From 2e2bbc039fad9eabad6c4c1a473c8b2554cdd2d4 Mon Sep 17 00:00:00 2001 From: Arnaldo Carvalho de Melo Date: Thu, 9 Feb 2017 14:48:46 -0300 Subject: [PATCH] perf tests: Avoid possible truncation with dirent->d_name + snprintf Addressing a few cases spotted by a new warning in gcc 7: tests/parse-events.c: In function 'test_pmu_events': tests/parse-events.c:1790:39: error: '%s' directive output may be truncated writing up to 255 bytes into a region of size 90 [-Werror=format-truncation=] snprintf(name, MAX_NAME, "cpu/event=%s/u", ent->d_name); ^~ In file included from /usr/include/stdio.h:939:0, from /git/linux/tools/perf/util/map.h:9, from /git/linux/tools/perf/util/symbol.h:7, from /git/linux/tools/perf/util/evsel.h:10, from tests/parse-events.c:3: /usr/include/bits/stdio2.h:64:10: note: '__builtin___snprintf_chk' output between 13 and 268 bytes into a destination of size 100 return __builtin___snprintf_chk (__s, __n, __USE_FORTIFY_LEVEL - 1, ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ __bos (__s), __fmt, __va_arg_pack ()); ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ tests/parse-events.c:1798:29: error: '%s' directive output may be truncated writing up to 255 bytes into a region of size 100 [-Werror=format-truncation=] snprintf(name, MAX_NAME, "%s:u,cpu/event=%s/u", ent->d_name, ent->d_name); Cc: Adrian Hunter Cc: David Ahern Cc: Jiri Olsa Cc: Namhyung Kim Cc: Wang Nan Fixes: 945aea220bb8 ("perf tests: Move test objects into 'tests' directory") Link: http://lkml.kernel.org/n/tip-ty4q2p8zp1dp3mskvubxskm5@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/tests/parse-events.c | 8 +++----- 1 file changed, 3 insertions(+), 5 deletions(-) diff --git a/tools/perf/tests/parse-events.c b/tools/perf/tests/parse-events.c index 20c2e641c422..aa9276bfe3e9 100644 --- a/tools/perf/tests/parse-events.c +++ b/tools/perf/tests/parse-events.c @@ -1779,15 +1779,14 @@ static int test_pmu_events(void) } while (!ret && (ent = readdir(dir))) { -#define MAX_NAME 100 struct evlist_test e; - char name[MAX_NAME]; + char name[2 * NAME_MAX + 1 + 12 + 3]; /* Names containing . are special and cannot be used directly */ if (strchr(ent->d_name, '.')) continue; - snprintf(name, MAX_NAME, "cpu/event=%s/u", ent->d_name); + snprintf(name, sizeof(name), "cpu/event=%s/u", ent->d_name); e.name = name; e.check = test__checkevent_pmu_events; @@ -1795,11 +1794,10 @@ static int test_pmu_events(void) ret = test_event(&e); if (ret) break; - snprintf(name, MAX_NAME, "%s:u,cpu/event=%s/u", ent->d_name, ent->d_name); + snprintf(name, sizeof(name), "%s:u,cpu/event=%s/u", ent->d_name, ent->d_name); e.name = name; e.check = test__checkevent_pmu_events_mix; ret = test_event(&e); -#undef MAX_NAME } closedir(dir); -- 2.20.1