[PATCH AUTOSEL 5.10 28/28] perf report: Fix memory leaks around perf_tip()

Sasha Levin
2021-11-26T02:40:34Z

From: Ian Rogers <irogers@google.com>

[ Upstream commit d9fc706108c15f8bc2d4ccccf8e50f74830fabd9 ]

perf_tip() may allocate memory or use a literal, this means memory
wasn't freed if allocated. Change the API so that literals aren't used.

At the same time add missing frees for system_path. These issues were
spotted using leak sanitizer.

Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lore.kernel.org/lkml/20211118073804.2149974-1-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
tools/perf/builtin-report.c | 15 +++++++++------
tools/perf/util/util.c | 14 +++++++-------
tools/perf/util/util.h | 2 +-
3 files changed, 17 insertions(+), 14 deletions(-)

diff --git a/tools/perf/builtin-report.c b/tools/perf/builtin-report.c
index 5824aa24acfcc..91cab5cdfbc16 100644
--- a/tools/perf/builtin-report.c
+++ b/tools/perf/builtin-report.c
@@ -610,14 +610,17 @@ static int report__browse_hists(struct report *rep)
int ret;
struct perf_session *session = rep->session;
struct evlist *evlist = session->evlist;
- const char *help = perf_tip(system_path(TIPDIR));
+ char *help = NULL, *path = NULL;

- if (help == NULL) {
+ path = system_path(TIPDIR);
+ if (perf_tip(&help, path) || help == NULL) {
/* fallback for people who don't install perf ;-) */
- help = perf_tip(DOCDIR);
- if (help == NULL)
- help = "Cannot load tips.txt file, please install perf!";
+ free(path);
+ path = system_path(DOCDIR);
+ if (perf_tip(&help, path) || help == NULL)
+ help = strdup("Cannot load tips.txt file, please install perf!");
}
+ free(path);

switch (use_browser) {
case 1:
@@ -644,7 +647,7 @@ static int report__browse_hists(struct report *rep)
ret = perf_evlist__tty_browse_hists(evlist, rep, help);
break;
}
-
+ free(help);
return ret;
}

diff --git a/tools/perf/util/util.c b/tools/perf/util/util.c
index 37a9492edb3eb..df3c4671be72a 100644
--- a/tools/perf/util/util.c
+++ b/tools/perf/util/util.c
@@ -379,32 +379,32 @@ fetch_kernel_version(unsigned int *puint, char *str,
return 0;
}

-const char *perf_tip(const char *dirpath)
+int perf_tip(char **strp, const char *dirpath)
{
struct strlist *tips;
struct str_node *node;
- char *tip = NULL;
struct strlist_config conf = {
.dirname = dirpath,
.file_only = true,
};
+ int ret = 0;

+ *strp = NULL;
tips = strlist__new("tips.txt", &conf);
if (tips == NULL)
- return errno == ENOENT ? NULL :
- "Tip: check path of tips.txt or get more memory! ;-p";
+ return -errno;

if (strlist__nr_entries(tips) == 0)
goto out;

node = strlist__entry(tips, random() % strlist__nr_entries(tips));
- if (asprintf(&tip, "Tip: %s", node->s) < 0)
- tip = (char *)"Tip: get more memory! ;-)";
+ if (asprintf(strp, "Tip: %s", node->s) < 0)
+ ret = -ENOMEM;

out:
strlist__delete(tips);

- return tip;
+ return ret;
}

char *perf_exe(char *buf, int len)
diff --git a/tools/perf/util/util.h b/tools/perf/util/util.h
index ad737052e5977..9f0d36ba77f2d 100644
--- a/tools/perf/util/util.h
+++ b/tools/perf/util/util.h
@@ -39,7 +39,7 @@ int fetch_kernel_version(unsigned int *puint,
#define KVER_FMT "%d.%d.%d"
#define KVER_PARAM(x) KVER_VERSION(x), KVER_PATCHLEVEL(x), KVER_SUBLEVEL(x)

-const char *perf_tip(const char *dirpath);
+int perf_tip(char **strp, const char *dirpath);

#ifndef HAVE_SCHED_GETCPU_SUPPORT
int sched_getcpu(void);
--
2.33.0