~hc/RK356X_SDK_RELEASE.git

..	..	@@ -1,3 +1,4 @@
	1	+// SPDX-License-Identifier: GPL-2.0-only
1	2	/*
2	3	* kernel/lockdep.c
3	4	*
..	..	@@ -45,11 +46,14 @@
45	46	#include <linux/hash.h>
46	47	#include <linux/ftrace.h>
47	48	#include <linux/stringify.h>
	49	+#include <linux/bitmap.h>
48	50	#include <linux/bitops.h>
49	51	#include <linux/gfp.h>
50	52	#include <linux/random.h>
51	53	#include <linux/jhash.h>
52	54	#include <linux/nmi.h>
	55	+#include <linux/rcupdate.h>
	56	+#include <linux/kprobes.h>
53	57
54	58	#include <asm/sections.h>
55	59
..	..	@@ -72,6 +76,23 @@
72	76	#define lock_stat 0
73	77	#endif
74	78
	79	+DEFINE_PER_CPU(unsigned int, lockdep_recursion);
	80	+EXPORT_PER_CPU_SYMBOL_GPL(lockdep_recursion);
	81	+
	82	+static __always_inline bool lockdep_enabled(void)
	83	+{
	84	+ if (!debug_locks)
	85	+ return false;
	86	+
	87	+ if (this_cpu_read(lockdep_recursion))
	88	+ return false;
	89	+
	90	+ if (current->lockdep_recursion)
	91	+ return false;
	92	+
	93	+ return true;
	94	+}
	95	+
75	96	/*
76	97	* lockdep_lock: protects the lockdep graph, the hashes and the
77	98	* class/list/hash allocators.
..	..	@@ -80,11 +101,41 @@
80	101	* to use a raw spinlock - we really dont want the spinlock
81	102	* code to recurse back into the lockdep code...
82	103	*/
83		-static arch_spinlock_t lockdep_lock = (arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED;
	104	+static arch_spinlock_t __lock = (arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED;
	105	+static struct task_struct *__owner;
	106	+
	107	+static inline void lockdep_lock(void)
	108	+{
	109	+ DEBUG_LOCKS_WARN_ON(!irqs_disabled());
	110	+
	111	+ __this_cpu_inc(lockdep_recursion);
	112	+ arch_spin_lock(&__lock);
	113	+ __owner = current;
	114	+}
	115	+
	116	+static inline void lockdep_unlock(void)
	117	+{
	118	+ DEBUG_LOCKS_WARN_ON(!irqs_disabled());
	119	+
	120	+ if (debug_locks && DEBUG_LOCKS_WARN_ON(__owner != current))
	121	+ return;
	122	+
	123	+ __owner = NULL;
	124	+ arch_spin_unlock(&__lock);
	125	+ __this_cpu_dec(lockdep_recursion);
	126	+}
	127	+
	128	+static inline bool lockdep_assert_locked(void)
	129	+{
	130	+ return DEBUG_LOCKS_WARN_ON(__owner != current);
	131	+}
	132	+
	133	+static struct task_struct *lockdep_selftest_task_struct;
	134	+
84	135
85	136	static int graph_lock(void)
86	137	{
87		- arch_spin_lock(&lockdep_lock);
	138	+ lockdep_lock();
88	139	/*
89	140	* Make sure that if another CPU detected a bug while
90	141	* walking the graph we dont change it (while the other
..	..	@@ -92,27 +143,15 @@
92	143	* dropped already)
93	144	*/
94	145	if (!debug_locks) {
95		- arch_spin_unlock(&lockdep_lock);
	146	+ lockdep_unlock();
96	147	return 0;
97	148	}
98		- /* prevent any recursions within lockdep from causing deadlocks */
99		- current->lockdep_recursion++;
100	149	return 1;
101	150	}
102	151
103		-static inline int graph_unlock(void)
	152	+static inline void graph_unlock(void)
104	153	{
105		- if (debug_locks && !arch_spin_is_locked(&lockdep_lock)) {
106		- /*
107		- * The lockdep graph lock isn't locked while we expect it to
108		- * be, we're confused now, bye!
109		- */
110		- return DEBUG_LOCKS_WARN_ON(1);
111		- }
112		-
113		- current->lockdep_recursion--;
114		- arch_spin_unlock(&lockdep_lock);
115		- return 0;
	154	+ lockdep_unlock();
116	155	}
117	156
118	157	/*
..	..	@@ -123,33 +162,50 @@
123	162	{
124	163	int ret = debug_locks_off();
125	164
126		- arch_spin_unlock(&lockdep_lock);
	165	+ lockdep_unlock();
127	166
128	167	return ret;
129	168	}
130	169
131	170	unsigned long nr_list_entries;
132	171	static struct lock_list list_entries[MAX_LOCKDEP_ENTRIES];
	172	+static DECLARE_BITMAP(list_entries_in_use, MAX_LOCKDEP_ENTRIES);
133	173
134	174	/*
135	175	* All data structures here are protected by the global debug_lock.
136	176	*
137		- * Mutex key structs only get allocated, once during bootup, and never
138		- * get freed - this significantly simplifies the debugging code.
	177	+ * nr_lock_classes is the number of elements of lock_classes[] that is
	178	+ * in use.
139	179	*/
	180	+#define KEYHASH_BITS (MAX_LOCKDEP_KEYS_BITS - 1)
	181	+#define KEYHASH_SIZE (1UL << KEYHASH_BITS)
	182	+static struct hlist_head lock_keys_hash[KEYHASH_SIZE];
140	183	unsigned long nr_lock_classes;
141		-static struct lock_class lock_classes[MAX_LOCKDEP_KEYS];
	184	+unsigned long nr_zapped_classes;
	185	+unsigned long max_lock_class_idx;
	186	+struct lock_class lock_classes[MAX_LOCKDEP_KEYS];
	187	+DECLARE_BITMAP(lock_classes_in_use, MAX_LOCKDEP_KEYS);
142	188
143	189	static inline struct lock_class hlock_class(struct held_lock hlock)
144	190	{
145		- if (!hlock->class_idx) {
	191	+ unsigned int class_idx = hlock->class_idx;
	192	+
	193	+ /* Don't re-read hlock->class_idx, can't use READ_ONCE() on bitfield */
	194	+ barrier();
	195	+
	196	+ if (!test_bit(class_idx, lock_classes_in_use)) {
146	197	/*
147	198	* Someone passed in garbage, we give up.
148	199	*/
149	200	DEBUG_LOCKS_WARN_ON(1);
150	201	return NULL;
151	202	}
152		- return lock_classes + hlock->class_idx - 1;
	203	+
	204	+ /*
	205	+ * At this point, if the passed hlock->class_idx is still garbage,
	206	+ * we just have to live with it
	207	+ */
	208	+ return lock_classes + class_idx;
153	209	}
154	210
155	211	#ifdef CONFIG_LOCK_STAT
..	..	@@ -274,11 +330,42 @@
274	330	#endif
275	331
276	332	/*
277		- * We keep a global list of all lock classes. The list only grows,
278		- * never shrinks. The list is only accessed with the lockdep
279		- * spinlock lock held.
	333	+ * We keep a global list of all lock classes. The list is only accessed with
	334	+ * the lockdep spinlock lock held. free_lock_classes is a list with free
	335	+ * elements. These elements are linked together by the lock_entry member in
	336	+ * struct lock_class.
280	337	*/
281		-LIST_HEAD(all_lock_classes);
	338	+static LIST_HEAD(all_lock_classes);
	339	+static LIST_HEAD(free_lock_classes);
	340	+
	341	+/**
	342	+ * struct pending_free - information about data structures about to be freed
	343	+ * @zapped: Head of a list with struct lock_class elements.
	344	+ * @lock_chains_being_freed: Bitmap that indicates which lock_chains[] elements
	345	+ * are about to be freed.
	346	+ */
	347	+struct pending_free {
	348	+ struct list_head zapped;
	349	+ DECLARE_BITMAP(lock_chains_being_freed, MAX_LOCKDEP_CHAINS);
	350	+};
	351	+
	352	+/**
	353	+ * struct delayed_free - data structures used for delayed freeing
	354	+ *
	355	+ * A data structure for delayed freeing of data structures that may be
	356	+ * accessed by RCU readers at the time these were freed.
	357	+ *
	358	+ * @rcu_head: Used to schedule an RCU callback for freeing data structures.
	359	+ * @index: Index of @pf to which freed data structures are added.
	360	+ * @scheduled: Whether or not an RCU callback has been scheduled.
	361	+ * @pf: Array with information about data structures about to be freed.
	362	+ */
	363	+static struct delayed_free {
	364	+ struct rcu_head rcu_head;
	365	+ int index;
	366	+ int scheduled;
	367	+ struct pending_free pf[2];
	368	+} delayed_free;
282	369
283	370	/*
284	371	* The lockdep classes are in a hash-table as well, for fast lookup:
..	..	@@ -302,6 +389,21 @@
302	389	static struct hlist_head chainhash_table[CHAINHASH_SIZE];
303	390
304	391	/*
	392	+ * the id of held_lock
	393	+ */
	394	+static inline u16 hlock_id(struct held_lock *hlock)
	395	+{
	396	+ BUILD_BUG_ON(MAX_LOCKDEP_KEYS_BITS + 2 > 16);
	397	+
	398	+ return (hlock->class_idx \| (hlock->read << MAX_LOCKDEP_KEYS_BITS));
	399	+}
	400	+
	401	+static inline unsigned int chain_hlock_class_idx(u16 hlock_id)
	402	+{
	403	+ return hlock_id & (MAX_LOCKDEP_KEYS - 1);
	404	+}
	405	+
	406	+/*
305	407	* The hash key of the lock dependency chains is a hash itself too:
306	408	* it's a hash of all locks taken up to that lock, including that lock.
307	409	* It's a 64-bit hash, because it's important for the keys to be
..	..	@@ -316,17 +418,28 @@
316	418	return k0 \| (u64)k1 << 32;
317	419	}
318	420
319		-void lockdep_off(void)
	421	+void lockdep_init_task(struct task_struct *task)
320	422	{
321		- current->lockdep_recursion++;
	423	+ task->lockdep_depth = 0; /* no locks held yet */
	424	+ task->curr_chain_key = INITIAL_CHAIN_KEY;
	425	+ task->lockdep_recursion = 0;
322	426	}
323		-EXPORT_SYMBOL(lockdep_off);
324	427
325		-void lockdep_on(void)
	428	+static __always_inline void lockdep_recursion_inc(void)
326	429	{
327		- current->lockdep_recursion--;
	430	+ __this_cpu_inc(lockdep_recursion);
328	431	}
329		-EXPORT_SYMBOL(lockdep_on);
	432	+
	433	+static __always_inline void lockdep_recursion_finish(void)
	434	+{
	435	+ if (WARN_ON_ONCE(__this_cpu_dec_return(lockdep_recursion)))
	436	+ __this_cpu_write(lockdep_recursion, 0);
	437	+}
	438	+
	439	+void lockdep_set_selftest_task(struct task_struct *task)
	440	+{
	441	+ lockdep_selftest_task_struct = task;
	442	+}
330	443
331	444	/*
332	445	* Debugging switches:
..	..	@@ -371,13 +484,6 @@
371	484	return 0;
372	485	}
373	486
374		-/*
375		- * Stack-trace: tightly packed array of stack backtrace
376		- * addresses. Protected by the graph_lock.
377		- */
378		-unsigned long nr_stack_trace_entries;
379		-static unsigned long stack_trace[MAX_STACK_TRACE_ENTRIES];
380		-
381	487	static void print_lockdep_off(const char *bug_msg)
382	488	{
383	489	printk(KERN_DEBUG "%s\n", bug_msg);
..	..	@@ -387,43 +493,105 @@
387	493	#endif
388	494	}
389	495
390		-static int save_trace(struct stack_trace *trace)
	496	+unsigned long nr_stack_trace_entries;
	497	+
	498	+#ifdef CONFIG_PROVE_LOCKING
	499	+/**
	500	+ * struct lock_trace - single stack backtrace
	501	+ * @hash_entry: Entry in a stack_trace_hash[] list.
	502	+ * @hash: jhash() of @entries.
	503	+ * @nr_entries: Number of entries in @entries.
	504	+ * @entries: Actual stack backtrace.
	505	+ */
	506	+struct lock_trace {
	507	+ struct hlist_node hash_entry;
	508	+ u32 hash;
	509	+ u32 nr_entries;
	510	+ unsigned long entries[] __aligned(sizeof(unsigned long));
	511	+};
	512	+#define LOCK_TRACE_SIZE_IN_LONGS \
	513	+ (sizeof(struct lock_trace) / sizeof(unsigned long))
	514	+/*
	515	+ * Stack-trace: sequence of lock_trace structures. Protected by the graph_lock.
	516	+ */
	517	+static unsigned long stack_trace[MAX_STACK_TRACE_ENTRIES];
	518	+static struct hlist_head stack_trace_hash[STACK_TRACE_HASH_SIZE];
	519	+
	520	+static bool traces_identical(struct lock_trace t1, struct lock_trace t2)
391	521	{
392		- trace->nr_entries = 0;
393		- trace->max_entries = MAX_STACK_TRACE_ENTRIES - nr_stack_trace_entries;
394		- trace->entries = stack_trace + nr_stack_trace_entries;
	522	+ return t1->hash == t2->hash && t1->nr_entries == t2->nr_entries &&
	523	+ memcmp(t1->entries, t2->entries,
	524	+ t1->nr_entries * sizeof(t1->entries[0])) == 0;
	525	+}
395	526
396		- trace->skip = 3;
	527	+static struct lock_trace *save_trace(void)
	528	+{
	529	+ struct lock_trace trace, t2;
	530	+ struct hlist_head *hash_head;
	531	+ u32 hash;
	532	+ int max_entries;
397	533
398		- save_stack_trace(trace);
	534	+ BUILD_BUG_ON_NOT_POWER_OF_2(STACK_TRACE_HASH_SIZE);
	535	+ BUILD_BUG_ON(LOCK_TRACE_SIZE_IN_LONGS >= MAX_STACK_TRACE_ENTRIES);
399	536
400		- /*
401		- * Some daft arches put -1 at the end to indicate its a full trace.
402		- *
403		- * <rant> this is buggy anyway, since it takes a whole extra entry so a
404		- * complete trace that maxes out the entries provided will be reported
405		- * as incomplete, friggin useless </rant>
406		- */
407		- if (trace->nr_entries != 0 &&
408		- trace->entries[trace->nr_entries-1] == ULONG_MAX)
409		- trace->nr_entries--;
	537	+ trace = (struct lock_trace *)(stack_trace + nr_stack_trace_entries);
	538	+ max_entries = MAX_STACK_TRACE_ENTRIES - nr_stack_trace_entries -
	539	+ LOCK_TRACE_SIZE_IN_LONGS;
410	540
411		- trace->max_entries = trace->nr_entries;
412		-
413		- nr_stack_trace_entries += trace->nr_entries;
414		-
415		- if (nr_stack_trace_entries >= MAX_STACK_TRACE_ENTRIES-1) {
	541	+ if (max_entries <= 0) {
416	542	if (!debug_locks_off_graph_unlock())
417		- return 0;
	543	+ return NULL;
418	544
419	545	print_lockdep_off("BUG: MAX_STACK_TRACE_ENTRIES too low!");
420	546	dump_stack();
421	547
422		- return 0;
	548	+ return NULL;
	549	+ }
	550	+ trace->nr_entries = stack_trace_save(trace->entries, max_entries, 3);
	551	+
	552	+ hash = jhash(trace->entries, trace->nr_entries *
	553	+ sizeof(trace->entries[0]), 0);
	554	+ trace->hash = hash;
	555	+ hash_head = stack_trace_hash + (hash & (STACK_TRACE_HASH_SIZE - 1));
	556	+ hlist_for_each_entry(t2, hash_head, hash_entry) {
	557	+ if (traces_identical(trace, t2))
	558	+ return t2;
	559	+ }
	560	+ nr_stack_trace_entries += LOCK_TRACE_SIZE_IN_LONGS + trace->nr_entries;
	561	+ hlist_add_head(&trace->hash_entry, hash_head);
	562	+
	563	+ return trace;
	564	+}
	565	+
	566	+/* Return the number of stack traces in the stack_trace[] array. */
	567	+u64 lockdep_stack_trace_count(void)
	568	+{
	569	+ struct lock_trace *trace;
	570	+ u64 c = 0;
	571	+ int i;
	572	+
	573	+ for (i = 0; i < ARRAY_SIZE(stack_trace_hash); i++) {
	574	+ hlist_for_each_entry(trace, &stack_trace_hash[i], hash_entry) {
	575	+ c++;
	576	+ }
423	577	}
424	578
425		- return 1;
	579	+ return c;
426	580	}
	581	+
	582	+/* Return the number of stack hash chains that have at least one stack trace. */
	583	+u64 lockdep_stack_hash_count(void)
	584	+{
	585	+ u64 c = 0;
	586	+ int i;
	587	+
	588	+ for (i = 0; i < ARRAY_SIZE(stack_trace_hash); i++)
	589	+ if (!hlist_empty(&stack_trace_hash[i]))
	590	+ c++;
	591	+
	592	+ return c;
	593	+}
	594	+#endif
427	595
428	596	unsigned int nr_hardirq_chains;
429	597	unsigned int nr_softirq_chains;
..	..	@@ -437,6 +605,7 @@
437	605	DEFINE_PER_CPU(struct lockdep_stats, lockdep_stats);
438	606	#endif
439	607
	608	+#ifdef CONFIG_PROVE_LOCKING
440	609	/*
441	610	* Locking printouts:
442	611	*/
..	..	@@ -453,9 +622,13 @@
453	622	#include "lockdep_states.h"
454	623	#undef LOCKDEP_STATE
455	624	[LOCK_USED] = "INITIAL USE",
	625	+ [LOCK_USED_READ] = "INITIAL READ USE",
	626	+ /* abused as string storage for verify_lock_unused() */
	627	+ [LOCK_USAGE_STATES] = "IN-NMI",
456	628	};
	629	+#endif
457	630
458		-const char * __get_key_name(struct lockdep_subclass_key key, char str)
	631	+const char __get_key_name(const struct lockdep_subclass_key key, char *str)
459	632	{
460	633	return kallsyms_lookup((unsigned long)key, NULL, NULL, NULL, str);
461	634	}
..	..	@@ -467,15 +640,26 @@
467	640
468	641	static char get_usage_char(struct lock_class *class, enum lock_usage_bit bit)
469	642	{
	643	+ /*
	644	+ * The usage character defaults to '.' (i.e., irqs disabled and not in
	645	+ * irq context), which is the safest usage category.
	646	+ */
470	647	char c = '.';
471	648
472		- if (class->usage_mask & lock_flag(bit + 2))
	649	+ /*
	650	+ * The order of the following usage checks matters, which will
	651	+ * result in the outcome character as follows:
	652	+ *
	653	+ * - '+': irq is enabled and not in irq context
	654	+ * - '-': in irq context and irq is disabled
	655	+ * - '?': in irq context and irq is enabled
	656	+ */
	657	+ if (class->usage_mask & lock_flag(bit + LOCK_USAGE_DIR_MASK)) {
473	658	c = '+';
474		- if (class->usage_mask & lock_flag(bit)) {
475		- c = '-';
476		- if (class->usage_mask & lock_flag(bit + 2))
	659	+ if (class->usage_mask & lock_flag(bit))
477	660	c = '?';
478		- }
	661	+ } else if (class->usage_mask & lock_flag(bit))
	662	+ c = '-';
479	663
480	664	return c;
481	665	}
..	..	@@ -519,7 +703,9 @@
519	703
520	704	printk(KERN_CONT " (");
521	705	__print_lock_name(class);
522		- printk(KERN_CONT "){%s}", usage);
	706	+ printk(KERN_CONT "){%s}-{%d:%d}", usage,
	707	+ class->wait_type_outer ?: class->wait_type_inner,
	708	+ class->wait_type_inner);
523	709	}
524	710
525	711	static void print_lockdep_cache(struct lockdep_map *lock)
..	..	@@ -539,19 +725,22 @@
539	725	/*
540	726	* We can be called locklessly through debug_show_all_locks() so be
541	727	* extra careful, the hlock might have been released and cleared.
	728	+ *
	729	+ * If this indeed happens, lets pretend it does not hurt to continue
	730	+ * to print the lock unless the hlock class_idx does not point to a
	731	+ * registered class. The rationale here is: since we don't attempt
	732	+ * to distinguish whether we are in this situation, if it just
	733	+ * happened we can't count on class_idx to tell either.
542	734	*/
543		- unsigned int class_idx = hlock->class_idx;
	735	+ struct lock_class *lock = hlock_class(hlock);
544	736
545		- /* Don't re-read hlock->class_idx, can't use READ_ONCE() on bitfields: */
546		- barrier();
547		-
548		- if (!class_idx \|\| (class_idx - 1) >= MAX_LOCKDEP_KEYS) {
	737	+ if (!lock) {
549	738	printk(KERN_CONT "<RELEASED>\n");
550	739	return;
551	740	}
552	741
553		- printk(KERN_CONT "%p", hlock->instance);
554		- print_lock_name(lock_classes + class_idx - 1);
	742	+ printk(KERN_CONT "%px", hlock->instance);
	743	+ print_lock_name(lock);
555	744	printk(KERN_CONT ", at: %pS\n", (void *)hlock->acquire_ip);
556	745	}
557	746
..	..	@@ -596,11 +785,14 @@
596	785	* Is this the address of a static object:
597	786	*/
598	787	#ifdef __KERNEL__
599		-static int static_obj(void *obj)
	788	+static int static_obj(const void *obj)
600	789	{
601	790	unsigned long start = (unsigned long) &_stext,
602	791	end = (unsigned long) &_end,
603	792	addr = (unsigned long) obj;
	793	+
	794	+ if (arch_is_kernel_initmem_freed(addr))
	795	+ return 0;
604	796
605	797	/*
606	798	* static variable?
..	..	@@ -626,7 +818,8 @@
626	818
627	819	/*
628	820	* To make lock name printouts unique, we calculate a unique
629		- * class->name_version generation counter:
	821	+ * class->name_version generation counter. The caller must hold the graph
	822	+ * lock.
630	823	*/
631	824	static int count_matching_names(struct lock_class *new_class)
632	825	{
..	..	@@ -636,7 +829,7 @@
636	829	if (!new_class->name)
637	830	return 0;
638	831
639		- list_for_each_entry_rcu(class, &all_lock_classes, lock_entry) {
	832	+ list_for_each_entry(class, &all_lock_classes, lock_entry) {
640	833	if (new_class->key - new_class->subclass == class->key)
641	834	return class->name_version;
642	835	if (class->name && !strcmp(class->name, new_class->name))
..	..	@@ -646,7 +839,8 @@
646	839	return count + 1;
647	840	}
648	841
649		-static inline struct lock_class *
	842	+/* used from NMI context -- must be lockless */
	843	+static noinstr struct lock_class *
650	844	look_up_lock_class(const struct lockdep_map *lock, unsigned int subclass)
651	845	{
652	846	struct lockdep_subclass_key *key;
..	..	@@ -654,12 +848,14 @@
654	848	struct lock_class *class;
655	849
656	850	if (unlikely(subclass >= MAX_LOCKDEP_SUBCLASSES)) {
	851	+ instrumentation_begin();
657	852	debug_locks_off();
658	853	printk(KERN_ERR
659	854	"BUG: looking up invalid subclass: %u\n", subclass);
660	855	printk(KERN_ERR
661	856	"turning off the locking correctness validator.\n");
662	857	dump_stack();
	858	+ instrumentation_end();
663	859	return NULL;
664	860	}
665	861
..	..	@@ -695,7 +891,8 @@
695	891	* Huh! same key, different name? Did someone trample
696	892	* on some memory? We're most confused.
697	893	*/
698		- WARN_ON_ONCE(class->name != lock->name);
	894	+ WARN_ON_ONCE(class->name != lock->name &&
	895	+ lock->key != &__lockdep_no_validate__);
699	896	return class;
700	897	}
701	898	}
..	..	@@ -711,6 +908,17 @@
711	908	static bool assign_lock_key(struct lockdep_map *lock)
712	909	{
713	910	unsigned long can_addr, addr = (unsigned long)lock;
	911	+
	912	+#ifdef __KERNEL__
	913	+ /*
	914	+ * lockdep_free_key_range() assumes that struct lock_class_key
	915	+ * objects do not overlap. Since we use the address of lock
	916	+ * objects as class key for static objects, check whether the
	917	+ * size of lock_class_key objects does not exceed the size of
	918	+ * the smallest lock object.
	919	+ */
	920	+ BUILD_BUG_ON(sizeof(struct lock_class_key) > sizeof(raw_spinlock_t));
	921	+#endif
714	922
715	923	if (__is_kernel_percpu_address(addr, &can_addr))
716	924	lock->key = (void *)can_addr;
..	..	@@ -732,6 +940,292 @@
732	940	return true;
733	941	}
734	942
	943	+#ifdef CONFIG_DEBUG_LOCKDEP
	944	+
	945	+/* Check whether element @e occurs in list @h */
	946	+static bool in_list(struct list_head e, struct list_head h)
	947	+{
	948	+ struct list_head *f;
	949	+
	950	+ list_for_each(f, h) {
	951	+ if (e == f)
	952	+ return true;
	953	+ }
	954	+
	955	+ return false;
	956	+}
	957	+
	958	+/*
	959	+ * Check whether entry @e occurs in any of the locks_after or locks_before
	960	+ * lists.
	961	+ */
	962	+static bool in_any_class_list(struct list_head *e)
	963	+{
	964	+ struct lock_class *class;
	965	+ int i;
	966	+
	967	+ for (i = 0; i < ARRAY_SIZE(lock_classes); i++) {
	968	+ class = &lock_classes[i];
	969	+ if (in_list(e, &class->locks_after) \|\|
	970	+ in_list(e, &class->locks_before))
	971	+ return true;
	972	+ }
	973	+ return false;
	974	+}
	975	+
	976	+static bool class_lock_list_valid(struct lock_class c, struct list_head h)
	977	+{
	978	+ struct lock_list *e;
	979	+
	980	+ list_for_each_entry(e, h, entry) {
	981	+ if (e->links_to != c) {
	982	+ printk(KERN_INFO "class %s: mismatch for lock entry %ld; class %s <> %s",
	983	+ c->name ? : "(?)",
	984	+ (unsigned long)(e - list_entries),
	985	+ e->links_to && e->links_to->name ?
	986	+ e->links_to->name : "(?)",
	987	+ e->class && e->class->name ? e->class->name :
	988	+ "(?)");
	989	+ return false;
	990	+ }
	991	+ }
	992	+ return true;
	993	+}
	994	+
	995	+#ifdef CONFIG_PROVE_LOCKING
	996	+static u16 chain_hlocks[MAX_LOCKDEP_CHAIN_HLOCKS];
	997	+#endif
	998	+
	999	+static bool check_lock_chain_key(struct lock_chain *chain)
	1000	+{
	1001	+#ifdef CONFIG_PROVE_LOCKING
	1002	+ u64 chain_key = INITIAL_CHAIN_KEY;
	1003	+ int i;
	1004	+
	1005	+ for (i = chain->base; i < chain->base + chain->depth; i++)
	1006	+ chain_key = iterate_chain_key(chain_key, chain_hlocks[i]);
	1007	+ /*
	1008	+ * The 'unsigned long long' casts avoid that a compiler warning
	1009	+ * is reported when building tools/lib/lockdep.
	1010	+ */
	1011	+ if (chain->chain_key != chain_key) {
	1012	+ printk(KERN_INFO "chain %lld: key %#llx <> %#llx\n",
	1013	+ (unsigned long long)(chain - lock_chains),
	1014	+ (unsigned long long)chain->chain_key,
	1015	+ (unsigned long long)chain_key);
	1016	+ return false;
	1017	+ }
	1018	+#endif
	1019	+ return true;
	1020	+}
	1021	+
	1022	+static bool in_any_zapped_class_list(struct lock_class *class)
	1023	+{
	1024	+ struct pending_free *pf;
	1025	+ int i;
	1026	+
	1027	+ for (i = 0, pf = delayed_free.pf; i < ARRAY_SIZE(delayed_free.pf); i++, pf++) {
	1028	+ if (in_list(&class->lock_entry, &pf->zapped))
	1029	+ return true;
	1030	+ }
	1031	+
	1032	+ return false;
	1033	+}
	1034	+
	1035	+static bool __check_data_structures(void)
	1036	+{
	1037	+ struct lock_class *class;
	1038	+ struct lock_chain *chain;
	1039	+ struct hlist_head *head;
	1040	+ struct lock_list *e;
	1041	+ int i;
	1042	+
	1043	+ /* Check whether all classes occur in a lock list. */
	1044	+ for (i = 0; i < ARRAY_SIZE(lock_classes); i++) {
	1045	+ class = &lock_classes[i];
	1046	+ if (!in_list(&class->lock_entry, &all_lock_classes) &&
	1047	+ !in_list(&class->lock_entry, &free_lock_classes) &&
	1048	+ !in_any_zapped_class_list(class)) {
	1049	+ printk(KERN_INFO "class %px/%s is not in any class list\n",
	1050	+ class, class->name ? : "(?)");
	1051	+ return false;
	1052	+ }
	1053	+ }
	1054	+
	1055	+ /* Check whether all classes have valid lock lists. */
	1056	+ for (i = 0; i < ARRAY_SIZE(lock_classes); i++) {
	1057	+ class = &lock_classes[i];
	1058	+ if (!class_lock_list_valid(class, &class->locks_before))
	1059	+ return false;
	1060	+ if (!class_lock_list_valid(class, &class->locks_after))
	1061	+ return false;
	1062	+ }
	1063	+
	1064	+ /* Check the chain_key of all lock chains. */
	1065	+ for (i = 0; i < ARRAY_SIZE(chainhash_table); i++) {
	1066	+ head = chainhash_table + i;
	1067	+ hlist_for_each_entry_rcu(chain, head, entry) {
	1068	+ if (!check_lock_chain_key(chain))
	1069	+ return false;
	1070	+ }
	1071	+ }
	1072	+
	1073	+ /*
	1074	+ * Check whether all list entries that are in use occur in a class
	1075	+ * lock list.
	1076	+ */
	1077	+ for_each_set_bit(i, list_entries_in_use, ARRAY_SIZE(list_entries)) {
	1078	+ e = list_entries + i;
	1079	+ if (!in_any_class_list(&e->entry)) {
	1080	+ printk(KERN_INFO "list entry %d is not in any class list; class %s <> %s\n",
	1081	+ (unsigned int)(e - list_entries),
	1082	+ e->class->name ? : "(?)",
	1083	+ e->links_to->name ? : "(?)");
	1084	+ return false;
	1085	+ }
	1086	+ }
	1087	+
	1088	+ /*
	1089	+ * Check whether all list entries that are not in use do not occur in
	1090	+ * a class lock list.
	1091	+ */
	1092	+ for_each_clear_bit(i, list_entries_in_use, ARRAY_SIZE(list_entries)) {
	1093	+ e = list_entries + i;
	1094	+ if (in_any_class_list(&e->entry)) {
	1095	+ printk(KERN_INFO "list entry %d occurs in a class list; class %s <> %s\n",
	1096	+ (unsigned int)(e - list_entries),
	1097	+ e->class && e->class->name ? e->class->name :
	1098	+ "(?)",
	1099	+ e->links_to && e->links_to->name ?
