Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull locking updates from Ingo Molnar: "The main change in this cycle are initial preparatory bits of dynamic lockdep keys support from Bart Van Assche. There are also misc changes, a comment cleanup and a data structure cleanup" * 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/fair: Clean up comment in nohz_idle_balance() locking/lockdep: Stop using RCU primitives to access 'all_lock_classes' locking/lockdep: Make concurrent lockdep_reset_lock() calls safe locking/lockdep: Remove a superfluous INIT_LIST_HEAD() statement locking/lockdep: Introduce lock_class_cache_is_registered() locking/lockdep: Inline __lockdep_init_map() locking/lockdep: Declare local symbols static tools/lib/lockdep/tests: Test the lockdep_reset_lock() implementation tools/lib/lockdep: Add dummy print_irqtrace_events() implementation tools/lib/lockdep: Rename "trywlock" into "trywrlock" tools/lib/lockdep/tests: Run lockdep tests a second time under Valgrind tools/lib/lockdep/tests: Improve testing accuracy tools/lib/lockdep/tests: Fix shellcheck warnings tools/lib/lockdep/tests: Display compiler warning and error messages locking/lockdep: Remove ::version from lock_class structure

Linus Torvalds committed 7 years ago

Commit 1eefdec2 parents 684019d 80eb86526 files · +131 −53Browse files

Unified · Split

26 files

include/linux/lockdep.h +0 −2
kernel/locking/lockdep.c +43 −33
kernel/sched/fair.c +1 −3
tools/lib/lockdep/include/liblockdep/common.h +1 −0
tools/lib/lockdep/include/liblockdep/mutex.h +1 −0
tools/lib/lockdep/include/liblockdep/rwlock.h +3 −3
tools/lib/lockdep/lockdep.c +5 −0
tools/lib/lockdep/run_tests.sh +27 −12
tools/lib/lockdep/tests/AA.sh +2 −0
tools/lib/lockdep/tests/ABA.sh +2 −0
tools/lib/lockdep/tests/ABBA.c +3 −0
tools/lib/lockdep/tests/ABBA.sh +2 −0
tools/lib/lockdep/tests/ABBA_2threads.sh +2 −0
tools/lib/lockdep/tests/ABBCCA.c +4 −0
tools/lib/lockdep/tests/ABBCCA.sh +2 −0
tools/lib/lockdep/tests/ABBCCDDA.c +5 −0
tools/lib/lockdep/tests/ABBCCDDA.sh +2 −0
tools/lib/lockdep/tests/ABCABC.c +4 −0
tools/lib/lockdep/tests/ABCABC.sh +2 −0
tools/lib/lockdep/tests/ABCDBCDA.c +5 −0
tools/lib/lockdep/tests/ABCDBCDA.sh +2 −0
tools/lib/lockdep/tests/ABCDBDDA.c +5 −0
tools/lib/lockdep/tests/ABCDBDDA.sh +2 −0
tools/lib/lockdep/tests/WW.sh +2 −0
tools/lib/lockdep/tests/unlock_balance.c +2 −0
tools/lib/lockdep/tests/unlock_balance.sh +2 −0

include/linux/lockdep.h+0−2

@@ -97,8 +97,6 @@ struct lock_class { · 96 unmodified lines
97	97	* Generation counter, when doing certain classes of graph walking,
98	98	* to ensure that we check one node only once:
99	99	*/
100		− unsigned int version;
101		−
102	100	int name_version;
103	101	const char *name;
104	102

