perf machine: Fix refcount usage when processing PERF_RECORD_KSYMBOL
ASan reported a memory leak of BPF-related ksymbols map and dso. The
leak is caused by refount never reaching 0, due to missing __put calls
in the function machine__process_ksymbol_register.
Once the dso is inserted in the map, dso__put() should be called
(map__new2() increases the refcount to 2).
The same thing applies for the map when it's inserted into maps
(maps__insert() increases the refcount to 2).
$ sudo ./perf record -- sleep 5
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.025 MB perf.data (8 samples) ]
=================================================================
==297735==ERROR: LeakSanitizer: detected memory leaks
Direct leak of 6992 byte(s) in 19 object(s) allocated from:
#0 0x4f43c7 in calloc (/home/user/linux/tools/perf/perf+0x4f43c7)
#1 0x8e4e53 in map__new2 /home/user/linux/tools/perf/util/map.c:216:20
#2 0x8cf68c in machine__process_ksymbol_register /home/user/linux/tools/perf/util/machine.c:778:10
[...]
Indirect leak of 8702 byte(s) in 19 object(s) allocated from:
#0 0x4f43c7 in calloc (/home/user/linux/tools/perf/perf+0x4f43c7)
#1 0x8728d7 in dso__new_id /home/user/linux/tools/perf/util/dso.c:1256:20
#2 0x872015 in dso__new /home/user/linux/tools/perf/util/dso.c:1295:9
#3 0x8cf623 in machine__process_ksymbol_register /home/user/linux/tools/perf/util/machine.c:774:21
[...]
Indirect leak of 1520 byte(s) in 19 object(s) allocated from:
#0 0x4f43c7 in calloc (/home/user/linux/tools/perf/perf+0x4f43c7)
#1 0x87b3da in symbol__new /home/user/linux/tools/perf/util/symbol.c:269:23
#2 0x888954 in map__process_kallsym_symbol /home/user/linux/tools/perf/util/symbol.c:710:8
[...]
Indirect leak of 1406 byte(s) in 19 object(s) allocated from:
#0 0x4f43c7 in calloc (/home/user/linux/tools/perf/perf+0x4f43c7)
#1 0x87b3da in symbol__new /home/user/linux/tools/perf/util/symbol.c:269:23
#2 0x8cfbd8 in machine__process_ksymbol_register /home/user/linux/tools/perf/util/machine.c:803:8
[...]
Signed-off-by: Riccardo Mancini <rickyman7@gmail.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tommi Rantala <tommi.t.rantala@nokia.com>
Link: http://lore.kernel.org/lkml/20210612173751.188582-1-rickyman7@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c
index 3ff4936..da19be7 100644
--- a/tools/perf/util/machine.c
+++ b/tools/perf/util/machine.c
@@ -776,10 +776,10 @@
if (dso) {
dso->kernel = DSO_SPACE__KERNEL;
map = map__new2(0, dso);
+ dso__put(dso);
}
if (!dso || !map) {
- dso__put(dso);
return -ENOMEM;
}
@@ -792,6 +792,7 @@
map->start = event->ksymbol.addr;
map->end = map->start + event->ksymbol.len;
maps__insert(&machine->kmaps, map);
+ map__put(map);
dso__set_loaded(dso);
if (is_bpf_image(event->ksymbol.name)) {
