From 1ddd439ef987c9f0209e6ce824b67518f2afe67b Mon Sep 17 00:00:00 2001 From: Hugh Dickins Date: Mon, 22 Oct 2007 20:45:12 -0700 Subject: [PATCH] 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 Cc: Coly Li Cc: Tony Luck Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/mmap.c | 3 +-- mm/mprotect.c | 2 +- 2 files changed, 2 insertions(+), 3 deletions(-) diff --git a/mm/mmap.c b/mm/mmap.c index 7a30c4988231..facc1a75bd4f 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -1171,8 +1171,7 @@ munmap_back: 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 55227845abbe..4de546899dc1 100644 --- a/mm/mprotect.c +++ b/mm/mprotect.c @@ -194,7 +194,7 @@ success: 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; } -- 2.20.1