From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=95.215.58.136 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794233366; b=JfLcyo2liK6+0eoD7fnnJzZBshcW5bfkgHX4kzJ/+OTA7ao3gLcaXecxNguIUq/vpDfe S2b2dKjiqt4UfVkzO+juqdIDvGPKzjs19t+Gs2/x0L+x2AIQ+whTfFnOQFQNLIq9OEmrA s0tKNIYL3ECfr0QXXqEV3/MF12DqwjKEyAJniP8hY7UkDyrA5G8CbsX51BMgwDz9vEqgX IQfriDfzSb/KLLHWdCGuRfxtcafjzJ327eLner9fpEO21GvGL+W6F78tGC8KmseTPD/tG hS+0FHq4J0xAfTe/pPrdcl2tggmVbwgWCWNESpsz6BYJY2hbjE1sB1vZOm9bvNZWeWA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794233366; h=DMARC-Filter:X-Envelope-To:DKIM-Signature:X-Envelope-To:Received: X-Mizu-Trace-ID:X-Migadu-Flow:From:To:Cc:Subject:Date:Message-ID: X-Mailer:In-Reply-To:References:MIME-Version: Content-Transfer-Encoding; bh=u7TsLdtgk4LWC1lUXMsOMIYHtzQPWQQhl7MK38/q4Eo=; b=U2/jVShszPcfCf5am8LTSehC6l8D42zMoZWA6UgtpG8+W38caPLTGchs+zPIajq6gYZh k9ptn094t9oj5yJ3AdJgoJLHPWho5kZf2wi4SYhC0GPH/bbNVrxDuPHcBecuRmjNxg2LR 5BypkXhlmg2x2YycDuVNbtGn0lKgr5o42x6zgQNQHI9oApTyNwiFxHa1IdzFLLy1nEy33 SXBKt0N6AerQc7dUeR+mCQpOLJYxGc1ecjs5oKS3d5zcLrSxWJSOeLvrTgL1qv8V4ILVC j/D32SPFrMQgIMbiIy3pj98MuwUwyhLZJpih3hAarzXJiMybrgF9VMCkI/mKfV6aNuw== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=SVYlI002; arc=none smtp.remote-ip=95.215.58.136 Received: from mta1.migadu.com (out-136.mta1.migadu.com [95.215.58.136]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 48A85606D801 for ; Mon, 9 Nov 2026 14:09:24 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 48A85606D801 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=SVYlI002 X-Envelope-To: linux-kernel@vger.kernel.org DKIM-Signature: a=rsa-sha256; bh=uL34otuXneMNkgVk69W35A0N6pkFsqt9VsOR9HNVZqc=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1794233363; v=1; x=1794838163; b=SVYlI002bTQ07DrMfsb4BDht/ipXeF3/AhJdDqt7Y8C/uHhixdE96O/FJRNpjUrfSez4UwUC PkdX4KmuOe4H3HEuh54ToQTjToOXI4Fs05jgTbmhgoILSaRdDxEI+eV19YPE6RyOqq29LTn2+6+ Nho8wIXu/e6KexndvbBQsVzs= X-Envelope-To: linux-kernel@vger.kernel.org Received: by smtp.migadu.com with ESMTPS id 942069c1ecef47fb; Mon, 09 Nov 2026 14:09:23 +0000 X-Mizu-Trace-ID: 942069c1ecef47fb X-Migadu-Flow: FLOW_OUT From: Leon Hwang To: bpf@vger.kernel.org Cc: Alexei Starovoitov , Daniel Borkmann , John Fastabend , Andrii Nakryiko , Eduard Zingerman , Kumar Kartikeya Dwivedi , Martin KaFai Lau , Song Liu , Yonghong Song , Jiri Olsa , Emil Tsalapatis , Ihor Solodrai , Steven Rostedt , Masami Hiramatsu , Mathieu Desnoyers , KP Singh , Matt Bobrowski , Shuah Khan , Leon Hwang , linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, netdev@vger.kernel.org Subject: [PATCH bpf-next 6/9] selftests/bpf: Verify tracing link_create logs Date: Mon, 9 Nov 2026 22:08:13 +0800 Message-ID: <20261109140816.5196-7-leon.hwang@linux.dev> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20261109140816.5196-1-leon.hwang@linux.dev> References: <20261109140816.5196-1-leon.hwang@linux.dev> X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Check the error code, log message, and reported log size for invalid tracing and freplace link creation parameters. Cover reattachment and attach-target checks, including incompatible kprobe_write_ctx settings. Signed-off-by: Leon Hwang --- .../selftests/bpf/prog_tests/tracing_link.c | 275 ++++++++++++++++++ 1 file changed, 275 insertions(+) create mode 100644 tools/testing/selftests/bpf/prog_tests/tracing_link.c diff --git a/tools/testing/selftests/bpf/prog_tests/tracing_link.c b/tools/testing/selftests/bpf/prog_tests/tracing_link.c new file mode 100644 index 000000000000..1b64cb3e9983 --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/tracing_link.c @@ -0,0 +1,275 @@ +// SPDX-License-Identifier: GPL-2.0 +#include +#include +#include "fentry_recursive.skel.h" +#include "priv_freplace_prog.skel.h" +#include "xdp_dummy.skel.h" +#include "kprobe_write_ctx.skel.h" + +static void test_fentry_link_create_log(int target_fd, __u32 target_btf_id, int cookie, + enum bpf_attach_type attach_type, + bool reattach, const char *msg) +{ + struct fentry_recursive *skel = NULL; + struct xdp_dummy *target; + char log_buf[128] = {}; + int err, fd, prog_fd; + LIBBPF_OPTS(bpf_log_opts, log_opts, + .buf = log_buf, + .size = sizeof(log_buf), + .level = 1, + ); + LIBBPF_OPTS(bpf_link_create_opts, opts, + .log_opts = &log_opts, + .target_btf_id = target_btf_id, + .tracing.cookie = cookie, + ); + + target = xdp_dummy__open_and_load(); + if (!ASSERT_OK_PTR(target, "xdp_dummy__open_and_load")) + return; + + skel = fentry_recursive__open(); + if (!ASSERT_OK_PTR(skel, "fentry_recursive__open")) + goto out; + + err = bpf_program__set_attach_target(skel->progs.recursive_attach, + bpf_program__fd(target->progs.xdp_dummy_prog), + "xdp_dummy_prog"); + if (!ASSERT_OK(err, "bpf_program__set_attach_target")) + goto out; + + err = fentry_recursive__load(skel); + if (!ASSERT_OK(err, "fentry_recursive__load")) + goto out; + + prog_fd = bpf_program__fd(skel->progs.recursive_attach); + if (reattach) { + /* Consume the initial target saved when the program was loaded. */ + fd = bpf_link_create(prog_fd, 0, BPF_TRACE_FENTRY, &opts); + if (!ASSERT_GE(fd, 0, "bpf_link_create first")) + goto out; + + close(fd); + memset(log_buf, 0, sizeof(log_buf)); + log_opts.true_size = 0; + } + + fd = bpf_link_create(prog_fd, target_fd, attach_type, &opts); + if (!ASSERT_LT(fd, 0, "bpf_link_create")) { + close(fd); + goto out; + } + + ASSERT_EQ(fd, -EINVAL, "err"); + ASSERT_STREQ(log_buf, msg, "log_buf"); + ASSERT_EQ(log_opts.true_size, strlen(msg) + 1, "log_size"); + +out: + fentry_recursive__destroy(skel); + xdp_dummy__destroy(target); +} + +static void test_log_invalid_attach_type(void) +{ + const char *msg = "Invalid attach_type.\n"; + + test_fentry_link_create_log(0, 0, 0, BPF_XDP, false, msg); +} + +static void test_log_tgt_prog_fd_only(void) +{ + const char *msg = "tgt_prog_fd and btf_id must be both set or both unset.\n"; + + test_fentry_link_create_log(-1, 0, 1, BPF_TRACE_FENTRY, false, msg); +} + +static void test_log_tgt_prog_fd_disallowed(void) +{ + const char *msg = "tgt_prog_fd is only allowed for freplace prog.\n"; + + test_fentry_link_create_log(-1, 1, 0, BPF_TRACE_FENTRY, false, msg); +} + +static void test_log_invalid_attach_btf(void) +{ + const char *msg = "Invalid attach_btf.\n"; + + test_fentry_link_create_log(0, 0, 1, BPF_TRACE_FENTRY, true, msg); +} + +static void test_freplace_link_create_log(int target_fd, __u32 target_btf_id, int err_exp, + bool reattach, const char *msg) +{ + struct priv_freplace_prog *skel = NULL; + char log_buf[256] = {}; + struct xdp_dummy *xdp; + int err, fd, prog_fd; + LIBBPF_OPTS(bpf_log_opts, log_opts, + .buf = log_buf, + .size = sizeof(log_buf), + .level = 1, + ); + LIBBPF_OPTS(bpf_link_create_opts, opts, + .log_opts = &log_opts, + .target_btf_id = target_btf_id, + ); + + xdp = xdp_dummy__open_and_load(); + if (!ASSERT_OK_PTR(xdp, "xdp_dummy__open_and_load")) + return; + + skel = priv_freplace_prog__open(); + if (!ASSERT_OK_PTR(skel, "priv_freplace_prog__open")) + goto out; + + err = bpf_program__set_attach_target(skel->progs.new_xdp_prog2, + bpf_program__fd(xdp->progs.xdp_dummy_prog), + "xdp_dummy_prog"); + if (!ASSERT_OK(err, "bpf_program__set_attach_target")) + goto out; + + err = priv_freplace_prog__load(skel); + if (!ASSERT_OK(err, "priv_freplace_prog__load")) + goto out; + + prog_fd = bpf_program__fd(skel->progs.new_xdp_prog2); + if (reattach) { + /* Consume the initial target saved when the program was loaded. */ + fd = bpf_link_create(prog_fd, 0, 0, &opts); + if (!ASSERT_GE(fd, 0, "bpf_link_create first")) + goto out; + + close(fd); + memset(log_buf, 0, sizeof(log_buf)); + log_opts.true_size = 0; + } + + if (!target_fd && target_btf_id) + target_fd = bpf_program__fd(xdp->progs.xdp_dummy_prog); + + fd = bpf_link_create(prog_fd, target_fd, 0, &opts); + if (!ASSERT_LT(fd, 0, "bpf_link_create")) { + close(fd); + goto out; + } + + ASSERT_EQ(fd, err_exp, "err"); + ASSERT_STREQ(log_buf, msg, "log_buf"); + ASSERT_EQ(log_opts.true_size, strlen(msg) + 1, "log_size"); + +out: + priv_freplace_prog__destroy(skel); + xdp_dummy__destroy(xdp); +} + +static void test_log_invalid_target_fd(void) +{ + const char *msg = "Invalid tgt_prog_fd.