[PATCH perf/core 14/22] perf: Fix dso__load_sym to put dso

Masami Hiramatsu
2015-12-09T02:19:16Z

Fix dso__load_sym to put dso because dsos__add already got it.

Refcnt debugger explain the problem:
----
==== [0] ====
Unreclaimed dso: 0x19dd200
Refcount +1 => 1 at
./perf(dso__new+0x1ff) [0x4a62df]
./perf(dso__load_sym+0xe89) [0x503509]
./perf(dso__load_vmlinux+0xbf) [0x4aa77f]
./perf(dso__load_vmlinux_path+0x8c) [0x4aa8dc]
./perf() [0x50539a]
./perf(convert_perf_probe_events+0xd79) [0x50ad39]
./perf() [0x45600f]
./perf(cmd_probe+0x6c) [0x4566bc]
./perf() [0x47abc5]
./perf(main+0x610) [0x421f90]
/lib64/libc.so.6(__libc_start_main+0xf5) [0x7f74dd0efaf5]
./perf() [0x4220a9]
Refcount +1 => 2 at
./perf(dso__get+0x34) [0x4a65f4]
./perf(map__new2+0x76) [0x4be216]
./perf(dso__load_sym+0xee1) [0x503561]
./perf(dso__load_vmlinux+0xbf) [0x4aa77f]
./perf(dso__load_vmlinux_path+0x8c) [0x4aa8dc]
./perf() [0x50539a]
./perf(convert_perf_probe_events+0xd79) [0x50ad39]
./perf() [0x45600f]
./perf(cmd_probe+0x6c) [0x4566bc]
./perf() [0x47abc5]
./perf(main+0x610) [0x421f90]
/lib64/libc.so.6(__libc_start_main+0xf5) [0x7f74dd0efaf5]
./perf() [0x4220a9]
Refcount +1 => 3 at
./perf(dsos__add+0xf3) [0x4a6bc3]
./perf(dso__load_sym+0xfc1) [0x503641]
./perf(dso__load_vmlinux+0xbf) [0x4aa77f]
./perf(dso__load_vmlinux_path+0x8c) [0x4aa8dc]
./perf() [0x50539a]
./perf(convert_perf_probe_events+0xd79) [0x50ad39]
./perf() [0x45600f]
./perf(cmd_probe+0x6c) [0x4566bc]
./perf() [0x47abc5]
./perf(main+0x610) [0x421f90]
/lib64/libc.so.6(__libc_start_main+0xf5) [0x7f74dd0efaf5]
./perf() [0x4220a9]
Refcount -1 => 2 at
./perf(dso__put+0x2f) [0x4a664f]
./perf(map_groups__exit+0xb9) [0x4bee29]
./perf(machine__delete+0xb0) [0x4b93d0]
./perf(exit_probe_symbol_maps+0x28) [0x506718]
./perf() [0x45628a]
./perf(cmd_probe+0x6c) [0x4566bc]
./perf() [0x47abc5]
./perf(main+0x610) [0x421f90]
/lib64/libc.so.6(__libc_start_main+0xf5) [0x7f74dd0efaf5]
./perf() [0x4220a9]
Refcount -1 => 1 at
./perf(dso__put+0x2f) [0x4a664f]
./perf(machine__delete+0xfe) [0x4b941e]
./perf(exit_probe_symbol_maps+0x28) [0x506718]
./perf() [0x45628a]
./perf(cmd_probe+0x6c) [0x4566bc]
./perf() [0x47abc5]
./perf(main+0x610) [0x421f90]
/lib64/libc.so.6(__libc_start_main+0xf5) [0x7f74dd0efaf5]
./perf() [0x4220a9]
----
So, in the dso__load_sym, dso is gotten 3 times, by dso__new,
map__new2, and dsos__add. The last 2 is actually released by
map_groups and machine__delete correspondingly. However, the
first reference by dso__new, is never released.

This solves this issue by putting dso right after dsos__add.

Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
---
tools/perf/util/symbol-elf.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/tools/perf/util/symbol-elf.c b/tools/perf/util/symbol-elf.c
index 53f1996..a5703ac 100644
--- a/tools/perf/util/symbol-elf.c
+++ b/tools/perf/util/symbol-elf.c
@@ -1045,6 +1045,8 @@ int dso__load_sym(struct dso *dso, struct map *map,
/* kmaps already got it */
map__put(curr_map);
dsos__add(&map->groups->machine->dsos, curr_dso);
+ /* curr_map and machine->dsos already got it */
+ dso__put(curr_dso);
dso__set_loaded(curr_dso, map->type);
} else
curr_dso = curr_map->dso;