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* [GIT PULL] locking fix
@ 2015-03-28 10:07 Ingo Molnar
  0 siblings, 0 replies; 48+ messages in thread
From: Ingo Molnar @ 2015-03-28 10:07 UTC (permalink / raw)
  To: Linus Torvalds
  Cc: linux-kernel, Peter Zijlstra, Thomas Gleixner, Paul E. McKenney,
	Rusty Russell, Andrew Morton

Linus,

Please pull the latest locking-urgent-for-linus git tree from:

   git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git locking-urgent-for-linus

   # HEAD: 35a9393c95b31870a74f51a3e7455f33f5657b6f lockdep: Fix the module unload key range freeing logic

A module unload lockdep race fix.

 Thanks,

	Ingo

------------------>
Peter Zijlstra (1):
      lockdep: Fix the module unload key range freeing logic


 kernel/locking/lockdep.c | 81 ++++++++++++++++++++++++++++++++----------------
 kernel/module.c          |  8 ++---
 2 files changed, 59 insertions(+), 30 deletions(-)

diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
index 88d0d4420ad2..ba77ab5f64dd 100644
--- a/kernel/locking/lockdep.c
+++ b/kernel/locking/lockdep.c
@@ -633,7 +633,7 @@ static int count_matching_names(struct lock_class *new_class)
 	if (!new_class->name)
 		return 0;
 
-	list_for_each_entry(class, &all_lock_classes, lock_entry) {
+	list_for_each_entry_rcu(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))
@@ -700,10 +700,12 @@ look_up_lock_class(struct lockdep_map *lock, unsigned int subclass)
 	hash_head = classhashentry(key);
 
 	/*
-	 * We can walk the hash lockfree, because the hash only
-	 * grows, and we are careful when adding entries to the end:
+	 * We do an RCU walk of the hash, see lockdep_free_key_range().
 	 */
-	list_for_each_entry(class, hash_head, hash_entry) {
+	if (DEBUG_LOCKS_WARN_ON(!irqs_disabled()))
+		return NULL;
+
+	list_for_each_entry_rcu(class, hash_head, hash_entry) {
 		if (class->key == key) {
 			/*
 			 * Huh! same key, different name? Did someone trample
@@ -728,7 +730,8 @@ register_lock_class(struct lockdep_map *lock, unsigned int subclass, int force)
 	struct lockdep_subclass_key *key;
 	struct list_head *hash_head;
 	struct lock_class *class;
-	unsigned long flags;
+
+	DEBUG_LOCKS_WARN_ON(!irqs_disabled());
 
 	class = look_up_lock_class(lock, subclass);
 	if (likely(class))
@@ -750,28 +753,26 @@ register_lock_class(struct lockdep_map *lock, unsigned int subclass, int force)
 	key = lock->key->subkeys + subclass;
 	hash_head = classhashentry(key);
 
-	raw_local_irq_save(flags);
 	if (!graph_lock()) {
-		raw_local_irq_restore(flags);
 		return NULL;
 	}
 	/*
 	 * We have to do the hash-walk again, to avoid races
 	 * with another CPU:
 	 */
-	list_for_each_entry(class, hash_head, hash_entry)
+	list_for_each_entry_rcu(class, hash_head, hash_entry) {
 		if (class->key == key)
 			goto out_unlock_set;
+	}
+
 	/*
 	 * Allocate a new key from the static array, and add it to
 	 * the hash:
 	 */
 	if (nr_lock_classes >= MAX_LOCKDEP_KEYS) {
 		if (!debug_locks_off_graph_unlock()) {
-			raw_local_irq_restore(flags);
 			return NULL;
 		}
-		raw_local_irq_restore(flags);
 
 		print_lockdep_off("BUG: MAX_LOCKDEP_KEYS too low!");
 		dump_stack();
@@ -798,7 +799,6 @@ register_lock_class(struct lockdep_map *lock, unsigned int subclass, int force)
 
 	if (verbose(class)) {
 		graph_unlock();
-		raw_local_irq_restore(flags);
 
 		printk("\nnew class %p: %s", class->key, class->name);
 		if (class->name_version > 1)
@@ -806,15 +806,12 @@ register_lock_class(struct lockdep_map *lock, unsigned int subclass, int force)
 		printk("\n");
 		dump_stack();
 
-		raw_local_irq_save(flags);
 		if (!graph_lock()) {
-			raw_local_irq_restore(flags);
 			return NULL;
 		}
 	}
 out_unlock_set:
 	graph_unlock();
-	raw_local_irq_restore(flags);
 
 out_set_class_cache:
 	if (!subclass || force)
@@ -870,11 +867,9 @@ static int add_lock_to_list(struct lock_class *class, struct lock_class *this,
 	entry->distance = distance;
 	entry->trace = *trace;
 	/*
-	 * Since we never remove from the dependency list, the list can
-	 * be walked lockless by other CPUs, it's only allocation
-	 * that must be protected by the spinlock. But this also means
-	 * we must make new entries visible only once writes to the
-	 * entry become visible - hence the RCU op:
+	 * Both allocation and removal are done under the graph lock; but
+	 * iteration is under RCU-sched; see look_up_lock_class() and
+	 * lockdep_free_key_range().
 	 */
 	list_add_tail_rcu(&entry->entry, head);
 
@@ -1025,7 +1020,9 @@ static int __bfs(struct lock_list *source_entry,
 		else
 			head = &lock->class->locks_before;
 
-		list_for_each_entry(entry, head, entry) {
+		DEBUG_LOCKS_WARN_ON(!irqs_disabled());
+
+		list_for_each_entry_rcu(entry, head, entry) {
 			if (!lock_accessed(entry)) {
 				unsigned int cq_depth;
 				mark_lock_accessed(entry, lock);
@@ -2022,7 +2019,7 @@ static inline int lookup_chain_cache(struct task_struct *curr,
 	 * We can walk it lock-free, because entries only get added
 	 * to the hash:
 	 */
-	list_for_each_entry(chain, hash_head, entry) {
+	list_for_each_entry_rcu(chain, hash_head, entry) {
 		if (chain->chain_key == chain_key) {
 cache_hit:
 			debug_atomic_inc(chain_lookup_hits);
@@ -2996,8 +2993,18 @@ void lockdep_init_map(struct lockdep_map *lock, const char *name,
 	if (unlikely(!debug_locks))
 		return;
 
-	if (subclass)
+	if (subclass) {
+		unsigned long flags;
+
+		if (DEBUG_LOCKS_WARN_ON(current->lockdep_recursion))
+			return;
+
+		raw_local_irq_save(flags);
+		current->lockdep_recursion = 1;
 		register_lock_class(lock, subclass, 1);
+		current->lockdep_recursion = 0;
+		raw_local_irq_restore(flags);
+	}
 }
 EXPORT_SYMBOL_GPL(lockdep_init_map);
 
@@ -3887,9 +3894,17 @@ static inline int within(const void *addr, void *start, unsigned long size)
 	return addr >= start && addr < start + size;
 }
 
