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>

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>
Andrew Morton · Linus Torvalds
1 parent 8767ba2796
Showing 1 changed file with 3 additions and 1 deletions Side-by-side Diff
mm/percpu.c
@@ -1271,13 +1271,15 @@
  */
 void free_percpu(void *ptr)
 {
-	void *addr = __pcpu_ptr_to_addr(ptr);
+	void *addr;
 	struct pcpu_chunk *chunk;
 	unsigned long flags;
 	int off;
  
 	if (!ptr)
 		return;
+
+	addr = __pcpu_ptr_to_addr(ptr);
  
 	spin_lock_irqsave(&pcpu_lock, flags);
...	...	@@ -1271,13 +1271,15 @@
1271	1271	*/
1272	1272	void free_percpu(void *ptr)
1273	1273	{
1274		- void *addr = __pcpu_ptr_to_addr(ptr);
	1274	+ void *addr;
1275	1275	struct pcpu_chunk *chunk;
1276	1276	unsigned long flags;
1277	1277	int off;
1278	1278
1279	1279	if (!ptr)
1280	1280	return;
	1281	+
	1282	+ addr = __pcpu_ptr_to_addr(ptr);
1281	1283
1282	1284	spin_lock_irqsave(&pcpu_lock, flags);
1283	1285