diff options
| author | Pekka Enberg <penberg@cs.helsinki.fi> | 2007-05-06 14:49:03 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-05-07 12:12:51 -0700 |
| commit | 714b8171af9c930a59a0da8f6fe50518e70ab035 (patch) | |
| tree | b63f21c4efd165637c938267d7e542df18d93c99 /mm/slab.c | |
| parent | 5f22df00a009e3f86301366c0ecddb63ebd22af9 (diff) | |
| download | lwn-714b8171af9c930a59a0da8f6fe50518e70ab035.tar.gz lwn-714b8171af9c930a59a0da8f6fe50518e70ab035.zip | |
slab: ensure cache_alloc_refill terminates
If slab->inuse is corrupted, cache_alloc_refill can enter an infinite
loop as detailed by Michael Richardson in the following post:
<http://lkml.org/lkml/2007/2/16/292>. This adds a BUG_ON to catch
those cases.
Cc: Michael Richardson <mcr@sandelman.ca>
Acked-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
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 | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/mm/slab.c b/mm/slab.c index 8b71a9c3daa4..21b2aef25254 100644 --- a/mm/slab.c +++ b/mm/slab.c @@ -2990,6 +2990,14 @@ retry: slabp = list_entry(entry, struct slab, list); check_slabp(cachep, slabp); check_spinlock_acquired(cachep); + + /* + * The slab was either on partial or free list so + * there must be at least one object available for + * allocation. + */ + BUG_ON(slabp->inuse < 0 || slabp->inuse >= cachep->num); + while (slabp->inuse < cachep->num && batchcount--) { STATS_INC_ALLOCED(cachep); STATS_INC_ACTIVE(cachep); |