Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751101AbbGKQh5 (ORCPT ); Sat, 11 Jul 2015 12:37:57 -0400 Received: from mail-la0-f43.google.com ([209.85.215.43]:36684 "EHLO mail-la0-f43.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750907AbbGKQh4 (ORCPT ); Sat, 11 Jul 2015 12:37:56 -0400 MIME-Version: 1.0 In-Reply-To: <1436591360-16210-2-git-send-email-brgerst@gmail.com> References: <1436591360-16210-1-git-send-email-brgerst@gmail.com> <1436591360-16210-2-git-send-email-brgerst@gmail.com> From: Andy Lutomirski Date: Sat, 11 Jul 2015 09:37:35 -0700 Message-ID: Subject: Re: [PATCH 1/5] x86/vm86: Move userspace accesses to do_sys_vm86() To: Brian Gerst Cc: X86 ML , "linux-kernel@vger.kernel.org" , Ingo Molnar , "H. Peter Anvin" , Denys Vlasenko , Linus Torvalds Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1299 Lines: 30 On Fri, Jul 10, 2015 at 10:09 PM, Brian Gerst wrote: > Move the userspace accesses down into the common function in > preparation for the next set of patches. > One thing I don't like about the current code that makes these patches harder to review is the bizarre approach to copying. If you changed this: > - tmp = copy_vm86_regs_from_user(&info.regs, &v86->regs, > - offsetof(struct kernel_vm86_struct, vm86plus) - > - sizeof(info.regs)); into a normal field-by-field get_user / copy_from_user (the latter for the big regs struct) then it would be clear what the ABI is and it would be much easier to read the patches and confirm that you aren't accidentally changing the ABI. You could also get rid of the constraint that certain fields in apparently kernel-internal structs had to be in a certain order. Other than that, patches 1-4 look good on cursory inspection. I'll look more carefully later. I need to think about patch 5 more. --Andy -- 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/