Commit 683263a5 authored by Jim Cromie's avatar Jim Cromie Committed by Greg Kroah-Hartman
Browse files

dyndbg: add test_dynamic_debug module 



Provide a simple module to allow testing DYNAMIC_DEBUG behavior.  It
calls do_prints() from module-init, and with a sysfs-node.

  dmesg -C
  dmesg -w &
  modprobe test_dynamic_debug dyndbg=+p
  echo 1 > /sys/module/dynamic_debug/parameters/verbose

  cat /sys/module/test_dynamic_debug/parameters/do_prints
  echo module test_dynamic_debug +mftl > /proc/dynamic_debug/control
  echo junk > /sys/module/test_dynamic_debug/parameters/do_prints

Acked-by: default avatarJason Baron <jbaron@akamai.com>
Acked-by: default avatarDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: default avatarJim Cromie <jim.cromie@gmail.com>
Link: https://lore.kernel.org/r/20220904214134.408619-9-jim.cromie@gmail.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent e75ef56f

MAINTAINERS

+2 −0
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@@ -7205,6 +7205,8 @@ M: Jason Baron <jbaron@akamai.com> 
S:	Maintained

F:	include/linux/dynamic_debug.h

F:	lib/dynamic_debug.c

M:	Jim Cromie <jim.cromie@gmail.com>

F:	lib/test_dynamic_debug.c









DYNAMIC INTERRUPT MODERATION









M:	Tal Gilboa <talgi@nvidia.com>


































lib/Kconfig.debug



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@@ -2546,6 +2546,16 @@ config TEST_STATIC_KEYS

















	  If unsure, say N.



















config TEST_DYNAMIC_DEBUG









	tristate "Test DYNAMIC_DEBUG"









	depends on DYNAMIC_DEBUG









	help









	  This module registers a tracer callback to count enabled









	  pr_debugs in a 'do_debugging' function, then alters their









	  enablements, calls the function, and compares counts.



















	  If unsure, say N.



















config TEST_KMOD









	tristate "kmod stress tester"









	depends on m


































lib/Makefile



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@@ -82,6 +82,7 @@ obj-$(CONFIG_TEST_SORT) += test_sort.o







obj-$(CONFIG_TEST_USER_COPY) += test_user_copy.o









obj-$(CONFIG_TEST_STATIC_KEYS) += test_static_keys.o









obj-$(CONFIG_TEST_STATIC_KEYS) += test_static_key_base.o









obj-$(CONFIG_TEST_DYNAMIC_DEBUG) += test_dynamic_debug.o









obj-$(CONFIG_TEST_PRINTF) += test_printf.o









obj-$(CONFIG_TEST_SCANF) += test_scanf.o









obj-$(CONFIG_TEST_BITMAP) += test_bitmap.o


































lib/test_dynamic_debug.c
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// SPDX-License-Identifier: GPL-2.0-only









/*









 * Kernel module for testing dynamic_debug









 *









 * Authors:









 *      Jim Cromie	<jim.cromie@gmail.com>









 */



















#define pr_fmt(fmt) "test_dd: " fmt



















#include <linux/module.h>



















static void do_prints(void); /* device under test */



















/* run tests by reading or writing sysfs node */



















static int param_set_do_prints(const char *instr, const struct kernel_param *kp)









{









	do_prints();









	return 0;









}



















static int param_get_do_prints(char *buffer, const struct kernel_param *kp)









{









	do_prints();









	return scnprintf(buffer, PAGE_SIZE, "did do_prints\n");









}



















static const struct kernel_param_ops param_ops_do_prints = {









	.set = param_set_do_prints,









	.get = param_get_do_prints,









};



















module_param_cb(do_prints, &param_ops_do_prints, NULL, 0600);



















static void do_alpha(void)









{









	pr_debug("do alpha\n");









}









static void do_beta(void)









{









	pr_debug("do beta\n");









}



















static void do_prints(void)









{









	do_alpha();









	do_beta();









}



















static int __init test_dynamic_debug_init(void)









{









	pr_debug("init start\n");



















	do_prints();



















	pr_debug("init done\n");









	return 0;









}



















static void __exit test_dynamic_debug_exit(void)









{









	pr_debug("exiting\n");









}



















module_init(test_dynamic_debug_init);









module_exit(test_dynamic_debug_exit);



















MODULE_AUTHOR("Jim Cromie <jim.cromie@gmail.com>");









MODULE_LICENSE("GPL");