From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755180AbbIIKYb (ORCPT ); Wed, 9 Sep 2015 06:24:31 -0400 Received: from mga14.intel.com ([192.55.52.115]:28653 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752626AbbIIKYW (ORCPT ); Wed, 9 Sep 2015 06:24:22 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.17,496,1437462000"; d="scan'208";a="800750939" From: Chen Yu To: kristen@linux.intel.com, rjw@rjwysocki.net, viresh.kumar@linaro.org Cc: s.ikarashi@jp.fujitsu.com, rui.zhang@intel.com, linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, Chen Yu Subject: [PATCH] [v2] intel_pstate: Fix user input of min/max to legal policy region Date: Wed, 9 Sep 2015 18:27:31 +0800 Message-Id: <1441794451-29979-1-git-send-email-yu.c.chen@intel.com> X-Mailer: git-send-email 1.8.4.2 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org In current code, max_perf_pct might be smaller than min_perf_pct by improper user input: $ grep . /sys/devices/system/cpu/intel_pstate/m*_perf_pct /sys/devices/system/cpu/intel_pstate/max_perf_pct:100 /sys/devices/system/cpu/intel_pstate/min_perf_pct:100 $ echo 80 > /sys/devices/system/cpu/intel_pstate/max_perf_pct $ grep . /sys/devices/system/cpu/intel_pstate/m*_perf_pct /sys/devices/system/cpu/intel_pstate/max_perf_pct:80 /sys/devices/system/cpu/intel_pstate/min_perf_pct:100 Fix this problem by 2 steps: 1.Normalize the user input to [min_policy, max_policy]. 2.Make sure max_perf_pct>=min_perf_pct, suggested by Seiichi Ikarashi. Signed-off-by: Chen Yu --- v2: - Add logic to ensure max_perf_pct>=min_perf_pct. --- drivers/cpufreq/intel_pstate.c | 17 ++++++++++++++--- 1 file changed, 14 insertions(+), 3 deletions(-) diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c index fcb929e..a0b935f 100644 --- a/drivers/cpufreq/intel_pstate.c +++ b/drivers/cpufreq/intel_pstate.c @@ -423,6 +423,8 @@ static ssize_t store_max_perf_pct(struct kobject *a, struct attribute *b, limits.max_sysfs_pct = clamp_t(int, input, 0 , 100); limits.max_perf_pct = min(limits.max_policy_pct, limits.max_sysfs_pct); + limits.max_perf_pct = max(limits.min_policy_pct, limits.max_perf_pct); + limits.max_perf_pct = max(limits.min_perf_pct, limits.max_perf_pct); limits.max_perf = div_fp(int_tofp(limits.max_perf_pct), int_tofp(100)); if (hwp_active) @@ -442,6 +444,8 @@ static ssize_t store_min_perf_pct(struct kobject *a, struct attribute *b, limits.min_sysfs_pct = clamp_t(int, input, 0 , 100); limits.min_perf_pct = max(limits.min_policy_pct, limits.min_sysfs_pct); + limits.min_perf_pct = min(limits.max_policy_pct, limits.min_perf_pct); + limits.min_perf_pct = min(limits.max_perf_pct, limits.min_perf_pct); limits.min_perf = div_fp(int_tofp(limits.min_perf_pct), int_tofp(100)); if (hwp_active) @@ -985,12 +989,19 @@ static int intel_pstate_set_policy(struct cpufreq_policy *policy) limits.min_policy_pct = (policy->min * 100) / policy->cpuinfo.max_freq; limits.min_policy_pct = clamp_t(int, limits.min_policy_pct, 0 , 100); - limits.min_perf_pct = max(limits.min_policy_pct, limits.min_sysfs_pct); - limits.min_perf = div_fp(int_tofp(limits.min_perf_pct), int_tofp(100)); - limits.max_policy_pct = (policy->max * 100) / policy->cpuinfo.max_freq; limits.max_policy_pct = clamp_t(int, limits.max_policy_pct, 0 , 100); + + /* Normalize user input to [min_policy_pct, max_policy_pct] */ + limits.min_perf_pct = max(limits.min_policy_pct, limits.min_sysfs_pct); + limits.min_perf_pct = min(limits.max_policy_pct, limits.min_perf_pct); limits.max_perf_pct = min(limits.max_policy_pct, limits.max_sysfs_pct); + limits.max_perf_pct = max(limits.min_policy_pct, limits.max_perf_pct); + + /* Make sure min_perf_pct <= max_perf_pct */ + limits.min_perf_pct = min(limits.max_perf_pct, limits.min_perf_pct); + + limits.min_perf = div_fp(int_tofp(limits.min_perf_pct), int_tofp(100)); limits.max_perf = div_fp(int_tofp(limits.max_perf_pct), int_tofp(100)); if (hwp_active) -- 1.8.4.2