[PATCH 5.19 697/717] perf intel-pt: Fix segfault in intel_pt_print_info() with uClibc

Greg Kroah-Hartman
2022-10-22T10:12:17Z

From: Adrian Hunter <adrian.hunter@intel.com>

commit 5a3d47071f0ced0431ef82a5fb6bd077ed9493db upstream.

uClibc segfaulted because NULL was passed as the format to fprintf().

That happened because one of the format strings was missing and
intel_pt_print_info() didn't check that before calling fprintf().

Add the missing format string, and check format is not NULL before calling
fprintf().

Fixes: 11fa7cb86b56d361 ("perf tools: Pass Intel PT information for decoding MTC and CYC")
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20221012082259.22394-2-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
tools/perf/util/intel-pt.c | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)

--- a/tools/perf/util/intel-pt.c
+++ b/tools/perf/util/intel-pt.c
@@ -3878,6 +3878,7 @@ static const char * const intel_pt_info_
[INTEL_PT_SNAPSHOT_MODE] = " Snapshot mode %"PRId64"\n",
[INTEL_PT_PER_CPU_MMAPS] = " Per-cpu maps %"PRId64"\n",
[INTEL_PT_MTC_BIT] = " MTC bit %#"PRIx64"\n",
+ [INTEL_PT_MTC_FREQ_BITS] = " MTC freq bits %#"PRIx64"\n",
[INTEL_PT_TSC_CTC_N] = " TSC:CTC numerator %"PRIu64"\n",
[INTEL_PT_TSC_CTC_D] = " TSC:CTC denominator %"PRIu64"\n",
[INTEL_PT_CYC_BIT] = " CYC bit %#"PRIx64"\n",
@@ -3892,8 +3893,12 @@ static void intel_pt_print_info(__u64 *a
if (!dump_trace)
return;

- for (i = start; i <= finish; i++)
- fprintf(stdout, intel_pt_info_fmts[i], arr[i]);
+ for (i = start; i <= finish; i++) {
+ const char *fmt = intel_pt_info_fmts[i];
+
+ if (fmt)
+ fprintf(stdout, fmt, arr[i]);
+ }
}

static void intel_pt_print_info_str(const char *name, const char *str)