Commit 7cb3007c authored by Marco Elver's avatar Marco Elver Committed by Linus Torvalds
Browse files

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@google.com


Signed-off-by: default avatarMarco Elver <elver@google.com>
Tested-by: default avatarShuah Khan <skhan@linuxfoundation.org>
Acked-by: default avatarSebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: default avatarAndrey Konovalov <andreyknvl@gmail.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: "Gustavo A. R. Silva" <gustavoars@kernel.org>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Taras Madan <tarasmadan@google.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vijayanand Jitta <vjitta@codeaurora.org>
Cc: Vinayak Menon <vinmenon@codeaurora.org>
Cc: Walter Wu <walter-zh.wu@mediatek.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 7594b347

include/linux/kasan.h

+2 −0
Original line number Diff line number Diff line
@@ -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 */

mm/kasan/generic.c

+12 −2
Original line number Diff line number Diff line
@@ -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,