kstrtox: fix compile warnings in test
[linux-2.6.git] / lib / fault-inject.c
1 #include <linux/kernel.h>
2 #include <linux/init.h>
3 #include <linux/random.h>
4 #include <linux/sched.h>
5 #include <linux/stat.h>
6 #include <linux/types.h>
7 #include <linux/fs.h>
8 #include <linux/module.h>
9 #include <linux/interrupt.h>
10 #include <linux/stacktrace.h>
11 #include <linux/kallsyms.h>
12 #include <linux/fault-inject.h>
13
14 /*
15  * setup_fault_attr() is a helper function for various __setup handlers, so it
16  * returns 0 on error, because that is what __setup handlers do.
17  */
18 int __init setup_fault_attr(struct fault_attr *attr, char *str)
19 {
20         unsigned long probability;
21         unsigned long interval;
22         int times;
23         int space;
24
25         /* "<interval>,<probability>,<space>,<times>" */
26         if (sscanf(str, "%lu,%lu,%d,%d",
27                         &interval, &probability, &space, &times) < 4) {
28                 printk(KERN_WARNING
29                         "FAULT_INJECTION: failed to parse arguments\n");
30                 return 0;
31         }
32
33         attr->probability = probability;
34         attr->interval = interval;
35         atomic_set(&attr->times, times);
36         atomic_set(&attr->space, space);
37
38         return 1;
39 }
40
41 static void fail_dump(struct fault_attr *attr)
42 {
43         if (attr->verbose > 0)
44                 printk(KERN_NOTICE "FAULT_INJECTION: forcing a failure\n");
45         if (attr->verbose > 1)
46                 dump_stack();
47 }
48
49 #define atomic_dec_not_zero(v)          atomic_add_unless((v), -1, 0)
50
51 static bool fail_task(struct fault_attr *attr, struct task_struct *task)
52 {
53         return !in_interrupt() && task->make_it_fail;
54 }
55
56 #define MAX_STACK_TRACE_DEPTH 32
57
58 #ifdef CONFIG_FAULT_INJECTION_STACKTRACE_FILTER
59
60 static bool fail_stacktrace(struct fault_attr *attr)
61 {
62         struct stack_trace trace;
63         int depth = attr->stacktrace_depth;
64         unsigned long entries[MAX_STACK_TRACE_DEPTH];
65         int n;
66         bool found = (attr->require_start == 0 && attr->require_end == ULONG_MAX);
67
68         if (depth == 0)
69                 return found;
70
71         trace.nr_entries = 0;
72         trace.entries = entries;
73         trace.max_entries = depth;
74         trace.skip = 1;
75
76         save_stack_trace(&trace);
77         for (n = 0; n < trace.nr_entries; n++) {
78                 if (attr->reject_start <= entries[n] &&
79                                entries[n] < attr->reject_end)
80                         return false;
81                 if (attr->require_start <= entries[n] &&
82                                entries[n] < attr->require_end)
83                         found = true;
84         }
85         return found;
86 }
87
88 #else
89
90 static inline bool fail_stacktrace(struct fault_attr *attr)
91 {
92         return true;
93 }
94
95 #endif /* CONFIG_FAULT_INJECTION_STACKTRACE_FILTER */
96
97 /*
98  * This code is stolen from failmalloc-1.0
99  * http://www.nongnu.org/failmalloc/
100  */
101
102 bool should_fail(struct fault_attr *attr, ssize_t size)
103 {
104         if (attr->task_filter && !fail_task(attr, current))
105                 return false;
106
107         if (atomic_read(&attr->times) == 0)
108                 return false;
109
110         if (atomic_read(&attr->space) > size) {
111                 atomic_sub(size, &attr->space);
112                 return false;
113         }
114
115         if (attr->interval > 1) {
116                 attr->count++;
117                 if (attr->count % attr->interval)
118                         return false;
119         }
120
121         if (attr->probability <= random32() % 100)
122                 return false;
123
124         if (!fail_stacktrace(attr))
125                 return false;
126
127         fail_dump(attr);
128
129         if (atomic_read(&attr->times) != -1)
130                 atomic_dec_not_zero(&attr->times);
131
132         return true;
133 }
134
135 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
136
137 static int debugfs_ul_set(void *data, u64 val)
138 {
139         *(unsigned long *)data = val;
140         return 0;
141 }
142
143 #ifdef CONFIG_FAULT_INJECTION_STACKTRACE_FILTER
144 static int debugfs_ul_set_MAX_STACK_TRACE_DEPTH(void *data, u64 val)
145 {
146         *(unsigned long *)data =
147                 val < MAX_STACK_TRACE_DEPTH ?
