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-rw-r--r--kernel/Makefile1
-rw-r--r--kernel/fork.c5
-rw-r--r--kernel/irq/manage.c6
-rw-r--r--kernel/lockdep.c2703
-rw-r--r--kernel/lockdep_internals.h78
-rw-r--r--kernel/module.c3
6 files changed, 2796 insertions, 0 deletions
diff --git a/kernel/Makefile b/kernel/Makefile
index e7fd20e70f1b..049aa79e5c1c 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -13,6 +13,7 @@ obj-y = sched.o fork.o exec_domain.o panic.o printk.o profile.o \
13obj-$(CONFIG_STACKTRACE) += stacktrace.o 13obj-$(CONFIG_STACKTRACE) += stacktrace.o
14obj-y += time/ 14obj-y += time/
15obj-$(CONFIG_DEBUG_MUTEXES) += mutex-debug.o 15obj-$(CONFIG_DEBUG_MUTEXES) += mutex-debug.o
16obj-$(CONFIG_LOCKDEP) += lockdep.o
16obj-$(CONFIG_FUTEX) += futex.o 17obj-$(CONFIG_FUTEX) += futex.o
17ifeq ($(CONFIG_COMPAT),y) 18ifeq ($(CONFIG_COMPAT),y)
18obj-$(CONFIG_FUTEX) += futex_compat.o 19obj-$(CONFIG_FUTEX) += futex_compat.o
diff --git a/kernel/fork.c b/kernel/fork.c
index b7db7fb74f53..7f48abdd7bb6 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1061,6 +1061,11 @@ static task_t *copy_process(unsigned long clone_flags,
1061 p->hardirq_context = 0; 1061 p->hardirq_context = 0;
1062 p->softirq_context = 0; 1062 p->softirq_context = 0;
1063#endif 1063#endif
1064#ifdef CONFIG_LOCKDEP
1065 p->lockdep_depth = 0; /* no locks held yet */
1066 p->curr_chain_key = 0;
1067 p->lockdep_recursion = 0;
1068#endif
1064 1069
1065 rt_mutex_init_task(p); 1070 rt_mutex_init_task(p);
1066 1071
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index c911c6ec4dd6..4e461438e48b 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -410,6 +410,12 @@ int request_irq(unsigned int irq,
410 struct irqaction *action; 410 struct irqaction *action;
411 int retval; 411 int retval;
412 412
413#ifdef CONFIG_LOCKDEP
414 /*
415 * Lockdep wants atomic interrupt handlers:
416 */
417 irqflags |= SA_INTERRUPT;
418#endif
413 /* 419 /*
414 * Sanity-check: shared interrupts must pass in a real dev-ID, 420 * Sanity-check: shared interrupts must pass in a real dev-ID,
415 * otherwise we'll have trouble later trying to figure out 421 * otherwise we'll have trouble later trying to figure out
diff --git a/kernel/lockdep.c b/kernel/lockdep.c
new file mode 100644
index 000000000000..dd0580910a97
--- /dev/null
+++ b/kernel/lockdep.c
@@ -0,0 +1,2703 @@
1/*
2 * kernel/lockdep.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 * this code maps all the lock dependencies as they occur in a live kernel
11 * and will warn about the following classes of locking bugs:
12 *
13 * - lock inversion scenarios
14 * - circular lock dependencies
15 * - hardirq/softirq safe/unsafe locking bugs
16 *
17 * Bugs are reported even if the current locking scenario does not cause
18 * any deadlock at this point.
19 *
20 * I.e. if anytime in the past two locks were taken in a different order,
21 * even if it happened for another task, even if those were different
22 * locks (but of the same class as this lock), this code will detect it.
23 *
24 * Thanks to Arjan van de Ven for coming up with the initial idea of
25 * mapping lock dependencies runtime.
26 */
27#include <linux/mutex.h>
28#include <linux/sched.h>
29#include <linux/delay.h>
30#include <linux/module.h>
31#include <linux/proc_fs.h>
32#include <linux/seq_file.h>
33#include <linux/spinlock.h>
34#include <linux/kallsyms.h>
35#include <linux/interrupt.h>
36#include <linux/stacktrace.h>
37#include <linux/debug_locks.h>
38#include <linux/irqflags.h>
39
40#include <asm/sections.h>
41
42#include "lockdep_internals.h"
43
44/*
45 * hash_lock: protects the lockdep hashes and class/list/hash allocators.
46 *
47 * This is one of the rare exceptions where it's justified
48 * to use a raw spinlock - we really dont want the spinlock
49 * code to recurse back into the lockdep code.
50 */
51static raw_spinlock_t hash_lock = (raw_spinlock_t)__RAW_SPIN_LOCK_UNLOCKED;
52
53static int lockdep_initialized;
54
55unsigned long nr_list_entries;
56static struct lock_list list_entries[MAX_LOCKDEP_ENTRIES];
57
58/*
59 * Allocate a lockdep entry. (assumes hash_lock held, returns
60 * with NULL on failure)
61 */
62static struct lock_list *alloc_list_entry(void)
63{
64 if (nr_list_entries >= MAX_LOCKDEP_ENTRIES) {
65 __raw_spin_unlock(&hash_lock);
66 debug_locks_off();
67 printk("BUG: MAX_LOCKDEP_ENTRIES too low!\n");
68 printk("turning off the locking correctness validator.\n");
69 return NULL;
70 }
71 return list_entries + nr_list_entries++;
72}
73
74/*
75 * All data structures here are protected by the global debug_lock.
76 *
77 * Mutex key structs only get allocated, once during bootup, and never
78 * get freed - this significantly simplifies the debugging code.
79 */
80unsigned long nr_lock_classes;
81static struct lock_class lock_classes[MAX_LOCKDEP_KEYS];
82
83/*
84 * We keep a global list of all lock classes. The list only grows,
85 * never shrinks. The list is only accessed with the lockdep
86 * spinlock lock held.
87 */
88LIST_HEAD(all_lock_classes);
89
90/*
91 * The lockdep classes are in a hash-table as well, for fast lookup:
92 */
93#define CLASSHASH_BITS (MAX_LOCKDEP_KEYS_BITS - 1)
94#define CLASSHASH_SIZE (1UL << CLASSHASH_BITS)
95#define CLASSHASH_MASK (CLASSHASH_SIZE - 1)
96#define __classhashfn(key) ((((unsigned long)key >> CLASSHASH_BITS) + (unsigned long)key) & CLASSHASH_MASK)
97#define classhashentry(key) (classhash_table + __classhashfn((key)))
98
99static struct list_head classhash_table[CLASSHASH_SIZE];
100
101unsigned long nr_lock_chains;
102static struct lock_chain lock_chains[MAX_LOCKDEP_CHAINS];
103
104/*
105 * We put the lock dependency chains into a hash-table as well, to cache
106 * their existence:
107 */
108#define CHAINHASH_BITS (MAX_LOCKDEP_CHAINS_BITS-1)
109#define CHAINHASH_SIZE (1UL << CHAINHASH_BITS)
110#define CHAINHASH_MASK (CHAINHASH_SIZE - 1)
111#define __chainhashfn(chain) \
112 (((chain >> CHAINHASH_BITS) + chain) & CHAINHASH_MASK)
113#define chainhashentry(chain) (chainhash_table + __chainhashfn((chain)))
114
115static struct list_head chainhash_table[CHAINHASH_SIZE];
116
117/*
118 * The hash key of the lock dependency chains is a hash itself too:
119 * it's a hash of all locks taken up to that lock, including that lock.
120 * It's a 64-bit hash, because it's important for the keys to be
121 * unique.
122 */
123#define iterate_chain_key(key1, key2) \
124 (((key1) << MAX_LOCKDEP_KEYS_BITS/2) ^ \
125 ((key1) >> (64-MAX_LOCKDEP_KEYS_BITS/2)) ^ \
126 (key2))
127
128void lockdep_off(void)
129{
130 current->lockdep_recursion++;
131}
132
133EXPORT_SYMBOL(lockdep_off);
134
135void lockdep_on(void)
136{
137 current->lockdep_recursion--;
138}
139
140EXPORT_SYMBOL(lockdep_on);
141
142int lockdep_internal(void)
143{
144 return current->lockdep_recursion != 0;
145}
146
147EXPORT_SYMBOL(lockdep_internal);
148
149/*
150 * Debugging switches:
151 */
152
153#define VERBOSE 0
154#ifdef VERBOSE
155# define VERY_VERBOSE 0
156#endif
157
158#if VERBOSE
159# define HARDIRQ_VERBOSE 1
160# define SOFTIRQ_VERBOSE 1
161#else
162# define HARDIRQ_VERBOSE 0
163# define SOFTIRQ_VERBOSE 0
164#endif
165
166#if VERBOSE || HARDIRQ_VERBOSE || SOFTIRQ_VERBOSE
167/*
168 * Quick filtering for interesting events:
169 */
170static int class_filter(struct lock_class *class)
171{
172 if (class->name_version == 1 &&
173 !strcmp(class->name, "&rl->lock"))
174 return 1;
175 if (class->name_version == 1 &&
176 !strcmp(class->name, "&ni->mrec_lock"))
177 return 1;
178 if (class->name_version == 1 &&
179 !strcmp(class->name, "mft_ni_runlist_lock"))
180 return 1;
181 if (class->name_version == 1 &&
182 !strcmp(class->name, "mft_ni_mrec_lock"))
183 return 1;
184 if (class->name_version == 1 &&
185 !strcmp(class->name, "&vol->lcnbmp_lock"))
186 return 1;
187 return 0;
188}
189#endif
190
191static int verbose(struct lock_class *class)
192{
193#if VERBOSE
194 return class_filter(class);
195#endif
196 return 0;
197}
198
199#ifdef CONFIG_TRACE_IRQFLAGS
200
201static int hardirq_verbose(struct lock_class *class)
202{
203#if HARDIRQ_VERBOSE
204 return class_filter(class);
205#endif
206 return 0;
207}
208
209static int softirq_verbose(struct lock_class *class)
210{
211#if SOFTIRQ_VERBOSE
212 return class_filter(class);
213#endif
214 return 0;
215}
216
217#endif
218
219/*
220 * Stack-trace: tightly packed array of stack backtrace
221 * addresses. Protected by the hash_lock.
222 */
223unsigned long nr_stack_trace_entries;
224static unsigned long stack_trace[MAX_STACK_TRACE_ENTRIES];
225
226static int save_trace(struct stack_trace *trace)
227{
228 trace->nr_entries = 0;
229 trace->max_entries = MAX_STACK_TRACE_ENTRIES - nr_stack_trace_entries;
230 trace->entries = stack_trace + nr_stack_trace_entries;
231
232 save_stack_trace(trace, NULL, 0, 3);
233
234 trace->max_entries = trace->nr_entries;
235
236 nr_stack_trace_entries += trace->nr_entries;
237 if (DEBUG_LOCKS_WARN_ON(nr_stack_trace_entries > MAX_STACK_TRACE_ENTRIES))
238 return 0;
239
240 if (nr_stack_trace_entries == MAX_STACK_TRACE_ENTRIES) {
241 __raw_spin_unlock(&hash_lock);
242 if (debug_locks_off()) {
243 printk("BUG: MAX_STACK_TRACE_ENTRIES too low!\n");
244 printk("turning off the locking correctness validator.\n");
245 dump_stack();
246 }
247 return 0;
248 }
249
250 return 1;
251}
252
253unsigned int nr_hardirq_chains;
254unsigned int nr_softirq_chains;
255unsigned int nr_process_chains;
256unsigned int max_lockdep_depth;
257unsigned int max_recursion_depth;
258
259#ifdef CONFIG_DEBUG_LOCKDEP
260/*
261 * We cannot printk in early bootup code. Not even early_printk()
262 * might work. So we mark any initialization errors and printk
263 * about it later on, in lockdep_info().
