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
| ||
|
Date: Thu, 26 Jun 2014 23:52:45 -0700
From: Martin Lau <kafai@...com>
To: Steven Rostedt <rostedt@...dmis.org>
CC: <linux-kernel@...r.kernel.org>, <clm@...com>
Subject: Re: [PATCH] ring-buffer: Fix polling on trace_pipe
Hi Steve,
I retried the test program (with the kernel patch). It does block from
time to time. I spotted the ee.events is not set to EPOLLIN before
calling epll_ctl(eft, EPOLL_CTL_ADD,...). I fixed it and ran
the test in a bash-loop.
I have the kafai-2 version attached (with some more logging in case
if it still blocks).
Can you retry?
Thanks,
Martin
On Thu, Jun 26, 2014 at 08:53:27PM -0400, Steven Rostedt wrote:
> On Thu, 26 Jun 2014 11:34:46 -0700
> Martin Lau <kafai@...com> wrote:
>
> > Hi Steve,
> >
> > Can the modified test program reproduce the problem in your test setup?
>
> Ah sorry, got distracted by other work.
>
> OK, I just tried it out, and here's my results:
>
> I ran you code with my current kernel and this is what I got:
>
> # ./ftrace-test-epoll-kafai
> <...>-3183 [002] ...1 81.777891: tracing_mark_write:
> some data 3183: waitting for more data......
> 3184: written more data
>
> And it just hung there.
>
>
> Then I applied your patch, compiled and booted it, and ran the test
> again, and I got this:
>
> # ./ftrace-test-epoll-kafai
>
> It just hung there. No forward progress.
>
> I don't think that was the result you intended.
>
> -- Steve
>
>
View attachment "ftrace-test-epoll-kafai-2.c" of type "text/plain" (2393 bytes)
Powered by blists - more mailing lists