linux-kernel - Re: [PATCH 4/6] ftrace, x86: make kernel text writable only for conversions

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]

Message-ID: <alpine.DEB.2.00.0902231322370.18221@gandalf.stny.rr.com>
Date:	Mon, 23 Feb 2009 13:23:55 -0500 (EST)
From:	Steven Rostedt <rostedt@...dmis.org>
To:	Mathieu Desnoyers <mathieu.desnoyers@...ymtl.ca>
cc:	Andi Kleen <andi@...stfloor.org>, linux-kernel@...r.kernel.org,
	Ingo Molnar <mingo@...e.hu>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Thomas Gleixner <tglx@...utronix.de>,
	Peter Zijlstra <peterz@...radead.org>,
	Frederic Weisbecker <fweisbec@...il.com>,
	Linus Torvalds <torvalds@...ux-foundation.org>,
	Arjan van de Ven <arjan@...radead.org>,
	Rusty Russell <rusty@...tcorp.com.au>,
	"H. Peter Anvin" <hpa@...or.com>,
	Steven Rostedt <srostedt@...hat.com>
Subject: Re: [PATCH 4/6] ftrace, x86: make kernel text writable only for
 conversions


On Mon, 23 Feb 2009, Mathieu Desnoyers wrote:
> 
> There is absolutely no link between stop_machine and text_poke. I argue
> against stop_machine saying that the breakpoint approach is less
> intrusive because it does not involve disabling interrupts for so long,
> and I argue against modifying the kernel page flags because that
> modifies the access rights of the core kernel and modules to RO

One correction. modules text is always mapped RW, event with 
CONFIG_DEBUG_RODATA. Perhaps we could fix that, but as it is today,
you do not need text_poke to modify module text.

-- Steve

> mappings, which is IMO a side-effect that we should eliminate _if we
> can_. Please keep those two concerns separate.

--
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/