264 */
265static int lockdep_init_error;
266
267/*
268 * Various lockdep statistics:
269 */
270atomic_t chain_lookup_hits;
271atomic_t chain_lookup_misses;
272atomic_t hardirqs_on_events;
273atomic_t hardirqs_off_events;
274atomic_t redundant_hardirqs_on;
275atomic_t redundant_hardirqs_off;
276atomic_t softirqs_on_events;
277atomic_t softirqs_off_events;
278atomic_t redundant_softirqs_on;
279atomic_t redundant_softirqs_off;
280atomic_t nr_unused_locks;
281atomic_t nr_cyclic_checks;
282atomic_t nr_cyclic_check_recursions;
283atomic_t nr_find_usage_forwards_checks;
284atomic_t nr_find_usage_forwards_recursions;
285atomic_t nr_find_usage_backwards_checks;
286atomic_t nr_find_usage_backwards_recursions;
287# define debug_atomic_inc(ptr) atomic_inc(ptr)
288# define debug_atomic_dec(ptr) atomic_dec(ptr)
289# define debug_atomic_read(ptr) atomic_read(ptr)
290#else
291# define debug_atomic_inc(ptr) do { } while (0)
292# define debug_atomic_dec(ptr) do { } while (0)
293# define debug_atomic_read(ptr) 0
294#endif
295
296/*
297 * Locking printouts:
298 */
299
300static const char *usage_str[] =
301{
302 [LOCK_USED] = "initial-use ",
303 [LOCK_USED_IN_HARDIRQ] = "in-hardirq-W",
304 [LOCK_USED_IN_SOFTIRQ] = "in-softirq-W",
305 [LOCK_ENABLED_SOFTIRQS] = "softirq-on-W",
306 [LOCK_ENABLED_HARDIRQS] = "hardirq-on-W",
307 [LOCK_USED_IN_HARDIRQ_READ] = "in-hardirq-R",
308 [LOCK_USED_IN_SOFTIRQ_READ] = "in-softirq-R",
309 [LOCK_ENABLED_SOFTIRQS_READ] = "softirq-on-R",
310 [LOCK_ENABLED_HARDIRQS_READ] = "hardirq-on-R",
311};
312
313const char * __get_key_name(struct lockdep_subclass_key *key, char *str)
314{
315 unsigned long offs, size;
316 char *modname;
317
318 return kallsyms_lookup((unsigned long)key, &size, &offs, &modname, str);
319}
320
321void
322get_usage_chars(struct lock_class *class, char *c1, char *c2, char *c3, char *c4)
323{
324 *c1 = '.', *c2 = '.', *c3 = '.', *c4 = '.';
325
326 if (class->usage_mask & LOCKF_USED_IN_HARDIRQ)
327 *c1 = '+';
328 else
329 if (class->usage_mask & LOCKF_ENABLED_HARDIRQS)
330 *c1 = '-';
331
332 if (class->usage_mask & LOCKF_USED_IN_SOFTIRQ)
333 *c2 = '+';
334 else
335 if (class->usage_mask & LOCKF_ENABLED_SOFTIRQS)
336 *c2 = '-';
337
338 if (class->usage_mask & LOCKF_ENABLED_HARDIRQS_READ)
339 *c3 = '-';
340 if (class->usage_mask & LOCKF_USED_IN_HARDIRQ_READ) {
341 *c3 = '+';
342 if (class->usage_mask & LOCKF_ENABLED_HARDIRQS_READ)
343 *c3 = '?';
344 }
345
346 if (class->usage_mask & LOCKF_ENABLED_SOFTIRQS_READ)
347 *c4 = '-';
348 if (class->usage_mask & LOCKF_USED_IN_SOFTIRQ_READ) {
349 *c4 = '+';
350 if (class->usage_mask & LOCKF_ENABLED_SOFTIRQS_READ)
351 *c4 = '?';
352 }
353}
354
355static void print_lock_name(struct lock_class *class)
356{
357 char str[128], c1, c2, c3, c4;
358 const char *name;
359
360 get_usage_chars(class, &c1, &c2, &c3, &c4);
361
362 name = class->name;
363 if (!name) {
364 name = __get_key_name(class->key, str);
365 printk(" (%s", name);
366 } else {
367 printk(" (%s", name);
368 if (class->name_version > 1)
369 printk("#%d", class->name_version);
370 if (class->subclass)
371 printk("/%d", class->subclass);
372 }
373 printk("){%c%c%c%c}", c1, c2, c3, c4);
374}
375
376static void print_lockdep_cache(struct lockdep_map *lock)
377{
378 const char *name;
379 char str[128];
380
381 name = lock->name;
382 if (!name)
383 name = __get_key_name(lock->key->subkeys, str);
384
385 printk("%s", name);
386}
387
388static void print_lock(struct held_lock *hlock)
389{
390 print_lock_name(hlock->class);
391 printk(", at: ");
392 print_ip_sym(hlock->acquire_ip);
393}
394
395static void lockdep_print_held_locks(struct task_struct *curr)
396{
397 int i, depth = curr->lockdep_depth;
398
399 if (!depth) {
400 printk("no locks held by %s/%d.\n", curr->comm, curr->pid);
401 return;
402 }
403 printk("%d lock%s held by %s/%d:\n",
404 depth, depth > 1 ? "s" : "", curr->comm, curr->pid);
405
406 for (i = 0; i < depth; i++) {
407 printk(" #%d: ", i);
408 print_lock(curr->held_locks + i);
409 }
410}
411/*
412 * Helper to print a nice hierarchy of lock dependencies:
413 */
414static void print_spaces(int nr)
415{
416 int i;
417
418 for (i = 0; i < nr; i++)
419 printk(" ");
420}
421
422static void print_lock_class_header(struct lock_class *class, int depth)
423{
424 int bit;
425
426 print_spaces(depth);
427 printk("->");
428 print_lock_name(class);
429 printk(" ops: %lu", class->ops);
430 printk(" {\n");
431
432 for (bit = 0; bit < LOCK_USAGE_STATES; bit++) {
433 if (class->usage_mask & (1 << bit)) {
434 int len = depth;
435
436 print_spaces(depth);
437 len += printk(" %s", usage_str[bit]);
438 len += printk(" at:\n");
439 print_stack_trace(class->usage_traces + bit, len);
440 }
441 }
442 print_spaces(depth);
443 printk(" }\n");
444
445 print_spaces(depth);
446 printk(" ... key at: ");
447 print_ip_sym((unsigned long)class->key);
448}
449
450/*
451 * printk all lock dependencies starting at <entry>:
452 */
453static void print_lock_dependencies(struct lock_class *class, int depth)
454{
455 struct lock_list *entry;
456
457 if (DEBUG_LOCKS_WARN_ON(depth >= 20))
458 return;
459
460 print_lock_class_header(class, depth);
461
462 list_for_each_entry(entry, &class->locks_after, entry) {
463 DEBUG_LOCKS_WARN_ON(!entry->class);
464 print_lock_dependencies(entry->class, depth + 1);
465
466 print_spaces(depth);
467 printk(" ... acquired at:\n");
468 print_stack_trace(&entry->trace, 2);
469 printk("\n");
470 }
471}
472
473/*
474 * Add a new dependency to the head of the list:
475 */
476static int add_lock_to_list(struct lock_class *class, struct lock_class *this,
477 struct list_head *head, unsigned long ip)
478{
479 struct lock_list *entry;
480 /*
481 * Lock not present yet - get a new dependency struct and
482 * add it to the list:
483 */
484 entry = alloc_list_entry();
485 if (!entry)
486 return 0;
487
488 entry->class = this;
489 save_trace(&entry->trace);
490
491 /*
492 * Since we never remove from the dependency list, the list can
493 * be walked lockless by other CPUs, it's only allocation
494 * that must be protected by the spinlock. But this also means
495 * we must make new entries visible only once writes to the
496 * entry become visible - hence the RCU op:
497 */
498 list_add_tail_rcu(&entry->entry, head);
499
500 return 1;
501}
502
503/*
504 * Recursive, forwards-direction lock-dependency checking, used for
505 * both noncyclic checking and for hardirq-unsafe/softirq-unsafe
506 * checking.
507 *
508 * (to keep the stackframe of the recursive functions small we
509 * use these global variables, and we also mark various helper
510 * functions as noinline.)
511 */
512static struct held_lock *check_source, *check_target;
513
514/*
515 * Print a dependency chain entry (this is only done when a deadlock
516 * has been detected):
517 */
518static noinline int
519print_circular_bug_entry(struct lock_list *target, unsigned int depth)
520{
521 if (debug_locks_silent)
522 return 0;
523 printk("\n-> #%u", depth);
524 print_lock_name(target->class);
525 printk(":\n");
526 print_stack_trace(&target->trace, 6);
527
528 return 0;
529}
530
531/*
532 * When a circular dependency is detected, print the
533 * header first:
534 */
535static noinline int
536print_circular_bug_header(struct lock_list *entry, unsigned int depth)
537{
538 struct task_struct *curr = current;
539
540 __raw_spin_unlock(&hash_lock);
541 debug_locks_off();
542 if (debug_locks_silent)
543 return 0;
544
545 printk("\n=======================================================\n");
546 printk( "[ INFO: possible circular locking dependency detected ]\n");
547 printk( "-------------------------------------------------------\n");
548 printk("%s/%d is trying to acquire lock:\n",
549 curr->comm, curr->pid);
550 print_lock(check_source);
551 printk("\nbut task is already holding lock:\n");
552 print_lock(check_target);
553 printk("\nwhich lock already depends on the new lock.\n\n");
554 printk("\nthe existing dependency chain (in reverse order) is:\n");
555
556 print_circular_bug_entry(entry, depth);
557
558 return 0;
559}
560
561static noinline int print_circular_bug_tail(void)
562{
563 struct task_struct *curr = current;
564 struct lock_list this;
565
566 if (debug_locks_silent)
567 return 0;
568
569 this.class = check_source->class;
570 save_trace(&this.trace);
571 print_circular_bug_entry(&this, 0);
572
573 printk("\nother info that might help us debug this:\n\n");
574 lockdep_print_held_locks(curr);
575
576 printk("\nstack backtrace:\n");
577 dump_stack();
578
579 return 0;
580}
581
582static int noinline print_infinite_recursion_bug(void)
583{
584 __raw_spin_unlock(&hash_lock);
585 DEBUG_LOCKS_WARN_ON(1);
586
587 return 0;
588}
589
590/*
591 * Prove that the dependency graph starting at <entry> can not
592 * lead to <target>. Print an error and return 0 if it does.
593 */
594static noinline int
595check_noncircular(struct lock_class *source, unsigned int depth)
596{
597 struct lock_list *entry;
598
599 debug_atomic_inc(&nr_cyclic_check_recursions);
600 if (depth > max_recursion_depth)
601 max_recursion_depth = depth;
602 if (depth >= 20)
603 return print_infinite_recursion_bug();
604 /*
605 * Check this lock's dependency list:
606 */
607 list_for_each_entry(entry, &source->locks_after, entry) {
608 if (entry->class == check_target->class)
609 return print_circular_bug_header(entry, depth+1);
610 debug_atomic_inc(&nr_cyclic_checks);
611 if (!check_noncircular(entry->class, depth+1))
612 return print_circular_bug_entry(entry, depth+1);
613 }
614 return 1;
615}
616
617static int very_verbose(struct lock_class *class)
618{
619#if VERY_VERBOSE
620 return class_filter(class);
621#endif
622 return 0;
623}
624#ifdef CONFIG_TRACE_IRQFLAGS
625
626/*
627 * Forwards and backwards subgraph searching, for the purposes of
628 * proving that two subgraphs can be connected by a new dependency
629 * without creating any illegal irq-safe -> irq-unsafe lock dependency.
630 */
631static enum lock_usage_bit find_usage_bit;
632static struct lock_class *forwards_match, *backwards_match;
633
634/*
635 * Find a node in the forwards-direction dependency sub-graph starting
636 * at <source> that matches <find_usage_bit>.
637 *
638 * Return 2 if such a node exists in the subgraph, and put that node
639 * into <forwards_match>.
640 *
641 * Return 1 otherwise and keep <forwards_match> unchanged.
642 * Return 0 on error.
643 */
644static noinline int
645find_usage_forwards(struct lock_class *source, unsigned int depth)
646{
647 struct lock_list *entry;
648 int ret;
649
650 if (depth > max_recursion_depth)
651 max_recursion_depth = depth;
652 if (depth >= 20)
653 return print_infinite_recursion_bug();
654
655 debug_atomic_inc(&nr_find_usage_forwards_checks);
656 if (source->usage_mask & (1 << find_usage_bit)) {
657 forwards_match = source;
658 return 2;
659 }
660
661 /*
662 * Check this lock's dependency list:
663 */
664 list_for_each_entry(entry, &source->locks_after, entry) {
665 debug_atomic_inc(&nr_find_usage_forwards_recursions);
666 ret = find_usage_forwards(entry->class, depth+1);
667 if (ret == 2 || ret == 0)
668 return ret;
669 }
670 return 1;
671}
672
673/*
674 * Find a node in the backwards-direction dependency sub-graph starting
675 * at <source> that matches <find_usage_bit>.
676 *
677 * Return 2 if such a node exists in the subgraph, and put that node
678 * into <backwards_match>.
679 *
680 * Return 1 otherwise and keep <backwards_match> unchanged.
681 * Return 0 on error.
