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
This commit is contained in:
Linus Torvalds 2018-12-26 14:25:52 -08:00
commit 1eefdec18e
26 changed files with 132 additions and 54 deletions

View File

@ -97,8 +97,6 @@ struct lock_class {
* Generation counter, when doing certain classes of graph walking,
* to ensure that we check one node only once:
*/
unsigned int version;
int name_version;
const char *name;

View File

@ -138,6 +138,9 @@ static struct lock_list list_entries[MAX_LOCKDEP_ENTRIES];
* get freed - this significantly simplifies the debugging code.
*/
unsigned long nr_lock_classes;
#ifndef CONFIG_DEBUG_LOCKDEP
static
#endif
struct lock_class lock_classes[MAX_LOCKDEP_KEYS];
static inline struct lock_class *hlock_class(struct held_lock *hlock)
@ -626,7 +629,8 @@ static int static_obj(void *obj)
/*
* To make lock name printouts unique, we calculate a unique
* class->name_version generation counter:
* class->name_version generation counter. The caller must hold the graph
* lock.
*/
static int count_matching_names(struct lock_class *new_class)
{
@ -636,7 +640,7 @@ static int count_matching_names(struct lock_class *new_class)
if (!new_class->name)
return 0;
list_for_each_entry_rcu(class, &all_lock_classes, lock_entry) {
list_for_each_entry(class, &all_lock_classes, lock_entry) {
if (new_class->key - new_class->subclass == class->key)
return class->name_version;
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)
class->key = key;
class->name = lock->name;
class->subclass = subclass;
INIT_LIST_HEAD(&class->lock_entry);
INIT_LIST_HEAD(&class->locks_before);
INIT_LIST_HEAD(&class->locks_after);
class->name_version = count_matching_names(class);
@ -801,7 +804,7 @@ register_lock_class(struct lockdep_map *lock, unsigned int subclass, int force)
/*
* Add it to the global list of classes:
*/
list_add_tail_rcu(&class->lock_entry, &all_lock_classes);
list_add_tail(&class->lock_entry, &all_lock_classes);
if (verbose(class)) {
graph_unlock();
@ -3088,7 +3091,7 @@ static int mark_lock(struct task_struct *curr, struct held_lock *this,
/*
* Initialize a lock instance's lock-class mapping info:
*/
static void __lockdep_init_map(struct lockdep_map *lock, const char *name,
void lockdep_init_map(struct lockdep_map *lock, const char *name,
struct lock_class_key *key, int subclass)
{
int i;
@ -3144,12 +3147,6 @@ static void __lockdep_init_map(struct lockdep_map *lock, const char *name,
raw_local_irq_restore(flags);
}
}
void lockdep_init_map(struct lockdep_map *lock, const char *name,
struct lock_class_key *key, int subclass)
{
__lockdep_init_map(lock, name, key, subclass);
}
EXPORT_SYMBOL_GPL(lockdep_init_map);
struct lock_class_key __lockdep_no_validate__;
@ -4126,6 +4123,9 @@ void lockdep_reset(void)
raw_local_irq_restore(flags);
}
/*
* Remove all references to a lock class. The caller must hold the graph lock.
*/
static void zap_class(struct lock_class *class)
{
int i;
@ -4142,7 +4142,7 @@ static void zap_class(struct lock_class *class)
* Unhash the class and remove it from the all_lock_classes list:
*/
hlist_del_rcu(&class->hash_entry);
list_del_rcu(&class->lock_entry);
list_del(&class->lock_entry);
RCU_INIT_POINTER(class->key, NULL);
RCU_INIT_POINTER(class->name, NULL);
@ -4204,15 +4204,36 @@ void lockdep_free_key_range(void *start, unsigned long size)
*/
}
void lockdep_reset_lock(struct lockdep_map *lock)
/*
* Check whether any element of the @lock->class_cache[] array refers to a
* registered lock class. The caller must hold either the graph lock or the
* RCU read lock.
*/
static bool lock_class_cache_is_registered(struct lockdep_map *lock)
{
struct lock_class *class;
struct hlist_head *head;
unsigned long flags;
int i, j;
int locked;
for (i = 0; i < CLASSHASH_SIZE; i++) {
head = classhash_table + i;
hlist_for_each_entry_rcu(class, head, hash_entry) {
for (j = 0; j < NR_LOCKDEP_CACHING_CLASSES; j++)
if (lock->class_cache[j] == class)
return true;
}
}
return false;
}
void lockdep_reset_lock(struct lockdep_map *lock)
{
struct lock_class *class;
unsigned long flags;
int j, locked;
raw_local_irq_save(flags);
locked = graph_lock();
/*
* Remove all classes this lock might have:
@ -4229,25 +4250,14 @@ void lockdep_reset_lock(struct lockdep_map *lock)
* Debug check: in the end all mapped classes should
* be gone.
*/
locked = graph_lock();
for (i = 0; i < CLASSHASH_SIZE; i++) {
head = classhash_table + i;
hlist_for_each_entry_rcu(class, head, hash_entry) {
int match = 0;
for (j = 0; j < NR_LOCKDEP_CACHING_CLASSES; j++)
match |= class == lock->class_cache[j];
if (unlikely(match)) {
if (debug_locks_off_graph_unlock()) {
/*
* We all just reset everything, how did it match?
*/
WARN_ON(1);
}
goto out_restore;
}
if (unlikely(lock_class_cache_is_registered(lock))) {
if (debug_locks_off_graph_unlock()) {
/*
* We all just reset everything, how did it match?
*/
WARN_ON(1);
}
goto out_restore;
}
if (locked)
graph_unlock();

