public inbox for linux-kernel@vger.kernel.org
 help / color / mirror / Atom feed
From: Ulrich Drepper <drepper@redhat.com>
To: Luca Barbieri <ldb@ldb.ods.org>
Cc: Linus Torvalds <torvalds@transmeta.com>,
	Linux-Kernel ML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] Set TIF_IRET in more places
Date: Mon, 06 Jan 2003 10:42:11 -0800	[thread overview]
Message-ID: <3E19CE03.6090307@redhat.com> (raw)
In-Reply-To: <20030106181737.GA6867@ldb>

Luca Barbieri wrote:

> 1. vfork seems to not set any TIF_ flags so a ptracer setting regs
> while a vforking task is stopped in ptrace_notify called from vfork
> would result in clobbered %ecx and %edx.


Just to be clear: the vfork syscall does not use sysenter.  It's not
possible with the current implementation.  The magic sysenter wrapping
code would have to recognize the syscall and handle it special by saving
the return address.  From glibc's POV the %edx register would be free
but I consider this interface far to fragile.

-- 
--------------.                        ,-.            444 Castro Street
Ulrich Drepper \    ,-----------------'   \ Mountain View, CA 94041 USA
Red Hat         `--' drepper at redhat.com `---------------------------


  reply	other threads:[~2003-01-06 18:33 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2003-01-06 14:46 [PATCH] Set TIF_IRET in more places Luca Barbieri
2003-01-06 16:04 ` Linus Torvalds
2003-01-06 18:17   ` Luca Barbieri
2003-01-06 18:42     ` Ulrich Drepper [this message]
2003-01-06 18:49     ` Linus Torvalds
2003-01-06 20:26       ` Luca Barbieri
  -- strict thread matches above, loose matches on Subject: below --
2003-01-06 21:34 Zack Weinberg
2003-01-07 11:19 ` Jamie Lokier
2003-01-07 17:42   ` Linus Torvalds
2003-01-07 19:27   ` Zack Weinberg
2003-01-08  1:21     ` Richard Henderson
2003-01-08  2:33       ` Linus Torvalds
2003-01-08  3:32         ` Daniel Jacobowitz
2003-01-08 16:29       ` Jamie Lokier
2003-01-09  6:49         ` Zack Weinberg

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=3E19CE03.6090307@redhat.com \
    --to=drepper@redhat.com \
    --cc=ldb@ldb.ods.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=torvalds@transmeta.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