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of: device: Fix overflow of coherent_dma_mask
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Size of the dma-range is calculated as coherent_dma_mask + 1
and passed to arch_setup_dma_ops further. It overflows when
the coherent_dma_mask is set for full 64 bits 0xFFFFFFFFFFFFFFFF,
resulting in size getting passed as 0 wrongly. Fix this by
passsing in max(mask, mask + 1). Note that in this case
when the mask is set to full 64bits, we will be passing the mask
itself to arch_setup_dma_ops instead of the size. The real fix
for this should be to make arch_setup_dma_ops receive the
mask and handle it, to be done in the future.

Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Sricharan R <sricharan@codeaurora.org>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
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Sricharan R authored and Joerg Roedel committed Apr 20, 2017
1 parent 1d9029d commit efc8551
Showing 1 changed file with 1 addition and 1 deletion.
2 changes: 1 addition & 1 deletion drivers/of/device.c
Original file line number Diff line number Diff line change
Expand Up @@ -107,7 +107,7 @@ void of_dma_configure(struct device *dev, struct device_node *np)
ret = of_dma_get_range(np, &dma_addr, &paddr, &size);
if (ret < 0) {
dma_addr = offset = 0;
size = dev->coherent_dma_mask + 1;
size = max(dev->coherent_dma_mask, dev->coherent_dma_mask + 1);
} else {
offset = PFN_DOWN(paddr - dma_addr);

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