + + if (is_kfunc_release(meta) && reg->ref_obj_id) + arg_type |= OBJ_RELEASE; + ret = check_func_arg_reg_off(env, reg, regno, arg_type); + if (ret < 0) + return ret; + + switch (kf_arg_type) { + case KF_ARG_PTR_TO_CTX: + if (reg->type != PTR_TO_CTX) { + verbose(env, "arg#%d expected pointer to ctx, but got %s\n", i, btf_type_str(t)); + return -EINVAL; + } + break; + case KF_ARG_PTR_TO_KPTR: + if (reg->type != PTR_TO_MAP_VALUE) { + verbose(env, "arg#0 expected pointer to map value\n"); + return -EINVAL; + } + ret = process_kf_arg_ptr_to_kptr_strong(env, reg, ref_t, ref_tname, meta, i); + if (ret < 0) + return ret; + break; + case KF_ARG_PTR_TO_DYNPTR: + if (reg->type != PTR_TO_STACK) { + verbose(env, "arg#%d expected pointer to stack\n", i); + return -EINVAL; + } + + if (!is_dynptr_reg_valid_init(env, reg)) { + verbose(env, "arg#%d pointer type %s %s must be valid and initialized\n", + i, btf_type_str(ref_t), ref_tname); + return -EINVAL; + } + + if (!is_dynptr_type_expected(env, reg, ARG_PTR_TO_DYNPTR | DYNPTR_TYPE_LOCAL)) { + verbose(env, "arg#%d pointer type %s %s points to unsupported dynamic pointer type\n", + i, btf_type_str(ref_t), ref_tname); + return -EINVAL; + } + break; + case KF_ARG_PTR_TO_BTF_ID: + /* Only base_type is checked, further checks are done here */ + if (reg->type != PTR_TO_BTF_ID && + (!reg2btf_ids[base_type(reg->type)] || type_flag(reg->type))) { + verbose(env, "arg#%d expected pointer to btf or socket\n", i); + return -EINVAL; + } + ret = process_kf_arg_ptr_to_btf_id(env, reg, ref_t, ref_tname, ref_id, meta, i); + if (ret < 0) + return ret; + break; + case KF_ARG_PTR_TO_MEM: + resolve_ret = btf_resolve_size(btf, ref_t, &type_size); + if (IS_ERR(resolve_ret)) { + verbose(env, "arg#%d reference type('%s %s') size cannot be determined: %ld\n", + i, btf_type_str(ref_t), ref_tname, PTR_ERR(resolve_ret)); + return -EINVAL; + } + ret = check_mem_reg(env, reg, regno, type_size); + if (ret < 0) + return ret; + break; + case KF_ARG_PTR_TO_MEM_SIZE: + ret = check_kfunc_mem_size_reg(env, ®s[regno + 1], regno + 1); + if (ret < 0) { + verbose(env, "arg#%d arg#%d memory, len pair leads to invalid memory access\n", i, i + 1); + return ret; + } + /* Skip next '__sz' argument */ + i++; + break; + } + } + + if (is_kfunc_release(meta) && !meta->release_regno) { + verbose(env, "release kernel function %s expects refcounted PTR_TO_BTF_ID\n", + func_name); + return -EINVAL; + } + + return 0; +} + static int check_kfunc_call(struct bpf_verifier_env *env, struct bpf_insn *insn, int *insn_idx_p) { const struct btf_type *t, *func, *func_proto, *ptr_type; struct bpf_reg_state *regs = cur_regs(env); - struct bpf_kfunc_arg_meta meta = { 0 }; const char *func_name, *ptr_type_name; + struct bpf_kfunc_call_arg_meta meta; u32 i, nargs, func_id, ptr_type_id; int err, insn_idx = *insn_idx_p; const struct btf_param *args; struct btf *desc_btf; u32 *kfunc_flags; - bool acq; /* skip for now, but return error when we find this in fixup_kfunc_call */ if (!insn->imm) @@ -7895,24 +8393,34 @@ static int check_kfunc_call(struct bpf_verifier_env *env, struct bpf_insn *insn, func_name); return -EACCES; } - if (*kfunc_flags & KF_DESTRUCTIVE && !capable(CAP_SYS_BOOT)) { - verbose(env, "destructive kfunc calls require CAP_SYS_BOOT capabilities\n"); + + /* Prepare kfunc call metadata */ + memset(&meta, 0, sizeof(meta)); + meta.btf = desc_btf; + meta.func_id = func_id; + meta.kfunc_flags = *kfunc_flags; + meta.func_proto = func_proto; + meta.func_name = func_name; + + if (is_kfunc_destructive(&meta) && !capable(CAP_SYS_BOOT)) { + verbose(env, "destructive kfunc calls require CAP_SYS_BOOT capability\n"); return -EACCES; } - acq = *kfunc_flags & KF_ACQUIRE; - - meta.flags = *kfunc_flags; + if (is_kfunc_sleepable(&meta) && !env->prog->aux->sleepable) { + verbose(env, "program must be sleepable to call sleepable kfunc %s\n", func_name); + return -EACCES; + } /* Check the arguments */ - err = btf_check_kfunc_arg_match(env, desc_btf, func_id, regs, &meta); + err = check_kfunc_args(env, &meta); if (err < 0) return err; /* In case of release function, we get register number of refcounted - * PTR_TO_BTF_ID back from btf_check_kfunc_arg_match, do the release now + * PTR_TO_BTF_ID in bpf_kfunc_arg_meta, do the release now. */ - if (err) { - err = release_reference(env, regs[err].ref_obj_id); + if (meta.release_regno) { + err = release_reference(env, regs[meta.release_regno].ref_obj_id); if (err) { verbose(env, "kfunc %s#%d reference has not been acquired before\n", func_name, func_id); @@ -7926,7 +8434,7 @@ static int check_kfunc_call(struct bpf_verifier_env *env, struct bpf_insn *insn, /* Check return type */ t = btf_type_skip_modifiers(desc_btf, func_proto->type, NULL); - if (acq && !btf_type_is_struct_ptr(desc_btf, t)) { + if (is_kfunc_acquire(&meta) && !btf_type_is_struct_ptr(meta.btf, t)) { verbose(env, "acquire kernel function does not return PTR_TO_BTF_ID\n"); return -EINVAL; } @@ -7965,20 +8473,23 @@ static int check_kfunc_call(struct bpf_verifier_env *env, struct bpf_insn *insn, regs[BPF_REG_0].type = PTR_TO_BTF_ID; regs[BPF_REG_0].btf_id = ptr_type_id; } - if (*kfunc_flags & KF_RET_NULL) { + if (is_kfunc_ret_null(&meta)) { regs[BPF_REG_0].type |= PTR_MAYBE_NULL; /* For mark_ptr_or_null_reg, see 93c230e3f5bd6 */ regs[BPF_REG_0].id = ++env->id_gen; } mark_btf_func_reg_size(env, BPF_REG_0, sizeof(void *)); - if (acq) { + if (is_kfunc_acquire(&meta)) { int id = acquire_reference_state(env, insn_idx); if (id < 0) return id; - regs[BPF_REG_0].id = id; + if (is_kfunc_ret_null(&meta)) + regs[BPF_REG_0].id = id; regs[BPF_REG_0].ref_obj_id = id; } + if (reg_may_point_to_spin_lock(®s[BPF_REG_0]) && !regs[BPF_REG_0].id) + regs[BPF_REG_0].id = ++env->id_gen; } /* else { add_kfunc_call() ensures it is btf_type_is_void(t) } */ nargs = btf_type_vlen(func_proto); diff --git a/tools/testing/selftests/bpf/prog_tests/kfunc_dynptr_param.c b/tools/testing/selftests/bpf/prog_tests/kfunc_dynptr_param.c index c210657d4d0a..55d641c1f126 100644 --- a/tools/testing/selftests/bpf/prog_tests/kfunc_dynptr_param.c +++ b/tools/testing/selftests/bpf/prog_tests/kfunc_dynptr_param.c @@ -22,7 +22,7 @@ static struct { "arg#0 pointer type STRUCT bpf_dynptr_kern points to unsupported dynamic pointer type", 0}, {"not_valid_dynptr", "arg#0 pointer type STRUCT bpf_dynptr_kern must be valid and initialized", 0}, - {"not_ptr_to_stack", "arg#0 pointer type STRUCT bpf_dynptr_kern not to stack", 0}, + {"not_ptr_to_stack", "arg#0 expected pointer to stack", 0}, {"dynptr_data_null", NULL, -EBADMSG}, }; diff --git a/tools/testing/selftests/bpf/verifier/calls.c b/tools/testing/selftests/bpf/verifier/calls.c index e1a937277b54..86d6fef2e3b4 100644 --- a/tools/testing/selftests/bpf/verifier/calls.c +++ b/tools/testing/selftests/bpf/verifier/calls.c @@ -109,7 +109,7 @@ }, .prog_type = BPF_PROG_TYPE_SCHED_CLS, .result = REJECT, - .errstr = "arg#0 pointer type STRUCT prog_test_ref_kfunc must point", + .errstr = "arg#0 expected pointer to btf or socket", .fixup_kfunc_btf_id = { { "bpf_kfunc_call_test_acquire", 3 }, { "bpf_kfunc_call_test_release", 5 }, diff --git a/tools/testing/selftests/bpf/verifier/ref_tracking.c b/tools/testing/selftests/bpf/verifier/ref_tracking.c index fd683a32a276..55cba01c99d5 100644 --- a/tools/testing/selftests/bpf/verifier/ref_tracking.c +++ b/tools/testing/selftests/bpf/verifier/ref_tracking.c @@ -142,7 +142,7 @@ .kfunc = "bpf", .expected_attach_type = BPF_LSM_MAC, .flags = BPF_F_SLEEPABLE, - .errstr = "arg#0 pointer type STRUCT bpf_key must point to scalar, or struct with scalar", + .errstr = "arg#0 expected pointer to btf or socket", .fixup_kfunc_btf_id = { { "bpf_lookup_user_key", 2 }, { "bpf_key_put", 4 }, @@ -163,7 +163,7 @@ .kfunc = "bpf", .expected_attach_type = BPF_LSM_MAC, .flags = BPF_F_SLEEPABLE, - .errstr = "arg#0 pointer type STRUCT bpf_key must point to scalar, or struct with scalar", + .errstr = "arg#0 expected pointer to btf or socket", .fixup_kfunc_btf_id = { { "bpf_lookup_system_key", 1 }, { "bpf_key_put", 3 }, From patchwork Thu Nov 17 22:54:59 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kumar Kartikeya Dwivedi X-Patchwork-Id: 13047436 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 434D7C4332F for ; Thu, 17 Nov 2022 22:56:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234954AbiKQW4I (ORCPT ); Thu, 17 Nov 2022 17:56:08 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53300 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234843AbiKQW4E (ORCPT ); Thu, 17 Nov 2022 17:56:04 -0500 Received: from mail-pl1-x642.google.com (mail-pl1-x642.google.com [IPv6:2607:f8b0:4864:20::642]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F2536186FC for ; Thu, 17 Nov 2022 14:56:02 -0800 (PST) Received: by mail-pl1-x642.google.com with SMTP id y10so1803450plp.3 for ; Thu, 17 Nov 2022 14:56:02 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=eADGO9O0PgU+rJUyTCDLhtk/CaV3wC5RG4davPZNCZE=; b=RdOc6J3/baOUpj4dvkJZ+Hi2iT3rnQmqE1JC23VorolDr75Lzweam301CN5xdHTBA4 5gohP7sbFPSAr2sEBxzSlQpe56bFK6Yk7dNi0d26fodBUt+aCU6/Mch9ptMtd46w7QpB omPDpj2VkUaNl95ieO2HZPjzmbBEecDCZrDsQy/lHX3h6+Ad0eTScPTsaIxPjB3caRi2 jU8MZckF430gsGrp0L1PTJ32S4SmYOqrRl9kYar4aUq+Lxfcbucs2Pmop2jl/zRmfYRB ZBIM5NPXTIUY1GjiL47RaGXdpRav5fjqnrEHIVvMcWj3plR0Gob1XZ1t+D8905unRvq+ 7uYQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=eADGO9O0PgU+rJUyTCDLhtk/CaV3wC5RG4davPZNCZE=; b=4rMXacm4QGe7Ez8B8if8rr5VtLLzY5SBZP5fJfaUr5v/y0DO3FbxGrN0MgS5CmooFg qUuLyYwqLlveNrBShDWNBIuVCJmaV2APBP82H/Xx8yLMfrOpVjOXkRhANI72rs9eoo2O v63Y140AsMf9wmHRGvwhKOjV3fUoHUVtWha6KIJzOfzwUbwJhGichC/ytUhbJIULC8V4 HPad5UnPQnTKhA6IT+VpZkXSZVHGu4SWyNcAYPYIgrESaHAw+H18GBtEC8UENvFUmmyu TITaXrYhuoDfSE8eeVu7CYCtgJmv0YNGHnxkJUqX9lNPdB858Nqkdq4fiYWd+356/SIP TFGQ== X-Gm-Message-State: ANoB5pmH6re8Vyu8zdX8nQ06wE2ovKetaYFn09Rsgr14A1CIMdXCIbk0 X1YlIwkw7GNpgZIGnr1nRUERJe0857Y= X-Google-Smtp-Source: AA0mqf7kaaV/AOnAc1/YkhSpcKCjBVTt9iSofz8kknCwM85nhQgq0N9stzLYtSf0NyhPkBXx1ztZCQ== X-Received: by 2002:a17:902:cf05:b0:186:de22:7968 with SMTP id i5-20020a170902cf0500b00186de227968mr4842657plg.3.1668725762249; Thu, 17 Nov 2022 14:56:02 -0800 (PST) Received: from localhost ([2409:40f4:8:955c:5484:8048:c08:7b3]) by smtp.gmail.com with ESMTPSA id p188-20020a625bc5000000b0056e32a2b88esm1630466pfb.219.2022.11.17.14.56.01 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 17 Nov 2022 14:56:01 -0800 (PST) From: Kumar Kartikeya Dwivedi To: bpf@vger.kernel.org Cc: Alexei Starovoitov , Andrii Nakryiko , Daniel Borkmann , Martin KaFai Lau , Dave Marchevsky Subject: [PATCH bpf-next v9 12/23] bpf: Support constant scalar arguments for kfuncs Date: Fri, 18 Nov 2022 04:24:59 +0530 Message-Id: <20221117225510.1676785-13-memxor@gmail.com> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20221117225510.1676785-1-memxor@gmail.com> References: <20221117225510.1676785-1-memxor@gmail.com> MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=5687; i=memxor@gmail.com; h=from:subject; bh=u9Qjbd5URIRAYF6yjvJAaOF9VBbO7P61kGUXFF2hQC8=; b=owEBbQKS/ZANAwAIAUzgyIZIvxHKAcsmYgBjdrkb4DuaBoKZ23L+NfrC+h4L+X+ye0wfHKmzQ4Su b3KhvUaJAjMEAAEIAB0WIQRLvip+Buz51YI8YRFM4MiGSL8RygUCY3a5GwAKCRBM4MiGSL8RytwLD/ 48kBJjdyYEa7Mqz2HTZ6xy7ck9VlH2kks5OZO2txfFDzrzEYtoaInLTn1RsRrZNAH08BVOVMO4MwAU Uqneabu2n/lN97Ol47Xil/yYDogoPIE56cFAqssiwq3napw2gai7NWXfKh6uwYX4QJpvrSD+bZwPsp OkJt80WFEn/Wz5NUYFxDQ4nR9JVUNokPeKkkvlJUxJFfEcjl4F312iVoXSv5t5Kro3+UF0S1xkXtLN /eybJXuwBIdpJXmDwORnReWuLfjeUxLo3+BQ3x6kYa0vfw9UHk988RuZuyDBF3E4k80I+ckGn57BVG 0bGSkX4D4AT9DvB0+jwvYK2moTOA76ukv+ym8zaL93MdN9nVdAK3Wmt+PzDCNPUYEmn6BhxRk/k+F1 Y3M21It0R6Z5XywkowNOZqTU54A5MJNkAzLpnjTIj6VBa7vUbcyftbDIwLnWqm+hTu8nth+FzPLvjE 3Y0NHyLuxkBcqYmGfUfl51AxlOPlXNGRle1WUcFRQfAvVCJQnw+qPkRG+AFdFuKM7dJjGaXHypQZqA wFvofExlEMYYY7r34gHgd6Fmsc2bw5pfviqDJ4+c0BB4V4IikK2xNp/GM86yYK8cvDO2le3Z8bR8pb YX2bg2sIRwJrXqd9yNyH9q/Rpl5Q7JPfuZPrAgVSFnhSXeJk8KcvPQXii4kA== X-Developer-Key: i=memxor@gmail.com; a=openpgp; fpr=4BBE2A7E06ECF9D5823C61114CE0C88648BF11CA Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net Allow passing known constant scalars as arguments to kfuncs that do not represent a size parameter. We use mark_chain_precision for the constant scalar argument to mark it precise. This makes the search pruning optimization of verifier more conservative for such kfunc calls, and each non-distinct argument is considered unequivalent. We will use this support to then expose a bpf_obj_new function where it takes the local type ID of a type in program BTF, and returns a PTR_TO_BTF_ID | MEM_ALLOC to the local type, and allows programs to allocate their own objects. Each type ID resolves to a distinct type with a possibly distinct size, hence the type ID constant matters in terms of program safety and its precision needs to be checked between old and cur states inside regsafe. The use of mark_chain_precision enables this. Signed-off-by: Kumar Kartikeya Dwivedi --- Documentation/bpf/kfuncs.rst | 24 +++++++++++++++ kernel/bpf/verifier.c | 57 +++++++++++++++++++++++++++--------- 2 files changed, 67 insertions(+), 14 deletions(-) diff --git a/Documentation/bpf/kfuncs.rst b/Documentation/bpf/kfuncs.rst index 0f858156371d..3b1501c3b6cd 100644 --- a/Documentation/bpf/kfuncs.rst +++ b/Documentation/bpf/kfuncs.rst @@ -72,6 +72,30 @@ argument as its size. By default, without __sz annotation, the size of the type of the pointer is used. Without __sz annotation, a kfunc cannot accept a void pointer. +2.2.2 __k Annotation +-------------------- + +This annotation is only understood for scalar arguments, where it indicates that +the verifier must check the scalar argument to be a known constant, which does +not indicate a size parameter, and the value of the constant is relevant to the +safety of the program. + +An example is given below:: + + void *bpf_obj_new(u32 local_type_id__k, ...) + { + ... + } + +Here, bpf_obj_new uses local_type_id argument to find out the size of that type +ID in program's BTF and return a sized pointer to it. Each type ID will have a +distinct size, hence it is crucial to treat each such call as distinct when +values don't match during verifier state pruning checks. + +Hence, whenever a constant scalar argument is accepted by a kfunc which is not a +size parameter, and the value of the constant matters for program safety, __k +suffix should be used. + .. _BPF_kfunc_nodef: 2.3 Using an existing kernel function diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index d85ecc673631..293417e5d732 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -7874,6 +7874,10 @@ struct bpf_kfunc_call_arg_meta { u8 release_regno; bool r0_rdonly; u64 r0_size; + struct { + u64 value; + bool found; + } arg_constant; }; static bool is_kfunc_acquire(struct bpf_kfunc_call_arg_meta *meta) @@ -7911,30 +7915,40 @@ static bool is_kfunc_arg_kptr_get(struct bpf_kfunc_call_arg_meta *meta, int arg) return arg == 0 && (meta->kfunc_flags & KF_KPTR_GET); } -static bool is_kfunc_arg_mem_size(const struct btf *btf, - const struct btf_param *arg, - const struct bpf_reg_state *reg) +static bool __kfunc_param_match_suffix(const struct btf *btf, + const struct btf_param *arg, + const char *suffix) { - int len, sfx_len = sizeof("__sz") - 1; - const struct btf_type *t; + int suffix_len = strlen(suffix), len; const char *param_name; - t = btf_type_skip_modifiers(btf, arg->type, NULL); - if (!btf_type_is_scalar(t) || reg->type != SCALAR_VALUE) - return false; - /* In the future, this can be ported to use BTF tagging */ param_name = btf_name_by_offset(btf, arg->name_off); if (str_is_empty(param_name)) return false; len = strlen(param_name); - if (len < sfx_len) + if (len < suffix_len) return false; - param_name += len - sfx_len; - if (strncmp(param_name, "__sz", sfx_len)) + param_name += len - suffix_len; + return !strncmp(param_name, suffix, suffix_len); +} + +static bool is_kfunc_arg_mem_size(const struct btf *btf, + const struct btf_param *arg, + const struct bpf_reg_state *reg) +{ + const struct btf_type *t; + + t = btf_type_skip_modifiers(btf, arg->type, NULL); + if (!btf_type_is_scalar(t) || reg->type != SCALAR_VALUE) return false; - return true; + return __kfunc_param_match_suffix(btf, arg, "__sz"); +} + +static bool is_kfunc_arg_constant(const struct btf *btf, const struct btf_param *arg) +{ + return __kfunc_param_match_suffix(btf, arg, "__k"); } static bool is_kfunc_arg_scalar_with_name(const struct btf *btf, @@ -8204,7 +8218,22 @@ static int check_kfunc_args(struct bpf_verifier_env *env, struct bpf_kfunc_call_ verbose(env, "R%d is not a scalar\n", regno); return -EINVAL; } - if (is_kfunc_arg_scalar_with_name(btf, &args[i], "rdonly_buf_size")) { + + if (is_kfunc_arg_constant(meta->btf, &args[i])) { + if (meta->arg_constant.found) { + verbose(env, "verifier internal error: only one constant argument permitted\n"); + return -EFAULT; + } + if (!tnum_is_const(reg->var_off)) { + verbose(env, "R%d must be a known constant\n", regno); + return -EINVAL; + } + ret = mark_chain_precision(env, regno); + if (ret < 0) + return ret; + meta->arg_constant.found = true; + meta->arg_constant.value = reg->var_off.value; + } else if (is_kfunc_arg_scalar_with_name(btf, &args[i], "rdonly_buf_size")) { meta->r0_rdonly = true; is_ret_buf_sz = true; } else if (is_kfunc_arg_scalar_with_name(btf, &args[i], "rdwr_buf_size")) { From patchwork Thu Nov 17 22:55:00 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kumar Kartikeya Dwivedi X-Patchwork-Id: 13047438 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 88BE6C4321E for ; Thu, 17 Nov 2022 22:56:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235000AbiKQW4J (ORCPT ); Thu, 17 Nov 2022 17:56:09 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53442 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234959AbiKQW4I (ORCPT ); Thu, 17 Nov 2022 17:56:08 -0500 Received: from mail-pj1-x1044.google.com (mail-pj1-x1044.google.com [IPv6:2607:f8b0:4864:20::1044]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 78E351B9FD for ; Thu, 17 Nov 2022 14:56:06 -0800 (PST) Received: by mail-pj1-x1044.google.com with SMTP id o7so2954454pjj.1 for ; Thu, 17 Nov 2022 14:56:06 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=MfxrFrgMBDykuTqnNhrB/kl2fmghxMGJFIhoi5stBXg=; b=fLGwVMyCJrNtcQt2MbOkXFwmJoeg/XTDSAcM3AOE5E/GLdWqgBokcQClxA3DPXIE8r MdpIxQFJq2ApDPCCe5Kqa5P4bebIigAk+whkYsbOVFlWLFiFNozAds/To+r6ahVnq7+p EOO2/P5aQu82SaTB/eaT12dLtsEQ0nPQtzkPrhUOYv1K+y1uSdONNe6cUOUX/0aUG11B uyIYNtfrCCEnrmMzntwwsNjokuQET8sdcs3PC+cLP213YJ/YRsJoMJEnpX48oup4l0PO fyuEJS1dzsfLWVVG+MlPHwKMVbmNnXS9xZkyODkZy6S/nmIRvWZ2SYZ5a//Ya4BWVStB uv3A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=MfxrFrgMBDykuTqnNhrB/kl2fmghxMGJFIhoi5stBXg=; b=wuCgScQvqT8DXwFg/UQFuNi0uPWgve1tcsDX0KEhrFo3v8l0HucBkhmHLAzyLX8v3o VypG9YUFZusgrYcDLEaiqt0FruxWzQxIvJKISWEyW7yr0Br2nxmCekmpLGOKnkvvCe8q B9INMIs2LuHWz6XjHFvewVi2pP8bpS5cYIjNatyYhPkxKApVykGSHyPaZEiRKuFGg4/v +oEFjOWb8PpBeH2QBFS54uY0gEu3wb+jdCJFluzvrOGuvGomcOQNgBR1T6Tzyq5OvryW RWnioKx37TsI7hc09XO+DZE4/y94toPbLWkk9QFbU9i7SkEpTrtdOV6duOiWA1SVOA7A JqaA== X-Gm-Message-State: ANoB5plXqJo/Q5cF6/YbxQvUnh4gQAd9Mzl35Vi2cIRNu5Zrv8H+F/x5 k4mIMnNkhA1uEhdc/nTJY3T+9pdmYSw= X-Google-Smtp-Source: AA0mqf7AZ8tI6oIzDeko1SgYhM1zNwfT9Df0eaNx7b0v1AyUTT9HvpQGWoysWfeBPqyNd/cEZBNP2g== X-Received: by 2002:a17:902:cf04:b0:186:95ca:1e4c with SMTP id i4-20020a170902cf0400b0018695ca1e4cmr4914348plg.13.1668725765599; Thu, 17 Nov 2022 14:56:05 -0800 (PST) Received: from localhost ([2409:40f4:8:955c:5484:8048:c08:7b3]) by smtp.gmail.com with ESMTPSA id o1-20020a170902d4c100b00186b1bfbe79sm2041790plg.66.2022.11.17.14.56.04 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 17 Nov 2022 14:56:05 -0800 (PST) From: Kumar Kartikeya Dwivedi To: bpf@vger.kernel.org Cc: Alexei Starovoitov , Andrii Nakryiko , Daniel Borkmann , Martin KaFai Lau , Dave Marchevsky Subject: [PATCH bpf-next v9 13/23] bpf: Introduce bpf_obj_new Date: Fri, 18 Nov 2022 04:25:00 +0530 Message-Id: <20221117225510.1676785-14-memxor@gmail.com> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20221117225510.1676785-1-memxor@gmail.com> References: <20221117225510.1676785-1-memxor@gmail.com> MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=15630; i=memxor@gmail.com; h=from:subject; bh=kc5j0OFpevOwggW/O95O8vbK8RzIpxEPWgXbIEphLE4=; b=owEBbQKS/ZANAwAIAUzgyIZIvxHKAcsmYgBjdrkbJ3kjppRK5kB3LESQzpurie5hjHIVCGX9rEJt oTsGiQqJAjMEAAEIAB0WIQRLvip+Buz51YI8YRFM4MiGSL8RygUCY3a5GwAKCRBM4MiGSL8RysnrEA CmdMS5cyMAZKaOi3WawI8r3Gco7NcTkaZ9rGyZcfZLn+qln8wfrVkDB60mJtE62n20o2ofn7QCbyah zSOQxAsXrUw/0gvWhG5SBfaH4zDzQHcNg5txRiy3AvYLw11f/tVO3Um0Nzt8Z3dgOujhjGgYxzrnVO 6z9j91V2mZWE2uO8EmRtLVjk9NWgT/NZ1puD0QrzCK++iGA9yjXavPCbx6/1EsW8OS2Nicdg9zhD9Y y64YzRBUvFejMUfZ8qcLCxzfO7mI2JtIv6VzvnwUbRgb9ZukK0DQ60V/k0M6p5H8LL+VawyTLBPNFJ SMvbS4H547wHqmGRf2CwlOjnaBDCc0CqW7FxtLent1gjrqdmUzKbtlNnDGnYCOlClAq1E8b7v5APYh /DLt+K3xCHG7Kqoo/tmvvv/Y/XH6ZKM/os+iB8LtE+IoPhTfqmUDBnoCNstmcdZSRoKTlj4cZn2qLo LGYQLYoCmCzxihvdTIHPVkD28fMaouZ7MTuGzzxsjS2puys4lXm7cJEWk31DMHJnfS2FOlVbsv50j+ VKK9nU3+mdtnGbgUu9A4dkKljFI0Ssy9Ubo8U0ytNArqQQDaEwyw2trHomj/4O23QoVlCSVwbYBR+i Mnmivnaj15jFpkMcxLpTyes1DZXNTAv6+ACafSz7XsW9W3Lo4qhvDfi7eADg== X-Developer-Key: i=memxor@gmail.com; a=openpgp; fpr=4BBE2A7E06ECF9D5823C61114CE0C88648BF11CA Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net Introduce type safe memory allocator bpf_obj_new for BPF programs. The kernel side kfunc is named bpf_obj_new_impl, as passing hidden arguments to kfuncs still requires having them in prototype, unlike BPF helpers which always take 5 arguments and have them checked using bpf_func_proto in verifier, ignoring unset argument types. Introduce __ign suffix to ignore a specific kfunc argument during type checks, then use this to introduce support for passing type metadata to the bpf_obj_new_impl kfunc. The user passes BTF ID of the type it wants to allocates in program BTF, the verifier