682 */
683static noinline int
684find_usage_backwards(struct lock_class *source, unsigned int depth)
685{
686 struct lock_list *entry;
687 int ret;
688
689 if (depth > max_recursion_depth)
690 max_recursion_depth = depth;
691 if (depth >= 20)
692 return print_infinite_recursion_bug();
693
694 debug_atomic_inc(&nr_find_usage_backwards_checks);
695 if (source->usage_mask & (1 << find_usage_bit)) {
696 backwards_match = source;
697 return 2;
698 }
699
700 /*
701 * Check this lock's dependency list:
702 */
703 list_for_each_entry(entry, &source->locks_before, entry) {
704 debug_atomic_inc(&nr_find_usage_backwards_recursions);
705 ret = find_usage_backwards(entry->class, depth+1);
706 if (ret == 2 || ret == 0)
707 return ret;
708 }
709 return 1;
710}
711
712static int
713print_bad_irq_dependency(struct task_struct *curr,
714 struct held_lock *prev,
715 struct held_lock *next,
716 enum lock_usage_bit bit1,
717 enum lock_usage_bit bit2,
718 const char *irqclass)
719{
720 __raw_spin_unlock(&hash_lock);
721 debug_locks_off();
722 if (debug_locks_silent)
723 return 0;
724
725 printk("\n======================================================\n");
726 printk( "[ INFO: %s-safe -> %s-unsafe lock order detected ]\n",
727 irqclass, irqclass);
728 printk( "------------------------------------------------------\n");
729 printk("%s/%d [HC%u[%lu]:SC%u[%lu]:HE%u:SE%u] is trying to acquire:\n",
730 curr->comm, curr->pid,
731 curr->hardirq_context, hardirq_count() >> HARDIRQ_SHIFT,
732 curr->softirq_context, softirq_count() >> SOFTIRQ_SHIFT,
733 curr->hardirqs_enabled,
734 curr->softirqs_enabled);
735 print_lock(next);
736
737 printk("\nand this task is already holding:\n");
738 print_lock(prev);
739 printk("which would create a new lock dependency:\n");
740 print_lock_name(prev->class);
741 printk(" ->");
742 print_lock_name(next->class);
743 printk("\n");
744
745 printk("\nbut this new dependency connects a %s-irq-safe lock:\n",
746 irqclass);
747 print_lock_name(backwards_match);
748 printk("\n... which became %s-irq-safe at:\n", irqclass);
749
750 print_stack_trace(backwards_match->usage_traces + bit1, 1);
751
752 printk("\nto a %s-irq-unsafe lock:\n", irqclass);
753 print_lock_name(forwards_match);
754 printk("\n... which became %s-irq-unsafe at:\n", irqclass);
755 printk("...");
756
757 print_stack_trace(forwards_match->usage_traces + bit2, 1);
758
759 printk("\nother info that might help us debug this:\n\n");
760 lockdep_print_held_locks(curr);
761
762 printk("\nthe %s-irq-safe lock's dependencies:\n", irqclass);
763 print_lock_dependencies(backwards_match, 0);
764
765 printk("\nthe %s-irq-unsafe lock's dependencies:\n", irqclass);
766 print_lock_dependencies(forwards_match, 0);
767
768 printk("\nstack backtrace:\n");
769 dump_stack();
770
771 return 0;
772}
773
774static int
775check_usage(struct task_struct *curr, struct held_lock *prev,
776 struct held_lock *next, enum lock_usage_bit bit_backwards,
777 enum lock_usage_bit bit_forwards, const char *irqclass)
778{
779 int ret;
780
781 find_usage_bit = bit_backwards;
782 /* fills in <backwards_match> */
783 ret = find_usage_backwards(prev->class, 0);
784 if (!ret || ret == 1)
785 return ret;
786
787 find_usage_bit = bit_forwards;
788 ret = find_usage_forwards(next->class, 0);
789 if (!ret || ret == 1)
790 return ret;
791 /* ret == 2 */
792 return print_bad_irq_dependency(curr, prev, next,
793 bit_backwards, bit_forwards, irqclass);
794}
795
796#endif
797
798static int
799print_deadlock_bug(struct task_struct *curr, struct held_lock *prev,
800 struct held_lock *next)
801{
802 debug_locks_off();
803 __raw_spin_unlock(&hash_lock);
804 if (debug_locks_silent)
805 return 0;
806
807 printk("\n=============================================\n");
808 printk( "[ INFO: possible recursive locking detected ]\n");
809 printk( "---------------------------------------------\n");
810 printk("%s/%d is trying to acquire lock:\n",
811 curr->comm, curr->pid);
812 print_lock(next);
813 printk("\nbut task is already holding lock:\n");
814 print_lock(prev);
815
816 printk("\nother info that might help us debug this:\n");
817 lockdep_print_held_locks(curr);
818
819 printk("\nstack backtrace:\n");
820 dump_stack();
821
822 return 0;
823}
824
825/*
826 * Check whether we are holding such a class already.
827 *
828 * (Note that this has to be done separately, because the graph cannot
829 * detect such classes of deadlocks.)
830 *
831 * Returns: 0 on deadlock detected, 1 on OK, 2 on recursive read
832 */
833static int
834check_deadlock(struct task_struct *curr, struct held_lock *next,
835 struct lockdep_map *next_instance, int read)
836{
837 struct held_lock *prev;
838 int i;
839
840 for (i = 0; i < curr->lockdep_depth; i++) {
841 prev = curr->held_locks + i;
842 if (prev->class != next->class)
843 continue;
844 /*
845 * Allow read-after-read recursion of the same
846 * lock instance (i.e. read_lock(lock)+read_lock(lock)):
847 */
848 if ((read == 2) && prev->read &&
849 (prev->instance == next_instance))
850 return 2;
851 return print_deadlock_bug(curr, prev, next);
852 }
853 return 1;
854}
855
856/*
857 * There was a chain-cache miss, and we are about to add a new dependency
858 * to a previous lock. We recursively validate the following rules:
859 *
860 * - would the adding of the <prev> -> <next> dependency create a
861 * circular dependency in the graph? [== circular deadlock]
862 *
863 * - does the new prev->next dependency connect any hardirq-safe lock
864 * (in the full backwards-subgraph starting at <prev>) with any
865 * hardirq-unsafe lock (in the full forwards-subgraph starting at
866 * <next>)? [== illegal lock inversion with hardirq contexts]
867 *
868 * - does the new prev->next dependency connect any softirq-safe lock
869 * (in the full backwards-subgraph starting at <prev>) with any
870 * softirq-unsafe lock (in the full forwards-subgraph starting at
871 * <next>)? [== illegal lock inversion with softirq contexts]
872 *
873 * any of these scenarios could lead to a deadlock.
874 *
875 * Then if all the validations pass, we add the forwards and backwards
876 * dependency.
877 */
878static int
879check_prev_add(struct task_struct *curr, struct held_lock *prev,
880 struct held_lock *next)
881{
882 struct lock_list *entry;
883 int ret;
884
885 /*
886 * Prove that the new <prev> -> <next> dependency would not
887 * create a circular dependency in the graph. (We do this by
888 * forward-recursing into the graph starting at <next>, and
889 * checking whether we can reach <prev>.)
890 *
891 * We are using global variables to control the recursion, to
892 * keep the stackframe size of the recursive functions low:
893 */
894 check_source = next;
895 check_target = prev;
896 if (!(check_noncircular(next->class, 0)))
897 return print_circular_bug_tail();
898
899#ifdef CONFIG_TRACE_IRQFLAGS
900 /*
901 * Prove that the new dependency does not connect a hardirq-safe
902 * lock with a hardirq-unsafe lock - to achieve this we search
903 * the backwards-subgraph starting at <prev>, and the
904 * forwards-subgraph starting at <next>:
905 */
906 if (!check_usage(curr, prev, next, LOCK_USED_IN_HARDIRQ,
907 LOCK_ENABLED_HARDIRQS, "hard"))
908 return 0;
909
910 /*
911 * Prove that the new dependency does not connect a hardirq-safe-read
912 * lock with a hardirq-unsafe lock - to achieve this we search
913 * the backwards-subgraph starting at <prev>, and the
914 * forwards-subgraph starting at <next>:
915 */
916 if (!check_usage(curr, prev, next, LOCK_USED_IN_HARDIRQ_READ,
917 LOCK_ENABLED_HARDIRQS, "hard-read"))
918 return 0;
919
920 /*
921 * Prove that the new dependency does not connect a softirq-safe
922 * lock with a softirq-unsafe lock - to achieve this we search
923 * the backwards-subgraph starting at <prev>, and the
924 * forwards-subgraph starting at <next>:
925 */
926 if (!check_usage(curr, prev, next, LOCK_USED_IN_SOFTIRQ,
927 LOCK_ENABLED_SOFTIRQS, "soft"))
928 return 0;
929 /*
930 * Prove that the new dependency does not connect a softirq-safe-read
931 * lock with a softirq-unsafe lock - to achieve this we search
932 * the backwards-subgraph starting at <prev>, and the
933 * forwards-subgraph starting at <next>:
934 */
935 if (!check_usage(curr, prev, next, LOCK_USED_IN_SOFTIRQ_READ,
936 LOCK_ENABLED_SOFTIRQS, "soft"))
937 return 0;
938#endif
939 /*
940 * For recursive read-locks we do all the dependency checks,
941 * but we dont store read-triggered dependencies (only
942 * write-triggered dependencies). This ensures that only the
943 * write-side dependencies matter, and that if for example a
944 * write-lock never takes any other locks, then the reads are
945 * equivalent to a NOP.
946 */
947 if (next->read == 2 || prev->read == 2)
948 return 1;
949 /*
950 * Is the <prev> -> <next> dependency already present?
951 *
952 * (this may occur even though this is a new chain: consider
953 * e.g. the L1 -> L2 -> L3 -> L4 and the L5 -> L1 -> L2 -> L3
954 * chains - the second one will be new, but L1 already has
955 * L2 added to its dependency list, due to the first chain.)
956 */
957 list_for_each_entry(entry, &prev->class->locks_after, entry) {
958 if (entry->class == next->class)
959 return 2;
960 }
961
962 /*
963 * Ok, all validations passed, add the new lock
964 * to the previous lock's dependency list:
965 */
966 ret = add_lock_to_list(prev->class, next->class,
967 &prev->class->locks_after, next->acquire_ip);
968 if (!ret)
969 return 0;
970 /*
971 * Return value of 2 signals 'dependency already added',
972 * in that case we dont have to add the backlink either.
973 */
974 if (ret == 2)
975 return 2;
976 ret = add_lock_to_list(next->class, prev->class,
977 &next->class->locks_before, next->acquire_ip);
978
979 /*
980 * Debugging printouts:
981 */
982 if (verbose(prev->class) || verbose(next->class)) {
983 __raw_spin_unlock(&hash_lock);
984 printk("\n new dependency: ");
985 print_lock_name(prev->class);
986 printk(" => ");
987 print_lock_name(next->class);
988 printk("\n");
989 dump_stack();
990 __raw_spin_lock(&hash_lock);
991 }
992 return 1;
993}
994
995/*
996 * Add the dependency to all directly-previous locks that are 'relevant'.
997 * The ones that are relevant are (in increasing distance from curr):
998 * all consecutive trylock entries and the final non-trylock entry - or
999 * the end of this context's lock-chain - whichever comes first.
1000 */
1001static int
1002check_prevs_add(struct task_struct *curr, struct held_lock *next)
1003{
1004 int depth = curr->lockdep_depth;
1005 struct held_lock *hlock;
1006
1007 /*
1008 * Debugging checks.
1009 *
1010 * Depth must not be zero for a non-head lock:
1011 */
1012 if (!depth)
1013 goto out_bug;
1014 /*
1015 * At least two relevant locks must exist for this
1016 * to be a head:
1017 */
1018 if (curr->held_locks[depth].irq_context !=
1019 curr->held_locks[depth-1].irq_context)
1020 goto out_bug;
1021
1022 for (;;) {
1023 hlock = curr->held_locks + depth-1;
1024 /*
1025 * Only non-recursive-read entries get new dependencies
1026 * added:
1027 */
1028 if (hlock->read != 2) {
1029 check_prev_add(curr, hlock, next);
1030 /*
1031 * Stop after the first non-trylock entry,
1032 * as non-trylock entries have added their
1033 * own direct dependencies already, so this
1034 * lock is connected to them indirectly:
1035 */
1036 if (!hlock->trylock)
1037 break;
1038 }
1039 depth--;
1040 /*
1041 * End of lock-stack?
