percpu: avoid calling __pcpu_ptr_to_addr(NULL)

__pcpu_ptr_to_addr() can be overridden by the architecture and might not
behave well if passed a NULL pointer.  So avoid calling it until we have
verified that its arg is not NULL.

Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Andrew Morton 2010-01-08 14:42:39 -08:00 committed by Linus Torvalds
parent 8767ba2796
commit 129182e562

View File

@ -1271,7 +1271,7 @@ static void pcpu_reclaim(struct work_struct *work)
*/
void free_percpu(void *ptr)
{
void *addr = __pcpu_ptr_to_addr(ptr);
void *addr;
struct pcpu_chunk *chunk;
unsigned long flags;
int off;
@ -1279,6 +1279,8 @@ void free_percpu(void *ptr)
if (!ptr)
return;
addr = __pcpu_ptr_to_addr(ptr);
spin_lock_irqsave(&pcpu_lock, flags);
chunk = pcpu_chunk_addr_search(addr);