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 6305D2E0412; Tue, 8 Jul 2025 13:27:16 +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=1751981236; cv=none; b=NgI1erzDxq6qjFFaPGQh0bht/cO9GPOgWKrvOibbHUGcknEgbRWIPb2qj+woijVsj/kULI0sdyKWOH0GGZFska3CYSshqxvgVla2wqtN9ZU/0AF/adJgWrWv/LqGSB0JqFp6N2wlYxO8Axxy+4VKVweKxXmxKA6m3Rfa/Ml/Ejw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1751981236; c=relaxed/simple; bh=Gm8o6DrpDVdKKnh+DD42VsNhdTEMaT4hgbZv1kDfCMQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=hU0TUV0Q3SLerSW931JDdhDxSiq/Rwd5cElSVCOVnFUWDQKjW1qL3ADOmJjrAec17ik1HugD/Z0SDkmXcv9RldDGHXxs0aPOhfnUB+gO8EPI8fIYFJKdQb779AJ40Pyt16ydGRlso9rLozGqTkhRG5x8o0C3IJcRmSIEDDbKV6o= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=ec98gzoJ; 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="ec98gzoJ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2F83DC4CEF0; Tue, 8 Jul 2025 13:27:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1751981236; bh=Gm8o6DrpDVdKKnh+DD42VsNhdTEMaT4hgbZv1kDfCMQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ec98gzoJptMjaY742eFfINT4o4cyWoiM0Wa3l43OnxHDmUeF6NUxEzmqvIHTfcbJn 0haZPY1X3x90yqyQ7Ci18dBjwx1gp7XTHfbdAHBRnmu4Ha5DafSoXlPHTtUJ7V69xJ GxhgaiFEumLiYAgytSOzCOQ89Ix2SpB3ffwr1JSOo9jSmTtNvTqa+i3vpvUlx6of59 +67bmlrS8DLv7rrbeZHpAGEO4FIJtYLirwx5oFK9wymXh+YhhriUhC20VzMITLPYRP 9fy7LzxGMLK+vyS0gaPvKidSuy1kKtYs8R0xAfjlZA+YfpIyxW/Fwt2LkpqbsL6YPk rhem5/DEP+neA== From: Jiri Olsa To: Oleg Nesterov , Peter Zijlstra , Andrii Nakryiko Cc: bpf@vger.kernel.org, linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, x86@kernel.org, Song Liu , Yonghong Song , John Fastabend , Hao Luo , Steven Rostedt , Masami Hiramatsu , Alan Maguire , David Laight , =?UTF-8?q?Thomas=20Wei=C3=9Fschuh?= , Ingo Molnar Subject: [PATCHv4 perf/core 18/22] selftests/bpf: Add uprobe_regs_equal test Date: Tue, 8 Jul 2025 15:23:27 +0200 Message-ID: <20250708132333.2739553-19-jolsa@kernel.org> X-Mailer: git-send-email 2.50.0 In-Reply-To: <20250708132333.2739553-1-jolsa@kernel.org> References: <20250708132333.2739553-1-jolsa@kernel.org> Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Changing uretprobe_regs_trigger to allow the test for both uprobe and uretprobe and renaming it to uprobe_regs_equal. We check that both uprobe and uretprobe probes (bpf programs) see expected registers with few exceptions. Signed-off-by: Jiri Olsa --- .../selftests/bpf/prog_tests/uprobe_syscall.c | 56 ++++++++++++++----- .../selftests/bpf/progs/uprobe_syscall.c | 4 +- 2 files changed, 44 insertions(+), 16 deletions(-) diff --git a/tools/testing/selftests/bpf/prog_tests/uprobe_syscall.c b/tools/testing/selftests/bpf/prog_tests/uprobe_syscall.c index bd59b4b5bd3c..fc0b75dd9c36 100644 --- a/tools/testing/selftests/bpf/prog_tests/uprobe_syscall.c +++ b/tools/testing/selftests/bpf/prog_tests/uprobe_syscall.c @@ -22,15 +22,17 @@ #pragma GCC diagnostic ignored "-Wattributes" -__naked unsigned long uretprobe_regs_trigger(void) +__attribute__((aligned(16))) +__nocf_check __weak __naked unsigned long uprobe_regs_trigger(void) { asm volatile ( + ".byte 0x0f, 0x1f, 0x44, 0x00, 0x00\n" /* nop5 */ "movq $0xdeadbeef, %rax\n" "ret\n" ); } -__naked void uretprobe_regs(struct pt_regs *before, struct pt_regs *after) +__naked void uprobe_regs(struct pt_regs *before, struct pt_regs *after) { asm volatile ( "movq %r15, 0(%rdi)\n" @@ -51,15 +53,17 @@ __naked void uretprobe_regs(struct pt_regs *before, struct pt_regs *after) "movq $0, 120(%rdi)\n" /* orig_rax */ "movq $0, 128(%rdi)\n" /* rip */ "movq $0, 136(%rdi)\n" /* cs */ + "pushq %rax\n" "pushf\n" "pop %rax\n" "movq %rax, 144(%rdi)\n" /* eflags */ + "pop %rax\n" "movq %rsp, 152(%rdi)\n" /* rsp */ "movq $0, 160(%rdi)\n" /* ss */ /* save 2nd argument */ "pushq %rsi\n" - "call uretprobe_regs_trigger\n" + "call uprobe_regs_trigger\n" /* save return value and load 2nd argument pointer to rax */ "pushq %rax\n" @@ -99,25 +103,37 @@ __naked void uretprobe_regs(struct pt_regs *before, struct pt_regs *after) ); } -static void test_uretprobe_regs_equal(void) +static void test_uprobe_regs_equal(bool