fix mprotect vma_wants_writenotify prot

Fix mprotect bug in recent commit 3ed75eb (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: Hugh Dickins <hugh@veritas.com> Cc: Coly Li <coyli@suse.de> Cc: Tony Luck <tony.luck@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
git-mirror · Oct 23, 2007 · 1ddd439 · 1ddd439
1 parent 4ae3f84
commit 1ddd439
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Showing 2 changed files with 2 additions and 3 deletions.
diff --git a/mm/mmap.c b/mm/mmap.c
@@ -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))) {

diff --git a/mm/mprotect.c b/mm/mprotect.c
@@ -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;
 	}