linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Jamie Lokier <jamie@shareable.org>
To: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Petr Vandrovec <vandrove@vc.cvut.cz>,
	lkml <linux-kernel@vger.kernel.org>
Subject: Re: TSCs are a no-no on i386
Date: Thu, 31 Jul 2003 19:37:30 +0100	[thread overview]
Message-ID: <20030731183730.GA7803@mail.jlokier.co.uk> (raw)
In-Reply-To: <1059667304.16608.47.camel@dhcp22.swansea.linux.org.uk>

Alan Cox wrote:
> > > And if the byte you are looking at was patched by another thread you've
> > > blown it. Your emulation can only be so good 8) People do stuff like
> > > patching instructions under software decode as a robustness check - its
> > > normally pretty amusing
> > 
> > On a uniprocessor 386, this is not a problem.  Just disable preemption
> > in the kernel decoder.
> 
> Wrong again. Thats a common myth but you see I can put the instruction on a page
> so that its executed from a page I just did a read() into in another process. If
> I'm really bored I'll use O_DIRECT but thats mostly for makign life really bad 
> for non cache coherent setups 8)

I wouldn't be surprised if even real CPUs mis-decode when there's a
concurrent DMA into the area they are reading instructions from! :)

-- Jamie

  reply	other threads:[~2003-07-31 18:37 UTC|newest]

Thread overview: 45+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2003-07-30 13:56 TSCs are a no-no on i386 Jan-Benedict Glaw
2003-07-30 14:18 ` Maciej W. Rozycki
2003-07-30 14:44   ` Jan-Benedict Glaw
2003-07-30 16:58 ` Matthew Garrett
2003-07-30 17:19   ` Alan Cox
2003-07-30 18:10 ` Adrian Bunk
2003-07-30 18:30   ` Mike Fedyk
2003-07-30 18:45     ` Adrian Bunk
2003-07-30 20:01       ` Alan Cox
2003-07-30 20:33         ` Jan-Benedict Glaw
2003-07-30 22:19           ` J.A. Magallon
2003-07-31  6:11             ` Jan-Benedict Glaw
2003-07-30 23:05           ` Alan Cox
2003-07-31 11:11             ` Richard B. Johnson
2003-07-31 11:26               ` Emulating i486+ insn on i386 (was: TSCs are a no-no on i386) Jan-Benedict Glaw
2003-07-31 11:41             ` TSCs are a no-no on i386 Jan-Benedict Glaw
2003-07-31  0:22           ` Adrian Bunk
2003-07-31  6:22             ` Jan-Benedict Glaw
2003-07-31  7:17               ` Willy Tarreau
2003-07-31 11:38                 ` Emulating i486 on i386 (was: TSCs are a no-no on i386) Jan-Benedict Glaw
2003-07-31 11:51                   ` Alan Cox
2003-07-31 12:14                     ` Jan-Benedict Glaw
2003-07-31 13:01                       ` Jan-Benedict Glaw
2003-07-31 15:09                         ` Martin Schlemmer
2003-07-31 15:33                           ` Jan-Benedict Glaw
2003-08-01  5:37                             ` Martin Schlemmer
2003-07-31 15:12                     ` Jamie Lokier
2003-07-31 15:32                       ` Jan-Benedict Glaw
2003-07-31 15:07                 ` TSCs are a no-no on i386 Jamie Lokier
2003-07-31 15:23                   ` Willy Tarreau
2003-07-31 15:50                   ` Richard B. Johnson
2003-07-31 16:24                     ` Jan-Benedict Glaw
2003-08-06 11:08         ` Pavel Machek
2003-08-06 14:33           ` Maciej W. Rozycki
2003-07-30 20:28       ` Jan-Benedict Glaw
2003-07-30 21:50         ` Petr Vandrovec
2003-07-30 23:10           ` Alan Cox
2003-07-31 15:10             ` Jamie Lokier
2003-07-31 16:01               ` Alan Cox
2003-07-31 18:37                 ` Jamie Lokier [this message]
2003-07-31 19:10                   ` Alan Cox
2003-07-31  6:29           ` Jan-Benedict Glaw
2003-07-30 20:27   ` Jan-Benedict Glaw
2003-08-06 16:41 James Bottomley
2003-08-06 16:45 James Bottomley

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=20030731183730.GA7803@mail.jlokier.co.uk \
    --to=jamie@shareable.org \
    --cc=alan@lxorguk.ukuu.org.uk \
    --cc=linux-kernel@vger.kernel.org \
    --cc=vandrove@vc.cvut.cz \
    /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).