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![John David Anglin](https://secure.gravatar.com/avatar/99583767ee57f36132ca71876d7ba046.jpg?s=96&d=mm)
John David Anglin committed 7a1ab6a2bf3
parisc: Fix race in pci-dma.c commit c0452fb9fb8f49c7d68ab9fa0ad092016be7b45f upstream. We are still troubled by occasional random segmentation faults and memory memory corruption on SMP machines. The causes quite a few package builds to fail on the Debian buildd machines for parisc. When gcc-6 failed to build three times in a row, I looked again at the TLB related code. I found a couple of issues. This is the first. In general, we need to ensure page table updates and corresponding TLB purges are atomic. The attached patch fixes an instance in pci-dma.c where the page table update was not guarded by the TLB lock. Tested on rp3440 and c8000. So far, no further random segmentation faults have been observed. Signed-off-by: John David Anglin <dave.anglin@bell.net> Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>