148                 val : MAX_STACK_TRACE_DEPTH;
149         return 0;
150 }
151 #endif /* CONFIG_FAULT_INJECTION_STACKTRACE_FILTER */
152
153 static int debugfs_ul_get(void *data, u64 *val)
154 {
155         *val = *(unsigned long *)data;
156         return 0;
157 }
158
159 DEFINE_SIMPLE_ATTRIBUTE(fops_ul, debugfs_ul_get, debugfs_ul_set, "%llu\n");
160
161 static struct dentry *debugfs_create_ul(const char *name, mode_t mode,
162                                 struct dentry *parent, unsigned long *value)
163 {
164         return debugfs_create_file(name, mode, parent, value, &fops_ul);
165 }
166
167 #ifdef CONFIG_FAULT_INJECTION_STACKTRACE_FILTER
168 DEFINE_SIMPLE_ATTRIBUTE(fops_ul_MAX_STACK_TRACE_DEPTH, debugfs_ul_get,
169                         debugfs_ul_set_MAX_STACK_TRACE_DEPTH, "%llu\n");
170
171 static struct dentry *debugfs_create_ul_MAX_STACK_TRACE_DEPTH(
172         const char *name, mode_t mode,
173         struct dentry *parent, unsigned long *value)
174 {
175         return debugfs_create_file(name, mode, parent, value,
176                                    &fops_ul_MAX_STACK_TRACE_DEPTH);
177 }
178 #endif /* CONFIG_FAULT_INJECTION_STACKTRACE_FILTER */
179
180 static int debugfs_atomic_t_set(void *data, u64 val)
181 {
182         atomic_set((atomic_t *)data, val);
183         return 0;
184 }
185
186 static int debugfs_atomic_t_get(void *data, u64 *val)
187 {
188         *val = atomic_read((atomic_t *)data);
189         return 0;
190 }
191
192 DEFINE_SIMPLE_ATTRIBUTE(fops_atomic_t, debugfs_atomic_t_get,
193                         debugfs_atomic_t_set, "%lld\n");
194
195 static struct dentry *debugfs_create_atomic_t(const char *name, mode_t mode,
196                                 struct dentry *parent, atomic_t *value)
197 {
198         return debugfs_create_file(name, mode, parent, value, &fops_atomic_t);
199 }
200
201 void cleanup_fault_attr_dentries(struct fault_attr *attr)
202 {
203         debugfs_remove(attr->dentries.probability_file);
204         attr->dentries.probability_file = NULL;
205
206         debugfs_remove(attr->dentries.interval_file);
207         attr->dentries.interval_file = NULL;
208
209         debugfs_remove(attr->dentries.times_file);
210         attr->dentries.times_file = NULL;
211
212         debugfs_remove(attr->dentries.space_file);
213         attr->dentries.space_file = NULL;
214
215         debugfs_remove(attr->dentries.verbose_file);
216         attr->dentries.verbose_file = NULL;
217
218         debugfs_remove(attr->dentries.task_filter_file);
219         attr->dentries.task_filter_file = NULL;
220
221 #ifdef CONFIG_FAULT_INJECTION_STACKTRACE_FILTER
222
223         debugfs_remove(attr->dentries.stacktrace_depth_file);
224         attr->dentries.stacktrace_depth_file = NULL;
225
226         debugfs_remove(attr->dentries.require_start_file);
227         attr->dentries.require_start_file = NULL;
228
229         debugfs_remove(attr->dentries.require_end_file);
230         attr->dentries.require_end_file = NULL;
231
232         debugfs_remove(attr->dentries.reject_start_file);
233         attr->dentries.reject_start_file = NULL;
234
235         debugfs_remove(attr->dentries.reject_end_file);
236         attr->dentries.reject_end_file = NULL;
237
238 #endif /* CONFIG_FAULT_INJECTION_STACKTRACE_FILTER */
239
240         if (attr->dentries.dir)
241                 WARN_ON(!simple_empty(attr->dentries.dir));
242
243         debugfs_remove(attr->dentries.dir);
244         attr->dentries.dir = NULL;
245 }
246
247 int init_fault_attr_dentries(struct fault_attr *attr, const char *name)
248 {
249         mode_t mode = S_IFREG | S_IRUSR | S_IWUSR;
250         struct dentry *dir;
251
252         memset(&attr->dentries, 0, sizeof(attr->dentries));
253
254         dir = debugfs_create_dir(name, NULL);
255         if (!dir)
256                 goto fail;
257         attr->dentries.dir = dir;
258
259         attr->dentries.probability_file =
260                 debugfs_create_ul("probability", mode, dir, &attr->probability);
261
262         attr->dentries.interval_file =
263                 debugfs_create_ul("interval", mode, dir, &attr->interval);
264
265         attr->dentries.times_file =
266                 debugfs_create_atomic_t("times", mode, dir, &attr->times);
267
268         attr->dentries.space_file =
269                 debugfs_create_atomic_t("space", mode, dir, &attr->space);
270
271         attr->dentries.verbose_file =
272                 debugfs_create_ul("verbose", mode, dir, &attr->verbose);
273
274         attr->dentries.task_filter_file = debugfs_create_bool("task-filter",
275                                                 mode, dir, &attr->task_filter);
276
277         if (!attr->dentries.probability_file || !attr->dentries.interval_file ||
278             !attr->dentries.times_file || !attr->dentries.space_file ||
279             !attr->dentries.verbose_file || !attr->dentries.task_filter_file)
280                 goto fail;
281
282 #ifdef CONFIG_FAULT_INJECTION_STACKTRACE_FILTER
283
284         attr->dentries.stacktrace_depth_file =
285                 debugfs_create_ul_MAX_STACK_TRACE_DEPTH(
286                         "stacktrace-depth", mode, dir, &attr->stacktrace_depth);
287
288         attr->dentries.require_start_file =
289                 debugfs_create_ul("require-start", mode, dir, &attr->require_start);
290
291         attr->dentries.require_end_file =
292                 debugfs_create_ul("require-end", mode, dir, &attr->require_end);
293
294         attr->dentries.reject_start_file =
295                 debugfs_create_ul("reject-start", mode, dir, &attr->reject_start);
296
297         attr->dentries.reject_end_file =
298                 debugfs_create_ul("reject-end", mode, dir, &attr->reject_end);
299
300         if (!attr->dentries.stacktrace_depth_file ||
301             !attr->dentries.require_start_file ||
302             !attr->dentries.require_end_file ||
303             !attr->dentries.reject_start_file ||
304             !attr->dentries.reject_end_file)
305                 goto fail;
306
307 #endif /* CONFIG_FAULT_INJECTION_STACKTRACE_FILTER */
308
309         return 0;
310 fail:
311         cleanup_fault_attr_dentries(attr);
312         return -ENOMEM;
313 }
314
315 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */