[PATCH v3 01/21] perf capstone: Fix kernel map reference count leak

[Tengda Wu]

In print_capstone_detail(), maps__find() is used to locate the kernel
map. This function increments the reference count of the found map
object. However, the current implementation fails to call map__put()
after the map is no longer needed, leading to a reference count leak.

Fix this by adding a map__put(map) call to properly release the
reference after use.

Fixes: 92dfc59463d5 ("perf annotate: Add symbol name when using capstone")
Signed-off-by: Tengda Wu <wutengda@xxxxxxxxxxxxxxx>
---
 tools/perf/util/capstone.c | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/tools/perf/util/capstone.c b/tools/perf/util/capstone.c
index 5ad537fea436..9bba78ee0c5a 100644
--- a/tools/perf/util/capstone.c
+++ b/tools/perf/util/capstone.c
@@ -302,6 +302,7 @@ static void print_capstone_detail(struct cs_insn *insn, char *buf, size_t len,
 	for (i = 0; i < insn->detail->x86.op_count; i++) {
 		struct cs_x86_op *op = &insn->detail->x86.operands[i];
 		u64 orig_addr;
+		struct map *found_map = NULL;
 
 		if (op->type != X86_OP_MEM)
 			continue;
@@ -317,19 +318,22 @@ static void print_capstone_detail(struct cs_insn *insn, char *buf, size_t len,
 		if (dso__kernel(map__dso(map))) {
 			/*
 			 * The kernel maps can be split into sections, let's
-			 * find the map first and the search the symbol.
+			 * find the map first and then search the symbol.
 			 */
-			map = maps__find(map__kmaps(map), addr);
-			if (map == NULL)
+			found_map = maps__find(map__kmaps(map), addr);
+			if (found_map == NULL)
 				continue;
+			map = found_map;
 		}
 
 		/* convert it to map-relative address for search */
 		addr = map__map_ip(map, addr);
 
 		sym = map__find_symbol(map, addr);
-		if (sym == NULL)
+		if (sym == NULL) {
+			map__put(found_map);
 			continue;
+		}
 
 		if (addr == sym->start) {
 			scnprintf(buf, len, "\t# %"PRIx64" <%s>",
@@ -338,6 +342,7 @@ static void print_capstone_detail(struct cs_insn *insn, char *buf, size_t len,
 			scnprintf(buf, len, "\t# %"PRIx64" <%s+%#"PRIx64">",
 				  orig_addr, sym->name, addr - sym->start);
 		}
+		map__put(found_map);
 		break;
 	}
 }
-- 
2.34.1