diff options
| author | Dmitry Safonov <dsafonov@virtuozzo.com> | 2016-02-18 00:11:37 +0300 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-02-19 03:23:24 +0300 |
| commit | 52b4b950b50740bff507a62907e86710743c22e7 (patch) | |
| tree | 16ec207435a99a4bc95482906acd8468fd322b82 /mm/slab.c | |
| parent | 1ac0b6dec656f3f78d1c3dd216fad84cb4d0a01e (diff) | |
| download | linux-52b4b950b50740bff507a62907e86710743c22e7.tar.xz | |
mm: slab: free kmem_cache_node after destroy sysfs file
When slub_debug alloc_calls_show is enabled we will try to track
location and user of slab object on each online node, kmem_cache_node
structure and cpu_cache/cpu_slub shouldn't be freed till there is the
last reference to sysfs file.
This fixes the following panic:
BUG: unable to handle kernel NULL pointer dereference at 0000000000000020
IP: list_locations+0x169/0x4e0
PGD 257304067 PUD 438456067 PMD 0
Oops: 0000 [#1] SMP
CPU: 3 PID: 973074 Comm: cat ve: 0 Not tainted 3.10.0-229.7.2.ovz.9.30-00007-japdoll-dirty #2 9.30
Hardware name: DEPO Computers To Be Filled By O.E.M./H67DE3, BIOS L1.60c 07/14/2011
task: ffff88042a5dc5b0 ti: ffff88037f8d8000 task.ti: ffff88037f8d8000
RIP: list_locations+0x169/0x4e0
Call Trace:
alloc_calls_show+0x1d/0x30
slab_attr_show+0x1b/0x30
sysfs_read_file+0x9a/0x1a0
vfs_read+0x9c/0x170
SyS_read+0x58/0xb0
system_call_fastpath+0x16/0x1b
Code: 5e 07 12 00 b9 00 04 00 00 3d 00 04 00 00 0f 4f c1 3d 00 04 00 00 89 45 b0 0f 84 c3 00 00 00 48 63 45 b0 49 8b 9c c4 f8 00 00 00 <48> 8b 43 20 48 85 c0 74 b6 48 89 df e8 46 37 44 00 48 8b 53 10
CR2: 0000000000000020
Separated __kmem_cache_release from __kmem_cache_shutdown which now
called on slab_kmem_cache_release (after the last reference to sysfs
file object has dropped).
Reintroduced locking in free_partial as sysfs file might access cache's
partial list after shutdowning - partial revert of the commit
69cb8e6b7c29 ("slub: free slabs without holding locks"). Zap
__remove_partial and use remove_partial (w/o underscores) as
free_partial now takes list_lock which s partial revert for commit
1e4dd9461fab ("slub: do not assert not having lock in removing freed
partial")
Signed-off-by: Dmitry Safonov <dsafonov@virtuozzo.com>
Suggested-by: Vladimir Davydov <vdavydov@virtuozzo.com>
Acked-by: Vladimir Davydov <vdavydov@virtuozzo.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>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/slab.c')
| -rw-r--r-- | mm/slab.c | 12 |
1 files changed, 6 insertions, 6 deletions
diff --git a/mm/slab.c b/mm/slab.c index 6ecc697a8bc4..621fbcb35a36 100644 --- a/mm/slab.c +++ b/mm/slab.c @@ -2275,7 +2275,7 @@ __kmem_cache_create (struct kmem_cache *cachep, unsigned long flags) err = setup_cpu_cache(cachep, gfp); if (err) { - __kmem_cache_shutdown(cachep); + __kmem_cache_release(cachep); return err; } @@ -2414,12 +2414,13 @@ int __kmem_cache_shrink(struct kmem_cache *cachep, bool deactivate) int __kmem_cache_shutdown(struct kmem_cache *cachep) { + return __kmem_cache_shrink(cachep, false); +} + +void __kmem_cache_release(struct kmem_cache *cachep) +{ int i; struct kmem_cache_node *n; - int rc = __kmem_cache_shrink(cachep, false); - - if (rc) - return rc; free_percpu(cachep->cpu_cache); @@ -2430,7 +2431,6 @@ int __kmem_cache_shutdown(struct kmem_cache *cachep) kfree(n); cachep->node[i] = NULL; } - return 0; } /* |