View File

@ -9533,9 +9533,7 @@ static bool nohz_idle_balance(struct rq *this_rq, enum cpu_idle_type idle)
return false;
}
/*
* barrier, pairs with nohz_balance_enter_idle(), ensures ...
*/
/* could be _relaxed() */
flags = atomic_fetch_andnot(NOHZ_KICK_MASK, nohz_flags(this_cpu));
if (!(flags & NOHZ_KICK_MASK))
return false;

View File

@ -44,6 +44,7 @@ void lock_acquire(struct lockdep_map *lock, unsigned int subclass,
struct lockdep_map *nest_lock, unsigned long ip);
void lock_release(struct lockdep_map *lock, int nested,
unsigned long ip);
void lockdep_reset_lock(struct lockdep_map *lock);
extern void debug_check_no_locks_freed(const void *from, unsigned long len);
#define STATIC_LOCKDEP_MAP_INIT(_name, _key) \

View File

@ -54,6 +54,7 @@ static inline int liblockdep_pthread_mutex_trylock(liblockdep_pthread_mutex_t *l
static inline int liblockdep_pthread_mutex_destroy(liblockdep_pthread_mutex_t *lock)
{
lockdep_reset_lock(&lock->dep_map);
return pthread_mutex_destroy(&lock->mutex);
}

View File

@ -60,10 +60,10 @@ static inline int liblockdep_pthread_rwlock_tryrdlock(liblockdep_pthread_rwlock_
return pthread_rwlock_tryrdlock(&lock->rwlock) == 0 ? 1 : 0;
}
static inline int liblockdep_pthread_rwlock_trywlock(liblockdep_pthread_rwlock_t *lock)
static inline int liblockdep_pthread_rwlock_trywrlock(liblockdep_pthread_rwlock_t *lock)
{
lock_acquire(&lock->dep_map, 0, 1, 0, 1, NULL, (unsigned long)_RET_IP_);
return pthread_rwlock_trywlock(&lock->rwlock) == 0 ? 1 : 0;
return pthread_rwlock_trywrlock(&lock->rwlock) == 0 ? 1 : 0;
}
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)
#define pthread_rwlock_unlock liblockdep_pthread_rwlock_unlock
#define pthread_rwlock_wrlock liblockdep_pthread_rwlock_wrlock
#define pthread_rwlock_tryrdlock liblockdep_pthread_rwlock_tryrdlock
#define pthread_rwlock_trywlock liblockdep_pthread_rwlock_trywlock
#define pthread_rwlock_trywrlock liblockdep_pthread_rwlock_trywrlock
#define pthread_rwlock_destroy liblockdep_rwlock_destroy
#endif

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@ -15,6 +15,11 @@ u32 prandom_u32(void)
abort();
}
void print_irqtrace_events(struct task_struct *curr)
{
abort();
}
static struct new_utsname *init_utsname(void)
{
static struct new_utsname n = (struct new_utsname) {

