Commit ea05c844 authored Oct 26, 2010 by Dima Zavin Committed by Linus Torvalds Oct 26, 2010

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 <dima@android.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent d65bfacb

mm/dmapool.c

+2 −0

Original line number	Diff line number	Diff line
		@@ -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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