Re: [perf] yet another 32/64-bit range check failure

From: Vince Weaver
Date: Thu May 15 2014 - 01:04:09 EST


On Thu, 24 Apr 2014, Vince Weaver wrote:

> On Wed, 23 Apr 2014, Peter Zijlstra wrote:
> >
> > Something like so should do I suppose.
> >
> > ---
> > Subject: perf: Fix perf_event_open(.flags) test
> >
> > Vince noticed that we test the (unsigned long) flags field against an
> > (unsigned int) constant. This would allow setting the high bits on 64bit
> > platforms and not get an error.
> >
> > There is nothing that uses the high bits, so it should be entirely
> > harmless, but we don't want userspace to accidentally set them anyway,
> > so fix the constants.
> >
> > Reported-by: Vince Weaver <vincent.weaver@xxxxxxxxx>
> > Signed-off-by: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
>
> Tested-by: Vince Weaver <vincent.weaver@xxxxxxxxx>
>
> Your patch fixes the problem, or at least the test I wrote to check the
> issue now fails properly.

Even though this isn't as pressing an issue as the other perf_event
problems, I wanted to make sure this patch didn't get forgotten...

Vince
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