	1100	+ e->links_to->name : "(?)");
	1101	+ return false;
	1102	+ }
	1103	+ }
	1104	+
	1105	+ return true;
	1106	+}
	1107	+
	1108	+int check_consistency = 0;
	1109	+module_param(check_consistency, int, 0644);
	1110	+
	1111	+static void check_data_structures(void)
	1112	+{
	1113	+ static bool once = false;
	1114	+
	1115	+ if (check_consistency && !once) {
	1116	+ if (!__check_data_structures()) {
	1117	+ once = true;
	1118	+ WARN_ON(once);
	1119	+ }
	1120	+ }
	1121	+}
	1122	+
	1123	+#else /* CONFIG_DEBUG_LOCKDEP */
	1124	+
	1125	+static inline void check_data_structures(void) { }
	1126	+
	1127	+#endif /* CONFIG_DEBUG_LOCKDEP */
	1128	+
	1129	+static void init_chain_block_buckets(void);
	1130	+
	1131	+/*
	1132	+ * Initialize the lock_classes[] array elements, the free_lock_classes list
	1133	+ * and also the delayed_free structure.
	1134	+ */
	1135	+static void init_data_structures_once(void)
	1136	+{
	1137	+ static bool __read_mostly ds_initialized, rcu_head_initialized;
	1138	+ int i;
	1139	+
	1140	+ if (likely(rcu_head_initialized))
	1141	+ return;
	1142	+
	1143	+ if (system_state >= SYSTEM_SCHEDULING) {
	1144	+ init_rcu_head(&delayed_free.rcu_head);
	1145	+ rcu_head_initialized = true;
	1146	+ }
	1147	+
	1148	+ if (ds_initialized)
	1149	+ return;
	1150	+
	1151	+ ds_initialized = true;
	1152	+
	1153	+ INIT_LIST_HEAD(&delayed_free.pf[0].zapped);
	1154	+ INIT_LIST_HEAD(&delayed_free.pf[1].zapped);
	1155	+
	1156	+ for (i = 0; i < ARRAY_SIZE(lock_classes); i++) {
	1157	+ list_add_tail(&lock_classes[i].lock_entry, &free_lock_classes);
	1158	+ INIT_LIST_HEAD(&lock_classes[i].locks_after);
	1159	+ INIT_LIST_HEAD(&lock_classes[i].locks_before);
	1160	+ }
	1161	+ init_chain_block_buckets();
	1162	+}
	1163	+
	1164	+static inline struct hlist_head keyhashentry(const struct lock_class_key key)
	1165	+{
	1166	+ unsigned long hash = hash_long((uintptr_t)key, KEYHASH_BITS);
	1167	+
	1168	+ return lock_keys_hash + hash;
	1169	+}
	1170	+
	1171	+/* Register a dynamically allocated key. */
	1172	+void lockdep_register_key(struct lock_class_key *key)
	1173	+{
	1174	+ struct hlist_head *hash_head;
	1175	+ struct lock_class_key *k;
	1176	+ unsigned long flags;
	1177	+
	1178	+ if (WARN_ON_ONCE(static_obj(key)))
	1179	+ return;
	1180	+ hash_head = keyhashentry(key);
	1181	+
	1182	+ raw_local_irq_save(flags);
	1183	+ if (!graph_lock())
	1184	+ goto restore_irqs;
	1185	+ hlist_for_each_entry_rcu(k, hash_head, hash_entry) {
	1186	+ if (WARN_ON_ONCE(k == key))
	1187	+ goto out_unlock;
	1188	+ }
	1189	+ hlist_add_head_rcu(&key->hash_entry, hash_head);
	1190	+out_unlock:
	1191	+ graph_unlock();
	1192	+restore_irqs:
	1193	+ raw_local_irq_restore(flags);
	1194	+}
	1195	+EXPORT_SYMBOL_GPL(lockdep_register_key);
	1196	+
	1197	+/* Check whether a key has been registered as a dynamic key. */
	1198	+static bool is_dynamic_key(const struct lock_class_key *key)
	1199	+{
	1200	+ struct hlist_head *hash_head;
	1201	+ struct lock_class_key *k;
	1202	+ bool found = false;
	1203	+
	1204	+ if (WARN_ON_ONCE(static_obj(key)))
	1205	+ return false;
	1206	+
	1207	+ /*
	1208	+ * If lock debugging is disabled lock_keys_hash[] may contain
	1209	+ * pointers to memory that has already been freed. Avoid triggering
	1210	+ * a use-after-free in that case by returning early.
	1211	+ */
	1212	+ if (!debug_locks)
	1213	+ return true;
	1214	+
	1215	+ hash_head = keyhashentry(key);
	1216	+
	1217	+ rcu_read_lock();
	1218	+ hlist_for_each_entry_rcu(k, hash_head, hash_entry) {
	1219	+ if (k == key) {
	1220	+ found = true;
	1221	+ break;
	1222	+ }
	1223	+ }
	1224	+ rcu_read_unlock();
	1225	+
	1226	+ return found;
	1227	+}
	1228	+
735	1229	/*
736	1230	* Register a lock's class in the hash-table, if the class is not present
737	1231	* yet. Otherwise we look it up. We cache the result in the lock object
..	..	@@ -743,6 +1237,7 @@
743	1237	struct lockdep_subclass_key *key;
744	1238	struct hlist_head *hash_head;
745	1239	struct lock_class *class;
	1240	+ int idx;
746	1241
747	1242	DEBUG_LOCKS_WARN_ON(!irqs_disabled());
748	1243
..	..	@@ -753,7 +1248,7 @@
753	1248	if (!lock->key) {
754	1249	if (!assign_lock_key(lock))
755	1250	return NULL;
756		- } else if (!static_obj(lock->key)) {
	1251	+ } else if (!static_obj(lock->key) && !is_dynamic_key(lock->key)) {
757	1252	return NULL;
758	1253	}
759	1254
..	..	@@ -772,11 +1267,12 @@
772	1267	goto out_unlock_set;
773	1268	}
774	1269
775		- /*
776		- * Allocate a new key from the static array, and add it to
777		- * the hash:
778		- */
779		- if (nr_lock_classes >= MAX_LOCKDEP_KEYS) {
	1270	+ init_data_structures_once();
	1271	+
	1272	+ /* Allocate a new lock class and add it to the hash. */
	1273	+ class = list_first_entry_or_null(&free_lock_classes, typeof(*class),
	1274	+ lock_entry);
	1275	+ if (!class) {
780	1276	if (!debug_locks_off_graph_unlock()) {
781	1277	return NULL;
782	1278	}
..	..	@@ -785,24 +1281,31 @@
785	1281	dump_stack();
786	1282	return NULL;
787	1283	}
788		- class = lock_classes + nr_lock_classes++;
	1284	+ nr_lock_classes++;
	1285	+ __set_bit(class - lock_classes, lock_classes_in_use);
789	1286	debug_atomic_inc(nr_unused_locks);
790	1287	class->key = key;
791	1288	class->name = lock->name;
792	1289	class->subclass = subclass;
793		- INIT_LIST_HEAD(&class->lock_entry);
794		- INIT_LIST_HEAD(&class->locks_before);
795		- INIT_LIST_HEAD(&class->locks_after);
	1290	+ WARN_ON_ONCE(!list_empty(&class->locks_before));
	1291	+ WARN_ON_ONCE(!list_empty(&class->locks_after));
796	1292	class->name_version = count_matching_names(class);
	1293	+ class->wait_type_inner = lock->wait_type_inner;
	1294	+ class->wait_type_outer = lock->wait_type_outer;
	1295	+ class->lock_type = lock->lock_type;
797	1296	/*
798	1297	* We use RCU's safe list-add method to make
799	1298	* parallel walking of the hash-list safe:
800	1299	*/
801	1300	hlist_add_head_rcu(&class->hash_entry, hash_head);
802	1301	/*
803		- * Add it to the global list of classes:
	1302	+ * Remove the class from the free list and add it to the global list
	1303	+ * of classes.
804	1304	*/
805		- list_add_tail_rcu(&class->lock_entry, &all_lock_classes);
	1305	+ list_move_tail(&class->lock_entry, &all_lock_classes);
	1306	+ idx = class - lock_classes;
	1307	+ if (idx > max_lock_class_idx)
	1308	+ max_lock_class_idx = idx;
806	1309
807	1310	if (verbose(class)) {
808	1311	graph_unlock();
..	..	@@ -843,7 +1346,10 @@
843	1346	*/
844	1347	static struct lock_list *alloc_list_entry(void)
845	1348	{
846		- if (nr_list_entries >= MAX_LOCKDEP_ENTRIES) {
	1349	+ int idx = find_first_zero_bit(list_entries_in_use,
	1350	+ ARRAY_SIZE(list_entries));
	1351	+
	1352	+ if (idx >= ARRAY_SIZE(list_entries)) {
847	1353	if (!debug_locks_off_graph_unlock())
848	1354	return NULL;
849	1355
..	..	@@ -851,15 +1357,18 @@
851	1357	dump_stack();
852	1358	return NULL;
853	1359	}
854		- return list_entries + nr_list_entries++;
	1360	+ nr_list_entries++;
	1361	+ __set_bit(idx, list_entries_in_use);
	1362	+ return list_entries + idx;
855	1363	}
856	1364
857	1365	/*
858	1366	* Add a new dependency to the head of the list:
859	1367	*/
860		-static int add_lock_to_list(struct lock_class this, struct list_head head,
861		- unsigned long ip, int distance,
862		- struct stack_trace *trace)
	1368	+static int add_lock_to_list(struct lock_class *this,
	1369	+ struct lock_class links_to, struct list_head head,
	1370	+ unsigned long ip, u16 distance, u8 dep,
	1371	+ const struct lock_trace *trace)
863	1372	{
864	1373	struct lock_list *entry;
865	1374	/*
..	..	@@ -871,8 +1380,10 @@
871	1380	return 0;
872	1381
873	1382	entry->class = this;
	1383	+ entry->links_to = links_to;
	1384	+ entry->dep = dep;
874	1385	entry->distance = distance;
875		- entry->trace = *trace;
	1386	+ entry->trace = trace;
876	1387	/*
877	1388	* Both allocation and removal are done under the graph lock; but
878	1389	* iteration is under RCU-sched; see look_up_lock_class() and
..	..	@@ -886,17 +1397,21 @@
886	1397	/*
887	1398	* For good efficiency of modular, we use power of 2
888	1399	*/
889		-#define MAX_CIRCULAR_QUEUE_SIZE 4096UL
	1400	+#define MAX_CIRCULAR_QUEUE_SIZE (1UL << CONFIG_LOCKDEP_CIRCULAR_QUEUE_BITS)
890	1401	#define CQ_MASK (MAX_CIRCULAR_QUEUE_SIZE-1)
891	1402
892	1403	/*
893		- * The circular_queue and helpers is used to implement the
894		- * breadth-first search(BFS)algorithem, by which we can build
895		- * the shortest path from the next lock to be acquired to the
896		- * previous held lock if there is a circular between them.
	1404	+ * The circular_queue and helpers are used to implement graph
	1405	+ * breadth-first search (BFS) algorithm, by which we can determine
	1406	+ * whether there is a path from a lock to another. In deadlock checks,
	1407	+ * a path from the next lock to be acquired to a previous held lock
	1408	+ * indicates that adding the <prev> -> <next> lock dependency will
	1409	+ * produce a circle in the graph. Breadth-first search instead of
	1410	+ * depth-first search is used in order to find the shortest (circular)
	1411	+ * path.
897	1412	*/
898	1413	struct circular_queue {
899		- unsigned long element[MAX_CIRCULAR_QUEUE_SIZE];
	1414	+ struct lock_list *element[MAX_CIRCULAR_QUEUE_SIZE];
900	1415	unsigned int front, rear;
901	1416	};
902	1417
..	..	@@ -922,7 +1437,7 @@
922	1437	return ((cq->rear + 1) & CQ_MASK) == cq->front;
923	1438	}
924	1439
925		-static inline int __cq_enqueue(struct circular_queue *cq, unsigned long elem)
	1440	+static inline int __cq_enqueue(struct circular_queue cq, struct lock_list elem)
926	1441	{
927	1442	if (__cq_full(cq))
928	1443	return -1;
..	..	@@ -932,14 +1447,21 @@
932	1447	return 0;
933	1448	}
934	1449
935		-static inline int __cq_dequeue(struct circular_queue cq, unsigned long elem)
	1450	+/*
	1451	+ * Dequeue an element from the circular_queue, return a lock_list if
	1452	+ * the queue is not empty, or NULL if otherwise.
	1453	+ */
	1454	+static inline struct lock_list * __cq_dequeue(struct circular_queue *cq)
936	1455	{
937		- if (__cq_empty(cq))
938		- return -1;
	1456	+ struct lock_list * lock;
939	1457
940		- *elem = cq->element[cq->front];
	1458	+ if (__cq_empty(cq))
	1459	+ return NULL;
	1460	+
	1461	+ lock = cq->element[cq->front];
941	1462	cq->front = (cq->front + 1) & CQ_MASK;
942		- return 0;
	1463	+
	1464	+ return lock;
943	1465	}
944	1466
945	1467	static inline unsigned int __cq_get_elem_count(struct circular_queue *cq)
..	..	@@ -947,23 +1469,19 @@
947	1469	return (cq->rear - cq->front) & CQ_MASK;
948	1470	}
949	1471
950		-static inline void mark_lock_accessed(struct lock_list *lock,
951		- struct lock_list *parent)
	1472	+static inline void mark_lock_accessed(struct lock_list *lock)
952	1473	{
953		- unsigned long nr;
954		-
955		- nr = lock - list_entries;
956		- WARN_ON(nr >= nr_list_entries); /* Out-of-bounds, input fail */
957		- lock->parent = parent;
958	1474	lock->class->dep_gen_id = lockdep_dependency_gen_id;
	1475	+}
	1476	+
	1477	+static inline void visit_lock_entry(struct lock_list *lock,
	1478	+ struct lock_list *parent)
	1479	+{
	1480	+ lock->parent = parent;
959	1481	}
960	1482
961	1483	static inline unsigned long lock_accessed(struct lock_list *lock)
962	1484	{
963		- unsigned long nr;
964		-
965		- nr = lock - list_entries;
966		- WARN_ON(nr >= nr_list_entries); /* Out-of-bounds, input fail */
967	1485	return lock->class->dep_gen_id == lockdep_dependency_gen_id;
968	1486	}
969	1487
..	..	@@ -984,114 +1502,321 @@
984	1502	return depth;
985	1503	}
986	1504
987		-static int __bfs(struct lock_list *source_entry,
988		- void *data,
989		- int (match)(struct lock_list entry, void *data),
990		- struct lock_list **target_entry,
991		- int forward)
	1505	+/*
	1506	+ * Return the forward or backward dependency list.
	1507	+ *
	1508	+ * @lock: the lock_list to get its class's dependency list
	1509	+ * @offset: the offset to struct lock_class to determine whether it is
	1510	+ * locks_after or locks_before
	1511	+ */
	1512	+static inline struct list_head get_dep_list(struct lock_list lock, int offset)
992	1513	{
993		- struct lock_list *entry;
994		- struct list_head *head;
995		- struct circular_queue *cq = &lock_cq;
996		- int ret = 1;
	1514	+ void *lock_class = lock->class;
997	1515
998		- if (match(source_entry, data)) {
999		- *target_entry = source_entry;
1000		- ret = 0;
1001		- goto exit;
1002		- }
1003		-
1004		- if (forward)
1005		- head = &source_entry->class->locks_after;
1006		- else
1007		- head = &source_entry->class->locks_before;
1008		-
1009		- if (list_empty(head))
1010		- goto exit;
1011		-
1012		- __cq_init(cq);
1013		- __cq_enqueue(cq, (unsigned long)source_entry);
1014		-
1015		- while (!__cq_empty(cq)) {
1016		- struct lock_list *lock;
1017		-
1018		- __cq_dequeue(cq, (unsigned long *)&lock);
1019		-
1020		- if (!lock->class) {
1021		- ret = -2;
1022		- goto exit;
1023		- }
1024		-
1025		- if (forward)
1026		- head = &lock->class->locks_after;
1027		- else
1028		- head = &lock->class->locks_before;
1029		-
1030		- DEBUG_LOCKS_WARN_ON(!irqs_disabled());
1031		-
1032		- list_for_each_entry_rcu(entry, head, entry) {
1033		- if (!lock_accessed(entry)) {
1034		- unsigned int cq_depth;
1035		- mark_lock_accessed(entry, lock);
1036		- if (match(entry, data)) {
1037		- *target_entry = entry;
1038		- ret = 0;
1039		- goto exit;
1040		- }
1041		-
1042		- if (__cq_enqueue(cq, (unsigned long)entry)) {
1043		- ret = -1;
1044		- goto exit;
1045		- }
1046		- cq_depth = __cq_get_elem_count(cq);
1047		- if (max_bfs_queue_depth < cq_depth)
1048		- max_bfs_queue_depth = cq_depth;
1049		- }
1050		- }
1051		- }
1052		-exit:
1053		- return ret;
	1516	+ return lock_class + offset;
1054	1517	}
	1518	+/*
	1519	+ * Return values of a bfs search:
	1520	+ *
	1521	+ * BFS_E* indicates an error
	1522	+ * BFS_R* indicates a result (match or not)
	1523	+ *
	1524	+ * BFS_EINVALIDNODE: Find a invalid node in the graph.
	1525	+ *
	1526	+ * BFS_EQUEUEFULL: The queue is full while doing the bfs.
	1527	+ *
	1528	+ * BFS_RMATCH: Find the matched node in the graph, and put that node into
	1529	+ * *@target_entry.
	1530	+ *
	1531	+ * BFS_RNOMATCH: Haven't found the matched node and keep *@target_entry
	1532	+ * _unchanged_.
	1533	+ */
	1534	+enum bfs_result {
	1535	+ BFS_EINVALIDNODE = -2,
	1536	+ BFS_EQUEUEFULL = -1,
	1537	+ BFS_RMATCH = 0,
	1538	+ BFS_RNOMATCH = 1,
	1539	+};
1055	1540
1056		-static inline int __bfs_forwards(struct lock_list *src_entry,
1057		- void *data,
1058		- int (match)(struct lock_list entry, void *data),
1059		- struct lock_list **target_entry)
	1541	+/*
	1542	+ * bfs_result < 0 means error
	1543	+ */
	1544	+static inline bool bfs_error(enum bfs_result res)
1060	1545	{
1061		- return __bfs(src_entry, data, match, target_entry, 1);
1062		-
1063		-}
1064		-
1065		-static inline int __bfs_backwards(struct lock_list *src_entry,
1066		- void *data,
1067		- int (match)(struct lock_list entry, void *data),
1068		- struct lock_list **target_entry)
1069		-{
1070		- return __bfs(src_entry, data, match, target_entry, 0);
1071		-
	1546	+ return res < 0;
1072	1547	}
1073	1548
1074	1549	/*
1075		- * Recursive, forwards-direction lock-dependency checking, used for
1076		- * both noncyclic checking and for hardirq-unsafe/softirq-unsafe
1077		- * checking.
	1550	+ * DEP_*_BIT in lock_list::dep
	1551	+ *
	1552	+ * For dependency @prev -> @next:
	1553	+ *
	1554	+ * SR: @prev is shared reader (->read != 0) and @next is recursive reader
	1555	+ * (->read == 2)
	1556	+ * ER: @prev is exclusive locker (->read == 0) and @next is recursive reader
	1557	+ * SN: @prev is shared reader and @next is non-recursive locker (->read != 2)
	1558	+ * EN: @prev is exclusive locker and @next is non-recursive locker
	1559	+ *
	1560	+ * Note that we define the value of DEP_*_BITs so that:
	1561	+ * bit0 is prev->read == 0
	1562	+ * bit1 is next->read != 2
1078	1563	*/
	1564	+#define DEP_SR_BIT (0 + (0 << 1)) /* 0 */
	1565	+#define DEP_ER_BIT (1 + (0 << 1)) /* 1 */
	1566	+#define DEP_SN_BIT (0 + (1 << 1)) /* 2 */
	1567	+#define DEP_EN_BIT (1 + (1 << 1)) /* 3 */
	1568	+
	1569	+#define DEP_SR_MASK (1U << (DEP_SR_BIT))
	1570	+#define DEP_ER_MASK (1U << (DEP_ER_BIT))
	1571	+#define DEP_SN_MASK (1U << (DEP_SN_BIT))
	1572	+#define DEP_EN_MASK (1U << (DEP_EN_BIT))
	1573	+
	1574	+static inline unsigned int
	1575	+__calc_dep_bit(struct held_lock prev, struct held_lock next)
	1576	+{
	1577	+ return (prev->read == 0) + ((next->read != 2) << 1);
	1578	+}
	1579	+
	1580	+static inline u8 calc_dep(struct held_lock prev, struct held_lock next)
	1581	+{
	1582	+ return 1U << __calc_dep_bit(prev, next);
	1583	+}
	1584	+
	1585	+/*
	1586	+ * calculate the dep_bit for backwards edges. We care about whether @prev is
	1587	+ * shared and whether @next is recursive.
	1588	+ */
	1589	+static inline unsigned int
	1590	+__calc_dep_bitb(struct held_lock prev, struct held_lock next)
	1591	+{
	1592	+ return (next->read != 2) + ((prev->read == 0) << 1);
	1593	+}
	1594	+
	1595	+static inline u8 calc_depb(struct held_lock prev, struct held_lock next)
	1596	+{
	1597	+ return 1U << __calc_dep_bitb(prev, next);
	1598	+}
	1599	+
	1600	+/*
	1601	+ * Initialize a lock_list entry @lock belonging to @class as the root for a BFS
	1602	+ * search.
	1603	+ */
	1604	+static inline void __bfs_init_root(struct lock_list *lock,
	1605	+ struct lock_class *class)
	1606	+{
	1607	+ lock->class = class;
	1608	+ lock->parent = NULL;
	1609	+ lock->only_xr = 0;
	1610	+}
	1611	+
	1612	+/*
	1613	+ * Initialize a lock_list entry @lock based on a lock acquisition @hlock as the
	1614	+ * root for a BFS search.
	1615	+ *
	1616	+ * ->only_xr of the initial lock node is set to @hlock->read == 2, to make sure
	1617	+ * that <prev> -> @hlock and @hlock -> <whatever __bfs() found> is not -(*R)->
	1618	+ * and -(S*)->.
	1619	+ */
	1620	+static inline void bfs_init_root(struct lock_list *lock,
	1621	+ struct held_lock *hlock)
	1622	+{
	1623	+ __bfs_init_root(lock, hlock_class(hlock));
	1624	+ lock->only_xr = (hlock->read == 2);
	1625	+}
	1626	+
	1627	+/*
	1628	+ * Similar to bfs_init_root() but initialize the root for backwards BFS.
	1629	+ *
	1630	+ * ->only_xr of the initial lock node is set to @hlock->read != 0, to make sure
	1631	+ * that <next> -> @hlock and @hlock -> <whatever backwards BFS found> is not
	1632	+ * -(S)-> and -(R)-> (reverse order of -(R)-> and -(S)->).
	1633	+ */
	1634	+static inline void bfs_init_rootb(struct lock_list *lock,
	1635	+ struct held_lock *hlock)
	1636	+{
	1637	+ __bfs_init_root(lock, hlock_class(hlock));
	1638	+ lock->only_xr = (hlock->read != 0);
	1639	+}
	1640	+
	1641	+static inline struct lock_list __bfs_next(struct lock_list lock, int offset)
	1642	+{
	1643	+ if (!lock \|\| !lock->parent)
	1644	+ return NULL;
	1645	+
	1646	+ return list_next_or_null_rcu(get_dep_list(lock->parent, offset),
	1647	+ &lock->entry, struct lock_list, entry);
	1648	+}
	1649	+
	1650	+/*
	1651	+ * Breadth-First Search to find a strong path in the dependency graph.
	1652	+ *
	1653	+ * @source_entry: the source of the path we are searching for.
	1654	+ * @data: data used for the second parameter of @match function
	1655	+ * @match: match function for the search
	1656	+ * @target_entry: pointer to the target of a matched path
	1657	+ * @offset: the offset to struct lock_class to determine whether it is
	1658	+ * locks_after or locks_before
	1659	+ *
	1660	+ * We may have multiple edges (considering different kinds of dependencies,
	1661	+ * e.g. ER and SN) between two nodes in the dependency graph. But
	1662	+ * only the strong dependency path in the graph is relevant to deadlocks. A
	1663	+ * strong dependency path is a dependency path that doesn't have two adjacent
	1664	+ * dependencies as -(R)-> -(S)->, please see:
	1665	+ *
	1666	+ * Documentation/locking/lockdep-design.rst
	1667	+ *
	1668	+ * for more explanation of the definition of strong dependency paths
	1669	+ *
	1670	+ * In __bfs(), we only traverse in the strong dependency path:
	1671	+ *
	1672	+ * In lock_list::only_xr, we record whether the previous dependency only
	1673	+ * has -(R)-> in the search, and if it does (prev only has -(R)->), we
	1674	+ * filter out any -(S*)-> in the current dependency and after that, the
	1675	+ * ->only_xr is set according to whether we only have -(*R)-> left.
	1676	+ */
	1677	+static enum bfs_result __bfs(struct lock_list *source_entry,
	1678	+ void *data,
	1679	+ bool (match)(struct lock_list entry, void *data),
	1680	+ struct lock_list **target_entry,
	1681	+ int offset)
	1682	+{
	1683	+ struct circular_queue *cq = &lock_cq;
	1684	+ struct lock_list *lock = NULL;
	1685	+ struct lock_list *entry;
	1686	+ struct list_head *head;
	1687	+ unsigned int cq_depth;
	1688	+ bool first;
	1689	+
	1690	+ lockdep_assert_locked();
	1691	+
	1692	+ __cq_init(cq);
	1693	+ __cq_enqueue(cq, source_entry);
	1694	+
	1695	+ while ((lock = __bfs_next(lock, offset)) \|\| (lock = __cq_dequeue(cq))) {
	1696	+ if (!lock->class)
	1697	+ return BFS_EINVALIDNODE;
	1698	+
	1699	+ /*
	1700	+ * Step 1: check whether we already finish on this one.
	1701	+ *
	1702	+ * If we have visited all the dependencies from this @lock to
	1703	+ * others (iow, if we have visited all lock_list entries in
	1704	+ * @lock->class->locks_{after,before}) we skip, otherwise go
	1705	+ * and visit all the dependencies in the list and mark this
	1706	+ * list accessed.
	1707	+ */
	1708	+ if (lock_accessed(lock))
	1709	+ continue;
	1710	+ else
	1711	+ mark_lock_accessed(lock);
	1712	+
	1713	+ /*
	1714	+ * Step 2: check whether prev dependency and this form a strong
	1715	+ * dependency path.
	1716	+ */
	1717	+ if (lock->parent) { /* Parent exists, check prev dependency */
	1718	+ u8 dep = lock->dep;
	1719	+ bool prev_only_xr = lock->parent->only_xr;
	1720	+
	1721	+ /*
	1722	+ * Mask out all -(S)-> if we only have R in previous
	1723	+ * step, because -(R)-> -(S)-> don't make up a strong
	1724	+ * dependency.
	1725	+ */
	1726	+ if (prev_only_xr)
	1727	+ dep &= ~(DEP_SR_MASK \| DEP_SN_MASK);
	1728	+
	1729	+ /* If nothing left, we skip */
	1730	+ if (!dep)
	1731	+ continue;
	1732	+
	1733	+ /* If there are only -(R)-> left, set that for the next step /
	1734	+ lock->only_xr = !(dep & (DEP_SN_MASK \| DEP_EN_MASK));
	1735	+ }
	1736	+
	1737	+ /*
	1738	+ * Step 3: we haven't visited this and there is a strong
	1739	+ * dependency path to this, so check with @match.
	1740	+ */
	1741	+ if (match(lock, data)) {
	1742	+ *target_entry = lock;
	1743	+ return BFS_RMATCH;
	1744	+ }
	1745	+
	1746	+ /*
	1747	+ * Step 4: if not match, expand the path by adding the
	1748	+ * forward or backwards dependencis in the search
	1749	+ *
	1750	+ */
	1751	+ first = true;
	1752	+ head = get_dep_list(lock, offset);
	1753	+ list_for_each_entry_rcu(entry, head, entry) {
	1754	+ visit_lock_entry(entry, lock);
	1755	+
	1756	+ /*
	1757	+ * Note we only enqueue the first of the list into the
	1758	+ * queue, because we can always find a sibling
	1759	+ * dependency from one (see __bfs_next()), as a result
	1760	+ * the space of queue is saved.
	1761	+ */
	1762	+ if (!first)
	1763	+ continue;
	1764	+
	1765	+ first = false;
	1766	+
	1767	+ if (__cq_enqueue(cq, entry))
	1768	+ return BFS_EQUEUEFULL;
	1769	+
	1770	+ cq_depth = __cq_get_elem_count(cq);
	1771	+ if (max_bfs_queue_depth < cq_depth)
	1772	+ max_bfs_queue_depth = cq_depth;
	1773	+ }
	1774	+ }
	1775	+
	1776	+ return BFS_RNOMATCH;
	1777	+}
	1778	+
	1779	+static inline enum bfs_result
	1780	+__bfs_forwards(struct lock_list *src_entry,
	1781	+ void *data,
	1782	+ bool (match)(struct lock_list entry, void *data),
	1783	+ struct lock_list **target_entry)
	1784	+{
	1785	+ return __bfs(src_entry, data, match, target_entry,
	1786	+ offsetof(struct lock_class, locks_after));
	1787	+
	1788	+}
	1789	+
	1790	+static inline enum bfs_result
	1791	+__bfs_backwards(struct lock_list *src_entry,
	1792	+ void *data,
	1793	+ bool (match)(struct lock_list entry, void *data),
	1794	+ struct lock_list **target_entry)
	1795	+{
	1796	+ return __bfs(src_entry, data, match, target_entry,
	1797	+ offsetof(struct lock_class, locks_before));
	1798	+
	1799	+}
	1800	+
	1801	+static void print_lock_trace(const struct lock_trace *trace,
	1802	+ unsigned int spaces)
	1803	+{
	1804	+ stack_trace_print(trace->entries, trace->nr_entries, spaces);
	1805	+}
1079	1806
1080	1807	/*
1081	1808	* Print a dependency chain entry (this is only done when a deadlock
1082	1809	* has been detected):
1083	1810	*/
1084		-static noinline int
	1811	+static noinline void
1085	1812	print_circular_bug_entry(struct lock_list *target, int depth)
1086	1813	{
1087	1814	if (debug_locks_silent)
1088		- return 0;
	1815	+ return;
1089	1816	printk("\n-> #%u", depth);
1090	1817	print_lock_name(target->class);
1091	1818	printk(KERN_CONT ":\n");
1092		- print_stack_trace(&target->trace, 6);
1093		-
1094		- return 0;
	1819	+ print_lock_trace(target->trace, 6);
1095	1820	}
1096	1821
1097	1822	static void
..	..	@@ -1148,7 +1873,7 @@
1148	1873	* When a circular dependency is detected, print the
1149	1874	* header first:
1150	1875	*/
1151		-static noinline int
	1876	+static noinline void
1152	1877	print_circular_bug_header(struct lock_list *entry, unsigned int depth,
1153	1878	struct held_lock *check_src,
1154	1879	struct held_lock *check_tgt)
..	..	@@ -1156,7 +1881,7 @@
1156	1881	struct task_struct *curr = current;
1157	1882
1158	1883	if (debug_locks_silent)
1159		- return 0;
	1884	+ return;
1160	1885
1161	1886	pr_warn("\n");
1162	1887	pr_warn("======================================================\n");
..	..	@@ -1174,20 +1899,74 @@
1174	1899	pr_warn("\nthe existing dependency chain (in reverse order) is:\n");
1175	1900
1176	1901	print_circular_bug_entry(entry, depth);
1177		-
1178		- return 0;
1179	1902	}
1180	1903
1181		-static inline int class_equal(struct lock_list entry, void data)
	1904	+/*
	1905	+ * We are about to add A -> B into the dependency graph, and in __bfs() a
	1906	+ * strong dependency path A -> .. -> B is found: hlock_class equals
	1907	+ * entry->class.
