linux-imx

// SPDX-License-Identifier: GPL-2.0

/*

 * trace context switch

 *

 * Copyright (C) 2007 Steven Rostedt <srostedt@redhat.com>

 *

 */

#include <linux/module.h>

#include <linux/kallsyms.h>

#include <linux/uaccess.h>

#include <linux/ftrace.h>

#include <trace/events/sched.h>

​

#include "trace.h"

​

#define RECORD_CMDLINE  1

#define RECORD_TGID 2

​

static int      sched_cmdline_ref;

static int      sched_tgid_ref;

static DEFINE_MUTEX(sched_register_mutex);

​

static void

probe_sched_switch(void *ignore, bool preempt,

           struct task_struct *prev, struct task_struct *next)

{

    int flags;

​

    flags = (RECORD_TGID * !!sched_tgid_ref) +

        (RECORD_CMDLINE * !!sched_cmdline_ref);

​

    if (!flags)

        return;

    tracing_record_taskinfo_sched_switch(prev, next, flags);

}

​

static void

probe_sched_wakeup(void *ignore, struct task_struct *wakee)

{

    int flags;

​

    flags = (RECORD_TGID * !!sched_tgid_ref) +

        (RECORD_CMDLINE * !!sched_cmdline_ref);

​

    if (!flags)

        return;

    tracing_record_taskinfo(current, flags);

}

​

static int tracing_sched_register(void)

{

    int ret;

​

    ret = register_trace_sched_wakeup(probe_sched_wakeup, NULL);

    if (ret) {

        pr_info("wakeup trace: Couldn't activate tracepoint"

            " probe to kernel_sched_wakeup\n");

        return ret;

    }

​

    ret = register_trace_sched_wakeup_new(probe_sched_wakeup, NULL);

    if (ret) {

        pr_info("wakeup trace: Couldn't activate tracepoint"

            " probe to kernel_sched_wakeup_new\n");

        goto fail_deprobe;

    }

​

    ret = register_trace_sched_switch(probe_sched_switch, NULL);

    if (ret) {

        pr_info("sched trace: Couldn't activate tracepoint"

            " probe to kernel_sched_switch\n");

        goto fail_deprobe_wake_new;

    }

​

    return ret;

fail_deprobe_wake_new:

    unregister_trace_sched_wakeup_new(probe_sched_wakeup, NULL);

fail_deprobe:

    unregister_trace_sched_wakeup(probe_sched_wakeup, NULL);

    return ret;

}

​

static void tracing_sched_unregister(void)

{

    unregister_trace_sched_switch(probe_sched_switch, NULL);

    unregister_trace_sched_wakeup_new(probe_sched_wakeup, NULL);

    unregister_trace_sched_wakeup(probe_sched_wakeup, NULL);

}

​

static void tracing_start_sched_switch(int ops)

{

    bool sched_register = (!sched_cmdline_ref && !sched_tgid_ref);