diff options
| author | Ian Rogers <irogers@google.com> | 2025-06-04 10:45:41 -0700 |
|---|---|---|
| committer | Namhyung Kim <namhyung@kernel.org> | 2025-06-09 11:18:18 -0700 |
| commit | bf1976dd28b4ec611d4f0bf5b0de40b1dd21b253 (patch) | |
| tree | f8a452a257fba88f3e04b58f9cc916898f2318f5 | |
| parent | 38f83cc9ab8f74732de66044d1a126ca46347eea (diff) | |
perf trace: Switch user option to use BPF filter
Finding user processes by scanning /proc is inherently racy and
results in perf_event_open failures. Use a BPF filter to drop samples
where the uid doesn't match. Ensure adding the BPF filter forces
system-wide.
Signed-off-by: Ian Rogers <irogers@google.com>
Link: https://lore.kernel.org/r/20250604174545.2853620-8-irogers@google.com
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
| -rw-r--r-- | tools/perf/builtin-trace.c | 26 |
1 files changed, 17 insertions, 9 deletions
diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c index 2ab1b8e05ad3..4bb062b96f51 100644 --- a/tools/perf/builtin-trace.c +++ b/tools/perf/builtin-trace.c @@ -236,6 +236,7 @@ struct trace { struct ordered_events data; u64 last; } oe; + const char *uid_str; }; static void trace__load_vmlinux_btf(struct trace *trace __maybe_unused) @@ -4412,8 +4413,8 @@ static int trace__run(struct trace *trace, int argc, const char **argv) evlist__add(evlist, pgfault_min); } - /* Enable ignoring missing threads when -u/-p option is defined. */ - trace->opts.ignore_missing_thread = trace->opts.target.uid != UINT_MAX || trace->opts.target.pid; + /* Enable ignoring missing threads when -p option is defined. */ + trace->opts.ignore_missing_thread = trace->opts.target.pid; if (trace->sched && evlist__add_newtp(evlist, "sched", "sched_stat_runtime", trace__sched_stat_runtime)) @@ -5445,8 +5446,7 @@ int cmd_trace(int argc, const char **argv) "child tasks do not inherit counters"), OPT_CALLBACK('m', "mmap-pages", &trace.opts.mmap_pages, "pages", "number of mmap data pages", evlist__parse_mmap_pages), - OPT_STRING('u', "uid", &trace.opts.target.uid_str, "user", - "user to profile"), + OPT_STRING('u', "uid", &trace.uid_str, "user", "user to profile"), OPT_CALLBACK(0, "duration", &trace, "float", "show only events with duration > N.M ms", trace__set_duration), @@ -5804,11 +5804,19 @@ init_augmented_syscall_tp: goto out_close; } - err = target__parse_uid(&trace.opts.target); - if (err) { - target__strerror(&trace.opts.target, err, bf, sizeof(bf)); - fprintf(trace.output, "%s", bf); - goto out_close; + if (trace.uid_str) { + uid_t uid = parse_uid(trace.uid_str); + + if (uid == UINT_MAX) { + ui__error("Invalid User: %s", trace.uid_str); + err = -EINVAL; + goto out_close; + } + err = parse_uid_filter(trace.evlist, uid); + if (err) + goto out_close; + + trace.opts.target.system_wide = true; } if (!argc && target__none(&trace.opts.target)) |