perf symbol: Avoid an undefined behavior warning

The node (nd) may be NULL and pointer arithmetic on NULL is undefined
behavior. Move the computation of next below the NULL check on the
node.

Signed-off-by: Ian Rogers <irogers@google.com>
Cc: James Clark <james.clark@arm.com>
Link: https://lore.kernel.org/r/20230914044233.1550195-1-irogers@google.com
Signed-off-by: Namhyung Kim <namhyung@kernel.org>

diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index 3f36675b7c8ff672e23b3528e2b1a089d2dbc87e..5b54d2639df4740ead32fb860bba4c26635bcb69 100644 (file)
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -202,11 +202,10 @@ void symbols__fixup_duplicate(struct rb_root_cached *symbols)
                curr = rb_entry(nd, struct symbol, rb_node);
 again:
                nd = rb_next(&curr->rb_node);
-               next = rb_entry(nd, struct symbol, rb_node);
-
                if (!nd)
                        break;
 
+               next = rb_entry(nd, struct symbol, rb_node);
                if (curr->start != next->start)
                        continue;