Commit e5c58dfd authored by Joonsoo Kim's avatar Joonsoo Kim Committed by Pekka Enberg
Browse files

slab: introduce helper functions to get/set free object 



In the following patches, to get/set free objects from the freelist
is changed so that simple casting doesn't work for it. Therefore,
introduce helper functions.

Acked-by: default avatarChristoph Lameter <cl@linux.com>
Signed-off-by: default avatarJoonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: default avatarPekka Enberg <penberg@kernel.org>
parent 9cef2e2b

mm/slab.c

+13 −7
Original line number Diff line number Diff line
@@ -2548,9 +2548,15 @@ static void *alloc_slabmgmt(struct kmem_cache *cachep, 
	return freelist;

}



static inline unsigned int *slab_freelist(struct page *page)

static inline unsigned int get_free_obj(struct page *page, unsigned int idx)

{

	return (unsigned int *)(page->freelist);

	return ((unsigned int *)page->freelist)[idx];

}



static inline void set_free_obj(struct page *page,

					unsigned int idx, unsigned int val)

{

	((unsigned int *)(page->freelist))[idx] = val;

}



static void cache_init_objs(struct kmem_cache *cachep,
@@ -2595,7 +2601,7 @@ static void cache_init_objs(struct kmem_cache *cachep, 
		if (cachep->ctor)

			cachep->ctor(objp);

#endif

		slab_freelist(page)[i] = i;

		set_free_obj(page, i, i);

	}

}
@@ -2614,7 +2620,7 @@ static void *slab_get_obj(struct kmem_cache *cachep, struct page *page, 
{

	void *objp;



	objp = index_to_obj(cachep, page, slab_freelist(page)[page->active]);

	objp = index_to_obj(cachep, page, get_free_obj(page, page->active));

	page->active++;

#if DEBUG

	WARN_ON(page_to_nid(virt_to_page(objp)) != nodeid);
@@ -2635,7 +2641,7 @@ static void slab_put_obj(struct kmem_cache *cachep, struct page *page, 


	/* Verify double free bug */

	for (i = page->active; i < cachep->num; i++) {

		if (slab_freelist(page)[i] == objnr) {

		if (get_free_obj(page, i) == objnr) {

			printk(KERN_ERR "slab: double free detected in cache "

					"'%s', objp %p\n", cachep->name, objp);

			BUG();
@@ -2643,7 +2649,7 @@ static void slab_put_obj(struct kmem_cache *cachep, struct page *page, 
	}

#endif

	page->active--;

	slab_freelist(page)[page->active] = objnr;

	set_free_obj(page, page->active, objnr);

}



/*
@@ -4216,7 +4222,7 @@ static void handle_slab(unsigned long *n, struct kmem_cache *c, 


		for (j = page->active; j < c->num; j++) {

			/* Skip freed item */

			if (slab_freelist(page)[j] == i) {

			if (get_free_obj(page, j) == i) {

				active = false;

				break;

			}