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-rw-r--r--kernel/locking/lock_events.h4
-rw-r--r--kernel/locking/lockdep.c204
-rw-r--r--kernel/locking/lockdep_internals.h3
-rw-r--r--kernel/locking/lockdep_proc.c2
-rw-r--r--kernel/locking/locktorture.c7
-rw-r--r--kernel/locking/mutex-debug.c12
-rw-r--r--kernel/locking/mutex.c53
-rw-r--r--kernel/locking/mutex.h27
-rw-r--r--kernel/locking/osq_lock.c3
-rw-r--r--kernel/locking/percpu-rwsem.c11
-rw-r--r--kernel/locking/qspinlock.c15
-rw-r--r--kernel/locking/qspinlock_paravirt.h81
-rw-r--r--kernel/locking/rtmutex.c78
-rw-r--r--kernel/locking/rtmutex_api.c22
-rw-r--r--kernel/locking/rtmutex_common.h7
-rw-r--r--kernel/locking/rwbase_rt.c8
-rw-r--r--kernel/locking/rwsem.c42
-rw-r--r--kernel/locking/semaphore.c13
-rw-r--r--kernel/locking/spinlock.c16
-rw-r--r--kernel/locking/spinlock_rt.c19
-rw-r--r--kernel/locking/test-ww_mutex.c18
-rw-r--r--kernel/locking/ww_mutex.h53
22 files changed, 449 insertions, 249 deletions
diff --git a/kernel/locking/lock_events.h b/kernel/locking/lock_events.h
index a6016b91803d..d2345e9c0190 100644
--- a/kernel/locking/lock_events.h
+++ b/kernel/locking/lock_events.h
@@ -53,8 +53,8 @@ static inline void __lockevent_add(enum lock_events event, int inc)
#else /* CONFIG_LOCK_EVENT_COUNTS */
#define lockevent_inc(ev)
-#define lockevent_add(ev, c)
-#define lockevent_cond_inc(ev, c)
+#define lockevent_add(ev, c) do { (void)(c); } while (0)
+#define lockevent_cond_inc(ev, c) do { (void)(c); } while (0)
#endif /* CONFIG_LOCK_EVENT_COUNTS */
diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
index 151bd3de5936..4470680f0226 100644
--- a/kernel/locking/lockdep.c
+++ b/kernel/locking/lockdep.c
@@ -56,6 +56,7 @@
#include <linux/kprobes.h>
#include <linux/lockdep.h>
#include <linux/context_tracking.h>
+#include <linux/console.h>
#include <asm/sections.h>
@@ -78,7 +79,7 @@ module_param(lock_stat, int, 0644);
#endif
#ifdef CONFIG_SYSCTL
-static struct ctl_table kern_lockdep_table[] = {
+static const struct ctl_table kern_lockdep_table[] = {
#ifdef CONFIG_PROVE_LOCKING
{
.procname = "prove_locking",
@@ -97,7 +98,6 @@ static struct ctl_table kern_lockdep_table[] = {
.proc_handler = proc_dointvec,
},
#endif /* CONFIG_LOCK_STAT */
- { }
};
static __init int kernel_lockdep_sysctls_init(void)
@@ -157,10 +157,12 @@ static inline void lockdep_unlock(void)
__this_cpu_dec(lockdep_recursion);
}
+#ifdef CONFIG_PROVE_LOCKING
static inline bool lockdep_assert_locked(void)
{
return DEBUG_LOCKS_WARN_ON(__owner != current);
}
+#endif
static struct task_struct *lockdep_selftest_task_struct;
@@ -430,7 +432,7 @@ static inline u16 hlock_id(struct held_lock *hlock)
return (hlock->class_idx | (hlock->read << MAX_LOCKDEP_KEYS_BITS));
}
-static inline unsigned int chain_hlock_class_idx(u16 hlock_id)
+static inline __maybe_unused unsigned int chain_hlock_class_idx(u16 hlock_id)
{
return hlock_id & (MAX_LOCKDEP_KEYS - 1);
}
@@ -574,8 +576,10 @@ static struct lock_trace *save_trace(void)
if (!debug_locks_off_graph_unlock())
return NULL;
+ nbcon_cpu_emergency_enter();
print_lockdep_off("BUG: MAX_STACK_TRACE_ENTRIES too low!");
dump_stack();
+ nbcon_cpu_emergency_exit();
return NULL;
}
@@ -786,7 +790,7 @@ static void lockdep_print_held_locks(struct task_struct *p)
printk("no locks held by %s/%d.\n", p->comm, task_pid_nr(p));
else
printk("%d lock%s held by %s/%d:\n", depth,
- depth > 1 ? "s" : "", p->comm, task_pid_nr(p));
+ str_plural(depth), p->comm, task_pid_nr(p));
/*
* It's not reliable to print a task's held locks if it's not sleeping
* and it's not the current task.
@@ -888,11 +892,13 @@ look_up_lock_class(const struct lockdep_map *lock, unsigned int subclass)
if (unlikely(subclass >= MAX_LOCKDEP_SUBCLASSES)) {
instrumentation_begin();
debug_locks_off();
+ nbcon_cpu_emergency_enter();
printk(KERN_ERR
"BUG: looking up invalid subclass: %u\n", subclass);
printk(KERN_ERR
"turning off the locking correctness validator.\n");
dump_stack();
+ nbcon_cpu_emergency_exit();
instrumentation_end();
return NULL;
}
@@ -969,11 +975,13 @@ static bool assign_lock_key(struct lockdep_map *lock)
else {
/* Debug-check: all keys must be persistent! */
debug_locks_off();
+ nbcon_cpu_emergency_enter();
pr_err("INFO: trying to register non-static key.\n");
pr_err("The code is fine but needs lockdep annotation, or maybe\n");
pr_err("you didn't initialize this object before use?\n");
pr_err("turning off the locking correctness validator.\n");
dump_stack();
+ nbcon_cpu_emergency_exit();
return false;
}
@@ -1317,8 +1325,10 @@ register_lock_class(struct lockdep_map *lock, unsigned int subclass, int force)
return NULL;
}
+ nbcon_cpu_emergency_enter();
print_lockdep_off("BUG: MAX_LOCKDEP_KEYS too low!");
dump_stack();
+ nbcon_cpu_emergency_exit();
return NULL;
}
nr_lock_classes++;
@@ -1350,11 +1360,13 @@ register_lock_class(struct lockdep_map *lock, unsigned int subclass, int force)
if (verbose(class)) {
graph_unlock();
+ nbcon_cpu_emergency_enter();
printk("\nnew class %px: %s", class->key, class->name);
if (class->name_version > 1)
printk(KERN_CONT "#%d", class->name_version);
printk(KERN_CONT "\n");
dump_stack();
+ nbcon_cpu_emergency_exit();
if (!graph_lock()) {
return NULL;
@@ -1393,8 +1405,10 @@ static struct lock_list *alloc_list_entry(void)
if (!debug_locks_off_graph_unlock())
return NULL;
+ nbcon_cpu_emergency_enter();
print_lockdep_off("BUG: MAX_LOCKDEP_ENTRIES too low!");
dump_stack();
+ nbcon_cpu_emergency_exit();
return NULL;
}
nr_list_entries++;
@@ -2040,6 +2054,8 @@ static noinline void print_circular_bug(struct lock_list *this,
depth = get_lock_depth(target);
+ nbcon_cpu_emergency_enter();
+
print_circular_bug_header(target, depth, check_src, check_tgt);
parent = get_lock_parent(target);
@@ -2058,6 +2074,8 @@ static noinline void print_circular_bug(struct lock_list *this,
printk("\nstack backtrace:\n");
dump_stack();
+
+ nbcon_cpu_emergency_exit();
}
static noinline void print_bfs_bug(int ret)
@@ -2068,6 +2086,9 @@ static noinline void print_bfs_bug(int ret)
/*
* Breadth-first-search failed, graph got corrupted?
*/
+ if (ret == BFS_EQUEUEFULL)
+ pr_warn("Increase LOCKDEP_CIRCULAR_QUEUE_BITS to avoid this warning:\n");
+
WARN(1, "lockdep bfs error:%d\n", ret);
}
@@ -2570,6 +2591,8 @@ print_bad_irq_dependency(struct task_struct *curr,
if (!debug_locks_off_graph_unlock() || debug_locks_silent)
return;
+ nbcon_cpu_emergency_enter();
+
pr_warn("\n");
pr_warn("=====================================================\n");
pr_warn("WARNING: %s-safe -> %s-unsafe lock order detected\n",
@@ -2619,11 +2642,13 @@ print_bad_irq_dependency(struct task_struct *curr,
pr_warn(" and %s-irq-unsafe lock:\n", irqclass);
next_root->trace = save_trace();
if (!next_root->trace)
- return;
+ goto out;
print_shortest_lock_dependencies(forwards_entry, next_root);
pr_warn("\nstack backtrace:\n");
dump_stack();
+out:
+ nbcon_cpu_emergency_exit();
}
static const char *state_names[] = {
@@ -2988,6 +3013,8 @@ print_deadlock_bug(struct task_struct *curr, struct held_lock *prev,
if (!debug_locks_off_graph_unlock() || debug_locks_silent)
return;
+ nbcon_cpu_emergency_enter();
+
pr_warn("\n");
pr_warn("============================================\n");
pr_warn("WARNING: possible recursive locking detected\n");
@@ -3010,6 +3037,8 @@ print_deadlock_bug(struct task_struct *curr, struct held_lock *prev,
pr_warn("\nstack backtrace:\n");
dump_stack();
+
+ nbcon_cpu_emergency_exit();
}
/*
@@ -3607,6 +3636,8 @@ static void print_collision(struct task_struct *curr,
struct held_lock *hlock_next,
struct lock_chain *chain)
{
+ nbcon_cpu_emergency_enter();
+
pr_warn("\n");
pr_warn("============================\n");
pr_warn("WARNING: chain_key collision\n");
@@ -3623,6 +3654,8 @@ static void print_collision(struct task_struct *curr,
pr_warn("\nstack backtrace:\n");
dump_stack();
+
+ nbcon_cpu_emergency_exit();
}
#endif
@@ -3713,8 +3746,10 @@ static inline int add_chain_cache(struct task_struct *curr,
if (!debug_locks_off_graph_unlock())
return 0;
+ nbcon_cpu_emergency_enter();
print_lockdep_off("BUG: MAX_LOCKDEP_CHAINS too low!");
dump_stack();
+ nbcon_cpu_emergency_exit();
return 0;
}
chain->chain_key = chain_key;
@@ -3731,8 +3766,10 @@ static inline int add_chain_cache(struct task_struct *curr,
if (!debug_locks_off_graph_unlock())
return 0;
+ nbcon_cpu_emergency_enter();
print_lockdep_off("BUG: MAX_LOCKDEP_CHAIN_HLOCKS too low!");
dump_stack();
+ nbcon_cpu_emergency_exit();
return 0;
}
@@ -3971,6 +4008,8 @@ print_usage_bug(struct task_struct *curr, struct held_lock *this,
if (!debug_locks_off() || debug_locks_silent)
return;
+ nbcon_cpu_emergency_enter();
+
pr_warn("\n");
pr_warn("================================\n");
pr_warn("WARNING: inconsistent lock state\n");
@@ -3999,6 +4038,8 @@ print_usage_bug(struct task_struct *curr, struct held_lock *this,
pr_warn("\nstack backtrace:\n");
dump_stack();
+
+ nbcon_cpu_emergency_exit();
}
/*
@@ -4033,6 +4074,8 @@ print_irq_inversion_bug(struct task_struct *curr,
if (!debug_locks_off_graph_unlock() || debug_locks_silent)
return;
+ nbcon_cpu_emergency_enter();
+
pr_warn("\n");
pr_warn("========================================================\n");
pr_warn("WARNING: possible irq lock inversion dependency detected\n");
@@ -4073,11 +4116,13 @@ print_irq_inversion_bug(struct task_struct *curr,
pr_warn("\nthe shortest dependencies between 2nd lock and 1st lock:\n");
root->trace = save_trace();
if (!root->trace)
- return;
+ goto out;
print_shortest_lock_dependencies(other, root);
pr_warn("\nstack backtrace:\n");
dump_stack();
+out:
+ nbcon_cpu_emergency_exit();
}
/*
@@ -4154,6 +4199,8 @@ void print_irqtrace_events(struct task_struct *curr)
{
const struct irqtrace_events *trace = &curr->irqtrace;
+ nbcon_cpu_emergency_enter();
+
printk("irq event stamp: %u\n", trace->irq_events);
printk("hardirqs last enabled at (%u): [<%px>] %pS\n",
trace->hardirq_enable_event, (void *)trace->hardirq_enable_ip,
@@ -4167,6 +4214,8 @@ void print_irqtrace_events(struct task_struct *curr)
printk("softirqs last disabled at (%u): [<%px>] %pS\n",
trace->softirq_disable_event, (void *)trace->softirq_disable_ip,
(void *)trace->softirq_disable_ip);
+
+ nbcon_cpu_emergency_exit();
}
static int HARDIRQ_verbose(struct lock_class *class)
@@ -4539,6 +4588,30 @@ void lockdep_softirqs_off(unsigned long ip)
debug_atomic_inc(redundant_softirqs_off);
}
+/**
+ * lockdep_cleanup_dead_cpu - Ensure CPU lockdep state is cleanly stopped
+ *
+ * @cpu: index of offlined CPU
+ * @idle: task pointer for offlined CPU's idle thread
+ *
+ * Invoked after the CPU is dead. Ensures that the tracing infrastructure
+ * is left in a suitable state for the CPU to be subsequently brought
+ * online again.
