mm: fix missing page table unmap for stack guard page failure case

.. which didn't show up in my tests because it's a no-op on x86-64 and
most other architectures.  But we enter the function with the last-level
page table mapped, and should unmap it at exit.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Linus Torvalds 2010-08-13 09:24:04 -07:00
parent 320b2b8de1
commit 5528f9132c

View File

@ -2792,8 +2792,10 @@ static int do_anonymous_page(struct mm_struct *mm, struct vm_area_struct *vma,
spinlock_t *ptl;
pte_t entry;
if (check_stack_guard_page(vma, address) < 0)
if (check_stack_guard_page(vma, address) < 0) {
pte_unmap(page_table);
return VM_FAULT_SIGBUS;
}
if (!(flags & FAULT_FLAG_WRITE)) {
entry = pte_mkspecial(pfn_pte(my_zero_pfn(address),