From 43717aadd2bc87fb10fbf1cd815c1cbae9bb95b3 Mon Sep 17 00:00:00 2001 From: Chen Yu Date: Wed, 9 Sep 2015 18:27:31 +0800 Subject: [PATCH] intel_pstate: Fix user input of min/max to legal policy region 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 Acked-by: Kristen Carlson Accardi Signed-off-by: Rafael J. Wysocki --- 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 31d0548638e8..63075cc4a476 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) @@ -989,12 +993,19 @@ 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)