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Daniel De Graaf authored
When we setup up the VMA flags for the mmap flag and we end up using the fallback mmap functionality we set the vma->vm_flags |= VM_IO. However we neglect to propagate the flag to the vma->vm_page_prot. This bug was found when Linux kernel was running under Xen. In that scenario, any page that has VM_IO flag to it, means that it MUST be a MMIO/VRAM backend memory , _not_ System RAM. That is what the fbmem.c does: sets VM_IO, ioremaps the region - everything is peachy. Well, not exactly. The vm_page_prot does not get the relevant PTE flags set (_PAGE_IOMAP) which under Xen is a death-kneel to pages that are referencing real physical devices but don't have that flag set. This patch fixes this. Signed-off-by:
Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by:
Daniel De Graaf <dgdegra@tycho.nsa.gov> Tested-by:
Eamon Walsh <ewalsh@tycho.nsa.gov> Cc: Florian Tobias Schandinat <FlorianSchandinat@gmx.de> Cc: Dave Airlie <airlied@linux.ie> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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