Re: [PATCH v2] perf: Handle compat ioctl

[Pawel Moll]

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@xxxxxxx>
> > > Signed-off-by: Pawel Moll <pawel.moll@xxxxxxx>
> > 
> > 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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