linux-kernel - Re: Linux v2.6.18-rc3

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: <20060730212746.4c2e1466.akpm@osdl.org>
Date:	Sun, 30 Jul 2006 21:27:46 -0700
From:	Andrew Morton <akpm@...l.org>
To:	"Jesse Brandeburg" <jesse.brandeburg@...il.com>
Cc:	linux-kernel@...r.kernel.org, torvalds@...l.org,
	Alan Stern <stern@...land.harvard.edu>,
	cpufreq@....linux.org.uk
Subject: Re: Linux v2.6.18-rc3

On Sun, 30 Jul 2006 21:13:48 -0700
"Jesse Brandeburg" <jesse.brandeburg@...il.com> wrote:

> On 7/29/06, Linus Torvalds <torvalds@...l.org> wrote:
> >
> > Ok, this missed a week (it should really have been -rc4, and we should
> > have had a -rc3 a week ago), but the fact is, with a lot of people at the
> > kernel summit and at OLS, it was so quiet for a week that there simply was
> > no point.
> 
> not sure if this is a regression or not, get this on my IBM thinkpad
> T43 when resuming from S3 or from hibernate to disk.
> 
> acpi acpi: suspend
> PM: Entering mem sleep
> Intel machine check architecture supported.
> Intel machine check reporting enabled on CPU#0.
> Back to C!
> BUG: sleeping function called from invalid context at kernel/rwsem.c:20
> in_atomic():0, irqs_disabled():1
>  [<c012d638>] down_read+0x12/0x1f
>  [<c012605b>] blocking_notifier_call_chain+0xe/0x29
>  [<c029199a>] cpufreq_resume+0x118/0x13f
>  [<c0231b68>] __sysdev_resume+0x20/0x53
>  [<c0231ca9>] sysdev_resume+0x16/0x47
>  [<c0235f93>] device_power_up+0x5/0xa
>  [<c013358d>] suspend_enter+0x3b/0x44
>  [<c011b644>] printk+0x1b/0x1f
>  [<c01336fe>] enter_state+0x168/0x198
>  [<c01337b3>] state_store+0x85/0x99
>  [<c013372e>] state_store+0x0/0x99
>  [<c019047a>] subsys_attr_store+0x1e/0x22
>  [<c01906ca>] sysfs_write_file+0xa6/0xcc
>  [<c0190624>] sysfs_write_file+0x0/0xcc
>  [<c015ae52>] vfs_write+0xa8/0x159
>  [<c015b398>] sys_write+0x41/0x67
>  [<c0102bc9>] sysenter_past_esp+0x56/0x79
> PM: Finishing wakeup.
> acpi acpi: resuming
> 
> full dmesg and .config attached, I can test patches.

I think this is the cpufreq problem wherein it sometimes requires that the
notifier chain be traversed from atomic context and at other times it
requires that sleeping functions be callable from within the traversal. 
IOW: we're screwed whatever type of locking we use on that chain.

I think Alan is cooking up a scheme wherein we fix this with an srcu-locked
notifier chain.  If so, it'd be nice to get that moving along a bit?

If not, I'm not sure what the fix is - perhaps create a second notifier
chain which has the same contents but uses a different locking approach?
-
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/