retprobe) { + LIBBPF_OPTS(bpf_uprobe_opts, opts, + .retprobe = retprobe, + ); struct uprobe_syscall *skel = NULL; struct pt_regs before = {}, after = {}; unsigned long *pb = (unsigned long *) &before; unsigned long *pa = (unsigned long *) &after; unsigned long *pp; + unsigned long offset; unsigned int i, cnt; - int err; + + offset = get_uprobe_offset(&uprobe_regs_trigger); + if (!ASSERT_GE(offset, 0, "get_uprobe_offset")) + return; skel = uprobe_syscall__open_and_load(); if (!ASSERT_OK_PTR(skel, "uprobe_syscall__open_and_load")) goto cleanup; - err = uprobe_syscall__attach(skel); - if (!ASSERT_OK(err, "uprobe_syscall__attach")) + skel->links.probe = bpf_program__attach_uprobe_opts(skel->progs.probe, + 0, "/proc/self/exe", offset, &opts); + if (!ASSERT_OK_PTR(skel->links.probe, "bpf_program__attach_uprobe_opts")) goto cleanup; - uretprobe_regs(&before, &after); + /* make sure uprobe gets optimized */ + if (!retprobe) + uprobe_regs_trigger(); + + uprobe_regs(&before, &after); pp = (unsigned long *) &skel->bss->regs; cnt = sizeof(before)/sizeof(*pb); @@ -126,7 +142,7 @@ static void test_uretprobe_regs_equal(void) unsigned int offset = i * sizeof(unsigned long); /* - * Check register before and after uretprobe_regs_trigger call + * Check register before and after uprobe_regs_trigger call * that triggers the uretprobe. */ switch (offset) { @@ -140,7 +156,7 @@ static void test_uretprobe_regs_equal(void) /* * Check register seen from bpf program and register after - * uretprobe_regs_trigger call + * uprobe_regs_trigger call (with rax exception, check below). */ switch (offset) { /* @@ -153,6 +169,15 @@ static void test_uretprobe_regs_equal(void) case offsetof(struct pt_regs, rsp): case offsetof(struct pt_regs, ss): break; + /* + * uprobe does not see return value in rax, it needs to see the + * original (before) rax value + */ + case offsetof(struct pt_regs, rax): + if (!retprobe) { + ASSERT_EQ(pp[i], pb[i], "uprobe rax prog-before value check"); + break; + } default: if (!ASSERT_EQ(pp[i], pa[i], "register prog-after value check")) fprintf(stdout, "failed register offset %u\n", offset); @@ -190,13 +215,13 @@ static void test_uretprobe_regs_change(void) unsigned long cnt = sizeof(before)/sizeof(*pb); unsigned int i, err, offset; - offset = get_uprobe_offset(uretprobe_regs_trigger); + offset = get_uprobe_offset(uprobe_regs_trigger); err = write_bpf_testmod_uprobe(offset); if (!ASSERT_OK(err, "register_uprobe")) return; - uretprobe_regs(&before, &after); + uprobe_regs(&before, &after); err = write_bpf_testmod_uprobe(0); if (!ASSERT_OK(err, "unregister_uprobe")) @@ -616,7 +641,8 @@ static void test_uretprobe_shadow_stack(void) /* Run all the tests with shadow stack in place. */ shstk_is_enabled = true; - test_uretprobe_regs_equal(); + test_uprobe_regs_equal(false); + test_uprobe_regs_equal(true); test_uretprobe_regs_change(); test_uretprobe_syscall_call(); @@ -772,7 +798,7 @@ static void test_uprobe_sigill(void) static void __test_uprobe_syscall(void) { if (test__start_subtest("uretprobe_regs_equal")) - test_uretprobe_regs_equal(); + test_uprobe_regs_equal(true); if (test__start_subtest("uretprobe_regs_change")) test_uretprobe_regs_change(); if (test__start_subtest("uretprobe_syscall_call")) @@ -791,6 +817,8 @@ static void __test_uprobe_syscall(void) test_uprobe_race(); if (test__start_subtest("uprobe_sigill")) test_uprobe_sigill(); + if (test__start_subtest("uprobe_regs_equal")) + test_uprobe_regs_equal(false); } #else static void __test_uprobe_syscall(void) diff --git a/tools/testing/selftests/bpf/progs/uprobe_syscall.c b/tools/testing/selftests/bpf/progs/uprobe_syscall.c index 8a4fa6c7ef59..e08c31669e5a 100644 --- a/tools/testing/selftests/bpf/progs/uprobe_syscall.c +++ b/tools/testing/selftests/bpf/progs/uprobe_syscall.c @@ -7,8 +7,8 @@ struct pt_regs regs; char _license[] SEC("license") = "GPL"; -SEC("uretprobe//proc/self/exe:uretprobe_regs_trigger") -int uretprobe(struct pt_regs *ctx) +SEC("uprobe") +int probe(struct pt_regs *ctx) { __builtin_memcpy(®s, ctx, sizeof(regs)); return 0; -- 2.50.0