+/*
+ * Used in module.c to remove lock classes from memory that is going to be
+ * freed; and possibly re-used by other modules.
+ *
+ * We will have had one sync_sched() before getting here, so we're guaranteed
+ * nobody will look up these exact classes -- they're properly dead but still
+ * allocated.
+ */
 void lockdep_free_key_range(void *start, unsigned long size)
 {
-	struct lock_class *class, *next;
+	struct lock_class *class;
 	struct list_head *head;
 	unsigned long flags;
 	int i;
@@ -3905,7 +3920,7 @@ void lockdep_free_key_range(void *start, unsigned long size)
 		head = classhash_table + i;
 		if (list_empty(head))
 			continue;
-		list_for_each_entry_safe(class, next, head, hash_entry) {
+		list_for_each_entry_rcu(class, head, hash_entry) {
 			if (within(class->key, start, size))
 				zap_class(class);
 			else if (within(class->name, start, size))
@@ -3916,11 +3931,25 @@ void lockdep_free_key_range(void *start, unsigned long size)
 	if (locked)
 		graph_unlock();
 	raw_local_irq_restore(flags);
+
+	/*
+	 * Wait for any possible iterators from look_up_lock_class() to pass
+	 * before continuing to free the memory they refer to.
+	 *
+	 * sync_sched() is sufficient because the read-side is IRQ disable.
+	 */
+	synchronize_sched();
+
+	/*
+	 * XXX at this point we could return the resources to the pool;
+	 * instead we leak them. We would need to change to bitmap allocators
+	 * instead of the linear allocators we have now.
+	 */
 }
 
 void lockdep_reset_lock(struct lockdep_map *lock)
 {
-	struct lock_class *class, *next;
+	struct lock_class *class;
 	struct list_head *head;
 	unsigned long flags;
 	int i, j;
@@ -3948,7 +3977,7 @@ void lockdep_reset_lock(struct lockdep_map *lock)
 		head = classhash_table + i;
 		if (list_empty(head))
 			continue;
-		list_for_each_entry_safe(class, next, head, hash_entry) {
+		list_for_each_entry_rcu(class, head, hash_entry) {
 			int match = 0;
 
 			for (j = 0; j < NR_LOCKDEP_CACHING_CLASSES; j++)
diff --git a/kernel/module.c b/kernel/module.c
index b3d634ed06c9..99fdf94efce8 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -1865,7 +1865,7 @@ static void free_module(struct module *mod)
 	kfree(mod->args);
 	percpu_modfree(mod);
 
-	/* Free lock-classes: */
+	/* Free lock-classes; relies on the preceding sync_rcu(). */
 	lockdep_free_key_range(mod->module_core, mod->core_size);
 
 	/* Finally, free the core (containing the module structure) */
@@ -3349,9 +3349,6 @@ static int load_module(struct load_info *info, const char __user *uargs,
 	module_bug_cleanup(mod);
 	mutex_unlock(&module_mutex);
 
-	/* Free lock-classes: */
-	lockdep_free_key_range(mod->module_core, mod->core_size);
-
 	/* we can't deallocate the module until we clear memory protection */
 	unset_module_init_ro_nx(mod);
 	unset_module_core_ro_nx(mod);
@@ -3375,6 +3372,9 @@ static int load_module(struct load_info *info, const char __user *uargs,
 	synchronize_rcu();
 	mutex_unlock(&module_mutex);
  free_module:
+	/* Free lock-classes; relies on the preceding sync_rcu() */
+	lockdep_free_key_range(mod->module_core, mod->core_size);
+
 	module_deallocate(mod, info);
  free_copy:
 	free_copy(info);

^ permalink raw reply related	[flat|nested] 48+ messages in thread
* [GIT PULL] locking fix
@ 2025-11-08 13:04 Ingo Molnar
  2025-11-08 17:15 ` pr-tracker-bot
  0 siblings, 1 reply; 48+ messages in thread
From: Ingo Molnar @ 2025-11-08 13:04 UTC (permalink / raw)
  To: Linus Torvalds
  Cc: linux-kernel, Peter Zijlstra, Will Deacon, Thomas Gleixner,
	Andrew Morton, Boqun Feng, Waiman Long, Borislav Petkov

Linus,

Please pull the latest locking/urgent Git tree from:

   git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git locking-urgent-2025-11-08

   # HEAD: 4cb5ac2626b5704ed712ac1d46b9d89fdfc12c5d futex: Optimize per-cpu reference counting

Fix (well, cut in half) a futex performance regression on PowerPC.

 Thanks,

	Ingo

------------------>
Peter Zijlstra (1):
      futex: Optimize per-cpu reference counting


 kernel/futex/core.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/kernel/futex/core.c b/kernel/futex/core.c
index 125804fbb5cb..2e77a6e5c865 100644
--- a/kernel/futex/core.c
+++ b/kernel/futex/core.c
@@ -1680,10 +1680,10 @@ static bool futex_ref_get(struct futex_private_hash *fph)
 {
 	struct mm_struct *mm = fph->mm;
 
-	guard(rcu)();
+	guard(preempt)();
 
-	if (smp_load_acquire(&fph->state) == FR_PERCPU) {
-		this_cpu_inc(*mm->futex_ref);
+	if (READ_ONCE(fph->state) == FR_PERCPU) {
+		__this_cpu_inc(*mm->futex_ref);
 		return true;
 	}
 
@@ -1694,10 +1694,10 @@ static bool futex_ref_put(struct futex_private_hash *fph)
 {
 	struct mm_struct *mm = fph->mm;
 
-	guard(rcu)();
+	guard(preempt)();
 
-	if (smp_load_acquire(&fph->state) == FR_PERCPU) {
-		this_cpu_dec(*mm->futex_ref);
+	if (READ_ONCE(fph->state) == FR_PERCPU) {
+		__this_cpu_dec(*mm->futex_ref);
 		return false;
 	}
 

^ permalink raw reply related	[flat|nested] 48+ messages in thread
* [GIT PULL] locking fix
@ 2025-09-07 10:16 Ingo Molnar
  2025-09-07 15:32 ` pr-tracker-bot
  0 siblings, 1 reply; 48+ messages in thread
From: Ingo Molnar @ 2025-09-07 10:16 UTC (permalink / raw)
  To: Linus Torvalds
  Cc: linux-kernel, Peter Zijlstra, Will Deacon, Thomas Gleixner,
	Andrew Morton, Boqun Feng, Waiman Long, Borislav Petkov

Linus,

Please pull the latest locking/urgent Git tree from:

   git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git locking-urgent-2025-09-07

   # HEAD: d9b05321e21e4b218de4ce8a590bf375f58b6346 futex: Move futex_hash_free() back to __mmput()

Fix an 'allocation from atomic context' regression in the futex vmalloc
variant.

 Thanks,

	Ingo

------------------>
Sebastian Andrzej Siewior (1):
      futex: Move futex_hash_free() back to __mmput()


 kernel/fork.c       |  2 +-
 kernel/futex/core.c | 16 ++++++++++++----
 2 files changed, 13 insertions(+), 5 deletions(-)

^ permalink raw reply	[flat|nested] 48+ messages in thread
* [GIT PULL] locking fix
@ 2025-02-28 19:02 Ingo Molnar
  2025-03-01  1:40 ` pr-tracker-bot
  0 siblings, 1 reply; 48+ messages in thread
From: Ingo Molnar @ 2025-02-28 19:02 UTC (permalink / raw)
  To: Linus Torvalds
  Cc: linux-kernel, Peter Zijlstra, Will Deacon, Thomas Gleixner,
	Andrew Morton, Boqun Feng, Waiman Long

Linus,

Please pull the latest locking/urgent Git tree from:

   git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git locking-urgent-2025-02-28

   # HEAD: b9a49520679e98700d3d89689cc91c08a1c88c1d rcuref: Plug slowpath race in rcuref_put()

Fix an rcuref_put() slowpath race.

