devmem: handle class_create() failure

I hit this when we had a bug in IDR for a few days.  Basically sysfs would
fail to create new inodes since it uses an IDR and therefore class_create
would fail.

While we are unlikely to see this fail we may as well handle it instead of
oopsing.

Signed-off-by: Anton Blanchard <anton@samba.org>
Reviewed-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 3 insertions, 0 deletions

diff --git a/drivers/char/mem.c b/drivers/char/mem.c
index 1f3215ac085b..47c8452f485f 100644
--- a/drivers/char/mem.c
+++ b/drivers/char/mem.c
@@ -908,6 +908,9 @@ static int __init chr_dev_init(void)
                 printk("unable to get major %d for memory devs\n", MEM_MAJOR);
 
         mem_class = class_create(THIS_MODULE, "mem");
+        if (IS_ERR(mem_class))
+                return PTR_ERR(mem_class);
+
         mem_class->devnode = mem_devnode;
         for (minor = 1; minor < ARRAY_SIZE(devlist); minor++) {
                 if (!devlist[minor].name)