From cc6b664aa26de93d9a3f99d4021a8d88b434ed06 Mon Sep 17 00:00:00 2001 From: Daeseok Youn Date: Wed, 4 Jun 2014 16:08:05 -0700 Subject: [PATCH] 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 Such a driver is probably outdated, possibly buggy and will need some attention if it starts triggering NULL derefs.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 Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/dmapool.c | 24 ++++++++---------------- 1 file 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; }