diff options
| author | Christopher Lameter <cl@linux.com> | 2020-06-02 07:45:53 +0300 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-06-02 20:59:06 +0300 |
| commit | aa456c7aebb14a4ff47611586397b5b3e84fbf37 (patch) | |
| tree | 6b39f7c734fc0375495bb493c711a078a91dc631 /mm/slub.c | |
| parent | d7660ce5914d396242bfc56c8f45ef117101fb58 (diff) | |
| download | linux-aa456c7aebb14a4ff47611586397b5b3e84fbf37.tar.xz | |
slub: remove kmalloc under list_lock from list_slab_objects() V2
list_slab_objects() is called when a slab is destroyed and there are
objects still left to list the objects in the syslog. This is a pretty
rare event.
And there it seems we take the list_lock and call kmalloc while holding
that lock.
Perform the allocation in free_partial() before the list_lock is taken.
Fixes: bbd7d57bfe852d9788bae5fb171c7edb4021d8ac ("slub: Potential stack overflow")
Signed-off-by: Christopher Lameter <cl@linux.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Cc: Yu Zhao <yuzhao@google.com>
Link: http://lkml.kernel.org/r/alpine.DEB.2.21.2002031721250.1668@www.lameter.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/slub.c')
| -rw-r--r-- | mm/slub.c | 20 |
1 files changed, 15 insertions, 5 deletions
diff --git a/mm/slub.c b/mm/slub.c index 2ae5580433af..3a76de69a268 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -3766,12 +3766,14 @@ error: } static void list_slab_objects(struct kmem_cache *s, struct page *page, - const char *text) + const char *text, unsigned long *map) { #ifdef CONFIG_SLUB_DEBUG void *addr = page_address(page); void *p; - unsigned long *map; + + if (!map) + return; slab_err(s, page, text, s->name); slab_lock(page); @@ -3784,8 +3786,6 @@ static void list_slab_objects(struct kmem_cache *s, struct page *page, print_tracking(s, p); } } - put_map(map); - slab_unlock(page); #endif } @@ -3799,6 +3799,11 @@ static void free_partial(struct kmem_cache *s, struct kmem_cache_node *n) { LIST_HEAD(discard); struct page *page, *h; + unsigned long *map = NULL; + +#ifdef CONFIG_SLUB_DEBUG + map = bitmap_alloc(oo_objects(s->max), GFP_KERNEL); +#endif BUG_ON(irqs_disabled()); spin_lock_irq(&n->list_lock); @@ -3808,11 +3813,16 @@ static void free_partial(struct kmem_cache *s, struct kmem_cache_node *n) list_add(&page->slab_list, &discard); } else { list_slab_objects(s, page, - "Objects remaining in %s on __kmem_cache_shutdown()"); + "Objects remaining in %s on __kmem_cache_shutdown()", + map); } } spin_unlock_irq(&n->list_lock); +#ifdef CONFIG_SLUB_DEBUG + bitmap_free(map); +#endif + list_for_each_entry_safe(page, h, &discard, slab_list) discard_slab(s, page); } |