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

[Vince Weaver]

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.

Oddly, with this patch applied, it's made it a lot harder (but not 
impossible) to trigger the memory corruption bug, although that might just 
be coincidence.

Vince
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