diff options
Diffstat (limited to 'mm/mlock.c')
| -rw-r--r-- | mm/mlock.c | 17 |
1 files changed, 15 insertions, 2 deletions
diff --git a/mm/mlock.c b/mm/mlock.c index bd6f0e466f6c..2d846cfe3990 100644 --- a/mm/mlock.c +++ b/mm/mlock.c @@ -99,14 +99,14 @@ void mlock_vma_page(struct page *page) * not get another chance to clear PageMlocked. If we successfully * isolate the page and try_to_munlock() detects other VM_LOCKED vmas * mapping the page, it will restore the PageMlocked state, unless the page - * is mapped in a non-linear vma. So, we go ahead and SetPageMlocked(), + * is mapped in a non-linear vma. So, we go ahead and ClearPageMlocked(), * perhaps redundantly. * If we lose the isolation race, and the page is mapped by other VM_LOCKED * vmas, we'll detect this in vmscan--via try_to_munlock() or try_to_unmap() * either of which will restore the PageMlocked state by calling * mlock_vma_page() above, if it can grab the vma's mmap sem. */ -static void munlock_vma_page(struct page *page) +void munlock_vma_page(struct page *page) { BUG_ON(!PageLocked(page)); @@ -138,6 +138,13 @@ static void munlock_vma_page(struct page *page) } } +static inline int stack_guard_page(struct vm_area_struct *vma, unsigned long addr) +{ + return (vma->vm_flags & VM_GROWSDOWN) && + (vma->vm_start == addr) && + !vma_stack_continue(vma->vm_prev, addr); +} + /** * __mlock_vma_pages_range() - mlock a range of pages in the vma. * @vma: target vma @@ -170,6 +177,12 @@ static long __mlock_vma_pages_range(struct vm_area_struct *vma, if (vma->vm_flags & VM_WRITE) gup_flags |= FOLL_WRITE; + /* We don't try to access the guard page of a stack vma */ + if (stack_guard_page(vma, start)) { + addr += PAGE_SIZE; + nr_pages--; + } + while (nr_pages > 0) { int i; |