Commit 836daba0 authored by Andrey Konovalov's avatar Andrey Konovalov Committed by Andrew Morton
Browse files

kasan: introduce kasan_init_object_meta 

Add a kasan_init_object_meta() helper that initializes metadata for a slab
object and use it in the common code.

For now, the implementations of this helper are the same for the Generic
and tag-based modes, but they will diverge later in the series.

This change hides references to alloc_meta from the common code.  This is
desired as only the Generic mode will be using per-object metadata after
this series.

Link: https://lkml.kernel.org/r/47c12938fc7f8105e7aaa592527c0e9d3c81fc37.1662411799.git.andreyknvl@google.com


Signed-off-by: default avatarAndrey Konovalov <andreyknvl@google.com>
Reviewed-by: default avatarMarco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Peter Collingbourne <pcc@google.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent f3647cbf

mm/kasan/common.c

+3 −7
Original line number Diff line number Diff line
@@ -313,13 +313,9 @@ static inline u8 assign_tag(struct kmem_cache *cache, 
void * __must_check __kasan_init_slab_obj(struct kmem_cache *cache,

						const void *object)

{

	struct kasan_alloc_meta *alloc_meta;



	if (kasan_stack_collection_enabled()) {

		alloc_meta = kasan_get_alloc_meta(cache, object);

		if (alloc_meta)

			__memset(alloc_meta, 0, sizeof(*alloc_meta));

	}

	/* Initialize per-object metadata if it is present. */

	if (kasan_stack_collection_enabled())

		kasan_init_object_meta(cache, object);



	/* Tag is ignored in set_tag() without CONFIG_KASAN_SW/HW_TAGS */

	object = set_tag(object, assign_tag(cache, object, true));

mm/kasan/generic.c

+9 −0
Original line number Diff line number Diff line
@@ -328,6 +328,15 @@ DEFINE_ASAN_SET_SHADOW(f3); 
DEFINE_ASAN_SET_SHADOW(f5);

DEFINE_ASAN_SET_SHADOW(f8);



void kasan_init_object_meta(struct kmem_cache *cache, const void *object)

{

	struct kasan_alloc_meta *alloc_meta;



	alloc_meta = kasan_get_alloc_meta(cache, object);

	if (alloc_meta)

		__memset(alloc_meta, 0, sizeof(*alloc_meta));

}



static void __kasan_record_aux_stack(void *addr, bool can_alloc)

{

	struct slab *slab = kasan_addr_to_slab(addr);

mm/kasan/kasan.h

+2 −0
Original line number Diff line number Diff line
@@ -279,6 +279,8 @@ void kasan_report_invalid_free(void *object, unsigned long ip, enum kasan_report 
struct page *kasan_addr_to_page(const void *addr);

struct slab *kasan_addr_to_slab(const void *addr);



void kasan_init_object_meta(struct kmem_cache *cache, const void *object);



depot_stack_handle_t kasan_save_stack(gfp_t flags, bool can_alloc);

void kasan_set_track(struct kasan_track *track, gfp_t flags);

void kasan_save_alloc_info(struct kmem_cache *cache, void *object, gfp_t flags);

mm/kasan/tags.c

+9 −0
Original line number Diff line number Diff line
@@ -17,6 +17,15 @@ 


#include "kasan.h"



void kasan_init_object_meta(struct kmem_cache *cache, const void *object)

{

	struct kasan_alloc_meta *alloc_meta;



	alloc_meta = kasan_get_alloc_meta(cache, object);

	if (alloc_meta)

		__memset(alloc_meta, 0, sizeof(*alloc_meta));

}



void kasan_save_alloc_info(struct kmem_cache *cache, void *object, gfp_t flags)

{

	struct kasan_alloc_meta *alloc_meta;