then rewrites the first argument as the size of this type, after performing some sanity checks (to ensure it exists and it is a struct type). The second argument is also fixed up and passed by the verifier. This is the btf_struct_meta for the type being allocated. It would be needed mostly for the offset array which is required for zero initializing special fields while leaving the rest of storage in unitialized state. It would also be needed in the next patch to perform proper destruction of the object's special fields. Under the hood, bpf_obj_new will call bpf_mem_alloc and bpf_mem_free, using the any context BPF memory allocator introduced recently. To this end, a global instance of the BPF memory allocator is initialized on boot to be used for this purpose. This 'bpf_global_ma' serves all allocations for bpf_obj_new. In the future, bpf_obj_new variants will allow specifying a custom allocator. Note that now that bpf_obj_new can be used to allocate objects that can be linked to BPF linked list (when future linked list helpers are available), we need to also free the elements using bpf_mem_free. However, since the draining of elements is done outside the bpf_spin_lock, we need to do migrate_disable around the call since bpf_list_head_free can be called from map free path where migration is enabled. Otherwise, when called from BPF programs migration is already disabled. A convenience macro is included in the bpf_experimental.h header to hide over the ugly details of the implementation, leading to user code looking similar to a language level extension which allocates and constructs fields of a user type. struct bar { struct bpf_list_node node; }; struct foo { struct bpf_spin_lock lock; struct bpf_list_head head __contains(bar, node); }; void prog(void) { struct foo *f; f = bpf_obj_new(typeof(*f)); if (!f) return; ... } A key piece of this story is still missing, i.e. the free function, which will come in the next patch. Signed-off-by: Kumar Kartikeya Dwivedi --- include/linux/bpf.h | 21 ++-- include/linux/bpf_verifier.h | 2 + kernel/bpf/core.c | 16 +++ kernel/bpf/helpers.c | 47 ++++++-- kernel/bpf/verifier.c | 102 ++++++++++++++++-- .../testing/selftests/bpf/bpf_experimental.h | 25 +++++ 6 files changed, 190 insertions(+), 23 deletions(-) create mode 100644 tools/testing/selftests/bpf/bpf_experimental.h diff --git a/include/linux/bpf.h b/include/linux/bpf.h index 0a74df731eb8..8b32376ce746 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -54,6 +54,8 @@ struct cgroup; extern struct idr btf_idr; extern spinlock_t btf_idr_lock; extern struct kobject *btf_kobj; +extern struct bpf_mem_alloc bpf_global_ma; +extern bool bpf_global_ma_set; typedef u64 (*bpf_callback_t)(u64, u64, u64, u64, u64); typedef int (*bpf_iter_init_seq_priv_t)(void *private_data, @@ -334,16 +336,19 @@ static inline bool btf_record_has_field(const struct btf_record *rec, enum btf_f return rec->field_mask & type; } -static inline void check_and_init_map_value(struct bpf_map *map, void *dst) +static inline void bpf_obj_init(const struct btf_field_offs *foffs, void *obj) { - if (!IS_ERR_OR_NULL(map->record)) { - struct btf_field *fields = map->record->fields; - u32 cnt = map->record->cnt; - int i; + int i; - for (i = 0; i < cnt; i++) - memset(dst + fields[i].offset, 0, btf_field_type_size(fields[i].type)); - } + if (!foffs) + return; + for (i = 0; i < foffs->cnt; i++) + memset(obj + foffs->field_off[i], 0, foffs->field_sz[i]); +} + +static inline void check_and_init_map_value(struct bpf_map *map, void *dst) +{ + bpf_obj_init(map->field_offs, dst); } /* memcpy that is used with 8-byte aligned pointers, power-of-8 size and diff --git a/include/linux/bpf_verifier.h b/include/linux/bpf_verifier.h index bc786457f51d..a159a8ffa716 100644 --- a/include/linux/bpf_verifier.h +++ b/include/linux/bpf_verifier.h @@ -433,6 +433,8 @@ struct bpf_insn_aux_data { */ struct bpf_loop_inline_state loop_inline_state; }; + u64 obj_new_size; /* remember the size of type passed to bpf_obj_new to rewrite R1 */ + struct btf_struct_meta *kptr_struct_meta; u64 map_key_state; /* constant (32 bit) key tracking for maps */ int ctx_field_size; /* the ctx field size for load insn, maybe 0 */ u32 seen; /* this insn was processed by the verifier at env->pass_cnt */ diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c index 9c16338bcbe8..2e57fc839a5c 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -34,6 +34,7 @@ #include #include #include +#include #include #include @@ -60,6 +61,9 @@ #define CTX regs[BPF_REG_CTX] #define IMM insn->imm +struct bpf_mem_alloc bpf_global_ma; +bool bpf_global_ma_set; + /* No hurry in this branch * * Exported for the bpf jit load helper. @@ -2746,6 +2750,18 @@ int __weak bpf_arch_text_invalidate(void *dst, size_t len) return -ENOTSUPP; } +#ifdef CONFIG_BPF_SYSCALL +static int __init bpf_global_ma_init(void) +{ + int ret; + + ret = bpf_mem_alloc_init(&bpf_global_ma, 0, false); + bpf_global_ma_set = !ret; + return ret; +} +late_initcall(bpf_global_ma_init); +#endif + DEFINE_STATIC_KEY_FALSE(bpf_stats_enabled_key); EXPORT_SYMBOL(bpf_stats_enabled_key); diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c index 5bc0b9f0f306..c4f1c22cc44c 100644 --- a/kernel/bpf/helpers.c +++ b/kernel/bpf/helpers.c @@ -19,6 +19,7 @@ #include #include #include +#include #include "../../lib/kstrtox.h" @@ -1735,25 +1736,57 @@ void bpf_list_head_free(const struct btf_field *field, void *list_head, obj -= field->list_head.node_offset; head = head->next; - /* TODO: Rework later */ - kfree(obj); + /* The contained type can also have resources, including a + * bpf_list_head which needs to be freed. + */ + bpf_obj_free_fields(field->list_head.value_rec, obj); + /* bpf_mem_free requires migrate_disable(), since we can be + * called from map free path as well apart from BPF program (as + * part of map ops doing bpf_obj_free_fields). + */ + migrate_disable(); + bpf_mem_free(&bpf_global_ma, obj); + migrate_enable(); } } -BTF_SET8_START(tracing_btf_ids) +__diag_push(); +__diag_ignore_all("-Wmissing-prototypes", + "Global functions as their definitions will be in vmlinux BTF"); + +void *bpf_obj_new_impl(u64 local_type_id__k, void *meta__ign) +{ + struct btf_struct_meta *meta = meta__ign; + u64 size = local_type_id__k; + void *p; + + if (unlikely(!bpf_global_ma_set)) + return NULL; + p = bpf_mem_alloc(&bpf_global_ma, size); + if (!p) + return NULL; + if (meta) + bpf_obj_init(meta->field_offs, p); + return p; +} + +__diag_pop(); + +BTF_SET8_START(generic_btf_ids) #ifdef CONFIG_KEXEC_CORE BTF_ID_FLAGS(func, crash_kexec, KF_DESTRUCTIVE) #endif -BTF_SET8_END(tracing_btf_ids) +BTF_ID_FLAGS(func, bpf_obj_new_impl, KF_ACQUIRE | KF_RET_NULL) +BTF_SET8_END(generic_btf_ids) -static const struct btf_kfunc_id_set tracing_kfunc_set = { +static const struct btf_kfunc_id_set generic_kfunc_set = { .owner = THIS_MODULE, - .set = &tracing_btf_ids, + .set = &generic_btf_ids, }; static int __init kfunc_init(void) { - return register_btf_kfunc_id_set(BPF_PROG_TYPE_TRACING, &tracing_kfunc_set); + return register_btf_kfunc_id_set(BPF_PROG_TYPE_TRACING, &generic_kfunc_set); } late_initcall(kfunc_init); diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 293417e5d732..ab91037df1c8 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -7951,6 +7951,11 @@ static bool is_kfunc_arg_constant(const struct btf *btf, const struct btf_param return __kfunc_param_match_suffix(btf, arg, "__k"); } +static bool is_kfunc_arg_ignore(const struct btf *btf, const struct btf_param *arg) +{ + return __kfunc_param_match_suffix(btf, arg, "__ign"); +} + static bool is_kfunc_arg_scalar_with_name(const struct btf *btf, const struct btf_param *arg, const char *name) @@ -8213,6 +8218,10 @@ static int check_kfunc_args(struct bpf_verifier_env *env, struct bpf_kfunc_call_ int kf_arg_type; t = btf_type_skip_modifiers(btf, args[i].type, NULL); + + if (is_kfunc_arg_ignore(btf, &args[i])) + continue; + if (btf_type_is_scalar(t)) { if (reg->type != SCALAR_VALUE) { verbose(env, "R%d is not a scalar\n", regno); @@ -8390,6 +8399,17 @@ static int check_kfunc_args(struct bpf_verifier_env *env, struct bpf_kfunc_call_ return 0; } +enum special_kfunc_type { + KF_bpf_obj_new_impl, +}; + +BTF_SET_START(special_kfunc_set) +BTF_ID(func, bpf_obj_new_impl) +BTF_SET_END(special_kfunc_set) + +BTF_ID_LIST(special_kfunc_list) +BTF_ID(func, bpf_obj_new_impl) + static int check_kfunc_call(struct bpf_verifier_env *env, struct bpf_insn *insn, int *insn_idx_p) { @@ -8464,17 +8484,59 @@ static int check_kfunc_call(struct bpf_verifier_env *env, struct bpf_insn *insn, t = btf_type_skip_modifiers(desc_btf, func_proto->type, NULL); if (is_kfunc_acquire(&meta) && !btf_type_is_struct_ptr(meta.btf, t)) { - verbose(env, "acquire kernel function does not return PTR_TO_BTF_ID\n"); - return -EINVAL; + /* Only exception is bpf_obj_new_impl */ + if (meta.btf != btf_vmlinux || meta.func_id != special_kfunc_list[KF_bpf_obj_new_impl]) { + verbose(env, "acquire kernel function does not return PTR_TO_BTF_ID\n"); + return -EINVAL; + } } if (btf_type_is_scalar(t)) { mark_reg_unknown(env, regs, BPF_REG_0); mark_btf_func_reg_size(env, BPF_REG_0, t->size); } else if (btf_type_is_ptr(t)) { - ptr_type = btf_type_skip_modifiers(desc_btf, t->type, - &ptr_type_id); - if (!btf_type_is_struct(ptr_type)) { + ptr_type = btf_type_skip_modifiers(desc_btf, t->type, &ptr_type_id); + + if (meta.btf == btf_vmlinux && btf_id_set_contains(&special_kfunc_set, meta.func_id)) { + if (meta.func_id == special_kfunc_list[KF_bpf_obj_new_impl]) { + const struct btf_type *ret_t; + struct btf *ret_btf; + u32 ret_btf_id; + + if (((u64)(u32)meta.arg_constant.value) != meta.arg_constant.value) { + verbose(env, "local type ID argument must be in range [0, U32_MAX]\n"); + return -EINVAL; + } + + ret_btf = env->prog->aux->btf; + ret_btf_id = meta.arg_constant.value; + + /* This may be NULL due to user not supplying a BTF */ + if (!ret_btf) { + verbose(env, "bpf_obj_new requires prog BTF\n"); + return -EINVAL; + } + + ret_t = btf_type_by_id(ret_btf, ret_btf_id); + if (!ret_t || !__btf_type_is_struct(ret_t)) { + verbose(env, "bpf_obj_new type ID argument must be of a struct\n"); + return -EINVAL; + } + + mark_reg_known_zero(env, regs, BPF_REG_0); + regs[BPF_REG_0].type = PTR_TO_BTF_ID | MEM_ALLOC; + regs[BPF_REG_0].btf = ret_btf; + regs[BPF_REG_0].btf_id = ret_btf_id; + + env->insn_aux_data[insn_idx].obj_new_size = ret_t->size; + env->insn_aux_data[insn_idx].kptr_struct_meta = + btf_find_struct_meta(ret_btf, ret_btf_id); + } else { + verbose(env, "kernel function %s unhandled dynamic return type\n", + meta.func_name); + return -EFAULT; + } + } else if (!__btf_type_is_struct(ptr_type)) { if (!meta.r0_size) { ptr_type_name = btf_name_by_offset(desc_btf, ptr_type->name_off); @@ -8502,6 +8564,7 @@ static int check_kfunc_call(struct bpf_verifier_env *env, struct bpf_insn *insn, regs[BPF_REG_0].type = PTR_TO_BTF_ID; regs[BPF_REG_0].btf_id = ptr_type_id; } + if (is_kfunc_ret_null(&meta)) { regs[BPF_REG_0].type |= PTR_MAYBE_NULL; /* For mark_ptr_or_null_reg, see 93c230e3f5bd6 */ @@ -14670,8 +14733,8 @@ static int fixup_call_args(struct bpf_verifier_env *env) return err; } -static int fixup_kfunc_call(struct bpf_verifier_env *env, - struct bpf_insn *insn) +static int fixup_kfunc_call(struct bpf_verifier_env *env, struct bpf_insn *insn, + struct bpf_insn *insn_buf, int insn_idx, int *cnt) { const struct bpf_kfunc_desc *desc; @@ -14690,8 +14753,21 @@ static int fixup_kfunc_call(struct bpf_verifier_env *env, return -EFAULT; } + *cnt = 0; insn->imm = desc->imm; + if (insn->off) + return 0; + if (desc->func_id == special_kfunc_list[KF_bpf_obj_new_impl]) { + struct btf_struct_meta *kptr_struct_meta = env->insn_aux_data[insn_idx].kptr_struct_meta; + struct bpf_insn addr[2] = { BPF_LD_IMM64(BPF_REG_2, (long)kptr_struct_meta) }; + u64 obj_new_size = env->insn_aux_data[insn_idx].obj_new_size; + insn_buf[0] = BPF_MOV64_IMM(BPF_REG_1, obj_new_size); + insn_buf[1] = addr[0]; + insn_buf[2] = addr[1]; + insn_buf[3] = *insn; + *cnt = 4; + } return 0; } @@ -14833,9 +14909,19 @@ static int do_misc_fixups(struct bpf_verifier_env *env) if (insn->src_reg == BPF_PSEUDO_CALL) continue; if (insn->src_reg == BPF_PSEUDO_KFUNC_CALL) { - ret = fixup_kfunc_call(env, insn); + ret = fixup_kfunc_call(env, insn, insn_buf, i + delta, &cnt); if (ret) return ret; + if (cnt == 0) + continue; + + new_prog = bpf_patch_insn_data(env, i + delta, insn_buf, cnt); + if (!new_prog) + return -ENOMEM; + + delta += cnt - 1; + env->prog = prog = new_prog; + insn = new_prog->insnsi + i + delta; continue; } diff --git a/tools/testing/selftests/bpf/bpf_experimental.h b/tools/testing/selftests/bpf/bpf_experimental.h new file mode 100644 index 000000000000..aeb6a7fcb7c4 --- /dev/null +++ b/tools/testing/selftests/bpf/bpf_experimental.h @@ -0,0 +1,25 @@ +#ifndef __BPF_EXPERIMENTAL__ +#define __BPF_EXPERIMENTAL__ + +#include +#include +#include +#include + +/* Description + * Allocates an object of the type represented by 'local_type_id' in + * program BTF. User may use the bpf_core_type_id_local macro to pass the + * type ID of a struct in program BTF. + * + * The 'local_type_id' parameter must be a known constant. + * The 'meta' parameter is a hidden argument that is ignored. + * Returns + * A pointer to an object of the type corresponding to the passed in + * 'local_type_id', or NULL on failure. + */ +extern void *bpf_obj_new_impl(__u64 local_type_id, void *meta) __ksym; + +/* Convenience macro to wrap over bpf_obj_new_impl */ +#define bpf_obj_new(type) ((type *)bpf_obj_new_impl(bpf_core_type_id_local(type), NULL)) + +#endif From patchwork Thu Nov 17 22:55:01 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kumar Kartikeya Dwivedi X-Patchwork-Id: 13047439 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 585EFC4332F for ; Thu, 17 Nov 2022 22:56:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234843AbiKQW4M (ORCPT ); Thu, 17 Nov 2022 17:56:12 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53542 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235006AbiKQW4K (ORCPT ); Thu, 17 Nov 2022 17:56:10 -0500 Received: from mail-pg1-x542.google.com (mail-pg1-x542.google.com [IPv6:2607:f8b0:4864:20::542]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AC276657F3 for ; Thu, 17 Nov 2022 14:56:09 -0800 (PST) Received: by mail-pg1-x542.google.com with SMTP id r18so3398481pgr.12 for ; Thu, 17 Nov 2022 14:56:09 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=++ULrfF8CmAP2xQVn0biv80cUJKxHLKHh12y4coOwaU=; b=m/9dLYPqUIDl56gmGLMERMYPtDrChkKkWcCCfbJiFmmx7UeRIZVrByWMCo26xpWpOz tXTbI97DzT6FXGUCmRHl3Kkncr+ucGW+UWFl0z7btepfTr8Bav9t54sLDkU6c3CMe/SZ 5NQp3pe5GL+TNCKiz1ksHnfIFiq1yiF5An7iEdkoKE6Y/6fV3q6Xef3BJKlYoIekxzdJ DBY9ZYUXG8Y1vHtxoIT0tQS9U/2+o35jvG1vBmFzBMwMyFP+O15W01Fovl0K1LrW3bNC zPXUslVm9+V2IG2zW1p33NBbJ+FSiXqzT9uqvv2PHbXmMrQA5QRTkKyfxxizTYUpmc+r Mrfg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=++ULrfF8CmAP2xQVn0biv80cUJKxHLKHh12y4coOwaU=; b=W82XAadG/hI0yl22/ql+qdzusJnKmI0+oKAbeCcVoAH0TgZ3w7yaiDjv4V2T/zgUKN aXI+Za+a7gMo/pmi1MAeU6oGws2yHlZV9vZmLFN8Ab/OVK3oe6WIeF0/IJXXfcqQbZVL E3N5cqQpz6ZeD3E6aHEx3cUcuvj3LnukHXcEv4ANYdoLqixFRI37a9EOhnTW/A2TbOEK RuK/OpW2XV3/ZwspuzFoxvUdgNv8Zb9iQNoKiPZyCRDJkEhirAiuyZeNYFkFILFLl+zx fV3S9cg26YjyQ206WP19KN33y8wcJAdmuQyhgW1sV/Ybk/K751dwELqftyPg09pJOdfP mWcw== X-Gm-Message-State: ANoB5pmd2joWpSYk6MIKgjpn4yDk+uJjxOxZh0ZnnEI9+lqgh0+nli/a mHWIErLuqM6Ig9pdcRBZo4f4CYtLRGY= X-Google-Smtp-Source: AA0mqf4anDXAwyMCqnidz7nRCJDwxHwEctZCLy4uLljbXnZECpb5BqiiQ9PohGi2Ql0bgnwTQNavaQ== X-Received: by 2002:a63:1760:0:b0:46f:9c0b:1e86 with SMTP id 32-20020a631760000000b0046f9c0b1e86mr3904530pgx.508.1668725768881; Thu, 17 Nov 2022 14:56:08 -0800 (PST) Received: from localhost ([2409:40f4:8:955c:5484:8048:c08:7b3]) by smtp.gmail.com with ESMTPSA id z11-20020aa7948b000000b0056262811c5fsm1706285pfk.59.2022.11.17.14.56.07 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 17 Nov 2022 14:56:08 -0800 (PST) From: Kumar Kartikeya Dwivedi To: bpf@vger.kernel.org Cc: Alexei Starovoitov , Andrii Nakryiko , Daniel Borkmann , Martin KaFai Lau , Dave Marchevsky Subject: [PATCH bpf-next v9 14/23] bpf: Introduce bpf_obj_drop Date: Fri, 18 Nov 2022 04:25:01 +0530 Message-Id: <20221117225510.1676785-15-memxor@gmail.com> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20221117225510.1676785-1-memxor@gmail.com> References: <20221117225510.1676785-1-memxor@gmail.com> MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=7736; i=memxor@gmail.com; h=from:subject; bh=mZvoCqtK4h6DgMb78xDqGgfqpZU5R/RixAo8Aq5Ac4M=; b=owEBbQKS/ZANAwAIAUzgyIZIvxHKAcsmYgBjdrkcy5zIvV+rHl3HnRQRK/23jp1DhZbBL7igEk0m 7vRD9rCJAjMEAAEIAB0WIQRLvip+Buz51YI8YRFM4MiGSL8RygUCY3a5HAAKCRBM4MiGSL8RyjH6EA Cm3/rAN7TeRtHMaj4wav1xPRAzLmFMn4P6Ezf1CokgXN9lkD+pNdOA7Vfeyxm+RJyTYf+l7tpLYfJs UHw9lIG2cLWeoCQzYjsrtA28kAOCrZiqI/i1OdpbvKL7gENxMN8h9m8yp4b7DqhISCEbyOB1iDtoMJ adZatYCbByXyMgtd0pA6LUEjObH5eKEuR4YdWJ5CN+bqtREg8hpNIrMAoYS7rOLGAsxOl61vRWDsGB vTDevJ4pPXPp/AK/zDYXXaDPaUuczMeHxnvT794YoYWgqaqKGZoK4GyZLaSIW3iy2NuuJPshfb8DkE pARczDtltYevtk160rKScwpYjEs37r8EpH29VkQY6kg7MuOd2eK8cm2n+/3sKpjuTvLHdENp9Z7Ggf zahIP36nowViLTQZAuMVItHkIKCWLZa4QlNO7dkw5D2Y2bCsdbEonon7Z6be5OwMGqnlaQ04FENU/m N+Z9I/B1X8eVJuNTNrqLUn6lkEVTLoX+D2vk3KhHcFQSgmpgMO89tQzxa/1Z1ecMxOu0SuSovZ2P47 yzQWmSKr9hyqvO918Mj4dHwFAc3lDWqnM1bjoYs0RsbKbpvA7idQ0OxYLuFPtYqz1COVek8I7CYpl+ 36DShHnHjPpA1W1viLJBYBleVdg1RXEMwaVOJcnmHgVoRtgPoh7WoTkQDKCA== X-Developer-Key: i=memxor@gmail.com; a=openpgp; fpr=4BBE2A7E06ECF9D5823C61114CE0C88648BF11CA Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net Introduce bpf_obj_drop, which is the kfunc used to free allocated objects (allocated using bpf_obj_new). Pairing with bpf_obj_new, it implicitly destructs the fields part of object automatically without user intervention. Just like the previous patch, btf_struct_meta that is needed to free up the special fields is passed as a hidden argument to the kfunc. For the user, a convenience macro hides over the kernel side kfunc which is named bpf_obj_drop_impl. Continuing the previous example: void prog(void) { struct foo *f; f = bpf_obj_new(typeof(*f)); if (!f) return; bpf_obj_drop(f); } Signed-off-by: Kumar Kartikeya Dwivedi --- kernel/bpf/helpers.c | 11 ++++ kernel/bpf/verifier.c | 66 +++++++++++++++---- .../testing/selftests/bpf/bpf_experimental.h | 13 ++++ 3 files changed, 79 insertions(+), 11 deletions(-) diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c index c4f1c22cc44c..71d803ca0c1d 100644 --- a/kernel/bpf/helpers.c +++ b/kernel/bpf/helpers.c @@ -1770,6 +1770,16 @@ void *bpf_obj_new_impl(u64 local_type_id__k, void *meta__ign) return p; } +void bpf_obj_drop_impl(void *p__alloc, void *meta__ign) +{ + struct btf_struct_meta *meta = meta__ign; + void *p = p__alloc; + + if (meta) + bpf_obj_free_fields(meta->record, p); + bpf_mem_free(&bpf_global_ma, p); +} + __diag_pop(); BTF_SET8_START(generic_btf_ids) @@ -1777,6 +1787,7 @@ BTF_SET8_START(generic_btf_ids) BTF_ID_FLAGS(func, crash_kexec, KF_DESTRUCTIVE) #endif BTF_ID_FLAGS(func, bpf_obj_new_impl, KF_ACQUIRE | KF_RET_NULL) +BTF_ID_FLAGS(func, bpf_obj_drop_impl, KF_RELEASE) BTF_SET8_END(generic_btf_ids) static const struct btf_kfunc_id_set generic_kfunc_set = { diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index ab91037df1c8..b96c525fa413 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -7878,6 +7878,10 @@ struct bpf_kfunc_call_arg_meta { u64 value; bool found; } arg_constant; + struct { + struct btf *btf; + u32 btf_id; + } arg_obj_drop; }; static bool is_kfunc_acquire(struct bpf_kfunc_call_arg_meta *meta) @@ -7956,6 +7960,11 @@ static bool is_kfunc_arg_ignore(const struct btf *btf, const struct btf_param *a return __kfunc_param_match_suffix(btf, arg, "__ign"); } +static bool is_kfunc_arg_alloc_obj(const struct btf *btf, const struct btf_param *arg) +{ + return __kfunc_param_match_suffix(btf, arg, "__alloc"); +} + static bool is_kfunc_arg_scalar_with_name(const struct btf *btf, const struct btf_param *arg, const char *name) @@ -8050,6 +8059,7 @@ static u32 *reg2btf_ids[__BPF_REG_TYPE_MAX] = { enum kfunc_ptr_arg_type { KF_ARG_PTR_TO_CTX, + KF_ARG_PTR_TO_ALLOC_BTF_ID, /* Allocated object */ KF_ARG_PTR_TO_KPTR, /* PTR_TO_KPTR but type specific */ KF_ARG_PTR_TO_DYNPTR, KF_ARG_PTR_TO_BTF_ID, /* Also covers reg2btf_ids conversions */ @@ -8057,6 +8067,20 @@ enum kfunc_ptr_arg_type { KF_ARG_PTR_TO_MEM_SIZE, /* Size derived from next argument, skip it */ }; +enum special_kfunc_type { + KF_bpf_obj_new_impl, + KF_bpf_obj_drop_impl, +}; + +BTF_SET_START(special_kfunc_set) +BTF_ID(func, bpf_obj_new_impl) +BTF_ID(func, bpf_obj_drop_impl) +BTF_SET_END(special_kfunc_set) + +BTF_ID_LIST(special_kfunc_list) +BTF_ID(func, bpf_obj_new_impl) +BTF_ID(func, bpf_obj_drop_impl) + static enum kfunc_ptr_arg_type get_kfunc_ptr_arg_type(struct bpf_verifier_env *env, struct bpf_kfunc_call_arg_meta *meta, @@ -8077,6 +8101,9 @@ get_kfunc_ptr_arg_type(struct bpf_verifier_env *env, if (btf_get_prog_ctx_type(&env->log, meta->btf, t, resolve_prog_type(env->prog), argno)) return KF_ARG_PTR_TO_CTX; + if (is_kfunc_arg_alloc_obj(meta->btf, &args[argno])) + return KF_ARG_PTR_TO_ALLOC_BTF_ID; + if (is_kfunc_arg_kptr_get(meta, argno)) { if (!btf_type_is_ptr(ref_t)) { verbose(env, "arg#0 BTF type must be a double pointer for kptr_get kfunc\n"); @@ -8293,6 +8320,7 @@ static int check_kfunc_args(struct bpf_verifier_env *env, struct bpf_kfunc_call_ return kf_arg_type; switch (kf_arg_type) { + case KF_ARG_PTR_TO_ALLOC_BTF_ID: case KF_ARG_PTR_TO_BTF_ID: if (!is_kfunc_trusted_args(meta)) break; @@ -8329,6 +8357,21 @@ static int check_kfunc_args(struct bpf_verifier_env *env, struct bpf_kfunc_call_ return -EINVAL; } break; + case KF_ARG_PTR_TO_ALLOC_BTF_ID: + if (reg->type != (PTR_TO_BTF_ID | MEM_ALLOC)) { + verbose(env, "arg#%d expected pointer