linux-kernel - Re: [PATCH -mm] kexec jump -v9

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:	Wed, 14 May 2008 13:49:34 -0400
From:	Vivek Goyal <vgoyal@...hat.com>
To:	"Huang, Ying" <ying.huang@...el.com>
Cc:	nigel@...el.suspend2.net,
	Kexec Mailing List <kexec@...ts.infradead.org>,
	linux-kernel@...r.kernel.org, "Rafael J. Wysocki" <rjw@...k.pl>,
	"Eric W. Biederman" <ebiederm@...ssion.com>,
	Pavel Machek <pavel@....cz>,
	Andrew Morton <akpm@...ux-foundation.org>,
	linux-pm@...ts.linux-foundation.org
Subject: Re: [PATCH -mm] kexec jump -v9

On Wed, May 14, 2008 at 12:03:29PM -0400, Vivek Goyal wrote:
> On Thu, Mar 06, 2008 at 11:13:08AM +0800, Huang, Ying wrote:
> > This is a minimal patch with only the essential features. All
> > additional features are split out and can be discussed later. I think
> > it may be easier to get consensus on this minimal patch.
> > 
> 
> Hi Huang,
> 
> Ok, after a long time, I am back to testing and reviewing this patch.
> 
> 
> [..]
> > 7. Boot kernel compiled in step 1 (kernel C). Use the rootfs.gz as
> >    root file system.
> > 
> > 8. In kernel C, load the memory image of kernel A as follow:
> > 
> >    /sbin/kexec -l --args-none --entry=`cat kexec_jump_back_entry` dump.elf
> > 
> 
> How do I got back to original kernel without loading dump.elf. I mean,
> original kernel is already in memory and I don't have to first save
> it to disk and then reload back. Is there a way to do it? If not, then
> we need to modify kexec-tools to support that.
> 
> Something like
> 
> kexec --entry=<entry point>, should tell kexec that kernel is already
> loaded. Just do the bit to set the entry point properly.
> 

Never mind. I found it. Following worked for me for returning back to
original kernel.

kexec --load-jump-back-helper --entry=<entry point>

Just wondering if "--load-jump-back-helper" should be an explicit option
or kexec should silently assume it if no "-l" or "-p" is given.

Thanks
Vivek
--
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/