| From 943bdd0cecad06da8392a33093230e30e501eccc Mon Sep 17 00:00:00 2001 |
| From: Colin Ian King <colin.king@canonical.com> |
| Date: Tue, 5 Jan 2021 10:19:57 +0000 |
| Subject: cpufreq: powernow-k8: pass policy rather than use cpufreq_cpu_get() |
| |
| 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 |
| @@ -887,9 +887,9 @@ 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; |
| @@ -921,9 +921,6 @@ 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); |
| @@ -978,7 +975,7 @@ 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"); |
