On Wed, 21 Mar 2018, Laurent Dufour wrote: > I found the root cause of this lockdep warning. > > In mmap_region(), unmap_region() may be called while vma_link() has not been > called. This happens during the error path if call_mmap() failed. > > The only to fix that particular case is to call > seqcount_init(&vma->vm_sequence) when initializing the vma in mmap_region(). > Ack, although that would require a fixup to dup_mmap() as well.
