Commit ea05c844 authored by Dima Zavin's avatar Dima Zavin Committed by Linus Torvalds

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: default avatarDima Zavin <dima@android.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent d65bfacb
......@@ -311,6 +311,8 @@ void *dma_pool_alloc(struct dma_pool *pool, gfp_t mem_flags,
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) {
......
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