[PATCH v2 02/10] DMA, CMA: fix possible memory leak

[Joonsoo Kim]

We should free memory for bitmap when we find zone mis-match,
otherwise this memory will leak.

Additionally, I copy code comment from ppc kvm's cma code to notify
why we need to check zone mis-match.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim at lge.com>

diff --git a/drivers/base/dma-contiguous.c b/drivers/base/dma-contiguous.c
index bd0bb81..fb0cdce 100644
--- a/drivers/base/dma-contiguous.c
+++ b/drivers/base/dma-contiguous.c
@@ -177,14 +177,24 @@ static int __init cma_activate_area(struct cma *cma)
 		base_pfn = pfn;
 		for (j = pageblock_nr_pages; j; --j, pfn++) {
 			WARN_ON_ONCE(!pfn_valid(pfn));
+			/*
+			 * alloc_contig_range requires the pfn range
+			 * specified to be in the same zone. Make this
+			 * simple by forcing the entire CMA resv range
+			 * to be in the same zone.
+			 */
 			if (page_zone(pfn_to_page(pfn)) != zone)
-				return -EINVAL;
+				goto err;
 		}
 		init_cma_reserved_pageblock(pfn_to_page(base_pfn));
 	} while (--i);
 
 	mutex_init(&cma->lock);
 	return 0;
+
+err:
+	kfree(cma->bitmap);
+	return -EINVAL;
 }
 
 static struct cma cma_areas[MAX_CMA_AREAS];
-- 
1.7.9.5