-stable review patch. If anyone has any objections, please let us know.
---------------------
From: Venkatesh Pallipadi <[email protected]>
upstream commit: 9cdec049389ce2c324fd1ec508a71528a27d4a07
While looking at the issue in the thread:
http://marc.info/?l=dri-devel&m=123606627824556&w=2
noticed a bug in pci PAT code and memory type setting.
PCI mmap code did not set the proper protection in vma, when it
inherited protection in reserve_memtype. This bug only affects
the case where there exists a WC mapping before X does an mmap
with /proc or /sys pci interface. This will cause X userlevel
mmap from /proc or /sysfs to fail on fork.
Reported-by: Kevin Winchester <[email protected]>
Signed-off-by: Venkatesh Pallipadi <[email protected]>
Signed-off-by: Suresh Siddha <[email protected]>
Cc: Jesse Barnes <[email protected]>
Cc: Dave Airlie <[email protected]>
Cc: <[email protected]>
LKML-Reference: <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Signed-off-by: Chris Wright <[email protected]>
---
arch/x86/pci/i386.c | 3 +++
1 file changed, 3 insertions(+)
--- a/arch/x86/pci/i386.c
+++ b/arch/x86/pci/i386.c
@@ -319,6 +319,9 @@ int pci_mmap_page_range(struct pci_dev *
return -EINVAL;
}
flags = new_flags;
+ vma->vm_page_prot = __pgprot(
+ (pgprot_val(vma->vm_page_prot) & ~_PAGE_CACHE_MASK) |
+ flags);
}
if (((vma->vm_pgoff < max_low_pfn_mapped) ||