@@ -862,17 +862,18 @@ static void check_unmap(struct dma_debug_entry *ref)
entry = bucket_find_exact(bucket, ref);
if (!entry) {
+ /* must drop lock before calling dma_mapping_error */
+ put_hash_bucket(bucket, &flags);
+
if (dma_mapping_error(ref->dev, ref->dev_addr)) {
err_printk(ref->dev, NULL,
- "DMA-API: device driver tries "
- "to free an invalid DMA memory address\n");
- return;
+ "DMA-API: device driver tries to free an invalid DMA memory address\n");
+ } else {
+ err_printk(ref->dev, NULL,
+ "DMA-API: device driver tries to free DMA memory it has not allocated [device address=0x%016llx] [size=%llu bytes]\n",
+ ref->dev_addr, ref->size);
}
- err_printk(ref->dev, NULL, "DMA-API: device driver tries "
- "to free DMA memory it has not allocated "
- "[device address=0x%016llx] [size=%llu bytes]\n",
- ref->dev_addr, ref->size);
- goto out;
+ return;
}
if (ref->size != entry->size) {
@@ -936,7 +937,6 @@ static void check_unmap(struct dma_debug_entry *ref)
hash_bucket_del(entry);
dma_entry_free(entry);
-out:
put_hash_bucket(bucket, &flags);
}
In check_unmap it is possible to get into a dead-locked state if dma_mapping_error is called. The problem is that the bucket is locked in check_unmap, and locked again by debug_dma_mapping_error which is called by dma_mapping_error. To resolve that we must release the lock on the bucket before making the call to dma_mapping_error. Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com> --- lib/dma-debug.c | 18 +++++++++--------- 1 files changed, 9 insertions(+), 9 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html