From patchwork Mon Feb 24 14:01:47 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jiri Olsa X-Patchwork-Id: 13988200 X-Patchwork-Delegate: bpf@iogearbox.net 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 D45FF13CA81; Mon, 24 Feb 2025 14:04:44 +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=1740405884; cv=none; b=sxLuYhsOzf4ETQWLDWVLE/1P+5ReBnXN0rpE25eS1s6ImQqgFbETG0MHxj2X3MuLF6nIgdKTHp2UN4MQDixySVjyGjx6wHY05VKn1FCj9sNM9BdotVab20/v3W6h0pXIVQHFVMeYVeSXgYg0rufn/iOSGby28WKta1m+oBlUZ6Q= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740405884; c=relaxed/simple; bh=08yQ2M1QgstTqrVMfXHy3RZ7HxixmsWT8XAzUUgbydU=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=fJLIKvJwwcDn1lqn8y4/zfR75YC1a/8lM6io89aWJOEEh/eYmGqLOtWZMoUNYOrBOsROps2O37pS1ohk3SFXZ9+YWGTfGERCcUl3AX9zno6OXqRMWCZYjHjWc6sc9RGi3KjdAXhW6B+2di37cpkvOwb6A8AbwTFlwXP1odwJd/s= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=injkndbs; 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="injkndbs" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7365DC4CED6; Mon, 24 Feb 2025 14:04:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1740405884; bh=08yQ2M1QgstTqrVMfXHy3RZ7HxixmsWT8XAzUUgbydU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=injkndbs5AF3zSz55cqvJ9AgjmVI9s35ei4aeqrvLoIdI/TOt4VoKTrlcIJCqOXY4 Z32b6JIzIpmd+oyGvFLylA4NIrFRLEHxZJ4WvUROLDlj8prGlxeIvEVyrJMxwvBCM4 2zBLEC0vNFPtoJvZ2W/qQhjuQ4yD359ZrEtpk0Qamkf5VFq7CEGMxPoMDyTxa+oFHp vBHfT5UXEN9qIZRHQRvTAGjim5IGNAUDZIiSAcJ5kjV0ThTWYCNwgI0AQYFMJPDBrY b/6iXxC4ig8MyNnEiCtMTnaNSarF2uldwv7DrgNdmlONNoxNioPq3MY8DbuSQFXhwb PtnuoQn6o+aAg== 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_Wei=C3=9Fschuh?= Subject: [PATCH RFCv2 15/18] selftests/bpf: Add uprobe/usdt syscall tests Date: Mon, 24 Feb 2025 15:01:47 +0100 Message-ID: <20250224140151.667679-16-jolsa@kernel.org> X-Mailer: git-send-email 2.48.1 In-Reply-To: <20250224140151.667679-1-jolsa@kernel.org> References: <20250224140151.667679-1-jolsa@kernel.org> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Patchwork-Delegate: bpf@iogearbox.net X-Patchwork-State: RFC Adding tests for optimized uprobe/usdt probes. Checking that we get expected trampoline and attached bpf programs get executed properly. Signed-off-by: Jiri Olsa --- .../selftests/bpf/prog_tests/uprobe_syscall.c | 221 +++++++++++++++++- .../bpf/progs/uprobe_syscall_executed.c | 34 ++- 2 files changed, 249 insertions(+), 6 deletions(-) diff --git a/tools/testing/selftests/bpf/prog_tests/uprobe_syscall.c b/tools/testing/selftests/bpf/prog_tests/uprobe_syscall.c index 2b00f16406c8..b337db6e12be 100644 --- a/tools/testing/selftests/bpf/prog_tests/uprobe_syscall.c +++ b/tools/testing/selftests/bpf/prog_tests/uprobe_syscall.c @@ -14,6 +14,7 @@ #include #include "uprobe_syscall.skel.h" #include "uprobe_syscall_executed.skel.h" +#include "sdt.h" __naked unsigned long uretprobe_regs_trigger(void) { @@ -277,10 +278,10 @@ static void test_uretprobe_syscall_call(void) _exit(0); } - skel->links.test = bpf_program__attach_uprobe_multi(skel->progs.test, pid, - "/proc/self/exe", - "uretprobe_syscall_call", &opts); - if (!ASSERT_OK_PTR(skel->links.test, "bpf_program__attach_uprobe_multi")) + skel->links.test_uretprobe_multi = bpf_program__attach_uprobe_multi(skel->progs.test_uretprobe_multi, + pid, "/proc/self/exe", + "uretprobe_syscall_call", &opts); + if (!ASSERT_OK_PTR(skel->links.test_uretprobe_multi, "bpf_program__attach_uprobe_multi")) goto