[PATCH v2] dma-buf: dma-heap: Add a size check for allocation

[<guangming.cao@mediatek.com>]

From: Guangming <Guangming.Cao@mediatek.com>

Add a size check for allcation since the allocation size is
always less than the total DRAM size.

Signed-off-by: Guangming <Guangming.Cao@mediatek.com>
Signed-off-by: jianjiao zeng <jianjiao.zeng@mediatek.com>
---
v2: 1. update size limitation as total_dram page size.
    2. update commit message
---
 drivers/dma-buf/dma-heap.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/dma-buf/dma-heap.c b/drivers/dma-buf/dma-heap.c
index 56bf5ad01ad5..e39d2be98d69 100644
--- a/drivers/dma-buf/dma-heap.c
+++ b/drivers/dma-buf/dma-heap.c
@@ -55,6 +55,8 @@ static int dma_heap_buffer_alloc(struct dma_heap *heap, size_t len,
 	struct dma_buf *dmabuf;
 	int fd;
 
+	if (len / PAGE_SIZE > totalram_pages())
+		return -EINVAL;
 	/*
 	 * Allocations from all heaps have to begin
 	 * and end on page boundaries.
-- 
2.17.1