tree 0b6efa9f80c4115949cc3d26eaddfd3e7031bbae
parent 44e33e8f95171b93968c3ac3cf8516998b1db65d
author Joonsoo Kim <js1304@gmail.com> 1355349113 -0800
committer Linus Torvalds <torvalds@linux-foundation.org> 1355362713 -0800

mm: WARN_ON_ONCE if f_op->mmap() change vma's start address

During reviewing the source code, I found a comment which mention that
after f_op->mmap(), vma's start address can be changed.  I didn't verify
that it is really possible, because there are so many f_op->mmap()
implementation.  But if there are some mmap() which change vma's start
address, it is possible error situation, because we already prepare prev
vma, rb_link and rb_parent and these are related to original address.

So add WARN_ON_ONCE for finding that this situtation really happens.

Signed-off-by: Joonsoo Kim <js1304@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>