From: "H. J. Lu" <hjl@lucon.org>
To: Jan Beulich <jbeulich@novell.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>, Andi Kleen <ak@suse.de>,
Chuck Ebbert <76306.1226@compuserve.com>,
Andrew Morton <akpm@osdl.org>,
linux-kernel@vger.kernel.org, Zachary Amsden <zach@vmware.com>
Subject: Re: [PATCH RFC 3/6] Use %gs as the PDA base-segment in the kernel.
Date: Mon, 28 Aug 2006 07:54:36 -0700 [thread overview]
Message-ID: <20060828145436.GA5710@lucon.org> (raw)
In-Reply-To: <44F2D8A4.76E4.0078.0@novell.com>
On Mon, Aug 28, 2006 at 10:51:00AM +0100, Jan Beulich wrote:
> >>> Andi Kleen <ak@suse.de> 27.08.06 20:19 >>>
> >On Sunday 27 August 2006 19:20, Jeremy Fitzhardinge wrote:
> >> Andi Kleen wrote:
> >> >> +1: movw GS(%esp), %gs
> >> >>
> >> >
> >> > movl is recommended in 32bit mode
> >> >
> >>
> >> arch/i386/kernel/entry.S: Assembler messages:
> >> arch/i386/kernel/entry.S:334: Error: suffix or operands invalid for `mov'
> >
> >Looks like a gas bug to me.
>
> This was an intentional change (by H.J. if I recall right) as using movl
> with segment registers gives the incorrect impression that one gets a
> 32-bit memory access (especially for stores this is important, since
> there's really nothing stored to the upper 16 bits). One should always
> use suffix-less 'mov' for segment register accesses.
mov will generate the optimal opcode with old and new assemblers.
H.J.
next prev parent reply other threads:[~2006-08-28 14:54 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-08-27 8:44 [PATCH RFC 0/6] Implement per-processor data areas for i386 Jeremy Fitzhardinge
2006-08-27 8:44 ` [PATCH RFC 1/6] Basic definitions for i386-pda Jeremy Fitzhardinge
2006-08-27 8:44 ` [PATCH RFC 2/6] Initialize the per-CPU data area Jeremy Fitzhardinge
2006-08-27 8:44 ` [PATCH RFC 3/6] Use %gs as the PDA base-segment in the kernel Jeremy Fitzhardinge
2006-08-27 9:49 ` Keith Owens
2006-08-27 10:01 ` Jeremy Fitzhardinge
2006-08-27 15:57 ` Andi Kleen
2006-08-27 16:36 ` Jeremy Fitzhardinge
2006-08-27 17:20 ` Jeremy Fitzhardinge
2006-08-27 18:19 ` Andi Kleen
2006-08-27 20:03 ` Jan Engelhardt
2006-08-27 23:38 ` Jeremy Fitzhardinge
2006-08-28 9:51 ` Jan Beulich
2006-08-28 14:54 ` H. J. Lu [this message]
2006-08-28 17:24 ` H. Peter Anvin
2006-08-27 8:44 ` [PATCH RFC 4/6] Fix places where using %gs changes the usermode ABI Jeremy Fitzhardinge
2006-08-27 15:59 ` Andi Kleen
2006-08-27 16:37 ` Jeremy Fitzhardinge
2006-08-27 8:44 ` [PATCH RFC 5/6] Implement smp_processor_id() with the PDA Jeremy Fitzhardinge
2006-08-27 8:44 ` [PATCH RFC 6/6] Implement "current" " Jeremy Fitzhardinge
2006-08-27 16:01 ` Andi Kleen
2006-08-27 16:38 ` Jeremy Fitzhardinge
2006-08-27 9:47 ` [PATCH RFC 0/6] Implement per-processor data areas for i386 Arjan van de Ven
2006-08-27 16:46 ` Jeremy Fitzhardinge
2006-08-27 17:44 ` Arjan van de Ven
2006-08-27 18:07 ` Andi Kleen
2006-08-27 18:27 ` Jeremy Fitzhardinge
2006-08-27 16:01 ` Andi Kleen
2006-08-27 16:41 ` Jeremy Fitzhardinge
2006-08-27 17:21 ` Andreas Mohr
2006-08-27 17:34 ` Jeremy Fitzhardinge
2006-08-27 18:23 ` Andreas Mohr
2006-08-27 18:04 ` Andi Kleen
2006-08-27 18:27 ` Andreas Mohr
2006-08-27 18:35 ` Andi Kleen
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=20060828145436.GA5710@lucon.org \
--to=hjl@lucon.org \
--cc=76306.1226@compuserve.com \
--cc=ak@suse.de \
--cc=akpm@osdl.org \
--cc=jbeulich@novell.com \
--cc=jeremy@goop.org \
--cc=linux-kernel@vger.kernel.org \
--cc=zach@vmware.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.