Commit 50730227 authored by Hui Zhu's avatar Hui Zhu Committed by Jinjiang Tu
Browse files

zsmalloc: zs_malloc: return ERR_PTR on failure 

mainline inclusion
from mainline-v6.0-rc1
commit c7e6f17b
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I7TWVA
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=c7e6f17b52e9486a9d997368819dfec032b550e2

-------------------------------------------

zs_malloc returns 0 if it fails.  zs_zpool_malloc will return -1 when
zs_malloc return 0.  But -1 makes the return value unclear.

For example, when zswap_frontswap_store calls zs_malloc through
zs_zpool_malloc, it will return -1 to its caller.  The other return value
is -EINVAL, -ENODEV or something else.

This commit changes zs_malloc to return ERR_PTR on failure.  It didn't
just let zs_zpool_malloc return -ENOMEM becaue zs_malloc has two types of
failure:

- size is not OK return -EINVAL
- memory alloc fail return -ENOMEM.

Link: https://lkml.kernel.org/r/20220714080757.12161-1-teawater@gmail.com


Signed-off-by: default avatarHui Zhu <teawater@antgroup.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Nitin Gupta <ngupta@vflare.org>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>

Conflicts:
	drivers/block/zram/zram_drv.c

Signed-off-by: default avatarJinjiang Tu <tujinjiang@huawei.com>
parent 369da114

drivers/block/zram/zram_drv.c

+5 −5
Original line number Diff line number Diff line
@@ -1488,7 +1488,7 @@ static int __zram_bvec_write(struct zram *zram, struct bio_vec *bvec, 
{

	int ret = 0;

	unsigned long alloced_pages;

	unsigned long handle = 0;

	unsigned long handle = -ENOMEM;

	unsigned int comp_len = 0;

	void *src, *dst, *mem;

	struct zcomp_strm *zstrm;
@@ -1534,21 +1534,21 @@ static int __zram_bvec_write(struct zram *zram, struct bio_vec *bvec, 
	 * if we have a 'non-null' handle here then we are coming

	 * from the slow path and handle has already been allocated.

	 */

	if (!handle)

	if (IS_ERR((void *)handle))

		handle = zs_malloc(zram->mem_pool, comp_len,

				__GFP_KSWAPD_RECLAIM |

				__GFP_NOWARN |

				__GFP_HIGHMEM |

				__GFP_MOVABLE);

	if (!handle) {

	if (IS_ERR((void *)handle)) {

		zcomp_stream_put(zram->comps[ZRAM_PRIMARY_COMP]);

		atomic64_inc(&zram->stats.writestall);

		handle = zs_malloc(zram->mem_pool, comp_len,

				GFP_NOIO | __GFP_HIGHMEM |

				__GFP_MOVABLE);

		if (handle)

		if (!IS_ERR((void *)handle))

			goto compress_again;

		return -ENOMEM;

		return PTR_ERR((void *)handle);

	}



	alloced_pages = zs_get_total_pages(zram->mem_pool);

mm/zsmalloc.c

+8 −5
Original line number Diff line number Diff line
@@ -401,7 +401,10 @@ static int zs_zpool_malloc(void *pool, size_t size, gfp_t gfp, 
			unsigned long *handle)

{

	*handle = zs_malloc(pool, size, gfp);

	return *handle ? 0 : -1;



	if (IS_ERR((void *)(*handle)))

		return PTR_ERR((void *)*handle);

	return 0;

}

static void zs_zpool_free(void *pool, unsigned long handle)

{
@@ -1428,7 +1431,7 @@ static unsigned long obj_malloc(struct size_class *class, 
 * @gfp: gfp flags when allocating object

 *

 * On success, handle to the allocated object is returned,

 * otherwise 0.

 * otherwise an ERR_PTR().

 * Allocation requests with size > ZS_MAX_ALLOC_SIZE will fail.

 */

unsigned long zs_malloc(struct zs_pool *pool, size_t size, gfp_t gfp)
@@ -1439,11 +1442,11 @@ unsigned long zs_malloc(struct zs_pool *pool, size_t size, gfp_t gfp) 
	struct zspage *zspage;



	if (unlikely(!size || size > ZS_MAX_ALLOC_SIZE))

		return 0;

		return (unsigned long)ERR_PTR(-EINVAL);



	handle = cache_alloc_handle(pool, gfp);

	if (!handle)

		return 0;

		return (unsigned long)ERR_PTR(-ENOMEM);



	/* extra space in chunk to keep the handle */

	size += ZS_HANDLE_SIZE;
@@ -1466,7 +1469,7 @@ unsigned long zs_malloc(struct zs_pool *pool, size_t size, gfp_t gfp) 
	zspage = alloc_zspage(pool, class, gfp);

	if (!zspage) {

		cache_free_handle(pool, handle);

		return 0;

		return (unsigned long)ERR_PTR(-ENOMEM);

	}



	spin_lock(&class->lock);