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=-6.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,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 9EB64C3A59E for ; Mon, 26 Aug 2019 05:36:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 64C8A217F4 for ; Mon, 26 Aug 2019 05:36:02 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=fossix-org.20150623.gappssmtp.com header.i=@fossix-org.20150623.gappssmtp.com header.b="nd0pExQX" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727866AbfHZFgB (ORCPT ); Mon, 26 Aug 2019 01:36:01 -0400 Received: from mail-pg1-f194.google.com ([209.85.215.194]:42470 "EHLO mail-pg1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725446AbfHZFgA (ORCPT ); Mon, 26 Aug 2019 01:36:00 -0400 Received: by mail-pg1-f194.google.com with SMTP id p3so9857525pgb.9 for ; Sun, 25 Aug 2019 22:36:00 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fossix-org.20150623.gappssmtp.com; s=20150623; h=from:to:cc:subject:in-reply-to:references:date:message-id :mime-version; bh=KdvhWx5STJQuh3h6H3k/gde8WO2PhkrNqGMLuEz+X7g=; b=nd0pExQXCUmwBnwOJDaiy3haAHBnMxeK18GFfX6DKysRajp/3+t/EoL2ktvKTIPeKU nCXANGDj7C2dqWaS5oxRVTnt87qrrAOD3/ZfUgkLnO3TM3nVDUxwSXJ15/gChK3CYZgw 07c304FGDN3hWgwsu5dCg/8wWOVu3wWXJbrxO5GzYIv2cpeaOVceYDIVrYCal/UwpkvP qkeMtnsAUxNidvn8t5zLMF9g29imsJGb4NQ1L4Z5JDFsbYO4hNcQCLMv7sKHp7g2D5FG 5ZOLEKcepdqtx6fYiz6z8bbncNalq8Jd3UlCPJLuvYpR278wnvLKJmxnnX1SkpVJG/Iu pJHA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:in-reply-to:references:date :message-id:mime-version; bh=KdvhWx5STJQuh3h6H3k/gde8WO2PhkrNqGMLuEz+X7g=; b=DOct9WzprmxHUUM7m9zur63mB7TJsTOmMsOfhkczdyoN8C3xdAlBUU4eUmkafFqsJl Xpg6ShHLG6rfZhqSRuos4R94pzDM4FUlCnZ7dJHsPP5SYvm0NZJj0ol8PGnb8SLGfRui Bfp0J9BA5PF7Ss4/PG4vl9+CoyCAF7ZWTgrflZvNr2t9SW3+oC0274KfuSyfflJ6qp7i nt6ABH3mNLzYhVTniHhxkHH5MDGgK8WfKNnZgePiIsBKpdTx3NiqKrHISWKwOI+NUw/p 6cstm+1MQFMPU6V5mhHnp17SFzEmLIIxQARx2/kkcMFViYx9tu2yck6iTR7APOvnspux HCDQ== X-Gm-Message-State: APjAAAUOqa+ExWms2jny3pUaOIcjnk2yCp/2BPRvhGKvnNUlOjSH9Sax xPU+BxAI9YGHnlczydLyFRJhXpSl710= X-Google-Smtp-Source: APXvYqzLbNe7kZu12nUvr9UjhYpZ1XPkr1S0moFNK89fzJ/s8JVOm7N4kheB0F+Id5psYyLjnP1AQw== X-Received: by 2002:a17:90a:cd04:: with SMTP id d4mr16762205pju.70.1566797760058; Sun, 25 Aug 2019 22:36:00 -0700 (PDT) Received: from localhost ([129.41.84.71]) by smtp.gmail.com with ESMTPSA id a128sm13260907pfb.185.2019.08.25.22.35.58 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 25 Aug 2019 22:35:59 -0700 (PDT) From: Santosh Sivaraj To: Christophe Leroy , Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] powerpc/mm: tell if a bad page fault on data is read or write. In-Reply-To: <4f88d7e6fda53b5f80a71040ab400242f6c8cb93.1566400889.git.christophe.leroy@c-s.fr> References: <4f88d7e6fda53b5f80a71040ab400242f6c8cb93.1566400889.git.christophe.leroy@c-s.fr> Date: Mon, 26 Aug 2019 11:05:56 +0530 Message-ID: <87k1b0ij43.fsf@santosiv.in.ibm.com> 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 Christophe Leroy writes: > DSISR has a bit to tell if the fault is due to a read or a write. > > Display it. > > Signed-off-by: Christophe Leroy Reviewed-by: Santosh Sivaraj > --- > arch/powerpc/mm/fault.c | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) > > diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c > index 8432c281de92..b5047f9b5dec 100644 > --- a/arch/powerpc/mm/fault.c > +++ b/arch/powerpc/mm/fault.c > @@ -645,6 +645,7 @@ NOKPROBE_SYMBOL(do_page_fault); > void bad_page_fault(struct pt_regs *regs, unsigned long address, int sig) > { > const struct exception_table_entry *entry; > + int is_write = page_fault_is_write(regs->dsisr); > > /* Are we prepared to handle this fault? */ > if ((entry = search_exception_tables(regs->nip)) != NULL) { > @@ -658,9 +659,10 @@ void bad_page_fault(struct pt_regs *regs, unsigned long address, int sig) > case 0x300: > case 0x380: > case 0xe00: > - pr_alert("BUG: %s at 0x%08lx\n", > + pr_alert("BUG: %s on %s at 0x%08lx\n", > regs->dar < PAGE_SIZE ? "Kernel NULL pointer dereference" : > - "Unable to handle kernel data access", regs->dar); > + "Unable to handle kernel data access", > + is_write ? "write" : "read", regs->dar); > break; > case 0x400: > case 0x480: > -- > 2.13.3