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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E4851C433F5 for ; Mon, 31 Jan 2022 02:22:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1357368AbiAaCWE (ORCPT ); Sun, 30 Jan 2022 21:22:04 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41446 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1357364AbiAaCWE (ORCPT ); Sun, 30 Jan 2022 21:22:04 -0500 Received: from mail-pl1-x62e.google.com (mail-pl1-x62e.google.com [IPv6:2607:f8b0:4864:20::62e]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 11C7FC061714; Sun, 30 Jan 2022 18:22:04 -0800 (PST) Received: by mail-pl1-x62e.google.com with SMTP id x11so11238437plg.6; Sun, 30 Jan 2022 18:22:04 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=subject:to:references:cc:from:message-id:date:user-agent :mime-version:in-reply-to:content-transfer-encoding; bh=JGXTPagH6lGpW134YHUKaZWL6DYDw6uonUsSiyh80Mk=; b=mRIKsqAi6q6BRlmw319EOJWUNQPhRGX/WmZ8wWcIK/QsbIkuMzNBDKpusqXc1HDUFs vthGm5YCLFSMMuEYnrSbbofp/zx5jpf2zbm5wLlq6lMsOVVw0bY1Z3UJnzZFJvHbR6CL qZvNJOT0Ks9SD9fGX66M/gdiKoswTayxiT/6pemq0bvkwm/EJFEmJhwAtHaBQ3WpGF9H YQG7yrXFBCHvbh5+Mw6FCKQ4M/Nsbtrs7Q/aOlO4snXYQevufDhNmqrGDfjOHi2zKZKN oUrUTY1b9OuYu+VnUXrmzQoCt+R0o598mqBwEW/17Rzohhr9CvPmPyzJ/DPI+s2dgCBR E2SQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:subject:to:references:cc:from:message-id:date :user-agent:mime-version:in-reply-to:content-transfer-encoding; bh=JGXTPagH6lGpW134YHUKaZWL6DYDw6uonUsSiyh80Mk=; b=3idMjCb6FOz0WeLePf+pQ8czqxZawxXYW/fngh1vbNlrRt233lT6TZlH9ziKB63cVC C/TMSnZftuly/pol4Fa7KeqHS5Fva635Vm+BUl9gcgFTbCicDbxldwvUss/SEMcVLdtM KQb/dDajqegTSmVP3mLyN/PHC1wdLSh8Jz6jHIzs8nC4LtNQu7ovTmVvPxusjK4tfTpj 0ixCjD/1BbSxbe2jcpMzAWHaMT8aGhKd348OMXU6K+FqvWwgJALyGWoNLXHxebV3UR0e xZlRzGKOgb8BMOe0fnTS2DV5IniAQpi8eXqMWX4EpivudrykPUAMHXMUXP0ADsg/y1Sk prJA== X-Gm-Message-State: AOAM531YA2Ys4JmVwK0UTTsKOyMVtOxxchpsOXToioKuCTwsDFdkfFvK sHibkqlBDjqIHH4CdjyaLkpx13nMfhA= X-Google-Smtp-Source: ABdhPJxfVGdQ7TqBy9J72ktgIeLw7gfqrn+WSBi2i7rEhrm0tQ6SW7M2T3U1jV45tJx53m9usEbUmw== X-Received: by 2002:a17:902:bf06:: with SMTP id bi6mr18951344plb.24.1643595723326; Sun, 30 Jan 2022 18:22:03 -0800 (PST) Received: from [10.1.1.24] (222-155-5-102-adsl.sparkbb.co.nz. [222.155.5.102]) by smtp.gmail.com with ESMTPSA id f3sm15610628pfe.43.2022.01.30.18.21.59 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Sun, 30 Jan 2022 18:22:02 -0800 (PST) Subject: Re: [PATCH] m68k: mm: Remove check for VM_IO to fix deferred I/O To: Geert Uytterhoeven , linux-m68k@lists.linux-m68k.org References: <20220128173006.1713210-1-geert@linux-m68k.org> Cc: Andrew Morton , linux-mm@kvack.org, linux-fbdev@vger.kernel.org, linux-kernel@vger.kernel.org From: Michael Schmitz Message-ID: Date: Mon, 31 Jan 2022 15:21:57 +1300 User-Agent: Mozilla/5.0 (X11; Linux ppc; rv:45.0) Gecko/20100101 Icedove/45.4.0 MIME-Version: 1.0 In-Reply-To: <20220128173006.1713210-1-geert@linux-m68k.org> Content-Type: text/plain; charset=iso-8859-15; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-fbdev@vger.kernel.org Hi Geert, Am 29.01.2022 um 06:30 schrieb Geert Uytterhoeven: > When an application accesses a mapped frame buffer backed by deferred > I/O, it receives a segmentation fault. Fix this by removing the check > for VM_IO in do_page_fault(). > > Signed-off-by: Geert Uytterhoeven Works fine on my Falcon030 when applied to v5.16. Tested-by: Michael Schmitz > --- > This check was never present in a fault handler on any other > architecture than m68k. > Some digging revealed that it was added in v2.1.106, but I couldn't find > an email with a patch adding it. That same kernel version extended the > use of the hwreg_present() helper to HP9000/300, so the check might have > been needed there, perhaps only during development? > The Atari kernel relies heavily on hwreg_present() (both the success and > failure cases), and these still work, at least on ARAnyM. > --- > arch/m68k/mm/fault.c | 2 -- > 1 file changed, 2 deletions(-) > > diff --git a/arch/m68k/mm/fault.c b/arch/m68k/mm/fault.c > index 1493cf5eac1e7a39..71aa9f6315dc8028 100644 > --- a/arch/m68k/mm/fault.c > +++ b/arch/m68k/mm/fault.c > @@ -93,8 +93,6 @@ int do_page_fault(struct pt_regs *regs, unsigned long address, > vma = find_vma(mm, address); > if (!vma) > goto map_err; > - if (vma->vm_flags & VM_IO) > - goto acc_err; > if (vma->vm_start <= address) > goto good_area; > if (!(vma->vm_flags & VM_GROWSDOWN)) >