From: Colin Ian King colin.king@canonical.com
commit 943bdd0cecad06da8392a33093230e30e501eccc upstream.
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()") Suggested-by: Viresh Kumar viresh.kumar@linaro.org Signed-off-by: Colin Ian King colin.king@canonical.com Acked-by: Viresh Kumar viresh.kumar@linaro.org Signed-off-by: Rafael J. Wysocki rafael.j.wysocki@intel.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/cpufreq/powernow-k8.c | 9 +++------ 1 file changed, 3 insertions(+), 6 deletions(-)
--- a/drivers/cpufreq/powernow-k8.c +++ b/drivers/cpufreq/powernow-k8.c @@ -878,9 +878,9 @@ static int get_transition_latency(struct
/* 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(s 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 *a
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");