diff options
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/sched/cpufreq_schedutil.c | 15 |
1 files changed, 13 insertions, 2 deletions
diff --git a/kernel/sched/cpufreq_schedutil.c b/kernel/sched/cpufreq_schedutil.c index a1782755efcc..49ccd6f1c185 100644 --- a/kernel/sched/cpufreq_schedutil.c +++ b/kernel/sched/cpufreq_schedutil.c @@ -62,6 +62,17 @@ static DEFINE_PER_CPU(struct sugov_cpu, sugov_cpu); /************************ Governor internals ***********************/ +static void sugov_update_rate_limit_us(struct sugov_policy *sg_policy) +{ + /* + * Cast rate_limit_us before multiplication to force 64-bit arithmetic. + * Otherwise, on 32-bit platforms, both operands are converted to + * 32-bit unsigned long and the multiplication may overflow. + */ + sg_policy->freq_update_delay_ns = + (s64)sg_policy->tunables->rate_limit_us * NSEC_PER_USEC; +} + static bool sugov_should_update_freq(struct sugov_policy *sg_policy, u64 time) { s64 delta_ns; @@ -608,7 +619,7 @@ rate_limit_us_store(struct gov_attr_set *attr_set, const char *buf, size_t count tunables->rate_limit_us = rate_limit_us; list_for_each_entry(sg_policy, &attr_set->policy_list, tunables_hook) - sg_policy->freq_update_delay_ns = rate_limit_us * NSEC_PER_USEC; + sugov_update_rate_limit_us(sg_policy); return count; } @@ -850,7 +861,7 @@ static int sugov_start(struct cpufreq_policy *policy) void (*uu)(struct update_util_data *data, u64 time, unsigned int flags); unsigned int cpu; - sg_policy->freq_update_delay_ns = sg_policy->tunables->rate_limit_us * NSEC_PER_USEC; + sugov_update_rate_limit_us(sg_policy); sg_policy->last_freq_update_time = 0; sg_policy->next_freq = 0; sg_policy->work_in_progress = false; |