From: Marco Elver <elver@xxxxxxxxxx> Subject: 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. Link: https://lkml.kernel.org/r/20210913112609.2651084-6-elver@xxxxxxxxxx Signed-off-by: Marco Elver <elver@xxxxxxxxxx> Tested-by: Shuah Khan <skhan@xxxxxxxxxxxxxxxxxxx> Acked-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx> Reviewed-by: Andrey Konovalov <andreyknvl@xxxxxxxxx> Cc: Alexander Potapenko <glider@xxxxxxxxxx> Cc: Andrey Ryabinin <ryabinin.a.a@xxxxxxxxx> Cc: Dmitry Vyukov <dvyukov@xxxxxxxxxx> Cc: "Gustavo A. R. Silva" <gustavoars@xxxxxxxxxx> Cc: Lai Jiangshan <jiangshanlai@xxxxxxxxx> Cc: Taras Madan <tarasmadan@xxxxxxxxxx> Cc: Tejun Heo <tj@xxxxxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Cc: Vijayanand Jitta <vjitta@xxxxxxxxxxxxxx> Cc: Vinayak Menon <vinmenon@xxxxxxxxxxxxxx> Cc: Walter Wu <walter-zh.wu@xxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- include/linux/kasan.h | 2 ++ mm/kasan/generic.c | 14 ++++++++++++-- 2 files changed, 14 insertions(+), 2 deletions(-) --- a/include/linux/kasan.h~kasan-generic-introduce-kasan_record_aux_stack_noalloc +++ a/include/linux/kasan.h @@ -370,12 +370,14 @@ static inline void kasan_unpoison_task_s 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 */ --- a/mm/kasan/generic.c~kasan-generic-introduce-kasan_record_aux_stack_noalloc +++ a/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, _
