On Mon, Jan 30, 2012 at 12:37:34PM +0400, Dmitry Antipov wrote:
Fix pcpu_alloc() to return ZERO_SIZE_PTR if requested size is 0; fix free_percpu() to check passed pointer with ZERO_OR_NULL_PTR.
Signed-off-by: Dmitry Antipov dmitry.antipov@linaro.org
mm/percpu.c | 16 +++++++++++----- 1 files changed, 11 insertions(+), 5 deletions(-)
diff --git a/mm/percpu.c b/mm/percpu.c index f47af91..e903a19 100644 --- a/mm/percpu.c +++ b/mm/percpu.c @@ -702,7 +702,8 @@ static struct pcpu_chunk *pcpu_chunk_addr_search(void *addr)
- Does GFP_KERNEL allocation.
- RETURNS:
- Percpu pointer to the allocated area on success, NULL on failure.
- ZERO_SIZE_PTR if @size is zero, percpu pointer to the
*/
- allocated area on success or NULL on failure.
static void __percpu *pcpu_alloc(size_t size, size_t align, bool reserved) { @@ -713,7 +714,10 @@ static void __percpu *pcpu_alloc(size_t size, size_t align, bool reserved) unsigned long flags; void __percpu *ptr;
- if (unlikely(!size || size > PCPU_MIN_UNIT_SIZE || align > PAGE_SIZE)) {
- if (unlikely(!size))
return ZERO_SIZE_PTR;
Percpu pointers are in a different address space and using ZERO_SIZE_PTR directly will trigger sparse address space warning. Also, I'm not entirely sure whether 16 is guaranteed to be unused in percpu address space (maybe it is but I don't think we have anything enforcing that).
Thanks.