diff options
Diffstat (limited to 'arch/x86/mm')
| -rw-r--r-- | arch/x86/mm/mpx.c | 24 |
1 files changed, 19 insertions, 5 deletions
diff --git a/arch/x86/mm/mpx.c b/arch/x86/mm/mpx.c index 18fcf737bdbd..6233d5195f01 100644 --- a/arch/x86/mm/mpx.c +++ b/arch/x86/mm/mpx.c @@ -937,16 +937,30 @@ static int try_unmap_single_bt(struct mm_struct *mm, void __user *bde_vaddr; int ret; /* + * We already unlinked the VMAs from the mm's rbtree so 'start' + * is guaranteed to be in a hole. This gets us the first VMA + * before the hole in to 'prev' and the next VMA after the hole + * in to 'next'. + */ + next = find_vma_prev(mm, start, &prev); + /* + * Do not count other MPX bounds table VMAs as neighbors. + * Although theoretically possible, we do not allow bounds + * tables for bounds tables so our heads do not explode. + * If we count them as neighbors here, we may end up with + * lots of tables even though we have no actual table + * entries in use. + */ + while (next && is_mpx_vma(next)) + next = next->vm_next; + while (prev && is_mpx_vma(prev)) + prev = prev->vm_prev; + /* * We know 'start' and 'end' lie within an area controlled * by a single bounds table. See if there are any other * VMAs controlled by that bounds table. If there are not * then we can "expand" the are we are unmapping to possibly * cover the entire table. - * - * We already unliked the VMAs from the mm's rbtree so 'start' - * is guaranteed to be in a hole. This gets us the first VMA - * before the hole in to 'prev' and the next VMA after the hole - * in to 'next'. */ next = find_vma_prev(mm, start, &prev); if ((!prev || prev->vm_end <= bta_start_vaddr) && |