cleanup; /* kick the child */ @@ -351,6 +352,212 @@ static void test_uretprobe_shadow_stack(void) ARCH_PRCTL(ARCH_SHSTK_DISABLE, ARCH_SHSTK_SHSTK); } +#define TRAMP "[uprobes-trampoline]" + +static unsigned char nop5[5] = { 0x0f, 0x1f, 0x44, 0x00, 0x00 }; + +__naked noinline void uprobe_test(void) +{ + asm volatile (" \n" + ".byte 0x0f, 0x1f, 0x44, 0x00, 0x00 \n" + "ret \n" + ); +} + +noinline void usdt_test(void) +{ + STAP_PROBE(optimized_uprobe, usdt); +} + +static void *find_nop5(void *fn) +{ + int i; + + for (i = 0; i < 10; i++) { + if (!memcmp(nop5, fn + i, 5)) + return fn + i; + } + return NULL; +} + +static int find_uprobes_trampoline(void **start, void **end) +{ + char line[128]; + int ret = -1; + FILE *maps; + + maps = fopen("/proc/self/maps", "r"); + if (!maps) { + fprintf(stderr, "cannot open maps\n"); + return -1; + } + + while (fgets(line, sizeof(line), maps)) { + int m = -1; + + /* We care only about private r-x mappings. */ + if (sscanf(line, "%p-%p r-xp %*x %*x:%*x %*u %n", start, end, &m) != 2) + continue; + if (m < 0) + continue; + if (!strncmp(&line[m], TRAMP, sizeof(TRAMP)-1)) { + ret = 0; + break; + } + } + + fclose(maps); + return ret; +} + +static void check_attach(struct uprobe_syscall_executed *skel, void (*trigger)(void), void *addr) +{ + void *tramp_start, *tramp_end; + struct __arch_relative_insn { + u8 op; + s32 raddr; + } __packed *call; + + s32 delta; + + /* Uprobe gets optimized after first trigger, so let's press twice. */ + trigger(); + trigger(); + + if (!ASSERT_OK(find_uprobes_trampoline(&tramp_start, &tramp_end), "uprobes_trampoline")) + return; + + /* Make sure bpf program got executed.. */ + ASSERT_EQ(skel->bss->executed, 2, "executed"); + + /* .. and check the trampoline is as expected. */ + call = (struct __arch_relative_insn *) addr; + delta = (unsigned long) tramp_start - ((unsigned long) addr + 5); + + ASSERT_EQ(call->op, 0xe8, "call"); + ASSERT_EQ(call->raddr, delta, "delta"); + ASSERT_EQ(tramp_end - tramp_start, 4096, "size"); +} + +static void check_detach(struct uprobe_syscall_executed *skel, void (*trigger)(void), void *addr) +{ + void *tramp_start, *tramp_end; + + /* [uprobes_trampoline] stays after detach */ + ASSERT_OK(find_uprobes_trampoline(&tramp_start, &tramp_end), "uprobes_trampoline"); + ASSERT_OK(memcmp(addr, nop5, 5), "nop5"); +} + +static void check(struct uprobe_syscall_executed *skel, struct bpf_link *link, + void (*trigger)(void), void *addr) +{ + check_attach(skel, trigger, addr); + bpf_link__destroy(link); + check_detach(skel, trigger, addr); +} + +static void test_uprobe_legacy(void) +{ + LIBBPF_OPTS(bpf_uprobe_opts, opts, + .retprobe = true, + ); + struct uprobe_syscall_executed *skel; + struct bpf_link *link; + unsigned long offset; + + skel = uprobe_syscall_executed__open_and_load(); + if (!ASSERT_OK_PTR(skel, "uprobe_syscall_executed__open_and_load")) + return; + + /* uprobe */ + offset = get_uprobe_offset(&uprobe_test); + if (!ASSERT_GE(offset, 0, "get_uprobe_offset")) + goto cleanup; + + link = bpf_program__attach_uprobe_opts(skel->progs.test_uprobe, + 0, "/proc/self/exe", offset, NULL); + if (!ASSERT_OK_PTR(link, "bpf_program__attach_uprobe_opts")) + goto cleanup; + + check(skel, link, uprobe_test, uprobe_test); + + /* uretprobe */ + skel->bss->executed = 0; + offset = get_uprobe_offset(&uprobe_test); + if (!ASSERT_GE(offset, 0, "get_uprobe_offset")) + goto