+ */
+void lockdep_cleanup_dead_cpu(unsigned int cpu, struct task_struct *idle)
+{
+ if (unlikely(!debug_locks))
+ return;
+
+ if (unlikely(per_cpu(hardirqs_enabled, cpu))) {
+ pr_warn("CPU %u left hardirqs enabled!", cpu);
+ if (idle)
+ print_irqtrace_events(idle);
+ /* Clean it up for when the CPU comes online again. */
+ per_cpu(hardirqs_enabled, cpu) = 0;
+ }
+}
+
static int
mark_usage(struct task_struct *curr, struct held_lock *hlock, int check)
{
@@ -4687,10 +4760,12 @@ unlock:
* We must printk outside of the graph_lock:
*/
if (ret == 2) {
+ nbcon_cpu_emergency_enter();
printk("\nmarked lock as {%s}:\n", usage_str[new_bit]);
print_lock(this);
print_irqtrace_events(curr);
dump_stack();
+ nbcon_cpu_emergency_exit();
}
return ret;
@@ -4731,6 +4806,8 @@ print_lock_invalid_wait_context(struct task_struct *curr,
if (debug_locks_silent)
return 0;
+ nbcon_cpu_emergency_enter();
+
pr_warn("\n");
pr_warn("=============================\n");
pr_warn("[ BUG: Invalid wait context ]\n");
@@ -4750,6 +4827,8 @@ print_lock_invalid_wait_context(struct task_struct *curr,
pr_warn("stack backtrace:\n");
dump_stack();
+ nbcon_cpu_emergency_exit();
+
return 0;
}
@@ -4918,6 +4997,9 @@ EXPORT_SYMBOL_GPL(lockdep_init_map_type);
struct lock_class_key __lockdep_no_validate__;
EXPORT_SYMBOL_GPL(__lockdep_no_validate__);
+struct lock_class_key __lockdep_no_track__;
+EXPORT_SYMBOL_GPL(__lockdep_no_track__);
+
#ifdef CONFIG_PROVE_LOCKING
void lockdep_set_lock_cmp_fn(struct lockdep_map *lock, lock_cmp_fn cmp_fn,
lock_print_fn print_fn)
@@ -4954,6 +5036,8 @@ print_lock_nested_lock_not_held(struct task_struct *curr,
if (debug_locks_silent)
return;
+ nbcon_cpu_emergency_enter();
+
pr_warn("\n");
pr_warn("==================================\n");
pr_warn("WARNING: Nested lock was not taken\n");
@@ -4974,6 +5058,8 @@ print_lock_nested_lock_not_held(struct task_struct *curr,
pr_warn("\nstack backtrace:\n");
dump_stack();
+
+ nbcon_cpu_emergency_exit();
}
static int __lock_is_held(const struct lockdep_map *lock, int read);
@@ -5002,6 +5088,9 @@ static int __lock_acquire(struct lockdep_map *lock, unsigned int subclass,
if (unlikely(!debug_locks))
return 0;
+ if (unlikely(lock->key == &__lockdep_no_track__))
+ return 0;
+
if (!prove_locking || lock->key == &__lockdep_no_validate__)
check = 0;
@@ -5019,11 +5108,13 @@ static int __lock_acquire(struct lockdep_map *lock, unsigned int subclass,
debug_class_ops_inc(class);
if (very_verbose(class)) {
+ nbcon_cpu_emergency_enter();
printk("\nacquire class [%px] %s", class->key, class->name);
if (class->name_version > 1)
printk(KERN_CONT "#%d", class->name_version);
printk(KERN_CONT "\n");
dump_stack();
+ nbcon_cpu_emergency_exit();
}
/*
@@ -5150,6 +5241,7 @@ static int __lock_acquire(struct lockdep_map *lock, unsigned int subclass,
#endif
if (unlikely(curr->lockdep_depth >= MAX_LOCK_DEPTH)) {
debug_locks_off();
+ nbcon_cpu_emergency_enter();
print_lockdep_off("BUG: MAX_LOCK_DEPTH too low!");
printk(KERN_DEBUG "depth: %i max: %lu!\n",
curr->lockdep_depth, MAX_LOCK_DEPTH);
@@ -5157,6 +5249,7 @@ static int __lock_acquire(struct lockdep_map *lock, unsigned int subclass,
lockdep_print_held_locks(current);
debug_show_all_locks();
dump_stack();
+ nbcon_cpu_emergency_exit();
return 0;
}
@@ -5176,6 +5269,8 @@ static void print_unlock_imbalance_bug(struct task_struct *curr,
if (debug_locks_silent)
return;
+ nbcon_cpu_emergency_enter();
+
pr_warn("\n");
pr_warn("=====================================\n");
pr_warn("WARNING: bad unlock balance detected!\n");
@@ -5192,6 +5287,8 @@ static void print_unlock_imbalance_bug(struct task_struct *curr,
pr_warn("\nstack backtrace:\n");
dump_stack();
+
+ nbcon_cpu_emergency_exit();
}
static noinstr int match_held_lock(const struct held_lock *hlock,
@@ -5764,7 +5861,8 @@ void lock_release(struct lockdep_map *lock, unsigned long ip)
trace_lock_release(lock, ip);
- if (unlikely(!lockdep_enabled()))
+ if (unlikely(!lockdep_enabled() ||
+ lock->key == &__lockdep_no_track__))
return;
raw_local_irq_save(flags);
@@ -5895,6 +5993,8 @@ static void print_lock_contention_bug(struct task_struct *curr,
if (debug_locks_silent)
return;
+ nbcon_cpu_emergency_enter();
+
pr_warn("\n");
pr_warn("=================================\n");
pr_warn("WARNING: bad contention detected!\n");
@@ -5911,6 +6011,8 @@ static void print_lock_contention_bug(struct task_struct *curr,
pr_warn("\nstack backtrace:\n");
dump_stack();
+
+ nbcon_cpu_emergency_exit();
}
static void
@@ -5930,6 +6032,9 @@ __lock_contended(struct lockdep_map *lock, unsigned long ip)
if (DEBUG_LOCKS_WARN_ON(!depth))
return;
+ if (unlikely(lock->key == &__lockdep_no_track__))
+ return;
+
hlock = find_held_lock(curr, lock, depth, &i);
if (!hlock) {
print_lock_contention_bug(curr, lock, ip);
@@ -5972,6 +6077,9 @@ __lock_acquired(struct lockdep_map *lock, unsigned long ip)
if (DEBUG_LOCKS_WARN_ON(!depth))
return;
+ if (unlikely(lock->key == &__lockdep_no_track__))
+ return;
+
hlock = find_held_lock(curr, lock, depth, &i);
if (!hlock) {
print_lock_contention_bug(curr, lock, _RET_IP_);
@@ -6184,25 +6292,27 @@ static struct pending_free *get_pending_free(void)
static void free_zapped_rcu(struct rcu_head *cb);
/*
- * Schedule an RCU callback if no RCU callback is pending. Must be called with
- * the graph lock held.
- */
-static void call_rcu_zapped(struct pending_free *pf)
+* See if we need to queue an RCU callback, must called with
+* the lockdep lock held, returns false if either we don't have
+* any pending free or the callback is already scheduled.
+* Otherwise, a call_rcu() must follow this function call.
+*/
+static bool prepare_call_rcu_zapped(struct pending_free *pf)
{
WARN_ON_ONCE(inside_selftest());
if (list_empty(&pf->zapped))
- return;
+ return false;
if (delayed_free.scheduled)
- return;
+ return false;
delayed_free.scheduled = true;
WARN_ON_ONCE(delayed_free.pf + delayed_free.index != pf);
delayed_free.index ^= 1;
- call_rcu(&delayed_free.rcu_head, free_zapped_rcu);
+ return true;
}
/* The caller must hold the graph lock. May be called from RCU context. */
@@ -6228,6 +6338,7 @@ static void free_zapped_rcu(struct rcu_head *ch)
{
struct pending_free *pf;
unsigned long flags;
+ bool need_callback;
if (WARN_ON_ONCE(ch != &delayed_free.rcu_head))
return;
@@ -6239,14 +6350,18 @@ static void free_zapped_rcu(struct rcu_head *ch)
pf = delayed_free.pf + (delayed_free.index ^ 1);
__free_zapped_classes(pf);
delayed_free.scheduled = false;
+ need_callback =
+ prepare_call_rcu_zapped(delayed_free.pf + delayed_free.index);
+ lockdep_unlock();
+ raw_local_irq_restore(flags);
/*
- * If there's anything on the open list, close and start a new callback.
- */
- call_rcu_zapped(delayed_free.pf + delayed_free.index);
+ * If there's pending free and its callback has not been scheduled,
+ * queue an RCU callback.
+ */
+ if (need_callback)
+ call_rcu(&delayed_free.rcu_head, free_zapped_rcu);
- lockdep_unlock();
- raw_local_irq_restore(flags);
}
/*
@@ -6286,6 +6401,7 @@ static void lockdep_free_key_range_reg(void *start, unsigned long size)
{
struct pending_free *pf;
unsigned long flags;
+ bool need_callback;
init_data_structures_once();
@@ -6293,10 +6409,11 @@ static void lockdep_free_key_range_reg(void *start, unsigned long size)
lockdep_lock();
pf = get_pending_free();
__lockdep_free_key_range(pf, start, size);
- call_rcu_zapped(pf);
+ need_callback = prepare_call_rcu_zapped(pf);
lockdep_unlock();
raw_local_irq_restore(flags);
-
+ if (need_callback)
+ call_rcu(&delayed_free.rcu_head, free_zapped_rcu);
/*
* Wait for any possible iterators from look_up_lock_class() to pass
* before continuing to free the memory they refer to.
