linux-kernel - Re: Hard lockup with timer events

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]

Date:	Wed, 11 Nov 2009 05:50:09 +0100
From:	Frederic Weisbecker <fweisbec@...il.com>
To:	Soeren Sandmann <sandmann@...mi.au.dk>
Cc:	linux-kernel@...r.kernel.org, mingo@...e.hu,
	a.p.zijlstra@...llo.nl, tglx@...utronix.de, acme@...hat.com,
	rosted@...dmis.org, paulus@...ba.org
Subject: Re: Hard lockup with timer events

On Thu, Oct 29, 2009 at 08:15:03PM +0100, Soeren Sandmann wrote:
> Hi,
> 
> This program
> 
>         http://www.daimi.au.dk/~sandmann/lockup.c
> 
> locks up hard for me on a Pentium 4 in 32 bit mode, with the hrtimer
> patches applied (-tip for example).
> 
> What the program does is spawn a thread that just spins, and then 400
> threads that each create a performance counter of type
> PERF_COUNT_SW_CPU_CLOCK and a sample period of 1000000 and a
> sample_type of
> 
>         PERF_SAMPLE_IP | PERF_SAMPLE_TID | PERF_SAMPLE_CALLCHAIN
> 
> These threads then map the event buffer and read it continuously.
> 
> It does not apparently lock up if SAMPLE_CALLCHAIN is removed; also I
> cannot get it to lock up on Core 2 Duo in either 32 or 64 bit mode.
> 
> 
> Soren



It locks up hard for me too, no more blinking cursor, nothing.
I've attached my config, it's against tip:master from yesterday.

Indeed it happens only with callchains enabled.
The nmi watchdog doesn't report anything. I will retry with
early_printk=vga (I don't have any serial line in my laptop).



View attachment ".config" of type "text/plain" (56885 bytes)