From 435ce5518ba15e21e165962fd9f8ff0abaa5bcf5 Mon Sep 17 00:00:00 2001 From: Yang Shi Date: Fri, 26 Oct 2018 15:07:15 -0700 Subject: [PATCH] mm: unmap VM_HUGETLB mappings with optimized path to #28718400 commit b4cefb36051244bcb5651026d862c332a6cac7df upstream. When unmapping VM_HUGETLB mappings, vm flags need to be updated. Since the vmas have been detached, so it sounds safe to update vm flags with read mmap_sem. Link: http://lkml.kernel.org/r/1537376621-51150-3-git-send-email-yang.shi@linux.alibaba.com Signed-off-by: Yang Shi Reviewed-by: Matthew Wilcox Acked-by: Kirill A. Shutemov Acked-by: Vlastimil Babka Cc: Michal Hocko Cc: Vlastimil Babka Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Xu Yu Reviewed-by: Yang Shi --- mm/mmap.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/mmap.c b/mm/mmap.c index 8ac57f99c223..ad34641cc966 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -2781,7 +2781,7 @@ static int __do_munmap(struct mm_struct *mm, unsigned long start, size_t len, * update vm_flags. */ if (downgrade && - (tmp->vm_flags & (VM_HUGETLB | VM_PFNMAP))) + (tmp->vm_flags & VM_PFNMAP)) downgrade = false; tmp = tmp->vm_next; -- GitLab