kernel/locking/lockdep.c+43−33

@@ -138,6 +138,9 @@ static struct lock_list list_entries[MAX_LOCKDEP_ENTRIES]; · 137 unmodified lines
138	138	* get freed - this significantly simplifies the debugging code.
139	139	*/
140	140	unsigned long nr_lock_classes;
	141	+#ifndef CONFIG_DEBUG_LOCKDEP
	142	+static
	143	+#endif
141	144	struct lock_class lock_classes[MAX_LOCKDEP_KEYS];
142	145
143	146	static inline struct lock_class hlock_class(struct held_lock hlock)
@@ -626,7 +629,8 @@ static int static_obj(void *obj) · 482 unmodified lines
626	629
627	630	/*
628	631	* To make lock name printouts unique, we calculate a unique
629		− * class->name_version generation counter:
	632	+ * class->name_version generation counter. The caller must hold the graph
	633	+ * lock.
630	634	*/
631	635	static int count_matching_names(struct lock_class *new_class)
632	636	{
@@ -636,7 +640,7 @@ static int count_matching_names(struct lock_class *new_class) · 3 unmodified lines
636	640	if (!new_class->name)
637	641	return 0;
638	642
639		− list_for_each_entry_rcu(class, &all_lock_classes, lock_entry) {
	643	+ list_for_each_entry(class, &all_lock_classes, lock_entry) {
640	644	if (new_class->key - new_class->subclass == class->key)
641	645	return class->name_version;
642	646	if (class->name && !strcmp(class->name, new_class->name))
@@ -789,7 +793,6 @@ register_lock_class(struct lockdep_map *lock, unsigned int subclass, int force) · 146 unmodified lines
789	793	class->key = key;
790	794	class->name = lock->name;
791	795	class->subclass = subclass;
792		− INIT_LIST_HEAD(&class->lock_entry);
793	796	INIT_LIST_HEAD(&class->locks_before);
794	797	INIT_LIST_HEAD(&class->locks_after);
795	798	class->name_version = count_matching_names(class);
@@ -801,7 +804,7 @@ register_lock_class(struct lockdep_map *lock, unsigned int subclass, int force) · 5 unmodified lines
801	804	/*
802	805	* Add it to the global list of classes:
803	806	*/
804		− list_add_tail_rcu(&class->lock_entry, &all_lock_classes);
	807	+ list_add_tail(&class->lock_entry, &all_lock_classes);
805	808
806	809	if (verbose(class)) {
807	810	graph_unlock();
@@ -3088,7 +3091,7 @@ static int mark_lock(struct task_struct curr, struct held_lock this, · 2280 unmodified lines
3088	3091	/*
3089	3092	* Initialize a lock instance's lock-class mapping info:
3090	3093	*/
3091		−static void __lockdep_init_map(struct lockdep_map lock, const char name,
	3094	+void lockdep_init_map(struct lockdep_map lock, const char name,
3092	3095	struct lock_class_key *key, int subclass)
3093	3096	{
3094	3097	int i;
@@ -3144,12 +3147,6 @@ static void __lockdep_init_map(struct lockdep_map lock, const char name, · 49 unmodified lines
3144	3147	raw_local_irq_restore(flags);
3145	3148	}
3146	3149	}
3147		−
3148		−void lockdep_init_map(struct lockdep_map lock, const char name,
3149		− struct lock_class_key *key, int subclass)
3150		−{
3151		− __lockdep_init_map(lock, name, key, subclass);
3152		−}
3153	3150	EXPORT_SYMBOL_GPL(lockdep_init_map);
3154	3151
3155	3152	struct lock_class_key __lockdep_no_validate__;
