From patchwork Mon Apr 10 08:59:07 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Feng Zhou X-Patchwork-Id: 13206200 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 A313BC77B71 for ; Mon, 10 Apr 2023 08:59:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229777AbjDJI7z (ORCPT ); Mon, 10 Apr 2023 04:59:55 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52818 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229794AbjDJI7y (ORCPT ); Mon, 10 Apr 2023 04:59:54 -0400 Received: from mail-pl1-x62e.google.com (mail-pl1-x62e.google.com [IPv6:2607:f8b0:4864:20::62e]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0271B3AAD for ; Mon, 10 Apr 2023 01:59:29 -0700 (PDT) Received: by mail-pl1-x62e.google.com with SMTP id h24so4293052plr.1 for ; Mon, 10 Apr 2023 01:59:29 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bytedance.com; s=google; t=1681117169; 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=ueHlf63HU9JRFKSuWrERCIbxEHTEvzXB14p8A02eQpo=; b=CbC7kM3gDgrsz/8uuOl3IsHCOrSEg1QePC6wsHtePGDcEdppy/6fDvhBkRWD7aQrkh CMFzel33HYF9q1bIlal4ejP5H1RyYVC9Xu0BKNsfvPU2sD+GBAOmEBDE4fZVIUY3tNqH NIqNcSjZdloqdwwU2sVwX+ECL34OQPaO3MAlUJh5j5gY7dcz+t6DMxHgX8neu25sDUgh Ij8G8mRN050YaUJ4v3SPVOUvp2KPOV2c1enYRJhrl+B2txm/l/XJQRxvkXdRhlBQGc/9 Trzi+X+9jKajfI61tHtWXNNXFvFKoW2a94Yz6ATFO5vXeBsHloPIYg8lD+Bct6LTkHKn XCxw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1681117169; 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=ueHlf63HU9JRFKSuWrERCIbxEHTEvzXB14p8A02eQpo=; b=PwUquSqZpdRFGp9rUc3IiymJG/Ozcpj7OCxdvuv4kFHzDx9zZOdC8QiQhlp/0lbF02 AVO1QsvaGvej54gBmssF2nO17nx7BN3mOcP2Yidm48q1AAmUxWlFTd1CFA+QqmSawrwu UrH3YGGQYJGo0v/tPp/B7UKUhXRhYC+XUP3Ahozs9htFDhZhQh5UytZAFtRMt3o+Z9el jqf6uZQQB4mVq3k2fmJWRQvmH41e93D+ebr9k+5tv3NVxnQBQlQ7D+PxhKu7+69rN2DW EUmYBj2r6QZ7z80E3Kbfw+WKj/XqIwLElIXr9Ib0W7exUuWvqQhl2MlQ9b8a7GYZsLhf I9Zw== X-Gm-Message-State: AAQBX9eFjt0Me+qvg4rH7vYe+mS0b2U6vmicai5Ye5axBAwF47ToPwi6 8PTDMeu3TZbwr0eMePE8YnSDSw== X-Google-Smtp-Source: AKy350Yo1QN1keYMBG5X4wrxjlA7RdV5x6e9ubtteeY2QslDbmfBLvvkwOiZQJX6rEtxB2KABWGVvw== X-Received: by 2002:a05:6a20:6707:b0:dd:f44a:2717 with SMTP id q7-20020a056a20670700b000ddf44a2717mr10980029pzh.8.1681117169277; Mon, 10 Apr 2023 01:59:29 -0700 (PDT) Received: from C02F52LSML85.bytedance.net ([139.177.225.238]) by smtp.gmail.com with ESMTPSA id s21-20020aa78295000000b0058bacd6c4e8sm7279526pfm.207.2023.04.10.01.59.21 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 10 Apr 2023 01:59:28 -0700 (PDT) From: Feng zhou To: martin.lau@linux.dev, ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org, song@kernel.org, yhs@fb.com, john.fastabend@gmail.com, kpsingh@kernel.org, sdf@google.com, haoluo@google.com, jolsa@kernel.org, davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, mykolal@fb.com, shuah@kernel.org Cc: bpf@vger.kernel.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, linux-kselftest@vger.kernel.org, yangzhenze@bytedance.com, wangdongdong.6@bytedance.com, zhouchengming@bytedance.com, zhoufeng.zf@bytedance.com Subject: [PATCH v3 1/2] bpf/btf: Fix is_int_ptr() Date: Mon, 10 Apr 2023 16:59:07 +0800 Message-Id: <20230410085908.98493-2-zhoufeng.zf@bytedance.com> X-Mailer: git-send-email 2.39.2 (Apple Git-143) In-Reply-To: <20230410085908.98493-1-zhoufeng.zf@bytedance.com> References: <20230410085908.98493-1-zhoufeng.zf@bytedance.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org From: Feng Zhou When tracing a kernel function with arg type is u32*, btf_ctx_access() would report error: arg2 type INT is not a struct. The commit bb6728d75611 ("bpf: Allow access to int pointer arguments in tracing programs") added support for int pointer, but don't skip modifiers before checking it's type. This patch fixes it. Fixes: bb6728d75611 ("bpf: Allow access to int pointer arguments in tracing programs") Co-developed-by: Chengming Zhou Signed-off-by: Chengming Zhou Signed-off-by: Feng Zhou --- kernel/bpf/btf.c | 8 ++------ 1 file changed, 2 insertions(+), 6 deletions(-) diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c