4.19-stable review patch. If anyone has any objections, please let me know.
------------------
From: Zhihao Cheng chengzhihao1@huawei.com
[ Upstream commit bcddf52b7a17adcebc768d26f4e27cf79adb424c ]
Since commit 4c39529663b9 ("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: d2158f69a7d4 ("UBI: Remove alloc_ai() slab name from parameter list") Fixes: fdf10ed710c0 ("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 --- drivers/mtd/ubi/attach.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-)
diff --git a/drivers/mtd/ubi/attach.c b/drivers/mtd/ubi/attach.c index 93ceea4f27d57..d62e5b69ba4b2 100644 --- a/drivers/mtd/ubi/attach.c +++ b/drivers/mtd/ubi/attach.c @@ -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;