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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 97CD3C433F5 for ; Fri, 12 Nov 2021 21:23:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7C302610A2 for ; Fri, 12 Nov 2021 21:23:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235758AbhKLV03 (ORCPT ); Fri, 12 Nov 2021 16:26:29 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50738 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235697AbhKLV02 (ORCPT ); Fri, 12 Nov 2021 16:26:28 -0500 Received: from mail-ed1-x52e.google.com (mail-ed1-x52e.google.com [IPv6:2a00:1450:4864:20::52e]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 22235C061767 for ; Fri, 12 Nov 2021 13:23:37 -0800 (PST) Received: by mail-ed1-x52e.google.com with SMTP id t18so23455988edd.8 for ; Fri, 12 Nov 2021 13:23:37 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=KlmzwGFA4fDlxdznEeqdTaCKPH1HhGcx4T9b9UE3wT0=; b=TR0JF1xqWQNnVJgjHkpEeGZQS7s/t2K2iAUV/M5BITryofsnC2nBJAEeD93mztRcDh 4XHpddduh39keAcpxpXdklSUgSJOaYSHCquSplv+WY99UjS56D8uX56ssfgke1cBfkQZ 1ECpoP11aDxGLVpb9SQACE+cR71d0MuBmQ23Y= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=KlmzwGFA4fDlxdznEeqdTaCKPH1HhGcx4T9b9UE3wT0=; b=Asv+92T2ft0bGrLFU4Uasy7XZD0jt9St3377ebrtvIn5tWPUvbKAdiy80zFpkADOyi Bsi/STLI+gY0EqLV1nw6h88RbhJqx+V2TfnSHCmQkF77LuBRLGGKvq+GybqijpHMkghv IOCRBXHZo/zihfd0l6w6q2DZ0rrLOQ9iPiudigkDVlAR4lrhuzjM+LZ6vBNRlBlzlLQq UWi9l6+z+QlBIcFjNmDY/NY5pF6AinijVgnpiBZ153g05ssmuNqOVyz+EEwJnrJEDhSx ixeP0a1MvAnpJnOSUMVgWbv2Nnj5kCH3PUVm64ZyFg5lS6J18PEIJoL0tRkzA3pmswg7 ra8g== X-Gm-Message-State: AOAM532zq2D5YNn5G9sBPhL9FfMu2/LKp3qbKab80TEneTPDMfgR/dh0 gT5pOydMWQMk9+s9TNOjYr80VgMgfi3ZldGGoN4= X-Google-Smtp-Source: ABdhPJyvvT0vnmAS3AWyZsG5C3nSX8h38nf7itSKy2+RG5CIDFa8SKb0r5GIPiVtiU9A6EEl/8G2fA== X-Received: by 2002:a17:907:d94:: with SMTP id go20mr23133765ejc.78.1636752215027; Fri, 12 Nov 2021 13:23:35 -0800 (PST) Received: from mail-wr1-f44.google.com (mail-wr1-f44.google.com. [209.85.221.44]) by smtp.gmail.com with ESMTPSA id e12sm2965100ejs.86.2021.11.12.13.23.33 for (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 12 Nov 2021 13:23:33 -0800 (PST) Received: by mail-wr1-f44.google.com with SMTP id i5so17842060wrb.2 for ; Fri, 12 Nov 2021 13:23:33 -0800 (PST) X-Received: by 2002:adf:cf05:: with SMTP id o5mr22951337wrj.325.1636752212641; Fri, 12 Nov 2021 13:23:32 -0800 (PST) MIME-Version: 1.0 References: <87y26nmwkb.fsf@disp2133> <20211020174406.17889-9-ebiederm@xmission.com> <874k8htmb2.fsf@email.froward.int.ebiederm.org> <87ilwxrvu9.fsf@email.froward.int.ebiederm.org> <87ee7lqe6k.fsf@email.froward.int.ebiederm.org> In-Reply-To: <87ee7lqe6k.fsf@email.froward.int.ebiederm.org> From: Linus Torvalds Date: Fri, 12 Nov 2021 13:23:16 -0800 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH 09/20] signal/vm86_32: Replace open coded BUG_ON with an actual BUG_ON To: "Eric W. Biederman" Cc: Brian Gerst , Linux Kernel Mailing List , Oleg Nesterov , Al Viro , Kees Cook , Thomas Gleixner , Ingo Molnar , Borislav Petkov , "the arch/x86 maintainers" , H Peter Anvin , Andy Lutomirski Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Nov 12, 2021 at 1:04 PM Eric W. Biederman wrote: > > Still if we are going to check for userspace being silly that it should > be in do_sys_vm86. Sore, something like if (!user_vm86) return -EINVAL; in do_sys_vm86() sounds fine to me. It could in theory break some odd test-case, but I can't see anybody putting the vm86 save area at 0 in a real situation. But I could see some quick test hack doing it - the IVT at boot is actually not at zero, but at fffxxxxx. 8086 is magic. Linus