 Thanks,

	Ingo

------------------>
Thomas Gleixner (1):
      rcuref: Plug slowpath race in rcuref_put()


 include/linux/rcuref.h | 9 ++++++---
 lib/rcuref.c           | 5 ++---
 2 files changed, 8 insertions(+), 6 deletions(-)

^ permalink raw reply	[flat|nested] 48+ messages in thread
* [GIT PULL] locking fix
@ 2025-02-08  9:08 Ingo Molnar
  2025-02-08 20:07 ` pr-tracker-bot
  0 siblings, 1 reply; 48+ messages in thread
From: Ingo Molnar @ 2025-02-08  9:08 UTC (permalink / raw)
  To: Linus Torvalds
  Cc: linux-kernel, Peter Zijlstra, Will Deacon, Thomas Gleixner,
	Andrew Morton, Boqun Feng, Waiman Long

Linus,

Please pull the latest locking/urgent Git tree from:

   git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git locking-urgent-2025-02-08

   # HEAD: 5e0e02f0d7e52cfc8b1adfc778dd02181d8b47b4 futex: Pass in task to futex_queue()

Fix a dangling pointer bug in the futex code used by the
uring code, which isn't causing problems at the moment
due to uring ABI limitations leaving it essentially
unused in current usages, but is a good idea to fix
nevertheless.

 Thanks,

	Ingo

------------------>
Jens Axboe (1):
      futex: Pass in task to futex_queue()


 io_uring/futex.c        |  2 +-
 kernel/futex/core.c     |  5 +++--
 kernel/futex/futex.h    | 11 ++++++++---
 kernel/futex/pi.c       |  2 +-
 kernel/futex/waitwake.c |  4 ++--
 5 files changed, 15 insertions(+), 9 deletions(-)

diff --git a/io_uring/futex.c b/io_uring/futex.c
index 30139cc150f2..e5cc208810ad 100644
--- a/io_uring/futex.c
+++ b/io_uring/futex.c
@@ -338,7 +338,7 @@ int io_futex_wait(struct io_kiocb *req, unsigned int issue_flags)
 		hlist_add_head(&req->hash_node, &ctx->futex_list);
 		io_ring_submit_unlock(ctx, issue_flags);
 
-		futex_queue(&ifd->q, hb);
+		futex_queue(&ifd->q, hb, NULL);
 		return IOU_ISSUE_SKIP_COMPLETE;
 	}
 
diff --git a/kernel/futex/core.c b/kernel/futex/core.c
index ebdd76b4ecbb..3db8567f5a44 100644
--- a/kernel/futex/core.c
+++ b/kernel/futex/core.c
@@ -532,7 +532,8 @@ void futex_q_unlock(struct futex_hash_bucket *hb)
 	futex_hb_waiters_dec(hb);
 }
 
-void __futex_queue(struct futex_q *q, struct futex_hash_bucket *hb)
+void __futex_queue(struct futex_q *q, struct futex_hash_bucket *hb,
+		   struct task_struct *task)
 {
 	int prio;
 
@@ -548,7 +549,7 @@ void __futex_queue(struct futex_q *q, struct futex_hash_bucket *hb)
 
 	plist_node_init(&q->list, prio);
 	plist_add(&q->list, &hb->chain);
-	q->task = current;
+	q->task = task;
 }
 
 /**
diff --git a/kernel/futex/futex.h b/kernel/futex/futex.h
index 99b32e728c4a..6b2f4c7eb720 100644
--- a/kernel/futex/futex.h
+++ b/kernel/futex/futex.h
@@ -285,13 +285,15 @@ static inline int futex_get_value_locked(u32 *dest, u32 __user *from)
 }
 
 extern void __futex_unqueue(struct futex_q *q);
-extern void __futex_queue(struct futex_q *q, struct futex_hash_bucket *hb);
+extern void __futex_queue(struct futex_q *q, struct futex_hash_bucket *hb,
+				struct task_struct *task);
 extern int futex_unqueue(struct futex_q *q);
 
 /**
  * futex_queue() - Enqueue the futex_q on the futex_hash_bucket
  * @q:	The futex_q to enqueue
  * @hb:	The destination hash bucket
+ * @task: Task queueing this futex
  *
  * The hb->lock must be held by the caller, and is released here. A call to
  * futex_queue() is typically paired with exactly one call to futex_unqueue().  The
@@ -299,11 +301,14 @@ extern int futex_unqueue(struct futex_q *q);
  * or nothing if the unqueue is done as part of the wake process and the unqueue
  * state is implicit in the state of woken task (see futex_wait_requeue_pi() for
  * an example).
+ *
+ * Note that @task may be NULL, for async usage of futexes.
  */
-static inline void futex_queue(struct futex_q *q, struct futex_hash_bucket *hb)
+static inline void futex_queue(struct futex_q *q, struct futex_hash_bucket *hb,
+			       struct task_struct *task)
 	__releases(&hb->lock)
 {
-	__futex_queue(q, hb);
+	__futex_queue(q, hb, task);
 	spin_unlock(&hb->lock);
 }
 
diff --git a/kernel/futex/pi.c b/kernel/futex/pi.c
index daea650b16f5..7a941845f7ee 100644
--- a/kernel/futex/pi.c
+++ b/kernel/futex/pi.c
@@ -982,7 +982,7 @@ int futex_lock_pi(u32 __user *uaddr, unsigned int flags, ktime_t *time, int tryl
 	/*
 	 * Only actually queue now that the atomic ops are done:
 	 */
-	__futex_queue(&q, hb);
+	__futex_queue(&q, hb, current);
 
 	if (trylock) {
 		ret = rt_mutex_futex_trylock(&q.pi_state->pi_mutex);
diff --git a/kernel/futex/waitwake.c b/kernel/futex/waitwake.c
index 3a10375d9521..a9056acb75ee 100644
--- a/kernel/futex/waitwake.c
+++ b/kernel/futex/waitwake.c
@@ -350,7 +350,7 @@ void futex_wait_queue(struct futex_hash_bucket *hb, struct futex_q *q,
 	 * access to the hash list and forcing another memory barrier.
 	 */
 	set_current_state(TASK_INTERRUPTIBLE|TASK_FREEZABLE);
-	futex_queue(q, hb);
+	futex_queue(q, hb, current);
 
 	/* Arm the timer */
 	if (timeout)
@@ -461,7 +461,7 @@ int futex_wait_multiple_setup(struct futex_vector *vs, int count, int *woken)
 			 * next futex. Queue each futex at this moment so hb can
 			 * be unlocked.
 			 */
-			futex_queue(q, hb);
+			futex_queue(q, hb, current);
 			continue;
 		}
 

^ permalink raw reply related	[flat|nested] 48+ messages in thread
* [GIT PULL] locking fix
@ 2024-12-29  8:46 Ingo Molnar
  2024-12-29 18:22 ` pr-tracker-bot
  0 siblings, 1 reply; 48+ messages in thread
From: Ingo Molnar @ 2024-12-29  8:46 UTC (permalink / raw)
  To: Linus Torvalds
  Cc: linux-kernel, Peter Zijlstra, Will Deacon, Thomas Gleixner,
	Andrew Morton, Boqun Feng, Waiman Long

Linus,

Please pull the latest locking/urgent Git tree from:

   git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git locking-urgent-2024-12-29

   # HEAD: 4a077914578183ec397ad09f7156a357e00e5d72 locking/rtmutex: Make sure we wake anything on the wake_q when we release the lock->wait_lock

Fix missed rtmutex wakeups causing sporadic boot hangs
and other misbehavior.

