perf tools: Fix a compiler warning of NULL pointer

A compiler warning on the second argument of bsearch() should not be
NULL, but there's a case we might pass it.  Let's return early if we
don't have any DSOs to search in __dsos__find_by_longname_id().

  util/dsos.c:184:8: runtime error: null pointer passed as argument 2, which is declared to never be null

Reported-by: kernel test robot <oliver.sang@intel.com>
Reviewed-by: Kan Liang <kan.liang@linux.intel.com>
Closes: https://lore.kernel.org/oe-lkp/202406180932.84be448c-oliver.sang@intel.com
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20240621170528.608772-4-namhyung@kernel.org

diff --git a/tools/perf/util/dsos.c b/tools/perf/util/dsos.c
index 846828ea1f00b1c114679aed56c6f42d536fd5e0..5e5e05f86dd3729b00977c8e31fd949f3bbc8fcd 100644 (file)
--- a/tools/perf/util/dsos.c
+++ b/tools/perf/util/dsos.c
@@ -164,6 +164,9 @@ static struct dso *__dsos__find_by_longname_id(struct dsos *dsos,
        };
        struct dso **res;
 
+       if (dsos->dsos == NULL)
+               return NULL;
+
        if (!dsos->sorted) {
                if (!write_locked) {
                        struct dso *dso;