1042 */
1043 if (!depth)
1044 break;
1045 /*
1046 * Stop the search if we cross into another context:
1047 */
1048 if (curr->held_locks[depth].irq_context !=
1049 curr->held_locks[depth-1].irq_context)
1050 break;
1051 }
1052 return 1;
1053out_bug:
1054 __raw_spin_unlock(&hash_lock);
1055 DEBUG_LOCKS_WARN_ON(1);
1056
1057 return 0;
1058}
1059
1060
1061/*
1062 * Is this the address of a static object:
1063 */
1064static int static_obj(void *obj)
1065{
1066 unsigned long start = (unsigned long) &_stext,
1067 end = (unsigned long) &_end,
1068 addr = (unsigned long) obj;
1069#ifdef CONFIG_SMP
1070 int i;
1071#endif
1072
1073 /*
1074 * static variable?
1075 */
1076 if ((addr >= start) && (addr < end))
1077 return 1;
1078
1079#ifdef CONFIG_SMP
1080 /*
1081 * percpu var?
1082 */
1083 for_each_possible_cpu(i) {
1084 start = (unsigned long) &__per_cpu_start + per_cpu_offset(i);
1085 end = (unsigned long) &__per_cpu_end + per_cpu_offset(i);
1086
1087 if ((addr >= start) && (addr < end))
1088 return 1;
1089 }
1090#endif
1091
1092 /*
1093 * module var?
1094 */
1095 return is_module_address(addr);
1096}
1097
1098/*
1099 * To make lock name printouts unique, we calculate a unique
1100 * class->name_version generation counter:
1101 */
1102static int count_matching_names(struct lock_class *new_class)
1103{
1104 struct lock_class *class;
1105 int count = 0;
1106
1107 if (!new_class->name)
1108 return 0;
1109
1110 list_for_each_entry(class, &all_lock_classes, lock_entry) {
1111 if (new_class->key - new_class->subclass == class->key)
1112 return class->name_version;
1113 if (class->name && !strcmp(class->name, new_class->name))
1114 count = max(count, class->name_version);
1115 }
1116
1117 return count + 1;
1118}
1119
1120extern void __error_too_big_MAX_LOCKDEP_SUBCLASSES(void);
1121
1122/*
1123 * Register a lock's class in the hash-table, if the class is not present
1124 * yet. Otherwise we look it up. We cache the result in the lock object
1125 * itself, so actual lookup of the hash should be once per lock object.
1126 */
1127static inline struct lock_class *
1128register_lock_class(struct lockdep_map *lock, unsigned int subclass)
1129{
1130 struct lockdep_subclass_key *key;
1131 struct list_head *hash_head;
1132 struct lock_class *class;
1133
1134#ifdef CONFIG_DEBUG_LOCKDEP
1135 /*
1136 * If the architecture calls into lockdep before initializing
1137 * the hashes then we'll warn about it later. (we cannot printk
1138 * right now)
1139 */
1140 if (unlikely(!lockdep_initialized)) {
1141 lockdep_init();
1142 lockdep_init_error = 1;
1143 }
1144#endif
1145
1146 /*
1147 * Static locks do not have their class-keys yet - for them the key
1148 * is the lock object itself:
1149 */
1150 if (unlikely(!lock->key))
1151 lock->key = (void *)lock;
1152
1153 /*
1154 * NOTE: the class-key must be unique. For dynamic locks, a static
1155 * lock_class_key variable is passed in through the mutex_init()
1156 * (or spin_lock_init()) call - which acts as the key. For static
1157 * locks we use the lock object itself as the key.
1158 */
1159 if (sizeof(struct lock_class_key) > sizeof(struct lock_class))
1160 __error_too_big_MAX_LOCKDEP_SUBCLASSES();
1161
1162 key = lock->key->subkeys + subclass;
1163
1164 hash_head = classhashentry(key);
1165
1166 /*
1167 * We can walk the hash lockfree, because the hash only
1168 * grows, and we are careful when adding entries to the end:
1169 */
1170 list_for_each_entry(class, hash_head, hash_entry)
1171 if (class->key == key)
1172 goto out_set;
1173
1174 /*
1175 * Debug-check: all keys must be persistent!
1176 */
1177 if (!static_obj(lock->key)) {
1178 debug_locks_off();
1179 printk("INFO: trying to register non-static key.\n");
1180 printk("the code is fine but needs lockdep annotation.\n");
1181 printk("turning off the locking correctness validator.\n");
1182 dump_stack();
1183
1184 return NULL;
1185 }
1186
1187 __raw_spin_lock(&hash_lock);
1188 /*
1189 * We have to do the hash-walk again, to avoid races
1190 * with another CPU:
1191 */
1192 list_for_each_entry(class, hash_head, hash_entry)
1193 if (class->key == key)
1194 goto out_unlock_set;
1195 /*
1196 * Allocate a new key from the static array, and add it to
1197 * the hash:
1198 */
1199 if (nr_lock_classes >= MAX_LOCKDEP_KEYS) {
1200 __raw_spin_unlock(&hash_lock);
1201 debug_locks_off();
1202 printk("BUG: MAX_LOCKDEP_KEYS too low!\n");
1203 printk("turning off the locking correctness validator.\n");
1204 return NULL;
1205 }
1206 class = lock_classes + nr_lock_classes++;
1207 debug_atomic_inc(&nr_unused_locks);
1208 class->key = key;
1209 class->name = lock->name;
1210 class->subclass = subclass;
1211 INIT_LIST_HEAD(&class->lock_entry);
1212 INIT_LIST_HEAD(&class->locks_before);
1213 INIT_LIST_HEAD(&class->locks_after);
1214 class->name_version = count_matching_names(class);
1215 /*
1216 * We use RCU's safe list-add method to make
1217 * parallel walking of the hash-list safe:
1218 */
1219 list_add_tail_rcu(&class->hash_entry, hash_head);
1220
1221 if (verbose(class)) {
1222 __raw_spin_unlock(&hash_lock);
1223 printk("\nnew class %p: %s", class->key, class->name);
1224 if (class->name_version > 1)
1225 printk("#%d", class->name_version);
1226 printk("\n");
1227 dump_stack();
1228 __raw_spin_lock(&hash_lock);
1229 }
1230out_unlock_set:
1231 __raw_spin_unlock(&hash_lock);
1232
1233out_set:
1234 lock->class[subclass] = class;
1235
1236 DEBUG_LOCKS_WARN_ON(class->subclass != subclass);
1237
1238 return class;
1239}
1240
1241/*
1242 * Look up a dependency chain. If the key is not present yet then
1243 * add it and return 0 - in this case the new dependency chain is
1244 * validated. If the key is already hashed, return 1.
1245 */
1246static inline int lookup_chain_cache(u64 chain_key)
1247{
1248 struct list_head *hash_head = chainhashentry(chain_key);
1249 struct lock_chain *chain;
1250
1251 DEBUG_LOCKS_WARN_ON(!irqs_disabled());
1252 /*
1253 * We can walk it lock-free, because entries only get added
1254 * to the hash:
1255 */
1256 list_for_each_entry(chain, hash_head, entry) {
1257 if (chain->chain_key == chain_key) {
1258cache_hit:
1259 debug_atomic_inc(&chain_lookup_hits);
1260 /*
1261 * In the debugging case, force redundant checking
1262 * by returning 1:
1263 */
1264#ifdef CONFIG_DEBUG_LOCKDEP
1265 __raw_spin_lock(&hash_lock);
1266 return 1;
1267#endif
1268 return 0;
1269 }
1270 }
1271 /*
1272 * Allocate a new chain entry from the static array, and add
1273 * it to the hash:
1274 */
1275 __raw_spin_lock(&hash_lock);
1276 /*
1277 * We have to walk the chain again locked - to avoid duplicates:
1278 */
1279 list_for_each_entry(chain, hash_head, entry) {
1280 if (chain->chain_key == chain_key) {
1281 __raw_spin_unlock(&hash_lock);
1282 goto cache_hit;
1283 }
1284 }
1285 if (unlikely(nr_lock_chains >= MAX_LOCKDEP_CHAINS)) {
1286 __raw_spin_unlock(&hash_lock);
1287 debug_locks_off();
1288 printk("BUG: MAX_LOCKDEP_CHAINS too low!\n");
1289 printk("turning off the locking correctness validator.\n");
1290 return 0;
1291 }
1292 chain = lock_chains + nr_lock_chains++;
1293 chain->chain_key = chain_key;
1294 list_add_tail_rcu(&chain->entry, hash_head);
1295 debug_atomic_inc(&chain_lookup_misses);
1296#ifdef CONFIG_TRACE_IRQFLAGS
1297 if (current->hardirq_context)
1298 nr_hardirq_chains++;
1299 else {
1300 if (current->softirq_context)
1301 nr_softirq_chains++;
1302 else
1303 nr_process_chains++;
1304 }
1305#else
1306 nr_process_chains++;
1307#endif
1308
1309 return 1;
1310}
1311
1312/*
1313 * We are building curr_chain_key incrementally, so double-check
1314 * it from scratch, to make sure that it's done correctly:
1315 */
1316static void check_chain_key(struct task_struct *curr)
1317{
1318#ifdef CONFIG_DEBUG_LOCKDEP
1319 struct held_lock *hlock, *prev_hlock = NULL;
1320 unsigned int i, id;
1321 u64 chain_key = 0;
1322
1323 for (i = 0; i < curr->lockdep_depth; i++) {
1324 hlock = curr->held_locks + i;
1325 if (chain_key != hlock->prev_chain_key) {
1326 debug_locks_off();
1327 printk("hm#1, depth: %u [%u], %016Lx != %016Lx\n",
1328 curr->lockdep_depth, i,
1329 (unsigned long long)chain_key,
1330 (unsigned long long)hlock->prev_chain_key);
1331 WARN_ON(1);
1332 return;
1333 }
1334 id = hlock->class - lock_classes;
1335 DEBUG_LOCKS_WARN_ON(id >= MAX_LOCKDEP_KEYS);
1336 if (prev_hlock && (prev_hlock->irq_context !=
1337 hlock->irq_context))
1338 chain_key = 0;
1339 chain_key = iterate_chain_key(chain_key, id);
1340 prev_hlock = hlock;
1341 }
1342 if (chain_key != curr->curr_chain_key) {
1343 debug_locks_off();
1344 printk("hm#2, depth: %u [%u], %016Lx != %016Lx\n",
1345 curr->lockdep_depth, i,
1346 (unsigned long long)chain_key,
1347 (unsigned long long)curr->curr_chain_key);
1348 WARN_ON(1);
1349 }
1350#endif
1351}
1352
1353#ifdef CONFIG_TRACE_IRQFLAGS
1354
1355/*
1356 * print irq inversion bug:
1357 */
1358static int
1359print_irq_inversion_bug(struct task_struct *curr, struct lock_class *other,
1360 struct held_lock *this, int forwards,
1361 const char *irqclass)
1362{
1363 __raw_spin_unlock(&hash_lock);
1364 debug_locks_off();
1365 if (debug_locks_silent)
1366 return 0;
1367
1368 printk("\n=========================================================\n");
1369 printk( "[ INFO: possible irq lock inversion dependency detected ]\n");
1370 printk( "---------------------------------------------------------\n");
1371 printk("%s/%d just changed the state of lock:\n",
1372 curr->comm, curr->pid);
1373 print_lock(this);
1374 if (forwards)
1375 printk("but this lock took another, %s-irq-unsafe lock in the past:\n", irqclass);
1376 else
1377 printk("but this lock was taken by another, %s-irq-safe lock in the past:\n", irqclass);
1378 print_lock_name(other);
1379 printk("\n\nand interrupts could create inverse lock ordering between them.\n\n");
1380
1381 printk("\nother info that might help us debug this:\n");
1382 lockdep_print_held_locks(curr);
1383
1384 printk("\nthe first lock's dependencies:\n");
1385 print_lock_dependencies(this->class, 0);
1386
1387 printk("\nthe second lock's dependencies:\n");
1388 print_lock_dependencies(other, 0);
