This can help to catch case where hardware is writting after dma free.
Signed-off-by: Matthieu Castet <matthieu.cas...@parrot.com>
---
mm/dmapool.c | 23 +++++++++++++++++++++++
1 file changed, 23 insertions(+)
diff --git a/mm/dmapool.c b/mm/dmapool.c
index c5ab33b..e10898a 100644
--- a/mm/dmapool.c
+++ b/mm/dmapool.c
@@ -346,6 +346,29 @@ 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(int); i < pool->size; i++) {
+ if (data[i] != POOL_POISON_FREED) {
+ if (pool->dev)
+ dev_err(pool->dev,
+ "dma_pool_alloc %s, %p
(corruped)\n",
+ pool->name, retval);
+ else
+ printk(KERN_ERR
+ "dma_pool_alloc %s, %p
(corruped)\n",
+ pool->name, retval);
+
+ /* we dump the first 4 bytes even if there 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
done:
--
1.7.10.4
--
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