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author | Nicolas Saenz Julienne <nsaenzjulienne@suse.de> | 2019-11-07 18:06:44 +0300 |
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committer | Christoph Hellwig <hch@lst.de> | 2019-11-11 12:52:18 +0300 |
commit | b12d66278dd627cbe1ea7c000aa4715aaf8830c8 (patch) | |
tree | 6ed0eb01fd50f5035d8808ba9fee7c2e85960506 /arch/mips/jazz | |
parent | 5e76f564572b85735de4b75a5e73b514be2562be (diff) | |
download | linux-b12d66278dd627cbe1ea7c000aa4715aaf8830c8.tar.xz |
dma-direct: check for overflows on 32 bit DMA addresses
As seen on the new Raspberry Pi 4 and sta2x11's DMA implementation it is
possible for a device configured with 32 bit DMA addresses and a partial
DMA mapping located at the end of the address space to overflow. It
happens when a higher physical address, not DMAable, is translated to
it's DMA counterpart.
For example the Raspberry Pi 4, configurable up to 4 GB of memory, has
an interconnect capable of addressing the lower 1 GB of physical memory
with a DMA offset of 0xc0000000. It transpires that, any attempt to
translate physical addresses higher than the first GB will result in an
overflow which dma_capable() can't detect as it only checks for
addresses bigger then the maximum allowed DMA address.
Fix this by verifying in dma_capable() if the DMA address range provided
is at any point lower than the minimum possible DMA address on the bus.
Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Diffstat (limited to 'arch/mips/jazz')
0 files changed, 0 insertions, 0 deletions