From: Xiongfeng Wang wangxiongfeng2@huawei.com
hulk inclusion category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I4HYY4?from=project-issue CVE: NA
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When I hot added a CPU, I found 'cpufreq' directory is not created below /sys/devices/system/cpu/cpuX/. It is because get_cpu_device() failed in add_cpu_dev_symlink().
cpufreq_add_dev() is the .add_dev callback of a CPU subsys interface. It will be called when the CPU device registered into the system. The stack is as follows. register_cpu() ->device_register() ->device_add() ->bus_probe_device() ->cpufreq_add_dev()
But only after the CPU device has been registered, we can get the CPU device by get_cpu_device(), otherwise it will return NULL. Since we already have the CPU device in cpufreq_add_dev(), pass it to add_cpu_dev_symlink().
Signed-off-by: Xiongfeng Wang wangxiongfeng2@huawei.com Reviewed-by: Keqian Zhu zhukeqian1@huawei.com Reviewed-by: Hanjun Guo guohanjun@huawei.com Signed-off-by: Yang Yingliang yangyingliang@huawei.com --- drivers/cpufreq/cpufreq.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-)
diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c index e35c397b1259f..99ca9c50a88f3 100644 --- a/drivers/cpufreq/cpufreq.c +++ b/drivers/cpufreq/cpufreq.c @@ -965,10 +965,9 @@ static struct kobj_type ktype_cpufreq = { .release = cpufreq_sysfs_release, };
-static void add_cpu_dev_symlink(struct cpufreq_policy *policy, unsigned int cpu) +static void add_cpu_dev_symlink(struct cpufreq_policy *policy, unsigned int cpu, + struct device *dev) { - struct device *dev = get_cpu_device(cpu); - if (!dev) return;
@@ -1241,7 +1240,7 @@ static int cpufreq_online(unsigned int cpu)
for_each_cpu(j, policy->related_cpus) { per_cpu(cpufreq_cpu_data, j) = policy; - add_cpu_dev_symlink(policy, j); + add_cpu_dev_symlink(policy, j, get_cpu_device(j)); } } else { policy->min = policy->user_policy.min; @@ -1366,7 +1365,7 @@ static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif) /* Create sysfs link on CPU registration */ policy = per_cpu(cpufreq_cpu_data, cpu); if (policy) - add_cpu_dev_symlink(policy, cpu); + add_cpu_dev_symlink(policy, cpu, dev);
return 0; }