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=-2.4 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS, URIBL_BLOCKED,USER_AGENT_MUTT 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 80948ECDE3D for ; Fri, 19 Oct 2018 04:17:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 353752145D for ; Fri, 19 Oct 2018 04:17:46 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=joelfernandes.org header.i=@joelfernandes.org header.b="RKBgQm2O" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 353752145D Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=joelfernandes.org 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 S1726566AbeJSMV7 (ORCPT ); Fri, 19 Oct 2018 08:21:59 -0400 Received: from mail-pl1-f196.google.com ([209.85.214.196]:32787 "EHLO mail-pl1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726648AbeJSMV7 (ORCPT ); Fri, 19 Oct 2018 08:21:59 -0400 Received: by mail-pl1-f196.google.com with SMTP id s4-v6so15302112plp.0 for ; Thu, 18 Oct 2018 21:17:43 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=joelfernandes.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=Lb9ipAF0X1qc723pxRiwYkaTJTsvnjoQaz9AFLyOAZA=; b=RKBgQm2OiQy/H7CBecA3mc+edR3ZXQctYAMSTHRyWoGBUUYxO4FRqn4malIDOpUj13 3NmOjoy9RUo1CUyaMFtu3htE+efy87qPVh4oeW+4cORSH2byR6VYl6sFOJwWgpru7IUm fdnSooqjt4Xttxti6+qDXenJTZr/v6lhqMBQY= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=Lb9ipAF0X1qc723pxRiwYkaTJTsvnjoQaz9AFLyOAZA=; b=Ten9PFf1QnGilyQ/ulYpMG+7HCCaPvgy7hzUr95rTbGP0wPf6Fq5IkWn7/tONPEDVe j2YJsQqnmBof7LhZzJ3u3yVx3dZ8+92sHvLghPjqP6Ji3MfOh4X3P8RjyvXzdYJtp6or rq8BDoazTGDU+j5/4ALtbFoLB8G+jNHlzTUaOyJ19Fa78aBOCkUkuOqjfswpV1wODull pIVK7uzUEjPnp/P4eKmr95c2sGmZxP9BUl0w/9tDKK/JBgtTjwSjjsmgqTOWaOqMwvdD PQzBHemOgKZUFsOaI2NBzEMCXPfBLggvYqkZQIv0LRess+2wDtiNn3Ein+lEIW2/iq1N BWrQ== X-Gm-Message-State: ABuFfogC5fhgTRlVtCDcWz76C+u5EcR2KSNCNeUdoDyXCpxsF8GerOsh wK4yzh+y68ui/ydc5knYPvKSSg== X-Google-Smtp-Source: ACcGV61z6Rp3Ocm3Sq0dX8QJPRSkSUYdG0WCat4yu2dbR33yb0H29Y8yxZxvklQhDryzgO3x5Fi+7g== X-Received: by 2002:a17:902:7109:: with SMTP id a9-v6mr32463219pll.310.1539922662831; Thu, 18 Oct 2018 21:17:42 -0700 (PDT) Received: from localhost ([2620:0:1000:1601:3aef:314f:b9ea:889f]) by smtp.gmail.com with ESMTPSA id 189-v6sm25701022pfe.121.2018.10.18.21.17.40 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Thu, 18 Oct 2018 21:17:41 -0700 (PDT) Date: Thu, 18 Oct 2018 21:17:40 -0700 From: Joel Fernandes To: Steven Rostedt Cc: Sai Prakash Ranjan , Stephen Boyd , Bjorn Andersson , Andy Gross , David Brown , Jiri Slaby , Kees Cook , Geliang Tang , Greg Kroah-Hartman , Pramod Gurav , linux-arm-msm@vger.kernel.org, linux-soc@vger.kernel.org, linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org, Rajendra Nayak , Vivek Gautam , Sibi Sankar Subject: Re: Crash in msm serial on dragonboard with ftrace bootargs Message-ID: <20181019041740.GB141835@joelaf.mtv.corp.google.com> References: <472db11e-49a6-a1ee-e298-791ee1bbb10b@codeaurora.org> <20181016141610.639b9000@gandalf.local.home> <20181016144123.24c47b38@gandalf.local.home> <7781815e-cba2-9e36-db6d-268298747876@codeaurora.org> <20181016150328.3450d718@gandalf.local.home> <20181017223334.29ca2837@vmware.local.home> <58d2474c-53cd-e6cb-2d25-db38d1a88da6@codeaurora.org> <20181018091706.62310b38@gandalf.local.home> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20181018091706.62310b38@gandalf.local.home> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Oct 18, 2018 at 09:17:06AM -0400, Steven Rostedt wrote: > On Thu, 18 Oct 2018 10:51:18 +0530 > Sai Prakash Ranjan wrote: > > > > So something else is causing an issue besides just msm_read. > > > > > > Can you do an objdump -dr of the entire vmlinux binary and gzip it and > > > post it somewhere. Not sure if it would be too big to email. You could > > > try sending it to me privately. I'd like to see the binary that you are > > > using. > > > > > > > I have sent the objdump and dot config to you privately. > > Thanks. I don't see anything that pops out, but then again, my arm asm > foo is very rusty (it has been literally decades since I did any arm > asm). I wonder if it could simply be a timing issue? > > ffff0000086eb538 : > ffff0000086eb538: a9be7bfd stp x29, x30, [sp,#-32]! > ffff0000086eb53c: 910003fd mov x29, sp > ffff0000086eb540: a90153f3 stp x19, x20, [sp,#16] > ffff0000086eb544: aa0003f4 mov x20, x0 > ffff0000086eb548: 2a0103f3 mov w19, w1 > ffff0000086eb54c: aa1e03e0 mov x0, x30 > ffff0000086eb550: 97e6bae4 bl ffff00000809a0e0 <_mcount> > > The above is changed to nop on boot, but then to: > > bl ftrace_caller > > When ftrace is enabled. > > ffff0000086eb554: 8b334280 add x0, x20, w19, uxtw > ffff0000086eb558: b9400000 ldr w0, [x0] > ffff0000086eb55c: a94153f3 ldp x19, x20, [sp,#16] > ffff0000086eb560: a8c27bfd ldp x29, x30, [sp],#32 > ffff0000086eb564: d65f03c0 ret > > > > ffff00000809a0e4 : > ffff00000809a0e4: a9bf7bfd stp x29, x30, [sp,#-16]! > ffff00000809a0e8: 910003fd mov x29, sp > ffff00000809a0ec: d10013c0 sub x0, x30, #0x4 > ffff00000809a0f0: f94003a1 ldr x1, [x29] > ffff00000809a0f4: f9400421 ldr x1, [x1,#8] > ffff00000809a0f8: d1001021 sub x1, x1, #0x4 > > ffff00000809a0fc : > ffff00000809a0fc: d503201f nop > > The above nop gets patched to: > > bl ftrace_ops_no_ops > > Which will iterate through all the registered functions. > > > ffff00000809a100 : > ffff00000809a100: d503201f nop > > The above only gets set when function graph tracer is enabled, which it > is not in this case. > > ffff00000809a104: a8c17bfd ldp x29, x30, [sp],#16 > ffff00000809a108: d65f03c0 ret > > > Anyone see any problems here? This seems sane to me, he says in the other thread that he put 'notrace' to the msm serial functions (which AIUI should prevent ftrace instrumentation) and he still sees the issue. thanks, - Joel