Please fix the subject as well :) On 05-01-21, 10:11, Colin King wrote: > From: Colin Ian King <[email protected]> > > Currently there is an unlikely case where cpufreq_cpu_get returns a > null policy and this will cause a null pointer dereference later on. > Fix this by passing the policy to transition_frequency_fidvid from the > caller and hence eliminating the need for the cpufreq_cpu_get and > cpufreq_cpu_put. Thanks to Viresh Kumar for suggesting the fix. > > Addresses-Coverity: ("Dereference null return") > Fixes: b43a7ffbf33b ("cpufreq: Notify all policy->cpus in > cpufreq_notify_transition()") > Signed-off-by: Colin Ian King <[email protected]> > --- > > V2: pass the policy to transition_frequency_fidvid rather than add > a null pointer check on the return from a cpufreq_cpu_get call. > --- > drivers/cpufreq/powernow-k8.c | 9 +++------ > 1 file changed, 3 insertions(+), 6 deletions(-) > > diff --git a/drivers/cpufreq/powernow-k8.c b/drivers/cpufreq/powernow-k8.c > index 0acc9e241cd7..b9ccb6a3dad9 100644 > --- a/drivers/cpufreq/powernow-k8.c > +++ b/drivers/cpufreq/powernow-k8.c > @@ -878,9 +878,9 @@ static int get_transition_latency(struct powernow_k8_data > *data) > > /* Take a frequency, and issue the fid/vid transition command */ > static int transition_frequency_fidvid(struct powernow_k8_data *data, > - unsigned int index) > + unsigned int index, > + struct cpufreq_policy *policy) > { > - struct cpufreq_policy *policy; > u32 fid = 0; > u32 vid = 0; > int res; > @@ -912,9 +912,6 @@ static int transition_frequency_fidvid(struct > powernow_k8_data *data, > freqs.old = find_khz_freq_from_fid(data->currfid); > freqs.new = find_khz_freq_from_fid(fid); > > - policy = cpufreq_cpu_get(smp_processor_id()); > - cpufreq_cpu_put(policy); > - > cpufreq_freq_transition_begin(policy, &freqs); > res = transition_fid_vid(data, fid, vid); > cpufreq_freq_transition_end(policy, &freqs, res); > @@ -969,7 +966,7 @@ static long powernowk8_target_fn(void *arg) > > powernow_k8_acpi_pst_values(data, newstate); > > - ret = transition_frequency_fidvid(data, newstate); > + ret = transition_frequency_fidvid(data, newstate, pol); > > if (ret) { > pr_err("transition frequency failed\n"); > -- > 2.29.2
-- viresh