to allocated object\n", i); + return -EINVAL; + } + if (!reg->ref_obj_id) { + verbose(env, "allocated object must be referenced\n"); + return -EINVAL; + } + if (meta->btf == btf_vmlinux && + meta->func_id == special_kfunc_list[KF_bpf_obj_drop_impl]) { + meta->arg_obj_drop.btf = reg->btf; + meta->arg_obj_drop.btf_id = reg->btf_id; + } + break; case KF_ARG_PTR_TO_KPTR: if (reg->type != PTR_TO_MAP_VALUE) { verbose(env, "arg#0 expected pointer to map value\n"); @@ -8399,17 +8442,6 @@ static int check_kfunc_args(struct bpf_verifier_env *env, struct bpf_kfunc_call_ return 0; } -enum special_kfunc_type { - KF_bpf_obj_new_impl, -}; - -BTF_SET_START(special_kfunc_set) -BTF_ID(func, bpf_obj_new_impl) -BTF_SET_END(special_kfunc_set) - -BTF_ID_LIST(special_kfunc_list) -BTF_ID(func, bpf_obj_new_impl) - static int check_kfunc_call(struct bpf_verifier_env *env, struct bpf_insn *insn, int *insn_idx_p) { @@ -8531,6 +8563,10 @@ static int check_kfunc_call(struct bpf_verifier_env *env, struct bpf_insn *insn, env->insn_aux_data[insn_idx].obj_new_size = ret_t->size; env->insn_aux_data[insn_idx].kptr_struct_meta = btf_find_struct_meta(ret_btf, ret_btf_id); + } else if (meta.func_id == special_kfunc_list[KF_bpf_obj_drop_impl]) { + env->insn_aux_data[insn_idx].kptr_struct_meta = + btf_find_struct_meta(meta.arg_obj_drop.btf, + meta.arg_obj_drop.btf_id); } else { verbose(env, "kernel function %s unhandled dynamic return type\n", meta.func_name); @@ -14767,6 +14803,14 @@ static int fixup_kfunc_call(struct bpf_verifier_env *env, struct bpf_insn *insn, insn_buf[2] = addr[1]; insn_buf[3] = *insn; *cnt = 4; + } else if (desc->func_id == special_kfunc_list[KF_bpf_obj_drop_impl]) { + struct btf_struct_meta *kptr_struct_meta = env->insn_aux_data[insn_idx].kptr_struct_meta; + struct bpf_insn addr[2] = { BPF_LD_IMM64(BPF_REG_2, (long)kptr_struct_meta) }; + + insn_buf[0] = addr[0]; + insn_buf[1] = addr[1]; + insn_buf[2] = *insn; + *cnt = 3; } return 0; } diff --git a/tools/testing/selftests/bpf/bpf_experimental.h b/tools/testing/selftests/bpf/bpf_experimental.h index aeb6a7fcb7c4..8473395a11af 100644 --- a/tools/testing/selftests/bpf/bpf_experimental.h +++ b/tools/testing/selftests/bpf/bpf_experimental.h @@ -22,4 +22,17 @@ extern void *bpf_obj_new_impl(__u64 local_type_id, void *meta) __ksym; /* Convenience macro to wrap over bpf_obj_new_impl */ #define bpf_obj_new(type) ((type *)bpf_obj_new_impl(bpf_core_type_id_local(type), NULL)) +/* Description + * Free an allocated object. All fields of the object that require + * destruction will be destructed before the storage is freed. + * + * The 'meta' parameter is a hidden argument that is ignored. + * Returns + * Void. + */ +extern void bpf_obj_drop_impl(void *kptr, void *meta) __ksym; + +/* Convenience macro to wrap over bpf_obj_drop_impl */ +#define bpf_obj_drop(kptr) bpf_obj_drop_impl(kptr, NULL) + #endif From patchwork Thu Nov 17 22:55:02 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kumar Kartikeya Dwivedi X-Patchwork-Id: 13047440 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D2A93C4332F for ; Thu, 17 Nov 2022 22:56:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235044AbiKQW4T (ORCPT ); Thu, 17 Nov 2022 17:56:19 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53726 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235129AbiKQW4Q (ORCPT ); Thu, 17 Nov 2022 17:56:16 -0500 Received: from mail-pf1-x441.google.com (mail-pf1-x441.google.com [IPv6:2607:f8b0:4864:20::441]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1E3B3657D3 for ; Thu, 17 Nov 2022 14:56:13 -0800 (PST) Received: by mail-pf1-x441.google.com with SMTP id b29so3172751pfp.13 for ; Thu, 17 Nov 2022 14:56:13 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=DPomuiw38Tc36JRhHYvhQJpHAo45CMYZVjWlALJ2I00=; b=jCXmre/Cdccl+ibrThBtWFk4fv0CZ8yAN1rRMvOm9RSUvBTu0ofgAg3ahjkwA/jc4x 4zSL1CsG97gfWqzxHe0LbQ4iczgGk9BmdKlruQE4qaGczzG5b+t+B3WHhbiFOWAVuQjS LwaxBh1YIQ9/JCMZEOMsVGiaDn4Rt58ohbqC7Ux23yVNhGjn2pZLVVCcvWau9v40PX6K RuuxsFSGTxMP+A0by1ES2xJlvcZftKKju+9STEAFjQWZMk/21VvZHBWFBw8JlGANtNeN ho2Cu/zohC8HsGxzOlFZbAJwTkXkYTDEvX4H5sJ7CK5Qt4FrW1iUXP9/YG1papw8q+Z9 VYug== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=DPomuiw38Tc36JRhHYvhQJpHAo45CMYZVjWlALJ2I00=; b=Q0x2MNRBuFT5hrmBCFk9eCc8cOSp7g/ptSjQlJDm9En9yQQCTai7MfBVmpaiYWGu4g EA+VfaBEpfXiAc49ceXO6gXw6Xm6aS8X+Mo/wNaaBNH0btUxArewxwHL5ZX7ZMTlqiEP dABKkmy5FrkS9PIg84Vf0Jce+xxm53MhUrFwngTqHP+xyCqXg8XOFUoOmvcJN8YSP+Ms HFVD3kgniJdwI4UQKGFD38pR6IL+VZICmjOThwGQ0r7LktX8uM7Q1SNrWYtFhFK8rABQ /hJcEQr8AFQjfjUzMhvtXGtTcdMR0JnYu3qaxhOiWu/Sj6GsHYVOie5UhNsT4Nrg5VQU PbXg== X-Gm-Message-State: ANoB5pmX6YRRNjP+mk330ATdG31MfqbQeHdOd5a0Kj5CaPy345i1CWvi rTjoTrbKrzq6xIG893BHA8sthvQxP5Y= X-Google-Smtp-Source: AA0mqf4xkenl+pR46635D3VWiUO4FbSFo1C6RiNfmaJ0H3aBiKa73WvNFpfh7Euw+lNYrHuwqGH1rg== X-Received: by 2002:a63:d741:0:b0:457:f843:ffcd with SMTP id w1-20020a63d741000000b00457f843ffcdmr4106613pgi.101.1668725772366; Thu, 17 Nov 2022 14:56:12 -0800 (PST) Received: from localhost ([2409:40f4:8:955c:5484:8048:c08:7b3]) by smtp.gmail.com with ESMTPSA id i6-20020a626d06000000b00572275e68f8sm1659190pfc.166.2022.11.17.14.56.11 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 17 Nov 2022 14:56:12 -0800 (PST) From: Kumar Kartikeya Dwivedi To: bpf@vger.kernel.org Cc: Alexei Starovoitov , Andrii Nakryiko , Daniel Borkmann , Martin KaFai Lau , Dave Marchevsky Subject: [PATCH bpf-next v9 15/23] bpf: Permit NULL checking pointer with non-zero fixed offset Date: Fri, 18 Nov 2022 04:25:02 +0530 Message-Id: <20221117225510.1676785-16-memxor@gmail.com> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20221117225510.1676785-1-memxor@gmail.com> References: <20221117225510.1676785-1-memxor@gmail.com> MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=2422; i=memxor@gmail.com; h=from:subject; bh=24iLGg5VsnwmsvtaAeQ9jk4cZGNEIECN8xis7P+9mPQ=; b=owEBbQKS/ZANAwAIAUzgyIZIvxHKAcsmYgBjdrkc+mohHswfHDzYNGMTg+MLWeTNlIOxWTD6wKYO D3uPfdGJAjMEAAEIAB0WIQRLvip+Buz51YI8YRFM4MiGSL8RygUCY3a5HAAKCRBM4MiGSL8RygUbD/ 9wOVyivjJwrY1UMdpWeJEmPAr6JLmujgPSVTNUSAJIDAyd0l74jYYsSe4a2zTn5tQf1BaHktsP9KYz U7maV2CuoxHT2IxHzl11HhR4O4HuNfGB0TId685o8qOBDgidih6wioXHFmkvTmxBIRDhTOorimgNV5 QNN+jgMWTdwm8XtEswAZ3MDxCUIgPk5867HrFixS2zgfxdbqxTMxM7tBn09zk+dKSxMJt7ralVOmH7 4vNxdDG2w/65fzIwljH5oe0OVE8vOoejVJRPxLawlw76/QczJLu5Sjs+USB0a8NJYqTK/LfkwyIqKd yIeYKUVfCLJLkApf9Nzy42OkLkceOmd+2+gsvCleVifTId2Lem9v347HbfE8GgZA/c+NLa2+8pwiae poeWAhEDExOkfYi9bQnvXDvWI0PH5JEwb8rIRbhq/BLLGYO4duVqkN1myMBvlOtstq9aEB0WZd9Sql JQ7l9FrQyoa+MCmKhMyzdQDhhrPIvwEquCYhdJ02wX0eCMYV/ev7A8L2iHbXGtDxLVdDxY2J3YOyGg uOdQ1ufsTxEP4+YyvOxEHEH01cQhQbyVxQYv0Q20Y6eEYW6CR6ni/DkX6izNV7HvWLuVzFUe4WnGJw sitk5BKvAN0Uaa3ForvwScc9pkICnXzmUPUQFtWPT4Pa/uqkCsuzaGO2pktQ== X-Developer-Key: i=memxor@gmail.com; a=openpgp; fpr=4BBE2A7E06ECF9D5823C61114CE0C88648BF11CA Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net Pointer increment on seeing PTR_MAYBE_NULL is already protected against, hence make an exception for PTR_TO_BTF_ID | MEM_ALLOC while still keeping the warning for other unintended cases that might creep in. bpf_list_pop_{front,_back} helpers planned to be introduced in next commit will return a MEM_ALLOC register with incremented offset pointing to bpf_list_node field. The user is supposed to then obtain the pointer to the entry using container_of after NULL checking it. The current restrictions trigger a warning when doing the NULL checking. Revisiting the reason, it is meant as an assertion which seems to actually work and catch the bad case. Hence, under no other circumstances can reg->off be non-zero for a register that has the PTR_MAYBE_NULL type flag set. Signed-off-by: Kumar Kartikeya Dwivedi --- kernel/bpf/verifier.c | 21 ++++++++++++--------- 1 file changed, 12 insertions(+), 9 deletions(-) diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index b96c525fa413..8951f50ae918 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -10790,16 +10790,19 @@ static void mark_ptr_or_null_reg(struct bpf_func_state *state, { if (type_may_be_null(reg->type) && reg->id == id && !WARN_ON_ONCE(!reg->id)) { - if (WARN_ON_ONCE(reg->smin_value || reg->smax_value || - !tnum_equals_const(reg->var_off, 0) || - reg->off)) { - /* Old offset (both fixed and variable parts) should - * have been known-zero, because we don't allow pointer - * arithmetic on pointers that might be NULL. If we - * see this happening, don't convert the register. - */ + /* Old offset (both fixed and variable parts) should have been + * known-zero, because we don't allow pointer arithmetic on + * pointers that might be NULL. If we see this happening, don't + * convert the register. + * + * But in some cases, some helpers that return local kptrs + * advance offset for the returned pointer. In those cases, it + * is fine to expect to see reg->off. + */ + if (WARN_ON_ONCE(reg->smin_value || reg->smax_value || !tnum_equals_const(reg->var_off, 0))) + return; + if (reg->type != (PTR_TO_BTF_ID | MEM_ALLOC | PTR_MAYBE_NULL) && WARN_ON_ONCE(reg->off)) return; - } if (is_null) { reg->type = SCALAR_VALUE; /* We don't need id and ref_obj_id from this point From patchwork Thu Nov 17 22:55:03 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kumar Kartikeya Dwivedi X-Patchwork-Id: 13047441 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A6593C433FE for ; Thu, 17 Nov 2022 22:56:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235033AbiKQW4U (ORCPT ); Thu, 17 Nov 2022 17:56:20 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53712 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235006AbiKQW4S (ORCPT ); Thu, 17 Nov 2022 17:56:18 -0500 Received: from mail-pg1-x544.google.com (mail-pg1-x544.google.com [IPv6:2607:f8b0:4864:20::544]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BBEF42B24F for ; Thu, 17 Nov 2022 14:56:16 -0800 (PST) Received: by mail-pg1-x544.google.com with SMTP id 6so3430664pgm.6 for ; Thu, 17 Nov 2022 14:56:16 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=TQuWhFjvFY07s9GPcnp6vIVMUlfxXkhG5xffKSuwok0=; b=b66Gn1/IHZDivh15xJR3OV8y/nbRgjJlJIO6nucfAFVBnX9fIzJOxQooI0vb9ZnUTN SS5Lo0T+gfuPgaptwhpG90bf6Vpjau5KsVEya6+zwit4A5ZrNyhj0n2DylT/Rhswz3i9 8TfPa7KAQF1ohXbMlxVlbWe1ClutglUu3vMitVbDBPBIubl0FMY1AGHk+6FZ2i6iwKkT XKz8KX5hCrswv+JTfMi9in/xDESw8zIiH/uHpQrX862/rJLALUHpXleBz6klJflyLJNI UH64/8qO00NS/9iCYnIEKlv21tioj7hgg+GpC/GFC/b95F3D0DzP9eiJF8CyL26UmPXi /uvQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=TQuWhFjvFY07s9GPcnp6vIVMUlfxXkhG5xffKSuwok0=; b=Xdrhu5VNwqSHI7mtC9asKi/HINj/Asb2qhTyr+SJYTF2Pn3paA5wX5mLvZ+oLezkLz c4gNg3mdYtW68jzyYQRSwjG7fkPx1KGN5Y2pioT+2RnimP4NSEC/xncg8e5GdXIpvnCE WFoETCjYybfEjZo1AalHCSQpyQJM1jzGl7SrN6wnPZKLw0ckh3bFi2FeSYO3KqSZUbkL KbQaOohadE2IrFXXPz9FF4GFBBAqn54VsMd4ANsRx1LERU1D3kH9TOcmalxKyQgLH+NU coYGb0zdnCz/DHyWJCBg2BjWBLvW7GXRKdI4dnEp6j4Y1AeUuz68vvmmVrbL0v6UW2W5 ZEIA== X-Gm-Message-State: ANoB5pkpuAhTg/nhzl3Yd/7mUb9oOdTVF+5i9Xd0lM0GF7e3O/YLx/dk gV0Pf+TPlai4iZJ1lhjcMhnqeqXcOB8= X-Google-Smtp-Source: AA0mqf7KiE9X0bMwT5qbrDDP+oi2ztD3ZCQhO57Qe5RZGTsl05tAZ/Nlio2uAU2Ra1ry/tvty9K+VA== X-Received: by 2002:a63:4302:0:b0:439:3ca0:5a29 with SMTP id q2-20020a634302000000b004393ca05a29mr4030290pga.443.1668725775854; Thu, 17 Nov 2022 14:56:15 -0800 (PST) Received: from localhost ([2409:40f4:8:955c:5484:8048:c08:7b3]) by smtp.gmail.com with ESMTPSA id p188-20020a625bc5000000b0056e32a2b88esm1630666pfb.219.2022.11.17.14.56.14 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 17 Nov 2022 14:56:15 -0800 (PST) From: Kumar Kartikeya Dwivedi To: bpf@vger.kernel.org Cc: Alexei Starovoitov , Andrii Nakryiko , Daniel Borkmann , Martin KaFai Lau , Dave Marchevsky Subject: [PATCH bpf-next v9 16/23] bpf: Introduce single ownership BPF linked list API Date: Fri, 18 Nov 2022 04:25:03 +0530 Message-Id: <20221117225510.1676785-17-memxor@gmail.com> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20221117225510.1676785-1-memxor@gmail.com> References: <20221117225510.1676785-1-memxor@gmail.com> MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=20750; i=memxor@gmail.com; h=from:subject; bh=k8OCyiQgiqJQUDaWcUfSw1vhCELcdXhsAVkU6y0W7lY=; b=owEBbQKS/ZANAwAIAUzgyIZIvxHKAcsmYgBjdrkcv67g/aH8WkAmkUL/NlCiZZR8wHR8DI0KYRDh JGDCy42JAjMEAAEIAB0WIQRLvip+Buz51YI8YRFM4MiGSL8RygUCY3a5HAAKCRBM4MiGSL8RykM5D/ 9zGTL+WLXwDWxyoR36vFTyIdjkdNbGNympP8+oq6Hw9OkTsGz+YB3e9DD7/17ZLnQ8t4wQgKKCCJMz FIJVLUOpYcjboeAb3lYxqTEeShmf9LJY2yT1wi/Eq6WYh8/5ZfnxbNjscQpCaOaSiK8CKu2/n3IUPA gYKR3Qy58uRxCUEIJT4YuyEq+l858iSjaFbK74P18nHBH2lfvHNrQXI2uMJ5FZB04Tx4omyUVfVGMp 97z0cUg6Rlg97lb3cRxSBEHjoX/fNP0KXSji8DXwr/yZliSV8c7KvKIUE8OgWbbxUErDJlcO7zgL/h mFjvNAkJTqDnnZyqOWCytgzb7dcrvJq/EsvAIkIOoDlyBhdEzL0qb2Es3ZzQKKdKwDCT/Xno4Rt1kS cjUyThS923js1jr+9MfBbefqgEkCzN9ahw8p6Pb8TvWxMIgrbda54d7PZSdB8geohfERCHj8qH1CWY ZSDNDKY+XQ3IbjPPqfpIcO7R26SCSWMZyy9U+h4afrItLTdltiXS8rmasqXqxglMM1/y2qRoY2K3ly khjpajo32Br2MjIJM67Fqh3eI53vh3cNO9kPqBZQnhSBPiYkhIYrq0dPJT04d62bYdTWc14TriHU3K 1DW8tpp2eYSwJxhrcMe1I2hLSlK+Db318DilIixy31SgPpvoQA2MQZ77iCyQ== X-Developer-Key: i=memxor@gmail.com; a=openpgp; fpr=4BBE2A7E06ECF9D5823C61114CE0C88648BF11CA Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net Add a linked list API for use in BPF programs, where it expects protection from the bpf_spin_lock in the same allocation as the bpf_list_head. For now, only one bpf_spin_lock can be present hence that is assumed to be the one protecting the bpf_list_head. The following functions are added to kick things off: // Add node to beginning of list void bpf_list_push_front(struct bpf_list_head *head, struct bpf_list_node *node); // Add node to end of list void bpf_list_push_back(struct bpf_list_head *head, struct bpf_list_node *node); // Remove node at beginning of list and return it struct bpf_list_node *bpf_list_pop_front(struct bpf_list_head *head); // Remove node at end of list and return it struct bpf_list_node *bpf_list_pop_back(struct bpf_list_head *head); The lock protecting the bpf_list_head needs to be taken for all operations. The verifier ensures that the lock that needs to be taken is always held, and only the correct lock is taken for these operations. These checks are made statically by relying on the reg->id preserved for registers pointing into regions having both bpf_spin_lock and the objects protected by it. The comment over check_reg_allocation_locked in this change describes the logic in detail. Note that bpf_list_push_front and bpf_list_push_back are meant to consume the object containing the node in the 1st argument, however that specific mechanism is intended to not release the ref_obj_id directly until the bpf_spin_unlock is called. In this commit, nothing is done, but the next commit will be introducing logic to handle this case, so it has been left as is for now. bpf_list_pop_front and bpf_list_pop_back delete the first or last item of the list respectively, and return pointer to the element at the list_node offset. The user can then use container_of style macro to get the actual entry type. The verifier however statically knows the actual type, so the safety properties are still preserved. With these additions, programs can now manage their own linked lists and store their objects in them. Signed-off-by: Kumar Kartikeya Dwivedi --- kernel/bpf/helpers.c | 55 +++- kernel/bpf/verifier.c | 294 +++++++++++++++++- .../testing/selftests/bpf/bpf_experimental.h | 28 ++ 3 files changed, 368 insertions(+), 9 deletions(-) diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c index 71d803ca0c1d..212e791d7452 100644 --- a/kernel/bpf/helpers.c +++ b/kernel/bpf/helpers.c @@ -1780,6 +1780,50 @@ void bpf_obj_drop_impl(void *p__alloc, void *meta__ign) bpf_mem_free(&bpf_global_ma, p); } +static void __bpf_list_add(struct bpf_list_node *node, struct bpf_list_head *head, bool tail) +{ + struct list_head *n = (void *)node, *h = (void *)head; + + if (unlikely(!h->next)) + INIT_LIST_HEAD(h); + if (unlikely(!n->next)) + INIT_LIST_HEAD(n); + tail ? list_add_tail(n, h) : list_add(n, h); +} + +void bpf_list_push_front(struct bpf_list_head *head, struct bpf_list_node *node) +{ + return __bpf_list_add(node, head, false); +} + +void bpf_list_push_back(struct bpf_list_head *head, struct bpf_list_node *node) +{ + return __bpf_list_add(node, head, true); +} + +static struct bpf_list_node *__bpf_list_del(struct bpf_list_head *head, bool tail) +{ + struct list_head *n, *h = (void *)head; + + if (unlikely(!h->next)) + INIT_LIST_HEAD(h); + if (list_empty(h)) + return NULL; + n = tail ? h->prev : h->next; + list_del_init(n); + return (struct bpf_list_node *)n; +} + +struct bpf_list_node *bpf_list_pop_front(struct bpf_list_head *head) +{ + return __bpf_list_del(head, false); +} + +struct bpf_list_node *bpf_list_pop_back(struct bpf_list_head *head) +{ + return __bpf_list_del(head, true); +} + __diag_pop(); BTF_SET8_START(generic_btf_ids) @@ -1788,6 +1832,10 @@ BTF_ID_FLAGS(func, crash_kexec, KF_DESTRUCTIVE) #endif BTF_ID_FLAGS(func, bpf_obj_new_impl, KF_ACQUIRE | KF_RET_NULL) BTF_ID_FLAGS(func, bpf_obj_drop_impl, KF_RELEASE) +BTF_ID_FLAGS(func, bpf_list_push_front) +BTF_ID_FLAGS(func, bpf_list_push_back) +BTF_ID_FLAGS(func, bpf_list_pop_front, KF_ACQUIRE | KF_RET_NULL) +BTF_ID_FLAGS(func, bpf_list_pop_back, KF_ACQUIRE | KF_RET_NULL) BTF_SET8_END(generic_btf_ids) static const struct btf_kfunc_id_set generic_kfunc_set = { @@ -1797,7 +1845,12 @@ static const struct btf_kfunc_id_set generic_kfunc_set = { static int __init kfunc_init(void) { - return register_btf_kfunc_id_set(BPF_PROG_TYPE_TRACING, &generic_kfunc_set); + int ret; + + ret = register_btf_kfunc_id_set(BPF_PROG_TYPE_TRACING, &generic_kfunc_set); + if (ret) + return ret; + return register_btf_kfunc_id_set(BPF_PROG_TYPE_SCHED_CLS, &generic_kfunc_set); } late_initcall(kfunc_init); diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 8951f50ae918..32e0fde49324 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -7882,6 +7882,9 @@ struct bpf_kfunc_call_arg_meta { struct btf *btf; u32 btf_id; } arg_obj_drop; + struct { + struct btf_field *field; + } arg_list_head; }; static bool is_kfunc_acquire(struct bpf_kfunc_call_arg_meta *meta) @@ -7986,13 +7989,17 @@ static bool is_kfunc_arg_scalar_with_name(const struct btf *btf, enum { KF_ARG_DYNPTR_ID, + KF_ARG_LIST_HEAD_ID, + KF_ARG_LIST_NODE_ID, }; BTF_ID_LIST(kf_arg_btf_ids) BTF_ID(struct, bpf_dynptr_kern) +BTF_ID(struct, bpf_list_head) +BTF_ID(struct, bpf_list_node) -static bool is_kfunc_arg_dynptr(const struct btf *btf, - const struct btf_param *arg) +static bool __is_kfunc_ptr_arg_type(const struct btf *btf, + const struct btf_param *arg, int type) { const struct btf_type *t; u32 res_id; @@ -8005,7 +8012,22 @@ static bool is_kfunc_arg_dynptr(const struct btf *btf, t = btf_type_skip_modifiers(btf, t->type, &res_id); if (!t) return false; - return btf_types_are_same(btf, res_id, btf_vmlinux, kf_arg_btf_ids[KF_ARG_DYNPTR_ID]); + return btf_types_are_same(btf, res_id, btf_vmlinux, kf_arg_btf_ids[type]); +} + +static bool is_kfunc_arg_dynptr(const struct btf *btf, const struct btf_param *arg) +{ + return __is_kfunc_ptr_arg_type(btf, arg, KF_ARG_DYNPTR_ID); +} + +static bool is_kfunc_arg_list_head(const struct btf *btf, const struct btf_param *arg) +{ + return __is_kfunc_ptr_arg_type(btf, arg, KF_ARG_LIST_HEAD_ID); +} + +static bool is_kfunc_arg_list_node(const struct btf *btf, const struct btf_param *arg) +{ + return __is_kfunc_ptr_arg_type(btf, arg, KF_ARG_LIST_NODE_ID); } /* Returns true if struct is composed of scalars, 4 levels of nesting allowed */ @@ -8062,6 +8084,8 @@ enum kfunc_ptr_arg_type { KF_ARG_PTR_TO_ALLOC_BTF_ID, /* Allocated object */ KF_ARG_PTR_TO_KPTR, /* PTR_TO_KPTR but type specific */ KF_ARG_PTR_TO_DYNPTR, + KF_ARG_PTR_TO_LIST_HEAD, + KF_ARG_PTR_TO_LIST_NODE, KF_ARG_PTR_TO_BTF_ID, /* Also covers reg2btf_ids conversions */ KF_ARG_PTR_TO_MEM, KF_ARG_PTR_TO_MEM_SIZE, /* Size derived from next argument, skip it */ @@ -8070,16 +8094,28 @@ enum kfunc_ptr_arg_type { enum special_kfunc_type { KF_bpf_obj_new_impl, KF_bpf_obj_drop_impl, + KF_bpf_list_push_front, + KF_bpf_list_push_back, + KF_bpf_list_pop_front, + KF_bpf_list_pop_back, }; BTF_SET_START(special_kfunc_set) BTF_ID(func, bpf_obj_new_impl) BTF_ID(func, bpf_obj_drop_impl) +BTF_ID(func, bpf_list_push_front) +BTF_ID(func, bpf_list_push_back) +BTF_ID(func, bpf_list_pop_front) +BTF_ID(func, bpf_list_pop_back) BTF_SET_END(special_kfunc_set) BTF_ID_LIST(special_kfunc_list) BTF_ID(func, bpf_obj_new_impl) BTF_ID(func, bpf_obj_drop_impl) +BTF_ID(func, bpf_list_push_front) +BTF_ID(func, bpf_list_push_back) +BTF_ID(func, bpf_list_pop_front) +BTF_ID(func, bpf_list_pop_back) static enum kfunc_ptr_arg_type get_kfunc_ptr_arg_type(struct bpf_verifier_env *env, @@ -8122,6 +8158,12 @@ get_kfunc_ptr_arg_type(struct bpf_verifier_env *env, if (is_kfunc_arg_dynptr(meta->btf, &args[argno])) return KF_ARG_PTR_TO_DYNPTR; + if (is_kfunc_arg_list_head(meta->btf, &args[argno])) + return KF_ARG_PTR_TO_LIST_HEAD; + + if (is_kfunc_arg_list_node(meta->btf, &args[argno])) + return KF_ARG_PTR_TO_LIST_NODE; + if ((base_type(reg->type) == PTR_TO_BTF_ID || reg2btf_ids[base_type(reg->type)])) { if (!btf_type_is_struct(ref_t)) { verbose(env, "kernel function %s args#%d pointer type %s %s is not supported\n", @@ -8217,6 +8259,201 @@ static int process_kf_arg_ptr_to_kptr_strong(struct bpf_verifier_env *env, return 0; } +/* Implementation details: + * + * Each register points to some region of memory, which we define as an + * allocation. Each allocation may embed a bpf_spin_lock which protects any + * special BPF objects (bpf_list_head, bpf_rb_root, etc.) part of the same + * allocation. The lock and the data it protects are colocated in the same + * memory region. + * + * Hence, everytime a register holds a pointer value pointing to such + * allocation, the verifier preserves a unique reg->id for it. + * + * The verifier remembers the lock 'ptr' and the lock 