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=-8.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 3E968C46475 for ; Thu, 25 Oct 2018 18:10:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0991C2084A for ; Thu, 25 Oct 2018 18:10:27 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="PPP1QGWm" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0991C2084A Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727802AbeJZCoP (ORCPT ); Thu, 25 Oct 2018 22:44:15 -0400 Received: from mail-wm1-f67.google.com ([209.85.128.67]:33051 "EHLO mail-wm1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727610AbeJZCoP (ORCPT ); Thu, 25 Oct 2018 22:44:15 -0400 Received: by mail-wm1-f67.google.com with SMTP id y140-v6so2489109wmd.0 for ; Thu, 25 Oct 2018 11:10:25 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id; bh=Lp/ggYCV1jr9KpgGQVrAqczAG346LMz0SpCFm0bs1EQ=; b=PPP1QGWmRXijA4JApHN5W8asoiJONMCcY0VBUp/2YLgzcxAm3vieEfPnijvkHWGXaS UsDnJKF1BBDnaAi/0U9NIlyXrWBMb7bvlFv5kkN8jLBMbwfBC4oOP8caNvnVcGi/FfIm XIcJEOpv5NkRQQcubpExSnj995vupH/CWyo0fmeuqr+wCTdosG7wAsff8PiQSQuhoJA2 OHIzPdWirzO6mXyCR5yYnwfBP/fccCnOKeT1kxa/YZ2SwvOWYL8TF6lXM97pu2v2sPDJ EU06sdw7AX0Ue0jXiIsEItvmVUtZ889AgJnAuqiDfTOeQO7YGTThv9oFIM6XXkVpX8hR PpSg== 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:date:message-id; bh=Lp/ggYCV1jr9KpgGQVrAqczAG346LMz0SpCFm0bs1EQ=; b=bkzxee9U7hYJRobBimLdco++S+2VMZ4YmcvxaFVDuegLFMZuOSBoktX+svON/RpJt9 J3EAK7de/zAOs2xtfDwjQDlRo4+CUDzse+DiMUXLHcbDNbvW6VBtuEU7q22JHhFgiHXw iHSgifYXFSwClfGm83Wt2/jiIrtSH72eepqtE9rJc5HRtaa8IYw00n8+aKjEk7U9fW96 F12q8dBaI+MGLda5/UO/FQmSbpyzFsMOzkXjQeHGjV4JkEEuLwF/sGKHt70Q4Zy2afXF mfxeD++mKzrABA+dC55oBlaSEtKs2a3LOVLaT8lPMByX43b27+/EjH1JCHm0+srTwGU7 KbVg== X-Gm-Message-State: AGRZ1gLi25NTMy9Yc7M1L7B2PVRU9gMhb4lPhpRgaMyUkRf2n8t8d4MW sfbn3dFzH9UqjaklKAEY832ZkoRe X-Google-Smtp-Source: AJdET5fopElO/mQ9FVw/sgjAp4nqvW4/VzD0ARro6u6ATV5GZfsZo6vR94amr6oX+gWnp8PgL2d2yw== X-Received: by 2002:a1c:3c82:: with SMTP id j124-v6mr2131321wma.62.1540491024159; Thu, 25 Oct 2018 11:10:24 -0700 (PDT) Received: from fainelli-desktop.igp.broadcom.net ([192.19.223.250]) by smtp.gmail.com with ESMTPSA id m136-v6sm2432291wmb.4.2018.10.25.11.10.21 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 25 Oct 2018 11:10:23 -0700 (PDT) From: Florian Fainelli To: linux-arm-kernel@lists.infradead.org Cc: andrew@lunn.ch, Florian Fainelli , Russell King , "Eric W. Biederman" , Tony Lindgren , Souptick Joarder , linux-kernel@vger.kernel.org (open list) Subject: [PATCH] ARM: mm: Facilitate debugging CONFIG_KUSER_HELPERS disabled Date: Thu, 25 Oct 2018 11:09:55 -0700 Message-Id: <20181025180957.7900-1-f.fainelli@gmail.com> X-Mailer: git-send-email 2.17.1 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Some software such as perf makes unconditional use of the special [vectors] page which is only provided when CONFIG_KUSER_HELPERS is enabled in the kernel. Facilitate the debugging of such situations by printing a debug message to the kernel log showing the task name and the faulting address. Suggested-by: Russell King Signed-off-by: Florian Fainelli --- arch/arm/mm/fault.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/arch/arm/mm/fault.c b/arch/arm/mm/fault.c index f4ea4c62c613..f17471fbc1c4 100644 --- a/arch/arm/mm/fault.c +++ b/arch/arm/mm/fault.c @@ -173,6 +173,11 @@ __do_user_fault(struct task_struct *tsk, unsigned long addr, show_regs(regs); } #endif +#ifndef CONFIG_KUSER_HELPERS + if ((sig == SIGSEGV) && ((addr & PAGE_MASK) == 0xffff0000)) + printk(KERN_DEBUG "%s: CONFIG_KUSER_HELPERS disabled at 0x%08lx\n", + tsk->comm, addr); +#endif tsk->thread.address = addr; tsk->thread.error_code = fsr; -- 2.17.1