linux-kernel - Re: do_boot_cpu can deadlock?

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:	Thu, 23 Oct 2008 23:51:19 +0530
From:	Gautham R Shenoy <ego@...ibm.com>
To:	Oleg Nesterov <oleg@...hat.com>
Cc:	Rusty Russell <rusty@...tcorp.com.au>,
	linux-kernel@...r.kernel.org, travis@....com,
	Ingo Molnar <mingo@...e.hu>
Subject: Re: do_boot_cpu can deadlock?

On Thu, Oct 23, 2008 at 07:02:12PM +0200, Oleg Nesterov wrote:
> Hmm. arch/x86/kernel/smpboot.c:do_boot_cpu() can deadlock ?
> 
> It is called from _cpu_up() under cpu_hotplug_begin(), and it
> waits for c_idle.work. Again, if we have the pending work which
> needs get_online_cpus() we seem to have problems.

Good point. Though this code gets triggered mostly during boot time when
the CPUs are being brought online for the first time. If we have some
work-item pending at that time, which needs get_online_cpus(), we could
possibly see this deadlock.

> 
> Oleg.

-- 
Thanks and Regards
gautham
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/