cleanup; + + link = bpf_program__attach_uprobe_opts(skel->progs.test_uretprobe, + 0, "/proc/self/exe", offset, NULL); + if (!ASSERT_OK_PTR(link, "bpf_program__attach_uprobe_opts")) + goto cleanup; + + check(skel, link, uprobe_test, uprobe_test); + +cleanup: + uprobe_syscall_executed__destroy(skel); +} + +static void test_uprobe_multi(void) +{ + LIBBPF_OPTS(bpf_uprobe_multi_opts, opts, + .retprobe = true, + ); + struct uprobe_syscall_executed *skel; + struct bpf_link *link; + + skel = uprobe_syscall_executed__open_and_load(); + if (!ASSERT_OK_PTR(skel, "uprobe_syscall_executed__open_and_load")) + return; + + /* uprobe.multi */ + link = bpf_program__attach_uprobe_multi(skel->progs.test_uprobe_multi, + 0, "/proc/self/exe", "uprobe_test", NULL); + if (!ASSERT_OK_PTR(link, "bpf_program__attach_uprobe_multi")) + goto cleanup; + + check(skel, link, uprobe_test, uprobe_test); + + /* uretprobe.multi */ + skel->bss->executed = 0; + link = bpf_program__attach_uprobe_multi(skel->progs.test_uretprobe_multi, + 0, "/proc/self/exe", "uprobe_test", &opts); + if (!ASSERT_OK_PTR(link, "bpf_program__attach_uprobe_multi")) + goto cleanup; + + check(skel, link, uprobe_test, uprobe_test); + +cleanup: + uprobe_syscall_executed__destroy(skel); +} + +static void test_uprobe_usdt(void) +{ + struct uprobe_syscall_executed *skel; + struct bpf_link *link; + void *addr; + + errno = 0; + addr = find_nop5(usdt_test); + if (!ASSERT_OK_PTR(addr, "find_nop5")) + return; + + skel = uprobe_syscall_executed__open_and_load(); + if (!ASSERT_OK_PTR(skel, "uprobe_syscall_executed__open_and_load")) + return; + + link = bpf_program__attach_usdt(skel->progs.test_usdt, + -1 /* all PIDs */, "/proc/self/exe", + "optimized_uprobe", "usdt", NULL); + if (!ASSERT_OK_PTR(link, "bpf_program__attach_usdt")) + goto cleanup; + + check(skel, link, usdt_test, addr); + +cleanup: + uprobe_syscall_executed__destroy(skel); +} + static void __test_uprobe_syscall(void) { if (test__start_subtest("uretprobe_regs_equal")) @@ -361,6 +568,12 @@ static void __test_uprobe_syscall(void) test_uretprobe_syscall_call(); if (test__start_subtest("uretprobe_shadow_stack")) test_uretprobe_shadow_stack(); + if (test__start_subtest("uprobe_legacy")) + test_uprobe_legacy(); + if (test__start_subtest("uprobe_multi")) + test_uprobe_multi(); + if (test__start_subtest("uprobe_usdt")) + test_uprobe_usdt(); } #else static void __test_uprobe_syscall(void) diff --git a/tools/testing/selftests/bpf/progs/uprobe_syscall_executed.c b/tools/testing/selftests/bpf/progs/uprobe_syscall_executed.c index 0d7f1a7db2e2..802fd562ce4c 100644 --- a/tools/testing/selftests/bpf/progs/uprobe_syscall_executed.c +++ b/tools/testing/selftests/bpf/progs/uprobe_syscall_executed.c @@ -1,6 +1,8 @@ // SPDX-License-Identifier: GPL-2.0 #include "vmlinux.h" #include +#include +#include #include struct pt_regs regs; @@ -9,9 +11,37 @@ char _license[] SEC("license") = "GPL"; int executed = 0; +SEC("uprobe") +int BPF_UPROBE(test_uprobe) +{ + executed++; + return 0; +} + +SEC("uretprobe") +int BPF_URETPROBE(test_uretprobe) +{ + executed++; + return 0; +} + +SEC("uprobe.multi") +int test_uprobe_multi(struct pt_regs *ctx) +{ + executed++; + return 0; +} + SEC("uretprobe.multi") -int test(struct pt_regs *regs) +int test_uretprobe_multi(struct pt_regs *ctx) +{ + executed++; + return 0; +} + +SEC("usdt") +int test_usdt(struct pt_regs *ctx) { - executed = 1; + executed++; return 0; }