From: Peter Zijlstra <peterz@infradead.org>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Tom Tromey <tromey@redhat.com>,
Kyle Moffett <kyle@moffetthome.net>,
"Frank Ch. Eigler" <fche@redhat.com>,
Oleg Nesterov <oleg@redhat.com>,
Andrew Morton <akpm@linux-foundation.org>,
Stephen Rothwell <sfr@canb.auug.org.au>,
Fr??d??ric Weisbecker <fweisbec@gmail.com>,
LKML <linux-kernel@vger.kernel.org>,
Steven Rostedt <rostedt@goodmis.org>,
Arnaldo Carvalho de Melo <acme@redhat.com>,
linux-next@vger.kernel.org, "H. Peter Anvin" <hpa@zytor.com>,
utrace-devel@redhat.com, Thomas Gleixner <tglx@linutronix.de>,
JimKeniston <jkenisto@us.ibm.com>
Subject: Re: linux-next: add utrace tree
Date: Wed, 27 Jan 2010 07:52:14 +0100 [thread overview]
Message-ID: <1264575134.4283.1983.camel@laptop> (raw)
In-Reply-To: <alpine.LFD.2.00.1001261535510.17519@localhost.localdomain>
On Tue, 2010-01-26 at 15:37 -0800, Linus Torvalds wrote:
>
> On Tue, 26 Jan 2010, Tom Tromey wrote:
> >
> > In non-stop mode (where you can stop one thread but leave the others
> > running), gdb wants to have the breakpoints always inserted. So,
> > something must emulate the displaced instruction.
>
> I'm almost totally uninterested in breakpoints that actually re-write
> instructions. It's impossible to do that efficiently and well, especially
> in threaded environments.
>
> So if you do instruction rewriting, I can only say "that's your problem".
Right, so you're going to love uprobes, which does exactly that. The
current proposal is overwriting the target instruction with an INT3 and
injecting an extra vma into the target process's address space
containing the original instruction(s) and possible jumps back to the
old code stream.
I'm all in favor of not doing that extra vma and instead use stack or
TLS space, but then people complain about having to make that executable
(which is something I don't really mind, x86 had executable everything
for very long, and also, its only so when debugging the thing anyway).
next prev parent reply other threads:[~2010-01-27 6:52 UTC|newest]
Thread overview: 125+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20100119211646.GF16096@redhat.com>
2010-01-20 0:12 ` linux-next: add utrace tree Stephen Rothwell
2010-01-20 5:49 ` Ingo Molnar
2010-01-20 6:15 ` Ananth N Mavinakayanahalli
2010-01-20 6:28 ` Ingo Molnar
2010-01-20 6:40 ` Ananth N Mavinakayanahalli
2010-01-20 10:43 ` Frederic Weisbecker
2010-01-20 6:59 ` Stephen Rothwell
2010-01-20 13:24 ` Frank Ch. Eigler
2010-01-20 7:29 ` Ingo Molnar
2010-01-20 14:38 ` Stephen Rothwell
2010-01-21 1:22 ` Roland McGrath
2010-01-22 0:17 ` Stephen Rothwell
2010-01-22 0:30 ` Andrew Morton
2010-01-22 0:31 ` Andrew Morton
2010-01-22 0:51 ` Frank Ch. Eigler
2010-01-22 1:05 ` Andrew Morton
2010-01-22 1:25 ` Frank Ch. Eigler
2010-01-22 1:32 ` Linus Torvalds
2010-01-22 2:22 ` Frank Ch. Eigler
2010-01-22 2:35 ` Linus Torvalds
2010-01-22 20:51 ` Oleg Nesterov
2010-01-23 6:04 ` Ingo Molnar
2010-01-23 12:03 ` Frank Ch. Eigler
2010-01-24 16:36 ` Thomas Gleixner
2010-01-22 1:28 ` Linus Torvalds
2010-01-22 5:21 ` Ananth N Mavinakayanahalli
2010-01-22 13:43 ` Valdis.Kletnieks
2010-01-22 19:39 ` Oleg Nesterov
2010-01-26 13:58 ` Pavel Machek
2010-01-22 18:28 ` Oleg Nesterov
2010-01-22 20:01 ` Frank Ch. Eigler