@@ -6390,6 +6507,7 @@ static void lockdep_reset_lock_reg(struct lockdep_map *lock)
struct pending_free *pf;
unsigned long flags;
int locked;
+ bool need_callback = false;
raw_local_irq_save(flags);
locked = graph_lock();
@@ -6398,11 +6516,13 @@ static void lockdep_reset_lock_reg(struct lockdep_map *lock)
pf = get_pending_free();
__lockdep_reset_lock(pf, lock);
- call_rcu_zapped(pf);
+ need_callback = prepare_call_rcu_zapped(pf);
graph_unlock();
out_irq:
raw_local_irq_restore(flags);
+ if (need_callback)
+ call_rcu(&delayed_free.rcu_head, free_zapped_rcu);
}
/*
@@ -6446,6 +6566,7 @@ void lockdep_unregister_key(struct lock_class_key *key)
struct pending_free *pf;
unsigned long flags;
bool found = false;
+ bool need_callback = false;
might_sleep();
@@ -6466,11 +6587,14 @@ void lockdep_unregister_key(struct lock_class_key *key)
if (found) {
pf = get_pending_free();
__lockdep_free_key_range(pf, key, 1);
- call_rcu_zapped(pf);
+ need_callback = prepare_call_rcu_zapped(pf);
}
lockdep_unlock();
raw_local_irq_restore(flags);
+ if (need_callback)
+ call_rcu(&delayed_free.rcu_head, free_zapped_rcu);
+
/* Wait until is_dynamic_key() has finished accessing k->hash_entry. */
synchronize_rcu();
}
@@ -6478,17 +6602,17 @@ EXPORT_SYMBOL_GPL(lockdep_unregister_key);
void __init lockdep_init(void)
{
- printk("Lock dependency validator: Copyright (c) 2006 Red Hat, Inc., Ingo Molnar\n");
+ pr_info("Lock dependency validator: Copyright (c) 2006 Red Hat, Inc., Ingo Molnar\n");
- printk("... MAX_LOCKDEP_SUBCLASSES: %lu\n", MAX_LOCKDEP_SUBCLASSES);
- printk("... MAX_LOCK_DEPTH: %lu\n", MAX_LOCK_DEPTH);
- printk("... MAX_LOCKDEP_KEYS: %lu\n", MAX_LOCKDEP_KEYS);
- printk("... CLASSHASH_SIZE: %lu\n", CLASSHASH_SIZE);
- printk("... MAX_LOCKDEP_ENTRIES: %lu\n", MAX_LOCKDEP_ENTRIES);
- printk("... MAX_LOCKDEP_CHAINS: %lu\n", MAX_LOCKDEP_CHAINS);
- printk("... CHAINHASH_SIZE: %lu\n", CHAINHASH_SIZE);
+ pr_info("... MAX_LOCKDEP_SUBCLASSES: %lu\n", MAX_LOCKDEP_SUBCLASSES);
+ pr_info("... MAX_LOCK_DEPTH: %lu\n", MAX_LOCK_DEPTH);
+ pr_info("... MAX_LOCKDEP_KEYS: %lu\n", MAX_LOCKDEP_KEYS);
+ pr_info("... CLASSHASH_SIZE: %lu\n", CLASSHASH_SIZE);
+ pr_info("... MAX_LOCKDEP_ENTRIES: %lu\n", MAX_LOCKDEP_ENTRIES);
+ pr_info("... MAX_LOCKDEP_CHAINS: %lu\n", MAX_LOCKDEP_CHAINS);
+ pr_info("... CHAINHASH_SIZE: %lu\n", CHAINHASH_SIZE);
- printk(" memory used by lock dependency info: %zu kB\n",
+ pr_info(" memory used by lock dependency info: %zu kB\n",
(sizeof(lock_classes) +
sizeof(lock_classes_in_use) +
sizeof(classhash_table) +
@@ -6506,12 +6630,12 @@ void __init lockdep_init(void)
);
#if defined(CONFIG_TRACE_IRQFLAGS) && defined(CONFIG_PROVE_LOCKING)
- printk(" memory used for stack traces: %zu kB\n",
+ pr_info(" memory used for stack traces: %zu kB\n",
(sizeof(stack_trace) + sizeof(stack_trace_hash)) / 1024
);
#endif
- printk(" per task-struct memory footprint: %zu bytes\n",
+ pr_info(" per task-struct memory footprint: %zu bytes\n",
sizeof(((struct task_struct *)NULL)->held_locks));
}
@@ -6524,6 +6648,8 @@ print_freed_lock_bug(struct task_struct *curr, const void *mem_from,
if (debug_locks_silent)
return;
+ nbcon_cpu_emergency_enter();
+
pr_warn("\n");
pr_warn("=========================\n");
pr_warn("WARNING: held lock freed!\n");
@@ -6536,6 +6662,8 @@ print_freed_lock_bug(struct task_struct *curr, const void *mem_from,
pr_warn("\nstack backtrace:\n");
dump_stack();
+
+ nbcon_cpu_emergency_exit();
}
static inline int not_in_range(const void* mem_from, unsigned long mem_len,
@@ -6582,6 +6710,8 @@ static void print_held_locks_bug(void)
if (debug_locks_silent)
return;
+ nbcon_cpu_emergency_enter();
+
pr_warn("\n");
pr_warn("====================================\n");
pr_warn("WARNING: %s/%d still has locks held!\n",
@@ -6591,6 +6721,8 @@ static void print_held_locks_bug(void)
lockdep_print_held_locks(current);
pr_warn("\nstack backtrace:\n");
dump_stack();
+
+ nbcon_cpu_emergency_exit();
}
void debug_check_no_locks_held(void)
@@ -6648,6 +6780,7 @@ asmlinkage __visible void lockdep_sys_exit(void)
if (unlikely(curr->lockdep_depth)) {
if (!debug_locks_off())
return;
+ nbcon_cpu_emergency_enter();
pr_warn("\n");
pr_warn("================================================\n");
pr_warn("WARNING: lock held when returning to user space!\n");
@@ -6656,6 +6789,7 @@ asmlinkage __visible void lockdep_sys_exit(void)
pr_warn("%s/%d is leaving the kernel with locks still held!\n",
curr->comm, curr->pid);
lockdep_print_held_locks(curr);
+ nbcon_cpu_emergency_exit();
}
/*
@@ -6672,6 +6806,7 @@ void lockdep_rcu_suspicious(const char *file, const int line, const char *s)
bool rcu = warn_rcu_enter();
/* Note: the following can be executed concurrently, so be careful. */
+ nbcon_cpu_emergency_enter();
pr_warn("\n");
pr_warn("=============================\n");
pr_warn("WARNING: suspicious RCU usage\n");
@@ -6710,6 +6845,7 @@ void lockdep_rcu_suspicious(const char *file, const int line, const char *s)
lockdep_print_held_locks(curr);
pr_warn("\nstack backtrace:\n");
dump_stack();
+ nbcon_cpu_emergency_exit();
warn_rcu_exit(rcu);
}
EXPORT_SYMBOL_GPL(lockdep_rcu_suspicious);
diff --git a/kernel/locking/lockdep_internals.h b/kernel/locking/lockdep_internals.h
index bbe9000260d0..20f9ef58d3d0 100644
--- a/kernel/locking/lockdep_internals.h
+++ b/kernel/locking/lockdep_internals.h
@@ -119,7 +119,8 @@ static const unsigned long LOCKF_USED_IN_IRQ_READ =
#define MAX_LOCKDEP_CHAINS (1UL << MAX_LOCKDEP_CHAINS_BITS)
-#define MAX_LOCKDEP_CHAIN_HLOCKS (MAX_LOCKDEP_CHAINS*5)
+#define AVG_LOCKDEP_CHAIN_DEPTH 5
+#define MAX_LOCKDEP_CHAIN_HLOCKS (MAX_LOCKDEP_CHAINS * AVG_LOCKDEP_CHAIN_DEPTH)
extern struct lock_chain lock_chains[];
diff --git a/kernel/locking/lockdep_proc.c b/kernel/locking/lockdep_proc.c
index e2bfb1db589d..6db0f43fc4df 100644
--- a/kernel/locking/lockdep_proc.c
+++ b/kernel/locking/lockdep_proc.c
@@ -424,7 +424,7 @@ static void seq_line(struct seq_file *m, char c, int offset, int length)
for (i = 0; i < offset; i++)
seq_puts(m, " ");
for (i = 0; i < length; i++)
- seq_printf(m, "%c", c);
+ seq_putc(m, c);
seq_puts(m, "\n");
}
diff --git a/kernel/locking/locktorture.c b/kernel/locking/locktorture.c
index 415d81e6ce70..cc33470f4de9 100644
--- a/kernel/locking/locktorture.c
+++ b/kernel/locking/locktorture.c
@@ -30,6 +30,7 @@
#include <linux/torture.h>
#include <linux/reboot.h>
+MODULE_DESCRIPTION("torture test facility for locking");
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Paul E. McKenney <paulmck@linux.ibm.com>");
@@ -105,7 +106,7 @@ static const struct kernel_param_ops lt_bind_ops = {
module_param_cb(bind_readers, &lt_bind_ops, &bind_readers, 0644);
module_param_cb(bind_writers, &lt_bind_ops, &bind_writers, 0644);
-long torture_sched_setaffinity(pid_t pid, const struct cpumask *in_mask);
+long torture_sched_setaffinity(pid_t pid, const struct cpumask *in_mask, bool dowarn);
static struct task_struct *stats_task;
static struct task_struct **writer_tasks;
@@ -1357,7 +1358,7 @@ static int __init lock_torture_init(void)
if (torture_init_error(firsterr))
goto unwind;
if (cpumask_nonempty(bind_writers))
- torture_sched_setaffinity(writer_tasks[i]->pid, bind_writers);
+ torture_sched_setaffinity(writer_tasks[i]->pid, bind_writers, true);
create_reader:
if (cxt.cur_ops->readlock == NULL || (j >= cxt.nrealreaders_stress))
@@ -1368,7 +1369,7 @@ static int __init lock_torture_init(void)
if (torture_init_error(firsterr))
goto unwind;
if (cpumask_nonempty(bind_readers))
- torture_sched_setaffinity(reader_tasks[j]->pid, bind_readers);
+ torture_sched_setaffinity(reader_tasks[j]->pid, bind_readers, true);
}
if (stat_interval > 0) {
firsterr = torture_create_kthread(lock_torture_stats, NULL,
diff --git a/kernel/locking/mutex-debug.c b/kernel/locking/mutex-debug.c
index bc8abb8549d2..6e6f6071cfa2 100644
--- a/kernel/locking/mutex-debug.c
+++ b/kernel/locking/mutex-debug.c
@@ -12,6 +12,7 @@
*/
#include <linux/mutex.h>
#include <linux/delay.h>
+#include <linux/device.h>
#include <linux/export.h>
#include <linux/poison.h>
#include <linux/sched.h>
@@ -89,6 +90,17 @@ void debug_mutex_init(struct mutex *lock, const char *name,
lock->magic = lock;
}
+static void devm_mutex_release(void *res)
+{
+ mutex_destroy(res);
+}
+
+int __devm_mutex_init(struct device *dev, struct mutex *lock)
+{
+ return devm_add_action_or_reset(dev, devm_mutex_release, lock);
+}
+EXPORT_SYMBOL_GPL(__devm_mutex_init);
+
/***
* mutex_destroy - mark a mutex unusable
* @lock: the mutex to be destroyed
diff --git a/kernel/locking/mutex.c b/kernel/locking/mutex.c
index cbae8c0b89ab..b36f23de48f1 100644
--- a/kernel/locking/mutex.c
+++ b/kernel/locking/mutex.c
@@ -56,31 +56,6 @@ __mutex_init(struct mutex *lock, const char *name, struct lock_class_key *key)
}
EXPORT_SYMBOL(__mutex_init);
-/*
- * @owner: contains: 'struct task_struct *' to the current lock owner,
- * NULL means not owned. Since task_struct pointers are aligned at
- * at least L1_CACHE_BYTES, we have low bits to store extra state.
- *
- * Bit0 indicates a non-empty waiter list; unlock must issue a wakeup.
- * Bit1 indicates unlock needs to hand the lock to the top-waiter
- * Bit2 indicates handoff has been done and we're waiting for pickup.
- */
-#define MUTEX_FLAG_WAITERS 0x01
-#define MUTEX_FLAG_HANDOFF 0x02
-#define MUTEX_FLAG_PICKUP 0x04
-
-#define MUTEX_FLAGS 0x07
-
-/*
- * Internal helper function; C doesn't allow us to hide it :/
- *
- * DO NOT USE (outside of mutex code).
- */
-static inline struct task_struct *__mutex_owner(struct mutex *lock)
-{
- return (struct task_struct *)(atomic_long_read(&lock->owner) & ~MUTEX_FLAGS);
-}
-
static inline struct task_struct *__owner_task(unsigned long owner)
{
return (struct task_struct *)(owner & ~MUTEX_FLAGS);
@@ -575,8 +550,10 @@ __mutex_lock_common(struct mutex *lock, unsigned int state, unsigned int subclas
struct lockdep_map *nest_lock, unsigned long ip,
struct ww_acquire_ctx *ww_ctx, const bool use_ww_ctx)
{
+ DEFINE_WAKE_Q(wake_q);
struct mutex_waiter waiter;
struct ww_mutex *ww;
+ unsigned long flags;
int ret;
if (!use_ww_ctx)
@@ -619,13 +596,13 @@ __mutex_lock_common(struct mutex *lock, unsigned int state, unsigned int subclas
return 0;
}
- raw_spin_lock(&lock->wait_lock);
+ raw_spin_lock_irqsave(&lock->wait_lock, flags);
/*
* After waiting to acquire the wait_lock, try again.