	1908	+ *
	1909	+ * If A -> .. -> B can replace A -> B in any __bfs() search (means the former
	1910	+ * is _stronger_ than or equal to the latter), we consider A -> B as redundant.
	1911	+ * For example if A -> .. -> B is -(EN)-> (i.e. A -(E)-> .. -(N)-> B), and A
	1912	+ * -> B is -(ER)-> or -(EN)->, then we don't need to add A -> B into the
	1913	+ * dependency graph, as any strong path ..-> A -> B ->.. we can get with
	1914	+ * having dependency A -> B, we could already get a equivalent path ..-> A ->
	1915	+ * .. -> B -> .. with A -> .. -> B. Therefore A -> B is reduntant.
	1916	+ *
	1917	+ * We need to make sure both the start and the end of A -> .. -> B is not
	1918	+ * weaker than A -> B. For the start part, please see the comment in
	1919	+ * check_redundant(). For the end part, we need:
	1920	+ *
	1921	+ * Either
	1922	+ *
	1923	+ * a) A -> B is -(*R)-> (everything is not weaker than that)
	1924	+ *
	1925	+ * or
	1926	+ *
	1927	+ * b) A -> .. -> B is -(*N)-> (nothing is stronger than this)
	1928	+ *
	1929	+ */
	1930	+static inline bool hlock_equal(struct lock_list entry, void data)
1182	1931	{
1183		- return entry->class == data;
	1932	+ struct held_lock hlock = (struct held_lock )data;
	1933	+
	1934	+ return hlock_class(hlock) == entry->class && /* Found A -> .. -> B */
	1935	+ (hlock->read == 2 \|\| /* A -> B is -(R)-> /
	1936	+ !entry->only_xr); /* A -> .. -> B is -(N)-> /
1184	1937	}
1185	1938
1186		-static noinline int print_circular_bug(struct lock_list *this,
	1939	+/*
	1940	+ * We are about to add B -> A into the dependency graph, and in __bfs() a
	1941	+ * strong dependency path A -> .. -> B is found: hlock_class equals
	1942	+ * entry->class.
	1943	+ *
	1944	+ * We will have a deadlock case (conflict) if A -> .. -> B -> A is a strong
	1945	+ * dependency cycle, that means:
	1946	+ *
	1947	+ * Either
	1948	+ *
	1949	+ * a) B -> A is -(E*)->
	1950	+ *
	1951	+ * or
	1952	+ *
	1953	+ * b) A -> .. -> B is -(N)-> (i.e. A -> .. -(N)-> B)
	1954	+ *
	1955	+ * as then we don't have -(R)-> -(S)-> in the cycle.
	1956	+ */
	1957	+static inline bool hlock_conflict(struct lock_list entry, void data)
	1958	+{
	1959	+ struct held_lock hlock = (struct held_lock )data;
	1960	+
	1961	+ return hlock_class(hlock) == entry->class && /* Found A -> .. -> B */
	1962	+ (hlock->read == 0 \|\| /* B -> A is -(E)-> /
	1963	+ !entry->only_xr); /* A -> .. -> B is -(N)-> /
	1964	+}
	1965	+
	1966	+static noinline void print_circular_bug(struct lock_list *this,
1187	1967	struct lock_list *target,
1188	1968	struct held_lock *check_src,
1189		- struct held_lock *check_tgt,
1190		- struct stack_trace *trace)
	1969	+ struct held_lock *check_tgt)
1191	1970	{
1192	1971	struct task_struct *curr = current;
1193	1972	struct lock_list *parent;
..	..	@@ -1195,10 +1974,11 @@
1195	1974	int depth;
1196	1975
1197	1976	if (!debug_locks_off_graph_unlock() \|\| debug_locks_silent)
1198		- return 0;
	1977	+ return;
1199	1978
1200		- if (!save_trace(&this->trace))
1201		- return 0;
	1979	+ this->trace = save_trace();
	1980	+ if (!this->trace)
	1981	+ return;
1202	1982
1203	1983	depth = get_lock_depth(target);
1204	1984
..	..	@@ -1220,33 +2000,29 @@
1220	2000
1221	2001	printk("\nstack backtrace:\n");
1222	2002	dump_stack();
1223		-
1224		- return 0;
1225	2003	}
1226	2004
1227		-static noinline int print_bfs_bug(int ret)
	2005	+static noinline void print_bfs_bug(int ret)
1228	2006	{
1229	2007	if (!debug_locks_off_graph_unlock())
1230		- return 0;
	2008	+ return;
1231	2009
1232	2010	/*
1233	2011	* Breadth-first-search failed, graph got corrupted?
1234	2012	*/
1235	2013	WARN(1, "lockdep bfs error:%d\n", ret);
1236		-
1237		- return 0;
1238	2014	}
1239	2015
1240		-static int noop_count(struct lock_list entry, void data)
	2016	+static bool noop_count(struct lock_list entry, void data)
1241	2017	{
1242	2018	((unsigned long )data)++;
1243		- return 0;
	2019	+ return false;
1244	2020	}
1245	2021
1246	2022	static unsigned long __lockdep_count_forward_deps(struct lock_list *this)
1247	2023	{
1248	2024	unsigned long count = 0;
1249		- struct lock_list *uninitialized_var(target_entry);
	2025	+ struct lock_list *target_entry;
1250	2026
1251	2027	__bfs_forwards(this, (void *)&count, noop_count, &target_entry);
1252	2028
..	..	@@ -1257,15 +2033,12 @@
1257	2033	unsigned long ret, flags;
1258	2034	struct lock_list this;
1259	2035
1260		- this.parent = NULL;
1261		- this.class = class;
	2036	+ __bfs_init_root(&this, class);
1262	2037
1263	2038	raw_local_irq_save(flags);
1264		- current->lockdep_recursion = 1;
1265		- arch_spin_lock(&lockdep_lock);
	2039	+ lockdep_lock();
1266	2040	ret = __lockdep_count_forward_deps(&this);
1267		- arch_spin_unlock(&lockdep_lock);
1268		- current->lockdep_recursion = 0;
	2041	+ lockdep_unlock();
1269	2042	raw_local_irq_restore(flags);
1270	2043
1271	2044	return ret;
..	..	@@ -1274,7 +2047,7 @@
1274	2047	static unsigned long __lockdep_count_backward_deps(struct lock_list *this)
1275	2048	{
1276	2049	unsigned long count = 0;
1277		- struct lock_list *uninitialized_var(target_entry);
	2050	+ struct lock_list *target_entry;
1278	2051
1279	2052	__bfs_backwards(this, (void *)&count, noop_count, &target_entry);
1280	2053
..	..	@@ -1286,83 +2059,199 @@
1286	2059	unsigned long ret, flags;
1287	2060	struct lock_list this;
1288	2061
1289		- this.parent = NULL;
1290		- this.class = class;
	2062	+ __bfs_init_root(&this, class);
1291	2063
1292	2064	raw_local_irq_save(flags);
1293		- current->lockdep_recursion = 1;
1294		- arch_spin_lock(&lockdep_lock);
	2065	+ lockdep_lock();
1295	2066	ret = __lockdep_count_backward_deps(&this);
1296		- arch_spin_unlock(&lockdep_lock);
1297		- current->lockdep_recursion = 0;
	2067	+ lockdep_unlock();
1298	2068	raw_local_irq_restore(flags);
1299	2069
1300	2070	return ret;
1301	2071	}
1302	2072
1303	2073	/*
1304		- * Prove that the dependency graph starting at <entry> can not
1305		- * lead to <target>. Print an error and return 0 if it does.
	2074	+ * Check that the dependency graph starting at <src> can lead to
	2075	+ * <target> or not.
1306	2076	*/
1307		-static noinline int
1308		-check_noncircular(struct lock_list root, struct lock_class target,
1309		- struct lock_list **target_entry)
	2077	+static noinline enum bfs_result
	2078	+check_path(struct held_lock target, struct lock_list src_entry,
	2079	+ bool (match)(struct lock_list entry, void *data),
	2080	+ struct lock_list **target_entry)
1310	2081	{
1311		- int result;
	2082	+ enum bfs_result ret;
	2083	+
	2084	+ ret = __bfs_forwards(src_entry, target, match, target_entry);
	2085	+
	2086	+ if (unlikely(bfs_error(ret)))
	2087	+ print_bfs_bug(ret);
	2088	+
	2089	+ return ret;
	2090	+}
	2091	+
	2092	+/*
	2093	+ * Prove that the dependency graph starting at <src> can not
	2094	+ * lead to <target>. If it can, there is a circle when adding
	2095	+ * <target> -> <src> dependency.
	2096	+ *
	2097	+ * Print an error and return BFS_RMATCH if it does.
	2098	+ */
	2099	+static noinline enum bfs_result
	2100	+check_noncircular(struct held_lock src, struct held_lock target,
	2101	+ struct lock_trace **const trace)
	2102	+{
	2103	+ enum bfs_result ret;
	2104	+ struct lock_list *target_entry;
	2105	+ struct lock_list src_entry;
	2106	+
	2107	+ bfs_init_root(&src_entry, src);
1312	2108
1313	2109	debug_atomic_inc(nr_cyclic_checks);
1314	2110
1315		- result = __bfs_forwards(root, target, class_equal, target_entry);
	2111	+ ret = check_path(target, &src_entry, hlock_conflict, &target_entry);
1316	2112
1317		- return result;
	2113	+ if (unlikely(ret == BFS_RMATCH)) {
	2114	+ if (!*trace) {
	2115	+ /*
	2116	+ * If save_trace fails here, the printing might
	2117	+ * trigger a WARN but because of the !nr_entries it
	2118	+ * should not do bad things.
	2119	+ */
	2120	+ *trace = save_trace();
	2121	+ }
	2122	+
	2123	+ print_circular_bug(&src_entry, target_entry, src, target);
	2124	+ }
	2125	+
	2126	+ return ret;
1318	2127	}
1319	2128
1320		-static noinline int
1321		-check_redundant(struct lock_list root, struct lock_class target,
1322		- struct lock_list **target_entry)
	2129	+#ifdef CONFIG_LOCKDEP_SMALL
	2130	+/*
	2131	+ * Check that the dependency graph starting at <src> can lead to
	2132	+ * <target> or not. If it can, <src> -> <target> dependency is already
	2133	+ * in the graph.
	2134	+ *
	2135	+ * Return BFS_RMATCH if it does, or BFS_RMATCH if it does not, return BFS_E* if
	2136	+ * any error appears in the bfs search.
	2137	+ */
	2138	+static noinline enum bfs_result
	2139	+check_redundant(struct held_lock src, struct held_lock target)
1323	2140	{
1324		- int result;
	2141	+ enum bfs_result ret;
	2142	+ struct lock_list *target_entry;
	2143	+ struct lock_list src_entry;
	2144	+
	2145	+ bfs_init_root(&src_entry, src);
	2146	+ /*
	2147	+ * Special setup for check_redundant().
	2148	+ *
	2149	+ * To report redundant, we need to find a strong dependency path that
	2150	+ * is equal to or stronger than <src> -> <target>. So if <src> is E,
	2151	+ * we need to let __bfs() only search for a path starting at a -(E*)->,
	2152	+ * we achieve this by setting the initial node's ->only_xr to true in
	2153	+ * that case. And if <prev> is S, we set initial ->only_xr to false
	2154	+ * because both -(S)-> (equal) and -(E)-> (stronger) are redundant.
	2155	+ */
	2156	+ src_entry.only_xr = src->read == 0;
1325	2157
1326	2158	debug_atomic_inc(nr_redundant_checks);
1327	2159
1328		- result = __bfs_forwards(root, target, class_equal, target_entry);
	2160	+ ret = check_path(target, &src_entry, hlock_equal, &target_entry);
1329	2161
1330		- return result;
	2162	+ if (ret == BFS_RMATCH)
	2163	+ debug_atomic_inc(nr_redundant);
	2164	+
	2165	+ return ret;
1331	2166	}
	2167	+#endif
1332	2168
1333		-#if defined(CONFIG_TRACE_IRQFLAGS) && defined(CONFIG_PROVE_LOCKING)
	2169	+#ifdef CONFIG_TRACE_IRQFLAGS
	2170	+
1334	2171	/*
1335	2172	* Forwards and backwards subgraph searching, for the purposes of
1336	2173	* proving that two subgraphs can be connected by a new dependency
1337	2174	* without creating any illegal irq-safe -> irq-unsafe lock dependency.
	2175	+ *
	2176	+ * A irq safe->unsafe deadlock happens with the following conditions:
	2177	+ *
	2178	+ * 1) We have a strong dependency path A -> ... -> B
	2179	+ *
	2180	+ * 2) and we have ENABLED_IRQ usage of B and USED_IN_IRQ usage of A, therefore
	2181	+ * irq can create a new dependency B -> A (consider the case that a holder
	2182	+ * of B gets interrupted by an irq whose handler will try to acquire A).
	2183	+ *
	2184	+ * 3) the dependency circle A -> ... -> B -> A we get from 1) and 2) is a
	2185	+ * strong circle:
	2186	+ *
	2187	+ * For the usage bits of B:
	2188	+ * a) if A -> B is -(*N)->, then B -> A could be any type, so any
	2189	+ * ENABLED_IRQ usage suffices.
	2190	+ * b) if A -> B is -(R)->, then B -> A must be -(E)->, so only
	2191	+ * ENABLED_IRQ_*_READ usage suffices.
	2192	+ *
	2193	+ * For the usage bits of A:
	2194	+ * c) if A -> B is -(E*)->, then B -> A could be any type, so any
	2195	+ * USED_IN_IRQ usage suffices.
	2196	+ * d) if A -> B is -(S)->, then B -> A must be -(N)->, so only
	2197	+ * USED_IN_IRQ_*_READ usage suffices.
1338	2198	*/
1339	2199
1340		-static inline int usage_match(struct lock_list entry, void bit)
	2200	+/*
	2201	+ * There is a strong dependency path in the dependency graph: A -> B, and now
	2202	+ * we need to decide which usage bit of A should be accumulated to detect
	2203	+ * safe->unsafe bugs.
	2204	+ *
	2205	+ * Note that usage_accumulate() is used in backwards search, so ->only_xr
	2206	+ * stands for whether A -> B only has -(S*)-> (in this case ->only_xr is true).
	2207	+ *
	2208	+ * As above, if only_xr is false, which means A -> B has -(E*)-> dependency
	2209	+ * path, any usage of A should be considered. Otherwise, we should only
	2210	+ * consider _READ usage.
	2211	+ */
	2212	+static inline bool usage_accumulate(struct lock_list entry, void mask)
1341	2213	{
1342		- return entry->class->usage_mask & (1 << (enum lock_usage_bit)bit);
	2214	+ if (!entry->only_xr)
	2215	+ (unsigned long )mask \|= entry->class->usage_mask;
	2216	+ else /* Mask out _READ usage bits */
	2217	+ (unsigned long )mask \|= (entry->class->usage_mask & LOCKF_IRQ);
	2218	+
	2219	+ return false;
1343	2220	}
1344	2221
1345		-
	2222	+/*
	2223	+ * There is a strong dependency path in the dependency graph: A -> B, and now
	2224	+ * we need to decide which usage bit of B conflicts with the usage bits of A,
	2225	+ * i.e. which usage bit of B may introduce safe->unsafe deadlocks.
	2226	+ *
	2227	+ * As above, if only_xr is false, which means A -> B has -(*N)-> dependency
	2228	+ * path, any usage of B should be considered. Otherwise, we should only
	2229	+ * consider _READ usage.
	2230	+ */
	2231	+static inline bool usage_match(struct lock_list entry, void mask)
	2232	+{
	2233	+ if (!entry->only_xr)
	2234	+ return !!(entry->class->usage_mask & (unsigned long )mask);
	2235	+ else /* Mask out _READ usage bits */
	2236	+ return !!((entry->class->usage_mask & LOCKF_IRQ) & (unsigned long )mask);
	2237	+}
1346	2238
1347	2239	/*
1348	2240	* Find a node in the forwards-direction dependency sub-graph starting
1349	2241	* at @root->class that matches @bit.
1350	2242	*
1351		- * Return 0 if such a node exists in the subgraph, and put that node
	2243	+ * Return BFS_MATCH if such a node exists in the subgraph, and put that node
1352	2244	* into *@target_entry.
1353		- *
1354		- * Return 1 otherwise and keep *@target_entry unchanged.
1355		- * Return <0 on error.
1356	2245	*/
1357		-static int
1358		-find_usage_forwards(struct lock_list *root, enum lock_usage_bit bit,
	2246	+static enum bfs_result
	2247	+find_usage_forwards(struct lock_list *root, unsigned long usage_mask,
1359	2248	struct lock_list **target_entry)
1360	2249	{
1361		- int result;
	2250	+ enum bfs_result result;
1362	2251
1363	2252	debug_atomic_inc(nr_find_usage_forwards_checks);
1364	2253
1365		- result = __bfs_forwards(root, (void *)bit, usage_match, target_entry);
	2254	+ result = __bfs_forwards(root, &usage_mask, usage_match, target_entry);
1366	2255
1367	2256	return result;
1368	2257	}
..	..	@@ -1370,22 +2259,16 @@
1370	2259	/*
1371	2260	* Find a node in the backwards-direction dependency sub-graph starting
1372	2261	* at @root->class that matches @bit.
1373		- *
1374		- * Return 0 if such a node exists in the subgraph, and put that node
1375		- * into *@target_entry.
1376		- *
1377		- * Return 1 otherwise and keep *@target_entry unchanged.
1378		- * Return <0 on error.
1379	2262	*/
1380		-static int
1381		-find_usage_backwards(struct lock_list *root, enum lock_usage_bit bit,
	2263	+static enum bfs_result
	2264	+find_usage_backwards(struct lock_list *root, unsigned long usage_mask,
1382	2265	struct lock_list **target_entry)
1383	2266	{
1384		- int result;
	2267	+ enum bfs_result result;
1385	2268
1386	2269	debug_atomic_inc(nr_find_usage_backwards_checks);
1387	2270
1388		- result = __bfs_backwards(root, (void *)bit, usage_match, target_entry);
	2271	+ result = __bfs_backwards(root, &usage_mask, usage_match, target_entry);
1389	2272
1390	2273	return result;
1391	2274	}
..	..	@@ -1396,16 +2279,18 @@
1396	2279
1397	2280	printk("%*s->", depth, "");
1398	2281	print_lock_name(class);
1399		- printk(KERN_CONT " ops: %lu", class->ops);
	2282	+#ifdef CONFIG_DEBUG_LOCKDEP
	2283	+ printk(KERN_CONT " ops: %lu", debug_class_ops_read(class));
	2284	+#endif
1400	2285	printk(KERN_CONT " {\n");
1401	2286
1402		- for (bit = 0; bit < LOCK_USAGE_STATES; bit++) {
	2287	+ for (bit = 0; bit < LOCK_TRACE_STATES; bit++) {
1403	2288	if (class->usage_mask & (1 << bit)) {
1404	2289	int len = depth;
1405	2290
1406	2291	len += printk("%*s %s", depth, "", usage_str[bit]);
1407	2292	len += printk(KERN_CONT " at:\n");
1408		- print_stack_trace(class->usage_traces + bit, len);
	2293	+ print_lock_trace(class->usage_traces[bit], len);
1409	2294	}
1410	2295	}
1411	2296	printk("%*s }\n", depth, "");
..	..	@@ -1415,11 +2300,60 @@
1415	2300	}
1416	2301
1417	2302	/*
1418		- * printk the shortest lock dependencies from @start to @end in reverse order:
	2303	+ * Dependency path printing:
	2304	+ *
	2305	+ * After BFS we get a lock dependency path (linked via ->parent of lock_list),
	2306	+ * printing out each lock in the dependency path will help on understanding how
	2307	+ * the deadlock could happen. Here are some details about dependency path
	2308	+ * printing:
	2309	+ *
	2310	+ * 1) A lock_list can be either forwards or backwards for a lock dependency,
	2311	+ * for a lock dependency A -> B, there are two lock_lists:
	2312	+ *
	2313	+ * a) lock_list in the ->locks_after list of A, whose ->class is B and
	2314	+ * ->links_to is A. In this case, we can say the lock_list is
	2315	+ * "A -> B" (forwards case).
	2316	+ *
	2317	+ * b) lock_list in the ->locks_before list of B, whose ->class is A
	2318	+ * and ->links_to is B. In this case, we can say the lock_list is
	2319	+ * "B <- A" (bacwards case).
	2320	+ *
	2321	+ * The ->trace of both a) and b) point to the call trace where B was
	2322	+ * acquired with A held.
	2323	+ *
	2324	+ * 2) A "helper" lock_list is introduced during BFS, this lock_list doesn't
	2325	+ * represent a certain lock dependency, it only provides an initial entry
	2326	+ * for BFS. For example, BFS may introduce a "helper" lock_list whose
	2327	+ * ->class is A, as a result BFS will search all dependencies starting with
	2328	+ * A, e.g. A -> B or A -> C.
	2329	+ *
	2330	+ * The notation of a forwards helper lock_list is like "-> A", which means
	2331	+ * we should search the forwards dependencies starting with "A", e.g A -> B
	2332	+ * or A -> C.
	2333	+ *
	2334	+ * The notation of a bacwards helper lock_list is like "<- B", which means
	2335	+ * we should search the backwards dependencies ending with "B", e.g.
	2336	+ * B <- A or B <- C.
	2337	+ */
	2338	+
	2339	+/*
	2340	+ * printk the shortest lock dependencies from @root to @leaf in reverse order.
	2341	+ *
	2342	+ * We have a lock dependency path as follow:
	2343	+ *
	2344	+ * @root @leaf
	2345	+ * \| \|
	2346	+ * V V
	2347	+ * ->parent ->parent
	2348	+ * \| lock_list \| <--------- \| lock_list \| ... \| lock_list \| <--------- \| lock_list \|
	2349	+ * \| -> L1 \| \| L1 -> L2 \| ... \|Ln-2 -> Ln-1\| \| Ln-1 -> Ln\|
	2350	+ *
	2351	+ * , so it's natural that we start from @leaf and print every ->class and
	2352	+ * ->trace until we reach the @root.
1419	2353	*/
1420	2354	static void __used
1421	2355	print_shortest_lock_dependencies(struct lock_list *leaf,
1422		- struct lock_list *root)
	2356	+ struct lock_list *root)
1423	2357	{
1424	2358	struct lock_list *entry = leaf;
1425	2359	int depth;
..	..	@@ -1430,7 +2364,7 @@
1430	2364	do {
1431	2365	print_lock_class_header(entry->class, depth);
1432	2366	printk("%*s ... acquired at:\n", depth, "");
1433		- print_stack_trace(&entry->trace, 2);
	2367	+ print_lock_trace(entry->trace, 2);
1434	2368	printk("\n");
1435	2369
1436	2370	if (depth == 0 && (entry != root)) {
..	..	@@ -1441,8 +2375,61 @@
1441	2375	entry = get_lock_parent(entry);
1442	2376	depth--;
1443	2377	} while (entry && (depth >= 0));
	2378	+}
1444	2379
1445		- return;
	2380	+/*
	2381	+ * printk the shortest lock dependencies from @leaf to @root.
	2382	+ *
	2383	+ * We have a lock dependency path (from a backwards search) as follow:
	2384	+ *
	2385	+ * @leaf @root
	2386	+ * \| \|
	2387	+ * V V
	2388	+ * ->parent ->parent
	2389	+ * \| lock_list \| ---------> \| lock_list \| ... \| lock_list \| ---------> \| lock_list \|
	2390	+ * \| L2 <- L1 \| \| L3 <- L2 \| ... \| Ln <- Ln-1 \| \| <- Ln \|
	2391	+ *
	2392	+ * , so when we iterate from @leaf to @root, we actually print the lock
	2393	+ * dependency path L1 -> L2 -> .. -> Ln in the non-reverse order.
	2394	+ *
	2395	+ * Another thing to notice here is that ->class of L2 <- L1 is L1, while the
	2396	+ * ->trace of L2 <- L1 is the call trace of L2, in fact we don't have the call
	2397	+ * trace of L1 in the dependency path, which is alright, because most of the
	2398	+ * time we can figure out where L1 is held from the call trace of L2.
	2399	+ */
	2400	+static void __used
	2401	+print_shortest_lock_dependencies_backwards(struct lock_list *leaf,
	2402	+ struct lock_list *root)
	2403	+{
	2404	+ struct lock_list *entry = leaf;
	2405	+ const struct lock_trace *trace = NULL;
	2406	+ int depth;
	2407	+
	2408	+ /compute depth from generated tree by BFS/
	2409	+ depth = get_lock_depth(leaf);
	2410	+
	2411	+ do {
	2412	+ print_lock_class_header(entry->class, depth);
	2413	+ if (trace) {
	2414	+ printk("%*s ... acquired at:\n", depth, "");
	2415	+ print_lock_trace(trace, 2);
	2416	+ printk("\n");
	2417	+ }
	2418	+
	2419	+ /*
	2420	+ * Record the pointer to the trace for the next lock_list
	2421	+ * entry, see the comments for the function.
	2422	+ */
	2423	+ trace = entry->trace;
	2424	+
	2425	+ if (depth == 0 && (entry != root)) {
	2426	+ printk("lockdep:%s bad path found in chain graph\n", __func__);
	2427	+ break;
	2428	+ }
	2429	+
	2430	+ entry = get_lock_parent(entry);
	2431	+ depth--;
	2432	+ } while (entry && (depth >= 0));
1446	2433	}
1447	2434
1448	2435	static void
..	..	@@ -1501,7 +2488,7 @@
1501	2488	printk("\n * DEADLOCK *\n\n");
1502	2489	}
1503	2490
1504		-static int
	2491	+static void
1505	2492	print_bad_irq_dependency(struct task_struct *curr,
1506	2493	struct lock_list *prev_root,
1507	2494	struct lock_list *next_root,
..	..	@@ -1514,7 +2501,7 @@
1514	2501	const char *irqclass)
1515	2502	{
1516	2503	if (!debug_locks_off_graph_unlock() \|\| debug_locks_silent)
1517		- return 0;
	2504	+ return;
1518	2505
1519	2506	pr_warn("\n");
1520	2507	pr_warn("=====================================================\n");
..	..	@@ -1524,9 +2511,9 @@
1524	2511	pr_warn("-----------------------------------------------------\n");
1525	2512	pr_warn("%s/%d [HC%u[%lu]:SC%u[%lu]:HE%u:SE%u] is trying to acquire:\n",
1526	2513	curr->comm, task_pid_nr(curr),
1527		- curr->hardirq_context, hardirq_count() >> HARDIRQ_SHIFT,
	2514	+ lockdep_hardirq_context(), hardirq_count() >> HARDIRQ_SHIFT,
1528	2515	curr->softirq_context, softirq_count() >> SOFTIRQ_SHIFT,
1529		- curr->hardirqs_enabled,
	2516	+ lockdep_hardirqs_enabled(),
1530	2517	curr->softirqs_enabled);
1531	2518	print_lock(next);
1532	2519
..	..	@@ -1543,14 +2530,14 @@
1543	2530	print_lock_name(backwards_entry->class);
1544	2531	pr_warn("\n... which became %s-irq-safe at:\n", irqclass);
1545	2532
1546		- print_stack_trace(backwards_entry->class->usage_traces + bit1, 1);
	2533	+ print_lock_trace(backwards_entry->class->usage_traces[bit1], 1);
1547	2534
1548	2535	pr_warn("\nto a %s-irq-unsafe lock:\n", irqclass);
1549	2536	print_lock_name(forwards_entry->class);
1550	2537	pr_warn("\n... which became %s-irq-unsafe at:\n", irqclass);
1551	2538	pr_warn("...");
1552	2539
1553		- print_stack_trace(forwards_entry->class->usage_traces + bit2, 1);
	2540	+ print_lock_trace(forwards_entry->class->usage_traces[bit2], 1);
1554	2541
1555	2542	pr_warn("\nother info that might help us debug this:\n\n");
1556	2543	print_irq_lock_scenario(backwards_entry, forwards_entry,
..	..	@@ -1559,53 +2546,20 @@
1559	2546	lockdep_print_held_locks(curr);
1560	2547
1561	2548	pr_warn("\nthe dependencies between %s-irq-safe lock and the holding lock:\n", irqclass);
1562		- if (!save_trace(&prev_root->trace))
1563		- return 0;
1564		- print_shortest_lock_dependencies(backwards_entry, prev_root);
	2549	+ prev_root->trace = save_trace();
	2550	+ if (!prev_root->trace)
	2551	+ return;
	2552	+ print_shortest_lock_dependencies_backwards(backwards_entry, prev_root);
1565	2553
1566	2554	pr_warn("\nthe dependencies between the lock to be acquired");
1567	2555	pr_warn(" and %s-irq-unsafe lock:\n", irqclass);
1568		- if (!save_trace(&next_root->trace))
1569		- return 0;
	2556	+ next_root->trace = save_trace();
	2557	+ if (!next_root->trace)
	2558	+ return;
1570	2559	print_shortest_lock_dependencies(forwards_entry, next_root);
1571	2560
1572	2561	pr_warn("\nstack backtrace:\n");
1573	2562	dump_stack();
1574		-
1575		- return 0;
1576		-}
1577		-
1578		-static int
1579		-check_usage(struct task_struct curr, struct held_lock prev,
1580		- struct held_lock *next, enum lock_usage_bit bit_backwards,
1581		- enum lock_usage_bit bit_forwards, const char *irqclass)
1582		-{
1583		- int ret;
1584		- struct lock_list this, that;
1585		- struct lock_list *uninitialized_var(target_entry);
1586		- struct lock_list *uninitialized_var(target_entry1);
1587		-
1588		- this.parent = NULL;
1589		-
1590		- this.class = hlock_class(prev);
1591		- ret = find_usage_backwards(&this, bit_backwards, &target_entry);
1592		- if (ret < 0)
1593		- return print_bfs_bug(ret);
1594		- if (ret == 1)
1595		- return ret;
1596		-
1597		- that.parent = NULL;
1598		- that.class = hlock_class(next);
1599		- ret = find_usage_forwards(&that, bit_forwards, &target_entry1);
1600		- if (ret < 0)
1601		- return print_bfs_bug(ret);
1602		- if (ret == 1)
1603		- return ret;
1604		-
1605		- return print_bad_irq_dependency(curr, &this, &that,
1606		- target_entry, target_entry1,
1607		- prev, next,
1608		- bit_backwards, bit_forwards, irqclass);
1609	2563	}
1610	2564
1611	2565	static const char *state_names[] = {
..	..	@@ -1624,103 +2578,266 @@
1624	2578
1625	2579	static inline const char *state_name(enum lock_usage_bit bit)
1626	2580	{
1627		- return (bit & 1) ? state_rnames[bit >> 2] : state_names[bit >> 2];
	2581	+ if (bit & LOCK_USAGE_READ_MASK)
	2582	+ return state_rnames[bit >> LOCK_USAGE_DIR_MASK];
	2583	+ else
	2584	+ return state_names[bit >> LOCK_USAGE_DIR_MASK];
1628	2585	}
1629	2586
	2587	+/*
	2588	+ * The bit number is encoded like:
	2589	+ *
	2590	+ * bit0: 0 exclusive, 1 read lock
	2591	+ * bit1: 0 used in irq, 1 irq enabled
	2592	+ * bit2-n: state
	2593	+ */
1630	2594	static int exclusive_bit(int new_bit)
1631	2595	{
1632		- /*
1633		- * USED_IN
1634		- * USED_IN_READ
1635		- * ENABLED
1636		- * ENABLED_READ
1637		- *
1638		- * bit 0 - write/read
1639		- * bit 1 - used_in/enabled
1640		- * bit 2+ state
1641		- */
1642		-
1643		- int state = new_bit & ~3;
1644		- int dir = new_bit & 2;
	2596	+ int state = new_bit & LOCK_USAGE_STATE_MASK;
	2597	+ int dir = new_bit & LOCK_USAGE_DIR_MASK;
1645	2598
1646	2599	/*
1647	2600	* keep state, bit flip the direction and strip read.