1389
1390 printk("\nstack backtrace:\n");
1391 dump_stack();
1392
1393 return 0;
1394}
1395
1396/*
1397 * Prove that in the forwards-direction subgraph starting at <this>
1398 * there is no lock matching <mask>:
1399 */
1400static int
1401check_usage_forwards(struct task_struct *curr, struct held_lock *this,
1402 enum lock_usage_bit bit, const char *irqclass)
1403{
1404 int ret;
1405
1406 find_usage_bit = bit;
1407 /* fills in <forwards_match> */
1408 ret = find_usage_forwards(this->class, 0);
1409 if (!ret || ret == 1)
1410 return ret;
1411
1412 return print_irq_inversion_bug(curr, forwards_match, this, 1, irqclass);
1413}
1414
1415/*
1416 * Prove that in the backwards-direction subgraph starting at <this>
1417 * there is no lock matching <mask>:
1418 */
1419static int
1420check_usage_backwards(struct task_struct *curr, struct held_lock *this,
1421 enum lock_usage_bit bit, const char *irqclass)
1422{
1423 int ret;
1424
1425 find_usage_bit = bit;
1426 /* fills in <backwards_match> */
1427 ret = find_usage_backwards(this->class, 0);
1428 if (!ret || ret == 1)
1429 return ret;
1430
1431 return print_irq_inversion_bug(curr, backwards_match, this, 0, irqclass);
1432}
1433
1434static inline void print_irqtrace_events(struct task_struct *curr)
1435{
1436 printk("irq event stamp: %u\n", curr->irq_events);
1437 printk("hardirqs last enabled at (%u): ", curr->hardirq_enable_event);
1438 print_ip_sym(curr->hardirq_enable_ip);
1439 printk("hardirqs last disabled at (%u): ", curr->hardirq_disable_event);
1440 print_ip_sym(curr->hardirq_disable_ip);
1441 printk("softirqs last enabled at (%u): ", curr->softirq_enable_event);
1442 print_ip_sym(curr->softirq_enable_ip);
1443 printk("softirqs last disabled at (%u): ", curr->softirq_disable_event);
1444 print_ip_sym(curr->softirq_disable_ip);
1445}
1446
1447#else
1448static inline void print_irqtrace_events(struct task_struct *curr)
1449{
1450}
1451#endif
1452
1453static int
1454print_usage_bug(struct task_struct *curr, struct held_lock *this,
1455 enum lock_usage_bit prev_bit, enum lock_usage_bit new_bit)
1456{
1457 __raw_spin_unlock(&hash_lock);
1458 debug_locks_off();
1459 if (debug_locks_silent)
1460 return 0;
1461
1462 printk("\n=================================\n");
1463 printk( "[ INFO: inconsistent lock state ]\n");
1464 printk( "---------------------------------\n");
1465
1466 printk("inconsistent {%s} -> {%s} usage.\n",
1467 usage_str[prev_bit], usage_str[new_bit]);
1468
1469 printk("%s/%d [HC%u[%lu]:SC%u[%lu]:HE%u:SE%u] takes:\n",
1470 curr->comm, curr->pid,
1471 trace_hardirq_context(curr), hardirq_count() >> HARDIRQ_SHIFT,
1472 trace_softirq_context(curr), softirq_count() >> SOFTIRQ_SHIFT,
1473 trace_hardirqs_enabled(curr),
1474 trace_softirqs_enabled(curr));
1475 print_lock(this);
1476
1477 printk("{%s} state was registered at:\n", usage_str[prev_bit]);
1478 print_stack_trace(this->class->usage_traces + prev_bit, 1);
1479
1480 print_irqtrace_events(curr);
1481 printk("\nother info that might help us debug this:\n");
1482 lockdep_print_held_locks(curr);
1483
1484 printk("\nstack backtrace:\n");
1485 dump_stack();
1486
1487 return 0;
1488}
1489
1490/*
1491 * Print out an error if an invalid bit is set:
1492 */
1493static inline int
1494valid_state(struct task_struct *curr, struct held_lock *this,
1495 enum lock_usage_bit new_bit, enum lock_usage_bit bad_bit)
1496{
1497 if (unlikely(this->class->usage_mask & (1 << bad_bit)))
1498 return print_usage_bug(curr, this, bad_bit, new_bit);
1499 return 1;
1500}
1501
1502#define STRICT_READ_CHECKS 1
1503
1504/*
1505 * Mark a lock with a usage bit, and validate the state transition:
1506 */
1507static int mark_lock(struct task_struct *curr, struct held_lock *this,
1508 enum lock_usage_bit new_bit, unsigned long ip)
1509{
1510 unsigned int new_mask = 1 << new_bit, ret = 1;
1511
1512 /*
1513 * If already set then do not dirty the cacheline,
1514 * nor do any checks:
1515 */
1516 if (likely(this->class->usage_mask & new_mask))
1517 return 1;
1518
1519 __raw_spin_lock(&hash_lock);
1520 /*
1521 * Make sure we didnt race:
1522 */
1523 if (unlikely(this->class->usage_mask & new_mask)) {
1524 __raw_spin_unlock(&hash_lock);
1525 return 1;
1526 }
1527
1528 this->class->usage_mask |= new_mask;
1529
1530#ifdef CONFIG_TRACE_IRQFLAGS
1531 if (new_bit == LOCK_ENABLED_HARDIRQS ||
1532 new_bit == LOCK_ENABLED_HARDIRQS_READ)
1533 ip = curr->hardirq_enable_ip;
1534 else if (new_bit == LOCK_ENABLED_SOFTIRQS ||
1535 new_bit == LOCK_ENABLED_SOFTIRQS_READ)
1536 ip = curr->softirq_enable_ip;
1537#endif
1538 if (!save_trace(this->class->usage_traces + new_bit))
1539 return 0;
1540
1541 switch (new_bit) {
1542#ifdef CONFIG_TRACE_IRQFLAGS
1543 case LOCK_USED_IN_HARDIRQ:
1544 if (!valid_state(curr, this, new_bit, LOCK_ENABLED_HARDIRQS))
1545 return 0;
1546 if (!valid_state(curr, this, new_bit,
1547 LOCK_ENABLED_HARDIRQS_READ))
1548 return 0;
1549 /*
1550 * just marked it hardirq-safe, check that this lock
1551 * took no hardirq-unsafe lock in the past:
1552 */
1553 if (!check_usage_forwards(curr, this,
1554 LOCK_ENABLED_HARDIRQS, "hard"))
1555 return 0;
1556#if STRICT_READ_CHECKS
1557 /*
1558 * just marked it hardirq-safe, check that this lock
1559 * took no hardirq-unsafe-read lock in the past:
1560 */
1561 if (!check_usage_forwards(curr, this,
1562 LOCK_ENABLED_HARDIRQS_READ, "hard-read"))
1563 return 0;
1564#endif
1565 if (hardirq_verbose(this->class))
1566 ret = 2;
1567 break;
1568 case LOCK_USED_IN_SOFTIRQ:
1569 if (!valid_state(curr, this, new_bit, LOCK_ENABLED_SOFTIRQS))
1570 return 0;
1571 if (!valid_state(curr, this, new_bit,
1572 LOCK_ENABLED_SOFTIRQS_READ))
1573 return 0;
1574 /*
1575 * just marked it softirq-safe, check that this lock
1576 * took no softirq-unsafe lock in the past:
1577 */
1578 if (!check_usage_forwards(curr, this,
1579 LOCK_ENABLED_SOFTIRQS, "soft"))
1580 return 0;
1581#if STRICT_READ_CHECKS
1582 /*
1583 * just marked it softirq-safe, check that this lock
1584 * took no softirq-unsafe-read lock in the past:
1585 */
1586 if (!check_usage_forwards(curr, this,
1587 LOCK_ENABLED_SOFTIRQS_READ, "soft-read"))
1588 return 0;
1589#endif
1590 if (softirq_verbose(this->class))
1591 ret = 2;
1592 break;
1593 case LOCK_USED_IN_HARDIRQ_READ:
1594 if (!valid_state(curr, this, new_bit, LOCK_ENABLED_HARDIRQS))
1595 return 0;
1596 /*
1597 * just marked it hardirq-read-safe, check that this lock
1598 * took no hardirq-unsafe lock in the past:
1599 */
1600 if (!check_usage_forwards(curr, this,
1601 LOCK_ENABLED_HARDIRQS, "hard"))
1602 return 0;
1603 if (hardirq_verbose(this->class))
1604 ret = 2;
1605 break;
1606 case LOCK_USED_IN_SOFTIRQ_READ:
1607 if (!valid_state(curr, this, new_bit, LOCK_ENABLED_SOFTIRQS))
1608 return 0;
1609 /*
1610 * just marked it softirq-read-safe, check that this lock
1611 * took no softirq-unsafe lock in the past:
1612 */
1613 if (!check_usage_forwards(curr, this,
1614 LOCK_ENABLED_SOFTIRQS, "soft"))
1615 return 0;
1616 if (softirq_verbose(this->class))
1617 ret = 2;
1618 break;
1619 case LOCK_ENABLED_HARDIRQS:
1620 if (!valid_state(curr, this, new_bit, LOCK_USED_IN_HARDIRQ))
1621 return 0;
1622 if (!valid_state(curr, this, new_bit,
1623 LOCK_USED_IN_HARDIRQ_READ))
1624 return 0;
1625 /*
1626 * just marked it hardirq-unsafe, check that no hardirq-safe
1627 * lock in the system ever took it in the past:
1628 */
1629 if (!check_usage_backwards(curr, this,
1630 LOCK_USED_IN_HARDIRQ, "hard"))
1631 return 0;
1632#if STRICT_READ_CHECKS
1633 /*
1634 * just marked it hardirq-unsafe, check that no
1635 * hardirq-safe-read lock in the system ever took
1636 * it in the past:
1637 */
1638 if (!check_usage_backwards(curr, this,
1639 LOCK_USED_IN_HARDIRQ_READ, "hard-read"))
1640 return 0;
1641#endif
1642 if (hardirq_verbose(this->class))
1643 ret = 2;
1644 break;
1645 case LOCK_ENABLED_SOFTIRQS:
1646 if (!valid_state(curr, this, new_bit, LOCK_USED_IN_SOFTIRQ))
1647 return 0;
1648 if (!valid_state(curr, this, new_bit,
1649 LOCK_USED_IN_SOFTIRQ_READ))
1650 return 0;
1651 /*
1652 * just marked it softirq-unsafe, check that no softirq-safe
1653 * lock in the system ever took it in the past:
1654 */
1655 if (!check_usage_backwards(curr, this,
1656 LOCK_USED_IN_SOFTIRQ, "soft"))
1657 return 0;
1658#if STRICT_READ_CHECKS
1659 /*
1660 * just marked it softirq-unsafe, check that no
1661 * softirq-safe-read lock in the system ever took
1662 * it in the past:
1663 */
1664 if (!check_usage_backwards(curr, this,
1665 LOCK_USED_IN_SOFTIRQ_READ, "soft-read"))
1666 return 0;
1667#endif
1668 if (softirq_verbose(this->class))
1669 ret = 2;
1670 break;
1671 case LOCK_ENABLED_HARDIRQS_READ:
1672 if (!valid_state(curr, this, new_bit, LOCK_USED_IN_HARDIRQ))
1673 return 0;
1674#if STRICT_READ_CHECKS
1675 /*
1676 * just marked it hardirq-read-unsafe, check that no
1677 * hardirq-safe lock in the system ever took it in the past:
1678 */
1679 if (!check_usage_backwards(curr, this,
1680 LOCK_USED_IN_HARDIRQ, "hard"))
1681 return 0;
1682#endif
1683 if (hardirq_verbose(this->class))
1684 ret = 2;
1685 break;
1686 case LOCK_ENABLED_SOFTIRQS_READ:
1687 if (!valid_state(curr, this, new_bit, LOCK_USED_IN_SOFTIRQ))
1688 return 0;
1689#if STRICT_READ_CHECKS
1690 /*
1691 * just marked it softirq-read-unsafe, check that no
1692 * softirq-safe lock in the system ever took it in the past:
1693 */
1694 if (!check_usage_backwards(curr, this,
1695 LOCK_USED_IN_SOFTIRQ, "soft"))
1696 return 0;
1697#endif
1698 if (softirq_verbose(this->class))
1699 ret = 2;
1700 break;
1701#endif
1702 case LOCK_USED:
1703 /*
1704 * Add it to the global list of classes:
1705 */
1706 list_add_tail_rcu(&this->class->lock_entry, &all_lock_classes);
1707 debug_atomic_dec(&nr_unused_locks);
1708 break;
1709 default:
1710 debug_locks_off();
1711 WARN_ON(1);
1712 return 0;
1713 }
1714
1715 __raw_spin_unlock(&hash_lock);
1716
1717 /*
1718 * We must printk outside of the hash_lock:
1719 */
1720 if (ret == 2) {
1721 printk("\nmarked lock as {%s}:\n", usage_str[new_bit]);
1722 print_lock(this);
1723 print_irqtrace_events(curr);
