mm/dmapool.c: remove redundant NULL check for dev in dma_pool_create()

"dev" cannot be NULL because it is already checked before calling
dma_pool_create().

If dev ever was NULL, the code would oops in dev_to_node() after enabling
CONFIG_NUMA.

It is possible that some driver is using dev==NULL and has never been run
on a NUMA machine.  Such a driver is probably outdated, possibly buggy and
will need some attention if it starts triggering NULL derefs.

Signed-off-by: Daeseok Youn <daeseok.youn@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 8 insertions, 16 deletions

diff --git a/mm/dmapool.c b/mm/dmapool.c
index 8058fcd7ae91..a3a1bfe91110 100644
--- a/mm/dmapool.c
+++ b/mm/dmapool.c
@@ -170,24 +170,16 @@ struct dma_pool *dma_pool_create(const char *name, struct device *dev,
         retval->boundary = boundary;
         retval->allocation = allocation;
 
-        if (dev) {
-                int ret;
+        INIT_LIST_HEAD(&retval->pools);
 
-                mutex_lock(&pools_lock);
-                if (list_empty(&dev->dma_pools))
-                        ret = device_create_file(dev, &dev_attr_pools);
-                else
-                        ret = 0;
-                /* note:  not currently insisting "name" be unique */
-                if (!ret)
-                        list_add(&retval->pools, &dev->dma_pools);
-                else {
-                        kfree(retval);
-                        retval = NULL;
-                }
-                mutex_unlock(&pools_lock);
+        mutex_lock(&pools_lock);
+        if (list_empty(&dev->dma_pools) &&
+            device_create_file(dev, &dev_attr_pools)) {
+                kfree(retval);
+                return NULL;
         } else
-                INIT_LIST_HEAD(&retval->pools);
+                list_add(&retval->pools, &dev->dma_pools);
+        mutex_unlock(&pools_lock);
 
         return retval;
 }