[PATCH 4.9 48/51] debugobjects: avoid recursive calls with kmemleak

From: Greg Kroah-Hartman
Date: Fri Dec 14 2018 - 07:13:07 EST


4.9-stable review patch. If anyone has any objections, please let me know.

------------------

[ Upstream commit 8de456cf87ba863e028c4dd01bae44255ce3d835 ]

CONFIG_DEBUG_OBJECTS_RCU_HEAD does not play well with kmemleak due to
recursive calls.

fill_pool
kmemleak_ignore
make_black_object
put_object
__call_rcu (kernel/rcu/tree.c)
debug_rcu_head_queue
debug_object_activate
debug_object_init
fill_pool
kmemleak_ignore
make_black_object
...

So add SLAB_NOLEAKTRACE to kmem_cache_create() to not register newly
allocated debug objects at all.

Link: http://lkml.kernel.org/r/20181126165343.2339-1-cai@xxxxxx
Signed-off-by: Qian Cai <cai@xxxxxx>
Suggested-by: Catalin Marinas <catalin.marinas@xxxxxxx>
Acked-by: Waiman Long <longman@xxxxxxxxxx>
Acked-by: Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Yang Shi <yang.shi@xxxxxxxxxxxxxxxxx>
Cc: Arnd Bergmann <arnd@xxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
lib/debugobjects.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/lib/debugobjects.c b/lib/debugobjects.c
index 88580e8ee39e..1c43d4c5d2ab 100644
--- a/lib/debugobjects.c
+++ b/lib/debugobjects.c
@@ -1110,7 +1110,8 @@ void __init debug_objects_mem_init(void)

obj_cache = kmem_cache_create("debug_objects_cache",
sizeof (struct debug_obj), 0,
- SLAB_DEBUG_OBJECTS, NULL);
+ SLAB_DEBUG_OBJECTS | SLAB_NOLEAKTRACE,
+ NULL);

if (!obj_cache || debug_objects_replace_static_objects()) {
debug_objects_enabled = 0;
--
2.19.1