From 098d9384609748bc12e6ea75038d0fc7659459a5 Mon Sep 17 00:00:00 2001 From: Marco Elver Date: Sun, 5 Sep 2021 17:12:33 +0200 Subject: [PATCH 3/4] kasan: generic: introduce kasan_record_aux_stack_noalloc() Introduce a variant of kasan_record_aux_stack() that does not do any memory allocation through stackdepot. This will permit using it in contexts that cannot allocate any memory. Signed-off-by: Marco Elver --- include/linux/kasan.h | 2 ++ mm/kasan/generic.c | 14 ++++++++++++-- 2 files changed, 14 insertions(+), 2 deletions(-) diff --git a/include/linux/kasan.h b/include/linux/kasan.h index dd874a1ee862..736d7b458996 100644 --- a/include/linux/kasan.h +++ b/include/linux/kasan.h @@ -370,12 +370,14 @@ static inline void kasan_unpoison_task_stack(struct task_struct *task) {} void kasan_cache_shrink(struct kmem_cache *cache); void kasan_cache_shutdown(struct kmem_cache *cache); void kasan_record_aux_stack(void *ptr); +void kasan_record_aux_stack_noalloc(void *ptr); #else /* CONFIG_KASAN_GENERIC */ static inline void kasan_cache_shrink(struct kmem_cache *cache) {} static inline void kasan_cache_shutdown(struct kmem_cache *cache) {} static inline void kasan_record_aux_stack(void *ptr) {} +static inline void kasan_record_aux_stack_noalloc(void *ptr) {} #endif /* CONFIG_KASAN_GENERIC */ diff --git a/mm/kasan/generic.c b/mm/kasan/generic.c index 2a8e59e6326d..84a038b07c6f 100644 --- a/mm/kasan/generic.c +++ b/mm/kasan/generic.c @@ -328,7 +328,7 @@ DEFINE_ASAN_SET_SHADOW(f3); DEFINE_ASAN_SET_SHADOW(f5); DEFINE_ASAN_SET_SHADOW(f8); -void kasan_record_aux_stack(void *addr) +static void __kasan_record_aux_stack(void *addr, bool can_alloc) { struct page *page = kasan_addr_to_page(addr); struct kmem_cache *cache; @@ -345,7 +345,17 @@ void kasan_record_aux_stack(void *addr) return; alloc_meta->aux_stack[1] = alloc_meta->aux_stack[0]; - alloc_meta->aux_stack[0] = kasan_save_stack(GFP_NOWAIT, true); + alloc_meta->aux_stack[0] = kasan_save_stack(GFP_NOWAIT, can_alloc); +} + +void kasan_record_aux_stack(void *addr) +{ + return __kasan_record_aux_stack(addr, true); +} + +void kasan_record_aux_stack_noalloc(void *addr) +{ + return __kasan_record_aux_stack(addr, false); } void kasan_set_free_info(struct kmem_cache *cache, -- 2.33.0.153.gba50c8fa24-goog