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Commit 6dab2778 authored by Arjan van de Ven's avatar Arjan van de Ven Committed by Ingo Molnar
Browse files

x86: add a simple backtrace test module 



During the work on the x86 32 and 64 bit backtrace code I found it useful
to have a simple test module to test a process and irq context backtrace.
Since the existing backtrace code was buggy, I figure it might be useful
to have such a test module in the kernel so that maybe we can even
detect such bugs earlier..

[ mingo@elte.hu: build fix ]

Signed-off-by: default avatarArjan van de Ven <arjan@linux.intel.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
parent 80b51f31

kernel/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -36,6 +36,7 @@ obj-$(CONFIG_KALLSYMS) += kallsyms.o 
obj-$(CONFIG_PM) += power/

obj-$(CONFIG_BSD_PROCESS_ACCT) += acct.o

obj-$(CONFIG_KEXEC) += kexec.o

obj-$(CONFIG_BACKTRACE_SELF_TEST) += backtracetest.o

obj-$(CONFIG_COMPAT) += compat.o

obj-$(CONFIG_CGROUPS) += cgroup.o

obj-$(CONFIG_CGROUP_DEBUG) += cgroup_debug.o

kernel/backtracetest.c

0 → 100644
+48 −0
Original line number Diff line number Diff line 
/*

 * Simple stack backtrace regression test module

 *

 * (C) Copyright 2008 Intel Corporation

 * Author: Arjan van de Ven <arjan@linux.intel.com>

 *

 * 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/module.h>

#include <linux/sched.h>

#include <linux/delay.h>



static struct timer_list backtrace_timer;



static void backtrace_test_timer(unsigned long data)

{

	printk("Testing a backtrace from irq context.\n");

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

	dump_stack();

}

static int backtrace_regression_test(void)

{

	printk("====[ backtrace testing ]===========\n");

	printk("Testing a backtrace from process context.\n");

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

	dump_stack();



	init_timer(&backtrace_timer);

	backtrace_timer.function = backtrace_test_timer;

	mod_timer(&backtrace_timer, jiffies + 10);



	msleep(10);

	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 <arjan@linux.intel.com>");

lib/Kconfig.debug

+12 −0
Original line number Diff line number Diff line
@@ -506,6 +506,18 @@ config KPROBES_SANITY_TEST 


	  Say N if you are unsure.



config BACKTRACE_SELF_TEST

	tristate "Self test for the backtrace code"

	depends on DEBUG_KERNEL

	default n

	help

	  This option provides a kernel module that can be used to test

	  the kernel stack backtrace code. This option is not useful

	  for distributions or general kernels, but only for kernel

	  developers working on architecture code.



	  Say N if you are unsure.



config LKDTM

	tristate "Linux Kernel Dump Test Tool Module"

	depends on DEBUG_KERNEL