'id' whenever + * bpf_spin_lock is called. + * + * To enable this, lock state in the verifier captures two values: + * active_lock.ptr = Register's type specific pointer + * active_lock.id = A unique ID for each register pointer value + * + * Currently, PTR_TO_MAP_VALUE and PTR_TO_BTF_ID | MEM_ALLOC are the two + * supported register types. + * + * The active_lock.ptr in case of map values is the reg->map_ptr, and in case of + * allocated objects is the reg->btf pointer. + * + * The active_lock.id is non-unique for maps supporting direct_value_addr, as we + * can establish the provenance of the map value statically for each distinct + * lookup into such maps. They always contain a single map value hence unique + * IDs for each pseudo load pessimizes the algorithm and rejects valid programs. + * + * So, in case of global variables, they use array maps with max_entries = 1, + * hence their active_lock.ptr becomes map_ptr and id = 0 (since they all point + * into the same map value as max_entries is 1, as described above). + * + * In case of inner map lookups, the inner map pointer has same map_ptr as the + * outer map pointer (in verifier context), but each lookup into an inner map + * assigns a fresh reg->id to the lookup, so while lookups into distinct inner + * maps from the same outer map share the same map_ptr as active_lock.ptr, they + * will get different reg->id assigned to each lookup, hence different + * active_lock.id. + * + * In case of allocated objects, active_lock.ptr is the reg->btf, and the + * reg->id is a unique ID preserved after the NULL pointer check on the pointer + * returned from bpf_obj_new. Each allocation receives a new reg->id. + */ +static int check_reg_allocation_locked(struct bpf_verifier_env *env, struct bpf_reg_state *reg) +{ + void *ptr; + u32 id; + + switch ((int)reg->type) { + case PTR_TO_MAP_VALUE: + ptr = reg->map_ptr; + break; + case PTR_TO_BTF_ID | MEM_ALLOC: + ptr = reg->btf; + break; + default: + verbose(env, "verifier internal error: unknown reg type for lock check\n"); + return -EFAULT; + } + id = reg->id; + + if (!env->cur_state->active_lock.ptr) + return -EINVAL; + if (env->cur_state->active_lock.ptr != ptr || + env->cur_state->active_lock.id != id) { + verbose(env, "held lock and object are not in the same allocation\n"); + return -EINVAL; + } + return 0; +} + +static bool is_bpf_list_api_kfunc(u32 btf_id) +{ + return btf_id == special_kfunc_list[KF_bpf_list_push_front] || + btf_id == special_kfunc_list[KF_bpf_list_push_back] || + btf_id == special_kfunc_list[KF_bpf_list_pop_front] || + btf_id == special_kfunc_list[KF_bpf_list_pop_back]; +} + +static int process_kf_arg_ptr_to_list_head(struct bpf_verifier_env *env, + struct bpf_reg_state *reg, u32 regno, + struct bpf_kfunc_call_arg_meta *meta) +{ + struct btf_record *rec = NULL; + struct btf_field *field; + u32 list_head_off; + + if (meta->btf != btf_vmlinux || !is_bpf_list_api_kfunc(meta->func_id)) { + verbose(env, "verifier internal error: bpf_list_head argument for unknown kfunc\n"); + return -EFAULT; + } + + if (reg->type == PTR_TO_MAP_VALUE) { + rec = reg->map_ptr->record; + } else /* PTR_TO_BTF_ID | MEM_ALLOC */ { + struct btf_struct_meta *meta; + + meta = btf_find_struct_meta(reg->btf, reg->btf_id); + if (!meta) { + verbose(env, "bpf_list_head not found for allocated object\n"); + return -EINVAL; + } + rec = meta->record; + } + + if (!tnum_is_const(reg->var_off)) { + verbose(env, + "R%d doesn't have constant offset. bpf_list_head has to be at the constant offset\n", + regno); + return -EINVAL; + } + + list_head_off = reg->off + reg->var_off.value; + field = btf_record_find(rec, list_head_off, BPF_LIST_HEAD); + if (!field) { + verbose(env, "bpf_list_head not found at offset=%u\n", list_head_off); + return -EINVAL; + } + + /* All functions require bpf_list_head to be protected using a bpf_spin_lock */ + if (check_reg_allocation_locked(env, reg)) { + verbose(env, "bpf_spin_lock at off=%d must be held for bpf_list_head\n", + rec->spin_lock_off); + return -EINVAL; + } + + if (meta->arg_list_head.field) { + verbose(env, "verifier internal error: repeating bpf_list_head arg\n"); + return -EFAULT; + } + meta->arg_list_head.field = field; + return 0; +} + +static int process_kf_arg_ptr_to_list_node(struct bpf_verifier_env *env, + struct bpf_reg_state *reg, u32 regno, + struct bpf_kfunc_call_arg_meta *meta) +{ + struct btf_struct_meta *struct_meta; + const struct btf_type *et, *t; + struct btf_field *field; + struct btf_record *rec; + u32 list_node_off; + + if (meta->btf != btf_vmlinux || + (meta->func_id != special_kfunc_list[KF_bpf_list_push_front] && + meta->func_id != special_kfunc_list[KF_bpf_list_push_back])) { + verbose(env, "verifier internal error: bpf_list_node argument for unknown kfunc\n"); + return -EFAULT; + } + + if (!tnum_is_const(reg->var_off)) { + verbose(env, + "R%d doesn't have constant offset. bpf_list_node has to be at the constant offset\n", + regno); + return -EINVAL; + } + + struct_meta = btf_find_struct_meta(reg->btf, reg->btf_id); + if (!struct_meta) { + verbose(env, "bpf_list_node not found for allocated object\n"); + return -EINVAL; + } + rec = struct_meta->record; + + list_node_off = reg->off + reg->var_off.value; + field = btf_record_find(rec, list_node_off, BPF_LIST_NODE); + if (!field || field->offset != list_node_off) { + verbose(env, "bpf_list_node not found at offset=%u\n", list_node_off); + return -EINVAL; + } + + field = meta->arg_list_head.field; + + et = btf_type_by_id(field->list_head.btf, field->list_head.value_btf_id); + t = btf_type_by_id(reg->btf, reg->btf_id); + if (!btf_struct_ids_match(&env->log, reg->btf, reg->btf_id, 0, field->list_head.btf, + field->list_head.value_btf_id, true)) { + verbose(env, "operation on bpf_list_head expects arg#1 bpf_list_node at offset=%d " + "in struct %s, but arg is at offset=%d in struct %s\n", + field->list_head.node_offset, btf_name_by_offset(field->list_head.btf, et->name_off), + list_node_off, btf_name_by_offset(reg->btf, t->name_off)); + return -EINVAL; + } + + if (list_node_off != field->list_head.node_offset) { + verbose(env, "arg#1 offset=%d, but expected bpf_list_node at offset=%d in struct %s\n", + list_node_off, field->list_head.node_offset, + btf_name_by_offset(field->list_head.btf, et->name_off)); + return -EINVAL; + } + return 0; +} + static int check_kfunc_args(struct bpf_verifier_env *env, struct bpf_kfunc_call_arg_meta *meta) { const char *func_name = meta->func_name, *ref_tname; @@ -8335,6 +8572,8 @@ static int check_kfunc_args(struct bpf_verifier_env *env, struct bpf_kfunc_call_ break; case KF_ARG_PTR_TO_KPTR: case KF_ARG_PTR_TO_DYNPTR: + case KF_ARG_PTR_TO_LIST_HEAD: + case KF_ARG_PTR_TO_LIST_NODE: case KF_ARG_PTR_TO_MEM: case KF_ARG_PTR_TO_MEM_SIZE: /* Trusted by default */ @@ -8399,6 +8638,33 @@ static int check_kfunc_args(struct bpf_verifier_env *env, struct bpf_kfunc_call_ return -EINVAL; } break; + case KF_ARG_PTR_TO_LIST_HEAD: + if (reg->type != PTR_TO_MAP_VALUE && + reg->type != (PTR_TO_BTF_ID | MEM_ALLOC)) { + verbose(env, "arg#%d expected pointer to map value or allocated object\n", i); + return -EINVAL; + } + if (reg->type == (PTR_TO_BTF_ID | MEM_ALLOC) && !reg->ref_obj_id) { + verbose(env, "allocated object must be referenced\n"); + return -EINVAL; + } + ret = process_kf_arg_ptr_to_list_head(env, reg, regno, meta); + if (ret < 0) + return ret; + break; + case KF_ARG_PTR_TO_LIST_NODE: + if (reg->type != (PTR_TO_BTF_ID | MEM_ALLOC)) { + verbose(env, "arg#%d expected pointer to allocated object\n", i); + return -EINVAL; + } + if (!reg->ref_obj_id) { + verbose(env, "allocated object must be referenced\n"); + return -EINVAL; + } + ret = process_kf_arg_ptr_to_list_node(env, reg, regno, meta); + if (ret < 0) + return ret; + break; case KF_ARG_PTR_TO_BTF_ID: /* Only base_type is checked, further checks are done here */ if (reg->type != PTR_TO_BTF_ID && @@ -8567,6 +8833,15 @@ static int check_kfunc_call(struct bpf_verifier_env *env, struct bpf_insn *insn, env->insn_aux_data[insn_idx].kptr_struct_meta = btf_find_struct_meta(meta.arg_obj_drop.btf, meta.arg_obj_drop.btf_id); + } else if (meta.func_id == special_kfunc_list[KF_bpf_list_pop_front] || + meta.func_id == special_kfunc_list[KF_bpf_list_pop_back]) { + struct btf_field *field = meta.arg_list_head.field; + + mark_reg_known_zero(env, regs, BPF_REG_0); + regs[BPF_REG_0].type = PTR_TO_BTF_ID | MEM_ALLOC; + regs[BPF_REG_0].btf = field->list_head.btf; + regs[BPF_REG_0].btf_id = field->list_head.value_btf_id; + regs[BPF_REG_0].off = field->list_head.node_offset; } else { verbose(env, "kernel function %s unhandled dynamic return type\n", meta.func_name); @@ -13263,11 +13538,14 @@ static int do_check(struct bpf_verifier_env *env) return -EINVAL; } - if (env->cur_state->active_lock.ptr && - (insn->src_reg == BPF_PSEUDO_CALL || - insn->imm != BPF_FUNC_spin_unlock)) { - verbose(env, "function calls are not allowed while holding a lock\n"); - return -EINVAL; + if (env->cur_state->active_lock.ptr) { + if ((insn->src_reg == BPF_REG_0 && insn->imm != BPF_FUNC_spin_unlock) || + (insn->src_reg == BPF_PSEUDO_CALL) || + (insn->src_reg == BPF_PSEUDO_KFUNC_CALL && + (insn->off != 0 || !is_bpf_list_api_kfunc(insn->imm)))) { + verbose(env, "function calls are not allowed while holding a lock\n"); + return -EINVAL; + } } if (insn->src_reg == BPF_PSEUDO_CALL) err = check_func_call(env, insn, &env->insn_idx); diff --git a/tools/testing/selftests/bpf/bpf_experimental.h b/tools/testing/selftests/bpf/bpf_experimental.h index 8473395a11af..d6b143275e82 100644 --- a/tools/testing/selftests/bpf/bpf_experimental.h +++ b/tools/testing/selftests/bpf/bpf_experimental.h @@ -35,4 +35,32 @@ extern void bpf_obj_drop_impl(void *kptr, void *meta) __ksym; /* Convenience macro to wrap over bpf_obj_drop_impl */ #define bpf_obj_drop(kptr) bpf_obj_drop_impl(kptr, NULL) +/* Description + * Add a new entry to the beginning of the BPF linked list. + * Returns + * Void. + */ +extern void bpf_list_push_front(struct bpf_list_head *head, struct bpf_list_node *node) __ksym; + +/* Description + * Add a new entry to the end of the BPF linked list. + * Returns + * Void. + */ +extern void bpf_list_push_back(struct bpf_list_head *head, struct bpf_list_node *node) __ksym; + +/* Description + * Remove the entry at the beginning of the BPF linked list. + * Returns + * Pointer to bpf_list_node of deleted entry, or NULL if list is empty. + */ +extern struct bpf_list_node *bpf_list_pop_front(struct bpf_list_head *head) __ksym; + +/* Description + * Remove the entry at the end of the BPF linked list. + * Returns + * Pointer to bpf_list_node of deleted entry, or NULL if list is empty. + */ +extern struct bpf_list_node *bpf_list_pop_back(struct bpf_list_head *head) __ksym; + #endif From patchwork Thu Nov 17 22:55:04 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kumar Kartikeya Dwivedi X-Patchwork-Id: 13047442 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3018AC4332F for ; Thu, 17 Nov 2022 22:56:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234997AbiKQW4X (ORCPT ); Thu, 17 Nov 2022 17:56:23 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53748 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235089AbiKQW4U (ORCPT ); Thu, 17 Nov 2022 17:56:20 -0500 Received: from mail-pj1-x1044.google.com (mail-pj1-x1044.google.com [IPv6:2607:f8b0:4864:20::1044]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E487C12620 for ; Thu, 17 Nov 2022 14:56:19 -0800 (PST) Received: by mail-pj1-x1044.google.com with SMTP id e7-20020a17090a77c700b00216928a3917so6700511pjs.4 for ; Thu, 17 Nov 2022 14:56:19 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=NCe9djUw60eHZstRoq1NUvEoHYm1TTPCbRO78TsBTdw=; b=fmZFaBy/g7Vtj6rz5NgKnt66rdV5cuUr9gvbNJMnLgUo5SkCBOqawFi6BcEWlDNEdT wBmHoWJy98R6BU66k0KmpnyI+CQJ6W9ejcnF+X9vfvk09EQ6Wd2FL42N3H6sfNqindUU iGK5BkMpLFCkyyeIwD4CIacbjzFBA4BOaua4YrPPJj+wJxQbglxhb2yC7SNgrmC/n1wB mmjJT/CB+w/abaS0LPK5Rd4jL6YZVnI8YYaqR/uBq/cbMWZpgYlA2exOUgoyCHZz59/G 7uKymbtcAUV6MPW5n6CZmB6VSb4KZOHdfuwl0naUp6EOUES7B1S0PCqnRGzQT8wGYxEM vMhA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=NCe9djUw60eHZstRoq1NUvEoHYm1TTPCbRO78TsBTdw=; b=NDps77jp65kf5K/zBaBnD0C5IeycOC7NOeK3zJnhW1D9flla+W5vjT03JLvNu2dcic 6EhDJuMWDkiKf4KCuy7+hioAO12KSkv6OH7yKw4yMUvtqmAL2mWgfkDExA1pRE9JO/iM nTKA3HEvELj3UjKve9l3IR9yjNB08p/GRbgwpypA1jOEoTVKWTc/JHZ2J7PIAftzVxUS 6/1A5r69U6IZ+lobw/fNKDd6eGyPgArKeRJKG1Tdw0n+cImMbCM0cic5YqUdMaovVG+a ER/Dp5a7K2hphThkYII133QnOT7pQg/TsiV3VKyy3xSES106GArr2O8cgbRRg84YqxVP b20A== X-Gm-Message-State: ANoB5pkkJsa7fp8QLhvv31WQiFQTCbvU7DWFX6M0ce7/I2paWWJQ5bkL Ds0MViJi+9gxvk3K7Sc2dY/yWYLUuXk= X-Google-Smtp-Source: AA0mqf46buFN56RImZyqBzkafWRF+u82P7vLc9poemQkplEAeWlKmMAyZW1FZ+3qQuFf0l2oSev30Q== X-Received: by 2002:a17:902:cccf:b0:176:a9d6:ed53 with SMTP id z15-20020a170902cccf00b00176a9d6ed53mr4710227ple.5.1668725779154; Thu, 17 Nov 2022 14:56:19 -0800 (PST) Received: from localhost ([2409:40f4:8:955c:5484:8048:c08:7b3]) by smtp.gmail.com with ESMTPSA id s184-20020a625ec1000000b0056ba7ce4d5asm1701172pfb.52.2022.11.17.14.56.18 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 17 Nov 2022 14:56:18 -0800 (PST) From: Kumar Kartikeya Dwivedi To: bpf@vger.kernel.org Cc: Dave Marchevsky , Alexei Starovoitov , Andrii Nakryiko , Daniel Borkmann , Martin KaFai Lau , Dave Marchevsky Subject: [PATCH bpf-next v9 17/23] bpf: Add 'release on unlock' logic for bpf_list_push_{front,back} Date: Fri, 18 Nov 2022 04:25:04 +0530 Message-Id: <20221117225510.1676785-18-memxor@gmail.com> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20221117225510.1676785-1-memxor@gmail.com> References: <20221117225510.1676785-1-memxor@gmail.com> MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=5501; i=memxor@gmail.com; h=from:subject; bh=YeqY7VpClPfaIo+bGh7Dtptyk2S4lBG8jMP3+XG0/gg=; b=owEBbQKS/ZANAwAIAUzgyIZIvxHKAcsmYgBjdrkcBExM59l0RgwVIa2AJIWmY3el4dZsFU8h6/l0 +GtH9gmJAjMEAAEIAB0WIQRLvip+Buz51YI8YRFM4MiGSL8RygUCY3a5HAAKCRBM4MiGSL8RyjteD/ 9Mxhg4i5fjKsnh21o/mU/fYNH8INbp07gfKJMrsadUezMjCrn292Xp8u1swsyMdDF4zLtrUi7G/ulw tTis9uMwWUWFdr+7K375P3IgzTH9vy8Qr919lvXJVs2Dhftwg78u5nV9B9v3+eypPSBvYh0qLIHMqU 80Lr6GlcLQFDfggP32dsDvnruahyWhl7lEICduOcoWAmBAjPGOQ4dfKWW1UQqCwPcZK6yDwj9TBXNT cnlqOVNHh8xfkqDGOhAXfHM+hy/wS7tzO3GKijHS2S0OTVQ7e9q8WSH+7r8cy0cyU11f1v+cbyVvZ9 qfx23UNzJ6tm+LMj7sGQHCUl+5jaRpxJr2BuwGlMBy+nHz7rWNly++mjy0EoOaAAfZJL/ozFA1ETxY JupnESHasnuQ8WZRRzd/XETZzYIljRE7Bf/R47JjR7xcxsLIVbPvOoSDlDBjcR0TmpUDhW5KhSO+DD cF27N7keyyyyoTQpRO2kOJy7G+hGYujkKihbBDm5Halu7xXoLstuCOerau9nWHpHZLkZE+tJnxUtKj HfUc4Wt4Xw/Y35yErb/milvjLnfsa8RAa09THs9l8nyoN/NOd8YuXJrhHSH8B5m1FyqBvPzH/VNuC9 /RkyNul2KOmF8dE+8Zzd7XRvn4buQdaVmFvzloMI4NgANM52D2c3Qx5E7YxQ== X-Developer-Key: i=memxor@gmail.com; a=openpgp; fpr=4BBE2A7E06ECF9D5823C61114CE0C88648BF11CA Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net This commit implements the delayed release logic for bpf_list_push_front and bpf_list_push_back. Once a node has been added to the list, it's pointer changes to PTR_UNTRUSTED. However, it is only released once the lock protecting the list is unlocked. For such PTR_TO_BTF_ID | MEM_ALLOC with PTR_UNTRUSTED set but an active ref_obj_id, it is still permitted to read them as long as the lock is held. Writing to them is not allowed. This allows having read access to push items we no longer own until we release the lock guarding the list, allowing a little more flexibility when working with these APIs. Note that enabling write support has fairly tricky interactions with what happens inside the critical section. Just as an example, currently, bpf_obj_drop is not permitted, but if it were, being able to write to the PTR_UNTRUSTED pointer while the object gets released back to the memory allocator would violate safety properties we wish to guarantee (i.e. not crashing the kernel). The memory could be reused for a different type in the BPF program or even in the kernel as it gets eventually kfree'd. Not enabling bpf_obj_drop inside the critical section would appear to prevent all of the above, but that is more of an artifical limitation right now. Since the write support is tangled with how we handle potential aliasing of nodes inside the critical section that may or may not be part of the list anymore, it has been deferred to a future patch. Acked-by: Dave Marchevsky Signed-off-by: Kumar Kartikeya Dwivedi --- include/linux/bpf_verifier.h | 5 ++++ kernel/bpf/verifier.c | 58 +++++++++++++++++++++++++++++++++++- 2 files changed, 62 insertions(+), 1 deletion(-) diff --git a/include/linux/bpf_verifier.h b/include/linux/bpf_verifier.h index a159a8ffa716..af2b14a43c1c 100644 --- a/include/linux/bpf_verifier.h +++ b/include/linux/bpf_verifier.h @@ -223,6 +223,11 @@ struct bpf_reference_state { * exiting a callback function. */ int callback_ref; + /* Mark the reference state to release the registers sharing the same id + * on bpf_spin_unlock (for nodes that we will lose ownership to but are + * safe to access inside the critical section). + */ + bool release_on_unlock; }; /* state of the program: diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 32e0fde49324..fd663b5ff6e0 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -5651,7 +5651,9 @@ static int process_spin_lock(struct bpf_verifier_env *env, int regno, cur->active_lock.ptr = btf; cur->active_lock.id = reg->id; } else { + struct bpf_func_state *fstate = cur_func(env); void *ptr; + int i; if (map) ptr = map; @@ -5669,6 +5671,23 @@ static int process_spin_lock(struct bpf_verifier_env *env, int regno, } cur->active_lock.ptr = NULL; cur->active_lock.id = 0; + + for (i = 0; i < fstate->acquired_refs; i++) { + int err; + + /* Complain on error because this reference state cannot + * be freed before this point, as bpf_spin_lock critical + * section does not allow functions that release the + * allocated object immediately. + */ + if (!fstate->refs[i].release_on_unlock) + continue; + err = release_reference(env, fstate->refs[i].id); + if (err) { + verbose(env, "failed to release release_on_unlock reference"); + return err; + } + } } return 0; } @@ -8259,6 +8278,42 @@ static int process_kf_arg_ptr_to_kptr_strong(struct bpf_verifier_env *env, return 0; } +static int ref_set_release_on_unlock(struct bpf_verifier_env *env, u32 ref_obj_id) +{ + struct bpf_func_state *state = cur_func(env); + struct bpf_reg_state *reg; + int i; + + /* bpf_spin_lock only allows calling list_push and list_pop, no BPF + * subprogs, no global functions. This means that the references would + * not be released inside the critical section but they may be added to + * the reference state, and the acquired_refs are never copied out for a + * different frame as BPF to BPF calls don't work in bpf_spin_lock + * critical sections. + */ + if (!ref_obj_id) { + verbose(env, "verifier internal error: ref_obj_id is zero for release_on_unlock\n"); + return -EFAULT; + } + for (i = 0; i < state->acquired_refs; i++) { + if (state->refs[i].id == ref_obj_id) { + if (state->refs[i].release_on_unlock) { + verbose(env, "verifier internal error: expected false release_on_unlock"); + return -EFAULT; + } + state->refs[i].release_on_unlock = true; + /* Now mark everyone sharing same ref_obj_id as untrusted */ + bpf_for_each_reg_in_vstate(env->cur_state, state, reg, ({ + if (reg->ref_obj_id == ref_obj_id) + reg->type |= PTR_UNTRUSTED; + })); + return 0; + } + } + verbose(env, "verifier internal error: ref state missing for ref_obj_id\n"); + return -EFAULT; +} + /* Implementation details: * * Each register points to some region of memory, which we define as an @@ -8451,7 +8506,8 @@ static int process_kf_arg_ptr_to_list_node(struct bpf_verifier_env *env, btf_name_by_offset(field->list_head.btf, et->name_off)); return -EINVAL; } - return 0; + /* Set arg#1 for expiration after unlock */ + return ref_set_release_on_unlock(env, reg->ref_obj_id); } static int check_kfunc_args(struct bpf_verifier_env *env, struct bpf_kfunc_call_arg_meta *meta) From patchwork Thu Nov 17 22:55:05 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kumar Kartikeya Dwivedi X-Patchwork-Id: 13047443 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B0967C43217 for ; Thu, 17 Nov 2022 22:56:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234999AbiKQW4Y (ORCPT ); Thu, 17 Nov 2022 17:56:24 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53822 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235006AbiKQW4X (ORCPT ); Thu, 17 Nov 2022 17:56:23 -0500 Received: from mail-pg1-x541.google.com (mail-pg1-x541.google.com [IPv6:2607:f8b0:4864:20::541]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4306E13E28 for ; Thu, 17 Nov 2022 14:56:23 -0800 (PST) Received: by mail-pg1-x541.google.com with SMTP id q1so3417571pgl.11 for ; Thu, 17 Nov 2022 14:56:23 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=Z+/EQMQ6v6vKQC+cnMv4I7AqJLmOpRFAqknb2KaBufw=; b=e48V6+gU/vIThtAGOEgcwMEyDvj5XVgjRVtnEOXaIqbu33PWscy+irLA98JrLXckrh 08EPT82TWB1iRFcIt697+rHJQ4Z0zDAgnJVGz9Ew5y5Qm0pkwg5HMsaz9p4g2H8i4vaj 13HGhUcT2MQfilNQa2uA3zuFRh97iP++HF7IgHX/ROsKsGD8qQAvNWTAG3LfKEGUULfK q3imQM2uTaXHwhtjEPqvQkHSVuh7KecaeQwJ7vJjJnSrKye/8uZtTZiFkX8aDx6ZU1N6 oHHqkhVcSrPuttWNYMCuTg05BPc7+ZTJxlpFrdKTpMP0V6Qj+EZTLlCoN7ajovmW0vU9 3YPg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=Z+/EQMQ6v6vKQC+cnMv4I7AqJLmOpRFAqknb2KaBufw=; b=1mvzhi0yUYodbzvH6LYDem3G51aefzxCtXzY9NUDNhLf7ZNe2zGQBX0fvTYJlc5baf 1c1WQK0W/LjKcNbmOoHcboe9rhYXcihkpz4wK9kgo5DuYJIdo9DqDKbNXNDaMcuZqTH4 ijdtOLCUTMVWvTLMl/0wgsmheV0XmdJ4TXjs5+cPLD8PuUWxQEp+wCQURCxEML+BEcVR vJTM2zR9QFnMMOPV2/km8EWnHBufSHJfyE44XPY+60k3JmiJAxbPQVXZvCdFhlofdq3A giLOVYzjV16AaeR+AaqiNR6Z45pP8YLz3f9ZHXQV7HEJa/rT2CFKskcAECVU0nTcbJuT dwrQ== X-Gm-Message-State: ANoB5pl02NL9ASEBgs8GJtB0uokMRIjx9TO5/R5eXrU3+9Oyn8XiVhNg RCEbtom+10fy1fPvwL6kjLeMsq9CV0Q= X-Google-Smtp-Source: AA0mqf40zjE+cU9gVPNha2BtcEUkon2X3MxWzW42Phj4KT40bwPwbxWr+NBQEzsM/QHlIAMUymlVSg== X-Received: by 2002:aa7:80d8:0:b0:56d:98e3:4df8 with SMTP id a24-20020aa780d8000000b0056d98e34df8mr4940804pfn.37.1668725782556; Thu, 17 Nov 2022 14:56:22 -0800 (PST) Received: from localhost ([2409:40f4:8:955c:5484:8048:c08:7b3]) by smtp.gmail.com with ESMTPSA id x15-20020aa78f0f000000b0056be4dbd4besm1686151pfr.111.2022.11.17.14.56.21 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 17 Nov 2022 14:56:22 -0800 (PST) From: Kumar Kartikeya Dwivedi To: bpf@vger.kernel.org Cc: Alexei Starovoitov , Andrii Nakryiko , Daniel Borkmann , Martin KaFai Lau , Dave Marchevsky Subject: [PATCH bpf-next v9 18/23] bpf: Add comments for map BTF matching requirement for bpf_list_head Date: Fri, 18 Nov 2022 04:25:05 +0530 Message-Id: <20221117225510.1676785-19-memxor@gmail.com> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20221117225510.1676785-1-memxor@gmail.com> References: <20221117225510.1676785-1-memxor@gmail.com> MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=3823; i=memxor@gmail.com; h=from:subject; bh=8EB7pnYAGpY+fX6VZEMfDdMfcD0meo1AzSNti6SYLes=; b=owEBbQKS/ZANAwAIAUzgyIZIvxHKAcsmYgBjdrkcHYID5GqJxo610atLK42sAOvTsiYCIccpKjAs EXQBal+JAjMEAAEIAB0WIQRLvip+Buz51YI8YRFM4MiGSL8RygUCY3a5HAAKCRBM4MiGSL8Ryq7XEA CSVv3NffGxmL80Clwu6ZiZ4QiYc6ErHRlC7SgSwxLj1iN/2ZttRb+MOxiK5oPSgH9vyWrZnLD7q6jd VsiQXwfjXpBSbvb/T4PQZKXnoJA0HG/74CcTbABvO3XL4HSOc646Oc+0FBBCV67UrDDgl8CgEcaEfG GbbOyVTbt01I3H1SFwQGXqW2h/ei5us8EDIvsFgB9BlG+lUgSgS62694AjJU4AUUh7psNMRDh2Cp5N XIft6O1ObFJw0X6VxCMFTxVOPXZRi++7ooMoOX6XstqM6WFlIM6R/CEBEXF31G7luBMuzieSxYFHUB pWDWaSMwMOPvxgwHYfSZxe0KfmAoqEHxVS8ut9PPUhKSP6eQx4Cl+WpP/UbGs8dxBrmyTUeN3+NHWJ Xm05iE4c42/n6a9b4w3vBBKuOXzalSilwEHcrxwcMkM63zVM+hVtUGn1QWcJVoRWVXtpQX/N5O7TDQ 0ybAdAfisW6FxnWrsqvxdRE/C8cV12PRDZYbVOVtgiGDGKu9o2rLeUDNY1sxkzLt5tphwlqUvH5NZW I4Eh0lLEWliMBWPZBz2EeMh3mqNUwRLIjKTY6hDzjqNsOGNtNM3e3UT3EcxsdXfd2vvzPy5i0DGXLy ruDHnbG33T4ZqVeyiKbs5sTrJIytOo8cURcL3qnfsZW4OX5TEZ8pACiGYplg== X-Developer-Key: i=memxor@gmail.com; a=openpgp; fpr=4BBE2A7E06ECF9D5823C61114CE0C88648BF11CA Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net The old behavior of bpf_map_meta_equal was that it compared timer_off to be equal (but not spin_lock_off, because that was not allowed), and did memcmp of kptr_off_tab. Now, we memcmp the btf_record of two bpf_map structs, which has all fields. We preserve backwards compat as we kzalloc the array, so if only spin lock and timer exist in map, we only compare offset while the rest of unused members in the btf_field struct are zeroed out. In case of kptr, btf and everything else is of vmlinux or module, so as long type is same it will match, since kernel btf, module, dtor pointer will be same across maps. Now with list_head in the mix, things are a bit complicated. We implicitly add a requirement that both BTFs are same, because struct btf_field_list_head has btf and value_rec members. We obviously shouldn't force BTFs to be equal by default, as that breaks backwards compatibility. Currently it is only implicitly required due to list_head matching struct btf and value_rec member. value_rec points back into a btf_record stashed in the map BTF (btf member of btf_field_list_head). So that pointer and btf member has to match exactly. Document all these subtle details so that things don't break in the future when touching this code. Signed-off-by: Kumar Kartikeya Dwivedi --- kernel/bpf/btf.c | 3 +++ kernel/bpf/map_in_map.c | 5 +++++ kernel/bpf/syscall.c | 14 ++++++++++++++ 3 files changed, 22 insertions(+) diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c index 4dcda4ae48c1..f7d5fab61535 100644 --- a/kernel/bpf/btf.c +++ b/kernel/bpf/btf.c @@ -3648,6 +3648,9 @@ struct btf_record *btf_parse_fields(const struct btf *btf, const struct btf_type return NULL; cnt = ret; + /* This needs to be kzalloc to zero out padding and unused fields, see + * comment in btf_record_equal. + */ rec = kzalloc(offsetof(struct btf_record, fields[cnt]), GFP_KERNEL | __GFP_NOWARN); if (!rec) return ERR_PTR(-ENOMEM); diff --git a/kernel/bpf/map_in_map.c b/kernel/bpf/map_in_map.c index 7cce2047c6ef..38136ec4e095 100644 --- a/kernel/bpf/map_in_map.c +++ b/kernel/bpf/map_in_map.c @@ -68,6 +68,11 @@ struct bpf_map *bpf_map_meta_alloc(int inner_map_ufd) } inner_map_meta->field_offs = field_offs; } + /* Note: We must use the same BTF, as we also used btf_record_dup above + * which relies on BTF being same for both maps, as some members like + * record->fields.list_head have pointers like value_rec pointing into + * inner_map->btf. + */ if (inner_map->btf) { btf_get(inner_map->btf); inner_map_meta->btf = inner_map->btf; diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index 6140cbc3ed8a..35972afb6850 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -611,6 +611,20 @@ bool btf_record_equal(const struct btf_record *rec_a, const struct btf_record *r if (rec_a->cnt != rec_b->cnt) return false; size = offsetof(struct btf_record, fields[rec_a->cnt]); + /* btf_parse_fields uses kzalloc to allocate a btf_record, so unused + * members are zeroed out. So memcmp is safe to do without worrying + * about padding/unused fields. + * + * While spin_lock, timer, and kptr have no relation to map BTF, + * list_head metadata is specific to map BTF, the btf and value_rec + * members in particular. btf is the map BTF, while value_rec points to + * btf_record in that map BTF. + * + * So while by default, we don't rely on the map BTF (which the records + * were parsed from) matching for both records, which is not backwards + * compatible, in case list_head is part of it, we implicitly rely on + * that by way of depending on memcmp succeeding for it. + */ return !memcmp(rec_a, rec_b, size); } From patchwork Thu Nov 17 22:55:06 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kumar Kartikeya Dwivedi X-Patchwork-Id: 13047444 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D8B04C4332F for ; Thu, 17 Nov 2022 22:56:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235120AbiKQW42 (ORCPT ); Thu, 17 Nov 2022 17:56:28 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53892 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234959AbiKQW41 (ORCPT ); Thu, 17 Nov 2022 17:56:27 -0500 Received: from mail-pl1-x644.google.com (mail-pl1-x644.google.com [IPv6:2607:f8b0:4864:20::644]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7CDB062CE for ; Thu, 17 Nov 2022 14:56:26 -0800 (PST) Received: by mail-pl1-x644.google.com with SMTP id y10so1804260plp.3 for ; Thu, 17 Nov 2022 14:56:26 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=/bydv3kCbIfnpZJCDWVNSsOM/hEDP+5Rsyiqy1sq5Ic=; b=FXfvG48rfXSGFzoMkxHqRsB3j1PENVIx92Dh1elmyr3wYYARq5m8SOEVICrsJljj7g TMURI3AB/RQkXY7JBSN0d3Q/AauGGeaxXDZ5nlKBFueSluznX7FsynQXM42a+lgMQxGj y/YgY2+/IvBDv+8RJpjayrx7BxULL7Ff6xtDt11iqoU47k9iXSlsIxduafi90ZsW2ohK QI/jaXYvgmP9XlceIdDnkCEKZduca0DJkdJumP88FCsDzqPxH3UdaPAxq3igmFYbOx1+ 8guF7L5FqtPryzPfM0ATUOVGdkRPTfFtR7Jtf/kWy7l5lLZ8v65zbjyQTq2hD6djLcUh LrEA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=/bydv3kCbIfnpZJCDWVNSsOM/hEDP+5Rsyiqy1sq5Ic=; b=Yap7l1czVUqKv7ZTJQBD2rb8vjzwp0rmn8K9Mle8ODswRA0CcGdKOGIdR1gGwUarYx uKTFihlfOw5i3SoxtgNbqxmANRerMJXBUg1CE/16KUpWqZ5PSFznCYNSlbKLtN2PUjS3 nWjc7eD2m1eRz0V/vJorauv4iSHc6C5www+XMHWM+SNzsqeLGLnAE/6BOsJ/Qk0QqM7g WR5wPRfTgZKGtrPBXnSCLex1noA0IA0ubBLlGQJdCwBS5418Zj0qdmephaBBJ08Yayve UKj1jKhgEkVgZR9ftaGiey74n0iBtwo4I+ND1y3FmAiPuUiMmhDu28tSbZT0q2z9hnNR j0OA== X-Gm-Message-State: ANoB5pm7yC+EUn4Sn7jNOENj45QqHqeSemfYW1f2Sx64J9Jtsb04R2Wc ewxSAvPDgcmyRE3cEwuY35ZPAz4tYLo= X-Google-Smtp-Source: AA0mqf6qqIRYMQBfFWnkue2HL5zRcCsULYc9LVqze+KXx0KbwkMvhW78IqnwR5Ml6zHLK+csHQd2hQ== X-Received: by 2002:a17:903:186:b0:188:4ba9:7a04 with SMTP id z6-20020a170903018600b001884ba97a04mr4808389plg.45.1668725785814; Thu, 17 Nov 2022 14:56:25 -0800 (PST) Received: from localhost ([2409:40f4:8:955c:5484:8048:c08:7b3]) by smtp.gmail.com with ESMTPSA id c5-20020a170902b68500b00186b758c9fasm1973844pls.33.2022.11.17.14.56.25 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 17 Nov 2022 14:56:25 -0800 (PST) From: Kumar Kartikeya Dwivedi To: bpf@vger.kernel.org Cc: Dave Marchevsky , Alexei Starovoitov , Andrii Nakryiko , Daniel Borkmann , Martin KaFai Lau , Dave Marchevsky Subject: [PATCH bpf-next v9 19/23] selftests/bpf: Add __contains macro to bpf_experimental.h Date: Fri, 18 Nov 2022 04:25:06 +0530 Message-Id: <20221117225510.1676785-20-memxor@gmail.com> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20221117225510.1676785-1-memxor@gmail.com> References: <20221117225510.1676785-1-memxor@gmail.com> MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=1007; i=memxor@gmail.com; h=from:subject; bh=QUh2azS5YwjYBzJI16lM6Jjvlpavd9KadUbWM8+nCmM=; b=owEBbQKS/ZANAwAIAUzgyIZIvxHKAcsmYgBjdrkcSV6X77+yli7nBHANFRr4j1zNcbG36mWEM3uR skI91oOJAjMEAAEIAB0WIQRLvip+Buz51YI8YRFM4MiGSL8RygUCY3a5HAAKCRBM4MiGSL8Ryl3OD/ 9wzb1ECpzmofiV0Q34owbSya6qKlcmCoyUxtfn8oLlm9JVOzV5OLThrx1oqVk+NkaT9qx6CqtnnKg/ Y22d9/SdlqiYWRwlygd+Z03jGD5n+VUMMdlTg0GFHKI7woM35/YRq1Vn0/orgXMPx+FeZ4tstgQbx+ 4uKVR7xBDd7MbEvnGJtWG66z038q58Gr1txUnWepMz7cBTtbwswbERRbg5a+dqcbmb3dRkjBAXgTtt Q6qsBQI3se9ryB3JXA38KbonUR+a3+P9LClOQn2J6HmwcIyY0hs/GBtHcRIzir9Fn5wgKC/gJ3H71j fvUJ6TABTNnMiyf11fsgsgYpSDxE6QObj0zwE+2/LeCTNikVMZiLBW29sV0r7vUgI8VAP2QSdHHUYH AGlTmgSc9EblFt7FtU07BdZhwfgjnJIucVm0KIL/NS374USJTjwNnSKiTkK0xspD08EXB/ebp5hrUt NsO9HBFHaoIG/xM0i3hMl8piWsYlW482bM7SBM1aZArX3yFS0HcA+4G86/BBiQ3U2lVT9zXlxnDkzo Pp5B76wJ4HfM3xDAYeR8mnbrDtYN+p1c91Wv38IMjnediRknj2MR1hxWqHigXbgUvd2AoyCwJpeO2j xMwIpue0BV5cPHdjpeP0t5yIw8bf01QOkAffGo3j/XBXJJKQWH1t65XjMe0Q== X-Developer-Key: i=memxor@gmail.com; a=openpgp; fpr=4BBE2A7E06ECF9D5823C61114CE0C88648BF11CA Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net Add user facing __contains macro which provides a convenient wrapper over the verbose kernel specific BTF declaration tag required to annotate BPF list head structs in user types. Acked-by: Dave Marchevsky Signed-off-by: Kumar Kartikeya Dwivedi --- tools/testing/selftests/bpf/bpf_experimental.h | 2 ++ 1 file changed, 2 insertions(+) diff --git a/tools/testing/selftests/bpf/bpf_experimental.h b/tools/testing/selftests/bpf/bpf_experimental.h index d6b143275e82..424f7bbbfe9b 100644 --- a/tools/testing/selftests/bpf/bpf_experimental.h +++ b/tools/testing/selftests/bpf/bpf_experimental.h @@ -6,6 +6,8 @@ #include #include +#define __contains(name, node) __attribute__((btf_decl_tag("contains:" #name ":" #node))) + /* Description * Allocates an object of the type represented by 'local_type_id' in * program BTF. User may use the bpf_core_type_id_local macro to pass the From patchwork Thu Nov 17 22:55:07 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kumar Kartikeya Dwivedi X-Patchwork-Id: 13047445 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B3BC1C433FE for ; Thu, 17 Nov 2022 22:56:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235058AbiKQW4d (ORCPT ); Thu, 17 Nov 2022 17:56:33 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53962 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234959AbiKQW4a (ORCPT ); Thu, 17 Nov 2022 17:56:30 -0500 Received: from mail-pl1-x643.google.com (mail-pl1-x643.google.com [IPv6:2607:f8b0:4864:20::643]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0A7D81A3BA for ; Thu, 17 Nov 2022 14:56:30 -0800 (PST) Received: by mail-pl1-x643.google.com with SMTP id jn7so1134464plb.13 for ; Thu, 17 Nov 2022 14:56:30 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=orrU9bkwct7hSaHpeFwTQHPvPh3WfieLrB51Oysef3o=; b=AEt8wmo4ikfncfr7mx+a0wEX+Xd2vn08+hMorLqGnepiNNKwqeaQImZvwsGnOLjWoU L0HAGbJ/xkpk4F4xe2vSLcNgrn7ZWchII+YcWwTxdretXnIZfu/Q6ongcYR2SptvSgNg iMVXqU51O1JI08pQCQIvldHLa7x9ibchN+rAXXUObzC6MgoQ05MrAI4+s2CLt0S3IVjO eZBv5R91xgZ5Bbc1VkNRGu5e46TeTz6pt6fbVnz2+i3kzP5Cgpj48Z1IhX+vJLo97Nw8 6oaYLGt/MkNuvDq0jWIqzQz2FneTVOVXpm+aiCmLU4/wZsHzP4epQxjtyHjCcTxWGAut HdrA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=orrU9bkwct7hSaHpeFwTQHPvPh3WfieLrB51Oysef3o=; b=C8A0Qq77dNbRR0eLlKXayu7PiFLRCLM9ToXZy87junvY8RTuPycCVo6oLza9Gdwr4L HL1ExnXWu5OzW97VWOuDnzjZDwDfxBaXpCVreKy2nO5Pq6rqD2Lxd3x6Pol92SVbhDHp clUAsp/p++68yhL5D0hpA2JTFRkmMjXxE32CxxFI+1xJVTtpVQKSaS0MwrJ2ke8yuGIx zim3sWw6SO+uQr4fc0tPwdrS7+N1ZJ2cmcFMdGtpZh7reSSkKXACcTqkHCy4WdNKdkTS W1D/HScsxxGufzVtir+0VEHk2pNwuXM4FhDHoS0r+h6xlq1sZ/T/jdjeWK1yRLzvUWQm vmyg== X-Gm-Message-State: ANoB5pnLBsmy0kl2d1Ijsln+OjFDpO9oiZUKRid+b+2+2aIAH8c/G2c3 XWa28grMt6Evrj05S/cHaqHPIej04k0= X-Google-Smtp-Source: AA0mqf6JWa4sUKOcLqymE52XdvVBELtJc2/LxBQBbPAUT6W/AH3H++uOX1DVwAuVQmxJAXQYBPgNSQ== X-Received: by 2002:a17:902:ecc3:b0:188:59d2:33e with SMTP id a3-20020a170902ecc300b0018859d2033emr4529858plh.142.1668725789303; Thu, 17 Nov 2022 14:56:29 -0800 (PST) Received: from localhost ([2409:40f4:8:955c:5484:8048:c08:7b3]) by smtp.gmail.com with ESMTPSA id k11-20020a170902c40b00b0017f5ad327casm2024583plk.103.2022.11.17.14.56.28 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 17 Nov 2022 14:56:28 -0800 (PST) From: Kumar Kartikeya Dwivedi To: bpf@vger.kernel.org Cc: Alexei Starovoitov , Andrii Nakryiko , Daniel Borkmann , Martin KaFai Lau , Dave Marchevsky Subject: [PATCH bpf-next v9 20/23] selftests/bpf: Update spinlock selftest Date: Fri, 18 Nov 2022 04:25:07 +0530 Message-Id: <20221117225510.1676785-21-memxor@gmail.com> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20221117225510.1676785-1-memxor@gmail.com> References: <20221117225510.1676785-1-memxor@gmail.com> MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=4240; i=memxor@gmail.com; h=from:subject; bh=7VEkgc+BO3uo7sABXUFzym09WvMjkfDkhbTvKZAA/+A=; b=owEBbQKS/ZANAwAIAUzgyIZIvxHKAcsmYgBjdrkc4CA2EmruSzd0pkEr5lKkj3lWXgt8hXk7B9gB YUq2/fyJAjMEAAEIAB0WIQRLvip+Buz51YI8YRFM4MiGSL8RygUCY3a5HAAKCRBM4MiGSL8Ryu5TD/ 91lYYfFBXqGePqF9i8tStr/oFNBQ9O+FzmlYa5N+TCiRjPFWw8NsaUw2fkzfPXyVMpavAk13Q2rxR2 luIUmnf2m17OubzXnEKl2mc0euZE/pZF3Sr1ja3y9Np1cdYWx/WLBxYBIOLZiaGT3ZvbAWXstSrncH OC//7nVtVRJSQtP+Fq+pwUb8FBxqEs/7ZOuFTfI1EF4nKGLDa2d4pATlzVGY0WcZRHl4szTpPlUqbj 9WJ/v2J34q2+s40+XpvSWR5ZoGpmjTHinYqFGQSxhlguXWHtNQbcoQN3P5OBp8aLndESbnlyjTFvR+ NP7qoPVOqEWHOIH7KYoONobvG1AIJYezm3SXoofqx2E/IdyxNs8lWh2kE0SvUHIqPhoSh9QNz+5UN2 wR+5dWJgiSIsnzNKehhjw+ZQahn06AtKjez8mhMSnP9IeexOby6LoWqtTT/bvzXn6be2eMkaMIYGc1 o4lvcGc10VAGnzXYuxebtLrVgz9JVloEwXDs8wANTvBvbvmtsa4VRGB4zD3F9Jqz3AoNaFFq2LIPS8 qcdVmWMUiHAS1jVKVxQ6gBJAn5aRrwNzB8ArFZilL9aVVQQE3oHUPky6RXPnM4SLD2fN98x8soNmaF wPPEX9ExhR4ihmCgQWjJl8tlnE8bgMsCvCaxBGNkkOhgfBOywUXJv4IarNBQ== X-Developer-Key: i=memxor@gmail.com; a=openpgp; fpr=4BBE2A7E06ECF9D5823C61114CE0C88648BF11CA Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net Make updates in preparation for adding more test cases to this selftest: - Convert from CHECK_ to ASSERT macros. - Use BPF skeleton - Fix typo sping -> spin - Rename spinlock.c -> spin_lock.c Signed-off-by: Kumar Kartikeya Dwivedi --- .../selftests/bpf/prog_tests/spin_lock.c | 49 +++++++++++++++++++ .../selftests/bpf/prog_tests/spinlock.c | 45 ----------------- .../selftests/bpf/progs/test_spin_lock.c | 4 +- 3 files changed, 51 insertions(+), 47 deletions(-) create mode 100644 tools/testing/selftests/bpf/prog_tests/spin_lock.c delete mode 100644 tools/testing/selftests/bpf/prog_tests/spinlock.c diff --git a/tools/testing/selftests/bpf/prog_tests/spin_lock.c b/tools/testing/selftests/bpf/prog_tests/spin_lock.c new file mode 100644 index 000000000000..fab061e9d77c --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/spin_lock.c @@ -0,0 +1,49 @@ +// SPDX-License-Identifier: GPL-2.0 +#include +#include + +#include "test_spin_lock.skel.h" + +static void *spin_lock_thread(void *arg) +{ + int err, prog_fd = *(u32 *) arg; + LIBBPF_OPTS(bpf_test_run_opts, topts, + .data_in = &pkt_v4, + .data_size_in = sizeof(pkt_v4), + .repeat = 10000, + ); + + err = bpf_prog_test_run_opts(prog_fd, &topts); + ASSERT_OK(err, "test_run"); + ASSERT_OK(topts.retval, "test_run retval"); + pthread_exit(arg); +} + +void test_spinlock(void) +{ + struct test_spin_lock *skel; + pthread_t thread_id[4]; + int prog_fd, i; + void *ret; + + skel = test_spin_lock__open_and_load(); + if (!ASSERT_OK_PTR(skel, "test_spin_lock__open_and_load")) + return; + prog_fd = bpf_program__fd(skel->progs.bpf_spin_lock_test); + for (i = 0; i < 4; i++) { + int err; + + err = pthread_create(&thread_id[i], NULL, &spin_lock_thread, &prog_fd); + if (!ASSERT_OK(err, "pthread_create")) + goto end; + } + + for (i = 0; i < 4; i++) { + if (!ASSERT_OK(pthread_join(thread_id[i], &ret), "pthread_join")) + goto end; + if (!ASSERT_EQ(ret, &prog_fd, "ret == prog_fd")) + goto end; + } +end: + test_spin_lock__destroy(skel); +} diff --git a/tools/testing/selftests/bpf/prog_tests/spinlock.c b/tools/testing/selftests/bpf/prog_tests/spinlock.c deleted file mode 100644 index 15eb1372d771..000000000000 --- a/tools/testing/selftests/bpf/prog_tests/spinlock.c +++ /dev/null @@ -1,45 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0 -#include -#include - -static void *spin_lock_thread(void *arg) -{ - int err, prog_fd = *(u32 *) arg; - LIBBPF_OPTS(bpf_test_run_opts, topts, - .data_in = &pkt_v4, - .data_size_in = sizeof(pkt_v4), - .repeat = 10000, - ); - - err = bpf_prog_test_run_opts(prog_fd, &topts); - ASSERT_OK(err, "test_run"); - ASSERT_OK(topts.retval, "test_run retval"); - pthread_exit(arg); -} - -void test_spinlock(void) -{ - const char *file = "./test_spin_lock.bpf.o"; - pthread_t thread_id[4]; - struct bpf_object *obj = NULL; - int prog_fd; - int err = 0, i; - void *ret; - - err = bpf_prog_test_load(file, BPF_PROG_TYPE_CGROUP_SKB, &obj, &prog_fd); - if (CHECK_FAIL(err)) { - printf("test_spin_lock:bpf_prog_test_load errno %d\n", errno); - goto close_prog; - } - for (i = 0; i < 4; i++) - if (CHECK_FAIL(pthread_create(&thread_id[i], NULL, - &spin_lock_thread, &prog_fd))) - goto close_prog; - - for (i = 0; i < 4; i++) - if (CHECK_FAIL(pthread_join(thread_id[i], &ret) || - ret != (void *)&prog_fd)) - goto close_prog; -close_prog: - bpf_object__close(obj); -} diff --git a/tools/testing/selftests/bpf/progs/test_spin_lock.c b/tools/testing/selftests/bpf/progs/test_spin_lock.c index 7e88309d3229..5bd10409285b 100644 --- a/tools/testing/selftests/bpf/progs/test_spin_lock.c +++ b/tools/testing/selftests/bpf/progs/test_spin_lock.c @@ -45,8 +45,8 @@ struct { #define CREDIT_PER_NS(delta, rate) (((delta) * rate) >> 20) -SEC("tc") -int bpf_sping_lock_test(struct __sk_buff *skb) +SEC("cgroup_skb/ingress") +int bpf_spin_lock_test(struct __sk_buff *skb) { volatile int credit = 0, max_credit = 100, pkt_len = 64; struct hmap_elem zero = {}, *val; From patchwork Thu Nov 17 22:55:08 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kumar Kartikeya Dwivedi X-Patchwork-Id: 13047446 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id F1BE5C433FE for ; Thu, 17 Nov 2022 22:56:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235079AbiKQW4j (ORCPT ); Thu, 17 Nov 2022 17:56:39 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54048 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234959AbiKQW4e (ORCPT ); Thu, 17 Nov 2022 17:56:34 -0500 Received: from mail-pg1-x542.google.com (mail-pg1-x542.google.com [IPv6:2607:f8b0:4864:20::542]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 732DD62CE for ; Thu, 17 Nov 2022 14:56:33 -0800 (PST) Received: by mail-pg1-x542.google.com with SMTP id b62so3494765pgc.0 for ; Thu, 17 Nov 2022 14:56:33 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=D5mhxE7t9/w1waItLCLixY08yGr4GoIXj2ByOScU2oQ=; b=MAsB/at2Z1Tt+jyhoDIH3e0EEy7dQodrChafpxFPdC2uYHZjoVYfrhdszyAzXvMjrr fHTy/OuwzPPdyqJAMyYMohA0tk/5PDlU7u8qLsDLy0TN+GSdxH5nCa+iLqWn1sU6NdgS q65t2riPGC6zwQiD5vhVk/qbTcqZoIeUr/SY+8/wewHO3wVcnVq7ardMpeVbyfIcn2Fg 5Z8k45/RKDdjq0o+3QKxeFHxIyB/5P/Q9zEUoEl9aVNBlxaEUtIAXBHcZ/e/RKZWEevy 3Uk1APD5WzT9w6Eivr7iAJ8gzIsDuL3wHdj+Rp+1zsI11YGmsBrjch3cc6NF08LNHis8 nRTg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=D5mhxE7t9/w1waItLCLixY08yGr4GoIXj2ByOScU2oQ=; b=QoUy5/OIZ9lPuWJ8xJxX9fQOPbrl92zpHbPXmLCJMZq67h9qeGq1QTtPO9iFS115fT hTQuPZJn4KpAhucrImje4OLZs3biDj2gmCkPhhQfiev7Edh/DWyvgQX3PrgiNruKUTWJ d8ZM9b0YlsyU2ChOmvRNNDEM8IMLlz8F7+o3YTrcVjaKWRjyY9hCEdbQorWjsdphYSxc BgVrrlU9z5cDDlk84ZFh9fjHAizTY3Yxs2mcFmErh2FzToCS4tSfJxDCuMVcEvPJNEMe i6yNr/3SKnUBiutuM+V6OHouiVW4OsXfL6s+97eOoUQGXCWsvU41DsiDQeWZJvhFDxGP PgZA== X-Gm-Message-State: ANoB5pmLSnEy+XzUXWoiC+ODjvDjervHNODO26iqy6B0EPda8ndlQ9P3 rn6tz1sNtrU09Zkj3TYN+ca9pjJV6W8= X-Google-Smtp-Source: AA0mqf5ok8Sm0C/7vky++7foSwx5mzF40rtfIjZ5iI6xLw3i34yzay9SOxypkUQgn3BDA4n2IgTkZQ== X-Received: by 2002:aa7:8694:0:b0:56d:78b0:16a0 with SMTP id d20-20020aa78694000000b0056d78b016a0mr4925577pfo.81.1668725792699; Thu, 17 Nov 2022 14:56:32 -0800 (PST) Received: from localhost ([2409:40f4:8:955c:5484:8048:c08:7b3]) by smtp.gmail.com with ESMTPSA id iw20-20020a170903045400b00179f370dbe7sm1848075plb.287.2022.11.17.14.56.31 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 17 Nov 2022 14:56:32 -0800 (PST) From: Kumar Kartikeya Dwivedi To: bpf@vger.kernel.org Cc: Alexei Starovoitov , Andrii Nakryiko , Daniel Borkmann , Martin KaFai Lau , Dave Marchevsky Subject: [PATCH bpf-next v9 21/23] selftests/bpf: Add failure test cases for spin lock pairing Date: Fri, 18 Nov 2022 04:25:08 +0530 Message-Id: <20221117225510.1676785-22-memxor@gmail.com> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20221117225510.1676785-1-memxor@gmail.com> References: <20221117225510.1676785-1-memxor@gmail.com> MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=10926; i=memxor@gmail.com; h=from:subject; bh=EgO226hLDLT8uUjs61C2Qe2aCLhsrlTx0+w4ds2Mqpc=; b=owEBbQKS/ZANAwAIAUzgyIZIvxHKAcsmYgBjdrkcgMT9Abs9cB+op+OrrkFyBfHhPTKvNDwLe6tH HY3gwCyJAjMEAAEIAB0WIQRLvip+Buz51YI8YRFM4MiGSL8RygUCY3a5HAAKCRBM4MiGSL8RyudaD/ sFMwhIylq6UGQnnNd++i0zhjQi0wiYn0kIqAhGFMBPC34FgaGsvWetRF3pY/Xls1Q327Xi92Rz0SV6 Mkqa46QpIzUJhDl6RJehIpa0FA1Ayr2ir/lq37oJL5NBIpwb8YTq8Go/wTzIz2MR/eqAqaWRcf3Mvf vJZe1/oSy2HVcjvrro6IpCeHalL5XMGLmPTq8wOHOpHf3KtBfJXQalY1d836DEjykj4gFXbdxmkPLw