From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 54CE0282EE for ; Tue, 21 May 2024 16:34:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1716309261; cv=none; b=RdhUrZozbiFO9uxklTby6totRMMS4K5h0SRC0n/c3koDrMFiG9PmJfErbRy4UTfKDBgfOhNvq8+1FLWsTljfvTNil9RlgBjEKcI3O37AUlE4SL2iPCJZpzKoGHj88DfdvXy2TV++82wo84Q0Oqo1mW/U7BXtuowl909ZbWPnAIg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1716309261; c=relaxed/simple; bh=Yqux7nSuFfyauKcuXg94gdqjx6nIFom1rp0gLXu0IIc=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=ulrx8HPLYge7K/kiycr+rEHpILw9yJS5FOUQwPJTIZ8rSHlAsoaN1xBPYqw968pG/5ML7N1GgOVgC3dsP1m916XUGEBt4pF3lvt6S8vuM7Dfb2uUlGHl4mnMu6M/2zXgQbIg9Jvyxp93xnHuZAuJcxk/FvFn5Zruenfn5VPe7JQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=UoS2T6SP; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="UoS2T6SP" Received: by smtp.kernel.org (Postfix) with ESMTPSA id BFA2AC32786; Tue, 21 May 2024 16:34:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1716309260; bh=Yqux7nSuFfyauKcuXg94gdqjx6nIFom1rp0gLXu0IIc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=UoS2T6SPDjfhPoxndaP3eEOr5FCltP5+wjcv5XCMTD0KUy+aAinmwAeG3NVRVuzBG s7RbC9nUYVD5Ps15te8LbesD+ds9y2/yJ4VLUBX9QlO24GJegnqjcjMKQkWSdyg9rQ nJVISn/gY4Sh//3E52zZKAoMgSE1+FhRPVoLAdh3js5kXilR8ErnapRx0rCaIyY+sF IgVYTN+pyEua8R+cMc+YgWenV4ATieV/ZGjPzURd5a7duHUYkwP5oZkxXd1l2cCf5T QOjuATXSETStTzjrjzqGDsTCnwSwGt6kU99s5x9EnVqq6LHHIW1eSXTCfshveNl567 pa3aGUUV9sIXw== From: Andrii Nakryiko To: bpf@vger.kernel.org, ast@kernel.org, daniel@iogearbox.net, martin.lau@kernel.org Cc: andrii@kernel.org, kernel-team@meta.com, Jiri Olsa Subject: [PATCH v2 bpf 5/5] selftests/bpf: extend multi-uprobe tests with USDTs Date: Tue, 21 May 2024 09:34:01 -0700 Message-ID: <20240521163401.3005045-6-andrii@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240521163401.3005045-1-andrii@kernel.org> References: <20240521163401.3005045-1-andrii@kernel.org> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Validate libbpf's USDT-over-multi-uprobe logic by adding USDTs to existing multi-uprobe tests. This checks correct libbpf fallback to singular uprobes (when run on older kernels with buggy PID filtering). We reuse already established child process and child thread testing infrastructure, so additions are minimal. These test fail on either older kernels or older version of libbpf that doesn't detect PID filtering problems. Acked-by: Jiri Olsa Signed-off-by: Andrii Nakryiko --- .../bpf/prog_tests/uprobe_multi_test.c | 25 ++++++++++++++ .../selftests/bpf/progs/uprobe_multi.c | 33 +++++++++++++++++-- 2 files changed, 56 insertions(+), 2 deletions(-) diff --git a/tools/testing/selftests/bpf/prog_tests/uprobe_multi_test.c b/tools/testing/selftests/bpf/prog_tests/uprobe_multi_test.c index 677232d31432..bf6ca8e3eb13 100644 --- a/tools/testing/selftests/bpf/prog_tests/uprobe_multi_test.c +++ b/tools/testing/selftests/bpf/prog_tests/uprobe_multi_test.c @@ -8,6 +8,7 @@ #include "uprobe_multi_usdt.skel.h" #include "bpf/libbpf_internal.h" #include "testing_helpers.h" +#include "../sdt.h" static char test_data[] = "test_data"; @@ -26,6 +27,11 @@ noinline void uprobe_multi_func_3(void) asm volatile (""); } +noinline void usdt_trigger(void) +{ + STAP_PROBE(test, pid_filter_usdt); +} + struct child { int go[2]; int c2p[2]; /* child -> parent channel */ @@ -90,6 +96,7 @@ static struct child *spawn_child(void) uprobe_multi_func_1(); uprobe_multi_func_2(); uprobe_multi_func_3(); + usdt_trigger(); exit(errno); } @@ -117,6 +124,7 @@ static void *child_thread(void *ctx) uprobe_multi_func_1(); uprobe_multi_func_2(); uprobe_multi_func_3(); + usdt_trigger(); err = 0; pthread_exit(&err); @@ -182,6 +190,7 @@ static void uprobe_multi_test_run(struct uprobe_multi *skel, struct child *child uprobe_multi_func_1(); uprobe_multi_func_2(); uprobe_multi_func_3(); + usdt_trigger(); } if (child) @@ -269,8 +278,24 @@ __test_attach_api(const char *binary, const char *pattern, struct bpf_uprobe_mul if (!ASSERT_OK_PTR(skel->links.uprobe_extra, "bpf_program__attach_uprobe_multi")) goto cleanup; + /* Attach (uprobe-backed) USDTs */ + skel->links.usdt_pid = bpf_program__attach_usdt(skel->progs.usdt_pid, pid, binary, + "test", "pid_filter_usdt", NULL); + if (!ASSERT_OK_PTR(skel->links.usdt_pid, "attach_usdt_pid")) + goto cleanup; + + skel->links.usdt_extra = bpf_program__attach_usdt(skel->progs.usdt_extra, -1, binary, + "test", "pid_filter_usdt", NULL); + if (!ASSERT_OK_PTR(skel->links.usdt_extra, "attach_usdt_extra")) + goto cleanup; + uprobe_multi_test_run(skel, child); + ASSERT_FALSE(skel->bss->bad_pid_seen_usdt, "bad_pid_seen_usdt"); + if (child) { + ASSERT_EQ(skel->bss->child_pid_usdt, child->pid, "usdt_multi_child_pid"); + ASSERT_EQ(skel->bss->child_tid_usdt, child->tid, "usdt_multi_child_tid"); + } cleanup: uprobe_multi__destroy(skel); } diff --git a/tools/testing/selftests/bpf/progs/uprobe_multi.c b/tools/testing/selftests/bpf/progs/uprobe_multi.c index 86a7ff5d3726..44190efcdba2 100644 --- a/tools/testing/selftests/bpf/progs/uprobe_multi.c +++ b/tools/testing/selftests/bpf/progs/uprobe_multi.c @@ -1,8 +1,8 @@ // SPDX-License-Identifier: GPL-2.0 -#include +#include "vmlinux.h" #include #include -#include +#include char _license[] SEC("license") = "GPL"; @@ -23,9 +23,12 @@ __u64 uprobe_multi_sleep_result = 0; int pid = 0; int child_pid = 0; int child_tid = 0; +int child_pid_usdt = 0; +int child_tid_usdt = 0; int expect_pid = 0; bool bad_pid_seen = false; +bool bad_pid_seen_usdt = false; bool test_cookie = false; void *user_ptr = 0; @@ -112,3 +115,29 @@ int uprobe_extra(struct pt_regs *ctx) /* we need this one just to mix PID-filtered and global uprobes */ return 0; } + +SEC("usdt") +int usdt_pid(struct pt_regs *ctx) +{ + __u64 cur_pid_tgid = bpf_get_current_pid_tgid(); + __u32 cur_pid; + + cur_pid = cur_pid_tgid >> 32; + if (pid && cur_pid != pid) + return 0; + + if (expect_pid && cur_pid != expect_pid) + bad_pid_seen_usdt = true; + + child_pid_usdt = cur_pid_tgid >> 32; + child_tid_usdt = (__u32)cur_pid_tgid; + + return 0; +} + +SEC("usdt") +int usdt_extra(struct pt_regs *ctx) +{ + /* we need this one just to mix PID-filtered and global USDT probes */ + return 0; +} -- 2.43.0