On Wed 16-11-16 17:27:55, Kirill A. Shutemov wrote: > On Wed, Nov 16, 2016 at 02:29:18PM +0100, Jan Kara wrote: > > On Wed 16-11-16 01:28:19, Kirill A. Shutemov wrote: > > > On Fri, Nov 04, 2016 at 05:25:07AM +0100, Jan Kara wrote: > > > > We don't check whether vma->vm_ops is NULL in do_shared_fault() so > > > > there's hardly any point in checking it in wp_page_shared() or > > > > wp_pfn_shared() which get called only for shared file mappings as well. > > > > > > > > Signed-off-by: Jan Kara <jack@xxxxxxx> > > > > > > Well, I'm not sure about this. > > > > > > do_shared_fault() doesn't have the check since we checked it upper by > > > stack: see vma_is_anonymous() in handle_pte_fault(). > > > > > > In principal, it should be fine. But random crappy driver has potential to > > > blow it up. > > > > Ok, so do you prefer me to keep this patch or discard it? Either is fine with > > me. It was just a cleanup I wrote when factoring out the functionality. > > I would rather drop it. > > Eventually, we need to make sure that all file-backed vma has vm_ops. > I tried to do this once, but that back-fired... OK, will do. Honza -- Jan Kara <jack@xxxxxxxx> SUSE Labs, CR -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>