[9/9] perf tools: Clear struct machine during machine__init()

Message ID 1449843752-28395-10-git-send-email-acme@kernel.org
State New
Headers show

Commit Message

Arnaldo Carvalho de Melo Dec. 11, 2015, 2:22 p.m.
From: Wang Nan <wangnan0@huawei.com>


There are so many test cases use stack allocated 'struct machine'.
Including:
  test__hists_link
  test__hists_filter
  test__mmap_thread_lookup
  test__thread_mg_share
  test__hists_output
  test__hists_cumulate

Also, in non-test code (for example, machine__new_host()) there are
code use 'malloc()' to alloc struct machine.

These are dangerous operations, cause some tests fail or hung in
machines__exit(). For example, in

 machines__exit ->
   machine__destroy_kernel_maps ->
     map_groups__remove ->
       maps__remove ->
         pthread_rwlock_wrlock

a incorrectly initialized lock causes unintended behavior.

This patch memset(0) that structure in machine__init() to ensure all
fields in 'struct machine' are initialized to zero.

Signed-off-by: Wang Nan <wangnan0@huawei.com>

Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1449541544-67621-17-git-send-email-wangnan0@huawei.com
[ Use memset, see 'man bzero' ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

---
 tools/perf/util/machine.c | 1 +
 1 file changed, 1 insertion(+)

-- 
2.1.0

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Patch

diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c
index f5882b8c8db9..1407d5107480 100644
--- a/tools/perf/util/machine.c
+++ b/tools/perf/util/machine.c
@@ -25,6 +25,7 @@  static void dsos__init(struct dsos *dsos)
 
 int machine__init(struct machine *machine, const char *root_dir, pid_t pid)
 {
+	memset(machine, 0, sizeof(*machine));
 	map_groups__init(&machine->kmaps, machine);
 	RB_CLEAR_NODE(&machine->rb_node);
 	dsos__init(&machine->dsos);