From 3aff8ba0a4c9c9191bb788171a1c54778e1246a2 Mon Sep 17 00:00:00 2001 From: Arnaldo Carvalho de Melo Date: Thu, 9 Feb 2017 14:39:42 -0300 Subject: [PATCH] perf bench numa: Avoid possible truncation when using snprintf() Addressing this warning from gcc 7: CC /tmp/build/perf/bench/numa.o bench/numa.c: In function '__bench_numa': bench/numa.c:1582:42: error: '%d' directive output may be truncated writing between 1 and 10 bytes into a region of size between 8 and 17 [-Werror=format-truncation=] snprintf(tname, 32, "process%d:thread%d", p, t); ^~ bench/numa.c:1582:25: note: directive argument in the range [0, 2147483647] snprintf(tname, 32, "process%d:thread%d", p, t); ^~~~~~~~~~~~~~~~~~~~ In file included from /usr/include/stdio.h:939:0, from bench/../util/util.h:47, from bench/../builtin.h:4, from bench/numa.c:11: /usr/include/bits/stdio2.h:64:10: note: '__builtin___snprintf_chk' output between 17 and 35 bytes into a destination of size 32 return __builtin___snprintf_chk (__s, __n, __USE_FORTIFY_LEVEL - 1, ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ __bos (__s), __fmt, __va_arg_pack ()); ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ cc1: all warnings being treated as errors Cc: Adrian Hunter Cc: David Ahern Cc: Jiri Olsa Cc: Namhyung Kim Cc: Petr Holasek Cc: Wang Nan Link: http://lkml.kernel.org/n/tip-twa37vsfqcie5gwpqwnjuuz9@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/bench/numa.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/tools/perf/bench/numa.c b/tools/perf/bench/numa.c index 8efe904e486b..9e5a02d6b9a9 100644 --- a/tools/perf/bench/numa.c +++ b/tools/perf/bench/numa.c @@ -1573,13 +1573,13 @@ static int __bench_numa(const char *name) "GB/sec,", "total-speed", "GB/sec total speed"); if (g->p.show_details >= 2) { - char tname[32]; + char tname[14 + 2 * 10 + 1]; struct thread_data *td; for (p = 0; p < g->p.nr_proc; p++) { for (t = 0; t < g->p.nr_threads; t++) { - memset(tname, 0, 32); + memset(tname, 0, sizeof(tname)); td = g->threads + p*g->p.nr_threads + t; - snprintf(tname, 32, "process%d:thread%d", p, t); + snprintf(tname, sizeof(tname), "process%d:thread%d", p, t); print_res(tname, td->speed_gbs, "GB/sec", "thread-speed", "GB/sec/thread speed"); print_res(tname, td->system_time_ns / NSEC_PER_SEC, -- 2.20.1