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

Joonsoo Kim
2014-06-12T03:21:39Z

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@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