*/
if (__mutex_trylock(lock)) {
if (ww_ctx)
- __ww_mutex_check_waiters(lock, ww_ctx);
+ __ww_mutex_check_waiters(lock, ww_ctx, &wake_q);
goto skip_wait;
}
@@ -645,7 +622,7 @@ __mutex_lock_common(struct mutex *lock, unsigned int state, unsigned int subclas
* Add in stamp order, waking up waiters that must kill
* themselves.
*/
- ret = __ww_mutex_add_waiter(&waiter, lock, ww_ctx);
+ ret = __ww_mutex_add_waiter(&waiter, lock, ww_ctx, &wake_q);
if (ret)
goto err_early_kill;
}
@@ -680,7 +657,8 @@ __mutex_lock_common(struct mutex *lock, unsigned int state, unsigned int subclas
goto err;
}
- raw_spin_unlock(&lock->wait_lock);
+ raw_spin_unlock_irqrestore_wake(&lock->wait_lock, flags, &wake_q);
+
schedule_preempt_disabled();
first = __mutex_waiter_is_first(lock, &waiter);
@@ -701,9 +679,9 @@ __mutex_lock_common(struct mutex *lock, unsigned int state, unsigned int subclas
trace_contention_begin(lock, LCB_F_MUTEX);
}
- raw_spin_lock(&lock->wait_lock);
+ raw_spin_lock_irqsave(&lock->wait_lock, flags);
}
- raw_spin_lock(&lock->wait_lock);
+ raw_spin_lock_irqsave(&lock->wait_lock, flags);
acquired:
__set_current_state(TASK_RUNNING);
@@ -714,7 +692,7 @@ acquired:
*/
if (!ww_ctx->is_wait_die &&
!__mutex_waiter_is_first(lock, &waiter))
- __ww_mutex_check_waiters(lock, ww_ctx);
+ __ww_mutex_check_waiters(lock, ww_ctx, &wake_q);
}
__mutex_remove_waiter(lock, &waiter);
@@ -729,7 +707,7 @@ skip_wait:
if (ww_ctx)
ww_mutex_lock_acquired(ww, ww_ctx);
- raw_spin_unlock(&lock->wait_lock);
+ raw_spin_unlock_irqrestore_wake(&lock->wait_lock, flags, &wake_q);
preempt_enable();
return 0;
@@ -738,7 +716,7 @@ err:
__mutex_remove_waiter(lock, &waiter);
err_early_kill:
trace_contention_end(lock, ret);
- raw_spin_unlock(&lock->wait_lock);
+ raw_spin_unlock_irqrestore_wake(&lock->wait_lock, flags, &wake_q);
debug_mutex_free_waiter(&waiter);
mutex_release(&lock->dep_map, ip);
preempt_enable();
@@ -908,6 +886,7 @@ static noinline void __sched __mutex_unlock_slowpath(struct mutex *lock, unsigne
struct task_struct *next = NULL;
DEFINE_WAKE_Q(wake_q);
unsigned long owner;
+ unsigned long flags;
mutex_release(&lock->dep_map, ip);
@@ -934,7 +913,7 @@ static noinline void __sched __mutex_unlock_slowpath(struct mutex *lock, unsigne
}
}
- raw_spin_lock(&lock->wait_lock);
+ raw_spin_lock_irqsave(&lock->wait_lock, flags);
debug_mutex_unlock(lock);
if (!list_empty(&lock->wait_list)) {
/* get the first entry from the wait-list: */
@@ -951,9 +930,7 @@ static noinline void __sched __mutex_unlock_slowpath(struct mutex *lock, unsigne
if (owner & MUTEX_FLAG_HANDOFF)
__mutex_handoff(lock, next);
- raw_spin_unlock(&lock->wait_lock);
-
- wake_up_q(&wake_q);
+ raw_spin_unlock_irqrestore_wake(&lock->wait_lock, flags, &wake_q);
}
#ifndef CONFIG_DEBUG_LOCK_ALLOC
diff --git a/kernel/locking/mutex.h b/kernel/locking/mutex.h
index 0b2a79c4013b..cbff35b9b7ae 100644
--- a/kernel/locking/mutex.h
+++ b/kernel/locking/mutex.h
@@ -20,6 +20,33 @@ struct mutex_waiter {
#endif
};
+/*
+ * @owner: contains: 'struct task_struct *' to the current lock owner,
+ * NULL means not owned. Since task_struct pointers are aligned at
+ * at least L1_CACHE_BYTES, we have low bits to store extra state.
+ *
+ * Bit0 indicates a non-empty waiter list; unlock must issue a wakeup.
+ * Bit1 indicates unlock needs to hand the lock to the top-waiter
+ * Bit2 indicates handoff has been done and we're waiting for pickup.
+ */
+#define MUTEX_FLAG_WAITERS 0x01
+#define MUTEX_FLAG_HANDOFF 0x02
+#define MUTEX_FLAG_PICKUP 0x04
+
+#define MUTEX_FLAGS 0x07
+
+/*
+ * Internal helper function; C doesn't allow us to hide it :/
+ *
+ * DO NOT USE (outside of mutex & scheduler code).
+ */
+static inline struct task_struct *__mutex_owner(struct mutex *lock)
+{
+ if (!lock)
+ return NULL;
+ return (struct task_struct *)(atomic_long_read(&lock->owner) & ~MUTEX_FLAGS);
+}
+
#ifdef CONFIG_DEBUG_MUTEXES
extern void debug_mutex_lock_common(struct mutex *lock,
struct mutex_waiter *waiter);
diff --git a/kernel/locking/osq_lock.c b/kernel/locking/osq_lock.c
index 75a6f6133866..b4233dc2c2b0 100644
--- a/kernel/locking/osq_lock.c
+++ b/kernel/locking/osq_lock.c
@@ -215,8 +215,7 @@ void osq_unlock(struct optimistic_spin_queue *lock)
/*
* Fast path for the uncontended case.
*/
- if (likely(atomic_cmpxchg_release(&lock->tail, curr,
- OSQ_UNLOCKED_VAL) == curr))
+ if (atomic_try_cmpxchg_release(&lock->tail, &curr, OSQ_UNLOCKED_VAL))
return;
/*
diff --git a/kernel/locking/percpu-rwsem.c b/kernel/locking/percpu-rwsem.c
index 185bd1c906b0..6083883c4fe0 100644
--- a/kernel/locking/percpu-rwsem.c
+++ b/kernel/locking/percpu-rwsem.c
@@ -223,9 +223,10 @@ static bool readers_active_check(struct percpu_rw_semaphore *sem)
void __sched percpu_down_write(struct percpu_rw_semaphore *sem)
{
+ bool contended = false;
+
might_sleep();
rwsem_acquire(&sem->dep_map, 0, 0, _RET_IP_);
- trace_contention_begin(sem, LCB_F_PERCPU | LCB_F_WRITE);
/* Notify readers to take the slow path. */
rcu_sync_enter(&sem->rss);
@@ -234,8 +235,11 @@ void __sched percpu_down_write(struct percpu_rw_semaphore *sem)
* Try set sem->block; this provides writer-writer exclusion.
* Having sem->block set makes new readers block.
*/
- if (!__percpu_down_write_trylock(sem))
+ if (!__percpu_down_write_trylock(sem)) {
+ trace_contention_begin(sem, LCB_F_PERCPU | LCB_F_WRITE);
percpu_rwsem_wait(sem, /* .reader = */ false);
+ contended = true;
+ }
/* smp_mb() implied by __percpu_down_write_trylock() on success -- D matches A */
@@ -247,7 +251,8 @@ void __sched percpu_down_write(struct percpu_rw_semaphore *sem)
/* Wait for all active readers to complete. */
rcuwait_wait_event(&sem->writer, readers_active_check(sem), TASK_UNINTERRUPTIBLE);
- trace_contention_end(sem, 0);
+ if (contended)
+ trace_contention_end(sem, 0);
}
EXPORT_SYMBOL_GPL(percpu_down_write);
diff --git a/kernel/locking/qspinlock.c b/kernel/locking/qspinlock.c
index ebe6b8ec7cb3..7d96bed718e4 100644
--- a/kernel/locking/qspinlock.c
+++ b/kernel/locking/qspinlock.c
@@ -220,21 +220,18 @@ static __always_inline void clear_pending_set_locked(struct qspinlock *lock)
*/
static __always_inline u32 xchg_tail(struct qspinlock *lock, u32 tail)
{
- u32 old, new, val = atomic_read(&lock->val);
+ u32 old, new;
- for (;;) {
- new = (val & _Q_LOCKED_PENDING_MASK) | tail;
+ old = atomic_read(&lock->val);
+ do {
+ new = (old & _Q_LOCKED_PENDING_MASK) | tail;
/*
* We can use relaxed semantics since the caller ensures that
* the MCS node is properly initialized before updating the
* tail.
*/
- old = atomic_cmpxchg_relaxed(&lock->val, val, new);
- if (old == val)
- break;
+ } while (!atomic_try_cmpxchg_relaxed(&lock->val, &old, new));
- val = old;
- }
return old;
}
#endif /* _Q_PENDING_BITS == 8 */
@@ -586,7 +583,7 @@ EXPORT_SYMBOL(queued_spin_lock_slowpath);
#include "qspinlock_paravirt.h"
#include "qspinlock.c"
-bool nopvspin __initdata;
+bool nopvspin;
static __init int parse_nopvspin(char *arg)
{
nopvspin = true;
diff --git a/kernel/locking/qspinlock_paravirt.h b/kernel/locking/qspinlock_paravirt.h
index 6a0184e9c234..dc1cb90e3644 100644
--- a/kernel/locking/qspinlock_paravirt.h
+++ b/kernel/locking/qspinlock_paravirt.h
@@ -38,13 +38,13 @@
#define PV_PREV_CHECK_MASK 0xff
/*
- * Queue node uses: vcpu_running & vcpu_halted.
- * Queue head uses: vcpu_running & vcpu_hashed.
+ * Queue node uses: VCPU_RUNNING & VCPU_HALTED.
+ * Queue head uses: VCPU_RUNNING & VCPU_HASHED.
*/
enum vcpu_state {
- vcpu_running = 0,
- vcpu_halted, /* Used only in pv_wait_node */
- vcpu_hashed, /* = pv_hash'ed + vcpu_halted */
+ VCPU_RUNNING = 0,
+ VCPU_HALTED, /* Used only in pv_wait_node */
+ VCPU_HASHED, /* = pv_hash'ed + VCPU_HALTED */
};
struct pv_node {
@@ -86,9 +86,10 @@ static inline bool pv_hybrid_queued_unfair_trylock(struct qspinlock *lock)
*/
for (;;) {
int val = atomic_read(&lock->val);
+ u8 old = 0;
if (!(val & _Q_LOCKED_PENDING_MASK) &&
- (cmpxchg_acquire(&lock->locked, 0, _Q_LOCKED_VAL) == 0)) {
+ try_cmpxchg_acquire(&lock->locked, &old, _Q_LOCKED_VAL)) {
lockevent_inc(pv_lock_stealing);
return true;
}
@@ -116,11 +117,12 @@ static __always_inline void set_pending(struct qspinlock *lock)
* barrier. Therefore, an atomic cmpxchg_acquire() is used to acquire the
* lock just to be sure that it will get it.
