linux-kernel - Re: [RFC][PATCH 07/11] perf: Provide PERF_SAMPLE

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:	Thu, 4 Mar 2010 12:04:29 +0100
From:	Ingo Molnar <mingo@...e.hu>
To:	Peter Zijlstra <peterz@...radead.org>
Cc:	Frederic Weisbecker <fweisbec@...il.com>,
	linux-kernel@...r.kernel.org, paulus@...ba.org, eranian@...gle.com,
	robert.richter@....com
Subject: Re: [RFC][PATCH 07/11] perf: Provide PERF_SAMPLE_REGS


* Peter Zijlstra <peterz@...radead.org> wrote:

> On Wed, 2010-03-03 at 23:02 +0100, Frederic Weisbecker wrote:
> > On Wed, Mar 03, 2010 at 05:39:43PM +0100, Peter Zijlstra wrote:
> > > Simply copy out the provided pt_regs in a u64 aligned fashion.
> > > 
> > > XXX: do task_pt_regs() and get_irq_regs() always clear everything or
> > >      are we now leaking data?
> > 
> > 
> > It looks like there is a leak in case of non trace syscalls.
> > where we don't appear to save r12-15.
> > 
> > Then task_pt_regs() may leak the top of a process stack...?
> 
> Right, I was afraid of that. I've put this PERF_SAMPLE_REGS thing in the 
> freezer for now as people seem unsure how to deal with it.

Also, we dont want to expose PEBS nor LBR on an ABI level without there being 
a user-space component making good use of it.

For example tools/perf/ support would qualify. Raw libraries alone dont really 
count as they generally lag plus there's no guarantee for a full feedback loop 
either.

Adding ABI details is always a tricky business and we only want to do it if 
there's direct, immediate, close involvement with the user-space side, and 
real, immediate benefits to users.

Thanks,

	Ingo
--
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/