linux-kernel - Re: [RFC][PATCH] x86: make text

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Mon, 2 Mar 2009 10:55:00 -0800
From:	Arjan van de Ven <arjan@...radead.org>
To:	Mathieu Desnoyers <mathieu.desnoyers@...ymtl.ca>
Cc:	Masami Hiramatsu <mhiramat@...hat.com>,
	Ingo Molnar <mingo@...e.hu>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Nick Piggin <npiggin@...e.de>,
	Steven Rostedt <rostedt@...dmis.org>,
	Andi Kleen <andi@...stfloor.org>, linux-kernel@...r.kernel.org,
	Thomas Gleixner <tglx@...utronix.de>,
	Peter Zijlstra <peterz@...radead.org>,
	Frederic Weisbecker <fweisbec@...il.com>,
	Linus Torvalds <torvalds@...ux-foundation.org>,
	Rusty Russell <rusty@...tcorp.com.au>,
	"H. Peter Anvin" <hpa@...or.com>,
	Steven Rostedt <srostedt@...hat.com>
Subject: Re: [RFC][PATCH] x86: make text_poke() atomic

On Mon, 2 Mar 2009 13:36:17 -0500
Mathieu Desnoyers <mathieu.desnoyers@...ymtl.ca> wrote:

> * Arjan van de Ven (arjan@...radead.org) wrote:
> > > 
> > > Use map_vm_area() instead of vmap() in text_poke() for avoiding
> > > page allocation and delayed unmapping, and call
> > > vunmap_page_range() and local_flush_tlb() directly because this
> > > mapping is temporary and local.
> > > 
> > > At the result of above change, text_poke() becomes atomic and can
> > > be called from stop_machine() etc.
> > 
> > .... but text_poke() realistically needs to call stop_machine()
> > since you can't poke live code.... so that makes me wonder how
> > useful this is...
> 
> Hi Arjan,
> 
> Stop machine is not required when inserting a breakpoint. 

that is your assumption; when I spoke with CPU architects they
cringed ;(



-- 
Arjan van de Ven 	Intel Open Source Technology Centre
For development, discussion and tips for power savings, 
visit http://www.lesswatts.org
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/