Messages in this thread | | | Date | Mon, 12 Feb 2018 15:59:00 +0530 | From | Viresh Kumar <> | Subject | Re: [PATCH] cpufreq: powernv: Check negative value returned by cpufreq_table_find_index_dl() |
| |
On 12-02-18, 15:51, Shilpasri G Bhat wrote: > This patch fixes the below Coverity warning: > > *** CID 182816: Memory - illegal accesses (NEGATIVE_RETURNS) > /drivers/cpufreq/powernv-cpufreq.c: 1008 in powernv_fast_switch() > 1002 unsigned int target_freq) > 1003 { > 1004 int index; > 1005 struct powernv_smp_call_data freq_data; > 1006 > 1007 index = cpufreq_table_find_index_dl(policy, target_freq); > >>> CID 182816: Memory - illegal accesses (NEGATIVE_RETURNS) > >>> Using variable "index" as an index to array "powernv_freqs". > 1008 freq_data.pstate_id = powernv_freqs[index].driver_data; > 1009 freq_data.gpstate_id = powernv_freqs[index].driver_data; > 1010 set_pstate(&freq_data); > 1011 > 1012 return powernv_freqs[index].frequency; > 1013 } > > Signed-off-by: Shilpasri G Bhat <shilpa.bhat@linux.vnet.ibm.com> > --- > drivers/cpufreq/powernv-cpufreq.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/drivers/cpufreq/powernv-cpufreq.c b/drivers/cpufreq/powernv-cpufreq.c > index 29cdec1..69edfe9 100644 > --- a/drivers/cpufreq/powernv-cpufreq.c > +++ b/drivers/cpufreq/powernv-cpufreq.c > @@ -1005,6 +1005,9 @@ static unsigned int powernv_fast_switch(struct cpufreq_policy *policy, > struct powernv_smp_call_data freq_data; > > index = cpufreq_table_find_index_dl(policy, target_freq); > + if (unlikely(index < 0)) > + index = get_nominal_index(); > +
AFAICT, you will get -1 here only if the freq table had no valid frequencies (or the freq table is empty). Why would that happen ?
> freq_data.pstate_id = powernv_freqs[index].driver_data; > freq_data.gpstate_id = powernv_freqs[index].driver_data; > set_pstate(&freq_data); > -- > 1.8.3.1
-- viresh
| |