From: Christoph Hellwig <hch@infradead.org>
To: "H. Peter Anvin" <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Christian Ehrhardt <lk@c--e.de>
Subject: Re: [GIT PULL] x86 setup: work around bug in Xen HVM
Date: Tue, 4 Sep 2007 23:33:04 +0100 [thread overview]
Message-ID: <20070904223303.GA22306@infradead.org> (raw)
In-Reply-To: <200709041655.l84GtjiJ008962@tazenda.hos.anvin.org>
On Tue, Sep 04, 2007 at 09:55:45AM -0700, H. Peter Anvin wrote:
>
> Apparently XEN does not keep the contents of the 48-bit gdt_48 data
> structure that is passed to lgdt in the XEN machine state. Instead it
> appears to save the _address_ of the 48-bit descriptor
> somewhere. Unfortunately this data happens to reside on the stack and
> is probably no longer availiable at the time of the actual protected
> mode jump.
>
> This is Xen bug but given that there is a one-line patch to work
> around this problem, the linux kernel should probably do this. My fix
> is to make the gdt_48 description in setup_gdt static (in setup_idt
> this is already the case). This allows the kernel to boot under
> Xen HVM again.
> - struct gdt_ptr gdt;
> + static struct gdt_ptr gdt;
It might make sense to add your above commit message to the code as a comment.
next prev parent reply other threads:[~2007-09-04 22:33 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-09-04 16:55 [GIT PULL] x86 setup: work around bug in Xen HVM H. Peter Anvin
2007-09-04 22:33 ` Christoph Hellwig [this message]
2007-09-05 1:39 ` H. Peter Anvin
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=20070904223303.GA22306@infradead.org \
--to=hch@infradead.org \
--cc=hpa@zytor.com \
--cc=linux-kernel@vger.kernel.org \
--cc=lk@c--e.de \
--cc=torvalds@linux-foundation.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