xen-devel.lists.xenproject.org archive mirror
 help / color / mirror / Atom feed
From: Ian Campbell <ian.campbell@citrix.com>
To: Andrew Cooper <andrew.cooper3@citrix.com>,
	Andreas Sundstrom <sunkan+lists.xen-devel@zappa.cx>,
	xen-devel@lists.xen.org
Subject: Re: [BUG] XEN domU crash when PV grub chainloads 32-bit domU grub
Date: Tue, 22 Sep 2015 09:52:35 +0100	[thread overview]
Message-ID: <1442911955.10338.116.camel@citrix.com> (raw)
In-Reply-To: <560101D2.5060005@citrix.com>

On Tue, 2015-09-22 at 08:22 +0100, Andrew Cooper wrote:
> 
> The segment registers indicate that the domU is executing in ring1 which
> makes it a 32bit guest (also why 32bit words are used for the stack
> dump), but r10 through r14 have 64bit values in.

r10..r14 are not visible to 32-bit guests but it appears that this dumping
function in Xen doesn't check for that and omit printing them.

I suspect that if these were zeroed or poisoned upon domain creation you
would see those values unmodified here.

> It does appear to be an intermittent bug in 32bit grub-xen in the
> eventual domU, but I have no help to offer with respect to debugging
> grub-xen further.

Me neither. I did suggest to Andreas that he also took it to grub-devel.
I'll reply to the original with a full quote and copy that list.

Ian.

  reply	other threads:[~2015-09-22  8:52 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-09-21 20:03 [BUG] XEN domU crash when PV grub chainloads 32-bit domU grub Andreas Sundstrom
2015-09-22  7:22 ` Andrew Cooper
2015-09-22  8:52   ` Ian Campbell [this message]
2015-09-22 13:26   ` Andreas Sundstrom
2015-09-22  8:53 ` Ian Campbell
2015-09-22 22:37 ` Samuel Thibault
2015-09-23  8:34   ` Ian Campbell
2015-09-23 12:47     ` Andreas Sundstrom
2015-09-23 14:18       ` Ian Campbell
2015-09-24 17:28         ` Andreas Sundstrom
2015-09-25  8:36           ` Ian Campbell
2015-09-25 13:23             ` Andreas Sundstrom
2015-09-23  8:37   ` Andreas Sundstrom
     [not found] ` <1442912018.10338.118.camel@citrix.com>
2016-01-22 12:56   ` Vladimir 'φ-coder/phcoder' Serbinenko
     [not found]   ` <56A226F8.3020301@gmail.com>
2016-01-22 13:01     ` Andrew Cooper
     [not found]     ` <56A22847.3020708@citrix.com>
2016-01-22 13:08       ` Vladimir 'φ-coder/phcoder' Serbinenko
     [not found]       ` <56A229DA.7030904@gmail.com>
2016-01-22 13:43         ` Andrew Cooper
2016-01-22 17:44     ` Andreas Sundstrom

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=1442911955.10338.116.camel@citrix.com \
    --to=ian.campbell@citrix.com \
    --cc=andrew.cooper3@citrix.com \
    --cc=sunkan+lists.xen-devel@zappa.cx \
    --cc=xen-devel@lists.xen.org \
    /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;
as well as URLs for NNTP newsgroup(s).