From: Numfor Mbiziwo-Tiapo <nums@google.com>
To: peterz@infradead.org, mingo@redhat.com, acme@kernel.org,
alexander.shishkin@linux.intel.com, jolsa@redhat.com,
namhyung@kernel.org, songliubraving@fb.com, mbd@fb.com
Cc: linux-kernel@vger.kernel.org, irogers@google.com,
eranian@google.com, Numfor Mbiziwo-Tiapo <nums@google.com>
Subject: [PATCH 1/3] Fix backward-ring-buffer.c format-truncation error
Date: Wed, 24 Jul 2019 11:45:10 -0700 [thread overview]
Message-ID: <20190724184512.162887-2-nums@google.com> (raw)
In-Reply-To: <20190724184512.162887-1-nums@google.com>
Perf does not build with the ubsan (undefined behavior sanitizer)
and there is an error that says:
tests/backward-ring-buffer.c:23:45: error: ‘%d’ directive output
may be truncated writing between 1 and 10 bytes into a region of
size 8 [-Werror=format-truncation=]
snprintf(proc_name, sizeof(proc_name), "p:%d\n", i);
This can be reproduced by running (from the tip directory):
make -C tools/perf USE_CLANG=1 EXTRA_CFLAGS="-fsanitize=undefined"
Th error occurs because they are writing to the 10 byte buffer - the
index 'i' of the for loop and the 2 byte hardcoded string. If somehow 'i'
was greater than 8 bytes (10 - 2), then the snprintf function would
truncate the string. Increasing the size of the buffer fixes the error.
Signed-off-by: Numfor Mbiziwo-Tiapo <nums@google.com>
---
tools/perf/tests/backward-ring-buffer.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/perf/tests/backward-ring-buffer.c b/tools/perf/tests/backward-ring-buffer.c
index 6d598cc071ae..1a9c3becf5ff 100644
--- a/tools/perf/tests/backward-ring-buffer.c
+++ b/tools/perf/tests/backward-ring-buffer.c
@@ -18,7 +18,7 @@ static void testcase(void)
int i;
for (i = 0; i < NR_ITERS; i++) {
- char proc_name[10];
+ char proc_name[15];
snprintf(proc_name, sizeof(proc_name), "p:%d\n", i);
prctl(PR_SET_NAME, proc_name);
--
2.22.0.657.g960e92d24f-goog
next prev parent reply other threads:[~2019-07-24 18:45 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-24 18:45 [PATCH 0/3] Perf UBsan Patches Numfor Mbiziwo-Tiapo
2019-07-24 18:45 ` Numfor Mbiziwo-Tiapo [this message]
2019-07-25 13:08 ` [PATCH 1/3] Fix backward-ring-buffer.c format-truncation error David Laight
2019-07-26 19:40 ` Arnaldo Carvalho de Melo
2019-07-29 20:57 ` [PATCH v2] Fix annotate.c use of uninitialized value error Numfor Mbiziwo-Tiapo
2019-08-07 11:32 ` Jiri Olsa
2019-10-25 22:11 ` Ian Rogers
2020-07-09 0:54 ` Ian Rogers
2020-07-09 15:38 ` Arnaldo Carvalho de Melo
2019-07-24 18:45 ` [PATCH 2/3] Fix ordered-events.c array-bounds error Numfor Mbiziwo-Tiapo
2019-07-26 19:33 ` Arnaldo Carvalho de Melo
2019-07-26 19:35 ` Arnaldo Carvalho de Melo
2019-07-24 18:45 ` [PATCH 3/3] Fix insn.c misaligned address error Numfor Mbiziwo-Tiapo
2019-07-25 13:06 ` David Laight
2019-07-25 21:18 ` Ian Rogers
2019-07-26 19:38 ` Arnaldo Carvalho de Melo
2019-07-27 9:46 ` Masami Hiramatsu
2019-07-29 8:22 ` Adrian Hunter
2019-07-29 19:32 ` Ian Rogers
2019-07-30 7:50 ` Adrian Hunter
2019-07-30 0:47 ` Masami Hiramatsu
2019-07-30 7:53 ` Adrian Hunter
2019-07-30 9:17 ` David Laight
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