1648	2601	*/
1649		- return state \| (dir ^ 2);
	2602	+ return state \| (dir ^ LOCK_USAGE_DIR_MASK);
1650	2603	}
1651	2604
1652		-static int check_irq_usage(struct task_struct curr, struct held_lock prev,
1653		- struct held_lock *next, enum lock_usage_bit bit)
	2605	+/*
	2606	+ * Observe that when given a bitmask where each bitnr is encoded as above, a
	2607	+ * right shift of the mask transforms the individual bitnrs as -1 and
	2608	+ * conversely, a left shift transforms into +1 for the individual bitnrs.
	2609	+ *
	2610	+ * So for all bits whose number have LOCK_ENABLED_* set (bitnr1 == 1), we can
	2611	+ * create the mask with those bit numbers using LOCK_USED_IN_* (bitnr1 == 0)
	2612	+ * instead by subtracting the bit number by 2, or shifting the mask right by 2.
	2613	+ *
	2614	+ * Similarly, bitnr1 == 0 becomes bitnr1 == 1 by adding 2, or shifting left 2.
	2615	+ *
	2616	+ * So split the mask (note that LOCKF_ENABLED_IRQ_ALL\|LOCKF_USED_IN_IRQ_ALL is
	2617	+ * all bits set) and recompose with bitnr1 flipped.
	2618	+ */
	2619	+static unsigned long invert_dir_mask(unsigned long mask)
1654	2620	{
1655		- /*
1656		- * Prove that the new dependency does not connect a hardirq-safe
1657		- * lock with a hardirq-unsafe lock - to achieve this we search
1658		- * the backwards-subgraph starting at <prev>, and the
1659		- * forwards-subgraph starting at <next>:
1660		- */
1661		- if (!check_usage(curr, prev, next, bit,
1662		- exclusive_bit(bit), state_name(bit)))
1663		- return 0;
	2621	+ unsigned long excl = 0;
1664	2622
1665		- bit++; /* _READ */
	2623	+ /* Invert dir */
	2624	+ excl \|= (mask & LOCKF_ENABLED_IRQ_ALL) >> LOCK_USAGE_DIR_MASK;
	2625	+ excl \|= (mask & LOCKF_USED_IN_IRQ_ALL) << LOCK_USAGE_DIR_MASK;
1666	2626
1667		- /*
1668		- * Prove that the new dependency does not connect a hardirq-safe-read
1669		- * lock with a hardirq-unsafe lock - to achieve this we search
1670		- * the backwards-subgraph starting at <prev>, and the
1671		- * forwards-subgraph starting at <next>:
1672		- */
1673		- if (!check_usage(curr, prev, next, bit,
1674		- exclusive_bit(bit), state_name(bit)))
1675		- return 0;
1676		-
1677		- return 1;
	2627	+ return excl;
1678	2628	}
1679	2629
1680		-static int
1681		-check_prev_add_irq(struct task_struct curr, struct held_lock prev,
1682		- struct held_lock *next)
	2630	+/*
	2631	+ * Note that a LOCK_ENABLED_IRQ__READ usage and a LOCK_USED_IN_IRQ__READ
	2632	+ * usage may cause deadlock too, for example:
	2633	+ *
	2634	+ * P1 P2
	2635	+ * <irq disabled>
	2636	+ * write_lock(l1); <irq enabled>
	2637	+ * read_lock(l2);
	2638	+ * write_lock(l2);
	2639	+ * <in irq>
	2640	+ * read_lock(l1);
	2641	+ *
	2642	+ * , in above case, l1 will be marked as LOCK_USED_IN_IRQ_HARDIRQ_READ and l2
	2643	+ * will marked as LOCK_ENABLE_IRQ_HARDIRQ_READ, and this is a possible
	2644	+ * deadlock.
	2645	+ *
	2646	+ * In fact, all of the following cases may cause deadlocks:
	2647	+ *
	2648	+ * LOCK_USED_IN_IRQ_* -> LOCK_ENABLED_IRQ_*
	2649	+ * LOCK_USED_IN_IRQ__READ -> LOCK_ENABLED_IRQ_
	2650	+ * LOCK_USED_IN_IRQ_* -> LOCK_ENABLED_IRQ_*_READ
	2651	+ * LOCK_USED_IN_IRQ__READ -> LOCK_ENABLED_IRQ__READ
	2652	+ *
	2653	+ * As a result, to calculate the "exclusive mask", first we invert the
	2654	+ * direction (USED_IN/ENABLED) of the original mask, and 1) for all bits with
	2655	+ * bitnr0 set (LOCK__READ), add those with bitnr0 cleared (LOCK_). 2) for all
	2656	+ * bits with bitnr0 cleared (LOCK__READ), add those with bitnr0 set (LOCK_).
	2657	+ */
	2658	+static unsigned long exclusive_mask(unsigned long mask)
1683	2659	{
1684		-#define LOCKDEP_STATE(__STATE) \
1685		- if (!check_irq_usage(curr, prev, next, LOCK_USED_IN_##__STATE)) \
1686		- return 0;
1687		-#include "lockdep_states.h"
1688		-#undef LOCKDEP_STATE
	2660	+ unsigned long excl = invert_dir_mask(mask);
1689	2661
1690		- return 1;
	2662	+ excl \|= (excl & LOCKF_IRQ_READ) >> LOCK_USAGE_READ_MASK;
	2663	+ excl \|= (excl & LOCKF_IRQ) << LOCK_USAGE_READ_MASK;
	2664	+
	2665	+ return excl;
1691	2666	}
1692	2667
1693		-static void inc_chains(void)
	2668	+/*
	2669	+ * Retrieve the _possible_ original mask to which @mask is
	2670	+ * exclusive. Ie: this is the opposite of exclusive_mask().
	2671	+ * Note that 2 possible original bits can match an exclusive
	2672	+ * bit: one has LOCK_USAGE_READ_MASK set, the other has it
	2673	+ * cleared. So both are returned for each exclusive bit.
	2674	+ */
	2675	+static unsigned long original_mask(unsigned long mask)
1694	2676	{
1695		- if (current->hardirq_context)
1696		- nr_hardirq_chains++;
1697		- else {
1698		- if (current->softirq_context)
1699		- nr_softirq_chains++;
1700		- else
1701		- nr_process_chains++;
	2677	+ unsigned long excl = invert_dir_mask(mask);
	2678	+
	2679	+ /* Include read in existing usages */
	2680	+ excl \|= (excl & LOCKF_IRQ_READ) >> LOCK_USAGE_READ_MASK;
	2681	+ excl \|= (excl & LOCKF_IRQ) << LOCK_USAGE_READ_MASK;
	2682	+
	2683	+ return excl;
	2684	+}
	2685	+
	2686	+/*
	2687	+ * Find the first pair of bit match between an original
	2688	+ * usage mask and an exclusive usage mask.
	2689	+ */
	2690	+static int find_exclusive_match(unsigned long mask,
	2691	+ unsigned long excl_mask,
	2692	+ enum lock_usage_bit *bitp,
	2693	+ enum lock_usage_bit *excl_bitp)
	2694	+{
	2695	+ int bit, excl, excl_read;
	2696	+
	2697	+ for_each_set_bit(bit, &mask, LOCK_USED) {
	2698	+ /*
	2699	+ * exclusive_bit() strips the read bit, however,
	2700	+ * LOCK_ENABLED_IRQ_*_READ may cause deadlocks too, so we need
	2701	+ * to search excl \| LOCK_USAGE_READ_MASK as well.
	2702	+ */
	2703	+ excl = exclusive_bit(bit);
	2704	+ excl_read = excl \| LOCK_USAGE_READ_MASK;
	2705	+ if (excl_mask & lock_flag(excl)) {
	2706	+ *bitp = bit;
	2707	+ *excl_bitp = excl;
	2708	+ return 0;
	2709	+ } else if (excl_mask & lock_flag(excl_read)) {
	2710	+ *bitp = bit;
	2711	+ *excl_bitp = excl_read;
	2712	+ return 0;
	2713	+ }
1702	2714	}
	2715	+ return -1;
	2716	+}
	2717	+
	2718	+/*
	2719	+ * Prove that the new dependency does not connect a hardirq-safe(-read)
	2720	+ * lock with a hardirq-unsafe lock - to achieve this we search
	2721	+ * the backwards-subgraph starting at <prev>, and the
	2722	+ * forwards-subgraph starting at <next>:
	2723	+ */
	2724	+static int check_irq_usage(struct task_struct curr, struct held_lock prev,
	2725	+ struct held_lock *next)
	2726	+{
	2727	+ unsigned long usage_mask = 0, forward_mask, backward_mask;
	2728	+ enum lock_usage_bit forward_bit = 0, backward_bit = 0;
	2729	+ struct lock_list *target_entry1;
	2730	+ struct lock_list *target_entry;
	2731	+ struct lock_list this, that;
	2732	+ enum bfs_result ret;
	2733	+
	2734	+ /*
	2735	+ * Step 1: gather all hard/soft IRQs usages backward in an
	2736	+ * accumulated usage mask.
	2737	+ */
	2738	+ bfs_init_rootb(&this, prev);
	2739	+
	2740	+ ret = __bfs_backwards(&this, &usage_mask, usage_accumulate, NULL);
	2741	+ if (bfs_error(ret)) {
	2742	+ print_bfs_bug(ret);
	2743	+ return 0;
	2744	+ }
	2745	+
	2746	+ usage_mask &= LOCKF_USED_IN_IRQ_ALL;
	2747	+ if (!usage_mask)
	2748	+ return 1;
	2749	+
	2750	+ /*
	2751	+ * Step 2: find exclusive uses forward that match the previous
	2752	+ * backward accumulated mask.
	2753	+ */
	2754	+ forward_mask = exclusive_mask(usage_mask);
	2755	+
	2756	+ bfs_init_root(&that, next);
	2757	+
	2758	+ ret = find_usage_forwards(&that, forward_mask, &target_entry1);
	2759	+ if (bfs_error(ret)) {
	2760	+ print_bfs_bug(ret);
	2761	+ return 0;
	2762	+ }
	2763	+ if (ret == BFS_RNOMATCH)
	2764	+ return 1;
	2765	+
	2766	+ /*
	2767	+ * Step 3: we found a bad match! Now retrieve a lock from the backward
	2768	+ * list whose usage mask matches the exclusive usage mask from the
	2769	+ * lock found on the forward list.
	2770	+ *
	2771	+ * Note, we should only keep the LOCKF_ENABLED_IRQ_ALL bits, considering
	2772	+ * the follow case:
	2773	+ *
	2774	+ * When trying to add A -> B to the graph, we find that there is a
	2775	+ * hardirq-safe L, that L -> ... -> A, and another hardirq-unsafe M,
	2776	+ * that B -> ... -> M. However M is softirq-safe, if we use exact
	2777	+ * invert bits of M's usage_mask, we will find another lock N that is
	2778	+ * softirq-unsafe and N -> ... -> A, however N -> .. -> M will not
	2779	+ * cause a inversion deadlock.
	2780	+ */
	2781	+ backward_mask = original_mask(target_entry1->class->usage_mask & LOCKF_ENABLED_IRQ_ALL);
	2782	+
	2783	+ ret = find_usage_backwards(&this, backward_mask, &target_entry);
	2784	+ if (bfs_error(ret)) {
	2785	+ print_bfs_bug(ret);
	2786	+ return 0;
	2787	+ }
	2788	+ if (DEBUG_LOCKS_WARN_ON(ret == BFS_RNOMATCH))
	2789	+ return 1;
	2790	+
	2791	+ /*
	2792	+ * Step 4: narrow down to a pair of incompatible usage bits
	2793	+ * and report it.
	2794	+ */
	2795	+ ret = find_exclusive_match(target_entry->class->usage_mask,
	2796	+ target_entry1->class->usage_mask,
	2797	+ &backward_bit, &forward_bit);
	2798	+ if (DEBUG_LOCKS_WARN_ON(ret == -1))
	2799	+ return 1;
	2800	+
	2801	+ print_bad_irq_dependency(curr, &this, &that,
	2802	+ target_entry, target_entry1,
	2803	+ prev, next,
	2804	+ backward_bit, forward_bit,
	2805	+ state_name(backward_bit));
	2806	+
	2807	+ return 0;
1703	2808	}
1704	2809
1705	2810	#else
1706	2811
1707		-static inline int
1708		-check_prev_add_irq(struct task_struct curr, struct held_lock prev,
1709		- struct held_lock *next)
	2812	+static inline int check_irq_usage(struct task_struct *curr,
	2813	+ struct held_lock prev, struct held_lock next)
1710	2814	{
1711	2815	return 1;
1712	2816	}
	2817	+#endif /* CONFIG_TRACE_IRQFLAGS */
1713	2818
1714		-static inline void inc_chains(void)
	2819	+static void inc_chains(int irq_context)
1715	2820	{
1716		- nr_process_chains++;
	2821	+ if (irq_context & LOCK_CHAIN_HARDIRQ_CONTEXT)
	2822	+ nr_hardirq_chains++;
	2823	+ else if (irq_context & LOCK_CHAIN_SOFTIRQ_CONTEXT)
	2824	+ nr_softirq_chains++;
	2825	+ else
	2826	+ nr_process_chains++;
1717	2827	}
1718	2828
1719		-#endif
	2829	+static void dec_chains(int irq_context)
	2830	+{
	2831	+ if (irq_context & LOCK_CHAIN_HARDIRQ_CONTEXT)
	2832	+ nr_hardirq_chains--;
	2833	+ else if (irq_context & LOCK_CHAIN_SOFTIRQ_CONTEXT)
	2834	+ nr_softirq_chains--;
	2835	+ else
	2836	+ nr_process_chains--;
	2837	+}
1720	2838
1721	2839	static void
1722		-print_deadlock_scenario(struct held_lock *nxt,
1723		- struct held_lock *prv)
	2840	+print_deadlock_scenario(struct held_lock nxt, struct held_lock prv)
1724	2841	{
1725	2842	struct lock_class *next = hlock_class(nxt);
1726	2843	struct lock_class *prev = hlock_class(prv);
..	..	@@ -1738,12 +2855,12 @@
1738	2855	printk(" May be due to missing lock nesting notation\n\n");
1739	2856	}
1740	2857
1741		-static int
	2858	+static void
1742	2859	print_deadlock_bug(struct task_struct curr, struct held_lock prev,
1743	2860	struct held_lock *next)
1744	2861	{
1745	2862	if (!debug_locks_off_graph_unlock() \|\| debug_locks_silent)
1746		- return 0;
	2863	+ return;
1747	2864
1748	2865	pr_warn("\n");
1749	2866	pr_warn("============================================\n");
..	..	@@ -1762,8 +2879,6 @@
1762	2879
1763	2880	pr_warn("\nstack backtrace:\n");
1764	2881	dump_stack();
1765		-
1766		- return 0;
1767	2882	}
1768	2883
1769	2884	/*
..	..	@@ -1772,11 +2887,12 @@
1772	2887	* (Note that this has to be done separately, because the graph cannot
1773	2888	* detect such classes of deadlocks.)
1774	2889	*
1775		- * Returns: 0 on deadlock detected, 1 on OK, 2 on recursive read
	2890	+ * Returns: 0 on deadlock detected, 1 on OK, 2 if another lock with the same
	2891	+ * lock class is held but nest_lock is also held, i.e. we rely on the
	2892	+ * nest_lock to avoid the deadlock.
1776	2893	*/
1777	2894	static int
1778		-check_deadlock(struct task_struct curr, struct held_lock next,
1779		- struct lockdep_map *next_instance, int read)
	2895	+check_deadlock(struct task_struct curr, struct held_lock next)
1780	2896	{
1781	2897	struct held_lock *prev;
1782	2898	struct held_lock *nest = NULL;
..	..	@@ -1795,8 +2911,8 @@
1795	2911	* Allow read-after-read recursion of the same
1796	2912	* lock class (i.e. read_lock(lock)+read_lock(lock)):
1797	2913	*/
1798		- if ((read == 2) && prev->read)
1799		- return 2;
	2914	+ if ((next->read == 2) && prev->read)
	2915	+ continue;
1800	2916
1801	2917	/*
1802	2918	* We're holding the nest_lock, which serializes this lock's
..	..	@@ -1805,14 +2921,15 @@
1805	2921	if (nest)
1806	2922	return 2;
1807	2923
1808		- return print_deadlock_bug(curr, prev, next);
	2924	+ print_deadlock_bug(curr, prev, next);
	2925	+ return 0;
1809	2926	}
1810	2927	return 1;
1811	2928	}
1812	2929
1813	2930	/*
1814	2931	* There was a chain-cache miss, and we are about to add a new dependency
1815		- * to a previous lock. We recursively validate the following rules:
	2932	+ * to a previous lock. We validate the following rules:
1816	2933	*
1817	2934	* - would the adding of the <prev> -> <next> dependency create a
1818	2935	* circular dependency in the graph? [== circular deadlock]
..	..	@@ -1834,53 +2951,47 @@
1834	2951	*/
1835	2952	static int
1836	2953	check_prev_add(struct task_struct curr, struct held_lock prev,
1837		- struct held_lock next, int distance, struct stack_trace trace,
1838		- int (save)(struct stack_trace trace))
	2954	+ struct held_lock *next, u16 distance,
	2955	+ struct lock_trace **const trace)
1839	2956	{
1840		- struct lock_list *uninitialized_var(target_entry);
1841	2957	struct lock_list *entry;
1842		- struct lock_list this;
1843		- int ret;
	2958	+ enum bfs_result ret;
	2959	+
	2960	+ if (!hlock_class(prev)->key \|\| !hlock_class(next)->key) {
	2961	+ /*
	2962	+ * The warning statements below may trigger a use-after-free
	2963	+ * of the class name. It is better to trigger a use-after free
	2964	+ * and to have the class name most of the time instead of not
	2965	+ * having the class name available.
	2966	+ */
	2967	+ WARN_ONCE(!debug_locks_silent && !hlock_class(prev)->key,
	2968	+ "Detected use-after-free of lock class %px/%s\n",
	2969	+ hlock_class(prev),
	2970	+ hlock_class(prev)->name);
	2971	+ WARN_ONCE(!debug_locks_silent && !hlock_class(next)->key,
	2972	+ "Detected use-after-free of lock class %px/%s\n",
	2973	+ hlock_class(next),
	2974	+ hlock_class(next)->name);
	2975	+ return 2;
	2976	+ }
1844	2977
1845	2978	/*
1846	2979	* Prove that the new <prev> -> <next> dependency would not
1847	2980	* create a circular dependency in the graph. (We do this by
1848		- * forward-recursing into the graph starting at <next>, and
1849		- * checking whether we can reach <prev>.)
	2981	+ * a breadth-first search into the graph starting at <next>,
	2982	+ * and check whether we can reach <prev>.)
1850	2983	*
1851		- * We are using global variables to control the recursion, to
1852		- * keep the stackframe size of the recursive functions low:
	2984	+ * The search is limited by the size of the circular queue (i.e.,
	2985	+ * MAX_CIRCULAR_QUEUE_SIZE) which keeps track of a breadth of nodes
	2986	+ * in the graph whose neighbours are to be checked.
1853	2987	*/
1854		- this.class = hlock_class(next);
1855		- this.parent = NULL;
1856		- ret = check_noncircular(&this, hlock_class(prev), &target_entry);
1857		- if (unlikely(!ret)) {
1858		- if (!trace->entries) {
1859		- /*
1860		- * If @save fails here, the printing might trigger
1861		- * a WARN but because of the !nr_entries it should
1862		- * not do bad things.
1863		- */
1864		- save(trace);
1865		- }
1866		- return print_circular_bug(&this, target_entry, next, prev, trace);
1867		- }
1868		- else if (unlikely(ret < 0))
1869		- return print_bfs_bug(ret);
1870		-
1871		- if (!check_prev_add_irq(curr, prev, next))
	2988	+ ret = check_noncircular(next, prev, trace);
	2989	+ if (unlikely(bfs_error(ret) \|\| ret == BFS_RMATCH))
1872	2990	return 0;
1873	2991
1874		- /*
1875		- * For recursive read-locks we do all the dependency checks,
1876		- * but we dont store read-triggered dependencies (only
1877		- * write-triggered dependencies). This ensures that only the
1878		- * write-side dependencies matter, and that if for example a
1879		- * write-lock never takes any other locks, then the reads are
1880		- * equivalent to a NOP.
1881		- */
1882		- if (next->read == 2 \|\| prev->read == 2)
1883		- return 1;
	2992	+ if (!check_irq_usage(curr, prev, next))
	2993	+ return 0;
	2994	+
1884	2995	/*
1885	2996	* Is the <prev> -> <next> dependency already present?
1886	2997	*
..	..	@@ -1893,41 +3004,73 @@
1893	3004	if (entry->class == hlock_class(next)) {
1894	3005	if (distance == 1)
1895	3006	entry->distance = 1;
1896		- return 1;
	3007	+ entry->dep \|= calc_dep(prev, next);
	3008	+
	3009	+ /*
	3010	+ * Also, update the reverse dependency in @next's
	3011	+ * ->locks_before list.
	3012	+ *
	3013	+ * Here we reuse @entry as the cursor, which is fine
	3014	+ * because we won't go to the next iteration of the
	3015	+ * outer loop:
	3016	+ *
	3017	+ * For normal cases, we return in the inner loop.
	3018	+ *
	3019	+ * If we fail to return, we have inconsistency, i.e.
	3020	+ * <prev>::locks_after contains <next> while
	3021	+ * <next>::locks_before doesn't contain <prev>. In
	3022	+ * that case, we return after the inner and indicate
	3023	+ * something is wrong.
	3024	+ */
	3025	+ list_for_each_entry(entry, &hlock_class(next)->locks_before, entry) {
	3026	+ if (entry->class == hlock_class(prev)) {
	3027	+ if (distance == 1)
	3028	+ entry->distance = 1;
	3029	+ entry->dep \|= calc_depb(prev, next);
	3030	+ return 1;
	3031	+ }
	3032	+ }
	3033	+
	3034	+ /* <prev> is not found in <next>::locks_before */
	3035	+ return 0;
1897	3036	}
1898	3037	}
1899	3038
	3039	+#ifdef CONFIG_LOCKDEP_SMALL
1900	3040	/*
1901	3041	* Is the <prev> -> <next> link redundant?
1902	3042	*/
1903		- this.class = hlock_class(prev);
1904		- this.parent = NULL;
1905		- ret = check_redundant(&this, hlock_class(next), &target_entry);
1906		- if (!ret) {
1907		- debug_atomic_inc(nr_redundant);
1908		- return 2;
1909		- }
1910		- if (ret < 0)
1911		- return print_bfs_bug(ret);
1912		-
1913		-
1914		- if (!trace->entries && !save(trace))
	3043	+ ret = check_redundant(prev, next);
	3044	+ if (bfs_error(ret))
1915	3045	return 0;
	3046	+ else if (ret == BFS_RMATCH)
	3047	+ return 2;
	3048	+#endif
	3049	+
	3050	+ if (!*trace) {
	3051	+ *trace = save_trace();
	3052	+ if (!*trace)
	3053	+ return 0;
	3054	+ }
1916	3055
1917	3056	/*
1918	3057	* Ok, all validations passed, add the new lock
1919	3058	* to the previous lock's dependency list:
1920	3059	*/
1921		- ret = add_lock_to_list(hlock_class(next),
	3060	+ ret = add_lock_to_list(hlock_class(next), hlock_class(prev),
1922	3061	&hlock_class(prev)->locks_after,
1923		- next->acquire_ip, distance, trace);
	3062	+ next->acquire_ip, distance,
	3063	+ calc_dep(prev, next),
	3064	+ *trace);
1924	3065
1925	3066	if (!ret)
1926	3067	return 0;
1927	3068
1928		- ret = add_lock_to_list(hlock_class(prev),
	3069	+ ret = add_lock_to_list(hlock_class(prev), hlock_class(next),
1929	3070	&hlock_class(next)->locks_before,
1930		- next->acquire_ip, distance, trace);
	3071	+ next->acquire_ip, distance,
	3072	+ calc_depb(prev, next),
	3073	+ *trace);
1931	3074	if (!ret)
1932	3075	return 0;
1933	3076
..	..	@@ -1943,14 +3086,9 @@
1943	3086	static int
1944	3087	check_prevs_add(struct task_struct curr, struct held_lock next)
1945	3088	{
	3089	+ struct lock_trace *trace = NULL;
1946	3090	int depth = curr->lockdep_depth;
1947	3091	struct held_lock *hlock;
1948		- struct stack_trace trace = {
1949		- .nr_entries = 0,
1950		- .max_entries = 0,
1951		- .entries = NULL,
1952		- .skip = 0,
1953		- };
1954	3092
1955	3093	/*
1956	3094	* Debugging checks.
..	..	@@ -1968,15 +3106,11 @@
1968	3106	goto out_bug;
1969	3107
1970	3108	for (;;) {
1971		- int distance = curr->lockdep_depth - depth + 1;
	3109	+ u16 distance = curr->lockdep_depth - depth + 1;
1972	3110	hlock = curr->held_locks + depth - 1;
1973	3111
1974		- /*
1975		- * Only non-recursive-read entries get new dependencies
1976		- * added:
1977		- */
1978		- if (hlock->read != 2 && hlock->check) {
1979		- int ret = check_prev_add(curr, hlock, next, distance, &trace, save_trace);
	3112	+ if (hlock->check) {
	3113	+ int ret = check_prev_add(curr, hlock, next, distance, &trace);
1980	3114	if (!ret)
1981	3115	return 0;
1982	3116
..	..	@@ -2018,14 +3152,244 @@
2018	3152	return 0;
2019	3153	}
2020	3154
2021		-unsigned long nr_lock_chains;
2022	3155	struct lock_chain lock_chains[MAX_LOCKDEP_CHAINS];
2023		-int nr_chain_hlocks;
	3156	+static DECLARE_BITMAP(lock_chains_in_use, MAX_LOCKDEP_CHAINS);
2024	3157	static u16 chain_hlocks[MAX_LOCKDEP_CHAIN_HLOCKS];
	3158	+unsigned long nr_zapped_lock_chains;
	3159	+unsigned int nr_free_chain_hlocks; /* Free chain_hlocks in buckets */
	3160	+unsigned int nr_lost_chain_hlocks; /* Lost chain_hlocks */
	3161	+unsigned int nr_large_chain_blocks; /* size > MAX_CHAIN_BUCKETS */
	3162	+
	3163	+/*
	3164	+ * The first 2 chain_hlocks entries in the chain block in the bucket
	3165	+ * list contains the following meta data:
	3166	+ *
	3167	+ * entry[0]:
	3168	+ * Bit 15 - always set to 1 (it is not a class index)
	3169	+ * Bits 0-14 - upper 15 bits of the next block index
	3170	+ * entry[1] - lower 16 bits of next block index
	3171	+ *
	3172	+ * A next block index of all 1 bits means it is the end of the list.
	3173	+ *
	3174	+ * On the unsized bucket (bucket-0), the 3rd and 4th entries contain
	3175	+ * the chain block size:
	3176	+ *
	3177	+ * entry[2] - upper 16 bits of the chain block size
	3178	+ * entry[3] - lower 16 bits of the chain block size
	3179	+ */
	3180	+#define MAX_CHAIN_BUCKETS 16
	3181	+#define CHAIN_BLK_FLAG (1U << 15)
	3182	+#define CHAIN_BLK_LIST_END 0xFFFFU
	3183	+
	3184	+static int chain_block_buckets[MAX_CHAIN_BUCKETS];
	3185	+
	3186	+static inline int size_to_bucket(int size)
	3187	+{
	3188	+ if (size > MAX_CHAIN_BUCKETS)
	3189	+ return 0;
	3190	+
	3191	+ return size - 1;
	3192	+}
	3193	+
	3194	+/*
	3195	+ * Iterate all the chain blocks in a bucket.
	3196	+ */
	3197	+#define for_each_chain_block(bucket, prev, curr) \
	3198	+ for ((prev) = -1, (curr) = chain_block_buckets[bucket]; \
	3199	+ (curr) >= 0; \
	3200	+ (prev) = (curr), (curr) = chain_block_next(curr))
	3201	+
	3202	+/*
	3203	+ * next block or -1
	3204	+ */
	3205	+static inline int chain_block_next(int offset)
	3206	+{
	3207	+ int next = chain_hlocks[offset];
	3208	+
	3209	+ WARN_ON_ONCE(!(next & CHAIN_BLK_FLAG));
	3210	+
	3211	+ if (next == CHAIN_BLK_LIST_END)
	3212	+ return -1;
	3213	+
	3214	+ next &= ~CHAIN_BLK_FLAG;
	3215	+ next <<= 16;
	3216	+ next \|= chain_hlocks[offset + 1];
	3217	+
	3218	+ return next;
	3219	+}
	3220	+
	3221	+/*
	3222	+ * bucket-0 only
	3223	+ */
	3224	+static inline int chain_block_size(int offset)
	3225	+{
	3226	+ return (chain_hlocks[offset + 2] << 16) \| chain_hlocks[offset + 3];
	3227	+}
	3228	+
	3229	+static inline void init_chain_block(int offset, int next, int bucket, int size)
	3230	+{
	3231	+ chain_hlocks[offset] = (next >> 16) \| CHAIN_BLK_FLAG;
	3232	+ chain_hlocks[offset + 1] = (u16)next;
	3233	+
	3234	+ if (size && !bucket) {
	3235	+ chain_hlocks[offset + 2] = size >> 16;
	3236	+ chain_hlocks[offset + 3] = (u16)size;
	3237	+ }
	3238	+}
	3239	+
	3240	+static inline void add_chain_block(int offset, int size)
	3241	+{
	3242	+ int bucket = size_to_bucket(size);
	3243	+ int next = chain_block_buckets[bucket];
	3244	+ int prev, curr;
	3245	+
	3246	+ if (unlikely(size < 2)) {
	3247	+ /*
	3248	+ * We can't store single entries on the freelist. Leak them.
