[PATCH 08/11] perf probe: Check for dup and fdopen failures

Arnaldo Carvalho de Melo
2016-08-15T22:01:47Z

From: Colin Ian King <colin.king@canonical.com>

dup and fdopen can potentially fail, so add some extra
error handling checks rather than assuming they always work.

Signed-off-by: Colin King <colin.king@canonical.com>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/1471038296-12956-1-git-send-email-colin.king@canonical.com
[ Free resources when those functions (now being verified) fail ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
tools/perf/util/probe-file.c | 24 ++++++++++++++++++++----
1 file changed, 20 insertions(+), 4 deletions(-)

diff --git a/tools/perf/util/probe-file.c b/tools/perf/util/probe-file.c
index 9aed9c332da6..a8e76233c088 100644
--- a/tools/perf/util/probe-file.c
+++ b/tools/perf/util/probe-file.c
@@ -133,7 +133,7 @@ int probe_file__open_both(int *kfd, int *ufd, int flag)
/* Get raw string list of current kprobe_events or uprobe_events */
struct strlist *probe_file__get_rawlist(int fd)
{
- int ret, idx;
+ int ret, idx, fddup;
FILE *fp;
char buf[MAX_CMDLEN];
char *p;
@@ -144,7 +144,14 @@ struct strlist *probe_file__get_rawlist(int fd)

sl = strlist__new(NULL, NULL);

- fp = fdopen(dup(fd), "r");
+ fddup = dup(fd);
+ if (fddup < 0)
+ goto out_free_sl;
+
+ fp = fdopen(fddup, "r");
+ if (!fp)
+ goto out_close_fddup;
+
while (!feof(fp)) {
p = fgets(buf, MAX_CMDLEN, fp);
if (!p)
@@ -163,6 +170,12 @@ struct strlist *probe_file__get_rawlist(int fd)
fclose(fp);

return sl;
+
+out_close_fddup:
+ close(fddup);
+out_free_sl:
+ strlist__delete(sl);
+ return NULL;
}

static struct strlist *__probe_file__get_namelist(int fd, bool include_group)
@@ -447,10 +460,13 @@ static int probe_cache__load(struct probe_cache *pcache)
{
struct probe_cache_entry *entry = NULL;
char buf[MAX_CMDLEN], *p;
- int ret = 0;
+ int ret = 0, fddup;
FILE *fp;

- fp = fdopen(dup(pcache->fd), "r");
+ fddup = dup(pcache->fd);
+ if (fddup < 0)
+ return -errno;
+ fp = fdopen(fddup, "r");
if (!fp)
return -EINVAL;

--
2.7.4