diff options
author | Shakeel Butt <shakeelb@google.com> | 2018-06-14 15:26:27 -0700 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2018-06-15 07:55:23 +0900 |
commit | 92ee383f6daab4da5471b86f6fdaba775e6928f6 (patch) | |
tree | c4e70bb32e51df2b0f4b35c82e3dc5c4f794c663 /include | |
parent | 2bdce74412c249ac01dfe36b6b0043ffd7a5361e (diff) |
mm: fix race between kmem_cache destroy, create and deactivate
The memcg kmem cache creation and deactivation (SLUB only) is
asynchronous. If a root kmem cache is destroyed whose memcg cache is in
the process of creation or deactivation, the kernel may crash.
Example of one such crash:
general protection fault: 0000 [#1] SMP PTI
CPU: 1 PID: 1721 Comm: kworker/14:1 Not tainted 4.17.0-smp
...
Workqueue: memcg_kmem_cache kmemcg_deactivate_workfn
RIP: 0010:has_cpu_slab
...
Call Trace:
? on_each_cpu_cond
__kmem_cache_shrink
kmemcg_cache_deact_after_rcu
kmemcg_deactivate_workfn
process_one_work
worker_thread
kthread
ret_from_fork+0x35/0x40
To fix this race, on root kmem cache destruction, mark the cache as
dying and flush the workqueue used for memcg kmem cache creation and
deactivation. SLUB's memcg kmem cache deactivation also includes RCU
callback and thus make sure all previous registered RCU callbacks have
completed as well.
[shakeelb@google.com: handle the RCU callbacks for SLUB deactivation]
Link: http://lkml.kernel.org/r/20180611192951.195727-1-shakeelb@google.com
[shakeelb@google.com: add more documentation, rename fields for readability]
Link: http://lkml.kernel.org/r/20180522201336.196994-1-shakeelb@google.com
[akpm@linux-foundation.org: fix build, per Shakeel]
[shakeelb@google.com: v3. Instead of refcount, flush the workqueue]
Link: http://lkml.kernel.org/r/20180530001204.183758-1-shakeelb@google.com
Link: http://lkml.kernel.org/r/20180521174116.171846-1-shakeelb@google.com
Signed-off-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Greg Thelen <gthelen@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include')
-rw-r--r-- | include/linux/slab.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/include/linux/slab.h b/include/linux/slab.h index 4d759e1ddc33..14e3fe4bd6a1 100644 --- a/include/linux/slab.h +++ b/include/linux/slab.h @@ -600,6 +600,7 @@ struct memcg_cache_params { struct memcg_cache_array __rcu *memcg_caches; struct list_head __root_caches_node; struct list_head children; + bool dying; }; struct { struct mem_cgroup *memcg; |