	3249	+ *
	3250	+ * One possible way out would be to uniquely mark them, other
	3251	+ * than with CHAIN_BLK_FLAG, such that we can recover them when
	3252	+ * the block before it is re-added.
	3253	+ */
	3254	+ if (size)
	3255	+ nr_lost_chain_hlocks++;
	3256	+ return;
	3257	+ }
	3258	+
	3259	+ nr_free_chain_hlocks += size;
	3260	+ if (!bucket) {
	3261	+ nr_large_chain_blocks++;
	3262	+
	3263	+ /*
	3264	+ * Variable sized, sort large to small.
	3265	+ */
	3266	+ for_each_chain_block(0, prev, curr) {
	3267	+ if (size >= chain_block_size(curr))
	3268	+ break;
	3269	+ }
	3270	+ init_chain_block(offset, curr, 0, size);
	3271	+ if (prev < 0)
	3272	+ chain_block_buckets[0] = offset;
	3273	+ else
	3274	+ init_chain_block(prev, offset, 0, 0);
	3275	+ return;
	3276	+ }
	3277	+ /*
	3278	+ * Fixed size, add to head.
	3279	+ */
	3280	+ init_chain_block(offset, next, bucket, size);
	3281	+ chain_block_buckets[bucket] = offset;
	3282	+}
	3283	+
	3284	+/*
	3285	+ * Only the first block in the list can be deleted.
	3286	+ *
	3287	+ * For the variable size bucket[0], the first block (the largest one) is
	3288	+ * returned, broken up and put back into the pool. So if a chain block of
	3289	+ * length > MAX_CHAIN_BUCKETS is ever used and zapped, it will just be
	3290	+ * queued up after the primordial chain block and never be used until the
	3291	+ * hlock entries in the primordial chain block is almost used up. That
	3292	+ * causes fragmentation and reduce allocation efficiency. That can be
	3293	+ * monitored by looking at the "large chain blocks" number in lockdep_stats.
	3294	+ */
	3295	+static inline void del_chain_block(int bucket, int size, int next)
	3296	+{
	3297	+ nr_free_chain_hlocks -= size;
	3298	+ chain_block_buckets[bucket] = next;
	3299	+
	3300	+ if (!bucket)
	3301	+ nr_large_chain_blocks--;
	3302	+}
	3303	+
	3304	+static void init_chain_block_buckets(void)
	3305	+{
	3306	+ int i;
	3307	+
	3308	+ for (i = 0; i < MAX_CHAIN_BUCKETS; i++)
	3309	+ chain_block_buckets[i] = -1;
	3310	+
	3311	+ add_chain_block(0, ARRAY_SIZE(chain_hlocks));
	3312	+}
	3313	+
	3314	+/*
	3315	+ * Return offset of a chain block of the right size or -1 if not found.
	3316	+ *
	3317	+ * Fairly simple worst-fit allocator with the addition of a number of size
	3318	+ * specific free lists.
	3319	+ */
	3320	+static int alloc_chain_hlocks(int req)
	3321	+{
	3322	+ int bucket, curr, size;
	3323	+
	3324	+ /*
	3325	+ * We rely on the MSB to act as an escape bit to denote freelist
	3326	+ * pointers. Make sure this bit isn't set in 'normal' class_idx usage.
	3327	+ */
	3328	+ BUILD_BUG_ON((MAX_LOCKDEP_KEYS-1) & CHAIN_BLK_FLAG);
	3329	+
	3330	+ init_data_structures_once();
	3331	+
	3332	+ if (nr_free_chain_hlocks < req)
	3333	+ return -1;
	3334	+
	3335	+ /*
	3336	+ * We require a minimum of 2 (u16) entries to encode a freelist
	3337	+ * 'pointer'.
	3338	+ */
	3339	+ req = max(req, 2);
	3340	+ bucket = size_to_bucket(req);
	3341	+ curr = chain_block_buckets[bucket];
	3342	+
	3343	+ if (bucket) {
	3344	+ if (curr >= 0) {
	3345	+ del_chain_block(bucket, req, chain_block_next(curr));
	3346	+ return curr;
	3347	+ }
	3348	+ /* Try bucket 0 */
	3349	+ curr = chain_block_buckets[0];
	3350	+ }
	3351	+
	3352	+ /*
	3353	+ * The variable sized freelist is sorted by size; the first entry is
	3354	+ * the largest. Use it if it fits.
	3355	+ */
	3356	+ if (curr >= 0) {
	3357	+ size = chain_block_size(curr);
	3358	+ if (likely(size >= req)) {
	3359	+ del_chain_block(0, size, chain_block_next(curr));
	3360	+ add_chain_block(curr + req, size - req);
	3361	+ return curr;
	3362	+ }
	3363	+ }
	3364	+
	3365	+ /*
	3366	+ * Last resort, split a block in a larger sized bucket.
	3367	+ */
	3368	+ for (size = MAX_CHAIN_BUCKETS; size > req; size--) {
	3369	+ bucket = size_to_bucket(size);
	3370	+ curr = chain_block_buckets[bucket];
	3371	+ if (curr < 0)
	3372	+ continue;
	3373	+
	3374	+ del_chain_block(bucket, size, chain_block_next(curr));
	3375	+ add_chain_block(curr + req, size - req);
	3376	+ return curr;
	3377	+ }
	3378	+
	3379	+ return -1;
	3380	+}
	3381	+
	3382	+static inline void free_chain_hlocks(int base, int size)
	3383	+{
	3384	+ add_chain_block(base, max(size, 2));
	3385	+}
2025	3386
2026	3387	struct lock_class lock_chain_get_class(struct lock_chain chain, int i)
2027	3388	{
2028		- return lock_classes + chain_hlocks[chain->base + i];
	3389	+ u16 chain_hlock = chain_hlocks[chain->base + i];
	3390	+ unsigned int class_idx = chain_hlock_class_idx(chain_hlock);
	3391	+
	3392	+ return lock_classes + class_idx;
2029	3393	}
2030	3394
2031	3395	/*
..	..	@@ -2051,12 +3415,12 @@
2051	3415	/*
2052	3416	* Returns the next chain_key iteration
2053	3417	*/
2054		-static u64 print_chain_key_iteration(int class_idx, u64 chain_key)
	3418	+static u64 print_chain_key_iteration(u16 hlock_id, u64 chain_key)
2055	3419	{
2056		- u64 new_chain_key = iterate_chain_key(chain_key, class_idx);
	3420	+ u64 new_chain_key = iterate_chain_key(chain_key, hlock_id);
2057	3421
2058		- printk(" class_idx:%d -> chain_key:%016Lx",
2059		- class_idx,
	3422	+ printk(" hlock_id:%d -> chain_key:%016Lx",
	3423	+ (unsigned int)hlock_id,
2060	3424	(unsigned long long)new_chain_key);
2061	3425	return new_chain_key;
2062	3426	}
..	..	@@ -2065,34 +3429,35 @@
2065	3429	print_chain_keys_held_locks(struct task_struct curr, struct held_lock hlock_next)
2066	3430	{
2067	3431	struct held_lock *hlock;
2068		- u64 chain_key = 0;
	3432	+ u64 chain_key = INITIAL_CHAIN_KEY;
2069	3433	int depth = curr->lockdep_depth;
2070		- int i;
	3434	+ int i = get_first_held_lock(curr, hlock_next);
2071	3435
2072		- printk("depth: %u\n", depth + 1);
2073		- for (i = get_first_held_lock(curr, hlock_next); i < depth; i++) {
	3436	+ printk("depth: %u (irq_context %u)\n", depth - i + 1,
	3437	+ hlock_next->irq_context);
	3438	+ for (; i < depth; i++) {
2074	3439	hlock = curr->held_locks + i;
2075		- chain_key = print_chain_key_iteration(hlock->class_idx, chain_key);
	3440	+ chain_key = print_chain_key_iteration(hlock_id(hlock), chain_key);
2076	3441
2077	3442	print_lock(hlock);
2078	3443	}
2079	3444
2080		- print_chain_key_iteration(hlock_next->class_idx, chain_key);
	3445	+ print_chain_key_iteration(hlock_id(hlock_next), chain_key);
2081	3446	print_lock(hlock_next);
2082	3447	}
2083	3448
2084	3449	static void print_chain_keys_chain(struct lock_chain *chain)
2085	3450	{
2086	3451	int i;
2087		- u64 chain_key = 0;
2088		- int class_id;
	3452	+ u64 chain_key = INITIAL_CHAIN_KEY;
	3453	+ u16 hlock_id;
2089	3454
2090	3455	printk("depth: %u\n", chain->depth);
2091	3456	for (i = 0; i < chain->depth; i++) {
2092		- class_id = chain_hlocks[chain->base + i];
2093		- chain_key = print_chain_key_iteration(class_id + 1, chain_key);
	3457	+ hlock_id = chain_hlocks[chain->base + i];
	3458	+ chain_key = print_chain_key_iteration(hlock_id, chain_key);
2094	3459
2095		- print_lock_name(lock_classes + class_id);
	3460	+ print_lock_name(lock_classes + chain_hlock_class_idx(hlock_id));
2096	3461	printk("\n");
2097	3462	}
2098	3463	}
..	..	@@ -2141,7 +3506,7 @@
2141	3506	}
2142	3507
2143	3508	for (j = 0; j < chain->depth - 1; j++, i++) {
2144		- id = curr->held_locks[i].class_idx - 1;
	3509	+ id = hlock_id(&curr->held_locks[i]);
2145	3510
2146	3511	if (DEBUG_LOCKS_WARN_ON(chain_hlocks[chain->base + j] != id)) {
2147	3512	print_collision(curr, hlock, chain);
..	..	@@ -2153,73 +3518,30 @@
2153	3518	}
2154	3519
2155	3520	/*
2156		- * This is for building a chain between just two different classes,
2157		- * instead of adding a new hlock upon current, which is done by
2158		- * add_chain_cache().
2159		- *
2160		- * This can be called in any context with two classes, while
2161		- * add_chain_cache() must be done within the lock owener's context
2162		- * since it uses hlock which might be racy in another context.
	3521	+ * Given an index that is >= -1, return the index of the next lock chain.
	3522	+ * Return -2 if there is no next lock chain.
2163	3523	*/
2164		-static inline int add_chain_cache_classes(unsigned int prev,
2165		- unsigned int next,
2166		- unsigned int irq_context,
2167		- u64 chain_key)
	3524	+long lockdep_next_lockchain(long i)
2168	3525	{
2169		- struct hlist_head *hash_head = chainhashentry(chain_key);
2170		- struct lock_chain *chain;
	3526	+ i = find_next_bit(lock_chains_in_use, ARRAY_SIZE(lock_chains), i + 1);
	3527	+ return i < ARRAY_SIZE(lock_chains) ? i : -2;
	3528	+}
2171	3529
2172		- /*
2173		- * Allocate a new chain entry from the static array, and add
2174		- * it to the hash:
2175		- */
	3530	+unsigned long lock_chain_count(void)
	3531	+{
	3532	+ return bitmap_weight(lock_chains_in_use, ARRAY_SIZE(lock_chains));
	3533	+}
2176	3534
2177		- /*
2178		- * We might need to take the graph lock, ensure we've got IRQs
2179		- * disabled to make this an IRQ-safe lock.. for recursion reasons
2180		- * lockdep won't complain about its own locking errors.
2181		- */
2182		- if (DEBUG_LOCKS_WARN_ON(!irqs_disabled()))
2183		- return 0;
	3535	+/* Must be called with the graph lock held. */
	3536	+static struct lock_chain *alloc_lock_chain(void)
	3537	+{
	3538	+ int idx = find_first_zero_bit(lock_chains_in_use,
	3539	+ ARRAY_SIZE(lock_chains));
2184	3540
2185		- if (unlikely(nr_lock_chains >= MAX_LOCKDEP_CHAINS)) {
2186		- if (!debug_locks_off_graph_unlock())
2187		- return 0;
2188		-
2189		- print_lockdep_off("BUG: MAX_LOCKDEP_CHAINS too low!");
2190		- dump_stack();
2191		- return 0;
2192		- }
2193		-
2194		- chain = lock_chains + nr_lock_chains++;
2195		- chain->chain_key = chain_key;
2196		- chain->irq_context = irq_context;
2197		- chain->depth = 2;
2198		- if (likely(nr_chain_hlocks + chain->depth <= MAX_LOCKDEP_CHAIN_HLOCKS)) {
2199		- chain->base = nr_chain_hlocks;
2200		- nr_chain_hlocks += chain->depth;
2201		- chain_hlocks[chain->base] = prev - 1;
2202		- chain_hlocks[chain->base + 1] = next -1;
2203		- }
2204		-#ifdef CONFIG_DEBUG_LOCKDEP
2205		- /*
2206		- * Important for check_no_collision().
2207		- */
2208		- else {
2209		- if (!debug_locks_off_graph_unlock())
2210		- return 0;
2211		-
2212		- print_lockdep_off("BUG: MAX_LOCKDEP_CHAIN_HLOCKS too low!");
2213		- dump_stack();
2214		- return 0;
2215		- }
2216		-#endif
2217		-
2218		- hlist_add_head_rcu(&chain->entry, hash_head);
2219		- debug_atomic_inc(chain_lookup_misses);
2220		- inc_chains();
2221		-
2222		- return 1;
	3541	+ if (unlikely(idx >= ARRAY_SIZE(lock_chains)))
	3542	+ return NULL;
	3543	+ __set_bit(idx, lock_chains_in_use);
	3544	+ return lock_chains + idx;
2223	3545	}
2224	3546
2225	3547	/*
..	..	@@ -2233,25 +3555,20 @@
2233	3555	struct held_lock *hlock,
2234	3556	u64 chain_key)
2235	3557	{
2236		- struct lock_class *class = hlock_class(hlock);
2237	3558	struct hlist_head *hash_head = chainhashentry(chain_key);
2238	3559	struct lock_chain *chain;
2239	3560	int i, j;
2240	3561
2241	3562	/*
2242		- * Allocate a new chain entry from the static array, and add
2243		- * it to the hash:
2244		- */
2245		-
2246		- /*
2247		- * We might need to take the graph lock, ensure we've got IRQs
	3563	+ * The caller must hold the graph lock, ensure we've got IRQs
2248	3564	* disabled to make this an IRQ-safe lock.. for recursion reasons
2249	3565	* lockdep won't complain about its own locking errors.
2250	3566	*/
2251		- if (DEBUG_LOCKS_WARN_ON(!irqs_disabled()))
	3567	+ if (lockdep_assert_locked())
2252	3568	return 0;
2253	3569
2254		- if (unlikely(nr_lock_chains >= MAX_LOCKDEP_CHAINS)) {
	3570	+ chain = alloc_lock_chain();
	3571	+ if (!chain) {
2255	3572	if (!debug_locks_off_graph_unlock())
2256	3573	return 0;
2257	3574
..	..	@@ -2259,7 +3576,6 @@
2259	3576	dump_stack();
2260	3577	return 0;
2261	3578	}
2262		- chain = lock_chains + nr_lock_chains++;
2263	3579	chain->chain_key = chain_key;
2264	3580	chain->irq_context = hlock->irq_context;
2265	3581	i = get_first_held_lock(curr, hlock);
..	..	@@ -2269,23 +3585,8 @@
2269	3585	BUILD_BUG_ON((1UL << 6) <= ARRAY_SIZE(curr->held_locks));
2270	3586	BUILD_BUG_ON((1UL << 8*sizeof(chain_hlocks[0])) <= ARRAY_SIZE(lock_classes));
2271	3587
2272		- if (likely(nr_chain_hlocks + chain->depth <= MAX_LOCKDEP_CHAIN_HLOCKS)) {
2273		- chain->base = nr_chain_hlocks;
2274		- for (j = 0; j < chain->depth - 1; j++, i++) {
2275		- int lock_id = curr->held_locks[i].class_idx - 1;
2276		- chain_hlocks[chain->base + j] = lock_id;
2277		- }
2278		- chain_hlocks[chain->base + j] = class - lock_classes;
2279		- }
2280		-
2281		- if (nr_chain_hlocks < MAX_LOCKDEP_CHAIN_HLOCKS)
2282		- nr_chain_hlocks += chain->depth;
2283		-
2284		-#ifdef CONFIG_DEBUG_LOCKDEP
2285		- /*
2286		- * Important for check_no_collision().
2287		- */
2288		- if (unlikely(nr_chain_hlocks > MAX_LOCKDEP_CHAIN_HLOCKS)) {
	3588	+ j = alloc_chain_hlocks(chain->depth);
	3589	+ if (j < 0) {
2289	3590	if (!debug_locks_off_graph_unlock())
2290	3591	return 0;
2291	3592
..	..	@@ -2293,29 +3594,32 @@
2293	3594	dump_stack();
2294	3595	return 0;
2295	3596	}
2296		-#endif
2297	3597
	3598	+ chain->base = j;
	3599	+ for (j = 0; j < chain->depth - 1; j++, i++) {
	3600	+ int lock_id = hlock_id(curr->held_locks + i);
	3601	+
	3602	+ chain_hlocks[chain->base + j] = lock_id;
	3603	+ }
	3604	+ chain_hlocks[chain->base + j] = hlock_id(hlock);
2298	3605	hlist_add_head_rcu(&chain->entry, hash_head);
2299	3606	debug_atomic_inc(chain_lookup_misses);
2300		- inc_chains();
	3607	+ inc_chains(chain->irq_context);
2301	3608
2302	3609	return 1;
2303	3610	}
2304	3611
2305	3612	/*
2306		- * Look up a dependency chain.
	3613	+ * Look up a dependency chain. Must be called with either the graph lock or
	3614	+ * the RCU read lock held.
2307	3615	*/
2308	3616	static inline struct lock_chain *lookup_chain_cache(u64 chain_key)
2309	3617	{
2310	3618	struct hlist_head *hash_head = chainhashentry(chain_key);
2311	3619	struct lock_chain *chain;
2312	3620
2313		- /*
2314		- * We can walk it lock-free, because entries only get added
2315		- * to the hash:
2316		- */
2317	3621	hlist_for_each_entry_rcu(chain, hash_head, entry) {
2318		- if (chain->chain_key == chain_key) {
	3622	+ if (READ_ONCE(chain->chain_key) == chain_key) {
2319	3623	debug_atomic_inc(chain_lookup_hits);
2320	3624	return chain;
2321	3625	}
..	..	@@ -2374,8 +3678,9 @@
2374	3678	return 1;
2375	3679	}
2376	3680
2377		-static int validate_chain(struct task_struct curr, struct lockdep_map lock,
2378		- struct held_lock *hlock, int chain_head, u64 chain_key)
	3681	+static int validate_chain(struct task_struct *curr,
	3682	+ struct held_lock *hlock,
	3683	+ int chain_head, u64 chain_key)
2379	3684	{
2380	3685	/*
2381	3686	* Trylock needs to maintain the stack of held locks, but it
..	..	@@ -2396,25 +3701,28 @@
2396	3701	* - is softirq-safe, if this lock is hardirq-unsafe
2397	3702	*
2398	3703	* And check whether the new lock's dependency graph
2399		- * could lead back to the previous lock.
	3704	+ * could lead back to the previous lock:
2400	3705	*
2401		- * any of these scenarios could lead to a deadlock. If
2402		- * All validations
	3706	+ * - within the current held-lock stack
	3707	+ * - across our accumulated lock dependency records
	3708	+ *
	3709	+ * any of these scenarios could lead to a deadlock.
2403	3710	*/
2404		- int ret = check_deadlock(curr, hlock, lock, hlock->read);
	3711	+ /*
	3712	+ * The simple case: does the current hold the same lock
	3713	+ * already?
	3714	+ */
	3715	+ int ret = check_deadlock(curr, hlock);
2405	3716
2406	3717	if (!ret)
2407	3718	return 0;
2408	3719	/*
2409		- * Mark recursive read, as we jump over it when
2410		- * building dependencies (just like we jump over
2411		- * trylock entries):
2412		- */
2413		- if (ret == 2)
2414		- hlock->read = 2;
2415		- /*
2416	3720	* Add dependency only if this lock is not the head
2417		- * of the chain, and if it's not a secondary read-lock:
	3721	+ * of the chain, and if the new lock introduces no more
	3722	+ * lock dependency (because we already hold a lock with the
	3723	+ * same lock class) nor deadlock (because the nest_lock
	3724	+ * serializes nesting locks), see the comments for
	3725	+ * check_deadlock().
2418	3726	*/
2419	3727	if (!chain_head && ret != 2) {
2420	3728	if (!check_prevs_add(curr, hlock))
..	..	@@ -2432,12 +3740,14 @@
2432	3740	}
2433	3741	#else
2434	3742	static inline int validate_chain(struct task_struct *curr,
2435		- struct lockdep_map lock, struct held_lock hlock,
2436		- int chain_head, u64 chain_key)
	3743	+ struct held_lock *hlock,
	3744	+ int chain_head, u64 chain_key)
2437	3745	{
2438	3746	return 1;
2439	3747	}
2440		-#endif
	3748	+
	3749	+static void init_chain_block_buckets(void) { }
	3750	+#endif /* CONFIG_PROVE_LOCKING */
2441	3751
2442	3752	/*
2443	3753	* We are building curr_chain_key incrementally, so double-check
..	..	@@ -2448,7 +3758,7 @@
2448	3758	#ifdef CONFIG_DEBUG_LOCKDEP
2449	3759	struct held_lock hlock, prev_hlock = NULL;
2450	3760	unsigned int i;
2451		- u64 chain_key = 0;
	3761	+ u64 chain_key = INITIAL_CHAIN_KEY;
2452	3762
2453	3763	for (i = 0; i < curr->lockdep_depth; i++) {
2454	3764	hlock = curr->held_locks + i;
..	..	@@ -2464,16 +3774,18 @@
2464	3774	(unsigned long long)hlock->prev_chain_key);
2465	3775	return;
2466	3776	}
	3777	+
2467	3778	/*
2468		- * Whoops ran out of static storage again?
	3779	+ * hlock->class_idx can't go beyond MAX_LOCKDEP_KEYS, but is
	3780	+ * it registered lock class index?
2469	3781	*/
2470		- if (DEBUG_LOCKS_WARN_ON(hlock->class_idx > MAX_LOCKDEP_KEYS))
	3782	+ if (DEBUG_LOCKS_WARN_ON(!test_bit(hlock->class_idx, lock_classes_in_use)))
2471	3783	return;
2472	3784
2473	3785	if (prev_hlock && (prev_hlock->irq_context !=
2474	3786	hlock->irq_context))
2475		- chain_key = 0;
2476		- chain_key = iterate_chain_key(chain_key, hlock->class_idx);
	3787	+ chain_key = INITIAL_CHAIN_KEY;
	3788	+ chain_key = iterate_chain_key(chain_key, hlock_id(hlock));
2477	3789	prev_hlock = hlock;
2478	3790	}
2479	3791	if (chain_key != curr->curr_chain_key) {
..	..	@@ -2490,8 +3802,11 @@
2490	3802	#endif
2491	3803	}
2492	3804
2493		-static void
2494		-print_usage_bug_scenario(struct held_lock *lock)
	3805	+#ifdef CONFIG_PROVE_LOCKING
	3806	+static int mark_lock(struct task_struct curr, struct held_lock this,
	3807	+ enum lock_usage_bit new_bit);
	3808	+
	3809	+static void print_usage_bug_scenario(struct held_lock *lock)
2495	3810	{
2496	3811	struct lock_class *class = hlock_class(lock);
2497	3812
..	..	@@ -2508,12 +3823,12 @@
2508	3823	printk("\n * DEADLOCK *\n\n");
2509	3824	}
2510	3825
2511		-static int
	3826	+static void
2512	3827	print_usage_bug(struct task_struct curr, struct held_lock this,
2513	3828	enum lock_usage_bit prev_bit, enum lock_usage_bit new_bit)
2514	3829	{
2515		- if (!debug_locks_off_graph_unlock() \|\| debug_locks_silent)
2516		- return 0;
	3830	+ if (!debug_locks_off() \|\| debug_locks_silent)
	3831	+ return;
2517	3832
2518	3833	pr_warn("\n");
2519	3834	pr_warn("================================\n");
..	..	@@ -2526,14 +3841,14 @@
2526	3841
2527	3842	pr_warn("%s/%d [HC%u[%lu]:SC%u[%lu]:HE%u:SE%u] takes:\n",
2528	3843	curr->comm, task_pid_nr(curr),
2529		- trace_hardirq_context(curr), hardirq_count() >> HARDIRQ_SHIFT,
2530		- trace_softirq_context(curr), softirq_count() >> SOFTIRQ_SHIFT,
2531		- trace_hardirqs_enabled(curr),
2532		- trace_softirqs_enabled(curr));
	3844	+ lockdep_hardirq_context(), hardirq_count() >> HARDIRQ_SHIFT,
	3845	+ lockdep_softirq_context(curr), softirq_count() >> SOFTIRQ_SHIFT,
	3846	+ lockdep_hardirqs_enabled(),
	3847	+ lockdep_softirqs_enabled(curr));
2533	3848	print_lock(this);
2534	3849
2535	3850	pr_warn("{%s} state was registered at:\n", usage_str[prev_bit]);
2536		- print_stack_trace(hlock_class(this)->usage_traces + prev_bit, 1);
	3851	+ print_lock_trace(hlock_class(this)->usage_traces[prev_bit], 1);
2537	3852
2538	3853	print_irqtrace_events(curr);
2539	3854	pr_warn("\nother info that might help us debug this:\n");
..	..	@@ -2543,8 +3858,6 @@
2543	3858
2544	3859	pr_warn("\nstack backtrace:\n");
2545	3860	dump_stack();
2546		-
2547		- return 0;
2548	3861	}
2549	3862
2550	3863	/*
..	..	@@ -2554,20 +3867,19 @@
2554	3867	valid_state(struct task_struct curr, struct held_lock this,
2555	3868	enum lock_usage_bit new_bit, enum lock_usage_bit bad_bit)
2556	3869	{
2557		- if (unlikely(hlock_class(this)->usage_mask & (1 << bad_bit)))
2558		- return print_usage_bug(curr, this, bad_bit, new_bit);
	3870	+ if (unlikely(hlock_class(this)->usage_mask & (1 << bad_bit))) {
	3871	+ graph_unlock();
	3872	+ print_usage_bug(curr, this, bad_bit, new_bit);
	3873	+ return 0;
	3874	+ }
2559	3875	return 1;
2560	3876	}
2561	3877
2562		-static int mark_lock(struct task_struct curr, struct held_lock this,
2563		- enum lock_usage_bit new_bit);
2564		-
2565		-#if defined(CONFIG_TRACE_IRQFLAGS) && defined(CONFIG_PROVE_LOCKING)
2566	3878
2567	3879	/*
2568	3880	* print irq inversion bug:
2569	3881	*/
2570		-static int
	3882	+static void
2571	3883	print_irq_inversion_bug(struct task_struct *curr,
2572	3884	struct lock_list root, struct lock_list other,
2573	3885	struct held_lock *this, int forwards,
..	..	@@ -2578,7 +3890,7 @@
2578	3890	int depth;
2579	3891
2580	3892	if (!debug_locks_off_graph_unlock() \|\| debug_locks_silent)
2581		- return 0;
	3893	+ return;
2582	3894
2583	3895	pr_warn("\n");
2584	3896	pr_warn("========================================================\n");
..	..	@@ -2618,14 +3930,13 @@
2618	3930	lockdep_print_held_locks(curr);
2619	3931
2620	3932	pr_warn("\nthe shortest dependencies between 2nd lock and 1st lock:\n");
2621		- if (!save_trace(&root->trace))
2622		- return 0;
	3933	+ root->trace = save_trace();
	3934	+ if (!root->trace)
	3935	+ return;
2623	3936	print_shortest_lock_dependencies(other, root);
2624	3937
2625	3938	pr_warn("\nstack backtrace:\n");
2626	3939	dump_stack();
2627		-
2628		- return 0;
2629	3940	}
2630	3941
2631	3942	/*
..	..	@@ -2634,22 +3945,33 @@
2634	3945	*/
2635	3946	static int
2636	3947	check_usage_forwards(struct task_struct curr, struct held_lock this,
2637		- enum lock_usage_bit bit, const char *irqclass)
	3948	+ enum lock_usage_bit bit)
2638	3949	{
2639		- int ret;
	3950	+ enum bfs_result ret;
2640	3951	struct lock_list root;
2641		- struct lock_list *uninitialized_var(target_entry);
	3952	+ struct lock_list *target_entry;
	3953	+ enum lock_usage_bit read_bit = bit + LOCK_USAGE_READ_MASK;
	3954	+ unsigned usage_mask = lock_flag(bit) \| lock_flag(read_bit);
2642	3955
2643		- root.parent = NULL;
2644		- root.class = hlock_class(this);
2645		- ret = find_usage_forwards(&root, bit, &target_entry);
2646		- if (ret < 0)
2647		- return print_bfs_bug(ret);
2648		- if (ret == 1)
2649		- return ret;
	3956	+ bfs_init_root(&root, this);
	3957	+ ret = find_usage_forwards(&root, usage_mask, &target_entry);
	3958	+ if (bfs_error(ret)) {
	3959	+ print_bfs_bug(ret);
	3960	+ return 0;
	3961	+ }
	3962	+ if (ret == BFS_RNOMATCH)
	3963	+ return 1;
2650	3964
2651		- return print_irq_inversion_bug(curr, &root, target_entry,
2652		- this, 1, irqclass);
	3965	+ /* Check whether write or read usage is the match */
	3966	+ if (target_entry->class->usage_mask & lock_flag(bit)) {
	3967	+ print_irq_inversion_bug(curr, &root, target_entry,
	3968	+ this, 1, state_name(bit));
	3969	+ } else {
	3970	+ print_irq_inversion_bug(curr, &root, target_entry,
	3971	+ this, 1, state_name(read_bit));
	3972	+ }
	3973	+
	3974	+ return 0;
2653	3975	}
2654	3976
2655	3977	/*
..	..	@@ -2658,39 +3980,52 @@
2658	3980	*/
2659	3981	static int
2660	3982	check_usage_backwards(struct task_struct curr, struct held_lock this,
2661		- enum lock_usage_bit bit, const char *irqclass)
	3983	+ enum lock_usage_bit bit)
2662	3984	{
2663		- int ret;
	3985	+ enum bfs_result ret;
2664	3986	struct lock_list root;
2665		- struct lock_list *uninitialized_var(target_entry);
	3987	+ struct lock_list *target_entry;
	3988	+ enum lock_usage_bit read_bit = bit + LOCK_USAGE_READ_MASK;
	3989	+ unsigned usage_mask = lock_flag(bit) \| lock_flag(read_bit);
2666	3990
2667		- root.parent = NULL;
2668		- root.class = hlock_class(this);
2669		- ret = find_usage_backwards(&root, bit, &target_entry);
2670		- if (ret < 0)
2671		- return print_bfs_bug(ret);
2672		- if (ret == 1)
2673		- return ret;
	3991	+ bfs_init_rootb(&root, this);
	3992	+ ret = find_usage_backwards(&root, usage_mask, &target_entry);
	3993	+ if (bfs_error(ret)) {
	3994	+ print_bfs_bug(ret);
	3995	+ return 0;
	3996	+ }
	3997	+ if (ret == BFS_RNOMATCH)
	3998	+ return 1;
2674	3999
2675		- return print_irq_inversion_bug(curr, &root, target_entry,
2676		- this, 0, irqclass);
	4000	+ /* Check whether write or read usage is the match */
	4001	+ if (target_entry->class->usage_mask & lock_flag(bit)) {
	4002	+ print_irq_inversion_bug(curr, &root, target_entry,
	4003	+ this, 0, state_name(bit));
	4004	+ } else {
	4005	+ print_irq_inversion_bug(curr, &root, target_entry,
	4006	+ this, 0, state_name(read_bit));
	4007	+ }
	4008	+
	4009	+ return 0;
2677	4010	}
2678	4011
2679	4012	void print_irqtrace_events(struct task_struct *curr)
2680	4013	{
2681		- printk("irq event stamp: %u\n", curr->irq_events);
	4014	+ const struct irqtrace_events *trace = &curr->irqtrace;
	4015	+
	4016	+ printk("irq event stamp: %u\n", trace->irq_events);
2682	4017	printk("hardirqs last enabled at (%u): [<%px>] %pS\n",
2683		- curr->hardirq_enable_event, (void *)curr->hardirq_enable_ip,
2684		- (void *)curr->hardirq_enable_ip);
	4018	+ trace->hardirq_enable_event, (void *)trace->hardirq_enable_ip,
	4019	+ (void *)trace->hardirq_enable_ip);
2685	4020	printk("hardirqs last disabled at (%u): [<%px>] %pS\n",
2686		- curr->hardirq_disable_event, (void *)curr->hardirq_disable_ip,
2687		- (void *)curr->hardirq_disable_ip);
	4021	+ trace->hardirq_disable_event, (void *)trace->hardirq_disable_ip,
	4022	+ (void *)trace->hardirq_disable_ip);
2688	4023	printk("softirqs last enabled at (%u): [<%px>] %pS\n",
2689		- curr->softirq_enable_event, (void *)curr->softirq_enable_ip,
2690		- (void *)curr->softirq_enable_ip);
	4024	+ trace->softirq_enable_event, (void *)trace->softirq_enable_ip,
	4025	+ (void *)trace->softirq_enable_ip);
2691	4026	printk("softirqs last disabled at (%u): [<%px>] %pS\n",
2692		- curr->softirq_disable_event, (void *)curr->softirq_disable_ip,
2693		- (void *)curr->softirq_disable_ip);
	4027	+ trace->softirq_disable_event, (void *)trace->softirq_disable_ip,
	4028	+ (void *)trace->softirq_disable_ip);
2694	4029	}
2695	4030
2696	4031	static int HARDIRQ_verbose(struct lock_class *class)
..	..	@@ -2709,8 +4044,6 @@
2709	4044	return 0;
2710	4045	}
2711	4046
2712		-#define STRICT_READ_CHECKS 1
2713		-
2714	4047	static int (state_verbose_f[])(struct lock_class class) = {
2715	4048	#define LOCKDEP_STATE(__STATE) \
2716	4049	__STATE##_verbose,
..	..	@@ -2721,7 +4054,7 @@
2721	4054	static inline int state_verbose(enum lock_usage_bit bit,
2722	4055	struct lock_class *class)
2723	4056	{
2724		- return state_verbose_f[bit >> 2](class);
	4057	+ return state_verbose_f[bit >> LOCK_USAGE_DIR_MASK](class);
2725	4058	}
2726	4059
2727	4060	typedef int (check_usage_f)(struct task_struct , struct held_lock *,
..	..	@@ -2732,18 +4065,8 @@
2732	4065	enum lock_usage_bit new_bit)
2733	4066	{
2734	4067	int excl_bit = exclusive_bit(new_bit);
2735		- int read = new_bit & 1;
2736		- int dir = new_bit & 2;
2737		-
2738		- /*
2739		- * mark USED_IN has to look forwards -- to ensure no dependency
2740		- * has ENABLED state, which would allow recursion deadlocks.