1724 dump_stack();
1725 }
1726
1727 return ret;
1728}
1729
1730#ifdef CONFIG_TRACE_IRQFLAGS
1731/*
1732 * Mark all held locks with a usage bit:
1733 */
1734static int
1735mark_held_locks(struct task_struct *curr, int hardirq, unsigned long ip)
1736{
1737 enum lock_usage_bit usage_bit;
1738 struct held_lock *hlock;
1739 int i;
1740
1741 for (i = 0; i < curr->lockdep_depth; i++) {
1742 hlock = curr->held_locks + i;
1743
1744 if (hardirq) {
1745 if (hlock->read)
1746 usage_bit = LOCK_ENABLED_HARDIRQS_READ;
1747 else
1748 usage_bit = LOCK_ENABLED_HARDIRQS;
1749 } else {
1750 if (hlock->read)
1751 usage_bit = LOCK_ENABLED_SOFTIRQS_READ;
1752 else
1753 usage_bit = LOCK_ENABLED_SOFTIRQS;
1754 }
1755 if (!mark_lock(curr, hlock, usage_bit, ip))
1756 return 0;
1757 }
1758
1759 return 1;
1760}
1761
1762/*
1763 * Debugging helper: via this flag we know that we are in
1764 * 'early bootup code', and will warn about any invalid irqs-on event:
1765 */
1766static int early_boot_irqs_enabled;
1767
1768void early_boot_irqs_off(void)
1769{
1770 early_boot_irqs_enabled = 0;
1771}
1772
1773void early_boot_irqs_on(void)
1774{
1775 early_boot_irqs_enabled = 1;
1776}
1777
1778/*
1779 * Hardirqs will be enabled:
1780 */
1781void trace_hardirqs_on(void)
1782{
1783 struct task_struct *curr = current;
1784 unsigned long ip;
1785
1786 if (unlikely(!debug_locks || current->lockdep_recursion))
1787 return;
1788
1789 if (DEBUG_LOCKS_WARN_ON(unlikely(!early_boot_irqs_enabled)))
1790 return;
1791
1792 if (unlikely(curr->hardirqs_enabled)) {
1793 debug_atomic_inc(&redundant_hardirqs_on);
1794 return;
1795 }
1796 /* we'll do an OFF -> ON transition: */
1797 curr->hardirqs_enabled = 1;
1798 ip = (unsigned long) __builtin_return_address(0);
1799
1800 if (DEBUG_LOCKS_WARN_ON(!irqs_disabled()))
1801 return;
1802 if (DEBUG_LOCKS_WARN_ON(current->hardirq_context))
1803 return;
1804 /*
1805 * We are going to turn hardirqs on, so set the
1806 * usage bit for all held locks:
1807 */
1808 if (!mark_held_locks(curr, 1, ip))
1809 return;
1810 /*
1811 * If we have softirqs enabled, then set the usage
1812 * bit for all held locks. (disabled hardirqs prevented
1813 * this bit from being set before)
1814 */
1815 if (curr->softirqs_enabled)
1816 if (!mark_held_locks(curr, 0, ip))
1817 return;
1818
1819 curr->hardirq_enable_ip = ip;
1820 curr->hardirq_enable_event = ++curr->irq_events;
1821 debug_atomic_inc(&hardirqs_on_events);
1822}
1823
1824EXPORT_SYMBOL(trace_hardirqs_on);
1825
1826/*
1827 * Hardirqs were disabled:
1828 */
1829void trace_hardirqs_off(void)
1830{
1831 struct task_struct *curr = current;
1832
1833 if (unlikely(!debug_locks || current->lockdep_recursion))
1834 return;
1835
1836 if (DEBUG_LOCKS_WARN_ON(!irqs_disabled()))
1837 return;
1838
1839 if (curr->hardirqs_enabled) {
1840 /*
1841 * We have done an ON -> OFF transition:
1842 */
1843 curr->hardirqs_enabled = 0;
1844 curr->hardirq_disable_ip = _RET_IP_;
1845 curr->hardirq_disable_event = ++curr->irq_events;
1846 debug_atomic_inc(&hardirqs_off_events);
1847 } else
1848 debug_atomic_inc(&redundant_hardirqs_off);
1849}
1850
1851EXPORT_SYMBOL(trace_hardirqs_off);
1852
1853/*
1854 * Softirqs will be enabled:
1855 */
1856void trace_softirqs_on(unsigned long ip)
1857{
1858 struct task_struct *curr = current;
1859
1860 if (unlikely(!debug_locks))
1861 return;
1862
1863 if (DEBUG_LOCKS_WARN_ON(!irqs_disabled()))
1864 return;
1865
1866 if (curr->softirqs_enabled) {
1867 debug_atomic_inc(&redundant_softirqs_on);
1868 return;
1869 }
1870
1871 /*
1872 * We'll do an OFF -> ON transition:
1873 */
1874 curr->softirqs_enabled = 1;
1875 curr->softirq_enable_ip = ip;
1876 curr->softirq_enable_event = ++curr->irq_events;
1877 debug_atomic_inc(&softirqs_on_events);
1878 /*
1879 * We are going to turn softirqs on, so set the
1880 * usage bit for all held locks, if hardirqs are
1881 * enabled too:
1882 */
1883 if (curr->hardirqs_enabled)
1884 mark_held_locks(curr, 0, ip);
1885}
1886
1887/*
1888 * Softirqs were disabled:
1889 */
1890void trace_softirqs_off(unsigned long ip)
1891{
1892 struct task_struct *curr = current;
1893
1894 if (unlikely(!debug_locks))
1895 return;
1896
1897 if (DEBUG_LOCKS_WARN_ON(!irqs_disabled()))
1898 return;
1899
1900 if (curr->softirqs_enabled) {
1901 /*
1902 * We have done an ON -> OFF transition:
1903 */
1904 curr->softirqs_enabled = 0;
1905 curr->softirq_disable_ip = ip;
1906 curr->softirq_disable_event = ++curr->irq_events;
1907 debug_atomic_inc(&softirqs_off_events);
1908 DEBUG_LOCKS_WARN_ON(!softirq_count());
1909 } else
1910 debug_atomic_inc(&redundant_softirqs_off);
1911}
1912
1913#endif
1914
1915/*
1916 * Initialize a lock instance's lock-class mapping info:
1917 */
1918void lockdep_init_map(struct lockdep_map *lock, const char *name,
1919 struct lock_class_key *key)
1920{
1921 if (unlikely(!debug_locks))
1922 return;
1923
1924 if (DEBUG_LOCKS_WARN_ON(!key))
1925 return;
1926 if (DEBUG_LOCKS_WARN_ON(!name))
1927 return;
1928 /*
1929 * Sanity check, the lock-class key must be persistent:
1930 */
1931 if (!static_obj(key)) {
1932 printk("BUG: key %p not in .data!\n", key);
1933 DEBUG_LOCKS_WARN_ON(1);
1934 return;
1935 }
1936 lock->name = name;
1937 lock->key = key;
1938 memset(lock->class, 0, sizeof(lock->class[0])*MAX_LOCKDEP_SUBCLASSES);
1939}
1940
1941EXPORT_SYMBOL_GPL(lockdep_init_map);
1942
1943/*
1944 * This gets called for every mutex_lock*()/spin_lock*() operation.
1945 * We maintain the dependency maps and validate the locking attempt:
1946 */
1947static int __lock_acquire(struct lockdep_map *lock, unsigned int subclass,
1948 int trylock, int read, int check, int hardirqs_off,
1949 unsigned long ip)
1950{
1951 struct task_struct *curr = current;
1952 struct held_lock *hlock;
1953 struct lock_class *class;
1954 unsigned int depth, id;
1955 int chain_head = 0;
1956 u64 chain_key;
1957
1958 if (unlikely(!debug_locks))
1959 return 0;
1960
1961 if (DEBUG_LOCKS_WARN_ON(!irqs_disabled()))
1962 return 0;
1963
1964 if (unlikely(subclass >= MAX_LOCKDEP_SUBCLASSES)) {
1965 debug_locks_off();
1966 printk("BUG: MAX_LOCKDEP_SUBCLASSES too low!\n");
1967 printk("turning off the locking correctness validator.\n");
1968 return 0;
1969 }
1970
1971 class = lock->class[subclass];
1972 /* not cached yet? */
1973 if (unlikely(!class)) {
1974 class = register_lock_class(lock, subclass);
1975 if (!class)
1976 return 0;
1977 }
1978 debug_atomic_inc((atomic_t *)&class->ops);
1979 if (very_verbose(class)) {
1980 printk("\nacquire class [%p] %s", class->key, class->name);
1981 if (class->name_version > 1)
1982 printk("#%d", class->name_version);
1983 printk("\n");
1984 dump_stack();
1985 }
1986
1987 /*
1988 * Add the lock to the list of currently held locks.
1989 * (we dont increase the depth just yet, up until the
1990 * dependency checks are done)
1991 */
1992 depth = curr->lockdep_depth;
1993 if (DEBUG_LOCKS_WARN_ON(depth >= MAX_LOCK_DEPTH))
1994 return 0;
1995
1996 hlock = curr->held_locks + depth;
1997
1998 hlock->class = class;
1999 hlock->acquire_ip = ip;
2000 hlock->instance = lock;
2001 hlock->trylock = trylock;
2002 hlock->read = read;
2003 hlock->check = check;
2004 hlock->hardirqs_off = hardirqs_off;
2005
2006 if (check != 2)
2007 goto out_calc_hash;
2008#ifdef CONFIG_TRACE_IRQFLAGS
2009 /*
2010 * If non-trylock use in a hardirq or softirq context, then
2011 * mark the lock as used in these contexts:
2012 */
2013 if (!trylock) {
2014 if (read) {
2015 if (curr->hardirq_context)
2016 if (!mark_lock(curr, hlock,
2017 LOCK_USED_IN_HARDIRQ_READ, ip))
2018 return 0;
2019 if (curr->softirq_context)
2020 if (!mark_lock(curr, hlock,
2021 LOCK_USED_IN_SOFTIRQ_READ, ip))
2022 return 0;
2023 } else {
2024 if (curr->hardirq_context)
2025 if (!mark_lock(curr, hlock, LOCK_USED_IN_HARDIRQ, ip))
2026 return 0;
2027 if (curr->softirq_context)
2028 if (!mark_lock(curr, hlock, LOCK_USED_IN_SOFTIRQ, ip))
2029 return 0;
2030 }
2031 }
2032 if (!hardirqs_off) {
2033 if (read) {
2034 if (!mark_lock(curr, hlock,
2035 LOCK_ENABLED_HARDIRQS_READ, ip))
2036 return 0;
2037 if (curr->softirqs_enabled)
2038 if (!mark_lock(curr, hlock,
2039 LOCK_ENABLED_SOFTIRQS_READ, ip))
2040 return 0;
2041 } else {
2042 if (!mark_lock(curr, hlock,
2043 LOCK_ENABLED_HARDIRQS, ip))
2044 return 0;
2045 if (curr->softirqs_enabled)
2046 if (!mark_lock(curr, hlock,
2047 LOCK_ENABLED_SOFTIRQS, ip))
2048 return 0;
2049 }
2050 }
2051#endif
2052 /* mark it as used: */
2053 if (!mark_lock(curr, hlock, LOCK_USED, ip))
2054 return 0;
2055out_calc_hash:
2056 /*
2057 * Calculate the chain hash: it's the combined has of all the
2058 * lock keys along the dependency chain. We save the hash value
2059 * at every step so that we can get the current hash easily
2060 * after unlock. The chain hash is then used to cache dependency
2061 * results.
2062 *
2063 * The 'key ID' is what is the most compact key value to drive
2064 * the hash, not class->key.
2065 */
2066 id = class - lock_classes;
2067 if (DEBUG_LOCKS_WARN_ON(id >= MAX_LOCKDEP_KEYS))
2068 return 0;
2069
2070 chain_key = curr->curr_chain_key;
2071 if (!depth) {
2072 if (DEBUG_LOCKS_WARN_ON(chain_key != 0))
2073 return 0;
2074 chain_head = 1;
2075 }
2076
2077 hlock->prev_chain_key = chain_key;
2078
2079#ifdef CONFIG_TRACE_IRQFLAGS
2080 /*
2081 * Keep track of points where we cross into an interrupt context:
2082 */
2083 hlock->irq_context = 2*(curr->hardirq_context ? 1 : 0) +
2084 curr->softirq_context;
2085 if (depth) {
2086 struct held_lock *prev_hlock;
2087
2088 prev_hlock = curr->held_locks + depth-1;
2089 /*
2090 * If we cross into another context, reset the
2091 * hash key (this also prevents the checking and the
2092 * adding of the dependency to 'prev'):
2093 */
2094 if (prev_hlock->irq_context != hlock->irq_context) {
2095 chain_key = 0;
2096 chain_head = 1;
2097 }
2098 }
2099#endif
2100 chain_key = iterate_chain_key(chain_key, id);
2101 curr->curr_chain_key = chain_key;
2102
2103 /*
2104 * Trylock needs to maintain the stack of held locks, but it
2105 * does not add new dependencies, because trylock can be done
2106 * in any order.
