Commit 1ddd439e authored by Hugh Dickins's avatar Hugh Dickins Committed by Linus Torvalds

fix mprotect vma_wants_writenotify prot

Fix mprotect bug in recent commit 3ed75eb8
(setup vma->vm_page_prot by vm_get_page_prot()): the vma_wants_writenotify
case was setting the same prot as when not.

Nothing wrong with the use of protection_map[] in mmap_region(),
but use vm_get_page_prot() there too in the same ~VM_SHARED way.
Signed-off-by: default avatarHugh Dickins <hugh@veritas.com>
Cc: Coly Li <coyli@suse.de>
Cc: Tony Luck <tony.luck@intel.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 4ae3f847
......@@ -1171,8 +1171,7 @@ unsigned long mmap_region(struct file *file, unsigned long addr,
vm_flags = vma->vm_flags;
if (vma_wants_writenotify(vma))
vma->vm_page_prot =
protection_map[vm_flags & (VM_READ|VM_WRITE|VM_EXEC)];
vma->vm_page_prot = vm_get_page_prot(vm_flags & ~VM_SHARED);
if (!file || !vma_merge(mm, prev, addr, vma->vm_end,
vma->vm_flags, NULL, file, pgoff, vma_policy(vma))) {
......
......@@ -194,7 +194,7 @@ mprotect_fixup(struct vm_area_struct *vma, struct vm_area_struct **pprev,
vma->vm_flags = newflags;
vma->vm_page_prot = vm_get_page_prot(newflags);
if (vma_wants_writenotify(vma)) {
vma->vm_page_prot = vm_get_page_prot(newflags);
vma->vm_page_prot = vm_get_page_prot(newflags & ~VM_SHARED);
dirty_accountable = 1;
}
......
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