backtracetest.c

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/*
 * Simple stack backtrace regression test module
 *
 * (C) Copyright 2008 Intel Corporation
 * Author: Arjan van de Ven <[email protected]>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; version 2
 * of the License.
 */

#include <linux/completion.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/stacktrace.h>

static void backtrace_test_normal(void)
{
    printk("Testing a backtrace from process context.\n");
    printk("The following trace is a kernel self test and not a bug!\n");

    dump_stack();
}

static DECLARE_COMPLETION(backtrace_work);

static void backtrace_test_irq_callback(unsigned long data)
{
    dump_stack();
    complete(&backtrace_work);
}

static DECLARE_TASKLET(backtrace_tasklet, &backtrace_test_irq_callback, 0);

static void backtrace_test_irq(void)
{
    printk("Testing a backtrace from irq context.\n");
    printk("The following trace is a kernel self test and not a bug!\n");

    init_completion(&backtrace_work);
    tasklet_schedule(&backtrace_tasklet);
    wait_for_completion(&backtrace_work);
}

#ifdef CONFIG_STACKTRACE
static void backtrace_test_saved(void)
{
    struct stack_trace trace;
    unsigned long entries[8];

    printk("Testing a saved backtrace.\n");
    printk("The following trace is a kernel self test and not a bug!\n");

    trace.nr_entries = 0;
    trace.max_entries = ARRAY_SIZE(entries);
    trace.entries = entries;
    trace.skip = 0;

    save_stack_trace(&trace);
    print_stack_trace(&trace, 0);
}
#else
static void backtrace_test_saved(void)
{
    printk("Saved backtrace test skipped.\n");
}
#endif

static int backtrace_regression_test(void)
{
    printk("====[ backtrace testing ]===========\n");

    backtrace_test_normal();
    backtrace_test_irq();
    backtrace_test_saved();

    printk("====[ end of backtrace testing ]====\n");
    return 0;
}

static void exitf(void)
{
}

module_init(backtrace_regression_test);
module_exit(exitf);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Arjan van de Ven <[email protected]>");