From: Namhyung Kim Date: Fri, 21 Jun 2024 17:05:28 +0000 (-0700) Subject: perf mem: Fix a segfault with NULL event->name X-Git-Tag: v6.11-rc1~130^2~35 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=c7a5592e8e4d5e0ece94694e3932891a744c2b96;p=thirdparty%2Fkernel%2Flinux.git perf mem: Fix a segfault with NULL event->name Guilherme reported a crash in perf mem record. It's because the perf_mem_event->name was NULL on his machine. It should just return a NULL string when it has no format string in the name. The backtrace at the crash is below: Program received signal SIGSEGV, Segmentation fault. __strchrnul_avx2 () at ../sysdeps/x86_64/multiarch/strchr-avx2.S:67 67 vmovdqu (%rdi), %ymm2 (gdb) bt #0 __strchrnul_avx2 () at ../sysdeps/x86_64/multiarch/strchr-avx2.S:67 #1 0x00007ffff6c982de in __find_specmb (format=0x0) at printf-parse.h:82 #2 __printf_buffer (buf=buf@entry=0x7fffffffc760, format=format@entry=0x0, ap=ap@entry=0x7fffffffc880, mode_flags=mode_flags@entry=0) at vfprintf-internal.c:649 #3 0x00007ffff6cb7840 in __vsnprintf_internal (string=, maxlen=, format=0x0, args=0x7fffffffc880, mode_flags=mode_flags@entry=0) at vsnprintf.c:96 #4 0x00007ffff6cb787f in ___vsnprintf (string=, maxlen=, format=, args=) at vsnprintf.c:103 #5 0x00005555557b9391 in scnprintf (buf=0x555555fe9320 "", size=100, fmt=0x0) at ../lib/vsprintf.c:21 #6 0x00005555557b74c3 in perf_pmu__mem_events_name (i=0, pmu=0x555556832180) at util/mem-events.c:106 #7 0x00005555557b7ab9 in perf_mem_events__record_args (rec_argv=0x55555684c000, argv_nr=0x7fffffffca20) at util/mem-events.c:252 #8 0x00005555555e370d in __cmd_record (argc=3, argv=0x7fffffffd760, mem=0x7fffffffcd80) at builtin-mem.c:156 #9 0x00005555555e49c4 in cmd_mem (argc=4, argv=0x7fffffffd760) at builtin-mem.c:514 #10 0x000055555569716c in run_builtin (p=0x555555fcde80 , argc=8, argv=0x7fffffffd760) at perf.c:349 #11 0x0000555555697402 in handle_internal_command (argc=8, argv=0x7fffffffd760) at perf.c:402 #12 0x0000555555697560 in run_argv (argcp=0x7fffffffd59c, argv=0x7fffffffd590) at perf.c:446 #13 0x00005555556978a6 in main (argc=8, argv=0x7fffffffd760) at perf.c:562 Reported-by: Guilherme Amadio Reviewed-by: Kan Liang Closes: https://lore.kernel.org/linux-perf-users/Zlns_o_IE5L28168@cern.ch Signed-off-by: Namhyung Kim Link: https://lore.kernel.org/r/20240621170528.608772-5-namhyung@kernel.org --- diff --git a/tools/perf/util/mem-events.c b/tools/perf/util/mem-events.c index 6dda47bb774fa..429079329e489 100644 --- a/tools/perf/util/mem-events.c +++ b/tools/perf/util/mem-events.c @@ -86,7 +86,7 @@ static const char *perf_pmu__mem_events_name(int i, struct perf_pmu *pmu) return NULL; e = &pmu->mem_events[i]; - if (!e) + if (!e || !e->name) return NULL; if (i == PERF_MEM_EVENTS__LOAD || i == PERF_MEM_EVENTS__LOAD_STORE) {