arm64: add missing PAGE_ALIGN() to __dma_free()
authorDean Nelson <dnelson@redhat.com>
Wed, 29 Apr 2015 15:09:18 +0000 (16:09 +0100)
committerWill Deacon <will.deacon@arm.com>
Wed, 29 Apr 2015 16:39:39 +0000 (17:39 +0100)
__dma_alloc() does a PAGE_ALIGN() on the passed in size argument before
doing anything else. __dma_free() does not. And because it doesn't, it is
possible to leak memory should size not be an integer multiple of PAGE_SIZE.

The solution is to add a PAGE_ALIGN() to __dma_free() like is done in
__dma_alloc().

Additionally, this patch removes a redundant PAGE_ALIGN() from
__dma_alloc_coherent(), since __dma_alloc_coherent() can only be called
from __dma_alloc(), which already does a PAGE_ALIGN() before the call.

Cc: stable@vger.kernel.org
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Dean Nelson <dnelson@redhat.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
arch/arm64/mm/dma-mapping.c

index e0f14ee26b6818167cde2a6e955ffb59e339c9ad..b0bd4e5fd5cf9c2599ddbc509bccb233838638a4 100644 (file)
@@ -104,7 +104,6 @@ static void *__dma_alloc_coherent(struct device *dev, size_t size,
                struct page *page;
                void *addr;
 
-               size = PAGE_ALIGN(size);
                page = dma_alloc_from_contiguous(dev, size >> PAGE_SHIFT,
                                                        get_order(size));
                if (!page)
@@ -193,6 +192,8 @@ static void __dma_free(struct device *dev, size_t size,
 {
        void *swiotlb_addr = phys_to_virt(dma_to_phys(dev, dma_handle));
 
+       size = PAGE_ALIGN(size);
+
        if (!is_device_dma_coherent(dev)) {
                if (__free_from_pool(vaddr, size))
                        return;