69 lines · c
1// SPDX-License-Identifier: GPL-2.02/*3 * lib/smp_processor_id.c4 *5 * DEBUG_PREEMPT variant of smp_processor_id().6 */7#include <linux/export.h>8#include <linux/kprobes.h>9#include <linux/sched.h>10 11noinstr static12unsigned int check_preemption_disabled(const char *what1, const char *what2)13{14 int this_cpu = raw_smp_processor_id();15 16 if (likely(preempt_count()))17 goto out;18 19 if (irqs_disabled())20 goto out;21 22 if (is_percpu_thread())23 goto out;24 25#ifdef CONFIG_SMP26 if (current->migration_disabled)27 goto out;28#endif29 30 /*31 * It is valid to assume CPU-locality during early bootup:32 */33 if (system_state < SYSTEM_SCHEDULING)34 goto out;35 36 /*37 * Avoid recursion:38 */39 preempt_disable_notrace();40 41 instrumentation_begin();42 if (!printk_ratelimit())43 goto out_enable;44 45 printk(KERN_ERR "BUG: using %s%s() in preemptible [%08x] code: %s/%d\n",46 what1, what2, preempt_count() - 1, current->comm, current->pid);47 48 printk("caller is %pS\n", __builtin_return_address(0));49 dump_stack();50 51out_enable:52 instrumentation_end();53 preempt_enable_no_resched_notrace();54out:55 return this_cpu;56}57 58noinstr unsigned int debug_smp_processor_id(void)59{60 return check_preemption_disabled("smp_processor_id", "");61}62EXPORT_SYMBOL(debug_smp_processor_id);63 64noinstr void __this_cpu_preempt_check(const char *op)65{66 check_preemption_disabled("__this_cpu_", op);67}68EXPORT_SYMBOL(__this_cpu_preempt_check);69