| // SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) |
| // Copyright (c) 2021 Hengqi Chen |
| // |
| // Based on statsnoop(8) from BCC by Brendan Gregg. |
| // 09-May-2021 Hengqi Chen Created this. |
| #include <argp.h> |
| #include <errno.h> |
| #include <signal.h> |
| #include <time.h> |
| |
| #include <bpf/libbpf.h> |
| #include <bpf/bpf.h> |
| #include "statsnoop.h" |
| #include "statsnoop.skel.h" |
| #include "trace_helpers.h" |
| |
| #define PERF_BUFFER_PAGES 16 |
| #define PERF_POLL_TIMEOUT_MS 100 |
| #define warn(...) fprintf(stderr, __VA_ARGS__) |
| |
| static volatile sig_atomic_t exiting = 0; |
| |
| static pid_t target_pid = 0; |
| static bool trace_failed_only = false; |
| static bool emit_timestamp = false; |
| |
| const char *argp_program_version = "statsnoop 0.1"; |
| const char *argp_program_bug_address = |
| "https://github.com/iovisor/bcc/tree/master/libbpf-tools"; |
| const char argp_program_doc[] = |
| "Trace stat syscalls.\n" |
| "\n" |
| "USAGE: statsnoop [-h] [-t] [-x] [-p PID]\n" |
| "\n" |
| "EXAMPLES:\n" |
| " statsnoop # trace all stat syscalls\n" |
| " statsnoop -t # include timestamps\n" |
| " statsnoop -x # only show failed stats\n" |
| " statsnoop -p 1216 # only trace PID 1216\n"; |
| |
| static const struct argp_option opts[] = { |
| {"pid", 'p', "PID", 0, "Process ID to trace"}, |
| {"failed", 'x', NULL, 0, "Only show failed stats"}, |
| {"timestamp", 't', NULL, 0, "Include timestamp on output"}, |
| {NULL, 'h', NULL, OPTION_HIDDEN, "Show the full help"}, |
| {}, |
| }; |
| |
| static error_t parse_arg(int key, char *arg, struct argp_state *state) |
| { |
| long pid; |
| |
| switch (key) { |
| case 'p': |
| errno = 0; |
| pid = strtol(arg, NULL, 10); |
| if (errno || pid <= 0) { |
| warn("Invalid PID: %s\n", arg); |
| argp_usage(state); |
| } |
| target_pid = pid; |
| break; |
| case 'x': |
| trace_failed_only = true; |
| break; |
| case 't': |
| emit_timestamp = true; |
| break; |
| case 'h': |
| argp_state_help(state, stderr, ARGP_HELP_STD_HELP); |
| break; |
| default: |
| return ARGP_ERR_UNKNOWN; |
| } |
| return 0; |
| } |
| |
| static void sig_int(int signo) |
| { |
| exiting = 1; |
| } |
| |
| static void handle_event(void *ctx, int cpu, void *data, __u32 data_sz) |
| { |
| static __u64 start_timestamp = 0; |
| const struct event *e = data; |
| int fd, err; |
| double ts = 0.0; |
| |
| if (e->ret >= 0) { |
| fd = e->ret; |
| err = 0; |
| } else { |
| fd = -1; |
| err = -e->ret; |
| } |
| if (!start_timestamp) |
| start_timestamp = e->ts_ns; |
| if (emit_timestamp) { |
| ts = (double)(e->ts_ns - start_timestamp) / 1000000000; |
| printf("%-14.9f ", ts); |
| } |
| printf("%-7d %-20s %-4d %-4d %-s\n", e->pid, e->comm, fd, err, e->pathname); |
| } |
| |
| static void handle_lost_events(void *ctx, int cpu, __u64 lost_cnt) |
| { |
| warn("lost %llu events on CPU #%d\n", lost_cnt, cpu); |
| } |
| |
| int main(int argc, char **argv) |
| { |
| static const struct argp argp = { |
| .options = opts, |
| .parser = parse_arg, |
| .doc = argp_program_doc, |
| }; |
| struct perf_buffer_opts pb_opts; |
| struct perf_buffer *pb = NULL; |
| struct statsnoop_bpf *obj; |
| int err; |
| |
| err = argp_parse(&argp, argc, argv, 0, NULL, NULL); |
| if (err) |
| return err; |
| |
| err = bump_memlock_rlimit(); |
| if (err) { |
| warn("failed to increase rlimit: %d\n", err); |
| return 1; |
| } |
| |
| obj = statsnoop_bpf__open(); |
| if (!obj) { |
| warn("failed to open BPF object\n"); |
| return 1; |
| } |
| |
| obj->rodata->target_pid = target_pid; |
| obj->rodata->trace_failed_only = trace_failed_only; |
| |
| err = statsnoop_bpf__load(obj); |
| if (err) { |
| warn("failed to load BPF object: %d\n", err); |
| goto cleanup; |
| } |
| |
| err = statsnoop_bpf__attach(obj); |
| if (err) { |
| warn("failed to attach BPF programs: %d\n", err); |
| goto cleanup; |
| } |
| |
| pb_opts.sample_cb = handle_event; |
| pb_opts.lost_cb = handle_lost_events; |
| pb = perf_buffer__new(bpf_map__fd(obj->maps.events), PERF_BUFFER_PAGES, |
| &pb_opts); |
| err = libbpf_get_error(pb); |
| if (err) { |
| warn("failed to open perf buffer: %d\n", err); |
| goto cleanup; |
| } |
| |
| if (signal(SIGINT, sig_int) == SIG_ERR) { |
| warn("can't set signal handler: %s\n", strerror(-errno)); |
| goto cleanup; |
| } |
| |
| if (emit_timestamp) |
| printf("%-14s ", "TIME(s)"); |
| printf("%-7s %-20s %-4s %-4s %-s\n", |
| "PID", "COMM", "RET", "ERR", "PATH"); |
| |
| while (1) { |
| if ((err = perf_buffer__poll(pb, PERF_POLL_TIMEOUT_MS)) < 0) |
| break; |
| if (exiting) |
| goto cleanup; |
| } |
| warn("error polling perf buffer: %d\n", err); |
| |
| cleanup: |
| statsnoop_bpf__destroy(obj); |
| |
| return err != 0; |
| } |