linux-kernel - Re: [patch v2 01/10] kdump: Add KEXEC_CRASH_CONTROL_MEMORY

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: <1312278664.4881.35.camel@br98xy6r>
Date:	Tue, 02 Aug 2011 11:51:04 +0200
From:	Michael Holzheu <holzheu@...ux.vnet.ibm.com>
To:	Vivek Goyal <vgoyal@...hat.com>
Cc:	ebiederm@...ssion.com, mahesh@...ux.vnet.ibm.com, hbabu@...ibm.com,
	oomichi@....nes.nec.co.jp, horms@...ge.net.au,
	schwidefsky@...ibm.com, heiko.carstens@...ibm.com,
	kexec@...ts.infradead.org, linux-kernel@...r.kernel.org,
	linux-s390@...r.kernel.org
Subject: Re: [patch v2 01/10] kdump: Add KEXEC_CRASH_CONTROL_MEMORY_LIMIT

Hello Vivek,

On Mon, 2011-08-01 at 16:16 -0400, Vivek Goyal wrote:
> On Wed, Jul 27, 2011 at 02:55:05PM +0200, Michael Holzheu wrote:
> > From: Michael Holzheu <holzheu@...ux.vnet.ibm.com>
> > 
> > On s390 there is a different KEXEC_CONTROL_MEMORY_LIMIT for the normal and
> > the kdump kexec case. Therefore this patch introduces a new macro
> > KEXEC_CRASH_CONTROL_MEMORY_LIMIT. This is set to
> > KEXEC_CONTROL_MEMORY_LIMIT for all architectures that do not define
> > KEXEC_CRASH_CONTROL_MEMORY_LIMIT.
> 
> Hi Michael,
> 
> Curious that why limit is different for kexec and kdump cases on s390
> only.

The standard kexec relocate_kernel code calls a machine instruction that
must run below 2 GiB. For kdump we currently do not use the control page
at all because no segments have to be moved in that case. Perhaps I am
still missing something here?

Michael

--
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/