{"id":808653,"url":"http://patchwork.ozlabs.org/api/patches/808653/?format=json","web_url":"http://patchwork.ozlabs.org/project/linux-arc/patch/d2b588da61b35312a3126b605685f22bc30fc3ae.1504265945.git.joabreu@synopsys.com/","project":{"id":48,"url":"http://patchwork.ozlabs.org/api/projects/48/?format=json","name":"Linux ARC development","link_name":"linux-arc","list_id":"linux-snps-arc.lists.infradead.org","list_email":"linux-snps-arc@lists.infradead.org","web_url":"","scm_url":"","webscm_url":"","list_archive_url":"","list_archive_url_format":"","commit_url_format":""},"msgid":"","list_archive_url":null,"date":"2017-09-01T11:39:57","name":"arc: Re-enable MMU upon die()","commit_ref":null,"pull_url":null,"state":"new","archived":false,"hash":"82cab7bcb92fd6af21b9c146d52fef4d3ab812f8","submitter":{"id":68387,"url":"http://patchwork.ozlabs.org/api/people/68387/?format=json","name":"Jose Abreu","email":"Jose.Abreu@synopsys.com"},"delegate":null,"mbox":"http://patchwork.ozlabs.org/project/linux-arc/patch/d2b588da61b35312a3126b605685f22bc30fc3ae.1504265945.git.joabreu@synopsys.com/mbox/","series":[{"id":1009,"url":"http://patchwork.ozlabs.org/api/series/1009/?format=json","web_url":"http://patchwork.ozlabs.org/project/linux-arc/list/?series=1009","date":"2017-09-01T11:39:57","name":"arc: Re-enable MMU upon die()","version":1,"mbox":"http://patchwork.ozlabs.org/series/1009/mbox/"}],"comments":"http://patchwork.ozlabs.org/api/patches/808653/comments/","check":"pending","checks":"http://patchwork.ozlabs.org/api/patches/808653/checks/","tags":{},"related":[],"headers":{"Return-Path":"","X-Original-To":"incoming@patchwork.ozlabs.org","Delivered-To":"patchwork-incoming@bilbo.ozlabs.org","Authentication-Results":["ozlabs.org; spf=none (mailfrom)\n\tsmtp.mailfrom=lists.infradead.org (client-ip=65.50.211.133;\n\thelo=bombadil.infradead.org;\n\tenvelope-from=linux-snps-arc-bounces+incoming=patchwork.ozlabs.org@lists.infradead.org;\n\treceiver=)","ozlabs.org; dkim=pass (2048-bit key;\n\tunprotected) header.d=lists.infradead.org\n\theader.i=@lists.infradead.org header.b=\"kosqEL+e\"; \n\tdkim-atps=neutral"],"Received":["from bombadil.infradead.org (bombadil.infradead.org\n\t[65.50.211.133])\n\t(using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256\n\tbits)) (No client certificate requested)\n\tby ozlabs.org (Postfix) with ESMTPS id 3xkHNw2Tgrz9sRV\n\tfor ;\n\tFri, 1 Sep 2017 21:40:32 +1000 (AEST)","from localhost ([127.0.0.1] helo=bombadil.infradead.org)\n\tby bombadil.infradead.org with esmtp (Exim 4.87 #1 (Red Hat Linux))\n\tid 1dnkJK-0001Xv-Vy; Fri, 01 Sep 2017 11:40:31 +0000","from smtprelay4.synopsys.com ([198.182.47.9]\n\thelo=smtprelay.synopsys.com)\n\tby bombadil.infradead.org with esmtps (Exim 4.87 #1 (Red Hat Linux))\n\tid 1dnkJI-0001Dd-9r for linux-snps-arc@lists.infradead.org;\n\tFri, 01 Sep 2017 11:40:29 +0000","from mailhost.synopsys.com (mailhost1.synopsys.com [10.12.238.239])\n\tby smtprelay.synopsys.com (Postfix) with ESMTP id 8A09D24E0E0A\n\tfor ;\n\tFri, 1 Sep 2017 04:40:05 -0700 (PDT)","from mailhost.synopsys.com (localhost [127.0.0.1])\n\tby mailhost.synopsys.com (Postfix) with ESMTP id 70809CB9;\n\tFri, 1 Sep 2017 04:40:05 -0700 (PDT)","from joabreu-VirtualBox.internal.synopsys.com\n\t(joabreu-e7440.internal.synopsys.com [10.107.19.75])\n\tby mailhost.synopsys.com (Postfix) with ESMTP id 4C84DC9B;\n\tFri, 1 Sep 2017 04:40:04 -0700 (PDT)"],"DKIM-Signature":"v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed;\n\td=lists.infradead.org; s=bombadil.20170209; h=Sender:\n\tContent-Transfer-Encoding:Content-Type:MIME-Version:Cc:List-Subscribe:\n\tList-Help:List-Post:List-Archive:List-Unsubscribe:List-Id:Message-Id:Date:\n\tSubject:To:From:Reply-To:Content-ID:Content-Description:Resent-Date:\n\tResent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:\n\tReferences:List-Owner; bh=1/dXjpwrS+3pM5hjpMvMHg2oTBcE4zKgMxKh2xK7wZQ=;\n\tb=kos\n\tqEL+e+IsF8+vIHQb9DRSltHFHIPNDdiUmbD7Gbz7QC3/un/zchIhGmXsZ1kdwLcttq9Hw1c6oaL3w\n\tgQmiHFFE84rDB8/TaUPYwvkpp+YDNvT+218uNH9JZcShVPUxUZMlkHvhlmhiHGkxD5YXZ2ecHq1C1\n\t9SOKW95IjjCyaEXhQm0R9uEz08J8+UjJQoDoYIY3sd4PO7FuvIlEH0ji585uPJxfujPlEAW00HTKR\n\trH5SgEq2iRF/rVqpdU0Jqglnl+uqtaMb4iQzdZbcIFgRvN3UUeYmnvxnRzczzMZ1dzkaDMsEMog99\n\ta+haI79jCxcclNF25cE0lceMa6zpQQw==;","From":"Jose Abreu ","To":"linux-snps-arc@lists.infradead.org","Subject":"[PATCH] arc: Re-enable MMU upon die()","Date":"Fri, 1 Sep 2017 12:39:57 +0100","Message-Id":"","X-Mailer":"git-send-email 1.9.1","X-CRM114-Version":"20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 ","X-CRM114-CacheID":"sfid-20170901_044028_356723_93DE8E1E ","X-CRM114-Status":"UNSURE ( 7.82 )","X-CRM114-Notice":"Please train this message.","X-Spam-Score":"-1.9 (-)","X-Spam-Report":"SpamAssassin version 3.4.1 on bombadil.infradead.org summary:\n\tContent analysis details: (-1.9 points)\n\tpts rule name description\n\t---- ----------------------\n\t--------------------------------------------------\n\t-0.0 RCVD_IN_DNSWL_NONE RBL: Sender listed at http://www.dnswl.org/,\n\tno trust [198.182.47.9 listed in list.dnswl.org]\n\t-0.0 RP_MATCHES_RCVD Envelope sender domain matches handover relay\n\tdomain\n\t-1.9 BAYES_00 BODY: Bayes spam probability is 0 to 1%\n\t[score: 0.0000]","X-BeenThere":"linux-snps-arc@lists.infradead.org","X-Mailman-Version":"2.1.21","Precedence":"list","List-Id":"Linux on Synopsys ARC Processors\n\t","List-Unsubscribe":", \n\t","List-Archive":"","List-Post":"","List-Help":"","List-Subscribe":", \n\t","Cc":"Jose Abreu ,\n\tVineet Gupta ,\n\tAlexey Brodkin ","MIME-Version":"1.0","Content-Type":"text/plain; charset=\"us-ascii\"","Content-Transfer-Encoding":"7bit","Sender":"\"linux-snps-arc\" ","Errors-To":"linux-snps-arc-bounces+incoming=patchwork.ozlabs.org@lists.infradead.org"},"content":"I recently came upon a scenario where I would get a double fault\nafter a machine check error. It turns out that for Ksymbol lookup\nto work with modules we need to have MMU enabled because module\naddress is mapped in the cached space.\n\nThis patch re-enables the MMU before start printing the stacktrace\nmaking stacktracing of modules work upon a fatal exception.\n\nSigned-off-by: Jose Abreu \nCc: Vineet Gupta \nCc: Alexey Brodkin \n---\n arch/arc/kernel/traps.c | 5 +++++\n 1 file changed, 5 insertions(+)","diff":"diff --git a/arch/arc/kernel/traps.c b/arch/arc/kernel/traps.c\nindex ff83e78..9533e06 100644\n--- a/arch/arc/kernel/traps.c\n+++ b/arch/arc/kernel/traps.c\n@@ -19,6 +19,8 @@\n #include \n #include \n #include \n+#include \n+#include \n #include \n #include \n #include \n@@ -30,6 +32,9 @@ void __init trap_init(void)\n \n void die(const char *str, struct pt_regs *regs, unsigned long address)\n {\n+\t/* MMU must be enabled for Ksymbol lookup in modules */\n+\twrite_aux_reg(ARC_REG_PID, MMU_ENABLE | read_aux_reg(ARC_REG_PID));\n+\n \tshow_kernel_fault_diag(str, regs, address);\n \n \t/* DEAD END */\n","prefixes":[]}