Fix null pointer dereference error liked below. This BUG can be easily re-produced by 'monkey --throttle 50' in android 6.0.
Unable to handle kernel NULL pointer dereference at virtual address 00000010 [KERN Warning] check backtrace: CPU: 0 PID: 10714 Comm: kschedfreq:0 Tainted: Call trace: [<ffffffc00008b8ac>] dump_backtrace+0x0/0x15c [<ffffffc00008ba18>] show_stack+0x10/0x1c [<ffffffc000b97bf8>] dump_stack+0x74/0xb8 [<ffffffc00036208c>] debug_locks_off+0x4c/0x7c [<ffffffc0000a3450>] oops_enter+0xc/0x28 [<ffffffc00008ba50>] die+0x2c/0x1a4 [<ffffffc000b96588>] __do_kernel_fault.part.5+0x70/0x84 [<ffffffc00009c728>] do_page_fault+0x344/0x348 [<ffffffc00009c7e8>] do_translation_fault+0xbc/0xf0 [<ffffffc0000822b0>] do_mem_abort+0x38/0x9c [<ffffffc000085c50>] el1_da+0x14/0x80 [<ffffffc0000c0168>] kthread+0xd4/0xec
Signed-off-by: Pingbo Wen pingbo.wen@linaro.org --- kernel/sched/cpufreq_sched.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/kernel/sched/cpufreq_sched.c b/kernel/sched/cpufreq_sched.c index e1d208e..93731ef 100644 --- a/kernel/sched/cpufreq_sched.c +++ b/kernel/sched/cpufreq_sched.c @@ -265,6 +265,8 @@ static int cpufreq_sched_policy_init(struct cpufreq_policy *policy) pr_debug("%s: throttle threshold = %u [ns]\n", __func__, gd->throttle_nsec);
+ policy->governor_data = gd; + if (cpufreq_driver_is_slow()) { cpufreq_driver_slow = true; gd->task = kthread_create(cpufreq_sched_thread, policy, @@ -281,7 +283,6 @@ static int cpufreq_sched_policy_init(struct cpufreq_policy *policy) init_irq_work(&gd->irq_work, cpufreq_sched_irq_work); }
- policy->governor_data = gd; set_sched_freq();
return 0; -- 1.9.1