Commit 28c553d0 authored Sep 17, 2015 by Andrew Morton Committed by Linus Torvalds Sep 17, 2015

revert "mm: make sure all file VMAs have ->vm_ops set"



Revert commit 6dc296e7 "mm: make sure all file VMAs have ->vm_ops
set".

Will Deacon reports that it "causes some mmap regressions in LTP, which
appears to use a MAP_PRIVATE mmap of /dev/zero as a way to get anonymous
pages in some of its tests (specifically mmap10 [1])".

William Shuman reports Oracle crashes.

So revert the patch while we work out what to do.

Reported-by: William Shuman <wshuman3@gmail.com>
Reported-by: Will Deacon <will.deacon@arm.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 0526109a

mm/mmap.c

+0 −8

Original line number	Diff line number	Diff line
		@@ -612,8 +612,6 @@ static unsigned long count_vma_pages_range(struct mm_struct *mm,
		void __vma_link_rb(struct mm_struct mm, struct vm_area_struct vma,
		struct rb_node *rb_link, struct rb_node rb_parent)
		{
		WARN_ONCE(vma->vm_file && !vma->vm_ops, "missing vma->vm_ops");

		/* Update tracking information for the gap following the new vma. */
		if (vma->vm_next)
		vma_gap_update(vma->vm_next);
		@@ -1638,12 +1636,6 @@ unsigned long mmap_region(struct file *file, unsigned long addr,
		*/
		WARN_ON_ONCE(addr != vma->vm_start);

		/* All file mapping must have ->vm_ops set */
		if (!vma->vm_ops) {
		static const struct vm_operations_struct dummy_ops = {};
		vma->vm_ops = &dummy_ops;
		}

		addr = vma->vm_start;
		vm_flags = vma->vm_flags;
		} else if (vm_flags & VM_SHARED) {