@@ -4126,6 +4123,9 @@ void lockdep_reset(void) · 970 unmodified lines
4126	4123	raw_local_irq_restore(flags);
4127	4124	}
4128	4125
	4126	+/*
	4127	+ * Remove all references to a lock class. The caller must hold the graph lock.
	4128	+ */
4129	4129	static void zap_class(struct lock_class *class)
4130	4130	{
4131	4131	int i;
@@ -4142,7 +4142,7 @@ static void zap_class(struct lock_class *class) · 10 unmodified lines
4142	4142	* Unhash the class and remove it from the all_lock_classes list:
4143	4143	*/
4144	4144	hlist_del_rcu(&class->hash_entry);
4145		− list_del_rcu(&class->lock_entry);
	4145	+ list_del(&class->lock_entry);
4146	4146
4147	4147	RCU_INIT_POINTER(class->key, NULL);
4148	4148	RCU_INIT_POINTER(class->name, NULL);
@@ -4204,15 +4204,36 @@ void lockdep_free_key_range(void *start, unsigned long size) · 55 unmodified lines
4204	4204	*/
4205	4205	}
4206	4206
4207		−void lockdep_reset_lock(struct lockdep_map *lock)
	4207	+/*
	4208	+ * Check whether any element of the @lock->class_cache[] array refers to a
	4209	+ * registered lock class. The caller must hold either the graph lock or the
	4210	+ * RCU read lock.
	4211	+ */
	4212	+static bool lock_class_cache_is_registered(struct lockdep_map *lock)
4208	4213	{
4209	4214	struct lock_class *class;
4210	4215	struct hlist_head *head;
4211		− unsigned long flags;
4212	4216	int i, j;
4213		− int locked;
	4217	+
	4218	+ for (i = 0; i < CLASSHASH_SIZE; i++) {
	4219	+ head = classhash_table + i;
	4220	+ hlist_for_each_entry_rcu(class, head, hash_entry) {
	4221	+ for (j = 0; j < NR_LOCKDEP_CACHING_CLASSES; j++)
	4222	+ if (lock->class_cache[j] == class)
	4223	+ return true;
	4224	+ }
	4225	+ }
	4226	+ return false;
	4227	+}
	4228	+
	4229	+void lockdep_reset_lock(struct lockdep_map *lock)
	4230	+{
	4231	+ struct lock_class *class;
	4232	+ unsigned long flags;
	4233	+ int j, locked;
4214	4234
4215	4235	raw_local_irq_save(flags);
	4236	+ locked = graph_lock();
4216	4237
4217	4238	/*
4218	4239	* Remove all classes this lock might have:
@@ -4229,25 +4250,14 @@ void lockdep_reset_lock(struct lockdep_map *lock) · 10 unmodified lines
4229	4250	* Debug check: in the end all mapped classes should
4230	4251	* be gone.
4231	4252	*/
4232		− locked = graph_lock();
4233		− for (i = 0; i < CLASSHASH_SIZE; i++) {
4234		− head = classhash_table + i;
4235		− hlist_for_each_entry_rcu(class, head, hash_entry) {
4236		− int match = 0;
4237		−
4238		− for (j = 0; j < NR_LOCKDEP_CACHING_CLASSES; j++)
4239		− match \|= class == lock->class_cache[j];
4240		−
4241		− if (unlikely(match)) {
4242		− if (debug_locks_off_graph_unlock()) {
4243		− /*
4244		− * We all just reset everything, how did it match?
4245		− */
4246		− WARN_ON(1);
4247		− }
4248		− goto out_restore;
4249		− }
	4253	+ if (unlikely(lock_class_cache_is_registered(lock))) {
	4254	+ if (debug_locks_off_graph_unlock()) {
	4255	+ /*
	4256	+ * We all just reset everything, how did it match?
	4257	+ */
	4258	+ WARN_ON(1);
4250	4259	}
	4260	+ goto out_restore;
4251	4261	}
4252	4262	if (locked)
4253	4263	graph_unlock();

