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Ingo Molnara8f24a32006-07-03 00:24:52 -07001/*
2 * kernel/lockdep_proc.c
3 *
4 * Runtime locking correctness validator
5 *
6 * Started by Ingo Molnar:
7 *
8 * Copyright (C) 2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
9 *
10 * Code for /proc/lockdep and /proc/lockdep_stats:
11 *
12 */
13#include <linux/sched.h>
14#include <linux/module.h>
15#include <linux/proc_fs.h>
16#include <linux/seq_file.h>
17#include <linux/kallsyms.h>
18#include <linux/debug_locks.h>
19
20#include "lockdep_internals.h"
21
22static void *l_next(struct seq_file *m, void *v, loff_t *pos)
23{
24 struct lock_class *class = v;
25
26 (*pos)++;
27
28 if (class->lock_entry.next != &all_lock_classes)
29 class = list_entry(class->lock_entry.next, struct lock_class,
30 lock_entry);
31 else
32 class = NULL;
33 m->private = class;
34
35 return class;
36}
37
38static void *l_start(struct seq_file *m, loff_t *pos)
39{
40 struct lock_class *class = m->private;
41
42 if (&class->lock_entry == all_lock_classes.next)
43 seq_printf(m, "all lock classes:\n");
44
45 return class;
46}
47
48static void l_stop(struct seq_file *m, void *v)
49{
50}
51
52static unsigned long count_forward_deps(struct lock_class *class)
53{
54 struct lock_list *entry;
55 unsigned long ret = 1;
56
57 /*
58 * Recurse this class's dependency list:
59 */
60 list_for_each_entry(entry, &class->locks_after, entry)
61 ret += count_forward_deps(entry->class);
62
63 return ret;
64}
65
66static unsigned long count_backward_deps(struct lock_class *class)
67{
68 struct lock_list *entry;
69 unsigned long ret = 1;
70
71 /*
72 * Recurse this class's dependency list:
73 */
74 list_for_each_entry(entry, &class->locks_before, entry)
75 ret += count_backward_deps(entry->class);
76
77 return ret;
78}
79
80static int l_show(struct seq_file *m, void *v)
81{
82 unsigned long nr_forward_deps, nr_backward_deps;
83 struct lock_class *class = m->private;
84 char str[128], c1, c2, c3, c4;
85 const char *name;
86
87 seq_printf(m, "%p", class->key);
88#ifdef CONFIG_DEBUG_LOCKDEP
89 seq_printf(m, " OPS:%8ld", class->ops);
90#endif
91 nr_forward_deps = count_forward_deps(class);
92 seq_printf(m, " FD:%5ld", nr_forward_deps);
93
94 nr_backward_deps = count_backward_deps(class);
95 seq_printf(m, " BD:%5ld", nr_backward_deps);
96
97 get_usage_chars(class, &c1, &c2, &c3, &c4);
98 seq_printf(m, " %c%c%c%c", c1, c2, c3, c4);
99
100 name = class->name;
101 if (!name) {
102 name = __get_key_name(class->key, str);
103 seq_printf(m, ": %s", name);
104 } else{
105 seq_printf(m, ": %s", name);
106 if (class->name_version > 1)
107 seq_printf(m, "#%d", class->name_version);
108 if (class->subclass)
109 seq_printf(m, "/%d", class->subclass);
110 }
111 seq_puts(m, "\n");
112
113 return 0;
114}
115
116static struct seq_operations lockdep_ops = {
117 .start = l_start,
118 .next = l_next,
119 .stop = l_stop,
120 .show = l_show,
121};
122
123static int lockdep_open(struct inode *inode, struct file *file)
124{
125 int res = seq_open(file, &lockdep_ops);
126 if (!res) {
127 struct seq_file *m = file->private_data;
128
129 if (!list_empty(&all_lock_classes))
130 m->private = list_entry(all_lock_classes.next,
131 struct lock_class, lock_entry);
132 else
133 m->private = NULL;
134 }
135 return res;
136}
137
138static struct file_operations proc_lockdep_operations = {
139 .open = lockdep_open,
140 .read = seq_read,
141 .llseek = seq_lseek,
142 .release = seq_release,
143};
144
145static void lockdep_stats_debug_show(struct seq_file *m)
