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| author | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2017-01-18 02:53:44 -0800 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2017-04-18 11:42:36 -0700 |
| commit | 5f0d5a3ae7cff0d7fa943c199c3a2e44f23e1fac (patch) | |
| tree | b7ba2116923723e193dfe7c633ec10056c6b1b53 /mm/kasan | |
| parent | 4495c08e84729385774601b5146d51d9e5849f81 (diff) | |
| download | linux-5f0d5a3ae7cff0d7fa943c199c3a2e44f23e1fac.tar.bz2 | |
mm: Rename SLAB_DESTROY_BY_RCU to SLAB_TYPESAFE_BY_RCU
A group of Linux kernel hackers reported chasing a bug that resulted
from their assumption that SLAB_DESTROY_BY_RCU provided an existence
guarantee, that is, that no block from such a slab would be reallocated
during an RCU read-side critical section. Of course, that is not the
case. Instead, SLAB_DESTROY_BY_RCU only prevents freeing of an entire
slab of blocks.
However, there is a phrase for this, namely "type safety". This commit
therefore renames SLAB_DESTROY_BY_RCU to SLAB_TYPESAFE_BY_RCU in order
to avoid future instances of this sort of confusion.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.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: Andrew Morton <akpm@linux-foundation.org>
Cc: <linux-mm@kvack.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
[ paulmck: Add comments mentioning the old name, as requested by Eric
Dumazet, in order to help people familiar with the old name find
the new one. ]
Acked-by: David Rientjes <rientjes@google.com>
Diffstat (limited to 'mm/kasan')
| -rw-r--r-- | mm/kasan/kasan.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/mm/kasan/kasan.c b/mm/kasan/kasan.c index 98b27195e38b..4b20061102f6 100644 --- a/mm/kasan/kasan.c +++ b/mm/kasan/kasan.c @@ -413,7 +413,7 @@ void kasan_cache_create(struct kmem_cache *cache, size_t *size, *size += sizeof(struct kasan_alloc_meta); /* Add free meta. */ - if (cache->flags & SLAB_DESTROY_BY_RCU || cache->ctor || + if (cache->flags & SLAB_TYPESAFE_BY_RCU || cache->ctor || cache->object_size < sizeof(struct kasan_free_meta)) { cache->kasan_info.free_meta_offset = *size; *size += sizeof(struct kasan_free_meta); @@ -561,7 +561,7 @@ static void kasan_poison_slab_free(struct kmem_cache *cache, void *object) unsigned long rounded_up_size = round_up(size, KASAN_SHADOW_SCALE_SIZE); /* RCU slabs could be legally used after free within the RCU period */ - if (unlikely(cache->flags & SLAB_DESTROY_BY_RCU)) + if (unlikely(cache->flags & SLAB_TYPESAFE_BY_RCU)) return; kasan_poison_shadow(object, rounded_up_size, KASAN_KMALLOC_FREE); @@ -572,7 +572,7 @@ bool kasan_slab_free(struct kmem_cache *cache, void *object) s8 shadow_byte; /* RCU slabs could be legally used after free within the RCU period */ - if (unlikely(cache->flags & SLAB_DESTROY_BY_RCU)) + if (unlikely(cache->flags & SLAB_TYPESAFE_BY_RCU)) return false; shadow_byte = READ_ONCE(*(s8 *)kasan_mem_to_shadow(object)); |