kernel/sched/fair.c+1−3

@@ -9533,9 +9533,7 @@ static bool nohz_idle_balance(struct rq *this_rq, enum cpu_idle_type idle) · 9532 unmodified lines
9533	9533	return false;
9534	9534	}
9535	9535
9536		− /*
9537		− * barrier, pairs with nohz_balance_enter_idle(), ensures ...
9538		− */
	9536	+ /* could be _relaxed() */
9539	9537	flags = atomic_fetch_andnot(NOHZ_KICK_MASK, nohz_flags(this_cpu));
9540	9538	if (!(flags & NOHZ_KICK_MASK))
9541	9539	return false;

tools/lib/lockdep/include/liblockdep/common.h+1−0

@@ -44,6 +44,7 @@ void lock_acquire(struct lockdep_map *lock, unsigned int subclass, · 43 unmodified lines
44	44	struct lockdep_map *nest_lock, unsigned long ip);
45	45	void lock_release(struct lockdep_map *lock, int nested,
46	46	unsigned long ip);
	47	+void lockdep_reset_lock(struct lockdep_map *lock);
47	48	extern void debug_check_no_locks_freed(const void *from, unsigned long len);
48	49
49	50	#define STATIC_LOCKDEP_MAP_INIT(_name, _key) \

tools/lib/lockdep/include/liblockdep/mutex.h+1−0

@@ -54,6 +54,7 @@ static inline int liblockdep_pthread_mutex_trylock(liblockdep_pthread_mutex_t *l · 53 unmodified lines
54	54
55	55	static inline int liblockdep_pthread_mutex_destroy(liblockdep_pthread_mutex_t *lock)
56	56	{
	57	+ lockdep_reset_lock(&lock->dep_map);
57	58	return pthread_mutex_destroy(&lock->mutex);
58	59	}
59	60

tools/lib/lockdep/include/liblockdep/rwlock.h+3−3

@@ -60,10 +60,10 @@ static inline int liblockdep_pthread_rwlock_tryrdlock(liblockdep_pthread_rwlock_ · 59 unmodified lines
60	60	return pthread_rwlock_tryrdlock(&lock->rwlock) == 0 ? 1 : 0;
61	61	}
62	62
63		−static inline int liblockdep_pthread_rwlock_trywlock(liblockdep_pthread_rwlock_t *lock)
	63	+static inline int liblockdep_pthread_rwlock_trywrlock(liblockdep_pthread_rwlock_t *lock)
64	64	{
65	65	lock_acquire(&lock->dep_map, 0, 1, 0, 1, NULL, (unsigned long)_RET_IP_);
66		− return pthread_rwlock_trywlock(&lock->rwlock) == 0 ? 1 : 0;
	66	+ return pthread_rwlock_trywrlock(&lock->rwlock) == 0 ? 1 : 0;
67	67	}
68	68
69	69	static inline int liblockdep_rwlock_destroy(liblockdep_pthread_rwlock_t *lock)
@@ -79,7 +79,7 @@ static inline int liblockdep_rwlock_destroy(liblockdep_pthread_rwlock_t *lock) · 9 unmodified lines
79	79	#define pthread_rwlock_unlock liblockdep_pthread_rwlock_unlock
80	80	#define pthread_rwlock_wrlock liblockdep_pthread_rwlock_wrlock
81	81	#define pthread_rwlock_tryrdlock liblockdep_pthread_rwlock_tryrdlock
82		−#define pthread_rwlock_trywlock liblockdep_pthread_rwlock_trywlock
	82	+#define pthread_rwlock_trywrlock liblockdep_pthread_rwlock_trywrlock
83	83	#define pthread_rwlock_destroy liblockdep_rwlock_destroy
84	84
85	85	#endif

tools/lib/lockdep/lockdep.c+5−0

@@ -15,6 +15,11 @@ u32 prandom_u32(void) · 14 unmodified lines
15	15	abort();
16	16	}
17	17
	18	+void print_irqtrace_events(struct task_struct *curr)
	19	+{
	20	+ abort();
	21	+}
	22	+
18	23	static struct new_utsname *init_utsname(void)
19	24	{
20	25	static struct new_utsname n = (struct new_utsname) {

