[PATCH 3.2 104/126] ARM: dma-mapping: don't allow DMA mappings to be marked executable

Ben Hutchings
2017-02-15T22:59:24Z

From: Russell King <rmk+kernel@arm.linux.org.uk>

commit 0ea1ec713f04bdfac343c9702b21cd3a7c711826 upstream.

DMA mapping permissions were being derived from pgprot_kernel directly
without using PAGE_KERNEL. This causes them to be marked with executable
permission, which is not what we want. Fix this.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
arch/arm/mm/dma-mapping.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

--- a/arch/arm/mm/dma-mapping.c
+++ b/arch/arm/mm/dma-mapping.c
@@ -374,7 +374,7 @@ dma_alloc_coherent(struct device *dev, s
return memory;

return __dma_alloc(dev, size, handle, gfp,
- pgprot_dmacoherent(pgprot_kernel));
+ pgprot_dmacoherent(PAGE_KERNEL));
}
EXPORT_SYMBOL(dma_alloc_coherent);

@@ -386,7 +386,7 @@ void *
dma_alloc_writecombine(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp)
{
return __dma_alloc(dev, size, handle, gfp,
- pgprot_writecombine(pgprot_kernel));
+ pgprot_writecombine(PAGE_KERNEL));
}
EXPORT_SYMBOL(dma_alloc_writecombine);