linux-kernel - Re: scheduling while atomic & hang.

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: <20130705065113.GA6588@gmail.com>
Date:	Fri, 5 Jul 2013 08:51:13 +0200
From:	Ingo Molnar <mingo@...nel.org>
To:	"H. Peter Anvin" <hpa@...or.com>,
	Frédéric Weisbecker <fweisbec@...il.com>
Cc:	Linus Torvalds <torvalds@...ux-foundation.org>,
	Dave Jones <davej@...hat.com>,
	Linux Kernel <linux-kernel@...r.kernel.org>,
	Thomas Gleixner <tglx@...utronix.de>
Subject: Re: scheduling while atomic & hang.


* H. Peter Anvin <hpa@...or.com> wrote:

> On 07/03/2013 07:49 PM, Linus Torvalds wrote:
> >> [<ffffffff816f42bf>] __schedule+0x94f/0x9c0
> >> [<ffffffff816f487e>] schedule_user+0x2e/0x70
> >> [<ffffffff816f6de4>] retint_careful+0x12/0x2e
> 
> This call trace does indeed indicate that we took a hardware
> interrupt which caused a reschedule.  It doesn't necessarily have to
> be a quantum expiration interrupt, it could just as easily be an I/O
> completion interrupt.

Too bad the kernel stack frame at this point is so small [we are just 
before return to userspace], so we don't really get our usual trace of 
recent activities via the '?' entries ...

It would be nice to have a full-kernel-stack backtrace printout as an 
option, which prints entries 'above' the current RSP.

I've Cc:-ed Frederic, maybe he has interest in implementing that?

Thanks,

	Ingo
--
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/