1// SPDX-License-Identifier: GPL-2.0-only
  2#include <linux/module.h>
  3
  4#include "notifier-error-inject.h"
  5
  6static int debugfs_errno_set(void *data, u64 val)
  7{
  8	*(int *)data = clamp_t(int, val, -MAX_ERRNO, 0);
  9	return 0;
 10}
 11
 12static int debugfs_errno_get(void *data, u64 *val)
 13{
 14	*val = *(int *)data;
 15	return 0;
 16}
 17
 18DEFINE_SIMPLE_ATTRIBUTE(fops_errno, debugfs_errno_get, debugfs_errno_set,
 19			"%lld\n");
 20
 21static struct dentry *debugfs_create_errno(const char *name, umode_t mode,
 22				struct dentry *parent, int *value)
 23{
 24	return debugfs_create_file(name, mode, parent, value, &fops_errno);
 25}
 26
 27static int notifier_err_inject_callback(struct notifier_block *nb,
 28				unsigned long val, void *p)
 29{
 30	int err = 0;
 31	struct notifier_err_inject *err_inject =
 32		container_of(nb, struct notifier_err_inject, nb);
 33	struct notifier_err_inject_action *action;
 34
 35	for (action = err_inject->actions; action->name; action++) {
 36		if (action->val == val) {
 37			err = action->error;
 38			break;
 39		}
 40	}
 41	if (err)
 42		pr_info("Injecting error (%d) to %s\n", err, action->name);
 43
 44	return notifier_from_errno(err);
 45}
 46
 47struct dentry *notifier_err_inject_dir;
 48EXPORT_SYMBOL_GPL(notifier_err_inject_dir);
 49
 50struct dentry *notifier_err_inject_init(const char *name, struct dentry *parent,
 51			struct notifier_err_inject *err_inject, int priority)
 52{
 53	struct notifier_err_inject_action *action;
 54	umode_t mode = S_IFREG | S_IRUSR | S_IWUSR;
 55	struct dentry *dir;
 56	struct dentry *actions_dir;
 57
 58	err_inject->nb.notifier_call = notifier_err_inject_callback;
 59	err_inject->nb.priority = priority;
 60
 61	dir = debugfs_create_dir(name, parent);
 62
 63	actions_dir = debugfs_create_dir("actions", dir);
 64
 65	for (action = err_inject->actions; action->name; action++) {
 66		struct dentry *action_dir;
 67
 68		action_dir = debugfs_create_dir(action->name, actions_dir);
 69
 70		/*
 71		 * Create debugfs r/w file containing action->error. If
 72		 * notifier call chain is called with action->val, it will
 73		 * fail with the error code
 74		 */
 75		debugfs_create_errno("error", mode, action_dir, &action->error);
 76	}
 77	return dir;
 78}
 79EXPORT_SYMBOL_GPL(notifier_err_inject_init);
 80
 81static int __init err_inject_init(void)
 82{
 83	notifier_err_inject_dir =
 84		debugfs_create_dir("notifier-error-inject", NULL);
 85
 86	if (!notifier_err_inject_dir)
 87		return -ENOMEM;
 88
 89	return 0;
 90}
 91
 92static void __exit err_inject_exit(void)
 93{
 94	debugfs_remove_recursive(notifier_err_inject_dir);
 95}
 96
 97module_init(err_inject_init);
 98module_exit(err_inject_exit);
 99
100MODULE_DESCRIPTION("Notifier error injection module");
101MODULE_LICENSE("GPL");
102MODULE_AUTHOR("Akinobu Mita <akinobu.mita@gmail.com>");

 1// SPDX-License-Identifier: GPL-2.0-only
 2#include <linux/module.h>
 3
 4#include "notifier-error-inject.h"
 5
 6static int debugfs_errno_set(void *data, u64 val)
 7{
 8	*(int *)data = clamp_t(int, val, -MAX_ERRNO, 0);
 9	return 0;
10}
11
12static int debugfs_errno_get(void *data, u64 *val)
13{
14	*val = *(int *)data;
15	return 0;
16}
17
18DEFINE_SIMPLE_ATTRIBUTE_SIGNED(fops_errno, debugfs_errno_get, debugfs_errno_set,
19			"%lld\n");
20
21static struct dentry *debugfs_create_errno(const char *name, umode_t mode,
22				struct dentry *parent, int *value)
23{
24	return debugfs_create_file(name, mode, parent, value, &fops_errno);
25}
26
27static int notifier_err_inject_callback(struct notifier_block *nb,
28				unsigned long val, void *p)
29{
30	int err = 0;
31	struct notifier_err_inject *err_inject =
32		container_of(nb, struct notifier_err_inject, nb);
33	struct notifier_err_inject_action *action;
34
35	for (action = err_inject->actions; action->name; action++) {
36		if (action->val == val) {
37			err = action->error;
38			break;
39		}
40	}
41	if (err)
42		pr_info("Injecting error (%d) to %s\n", err, action->name);
43
44	return notifier_from_errno(err);
45}
46
47struct dentry *notifier_err_inject_dir;
48EXPORT_SYMBOL_GPL(notifier_err_inject_dir);
49
50struct dentry *notifier_err_inject_init(const char *name, struct dentry *parent,
51			struct notifier_err_inject *err_inject, int priority)
52{
53	struct notifier_err_inject_action *action;
54	umode_t mode = S_IFREG | S_IRUSR | S_IWUSR;
55	struct dentry *dir;
56	struct dentry *actions_dir;
57
58	err_inject->nb.notifier_call = notifier_err_inject_callback;
59	err_inject->nb.priority = priority;
60
61	dir = debugfs_create_dir(name, parent);
62
63	actions_dir = debugfs_create_dir("actions", dir);
64
65	for (action = err_inject->actions; action->name; action++) {
66		struct dentry *action_dir;
67
68		action_dir = debugfs_create_dir(action->name, actions_dir);
69
70		/*
71		 * Create debugfs r/w file containing action->error. If
72		 * notifier call chain is called with action->val, it will
73		 * fail with the error code
74		 */
75		debugfs_create_errno("error", mode, action_dir, &action->error);
76	}
77	return dir;
78}
79EXPORT_SYMBOL_GPL(notifier_err_inject_init);
80
81static int __init err_inject_init(void)
82{
83	notifier_err_inject_dir =
84		debugfs_create_dir("notifier-error-inject", NULL);
 
 
 
85
86	return 0;
87}
88
89static void __exit err_inject_exit(void)
90{
91	debugfs_remove_recursive(notifier_err_inject_dir);
92}
93
94module_init(err_inject_init);
95module_exit(err_inject_exit);
96
97MODULE_DESCRIPTION("Notifier error injection module");
98MODULE_LICENSE("GPL");
99MODULE_AUTHOR("Akinobu Mita <akinobu.mita@gmail.com>");