linux-kernel - Re: [RFC] gcc feature request: Moving blocks into sections

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: <20130806203319.GA16170@Krystal>
Date:	Tue, 6 Aug 2013 16:33:19 -0400
From:	Mathieu Desnoyers <mathieu.desnoyers@...icios.com>
To:	Steven Rostedt <rostedt@...dmis.org>
Cc:	Linus Torvalds <torvalds@...ux-foundation.org>,
	LKML <linux-kernel@...r.kernel.org>, gcc <gcc@....gnu.org>,
	Ingo Molnar <mingo@...nel.org>,
	"H. Peter Anvin" <hpa@...ux.intel.com>,
	Thomas Gleixner <tglx@...utronix.de>,
	David Daney <ddaney.cavm@...il.com>,
	Behan Webster <behanw@...verseincode.com>,
	Peter Zijlstra <peterz@...radead.org>,
	Herbert Xu <herbert@...dor.apana.org.au>
Subject: Re: [RFC] gcc feature request: Moving blocks into sections

* Steven Rostedt (rostedt@...dmis.org) wrote:
> On Tue, 2013-08-06 at 10:48 -0700, Linus Torvalds wrote:
> 
> > So I wonder if this is a "ok, let's not bother, it's not worth the
> > pain" issue. 128 bytes of offset is very small, so there probably
> > aren't all that many cases that would use it.
> 
> OK, I'll forward port the original patches for the hell of it anyway,
> and post it as an RFC. Let people play with it if they want, and if it
> seems like it would benefit the kernel perhaps we can reconsider.
> 
> It shouldn't be too hard to do the forward port, and if we don't ever
> take it, it would be a fun exercise regardless ;-)
> 
> Actually, the first three patches should be added as they are clean ups
> and safety checks. Nothing to do with the actual 2-5 byte jumps. They
> were lost due to their association with the complex patches. :-/

Steve, perhaps you could add a mode to your binary rewriting program
that counts the number of 2-byte vs 5-byte jumps found, and if possible
get a breakdown of those per subsystem ? It might help us getting a
clearer picture of how many important sites, insn cache-wise, are being
shrinked by this approach.

Thanks,

Mathieu

> 
> -- Steve
> 
> 

-- 
Mathieu Desnoyers
EfficiOS Inc.
http://www.efficios.com
--
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/