[PATCH v2 2/3] perf disasm: Use disasm_line__free() to properly free disasm_line

From: Li Huafei
Date: Sat Oct 19 2024 - 03:58:59 EST


symbol__disassemble_capstone_powerpc() goto the 'err' label when it
failed in the loop that created disasm_line, and then used free()
directly to free disasm_line. Since the structure disasm_line contains
members that allocate memory dynamically, this can result in a memory
leak. In fact, we can simply break the loop when it fails in the middle
of the loop, and disasm_line__free() will then be called to properly
free the created line. Other error paths do not need to consider freeing
disasm_line.

Fixes: c5d60de1813a ("perf annotate: Add support to use libcapstone in powerpc")
Signed-off-by: Li Huafei <lihuafei1@xxxxxxxxxx>
---
Changes in v2:
- Break directly in the loop when it fails, then free disasm_line.
- Remove the free under the 'err' label.
---
tools/perf/util/disasm.c | 14 +-------------
1 file changed, 1 insertion(+), 13 deletions(-)

diff --git a/tools/perf/util/disasm.c b/tools/perf/util/disasm.c
index 42222d61ceb5..8a24e31a1534 100644
--- a/tools/perf/util/disasm.c
+++ b/tools/perf/util/disasm.c
@@ -1573,7 +1573,7 @@ static int symbol__disassemble_capstone_powerpc(char *filename, struct symbol *s

dl = disasm_line__new(args);
if (dl == NULL)
- goto err;
+ break;

annotation_line__add(&dl->al, &notes->src->source);

@@ -1603,18 +1603,6 @@ static int symbol__disassemble_capstone_powerpc(char *filename, struct symbol *s
err:
if (fd >= 0)
close(fd);
- if (needs_cs_close) {
- struct disasm_line *tmp;
-
- /*
- * It probably failed in the middle of the above loop.
- * Release any resources it might add.
- */
- list_for_each_entry_safe(dl, tmp, &notes->src->source, al.node) {
- list_del(&dl->al.node);
- free(dl);
- }
- }
count = -1;
goto out;
}
--
2.25.1