\n"; + + test_freplace_link_create_log(-1, 1, -EBADF, false, msg); +} + +static void test_log_reattach_without_target(void) +{ + const char *msg = "Only allow re-attach for tracing and lsm progs.\n"; + + test_freplace_link_create_log(0, 0, -EINVAL, true, msg); +} + +static void test_log_invalid_target_btf_id(void) +{ + const char *msg = "attach_btf_id 4294967295 is invalid\n"; + + test_freplace_link_create_log(0, ~0U, -EINVAL, false, msg); +} + +#ifdef __x86_64__ +static void test_log_invalid_kprobe_write_ctx(void) +{ + struct kprobe_write_ctx *skel_kprobe, *skel_freplace = NULL; + struct bpf_program *prog_kprobe, *prog_freplace; + const char *msg = "Invalid kprobe_write_ctx.\n"; + int err, prog_fd, btf_id, fd; + char log_buf[128] = {}; + LIBBPF_OPTS(bpf_log_opts, log_opts, + .buf = log_buf, + .size = sizeof(log_buf), + .level = 1, + ); + LIBBPF_OPTS(bpf_link_create_opts, link_opts, + .log_opts = &log_opts, + ); + + skel_kprobe = kprobe_write_ctx__open(); + if (!ASSERT_OK_PTR(skel_kprobe, "kprobe_write_ctx__open kprobe")) + return; + + prog_kprobe = skel_kprobe->progs.kprobe_dummy; + bpf_program__set_autoload(prog_kprobe, true); + + err = kprobe_write_ctx__load(skel_kprobe); + if (!ASSERT_OK(err, "kprobe_write_ctx__load kprobe")) + goto out; + + skel_freplace = kprobe_write_ctx__open(); + if (!ASSERT_OK_PTR(skel_freplace, "kprobe_write_ctx__open freplace")) + goto out; + + prog_freplace = skel_freplace->progs.freplace_kprobe; + bpf_program__set_autoload(prog_freplace, true); + + prog_fd = bpf_program__fd(skel_kprobe->progs.kprobe_write_ctx); + bpf_program__set_attach_target(prog_freplace, prog_fd, "kprobe_write_ctx"); + + err = kprobe_write_ctx__load(skel_freplace); + if (!ASSERT_OK(err, "kprobe_write_ctx__load freplace")) + goto out; + + prog_fd = bpf_program__fd(prog_kprobe); + btf_id = btf__find_by_name_kind(bpf_object__btf(skel_kprobe->obj), "kprobe_dummy", + BTF_KIND_FUNC); + if (!ASSERT_GT(btf_id, 0, "btf__find_by_name_kind")) + goto out; + + link_opts.target_btf_id = btf_id; + fd = bpf_link_create(bpf_program__fd(prog_freplace), prog_fd, 0, &link_opts); + if (!ASSERT_LT(fd, 0, "bpf_link_create")) { + close(fd); + goto out; + } + + ASSERT_EQ(fd, -EINVAL, "err"); + ASSERT_STREQ(log_buf, msg, "log_buf"); + ASSERT_EQ(log_opts.true_size, strlen(msg) + 1, "log_size"); + +out: + kprobe_write_ctx__destroy(skel_freplace); + kprobe_write_ctx__destroy(skel_kprobe); +} +#else +static void test_log_invalid_kprobe_write_ctx(void) +{ + test__skip(); +} +#endif + +void test_tracing_link_log(void) +{ + if (test__start_subtest("invalid_attach_type")) + test_log_invalid_attach_type(); + if (test__start_subtest("tgt_prog_fd_only")) + test_log_tgt_prog_fd_only(); + if (test__start_subtest("tgt_prog_fd_disallowed")) + test_log_tgt_prog_fd_disallowed(); + if (test__start_subtest("invalid_attach_btf")) + test_log_invalid_attach_btf(); + if (test__start_subtest("invalid_target_fd")) + test_log_invalid_target_fd(); + if (test__start_subtest("reattach_without_target")) + test_log_reattach_without_target(); + if (test__start_subtest("invalid_target_btf_id")) + test_log_invalid_target_btf_id(); + if (test__start_subtest("invalid_kprobe_write_ctx")) + test_log_invalid_kprobe_write_ctx(); +} -- 2.55.0