2107 *
2108 * We look up the chain_key and do the O(N^2) check and update of
2109 * the dependencies only if this is a new dependency chain.
2110 * (If lookup_chain_cache() returns with 1 it acquires
2111 * hash_lock for us)
2112 */
2113 if (!trylock && (check == 2) && lookup_chain_cache(chain_key)) {
2114 /*
2115 * Check whether last held lock:
2116 *
2117 * - is irq-safe, if this lock is irq-unsafe
2118 * - is softirq-safe, if this lock is hardirq-unsafe
2119 *
2120 * And check whether the new lock's dependency graph
2121 * could lead back to the previous lock.
2122 *
2123 * any of these scenarios could lead to a deadlock. If
2124 * All validations
2125 */
2126 int ret = check_deadlock(curr, hlock, lock, read);
2127
2128 if (!ret)
2129 return 0;
2130 /*
2131 * Mark recursive read, as we jump over it when
2132 * building dependencies (just like we jump over
2133 * trylock entries):
2134 */
2135 if (ret == 2)
2136 hlock->read = 2;
2137 /*
2138 * Add dependency only if this lock is not the head
2139 * of the chain, and if it's not a secondary read-lock:
2140 */
2141 if (!chain_head && ret != 2)
2142 if (!check_prevs_add(curr, hlock))
2143 return 0;
2144 __raw_spin_unlock(&hash_lock);
2145 }
2146 curr->lockdep_depth++;
2147 check_chain_key(curr);
2148 if (unlikely(curr->lockdep_depth >= MAX_LOCK_DEPTH)) {
2149 debug_locks_off();
2150 printk("BUG: MAX_LOCK_DEPTH too low!\n");
2151 printk("turning off the locking correctness validator.\n");
2152 return 0;
2153 }
2154 if (unlikely(curr->lockdep_depth > max_lockdep_depth))
2155 max_lockdep_depth = curr->lockdep_depth;
2156
2157 return 1;
2158}
2159
2160static int
2161print_unlock_inbalance_bug(struct task_struct *curr, struct lockdep_map *lock,
2162 unsigned long ip)
2163{
2164 if (!debug_locks_off())
2165 return 0;
2166 if (debug_locks_silent)
2167 return 0;
2168
2169 printk("\n=====================================\n");
2170 printk( "[ BUG: bad unlock balance detected! ]\n");
2171 printk( "-------------------------------------\n");
2172 printk("%s/%d is trying to release lock (",
2173 curr->comm, curr->pid);
2174 print_lockdep_cache(lock);
2175 printk(") at:\n");
2176 print_ip_sym(ip);
2177 printk("but there are no more locks to release!\n");
2178 printk("\nother info that might help us debug this:\n");
2179 lockdep_print_held_locks(curr);
2180
2181 printk("\nstack backtrace:\n");
2182 dump_stack();
2183
2184 return 0;
2185}
2186
2187/*
2188 * Common debugging checks for both nested and non-nested unlock:
2189 */
2190static int check_unlock(struct task_struct *curr, struct lockdep_map *lock,
2191 unsigned long ip)
2192{
2193 if (unlikely(!debug_locks))
2194 return 0;
2195 if (DEBUG_LOCKS_WARN_ON(!irqs_disabled()))
2196 return 0;
2197
2198 if (curr->lockdep_depth <= 0)
2199 return print_unlock_inbalance_bug(curr, lock, ip);
2200
2201 return 1;
2202}
2203
2204/*
2205 * Remove the lock to the list of currently held locks in a
2206 * potentially non-nested (out of order) manner. This is a
2207 * relatively rare operation, as all the unlock APIs default
2208 * to nested mode (which uses lock_release()):
2209 */
2210static int
2211lock_release_non_nested(struct task_struct *curr,
2212 struct lockdep_map *lock, unsigned long ip)
2213{
2214 struct held_lock *hlock, *prev_hlock;
2215 unsigned int depth;
2216 int i;
2217
2218 /*
2219 * Check whether the lock exists in the current stack
2220 * of held locks:
2221 */
2222 depth = curr->lockdep_depth;
2223 if (DEBUG_LOCKS_WARN_ON(!depth))
2224 return 0;
2225
2226 prev_hlock = NULL;
2227 for (i = depth-1; i >= 0; i--) {
2228 hlock = curr->held_locks + i;
2229 /*
2230 * We must not cross into another context:
2231 */
2232 if (prev_hlock && prev_hlock->irq_context != hlock->irq_context)
2233 break;
2234 if (hlock->instance == lock)
2235 goto found_it;
2236 prev_hlock = hlock;
2237 }
2238 return print_unlock_inbalance_bug(curr, lock, ip);
2239
2240found_it:
2241 /*
2242 * We have the right lock to unlock, 'hlock' points to it.
2243 * Now we remove it from the stack, and add back the other
2244 * entries (if any), recalculating the hash along the way:
2245 */
2246 curr->lockdep_depth = i;
2247 curr->curr_chain_key = hlock->prev_chain_key;
2248
2249 for (i++; i < depth; i++) {
2250 hlock = curr->held_locks + i;
2251 if (!__lock_acquire(hlock->instance,
2252 hlock->class->subclass, hlock->trylock,
2253 hlock->read, hlock->check, hlock->hardirqs_off,
2254 hlock->acquire_ip))
2255 return 0;
2256 }
2257
2258 if (DEBUG_LOCKS_WARN_ON(curr->lockdep_depth != depth - 1))
2259 return 0;
2260 return 1;
2261}
2262
2263/*
2264 * Remove the lock to the list of currently held locks - this gets
2265 * called on mutex_unlock()/spin_unlock*() (or on a failed
2266 * mutex_lock_interruptible()). This is done for unlocks that nest
2267 * perfectly. (i.e. the current top of the lock-stack is unlocked)
2268 */
2269static int lock_release_nested(struct task_struct *curr,
2270 struct lockdep_map *lock, unsigned long ip)
2271{
2272 struct held_lock *hlock;
2273 unsigned int depth;
2274
2275 /*
2276 * Pop off the top of the lock stack:
2277 */
2278 depth = curr->lockdep_depth - 1;
2279 hlock = curr->held_locks + depth;
2280
2281 /*
2282 * Is the unlock non-nested:
2283 */
2284 if (hlock->instance != lock)
2285 return lock_release_non_nested(curr, lock, ip);
2286 curr->lockdep_depth--;
2287
2288 if (DEBUG_LOCKS_WARN_ON(!depth && (hlock->prev_chain_key != 0)))
2289 return 0;
2290
2291 curr->curr_chain_key = hlock->prev_chain_key;
2292
2293#ifdef CONFIG_DEBUG_LOCKDEP
2294 hlock->prev_chain_key = 0;
2295 hlock->class = NULL;
2296 hlock->acquire_ip = 0;
2297 hlock->irq_context = 0;
2298#endif
2299 return 1;
2300}
2301
2302/*
2303 * Remove the lock to the list of currently held locks - this gets
2304 * called on mutex_unlock()/spin_unlock*() (or on a failed
2305 * mutex_lock_interruptible()). This is done for unlocks that nest
2306 * perfectly. (i.e. the current top of the lock-stack is unlocked)
2307 */
2308static void
2309__lock_release(struct lockdep_map *lock, int nested, unsigned long ip)
2310{
2311 struct task_struct *curr = current;
2312
2313 if (!check_unlock(curr, lock, ip))
2314 return;
2315
2316 if (nested) {
2317 if (!lock_release_nested(curr, lock, ip))
2318 return;
2319 } else {
2320 if (!lock_release_non_nested(curr, lock, ip))
2321 return;
2322 }
2323
2324 check_chain_key(curr);
2325}
2326
2327/*
2328 * Check whether we follow the irq-flags state precisely:
2329 */
2330static void check_flags(unsigned long flags)
2331{
2332#if defined(CONFIG_DEBUG_LOCKDEP) && defined(CONFIG_TRACE_IRQFLAGS)
2333 if (!debug_locks)
2334 return;
2335
2336 if (irqs_disabled_flags(flags))
2337 DEBUG_LOCKS_WARN_ON(current->hardirqs_enabled);
2338 else
2339 DEBUG_LOCKS_WARN_ON(!current->hardirqs_enabled);
2340
2341 /*
2342 * We dont accurately track softirq state in e.g.
2343 * hardirq contexts (such as on 4KSTACKS), so only
2344 * check if not in hardirq contexts:
2345 */
2346 if (!hardirq_count()) {
2347 if (softirq_count())
2348 DEBUG_LOCKS_WARN_ON(current->softirqs_enabled);
2349 else
2350 DEBUG_LOCKS_WARN_ON(!current->softirqs_enabled);
2351 }
2352
2353 if (!debug_locks)
2354 print_irqtrace_events(current);
2355#endif
2356}
2357
2358/*
2359 * We are not always called with irqs disabled - do that here,
2360 * and also avoid lockdep recursion:
2361 */
2362void lock_acquire(struct lockdep_map *lock, unsigned int subclass,
2363 int trylock, int read, int check, unsigned long ip)
2364{
2365 unsigned long flags;
2366
2367 if (unlikely(current->lockdep_recursion))
2368 return;
2369
2370 raw_local_irq_save(flags);
2371 check_flags(flags);
2372
2373 current->lockdep_recursion = 1;
2374 __lock_acquire(lock, subclass, trylock, read, check,
2375 irqs_disabled_flags(flags), ip);
2376 current->lockdep_recursion = 0;
2377 raw_local_irq_restore(flags);
2378}
2379
2380EXPORT_SYMBOL_GPL(lock_acquire);
2381
2382void lock_release(struct lockdep_map *lock, int nested, unsigned long ip)
2383{
2384 unsigned long flags;
2385
2386 if (unlikely(current->lockdep_recursion))
2387 return;
2388
2389 raw_local_irq_save(flags);
2390 check_flags(flags);
2391 current->lockdep_recursion = 1;
2392 __lock_release(lock, nested, ip);
2393 current->lockdep_recursion = 0;
2394 raw_local_irq_restore(flags);
2395}
2396
2397EXPORT_SYMBOL_GPL(lock_release);
2398
2399/*
2400 * Used by the testsuite, sanitize the validator state
2401 * after a simulated failure:
2402 */
2403
2404void lockdep_reset(void)
2405{
2406 unsigned long flags;
2407
2408 raw_local_irq_save(flags);
2409 current->curr_chain_key = 0;
2410 current->lockdep_depth = 0;
2411 current->lockdep_recursion = 0;
2412 memset(current->held_locks, 0, MAX_LOCK_DEPTH*sizeof(struct held_lock));
2413 nr_hardirq_chains = 0;
2414 nr_softirq_chains = 0;
2415 nr_process_chains = 0;
2416 debug_locks = 1;
2417 raw_local_irq_restore(flags);
2418}
2419
2420static void zap_class(struct lock_class *class)
2421{
2422 int i;
2423
2424 /*
2425 * Remove all dependencies this lock is
2426 * involved in:
2427 */
2428 for (i = 0; i < nr_list_entries; i++) {
2429 if (list_entries[i].class == class)
2430 list_del_rcu(&list_entries[i].entry);
2431 }
2432 /*
2433 * Unhash the class and remove it from the all_lock_classes list:
2434 */
2435 list_del_rcu(&class->hash_entry);
2436 list_del_rcu(&class->lock_entry);
2437
2438}
2439
2440static inline int within(void *addr, void *start, unsigned long size)
2441{
2442 return addr >= start && addr < start + size;
2443}
2444
2445void lockdep_free_key_range(void *start, unsigned long size)
2446{
2447 struct lock_class *class, *next;
2448 struct list_head *head;
2449 unsigned long flags;
2450 int i;
2451
2452 raw_local_irq_save(flags);
2453 __raw_spin_lock(&hash_lock);
2454
2455 /*
2456 * Unhash all classes that were created by this module:
2457 */
2458 for (i = 0; i < CLASSHASH_SIZE; i++) {
2459 head = classhash_table + i;
2460 if (list_empty(head))
2461 continue;
2462 list_for_each_entry_safe(class, next, head, hash_entry)
2463 if (within(class->key, start, size))
2464 zap_class(class);
2465 }
2466
2467 __raw_spin_unlock(&hash_lock);
2468 raw_local_irq_restore(flags);
2469}
2470
2471void lockdep_reset_lock(struct lockdep_map *lock)
2472{
2473 struct lock_class *class, *next, *entry;
2474 struct list_head *head;
2475 unsigned long flags;
2476 int i, j;
2477
2478 raw_local_irq_save(flags);
2479 __raw_spin_lock(&hash_lock);
2480
2481 /*
2482 * Remove all classes this lock has:
2483 */
2484 for (i = 0; i < CLASSHASH_SIZE; i++) {
2485 head = classhash_table + i;
2486 if (list_empty(head))
2487 continue;
2488 list_for_each_entry_safe(class, next, head, hash_entry) {
2489 for (j = 0; j < MAX_LOCKDEP_SUBCLASSES; j++) {
2490 entry = lock->class[j];
2491 if (class == entry) {
2492 zap_class(class);
2493 lock->class[j] = NULL;
2494 break;
2495 }
2496 }
2497 }
2498 }
2499
2500 /*
2501 * Debug check: in the end all mapped classes should
2502 * be gone.
