From 6dab27784b2a97823b522e1cb88e40be40a93d45 Mon Sep 17 00:00:00 2001 From: Arjan van de Ven Date: Wed, 30 Jan 2008 13:33:08 +0100 Subject: [PATCH] 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: Arjan van de Ven Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- kernel/Makefile | 1 + kernel/backtracetest.c | 48 ++++++++++++++++++++++++++++++++++++++++++ lib/Kconfig.debug | 12 +++++++++++ 3 files changed, 61 insertions(+) create mode 100644 kernel/backtracetest.c diff --git a/kernel/Makefile b/kernel/Makefile index 62015c3d8d9..8885627ea02 100644 --- a/kernel/Makefile +++ b/kernel/Makefile @@ -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 diff --git a/kernel/backtracetest.c b/kernel/backtracetest.c new file mode 100644 index 00000000000..d1a7605c5b8 --- /dev/null +++ b/kernel/backtracetest.c @@ -0,0 +1,48 @@ +/* + * Simple stack backtrace regression test module + * + * (C) Copyright 2008 Intel Corporation + * Author: Arjan van de Ven + * + * 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 +#include +#include + +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 "); diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index f535b9b5eb0..aa56e631580 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -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 -- 2.41.1