From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933062AbaFIWt7 (ORCPT ); Mon, 9 Jun 2014 18:49:59 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:57195 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933172AbaFIWqN (ORCPT ); Mon, 9 Jun 2014 18:46:13 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Knut Petersen , Peter Zijlstra , Ingo Molnar , Weng Meiling Subject: [PATCH 3.10 38/40] perf: Enforce 1 as lower limit for perf_event_max_sample_rate Date: Mon, 9 Jun 2014 15:49:09 -0700 Message-Id: <20140609224840.454950708@linuxfoundation.org> X-Mailer: git-send-email 1.9.0 In-Reply-To: <20140609224839.127615063@linuxfoundation.org> References: <20140609224839.127615063@linuxfoundation.org> User-Agent: quilt/0.63-1 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Knut Petersen commit 723478c8a471403c53cf144999701f6e0c4bbd11 upstream. /proc/sys/kernel/perf_event_max_sample_rate will accept negative values as well as 0. Negative values are unreasonable, and 0 causes a divide by zero exception in perf_proc_update_handler. This patch enforces a lower limit of 1. Signed-off-by: Knut Petersen Signed-off-by: Peter Zijlstra Link: http://lkml.kernel.org/r/5242DB0C.4070005@t-online.de Signed-off-by: Ingo Molnar Cc: Weng Meiling Signed-off-by: Greg Kroah-Hartman --- kernel/events/core.c | 2 +- kernel/sysctl.c | 1 + 2 files changed, 2 insertions(+), 1 deletion(-) --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -190,7 +190,7 @@ int perf_proc_update_handler(struct ctl_ void __user *buffer, size_t *lenp, loff_t *ppos) { - int ret = proc_dointvec(table, write, buffer, lenp, ppos); + int ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos); if (ret || !write) return ret; --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -1049,6 +1049,7 @@ static struct ctl_table kern_table[] = { .maxlen = sizeof(sysctl_perf_event_sample_rate), .mode = 0644, .proc_handler = perf_proc_update_handler, + .extra1 = &one, }, { .procname = "perf_cpu_time_max_percent",