2741		- *
2742		- * mark ENABLED has to look backwards -- to ensure no dependee
2743		- * has USED_IN state, which, again, would allow recursion deadlocks.
2744		- */
2745		- check_usage_f usage = dir ?
2746		- check_usage_backwards : check_usage_forwards;
	4068	+ int read = new_bit & LOCK_USAGE_READ_MASK;
	4069	+ int dir = new_bit & LOCK_USAGE_DIR_MASK;
2747	4070
2748	4071	/*
2749	4072	* Validate that this particular lock does not have conflicting
..	..	@@ -2753,23 +4076,30 @@
2753	4076	return 0;
2754	4077
2755	4078	/*
	4079	+ * Check for read in write conflicts
	4080	+ */
	4081	+ if (!read && !valid_state(curr, this, new_bit,
	4082	+ excl_bit + LOCK_USAGE_READ_MASK))
	4083	+ return 0;
	4084	+
	4085	+
	4086	+ /*
2756	4087	* Validate that the lock dependencies don't have conflicting usage
2757	4088	* states.
2758	4089	*/
2759		- if ((!read \|\| !dir \|\| STRICT_READ_CHECKS) &&
2760		- !usage(curr, this, excl_bit, state_name(new_bit & ~1)))
2761		- return 0;
2762		-
2763		- /*
2764		- * Check for read in write conflicts
2765		- */
2766		- if (!read) {
2767		- if (!valid_state(curr, this, new_bit, excl_bit + 1))
	4090	+ if (dir) {
	4091	+ /*
	4092	+ * mark ENABLED has to look backwards -- to ensure no dependee
	4093	+ * has USED_IN state, which, again, would allow recursion deadlocks.
	4094	+ */
	4095	+ if (!check_usage_backwards(curr, this, excl_bit))
2768	4096	return 0;
2769		-
2770		- if (STRICT_READ_CHECKS &&
2771		- !usage(curr, this, excl_bit + 1,
2772		- state_name(new_bit + 1)))
	4097	+ } else {
	4098	+ /*
	4099	+ * mark USED_IN has to look forwards -- to ensure no dependency
	4100	+ * has ENABLED state, which would allow recursion deadlocks.
	4101	+ */
	4102	+ if (!check_usage_forwards(curr, this, excl_bit))
2773	4103	return 0;
2774	4104	}
2775	4105
..	..	@@ -2779,35 +4109,28 @@
2779	4109	return 1;
2780	4110	}
2781	4111
2782		-enum mark_type {
2783		-#define LOCKDEP_STATE(__STATE) __STATE,
2784		-#include "lockdep_states.h"
2785		-#undef LOCKDEP_STATE
2786		-};
2787		-
2788	4112	/*
2789	4113	* Mark all held locks with a usage bit:
2790	4114	*/
2791	4115	static int
2792		-mark_held_locks(struct task_struct *curr, enum mark_type mark)
	4116	+mark_held_locks(struct task_struct *curr, enum lock_usage_bit base_bit)
2793	4117	{
2794		- enum lock_usage_bit usage_bit;
2795	4118	struct held_lock *hlock;
2796	4119	int i;
2797	4120
2798	4121	for (i = 0; i < curr->lockdep_depth; i++) {
	4122	+ enum lock_usage_bit hlock_bit = base_bit;
2799	4123	hlock = curr->held_locks + i;
2800	4124
2801		- usage_bit = 2 + (mark << 2); /* ENABLED */
2802	4125	if (hlock->read)
2803		- usage_bit += 1; /* READ */
	4126	+ hlock_bit += LOCK_USAGE_READ_MASK;
2804	4127
2805		- BUG_ON(usage_bit >= LOCK_USAGE_STATES);
	4128	+ BUG_ON(hlock_bit >= LOCK_USAGE_STATES);
2806	4129
2807	4130	if (!hlock->check)
2808	4131	continue;
2809	4132
2810		- if (!mark_lock(curr, hlock, usage_bit))
	4133	+ if (!mark_lock(curr, hlock, hlock_bit))
2811	4134	return 0;
2812	4135	}
2813	4136
..	..	@@ -2817,18 +4140,15 @@
2817	4140	/*
2818	4141	* Hardirqs will be enabled:
2819	4142	*/
2820		-static void __trace_hardirqs_on_caller(unsigned long ip)
	4143	+static void __trace_hardirqs_on_caller(void)
2821	4144	{
2822	4145	struct task_struct *curr = current;
2823		-
2824		- /* we'll do an OFF -> ON transition: */
2825		- curr->hardirqs_enabled = 1;
2826	4146
2827	4147	/*
2828	4148	* We are going to turn hardirqs on, so set the
2829	4149	* usage bit for all held locks:
2830	4150	*/
2831		- if (!mark_held_locks(curr, HARDIRQ))
	4151	+ if (!mark_held_locks(curr, LOCK_ENABLED_HARDIRQ))
2832	4152	return;
2833	4153	/*
2834	4154	* If we have softirqs enabled, then set the usage
..	..	@@ -2836,20 +4156,33 @@
2836	4156	* this bit from being set before)
2837	4157	*/
2838	4158	if (curr->softirqs_enabled)
2839		- if (!mark_held_locks(curr, SOFTIRQ))
2840		- return;
2841		-
2842		- curr->hardirq_enable_ip = ip;
2843		- curr->hardirq_enable_event = ++curr->irq_events;
2844		- debug_atomic_inc(hardirqs_on_events);
	4159	+ mark_held_locks(curr, LOCK_ENABLED_SOFTIRQ);
2845	4160	}
2846	4161
2847		-void lockdep_hardirqs_on(unsigned long ip)
	4162	+/**
	4163	+ * lockdep_hardirqs_on_prepare - Prepare for enabling interrupts
	4164	+ * @ip: Caller address
	4165	+ *
	4166	+ * Invoked before a possible transition to RCU idle from exit to user or
	4167	+ * guest mode. This ensures that all RCU operations are done before RCU
	4168	+ * stops watching. After the RCU transition lockdep_hardirqs_on() has to be
	4169	+ * invoked to set the final state.
	4170	+ */
	4171	+void lockdep_hardirqs_on_prepare(unsigned long ip)
2848	4172	{
2849		- if (unlikely(!debug_locks \|\| current->lockdep_recursion))
	4173	+ if (unlikely(!debug_locks))
2850	4174	return;
2851	4175
2852		- if (unlikely(current->hardirqs_enabled)) {
	4176	+ /*
	4177	+ * NMIs do not (and cannot) track lock dependencies, nothing to do.
	4178	+ */
	4179	+ if (unlikely(in_nmi()))
	4180	+ return;
	4181	+
	4182	+ if (unlikely(this_cpu_read(lockdep_recursion)))
	4183	+ return;
	4184	+
	4185	+ if (unlikely(lockdep_hardirqs_enabled())) {
2853	4186	/*
2854	4187	* Neither irq nor preemption are disabled here
2855	4188	* so this is racy by nature but losing one hit
..	..	@@ -2870,29 +4203,105 @@
2870	4203	/*
2871	4204	* See the fine text that goes along with this variable definition.
2872	4205	*/
2873		- if (DEBUG_LOCKS_WARN_ON(unlikely(early_boot_irqs_disabled)))
	4206	+ if (DEBUG_LOCKS_WARN_ON(early_boot_irqs_disabled))
2874	4207	return;
2875	4208
2876	4209	/*
2877	4210	* Can't allow enabling interrupts while in an interrupt handler,
2878	4211	* that's general bad form and such. Recursion, limited stack etc..
2879	4212	*/
2880		- if (DEBUG_LOCKS_WARN_ON(current->hardirq_context))
	4213	+ if (DEBUG_LOCKS_WARN_ON(lockdep_hardirq_context()))
2881	4214	return;
2882	4215
2883		- current->lockdep_recursion = 1;
2884		- __trace_hardirqs_on_caller(ip);
2885		- current->lockdep_recursion = 0;
	4216	+ current->hardirq_chain_key = current->curr_chain_key;
	4217	+
	4218	+ lockdep_recursion_inc();
	4219	+ __trace_hardirqs_on_caller();
	4220	+ lockdep_recursion_finish();
2886	4221	}
	4222	+EXPORT_SYMBOL_GPL(lockdep_hardirqs_on_prepare);
	4223	+
	4224	+void noinstr lockdep_hardirqs_on(unsigned long ip)
	4225	+{
	4226	+ struct irqtrace_events *trace = &current->irqtrace;
	4227	+
	4228	+ if (unlikely(!debug_locks))
	4229	+ return;
	4230	+
	4231	+ /*
	4232	+ * NMIs can happen in the middle of local_irq_{en,dis}able() where the
	4233	+ * tracking state and hardware state are out of sync.
	4234	+ *
	4235	+ * NMIs must save lockdep_hardirqs_enabled() to restore IRQ state from,
	4236	+ * and not rely on hardware state like normal interrupts.
	4237	+ */
	4238	+ if (unlikely(in_nmi())) {
	4239	+ if (!IS_ENABLED(CONFIG_TRACE_IRQFLAGS_NMI))
	4240	+ return;
	4241	+
	4242	+ /*
	4243	+ * Skip:
	4244	+ * - recursion check, because NMI can hit lockdep;
	4245	+ * - hardware state check, because above;
	4246	+ * - chain_key check, see lockdep_hardirqs_on_prepare().
	4247	+ */
	4248	+ goto skip_checks;
	4249	+ }
	4250	+
	4251	+ if (unlikely(this_cpu_read(lockdep_recursion)))
	4252	+ return;
	4253	+
	4254	+ if (lockdep_hardirqs_enabled()) {
	4255	+ /*
	4256	+ * Neither irq nor preemption are disabled here
	4257	+ * so this is racy by nature but losing one hit
	4258	+ * in a stat is not a big deal.
	4259	+ */
	4260	+ __debug_atomic_inc(redundant_hardirqs_on);
	4261	+ return;
	4262	+ }
	4263	+
	4264	+ /*
	4265	+ * We're enabling irqs and according to our state above irqs weren't
	4266	+ * already enabled, yet we find the hardware thinks they are in fact
	4267	+ * enabled.. someone messed up their IRQ state tracing.
	4268	+ */
	4269	+ if (DEBUG_LOCKS_WARN_ON(!irqs_disabled()))
	4270	+ return;
	4271	+
	4272	+ /*
	4273	+ * Ensure the lock stack remained unchanged between
	4274	+ * lockdep_hardirqs_on_prepare() and lockdep_hardirqs_on().
	4275	+ */
	4276	+ DEBUG_LOCKS_WARN_ON(current->hardirq_chain_key !=
	4277	+ current->curr_chain_key);
	4278	+
	4279	+skip_checks:
	4280	+ /* we'll do an OFF -> ON transition: */
	4281	+ __this_cpu_write(hardirqs_enabled, 1);
	4282	+ trace->hardirq_enable_ip = ip;
	4283	+ trace->hardirq_enable_event = ++trace->irq_events;
	4284	+ debug_atomic_inc(hardirqs_on_events);
	4285	+}
	4286	+EXPORT_SYMBOL_GPL(lockdep_hardirqs_on);
2887	4287
2888	4288	/*
2889	4289	* Hardirqs were disabled:
2890	4290	*/
2891		-void lockdep_hardirqs_off(unsigned long ip)
	4291	+void noinstr lockdep_hardirqs_off(unsigned long ip)
2892	4292	{
2893		- struct task_struct *curr = current;
	4293	+ if (unlikely(!debug_locks))
	4294	+ return;
2894	4295
2895		- if (unlikely(!debug_locks \|\| current->lockdep_recursion))
	4296	+ /*
	4297	+ * Matching lockdep_hardirqs_on(), allow NMIs in the middle of lockdep;
	4298	+ * they will restore the software state. This ensures the software
	4299	+ * state is consistent inside NMIs as well.
	4300	+ */
	4301	+ if (in_nmi()) {
	4302	+ if (!IS_ENABLED(CONFIG_TRACE_IRQFLAGS_NMI))
	4303	+ return;
	4304	+ } else if (__this_cpu_read(lockdep_recursion))
2896	4305	return;
2897	4306
2898	4307	/*
..	..	@@ -2902,26 +4311,30 @@
2902	4311	if (DEBUG_LOCKS_WARN_ON(!irqs_disabled()))
2903	4312	return;
2904	4313
2905		- if (curr->hardirqs_enabled) {
	4314	+ if (lockdep_hardirqs_enabled()) {
	4315	+ struct irqtrace_events *trace = &current->irqtrace;
	4316	+
2906	4317	/*
2907	4318	* We have done an ON -> OFF transition:
2908	4319	*/
2909		- curr->hardirqs_enabled = 0;
2910		- curr->hardirq_disable_ip = ip;
2911		- curr->hardirq_disable_event = ++curr->irq_events;
	4320	+ __this_cpu_write(hardirqs_enabled, 0);
	4321	+ trace->hardirq_disable_ip = ip;
	4322	+ trace->hardirq_disable_event = ++trace->irq_events;
2912	4323	debug_atomic_inc(hardirqs_off_events);
2913		- } else
	4324	+ } else {
2914	4325	debug_atomic_inc(redundant_hardirqs_off);
	4326	+ }
2915	4327	}
	4328	+EXPORT_SYMBOL_GPL(lockdep_hardirqs_off);
2916	4329
2917	4330	/*
2918	4331	* Softirqs will be enabled:
2919	4332	*/
2920		-void trace_softirqs_on(unsigned long ip)
	4333	+void lockdep_softirqs_on(unsigned long ip)
2921	4334	{
2922		- struct task_struct *curr = current;
	4335	+ struct irqtrace_events *trace = &current->irqtrace;
2923	4336
2924		- if (unlikely(!debug_locks \|\| current->lockdep_recursion))
	4337	+ if (unlikely(!lockdep_enabled()))
2925	4338	return;
2926	4339
2927	4340	/*
..	..	@@ -2931,37 +4344,35 @@
2931	4344	if (DEBUG_LOCKS_WARN_ON(!irqs_disabled()))
2932	4345	return;
2933	4346
2934		- if (curr->softirqs_enabled) {
	4347	+ if (current->softirqs_enabled) {
2935	4348	debug_atomic_inc(redundant_softirqs_on);
2936	4349	return;
2937	4350	}
2938	4351
2939		- current->lockdep_recursion = 1;
	4352	+ lockdep_recursion_inc();
2940	4353	/*
2941	4354	* We'll do an OFF -> ON transition:
2942	4355	*/
2943		- curr->softirqs_enabled = 1;
2944		- curr->softirq_enable_ip = ip;
2945		- curr->softirq_enable_event = ++curr->irq_events;
	4356	+ current->softirqs_enabled = 1;
	4357	+ trace->softirq_enable_ip = ip;
	4358	+ trace->softirq_enable_event = ++trace->irq_events;
2946	4359	debug_atomic_inc(softirqs_on_events);
2947	4360	/*
2948	4361	* We are going to turn softirqs on, so set the
2949	4362	* usage bit for all held locks, if hardirqs are
2950	4363	* enabled too:
2951	4364	*/
2952		- if (curr->hardirqs_enabled)
2953		- mark_held_locks(curr, SOFTIRQ);
2954		- current->lockdep_recursion = 0;
	4365	+ if (lockdep_hardirqs_enabled())
	4366	+ mark_held_locks(current, LOCK_ENABLED_SOFTIRQ);
	4367	+ lockdep_recursion_finish();
2955	4368	}
2956	4369
2957	4370	/*
2958	4371	* Softirqs were disabled:
2959	4372	*/
2960		-void trace_softirqs_off(unsigned long ip)
	4373	+void lockdep_softirqs_off(unsigned long ip)
2961	4374	{
2962		- struct task_struct *curr = current;
2963		-
2964		- if (unlikely(!debug_locks \|\| current->lockdep_recursion))
	4375	+ if (unlikely(!lockdep_enabled()))
2965	4376	return;
2966	4377
2967	4378	/*
..	..	@@ -2970,13 +4381,15 @@
2970	4381	if (DEBUG_LOCKS_WARN_ON(!irqs_disabled()))
2971	4382	return;
2972	4383
2973		- if (curr->softirqs_enabled) {
	4384	+ if (current->softirqs_enabled) {
	4385	+ struct irqtrace_events *trace = &current->irqtrace;
	4386	+
2974	4387	/*
2975	4388	* We have done an ON -> OFF transition:
2976	4389	*/
2977		- curr->softirqs_enabled = 0;
2978		- curr->softirq_disable_ip = ip;
2979		- curr->softirq_disable_event = ++curr->irq_events;
	4390	+ current->softirqs_enabled = 0;
	4391	+ trace->softirq_disable_ip = ip;
	4392	+ trace->softirq_disable_event = ++trace->irq_events;
2980	4393	debug_atomic_inc(softirqs_off_events);
2981	4394	/*
2982	4395	* Whoops, we wanted softirqs off, so why aren't they?
..	..	@@ -2986,15 +4399,19 @@
2986	4399	debug_atomic_inc(redundant_softirqs_off);
2987	4400	}
2988	4401
2989		-static int mark_irqflags(struct task_struct curr, struct held_lock hlock)
	4402	+static int
	4403	+mark_usage(struct task_struct curr, struct held_lock hlock, int check)
2990	4404	{
	4405	+ if (!check)
	4406	+ goto lock_used;
	4407	+
2991	4408	/*
2992	4409	* If non-trylock use in a hardirq or softirq context, then
2993	4410	* mark the lock as used in these contexts:
2994	4411	*/
2995	4412	if (!hlock->trylock) {
2996	4413	if (hlock->read) {
2997		- if (curr->hardirq_context)
	4414	+ if (lockdep_hardirq_context())
2998	4415	if (!mark_lock(curr, hlock,
2999	4416	LOCK_USED_IN_HARDIRQ_READ))
3000	4417	return 0;
..	..	@@ -3003,7 +4420,7 @@
3003	4420	LOCK_USED_IN_SOFTIRQ_READ))
3004	4421	return 0;
3005	4422	} else {
3006		- if (curr->hardirq_context)
	4423	+ if (lockdep_hardirq_context())
3007	4424	if (!mark_lock(curr, hlock, LOCK_USED_IN_HARDIRQ))
3008	4425	return 0;
3009	4426	if (curr->softirq_context)
..	..	@@ -3031,12 +4448,18 @@
3031	4448	}
3032	4449	}
3033	4450
	4451	+lock_used:
	4452	+ /* mark it as used: */
	4453	+ if (!mark_lock(curr, hlock, LOCK_USED))
	4454	+ return 0;
	4455	+
3034	4456	return 1;
3035	4457	}
3036	4458
3037	4459	static inline unsigned int task_irq_context(struct task_struct *task)
3038	4460	{
3039		- return 2 * !!task->hardirq_context + !!task->softirq_context;
	4461	+ return LOCK_CHAIN_HARDIRQ_CONTEXT * !!lockdep_hardirq_context() +
	4462	+ LOCK_CHAIN_SOFTIRQ_CONTEXT * !!task->softirq_context;
3040	4463	}
3041	4464
3042	4465	static int separate_irq_context(struct task_struct *curr,
..	..	@@ -3062,42 +4485,23 @@
3062	4485	return 0;
3063	4486	}
3064	4487
3065		-#else /* defined(CONFIG_TRACE_IRQFLAGS) && defined(CONFIG_PROVE_LOCKING) */
3066		-
3067		-static inline
3068		-int mark_lock_irq(struct task_struct curr, struct held_lock this,
3069		- enum lock_usage_bit new_bit)
3070		-{
3071		- WARN_ON(1); /* Impossible innit? when we don't have TRACE_IRQFLAG */
3072		- return 1;
3073		-}
3074		-
3075		-static inline int mark_irqflags(struct task_struct *curr,
3076		- struct held_lock *hlock)
3077		-{
3078		- return 1;
3079		-}
3080		-
3081		-static inline unsigned int task_irq_context(struct task_struct *task)
3082		-{
3083		- return 0;
3084		-}
3085		-
3086		-static inline int separate_irq_context(struct task_struct *curr,
3087		- struct held_lock *hlock)
3088		-{
3089		- return 0;
3090		-}
3091		-
3092		-#endif /* defined(CONFIG_TRACE_IRQFLAGS) && defined(CONFIG_PROVE_LOCKING) */
3093		-
3094	4488	/*
3095	4489	* Mark a lock with a usage bit, and validate the state transition:
3096	4490	*/
3097	4491	static int mark_lock(struct task_struct curr, struct held_lock this,
3098	4492	enum lock_usage_bit new_bit)
3099	4493	{
3100		- unsigned int new_mask = 1 << new_bit, ret = 1;
	4494	+ unsigned int new_mask, ret = 1;
	4495	+
	4496	+ if (new_bit >= LOCK_USAGE_STATES) {
	4497	+ DEBUG_LOCKS_WARN_ON(1);
	4498	+ return 0;
	4499	+ }
	4500	+
	4501	+ if (new_bit == LOCK_USED && this->read)
	4502	+ new_bit = LOCK_USED_READ;
	4503	+
	4504	+ new_mask = 1 << new_bit;
3101	4505
3102	4506	/*
3103	4507	* If already set then do not dirty the cacheline,
..	..	@@ -3111,38 +4515,26 @@
3111	4515	/*
3112	4516	* Make sure we didn't race:
3113	4517	*/
3114		- if (unlikely(hlock_class(this)->usage_mask & new_mask)) {
3115		- graph_unlock();
3116		- return 1;
3117		- }
	4518	+ if (unlikely(hlock_class(this)->usage_mask & new_mask))
	4519	+ goto unlock;
	4520	+
	4521	+ if (!hlock_class(this)->usage_mask)
	4522	+ debug_atomic_dec(nr_unused_locks);
3118	4523
3119	4524	hlock_class(this)->usage_mask \|= new_mask;
3120	4525
3121		- if (!save_trace(hlock_class(this)->usage_traces + new_bit))
3122		- return 0;
	4526	+ if (new_bit < LOCK_TRACE_STATES) {
	4527	+ if (!(hlock_class(this)->usage_traces[new_bit] = save_trace()))
	4528	+ return 0;
	4529	+ }
3123	4530
3124		- switch (new_bit) {
3125		-#define LOCKDEP_STATE(__STATE) \
3126		- case LOCK_USED_IN_##__STATE: \
3127		- case LOCK_USED_IN_##__STATE##_READ: \
3128		- case LOCK_ENABLED_##__STATE: \
3129		- case LOCK_ENABLED_##__STATE##_READ:
3130		-#include "lockdep_states.h"
3131		-#undef LOCKDEP_STATE
	4531	+ if (new_bit < LOCK_USED) {
3132	4532	ret = mark_lock_irq(curr, this, new_bit);
3133	4533	if (!ret)
3134	4534	return 0;
3135		- break;
3136		- case LOCK_USED:
3137		- debug_atomic_dec(nr_unused_locks);
3138		- break;
3139		- default:
3140		- if (!debug_locks_off_graph_unlock())
3141		- return 0;
3142		- WARN_ON(1);
3143		- return 0;
3144	4535	}
3145	4536
	4537	+unlock:
3146	4538	graph_unlock();
3147	4539
3148	4540	/*
..	..	@@ -3158,11 +4550,157 @@
3158	4550	return ret;
3159	4551	}
3160	4552
	4553	+static inline short task_wait_context(struct task_struct *curr)
	4554	+{
	4555	+ /*
	4556	+ * Set appropriate wait type for the context; for IRQs we have to take
	4557	+ * into account force_irqthread as that is implied by PREEMPT_RT.
	4558	+ */
	4559	+ if (lockdep_hardirq_context()) {
	4560	+ /*
	4561	+ * Check if force_irqthreads will run us threaded.
	4562	+ */
	4563	+ if (curr->hardirq_threaded \|\| curr->irq_config)
	4564	+ return LD_WAIT_CONFIG;
	4565	+
	4566	+ return LD_WAIT_SPIN;
	4567	+ } else if (curr->softirq_context) {
	4568	+ /*
	4569	+ * Softirqs are always threaded.
	4570	+ */
	4571	+ return LD_WAIT_CONFIG;
	4572	+ }
	4573	+
	4574	+ return LD_WAIT_MAX;
	4575	+}
	4576	+
	4577	+static int
	4578	+print_lock_invalid_wait_context(struct task_struct *curr,
	4579	+ struct held_lock *hlock)
	4580	+{
	4581	+ short curr_inner;
	4582	+
	4583	+ if (!debug_locks_off())
	4584	+ return 0;
	4585	+ if (debug_locks_silent)
	4586	+ return 0;
	4587	+
	4588	+ pr_warn("\n");
	4589	+ pr_warn("=============================\n");
	4590	+ pr_warn("[ BUG: Invalid wait context ]\n");
	4591	+ print_kernel_ident();
	4592	+ pr_warn("-----------------------------\n");
	4593	+
	4594	+ pr_warn("%s/%d is trying to lock:\n", curr->comm, task_pid_nr(curr));
	4595	+ print_lock(hlock);
	4596	+
	4597	+ pr_warn("other info that might help us debug this:\n");
	4598	+
	4599	+ curr_inner = task_wait_context(curr);
	4600	+ pr_warn("context-{%d:%d}\n", curr_inner, curr_inner);
	4601	+
	4602	+ lockdep_print_held_locks(curr);
	4603	+
	4604	+ pr_warn("stack backtrace:\n");
	4605	+ dump_stack();
	4606	+
	4607	+ return 0;
	4608	+}
	4609	+
	4610	+/*
	4611	+ * Verify the wait_type context.
	4612	+ *
	4613	+ * This check validates we takes locks in the right wait-type order; that is it
	4614	+ * ensures that we do not take mutexes inside spinlocks and do not attempt to
	4615	+ * acquire spinlocks inside raw_spinlocks and the sort.
	4616	+ *
	4617	+ * The entire thing is slightly more complex because of RCU, RCU is a lock that
	4618	+ * can be taken from (pretty much) any context but also has constraints.
	4619	+ * However when taken in a stricter environment the RCU lock does not loosen
	4620	+ * the constraints.
	4621	+ *
	4622	+ * Therefore we must look for the strictest environment in the lock stack and
	4623	+ * compare that to the lock we're trying to acquire.
	4624	+ */
	4625	+static int check_wait_context(struct task_struct curr, struct held_lock next)
	4626	+{
	4627	+ u8 next_inner = hlock_class(next)->wait_type_inner;
	4628	+ u8 next_outer = hlock_class(next)->wait_type_outer;
	4629	+ u8 curr_inner;
	4630	+ int depth;
	4631	+
	4632	+ if (!next_inner \|\| next->trylock)
	4633	+ return 0;
	4634	+
	4635	+ if (!next_outer)
	4636	+ next_outer = next_inner;
	4637	+
	4638	+ /*
	4639	+ * Find start of current irq_context..