 Thanks,

	Ingo

------------------>
John Stultz (1):
      locking/rtmutex: Make sure we wake anything on the wake_q when we release the lock->wait_lock


 kernel/locking/rtmutex.c     | 18 ++++++++++++++++--
 kernel/locking/rtmutex_api.c |  2 +-
 2 files changed, 17 insertions(+), 3 deletions(-)

diff --git a/kernel/locking/rtmutex.c b/kernel/locking/rtmutex.c
index e858de203eb6..697a56d3d949 100644
--- a/kernel/locking/rtmutex.c
+++ b/kernel/locking/rtmutex.c
@@ -1292,7 +1292,13 @@ static int __sched task_blocks_on_rt_mutex(struct rt_mutex_base *lock,
 	 */
 	get_task_struct(owner);
 
+	preempt_disable();
 	raw_spin_unlock_irq(&lock->wait_lock);
+	/* wake up any tasks on the wake_q before calling rt_mutex_adjust_prio_chain */
+	wake_up_q(wake_q);
+	wake_q_init(wake_q);
+	preempt_enable();
+
 
 	res = rt_mutex_adjust_prio_chain(owner, chwalk, lock,
 					 next_lock, waiter, task);
@@ -1596,6 +1602,7 @@ 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
  */
@@ -1603,7 +1610,8 @@ 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);
@@ -1634,7 +1642,13 @@ static int __sched rt_mutex_slowlock_block(struct rt_mutex_base *lock,
 			owner = rt_mutex_owner(lock);
 		else
 			owner = NULL;
+		preempt_disable();
 		raw_spin_unlock_irq(&lock->wait_lock);
+		if (wake_q) {
+			wake_up_q(wake_q);
+			wake_q_init(wake_q);
+		}
+		preempt_enable();
 
 		if (!owner || !rtmutex_spin_on_owner(lock, waiter, owner))
 			rt_mutex_schedule();
@@ -1708,7 +1722,7 @@ static int __sched __rt_mutex_slowlock(struct rt_mutex_base *lock,
 
 	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 */
diff --git a/kernel/locking/rtmutex_api.c b/kernel/locking/rtmutex_api.c
index 33ea31d6a7b3..191e4720e546 100644
--- a/kernel/locking/rtmutex_api.c
+++ b/kernel/locking/rtmutex_api.c
@@ -383,7 +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.

^ permalink raw reply related	[flat|nested] 48+ messages in thread
* [GIT PULL] locking fix
@ 2024-06-08  7:35 Ingo Molnar
  2024-06-08 16:50 ` pr-tracker-bot
  0 siblings, 1 reply; 48+ messages in thread
From: Ingo Molnar @ 2024-06-08  7:35 UTC (permalink / raw)
  To: Linus Torvalds
  Cc: linux-kernel, Peter Zijlstra, Thomas Gleixner, Will Deacon,
	Waiman Long, Boqun Feng

Linus,

Please pull the latest locking/urgent Git tree from:

   git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git locking-urgent-2024-06-08

   # HEAD: f92a59f6d12e31ead999fee9585471b95a8ae8a3 locking/atomic: scripts: fix ${atomic}_sub_and_test() kerneldoc

Fix typos in the kerneldoc of some of the atomic APIs.

 Thanks,

	Ingo

------------------>
Carlos Llamas (1):
      locking/atomic: scripts: fix ${atomic}_sub_and_test() kerneldoc


 include/linux/atomic/atomic-arch-fallback.h | 6 +++---
 include/linux/atomic/atomic-instrumented.h  | 8 ++++----
 include/linux/atomic/atomic-long.h          | 4 ++--
 scripts/atomic/kerneldoc/sub_and_test       | 2 +-
 4 files changed, 10 insertions(+), 10 deletions(-)

^ permalink raw reply	[flat|nested] 48+ messages in thread
* [GIT PULL] locking fix
@ 2024-04-14  8:01 Ingo Molnar
  2024-04-14 18:48 ` pr-tracker-bot
  0 siblings, 1 reply; 48+ messages in thread
From: Ingo Molnar @ 2024-04-14  8:01 UTC (permalink / raw)
  To: Linus Torvalds
  Cc: linux-kernel, Peter Zijlstra, Thomas Gleixner, Will Deacon,
	Waiman Long, Boqun Feng

Linus,

Please pull the latest locking/urgent git tree from:

   git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git locking-urgent-2024-04-14

   # HEAD: fa1f51162338b3e2f520d4bfedc42b3b2e00da6d locking: Make rwsem_assert_held_write_nolockdep() build with PREEMPT_RT=y

Fix a PREEMPT_RT build bug.

Thanks,

	Ingo

------------------>
Sebastian Andrzej Siewior (1):
      locking: Make rwsem_assert_held_write_nolockdep() build with PREEMPT_RT=y


 include/linux/rwbase_rt.h | 4 ++--
 include/linux/rwsem.h     | 6 +++---
 2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/include/linux/rwbase_rt.h b/include/linux/rwbase_rt.h
index 29c4e4f243e4..f2394a409c9d 100644
--- a/include/linux/rwbase_rt.h
+++ b/include/linux/rwbase_rt.h
@@ -31,9 +31,9 @@ static __always_inline bool rw_base_is_locked(const struct rwbase_rt *rwb)
 	return atomic_read(&rwb->readers) != READER_BIAS;
 }
 
-static inline void rw_base_assert_held_write(const struct rwbase_rt *rwb)
+static __always_inline bool rw_base_is_write_locked(const struct rwbase_rt *rwb)
 {
-	WARN_ON(atomic_read(&rwb->readers) != WRITER_BIAS);
+	return atomic_read(&rwb->readers) == WRITER_BIAS;
 }
 
 static __always_inline bool rw_base_is_contended(const struct rwbase_rt *rwb)
diff --git a/include/linux/rwsem.h b/include/linux/rwsem.h
index 4f1c18992f76..c8b543d428b0 100644
--- a/include/linux/rwsem.h
+++ b/include/linux/rwsem.h
@@ -167,14 +167,14 @@ static __always_inline int rwsem_is_locked(const struct rw_semaphore *sem)
 	return rw_base_is_locked(&sem->rwbase);
 }
 
-static inline void rwsem_assert_held_nolockdep(const struct rw_semaphore *sem)
+static __always_inline void rwsem_assert_held_nolockdep(const struct rw_semaphore *sem)
 {
 	WARN_ON(!rwsem_is_locked(sem));
 }
 
-static inline void rwsem_assert_held_write_nolockdep(const struct rw_semaphore *sem)
+static __always_inline void rwsem_assert_held_write_nolockdep(const struct rw_semaphore *sem)
 {
-	rw_base_assert_held_write(sem);
+	WARN_ON(!rw_base_is_write_locked(&sem->rwbase));
 }
 
 static __always_inline int rwsem_is_contended(struct rw_semaphore *sem)

^ permalink raw reply related	[flat|nested] 48+ messages in thread
* [GIT PULL] locking fix
@ 2023-11-26  9:39 Ingo Molnar
  2023-11-26 17:16 ` pr-tracker-bot
  0 siblings, 1 reply; 48+ messages in thread
From: Ingo Molnar @ 2023-11-26  9:39 UTC (permalink / raw)
  To: Linus Torvalds
  Cc: linux-kernel, Peter Zijlstra, Thomas Gleixner, Will Deacon,
	Waiman Long, Boqun Feng

Linus,

Please pull the latest locking/urgent git tree from:

   git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git locking-urgent-2023-11-26

   # HEAD: bca4104b00fec60be330cd32818dd5c70db3d469 lockdep: Fix block chain corruption

Fix lockdep block chain corruption resulting in KASAN warnings.

