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Message-ID: <1408011468.21373.4.camel@hornet>
Date: Thu, 14 Aug 2014 11:17:48 +0100
From: Pawel Moll <pawel.moll@....com>
To: Peter Zijlstra <peterz@...radead.org>
Cc: Paul Mackerras <paulus@...ba.org>, Ingo Molnar <mingo@...hat.com>,
Arnaldo Carvalho de Melo <acme@...nel.org>,
"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
Drew Richardson <Drew.Richardson@....com>
Subject: Re: [PATCH v2] perf: Handle compat ioctl
On Mon, 2014-07-07 at 13:43 +0100, Peter Zijlstra wrote:
> On Tue, Jul 01, 2014 at 05:06:00PM +0100, Pawel Moll wrote:
> > On Tue, 2014-06-17 at 13:43 +0100, Pawel Moll wrote:
> > > When running a 32-bit userspace on a 64-bit kernel (eg. i386
> > > application on x86_64 kernel or 32-bit arm userspace on arm64
> > > kernel) some of the perf ioctls must be treated with special
> > > care, as they have a pointer size encoded in the command.
> > >
> > > For example, PERF_EVENT_IOC_ID in 32-bit world will be encoded
> > > as 0x80042407, but 64-bit kernel will expect 0x80082407. In
> > > result the ioctl will fail returning -ENOTTY.
> > >
> > > This patch solves the problem by adding code fixing up the
> > > size as compat_ioctl file operation.
> > >
> > > Reported-by: Drew Richardson <drew.richardson@....com>
> > > Signed-off-by: Pawel Moll <pawel.moll@....com>
> >
> > This just is a polite and friendly nag...
> >
> > Any, strong or not, opinions on the matter?
>
> Sorry, travel, cracks, falling, etc..
>
> Queued it, we'll see what happens with this one ;-)
Has it managed to hold on to the ground between the cracks then? ;-)
(asking because can't see it in your perf/core branch on git.kernel.org)
Pawel
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