	4640	+ */
	4641	+ for (depth = curr->lockdep_depth - 1; depth >= 0; depth--) {
	4642	+ struct held_lock *prev = curr->held_locks + depth;
	4643	+ if (prev->irq_context != next->irq_context)
	4644	+ break;
	4645	+ }
	4646	+ depth++;
	4647	+
	4648	+ curr_inner = task_wait_context(curr);
	4649	+
	4650	+ for (; depth < curr->lockdep_depth; depth++) {
	4651	+ struct held_lock *prev = curr->held_locks + depth;
	4652	+ u8 prev_inner = hlock_class(prev)->wait_type_inner;
	4653	+
	4654	+ if (prev_inner) {
	4655	+ /*
	4656	+ * We can have a bigger inner than a previous one
	4657	+ * when outer is smaller than inner, as with RCU.
	4658	+ *
	4659	+ * Also due to trylocks.
	4660	+ */
	4661	+ curr_inner = min(curr_inner, prev_inner);
	4662	+ }
	4663	+ }
	4664	+
	4665	+ if (next_outer > curr_inner)
	4666	+ return print_lock_invalid_wait_context(curr, next);
	4667	+
	4668	+ return 0;
	4669	+}
	4670	+
	4671	+#else /* CONFIG_PROVE_LOCKING */
	4672	+
	4673	+static inline int
	4674	+mark_usage(struct task_struct curr, struct held_lock hlock, int check)
	4675	+{
	4676	+ return 1;
	4677	+}
	4678	+
	4679	+static inline unsigned int task_irq_context(struct task_struct *task)
	4680	+{
	4681	+ return 0;
	4682	+}
	4683	+
	4684	+static inline int separate_irq_context(struct task_struct *curr,
	4685	+ struct held_lock *hlock)
	4686	+{
	4687	+ return 0;
	4688	+}
	4689	+
	4690	+static inline int check_wait_context(struct task_struct *curr,
	4691	+ struct held_lock *next)
	4692	+{
	4693	+ return 0;
	4694	+}
	4695	+
	4696	+#endif /* CONFIG_PROVE_LOCKING */
	4697	+
3161	4698	/*
3162	4699	* Initialize a lock instance's lock-class mapping info:
3163	4700	*/
3164		-static void __lockdep_init_map(struct lockdep_map lock, const char name,
3165		- struct lock_class_key *key, int subclass)
	4701	+void lockdep_init_map_type(struct lockdep_map lock, const char name,
	4702	+ struct lock_class_key *key, int subclass,
	4703	+ u8 inner, u8 outer, u8 lock_type)
3166	4704	{
3167	4705	int i;
3168	4706
..	..	@@ -3183,19 +4721,22 @@
3183	4721
3184	4722	lock->name = name;
3185	4723
	4724	+ lock->wait_type_outer = outer;
	4725	+ lock->wait_type_inner = inner;
	4726	+ lock->lock_type = lock_type;
	4727	+
3186	4728	/*
3187	4729	* No key, no joy, we need to hash something.
3188	4730	*/
3189	4731	if (DEBUG_LOCKS_WARN_ON(!key))
3190	4732	return;
3191	4733	/*
3192		- * Sanity check, the lock-class key must be persistent:
	4734	+ * Sanity check, the lock-class key must either have been allocated
	4735	+ * statically or must have been registered as a dynamic key.
3193	4736	*/
3194		- if (!static_obj(key)) {
3195		- printk("BUG: key %px not in .data!\n", key);
3196		- /*
3197		- * What it says above ^^^^^, I suggest you read it.
3198		- */
	4737	+ if (!static_obj(key) && !is_dynamic_key(key)) {
	4738	+ if (debug_locks)
	4739	+ printk(KERN_ERR "BUG: key %px has not been registered!\n", key);
3199	4740	DEBUG_LOCKS_WARN_ON(1);
3200	4741	return;
3201	4742	}
..	..	@@ -3207,36 +4748,30 @@
3207	4748	if (subclass) {
3208	4749	unsigned long flags;
3209	4750
3210		- if (DEBUG_LOCKS_WARN_ON(current->lockdep_recursion))
	4751	+ if (DEBUG_LOCKS_WARN_ON(!lockdep_enabled()))
3211	4752	return;
3212	4753
3213	4754	raw_local_irq_save(flags);
3214		- current->lockdep_recursion = 1;
	4755	+ lockdep_recursion_inc();
3215	4756	register_lock_class(lock, subclass, 1);
3216		- current->lockdep_recursion = 0;
	4757	+ lockdep_recursion_finish();
3217	4758	raw_local_irq_restore(flags);
3218	4759	}
3219	4760	}
3220		-
3221		-void lockdep_init_map(struct lockdep_map lock, const char name,
3222		- struct lock_class_key *key, int subclass)
3223		-{
3224		- __lockdep_init_map(lock, name, key, subclass);
3225		-}
3226		-EXPORT_SYMBOL_GPL(lockdep_init_map);
	4761	+EXPORT_SYMBOL_GPL(lockdep_init_map_type);
3227	4762
3228	4763	struct lock_class_key __lockdep_no_validate__;
3229	4764	EXPORT_SYMBOL_GPL(__lockdep_no_validate__);
3230	4765
3231		-static int
	4766	+static void
3232	4767	print_lock_nested_lock_not_held(struct task_struct *curr,
3233	4768	struct held_lock *hlock,
3234	4769	unsigned long ip)
3235	4770	{
3236	4771	if (!debug_locks_off())
3237		- return 0;
	4772	+ return;
3238	4773	if (debug_locks_silent)
3239		- return 0;
	4774	+ return;
3240	4775
3241	4776	pr_warn("\n");
3242	4777	pr_warn("==================================\n");
..	..	@@ -3258,8 +4793,6 @@
3258	4793
3259	4794	pr_warn("\nstack backtrace:\n");
3260	4795	dump_stack();
3261		-
3262		- return 0;
3263	4796	}
3264	4797
3265	4798	static int __lock_is_held(const struct lockdep_map *lock, int read);
..	..	@@ -3267,6 +4800,10 @@
3267	4800	/*
3268	4801	* This gets called for every mutex_lock()/spin_lock() operation.
3269	4802	* We maintain the dependency maps and validate the locking attempt:
	4803	+ *
	4804	+ * The callers must make sure that IRQs are disabled before calling it,
	4805	+ * otherwise we could get an interrupt which would want to take locks,
	4806	+ * which would end up in lockdep again.
3270	4807	*/
3271	4808	static int __lock_acquire(struct lockdep_map *lock, unsigned int subclass,
3272	4809	int trylock, int read, int check, int hardirqs_off,
..	..	@@ -3284,14 +4821,6 @@
3284	4821	if (unlikely(!debug_locks))
3285	4822	return 0;
3286	4823
3287		- /*
3288		- * Lockdep should run with IRQs disabled, otherwise we could
3289		- * get an interrupt which would want to take locks, which would
3290		- * end up in lockdep and have you got a head-ache already?
3291		- */
3292		- if (DEBUG_LOCKS_WARN_ON(!irqs_disabled()))
3293		- return 0;
3294		-
3295	4824	if (!prove_locking \|\| lock->key == &__lockdep_no_validate__)
3296	4825	check = 0;
3297	4826
..	..	@@ -3305,7 +4834,9 @@
3305	4834	if (!class)
3306	4835	return 0;
3307	4836	}
3308		- atomic_inc((atomic_t *)&class->ops);
	4837	+
	4838	+ debug_class_ops_inc(class);
	4839	+
3309	4840	if (very_verbose(class)) {
3310	4841	printk("\nacquire class [%px] %s", class->key, class->name);
3311	4842	if (class->name_version > 1)
..	..	@@ -3326,9 +4857,9 @@
3326	4857	if (DEBUG_LOCKS_WARN_ON(depth >= MAX_LOCK_DEPTH))
3327	4858	return 0;
3328	4859
3329		- class_idx = class - lock_classes + 1;
	4860	+ class_idx = class - lock_classes;
3330	4861
3331		- if (depth) {
	4862	+ if (depth) { /* we're holding locks */
3332	4863	hlock = curr->held_locks + depth - 1;
3333	4864	if (hlock->class_idx == class_idx && nest_lock) {
3334	4865	if (!references)
..	..	@@ -3343,7 +4874,7 @@
3343	4874	if (DEBUG_LOCKS_WARN_ON(hlock->references < references))
3344	4875	return 0;
3345	4876
3346		- return 1;
	4877	+ return 2;
3347	4878	}
3348	4879	}
3349	4880
..	..	@@ -3370,11 +4901,11 @@
3370	4901	#endif
3371	4902	hlock->pin_count = pin_count;
3372	4903
3373		- if (check && !mark_irqflags(curr, hlock))
	4904	+ if (check_wait_context(curr, hlock))
3374	4905	return 0;
3375	4906
3376		- /* mark it as used: */
3377		- if (!mark_lock(curr, hlock, LOCK_USED))
	4907	+ /* Initialize the lock usage bit */
	4908	+ if (!mark_usage(curr, hlock, check))
3378	4909	return 0;
3379	4910
3380	4911	/*
..	..	@@ -3388,9 +4919,9 @@
3388	4919	* the hash, not class->key.
3389	4920	*/
3390	4921	/*
3391		- * Whoops, we did it again.. ran straight out of our static allocation.
	4922	+ * Whoops, we did it again.. class_idx is invalid.
3392	4923	*/
3393		- if (DEBUG_LOCKS_WARN_ON(class_idx > MAX_LOCKDEP_KEYS))
	4924	+ if (DEBUG_LOCKS_WARN_ON(!test_bit(class_idx, lock_classes_in_use)))
3394	4925	return 0;
3395	4926
3396	4927	chain_key = curr->curr_chain_key;
..	..	@@ -3398,22 +4929,29 @@
3398	4929	/*
3399	4930	* How can we have a chain hash when we ain't got no keys?!
3400	4931	*/
3401		- if (DEBUG_LOCKS_WARN_ON(chain_key != 0))
	4932	+ if (DEBUG_LOCKS_WARN_ON(chain_key != INITIAL_CHAIN_KEY))
3402	4933	return 0;
3403	4934	chain_head = 1;
3404	4935	}
3405	4936
3406	4937	hlock->prev_chain_key = chain_key;
3407	4938	if (separate_irq_context(curr, hlock)) {
3408		- chain_key = 0;
	4939	+ chain_key = INITIAL_CHAIN_KEY;
3409	4940	chain_head = 1;
3410	4941	}
3411		- chain_key = iterate_chain_key(chain_key, class_idx);
	4942	+ chain_key = iterate_chain_key(chain_key, hlock_id(hlock));
3412	4943
3413		- if (nest_lock && !__lock_is_held(nest_lock, -1))
3414		- return print_lock_nested_lock_not_held(curr, hlock, ip);
	4944	+ if (nest_lock && !__lock_is_held(nest_lock, -1)) {
	4945	+ print_lock_nested_lock_not_held(curr, hlock, ip);
	4946	+ return 0;
	4947	+ }
3415	4948
3416		- if (!validate_chain(curr, lock, hlock, chain_head, chain_key))
	4949	+ if (!debug_locks_silent) {
	4950	+ WARN_ON_ONCE(depth && !hlock_class(hlock - 1)->key);
	4951	+ WARN_ON_ONCE(!hlock_class(hlock)->key);
	4952	+ }
	4953	+
	4954	+ if (!validate_chain(curr, hlock, chain_head, chain_key))
3417	4955	return 0;
3418	4956
3419	4957	curr->curr_chain_key = chain_key;
..	..	@@ -3442,14 +4980,14 @@
3442	4980	return 1;
3443	4981	}
3444	4982
3445		-static int
3446		-print_unlock_imbalance_bug(struct task_struct curr, struct lockdep_map lock,
3447		- unsigned long ip)
	4983	+static void print_unlock_imbalance_bug(struct task_struct *curr,
	4984	+ struct lockdep_map *lock,
	4985	+ unsigned long ip)
3448	4986	{
3449	4987	if (!debug_locks_off())
3450		- return 0;
	4988	+ return;
3451	4989	if (debug_locks_silent)
3452		- return 0;
	4990	+ return;
3453	4991
3454	4992	pr_warn("\n");
3455	4993	pr_warn("=====================================\n");
..	..	@@ -3460,19 +4998,17 @@
3460	4998	curr->comm, task_pid_nr(curr));
3461	4999	print_lockdep_cache(lock);
3462	5000	pr_cont(") at:\n");
3463		- print_ip_sym(ip);
	5001	+ print_ip_sym(KERN_WARNING, ip);
3464	5002	pr_warn("but there are no more locks to release!\n");
3465	5003	pr_warn("\nother info that might help us debug this:\n");
3466	5004	lockdep_print_held_locks(curr);
3467	5005
3468	5006	pr_warn("\nstack backtrace:\n");
3469	5007	dump_stack();
3470		-
3471		- return 0;
3472	5008	}
3473	5009
3474		-static int match_held_lock(const struct held_lock *hlock,
3475		- const struct lockdep_map *lock)
	5010	+static noinstr int match_held_lock(const struct held_lock *hlock,
	5011	+ const struct lockdep_map *lock)
3476	5012	{
3477	5013	if (hlock->instance == lock)
3478	5014	return 1;
..	..	@@ -3500,7 +5036,7 @@
3500	5036	if (DEBUG_LOCKS_WARN_ON(!hlock->nest_lock))
3501	5037	return 0;
3502	5038
3503		- if (hlock->class_idx == class - lock_classes + 1)
	5039	+ if (hlock->class_idx == class - lock_classes)
3504	5040	return 1;
3505	5041	}
3506	5042
..	..	@@ -3544,19 +5080,33 @@
3544	5080	}
3545	5081
3546	5082	static int reacquire_held_locks(struct task_struct *curr, unsigned int depth,
3547		- int idx)
	5083	+ int idx, unsigned int *merged)
3548	5084	{
3549	5085	struct held_lock *hlock;
	5086	+ int first_idx = idx;
	5087	+
	5088	+ if (DEBUG_LOCKS_WARN_ON(!irqs_disabled()))
	5089	+ return 0;
3550	5090
3551	5091	for (hlock = curr->held_locks + idx; idx < depth; idx++, hlock++) {
3552		- if (!__lock_acquire(hlock->instance,
	5092	+ switch (__lock_acquire(hlock->instance,
3553	5093	hlock_class(hlock)->subclass,
3554	5094	hlock->trylock,
3555	5095	hlock->read, hlock->check,
3556	5096	hlock->hardirqs_off,
3557	5097	hlock->nest_lock, hlock->acquire_ip,
3558		- hlock->references, hlock->pin_count))
	5098	+ hlock->references, hlock->pin_count)) {
	5099	+ case 0:
3559	5100	return 1;
	5101	+ case 1:
	5102	+ break;
	5103	+ case 2:
	5104	+ *merged += (idx == first_idx);
	5105	+ break;
	5106	+ default:
	5107	+ WARN_ON(1);
	5108	+ return 0;
	5109	+ }
3560	5110	}
3561	5111	return 0;
3562	5112	}
..	..	@@ -3567,47 +5117,9 @@
3567	5117	unsigned long ip)
3568	5118	{
3569	5119	struct task_struct *curr = current;
	5120	+ unsigned int depth, merged = 0;
3570	5121	struct held_lock *hlock;
3571	5122	struct lock_class *class;
3572		- unsigned int depth;
3573		- int i;
3574		-
3575		- depth = curr->lockdep_depth;
3576		- /*
3577		- * This function is about (re)setting the class of a held lock,
3578		- * yet we're not actually holding any locks. Naughty user!
3579		- */
3580		- if (DEBUG_LOCKS_WARN_ON(!depth))
3581		- return 0;
3582		-
3583		- hlock = find_held_lock(curr, lock, depth, &i);
3584		- if (!hlock)
3585		- return print_unlock_imbalance_bug(curr, lock, ip);
3586		-
3587		- lockdep_init_map(lock, name, key, 0);
3588		- class = register_lock_class(lock, subclass, 0);
3589		- hlock->class_idx = class - lock_classes + 1;
3590		-
3591		- curr->lockdep_depth = i;
3592		- curr->curr_chain_key = hlock->prev_chain_key;
3593		-
3594		- if (reacquire_held_locks(curr, depth, i))
3595		- return 0;
3596		-
3597		- /*
3598		- * I took it apart and put it back together again, except now I have
3599		- * these 'spare' parts.. where shall I put them.
3600		- */
3601		- if (DEBUG_LOCKS_WARN_ON(curr->lockdep_depth != depth))
3602		- return 0;
3603		- return 1;
3604		-}
3605		-
3606		-static int __lock_downgrade(struct lockdep_map *lock, unsigned long ip)
3607		-{
3608		- struct task_struct *curr = current;
3609		- struct held_lock *hlock;
3610		- unsigned int depth;
3611	5123	int i;
3612	5124
3613	5125	if (unlikely(!debug_locks))
..	..	@@ -3622,8 +5134,56 @@
3622	5134	return 0;
3623	5135
3624	5136	hlock = find_held_lock(curr, lock, depth, &i);
3625		- if (!hlock)
3626		- return print_unlock_imbalance_bug(curr, lock, ip);
	5137	+ if (!hlock) {
	5138	+ print_unlock_imbalance_bug(curr, lock, ip);
	5139	+ return 0;
	5140	+ }
	5141	+
	5142	+ lockdep_init_map_type(lock, name, key, 0,
	5143	+ lock->wait_type_inner,
	5144	+ lock->wait_type_outer,
	5145	+ lock->lock_type);
	5146	+ class = register_lock_class(lock, subclass, 0);
	5147	+ hlock->class_idx = class - lock_classes;
	5148	+
	5149	+ curr->lockdep_depth = i;
	5150	+ curr->curr_chain_key = hlock->prev_chain_key;
	5151	+
	5152	+ if (reacquire_held_locks(curr, depth, i, &merged))
	5153	+ return 0;
	5154	+
	5155	+ /*
	5156	+ * I took it apart and put it back together again, except now I have
	5157	+ * these 'spare' parts.. where shall I put them.
	5158	+ */
	5159	+ if (DEBUG_LOCKS_WARN_ON(curr->lockdep_depth != depth - merged))
	5160	+ return 0;
	5161	+ return 1;
	5162	+}
	5163	+
	5164	+static int __lock_downgrade(struct lockdep_map *lock, unsigned long ip)
	5165	+{
	5166	+ struct task_struct *curr = current;
	5167	+ unsigned int depth, merged = 0;
	5168	+ struct held_lock *hlock;
	5169	+ int i;
	5170	+
	5171	+ if (unlikely(!debug_locks))
	5172	+ return 0;
	5173	+
	5174	+ depth = curr->lockdep_depth;
	5175	+ /*
	5176	+ * This function is about (re)setting the class of a held lock,
	5177	+ * yet we're not actually holding any locks. Naughty user!
	5178	+ */
	5179	+ if (DEBUG_LOCKS_WARN_ON(!depth))
	5180	+ return 0;
	5181	+
	5182	+ hlock = find_held_lock(curr, lock, depth, &i);
	5183	+ if (!hlock) {
	5184	+ print_unlock_imbalance_bug(curr, lock, ip);
	5185	+ return 0;
	5186	+ }
3627	5187
3628	5188	curr->lockdep_depth = i;
3629	5189	curr->curr_chain_key = hlock->prev_chain_key;
..	..	@@ -3632,7 +5192,11 @@
3632	5192	hlock->read = 1;
3633	5193	hlock->acquire_ip = ip;
3634	5194
3635		- if (reacquire_held_locks(curr, depth, i))
	5195	+ if (reacquire_held_locks(curr, depth, i, &merged))
	5196	+ return 0;
	5197	+
	5198	+ /* Merging can't happen with unchanged classes.. */
	5199	+ if (DEBUG_LOCKS_WARN_ON(merged))
3636	5200	return 0;
3637	5201
3638	5202	/*
..	..	@@ -3641,22 +5205,21 @@
3641	5205	*/
3642	5206	if (DEBUG_LOCKS_WARN_ON(curr->lockdep_depth != depth))
3643	5207	return 0;
	5208	+
3644	5209	return 1;
3645	5210	}
3646	5211
3647	5212	/*
3648		- * Remove the lock to the list of currently held locks - this gets
	5213	+ * Remove the lock from the list of currently held locks - this gets
3649	5214	* called on mutex_unlock()/spin_unlock*() (or on a failed
3650	5215	* mutex_lock_interruptible()).
3651		- *
3652		- * @nested is an hysterical artifact, needs a tree wide cleanup.
3653	5216	*/
3654	5217	static int
3655		-__lock_release(struct lockdep_map *lock, int nested, unsigned long ip)
	5218	+__lock_release(struct lockdep_map *lock, unsigned long ip)
3656	5219	{
3657	5220	struct task_struct *curr = current;
	5221	+ unsigned int depth, merged = 1;
3658	5222	struct held_lock *hlock;
3659		- unsigned int depth;
3660	5223	int i;
3661	5224
3662	5225	if (unlikely(!debug_locks))
..	..	@@ -3667,16 +5230,20 @@
3667	5230	* So we're all set to release this lock.. wait what lock? We don't
3668	5231	* own any locks, you've been drinking again?
3669	5232	*/
3670		- if (DEBUG_LOCKS_WARN_ON(depth <= 0))
3671		- return print_unlock_imbalance_bug(curr, lock, ip);
	5233	+ if (depth <= 0) {
	5234	+ print_unlock_imbalance_bug(curr, lock, ip);
	5235	+ return 0;
	5236	+ }
3672	5237
3673	5238	/*
3674	5239	* Check whether the lock exists in the current stack
3675	5240	* of held locks:
3676	5241	*/
3677	5242	hlock = find_held_lock(curr, lock, depth, &i);
3678		- if (!hlock)
3679		- return print_unlock_imbalance_bug(curr, lock, ip);
	5243	+ if (!hlock) {
	5244	+ print_unlock_imbalance_bug(curr, lock, ip);
	5245	+ return 0;
	5246	+ }
3680	5247
3681	5248	if (hlock->instance == lock)
3682	5249	lock_release_holdtime(hlock);
..	..	@@ -3704,20 +5271,33 @@
3704	5271	curr->lockdep_depth = i;
3705	5272	curr->curr_chain_key = hlock->prev_chain_key;
3706	5273
3707		- if (reacquire_held_locks(curr, depth, i + 1))
	5274	+ /*
	5275	+ * The most likely case is when the unlock is on the innermost
	5276	+ * lock. In this case, we are done!
	5277	+ */
	5278	+ if (i == depth-1)
	5279	+ return 1;
	5280	+
	5281	+ if (reacquire_held_locks(curr, depth, i + 1, &merged))
3708	5282	return 0;
3709	5283
3710	5284	/*
3711	5285	* We had N bottles of beer on the wall, we drank one, but now
3712	5286	* there's not N-1 bottles of beer left on the wall...
	5287	+ * Pouring two of the bottles together is acceptable.
3713	5288	*/
3714		- if (DEBUG_LOCKS_WARN_ON(curr->lockdep_depth != depth - 1))
3715		- return 0;
	5289	+ DEBUG_LOCKS_WARN_ON(curr->lockdep_depth != depth - merged);
3716	5290
3717		- return 1;
	5291	+ /*
	5292	+ * Since reacquire_held_locks() would have called check_chain_key()
	5293	+ * indirectly via __lock_acquire(), we don't need to do it again
	5294	+ * on return.
	5295	+ */
	5296	+ return 0;
3718	5297	}
3719	5298
3720		-static int __lock_is_held(const struct lockdep_map *lock, int read)
	5299	+static __always_inline
	5300	+int __lock_is_held(const struct lockdep_map *lock, int read)
3721	5301	{
3722	5302	struct task_struct *curr = current;
3723	5303	int i;
..	..	@@ -3726,7 +5306,7 @@
3726	5306	struct held_lock *hlock = curr->held_locks + i;
3727	5307
3728	5308	if (match_held_lock(hlock, lock)) {
3729		- if (read == -1 \|\| hlock->read == read)
	5309	+ if (read == -1 \|\| !!hlock->read == read)
3730	5310	return 1;
3731	5311
3732	5312	return 0;
..	..	@@ -3814,19 +5394,21 @@
3814	5394	/*
3815	5395	* Check whether we follow the irq-flags state precisely:
3816	5396	*/
3817		-static void check_flags(unsigned long flags)
	5397	+static noinstr void check_flags(unsigned long flags)
3818	5398	{
3819		-#if defined(CONFIG_PROVE_LOCKING) && defined(CONFIG_DEBUG_LOCKDEP) && \
3820		- defined(CONFIG_TRACE_IRQFLAGS)
	5399	+#if defined(CONFIG_PROVE_LOCKING) && defined(CONFIG_DEBUG_LOCKDEP)
3821	5400	if (!debug_locks)
3822	5401	return;
3823	5402
	5403	+ /* Get the warning out.. */
	5404	+ instrumentation_begin();
	5405	+
3824	5406	if (irqs_disabled_flags(flags)) {
3825		- if (DEBUG_LOCKS_WARN_ON(current->hardirqs_enabled)) {
	5407	+ if (DEBUG_LOCKS_WARN_ON(lockdep_hardirqs_enabled())) {
3826	5408	printk("possible reason: unannotated irqs-off.\n");
3827	5409	}
3828	5410	} else {
3829		- if (DEBUG_LOCKS_WARN_ON(!current->hardirqs_enabled)) {
	5411	+ if (DEBUG_LOCKS_WARN_ON(!lockdep_hardirqs_enabled())) {
3830	5412	printk("possible reason: unannotated irqs-on.\n");
3831	5413	}
3832	5414	}
..	..	@@ -3848,6 +5430,8 @@
3848	5430
3849	5431	if (!debug_locks)
3850	5432	print_irqtrace_events(current);
	5433	+
	5434	+ instrumentation_end();
3851	5435	#endif
3852	5436	}
3853	5437
..	..	@@ -3857,15 +5441,15 @@
3857	5441	{
3858	5442	unsigned long flags;
3859	5443
3860		- if (unlikely(current->lockdep_recursion))
	5444	+ if (unlikely(!lockdep_enabled()))
3861	5445	return;
3862	5446
3863	5447	raw_local_irq_save(flags);
3864		- current->lockdep_recursion = 1;
	5448	+ lockdep_recursion_inc();
3865	5449	check_flags(flags);
3866	5450	if (__lock_set_class(lock, name, key, subclass, ip))
3867	5451	check_chain_key(current);
3868		- current->lockdep_recursion = 0;
	5452	+ lockdep_recursion_finish();
3869	5453	raw_local_irq_restore(flags);
3870	5454	}
3871	5455	EXPORT_SYMBOL_GPL(lock_set_class);
..	..	@@ -3874,18 +5458,70 @@
3874	5458	{
3875	5459	unsigned long flags;
3876	5460
3877		- if (unlikely(current->lockdep_recursion))
	5461	+ if (unlikely(!lockdep_enabled()))
3878	5462	return;
3879	5463
3880	5464	raw_local_irq_save(flags);
3881		- current->lockdep_recursion = 1;
	5465	+ lockdep_recursion_inc();
3882	5466	check_flags(flags);
3883	5467	if (__lock_downgrade(lock, ip))
3884	5468	check_chain_key(current);
3885		- current->lockdep_recursion = 0;
	5469	+ lockdep_recursion_finish();
3886	5470	raw_local_irq_restore(flags);
3887	5471	}
3888	5472	EXPORT_SYMBOL_GPL(lock_downgrade);
	5473	+
	5474	+/* NMI context !!! */
	5475	+static void verify_lock_unused(struct lockdep_map lock, struct held_lock hlock, int subclass)
	5476	+{
	5477	+#ifdef CONFIG_PROVE_LOCKING
	5478	+ struct lock_class *class = look_up_lock_class(lock, subclass);
	5479	+ unsigned long mask = LOCKF_USED;
	5480	+
	5481	+ /* if it doesn't have a class (yet), it certainly hasn't been used yet */
	5482	+ if (!class)
	5483	+ return;
	5484	+
	5485	+ /*
	5486	+ * READ locks only conflict with USED, such that if we only ever use
	5487	+ * READ locks, there is no deadlock possible -- RCU.
	5488	+ */
	5489	+ if (!hlock->read)
	5490	+ mask \|= LOCKF_USED_READ;
	5491	+
	5492	+ if (!(class->usage_mask & mask))
	5493	+ return;
	5494	+
	5495	+ hlock->class_idx = class - lock_classes;
	5496	+
	5497	+ print_usage_bug(current, hlock, LOCK_USED, LOCK_USAGE_STATES);
	5498	+#endif
	5499	+}
	5500	+
	5501	+static bool lockdep_nmi(void)
	5502	+{
	5503	+ if (raw_cpu_read(lockdep_recursion))
	5504	+ return false;
	5505	+
	5506	+ if (!in_nmi())
	5507	+ return false;
	5508	+
	5509	+ return true;
	5510	+}
	5511	+
	5512	+/*
	5513	+ * read_lock() is recursive if:
	5514	+ * 1. We force lockdep think this way in selftests or
	5515	+ * 2. The implementation is not queued read/write lock or
	5516	+ * 3. The locker is at an in_interrupt() context.
