diff options
Diffstat (limited to 'mm/kfence/core.c')
| -rw-r--r-- | mm/kfence/core.c | 19 |
1 files changed, 16 insertions, 3 deletions
diff --git a/mm/kfence/core.c b/mm/kfence/core.c index d7666ace9d2e..575c685aa642 100644 --- a/mm/kfence/core.c +++ b/mm/kfence/core.c @@ -734,6 +734,22 @@ void kfence_shutdown_cache(struct kmem_cache *s) void *__kfence_alloc(struct kmem_cache *s, size_t size, gfp_t flags) { /* + * Perform size check before switching kfence_allocation_gate, so that + * we don't disable KFENCE without making an allocation. + */ + if (size > PAGE_SIZE) + return NULL; + + /* + * Skip allocations from non-default zones, including DMA. We cannot + * guarantee that pages in the KFENCE pool will have the requested + * properties (e.g. reside in DMAable memory). + */ + if ((flags & GFP_ZONEMASK) || + (s->flags & (SLAB_CACHE_DMA | SLAB_CACHE_DMA32))) + return NULL; + + /* * allocation_gate only needs to become non-zero, so it doesn't make * sense to continue writing to it and pay the associated contention * cost, in case we have a large number of concurrent allocations. @@ -757,9 +773,6 @@ void *__kfence_alloc(struct kmem_cache *s, size_t size, gfp_t flags) if (!READ_ONCE(kfence_enabled)) return NULL; - if (size > PAGE_SIZE) - return NULL; - return kfence_guarded_alloc(s, size, flags); } |