/* * lib/smp_processor_id.c * * DEBUG_PREEMPT variant of smp_processor_id(). */#include <linux/module.h>#include <linux/kallsyms.h>#include <linux/sched.h> unsigned int debug_smp_processor_id(void){	unsigned long preempt_count = preempt_count();	int this_cpu = raw_smp_processor_id();	cpumask_t this_mask; 	if (likely(preempt_count))		goto out; 	if (irqs_disabled())		goto out; 	/*	 * Kernel threads bound to a single CPU can safely use	 * smp_processor_id():	 */	this_mask = cpumask_of_cpu(this_cpu); 	if (cpus_equal(current->cpus_allowed, this_mask))		goto out; 	/*	 * It is valid to assume CPU-locality during early bootup:	 */	if (system_state != SYSTEM_RUNNING)		goto out; 	/*	 * Avoid recursion:	 */	preempt_disable(); 	if (!printk_ratelimit())		goto out_enable; 	printk(KERN_ERR "BUG: using smp_processor_id() in preemptible [%08x] code: %s/%d\n", preempt_count(), current->comm, current->pid);	print_symbol("caller is %s\n", (long)__builtin_return_address(0));	dump_stack(); out_enable:	preempt_enable_no_resched();out:	return this_cpu;} EXPORT_SYMBOL(debug_smp_processor_id);