*/
-static __always_inline int trylock_clear_pending(struct qspinlock *lock)
+static __always_inline bool trylock_clear_pending(struct qspinlock *lock)
{
+ u16 old = _Q_PENDING_VAL;
+
return !READ_ONCE(lock->locked) &&
- (cmpxchg_acquire(&lock->locked_pending, _Q_PENDING_VAL,
- _Q_LOCKED_VAL) == _Q_PENDING_VAL);
+ try_cmpxchg_acquire(&lock->locked_pending, &old, _Q_LOCKED_VAL);
}
#else /* _Q_PENDING_BITS == 8 */
static __always_inline void set_pending(struct qspinlock *lock)
@@ -128,27 +130,21 @@ static __always_inline void set_pending(struct qspinlock *lock)
atomic_or(_Q_PENDING_VAL, &lock->val);
}
-static __always_inline int trylock_clear_pending(struct qspinlock *lock)
+static __always_inline bool trylock_clear_pending(struct qspinlock *lock)
{
- int val = atomic_read(&lock->val);
-
- for (;;) {
- int old, new;
-
- if (val & _Q_LOCKED_MASK)
- break;
+ int old, new;
+ old = atomic_read(&lock->val);
+ do {
+ if (old & _Q_LOCKED_MASK)
+ return false;
/*
* Try to clear pending bit & set locked bit
*/
- old = val;
- new = (val & ~_Q_PENDING_MASK) | _Q_LOCKED_VAL;
- val = atomic_cmpxchg_acquire(&lock->val, old, new);
+ new = (old & ~_Q_PENDING_MASK) | _Q_LOCKED_VAL;
+ } while (!atomic_try_cmpxchg_acquire (&lock->val, &old, new));
- if (val == old)
- return 1;
- }
- return 0;
+ return true;
}
#endif /* _Q_PENDING_BITS == 8 */
@@ -216,8 +212,9 @@ static struct qspinlock **pv_hash(struct qspinlock *lock, struct pv_node *node)
int hopcnt = 0;
for_each_hash_entry(he, offset, hash) {
+ struct qspinlock *old = NULL;
hopcnt++;
- if (!cmpxchg(&he->lock, NULL, lock)) {
+ if (try_cmpxchg(&he->lock, &old, lock)) {
WRITE_ONCE(he->node, node);
lockevent_pv_hop(hopcnt);
return &he->lock;
@@ -269,7 +266,7 @@ pv_wait_early(struct pv_node *prev, int loop)
if ((loop & PV_PREV_CHECK_MASK) != 0)
return false;
- return READ_ONCE(prev->state) != vcpu_running;
+ return READ_ONCE(prev->state) != VCPU_RUNNING;
}
/*
@@ -282,7 +279,7 @@ static void pv_init_node(struct mcs_spinlock *node)
BUILD_BUG_ON(sizeof(struct pv_node) > sizeof(struct qnode));
pn->cpu = smp_processor_id();
- pn->state = vcpu_running;
+ pn->state = VCPU_RUNNING;
}
/*
@@ -294,8 +291,8 @@ static void pv_wait_node(struct mcs_spinlock *node, struct mcs_spinlock *prev)
{
struct pv_node *pn = (struct pv_node *)node;
struct pv_node *pp = (struct pv_node *)prev;
- int loop;
bool wait_early;
+ int loop;
for (;;) {
for (wait_early = false, loop = SPIN_THRESHOLD; loop; loop--) {
@@ -311,26 +308,26 @@ static void pv_wait_node(struct mcs_spinlock *node, struct mcs_spinlock *prev)
/*
* Order pn->state vs pn->locked thusly:
*
- * [S] pn->state = vcpu_halted [S] next->locked = 1
+ * [S] pn->state = VCPU_HALTED [S] next->locked = 1
* MB MB
- * [L] pn->locked [RmW] pn->state = vcpu_hashed
+ * [L] pn->locked [RmW] pn->state = VCPU_HASHED
*
* Matches the cmpxchg() from pv_kick_node().
*/
- smp_store_mb(pn->state, vcpu_halted);
+ smp_store_mb(pn->state, VCPU_HALTED);
if (!READ_ONCE(node->locked)) {
lockevent_inc(pv_wait_node);
lockevent_cond_inc(pv_wait_early, wait_early);
- pv_wait(&pn->state, vcpu_halted);
+ pv_wait(&pn->state, VCPU_HALTED);
}
/*
- * If pv_kick_node() changed us to vcpu_hashed, retain that
+ * If pv_kick_node() changed us to VCPU_HASHED, retain that
* value so that pv_wait_head_or_lock() knows to not also try
* to hash this lock.
*/
- cmpxchg(&pn->state, vcpu_halted, vcpu_running);
+ cmpxchg(&pn->state, VCPU_HALTED, VCPU_RUNNING);
/*
* If the locked flag is still not set after wakeup, it is a
@@ -360,7 +357,7 @@ static void pv_wait_node(struct mcs_spinlock *node, struct mcs_spinlock *prev)
static void pv_kick_node(struct qspinlock *lock, struct mcs_spinlock *node)
{
struct pv_node *pn = (struct pv_node *)node;
-
+ u8 old = VCPU_HALTED;
/*
* If the vCPU is indeed halted, advance its state to match that of
* pv_wait_node(). If OTOH this fails, the vCPU was running and will
@@ -377,8 +374,7 @@ static void pv_kick_node(struct qspinlock *lock, struct mcs_spinlock *node)
* subsequent writes.
*/
smp_mb__before_atomic();
- if (cmpxchg_relaxed(&pn->state, vcpu_halted, vcpu_hashed)
- != vcpu_halted)
+ if (!try_cmpxchg_relaxed(&pn->state, &old, VCPU_HASHED))
return;
/*
@@ -411,7 +407,7 @@ pv_wait_head_or_lock(struct qspinlock *lock, struct mcs_spinlock *node)
* If pv_kick_node() already advanced our state, we don't need to
* insert ourselves into the hash table anymore.
*/
- if (READ_ONCE(pn->state) == vcpu_hashed)
+ if (READ_ONCE(pn->state) == VCPU_HASHED)
lp = (struct qspinlock **)1;
/*
@@ -424,7 +420,7 @@ pv_wait_head_or_lock(struct qspinlock *lock, struct mcs_spinlock *node)
* Set correct vCPU state to be used by queue node wait-early
* mechanism.
*/
- WRITE_ONCE(pn->state, vcpu_running);
+ WRITE_ONCE(pn->state, VCPU_RUNNING);
/*
* Set the pending bit in the active lock spinning loop to
@@ -464,7 +460,7 @@ pv_wait_head_or_lock(struct qspinlock *lock, struct mcs_spinlock *node)
goto gotlock;
}
}
- WRITE_ONCE(pn->state, vcpu_hashed);
+ WRITE_ONCE(pn->state, VCPU_HASHED);
lockevent_inc(pv_wait_head);
lockevent_cond_inc(pv_wait_again, waitcnt);
pv_wait(&lock->locked, _Q_SLOW_VAL);
@@ -546,15 +542,14 @@ __pv_queued_spin_unlock_slowpath(struct qspinlock *lock, u8 locked)
#ifndef __pv_queued_spin_unlock
__visible __lockfunc void __pv_queued_spin_unlock(struct qspinlock *lock)
{
- u8 locked;
+ u8 locked = _Q_LOCKED_VAL;
/*
* We must not unlock if SLOW, because in that case we must first
* unhash. Otherwise it would be possible to have multiple @lock
* entries, which would be BAD.
*/
- locked = cmpxchg_release(&lock->locked, _Q_LOCKED_VAL, 0);
- if (likely(locked == _Q_LOCKED_VAL))
+ if (try_cmpxchg_release(&lock->locked, &locked, 0))
return;
__pv_queued_spin_unlock_slowpath(lock, locked);
diff --git a/kernel/locking/rtmutex.c b/kernel/locking/rtmutex.c
index 4a10e8c16fd2..4a8df1800cbb 100644
--- a/kernel/locking/rtmutex.c
+++ b/kernel/locking/rtmutex.c
@@ -34,13 +34,15 @@
static inline int __ww_mutex_add_waiter(struct rt_mutex_waiter *waiter,
struct rt_mutex *lock,
- struct ww_acquire_ctx *ww_ctx)
+ struct ww_acquire_ctx *ww_ctx,
+ struct wake_q_head *wake_q)
{
return 0;
}
static inline void __ww_mutex_check_waiters(struct rt_mutex *lock,
- struct ww_acquire_ctx *ww_ctx)
+ struct ww_acquire_ctx *ww_ctx,
+ struct wake_q_head *wake_q)
{
}
@@ -237,12 +239,13 @@ static __always_inline bool rt_mutex_cmpxchg_release(struct rt_mutex_base *lock,
*/
static __always_inline void mark_rt_mutex_waiters(struct rt_mutex_base *lock)
{
- unsigned long owner, *p = (unsigned long *) &lock->owner;
+ unsigned long *p = (unsigned long *) &lock->owner;
+ unsigned long owner, new;
+ owner = READ_ONCE(*p);
do {
- owner = *p;
- } while (cmpxchg_relaxed(p, owner,
- owner | RT_MUTEX_HAS_WAITERS) != owner);
+ new = owner | RT_MUTEX_HAS_WAITERS;
+ } while (!try_cmpxchg_relaxed(p, &owner, new));
/*
* The cmpxchg loop above is relaxed to avoid back-to-back ACQUIRE
@@ -346,7 +349,7 @@ static __always_inline int __waiter_prio(struct task_struct *task)
{
int prio = task->prio;
- if (!rt_prio(prio))
+ if (!rt_or_dl_prio(prio))
return DEFAULT_PRIO;
return prio;
@@ -434,7 +437,7 @@ static inline bool rt_mutex_steal(struct rt_mutex_waiter *waiter,
* Note that RT tasks are excluded from same priority (lateral)
* steals to prevent the introduction of an unbounded latency.
*/
- if (rt_prio(waiter->tree.prio) || dl_prio(waiter->tree.prio))
+ if (rt_or_dl_prio(waiter->tree.prio))
return false;
return rt_waiter_node_equal(&waiter->tree, &top_waiter->tree);
@@ -1200,7 +1203,8 @@ static int __sched task_blocks_on_rt_mutex(struct rt_mutex_base *lock,
struct rt_mutex_waiter *waiter,
struct task_struct *task,
struct ww_acquire_ctx *ww_ctx,
- enum rtmutex_chainwalk chwalk)
+ enum rtmutex_chainwalk chwalk,
+ struct wake_q_head *wake_q)
{
struct task_struct *owner = rt_mutex_owner(lock);
struct rt_mutex_waiter *top_waiter = waiter;
@@ -1244,7 +1248,7 @@ static int __sched task_blocks_on_rt_mutex(struct rt_mutex_base *lock,
/* Check whether the waiter should back out immediately */
rtm = container_of(lock, struct rt_mutex, rtmutex);
- res = __ww_mutex_add_waiter(waiter, rtm, ww_ctx);
+ res = __ww_mutex_add_waiter(waiter, rtm, ww_ctx, wake_q);
if (res) {
raw_spin_lock(&task->pi_lock);
rt_mutex_dequeue(lock, waiter);
@@ -1288,7 +1292,7 @@ static int __sched task_blocks_on_rt_mutex(struct rt_mutex_base *lock,
*/
get_task_struct(owner);
- raw_spin_unlock_irq(&lock->wait_lock);
+ raw_spin_unlock_irq_wake(&lock->wait_lock, wake_q);
res = rt_mutex_adjust_prio_chain(owner, chwalk, lock,
next_lock, waiter, task);
@@ -1592,6 +1596,7 @@ static void __sched remove_waiter(struct rt_mutex_base *lock,
* or TASK_UNINTERRUPTIBLE)
* @timeout: the pre-initialized and started timer, or NULL for none
* @waiter: the pre-initialized rt_mutex_waiter
+ * @wake_q: wake_q of tasks to wake when we drop the lock->wait_lock
*
* Must be called with lock->wait_lock held and interrupts disabled
*/
@@ -1599,7 +1604,9 @@ static int __sched rt_mutex_slowlock_block(struct rt_mutex_base *lock,
struct ww_acquire_ctx *ww_ctx,
unsigned int state,
struct hrtimer_sleeper *timeout,
- struct rt_mutex_waiter *waiter)
+ struct rt_mutex_waiter *waiter,
+ struct wake_q_head *wake_q)
+ __releases(&lock->wait_lock) __acquires(&lock->wait_lock)
{
struct rt_mutex *rtm = container_of(lock, struct rt_mutex, rtmutex);
struct task_struct *owner;
@@ -1629,7 +1636,7 @@ static int __sched rt_mutex_slowlock_block(struct rt_mutex_base *lock,
owner = rt_mutex_owner(lock);
else
owner = NULL;
- raw_spin_unlock_irq(&lock->wait_lock);
+ raw_spin_unlock_irq_wake(&lock->wait_lock, wake_q);
if (!owner || !rtmutex_spin_on_owner(lock, waiter, owner))
rt_mutex_schedule();
@@ -1643,6 +1650,7 @@ static int __sched rt_mutex_slowlock_block(struct rt_mutex_base *lock,
}
static void __sched rt_mutex_handle_deadlock(int res, int detect_deadlock,
+ struct rt_mutex_base *lock,
struct rt_mutex_waiter *w)
{
/*
@@ -1655,10 +1663,10 @@ static void __sched rt_mutex_handle_deadlock(int res, int detect_deadlock,
if (build_ww_mutex() && w->ww_ctx)
return;
- /*
- * Yell loudly and stop the task right here.
