mm: add a might_sleep_if() to dma_pool_alloc()
Buggy drivers (e.g. fsl_udc) could call dma_pool_alloc from atomic
context with GFP_KERNEL. In most instances, the first pool_alloc_page
call would succeed and the sleeping functions would never be called. This
allowed the buggy drivers to slip through the cracks.
Add a might_sleep_if() checking for __GFP_WAIT in flags.
Signed-off-by: Dima Zavin <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
diff --git a/mm/dmapool.c b/mm/dmapool.c
index 3df0637..4df2de7 100644
--- a/mm/dmapool.c
+++ b/mm/dmapool.c
@@ -311,6 +311,8 @@
size_t offset;
void *retval;
+ might_sleep_if(mem_flags & __GFP_WAIT);
+
spin_lock_irqsave(&pool->lock, flags);
restart:
list_for_each_entry(page, &pool->page_list, page_list) {
