linux-kernel - Re: [PATCH] perf: powerpc: Disable pagefaults during callchain stack read

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, 01 Aug 2011 20:39:07 +1000
From:	Benjamin Herrenschmidt <benh@...nel.crashing.org>
To:	Peter Zijlstra <peterz@...radead.org>
Cc:	David Ahern <dsahern@...il.com>, anton@...ba.org,
	acme@...stprotocols.net, mingo@...e.hu, paulus@...ba.org,
	linuxppc-dev@...ts.ozlabs.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] perf: powerpc: Disable pagefaults during callchain
 stack read

On Mon, 2011-08-01 at 11:59 +0200, Peter Zijlstra wrote:
> > Signed-off-by: David Ahern <dsahern@...il.com>
> > CC: Benjamin Herrenschmidt <benh@...nel.crashing.org>
> > CC: Anton Blanchard <anton@...ba.org> 
> 
> Hmm, Paul, didn't you fix something like this early on? Anyway, I've
> no
> objections since I'm really not familiar enough with the PPC side of
> things. 

I'm travelling so I haven't had a chance to review properly or even test
but it looks like an ad-hoc fix for the immediate problem.

Ultimately, I want to rework that stuff to do a __gup_fast like x86 does
(maybe as a fallback from an attempt at access first) so we work around
access permissions blocked by lack of dirty/accessed bits but in the
meantime, this should fix the immediate issue.

Cheers,
Ben.


--
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/