[PATCH v2 15/16] perf test pmu: Avoid 2 static path arrays

From: Ian Rogers
Date: Fri May 26 2023 - 14:35:55 EST


Avoid two static paths that contributed 8,192 bytes to .bss are only
used duing the perf parse pmu test. This change helps FORTIFY
triggering 2 warnings like:

```
tests/pmu.c: In function ‘test__pmu’:
tests/pmu.c:121:43: error: ‘%s’ directive output may be truncated writing up to 4095 bytes into a region of size 4090 [-Werror=format-truncation=]
121 | snprintf(buf, sizeof(buf), "rm -f %s/*\n", dir);
```

So make buf a little larger.

Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>
---
tools/perf/tests/pmu.c | 17 +++++++++--------
1 file changed, 9 insertions(+), 8 deletions(-)

diff --git a/tools/perf/tests/pmu.c b/tools/perf/tests/pmu.c
index 3cf25f883df7..a4452639a3d4 100644
--- a/tools/perf/tests/pmu.c
+++ b/tools/perf/tests/pmu.c
@@ -86,17 +86,16 @@ static struct parse_events_term test_terms[] = {
* Prepare format directory data, exported by kernel
* at /sys/bus/event_source/devices/<dev>/format.
*/
-static char *test_format_dir_get(void)
+static char *test_format_dir_get(char *dir, size_t sz)
{
- static char dir[PATH_MAX];
unsigned int i;

- snprintf(dir, PATH_MAX, "/tmp/perf-pmu-test-format-XXXXXX");
+ snprintf(dir, sz, "/tmp/perf-pmu-test-format-XXXXXX");
if (!mkdtemp(dir))
return NULL;

for (i = 0; i < ARRAY_SIZE(test_formats); i++) {
- static char name[PATH_MAX];
+ char name[PATH_MAX];
struct test_format *format = &test_formats[i];
FILE *file;

@@ -118,12 +117,13 @@ static char *test_format_dir_get(void)
/* Cleanup format directory. */
static int test_format_dir_put(char *dir)
{
- char buf[PATH_MAX];
- snprintf(buf, PATH_MAX, "rm -f %s/*\n", dir);
+ char buf[PATH_MAX + 20];
+
+ snprintf(buf, sizeof(buf), "rm -f %s/*\n", dir);
if (system(buf))
return -1;

- snprintf(buf, PATH_MAX, "rmdir %s\n", dir);
+ snprintf(buf, sizeof(buf), "rmdir %s\n", dir);
return system(buf);
}

@@ -140,7 +140,8 @@ static struct list_head *test_terms_list(void)

static int test__pmu(struct test_suite *test __maybe_unused, int subtest __maybe_unused)
{
- char *format = test_format_dir_get();
+ char dir[PATH_MAX];
+ char *format = test_format_dir_get(dir, sizeof(dir));
LIST_HEAD(formats);
struct list_head *terms = test_terms_list();
int ret;
--
2.41.0.rc0.172.g3f132b7071-goog