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 0C73AC46475 for ; Thu, 25 Oct 2018 19:01:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B032A2082E for ; Thu, 25 Oct 2018 19:01:39 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="cVndotcq" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B032A2082E 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 S1727687AbeJZDfh (ORCPT ); Thu, 25 Oct 2018 23:35:37 -0400 Received: from mail-pf1-f196.google.com ([209.85.210.196]:41430 "EHLO mail-pf1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727466AbeJZDfh (ORCPT ); Thu, 25 Oct 2018 23:35:37 -0400 Received: by mail-pf1-f196.google.com with SMTP id a19-v6so4641025pfo.8 for ; Thu, 25 Oct 2018 12:01:37 -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=8S9m4MWvb18JXBx4d0GbFiXW2VAIEnxv/Q8oXWj2Ak0=; b=cVndotcqgTFj7NSdQ+sn8ZhQ2N0swYhKxJBiuGmQRCE8EiMnkqZ2eFquAYzvHGOV0G TVY5g+iz4fCnnDHFo7MGWpZ9/zVLhxwv5QoiufQPMKlZq3ywngut0pLA5RXbq5pTkv/D gJSpH4Tt6IqZAmv/h9kiWeEOmThT/thI/xIHonZRdLgfMwjceB89FsUi+qjCmqmAAjB5 WCa0GBinb6DZGl998EeM5ilxGPxJbp1fNfSoFaueFacGfRovnGf8W9jAw+QRgXbfswz6 mKmC1ZCqPaIvOfV1MpBoDlNMxyTpJOhdI7e/KJvIe/8KSzcNms4CDR+knSj2iEMiKruI 5DXg== 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=8S9m4MWvb18JXBx4d0GbFiXW2VAIEnxv/Q8oXWj2Ak0=; b=WQTkR6aH1EY0sjuBzo13YTeh4zA4r3wMbQx+bdWS95oKkInYYmPGYpLWQRLfU4G4Te aVH735vZcmWQ28NvFXyG4K4MJdK8oFNP1cL0QqT93t73kscychGUE0wV4LOowvRnnUMP 3tvuT9X9/PBUaaANNBcr7Mit1XqTrCYinOYUQTMlOnwGNAAILHSKVwlBGjFOSzGozNiB 2obuRbwTsKTYDc1laLc8I+m3HQkcXHteA+/5tpsdWCaCm25QiJC/e2dOaocG3PSyZdpW d1+KEQUU87c2eyh3pTgZH/Dlx99mhkXl5XA2dO3LGiGszf/Uq1OBb1zB8ZpQZRO0RnBa +Z0g== X-Gm-Message-State: AGRZ1gLuKueb8CxZMzf/8gIZQUd34eQAiOgTtKoE4UZFr87Ljb1cWVNu oytSRvc77mE1M1dShp3sq0U= X-Google-Smtp-Source: AJdET5cQxkvQ/Bmi/oGSgGe2n6DEcnbc5bXDaj39dl1SG/77ZQExlJB9I6wx6dLFLTJ78QA5YsLIJQ== X-Received: by 2002:a62:9fc4:: with SMTP id v65-v6mr415074pfk.130.1540494097110; Thu, 25 Oct 2018 12:01:37 -0700 (PDT) Received: from fainelli-desktop.igp.broadcom.net ([192.19.223.250]) by smtp.gmail.com with ESMTPSA id l129-v6sm12163415pfc.155.2018.10.25.12.01.35 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 25 Oct 2018 12:01:35 -0700 (PDT) From: Florian Fainelli To: linux-arm-kernel@lists.infradead.org Cc: andrew@lunn.ch, ebiederm@xmission.com, Florian Fainelli , Russell King , Andrew Morton , Souptick Joarder , Tony Lindgren , linux-kernel@vger.kernel.org (open list) Subject: [PATCH v2] ARM: mm: Facilitate debugging CONFIG_KUSER_HELPERS disabled Date: Thu, 25 Oct 2018 12:01:08 -0700 Message-Id: <20181025190110.7564-1-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 | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/arch/arm/mm/fault.c b/arch/arm/mm/fault.c index f4ea4c62c613..58f69fa07df9 100644 --- a/arch/arm/mm/fault.c +++ b/arch/arm/mm/fault.c @@ -173,6 +173,12 @@ __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_ratelimited(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