linux-kernel - Re: [PATCH] kselftests: ftrace: limit the executing time by reading from cached trace

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20211026211331.8496340b0011127e6505b5ff@kernel.org>
Date:   Tue, 26 Oct 2021 21:13:31 +0900
From:   Masami Hiramatsu <mhiramat@...nel.org>
To:     Steven Rostedt <rostedt@...dmis.org>
Cc:     Li Zhijian <lizhijian@...fujitsu.com>, <mingo@...hat.com>,
        <shuah@...nel.org>, <linux-kselftest@...r.kernel.org>,
        <linux-kernel@...r.kernel.org>, Philip Li <philip.li@...el.com>,
        kernel test robot <lkp@...el.com>
Subject: Re: [PATCH] kselftests: ftrace: limit the executing time by reading
 from cached trace

On Mon, 25 Oct 2021 22:17:17 -0400
Steven Rostedt <rostedt@...dmis.org> wrote:

> On Thu, 21 Oct 2021 09:31:31 +0900
> Masami Hiramatsu <mhiramat@...nel.org> wrote:
> 
> > > > +# Stop tracing while reading the trace file by default, to prevent
> > > > +# the test results while checking it and to avoid taking a long time
> > > > +# to check the result.
> > > > +    [ -f options/pause-on-trace ] && echo 1 > options/pause-on-trace
> > > > +  
> > > 
> > > Is there a way we can save the previous setting and put it back on reset?  
> > 
> > No, since each testcase must be run under the clean state. Would we need to
> > recover the settings?
> 
> I would at least put it back to the default. If someone runs the tests,
> it should at least put it back to what it was at boot. Otherwise,
> someone might run the tests, and then wonder why events are being
> dropped when they are reading the trace.

Umm, we may need to have a knob to reset the ftrace options...
Can we warn such user that if the ftracetest finds that the current
value is not the same what it sets?

Thank you,

-- 
Masami Hiramatsu <mhiramat@...nel.org>