diff options
Diffstat (limited to 'tools')
| -rw-r--r-- | tools/bpf/bpftool/Documentation/bpftool-prog.rst | 7 | ||||
| -rw-r--r-- | tools/bpf/bpftool/bash-completion/bpftool | 16 | ||||
| -rw-r--r-- | tools/bpf/bpftool/prog.c | 49 | ||||
| -rw-r--r-- | tools/include/uapi/linux/bpf.h | 24 | ||||
| -rw-r--r-- | tools/lib/bpf/bpf.c | 20 | ||||
| -rw-r--r-- | tools/lib/bpf/bpf.h | 21 | ||||
| -rw-r--r-- | tools/lib/bpf/bpf_helpers.h | 16 | ||||
| -rw-r--r-- | tools/lib/bpf/libbpf.map | 1 | ||||
| -rw-r--r-- | tools/testing/selftests/bpf/prog_tests/stream.c | 141 | ||||
| -rw-r--r-- | tools/testing/selftests/bpf/progs/stream.c | 79 | ||||
| -rw-r--r-- | tools/testing/selftests/bpf/progs/stream_fail.c | 33 |
11 files changed, 405 insertions, 2 deletions
diff --git a/tools/bpf/bpftool/Documentation/bpftool-prog.rst b/tools/bpf/bpftool/Documentation/bpftool-prog.rst index da3152c16228..f69fd92df8d8 100644 --- a/tools/bpf/bpftool/Documentation/bpftool-prog.rst +++ b/tools/bpf/bpftool/Documentation/bpftool-prog.rst @@ -35,6 +35,7 @@ PROG COMMANDS | **bpftool** **prog attach** *PROG* *ATTACH_TYPE* [*MAP*] | **bpftool** **prog detach** *PROG* *ATTACH_TYPE* [*MAP*] | **bpftool** **prog tracelog** +| **bpftool** **prog tracelog** [ { **stdout** | **stderr** } *PROG* ] | **bpftool** **prog run** *PROG* **data_in** *FILE* [**data_out** *FILE* [**data_size_out** *L*]] [**ctx_in** *FILE* [**ctx_out** *FILE* [**ctx_size_out** *M*]]] [**repeat** *N*] | **bpftool** **prog profile** *PROG* [**duration** *DURATION*] *METRICs* | **bpftool** **prog help** @@ -179,6 +180,12 @@ bpftool prog tracelog purposes. For streaming data from BPF programs to user space, one can use perf events (see also **bpftool-map**\ (8)). +bpftool prog tracelog { stdout | stderr } *PROG* + Dump the BPF stream of the program. BPF programs can write to these streams + at runtime with the **bpf_stream_vprintk**\ () kfunc. The kernel may write + error messages to the standard error stream. This facility should be used + only for debugging purposes. + bpftool prog run *PROG* data_in *FILE* [data_out *FILE* [data_size_out *L*]] [ctx_in *FILE* [ctx_out *FILE* [ctx_size_out *M*]]] [repeat *N*] Run BPF program *PROG* in the kernel testing infrastructure for BPF, meaning that the program works on the data and context provided by the diff --git a/tools/bpf/bpftool/bash-completion/bpftool b/tools/bpf/bpftool/bash-completion/bpftool index 27512feb5c70..a759ba24471d 100644 --- a/tools/bpf/bpftool/bash-completion/bpftool +++ b/tools/bpf/bpftool/bash-completion/bpftool @@ -518,7 +518,21 @@ _bpftool() esac ;; tracelog) - return 0 + case $prev in + $command) + COMPREPLY+=( $( compgen -W "stdout stderr" -- \ + "$cur" ) ) + return 0 + ;; + stdout|stderr) + COMPREPLY=( $( compgen -W "$PROG_TYPE" -- \ + "$cur" ) ) + return 0 + ;; + *) + return 0 + ;; + esac ;; profile) case $cword in diff --git a/tools/bpf/bpftool/prog.c b/tools/bpf/bpftool/prog.c index deeaa5c1ed7d..9722d841abc0 100644 --- a/tools/bpf/bpftool/prog.c +++ b/tools/bpf/bpftool/prog.c @@ -1113,6 +1113,52 @@ static int do_detach(int argc, char **argv) return 0; } +enum prog_tracelog_mode { + TRACE_STDOUT, + TRACE_STDERR, +}; + +static int +prog_tracelog_stream(int prog_fd, enum prog_tracelog_mode mode) +{ + FILE *file = mode == TRACE_STDOUT ? stdout : stderr; + int stream_id = mode == TRACE_STDOUT ? 