- */
+ raw_spin_unlock_irq(&lock->wait_lock);
+
WARN(1, "rtmutex deadlock detected\n");
+
while (1) {
set_current_state(TASK_INTERRUPTIBLE);
rt_mutex_schedule();
@@ -1672,12 +1680,14 @@ static void __sched rt_mutex_handle_deadlock(int res, int detect_deadlock,
* @state: The task state for sleeping
* @chwalk: Indicator whether full or partial chainwalk is requested
* @waiter: Initializer waiter for blocking
+ * @wake_q: The wake_q to wake tasks after we release the wait_lock
*/
static int __sched __rt_mutex_slowlock(struct rt_mutex_base *lock,
struct ww_acquire_ctx *ww_ctx,
unsigned int state,
enum rtmutex_chainwalk chwalk,
- struct rt_mutex_waiter *waiter)
+ struct rt_mutex_waiter *waiter,
+ struct wake_q_head *wake_q)
{
struct rt_mutex *rtm = container_of(lock, struct rt_mutex, rtmutex);
struct ww_mutex *ww = ww_container_of(rtm);
@@ -1688,7 +1698,7 @@ static int __sched __rt_mutex_slowlock(struct rt_mutex_base *lock,
/* Try to acquire the lock again: */
if (try_to_take_rt_mutex(lock, current, NULL)) {
if (build_ww_mutex() && ww_ctx) {
- __ww_mutex_check_waiters(rtm, ww_ctx);
+ __ww_mutex_check_waiters(rtm, ww_ctx, wake_q);
ww_mutex_lock_acquired(ww, ww_ctx);
}
return 0;
@@ -1698,21 +1708,21 @@ static int __sched __rt_mutex_slowlock(struct rt_mutex_base *lock,
trace_contention_begin(lock, LCB_F_RT);
- ret = task_blocks_on_rt_mutex(lock, waiter, current, ww_ctx, chwalk);
+ ret = task_blocks_on_rt_mutex(lock, waiter, current, ww_ctx, chwalk, wake_q);
if (likely(!ret))
- ret = rt_mutex_slowlock_block(lock, ww_ctx, state, NULL, waiter);
+ ret = rt_mutex_slowlock_block(lock, ww_ctx, state, NULL, waiter, wake_q);
if (likely(!ret)) {
/* acquired the lock */
if (build_ww_mutex() && ww_ctx) {
if (!ww_ctx->is_wait_die)
- __ww_mutex_check_waiters(rtm, ww_ctx);
+ __ww_mutex_check_waiters(rtm, ww_ctx, wake_q);
ww_mutex_lock_acquired(ww, ww_ctx);
}
} else {
__set_current_state(TASK_RUNNING);
remove_waiter(lock, waiter);
- rt_mutex_handle_deadlock(ret, chwalk, waiter);
+ rt_mutex_handle_deadlock(ret, chwalk, lock, waiter);
}
/*
@@ -1728,7 +1738,8 @@ static int __sched __rt_mutex_slowlock(struct rt_mutex_base *lock,
static inline int __rt_mutex_slowlock_locked(struct rt_mutex_base *lock,
struct ww_acquire_ctx *ww_ctx,
- unsigned int state)
+ unsigned int state,
+ struct wake_q_head *wake_q)
{
struct rt_mutex_waiter waiter;
int ret;
@@ -1737,7 +1748,7 @@ static inline int __rt_mutex_slowlock_locked(struct rt_mutex_base *lock,
waiter.ww_ctx = ww_ctx;
ret = __rt_mutex_slowlock(lock, ww_ctx, state, RT_MUTEX_MIN_CHAINWALK,
- &waiter);
+ &waiter, wake_q);
debug_rt_mutex_free_waiter(&waiter);
return ret;
@@ -1753,6 +1764,7 @@ static int __sched rt_mutex_slowlock(struct rt_mutex_base *lock,
struct ww_acquire_ctx *ww_ctx,
unsigned int state)
{
+ DEFINE_WAKE_Q(wake_q);
unsigned long flags;
int ret;
@@ -1774,8 +1786,8 @@ static int __sched rt_mutex_slowlock(struct rt_mutex_base *lock,
* irqsave/restore variants.
*/
raw_spin_lock_irqsave(&lock->wait_lock, flags);
- ret = __rt_mutex_slowlock_locked(lock, ww_ctx, state);
- raw_spin_unlock_irqrestore(&lock->wait_lock, flags);
+ ret = __rt_mutex_slowlock_locked(lock, ww_ctx, state, &wake_q);
+ raw_spin_unlock_irqrestore_wake(&lock->wait_lock, flags, &wake_q);
rt_mutex_post_schedule();
return ret;
@@ -1801,8 +1813,11 @@ static __always_inline int __rt_mutex_lock(struct rt_mutex_base *lock,
/**
* rtlock_slowlock_locked - Slow path lock acquisition for RT locks
* @lock: The underlying RT mutex
+ * @wake_q: The wake_q to wake tasks after we release the wait_lock
*/
-static void __sched rtlock_slowlock_locked(struct rt_mutex_base *lock)
+static void __sched rtlock_slowlock_locked(struct rt_mutex_base *lock,
+ struct wake_q_head *wake_q)
+ __releases(&lock->wait_lock) __acquires(&lock->wait_lock)
{
struct rt_mutex_waiter waiter;
struct task_struct *owner;
@@ -1819,7 +1834,7 @@ static void __sched rtlock_slowlock_locked(struct rt_mutex_base *lock)
trace_contention_begin(lock, LCB_F_RT);
- task_blocks_on_rt_mutex(lock, &waiter, current, NULL, RT_MUTEX_MIN_CHAINWALK);
+ task_blocks_on_rt_mutex(lock, &waiter, current, NULL, RT_MUTEX_MIN_CHAINWALK, wake_q);
for (;;) {
/* Try to acquire the lock again */
@@ -1830,7 +1845,7 @@ static void __sched rtlock_slowlock_locked(struct rt_mutex_base *lock)
owner = rt_mutex_owner(lock);
else
owner = NULL;
- raw_spin_unlock_irq(&lock->wait_lock);
+ raw_spin_unlock_irq_wake(&lock->wait_lock, wake_q);
if (!owner || !rtmutex_spin_on_owner(lock, &waiter, owner))
schedule_rtlock();
@@ -1855,10 +1870,11 @@ static void __sched rtlock_slowlock_locked(struct rt_mutex_base *lock)
static __always_inline void __sched rtlock_slowlock(struct rt_mutex_base *lock)
{
unsigned long flags;
+ DEFINE_WAKE_Q(wake_q);
raw_spin_lock_irqsave(&lock->wait_lock, flags);
- rtlock_slowlock_locked(lock);
- raw_spin_unlock_irqrestore(&lock->wait_lock, flags);
+ rtlock_slowlock_locked(lock, &wake_q);
+ raw_spin_unlock_irqrestore_wake(&lock->wait_lock, flags, &wake_q);
}
#endif /* RT_MUTEX_BUILD_SPINLOCKS */
diff --git a/kernel/locking/rtmutex_api.c b/kernel/locking/rtmutex_api.c
index a6974d044593..191e4720e546 100644
--- a/kernel/locking/rtmutex_api.c
+++ b/kernel/locking/rtmutex_api.c
@@ -175,10 +175,10 @@ bool __sched __rt_mutex_futex_unlock(struct rt_mutex_base *lock,
}
/*
- * We've already deboosted, mark_wakeup_next_waiter() will
- * retain preempt_disabled when we drop the wait_lock, to
- * avoid inversion prior to the wakeup. preempt_disable()
- * therein pairs with rt_mutex_postunlock().
+ * mark_wakeup_next_waiter() deboosts and retains preemption
+ * disabled when dropping the wait_lock, to avoid inversion prior
+ * to the wakeup. preempt_disable() therein pairs with the
+ * preempt_enable() in rt_mutex_postunlock().
*/
mark_wakeup_next_waiter(wqh, lock);
@@ -275,6 +275,7 @@ void __sched rt_mutex_proxy_unlock(struct rt_mutex_base *lock)
* @lock: the rt_mutex to take
* @waiter: the pre-initialized rt_mutex_waiter
* @task: the task to prepare
+ * @wake_q: the wake_q to wake tasks after we release the wait_lock
*
* Starts the rt_mutex acquire; it enqueues the @waiter and does deadlock
* detection. It does not wait, see rt_mutex_wait_proxy_lock() for that.
@@ -291,7 +292,8 @@ void __sched rt_mutex_proxy_unlock(struct rt_mutex_base *lock)
*/
int __sched __rt_mutex_start_proxy_lock(struct rt_mutex_base *lock,
struct rt_mutex_waiter *waiter,
- struct task_struct *task)
+ struct task_struct *task,
+ struct wake_q_head *wake_q)
{
int ret;
@@ -302,7 +304,7 @@ int __sched __rt_mutex_start_proxy_lock(struct rt_mutex_base *lock,
/* We enforce deadlock detection for futexes */
ret = task_blocks_on_rt_mutex(lock, waiter, task, NULL,
- RT_MUTEX_FULL_CHAINWALK);
+ RT_MUTEX_FULL_CHAINWALK, wake_q);
if (ret && !rt_mutex_owner(lock)) {
/*
@@ -341,12 +343,16 @@ int __sched rt_mutex_start_proxy_lock(struct rt_mutex_base *lock,
struct task_struct *task)
{
int ret;
+ DEFINE_WAKE_Q(wake_q);
raw_spin_lock_irq(&lock->wait_lock);
- ret = __rt_mutex_start_proxy_lock(lock, waiter, task);
+ ret = __rt_mutex_start_proxy_lock(lock, waiter, task, &wake_q);
if (unlikely(ret))
remove_waiter(lock, waiter);
+ preempt_disable();
raw_spin_unlock_irq(&lock->wait_lock);
+ wake_up_q(&wake_q);
+ preempt_enable();
return ret;
}
@@ -377,7 +383,7 @@ int __sched rt_mutex_wait_proxy_lock(struct rt_mutex_base *lock,
raw_spin_lock_irq(&lock->wait_lock);
/* sleep on the mutex */
set_current_state(TASK_INTERRUPTIBLE);
- ret = rt_mutex_slowlock_block(lock, NULL, TASK_INTERRUPTIBLE, to, waiter);
+ ret = rt_mutex_slowlock_block(lock, NULL, TASK_INTERRUPTIBLE, to, waiter, NULL);
/*
* try_to_take_rt_mutex() sets the waiter bit unconditionally. We might
* have to fix that up.
diff --git a/kernel/locking/rtmutex_common.h b/kernel/locking/rtmutex_common.h
index 1162e07cdaea..78dd3d8c6554 100644
--- a/kernel/locking/rtmutex_common.h
+++ b/kernel/locking/rtmutex_common.h
@@ -59,8 +59,8 @@ struct rt_mutex_waiter {
};
/**
- * rt_wake_q_head - Wrapper around regular wake_q_head to support
- * "sleeping" spinlocks on RT
+ * struct rt_wake_q_head - Wrapper around regular wake_q_head to support
+ * "sleeping" spinlocks on RT
* @head: The regular wake_q_head for sleeping lock variants
* @rtlock_task: Task pointer for RT lock (spin/rwlock) wakeups
*/
@@ -83,7 +83,8 @@ extern void rt_mutex_init_proxy_locked(struct rt_mutex_base *lock,
extern void rt_mutex_proxy_unlock(struct rt_mutex_base *lock);
extern int __rt_mutex_start_proxy_lock(struct rt_mutex_base *lock,
struct rt_mutex_waiter *waiter,
- struct task_struct *task);
+ struct task_struct *task,
+ struct wake_q_head *);
extern int rt_mutex_start_proxy_lock(struct rt_mutex_base *lock,
struct rt_mutex_waiter *waiter,
struct task_struct *task);
diff --git a/kernel/locking/rwbase_rt.c b/kernel/locking/rwbase_rt.c
index 34a59569db6b..9f4322c07486 100644
--- a/kernel/locking/rwbase_rt.c
+++ b/kernel/locking/rwbase_rt.c
@@ -69,6 +69,7 @@ static int __sched __rwbase_read_lock(struct rwbase_rt *rwb,
unsigned int state)
{
struct rt_mutex_base *rtm = &rwb->rtmutex;
+ DEFINE_WAKE_Q(wake_q);
int ret;
rwbase_pre_schedule();
@@ -110,7 +111,7 @@ static int __sched __rwbase_read_lock(struct rwbase_rt *rwb,
* For rwlocks this returns 0 unconditionally, so the below
* !ret conditionals are optimized out.
