The SLAB_KASAN flag prevents merging of caches in some configurations, which is handled in a rather complicated way via kasan_never_merge(). Since we now have a generic SLAB_NO_MERGE flag, we can instead use it for KASAN caches in addition to SLAB_KASAN in those configurations, and simplify the SLAB_NEVER_MERGE handling. Signed-off-by: Vlastimil Babka <vbabka@xxxxxxx> --- include/linux/kasan.h | 6 ------ mm/kasan/generic.c | 16 ++++------------ mm/slab_common.c | 2 +- 3 files changed, 5 insertions(+), 19 deletions(-) diff --git a/include/linux/kasan.h b/include/linux/kasan.h index dbb06d789e74..70d6a8f6e25d 100644 --- a/include/linux/kasan.h +++ b/include/linux/kasan.h @@ -429,7 +429,6 @@ struct kasan_cache { }; size_t kasan_metadata_size(struct kmem_cache *cache, bool in_object); -slab_flags_t kasan_never_merge(void); void kasan_cache_create(struct kmem_cache *cache, unsigned int *size, slab_flags_t *flags); @@ -446,11 +445,6 @@ static inline size_t kasan_metadata_size(struct kmem_cache *cache, { return 0; } -/* And thus nothing prevents cache merging. */ -static inline slab_flags_t kasan_never_merge(void) -{ - return 0; -} /* And no cache-related metadata initialization is required. */ static inline void kasan_cache_create(struct kmem_cache *cache, unsigned int *size, diff --git a/mm/kasan/generic.c b/mm/kasan/generic.c index df6627f62402..d8b78d273b9f 100644 --- a/mm/kasan/generic.c +++ b/mm/kasan/generic.c @@ -334,14 +334,6 @@ DEFINE_ASAN_SET_SHADOW(f3); DEFINE_ASAN_SET_SHADOW(f5); DEFINE_ASAN_SET_SHADOW(f8); -/* Only allow cache merging when no per-object metadata is present. */ -slab_flags_t kasan_never_merge(void) -{ - if (!kasan_requires_meta()) - return 0; - return SLAB_KASAN; -} - /* * Adaptive redzone policy taken from the userspace AddressSanitizer runtime. * For larger allocations larger redzones are used. @@ -372,13 +364,13 @@ void kasan_cache_create(struct kmem_cache *cache, unsigned int *size, /* * SLAB_KASAN is used to mark caches that are sanitized by KASAN * and that thus have per-object metadata. - * Currently this flag is used in two places: + * Currently this flag is used in one place: * 1. In slab_ksize() to account for per-object metadata when * calculating the size of the accessible memory within the object. - * 2. In slab_common.c via kasan_never_merge() to prevent merging of - * caches with per-object metadata. + * Additionally, we use SLAB_NO_MERGE to prevent merging of caches + * with per-object metadata. */ - *flags |= SLAB_KASAN; + *flags |= SLAB_KASAN | SLAB_NO_MERGE; ok_size = *size; diff --git a/mm/slab_common.c b/mm/slab_common.c index 238293b1dbe1..7cfa2f1ce655 100644 --- a/mm/slab_common.c +++ b/mm/slab_common.c @@ -50,7 +50,7 @@ static DECLARE_WORK(slab_caches_to_rcu_destroy_work, */ #define SLAB_NEVER_MERGE (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER | \ SLAB_TRACE | SLAB_TYPESAFE_BY_RCU | SLAB_NOLEAKTRACE | \ - SLAB_FAILSLAB | SLAB_NO_MERGE | kasan_never_merge()) + SLAB_FAILSLAB | SLAB_NO_MERGE) #define SLAB_MERGE_SAME (SLAB_RECLAIM_ACCOUNT | SLAB_CACHE_DMA | \ SLAB_CACHE_DMA32 | SLAB_ACCOUNT) -- 2.43.1