1 : 2; + char buf[512]; + int ret; + + ret = 0; + do { + ret = bpf_prog_stream_read(prog_fd, stream_id, buf, sizeof(buf), NULL); + if (ret > 0) + fwrite(buf, sizeof(buf[0]), ret, file); + } while (ret > 0); + + fflush(file); + return ret ? -1 : 0; +} + +static int do_tracelog_any(int argc, char **argv) +{ + enum prog_tracelog_mode mode; + int fd; + + if (argc == 0) + return do_tracelog(argc, argv); + if (!is_prefix(*argv, "stdout") && !is_prefix(*argv, "stderr")) + usage(); + mode = is_prefix(*argv, "stdout") ? TRACE_STDOUT : TRACE_STDERR; + NEXT_ARG(); + + if (!REQ_ARGS(2)) + return -1; + + fd = prog_parse_fd(&argc, &argv); + if (fd < 0) + return -1; + + return prog_tracelog_stream(fd, mode); +} + static int check_single_stdin(char *file_data_in, char *file_ctx_in) { if (file_data_in && file_ctx_in && @@ -2493,6 +2539,7 @@ static int do_help(int argc, char **argv) " [repeat N]\n" " %1$s %2$s profile PROG [duration DURATION] METRICs\n" " %1$s %2$s tracelog\n" + " %1$s %2$s tracelog { stdout | stderr } PROG\n" " %1$s %2$s help\n" "\n" " " HELP_SPEC_MAP "\n" @@ -2532,7 +2579,7 @@ static const struct cmd cmds[] = { { "loadall", do_loadall }, { "attach", do_attach }, { "detach", do_detach }, - { "tracelog", do_tracelog }, + { "tracelog", do_tracelog_any }, { "run", do_run }, { "profile", do_profile }, { 0 } diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index 719ba230032f..0670e15a6100 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -906,6 +906,17 @@ union bpf_iter_link_info { * A new file descriptor (a nonnegative integer), or -1 if an * error occurred (in which case, *errno* is set appropriately). * + * BPF_PROG_STREAM_READ_BY_FD + * Description + * Read data of a program's BPF stream. The program is identified + * by *prog_fd*, and the stream is identified by the *stream_id*. + * The data is copied to a buffer pointed to by *stream_buf*, and + * filled less than or equal to *stream_buf_len* bytes. + * + * Return + * Number of bytes read from the stream on success, or -1 if an + * error occurred (in which case, *errno* is set appropriately). + * * NOTES * eBPF objects (maps and programs) can be shared between processes. * @@ -961,6 +972,7 @@ enum bpf_cmd { BPF_LINK_DETACH, BPF_PROG_BIND_MAP, BPF_TOKEN_CREATE, + BPF_PROG_STREAM_READ_BY_FD, __MAX_BPF_CMD, }; @@ -1463,6 +1475,11 @@ struct bpf_stack_build_id { #define BPF_OBJ_NAME_LEN 16U +enum { + BPF_STREAM_STDOUT = 1, + BPF_STREAM_STDERR = 2, +}; + union bpf_attr { struct { /* anonymous struct used by BPF_MAP_CREATE command */ __u32 map_type; /* one of enum bpf_map_type */ @@ -1849,6 +1866,13 @@ union bpf_attr { __u32 bpffs_fd; } token_create; + struct { + __aligned_u64 stream_buf; + __u32 stream_buf_len; + __u32 stream_id; + __u32 prog_fd; + } prog_stream_read; + } __attribute__((aligned(8))); /* The description below is an attempt at providing documentation to eBPF diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c index 6eb421ccf91b..ab40dbf9f020 100644 --- a/tools/lib/bpf/bpf.c +++ b/tools/lib/bpf/bpf.c @@ -1375,3 +1375,23 @@ int bpf_token_create(int bpffs_fd, struct bpf_token_create_opts *opts) fd = sys_bpf_fd(BPF_TOKEN_CREATE, &attr, attr_sz); return libbpf_err_errno(fd); } + +int bpf_prog_stream_read(int prog_fd, __u32 stream_id, void *buf, __u32 buf_len, + struct bpf_prog_stream_read_opts *opts) +{ + const size_t attr_sz = offsetofend(union bpf_attr, prog_stream_read); + union bpf_attr attr; + int err; + + if (!OPTS_VALID(opts, bpf_prog_stream_read_opts)) + return