tree cfc41a29b49dfd3879749793fdb118d43c9c23bf
parent c6c71b0a399e5832f09b71bbe5fd1a8fc14f0f79
author Peter Zijlstra <peterz@infradead.org> 1400178228 +0200
committer chrmhoffmann <chrmhoffmann@gmail.com> 1502528356 +0200

perf: Limit perf_event_attr::sample_period to 63 bits

commit 0819b2e30ccb93edf04876237b6205eef84ec8d2 upstream.

Vince reported that using a large sample_period (one with bit 63 set)
results in wreckage since while the sample_period is fundamentally
unsigned (negative periods don't make sense) the way we implement
things very much rely on signed logic.

So limit sample_period to 63 bits to avoid tripping over this.

Change-Id: I80055207c31cb1f321aea305950c05428006d90e
Original-Change-Id: I6f620812992a0e76bb500dd51fdcdde219779306
Reported-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/n/tip-p25fhunibl4y3qi0zuqmyf4b@git.kernel.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>