From fce000b1bc08c64c0cff4bb705b3970bd6fc1e34 Mon Sep 17 00:00:00 2001 From: Liam Howlett Date: Tue, 4 May 2021 18:38:06 -0700 Subject: [PATCH] mm/mmap.c: don't unlock VMAs in remap_file_pages() Since this call uses MAP_FIXED, do_mmap() will munlock the necessary range. There is also an error in the loop test expression which will evaluate as false and the loop body has never execute. Link: https://lkml.kernel.org/r/20210223235010.2296915-1-Liam.Howlett@Oracle.com Signed-off-by: Liam R. Howlett Acked-by: Hugh Dickins Reviewed-by: Matthew Wilcox (Oracle) Reviewed-by: David Hildenbrand Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/mmap.c | 18 +----------------- 1 file changed, 1 insertion(+), 17 deletions(-) diff --git a/mm/mmap.c b/mm/mmap.c index 347ef9b83bb5..c1b848fa7da6 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -3029,25 +3029,9 @@ SYSCALL_DEFINE5(remap_file_pages, unsigned long, start, unsigned long, size, flags &= MAP_NONBLOCK; flags |= MAP_SHARED | MAP_FIXED | MAP_POPULATE; - if (vma->vm_flags & VM_LOCKED) { - struct vm_area_struct *tmp; + if (vma->vm_flags & VM_LOCKED) flags |= MAP_LOCKED; - /* drop PG_Mlocked flag for over-mapped range */ - for (tmp = vma; tmp->vm_start >= start + size; - tmp = tmp->vm_next) { - /* - * Split pmd and munlock page on the border - * of the range. - */ - vma_adjust_trans_huge(tmp, start, start + size, 0); - - munlock_vma_pages_range(tmp, - max(tmp->vm_start, start), - min(tmp->vm_end, start + size)); - } - } - file = get_file(vma->vm_file); ret = do_mmap(vma->vm_file, start, size, prot, flags, pgoff, &populate, NULL);