FBabFJBMB1UgmRFJyHq9BkoEUGzGeCSBAajlHMf5YMZKWLyumOZMbbkCEeAAAGbvQ6WdbX0eBBw8Yg mI/sPzdlM/phpZ++wakZVcFiUVNe9JkWe4YAuW5VLBuDs3y2E5xKy+fnX8PPYXf034iMXKmwbkAOdc 9uwp71ZXVNU0v8uvEJImTfeqWGf3H8BwdPQQqkpzjMjqcgolXlveTO7YoKpl/JtxgrZbzqcbu7Bw8o bnjgkdZYXE5YXlHuPHKdz51JX7Tk4usZ/HivO3sHfx/bHDsECkjJNsI91hPd5XedF+PLUpJFdaWErw 48VJ8/IuzKC1s+k+syb27gNg9kh2kga0lcdVP4e/gVt8fAhBuLkCgiAP9J2brEupdCoPN4MQzCfHiw 4xdHVB0+2/9MgeFb0SHdGAnEsWVItqcnuD/R3Hrykeih/+qjEDy5xxjbiVjw== X-Developer-Key: i=memxor@gmail.com; a=openpgp; fpr=4BBE2A7E06ECF9D5823C61114CE0C88648BF11CA Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net First, ensure that whenever a bpf_spin_lock is present in an allocation, the reg->id is preserved. This won't be true for global variables however, since they have a single map value per map, hence the verifier harcodes it to 0 (so that multiple pseudo ldimm64 insns can yield the same lock object per map at a given offset). Next, add test cases for all possible combinations (kptr, global, map value, inner map value). Since we lifted restriction on locking in inner maps, also add test cases for them. Currently, each lookup into an inner map gets a fresh reg->id, so even if the reg->map_ptr is same, they will be treated as separate allocations and the incorrect unlock pairing will be rejected. Signed-off-by: Kumar Kartikeya Dwivedi --- .../selftests/bpf/prog_tests/spin_lock.c | 89 +++++++- .../selftests/bpf/progs/test_spin_lock_fail.c | 204 ++++++++++++++++++ 2 files changed, 292 insertions(+), 1 deletion(-) create mode 100644 tools/testing/selftests/bpf/progs/test_spin_lock_fail.c diff --git a/tools/testing/selftests/bpf/prog_tests/spin_lock.c b/tools/testing/selftests/bpf/prog_tests/spin_lock.c index fab061e9d77c..72282e92a78a 100644 --- a/tools/testing/selftests/bpf/prog_tests/spin_lock.c +++ b/tools/testing/selftests/bpf/prog_tests/spin_lock.c @@ -3,6 +3,79 @@ #include #include "test_spin_lock.skel.h" +#include "test_spin_lock_fail.skel.h" + +static char log_buf[1024 * 1024]; + +static struct { + const char *prog_name; + const char *err_msg; +} spin_lock_fail_tests[] = { + { "lock_id_kptr_preserve", + "5: (bf) r1 = r0 ; R0_w=ptr_foo(id=2,ref_obj_id=2,off=0,imm=0) " + "R1_w=ptr_foo(id=2,ref_obj_id=2,off=0,imm=0) refs=2\n6: (85) call bpf_this_cpu_ptr#154\n" + "R1 type=ptr_ expected=percpu_ptr_" }, + { "lock_id_global_zero", + "; R1_w=map_value(off=0,ks=4,vs=4,imm=0)\n2: (85) call bpf_this_cpu_ptr#154\n" + "R1 type=map_value expected=percpu_ptr_" }, + { "lock_id_mapval_preserve", + "8: (bf) r1 = r0 ; R0_w=map_value(id=1,off=0,ks=4,vs=8,imm=0) " + "R1_w=map_value(id=1,off=0,ks=4,vs=8,imm=0)\n9: (85) call bpf_this_cpu_ptr#154\n" + "R1 type=map_value expected=percpu_ptr_" }, + { "lock_id_innermapval_preserve", + "13: (bf) r1 = r0 ; R0=map_value(id=2,off=0,ks=4,vs=8,imm=0) " + "R1_w=map_value(id=2,off=0,ks=4,vs=8,imm=0)\n14: (85) call bpf_this_cpu_ptr#154\n" + "R1 type=map_value expected=percpu_ptr_" }, + { "lock_id_mismatch_kptr_kptr", "bpf_spin_unlock of different lock" }, + { "lock_id_mismatch_kptr_global", "bpf_spin_unlock of different lock" }, + { "lock_id_mismatch_kptr_mapval", "bpf_spin_unlock of different lock" }, + { "lock_id_mismatch_kptr_innermapval", "bpf_spin_unlock of different lock" }, + { "lock_id_mismatch_global_global", "bpf_spin_unlock of different lock" }, + { "lock_id_mismatch_global_kptr", "bpf_spin_unlock of different lock" }, + { "lock_id_mismatch_global_mapval", "bpf_spin_unlock of different lock" }, + { "lock_id_mismatch_global_innermapval", "bpf_spin_unlock of different lock" }, + { "lock_id_mismatch_mapval_mapval", "bpf_spin_unlock of different lock" }, + { "lock_id_mismatch_mapval_kptr", "bpf_spin_unlock of different lock" }, + { "lock_id_mismatch_mapval_global", "bpf_spin_unlock of different lock" }, + { "lock_id_mismatch_mapval_innermapval", "bpf_spin_unlock of different lock" }, + { "lock_id_mismatch_innermapval_innermapval1", "bpf_spin_unlock of different lock" }, + { "lock_id_mismatch_innermapval_innermapval2", "bpf_spin_unlock of different lock" }, + { "lock_id_mismatch_innermapval_kptr", "bpf_spin_unlock of different lock" }, + { "lock_id_mismatch_innermapval_global", "bpf_spin_unlock of different lock" }, + { "lock_id_mismatch_innermapval_mapval", "bpf_spin_unlock of different lock" }, +}; + +static void test_spin_lock_fail_prog(const char *prog_name, const char *err_msg) +{ + LIBBPF_OPTS(bpf_object_open_opts, opts, .kernel_log_buf = log_buf, + .kernel_log_size = sizeof(log_buf), + .kernel_log_level = 1); + struct test_spin_lock_fail *skel; + struct bpf_program *prog; + int ret; + + skel = test_spin_lock_fail__open_opts(&opts); + if (!ASSERT_OK_PTR(skel, "test_spin_lock_fail__open_opts")) + return; + + prog = bpf_object__find_program_by_name(skel->obj, prog_name); + if (!ASSERT_OK_PTR(prog, "bpf_object__find_program_by_name")) + goto end; + + bpf_program__set_autoload(prog, true); + + ret = test_spin_lock_fail__load(skel); + if (!ASSERT_ERR(ret, "test_spin_lock_fail__load must fail")) + goto end; + + if (!ASSERT_OK_PTR(strstr(log_buf, err_msg), "expected error message")) { + fprintf(stderr, "Expected: %s\n", err_msg); + fprintf(stderr, "Verifier: %s\n", log_buf); + } + +end: + test_spin_lock_fail__destroy(skel); +} static void *spin_lock_thread(void *arg) { @@ -19,7 +92,7 @@ static void *spin_lock_thread(void *arg) pthread_exit(arg); } -void test_spinlock(void) +void test_spin_lock_success(void) { struct test_spin_lock *skel; pthread_t thread_id[4]; @@ -47,3 +120,17 @@ void test_spinlock(void) end: test_spin_lock__destroy(skel); } + +void test_spin_lock(void) +{ + int i; + + test_spin_lock_success(); + + for (i = 0; i < ARRAY_SIZE(spin_lock_fail_tests); i++) { + if (!test__start_subtest(spin_lock_fail_tests[i].prog_name)) + continue; + test_spin_lock_fail_prog(spin_lock_fail_tests[i].prog_name, + spin_lock_fail_tests[i].err_msg); + } +} diff --git a/tools/testing/selftests/bpf/progs/test_spin_lock_fail.c b/tools/testing/selftests/bpf/progs/test_spin_lock_fail.c new file mode 100644 index 000000000000..86cd183ef6dc --- /dev/null +++ b/tools/testing/selftests/bpf/progs/test_spin_lock_fail.c @@ -0,0 +1,204 @@ +// SPDX-License-Identifier: GPL-2.0 +#include +#include +#include +#include "bpf_experimental.h" + +struct foo { + struct bpf_spin_lock lock; + int data; +}; + +struct array_map { + __uint(type, BPF_MAP_TYPE_ARRAY); + __type(key, int); + __type(value, struct foo); + __uint(max_entries, 1); +} array_map SEC(".maps"); + +struct { + __uint(type, BPF_MAP_TYPE_ARRAY_OF_MAPS); + __uint(max_entries, 1); + __type(key, int); + __type(value, int); + __array(values, struct array_map); +} map_of_maps SEC(".maps") = { + .values = { + [0] = &array_map, + }, +}; + +SEC(".data.A") struct bpf_spin_lock lockA; +SEC(".data.B") struct bpf_spin_lock lockB; + +SEC("?tc") +int lock_id_kptr_preserve(void *ctx) +{ + struct foo *f; + + f = bpf_obj_new(typeof(*f)); + if (!f) + return 0; + bpf_this_cpu_ptr(f); + return 0; +} + +SEC("?tc") +int lock_id_global_zero(void *ctx) +{ + bpf_this_cpu_ptr(&lockA); + return 0; +} + +SEC("?tc") +int lock_id_mapval_preserve(void *ctx) +{ + struct foo *f; + int key = 0; + + f = bpf_map_lookup_elem(&array_map, &key); + if (!f) + return 0; + bpf_this_cpu_ptr(f); + return 0; +} + +SEC("?tc") +int lock_id_innermapval_preserve(void *ctx) +{ + struct foo *f; + int key = 0; + void *map; + + map = bpf_map_lookup_elem(&map_of_maps, &key); + if (!map) + return 0; + f = bpf_map_lookup_elem(map, &key); + if (!f) + return 0; + bpf_this_cpu_ptr(f); + return 0; +} + +#define CHECK(test, A, B) \ + SEC("?tc") \ + int lock_id_mismatch_##test(void *ctx) \ + { \ + struct foo *f1, *f2, *v, *iv; \ + int key = 0; \ + void *map; \ + \ + map = bpf_map_lookup_elem(&map_of_maps, &key); \ + if (!map) \ + return 0; \ + iv = bpf_map_lookup_elem(map, &key); \ + if (!iv) \ + return 0; \ + v = bpf_map_lookup_elem(&array_map, &key); \ + if (!v) \ + return 0; \ + f1 = bpf_obj_new(typeof(*f1)); \ + if (!f1) \ + return 0; \ + f2 = bpf_obj_new(typeof(*f2)); \ + if (!f2) { \ + bpf_obj_drop(f1); \ + return 0; \ + } \ + bpf_spin_lock(A); \ + bpf_spin_unlock(B); \ + return 0; \ + } + +CHECK(kptr_kptr, &f1->lock, &f2->lock); +CHECK(kptr_global, &f1->lock, &lockA); +CHECK(kptr_mapval, &f1->lock, &v->lock); +CHECK(kptr_innermapval, &f1->lock, &iv->lock); + +CHECK(global_global, &lockA, &lockB); +CHECK(global_kptr, &lockA, &f1->lock); +CHECK(global_mapval, &lockA, &v->lock); +CHECK(global_innermapval, &lockA, &iv->lock); + +SEC("?tc") +int lock_id_mismatch_mapval_mapval(void *ctx) +{ + struct foo *f1, *f2; + int key = 0; + + f1 = bpf_map_lookup_elem(&array_map, &key); + if (!f1) + return 0; + f2 = bpf_map_lookup_elem(&array_map, &key); + if (!f2) + return 0; + + bpf_spin_lock(&f1->lock); + f1->data = 42; + bpf_spin_unlock(&f2->lock); + + return 0; +} + +CHECK(mapval_kptr, &v->lock, &f1->lock); +CHECK(mapval_global, &v->lock, &lockB); +CHECK(mapval_innermapval, &v->lock, &iv->lock); + +SEC("?tc") +int lock_id_mismatch_innermapval_innermapval1(void *ctx) +{ + struct foo *f1, *f2; + int key = 0; + void *map; + + map = bpf_map_lookup_elem(&map_of_maps, &key); + if (!map) + return 0; + f1 = bpf_map_lookup_elem(map, &key); + if (!f1) + return 0; + f2 = bpf_map_lookup_elem(map, &key); + if (!f2) + return 0; + + bpf_spin_lock(&f1->lock); + f1->data = 42; + bpf_spin_unlock(&f2->lock); + + return 0; +} + +SEC("?tc") +int lock_id_mismatch_innermapval_innermapval2(void *ctx) +{ + struct foo *f1, *f2; + int key = 0; + void *map; + + map = bpf_map_lookup_elem(&map_of_maps, &key); + if (!map) + return 0; + f1 = bpf_map_lookup_elem(map, &key); + if (!f1) + return 0; + map = bpf_map_lookup_elem(&map_of_maps, &key); + if (!map) + return 0; + f2 = bpf_map_lookup_elem(map, &key); + if (!f2) + return 0; + + bpf_spin_lock(&f1->lock); + f1->data = 42; + bpf_spin_unlock(&f2->lock); + + return 0; +} + +CHECK(innermapval_kptr, &iv->lock, &f1->lock); +CHECK(innermapval_global, &iv->lock, &lockA); +CHECK(innermapval_mapval, &iv->lock, &v->lock); + +#undef CHECK + +char _license[] SEC("license") = "GPL"; From patchwork Thu Nov 17 22:55:09 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kumar Kartikeya Dwivedi X-Patchwork-Id: 13047447 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5CB15C4332F for ; Thu, 17 Nov 2022 22:56:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239672AbiKQW4p (ORCPT ); Thu, 17 Nov 2022 17:56:45 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53962 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239612AbiKQW4k (ORCPT ); Thu, 17 Nov 2022 17:56:40 -0500 Received: from mail-pj1-x1043.google.com (mail-pj1-x1043.google.com [IPv6:2607:f8b0:4864:20::1043]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 83EFF15829 for ; Thu, 17 Nov 2022 14:56:37 -0800 (PST) Received: by mail-pj1-x1043.google.com with SMTP id d13-20020a17090a3b0d00b00213519dfe4aso3405108pjc.2 for ; Thu, 17 Nov 2022 14:56:37 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=Ynksgp8twsO6Y1FQ4YqD+43XOlOF3xdl4b+xGA4Qj48=; b=qP/MwX0uABTdPbIuC0nDZeBRZV9CimLCOmI64hTnSuD4De+o+SaowfrsSv8hamI55O Lqv+299URCpCbgw5dA0N1pzpCX1p6qMwrHZCMKPMuli3Odz+k3tnjZ3OH9CuCtDt/lqF +StM9245IdRbSI23RNM3bLwf763V75BW2ooLCzAYo8VLOljpiJRR+nGqVVY+ao+zR/mq Qxq9ZvL+FP72E1LWiw0xpZAQcfJvw96C3hvILe4MiNhStkoWJFCCGI6aJgEvSght57Cx eQpDsHpQW6Q90L8Z7WOLjkafyXoVG7wZDrfFqlmr5DP83ghpYWhdqW4cEGPOUD7flM4X tQbQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=Ynksgp8twsO6Y1FQ4YqD+43XOlOF3xdl4b+xGA4Qj48=; b=d3owmzlRm4DdA/AkJVeVWLDxYNNJ8GbU6QnztHWbNs7WNtHqwgUXdacrNj9GYAFVXO ACfsiz34ebmJqI6m0JBJ8k9XFWGAmIqS7FGfV3kxMzaqriTnsGj+LnE+CG6v+Ge6Ul3Q jpE8qCxcYSa/IiiGmMW2UQgDsVM/F7IWqqyQSAE1FcCTGjnMmxAsrgTP9KCTVOHoFoQF /nY4DYv96kayKJmlgC8IqVIE52t7AIei8XBaLJBE+J8rZc1ek/9ly3y4VHnsYIlu5wp4 Psh1h4IWBl1V6Hgg0JjUBmLhK4aG/3sP2EjozGOP/WGD8D1wn4xMasIaDL+6k5nSxQSz HHPg== X-Gm-Message-State: ANoB5pkohKQ+OLNvwDsSgF8BIxaTB/5JjqhpQfyqs5zMPrtQKdd5nebc Uo6ftXlTawUH5QYNvx2vnki/cTyl0d0= X-Google-Smtp-Source: AA0mqf54STlAcLJj20qbvghK3tDnfoD0PBY2NYGUulmjBRgsXcQUpi9B3XeVxxQKEcJ85HIArYg91A== X-Received: by 2002:a17:902:c211:b0:186:61c8:c512 with SMTP id 17-20020a170902c21100b0018661c8c512mr4731535pll.155.1668725796452; Thu, 17 Nov 2022 14:56:36 -0800 (PST) Received: from localhost ([2409:40f4:8:955c:5484:8048:c08:7b3]) by smtp.gmail.com with ESMTPSA id 139-20020a630591000000b0046fb6e0e691sm1606914pgf.6.2022.11.17.14.56.35 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 17 Nov 2022 14:56:36 -0800 (PST) From: Kumar Kartikeya Dwivedi To: bpf@vger.kernel.org Cc: Alexei Starovoitov , Andrii Nakryiko , Daniel Borkmann , Martin KaFai Lau , Dave Marchevsky Subject: [PATCH bpf-next v9 22/23] selftests/bpf: Add BPF linked list API tests Date: Fri, 18 Nov 2022 04:25:09 +0530 Message-Id: <20221117225510.1676785-23-memxor@gmail.com> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20221117225510.1676785-1-memxor@gmail.com> References: <20221117225510.1676785-1-memxor@gmail.com> MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=35582; i=memxor@gmail.com; h=from:subject; bh=xcWYinC8acEQFzfgFKc173VS8phsDiQ1rNQiZ1dG2Zo=; b=owEBbQKS/ZANAwAIAUzgyIZIvxHKAcsmYgBjdrkch2/BVOcb1sChUrhWg8eVu0I/3rPayXbuSiNL 1MEMuUmJAjMEAAEIAB0WIQRLvip+Buz51YI8YRFM4MiGSL8RygUCY3a5HAAKCRBM4MiGSL8RyoVhD/ 9oiXJTyZxdu6V+zLMch1slqelw3oZkhQ2K5wPSUeCBfTQLdIdC6zel2P8lN+nMz/aAMPA9K89pGjFx 4sveqgTxvXuk8CPD6EWbNyjleopAyuqrjMI9u9dlPMzQN5BBAKdBUSCm7Q+gernmgX0bUYAUXc885j QR047mv6qZn1m4HSotF8hfbrPZNg89z2zuC42PkTEXDiODyy/DUGC9r6uviYybytX1Q7hIQX+pxcO2 AoGHv13lXxlx+I0aq83bKEQJHkcrgT+aTSh+nAYAfYXXBbntBpeIPqw/litDfRAXzXsFlXv09klEfb MBkX9YfEWHQLF77LAURiKN6Uw/2Y/dtDge9I0LqU6KQewJSY8miF/u+40MIczApfjyrIFCbCdz/m0D Mg2n1LiITlhK+vQv6sdNUTpeVFIwg+NlM7kiYNkEFa9SEA97wKFALIYHeoivrkeHFPM4gDBqRe2O+J pOt8aF6On5pWMP4WHVgmqi7QhvWkufIgLjFgZmIIwHpayMP3g+R62awwGbDHIE6q9DHvE/AP5RQqfi iwD2fU0FYWIR+iETKb5+dlpD7q/C6UI6chAYiP4yV8YjPDSfwTk2A9uTaCPljd8LVRvEeqzrfTEL4E fyB2u6lwftb+e4yK3/Y8pcVQCpO1j6iqrhGa47aCnZeHOiHSurIy1hMmufHA== X-Developer-Key: i=memxor@gmail.com; a=openpgp; fpr=4BBE2A7E06ECF9D5823C61114CE0C88648BF11CA Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net Include various tests covering the success and failure cases. Also, run the success cases at runtime to verify correctness of linked list manipulation routines, in addition to ensuring successful verification. Signed-off-by: Kumar Kartikeya Dwivedi --- tools/testing/selftests/bpf/DENYLIST.s390x | 1 + .../selftests/bpf/prog_tests/linked_list.c | 255 ++++++++ .../testing/selftests/bpf/progs/linked_list.c | 370 +++++++++++ .../testing/selftests/bpf/progs/linked_list.h | 56 ++ .../selftests/bpf/progs/linked_list_fail.c | 581 ++++++++++++++++++ 5 files changed, 1263 insertions(+) create mode 100644 tools/testing/selftests/bpf/prog_tests/linked_list.c create mode 100644 tools/testing/selftests/bpf/progs/linked_list.c create mode 100644 tools/testing/selftests/bpf/progs/linked_list.h create mode 100644 tools/testing/selftests/bpf/progs/linked_list_fail.c diff --git a/tools/testing/selftests/bpf/DENYLIST.s390x b/tools/testing/selftests/bpf/DENYLIST.s390x index be4e3d47ea3e..072243af93b0 100644 --- a/tools/testing/selftests/bpf/DENYLIST.s390x +++ b/tools/testing/selftests/bpf/DENYLIST.s390x @@ -33,6 +33,7 @@ ksyms_module # test_ksyms_module__open_and_load unex ksyms_module_libbpf # JIT does not support calling kernel function (kfunc) ksyms_module_lskel # test_ksyms_module_lskel__open_and_load unexpected error: -9 (?) libbpf_get_fd_by_id_opts # failed to attach: ERROR: strerror_r(-524)=22 (trampoline) +linked_list # JIT does not support calling kernel function (kfunc) lookup_key # JIT does not support calling kernel function (kfunc) lru_bug # prog 'printk': failed to auto-attach: -524 map_kptr # failed to open_and_load program: -524 (trampoline) diff --git a/tools/testing/selftests/bpf/prog_tests/linked_list.c b/tools/testing/selftests/bpf/prog_tests/linked_list.c new file mode 100644 index 000000000000..32ff1684a7d3 --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/linked_list.c @@ -0,0 +1,255 @@ +// SPDX-License-Identifier: GPL-2.0 +#include +#include + +#include "linked_list.skel.h" +#include "linked_list_fail.skel.h" + +static char log_buf[1024 * 1024]; + +static struct { + const char *prog_name; + const char *err_msg; +} linked_list_fail_tests[] = { +#define TEST(test, off) \ + { #test "_missing_lock_push_front", \ + "bpf_spin_lock at off=" #off " must be held for bpf_list_head" }, \ + { #test "_missing_lock_push_back", \ + "bpf_spin_lock at off=" #off " must be held for bpf_list_head" }, \ + { #test "_missing_lock_pop_front", \ + "bpf_spin_lock at off=" #off " must be held for bpf_list_head" }, \ + { #test "_missing_lock_pop_back", \ + "bpf_spin_lock at off=" #off " must be held for bpf_list_head" }, + TEST(kptr, 32) + TEST(global, 16) + TEST(map, 0) + TEST(inner_map, 0) +#undef TEST +#define TEST(test, op) \ + { #test "_kptr_incorrect_lock_" #op, \ + "held lock and object are not in the same allocation\n" \ + "bpf_spin_lock at off=32 must be held for bpf_list_head" }, \ + { #test "_global_incorrect_lock_" #op, \ + "held lock and object are not in the same allocation\n" \ + "bpf_spin_lock at off=16 must be held for bpf_list_head" }, \ + { #test "_map_incorrect_lock_" #op, \ + "held lock and object are not in the same allocation\n" \ + "bpf_spin_lock at off=0 must be held for bpf_list_head" }, \ + { #test "_inner_map_incorrect_lock_" #op, \ + "held lock and object are not in the same allocation\n" \ + "bpf_spin_lock at off=0 must be held for bpf_list_head" }, + TEST(kptr, push_front) + TEST(kptr, push_back) + TEST(kptr, pop_front) + TEST(kptr, pop_back) + TEST(global, push_front) + TEST(global, push_back) + TEST(global, pop_front) + TEST(global, pop_back) + TEST(map, push_front) + TEST(map, push_back) + TEST(map, pop_front) + TEST(map, pop_back) + TEST(inner_map, push_front) + TEST(inner_map, push_back) + TEST(inner_map, pop_front) + TEST(inner_map, pop_back) +#undef TEST + { "map_compat_kprobe", "tracing progs cannot use bpf_list_head yet" }, + { "map_compat_kretprobe", "tracing progs cannot use bpf_list_head yet" }, + { "map_compat_tp", "tracing progs cannot use bpf_list_head yet" }, + { "map_compat_perf", "tracing progs cannot use bpf_list_head yet" }, + { "map_compat_raw_tp", "tracing progs cannot use bpf_list_head yet" }, + { "map_compat_raw_tp_w", "tracing progs cannot use bpf_list_head yet" }, + { "obj_type_id_oor", "local type ID argument must be in range [0, U32_MAX]" }, + { "obj_new_no_composite", "bpf_obj_new type ID argument must be of a struct" }, + { "obj_new_no_struct", "bpf_obj_new type ID argument must be of a struct" }, + { "obj_drop_non_zero_off", "R1 must have zero offset when passed to release func" }, + { "new_null_ret", "R0 invalid mem access 'ptr_or_null_'" }, + { "obj_new_acq", "Unreleased reference id=" }, + { "use_after_drop", "invalid mem access 'scalar'" }, + { "ptr_walk_scalar", "type=scalar expected=percpu_ptr_" }, + { "direct_read_lock", "direct access to bpf_spin_lock is disallowed" }, + { "direct_write_lock", "direct access to bpf_spin_lock is disallowed" }, + { "direct_read_head", "direct access to bpf_list_head is disallowed" }, + { "direct_write_head", "direct access to bpf_list_head is disallowed" }, + { "direct_read_node", "direct access to bpf_list_node is disallowed" }, + { "direct_write_node", "direct access to bpf_list_node is disallowed" }, + { "write_after_push_front", "only read is supported" }, + { "write_after_push_back", "only read is supported" }, + { "use_after_unlock_push_front", "invalid mem access 'scalar'" }, + { "use_after_unlock_push_back", "invalid mem access 'scalar'" }, + { "double_push_front", "arg#1 expected pointer to allocated object" }, + { "double_push_back", "arg#1 expected pointer to allocated object" }, + { "no_node_value_type", "bpf_list_node not found for allocated object\n" }, + { "incorrect_value_type", + "operation on bpf_list_head expects arg#1 bpf_list_node at offset=0 in struct foo, " + "but arg is at offset=0 in struct bar" }, + { "incorrect_node_var_off", "variable ptr_ access var_off=(0x0; 0xffffffff) disallowed" }, + { "incorrect_node_off1", "bpf_list_node not found at offset=1" }, + { "incorrect_node_off2", "arg#1 offset=40, but expected bpf_list_node at offset=0 in struct foo" }, + { "no_head_type", "bpf_list_head not found for allocated object" }, + { "incorrect_head_var_off1", "R1 doesn't have constant offset" }, + { "incorrect_head_var_off2", "variable ptr_ access var_off=(0x0; 0xffffffff) disallowed" }, + { "incorrect_head_off1", "bpf_list_head not found at offset=17" }, + { "incorrect_head_off2", "bpf_list_head not found at offset=1" }, + { "pop_front_off", + "15: (bf) r1 = r6 ; R1_w=ptr_or_null_foo(id=4,ref_obj_id=4,off=40,imm=0) " + "R6_w=ptr_or_null_foo(id=4,ref_obj_id=4,off=40,imm=0) refs=2,4\n" + "16: (85) call bpf_this_cpu_ptr#154\nR1 type=ptr_or_null_ expected=percpu_ptr_" }, + { "pop_back_off", + "15: (bf) r1 = r6 ; R1_w=ptr_or_null_foo(id=4,ref_obj_id=4,off=40,imm=0) " + "R6_w=ptr_or_null_foo(id=4,ref_obj_id=4,off=40,imm=0) refs=2,4\n" + "16: (85) call bpf_this_cpu_ptr#154\nR1 type=ptr_or_null_ expected=percpu_ptr_" }, +}; + +static void test_linked_list_fail_prog(const char *prog_name, const char *err_msg) +{ + LIBBPF_OPTS(bpf_object_open_opts, opts, .kernel_log_buf = log_buf, + .kernel_log_size = sizeof(log_buf), + .kernel_log_level = 1); + struct linked_list_fail *skel; + struct bpf_program *prog; + int ret; + + skel = linked_list_fail__open_opts(&opts); + if (!ASSERT_OK_PTR(skel, "linked_list_fail__open_opts")) + return; + + prog = bpf_object__find_program_by_name(skel->obj, prog_name); + if (!ASSERT_OK_PTR(prog, "bpf_object__find_program_by_name")) + goto end; + + bpf_program__set_autoload(prog, true); + + ret = linked_list_fail__load(skel); + if (!ASSERT_ERR(ret, "linked_list_fail__load must fail")) + goto end; + + if (!ASSERT_OK_PTR(strstr(log_buf, err_msg), "expected error message")) { + fprintf(stderr, "Expected: %s\n", err_msg); + fprintf(stderr, "Verifier: %s\n", log_buf); + } + +end: + linked_list_fail__destroy(skel); +} + +static void clear_fields(struct bpf_map *map) +{ + char buf[24]; + int key = 0; + + memset(buf, 0xff, sizeof(buf)); + ASSERT_OK(bpf_map__update_elem(map, &key, sizeof(key), buf, sizeof(buf), 0), "check_and_free_fields"); +} + +enum { + TEST_ALL, + PUSH_POP, + PUSH_POP_MULT, + LIST_IN_LIST, +}; + +static void test_linked_list_success(int mode, bool leave_in_map) +{ + LIBBPF_OPTS(bpf_test_run_opts, opts, + .data_in = &pkt_v4, + .data_size_in = sizeof(pkt_v4), + .repeat = 1, + ); + struct linked_list *skel; + int ret; + + skel = linked_list__open_and_load(); + if (!ASSERT_OK_PTR(skel, "linked_list__open_and_load")) + return; + + if (mode == LIST_IN_LIST) + goto lil; + if (mode == PUSH_POP_MULT) + goto ppm; + + ret = bpf_prog_test_run_opts(bpf_program__fd(skel->progs.map_list_push_pop), &opts); + ASSERT_OK(ret, "map_list_push_pop"); + ASSERT_OK(opts.retval, "map_list_push_pop retval"); + if (!leave_in_map) + clear_fields(skel->maps.array_map); + + ret = bpf_prog_test_run_opts(bpf_program__fd(skel->progs.inner_map_list_push_pop), &opts); + ASSERT_OK(ret, "inner_map_list_push_pop"); + ASSERT_OK(opts.retval, "inner_map_list_push_pop retval"); + if (!leave_in_map) + clear_fields(skel->maps.inner_map); + + ret = bpf_prog_test_run_opts(bpf_program__fd(skel->progs.global_list_push_pop), &opts); + ASSERT_OK(ret, "global_list_push_pop"); + ASSERT_OK(opts.retval, "global_list_push_pop retval"); + if (!leave_in_map) + clear_fields(skel->maps.data_A); + + if (mode == PUSH_POP) + goto end; + +ppm: + ret = bpf_prog_test_run_opts(bpf_program__fd(skel->progs.map_list_push_pop_multiple), &opts); + ASSERT_OK(ret, "map_list_push_pop_multiple"); + ASSERT_OK(opts.retval, "map_list_push_pop_multiple retval"); + if (!leave_in_map) + clear_fields(skel->maps.array_map); + + ret = bpf_prog_test_run_opts(bpf_program__fd(skel->progs.inner_map_list_push_pop_multiple), &opts); + ASSERT_OK(ret, "inner_map_list_push_pop_multiple"); + ASSERT_OK(opts.retval, "inner_map_list_push_pop_multiple retval"); + if (!leave_in_map) + clear_fields(skel->maps.inner_map); + + ret = bpf_prog_test_run_opts(bpf_program__fd(skel->progs.global_list_push_pop_multiple), &opts); + ASSERT_OK(ret, "global_list_push_pop_multiple"); + ASSERT_OK(opts.retval, "global_list_push_pop_multiple retval"); + if (!leave_in_map) + clear_fields(skel->maps.data_A); + + if (mode == PUSH_POP_MULT) + goto end; + +lil: + ret = bpf_prog_test_run_opts(bpf_program__fd(skel->progs.map_list_in_list), &opts); + ASSERT_OK(ret, "map_list_in_list"); + ASSERT_OK(opts.retval, "map_list_in_list retval"); + if (!leave_in_map) + clear_fields(skel->maps.array_map); + + ret = bpf_prog_test_run_opts(bpf_program__fd(skel->progs.inner_map_list_in_list), &opts); + ASSERT_OK(ret, "inner_map_list_in_list"); + ASSERT_OK(opts.retval, "inner_map_list_in_list retval"); + if (!leave_in_map) + clear_fields(skel->maps.inner_map); + + ret = bpf_prog_test_run_opts(bpf_program__fd(skel->progs.global_list_in_list), &opts); + ASSERT_OK(ret, "global_list_in_list"); + ASSERT_OK(opts.retval, "global_list_in_list retval"); + if (!leave_in_map) + clear_fields(skel->maps.data_A); +end: + linked_list__destroy(skel); +} + +void test_linked_list(void) +{ + int i; + + for (i = 0; i < ARRAY_SIZE(linked_list_fail_tests); i++) { + if (!test__start_subtest(linked_list_fail_tests[i].prog_name)) + continue; + test_linked_list_fail_prog(linked_list_fail_tests[i].prog_name, + linked_list_fail_tests[i].err_msg); + } + test_linked_list_success(PUSH_POP, false); + test_linked_list_success(PUSH_POP, true); + test_linked_list_success(PUSH_POP_MULT, false); + test_linked_list_success(PUSH_POP_MULT, true); + test_linked_list_success(LIST_IN_LIST, false); + test_linked_list_success(LIST_IN_LIST, true); + test_linked_list_success(TEST_ALL, false); +} diff --git a/tools/testing/selftests/bpf/progs/linked_list.c b/tools/testing/selftests/bpf/progs/linked_list.c new file mode 100644 index 000000000000..2c7b615c6d41 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/linked_list.c @@ -0,0 +1,370 @@ +// SPDX-License-Identifier: GPL-2.0 +#include +#include +#include +#include +#include "bpf_experimental.h" + +#ifndef ARRAY_SIZE +#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0])) +#endif + +#include "linked_list.h" + +static __always_inline +int list_push_pop(struct bpf_spin_lock *lock, struct bpf_list_head *head, bool leave_in_map) +{ + struct bpf_list_node *n; + struct foo *f; + + f = bpf_obj_new(typeof(*f)); + if (!f) + return 2; + + bpf_spin_lock(lock); + n = bpf_list_pop_front(head); + bpf_spin_unlock(lock); + if (n) { + bpf_obj_drop(container_of(n, struct foo, node)); + bpf_obj_drop(f); + return 3; + } + + bpf_spin_lock(lock); + n = bpf_list_pop_back(head); + bpf_spin_unlock(lock); + if (n) { + bpf_obj_drop(container_of(n, struct foo, node)); + bpf_obj_drop(f); + return 4; + } + + + bpf_spin_lock(lock); + f->data = 42; + bpf_list_push_front(head, &f->node); + bpf_spin_unlock(lock); + if (leave_in_map) + return 0; + bpf_spin_lock(lock); + n = bpf_list_pop_back(head); + bpf_spin_unlock(lock); + if (!n) + return 5; + f = container_of(n, struct foo, node); + if (f->data != 42) { + bpf_obj_drop(f); + return 6; + } + + bpf_spin_lock(lock); + f->data = 13; + bpf_list_push_front(head, &f->node); + bpf_spin_unlock(lock); + bpf_spin_lock(lock); + n = bpf_list_pop_front(head); + bpf_spin_unlock(lock); + if (!n) + return 7; + f = container_of(n, struct foo, node); + if (f->data != 13) { + bpf_obj_drop(f); + return 8; + } + bpf_obj_drop(f); + + bpf_spin_lock(lock); + n = bpf_list_pop_front(head); + bpf_spin_unlock(lock); + if (n) { + bpf_obj_drop(container_of(n, struct foo, node)); + return 9; + } + + bpf_spin_lock(lock); + n = bpf_list_pop_back(head); + bpf_spin_unlock(lock); + if (n) { + bpf_obj_drop(container_of(n, struct foo, node)); + return 10; + } + return 0; +} + + +static __always_inline +int list_push_pop_multiple(struct bpf_spin_lock *lock, struct bpf_list_head *head, bool leave_in_map) +{ + struct bpf_list_node *n; + struct foo *f[8], *pf; + int i; + + for (i = 0; i < ARRAY_SIZE(f); i++) { + f[i] = bpf_obj_new(typeof(**f)); + if (!f[i]) + return 2; + f[i]->data = i; + bpf_spin_lock(lock); + bpf_list_push_front(head, &f[i]->node); + bpf_spin_unlock(lock); + } + + for (i = 0; i < ARRAY_SIZE(f); i++) { + bpf_spin_lock(lock); + n = bpf_list_pop_front(head); + bpf_spin_unlock(lock); + if (!n) + return 3; + pf = container_of(n, struct foo, node); + if (pf->data != (ARRAY_SIZE(f) - i - 1)) { + bpf_obj_drop(pf); + return 4; + } + bpf_spin_lock(lock); + bpf_list_push_back(head, &pf->node); + bpf_spin_unlock(lock); + } + + if (leave_in_map) + return 0; + + for (i = 0; i < ARRAY_SIZE(f); i++) { + bpf_spin_lock(lock); + n = bpf_list_pop_back(head); + bpf_spin_unlock(lock); + if (!n) + return 5; + pf = container_of(n, struct foo, node); + if (pf->data != i) { + bpf_obj_drop(pf); + return 6; + } + bpf_obj_drop(pf); + } + bpf_spin_lock(lock); + n = bpf_list_pop_back(head); + bpf_spin_unlock(lock); + if (n) { + bpf_obj_drop(container_of(n, struct foo, node)); + return 7; + } + + bpf_spin_lock(lock); + n = bpf_list_pop_front(head); + bpf_spin_unlock(lock); + if (n) { + bpf_obj_drop(container_of(n, struct foo, node)); + return 8; + } + return 0; +} + +static __always_inline +int list_in_list(struct bpf_spin_lock *lock, struct bpf_list_head *head, bool leave_in_map) +{ + struct bpf_list_node *n; + struct bar *ba[8], *b; + struct foo *f; + int i; + + f = bpf_obj_new(typeof(*f)); + if (!f) + return 2; + for (i = 0; i < ARRAY_SIZE(ba); i++) { + b = bpf_obj_new(typeof(*b)); + if (!b) { + bpf_obj_drop(f); + return 3; + } + b->data = i; + bpf_spin_lock(&f->lock); + bpf_list_push_back(&f->head, &b->node); + bpf_spin_unlock(&f->lock); + } + + bpf_spin_lock(lock); + f->data = 42; + bpf_list_push_front(head, &f->node); + bpf_spin_unlock(lock); + + if (leave_in_map) + return 0; + + bpf_spin_lock(lock); + n = bpf_list_pop_front(head); + bpf_spin_unlock(lock); + if (!n) + return 4; + f = container_of(n, struct foo, node); + if (f->data != 42) { + bpf_obj_drop(f); + return 5; + } + + for (i = 0; i < ARRAY_SIZE(ba); i++) { + bpf_spin_lock(&f->lock); + n = bpf_list_pop_front(&f->head); + bpf_spin_unlock(&f->lock); + if (!n) { + bpf_obj_drop(f); + return 6; + } + b = container_of(n, struct bar, node); + if (b->data != i) { + bpf_obj_drop(f); + bpf_obj_drop(b); + return 7; + } + bpf_obj_drop(b); + } + bpf_spin_lock(&f->lock); + n = bpf_list_pop_front(&f->head); + bpf_spin_unlock(&f->lock); + if (n) { + bpf_obj_drop(f); + bpf_obj_drop(container_of(n, struct bar, node)); + return 8; + } + bpf_obj_drop(f); + return 0; +} + +static __always_inline +int test_list_push_pop(struct bpf_spin_lock *lock, struct bpf_list_head *head) +{ + int ret; + + ret = list_push_pop(lock, head, false); + if (ret) + return ret; + return list_push_pop(lock, head, true); +} + +static __always_inline +int test_list_push_pop_multiple(struct bpf_spin_lock *lock, struct bpf_list_head *head) +{ + int ret; + + ret = list_push_pop_multiple(lock ,head, false); + if (ret) + return ret; + return list_push_pop_multiple(lock, head, true); +} + +static __always_inline +int test_list_in_list(struct bpf_spin_lock *lock, struct bpf_list_head *head) +{ + int ret; + + ret = list_in_list(lock, head, false); + if (ret) + return ret; + return list_in_list(lock, head, true); +} + +SEC("tc") +int map_list_push_pop(void *ctx) +{ + struct map_value *v; + + v = bpf_map_lookup_elem(&array_map, &(int){0}); + if (!v) + return 1; + return test_list_push_pop(&v->lock, &v->head); +} + +SEC("tc") +int inner_map_list_push_pop(void *ctx) +{ + struct map_value *v; + void *map; + + map = bpf_map_lookup_elem(&map_of_maps, &(int){0}); + if (!map) + return 1; + v = bpf_map_lookup_elem(map, &(int){0}); + if (!v) + return 1; + return test_list_push_pop(&v->lock, &v->head); +} + +SEC("tc") +int global_list_push_pop(void *ctx) +{ + return test_list_push_pop(&glock, &ghead); +} + +SEC("tc") +int map_list_push_pop_multiple(void *ctx) +{ + struct map_value *v; + int ret; + + v = bpf_map_lookup_elem(&array_map, &(int){0}); + if (!v) + return 1; + return test_list_push_pop_multiple(&v->lock, &v->head); +} + +SEC("tc") +int inner_map_list_push_pop_multiple(void *ctx) +{ + struct map_value *v; + void *map; + int ret; + + map = bpf_map_lookup_elem(&map_of_maps, &(int){0}); + if (!map) + return 1; + v = bpf_map_lookup_elem(map, &(int){0}); + if (!v) + return 1; + return test_list_push_pop_multiple(&v->lock, &v->head); +} + +SEC("tc") +int global_list_push_pop_multiple(void *ctx) +{ + int ret; + + ret = list_push_pop_multiple(&glock, &ghead, false); + if (ret) + return ret; + return list_push_pop_multiple(&glock, &ghead, true); +} + +SEC("tc") +int map_list_in_list(void *ctx) +{ + struct map_value *v; + int ret; + + v = bpf_map_lookup_elem(&array_map, &(int){0}); + if (!v) + return 1; + return test_list_in_list(&v->lock, &v->head); +} + +SEC("tc") +int inner_map_list_in_list(void *ctx) +{ + struct map_value *v; + void *map; + int ret; + + map = bpf_map_lookup_elem(&map_of_maps, &(int){0}); + if (!map) + return 1; + v = bpf_map_lookup_elem(map, &(int){0}); + if (!v) + return 1; + return test_list_in_list(&v->lock, &v->head); +} + +SEC("tc") +int global_list_in_list(void *ctx) +{ + return test_list_in_list(&glock, &ghead); +} + +char _license[] SEC("license") = "GPL"; diff --git a/tools/testing/selftests/bpf/progs/linked_list.h b/tools/testing/selftests/bpf/progs/linked_list.h new file mode 100644 index 000000000000..8db80ed64db1 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/linked_list.h @@ -0,0 +1,56 @@ +// SPDX-License-Identifier: GPL-2.0 +#ifndef LINKED_LIST_H +#define LINKED_LIST_H + +#include +#include +#include "bpf_experimental.h" + +struct bar { + struct bpf_list_node node; + int data; +}; + +struct foo { + struct bpf_list_node node; + struct bpf_list_head head __contains(bar, node); + struct bpf_spin_lock lock; + int data; + struct bpf_list_node node2; +}; + +struct map_value { + struct bpf_spin_lock lock; + int data; + struct bpf_list_head head __contains(foo, node); +}; + +struct array_map { + __uint(type, BPF_MAP_TYPE_ARRAY); + __type(key, int); + __type(value, struct map_value); + __uint(max_entries, 1); +}; + +struct array_map array_map SEC(".maps"); +struct array_map inner_map SEC(".maps"); + +struct { + __uint(type, BPF_MAP_TYPE_ARRAY_OF_MAPS); + __uint(max_entries, 1); + __type(key, int); + __type(value, int); + __array(values, struct array_map); +} map_of_maps SEC(".maps") = { + .values = { + [0] = &inner_map, + }, +}; + +#define private(name) SEC(".data." #name) __hidden __attribute__((aligned(8))) + +private(A) struct bpf_spin_lock glock; +private(A) struct bpf_list_head ghead __contains(foo, node); +private(B) struct bpf_spin_lock glock2; + +#endif diff --git a/tools/testing/selftests/bpf/progs/linked_list_fail.c b/tools/testing/selftests/bpf/progs/linked_list_fail.c new file mode 100644 index 000000000000..1d9017240e19 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/linked_list_fail.c @@ -0,0 +1,581 @@ +// SPDX-License-Identifier: GPL-2.0 +#include +#include +#include +#include +#include "bpf_experimental.h" + +#include "linked_list.h" + +#define INIT \ + struct map_value *v, *v2, *iv, *iv2; \ + struct foo *f, *f1, *f2; \ + struct bar *b; \ + void *map; \ + \ + map = bpf_map_lookup_elem(&map_of_maps, &(int){ 0 }); \ + if (!map) \ + return 0; \ + v = bpf_map_lookup_elem(&array_map, &(int){ 0 }); \ + if (!v) \ + return 0; \ + v2 = bpf_map_lookup_elem(&array_map, &(int){ 0 }); \ + if (!v2) \ + return 0; \ + iv = bpf_map_lookup_elem(map, &(int){ 0 }); \ + if (!iv) \ + return 0; \ + iv2 = bpf_map_lookup_elem(map, &(int){ 0 }); \ + if (!iv2) \ + return 0; \ + f = bpf_obj_new(typeof(*f)); \ + if (!f) \ + return 0; \ + f1 = f; \ + f2 = bpf_obj_new(typeof(*f2)); \ + if (!f2) { \ + bpf_obj_drop(f1); \ + return 0; \ + } \ + b = bpf_obj_new(typeof(*b)); \ + if (!b) { \ + bpf_obj_drop(f2); \ + bpf_obj_drop(f1); \ + return 0; \ + } + +#define CHECK(test, op, hexpr) \ + SEC("?tc") \ + int test##_missing_lock_##op(void *ctx) \ + { \ + INIT; \ + void (*p)(void *) = (void *)&bpf_list_##op; \ + p(hexpr); \ + return 0; \ + } + +CHECK(kptr, push_front, &f->head); +CHECK(kptr, push_back, &f->head); +CHECK(kptr, pop_front, &f->head); +CHECK(kptr, pop_back, &f->head); + +CHECK(global, push_front, &ghead); +CHECK(global, push_back, &ghead); +CHECK(global, pop_front, &ghead); +CHECK(global, pop_back, &ghead); + +CHECK(map, push_front, &v->head); +CHECK(map, push_back, &v->head); +CHECK(map, pop_front, &v->head); +CHECK(map, pop_back, &v->head); + +CHECK(inner_map, push_front, &iv->head); +CHECK(inner_map, push_back, &iv->head); +CHECK(inner_map, pop_front, &iv->head); +CHECK(inner_map, pop_back, &iv->head); + +#undef CHECK + +#define CHECK(test, op, lexpr, hexpr) \ + SEC("?tc") \ + int test##_incorrect_lock_##op(void *ctx) \ + { \ + INIT; \ + void (*p)(void *) = (void *)&bpf_list_##op; \ + bpf_spin_lock(lexpr); \ + p(hexpr); \ + return 0; \ + } + +#define CHECK_OP(op) \ + CHECK(kptr_kptr, op, &f1->lock, &f2->head); \ + CHECK(kptr_global, op, &f1->lock, &ghead); \ + CHECK(kptr_map, op, &f1->lock, &v->head); \ + CHECK(kptr_inner_map, op, &f1->lock, &iv->head); \ + \ + CHECK(global_global, op, &glock2, &ghead); \ + CHECK(global_kptr, op, &glock, &f1->head); \ + CHECK(global_map, op, &glock, &v->head); \ + CHECK(global_inner_map, op, &glock, &iv->head); \ + \ + CHECK(map_map, op, &v->lock, &v2->head); \ + CHECK(map_kptr, op, &v->lock, &f2->head); \ + CHECK(map_global, op, &v->lock, &ghead); \ + CHECK(map_inner_map, op, &v->lock, &iv->head); \ + \ + CHECK(inner_map_inner_map, op, &iv->lock, &iv2->head); \ + CHECK(inner_map_kptr, op, &iv->lock, &f2->head); \ + CHECK(inner_map_global, op, &iv->lock, &ghead); \ + CHECK(inner_map_map, op, &iv->lock, &v->head); + +CHECK_OP(push_front); +CHECK_OP(push_back); +CHECK_OP(pop_front); +CHECK_OP(pop_back); + +#undef CHECK +#undef CHECK_OP +#undef INIT + +SEC("?kprobe/xyz") +int map_compat_kprobe(void *ctx) +{ + bpf_list_push_front(&ghead, NULL); + return 0; +} + +SEC("?kretprobe/xyz") +int map_compat_kretprobe(void *ctx) +{ + bpf_list_push_front(&ghead, NULL); + return 0; +} + +SEC("?tracepoint/xyz") +int map_compat_tp(void *ctx) +{ + bpf_list_push_front(&ghead, NULL); + return 0; +} + +SEC("?perf_event") +int map_compat_perf(void *ctx) +{ + bpf_list_push_front(&ghead, NULL); + return 0; +} + +SEC("?raw_tp/xyz") +int map_compat_raw_tp(void *ctx) +{ + bpf_list_push_front(&ghead, NULL); + return 0; +} + +SEC("?raw_tp.w/xyz") +int map_compat_raw_tp_w(void *ctx) +{ + bpf_list_push_front(&ghead, NULL); + return 0; +} + +SEC("?tc") +int obj_type_id_oor(void *ctx) +{ + bpf_obj_new_impl(~0UL, NULL); + return 0; +} + +SEC("?tc") +int obj_new_no_composite(void *ctx) +{ + bpf_obj_new_impl(bpf_core_type_id_local(int), (void *)42); + return 0; +} + +SEC("?tc") +int obj_new_no_struct(void *ctx) +{ + + bpf_obj_new(union { int data; unsigned udata; }); + return 0; +} + +SEC("?tc") +int obj_drop_non_zero_off(void *ctx) +{ + void *f; + + f = bpf_obj_new(struct foo); + if (!f) + return 0; + bpf_obj_drop(f+1); + return 0; +} + +SEC("?tc") +int new_null_ret(void *ctx) +{ + return bpf_obj_new(struct foo)->data; +} + +SEC("?tc") +int obj_new_acq(void *ctx) +{ + bpf_obj_new(struct foo); + return 0; +} + +SEC("?tc") +int use_after_drop(void *ctx) +{ + struct foo *f; + + f = bpf_obj_new(typeof(*f)); + if (!f) + return 0; + bpf_obj_drop(f); + return f->data; +} + +SEC("?tc") +int ptr_walk_scalar(void *ctx) +{ + struct test1 { + struct test2 { + struct test2 *next; + } *ptr; + } *p; + + p = bpf_obj_new(typeof(*p)); + if (!p) + return 0; + bpf_this_cpu_ptr(p->ptr); + return 0; +} + +SEC("?tc") +int direct_read_lock(void *ctx) +{ + struct foo *f; + + f = bpf_obj_new(typeof(*f)); + if (!f) + return 0; + return *(int *)&f->lock; +} + +SEC("?tc") +int direct_write_lock(void *ctx) +{ + struct foo *f; + + f = bpf_obj_new(typeof(*f)); + if (!f) + return 0; + *(int *)&f->lock = 0; + return 0; +} + +SEC("?tc") +int direct_read_head(void *ctx) +{ + struct foo *f; + + f = bpf_obj_new(typeof(*f)); + if (!f) + return 0; + return *(int *)&f->head; +} + +SEC("?tc") +int direct_write_head(void *ctx) +{ + struct foo *f; + + f = bpf_obj_new(typeof(*f)); + if (!f) + return 0; + *(int *)&f->head = 0; + return 0; +} + +SEC("?tc") +int direct_read_node(void *ctx) +{ + struct foo *f; + + f = bpf_obj_new(typeof(*f)); + if (!f) + return 0; + return *(int *)&f->node; +} + +SEC("?tc") +int direct_write_node(void *ctx) +{ + struct foo *f; + + f = bpf_obj_new(typeof(*f)); + if (!f) + return 0; + *(int *)&f->node = 0; + return 0; +} + +static __always_inline +int write_after_op(void (*push_op)(void *head, void *node)) +{ + struct foo *f; + + f = bpf_obj_new(typeof(*f)); + if (!f) + return 0; + bpf_spin_lock(&glock); + push_op(&ghead, &f->node); + f->data = 42; + bpf_spin_unlock(&glock); + + return 0; +} + +SEC("?tc") +int write_after_push_front(void *ctx) +{ + return write_after_op((void *)bpf_list_push_front); +} + +SEC("?tc") +int write_after_push_back(void *ctx) +{ + return write_after_op((void *)bpf_list_push_back); +} + +static __always_inline +int use_after_unlock(void (*op)(void *head, void *node)) +{ + struct foo *f; + + f = bpf_obj_new(typeof(*f)); + if (!f) + return 0; + bpf_spin_lock(&glock); + f->data = 42; + op(&ghead, &f->node); + bpf_spin_unlock(&glock); + + return f->data; +} + +SEC("?tc") +int use_after_unlock_push_front(void *ctx) +{ + return use_after_unlock((void *)bpf_list_push_front); +} + +SEC("?tc") +int use_after_unlock_push_back(void *ctx) +{ + return use_after_unlock((void *)bpf_list_push_back); +} + +static __always_inline +int list_double_add(void (*op)(void *head, void *node)) +{ + struct foo *f; + + f = bpf_obj_new(typeof(*f)); + if (!f) + return 0; + bpf_spin_lock(&glock); + op(&ghead, &f->node); + op(&ghead, &f->node); + bpf_spin_unlock(&glock); + + return 0; +} + +SEC("?tc") +int double_push_front(void *ctx) +{ + return list_double_add((void *)bpf_list_push_front); +} + +SEC("?tc") +int double_push_back(void *ctx) +{ + return list_double_add((void *)bpf_list_push_back); +} + +SEC("?tc") +int no_node_value_type(void *ctx) +{ + void *p; + + p = bpf_obj_new(struct { int data; }); + if (!p) + return 0; + bpf_spin_lock(&glock); + bpf_list_push_front(&ghead, p); + bpf_spin_unlock(&glock); + + return 0; +} + +SEC("?tc") +int incorrect_value_type(void *ctx) +{ + struct bar *b; + + b = bpf_obj_new(typeof(*b)); + if (!b) + return 0; + bpf_spin_lock(&glock); + bpf_list_push_front(&ghead, &b->node); + bpf_spin_unlock(&glock); + + return 0; +} + +SEC("?tc") +int incorrect_node_var_off(struct __sk_buff *ctx) +{ + struct foo *f; + + f = bpf_obj_new(typeof(*f)); + if (!f) + return 0; + bpf_spin_lock(&glock); + bpf_list_push_front(&ghead, (void *)&f->node + ctx->protocol); + bpf_spin_unlock(&glock); + + return 0; +} + +SEC("?tc") +int incorrect_node_off1(void *ctx) +{ + struct foo *f; + + f = bpf_obj_new(typeof(*f)); + if (!f) + return 0; + bpf_spin_lock(&glock); + bpf_list_push_front(&ghead, (void *)&f->node + 1); + bpf_spin_unlock(&glock); + + return 0; +} + +SEC("?tc") +int incorrect_node_off2(void *ctx) +{ + struct foo *f; + + f = bpf_obj_new(typeof(*f)); + if (!f) + return 0; + bpf_spin_lock(&glock); + bpf_list_push_front(&ghead, &f->node2); + bpf_spin_unlock(&glock); + + return 0; +} + +SEC("?tc") +int no_head_type(void *ctx) +{ + void *p; + + p = bpf_obj_new(typeof(struct { int data; })); + if (!p) + return 0; + bpf_spin_lock(&glock); + bpf_list_push_front(p, NULL); + bpf_spin_lock(&glock); + + return 