On Tue, Feb 02, 2021 at 04:31:33PM -0800, Suren Baghdasaryan wrote: > Replace BUG_ON(vma->vm_flags & VM_PFNMAP) in vm_insert_page with > WARN_ON_ONCE and returning an error. This is to ensure users of the > vm_insert_page that set VM_PFNMAP are notified of the wrong flag usage > and get an indication of an error without panicing the kernel. > This will help identifying drivers that need to clear VM_PFNMAP before > using dmabuf system heap which is moving to use vm_insert_page. NACK. The system may not _panic_, but it is clearly now _broken_. The device doesn't work, and so the system is useless. You haven't really improved anything here. Just bloated the kernel with yet another _ONCE variable that in a normal system will never ever ever be triggered.