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Commit a947eb95 authored by Suleiman Souhlal's avatar Suleiman Souhlal Committed by Pekka Enberg
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SLAB: Record actual last user of freed objects. 



Currently, when using CONFIG_DEBUG_SLAB, we put in kfree() or
kmem_cache_free() as the last user of free objects, which is not
very useful, so change it to the caller of those functions instead.

Acked-by: default avatarDavid Rientjes <rientjes@google.com>
Acked-by: default avatarChristoph Lameter <cl@linux.com>
Signed-off-by: default avatarSuleiman Souhlal <suleiman@google.com>
Signed-off-by: default avatarPekka Enberg <penberg@kernel.org>
parent d4d84fef

mm/slab.c

+5 −4
Original line number Original line Diff line number Diff line
@@ -3604,13 +3604,14 @@ static void cache_flusharray(struct kmem_cache *cachep, struct array_cache *ac) 
 * Release an obj back to its cache. If the obj has a constructed state, it must

 * Release an obj back to its cache. If the obj has a constructed state, it must

 * be in this state _before_ it is released.  Called with disabled ints.

 * be in this state _before_ it is released.  Called with disabled ints.

 */

 */

static inline void __cache_free(struct kmem_cache *cachep, void *objp)

static inline void __cache_free(struct kmem_cache *cachep, void *objp,

    void *caller)

{

{

	struct array_cache *ac = cpu_cache_get(cachep);

	struct array_cache *ac = cpu_cache_get(cachep);





	check_irq_off();

	check_irq_off();

	kmemleak_free_recursive(objp, cachep->flags);

	kmemleak_free_recursive(objp, cachep->flags);

	objp = cache_free_debugcheck(cachep, objp, __builtin_return_address(0));

	objp = cache_free_debugcheck(cachep, objp, caller);





	kmemcheck_slab_free(cachep, objp, obj_size(cachep));

	kmemcheck_slab_free(cachep, objp, obj_size(cachep));
@@ -3801,7 +3802,7 @@ void kmem_cache_free(struct kmem_cache *cachep, void *objp) 
	debug_check_no_locks_freed(objp, obj_size(cachep));

	debug_check_no_locks_freed(objp, obj_size(cachep));

	if (!(cachep->flags & SLAB_DEBUG_OBJECTS))

	if (!(cachep->flags & SLAB_DEBUG_OBJECTS))

		debug_check_no_obj_freed(objp, obj_size(cachep));

		debug_check_no_obj_freed(objp, obj_size(cachep));

	__cache_free(cachep, objp);

	__cache_free(cachep, objp, __builtin_return_address(0));

	local_irq_restore(flags);

	local_irq_restore(flags);





	trace_kmem_cache_free(_RET_IP_, objp);

	trace_kmem_cache_free(_RET_IP_, objp);
@@ -3831,7 +3832,7 @@ void kfree(const void *objp) 
	c = virt_to_cache(objp);

	c = virt_to_cache(objp);

	debug_check_no_locks_freed(objp, obj_size(c));

	debug_check_no_locks_freed(objp, obj_size(c));

	debug_check_no_obj_freed(objp, obj_size(c));

	debug_check_no_obj_freed(objp, obj_size(c));

	__cache_free(c, (void *)objp);

	__cache_free(c, (void *)objp, __builtin_return_address(0));

	local_irq_restore(flags);

	local_irq_restore(flags);

}

}

EXPORT_SYMBOL(kfree);

EXPORT_SYMBOL(kfree);