lkml.org 
[lkml]   [2017]   [Feb]   [10]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[tip:perf/core] perf tests: Avoid possible truncation with dirent->d_name + snprintf
Commit-ID:  2e2bbc039fad9eabad6c4c1a473c8b2554cdd2d4
Gitweb: http://git.kernel.org/tip/2e2bbc039fad9eabad6c4c1a473c8b2554cdd2d4
Author: Arnaldo Carvalho de Melo <acme@redhat.com>
AuthorDate: Thu, 9 Feb 2017 14:48:46 -0300
Committer: Arnaldo Carvalho de Melo <acme@redhat.com>
CommitDate: Thu, 9 Feb 2017 14:48:46 -0300

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 <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
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 <acme@redhat.com>
---
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 20c2e64..aa9276b 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);
\
 
 \ /
  Last update: 2017-02-10 08:57    [W:0.087 / U:0.928 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site