146{
147#ifdef CONFIG_DEBUG_LOCKDEP
148 unsigned int hi1 = debug_atomic_read(&hardirqs_on_events),
149 hi2 = debug_atomic_read(&hardirqs_off_events),
150 hr1 = debug_atomic_read(&redundant_hardirqs_on),
151 hr2 = debug_atomic_read(&redundant_hardirqs_off),
152 si1 = debug_atomic_read(&softirqs_on_events),
153 si2 = debug_atomic_read(&softirqs_off_events),
154 sr1 = debug_atomic_read(&redundant_softirqs_on),
155 sr2 = debug_atomic_read(&redundant_softirqs_off);
156
157 seq_printf(m, " chain lookup misses: %11u\n",
158 debug_atomic_read(&chain_lookup_misses));
159 seq_printf(m, " chain lookup hits: %11u\n",
160 debug_atomic_read(&chain_lookup_hits));
161 seq_printf(m, " cyclic checks: %11u\n",
162 debug_atomic_read(&nr_cyclic_checks));
163 seq_printf(m, " cyclic-check recursions: %11u\n",
164 debug_atomic_read(&nr_cyclic_check_recursions));
165 seq_printf(m, " find-mask forwards checks: %11u\n",
166 debug_atomic_read(&nr_find_usage_forwards_checks));
167 seq_printf(m, " find-mask forwards recursions: %11u\n",
168 debug_atomic_read(&nr_find_usage_forwards_recursions));
169 seq_printf(m, " find-mask backwards checks: %11u\n",
170 debug_atomic_read(&nr_find_usage_backwards_checks));
171 seq_printf(m, " find-mask backwards recursions:%11u\n",
172 debug_atomic_read(&nr_find_usage_backwards_recursions));
173
174 seq_printf(m, " hardirq on events: %11u\n", hi1);
175 seq_printf(m, " hardirq off events: %11u\n", hi2);
176 seq_printf(m, " redundant hardirq ons: %11u\n", hr1);
177 seq_printf(m, " redundant hardirq offs: %11u\n", hr2);
178 seq_printf(m, " softirq on events: %11u\n", si1);
179 seq_printf(m, " softirq off events: %11u\n", si2);
180 seq_printf(m, " redundant softirq ons: %11u\n", sr1);
181 seq_printf(m, " redundant softirq offs: %11u\n", sr2);
182#endif
183}
184
185static int lockdep_stats_show(struct seq_file *m, void *v)
186{
187 struct lock_class *class;
188 unsigned long nr_unused = 0, nr_uncategorized = 0,
189 nr_irq_safe = 0, nr_irq_unsafe = 0,
190 nr_softirq_safe = 0, nr_softirq_unsafe = 0,
191 nr_hardirq_safe = 0, nr_hardirq_unsafe = 0,
192 nr_irq_read_safe = 0, nr_irq_read_unsafe = 0,
193 nr_softirq_read_safe = 0, nr_softirq_read_unsafe = 0,
194 nr_hardirq_read_safe = 0, nr_hardirq_read_unsafe = 0,
195 sum_forward_deps = 0, factor = 0;
196
197 list_for_each_entry(class, &all_lock_classes, lock_entry) {
198
199 if (class->usage_mask == 0)
200 nr_unused++;
201 if (class->usage_mask == LOCKF_USED)
202 nr_uncategorized++;
203 if (class->usage_mask & LOCKF_USED_IN_IRQ)
204 nr_irq_safe++;
205 if (class->usage_mask & LOCKF_ENABLED_IRQS)
206 nr_irq_unsafe++;
207 if (class->usage_mask & LOCKF_USED_IN_SOFTIRQ)
208 nr_softirq_safe++;
209 if (class->usage_mask & LOCKF_ENABLED_SOFTIRQS)
210 nr_softirq_unsafe++;
211 if (class->usage_mask & LOCKF_USED_IN_HARDIRQ)
212 nr_hardirq_safe++;
213 if (class->usage_mask & LOCKF_ENABLED_HARDIRQS)
214 nr_hardirq_unsafe++;
215 if (class->usage_mask & LOCKF_USED_IN_IRQ_READ)
216 nr_irq_read_safe++;
217 if (class->usage_mask & LOCKF_ENABLED_IRQS_READ)
218 nr_irq_read_unsafe++;
219 if (class->usage_mask & LOCKF_USED_IN_SOFTIRQ_READ)
220 nr_softirq_read_safe++;
221 if (class->usage_mask & LOCKF_ENABLED_SOFTIRQS_READ)
222 nr_softirq_read_unsafe++;
223 if (class->usage_mask & LOCKF_USED_IN_HARDIRQ_READ)
224 nr_hardirq_read_safe++;
225 if (class->usage_mask & LOCKF_ENABLED_HARDIRQS_READ)
226 nr_hardirq_read_unsafe++;
227
228 sum_forward_deps += count_forward_deps(class);
229 }
230#ifdef CONFIG_LOCKDEP_DEBUG
