[PATCH 06/12] perf jitdump: Fix funlockfile on unlocked stream in jit_open() error path

[Arnaldo Carvalho de Melo]

From: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>

If the malloc() for the initial read buffer fails, jit_open() jumps to
the error label which calls funlockfile(jd->in).  However, flockfile()
is called later in the function, so at this point the stream was never
locked.  Calling funlockfile() on an unlocked stream is undefined
behavior per POSIX.

Split the error path into two labels: 'error' (after flockfile) calls
funlockfile before cleanup, 'error_noflock' (before flockfile) skips
the unlock.

Fixes: 9b07e27f88b9 ("perf inject: Add jitdump mmap injection support")
Reported-by: sashiko-bot <sashiko-bot@xxxxxxxxxx>
Cc: Stephane Eranian <eranian@xxxxxxxxxx>
Assisted-by: Claude:claude-opus-4.6
Reviewed-by: Ian Rogers <irogers@xxxxxxxxxx>
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
 tools/perf/util/jitdump.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/tools/perf/util/jitdump.c b/tools/perf/util/jitdump.c
index d7e3dcfc63b78edb..e865a43f6ea8f884 100644
--- a/tools/perf/util/jitdump.c
+++ b/tools/perf/util/jitdump.c
@@ -155,7 +155,7 @@ jit_open(struct jit_buf_desc *jd, const char *name)
 
 	buf = malloc(bsz);
 	if (!buf)
-		goto error;
+		goto error_noflock;
 
 	/*
 	 * protect from writer modifying the file while we are reading it
@@ -244,8 +244,9 @@ jit_open(struct jit_buf_desc *jd, const char *name)
 
 	return 0;
 error:
-	free(buf);
 	funlockfile(jd->in);
+error_noflock:
+	free(buf);
 	fclose(jd->in);
 	return retval;
 }
-- 
2.55.0