0; +} + +SEC("?tc") +int incorrect_head_var_off1(struct __sk_buff *ctx) +{ + struct foo *f; + + f = bpf_obj_new(typeof(*f)); + if (!f) + return 0; + bpf_spin_lock(&glock); + bpf_list_push_front((void *)&ghead + ctx->protocol, &f->node); + bpf_spin_unlock(&glock); + + return 0; +} + +SEC("?tc") +int incorrect_head_var_off2(struct __sk_buff *ctx) +{ + struct foo *f; + + f = bpf_obj_new(typeof(*f)); + if (!f) + return 0; + bpf_spin_lock(&glock); + bpf_list_push_front((void *)&f->head + ctx->protocol, &f->node); + bpf_spin_unlock(&glock); + + return 0; +} + +SEC("?tc") +int incorrect_head_off1(void *ctx) +{ + struct foo *f; + struct bar *b; + + f = bpf_obj_new(typeof(*f)); + if (!f) + return 0; + b = bpf_obj_new(typeof(*b)); + if (!b) { + bpf_obj_drop(f); + return 0; + } + + bpf_spin_lock(&f->lock); + bpf_list_push_front((void *)&f->head + 1, &b->node); + bpf_spin_unlock(&f->lock); + + return 0; +} + +SEC("?tc") +int incorrect_head_off2(void *ctx) +{ + struct foo *f; + struct bar *b; + + f = bpf_obj_new(typeof(*f)); + if (!f) + return 0; + + bpf_spin_lock(&glock); + bpf_list_push_front((void *)&ghead + 1, &f->node); + bpf_spin_unlock(&glock); + + return 0; +} + +static __always_inline +int pop_ptr_off(void *(*op)(void *head)) +{ + struct { + struct bpf_list_head head __contains(foo, node2); + struct bpf_spin_lock lock; + } *p; + struct bpf_list_node *n; + + p = bpf_obj_new(typeof(*p)); + if (!p) + return 0; + bpf_spin_lock(&p->lock); + n = op(&p->head); + bpf_spin_unlock(&p->lock); + + bpf_this_cpu_ptr(n); + return 0; +} + +SEC("?tc") +int pop_front_off(void *ctx) +{ + return pop_ptr_off((void *)bpf_list_pop_front); +} + +SEC("?tc") +int pop_back_off(void *ctx) +{ + return pop_ptr_off((void *)bpf_list_pop_back); +} + +char _license[] SEC("license") = "GPL"; From patchwork Thu Nov 17 22:55:10 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kumar Kartikeya Dwivedi X-Patchwork-Id: 13047448 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 904EFC433FE for ; Thu, 17 Nov 2022 22:56:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235086AbiKQW4s (ORCPT ); Thu, 17 Nov 2022 17:56:48 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54068 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239958AbiKQW4o (ORCPT ); Thu, 17 Nov 2022 17:56:44 -0500 Received: from mail-pl1-x641.google.com (mail-pl1-x641.google.com [IPv6:2607:f8b0:4864:20::641]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4E6746454C for ; Thu, 17 Nov 2022 14:56:42 -0800 (PST) Received: by mail-pl1-x641.google.com with SMTP id b21so2980829plc.9 for ; Thu, 17 Nov 2022 14:56:42 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=XwhI9UjMlgnSaJ4yIwRB3YYhVYaUoO/AJsMpZl09zdI=; b=MWdJEdoop+q7mBtB8LzC9xtrhK8nyauClX+u9HtipH+8eCgUmOqJgCks9pXw3EU+j/ IfF9DMD1cy6yehGhaHYQWSdyvl85N10zJ2Q6DIQyVhnDl1enhddzr47Xc79bxZkctBbE ecVww+fhzhRM7xoFX11iKUwhC5cBo+nZkvpTouxRkvZfKduDXkIjOoD+uA+IsGSotBPK iDDYkq1VJb01RH2c5O0KeOqXBhKgtBEVMo47Bi1yyDm5svee3urZDnJDChVJhbZe0cRq 9mAmjvl2kKm++A2rd3ZYN7VcMl0QfLtnO/J0WdblTFQ6LSCg8TGad+KbhvF0Osbv29eJ o8Xw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=XwhI9UjMlgnSaJ4yIwRB3YYhVYaUoO/AJsMpZl09zdI=; b=tzkPEwu8tpUYwGKvfvXHbtpk4fFMfTX3IweWJJ/+4mynQ8fUSofDj2NVlF1qTXKsyF SEk5EcB/HXJow85O6FrrbEBusLuhRUIuelIK1yYR1n4HQPUBeI2IbrpMzIyLa5l1fvQB LpUtczLP4S6VHaU3nAFWLcy7bb/6t9dAkomKdFLBJw5tZWBi7zzaz4C9FzIjQZ16+X8K FgMi/HspGvfCjRcTUdZxGkTROsDuCRPlfpN8UnmIKlMy1hWnwTyVskkoaYokrP1aBBW3 08w2ZiWzlNf1kbmNacIwTvndfwJo8CbYa6HCm6SC2t1dFHD0QBo5qk7Evqyzvbj+8dHc tWiQ== X-Gm-Message-State: ANoB5pl+ZdwY+2AkuepJ5DCeA0bBb6p99KjDODYW1sypdloNqHEJ21PY +lsyaJQaR+Lbd/vNLPn7VVlq9ZuSEIY= X-Google-Smtp-Source: AA0mqf5TdhtytvcEy36sruiDeqjiEWnZ+17pRuICpR3dVIHntb/kL/4Q/pdxShHQx9KneR/hjYGbEw== X-Received: by 2002:a17:902:6946:b0:188:5c52:83e1 with SMTP id k6-20020a170902694600b001885c5283e1mr4848914plt.128.1668725801402; Thu, 17 Nov 2022 14:56:41 -0800 (PST) Received: from localhost ([2409:40f4:8:955c:5484:8048:c08:7b3]) by smtp.gmail.com with ESMTPSA id a76-20020a621a4f000000b0056203db46ffsm1706087pfa.172.2022.11.17.14.56.40 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 17 Nov 2022 14:56:40 -0800 (PST) From: Kumar Kartikeya Dwivedi To: bpf@vger.kernel.org Cc: Alexei Starovoitov , Andrii Nakryiko , Daniel Borkmann , Martin KaFai Lau , Dave Marchevsky Subject: [PATCH bpf-next v9 23/23] selftests/bpf: Add BTF sanity tests Date: Fri, 18 Nov 2022 04:25:10 +0530 Message-Id: <20221117225510.1676785-24-memxor@gmail.com> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20221117225510.1676785-1-memxor@gmail.com> References: <20221117225510.1676785-1-memxor@gmail.com> MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=17214; i=memxor@gmail.com; h=from:subject; bh=m6mr5NFhPzJ/0Ot1CEDqx+U9ru5SwrUF5yhiRrCE9Tw=; b=owEBbQKS/ZANAwAIAUzgyIZIvxHKAcsmYgBjdrkcr+BrcJbYD7UsjfSKLUkfQgC6fToUU+lmHaWE YhF9B8qJAjMEAAEIAB0WIQRLvip+Buz51YI8YRFM4MiGSL8RygUCY3a5HAAKCRBM4MiGSL8RynsgD/ 42uZZNc8NZVwkt+Q/xavu+2RMfgAoNnvVfiI1cD63V0XUt0iZEA0w2aAdId+5I38/m50LX5BTZnMEX qYZ2KlyLSluc/Hy0CA8mjIjeDPF3s07t4zpFcjE/MY+a8oHwUmkbmrUZh7kYvAxh1YI/hBn8ikAs0+ meduzMI2FU8wSQR4M87BdPg3zbAoffZJpOJbNMAEhZCQIBSyAwme8vsQrVytccpn2A556+JxWM0erV RUZIw2WyrWCUoaZziywvEhHrV/zUjtRM01ldPXElhi5ZHp+hUyBuCPoKNFXdVMrLjUX17eqEn8sL6y D8BER1l4rsakjVrDpTo2QkEbwAuqPA4juYGFUeVe4T76TF0bULvi38qQFgrefKONLL1kX/FIdGevZv yP4Z8yqmst5kpWQBf8LcYHCf7iJ4SIPAAJYEliIxsYXmyLaD3r8nwBi4jRcsEtqLQKimDL6zwyDT6n EI8dExNfVTiop9v+PBmi71A3DWZBdf5uimiLt0mSvekBBtUcIk/aGQORQCHnFiIKhaC5oIGlhiRfVy fK+LR/tbmrfDHw+FGDTGIGpb9EFq0jnpi3VHMQgeRrBolKj0V4BaCqVwLTFX6izJVMWe6WMXtbL92u juGNNM88aNaiunfG7/MLs93kEwJSmdYtkoyQ1Lt0dNIVqQAzYgFw8Ubw7Q8g== X-Developer-Key: i=memxor@gmail.com; a=openpgp; fpr=4BBE2A7E06ECF9D5823C61114CE0C88648BF11CA Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net Preparing the metadata for bpf_list_head involves a complicated parsing step and type resolution for the contained value. Ensure that corner cases are tested against and invalid specifications in source are duly rejected. Also include tests for incorrect ownership relationships in the BTF. Signed-off-by: Kumar Kartikeya Dwivedi --- .../selftests/bpf/prog_tests/linked_list.c | 485 ++++++++++++++++++ 1 file changed, 485 insertions(+) diff --git a/tools/testing/selftests/bpf/prog_tests/linked_list.c b/tools/testing/selftests/bpf/prog_tests/linked_list.c index 32ff1684a7d3..70241be92714 100644 --- a/tools/testing/selftests/bpf/prog_tests/linked_list.c +++ b/tools/testing/selftests/bpf/prog_tests/linked_list.c @@ -1,4 +1,7 @@ // SPDX-License-Identifier: GPL-2.0 +#include +#include +#include #include #include @@ -235,6 +238,487 @@ static void test_linked_list_success(int mode, bool leave_in_map) linked_list__destroy(skel); } +#define SPIN_LOCK 2 +#define LIST_HEAD 3 +#define LIST_NODE 4 + +static struct btf *init_btf(void) +{ + int id, lid, hid, nid; + struct btf *btf; + + btf = btf__new_empty(); + if (!ASSERT_OK_PTR(btf, "btf__new_empty")) + return NULL; + id = btf__add_int(btf, "int", 4, BTF_INT_SIGNED); + if (!ASSERT_EQ(id, 1, "btf__add_int")) + goto end; + lid = btf__add_struct(btf, "bpf_spin_lock", 4); + if (!ASSERT_EQ(lid, SPIN_LOCK, "btf__add_struct bpf_spin_lock")) + goto end; + hid = btf__add_struct(btf, "bpf_list_head", 16); + if (!ASSERT_EQ(hid, LIST_HEAD, "btf__add_struct bpf_list_head")) + goto end; + nid = btf__add_struct(btf, "bpf_list_node", 16); + if (!ASSERT_EQ(nid, LIST_NODE, "btf__add_struct bpf_list_node")) + goto end; + return btf; +end: + btf__free(btf); + return NULL; +} + +static void test_btf(void) +{ + struct btf *btf = NULL; + int id, err; + + while (test__start_subtest("btf: too many locks")) { + btf = init_btf(); + if (!ASSERT_OK_PTR(btf, "init_btf")) + break; + id = btf__add_struct(btf, "foo", 24); + if (!ASSERT_EQ(id, 5, "btf__add_struct foo")) + break; + err = btf__add_field(btf, "a", SPIN_LOCK, 0, 0); + if (!ASSERT_OK(err, "btf__add_struct foo::a")) + break; + err = btf__add_field(btf, "b", SPIN_LOCK, 32, 0); + if (!ASSERT_OK(err, "btf__add_struct foo::a")) + break; + err = btf__add_field(btf, "c", LIST_HEAD, 64, 0); + if (!ASSERT_OK(err, "btf__add_struct foo::a")) + break; + + err = btf__load_into_kernel(btf); + ASSERT_EQ(err, -E2BIG, "check btf"); + btf__free(btf); + break; + } + + while (test__start_subtest("btf: missing lock")) { + btf = init_btf(); + if (!ASSERT_OK_PTR(btf, "init_btf")) + break; + id = btf__add_struct(btf, "foo", 16); + if (!ASSERT_EQ(id, 5, "btf__add_struct foo")) + break; + err = btf__add_field(btf, "a", LIST_HEAD, 0, 0); + if (!ASSERT_OK(err, "btf__add_struct foo::a")) + break; + id = btf__add_decl_tag(btf, "contains:baz:a", 5, 0); + if (!ASSERT_EQ(id, 6, "btf__add_decl_tag contains:baz:a")) + break; + id = btf__add_struct(btf, "baz", 16); + if (!ASSERT_EQ(id, 7, "btf__add_struct baz")) + break; + err = btf__add_field(btf, "a", LIST_NODE, 0, 0); + if (!ASSERT_OK(err, "btf__add_field baz::a")) + break; + + err = btf__load_into_kernel(btf); + ASSERT_EQ(err, -EINVAL, "check btf"); + btf__free(btf); + break; + } + + while (test__start_subtest("btf: bad offset")) { + btf = init_btf(); + if (!ASSERT_OK_PTR(btf, "init_btf")) + break; + id = btf__add_struct(btf, "foo", 36); + if (!ASSERT_EQ(id, 5, "btf__add_struct foo")) + break; + err = btf__add_field(btf, "a", LIST_HEAD, 0, 0); + if (!ASSERT_OK(err, "btf__add_field foo::a")) + break; + err = btf__add_field(btf, "b", LIST_NODE, 0, 0); + if (!ASSERT_OK(err, "btf__add_field foo::b")) + break; + err = btf__add_field(btf, "c", SPIN_LOCK, 0, 0); + if (!ASSERT_OK(err, "btf__add_field foo::c")) + break; + id = btf__add_decl_tag(btf, "contains:foo:b", 5, 0); + if (!ASSERT_EQ(id, 6, "btf__add_decl_tag contains:foo:b")) + break; + + err = btf__load_into_kernel(btf); + ASSERT_EQ(err, -EEXIST, "check btf"); + btf__free(btf); + break; + } + + while (test__start_subtest("btf: missing contains:")) { + btf = init_btf(); + if (!ASSERT_OK_PTR(btf, "init_btf")) + break; + id = btf__add_struct(btf, "foo", 24); + if (!ASSERT_EQ(id, 5, "btf__add_struct foo")) + break; + err = btf__add_field(btf, "a", SPIN_LOCK, 0, 0); + if (!ASSERT_OK(err, "btf__add_field foo::a")) + break; + err = btf__add_field(btf, "b", LIST_HEAD, 64, 0); + if (!ASSERT_OK(err, "btf__add_field foo::b")) + break; + + err = btf__load_into_kernel(btf); + ASSERT_EQ(err, -EINVAL, "check btf"); + btf__free(btf); + break; + } + + while (test__start_subtest("btf: missing struct")) { + btf = init_btf(); + if (!ASSERT_OK_PTR(btf, "init_btf")) + break; + id = btf__add_struct(btf, "foo", 24); + if (!ASSERT_EQ(id, 5, "btf__add_struct foo")) + break; + err = btf__add_field(btf, "a", SPIN_LOCK, 0, 0); + if (!ASSERT_OK(err, "btf__add_field foo::a")) + break; + err = btf__add_field(btf, "b", LIST_HEAD, 64, 0); + if (!ASSERT_OK(err, "btf__add_field foo::b")) + break; + id = btf__add_decl_tag(btf, "contains:bar:bar", 5, 1); + if (!ASSERT_EQ(id, 6, "btf__add_decl_tag contains:bar:bar")) + break; + + err = btf__load_into_kernel(btf); + ASSERT_EQ(err, -ENOENT, "check btf"); + btf__free(btf); + break; + } + + while (test__start_subtest("btf: missing node")) { + btf = init_btf(); + if (!ASSERT_OK_PTR(btf, "init_btf")) + break; + id = btf__add_struct(btf, "foo", 24); + if (!ASSERT_EQ(id, 5, "btf__add_struct foo")) + break; + err = btf__add_field(btf, "a", SPIN_LOCK, 0, 0); + if (!ASSERT_OK(err, "btf__add_field foo::a")) + break; + err = btf__add_field(btf, "b", LIST_HEAD, 64, 0); + if (!ASSERT_OK(err, "btf__add_field foo::b")) + break; + id = btf__add_decl_tag(btf, "contains:foo:c", 5, 1); + if (!ASSERT_EQ(id, 6, "btf__add_decl_tag contains:foo:c")) + break; + + err = btf__load_into_kernel(btf); + btf__free(btf); + ASSERT_EQ(err, -ENOENT, "check btf"); + break; + } + + while (test__start_subtest("btf: node incorrect type")) { + btf = init_btf(); + if (!ASSERT_OK_PTR(btf, "init_btf")) + break; + id = btf__add_struct(btf, "foo", 20); + if (!ASSERT_EQ(id, 5, "btf__add_struct foo")) + break; + err = btf__add_field(btf, "a", LIST_HEAD, 0, 0); + if (!ASSERT_OK(err, "btf__add_field foo::a")) + break; + err = btf__add_field(btf, "b", SPIN_LOCK, 128, 0); + if (!ASSERT_OK(err, "btf__add_field foo::b")) + break; + id = btf__add_decl_tag(btf, "contains:bar:a", 5, 0); + if (!ASSERT_EQ(id, 6, "btf__add_decl_tag contains:bar:a")) + break; + id = btf__add_struct(btf, "bar", 4); + if (!ASSERT_EQ(id, 7, "btf__add_struct bar")) + break; + err = btf__add_field(btf, "a", SPIN_LOCK, 0, 0); + if (!ASSERT_OK(err, "btf__add_field bar::a")) + break; + + err = btf__load_into_kernel(btf); + ASSERT_EQ(err, -EINVAL, "check btf"); + btf__free(btf); + break; + } + + while (test__start_subtest("btf: multiple bpf_list_node with name b")) { + btf = init_btf(); + if (!ASSERT_OK_PTR(btf, "init_btf")) + break; + id = btf__add_struct(btf, "foo", 52); + if (!ASSERT_EQ(id, 5, "btf__add_struct foo")) + break; + err = btf__add_field(btf, "a", LIST_HEAD, 0, 0); + if (!ASSERT_OK(err, "btf__add_field foo::a")) + break; + err = btf__add_field(btf, "b", LIST_NODE, 128, 0); + if (!ASSERT_OK(err, "btf__add_field foo::b")) + break; + err = btf__add_field(btf, "b", LIST_NODE, 256, 0); + if (!ASSERT_OK(err, "btf__add_field foo::c")) + break; + err = btf__add_field(btf, "d", SPIN_LOCK, 384, 0); + if (!ASSERT_OK(err, "btf__add_field foo::d")) + break; + id = btf__add_decl_tag(btf, "contains:foo:b", 5, 0); + if (!ASSERT_EQ(id, 6, "btf__add_decl_tag contains:foo:b")) + break; + + err = btf__load_into_kernel(btf); + ASSERT_EQ(err, -EINVAL, "check btf"); + btf__free(btf); + break; + } + + while (test__start_subtest("btf: owning | owned AA cycle")) { + btf = init_btf(); + if (!ASSERT_OK_PTR(btf, "init_btf")) + break; + id = btf__add_struct(btf, "foo", 36); + if (!ASSERT_EQ(id, 5, "btf__add_struct foo")) + break; + err = btf__add_field(btf, "a", LIST_HEAD, 0, 0); + if (!ASSERT_OK(err, "btf__add_field foo::a")) + break; + err = btf__add_field(btf, "b", LIST_NODE, 128, 0); + if (!ASSERT_OK(err, "btf__add_field foo::b")) + break; + err = btf__add_field(btf, "c", SPIN_LOCK, 256, 0); + if (!ASSERT_OK(err, "btf__add_field foo::c")) + break; + id = btf__add_decl_tag(btf, "contains:foo:b", 5, 0); + if (!ASSERT_EQ(id, 6, "btf__add_decl_tag contains:foo:b")) + break; + + err = btf__load_into_kernel(btf); + ASSERT_EQ(err, -ELOOP, "check btf"); + btf__free(btf); + break; + } + + while (test__start_subtest("btf: owning | owned ABA cycle")) { + btf = init_btf(); + if (!ASSERT_OK_PTR(btf, "init_btf")) + break; + id = btf__add_struct(btf, "foo", 36); + if (!ASSERT_EQ(id, 5, "btf__add_struct foo")) + break; + err = btf__add_field(btf, "a", LIST_HEAD, 0, 0); + if (!ASSERT_OK(err, "btf__add_field foo::a")) + break; + err = btf__add_field(btf, "b", LIST_NODE, 128, 0); + if (!ASSERT_OK(err, "btf__add_field foo::b")) + break; + err = btf__add_field(btf, "c", SPIN_LOCK, 256, 0); + if (!ASSERT_OK(err, "btf__add_field foo::c")) + break; + id = btf__add_decl_tag(btf, "contains:bar:b", 5, 0); + if (!ASSERT_EQ(id, 6, "btf__add_decl_tag contains:bar:b")) + break; + id = btf__add_struct(btf, "bar", 36); + if (!ASSERT_EQ(id, 7, "btf__add_struct bar")) + break; + err = btf__add_field(btf, "a", LIST_HEAD, 0, 0); + if (!ASSERT_OK(err, "btf__add_field bar::a")) + break; + err = btf__add_field(btf, "b", LIST_NODE, 128, 0); + if (!ASSERT_OK(err, "btf__add_field bar::b")) + break; + err = btf__add_field(btf, "c", SPIN_LOCK, 256, 0); + if (!ASSERT_OK(err, "btf__add_field bar::c")) + break; + id = btf__add_decl_tag(btf, "contains:foo:b", 7, 0); + if (!ASSERT_EQ(id, 8, "btf__add_decl_tag contains:foo:b")) + break; + + err = btf__load_into_kernel(btf); + ASSERT_EQ(err, -ELOOP, "check btf"); + btf__free(btf); + break; + } + + while (test__start_subtest("btf: owning -> owned")) { + btf = init_btf(); + if (!ASSERT_OK_PTR(btf, "init_btf")) + break; + id = btf__add_struct(btf, "foo", 20); + if (!ASSERT_EQ(id, 5, "btf__add_struct foo")) + break; + err = btf__add_field(btf, "a", LIST_HEAD, 0, 0); + if (!ASSERT_OK(err, "btf__add_field foo::a")) + break; + err = btf__add_field(btf, "b", SPIN_LOCK, 128, 0); + if (!ASSERT_OK(err, "btf__add_field foo::b")) + break; + id = btf__add_decl_tag(btf, "contains:bar:a", 5, 0); + if (!ASSERT_EQ(id, 6, "btf__add_decl_tag contains:bar:a")) + break; + id = btf__add_struct(btf, "bar", 16); + if (!ASSERT_EQ(id, 7, "btf__add_struct bar")) + break; + err = btf__add_field(btf, "a", LIST_NODE, 0, 0); + if (!ASSERT_OK(err, "btf__add_field bar::a")) + break; + + err = btf__load_into_kernel(btf); + ASSERT_EQ(err, 0, "check btf"); + btf__free(btf); + break; + } + + while (test__start_subtest("btf: owning -> owning | owned -> owned")) { + btf = init_btf(); + if (!ASSERT_OK_PTR(btf, "init_btf")) + break; + id = btf__add_struct(btf, "foo", 20); + if (!ASSERT_EQ(id, 5, "btf__add_struct foo")) + break; + err = btf__add_field(btf, "a", LIST_HEAD, 0, 0); + if (!ASSERT_OK(err, "btf__add_field foo::a")) + break; + err = btf__add_field(btf, "b", SPIN_LOCK, 128, 0); + if (!ASSERT_OK(err, "btf__add_field foo::b")) + break; + id = btf__add_decl_tag(btf, "contains:bar:b", 5, 0); + if (!ASSERT_EQ(id, 6, "btf__add_decl_tag contains:bar:b")) + break; + id = btf__add_struct(btf, "bar", 36); + if (!ASSERT_EQ(id, 7, "btf__add_struct bar")) + break; + err = btf__add_field(btf, "a", LIST_HEAD, 0, 0); + if (!ASSERT_OK(err, "btf__add_field bar::a")) + break; + err = btf__add_field(btf, "b", LIST_NODE, 128, 0); + if (!ASSERT_OK(err, "btf__add_field bar::b")) + break; + err = btf__add_field(btf, "c", SPIN_LOCK, 256, 0); + if (!ASSERT_OK(err, "btf__add_field bar::c")) + break; + id = btf__add_decl_tag(btf, "contains:baz:a", 7, 0); + if (!ASSERT_EQ(id, 8, "btf__add_decl_tag contains:baz:a")) + break; + id = btf__add_struct(btf, "baz", 16); + if (!ASSERT_EQ(id, 9, "btf__add_struct baz")) + break; + err = btf__add_field(btf, "a", LIST_NODE, 0, 0); + if (!ASSERT_OK(err, "btf__add_field baz:a")) + break; + + err = btf__load_into_kernel(btf); + ASSERT_EQ(err, 0, "check btf"); + btf__free(btf); + break; + } + + while (test__start_subtest("btf: owning | owned -> owning | owned -> owned")) { + btf = init_btf(); + if (!ASSERT_OK_PTR(btf, "init_btf")) + break; + id = btf__add_struct(btf, "foo", 36); + if (!ASSERT_EQ(id, 5, "btf__add_struct foo")) + break; + err = btf__add_field(btf, "a", LIST_HEAD, 0, 0); + if (!ASSERT_OK(err, "btf__add_field foo::a")) + break; + err = btf__add_field(btf, "b", LIST_NODE, 128, 0); + if (!ASSERT_OK(err, "btf__add_field foo::b")) + break; + err = btf__add_field(btf, "c", SPIN_LOCK, 256, 0); + if (!ASSERT_OK(err, "btf__add_field foo::c")) + break; + id = btf__add_decl_tag(btf, "contains:bar:b", 5, 0); + if (!ASSERT_EQ(id, 6, "btf__add_decl_tag contains:bar:b")) + break; + id = btf__add_struct(btf, "bar", 36); + if (!ASSERT_EQ(id, 7, "btf__add_struct bar")) + break; + err = btf__add_field(btf, "a", LIST_HEAD, 0, 0); + if (!ASSERT_OK(err, "btf__add_field bar:a")) + break; + err = btf__add_field(btf, "b", LIST_NODE, 128, 0); + if (!ASSERT_OK(err, "btf__add_field bar:b")) + break; + err = btf__add_field(btf, "c", SPIN_LOCK, 256, 0); + if (!ASSERT_OK(err, "btf__add_field bar:c")) + break; + id = btf__add_decl_tag(btf, "contains:baz:a", 7, 0); + if (!ASSERT_EQ(id, 8, "btf__add_decl_tag contains:baz:a")) + break; + id = btf__add_struct(btf, "baz", 16); + if (!ASSERT_EQ(id, 9, "btf__add_struct baz")) + break; + err = btf__add_field(btf, "a", LIST_NODE, 0, 0); + if (!ASSERT_OK(err, "btf__add_field baz:a")) + break; + + err = btf__load_into_kernel(btf); + ASSERT_EQ(err, -ELOOP, "check btf"); + btf__free(btf); + break; + } + + while (test__start_subtest("btf: owning -> owning | owned -> owning | owned -> owned")) { + btf = init_btf(); + if (!ASSERT_OK_PTR(btf, "init_btf")) + break; + id = btf__add_struct(btf, "foo", 20); + if (!ASSERT_EQ(id, 5, "btf__add_struct foo")) + break; + err = btf__add_field(btf, "a", LIST_HEAD, 0, 0); + if (!ASSERT_OK(err, "btf__add_field foo::a")) + break; + err = btf__add_field(btf, "b", SPIN_LOCK, 128, 0); + if (!ASSERT_OK(err, "btf__add_field foo::b")) + break; + id = btf__add_decl_tag(btf, "contains:bar:b", 5, 0); + if (!ASSERT_EQ(id, 6, "btf__add_decl_tag contains:bar:b")) + break; + id = btf__add_struct(btf, "bar", 36); + if (!ASSERT_EQ(id, 7, "btf__add_struct bar")) + break; + err = btf__add_field(btf, "a", LIST_HEAD, 0, 0); + if (!ASSERT_OK(err, "btf__add_field bar::a")) + break; + err = btf__add_field(btf, "b", LIST_NODE, 128, 0); + if (!ASSERT_OK(err, "btf__add_field bar::b")) + break; + err = btf__add_field(btf, "c", SPIN_LOCK, 256, 0); + if (!ASSERT_OK(err, "btf__add_field bar::c")) + break; + id = btf__add_decl_tag(btf, "contains:baz:b", 7, 0); + if (!ASSERT_EQ(id, 8, "btf__add_decl_tag")) + break; + id = btf__add_struct(btf, "baz", 36); + if (!ASSERT_EQ(id, 9, "btf__add_struct baz")) + break; + err = btf__add_field(btf, "a", LIST_HEAD, 0, 0); + if (!ASSERT_OK(err, "btf__add_field bar::a")) + break; + err = btf__add_field(btf, "b", LIST_NODE, 128, 0); + if (!ASSERT_OK(err, "btf__add_field bar::b")) + break; + err = btf__add_field(btf, "c", SPIN_LOCK, 256, 0); + if (!ASSERT_OK(err, "btf__add_field bar::c")) + break; + id = btf__add_decl_tag(btf, "contains:bam:a", 9, 0); + if (!ASSERT_EQ(id, 10, "btf__add_decl_tag contains:bam:a")) + break; + id = btf__add_struct(btf, "bam", 16); + if (!ASSERT_EQ(id, 11, "btf__add_struct bam")) + break; + err = btf__add_field(btf, "a", LIST_NODE, 0, 0); + if (!ASSERT_OK(err, "btf__add_field bam::a")) + break; + + err = btf__load_into_kernel(btf); + ASSERT_EQ(err, -ELOOP, "check btf"); + btf__free(btf); + break; + } +} + void test_linked_list(void) { int i; @@ -245,6 +729,7 @@ void test_linked_list(void) test_linked_list_fail_prog(linked_list_fail_tests[i].prog_name, linked_list_fail_tests[i].err_msg); } + test_btf(); test_linked_list_success(PUSH_POP, false); test_linked_list_success(PUSH_POP, true); test_linked_list_success(PUSH_POP_MULT, false);