2010-01-22 20:16 ` Peter Zijlstra
2010-01-22 21:44 ` Frank Ch. Eigler
2010-01-22 21:59 ` Linus Torvalds
2010-01-22 22:13 ` Frank Ch. Eigler
2010-01-23 0:11 ` Linus Torvalds
2010-01-23 0:22 ` Linus Torvalds
2010-01-23 6:20 ` Kyle Moffett
2010-01-23 11:01 ` Alan Cox
2010-01-23 11:51 ` Frank Ch. Eigler
2010-01-23 15:57 ` Arnaldo Carvalho de Melo
2010-01-23 11:23 ` Ingo Molnar
2010-01-23 11:47 ` Frank Ch. Eigler
2010-01-23 19:48 ` tytso
2010-01-24 18:01 ` Frank Ch. Eigler
2010-01-25 1:42 ` Kyle Moffett
2010-01-25 4:55 ` tytso
2010-01-25 16:52 ` Linus Torvalds
2010-01-25 17:02 ` Frank Ch. Eigler
2010-01-25 17:36 ` Linus Torvalds
2010-01-25 17:45 ` Linus Torvalds
2010-01-25 17:54 ` Steven Rostedt
2010-01-25 18:03 ` Alan Cox
2010-01-25 18:12 ` Linus Torvalds
2010-01-25 18:30 ` Steven Rostedt
2010-01-25 18:45 ` Thomas Gleixner
2010-01-25 20:34 ` Ingo Molnar
2010-01-25 20:30 ` Mark Wielaard
2010-01-25 20:42 ` Linus Torvalds
2010-01-26 0:02 ` Renzo Davoli
2010-01-26 0:07 ` Linus Torvalds
2010-01-26 16:08 ` Johannes Stezenbach
2010-01-26 16:28 ` Linus Torvalds
2010-01-26 16:34 ` Christoph Hellwig
2010-01-28 23:53 ` Benjamin Herrenschmidt
2010-01-29 0:21 ` Linus Torvalds
2010-01-25 4:59 ` Ananth N Mavinakayanahalli
2010-01-25 10:13 ` Peter Zijlstra
2010-01-24 5:04 ` Linus Torvalds
2010-01-24 10:25 ` tytso
2010-01-24 13:20 ` Frank Ch. Eigler
2010-01-25 21:05 ` Tom Tromey
2010-01-25 21:41 ` Linus Torvalds
2010-01-26 14:21 ` Ananth N Mavinakayanahalli
2010-01-26 23:20 ` Tom Tromey
2010-01-26 23:37 ` Linus Torvalds
2010-01-27 6:52 ` Peter Zijlstra [this message]
2010-01-27 8:54 ` Ingo Molnar
2010-01-28 1:52 ` Jim Keniston
2010-01-28 8:55 ` Ingo Molnar
2010-01-29 0:59 ` Jim Keniston
2010-01-29 7:39 ` Ingo Molnar
2010-01-29 7:52 ` Ananth N Mavinakayanahalli
2010-01-29 7:55 ` Ananth N Mavinakayanahalli
2010-01-29 9:16 ` Ingo Molnar
2010-01-29 9:11 ` Ingo Molnar
2010-01-29 9:31 ` Ananth N Mavinakayanahalli
2010-01-29 9:51 ` Ingo Molnar
2010-01-29 18:13 ` Frank Ch. Eigler
2010-01-29 4:55 ` Ananth N Mavinakayanahalli
2010-01-29 7:42 ` Ingo Molnar
2010-01-30 17:49 ` Steven Rostedt
2010-01-30 17:59 ` Linus Torvalds
2010-02-02 6:47 ` Masami Hiramatsu
2010-01-27 10:43 ` Linus Torvalds
2010-01-27 10:55 ` Peter Zijlstra
2010-01-27 10:58 ` Peter Zijlstra
2010-01-27 11:04 ` Linus Torvalds
2010-01-27 16:01 ` Frederic Weisbecker
2010-01-27 11:05 ` Ananth N Mavinakayanahalli
2010-01-27 11:08 ` Peter Zijlstra
2010-01-27 11:20 ` Ananth N Mavinakayanahalli
2010-02-08 10:09 ` Avi Kivity
2010-01-27 11:07 ` Srikar Dronamraju
2010-01-27 13:59 ` Steven Rostedt
2010-01-27 17:42 ` H. Peter Anvin
2010-01-27 18:53 ` Steven Rostedt
2010-02-08 6:54 ` Pavel Machek
2010-02-08 9:30 ` H. Peter Anvin
2010-02-08 9:53 ` Arjan van de Ven
2010-01-27 19:18 ` H. Peter Anvin
2010-01-27 0:38 ` Frank Ch. Eigler
2010-01-26 15:00 ` Frank Ch. Eigler
2010-01-26 17:33 ` Andi Kleen
2010-01-26 18:46 ` Linus Torvalds
2010-01-26 21:02 ` Andi Kleen
2010-01-26 21:53 ` Oleg Nesterov
2010-01-26 22:03 ` Andi Kleen
2010-01-26 23:32 ` Oleg Nesterov
2010-01-26 21:30 ` Oleg Nesterov
2010-01-26 23:27 ` Tom Tromey
2010-01-23 8:05 ` Alexey Dobriyan
2010-01-22 17:45 ` Oleg Nesterov
2010-01-20 8:52 ` Peter Zijlstra
2010-01-20 13:01 ` Frank Ch. Eigler
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