um: Mark stub pages mapping with VM_PFNMAP

Ensure that a process cannot destroy his stub pages with
using MADV_DONTNEED and friends.

Reported-by: toralf.foerster@gmx.de
Signed-off-by: Richard Weinberger <richard@nod.at>
This commit is contained in:
Richard Weinberger 2013-05-12 23:26:03 +02:00
parent 3179ce7254
commit dee20035b4

View File

@ -123,7 +123,7 @@ void uml_setup_stubs(struct mm_struct *mm)
/* dup_mmap already holds mmap_sem */
err = install_special_mapping(mm, STUB_START, STUB_END - STUB_START,
VM_READ | VM_MAYREAD | VM_EXEC |
VM_MAYEXEC | VM_DONTCOPY,
VM_MAYEXEC | VM_DONTCOPY | VM_PFNMAP,
mm->context.stub_pages);
if (err) {
printk(KERN_ERR "install_special_mapping returned %d\n", err);