// SPDX-License-Identifier: GPL-2.0/* * lib/smp_processor_id.c * * DEBUG_PREEMPT variant of smp_processor_id(). */#include <linux/export.h>#include <linux/kprobes.h>#include <linux/sched.h> noinstr staticunsigned int check_preemption_disabled(const char *what1, const char *what2){	int this_cpu = raw_smp_processor_id(); 	if (likely(preempt_count()))		goto out; 	if (irqs_disabled())		goto out; 	/*	 * Kernel threads bound to a single CPU can safely use	 * smp_processor_id():	 */	if (current->nr_cpus_allowed == 1)		goto out; 	/*	 * It is valid to assume CPU-locality during early bootup:	 */	if (system_state < SYSTEM_SCHEDULING)		goto out; 	/*	 * Avoid recursion:	 */	preempt_disable_notrace(); 	instrumentation_begin();	if (!printk_ratelimit())		goto out_enable; 	printk(KERN_ERR "BUG: using %s%s() in preemptible [%08x] code: %s/%d\n",		what1, what2, preempt_count() - 1, current->comm, current->pid); 	printk("caller is %pS\n", __builtin_return_address(0));	dump_stack();	instrumentation_end(); out_enable:	preempt_enable_no_resched_notrace();out:	return this_cpu;} noinstr unsigned int debug_smp_processor_id(void){	return check_preemption_disabled("smp_processor_id", "");}EXPORT_SYMBOL(debug_smp_processor_id); noinstr void __this_cpu_preempt_check(const char *op){	check_preemption_disabled("__this_cpu_", op);}EXPORT_SYMBOL(__this_cpu_preempt_check);