Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932711AbbFWPFO (ORCPT ); Tue, 23 Jun 2015 11:05:14 -0400 Received: from mx2.parallels.com ([199.115.105.18]:48009 "EHLO mx2.parallels.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932587AbbFWPFA (ORCPT ); Tue, 23 Jun 2015 11:05:00 -0400 Message-ID: <5589758B.6030804@parallels.com> Date: Tue, 23 Jun 2015 18:04:43 +0300 From: Pavel Emelyanov User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.3.0 MIME-Version: 1.0 To: Oleg Nesterov , Andrew Morton CC: Al Viro , Benjamin LaHaise , Hugh Dickins , Jeff Moyer , Kirill Shutemov , Linus Torvalds , , Andy Lutomirski Subject: Re: vdso && f_op->mremap (Was: special_mapping_fault() is broken) References: <20150621210725.GA18220@redhat.com> <20150621211951.GA18593@redhat.com> <20150623004744.GA11212@redhat.com> In-Reply-To: <20150623004744.GA11212@redhat.com> Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 7bit X-Originating-IP: [178.168.180.150] X-ClientProxiedBy: US-EXCH2.sw.swsoft.com (10.255.249.46) To US-EXCH2.sw.swsoft.com (10.255.249.46) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1424 Lines: 40 On 06/23/2015 03:47 AM, Oleg Nesterov wrote: > On 06/21, Oleg Nesterov wrote: >> >> Forgot to add Andy... > > Add Pavel ;) > > I never understood why ->mremap() lives in file_operations, not in > vm_operations_struct. To me vma->vm_file->f_op in move_vma() just > looks strange, vma->vm_ops->mremap(new_vma) looks "obviously better". > > And afaics more useful. CRIU remaps vdso, but this does not update > mm->context.vdso. OK, probably this does not matter currently, CRIU > can't c/r the compat tasks, and 64-bit apps do not use context.vdso. Yup, the context.vdso exists not for all vdso-s. There should have been a patch for power arch adding this change. > Afaics. Still, I think we might want to have special_mapping_remap() > and we can't do this because ->vm_file == NULL. For aio (the single for now mapping with mremap callback) the vm_file is not NULL. > And perhaps other architectures can depend on the "correct" value > in >context.vdso more then x86, I dunno... > > In short. Shouldn't we move ->mremap() to vm_operations_struct before > it has another user? We need to fix aio.c, but this is trivial. > > No? I will be OK with this change :) -- Pavel -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/