tools/lib/lockdep/run_tests.sh+27−12

@@ -1,32 +1,47 @@
1	1	#! /bin/bash
2	2	# SPDX-License-Identifier: GPL-2.0
3	3
4		−make &> /dev/null
	4	+if ! make >/dev/null; then
	5	+ echo "Building liblockdep failed."
	6	+ echo "FAILED!"
	7	+ exit 1
	8	+fi
5	9
6		−for i in `ls tests/*.c`; do
	10	+find tests -name '*.c' \| sort \| while read -r i; do
7	11	testname=$(basename "$i" .c)
8		− gcc -o tests/$testname -pthread $i liblockdep.a -Iinclude -D__USE_LIBLOCKDEP &> /dev/null
9	12	echo -ne "$testname... "
10		− if [ $(timeout 1 ./tests/$testname 2>&1 \| wc -l) -gt 0 ]; then
	13	+ if gcc -o "tests/$testname" -pthread "$i" liblockdep.a -Iinclude -D__USE_LIBLOCKDEP &&
	14	+ timeout 1 "tests/$testname" 2>&1 \| "tests/${testname}.sh"; then
11	15	echo "PASSED!"
12	16	else
13	17	echo "FAILED!"
14	18	fi
15		− if [ -f "tests/$testname" ]; then
16		− rm tests/$testname
17		− fi
	19	+ rm -f "tests/$testname"
18	20	done
19	21
20		−for i in `ls tests/*.c`; do
	22	+find tests -name '*.c' \| sort \| while read -r i; do
21	23	testname=$(basename "$i" .c)
22		− gcc -o tests/$testname -pthread -Iinclude $i &> /dev/null
23	24	echo -ne "(PRELOAD) $testname... "
24		− if [ $(timeout 1 ./lockdep ./tests/$testname 2>&1 \| wc -l) -gt 0 ]; then
	25	+ if gcc -o "tests/$testname" -pthread -Iinclude "$i" &&
	26	+ timeout 1 ./lockdep "tests/$testname" 2>&1 \|
	27	+ "tests/${testname}.sh"; then
25	28	echo "PASSED!"
26	29	else
27	30	echo "FAILED!"
28	31	fi
29		− if [ -f "tests/$testname" ]; then
30		− rm tests/$testname
	32	+ rm -f "tests/$testname"
	33	+done
	34	+
	35	+find tests -name '*.c' \| sort \| while read -r i; do
	36	+ testname=$(basename "$i" .c)
	37	+ echo -ne "(PRELOAD + Valgrind) $testname... "
	38	+ if gcc -o "tests/$testname" -pthread -Iinclude "$i" &&
	39	+ { timeout 10 valgrind --read-var-info=yes ./lockdep "./tests/$testname" >& "tests/${testname}.vg.out"; true; } &&
	40	+ "tests/${testname}.sh" < "tests/${testname}.vg.out" &&
	41	+ ! grep -Eq '(^==[0-9]*== (Invalid \|Uninitialised ))\|Mismatched free\|Source and destination overlap\| UME ' "tests/${testname}.vg.out"; then
	42	+ echo "PASSED!"
	43	+ else
	44	+ echo "FAILED!"
31	45	fi
	46	+ rm -f "tests/$testname"
32	47	done

tools/lib/lockdep/tests/AA.sh+2−0

@@ -0,0 +1,2 @@
	1	+#!/bin/bash
	2	+grep -q 'WARNING: possible recursive locking detected'

tools/lib/lockdep/tests/ABA.sh+2−0

@@ -0,0 +1,2 @@
	1	+#!/bin/bash
	2	+grep -q 'WARNING: possible recursive locking detected'

tools/lib/lockdep/tests/ABBA.c+3−0

@@ -11,4 +11,7 @@ void main(void) · 10 unmodified lines
11	11
12	12	LOCK_UNLOCK_2(a, b);
13	13	LOCK_UNLOCK_2(b, a);
	14	+
	15	+ pthread_mutex_destroy(&b);
	16	+ pthread_mutex_destroy(&a);
14	17	}

tools/lib/lockdep/tests/ABBA.sh+2−0

@@ -0,0 +1,2 @@
	1	+#!/bin/bash
	2	+grep -q 'WARNING: possible circular locking dependency detected'

tools/lib/lockdep/tests/ABBA_2threads.sh+2−0

@@ -0,0 +1,2 @@
	1	+#!/bin/bash
	2	+grep -q 'WARNING: possible circular locking dependency detected'

tools/lib/lockdep/tests/ABBCCA.c+4−0

@@ -13,4 +13,8 @@ void main(void) · 12 unmodified lines
13	13	LOCK_UNLOCK_2(a, b);
14	14	LOCK_UNLOCK_2(b, c);
15	15	LOCK_UNLOCK_2(c, a);
	16	+
	17	+ pthread_mutex_destroy(&c);
	18	+ pthread_mutex_destroy(&b);
	19	+ pthread_mutex_destroy(&a);
16	20	}

