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authorJan Kara <jack@suse.cz>2016-12-14 15:07:50 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2016-12-14 16:04:09 -0800
commit2f89dc12a25ddf995b9acd7b6543fe892e3473d6 (patch)
treed162312aa8bdcb6602a9c30dd5810c0f2f8e0a16 /mm
parenta6abc2c0e77b16480f4d2c1eb7925e5287ae1526 (diff)
downloadlinux-2f89dc12a25ddf995b9acd7b6543fe892e3473d6.tar.bz2
dax: protect PTE modification on WP fault by radix tree entry lock
Currently PTE gets updated in wp_pfn_shared() after dax_pfn_mkwrite() has released corresponding radix tree entry lock. When we want to writeprotect PTE on cache flush, we need PTE modification to happen under radix tree entry lock to ensure consistent updates of PTE and radix tree (standard faults use page lock to ensure this consistency). So move update of PTE bit into dax_pfn_mkwrite(). Link: http://lkml.kernel.org/r/1479460644-25076-20-git-send-email-jack@suse.cz Signed-off-by: Jan Kara <jack@suse.cz> Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm')
-rw-r--r--mm/memory.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/mm/memory.c b/mm/memory.c
index edd899d0decb..57d0bd1bd2c4 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -2315,7 +2315,7 @@ static int wp_pfn_shared(struct vm_fault *vmf)
pte_unmap_unlock(vmf->pte, vmf->ptl);
vmf->flags |= FAULT_FLAG_MKWRITE;
ret = vma->vm_ops->pfn_mkwrite(vma, vmf);
- if (ret & VM_FAULT_ERROR)
+ if (ret & (VM_FAULT_ERROR | VM_FAULT_NOPAGE))
return ret;
return finish_mkwrite_fault(vmf);
}