	5517	+ */
	5518	+bool read_lock_is_recursive(void)
	5519	+{
	5520	+ return force_read_lock_recursive \|\|
	5521	+ !IS_ENABLED(CONFIG_QUEUED_RWLOCKS) \|\|
	5522	+ in_interrupt();
	5523	+}
	5524	+EXPORT_SYMBOL_GPL(read_lock_is_recursive);
3889	5525
3890	5526	/*
3891	5527	* We are not always called with irqs disabled - do that here,
..	..	@@ -3897,74 +5533,97 @@
3897	5533	{
3898	5534	unsigned long flags;
3899	5535
3900		- if (unlikely(current->lockdep_recursion))
	5536	+ trace_lock_acquire(lock, subclass, trylock, read, check, nest_lock, ip);
	5537	+
	5538	+ if (!debug_locks)
3901	5539	return;
	5540	+
	5541	+ if (unlikely(!lockdep_enabled())) {
	5542	+ /* XXX allow trylock from NMI ?!? */
	5543	+ if (lockdep_nmi() && !trylock) {
	5544	+ struct held_lock hlock;
	5545	+
	5546	+ hlock.acquire_ip = ip;
	5547	+ hlock.instance = lock;
	5548	+ hlock.nest_lock = nest_lock;
	5549	+ hlock.irq_context = 2; // XXX
	5550	+ hlock.trylock = trylock;
	5551	+ hlock.read = read;
	5552	+ hlock.check = check;
	5553	+ hlock.hardirqs_off = true;
	5554	+ hlock.references = 0;
	5555	+
	5556	+ verify_lock_unused(lock, &hlock, subclass);
	5557	+ }
	5558	+ return;
	5559	+ }
3902	5560
3903	5561	raw_local_irq_save(flags);
3904	5562	check_flags(flags);
3905	5563
3906		- current->lockdep_recursion = 1;
3907		- trace_lock_acquire(lock, subclass, trylock, read, check, nest_lock, ip);
	5564	+ lockdep_recursion_inc();
3908	5565	__lock_acquire(lock, subclass, trylock, read, check,
3909	5566	irqs_disabled_flags(flags), nest_lock, ip, 0, 0);
3910		- current->lockdep_recursion = 0;
	5567	+ lockdep_recursion_finish();
3911	5568	raw_local_irq_restore(flags);
3912	5569	}
3913	5570	EXPORT_SYMBOL_GPL(lock_acquire);
3914	5571
3915		-void lock_release(struct lockdep_map *lock, int nested,
3916		- unsigned long ip)
	5572	+void lock_release(struct lockdep_map *lock, unsigned long ip)
3917	5573	{
3918	5574	unsigned long flags;
3919	5575
3920		- if (unlikely(current->lockdep_recursion))
	5576	+ trace_lock_release(lock, ip);
	5577	+
	5578	+ if (unlikely(!lockdep_enabled()))
3921	5579	return;
3922	5580
3923	5581	raw_local_irq_save(flags);
3924	5582	check_flags(flags);
3925		- current->lockdep_recursion = 1;
3926		- trace_lock_release(lock, ip);
3927		- if (__lock_release(lock, nested, ip))
	5583	+
	5584	+ lockdep_recursion_inc();
	5585	+ if (__lock_release(lock, ip))
3928	5586	check_chain_key(current);
3929		- current->lockdep_recursion = 0;
	5587	+ lockdep_recursion_finish();
3930	5588	raw_local_irq_restore(flags);
3931	5589	}
3932	5590	EXPORT_SYMBOL_GPL(lock_release);
3933	5591
3934		-int lock_is_held_type(const struct lockdep_map *lock, int read)
	5592	+noinstr int lock_is_held_type(const struct lockdep_map *lock, int read)
3935	5593	{
3936	5594	unsigned long flags;
3937	5595	int ret = 0;
3938	5596
3939		- if (unlikely(current->lockdep_recursion))
	5597	+ if (unlikely(!lockdep_enabled()))
3940	5598	return 1; /* avoid false negative lockdep_assert_held() */
3941	5599
3942	5600	raw_local_irq_save(flags);
3943	5601	check_flags(flags);
3944	5602
3945		- current->lockdep_recursion = 1;
	5603	+ lockdep_recursion_inc();
3946	5604	ret = __lock_is_held(lock, read);
3947		- current->lockdep_recursion = 0;
	5605	+ lockdep_recursion_finish();
3948	5606	raw_local_irq_restore(flags);
3949	5607
3950	5608	return ret;
3951	5609	}
3952	5610	EXPORT_SYMBOL_GPL(lock_is_held_type);
	5611	+NOKPROBE_SYMBOL(lock_is_held_type);
3953	5612
3954	5613	struct pin_cookie lock_pin_lock(struct lockdep_map *lock)
3955	5614	{
3956	5615	struct pin_cookie cookie = NIL_COOKIE;
3957	5616	unsigned long flags;
3958	5617
3959		- if (unlikely(current->lockdep_recursion))
	5618	+ if (unlikely(!lockdep_enabled()))
3960	5619	return cookie;
3961	5620
3962	5621	raw_local_irq_save(flags);
3963	5622	check_flags(flags);
3964	5623
3965		- current->lockdep_recursion = 1;
	5624	+ lockdep_recursion_inc();
3966	5625	cookie = __lock_pin_lock(lock);
3967		- current->lockdep_recursion = 0;
	5626	+ lockdep_recursion_finish();
3968	5627	raw_local_irq_restore(flags);
3969	5628
3970	5629	return cookie;
..	..	@@ -3975,15 +5634,15 @@
3975	5634	{
3976	5635	unsigned long flags;
3977	5636
3978		- if (unlikely(current->lockdep_recursion))
	5637	+ if (unlikely(!lockdep_enabled()))
3979	5638	return;
3980	5639
3981	5640	raw_local_irq_save(flags);
3982	5641	check_flags(flags);
3983	5642
3984		- current->lockdep_recursion = 1;
	5643	+ lockdep_recursion_inc();
3985	5644	__lock_repin_lock(lock, cookie);
3986		- current->lockdep_recursion = 0;
	5645	+ lockdep_recursion_finish();
3987	5646	raw_local_irq_restore(flags);
3988	5647	}
3989	5648	EXPORT_SYMBOL_GPL(lock_repin_lock);
..	..	@@ -3992,28 +5651,28 @@
3992	5651	{
3993	5652	unsigned long flags;
3994	5653
3995		- if (unlikely(current->lockdep_recursion))
	5654	+ if (unlikely(!lockdep_enabled()))
3996	5655	return;
3997	5656
3998	5657	raw_local_irq_save(flags);
3999	5658	check_flags(flags);
4000	5659
4001		- current->lockdep_recursion = 1;
	5660	+ lockdep_recursion_inc();
4002	5661	__lock_unpin_lock(lock, cookie);
4003		- current->lockdep_recursion = 0;
	5662	+ lockdep_recursion_finish();
4004	5663	raw_local_irq_restore(flags);
4005	5664	}
4006	5665	EXPORT_SYMBOL_GPL(lock_unpin_lock);
4007	5666
4008	5667	#ifdef CONFIG_LOCK_STAT
4009		-static int
4010		-print_lock_contention_bug(struct task_struct curr, struct lockdep_map lock,
4011		- unsigned long ip)
	5668	+static void print_lock_contention_bug(struct task_struct *curr,
	5669	+ struct lockdep_map *lock,
	5670	+ unsigned long ip)
4012	5671	{
4013	5672	if (!debug_locks_off())
4014		- return 0;
	5673	+ return;
4015	5674	if (debug_locks_silent)
4016		- return 0;
	5675	+ return;
4017	5676
4018	5677	pr_warn("\n");
4019	5678	pr_warn("=================================\n");
..	..	@@ -4024,15 +5683,13 @@
4024	5683	curr->comm, task_pid_nr(curr));
4025	5684	print_lockdep_cache(lock);
4026	5685	pr_cont(") at:\n");
4027		- print_ip_sym(ip);
	5686	+ print_ip_sym(KERN_WARNING, ip);
4028	5687	pr_warn("but there are no locks held!\n");
4029	5688	pr_warn("\nother info that might help us debug this:\n");
4030	5689	lockdep_print_held_locks(curr);
4031	5690
4032	5691	pr_warn("\nstack backtrace:\n");
4033	5692	dump_stack();
4034		-
4035		- return 0;
4036	5693	}
4037	5694
4038	5695	static void
..	..	@@ -4110,8 +5767,6 @@
4110	5767	hlock->holdtime_stamp = now;
4111	5768	}
4112	5769
4113		- trace_lock_acquired(lock, ip);
4114		-
4115	5770	stats = get_lock_stats(hlock_class(hlock));
4116	5771	if (waittime) {
4117	5772	if (hlock->read)
..	..	@@ -4130,18 +5785,16 @@
4130	5785	{
4131	5786	unsigned long flags;
4132	5787
4133		- if (unlikely(!lock_stat \|\| !debug_locks))
4134		- return;
	5788	+ trace_lock_contended(lock, ip);
4135	5789
4136		- if (unlikely(current->lockdep_recursion))
	5790	+ if (unlikely(!lock_stat \|\| !lockdep_enabled()))
4137	5791	return;
4138	5792
4139	5793	raw_local_irq_save(flags);
4140	5794	check_flags(flags);
4141		- current->lockdep_recursion = 1;
4142		- trace_lock_contended(lock, ip);
	5795	+ lockdep_recursion_inc();
4143	5796	__lock_contended(lock, ip);
4144		- current->lockdep_recursion = 0;
	5797	+ lockdep_recursion_finish();
4145	5798	raw_local_irq_restore(flags);
4146	5799	}
4147	5800	EXPORT_SYMBOL_GPL(lock_contended);
..	..	@@ -4150,17 +5803,16 @@
4150	5803	{
4151	5804	unsigned long flags;
4152	5805
4153		- if (unlikely(!lock_stat \|\| !debug_locks))
4154		- return;
	5806	+ trace_lock_acquired(lock, ip);
4155	5807
4156		- if (unlikely(current->lockdep_recursion))
	5808	+ if (unlikely(!lock_stat \|\| !lockdep_enabled()))
4157	5809	return;
4158	5810
4159	5811	raw_local_irq_save(flags);
4160	5812	check_flags(flags);
4161		- current->lockdep_recursion = 1;
	5813	+ lockdep_recursion_inc();
4162	5814	__lock_acquired(lock, ip);
4163		- current->lockdep_recursion = 0;
	5815	+ lockdep_recursion_finish();
4164	5816	raw_local_irq_restore(flags);
4165	5817	}
4166	5818	EXPORT_SYMBOL_GPL(lock_acquired);
..	..	@@ -4177,9 +5829,7 @@
4177	5829	int i;
4178	5830
4179	5831	raw_local_irq_save(flags);
4180		- current->curr_chain_key = 0;
4181		- current->lockdep_depth = 0;
4182		- current->lockdep_recursion = 0;
	5832	+ lockdep_init_task(current);
4183	5833	memset(current->held_locks, 0, MAX_LOCK_DEPTH*sizeof(struct held_lock));
4184	5834	nr_hardirq_chains = 0;
4185	5835	nr_softirq_chains = 0;
..	..	@@ -4190,26 +5840,111 @@
4190	5840	raw_local_irq_restore(flags);
4191	5841	}
4192	5842
4193		-static void zap_class(struct lock_class *class)
	5843	+/* Remove a class from a lock chain. Must be called with the graph lock held. */
	5844	+static void remove_class_from_lock_chain(struct pending_free *pf,
	5845	+ struct lock_chain *chain,
	5846	+ struct lock_class *class)
4194	5847	{
	5848	+#ifdef CONFIG_PROVE_LOCKING
4195	5849	int i;
	5850	+
	5851	+ for (i = chain->base; i < chain->base + chain->depth; i++) {
	5852	+ if (chain_hlock_class_idx(chain_hlocks[i]) != class - lock_classes)
	5853	+ continue;
	5854	+ /*
	5855	+ * Each lock class occurs at most once in a lock chain so once
	5856	+ * we found a match we can break out of this loop.
	5857	+ */
	5858	+ goto free_lock_chain;
	5859	+ }
	5860	+ /* Since the chain has not been modified, return. */
	5861	+ return;
	5862	+
	5863	+free_lock_chain:
	5864	+ free_chain_hlocks(chain->base, chain->depth);
	5865	+ /* Overwrite the chain key for concurrent RCU readers. */
	5866	+ WRITE_ONCE(chain->chain_key, INITIAL_CHAIN_KEY);
	5867	+ dec_chains(chain->irq_context);
	5868	+
	5869	+ /*
	5870	+ * Note: calling hlist_del_rcu() from inside a
	5871	+ * hlist_for_each_entry_rcu() loop is safe.
	5872	+ */
	5873	+ hlist_del_rcu(&chain->entry);
	5874	+ __set_bit(chain - lock_chains, pf->lock_chains_being_freed);
	5875	+ nr_zapped_lock_chains++;
	5876	+#endif
	5877	+}
	5878	+
	5879	+/* Must be called with the graph lock held. */
	5880	+static void remove_class_from_lock_chains(struct pending_free *pf,
	5881	+ struct lock_class *class)
	5882	+{
	5883	+ struct lock_chain *chain;
	5884	+ struct hlist_head *head;
	5885	+ int i;
	5886	+
	5887	+ for (i = 0; i < ARRAY_SIZE(chainhash_table); i++) {
	5888	+ head = chainhash_table + i;
	5889	+ hlist_for_each_entry_rcu(chain, head, entry) {
	5890	+ remove_class_from_lock_chain(pf, chain, class);
	5891	+ }
	5892	+ }
	5893	+}
	5894	+
	5895	+/*
	5896	+ * Remove all references to a lock class. The caller must hold the graph lock.
	5897	+ */
	5898	+static void zap_class(struct pending_free pf, struct lock_class class)
	5899	+{
	5900	+ struct lock_list *entry;
	5901	+ int i;
	5902	+
	5903	+ WARN_ON_ONCE(!class->key);
4196	5904
4197	5905	/*
4198	5906	* Remove all dependencies this lock is
4199	5907	* involved in:
4200	5908	*/
4201		- for (i = 0; i < nr_list_entries; i++) {
4202		- if (list_entries[i].class == class)
4203		- list_del_rcu(&list_entries[i].entry);
	5909	+ for_each_set_bit(i, list_entries_in_use, ARRAY_SIZE(list_entries)) {
	5910	+ entry = list_entries + i;
	5911	+ if (entry->class != class && entry->links_to != class)
	5912	+ continue;
	5913	+ __clear_bit(i, list_entries_in_use);
	5914	+ nr_list_entries--;
	5915	+ list_del_rcu(&entry->entry);
4204	5916	}
4205		- /*
4206		- * Unhash the class and remove it from the all_lock_classes list:
4207		- */
4208		- hlist_del_rcu(&class->hash_entry);
4209		- list_del_rcu(&class->lock_entry);
	5917	+ if (list_empty(&class->locks_after) &&
	5918	+ list_empty(&class->locks_before)) {
	5919	+ list_move_tail(&class->lock_entry, &pf->zapped);
	5920	+ hlist_del_rcu(&class->hash_entry);
	5921	+ WRITE_ONCE(class->key, NULL);
	5922	+ WRITE_ONCE(class->name, NULL);
	5923	+ nr_lock_classes--;
	5924	+ __clear_bit(class - lock_classes, lock_classes_in_use);
	5925	+ if (class - lock_classes == max_lock_class_idx)
	5926	+ max_lock_class_idx--;
	5927	+ } else {
	5928	+ WARN_ONCE(true, "%s() failed for class %s\n", __func__,
	5929	+ class->name);
	5930	+ }
4210	5931
4211		- RCU_INIT_POINTER(class->key, NULL);
4212		- RCU_INIT_POINTER(class->name, NULL);
	5932	+ remove_class_from_lock_chains(pf, class);
	5933	+ nr_zapped_classes++;
	5934	+}
	5935	+
	5936	+static void reinit_class(struct lock_class *class)
	5937	+{
	5938	+ void *const p = class;
	5939	+ const unsigned int offset = offsetof(struct lock_class, key);
	5940	+
	5941	+ WARN_ON_ONCE(!class->lock_entry.next);
	5942	+ WARN_ON_ONCE(!list_empty(&class->locks_after));
	5943	+ WARN_ON_ONCE(!list_empty(&class->locks_before));
	5944	+ memset(p + offset, 0, sizeof(*class) - offset);
	5945	+ WARN_ON_ONCE(!class->lock_entry.next);
	5946	+ WARN_ON_ONCE(!list_empty(&class->locks_after));
	5947	+ WARN_ON_ONCE(!list_empty(&class->locks_before));
4213	5948	}
4214	5949
4215	5950	static inline int within(const void addr, void start, unsigned long size)
..	..	@@ -4217,66 +5952,197 @@
4217	5952	return addr >= start && addr < start + size;
4218	5953	}
4219	5954
	5955	+static bool inside_selftest(void)
	5956	+{
	5957	+ return current == lockdep_selftest_task_struct;
	5958	+}
	5959	+
	5960	+/* The caller must hold the graph lock. */
	5961	+static struct pending_free *get_pending_free(void)
	5962	+{
	5963	+ return delayed_free.pf + delayed_free.index;
	5964	+}
	5965	+
	5966	+static void free_zapped_rcu(struct rcu_head *cb);
	5967	+
	5968	+/*
	5969	+ * Schedule an RCU callback if no RCU callback is pending. Must be called with
	5970	+ * the graph lock held.
	5971	+ */
	5972	+static void call_rcu_zapped(struct pending_free *pf)
	5973	+{
	5974	+ WARN_ON_ONCE(inside_selftest());
	5975	+
	5976	+ if (list_empty(&pf->zapped))
	5977	+ return;
	5978	+
	5979	+ if (delayed_free.scheduled)
	5980	+ return;
	5981	+
	5982	+ delayed_free.scheduled = true;
	5983	+
	5984	+ WARN_ON_ONCE(delayed_free.pf + delayed_free.index != pf);
	5985	+ delayed_free.index ^= 1;
	5986	+
	5987	+ call_rcu(&delayed_free.rcu_head, free_zapped_rcu);
	5988	+}
	5989	+
	5990	+/* The caller must hold the graph lock. May be called from RCU context. */
	5991	+static void __free_zapped_classes(struct pending_free *pf)
	5992	+{
	5993	+ struct lock_class *class;
	5994	+
	5995	+ check_data_structures();
	5996	+
	5997	+ list_for_each_entry(class, &pf->zapped, lock_entry)
	5998	+ reinit_class(class);
	5999	+
	6000	+ list_splice_init(&pf->zapped, &free_lock_classes);
	6001	+
	6002	+#ifdef CONFIG_PROVE_LOCKING
	6003	+ bitmap_andnot(lock_chains_in_use, lock_chains_in_use,
	6004	+ pf->lock_chains_being_freed, ARRAY_SIZE(lock_chains));
	6005	+ bitmap_clear(pf->lock_chains_being_freed, 0, ARRAY_SIZE(lock_chains));
	6006	+#endif
	6007	+}
	6008	+
	6009	+static void free_zapped_rcu(struct rcu_head *ch)
	6010	+{
	6011	+ struct pending_free *pf;
	6012	+ unsigned long flags;
	6013	+
	6014	+ if (WARN_ON_ONCE(ch != &delayed_free.rcu_head))
	6015	+ return;
	6016	+
	6017	+ raw_local_irq_save(flags);
	6018	+ lockdep_lock();
	6019	+
	6020	+ /* closed head */
	6021	+ pf = delayed_free.pf + (delayed_free.index ^ 1);
	6022	+ __free_zapped_classes(pf);
	6023	+ delayed_free.scheduled = false;
	6024	+
	6025	+ /*
	6026	+ * If there's anything on the open list, close and start a new callback.
	6027	+ */
	6028	+ call_rcu_zapped(delayed_free.pf + delayed_free.index);
	6029	+
	6030	+ lockdep_unlock();
	6031	+ raw_local_irq_restore(flags);
	6032	+}
	6033	+
	6034	+/*
	6035	+ * Remove all lock classes from the class hash table and from the
	6036	+ * all_lock_classes list whose key or name is in the address range [start,
	6037	+ * start + size). Move these lock classes to the zapped_classes list. Must
	6038	+ * be called with the graph lock held.
	6039	+ */
	6040	+static void __lockdep_free_key_range(struct pending_free pf, void start,
	6041	+ unsigned long size)
	6042	+{
	6043	+ struct lock_class *class;
	6044	+ struct hlist_head *head;
	6045	+ int i;
	6046	+
	6047	+ /* Unhash all classes that were created by a module. */
	6048	+ for (i = 0; i < CLASSHASH_SIZE; i++) {
	6049	+ head = classhash_table + i;
	6050	+ hlist_for_each_entry_rcu(class, head, hash_entry) {
	6051	+ if (!within(class->key, start, size) &&
	6052	+ !within(class->name, start, size))
	6053	+ continue;
	6054	+ zap_class(pf, class);
	6055	+ }
	6056	+ }
	6057	+}
	6058	+
4220	6059	/*
4221	6060	* Used in module.c to remove lock classes from memory that is going to be
4222	6061	* freed; and possibly re-used by other modules.
4223	6062	*
4224		- * We will have had one sync_sched() before getting here, so we're guaranteed
4225		- * nobody will look up these exact classes -- they're properly dead but still
4226		- * allocated.
	6063	+ * We will have had one synchronize_rcu() before getting here, so we're
	6064	+ * guaranteed nobody will look up these exact classes -- they're properly dead
	6065	+ * but still allocated.
4227	6066	*/
4228		-void lockdep_free_key_range(void *start, unsigned long size)
	6067	+static void lockdep_free_key_range_reg(void *start, unsigned long size)
4229	6068	{
4230		- struct lock_class *class;
4231		- struct hlist_head *head;
	6069	+ struct pending_free *pf;
4232	6070	unsigned long flags;
4233		- int i;
4234		- int locked;
	6071	+
	6072	+ init_data_structures_once();
4235	6073
4236	6074	raw_local_irq_save(flags);
4237		- locked = graph_lock();
4238		-
4239		- /*
4240		- * Unhash all classes that were created by this module:
4241		- */
4242		- for (i = 0; i < CLASSHASH_SIZE; i++) {
4243		- head = classhash_table + i;
4244		- hlist_for_each_entry_rcu(class, head, hash_entry) {
4245		- if (within(class->key, start, size))
4246		- zap_class(class);
4247		- else if (within(class->name, start, size))
4248		- zap_class(class);
4249		- }
4250		- }
4251		-
4252		- if (locked)
4253		- graph_unlock();
	6075	+ lockdep_lock();
	6076	+ pf = get_pending_free();
	6077	+ __lockdep_free_key_range(pf, start, size);
	6078	+ call_rcu_zapped(pf);
	6079	+ lockdep_unlock();
4254	6080	raw_local_irq_restore(flags);
4255	6081
4256	6082	/*
4257	6083	* Wait for any possible iterators from look_up_lock_class() to pass
4258	6084	* before continuing to free the memory they refer to.
4259		- *
4260		- * sync_sched() is sufficient because the read-side is IRQ disable.
4261	6085	*/
4262		- synchronize_sched();
4263		-
4264		- /*
4265		- * XXX at this point we could return the resources to the pool;
4266		- * instead we leak them. We would need to change to bitmap allocators
4267		- * instead of the linear allocators we have now.
4268		- */
	6086	+ synchronize_rcu();
4269	6087	}
4270	6088
4271		-void lockdep_reset_lock(struct lockdep_map *lock)
	6089	+/*
	6090	+ * Free all lockdep keys in the range [start, start+size). Does not sleep.
	6091	+ * Ignores debug_locks. Must only be used by the lockdep selftests.
	6092	+ */
	6093	+static void lockdep_free_key_range_imm(void *start, unsigned long size)
	6094	+{
	6095	+ struct pending_free *pf = delayed_free.pf;
	6096	+ unsigned long flags;
	6097	+
	6098	+ init_data_structures_once();
	6099	+
	6100	+ raw_local_irq_save(flags);
	6101	+ lockdep_lock();
	6102	+ __lockdep_free_key_range(pf, start, size);
	6103	+ __free_zapped_classes(pf);
	6104	+ lockdep_unlock();
	6105	+ raw_local_irq_restore(flags);
	6106	+}
	6107	+
	6108	+void lockdep_free_key_range(void *start, unsigned long size)
	6109	+{
	6110	+ init_data_structures_once();
	6111	+
	6112	+ if (inside_selftest())
	6113	+ lockdep_free_key_range_imm(start, size);
	6114	+ else
	6115	+ lockdep_free_key_range_reg(start, size);
	6116	+}
	6117	+
	6118	+/*
	6119	+ * Check whether any element of the @lock->class_cache[] array refers to a
	6120	+ * registered lock class. The caller must hold either the graph lock or the
	6121	+ * RCU read lock.
	6122	+ */
	6123	+static bool lock_class_cache_is_registered(struct lockdep_map *lock)
4272	6124	{
4273	6125	struct lock_class *class;
4274	6126	struct hlist_head *head;
4275		- unsigned long flags;
4276	6127	int i, j;
4277		- int locked;
4278	6128
4279		- raw_local_irq_save(flags);
	6129	+ for (i = 0; i < CLASSHASH_SIZE; i++) {
	6130	+ head = classhash_table + i;
	6131	+ hlist_for_each_entry_rcu(class, head, hash_entry) {
	6132	+ for (j = 0; j < NR_LOCKDEP_CACHING_CLASSES; j++)
	6133	+ if (lock->class_cache[j] == class)
	6134	+ return true;
	6135	+ }
	6136	+ }
	6137	+ return false;
	6138	+}
	6139	+
	6140	+/* The caller must hold the graph lock. Does not sleep. */
	6141	+static void __lockdep_reset_lock(struct pending_free *pf,
	6142	+ struct lockdep_map *lock)
	6143	+{
	6144	+ struct lock_class *class;
	6145	+ int j;
4280	6146
4281	6147	/*
4282	6148	* Remove all classes this lock might have:
..	..	@@ -4287,38 +6153,110 @@
4287	6153	*/
4288	6154	class = look_up_lock_class(lock, j);
4289	6155	if (class)
4290		- zap_class(class);
	6156	+ zap_class(pf, class);
4291	6157	}
4292	6158	/*
4293	6159	* Debug check: in the end all mapped classes should
4294	6160	* be gone.
4295	6161	*/
	6162	+ if (WARN_ON_ONCE(lock_class_cache_is_registered(lock)))
	6163	+ debug_locks_off();
	6164	+}
	6165	+
	6166	+/*
	6167	+ * Remove all information lockdep has about a lock if debug_locks == 1. Free
	6168	+ * released data structures from RCU context.
	6169	+ */
	6170	+static void lockdep_reset_lock_reg(struct lockdep_map *lock)
	6171	+{
	6172	+ struct pending_free *pf;
	6173	+ unsigned long flags;
	6174	+ int locked;
	6175	+
	6176	+ raw_local_irq_save(flags);
4296	6177	locked = graph_lock();
4297		- for (i = 0; i < CLASSHASH_SIZE; i++) {
4298		- head = classhash_table + i;
4299		- hlist_for_each_entry_rcu(class, head, hash_entry) {
4300		- int match = 0;
	6178	+ if (!locked)
	6179	+ goto out_irq;
4301	6180
4302		- for (j = 0; j < NR_LOCKDEP_CACHING_CLASSES; j++)
4303		- match \|= class == lock->class_cache[j];
	6181	+ pf = get_pending_free();
	6182	+ __lockdep_reset_lock(pf, lock);
	6183	+ call_rcu_zapped(pf);
4304	6184
4305		- if (unlikely(match)) {
4306		- if (debug_locks_off_graph_unlock()) {
4307		- /*
4308		- * We all just reset everything, how did it match?
4309		- */
4310		- WARN_ON(1);
4311		- }
4312		- goto out_restore;
4313		- }
4314		- }
4315		- }
4316		- if (locked)
4317		- graph_unlock();
4318		-
4319		-out_restore:
	6185	+ graph_unlock();
	6186	+out_irq:
4320	6187	raw_local_irq_restore(flags);
4321	6188	}
	6189	+
	6190	+/*
	6191	+ * Reset a lock. Does not sleep. Ignores debug_locks. Must only be used by the
	6192	+ * lockdep selftests.
	6193	+ */
	6194	+static void lockdep_reset_lock_imm(struct lockdep_map *lock)
	6195	+{
	6196	+ struct pending_free *pf = delayed_free.pf;
	6197	+ unsigned long flags;
	6198	+
	6199	+ raw_local_irq_save(flags);
	6200	+ lockdep_lock();
	6201	+ __lockdep_reset_lock(pf, lock);
	6202	+ __free_zapped_classes(pf);
	6203	+ lockdep_unlock();
	6204	+ raw_local_irq_restore(flags);
	6205	+}
	6206	+
	6207	+void lockdep_reset_lock(struct lockdep_map *lock)
	6208	+{
	6209	+ init_data_structures_once();
	6210	+
	6211	+ if (inside_selftest())
	6212	+ lockdep_reset_lock_imm(lock);
	6213	+ else
	6214	+ lockdep_reset_lock_reg(lock);
	6215	+}
	6216	+
	6217	+/*
	6218	+ * Unregister a dynamically allocated key.
	6219	+ *
	6220	+ * Unlike lockdep_register_key(), a search is always done to find a matching
	6221	+ * key irrespective of debug_locks to avoid potential invalid access to freed
	6222	+ * memory in lock_class entry.
	6223	+ */
	6224	+void lockdep_unregister_key(struct lock_class_key *key)
	6225	+{
	6226	+ struct hlist_head *hash_head = keyhashentry(key);
	6227	+ struct lock_class_key *k;
	6228	+ struct pending_free *pf;
	6229	+ unsigned long flags;
	6230	+ bool found = false;
	6231	+
	6232	+ might_sleep();
	6233	+
	6234	+ if (WARN_ON_ONCE(static_obj(key)))
	6235	+ return;
	6236	+
	6237	+ raw_local_irq_save(flags);
	6238	+ lockdep_lock();
	6239	+
	6240	+ hlist_for_each_entry_rcu(k, hash_head, hash_entry) {
	6241	+ if (k == key) {
	6242	+ hlist_del_rcu(&k->hash_entry);
	6243	+ found = true;
	6244	+ break;
	6245	+ }
	6246	+ }
	6247	+ WARN_ON_ONCE(!found && debug_locks);
	6248	+ if (found) {
	6249	+ pf = get_pending_free();
	6250	+ __lockdep_free_key_range(pf, key, 1);
	6251	+ call_rcu_zapped(pf);
	6252	+ }
	6253	+ lockdep_unlock();
	6254	+ raw_local_irq_restore(flags);
	6255	+
	6256	+ /* Wait until is_dynamic_key() has finished accessing k->hash_entry. */
	6257	+ synchronize_rcu();
	6258	+}
	6259	+EXPORT_SYMBOL_GPL(lockdep_unregister_key);
4322	6260
4323	6261	void __init lockdep_init(void)
4324	6262	{
..	..	@@ -4332,20 +6270,31 @@
4332	6270	printk("... MAX_LOCKDEP_CHAINS: %lu\n", MAX_LOCKDEP_CHAINS);
4333	6271	printk("... CHAINHASH_SIZE: %lu\n", CHAINHASH_SIZE);
4334	6272
4335		- printk(" memory used by lock dependency info: %lu kB\n",
4336		- (sizeof(struct lock_class) * MAX_LOCKDEP_KEYS +
4337		- sizeof(struct list_head) * CLASSHASH_SIZE +
4338		- sizeof(struct lock_list) * MAX_LOCKDEP_ENTRIES +
4339		- sizeof(struct lock_chain) * MAX_LOCKDEP_CHAINS +
4340		- sizeof(struct list_head) * CHAINHASH_SIZE
	6273	+ printk(" memory used by lock dependency info: %zu kB\n",
	6274	+ (sizeof(lock_classes) +
	6275	+ sizeof(lock_classes_in_use) +
	6276	+ sizeof(classhash_table) +
	6277	+ sizeof(list_entries) +
	6278	+ sizeof(list_entries_in_use) +
	6279	+ sizeof(chainhash_table) +
	6280	+ sizeof(delayed_free)
4341	6281	#ifdef CONFIG_PROVE_LOCKING
4342		- + sizeof(struct circular_queue)
	6282	+ + sizeof(lock_cq)
	6283	+ + sizeof(lock_chains)
	6284	+ + sizeof(lock_chains_in_use)
	6285	+ + sizeof(chain_hlocks)
4343	6286	#endif
4344	6287	) / 1024
4345	6288	);
4346	6289
4347		- printk(" per task-struct memory footprint: %lu bytes\n",
4348		- sizeof(struct held_lock) * MAX_LOCK_DEPTH);
	6290	+#if defined(CONFIG_TRACE_IRQFLAGS) && defined(CONFIG_PROVE_LOCKING)
	6291	+ printk(" memory used for stack traces: %zu kB\n",
	6292	+ (sizeof(stack_trace) + sizeof(stack_trace_hash)) / 1024
	6293	+ );
	6294	+#endif
	6295	+
	6296	+ printk(" per task-struct memory footprint: %zu bytes\n",
	6297	+ sizeof(((struct task_struct *)NULL)->held_locks));
4349	6298	}
4350	6299
4351	6300	static void
..	..	@@ -4513,9 +6462,7 @@
4513	6462	pr_warn("\n%srcu_scheduler_active = %d, debug_locks = %d\n",
4514	6463	!rcu_lockdep_current_cpu_online()
4515	6464	? "RCU used illegally from offline CPU!\n"
4516		- : !rcu_is_watching()
4517		- ? "RCU used illegally from idle CPU!\n"
4518		- : "",
	6465	+ : "",
4519	6466	rcu_scheduler_active, debug_locks);
4520	6467
4521	6468	/*