 Thanks,

	Ingo

------------------>
Peter Zijlstra (1):
      lockdep: Fix block chain corruption


 kernel/locking/lockdep.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
index e85b5ad3e206..151bd3de5936 100644
--- a/kernel/locking/lockdep.c
+++ b/kernel/locking/lockdep.c
@@ -3497,7 +3497,8 @@ static int alloc_chain_hlocks(int req)
 		size = chain_block_size(curr);
 		if (likely(size >= req)) {
 			del_chain_block(0, size, chain_block_next(curr));
-			add_chain_block(curr + req, size - req);
+			if (size > req)
+				add_chain_block(curr + req, size - req);
 			return curr;
 		}
 	}

^ permalink raw reply related	[flat|nested] 48+ messages in thread
* [GIT PULL] locking fix
@ 2023-02-11  8:54 Ingo Molnar
  2023-02-11 19:24 ` pr-tracker-bot
  0 siblings, 1 reply; 48+ messages in thread
From: Ingo Molnar @ 2023-02-11  8:54 UTC (permalink / raw)
  To: Linus Torvalds
  Cc: linux-kernel, Thomas Gleixner, Peter Zijlstra, Andrew Morton,
	Borislav Petkov

Linus,

Please pull the latest locking/urgent git tree from:

   git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git locking-urgent-2023-02-11

   # HEAD: db370a8b9f67ae5f17e3d5482493294467784504 rtmutex: Ensure that the top waiter is always woken up

Fix an rtmutex missed-wakeup bug.

 Thanks,

	Ingo

------------------>
Wander Lairson Costa (1):
      rtmutex: Ensure that the top waiter is always woken up


 kernel/locking/rtmutex.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/kernel/locking/rtmutex.c b/kernel/locking/rtmutex.c
index 010cf4e6d0b8..728f434de2bb 100644
--- a/kernel/locking/rtmutex.c
+++ b/kernel/locking/rtmutex.c
@@ -901,8 +901,9 @@ static int __sched rt_mutex_adjust_prio_chain(struct task_struct *task,
 		 * then we need to wake the new top waiter up to try
 		 * to get the lock.
 		 */
-		if (prerequeue_top_waiter != rt_mutex_top_waiter(lock))
-			wake_up_state(waiter->task, waiter->wake_state);
+		top_waiter = rt_mutex_top_waiter(lock);
+		if (prerequeue_top_waiter != top_waiter)
+			wake_up_state(top_waiter->task, top_waiter->wake_state);
 		raw_spin_unlock_irq(&lock->wait_lock);
 		return 0;
 	}

^ permalink raw reply related	[flat|nested] 48+ messages in thread
* [GIT PULL] locking fix
@ 2021-03-28 10:28 Ingo Molnar
  2021-03-28 19:22 ` pr-tracker-bot
  0 siblings, 1 reply; 48+ messages in thread
From: Ingo Molnar @ 2021-03-28 10:28 UTC (permalink / raw)
  To: Linus Torvalds
  Cc: linux-kernel, Thomas Gleixner, Peter Zijlstra, Andrew Morton

Linus,

Please pull the latest locking/urgent git tree from:

   git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git locking-urgent-2021-03-28

   # HEAD: 291da9d4a9eb3a1cb0610b7f4480f5b52b1825e7 locking/mutex: Fix non debug version of mutex_lock_io_nested()

Fix the non-debug mutex_lock_io_nested() method to map to mutex_lock_io() instead of mutex_lock().

Right now nothing uses this API explicitly, but this is an accident waiting to happen.

 Thanks,

	Ingo

------------------>
Thomas Gleixner (1):
      locking/mutex: Fix non debug version of mutex_lock_io_nested()


 include/linux/mutex.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/linux/mutex.h b/include/linux/mutex.h
index 0cd631a19727..515cff77a4f4 100644
--- a/include/linux/mutex.h
+++ b/include/linux/mutex.h
@@ -185,7 +185,7 @@ extern void mutex_lock_io(struct mutex *lock);
 # define mutex_lock_interruptible_nested(lock, subclass) mutex_lock_interruptible(lock)
 # define mutex_lock_killable_nested(lock, subclass) mutex_lock_killable(lock)
 # define mutex_lock_nest_lock(lock, nest_lock) mutex_lock(lock)
-# define mutex_lock_io_nested(lock, subclass) mutex_lock(lock)
+# define mutex_lock_io_nested(lock, subclass) mutex_lock_io(lock)
 #endif
 
 /*

^ permalink raw reply related	[flat|nested] 48+ messages in thread
* [GIT PULL] locking fix
@ 2019-07-14 11:36 Ingo Molnar
  2019-07-14 18:45 ` pr-tracker-bot
  0 siblings, 1 reply; 48+ messages in thread
From: Ingo Molnar @ 2019-07-14 11:36 UTC (permalink / raw)
  To: Linus Torvalds
  Cc: linux-kernel, Peter Zijlstra, Thomas Gleixner, Will Deacon,
	Andrew Morton

Linus,

Please pull the latest locking-urgent-for-linus git tree from:

   git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git locking-urgent-for-linus

   # HEAD: 68d41d8c94a31dfb8233ab90b9baf41a2ed2da68 locking/lockdep: Fix lock used or unused stats error

A single fix for a locking statistics bug.

 Thanks,

	Ingo

------------------>
Yuyang Du (1):
      locking/lockdep: Fix lock used or unused stats error


 kernel/locking/lockdep_proc.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/kernel/locking/lockdep_proc.c b/kernel/locking/lockdep_proc.c
index 9c49ec645d8b..65b6a1600c8f 100644
--- a/kernel/locking/lockdep_proc.c
+++ b/kernel/locking/lockdep_proc.c
@@ -210,6 +210,7 @@ static int lockdep_stats_show(struct seq_file *m, void *v)
 		      nr_hardirq_read_safe = 0, nr_hardirq_read_unsafe = 0,
 		      sum_forward_deps = 0;
 
+#ifdef CONFIG_PROVE_LOCKING
 	list_for_each_entry(class, &all_lock_classes, lock_entry) {
 
 		if (class->usage_mask == 0)
@@ -241,12 +242,12 @@ static int lockdep_stats_show(struct seq_file *m, void *v)
 		if (class->usage_mask & LOCKF_ENABLED_HARDIRQ_READ)
 			nr_hardirq_read_unsafe++;
 