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@ -1,32 +1,47 @@
#! /bin/bash
# SPDX-License-Identifier: GPL-2.0
make &> /dev/null
if ! make >/dev/null; then
echo "Building liblockdep failed."
echo "FAILED!"
exit 1
fi
for i in `ls tests/*.c`; do
find tests -name '*.c' | sort | while read -r i; do
testname=$(basename "$i" .c)
gcc -o tests/$testname -pthread $i liblockdep.a -Iinclude -D__USE_LIBLOCKDEP &> /dev/null
echo -ne "$testname... "
if [ $(timeout 1 ./tests/$testname 2>&1 | wc -l) -gt 0 ]; then
if gcc -o "tests/$testname" -pthread "$i" liblockdep.a -Iinclude -D__USE_LIBLOCKDEP &&
timeout 1 "tests/$testname" 2>&1 | "tests/${testname}.sh"; then
echo "PASSED!"
else
echo "FAILED!"
fi
if [ -f "tests/$testname" ]; then
rm tests/$testname
fi
rm -f "tests/$testname"
done
for i in `ls tests/*.c`; do
find tests -name '*.c' | sort | while read -r i; do
testname=$(basename "$i" .c)
gcc -o tests/$testname -pthread -Iinclude $i &> /dev/null
echo -ne "(PRELOAD) $testname... "
if [ $(timeout 1 ./lockdep ./tests/$testname 2>&1 | wc -l) -gt 0 ]; then
if gcc -o "tests/$testname" -pthread -Iinclude "$i" &&
timeout 1 ./lockdep "tests/$testname" 2>&1 |
"tests/${testname}.sh"; then
echo "PASSED!"
else
echo "FAILED!"
fi
if [ -f "tests/$testname" ]; then
rm tests/$testname
fi
rm -f "tests/$testname"
done
find tests -name '*.c' | sort | while read -r i; do
testname=$(basename "$i" .c)
echo -ne "(PRELOAD + Valgrind) $testname... "
if gcc -o "tests/$testname" -pthread -Iinclude "$i" &&
{ timeout 10 valgrind --read-var-info=yes ./lockdep "./tests/$testname" >& "tests/${testname}.vg.out"; true; } &&
"tests/${testname}.sh" < "tests/${testname}.vg.out" &&
! grep -Eq '(^==[0-9]*== (Invalid |Uninitialised ))|Mismatched free|Source and destination overlap| UME ' "tests/${testname}.vg.out"; then
echo "PASSED!"
else
echo "FAILED!"
fi
rm -f "tests/$testname"
done

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

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

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@ -11,4 +11,7 @@ void main(void)
LOCK_UNLOCK_2(a, b);
LOCK_UNLOCK_2(b, a);
pthread_mutex_destroy(&b);
pthread_mutex_destroy(&a);
}

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

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

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@ -13,4 +13,8 @@ void main(void)
LOCK_UNLOCK_2(a, b);
LOCK_UNLOCK_2(b, c);
LOCK_UNLOCK_2(c, a);
pthread_mutex_destroy(&c);
pthread_mutex_destroy(&b);
pthread_mutex_destroy(&a);
}

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

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@ -15,4 +15,9 @@ void main(void)
LOCK_UNLOCK_2(b, c);
LOCK_UNLOCK_2(c, d);
LOCK_UNLOCK_2(d, a);
pthread_mutex_destroy(&d);
pthread_mutex_destroy(&c);
pthread_mutex_destroy(&b);
pthread_mutex_destroy(&a);
}

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

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@ -13,4 +13,8 @@ void main(void)
LOCK_UNLOCK_2(a, b);
LOCK_UNLOCK_2(c, a);
LOCK_UNLOCK_2(b, c);
pthread_mutex_destroy(&c);
pthread_mutex_destroy(&b);
pthread_mutex_destroy(&a);
}

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

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@ -15,4 +15,9 @@ void main(void)
LOCK_UNLOCK_2(c, d);
LOCK_UNLOCK_2(b, c);
LOCK_UNLOCK_2(d, a);
pthread_mutex_destroy(&d);
pthread_mutex_destroy(&c);
pthread_mutex_destroy(&b);
pthread_mutex_destroy(&a);
}

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

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@ -15,4 +15,9 @@ void main(void)
LOCK_UNLOCK_2(c, d);
LOCK_UNLOCK_2(b, d);
LOCK_UNLOCK_2(d, a);
pthread_mutex_destroy(&d);
pthread_mutex_destroy(&c);
pthread_mutex_destroy(&b);
pthread_mutex_destroy(&a);
}

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

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

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@ -10,4 +10,6 @@ void main(void)
pthread_mutex_lock(&a);
pthread_mutex_unlock(&a);
pthread_mutex_unlock(&a);
pthread_mutex_destroy(&a);
}

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