smp_processor_id() checks are enabled after the boot process is done. That hides bugs in the smp bringup and driver initialization code. Enable it right before the first non-boot CPU is brought up. Signed-off-by: Thomas Gleixner --- init/main.c | 3 +++ lib/smp_processor_id.c | 2 +- 2 files changed, 4 insertions(+), 1 deletion(-) Signed-off-by: Thomas Gleixner --- init/main.c | 3 +++ lib/smp_processor_id.c | 2 +- 2 files changed, 4 insertions(+), 1 deletion(-) --- a/init/main.c +++ b/init/main.c @@ -1025,6 +1025,9 @@ static noinline void __init kernel_init_ */ set_cpus_allowed_ptr(current, cpumask_of(raw_smp_processor_id())); + /* Enable smp_processor_id() checks */ + system_state = SYSTEM_BOOTING_SMP; + cad_pid = task_pid(current); smp_prepare_cpus(setup_max_cpus); --- a/lib/smp_processor_id.c +++ b/lib/smp_processor_id.c @@ -28,7 +28,7 @@ notrace static unsigned int check_preemp /* * It is valid to assume CPU-locality during early bootup: */ - if (system_state != SYSTEM_RUNNING) + if (system_state < SYSTEM_BOOTING_SMP) goto out; /*