-#ifdef CONFIG_PROVE_LOCKING
 		sum_forward_deps += lockdep_count_forward_deps(class);
-#endif
 	}
 #ifdef CONFIG_DEBUG_LOCKDEP
 	DEBUG_LOCKS_WARN_ON(debug_atomic_read(nr_unused_locks) != nr_unused);
+#endif
+
 #endif
 	seq_printf(m, " lock-classes:                  %11lu [max: %lu]\n",
 			nr_lock_classes, MAX_LOCKDEP_KEYS);

^ permalink raw reply related	[flat|nested] 48+ messages in thread
* [GIT PULL] locking fix
@ 2019-05-16 16:01 Ingo Molnar
  2019-05-16 17:57 ` Linus Torvalds
  2019-05-16 18:20 ` pr-tracker-bot
  0 siblings, 2 replies; 48+ messages in thread
From: Ingo Molnar @ 2019-05-16 16:01 UTC (permalink / raw)
  To: Linus Torvalds
  Cc: linux-kernel, Peter Zijlstra, Thomas Gleixner, Andrew Morton

Linus,

Please pull the latest locking-urgent-for-linus git tree from:

   git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git locking-urgent-for-linus

   # HEAD: a9e9bcb45b1525ba7aea26ed9441e8632aeeda58 locking/rwsem: Prevent decrement of reader count before increment

A single rwsem fix.

 Thanks,

	Ingo

------------------>
Waiman Long (1):
      locking/rwsem: Prevent decrement of reader count before increment


 kernel/locking/rwsem-xadd.c | 46 ++++++++++++++++++++++++++++++---------------
 1 file changed, 31 insertions(+), 15 deletions(-)

diff --git a/kernel/locking/rwsem-xadd.c b/kernel/locking/rwsem-xadd.c
index 6b3ee9948bf1..0b1f77957240 100644
--- a/kernel/locking/rwsem-xadd.c
+++ b/kernel/locking/rwsem-xadd.c
@@ -130,6 +130,7 @@ static void __rwsem_mark_wake(struct rw_semaphore *sem,
 {
 	struct rwsem_waiter *waiter, *tmp;
 	long oldcount, woken = 0, adjustment = 0;
+	struct list_head wlist;
 
 	/*
 	 * Take a peek at the queue head waiter such that we can determine
@@ -188,18 +189,43 @@ static void __rwsem_mark_wake(struct rw_semaphore *sem,
 	 * of the queue. We know that woken will be at least 1 as we accounted
 	 * for above. Note we increment the 'active part' of the count by the
 	 * number of readers before waking any processes up.
+	 *
+	 * We have to do wakeup in 2 passes to prevent the possibility that
+	 * the reader count may be decremented before it is incremented. It
+	 * is because the to-be-woken waiter may not have slept yet. So it
+	 * may see waiter->task got cleared, finish its critical section and
+	 * do an unlock before the reader count increment.
+	 *
+	 * 1) Collect the read-waiters in a separate list, count them and
+	 *    fully increment the reader count in rwsem.
+	 * 2) For each waiters in the new list, clear waiter->task and
+	 *    put them into wake_q to be woken up later.
 	 */
-	list_for_each_entry_safe(waiter, tmp, &sem->wait_list, list) {
-		struct task_struct *tsk;
-
+	list_for_each_entry(waiter, &sem->wait_list, list) {
 		if (waiter->type == RWSEM_WAITING_FOR_WRITE)
 			break;
 
 		woken++;
-		tsk = waiter->task;
+	}
+	list_cut_before(&wlist, &sem->wait_list, &waiter->list);
+
+	adjustment = woken * RWSEM_ACTIVE_READ_BIAS - adjustment;
+	lockevent_cond_inc(rwsem_wake_reader, woken);
+	if (list_empty(&sem->wait_list)) {
+		/* hit end of list above */
+		adjustment -= RWSEM_WAITING_BIAS;
+	}
+
+	if (adjustment)
+		atomic_long_add(adjustment, &sem->count);
+
+	/* 2nd pass */
+	list_for_each_entry_safe(waiter, tmp, &wlist, list) {
+		struct task_struct *tsk;
 
+		tsk = waiter->task;
 		get_task_struct(tsk);
-		list_del(&waiter->list);
+
 		/*
 		 * Ensure calling get_task_struct() before setting the reader
 		 * waiter to nil such that rwsem_down_read_failed() cannot
@@ -213,16 +239,6 @@ static void __rwsem_mark_wake(struct rw_semaphore *sem,
 		 */
 		wake_q_add_safe(wake_q, tsk);
 	}
-
-	adjustment = woken * RWSEM_ACTIVE_READ_BIAS - adjustment;
-	lockevent_cond_inc(rwsem_wake_reader, woken);
-	if (list_empty(&sem->wait_list)) {
-		/* hit end of list above */
-		adjustment -= RWSEM_WAITING_BIAS;
-	}
-
-	if (adjustment)
-		atomic_long_add(adjustment, &sem->count);
 }
 
 /*

^ permalink raw reply related	[flat|nested] 48+ messages in thread
* [GIT PULL] locking fix
@ 2019-04-12 11:53 Ingo Molnar
  2019-04-13  4:05 ` pr-tracker-bot
  0 siblings, 1 reply; 48+ messages in thread
From: Ingo Molnar @ 2019-04-12 11:53 UTC (permalink / raw)
  To: Linus Torvalds
  Cc: linux-kernel, Thomas Gleixner, Peter Zijlstra, Andrew Morton

Linus,

Please pull the latest locking-urgent-for-linus git tree from:

   git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git locking-urgent-for-linus

   # HEAD: 90c1cba2b3b3851c151229f61801919b2904d437 locking/lockdep: Zap lock classes even with lock debugging disabled

Fixes a crash when accessing /proc/lockdep.

 Thanks,

	Ingo

------------------>
Bart Van Assche (1):
      locking/lockdep: Zap lock classes even with lock debugging disabled


 kernel/locking/lockdep.c | 29 ++++++++++++-----------------
 1 file changed, 12 insertions(+), 17 deletions(-)

diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
index 34cdcbedda49..e16766ff184b 100644
--- a/kernel/locking/lockdep.c
+++ b/kernel/locking/lockdep.c
@@ -4689,8 +4689,8 @@ static void free_zapped_rcu(struct rcu_head *ch)
 		return;
 
 	raw_local_irq_save(flags);
-	if (!graph_lock())
-		goto out_irq;
+	arch_spin_lock(&lockdep_lock);
+	current->lockdep_recursion = 1;
 
 	/* closed head */
 	pf = delayed_free.pf + (delayed_free.index ^ 1);
@@ -4702,8 +4702,8 @@ static void free_zapped_rcu(struct rcu_head *ch)
 	 */
 	call_rcu_zapped(delayed_free.pf + delayed_free.index);
 
-	graph_unlock();
-out_irq:
+	current->lockdep_recursion = 0;
+	arch_spin_unlock(&lockdep_lock);
 	raw_local_irq_restore(flags);
 }
 
@@ -4744,21 +4744,17 @@ static void lockdep_free_key_range_reg(void *start, unsigned long size)
 {
 	struct pending_free *pf;
 	unsigned long flags;
-	int locked;
 
 	init_data_structures_once();
 
 	raw_local_irq_save(flags);
-	locked = graph_lock();
-	if (!locked)
-		goto out_irq;
-
+	arch_spin_lock(&lockdep_lock);
+	current->lockdep_recursion = 1;
 	pf = get_pending_free();
 	__lockdep_free_key_range(pf, start, size);
 	call_rcu_zapped(pf);
-
-	graph_unlock();
-out_irq:
+	current->lockdep_recursion = 0;
+	arch_spin_unlock(&lockdep_lock);
 	raw_local_irq_restore(flags);
 
