From: ebiederm@xmission.com (Eric W. Biederman)
To: Bernhard Walle <bwalle@suse.de>
Cc: Sharyathi Nagesh <sharyath@in.ibm.com>,
akpm@osdl.org, mohd.omar@in.ibm.com, IndhuDurai@in.ibm.com,
Kexec Mailing List <kexec@lists.infradead.org>,
fastboot@lists.osdl.org, linux-kernel@vger.kernel.org,
mohan@in.ibm.com, sachinp@in.ibm.com
Subject: Re: correction to compat_sys_kexec_load
Date: Fri, 23 May 2008 17:36:26 -0700 [thread overview]
Message-ID: <m1od6w4jxx.fsf@frodo.ebiederm.org> (raw)
In-Reply-To: <20080523233348.13fe0c63@kopernikus.site> (Bernhard Walle's message of "Fri, 23 May 2008 23:33:48 +0200")
Bernhard Walle <bwalle@suse.de> writes:
> * ebiederm@xmission.com (Eric W. Biederman) [2008-05-23 13:14]:
>>
>> What we need to do is fix /sbin/kexec to pass in the correct
>> architecture of the kernel for unload as it does for load.
>
> How should it know that it unloads a 32 bit kernel on a 64 bit system?
> It doesn't have access to the kernel any more once it has been loaded.
The architecture parameter is the architecture of the running kernel
that implements sys_kexec_load.
Because it is a pain for testing and in general impossible we don't
change cpu modes during a kexec. So a 32bit caller of sys_kexec_load
will need to passing in different code if it is running on a 32bit or
a 64bit kernel.
The trampoline code in /sbin/kexec does change modes on x86 when
appropriate.
Caring if you know the architecture in the unload case is a bit
silly. As there is no real justification for it. At this
point getting user space fixed so that it works on older kernels
seems important.
Eric
next prev parent reply other threads:[~2008-05-24 0:40 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-05-23 11:36 Sharyathi Nagesh
2008-05-23 20:14 ` Eric W. Biederman
2008-05-23 21:33 ` Bernhard Walle
2008-05-24 0:36 ` Eric W. Biederman [this message]
2008-05-26 20:32 ` Bernhard Walle
2008-05-28 4:39 ` Sharyathi Nagesh
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=m1od6w4jxx.fsf@frodo.ebiederm.org \
--to=ebiederm@xmission.com \
--cc=IndhuDurai@in.ibm.com \
--cc=akpm@osdl.org \
--cc=bwalle@suse.de \
--cc=fastboot@lists.osdl.org \
--cc=kexec@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mohan@in.ibm.com \
--cc=mohd.omar@in.ibm.com \
--cc=sachinp@in.ibm.com \
--cc=sharyath@in.ibm.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox
Powered by JetHome