[PATCH 6.18 1051/1518] perf synthetic-events: Fix uninitialized pthread_join

6.18-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Ian Rogers <irogers@google.com>

[ Upstream commit 54ba44db4dddc4ca06b49bae0f9d6c5861430b18 ]

In perf_event__synthesize_threads(), fix an uninitialized pthread_join()
call when thread creation fails by only joining the successfully
created threads.

Assisted-by: Antigravity:gemini-3.1-pro
Fixes: 340b47f510bb ("perf top: Implement multithreading for perf_event__synthesize_threads")
Signed-off-by: Ian Rogers <irogers@google.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 tools/perf/util/synthetic-events.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/tools/perf/util/synthetic-events.c b/tools/perf/util/synthetic-events.c
index c5b0ba775098f..f2d09fcaafb76 100644
--- a/tools/perf/util/synthetic-events.c
+++ b/tools/perf/util/synthetic-events.c

@@ -1104,8 +1104,8 @@ int perf_event__synthesize_threads(const struct perf_tool *tool,
 	}
 	err = 0;
 out_join:
-	for (i = 0; i < thread_nr; i++)
-		pthread_join(synthesize_threads[i], NULL);
+	for (j = 0; j < i; j++)
+		pthread_join(synthesize_threads[j], NULL);
 	free(args);
 free_threads:
 	free(synthesize_threads);

-- 
2.53.0