[PATCH] dmapool: remove redundant NULL check for dev in dma_pool_create()

From: Daeseok Youn
Date: Mon Apr 28 2014 - 22:53:44 EST


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

Signed-off-by: Daeseok Youn <daeseok.youn@xxxxxxxxx>
---
If dev can be NULL, it has NULL deferencing when kmalloc_node()
is called after enabling CONFIG_NUMA.

mm/dmapool.c | 26 +++++++++-----------------
1 files changed, 9 insertions(+), 17 deletions(-)

diff --git a/mm/dmapool.c b/mm/dmapool.c
index c69781e..38dfcdd 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;
}
--
1.7.4.4

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