[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] [PATCH 5/9] cpufreq: avoid integer overflows.
Tim Deegan wrote: > The def_sampling_rate() one is, I think, a real bug. The others were > spotted at the same time and are probably not bugs until we start > dealing with 40GHz CPus. > > Coverity CID 1055682 > Coverity CID 1055683 > > Signed-off-by: Tim Deegan <tim@xxxxxxx> > Cc: Jan Beulich <jbeulich@xxxxxxxx> > Cc: Liu Jinsong <jinsong.liu@xxxxxxxxx> > --- > xen/drivers/cpufreq/cpufreq_ondemand.c | 7 ++++--- > 1 file changed, 4 insertions(+), 3 deletions(-) > > diff --git a/xen/drivers/cpufreq/cpufreq_ondemand.c > b/xen/drivers/cpufreq/cpufreq_ondemand.c index b3f9ab8..7fdba03 100644 > --- a/xen/drivers/cpufreq/cpufreq_ondemand.c > +++ b/xen/drivers/cpufreq/cpufreq_ondemand.c > @@ -144,7 +144,7 @@ static void dbs_check_cpu(struct cpu_dbs_info_s > *this_dbs_info) } > > /* Check for frequency increase */ > - if (max_load_freq > dbs_tuners_ins.up_threshold * policy->cur) { > + if (max_load_freq > (uint64_t) dbs_tuners_ins.up_threshold * > policy->cur) { /* if we are already at full speed then break > out early */ if (policy->cur == max) > return; > @@ -162,7 +162,8 @@ static void dbs_check_cpu(struct cpu_dbs_info_s > *this_dbs_info) > * can support the current CPU usage without triggering the up > * policy. To be safe, we focus 10 points under the threshold. > */ > - if (max_load_freq < (dbs_tuners_ins.up_threshold - 10) * > policy->cur) { + if (max_load_freq > + < (uint64_t) (dbs_tuners_ins.up_threshold - 10) * > policy->cur) { uint64_t freq_next; > > freq_next = max_load_freq / (dbs_tuners_ins.up_threshold - > 10); @@ -246,7 +247,7 @@ int cpufreq_governor_dbs(struct > cpufreq_policy *policy, unsigned int event) > * is used for first time > */ > if ((dbs_enable == 1) && !dbs_tuners_ins.sampling_rate) { > - def_sampling_rate = policy->cpuinfo.transition_latency * > + def_sampling_rate = (uint64_t) > policy->cpuinfo.transition_latency * > DEF_SAMPLING_RATE_LATENCY_MULTIPLIER; > > if (def_sampling_rate < MIN_STAT_SAMPLING_RATE) Acked-by: Liu Jinsong <jinsong.liu@xxxxxxxxx> _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx http://lists.xen.org/xen-devel
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