perf data: Fix error return code in perf_data__create_dir()

From: Zhen Lei <[email protected]>

[ Upstream commit f2211881e737cade55e0ee07cf6a26d91a35a6fe ]

Although 'ret' has been initialized to -1, but it will be reassigned by the "ret = open(...)" statement in the for loop. So that, the value of 'ret' is unknown when asprintf() failed.

---
 tools/perf/util/data.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

index 88fba2ba549f..7534455ffc6a 100644
@@ -35,7 +35,7 @@ void perf_data__close_dir(struct perf_data *data)
 int perf_data__create_dir(struct perf_data *data, int nr)
 {
 	struct perf_data_file *files = NULL;
-	int i, ret = -1;
+	int i, ret;
 
 	if (WARN_ON(!data->is_dir))
 		return -EINVAL;

@@ -51,7 +51,8 @@ int perf_data__create_dir(struct perf_data *data, int nr)
 	for (i = 0; i < nr; i++) {
 		struct perf_data_file *file = &files[i];
 
-		if (asprintf(&file->path, "%s/data.%d", data->path, i) < 0)
+		ret = asprintf(&file->path, "%s/data.%d", data->path, i);
+		if (ret < 0)
 			goto out_err;
 
 		ret = open(file->path, O_RDWR|O_CREAT|O_TRUNC, S_IRUSR|S_IWUSR);

2.30.2

From: Thomas Richter <[email protected]>

[ Upstream commit 671b60cb6a897a5b3832fe57657152f2c3995e25 ]

Command 'perf ftrace -v -- ls' fails in s390 (at least 5.12.0rc6).

The root cause is a missing pointer dereference which causes an array element address to be used as PID.

Fix this by extracting the PID.

Output before:

  # ./perf ftrace -v -- ls
  function_graph tracer is used
  write '-263732416' to tracing/set_ftrace_pid failed: Invalid argument
  failed to set ftrace pid
  #

Output after:
./perf ftrace -v -- ls
function_graph tracer is used
# tracer: function_graph
#
# CPU DURATION FUNCTION CALLS
# | | | | | | |

   4)               |  rcu_read_lock_sched_held() {
   4)   0.552 us    |    rcu_lockdep_current_cpu_online();
   4)   6.124 us    |  }

---
 tools/perf/builtin-ftrace.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

index d5adc417a4ca..40b179f54428 100644
@@ -161,7 +161,7 @@ static int set_tracing_pid(struct perf_ftrace *ftrace)
 
 	for (i = 0; i < perf_thread_map__nr(ftrace->evlist->core.threads); i++) {
 		scnprintf(buf, sizeof(buf), "%d",
-			  ftrace->evlist->core.threads->map[i]);
+			  perf_thread_map__pid(ftrace->evlist->core.threads, i));
 		if (append_tracing_file("set_ftrace_pid", buf) < 0)
 			return -1;
 	}

2.30.2