libbpf_err(-EINVAL); + + memset(&attr, 0, attr_sz); + attr.prog_stream_read.stream_buf = ptr_to_u64(buf); + attr.prog_stream_read.stream_buf_len = buf_len; + attr.prog_stream_read.stream_id = stream_id; + attr.prog_stream_read.prog_fd = prog_fd; + + err = sys_bpf(BPF_PROG_STREAM_READ_BY_FD, &attr, attr_sz); + return libbpf_err_errno(err); +} diff --git a/tools/lib/bpf/bpf.h b/tools/lib/bpf/bpf.h index 1342564214c8..7252150e7ad3 100644 --- a/tools/lib/bpf/bpf.h +++ b/tools/lib/bpf/bpf.h @@ -709,6 +709,27 @@ struct bpf_token_create_opts { LIBBPF_API int bpf_token_create(int bpffs_fd, struct bpf_token_create_opts *opts); +struct bpf_prog_stream_read_opts { + size_t sz; + size_t :0; +}; +#define bpf_prog_stream_read_opts__last_field sz +/** + * @brief **bpf_prog_stream_read** reads data from the BPF stream of a given BPF + * program. + * + * @param prog_fd FD for the BPF program whose BPF stream is to be read. + * @param stream_id ID of the BPF stream to be read. + * @param buf Buffer to read data into from the BPF stream. + * @param buf_len Maximum number of bytes to read from the BPF stream. + * @param opts optional options, can be NULL + * + * @return The number of bytes read, on success; negative error code, otherwise + * (errno is also set to the error code) + */ +LIBBPF_API int bpf_prog_stream_read(int prog_fd, __u32 stream_id, void *buf, __u32 buf_len, + struct bpf_prog_stream_read_opts *opts); + #ifdef __cplusplus } /* extern "C" */ #endif diff --git a/tools/lib/bpf/bpf_helpers.h b/tools/lib/bpf/bpf_helpers.h index a50773d4616e..76b127a9f24d 100644 --- a/tools/lib/bpf/bpf_helpers.h +++ b/tools/lib/bpf/bpf_helpers.h @@ -314,6 +314,22 @@ enum libbpf_tristate { ___param, sizeof(___param)); \ }) +extern int bpf_stream_vprintk(int stream_id, const char *fmt__str, const void *args, + __u32 len__sz, void *aux__prog) __weak __ksym; + +#define bpf_stream_printk(stream_id, fmt, args...) \ +({ \ + static const char ___fmt[] = fmt; \ + unsigned long long ___param[___bpf_narg(args)]; \ + \ + _Pragma("GCC diagnostic push") \ + _Pragma("GCC diagnostic ignored \"-Wint-conversion\"") \ + ___bpf_fill(___param, args); \ + _Pragma("GCC diagnostic pop") \ + \ + bpf_stream_vprintk(stream_id, ___fmt, ___param, sizeof(___param), NULL);\ +}) + /* Use __bpf_printk when bpf_printk call has 3 or fewer fmt args * Otherwise use __bpf_vprintk */ diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map index c7fc0bde5648..1bbf77326420 100644 --- a/tools/lib/bpf/libbpf.map +++ b/tools/lib/bpf/libbpf.map @@ -437,6 +437,7 @@ LIBBPF_1.6.0 { bpf_linker__add_fd; bpf_linker__new_fd; bpf_object__prepare; + bpf_prog_stream_read; bpf_program__attach_cgroup_opts; bpf_program__func_info; bpf_program__func_info_cnt; 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 000000000000..d9f0185dca61 --- /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 <test_progs.h> +#include <sys/mman.h> +#include <regex.h> + +#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 000000000000..35790897dc87 --- /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 <vmlinux.h> +#include <bpf/bpf_tracing.h> +#include <bpf/bpf_helpers.h> +#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 000000000000..b4a0d0cc8ec8 --- /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 <vmlinux.h> +#include <bpf/bpf_tracing.h> +#include <bpf/bpf_helpers.h> +#include <bpf/bpf_core_read.h> +#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"; |