From 5697683e133d05e6333ee1f12a7e8dd402593258 Mon Sep 17 00:00:00 2001 From: Kumar Kartikeya Dwivedi Date: Thu, 3 Jul 2025 13:48:18 -0700 Subject: [PATCH] selftests/bpf: Add tests for prog streams Add selftests to stress test the various facets of the stream API, memory allocation pattern, and ensuring dumping support is tested and functional. Reviewed-by: Emil Tsalapatis Signed-off-by: Kumar Kartikeya Dwivedi Link: https://lore.kernel.org/r/20250703204818.925464-13-memxor@gmail.com Signed-off-by: Alexei Starovoitov --- .../testing/selftests/bpf/prog_tests/stream.c | 141 ++++++++++++++++++ tools/testing/selftests/bpf/progs/stream.c | 79 ++++++++++ .../testing/selftests/bpf/progs/stream_fail.c | 33 ++++ 3 files changed, 253 insertions(+) create mode 100644 tools/testing/selftests/bpf/prog_tests/stream.c create mode 100644 tools/testing/selftests/bpf/progs/stream.c create mode 100644 tools/testing/selftests/bpf/progs/stream_fail.c diff --git a/tools/testing/selftests/bpf/prog_tests/stream.c b/tools/testing/selftests/bpf/prog_tests/stream.c new file mode 100644 index 0000000000000..d9f0185dca61b --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/stream.c @@ -0,0 +1,141 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2025 Meta Platforms, Inc. and affiliates. */ +#include +#include +#include + +#include "stream.skel.h" +#include "stream_fail.skel.h" + +void test_stream_failure(void) +{ + RUN_TESTS(stream_fail); +} + +void test_stream_success(void) +{ + RUN_TESTS(stream); + return; +} + +struct { + int prog_off; + const char *errstr; +} stream_error_arr[] = { + { + offsetof(struct stream, progs.stream_cond_break), + "ERROR: Timeout detected for may_goto instruction\n" + "CPU: [0-9]+ UID: 0 PID: [0-9]+ Comm: .*\n" + "Call trace:\n" + "([a-zA-Z_][a-zA-Z0-9_]*\\+0x[0-9a-fA-F]+/0x[0-9a-fA-F]+\n" + "|[ \t]+[^\n]+\n)*", + }, + { + offsetof(struct stream, progs.stream_deadlock), + "ERROR: AA or ABBA deadlock detected for bpf_res_spin_lock\n" + "Attempted lock = (0x[0-9a-fA-F]+)\n" + "Total held locks = 1\n" + "Held lock\\[ 0\\] = \\1\n" // Lock address must match + "CPU: [0-9]+ UID: 0 PID: [0-9]+ Comm: .*\n" + "Call trace:\n" + "([a-zA-Z_][a-zA-Z0-9_]*\\+0x[0-9a-fA-F]+/0x[0-9a-fA-F]+\n" + "|[ \t]+[^\n]+\n)*", + }, +}; + +static int match_regex(const char *pattern, const char *string) +{ + int err, rc; + regex_t re; + + err = regcomp(&re, pattern, REG_EXTENDED | REG_NEWLINE); + if (err) + return -1; + rc = regexec(&re, string, 0, NULL, 0); + regfree(&re); + return rc == 0 ? 1 : 0; +} + +void test_stream_errors(void) +{ + LIBBPF_OPTS(bpf_test_run_opts, opts); + LIBBPF_OPTS(bpf_prog_stream_read_opts, ropts); + struct stream *skel; + int ret, prog_fd; + char buf[1024]; + + skel = stream__open_and_load(); + if (!ASSERT_OK_PTR(skel, "stream__open_and_load")) + return; + + for (int i = 0; i < ARRAY_SIZE(stream_error_arr); i++) { + struct bpf_program **prog; + + prog = (struct bpf_program **)(((char *)skel) + stream_error_arr[i].prog_off); + prog_fd = bpf_program__fd(*prog); + ret = bpf_prog_test_run_opts(prog_fd, &opts); + ASSERT_OK(ret, "ret"); + ASSERT_OK(opts.retval, "retval"); + +#if !defined(__x86_64__) + ASSERT_TRUE(1, "Timed may_goto unsupported, skip."); + if (i == 0) { + ret = bpf_prog_stream_read(prog_fd, 2, buf, sizeof(buf), &ropts); + ASSERT_EQ(ret, 0, "stream read"); + continue; + } +#endif + + ret = bpf_prog_stream_read(prog_fd, BPF_STREAM_STDERR, buf, sizeof(buf), &ropts); + ASSERT_GT(ret, 0, "stream read"); + ASSERT_LE(ret, 1023, "len for buf"); + buf[ret] = '\0'; + + ret = match_regex(stream_error_arr[i].errstr, buf); + if (!ASSERT_TRUE(ret == 1, "regex match")) + fprintf(stderr, "Output from stream:\n%s\n", buf); + } + + stream__destroy(skel); +} + +void test_stream_syscall(void) +{ + LIBBPF_OPTS(bpf_test_run_opts, opts); + LIBBPF_OPTS(bpf_prog_stream_read_opts, ropts); + struct stream *skel; + int ret, prog_fd; + char buf[64]; + + skel = stream__open_and_load(); + if (!ASSERT_OK_PTR(skel, "stream__open_and_load")) + return; + + prog_fd = bpf_program__fd(skel->progs.stream_syscall); + ret = bpf_prog_test_run_opts(prog_fd, &opts); + ASSERT_OK(ret, "ret"); + ASSERT_OK(opts.retval, "retval"); + + ASSERT_LT(bpf_prog_stream_read(0, BPF_STREAM_STDOUT, buf, sizeof(buf), &ropts), 0, "error"); + ret = -errno; + ASSERT_EQ(ret, -EINVAL, "bad prog_fd"); + + ASSERT_LT(bpf_prog_stream_read(prog_fd, 0, buf, sizeof(buf), &ropts), 0, "error"); + ret = -errno; + ASSERT_EQ(ret, -ENOENT, "bad stream id"); + + ASSERT_LT(bpf_prog_stream_read(prog_fd, BPF_STREAM_STDOUT, NULL, sizeof(buf), NULL), 0, "error"); + ret = -errno; + ASSERT_EQ(ret, -EFAULT, "bad stream buf"); + + ret = bpf_prog_stream_read(prog_fd, BPF_STREAM_STDOUT, buf, 2, NULL); + ASSERT_EQ(ret, 2, "bytes"); + ret = bpf_prog_stream_read(prog_fd, BPF_STREAM_STDOUT, buf, 2, NULL); + ASSERT_EQ(ret, 1, "bytes"); + ret = bpf_prog_stream_read(prog_fd, BPF_STREAM_STDOUT, buf, 1, &ropts); + ASSERT_EQ(ret, 0, "no bytes stdout"); + ret = bpf_prog_stream_read(prog_fd, BPF_STREAM_STDERR, buf, 1, &ropts); + ASSERT_EQ(ret, 0, "no bytes stderr"); + + stream__destroy(skel); +} diff --git a/tools/testing/selftests/bpf/progs/stream.c b/tools/testing/selftests/bpf/progs/stream.c new file mode 100644 index 0000000000000..35790897dc879 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/stream.c @@ -0,0 +1,79 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2025 Meta Platforms, Inc. and affiliates. */ +#include +#include +#include +#include "bpf_misc.h" +#include "bpf_experimental.h" + +struct arr_elem { + struct bpf_res_spin_lock lock; +}; + +struct { + __uint(type, BPF_MAP_TYPE_ARRAY); + __uint(max_entries, 1); + __type(key, int); + __type(value, struct arr_elem); +} arrmap SEC(".maps"); + +#define ENOSPC 28 +#define _STR "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx" + +int size; + +SEC("syscall") +__success __retval(0) +int stream_exhaust(void *ctx) +{ + /* Use global variable for loop convergence. */ + size = 0; + bpf_repeat(BPF_MAX_LOOPS) { + if (bpf_stream_printk(BPF_STDOUT, _STR) == -ENOSPC && size == 99954) + return 0; + size += sizeof(_STR) - 1; + } + return 1; +} + +SEC("syscall") +__success __retval(0) +int stream_cond_break(void *ctx) +{ + while (can_loop) + ; + return 0; +} + +SEC("syscall") +__success __retval(0) +int stream_deadlock(void *ctx) +{ + struct bpf_res_spin_lock *lock, *nlock; + + lock = bpf_map_lookup_elem(&arrmap, &(int){0}); + if (!lock) + return 1; + nlock = bpf_map_lookup_elem(&arrmap, &(int){0}); + if (!nlock) + return 1; + if (bpf_res_spin_lock(lock)) + return 1; + if (bpf_res_spin_lock(nlock)) { + bpf_res_spin_unlock(lock); + return 0; + } + bpf_res_spin_unlock(nlock); + bpf_res_spin_unlock(lock); + return 1; +} + +SEC("syscall") +__success __retval(0) +int stream_syscall(void *ctx) +{ + bpf_stream_printk(BPF_STDOUT, "foo"); + return 0; +} + +char _license[] SEC("license") = "GPL"; diff --git a/tools/testing/selftests/bpf/progs/stream_fail.c b/tools/testing/selftests/bpf/progs/stream_fail.c new file mode 100644 index 0000000000000..b4a0d0cc8ec8a --- /dev/null +++ b/tools/testing/selftests/bpf/progs/stream_fail.c @@ -0,0 +1,33 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2025 Meta Platforms, Inc. and affiliates. */ +#include +#include +#include +#include +#include "bpf_misc.h" + +SEC("syscall") +__failure __msg("Possibly NULL pointer passed") +int stream_vprintk_null_arg(void *ctx) +{ + bpf_stream_vprintk(BPF_STDOUT, "", NULL, 0, NULL); + return 0; +} + +SEC("syscall") +__failure __msg("R3 type=scalar expected=") +int stream_vprintk_scalar_arg(void *ctx) +{ + bpf_stream_vprintk(BPF_STDOUT, "", (void *)46, 0, NULL); + return 0; +} + +SEC("syscall") +__failure __msg("arg#1 doesn't point to a const string") +int stream_vprintk_string_arg(void *ctx) +{ + bpf_stream_vprintk(BPF_STDOUT, ctx, NULL, 0, NULL); + return 0; +} + +char _license[] SEC("license") = "GPL"; -- 2.47.2