 	/*
@@ -4911,9 +4907,8 @@ void lockdep_unregister_key(struct lock_class_key *key)
 		return;
 
 	raw_local_irq_save(flags);
-	if (!graph_lock())
-		goto out_irq;
-
+	arch_spin_lock(&lockdep_lock);
+	current->lockdep_recursion = 1;
 	pf = get_pending_free();
 	hlist_for_each_entry_rcu(k, hash_head, hash_entry) {
 		if (k == key) {
@@ -4925,8 +4920,8 @@ void lockdep_unregister_key(struct lock_class_key *key)
 	WARN_ON_ONCE(!found);
 	__lockdep_free_key_range(pf, key, 1);
 	call_rcu_zapped(pf);
-	graph_unlock();
-out_irq:
+	current->lockdep_recursion = 0;
+	arch_spin_unlock(&lockdep_lock);
 	raw_local_irq_restore(flags);
 
 	/* Wait until is_dynamic_key() has finished accessing k->hash_entry. */

^ permalink raw reply related	[flat|nested] 48+ messages in thread
* [GIT PULL] locking fix
@ 2017-07-21 10:11 Ingo Molnar
  0 siblings, 0 replies; 48+ messages in thread
From: Ingo Molnar @ 2017-07-21 10:11 UTC (permalink / raw)
  To: Linus Torvalds
  Cc: linux-kernel, Thomas Gleixner, Peter Zijlstra, Andrew Morton

Linus,

Please pull the latest locking-urgent-for-linus git tree from:

   git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git locking-urgent-for-linus

   # HEAD: 69f0d429c413fe96db2c187475cebcc6e3a8c7f5 locking/rtmutex: Remove unnecessary priority adjustment

Remove an unnecessary priority adjustment in the rtmutex code.

 Thanks,

	Ingo

------------------>
Alex Shi (1):
      locking/rtmutex: Remove unnecessary priority adjustment


 kernel/locking/rtmutex.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/kernel/locking/rtmutex.c b/kernel/locking/rtmutex.c
index 78069895032a..649dc9d3951a 100644
--- a/kernel/locking/rtmutex.c
+++ b/kernel/locking/rtmutex.c
@@ -963,7 +963,6 @@ static int task_blocks_on_rt_mutex(struct rt_mutex *lock,
 		return -EDEADLK;
 
 	raw_spin_lock(&task->pi_lock);
-	rt_mutex_adjust_prio(task);
 	waiter->task = task;
 	waiter->lock = lock;
 	waiter->prio = task->prio;

^ permalink raw reply related	[flat|nested] 48+ messages in thread
* [GIT PULL] locking fix
@ 2016-09-13 18:11 Ingo Molnar
  0 siblings, 0 replies; 48+ messages in thread
From: Ingo Molnar @ 2016-09-13 18:11 UTC (permalink / raw)
  To: Linus Torvalds
  Cc: linux-kernel, Peter Zijlstra, Thomas Gleixner, Paul E. McKenney,
	Andrew Morton

Linus,

Please pull the latest locking-urgent-for-linus git tree from:

   git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git locking-urgent-for-linus

   # HEAD: d7127b5e5fa0551be21b86640f1648b224e36d43 locking/barriers: Don't use sizeof(void) in lockless_dereference()

Another lockless_dereference() Sparse fix.

 Thanks,

	Ingo

------------------>
Johannes Berg (1):
      locking/barriers: Don't use sizeof(void) in lockless_dereference()


 include/linux/compiler.h | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/include/linux/compiler.h b/include/linux/compiler.h
index 436aa4e42221..668569844d37 100644
--- a/include/linux/compiler.h
+++ b/include/linux/compiler.h
@@ -527,13 +527,14 @@ static __always_inline void __write_once_size(volatile void *p, void *res, int s
  * object's lifetime is managed by something other than RCU.  That
  * "something other" might be reference counting or simple immortality.
  *
- * The seemingly unused size_t variable is to validate @p is indeed a pointer
- * type by making sure it can be dereferenced.
+ * The seemingly unused variable ___typecheck_p validates that @p is
+ * indeed a pointer type by using a pointer to typeof(*p) as the type.
+ * Taking a pointer to typeof(*p) again is needed in case p is void *.
  */
 #define lockless_dereference(p) \
 ({ \
 	typeof(p) _________p1 = READ_ONCE(p); \
-	size_t __maybe_unused __size_of_ptr = sizeof(*(p)); \
+	typeof(*(p)) *___typecheck_p __maybe_unused; \
 	smp_read_barrier_depends(); /* Dependency order vs. p above. */ \
 	(_________p1); \
 })

^ permalink raw reply related	[flat|nested] 48+ messages in thread
* [GIT PULL] locking fix
@ 2016-04-16  9:16 Ingo Molnar
  0 siblings, 0 replies; 48+ messages in thread
From: Ingo Molnar @ 2016-04-16  9:16 UTC (permalink / raw)
  To: Linus Torvalds
  Cc: linux-kernel, Peter Zijlstra, Thomas Gleixner, Andrew Morton,
	Paul E. McKenney

Linus,

Please pull the latest locking-urgent-for-linus git tree from:

   git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git locking-urgent-for-linus

   # HEAD: 5c8a010c2411729a07cb1b90c09fa978ac0ac6c0 locking/lockdep: Fix print_collision() unused warning

Fixes a build warning on certain Kconfig combinations.

 Thanks,

	Ingo

------------------>
Borislav Petkov (1):
      locking/lockdep: Fix print_collision() unused warning


 kernel/locking/lockdep.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
index 2324ba5310db..ed9410936a22 100644
--- a/kernel/locking/lockdep.c
+++ b/kernel/locking/lockdep.c
@@ -1999,6 +1999,7 @@ static inline int get_first_held_lock(struct task_struct *curr,
 	return ++i;
 }
 
+#ifdef CONFIG_DEBUG_LOCKDEP
 /*
  * Returns the next chain_key iteration
  */
@@ -2069,6 +2070,7 @@ static void print_collision(struct task_struct *curr,
 	printk("\nstack backtrace:\n");
 	dump_stack();
 }
+#endif
 
 /*
  * Checks whether the chain and the current held locks are consistent

^ permalink raw reply related	[flat|nested] 48+ messages in thread
* [GIT PULL] locking fix
@ 2015-08-14  7:08 Ingo Molnar
  0 siblings, 0 replies; 48+ messages in thread
From: Ingo Molnar @ 2015-08-14  7:08 UTC (permalink / raw)
  To: Linus Torvalds
  Cc: linux-kernel, Peter Zijlstra, Thomas Gleixner, Paul E. McKenney,
	Andrew Morton

Linus,

Please pull the latest locking-urgent-for-linus git tree from:

   git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git locking-urgent-for-linus

   # HEAD: cba77f03f2c7b6cc0b0a44a3c679e0abade7da62 locking/pvqspinlock: Fix kernel panic in locking-selftest

A single fix for a locking self-test crash.

