From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754013AbaESMtM (ORCPT ); Mon, 19 May 2014 08:49:12 -0400 Received: from terminus.zytor.com ([198.137.202.10]:58949 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752085AbaESMtK (ORCPT ); Mon, 19 May 2014 08:49:10 -0400 Date: Mon, 19 May 2014 05:48:28 -0700 From: tip-bot for Peter Zijlstra Message-ID: Cc: linux-kernel@vger.kernel.org, hpa@zytor.com, mingo@kernel.org, vincent.weaver@maine.edu, peterz@infradead.org, tglx@linutronix.de Reply-To: mingo@kernel.org, hpa@zytor.com, linux-kernel@vger.kernel.org, vincent.weaver@maine.edu, peterz@infradead.org, tglx@linutronix.de To: linux-tip-commits@vger.kernel.org Subject: [tip:perf/urgent] perf: Limit perf_event_attr:: sample_period to 63 bits Git-Commit-ID: 0819b2e30ccb93edf04876237b6205eef84ec8d2 X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 0819b2e30ccb93edf04876237b6205eef84ec8d2 Gitweb: http://git.kernel.org/tip/0819b2e30ccb93edf04876237b6205eef84ec8d2 Author: Peter Zijlstra AuthorDate: Thu, 15 May 2014 20:23:48 +0200 Committer: Thomas Gleixner CommitDate: Mon, 19 May 2014 21:44:55 +0900 perf: Limit perf_event_attr::sample_period to 63 bits 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. Reported-by: Vince Weaver Signed-off-by: Peter Zijlstra Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/n/tip-p25fhunibl4y3qi0zuqmyf4b@git.kernel.org Signed-off-by: Thomas Gleixner --- kernel/events/core.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/kernel/events/core.c b/kernel/events/core.c index 7123284..1d1ec64 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -7029,6 +7029,9 @@ SYSCALL_DEFINE5(perf_event_open, if (attr.freq) { if (attr.sample_freq > sysctl_perf_event_sample_rate) return -EINVAL; + } else { + if (attr.sample_period & (1ULL << 63)) + return -EINVAL; } /*