index 593c45a294d0..5abd8dfa6b70 100644 --- a/kernel/bpf/btf.c +++ b/kernel/bpf/btf.c @@ -5910,12 +5910,8 @@ struct btf *bpf_prog_get_target_btf(const struct bpf_prog *prog) static bool is_int_ptr(struct btf *btf, const struct btf_type *t) { - /* t comes in already as a pointer */ - t = btf_type_by_id(btf, t->type); - - /* allow const */ - if (BTF_INFO_KIND(t->info) == BTF_KIND_CONST) - t = btf_type_by_id(btf, t->type); + /* skip modifiers */ + t = btf_type_skip_modifiers(btf, t->type, NULL); return btf_type_is_int(t); } From patchwork Mon Apr 10 08:59:08 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Feng Zhou X-Patchwork-Id: 13206201 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 DF073C76196 for ; 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Mon, 10 Apr 2023 01:59:37 -0700 (PDT) Received: from C02F52LSML85.bytedance.net ([139.177.225.238]) by smtp.gmail.com with ESMTPSA id s21-20020aa78295000000b0058bacd6c4e8sm7279526pfm.207.2023.04.10.01.59.29 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 10 Apr 2023 01:59:37 -0700 (PDT) From: Feng zhou To: martin.lau@linux.dev, ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org, song@kernel.org, yhs@fb.com, john.fastabend@gmail.com, kpsingh@kernel.org, sdf@google.com, haoluo@google.com, jolsa@kernel.org, davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, mykolal@fb.com, shuah@kernel.org Cc: bpf@vger.kernel.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, linux-kselftest@vger.kernel.org, yangzhenze@bytedance.com, wangdongdong.6@bytedance.com, zhouchengming@bytedance.com, zhoufeng.zf@bytedance.com Subject: [PATCH v3 2/2] selftests/bpf: Add test to access u32 ptr argument in tracing program Date: Mon, 10 Apr 2023 16:59:08 +0800 Message-Id: <20230410085908.98493-3-zhoufeng.zf@bytedance.com> X-Mailer: git-send-email 2.39.2 (Apple Git-143) In-Reply-To: <20230410085908.98493-1-zhoufeng.zf@bytedance.com> References: <20230410085908.98493-1-zhoufeng.zf@bytedance.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org From: Feng Zhou Adding verifier test for accessing u32 pointer argument in tracing programs. The test program loads 1nd argument of bpf_fentry_test9 function which is u32 pointer and checks that verifier allows that. Co-developed-by: Chengming Zhou Signed-off-by: Chengming Zhou Signed-off-by: Feng Zhou --- net/bpf/test_run.c | 8 +++++++- .../testing/selftests/bpf/verifier/btf_ctx_access.c | 13 +++++++++++++ 2 files changed, 20 insertions(+), 1 deletion(-) diff --git a/net/bpf/test_run.c b/net/bpf/test_run.c index f1652f5fbd2e..68bdfc041a7b 100644 --- a/net/bpf/test_run.c +++ b/net/bpf/test_run.c @@ -541,6 +541,11 @@ int noinline bpf_fentry_test8(struct bpf_fentry_test_t *arg) return (long)arg->a; } +__bpf_kfunc u32 bpf_fentry_test9(u32 *a) +{ + return *a; +} + __bpf_kfunc int bpf_modify_return_test(int a, int *b) { *b += 1; @@ -855,7 +860,8 @@ int bpf_prog_test_run_tracing(struct bpf_prog *prog, bpf_fentry_test5(11, (void *)12, 13, 14, 15) != 65 || bpf_fentry_test6(16, (void *)17, 18, 19, (void *)20, 21) != 111 || bpf_fentry_test7((struct bpf_fentry_test_t *)0) != 0 || - bpf_fentry_test8(&arg) != 0) + bpf_fentry_test8(&arg) != 0 || + bpf_fentry_test9(&retval) != 0) goto out; break; case BPF_MODIFY_RETURN: diff --git a/tools/testing/selftests/bpf/verifier/btf_ctx_access.c b/tools/testing/selftests/bpf/verifier/btf_ctx_access.c index 6340db6b46dc..0484d3de040d 100644 --- a/tools/testing/selftests/bpf/verifier/btf_ctx_access.c +++ b/tools/testing/selftests/bpf/verifier/btf_ctx_access.c @@ -10,3 +10,16 @@ .expected_attach_type = BPF_TRACE_FENTRY, .kfunc = "bpf_modify_return_test", }, + +{ + "btf_ctx_access u32 pointer accept", + .insns = { + BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1, 0), /* load 1nd argument value (u32 pointer) */ + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + }, + .result = ACCEPT, + .prog_type = BPF_PROG_TYPE_TRACING, + .expected_attach_type = BPF_TRACE_FENTRY, + .kfunc = "bpf_fentry_test9", +},