linux-kernel - Re: [PATCH][RFC v3] x86, hotplug: Use hlt instead of mwait if invoked from disable_nonboot

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, 07 Jul 2016 17:03:19 +0100
From:	James Morse <james.morse@....com>
To:	"Chen, Yu C" <yu.c.chen@...el.com>,
	"Rafael J. Wysocki" <rjw@...ysocki.net>
CC:	"linux-pm@...r.kernel.org" <linux-pm@...r.kernel.org>,
	Thomas Gleixner <tglx@...utronix.de>,
	"H. Peter Anvin" <hpa@...or.com>, Pavel Machek <pavel@....cz>,
	Borislav Petkov <bp@...e.de>,
	Peter Zijlstra <peterz@...radead.org>,
	Ingo Molnar <mingo@...hat.com>, Len Brown <lenb@...nel.org>,
	"x86@...nel.org" <x86@...nel.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH][RFC v3] x86, hotplug: Use hlt instead of mwait if invoked
 from disable_nonboot_cpus

Hi,

On 07/07/16 03:50, Chen, Yu C wrote:
>> From: Rafael J. Wysocki [mailto:rjw@...ysocki.net]
>> Below is my sort of version of this (untested) and I did it this way, because the
>> issue is specific to resume from hibernation (the workaround need not be
>> applied anywhere else) and the hibernate_resume_nonboot_cpu_disable()
>> thing may be useful to arm64 too if I'm not mistaken (James?).
> 
> James might want a flag to distinguish whether it is from suspend or resume,
> in his arch-specific disabled_nonboot_cpus?

That isn't serious, we can work out whether it is hibernate/resume based on
whether we've read data out of the the arch header. I added it in the other
series as it looked cleaner to pass the value in instead of inferring it.


Thanks,

James