linux-kernel - Re: Hibernation considerations

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: <Pine.LNX.4.64.0707171335180.2467@asgard.lang.hm>
Date:	Tue, 17 Jul 2007 13:37:08 -0700 (PDT)
From:	david@...g.hm
To:	Jeremy Maitin-Shepard <jbms@....edu>
cc:	"Rafael J. Wysocki" <rjw@...k.pl>,
	Alan Stern <stern@...land.harvard.edu>,
	LKML <linux-kernel@...r.kernel.org>,
	Andrew Morton <akpm@...ux-foundation.org>,
	"Eric W. Biederman" <ebiederm@...ssion.com>,
	"Huang, Ying" <ying.huang@...el.com>,
	Kyle Moffett <mrmacman_g4@....com>,
	Nigel Cunningham <nigel@...el.suspend2.net>,
	Pavel Machek <pavel@....cz>,
	pm list <linux-pm@...ts.linux-foundation.org>,
	Al Boldi <a1426z@...ab.com>
Subject: Re: Hibernation considerations

On Tue, 17 Jul 2007, Jeremy Maitin-Shepard wrote:

> "Rafael J. Wysocki" <rjw@...k.pl> writes:
>
> [snip]
>
>>> Rafael, for those of us who aren't thoroughly familiar with all the ins
>>> and outs of the ACPI spec, could you please summarize a list of the
>>> ACPI calls needed in the second and third cases above?  Indicate which
>>> ones need to be done from within the original kernel and which should
>>> be done from within a kexec'd hibernation kernel.
>
>> Sure.
>
>> In the third case (ie. transition to S4) we are supposed to do the following:
>
>> (1) Upon entering the sleep state, which IMO can be done _after_ the image
>>     has been saved:
>
> I assume you mean "in order to enter the sleep state", rather than "upon
> entering the sleep state".  I still don't understand what you mean by
> "which IMO can be done _after_ the image has been saved"; as far as I
> understand, the last step of this process, "make the platform enter S4",
> is almost like a shutdown as far as the kernel is concerned (except for
> the tiny detail of having to call those special ACPI methods on resume);
> consequently, it would seem that nothing can be done after that step.
>
>>   * figure out which devices can wake up
>>   * put devices into low power states (wake-up devices are placed in the Dx
>>     states compatible with the wake capability, the others are powered off)

this can't be done by the image-saving kernel if that kernel doesn't know 
about the device.

David Lang
-
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/