From: Ian Rogers <irogers@google.com>
Date: Fri, 28 Feb 2025 22:22:58 +0000 (-0800)
Subject: perf debug: Avoid stack overflow in recursive error message
X-Git-Tag: v6.12.23~233
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=7cd1096d3bead15446433559e4419bbffa033e03;p=thirdparty%2Fkernel%2Fstable.git

perf debug: Avoid stack overflow in recursive error message

[ Upstream commit bda840191d2aae3b7cadc3ac21835dcf29487191 ]

In debug_file, pr_warning_once is called on error. As that function
calls debug_file the function will yield a stack overflow. Switch the
location of the call so the recursion is avoided.

Reviewed-by: Howard Chu <howardchu95@gmail.com>
Signed-off-by: Ian Rogers <irogers@google.com>
Reviewed-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Link: https://lore.kernel.org/r/20250228222308.626803-2-irogers@google.com
Fixes: ec49230cf6dda704 ("perf debug: Expose debug file")
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---

diff --git a/tools/perf/util/debug.c b/tools/perf/util/debug.c
index d633d15329fa0..e56330c85fe7e 100644
--- a/tools/perf/util/debug.c
+++ b/tools/perf/util/debug.c
@@ -46,8 +46,8 @@ int debug_type_profile;
 FILE *debug_file(void)
 {
 	if (!_debug_file) {
-		pr_warning_once("debug_file not set");
 		debug_set_file(stderr);
+		pr_warning_once("debug_file not set");
 	}
 	return _debug_file;
 }