From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, UNPARSEABLE_RELAY,URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 42977C43461 for ; Sat, 12 Sep 2020 07:54:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0C60020796 for ; Sat, 12 Sep 2020 07:54:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725868AbgILHyK (ORCPT ); Sat, 12 Sep 2020 03:54:10 -0400 Received: from bhuna.collabora.co.uk ([46.235.227.227]:45646 "EHLO bhuna.collabora.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725809AbgILHyG (ORCPT ); Sat, 12 Sep 2020 03:54:06 -0400 Received: from [127.0.0.1] (localhost [127.0.0.1]) (Authenticated sender: krisman) with ESMTPSA id 08D8629B631 From: Gabriel Krisman Bertazi To: Christoph Hellwig Cc: luto@kernel.org, tglx@linutronix.de, hpa@zytor.com, bp@alien8.de, rric@kernel.org, peterz@infradead.org, mingo@redhat.com, x86@kernel.org, linux-kernel@vger.kernel.org, kernel@collabora.com Subject: Re: [PATCH 2/6] x86: Simplify compat syscall userspace allocation Organization: Collabora References: <20200912070553.330622-1-krisman@collabora.com> <20200912070553.330622-3-krisman@collabora.com> <20200912070802.GA19621@lst.de> Date: Sat, 12 Sep 2020 03:54:01 -0400 In-Reply-To: <20200912070802.GA19621@lst.de> (Christoph Hellwig's message of "Sat, 12 Sep 2020 09:08:02 +0200") Message-ID: <87zh5vmnvq.fsf@collabora.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.3 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Christoph Hellwig writes: > On Sat, Sep 12, 2020 at 03:05:49AM -0400, Gabriel Krisman Bertazi wrote: >> When allocating user memory space for a compat system call, don't >> consider whether the originating code is IA32 or X32, just allocate from >> a safe region for both, beyond the redzone. This should be safe for >> IA32, and has the benefit of avoiding TIF_IA32, which we want to drop. > > This doesn't look wrong, by why bother (maybe Ccing me on the whole > seris as you always should instead of sending annoying out of context > single patches would have told..). Hi Chris, Thanks for the quick reply. sorry and I will make sure to cc you for the rest of the series if this spin again. The reason is the removal of TIF_IA32 to reclaim some bits in the ti flags. If you want to see the rest of it immediately: > We will hopefully kill off compat_alloc_user_space in the next few > merge windows.. I plan to kill TIF_IA32 hopefully in the next merge window, to facilitate other work I'm doing and I wouldn't like to wait for other stuff, since this is trivial enough. Can I get your reviewed-by here? Thanks, -- Gabriel Krisman Bertazi