linux-imx

// 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>

​

notrace static nokprobe_inline

unsigned 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 (cpumask_equal(&current->cpus_allowed, cpumask_of(this_cpu)))

        goto out;

​

    /*

     * It is valid to assume CPU-locality during early bootup:

     */

    if (system_state < SYSTEM_SCHEDULING)

        goto out;

​

    /*

     * Avoid recursion:

     */

    preempt_disable_notrace();

​

    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();

​

out_enable:

    preempt_enable_no_resched_notrace();

out:

    return this_cpu;

}

​

notrace unsigned int debug_smp_processor_id(void)

{

    return check_preemption_disabled("smp_processor_id", "");

}

EXPORT_SYMBOL(debug_smp_processor_id);

NOKPROBE_SYMBOL(debug_smp_processor_id);

​

notrace void __this_cpu_preempt_check(const char *op)

{