tools/lib/lockdep/tests/ABBCCA.sh+2−0

@@ -0,0 +1,2 @@
	1	+#!/bin/bash
	2	+grep -q 'WARNING: possible circular locking dependency detected'

tools/lib/lockdep/tests/ABBCCDDA.c+5−0

@@ -15,4 +15,9 @@ void main(void) · 14 unmodified lines
15	15	LOCK_UNLOCK_2(b, c);
16	16	LOCK_UNLOCK_2(c, d);
17	17	LOCK_UNLOCK_2(d, a);
	18	+
	19	+ pthread_mutex_destroy(&d);
	20	+ pthread_mutex_destroy(&c);
	21	+ pthread_mutex_destroy(&b);
	22	+ pthread_mutex_destroy(&a);
18	23	}

tools/lib/lockdep/tests/ABBCCDDA.sh+2−0

@@ -0,0 +1,2 @@
	1	+#!/bin/bash
	2	+grep -q 'WARNING: possible circular locking dependency detected'

tools/lib/lockdep/tests/ABCABC.c+4−0

@@ -13,4 +13,8 @@ void main(void) · 12 unmodified lines
13	13	LOCK_UNLOCK_2(a, b);
14	14	LOCK_UNLOCK_2(c, a);
15	15	LOCK_UNLOCK_2(b, c);
	16	+
	17	+ pthread_mutex_destroy(&c);
	18	+ pthread_mutex_destroy(&b);
	19	+ pthread_mutex_destroy(&a);
16	20	}

tools/lib/lockdep/tests/ABCABC.sh+2−0

@@ -0,0 +1,2 @@
	1	+#!/bin/bash
	2	+grep -q 'WARNING: possible circular locking dependency detected'

tools/lib/lockdep/tests/ABCDBCDA.c+5−0

@@ -15,4 +15,9 @@ void main(void) · 14 unmodified lines
15	15	LOCK_UNLOCK_2(c, d);
16	16	LOCK_UNLOCK_2(b, c);
17	17	LOCK_UNLOCK_2(d, a);
	18	+
	19	+ pthread_mutex_destroy(&d);
	20	+ pthread_mutex_destroy(&c);
	21	+ pthread_mutex_destroy(&b);
	22	+ pthread_mutex_destroy(&a);
18	23	}

tools/lib/lockdep/tests/ABCDBCDA.sh+2−0

@@ -0,0 +1,2 @@
	1	+#!/bin/bash
	2	+grep -q 'WARNING: possible circular locking dependency detected'

tools/lib/lockdep/tests/ABCDBDDA.c+5−0

@@ -15,4 +15,9 @@ void main(void) · 14 unmodified lines
15	15	LOCK_UNLOCK_2(c, d);
16	16	LOCK_UNLOCK_2(b, d);
17	17	LOCK_UNLOCK_2(d, a);
	18	+
	19	+ pthread_mutex_destroy(&d);
	20	+ pthread_mutex_destroy(&c);
	21	+ pthread_mutex_destroy(&b);
	22	+ pthread_mutex_destroy(&a);
18	23	}

tools/lib/lockdep/tests/ABCDBDDA.sh+2−0

@@ -0,0 +1,2 @@
	1	+#!/bin/bash
	2	+grep -q 'WARNING: possible circular locking dependency detected'

tools/lib/lockdep/tests/WW.sh+2−0

@@ -0,0 +1,2 @@
	1	+#!/bin/bash
	2	+grep -q 'WARNING: possible recursive locking detected'

tools/lib/lockdep/tests/unlock_balance.c+2−0

@@ -10,4 +10,6 @@ void main(void) · 9 unmodified lines
10	10	pthread_mutex_lock(&a);
11	11	pthread_mutex_unlock(&a);
12	12	pthread_mutex_unlock(&a);
	13	+
	14	+ pthread_mutex_destroy(&a);
13	15	}

tools/lib/lockdep/tests/unlock_balance.sh+2−0

@@ -0,0 +1,2 @@
	1	+#!/bin/bash
	2	+grep -q 'WARNING: bad unlock balance detected'