[PATCH] perf jitdump: Fix a build error with ASAN

[PATCH] perf jitdump: Fix a build error with ASAN

[Namhyung Kim]

I found this error when I pass EXTRA_CFLAGS=-fsanitize=address on Fedora
44 with GCC 16.  Fix it by copying one less byte.

    CC      util/jitdump.o
  util/jitdump.c: In function ‘jit_process’:
  util/jitdump.c:237:9: error: ‘__builtin_strncpy’ specified bound 4096 equals destination size
                               [-Werror=stringop-truncation]
    237 |         strncpy(jd->dir, name, PATH_MAX);
        |         ^
  cc1: all warnings being treated as errors
  make[4]: *** [tools/build/Makefile.build:95: util/jitdump.o] Error 1
  make[4]: *** Waiting for unfinished jobs....
  make[3]: *** [tools/build/Makefile.build:158: util] Error 2
  make[2]: *** [Makefile.perf:578: perf-util-in.o] Error 2
  make[1]: *** [Makefile.perf:288: sub-make] Error 2
  make: *** [Makefile:76: all] Error 2

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---
 tools/perf/util/jitdump.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/perf/util/jitdump.c b/tools/perf/util/jitdump.c
index 18fd84a82153c2ab..83005b30b9bf3fd7 100644
--- a/tools/perf/util/jitdump.c
+++ b/tools/perf/util/jitdump.c
@@ -234,7 +234,7 @@ jit_open(struct jit_buf_desc *jd, const char *name)
 	/*
 	 * keep dirname for generating files and mmap records
 	 */
-	strncpy(jd->dir, name, PATH_MAX);
+	strncpy(jd->dir, name, PATH_MAX - 1);
 	jd->dir[PATH_MAX - 1] = '\0';
 	dirname(jd->dir);
 	free(buf);
-- 
2.54.0