Re: [patch] driver-core: dev_to_node() should handle NULL pointers
On Fri, Jul 20, 2012 at 06:18:46PM +0300, Dan Carpenter wrote:
On Fri, Jul 20, 2012 at 08:00:42AM -0700, Greg Kroah-Hartman wrote:
On Fri, Jul 20, 2012 at 09:56:23AM +0300, Dan Carpenter wrote:
What prompted this patch is that in dma_pool_create() we call
dev_to_node() before checking whether dev is NULL. It looks like
there are places which call dma_pool_create() with a NULL pointer. An
example is in drivers/usb/gadget/amd5536udc.c.
Signed-off-by: Dan Carpenter dan.carpen...@oracle.com
---
Static checker fix.
diff --git a/include/linux/device.h b/include/linux/device.h
index aa7b3b4..c80e7a8d 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -714,7 +714,9 @@ int dev_set_name(struct device *dev, const char
*name, ...);
#ifdef CONFIG_NUMA
static inline int dev_to_node(struct device *dev)
{
- return dev-numa_node;
+ if (dev)
+ return dev-numa_node;
+ return -1;
What happens if this function returns -1? Can the callers properly
handle this?
Gar. Now I'm not sure any more.
-1 means no affinity and it's what the dev_to_node() returns if NUMA
is disabled. But now I think probably it's important to get the
NUMA node correct in dma_pool_create() so this isn't the right
answer.
dma_pool_create() is not correct. It has code to handle a NULL
dev pointer, but the dev_to_node() dereference will cause an oops
before we reach it. I'm think this is a real issue that affects a
couple drivers. Maybe those people compile without NUMA?
I'm not sure the right fix now.
Ok, I'll drop this one then.
greg k-h
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[patch] driver-core: dev_to_node() should handle NULL pointers
What prompted this patch is that in dma_pool_create() we call
dev_to_node() before checking whether dev is NULL. It looks like
there are places which call dma_pool_create() with a NULL pointer. An
example is in drivers/usb/gadget/amd5536udc.c.
Signed-off-by: Dan Carpenter dan.carpen...@oracle.com
---
Static checker fix.
diff --git a/include/linux/device.h b/include/linux/device.h
index aa7b3b4..c80e7a8d 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -714,7 +714,9 @@ int dev_set_name(struct device *dev, const char *name, ...);
#ifdef CONFIG_NUMA
static inline int dev_to_node(struct device *dev)
{
- return dev-numa_node;
+ if (dev)
+ return dev-numa_node;
+ return -1;
}
static inline void set_dev_node(struct device *dev, int node)
{
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Re: [patch] driver-core: dev_to_node() should handle NULL pointers
On Fri, Jul 20, 2012 at 08:00:42AM -0700, Greg Kroah-Hartman wrote:
On Fri, Jul 20, 2012 at 09:56:23AM +0300, Dan Carpenter wrote:
What prompted this patch is that in dma_pool_create() we call
dev_to_node() before checking whether dev is NULL. It looks like
there are places which call dma_pool_create() with a NULL pointer. An
example is in drivers/usb/gadget/amd5536udc.c.
Signed-off-by: Dan Carpenter dan.carpen...@oracle.com
---
Static checker fix.
diff --git a/include/linux/device.h b/include/linux/device.h
index aa7b3b4..c80e7a8d 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -714,7 +714,9 @@ int dev_set_name(struct device *dev, const char *name,
...);
#ifdef CONFIG_NUMA
static inline int dev_to_node(struct device *dev)
{
- return dev-numa_node;
+ if (dev)
+ return dev-numa_node;
+ return -1;
What happens if this function returns -1? Can the callers properly
handle this?
Gar. Now I'm not sure any more.
-1 means no affinity and it's what the dev_to_node() returns if NUMA
is disabled. But now I think probably it's important to get the
NUMA node correct in dma_pool_create() so this isn't the right
answer.
dma_pool_create() is not correct. It has code to handle a NULL
dev pointer, but the dev_to_node() dereference will cause an oops
before we reach it. I'm think this is a real issue that affects a
couple drivers. Maybe those people compile without NUMA?
I'm not sure the right fix now.
regards,
dan carpenter
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