fix mprotect vma_wants_writenotify prot
Fix mprotect bug in recent commit 3ed75eb8f1cd89565966599c4f77d2edb086d5b0
(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>
diff --git a/mm/mmap.c b/mm/mmap.c
index 7a30c49..facc1a7 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -1171,8 +1171,7 @@
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
index 5522784..4de5468 100644
--- a/mm/mprotect.c
+++ b/mm/mprotect.c
@@ -194,7 +194,7 @@
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;
}