[tip:perf/urgent] perf probe: Check for dup and fdopen failures

[tip-bot for Colin Ian King <tipbot@zytor.com>]

Commit-ID:  0325862dc364d8af524bf2db53ef4360ed55b989
Gitweb:     http://git.kernel.org/tip/0325862dc364d8af524bf2db53ef4360ed55b989
Author:     Colin Ian King <colin.king@canonical.com>
AuthorDate: Fri, 12 Aug 2016 22:44:56 +0100
Committer:  Arnaldo Carvalho de Melo <acme@redhat.com>
CommitDate: Mon, 15 Aug 2016 17:06:19 -0300

perf probe: Check for dup and fdopen failures

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 9aed9c3..a8e7623 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;