*/
- ret = rwbase_rtmutex_slowlock_locked(rtm, state);
+ ret = rwbase_rtmutex_slowlock_locked(rtm, state, &wake_q);
/*
* On success the rtmutex is held, so there can't be a writer
@@ -121,7 +122,12 @@ static int __sched __rwbase_read_lock(struct rwbase_rt *rwb,
*/
if (!ret)
atomic_inc(&rwb->readers);
+
+ preempt_disable();
raw_spin_unlock_irq(&rtm->wait_lock);
+ wake_up_q(&wake_q);
+ preempt_enable();
+
if (!ret)
rwbase_rtmutex_unlock(rtm);
diff --git a/kernel/locking/rwsem.c b/kernel/locking/rwsem.c
index 2340b6d90ec6..2ddb827e3bea 100644
--- a/kernel/locking/rwsem.c
+++ b/kernel/locking/rwsem.c
@@ -35,7 +35,7 @@
/*
* The least significant 2 bits of the owner value has the following
* meanings when set.
- * - Bit 0: RWSEM_READER_OWNED - The rwsem is owned by readers
+ * - Bit 0: RWSEM_READER_OWNED - rwsem may be owned by readers (just a hint)
* - Bit 1: RWSEM_NONSPINNABLE - Cannot spin on a reader-owned lock
*
* When the rwsem is reader-owned and a spinning writer has timed out,
@@ -181,12 +181,21 @@ static inline void rwsem_set_reader_owned(struct rw_semaphore *sem)
__rwsem_set_reader_owned(sem, current);
}
+#ifdef CONFIG_DEBUG_RWSEMS
+/*
+ * Return just the real task structure pointer of the owner
+ */
+static inline struct task_struct *rwsem_owner(struct rw_semaphore *sem)
+{
+ return (struct task_struct *)
+ (atomic_long_read(&sem->owner) & ~RWSEM_OWNER_FLAGS_MASK);
+}
+
/*
* Return true if the rwsem is owned by a reader.
*/
static inline bool is_rwsem_reader_owned(struct rw_semaphore *sem)
{
-#ifdef CONFIG_DEBUG_RWSEMS
/*
* Check the count to see if it is write-locked.
*/
@@ -194,11 +203,9 @@ static inline bool is_rwsem_reader_owned(struct rw_semaphore *sem)
if (count & RWSEM_WRITER_MASK)
return false;
-#endif
return rwsem_test_oflags(sem, RWSEM_READER_OWNED);
}
-#ifdef CONFIG_DEBUG_RWSEMS
/*
* With CONFIG_DEBUG_RWSEMS configured, it will make sure that if there
* is a task pointer in owner of a reader-owned rwsem, it will be the
@@ -266,15 +273,6 @@ static inline bool rwsem_write_trylock(struct rw_semaphore *sem)
}
/*
- * Return just the real task structure pointer of the owner
- */
-static inline struct task_struct *rwsem_owner(struct rw_semaphore *sem)
-{
- return (struct task_struct *)
- (atomic_long_read(&sem->owner) & ~RWSEM_OWNER_FLAGS_MASK);
-}
-
-/*
* Return the real task structure pointer of the owner and the embedded
* flags in the owner. pflags must be non-NULL.
*/
@@ -631,7 +629,7 @@ static inline bool rwsem_try_write_lock(struct rw_semaphore *sem,
* if it is an RT task or wait in the wait queue
* for too long.
*/
- if (has_handoff || (!rt_task(waiter->task) &&
+ if (has_handoff || (!rt_or_dl_task(waiter->task) &&
!time_after(jiffies, waiter->timeout)))
return false;
@@ -914,7 +912,7 @@ static bool rwsem_optimistic_spin(struct rw_semaphore *sem)
if (owner_state != OWNER_WRITER) {
if (need_resched())
break;
- if (rt_task(current) &&
+ if (rt_or_dl_task(current) &&
(prev_owner_state != OWNER_WRITER))
break;
}
@@ -1002,8 +1000,8 @@ rwsem_down_read_slowpath(struct rw_semaphore *sem, long count, unsigned int stat
/*
* To prevent a constant stream of readers from starving a sleeping
- * waiter, don't attempt optimistic lock stealing if the lock is
- * currently owned by readers.
+ * writer, don't attempt optimistic lock stealing if the lock is
+ * very likely owned by readers.
*/
if ((atomic_long_read(&sem->owner) & RWSEM_READER_OWNED) &&
(rcnt > 1) && !(count & RWSEM_WRITER_LOCKED))
@@ -1297,7 +1295,7 @@ static inline int __down_read_trylock(struct rw_semaphore *sem)
/*
* lock for writing
*/
-static inline int __down_write_common(struct rw_semaphore *sem, int state)
+static __always_inline int __down_write_common(struct rw_semaphore *sem, int state)
{
int ret = 0;
@@ -1310,12 +1308,12 @@ static inline int __down_write_common(struct rw_semaphore *sem, int state)
return ret;
}
-static inline void __down_write(struct rw_semaphore *sem)
+static __always_inline void __down_write(struct rw_semaphore *sem)
{
__down_write_common(sem, TASK_UNINTERRUPTIBLE);
}
-static inline int __down_write_killable(struct rw_semaphore *sem)
+static __always_inline int __down_write_killable(struct rw_semaphore *sem)
{
return __down_write_common(sem, TASK_KILLABLE);
}
@@ -1415,8 +1413,8 @@ static inline void __downgrade_write(struct rw_semaphore *sem)
#define rwbase_rtmutex_lock_state(rtm, state) \
__rt_mutex_lock(rtm, state)
-#define rwbase_rtmutex_slowlock_locked(rtm, state) \
- __rt_mutex_slowlock_locked(rtm, NULL, state)
+#define rwbase_rtmutex_slowlock_locked(rtm, state, wq) \
+ __rt_mutex_slowlock_locked(rtm, NULL, state, wq)
#define rwbase_rtmutex_unlock(rtm) \
__rt_mutex_unlock(rtm)
diff --git a/kernel/locking/semaphore.c b/kernel/locking/semaphore.c
index 34bfae72f295..de9117c0e671 100644
--- a/kernel/locking/semaphore.c
+++ b/kernel/locking/semaphore.c
@@ -29,6 +29,7 @@
#include <linux/export.h>
#include <linux/sched.h>
#include <linux/sched/debug.h>
+#include <linux/sched/wake_q.h>
#include <linux/semaphore.h>
#include <linux/spinlock.h>
#include <linux/ftrace.h>
@@ -38,7 +39,7 @@ static noinline void __down(struct semaphore *sem);
static noinline int __down_interruptible(struct semaphore *sem);
static noinline int __down_killable(struct semaphore *sem);
static noinline int __down_timeout(struct semaphore *sem, long timeout);
-static noinline void __up(struct semaphore *sem);
+static noinline void __up(struct semaphore *sem, struct wake_q_head *wake_q);
/**
* down - acquire the semaphore
@@ -183,13 +184,16 @@ EXPORT_SYMBOL(down_timeout);
void __sched up(struct semaphore *sem)
{
unsigned long flags;
+ DEFINE_WAKE_Q(wake_q);
raw_spin_lock_irqsave(&sem->lock, flags);
if (likely(list_empty(&sem->wait_list)))
sem->count++;
else
- __up(sem);
+ __up(sem, &wake_q);
raw_spin_unlock_irqrestore(&sem->lock, flags);
+ if (!wake_q_empty(&wake_q))
+ wake_up_q(&wake_q);
}
EXPORT_SYMBOL(up);
@@ -269,11 +273,12 @@ static noinline int __sched __down_timeout(struct semaphore *sem, long timeout)
return __down_common(sem, TASK_UNINTERRUPTIBLE, timeout);
}
-static noinline void __sched __up(struct semaphore *sem)
+static noinline void __sched __up(struct semaphore *sem,
+ struct wake_q_head *wake_q)
{
struct semaphore_waiter *waiter = list_first_entry(&sem->wait_list,
struct semaphore_waiter, list);
list_del(&waiter->list);
waiter->up = true;
- wake_up_process(waiter->task);
+ wake_q_add(wake_q, waiter->task);
}
diff --git a/kernel/locking/spinlock.c b/kernel/locking/spinlock.c
index 8475a0794f8c..7685defd7c52 100644
--- a/kernel/locking/spinlock.c
+++ b/kernel/locking/spinlock.c
@@ -65,7 +65,7 @@ EXPORT_PER_CPU_SYMBOL(__mmiowb_state);
* towards that other CPU that it should break the lock ASAP.