231 DEBUG_LOCKS_WARN_ON(debug_atomic_read(&nr_unused_locks) != nr_unused);
232#endif
233 seq_printf(m, " lock-classes: %11lu [max: %lu]\n",
234 nr_lock_classes, MAX_LOCKDEP_KEYS);
235 seq_printf(m, " direct dependencies: %11lu [max: %lu]\n",
236 nr_list_entries, MAX_LOCKDEP_ENTRIES);
237 seq_printf(m, " indirect dependencies: %11lu\n",
238 sum_forward_deps);
239
240 /*
241 * Total number of dependencies:
242 *
243 * All irq-safe locks may nest inside irq-unsafe locks,
244 * plus all the other known dependencies:
245 */
246 seq_printf(m, " all direct dependencies: %11lu\n",
247 nr_irq_unsafe * nr_irq_safe +
248 nr_hardirq_unsafe * nr_hardirq_safe +
249 nr_list_entries);
250
251 /*
252 * Estimated factor between direct and indirect
253 * dependencies:
254 */
255 if (nr_list_entries)
256 factor = sum_forward_deps / nr_list_entries;
257
258 seq_printf(m, " dependency chains: %11lu [max: %lu]\n",
259 nr_lock_chains, MAX_LOCKDEP_CHAINS);
260
261#ifdef CONFIG_TRACE_IRQFLAGS
262 seq_printf(m, " in-hardirq chains: %11u\n",
263 nr_hardirq_chains);
264 seq_printf(m, " in-softirq chains: %11u\n",
265 nr_softirq_chains);
266#endif
267 seq_printf(m, " in-process chains: %11u\n",
268 nr_process_chains);
269 seq_printf(m, " stack-trace entries: %11lu [max: %lu]\n",
270 nr_stack_trace_entries, MAX_STACK_TRACE_ENTRIES);
271 seq_printf(m, " combined max dependencies: %11u\n",
272 (nr_hardirq_chains + 1) *
273 (nr_softirq_chains + 1) *
274 (nr_process_chains + 1)
275 );
276 seq_printf(m, " hardirq-safe locks: %11lu\n",
277 nr_hardirq_safe);
278 seq_printf(m, " hardirq-unsafe locks: %11lu\n",
279 nr_hardirq_unsafe);
280 seq_printf(m, " softirq-safe locks: %11lu\n",
281 nr_softirq_safe);
282 seq_printf(m, " softirq-unsafe locks: %11lu\n",
283 nr_softirq_unsafe);
284 seq_printf(m, " irq-safe locks: %11lu\n",
285 nr_irq_safe);
286 seq_printf(m, " irq-unsafe locks: %11lu\n",
287 nr_irq_unsafe);
288
289 seq_printf(m, " hardirq-read-safe locks: %11lu\n",
290 nr_hardirq_read_safe);
291 seq_printf(m, " hardirq-read-unsafe locks: %11lu\n",
292 nr_hardirq_read_unsafe);
293 seq_printf(m, " softirq-read-safe locks: %11lu\n",
294 nr_softirq_read_safe);
295 seq_printf(m, " softirq-read-unsafe locks: %11lu\n",
296 nr_softirq_read_unsafe);
297 seq_printf(m, " irq-read-safe locks: %11lu\n",
298 nr_irq_read_safe);
299 seq_printf(m, " irq-read-unsafe locks: %11lu\n",
300 nr_irq_read_unsafe);
301
302 seq_printf(m, " uncategorized locks: %11lu\n",
303 nr_uncategorized);
304 seq_printf(m, " unused locks: %11lu\n",
305 nr_unused);
306 seq_printf(m, " max locking depth: %11u\n",
307 max_lockdep_depth);
308 seq_printf(m, " max recursion depth: %11u\n",
309 max_recursion_depth);
310 lockdep_stats_debug_show(m);
311 seq_printf(m, " debug_locks: %11u\n",
312 debug_locks);
313
314 return 0;
315}
316
317static int lockdep_stats_open(struct inode *inode, struct file *file)
318{
319 return single_open(file, lockdep_stats_show, NULL);
320}
321
322static struct file_operations proc_lockdep_stats_operations = {
323 .open = lockdep_stats_open,
324 .read = seq_read,
325 .llseek = seq_lseek,
326 .release = seq_release,
327};
328
329static int __init lockdep_proc_init(void)
330{
331 struct proc_dir_entry *entry;
332
333 entry = create_proc_entry("lockdep", S_IRUSR, NULL);
334 if (entry)
335 entry->proc_fops = &proc_lockdep_operations;
336
337 entry = create_proc_entry("lockdep_stats", S_IRUSR, NULL);
338 if (entry)
339 entry->proc_fops = &proc_lockdep_stats_operations;
340
341 return 0;
342}
343
344__initcall(lockdep_proc_init);
345