Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 5de55b26 authored by Matthieu CASTET's avatar Matthieu CASTET Committed by Linus Torvalds
Browse files

dmapool: make DMAPOOL_DEBUG detect corruption of free marker 



This can help to catch the case where hardware is writing after dma free.

[akpm@linux-foundation.org: tidy code, fix comment, use sizeof(page->offset), use pr_err()]
Signed-off-by: default avatarMatthieu Castet <matthieu.castet@parrot.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 9ff4868e

mm/dmapool.c

+24 −0
Original line number Diff line number Diff line
@@ -332,6 +332,30 @@ void *dma_pool_alloc(struct dma_pool *pool, gfp_t mem_flags, 
	retval = offset + page->vaddr;

	*handle = offset + page->dma;

#ifdef	DMAPOOL_DEBUG

	{

		int i;

		u8 *data = retval;

		/* page->offset is stored in first 4 bytes */

		for (i = sizeof(page->offset); i < pool->size; i++) {

			if (data[i] == POOL_POISON_FREED)

				continue;

			if (pool->dev)

				dev_err(pool->dev,

					"dma_pool_alloc %s, %p (corruped)\n",

					pool->name, retval);

			else

				pr_err("dma_pool_alloc %s, %p (corruped)\n",

					pool->name, retval);



			/*

			 * Dump the first 4 bytes even if they are not

			 * POOL_POISON_FREED

			 */

			print_hex_dump(KERN_ERR, "", DUMP_PREFIX_OFFSET, 16, 1,

					data, pool->size, 1);

			break;

		}

	}

	memset(retval, POOL_POISON_ALLOCATED, pool->size);

#endif

	spin_unlock_irqrestore(&pool->lock, flags);