*/
#define BUILD_LOCK_OPS(op, locktype) \
-void __lockfunc __raw_##op##_lock(locktype##_t *lock) \
+static void __lockfunc __raw_##op##_lock(locktype##_t *lock) \
{ \
for (;;) { \
preempt_disable(); \
@@ -77,7 +77,7 @@ void __lockfunc __raw_##op##_lock(locktype##_t *lock) \
} \
} \
\
-unsigned long __lockfunc __raw_##op##_lock_irqsave(locktype##_t *lock) \
+static unsigned long __lockfunc __raw_##op##_lock_irqsave(locktype##_t *lock) \
{ \
unsigned long flags; \
\
@@ -95,12 +95,12 @@ unsigned long __lockfunc __raw_##op##_lock_irqsave(locktype##_t *lock) \
return flags; \
} \
\
-void __lockfunc __raw_##op##_lock_irq(locktype##_t *lock) \
+static void __lockfunc __raw_##op##_lock_irq(locktype##_t *lock) \
{ \
_raw_##op##_lock_irqsave(lock); \
} \
\
-void __lockfunc __raw_##op##_lock_bh(locktype##_t *lock) \
+static void __lockfunc __raw_##op##_lock_bh(locktype##_t *lock) \
{ \
unsigned long flags; \
\
@@ -413,3 +413,11 @@ notrace int in_lock_functions(unsigned long addr)
&& addr < (unsigned long)__lock_text_end;
}
EXPORT_SYMBOL(in_lock_functions);
+
+#if defined(CONFIG_PROVE_LOCKING) && defined(CONFIG_PREEMPT_RT)
+void notrace lockdep_assert_in_softirq_func(void)
+{
+ lockdep_assert_in_softirq();
+}
+EXPORT_SYMBOL(lockdep_assert_in_softirq_func);
+#endif
diff --git a/kernel/locking/spinlock_rt.c b/kernel/locking/spinlock_rt.c
index 38e292454fcc..db1e11b45de6 100644
--- a/kernel/locking/spinlock_rt.c
+++ b/kernel/locking/spinlock_rt.c
@@ -51,7 +51,7 @@ static __always_inline void __rt_spin_lock(spinlock_t *lock)
migrate_disable();
}
-void __sched rt_spin_lock(spinlock_t *lock)
+void __sched rt_spin_lock(spinlock_t *lock) __acquires(RCU)
{
spin_acquire(&lock->dep_map, 0, 0, _RET_IP_);
__rt_spin_lock(lock);
@@ -75,7 +75,7 @@ void __sched rt_spin_lock_nest_lock(spinlock_t *lock,
EXPORT_SYMBOL(rt_spin_lock_nest_lock);
#endif
-void __sched rt_spin_unlock(spinlock_t *lock)
+void __sched rt_spin_unlock(spinlock_t *lock) __releases(RCU)
{
spin_release(&lock->dep_map, _RET_IP_);
migrate_enable();
@@ -162,9 +162,10 @@ rwbase_rtmutex_lock_state(struct rt_mutex_base *rtm, unsigned int state)
}
static __always_inline int
-rwbase_rtmutex_slowlock_locked(struct rt_mutex_base *rtm, unsigned int state)
+rwbase_rtmutex_slowlock_locked(struct rt_mutex_base *rtm, unsigned int state,
+ struct wake_q_head *wake_q)
{
- rtlock_slowlock_locked(rtm);
+ rtlock_slowlock_locked(rtm, wake_q);
return 0;
}
@@ -225,7 +226,7 @@ int __sched rt_write_trylock(rwlock_t *rwlock)
}
EXPORT_SYMBOL(rt_write_trylock);
-void __sched rt_read_lock(rwlock_t *rwlock)
+void __sched rt_read_lock(rwlock_t *rwlock) __acquires(RCU)
{
rtlock_might_resched();
rwlock_acquire_read(&rwlock->dep_map, 0, 0, _RET_IP_);
@@ -235,7 +236,7 @@ void __sched rt_read_lock(rwlock_t *rwlock)
}
EXPORT_SYMBOL(rt_read_lock);
-void __sched rt_write_lock(rwlock_t *rwlock)
+void __sched rt_write_lock(rwlock_t *rwlock) __acquires(RCU)
{
rtlock_might_resched();
rwlock_acquire(&rwlock->dep_map, 0, 0, _RET_IP_);
@@ -246,7 +247,7 @@ void __sched rt_write_lock(rwlock_t *rwlock)
EXPORT_SYMBOL(rt_write_lock);
#ifdef CONFIG_DEBUG_LOCK_ALLOC
-void __sched rt_write_lock_nested(rwlock_t *rwlock, int subclass)
+void __sched rt_write_lock_nested(rwlock_t *rwlock, int subclass) __acquires(RCU)
{
rtlock_might_resched();
rwlock_acquire(&rwlock->dep_map, subclass, 0, _RET_IP_);
@@ -257,7 +258,7 @@ void __sched rt_write_lock_nested(rwlock_t *rwlock, int subclass)
EXPORT_SYMBOL(rt_write_lock_nested);
#endif
-void __sched rt_read_unlock(rwlock_t *rwlock)
+void __sched rt_read_unlock(rwlock_t *rwlock) __releases(RCU)
{
rwlock_release(&rwlock->dep_map, _RET_IP_);
migrate_enable();
@@ -266,7 +267,7 @@ void __sched rt_read_unlock(rwlock_t *rwlock)
}
EXPORT_SYMBOL(rt_read_unlock);
-void __sched rt_write_unlock(rwlock_t *rwlock)
+void __sched rt_write_unlock(rwlock_t *rwlock) __releases(RCU)
{
rwlock_release(&rwlock->dep_map, _RET_IP_);
rcu_read_unlock();
diff --git a/kernel/locking/test-ww_mutex.c b/kernel/locking/test-ww_mutex.c
index 78719e1ef1b1..bcb1b9fea588 100644
--- a/kernel/locking/test-ww_mutex.c
+++ b/kernel/locking/test-ww_mutex.c
@@ -62,7 +62,8 @@ static int __test_mutex(unsigned int flags)
int ret;
ww_mutex_init(&mtx.mutex, &ww_class);
- ww_acquire_init(&ctx, &ww_class);
+ if (flags & TEST_MTX_CTX)
+ ww_acquire_init(&ctx, &ww_class);
INIT_WORK_ONSTACK(&mtx.work, test_mutex_work);
init_completion(&mtx.ready);
@@ -90,7 +91,8 @@ static int __test_mutex(unsigned int flags)
ret = wait_for_completion_timeout(&mtx.done, TIMEOUT);
}
ww_mutex_unlock(&mtx.mutex);
- ww_acquire_fini(&ctx);
+ if (flags & TEST_MTX_CTX)
+ ww_acquire_fini(&ctx);
if (ret) {
pr_err("%s(flags=%x): mutual exclusion failure\n",
@@ -402,7 +404,7 @@ static inline u32 prandom_u32_below(u32 ceil)
static int *get_random_order(int count)
{
int *order;
- int n, r, tmp;
+ int n, r;
order = kmalloc_array(count, sizeof(*order), GFP_KERNEL);
if (!order)
@@ -413,11 +415,8 @@ static int *get_random_order(int count)
for (n = count - 1; n > 1; n--) {
r = prandom_u32_below(n + 1);
- if (r != n) {
- tmp = order[n];
- order[n] = order[r];
- order[r] = tmp;
- }
+ if (r != n)
+ swap(order[n], order[r]);
}
return order;
@@ -679,7 +678,7 @@ static int __init test_ww_mutex_init(void)
if (ret)
return ret;
- ret = stress(2047, hweight32(STRESS_ALL)*ncpus, STRESS_ALL);
+ ret = stress(2046, hweight32(STRESS_ALL)*ncpus, STRESS_ALL);
if (ret)
return ret;
@@ -697,3 +696,4 @@ module_exit(test_ww_mutex_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Intel Corporation");
+MODULE_DESCRIPTION("API test facility for ww_mutexes");
diff --git a/kernel/locking/ww_mutex.h b/kernel/locking/ww_mutex.h
index 3ad2cc4823e5..37f025a096c9 100644
--- a/kernel/locking/ww_mutex.h
+++ b/kernel/locking/ww_mutex.h
@@ -70,14 +70,14 @@ __ww_mutex_has_waiters(struct mutex *lock)
return atomic_long_read(&lock->owner) & MUTEX_FLAG_WAITERS;
}
-static inline void lock_wait_lock(struct mutex *lock)
+static inline void lock_wait_lock(struct mutex *lock, unsigned long *flags)
{
- raw_spin_lock(&lock->wait_lock);
+ raw_spin_lock_irqsave(&lock->wait_lock, *flags);
}
-static inline void unlock_wait_lock(struct mutex *lock)
+static inline void unlock_wait_lock(struct mutex *lock, unsigned long *flags)
{
- raw_spin_unlock(&lock->wait_lock);
+ raw_spin_unlock_irqrestore(&lock->wait_lock, *flags);
}
static inline void lockdep_assert_wait_lock_held(struct mutex *lock)
@@ -144,14 +144,14 @@ __ww_mutex_has_waiters(struct rt_mutex *lock)
return rt_mutex_has_waiters(&lock->rtmutex);
}
-static inline void lock_wait_lock(struct rt_mutex *lock)
+static inline void lock_wait_lock(struct rt_mutex *lock, unsigned long *flags)
{
- raw_spin_lock(&lock->rtmutex.wait_lock);
+ raw_spin_lock_irqsave(&lock->rtmutex.wait_lock, *flags);
}
-static inline void unlock_wait_lock(struct rt_mutex *lock)
+static inline void unlock_wait_lock(struct rt_mutex *lock, unsigned long *flags)
{
- raw_spin_unlock(&lock->rtmutex.wait_lock);
+ raw_spin_unlock_irqrestore(&lock->rtmutex.wait_lock, *flags);
}
static inline void lockdep_assert_wait_lock_held(struct rt_mutex *lock)
@@ -237,7 +237,7 @@ __ww_ctx_less(struct ww_acquire_ctx *a, struct ww_acquire_ctx *b)
int a_prio = a->task->prio;
int b_prio = b->task->prio;
- if (rt_prio(a_prio) || rt_prio(b_prio)) {
+ if (rt_or_dl_prio(a_prio) || rt_or_dl_prio(b_prio)) {
if (a_prio > b_prio)
return true;
@@ -275,7 +275,7 @@ __ww_ctx_less(struct ww_acquire_ctx *a, struct ww_acquire_ctx *b)
*/
static bool
__ww_mutex_die(struct MUTEX *lock, struct MUTEX_WAITER *waiter,
- struct ww_acquire_ctx *ww_ctx)
+ struct ww_acquire_ctx *ww_ctx, struct wake_q_head *wake_q)
{
if (!ww_ctx->is_wait_die)
return false;
@@ -284,7 +284,7 @@ __ww_mutex_die(struct MUTEX *lock, struct MUTEX_WAITER *waiter,
#ifndef WW_RT
debug_mutex_wake_waiter(lock, waiter);
#endif
- wake_up_process(waiter->task);
+ wake_q_add(wake_q, waiter->task);
}
return true;
@@ -299,7 +299,8 @@ __ww_mutex_die(struct MUTEX *lock, struct MUTEX_WAITER *waiter,
*/
static bool __ww_mutex_wound(struct MUTEX *lock,
struct ww_acquire_ctx *ww_ctx,
- struct ww_acquire_ctx *hold_ctx)
+ struct ww_acquire_ctx *hold_ctx,
+ struct wake_q_head *wake_q)
{
struct task_struct *owner = __ww_mutex_owner(lock);
@@ -331,7 +332,7 @@ static bool __ww_mutex_wound(struct MUTEX *lock,
* wakeup pending to re-read the wounded state.
*/
if (owner != current)
- wake_up_process(owner);
+ wake_q_add(wake_q, owner);
return true;
}
@@ -352,7 +353,8 @@ static bool __ww_mutex_wound(struct MUTEX *lock,
* The current task must not be on the wait list.
*/
static void
-__ww_mutex_check_waiters(struct MUTEX *lock, struct ww_acquire_ctx *ww_ctx)
+__ww_mutex_check_waiters(struct MUTEX *lock, struct ww_acquire_ctx *ww_ctx,
+ struct wake_q_head *wake_q)
{
struct MUTEX_WAITER *cur;
@@ -364,8 +366,8 @@ __ww_mutex_check_waiters(struct MUTEX *lock, struct ww_acquire_ctx *ww_ctx)
if (!cur->ww_ctx)
continue;
- if (__ww_mutex_die(lock, cur, ww_ctx) ||
- __ww_mutex_wound(lock, cur->ww_ctx, ww_ctx))
+ if (__ww_mutex_die(lock, cur, ww_ctx, wake_q) ||
+ __ww_mutex_wound(lock, cur->ww_ctx, ww_ctx, wake_q))
break;
}
}
@@ -377,6 +379,9 @@ __ww_mutex_check_waiters(struct MUTEX *lock, struct ww_acquire_ctx *ww_ctx)
static __always_inline void
ww_mutex_set_context_fastpath(struct ww_mutex *lock, struct ww_acquire_ctx *ctx)
{
+ DEFINE_WAKE_Q(wake_q);
+ unsigned long flags;
+
ww_mutex_lock_acquired(lock, ctx);
/*
@@ -404,9 +409,12 @@ ww_mutex_set_context_fastpath(struct ww_mutex *lock, struct ww_acquire_ctx *ctx)
* Uh oh, we raced in fastpath, check if any of the waiters need to
* die or wound us.
*/
- lock_wait_lock(&lock->base);
- __ww_mutex_check_waiters(&lock->base, ctx);
- unlock_wait_lock(&lock->base);
+ lock_wait_lock(&lock->base, &flags);
+ __ww_mutex_check_waiters(&lock->base, ctx, &wake_q);
+ preempt_disable();
+ unlock_wait_lock(&lock->base, &flags);
+ wake_up_q(&wake_q);
+ preempt_enable();
}
static __always_inline int
@@ -488,7 +496,8 @@ __ww_mutex_check_kill(struct MUTEX *lock, struct MUTEX_WAITER *waiter,
static inline int
__ww_mutex_add_waiter(struct MUTEX_WAITER *waiter,
struct MUTEX *lock,
- struct ww_acquire_ctx *ww_ctx)
+ struct ww_acquire_ctx *ww_ctx,
+ struct wake_q_head *wake_q)
{
struct MUTEX_WAITER *cur, *pos = NULL;
bool is_wait_die;
@@ -532,7 +541,7 @@ __ww_mutex_add_waiter(struct MUTEX_WAITER *waiter,
pos = cur;
/* Wait-Die: ensure younger waiters die. */
- __ww_mutex_die(lock, cur, ww_ctx);
+ __ww_mutex_die(lock, cur, ww_ctx, wake_q);
}
__ww_waiter_add(lock, waiter, pos);
@@ -550,7 +559,7 @@ __ww_mutex_add_waiter(struct MUTEX_WAITER *waiter,
* such that either we or the fastpath will wound @ww->ctx.
*/
smp_mb();
- __ww_mutex_wound(lock, ww_ctx, ww->ctx);
+ __ww_mutex_wound(lock, ww_ctx, ww->ctx, wake_q);
}
return 0;
generated by cgit (git 2.34.1) at 2025-07-28 17:41:46 +0000