Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Date:   Fri, 19 Oct 2018 09:51:22 -0400
From:   Steven Rostedt <rostedt@goodmis.org>
To:     Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org>
Cc:     Joel Fernandes <joel@joelfernandes.org>,
        Stephen Boyd <sboyd@kernel.org>,
        Bjorn Andersson <bjorn.andersson@linaro.org>,
        Andy Gross <andy.gross@linaro.org>,
        David Brown <david.brown@linaro.org>,
        Jiri Slaby <jslaby@suse.com>,
        Kees Cook <keescook@chromium.org>,
        Geliang Tang <geliangtang@gmail.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Pramod Gurav <gpramod@codeaurora.org>,
        linux-arm-msm@vger.kernel.org, linux-soc@vger.kernel.org,
        linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org,
        Rajendra Nayak <rnayak@codeaurora.org>,
        Vivek Gautam <vivek.gautam@codeaurora.org>,
        Sibi Sankar <sibis@codeaurora.org>
Subject: Re: Crash in msm serial on dragonboard with ftrace bootargs
Message-ID: <20181019095122.0f1c0946@gandalf.local.home>
In-Reply-To: <8a75f2d5-f1bd-504e-b545-ae2e2f61ca8f@codeaurora.org>
References: <472db11e-49a6-a1ee-e298-791ee1bbb10b@codeaurora.org>
        <20181016141610.639b9000@gandalf.local.home>
        <accdce6d-8fd2-9f15-d4cd-704cbf0b32eb@codeaurora.org>
        <20181016144123.24c47b38@gandalf.local.home>
        <7781815e-cba2-9e36-db6d-268298747876@codeaurora.org>
        <20181016150328.3450d718@gandalf.local.home>
        <c94103d2-ed5d-bf43-fc71-c60e108f303e@codeaurora.org>
        <20181017223334.29ca2837@vmware.local.home>
        <58d2474c-53cd-e6cb-2d25-db38d1a88da6@codeaurora.org>
        <20181018091706.62310b38@gandalf.local.home>
        <20181019041740.GB141835@joelaf.mtv.corp.google.com>
        <8a75f2d5-f1bd-504e-b545-ae2e2f61ca8f@codeaurora.org>
MIME-Version: 1.0
Content-Type: text/plain; charset=US-ASCII
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On Fri, 19 Oct 2018 12:24:05 +0530
Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org> wrote:

> >> 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.
> >   
> 
> Yes I did add notrace to all functions in msm serial and checked the 
> objdump to make sure that those were not instrumented, and yet the 
> target crashed. This doesnt seem like an issue with ftrace but rather 
> with msm early con.

The thing that still bothers me is that it boots fine without ftrace
running, and that it requires tracing something to cause the problem.
This tells me that ftrace has something to do with it. Perhaps it's
just changing the timing.

You said that if you add 'ftrace_filter=msm_read' to the command line,
it still crashes?

So only tracing that function we have an issue, right?

-- Steve