From patchwork Tue Jun 28 16:19:44 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: KP Singh X-Patchwork-Id: 12898537 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 03189C433EF for ; Tue, 28 Jun 2022 16:30:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236271AbiF1QaY (ORCPT ); Tue, 28 Jun 2022 12:30:24 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47532 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1347466AbiF1Q3J (ORCPT ); Tue, 28 Jun 2022 12:29:09 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 581603A182; Tue, 28 Jun 2022 09:19:58 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 16A83B81F15; Tue, 28 Jun 2022 16:19:57 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1614EC341CD; Tue, 28 Jun 2022 16:19:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1656433195; bh=uZ0a5aDXW8MZkIEq0XmbcRjUTh8YkwmgzJs6XG0ENok=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=qCz6rDAbKU0oO71+34+lZjqNMXkCbW6WI+5/itTKjwMCcKz6Ukno9pgLnu0CrrQdQ YbGOa/8PMeu2M8Nw+G3b7CGJ9Pp71MEMY/lJw/O/yNuL1FjP/8D3aX5ooyUx+Qgxbf 1Z/aOr0tbvoOwvEzuaN3ViIWWLBloc+fRcDinX58eTrzolVw6LS5ac3XVX8pi6JQXg Mb/puUcabKhLRL22bKcJU6JlqPv0Vo4T9mZqmHB2v4LhQQ4la68DtBV5FdKe772o6y UQ4lrA4OM796Ud5f4deH88uo6gKU1LKnjFAvdSBtvCHassLxWROhMpodfqUqA+eH5X G9c2WfOI3xFgA== From: KP Singh To: bpf@vger.kernel.org, linux-security-module@vger.kernel.org, linux-fsdevel@vger.kernel.org Cc: KP Singh , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Benjamin Tissoires , Yosry Ahmed Subject: [PATCH v5 bpf-next 1/5] btf: Add a new kfunc set which allows to mark a function to be sleepable Date: Tue, 28 Jun 2022 16:19:44 +0000 Message-Id: <20220628161948.475097-2-kpsingh@kernel.org> X-Mailer: git-send-email 2.37.0.rc0.161.g10f37bed90-goog In-Reply-To: <20220628161948.475097-1-kpsingh@kernel.org> References: <20220628161948.475097-1-kpsingh@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org From: Benjamin Tissoires This allows to declare a kfunc as sleepable and prevents its use in a non sleepable program. Acked-by: KP Singh Signed-off-by: Benjamin Tissoires Signed-off-by: KP Singh --- include/linux/btf.h | 2 ++ kernel/bpf/btf.c | 12 ++++++++++-- 2 files changed, 12 insertions(+), 2 deletions(-) diff --git a/include/linux/btf.h b/include/linux/btf.h index 1bfed7fa0428..6e7517573d9e 100644 --- a/include/linux/btf.h +++ b/include/linux/btf.h @@ -18,6 +18,7 @@ enum btf_kfunc_type { BTF_KFUNC_TYPE_RELEASE, BTF_KFUNC_TYPE_RET_NULL, BTF_KFUNC_TYPE_KPTR_ACQUIRE, + BTF_KFUNC_TYPE_SLEEPABLE, BTF_KFUNC_TYPE_MAX, }; @@ -37,6 +38,7 @@ struct btf_kfunc_id_set { struct btf_id_set *release_set; struct btf_id_set *ret_null_set; struct btf_id_set *kptr_acquire_set; + struct btf_id_set *sleepable_set; }; struct btf_id_set *sets[BTF_KFUNC_TYPE_MAX]; }; diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c index 2e2066d6af94..37bc77b3b499 100644 --- a/kernel/bpf/btf.c +++ b/kernel/bpf/btf.c @@ -6171,7 +6171,7 @@ static int btf_check_func_arg_match(struct bpf_verifier_env *env, struct bpf_verifier_log *log = &env->log; u32 i, nargs, ref_id, ref_obj_id = 0; bool is_kfunc = btf_is_kernel(btf); - bool rel = false, kptr_get = false; + bool rel = false, kptr_get = false, sleepable = false; const char *func_name, *ref_tname; const struct btf_type *t, *ref_t; const struct btf_param *args; @@ -6202,9 +6202,10 @@ static int btf_check_func_arg_match(struct bpf_verifier_env *env, } if (is_kfunc) { - /* Only kfunc can be release func */ rel = btf_kfunc_id_set_contains(btf, resolve_prog_type(env->prog), BTF_KFUNC_TYPE_RELEASE, func_id); + sleepable = btf_kfunc_id_set_contains(btf, resolve_prog_type(env->prog), + BTF_KFUNC_TYPE_SLEEPABLE, func_id); kptr_get = btf_kfunc_id_set_contains(btf, resolve_prog_type(env->prog), BTF_KFUNC_TYPE_KPTR_ACQUIRE, func_id); } @@ -6404,6 +6405,13 @@ static int btf_check_func_arg_match(struct bpf_verifier_env *env, 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; + } + /* returns argument register number > 0 in case of reference release kfunc */ return rel ? ref_regno : 0; }