mm: slub: introduce virt_to_obj function

virt_to_obj takes kmem_cache address, address of slab page, address x
pointing somewhere inside slab object, and returns address of the
beginning of object.

Signed-off-by: Andrey Ryabinin <a.ryabinin@samsung.com>
Acked-by: Christoph Lameter <cl@linux.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Konstantin Serebryany <kcc@google.com>
Cc: Dmitry Chernenkov <dmitryc@google.com>
Signed-off-by: Andrey Konovalov <adech.fo@gmail.com>
Cc: Yuri Gribov <tetra2005@gmail.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Andrey Ryabinin 2015-02-13 14:39:31 -08:00 committed by Linus Torvalds
parent b8c73fc249
commit 912f5fbf1d

View File

@ -110,4 +110,20 @@ static inline void sysfs_slab_remove(struct kmem_cache *s)
}
#endif
/**
* virt_to_obj - returns address of the beginning of object.
* @s: object's kmem_cache
* @slab_page: address of slab page
* @x: address within object memory range
*
* Returns address of the beginning of object
*/
static inline void *virt_to_obj(struct kmem_cache *s,
const void *slab_page,
const void *x)
{
return (void *)x - ((x - slab_page) % s->size);
}
#endif /* _LINUX_SLUB_DEF_H */