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=-1.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_PASS autolearn=ham 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 9F81EC43381 for ; Thu, 7 Mar 2019 19:07:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6D73820675 for ; Thu, 7 Mar 2019 19:07:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1551985633; bh=xUQpkflw/lleDy8DtQBoKdYhV0IIr3oEasuhYJKVhXU=; h=References:In-Reply-To:From:Date:Subject:To:Cc:List-ID:From; b=Bc1L79jG2tTYItvN0Nu1FL0gjezqrV70e4Cbm4LFuEmFAulSaNLssY20PRGhaNM5h 6jGwzr1fqIyBMjRrQVr6iuCAPiQFJmKCy5OsyiVV6MnIvxCOd4L95CsmKtuB/ny0uq //ZGtf5nvXjd8nlm3vxyPzzy7LWjZC2gldBg8PXI= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726552AbfCGTHL (ORCPT ); Thu, 7 Mar 2019 14:07:11 -0500 Received: from mail.kernel.org ([198.145.29.99]:33380 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726127AbfCGTHL (ORCPT ); Thu, 7 Mar 2019 14:07:11 -0500 Received: from mail-wm1-f50.google.com (mail-wm1-f50.google.com [209.85.128.50]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 6373D20879 for ; Thu, 7 Mar 2019 19:07:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1551985630; bh=xUQpkflw/lleDy8DtQBoKdYhV0IIr3oEasuhYJKVhXU=; h=References:In-Reply-To:From:Date:Subject:To:Cc:From; b=MQWTcQNrxXs40b9iel8ZXoBNgMhUYD0iKoVEJojuX23yICstqRzq7TCTnHzuwoYz4 kjgLiOZDz8Qjlu1Em0Ua1YooprbSOPqHzhVF69vZGAyHbBIKG9tqClGSLNjj7aBJzG kQyO9OI2WRXBKBZ2gkDPyo6c1WiYLc8TJ97AYkuo= Received: by mail-wm1-f50.google.com with SMTP id x10so10277844wmg.2 for ; Thu, 07 Mar 2019 11:07:10 -0800 (PST) X-Gm-Message-State: APjAAAWBkR8qjjsKFRK+bjMRYjbavRJPAv/NP3NUwoKkdN2y+LuVIJ0l ihR9R1UNDDB1nDHf6PBB8G8dVikYx2LF2ih7gWYInw== X-Google-Smtp-Source: APXvYqzo4Ns5h0u4buT0c9QRjKer1un+yQxFMHoSGcRD2HAdGIwknv1ta6WvfhD/XU00s0Jb3GXvuDca3ANCLWlatYQ= X-Received: by 2002:a1c:7906:: with SMTP id l6mr6491195wme.83.1551985628850; Thu, 07 Mar 2019 11:07:08 -0800 (PST) MIME-Version: 1.0 References: <20190307114511.870090179@infradead.org> <20190307115159.708180729@infradead.org> <20190307185922.GA2482@worktop.programming.kicks-ass.net> In-Reply-To: <20190307185922.GA2482@worktop.programming.kicks-ass.net> From: Andy Lutomirski Date: Thu, 7 Mar 2019 11:06:57 -0800 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH 07/20] x86/uaccess: Always inline force_valid_ss() To: Peter Zijlstra Cc: Linus Torvalds , Thomas Gleixner , "H. Peter Anvin" , Julien Thierry , Will Deacon , Ingo Molnar , Catalin Marinas , James Morse , valentin.schneider@arm.com, Brian Gerst , Josh Poimboeuf , Andrew Lutomirski , Borislav Petkov , Denys Vlasenko , LKML , Dmitry Vyukov , Steven Rostedt Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Mar 7, 2019 at 10:59 AM Peter Zijlstra wrote: > > On Thu, Mar 07, 2019 at 10:05:43AM -0800, Andy Lutomirski wrote: > > On Thu, Mar 7, 2019 at 3:52 AM Peter Zijlstra wrote: > > > > > > arch/x86/kernel/signal.o: warning: objtool: restore_sigcontext()+0x3cc: call to force_valid_ss.isra.5() with UACCESS enabled > > > > > > XXX: move the callsite out of te AC=1 region instead? > > > > Let's move it instead. I looked at the code and it should be fine. > > Something like so; or did I miss something subtle? Reviewed-by: Andy Lutomirski Also, this stuff is pretty well covered by the x86 selftests, mostly because getting it right in the first place was way too subtle for comfort. --Andy