diff options
| author | Benjamin Peterson <benjamin@engflow.com> | 2024-11-07 23:21:27 +0000 |
|---|---|---|
| committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2024-11-14 18:06:52 -0300 |
| commit | 1302e352b26f34991b619b5d0b621b76d20a3883 (patch) | |
| tree | 837a92286e2639d02cfd47e3644504ba0f5f5b3e /tools/perf | |
| parent | 3fd7c36973a250e17a4ee305a31545a9426021f4 (diff) | |
perf trace: Avoid garbage when not printing a syscall's arguments
syscall__scnprintf_args may not place anything in the output buffer
(e.g., because the arguments are all zero). If that happened in
trace__fprintf_sys_enter, its fprintf would receive an unitialized
buffer leading to garbage output.
Fix the problem by passing the (possibly zero) bounds of the argument
buffer to the output fprintf.
Fixes: a98392bb1e169a04 ("perf trace: Use beautifiers on syscalls:sys_enter_ handlers")
Signed-off-by: Benjamin Peterson <benjamin@engflow.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Tested-by: Howard Chu <howardchu95@gmail.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20241107232128.108981-2-benjamin@engflow.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/perf')
| -rw-r--r-- | tools/perf/builtin-trace.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c index ca5c3f5d6c38..6a1a128fe645 100644 --- a/tools/perf/builtin-trace.c +++ b/tools/perf/builtin-trace.c @@ -2702,6 +2702,7 @@ static int trace__fprintf_sys_enter(struct trace *trace, struct evsel *evsel, char msg[1024]; void *args, *augmented_args = NULL; int augmented_args_size; + size_t printed = 0; if (sc == NULL) return -1; @@ -2717,8 +2718,8 @@ static int trace__fprintf_sys_enter(struct trace *trace, struct evsel *evsel, args = perf_evsel__sc_tp_ptr(evsel, args, sample); augmented_args = syscall__augmented_args(sc, sample, &augmented_args_size, trace->raw_augmented_syscalls_args_size); - syscall__scnprintf_args(sc, msg, sizeof(msg), args, augmented_args, augmented_args_size, trace, thread); - fprintf(trace->output, "%s", msg); + printed += syscall__scnprintf_args(sc, msg, sizeof(msg), args, augmented_args, augmented_args_size, trace, thread); + fprintf(trace->output, "%.*s", (int)printed, msg); err = 0; out_put: thread__put(thread); |