ubi: fastmap: Fix duplicate slab cache names while attaching

[ Upstream commit bcddf52b7a ]

Since commit 4c39529663 ("slab: Warn on duplicate cache names when
DEBUG_VM=y"), the duplicate slab cache names can be detected and a
kernel WARNING is thrown out.
In UBI fast attaching process, alloc_ai() could be invoked twice
with the same slab cache name 'ubi_aeb_slab_cache', which will trigger
following warning messages:
 kmem_cache of name 'ubi_aeb_slab_cache' already exists
 WARNING: CPU: 0 PID: 7519 at mm/slab_common.c:107
          __kmem_cache_create_args+0x100/0x5f0
 Modules linked in: ubi(+) nandsim [last unloaded: nandsim]
 CPU: 0 UID: 0 PID: 7519 Comm: modprobe Tainted: G 6.12.0-rc2
 RIP: 0010:__kmem_cache_create_args+0x100/0x5f0
 Call Trace:
   __kmem_cache_create_args+0x100/0x5f0
   alloc_ai+0x295/0x3f0 [ubi]
   ubi_attach+0x3c3/0xcc0 [ubi]
   ubi_attach_mtd_dev+0x17cf/0x3fa0 [ubi]
   ubi_init+0x3fb/0x800 [ubi]
   do_init_module+0x265/0x7d0
   __x64_sys_finit_module+0x7a/0xc0

The problem could be easily reproduced by loading UBI device by fastmap
with CONFIG_DEBUG_VM=y.
Fix it by using different slab names for alloc_ai() callers.

Fixes: d2158f69a7 ("UBI: Remove alloc_ai() slab name from parameter list")
Fixes: fdf10ed710 ("ubi: Rework Fastmap attach base code")
Signed-off-by: Zhihao Cheng <chengzhihao1@huawei.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Zhihao Cheng 2024-10-11 12:50:02 +08:00 committed by Greg Kroah-Hartman
parent 4be5be8e4d
commit ef52b7191a

View File

@ -1459,7 +1459,7 @@ static int scan_all(struct ubi_device *ubi, struct ubi_attach_info *ai,
return err;
}
static struct ubi_attach_info *alloc_ai(void)
static struct ubi_attach_info *alloc_ai(const char *slab_name)
{
struct ubi_attach_info *ai;
@ -1473,7 +1473,7 @@ static struct ubi_attach_info *alloc_ai(void)
INIT_LIST_HEAD(&ai->alien);
INIT_LIST_HEAD(&ai->fastmap);
ai->volumes = RB_ROOT;
ai->aeb_slab_cache = kmem_cache_create("ubi_aeb_slab_cache",
ai->aeb_slab_cache = kmem_cache_create(slab_name,
sizeof(struct ubi_ainf_peb),
0, 0, NULL);
if (!ai->aeb_slab_cache) {
@ -1503,7 +1503,7 @@ static int scan_fast(struct ubi_device *ubi, struct ubi_attach_info **ai)
err = -ENOMEM;
scan_ai = alloc_ai();
scan_ai = alloc_ai("ubi_aeb_slab_cache_fastmap");
if (!scan_ai)
goto out;
@ -1569,7 +1569,7 @@ int ubi_attach(struct ubi_device *ubi, int force_scan)
int err;
struct ubi_attach_info *ai;
ai = alloc_ai();
ai = alloc_ai("ubi_aeb_slab_cache");
if (!ai)
return -ENOMEM;
@ -1587,7 +1587,7 @@ int ubi_attach(struct ubi_device *ubi, int force_scan)
if (err > 0 || mtd_is_eccerr(err)) {
if (err != UBI_NO_FASTMAP) {
destroy_ai(ai);
ai = alloc_ai();
ai = alloc_ai("ubi_aeb_slab_cache");
if (!ai)
return -ENOMEM;
@ -1626,7 +1626,7 @@ int ubi_attach(struct ubi_device *ubi, int force_scan)
if (ubi->fm && ubi_dbg_chk_fastmap(ubi)) {
struct ubi_attach_info *scan_ai;
scan_ai = alloc_ai();
scan_ai = alloc_ai("ubi_aeb_slab_cache_dbg_chk_fastmap");
if (!scan_ai) {
err = -ENOMEM;
goto out_wl;