2503 */
2504 for (j = 0; j < MAX_LOCKDEP_SUBCLASSES; j++) {
2505 entry = lock->class[j];
2506 if (!entry)
2507 continue;
2508 __raw_spin_unlock(&hash_lock);
2509 DEBUG_LOCKS_WARN_ON(1);
2510 raw_local_irq_restore(flags);
2511 return;
2512 }
2513
2514 __raw_spin_unlock(&hash_lock);
2515 raw_local_irq_restore(flags);
2516}
2517
2518void __init lockdep_init(void)
2519{
2520 int i;
2521
2522 /*
2523 * Some architectures have their own start_kernel()
2524 * code which calls lockdep_init(), while we also
2525 * call lockdep_init() from the start_kernel() itself,
2526 * and we want to initialize the hashes only once:
2527 */
2528 if (lockdep_initialized)
2529 return;
2530
2531 for (i = 0; i < CLASSHASH_SIZE; i++)
2532 INIT_LIST_HEAD(classhash_table + i);
2533
2534 for (i = 0; i < CHAINHASH_SIZE; i++)
2535 INIT_LIST_HEAD(chainhash_table + i);
2536
2537 lockdep_initialized = 1;
2538}
2539
2540void __init lockdep_info(void)
2541{
2542 printk("Lock dependency validator: Copyright (c) 2006 Red Hat, Inc., Ingo Molnar\n");
2543
2544 printk("... MAX_LOCKDEP_SUBCLASSES: %lu\n", MAX_LOCKDEP_SUBCLASSES);
2545 printk("... MAX_LOCK_DEPTH: %lu\n", MAX_LOCK_DEPTH);
2546 printk("... MAX_LOCKDEP_KEYS: %lu\n", MAX_LOCKDEP_KEYS);
2547 printk("... CLASSHASH_SIZE: %lu\n", CLASSHASH_SIZE);
2548 printk("... MAX_LOCKDEP_ENTRIES: %lu\n", MAX_LOCKDEP_ENTRIES);
2549 printk("... MAX_LOCKDEP_CHAINS: %lu\n", MAX_LOCKDEP_CHAINS);
2550 printk("... CHAINHASH_SIZE: %lu\n", CHAINHASH_SIZE);
2551
2552 printk(" memory used by lock dependency info: %lu kB\n",
2553 (sizeof(struct lock_class) * MAX_LOCKDEP_KEYS +
2554 sizeof(struct list_head) * CLASSHASH_SIZE +
2555 sizeof(struct lock_list) * MAX_LOCKDEP_ENTRIES +
2556 sizeof(struct lock_chain) * MAX_LOCKDEP_CHAINS +
2557 sizeof(struct list_head) * CHAINHASH_SIZE) / 1024);
2558
2559 printk(" per task-struct memory footprint: %lu bytes\n",
2560 sizeof(struct held_lock) * MAX_LOCK_DEPTH);
2561
2562#ifdef CONFIG_DEBUG_LOCKDEP
2563 if (lockdep_init_error)
2564 printk("WARNING: lockdep init error! Arch code didnt call lockdep_init() early enough?\n");
2565#endif
2566}
2567
2568static inline int in_range(const void *start, const void *addr, const void *end)
2569{
2570 return addr >= start && addr <= end;
2571}
2572
2573static void
2574print_freed_lock_bug(struct task_struct *curr, const void *mem_from,
2575 const void *mem_to)
2576{
2577 if (!debug_locks_off())
2578 return;
2579 if (debug_locks_silent)
2580 return;
2581
2582 printk("\n=========================\n");
2583 printk( "[ BUG: held lock freed! ]\n");
2584 printk( "-------------------------\n");
2585 printk("%s/%d is freeing memory %p-%p, with a lock still held there!\n",
2586 curr->comm, curr->pid, mem_from, mem_to-1);
2587 lockdep_print_held_locks(curr);
2588
2589 printk("\nstack backtrace:\n");
2590 dump_stack();
2591}
2592
2593/*
2594 * Called when kernel memory is freed (or unmapped), or if a lock
2595 * is destroyed or reinitialized - this code checks whether there is
2596 * any held lock in the memory range of <from> to <to>:
2597 */
2598void debug_check_no_locks_freed(const void *mem_from, unsigned long mem_len)
2599{
2600 const void *mem_to = mem_from + mem_len, *lock_from, *lock_to;
2601 struct task_struct *curr = current;
2602 struct held_lock *hlock;
2603 unsigned long flags;
2604 int i;
2605
2606 if (unlikely(!debug_locks))
2607 return;
2608
2609 local_irq_save(flags);
2610 for (i = 0; i < curr->lockdep_depth; i++) {
2611 hlock = curr->held_locks + i;
2612
2613 lock_from = (void *)hlock->instance;
2614 lock_to = (void *)(hlock->instance + 1);
2615
2616 if (!in_range(mem_from, lock_from, mem_to) &&
2617 !in_range(mem_from, lock_to, mem_to))
2618 continue;
2619
2620 print_freed_lock_bug(curr, mem_from, mem_to);
2621 break;
2622 }
2623 local_irq_restore(flags);
2624}
2625
2626static void print_held_locks_bug(struct task_struct *curr)
2627{
2628 if (!debug_locks_off())
2629 return;
2630 if (debug_locks_silent)
2631 return;
2632
2633 printk("\n=====================================\n");
2634 printk( "[ BUG: lock held at task exit time! ]\n");
2635 printk( "-------------------------------------\n");
2636 printk("%s/%d is exiting with locks still held!\n",
2637 curr->comm, curr->pid);
2638 lockdep_print_held_locks(curr);
2639
2640 printk("\nstack backtrace:\n");
2641 dump_stack();
2642}
2643
2644void debug_check_no_locks_held(struct task_struct *task)
2645{
2646 if (unlikely(task->lockdep_depth > 0))
2647 print_held_locks_bug(task);
2648}
2649
2650void debug_show_all_locks(void)
2651{
2652 struct task_struct *g, *p;
2653 int count = 10;
2654 int unlock = 1;
2655
2656 printk("\nShowing all locks held in the system:\n");
2657
2658 /*
2659 * Here we try to get the tasklist_lock as hard as possible,
2660 * if not successful after 2 seconds we ignore it (but keep
2661 * trying). This is to enable a debug printout even if a
2662 * tasklist_lock-holding task deadlocks or crashes.
2663 */
2664retry:
2665 if (!read_trylock(&tasklist_lock)) {
2666 if (count == 10)
2667 printk("hm, tasklist_lock locked, retrying... ");
2668 if (count) {
2669 count--;
2670 printk(" #%d", 10-count);
2671 mdelay(200);
2672 goto retry;
2673 }
2674 printk(" ignoring it.\n");
2675 unlock = 0;
2676 }
2677 if (count != 10)
2678 printk(" locked it.\n");
2679
2680 do_each_thread(g, p) {
2681 if (p->lockdep_depth)
2682 lockdep_print_held_locks(p);
2683 if (!unlock)
2684 if (read_trylock(&tasklist_lock))
2685 unlock = 1;
2686 } while_each_thread(g, p);
2687
2688 printk("\n");
2689 printk("=============================================\n\n");
2690
2691 if (unlock)
2692 read_unlock(&tasklist_lock);
2693}
2694
2695EXPORT_SYMBOL_GPL(debug_show_all_locks);
2696
2697void debug_show_held_locks(struct task_struct *task)
2698{
2699 lockdep_print_held_locks(task);
2700}
2701
2702EXPORT_SYMBOL_GPL(debug_show_held_locks);
2703
diff --git a/kernel/lockdep_internals.h b/kernel/lockdep_internals.h
new file mode 100644
index 000000000000..0d355f24fe04
--- /dev/null
+++ b/kernel/lockdep_internals.h
@@ -0,0 +1,78 @@
1/*
2 * kernel/lockdep_internals.h
3 *
4 * Runtime locking correctness validator
5 *
6 * lockdep subsystem internal functions and variables.
7 */
8
9/*
10 * MAX_LOCKDEP_ENTRIES is the maximum number of lock dependencies
11 * we track.
12 *
13 * We use the per-lock dependency maps in two ways: we grow it by adding
14 * every to-be-taken lock to all currently held lock's own dependency
15 * table (if it's not there yet), and we check it for lock order
16 * conflicts and deadlocks.
17 */
18#define MAX_LOCKDEP_ENTRIES 8192UL
19
20#define MAX_LOCKDEP_KEYS_BITS 11
21#define MAX_LOCKDEP_KEYS (1UL << MAX_LOCKDEP_KEYS_BITS)
22
23#define MAX_LOCKDEP_CHAINS_BITS 13
24#define MAX_LOCKDEP_CHAINS (1UL << MAX_LOCKDEP_CHAINS_BITS)
25
26/*
27 * Stack-trace: tightly packed array of stack backtrace
28 * addresses. Protected by the hash_lock.
29 */
30#define MAX_STACK_TRACE_ENTRIES 131072UL
31
32extern struct list_head all_lock_classes;
33
34extern void
35get_usage_chars(struct lock_class *class, char *c1, char *c2, char *c3, char *c4);
36
37extern const char * __get_key_name(struct lockdep_subclass_key *key, char *str);
38
39extern unsigned long nr_lock_classes;
40extern unsigned long nr_list_entries;
41extern unsigned long nr_lock_chains;
42extern unsigned long nr_stack_trace_entries;
43
44extern unsigned int nr_hardirq_chains;
45extern unsigned int nr_softirq_chains;
46extern unsigned int nr_process_chains;
47extern unsigned int max_lockdep_depth;
48extern unsigned int max_recursion_depth;
49
50#ifdef CONFIG_DEBUG_LOCKDEP
51/*
52 * Various lockdep statistics:
53 */
54extern atomic_t chain_lookup_hits;
55extern atomic_t chain_lookup_misses;
56extern atomic_t hardirqs_on_events;
57extern atomic_t hardirqs_off_events;
58extern atomic_t redundant_hardirqs_on;
59extern atomic_t redundant_hardirqs_off;
60extern atomic_t softirqs_on_events;
61extern atomic_t softirqs_off_events;
62extern atomic_t redundant_softirqs_on;
63extern atomic_t redundant_softirqs_off;
64extern atomic_t nr_unused_locks;
65extern atomic_t nr_cyclic_checks;
66extern atomic_t nr_cyclic_check_recursions;
67extern atomic_t nr_find_usage_forwards_checks;
68extern atomic_t nr_find_usage_forwards_recursions;
69extern atomic_t nr_find_usage_backwards_checks;
70extern atomic_t nr_find_usage_backwards_recursions;
71# define debug_atomic_inc(ptr) atomic_inc(ptr)
72# define debug_atomic_dec(ptr) atomic_dec(ptr)
73# define debug_atomic_read(ptr) atomic_read(ptr)
74#else
75# define debug_atomic_inc(ptr) do { } while (0)
76# define debug_atomic_dec(ptr) do { } while (0)
77# define debug_atomic_read(ptr) 0
78#endif
diff --git a/kernel/module.c b/kernel/module.c
index 0351625767b1..35e1b1f859d7 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -1121,6 +1121,9 @@ static void free_module(struct module *mod)
1121 if (mod->percpu) 1121 if (mod->percpu)
1122 percpu_modfree(mod->percpu); 1122 percpu_modfree(mod->percpu);
1123 1123
1124 /* Free lock-classes: */
1125 lockdep_free_key_range(mod->module_core, mod->core_size);
1126
1124 /* Finally, free the core (containing the module structure) */ 1127 /* Finally, free the core (containing the module structure) */
1125 module_free(mod, mod->module_core); 1128 module_free(mod, mod->module_core);
1126} 1129}
generated by cgit v1.2.2 (git 2.25.0) at 2024-11-16 11:32:06 -0500