From ce37eec0ab62fb1f04509b83161845859815ee13 Mon Sep 17 00:00:00 2001 From: Andrey Konovalov Date: Tue, 19 Dec 2023 23:28:54 +0100 Subject: kasan: clean up and rename ____kasan_kmalloc Introduce a new poison_kmalloc_redzone helper function that poisons the redzone for kmalloc object. Drop the confusingly named ____kasan_kmalloc function and instead use poison_kmalloc_redzone along with the other required parts of ____kasan_kmalloc in the callers' code. This is a preparatory change for the following patches in this series. Link: https://lkml.kernel.org/r/5881232ad357ec0d59a5b1aefd9e0673a386399a.1703024586.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov Cc: Alexander Lobakin Cc: Alexander Potapenko Cc: Andrey Ryabinin Cc: Breno Leitao Cc: Dmitry Vyukov Cc: Evgenii Stepanov Cc: Marco Elver Signed-off-by: Andrew Morton --- mm/kasan/common.c | 42 ++++++++++++++++++++++-------------------- 1 file changed, 22 insertions(+), 20 deletions(-) (limited to 'mm/kasan') diff --git a/mm/kasan/common.c b/mm/kasan/common.c index 59146886e57d..1217b260abc3 100644 --- a/mm/kasan/common.c +++ b/mm/kasan/common.c @@ -312,26 +312,12 @@ void * __must_check __kasan_slab_alloc(struct kmem_cache *cache, return tagged_object; } -static inline void *____kasan_kmalloc(struct kmem_cache *cache, +static inline void poison_kmalloc_redzone(struct kmem_cache *cache, const void *object, size_t size, gfp_t flags) { unsigned long redzone_start; unsigned long redzone_end; - if (gfpflags_allow_blocking(flags)) - kasan_quarantine_reduce(); - - if (unlikely(object == NULL)) - return NULL; - - if (is_kfence_address(kasan_reset_tag(object))) - return (void *)object; - - /* - * The object has already been unpoisoned by kasan_slab_alloc() for - * kmalloc() or by kasan_krealloc() for krealloc(). - */ - /* * The redzone has byte-level precision for the generic mode. * Partially poison the last object granule to cover the unaligned @@ -355,14 +341,25 @@ static inline void *____kasan_kmalloc(struct kmem_cache *cache, if (kasan_stack_collection_enabled() && is_kmalloc_cache(cache)) kasan_save_alloc_info(cache, (void *)object, flags); - /* Keep the tag that was set by kasan_slab_alloc(). */ - return (void *)object; } void * __must_check __kasan_kmalloc(struct kmem_cache *cache, const void *object, size_t size, gfp_t flags) { - return ____kasan_kmalloc(cache, object, size, flags); + if (gfpflags_allow_blocking(flags)) + kasan_quarantine_reduce(); + + if (unlikely(object == NULL)) + return NULL; + + if (is_kfence_address(kasan_reset_tag(object))) + return (void *)object; + + /* The object has already been unpoisoned by kasan_slab_alloc(). */ + poison_kmalloc_redzone(cache, object, size, flags); + + /* Keep the tag that was set by kasan_slab_alloc(). */ + return (void *)object; } EXPORT_SYMBOL(__kasan_kmalloc); @@ -408,6 +405,9 @@ void * __must_check __kasan_krealloc(const void *object, size_t size, gfp_t flag if (unlikely(object == ZERO_SIZE_PTR)) return (void *)object; + if (is_kfence_address(kasan_reset_tag(object))) + return (void *)object; + /* * Unpoison the object's data. * Part of it might already have been unpoisoned, but it's unknown @@ -420,8 +420,10 @@ void * __must_check __kasan_krealloc(const void *object, size_t size, gfp_t flag /* Piggy-back on kmalloc() instrumentation to poison the redzone. */ if (unlikely(!slab)) return __kasan_kmalloc_large(object, size, flags); - else - return ____kasan_kmalloc(slab->slab_cache, object, size, flags); + else { + poison_kmalloc_redzone(slab->slab_cache, object, size, flags); + return (void *)object; + } } bool __kasan_mempool_poison_pages(struct page *page, unsigned int order, -- cgit v1.2.3