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  Such a driver is probably outdated, possibly buggy and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>

diff --git a/mm/dmapool.c b/mm/dmapool.c
index 8058fcd..a3a1bfe 100644 (file)
--- 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;
 }