 Thanks,

	Ingo

------------------>
Waiman Long (1):
      locking/pvqspinlock: Fix kernel panic in locking-selftest


 kernel/locking/qspinlock_paravirt.h | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/kernel/locking/qspinlock_paravirt.h b/kernel/locking/qspinlock_paravirt.h
index 04ab18151cc8..df19ae4debd0 100644
--- a/kernel/locking/qspinlock_paravirt.h
+++ b/kernel/locking/qspinlock_paravirt.h
@@ -4,6 +4,7 @@
 
 #include <linux/hash.h>
 #include <linux/bootmem.h>
+#include <linux/debug_locks.h>
 
 /*
  * Implement paravirt qspinlocks; the general idea is to halt the vcpus instead
@@ -286,15 +287,23 @@ __visible void __pv_queued_spin_unlock(struct qspinlock *lock)
 {
 	struct __qspinlock *l = (void *)lock;
 	struct pv_node *node;
+	u8 lockval = cmpxchg(&l->locked, _Q_LOCKED_VAL, 0);
 
 	/*
 	 * 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.
 	 */
-	if (likely(cmpxchg(&l->locked, _Q_LOCKED_VAL, 0) == _Q_LOCKED_VAL))
+	if (likely(lockval == _Q_LOCKED_VAL))
 		return;
 
+	if (unlikely(lockval != _Q_SLOW_VAL)) {
+		if (debug_locks_silent)
+			return;
+		WARN(1, "pvqspinlock: lock %p has corrupted value 0x%x!\n", lock, atomic_read(&lock->val));
+		return;
+	}
+
 	/*
 	 * Since the above failed to release, this must be the SLOW path.
 	 * Therefore start by looking up the blocked node and unhashing it.

^ permalink raw reply related	[flat|nested] 48+ messages in thread
* [GIT PULL] locking fix
@ 2015-03-01 16:57 Ingo Molnar
  0 siblings, 0 replies; 48+ messages in thread
From: Ingo Molnar @ 2015-03-01 16:57 UTC (permalink / raw)
  To: Linus Torvalds
  Cc: linux-kernel, Peter Zijlstra, Thomas Gleixner, Paul E. McKenney,
	Andrew Morton, Mike Galbraith

Linus,

Please pull the latest locking-urgent-for-linus git tree from:

   git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git locking-urgent-for-linus

   # HEAD: 9d3e2d02f54160725d97f4ab1e1e8de493fbf33a locking/rtmutex: Set state back to running on error

An rtmutex deadlock path fixlet.

 Thanks,

	Ingo

------------------>
Sebastian Andrzej Siewior (1):
      locking/rtmutex: Set state back to running on error


 kernel/locking/rtmutex.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/kernel/locking/rtmutex.c b/kernel/locking/rtmutex.c
index e16e5542bf13..6357265a31ad 100644
--- a/kernel/locking/rtmutex.c
+++ b/kernel/locking/rtmutex.c
@@ -1193,6 +1193,7 @@ rt_mutex_slowlock(struct rt_mutex *lock, int state,
 		ret = __rt_mutex_slowlock(lock, state, timeout, &waiter);
 
 	if (unlikely(ret)) {
+		__set_current_state(TASK_RUNNING);
 		if (rt_mutex_has_waiters(lock))
 			remove_waiter(lock, &waiter);
 		rt_mutex_handle_deadlock(ret, chwalk, &waiter);

^ permalink raw reply related	[flat|nested] 48+ messages in thread
* [GIT PULL] locking fix
@ 2013-10-26 12:19 Ingo Molnar
  2013-10-27 17:28 ` Linus Torvalds
  0 siblings, 1 reply; 48+ messages in thread
From: Ingo Molnar @ 2013-10-26 12:19 UTC (permalink / raw)
  To: Linus Torvalds
  Cc: linux-kernel, Peter Zijlstra, Thomas Gleixner, Andrew Morton

Linus,

Please pull the latest core-urgent-for-linus git tree from:

   git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git core-urgent-for-linus

   # HEAD: b0267507dfd0187fb7840a0ec461a510a7f041c5 mutex: Avoid gcc version dependent __builtin_constant_p() usage

This tree fixes a boot crash in CONFIG_DEBUG_MUTEXES=y kernels, on 
kernels built with GCC 3.x. (There are still such distros.)

 Thanks,

	Ingo

------------------>
Tetsuo Handa (1):
      mutex: Avoid gcc version dependent __builtin_constant_p() usage


 kernel/mutex.c | 32 ++++++++++++++++----------------
 1 file changed, 16 insertions(+), 16 deletions(-)

diff --git a/kernel/mutex.c b/kernel/mutex.c
index 6d647ae..d24105b 100644
--- a/kernel/mutex.c
+++ b/kernel/mutex.c
@@ -410,7 +410,7 @@ ww_mutex_set_context_fastpath(struct ww_mutex *lock,
 static __always_inline int __sched
 __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass,
 		    struct lockdep_map *nest_lock, unsigned long ip,
-		    struct ww_acquire_ctx *ww_ctx)
+		    struct ww_acquire_ctx *ww_ctx, const bool use_ww_ctx)
 {
 	struct task_struct *task = current;
 	struct mutex_waiter waiter;
@@ -450,7 +450,7 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass,
 		struct task_struct *owner;
 		struct mspin_node  node;
 
-		if (!__builtin_constant_p(ww_ctx == NULL) && ww_ctx->acquired > 0) {
+		if (use_ww_ctx && ww_ctx->acquired > 0) {
 			struct ww_mutex *ww;
 
 			ww = container_of(lock, struct ww_mutex, base);
@@ -480,7 +480,7 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass,
 		if ((atomic_read(&lock->count) == 1) &&
 		    (atomic_cmpxchg(&lock->count, 1, 0) == 1)) {
 			lock_acquired(&lock->dep_map, ip);
-			if (!__builtin_constant_p(ww_ctx == NULL)) {
+			if (use_ww_ctx) {
 				struct ww_mutex *ww;
 				ww = container_of(lock, struct ww_mutex, base);
 
@@ -551,7 +551,7 @@ slowpath:
 			goto err;
 		}
 
-		if (!__builtin_constant_p(ww_ctx == NULL) && ww_ctx->acquired > 0) {
+		if (use_ww_ctx && ww_ctx->acquired > 0) {
 			ret = __mutex_lock_check_stamp(lock, ww_ctx);
 			if (ret)
 				goto err;
@@ -575,7 +575,7 @@ skip_wait:
 	lock_acquired(&lock->dep_map, ip);
 	mutex_set_owner(lock);
 
-	if (!__builtin_constant_p(ww_ctx == NULL)) {
+	if (use_ww_ctx) {
 		struct ww_mutex *ww = container_of(lock, struct ww_mutex, base);
 		struct mutex_waiter *cur;
 
@@ -615,7 +615,7 @@ mutex_lock_nested(struct mutex *lock, unsigned int subclass)
 {
 	might_sleep();
 	__mutex_lock_common(lock, TASK_UNINTERRUPTIBLE,
-			    subclass, NULL, _RET_IP_, NULL);
+			    subclass, NULL, _RET_IP_, NULL, 0);
 }
 
 EXPORT_SYMBOL_GPL(mutex_lock_nested);
@@ -625,7 +625,7 @@ _mutex_lock_nest_lock(struct mutex *lock, struct lockdep_map *nest)
 {
 	might_sleep();
 	__mutex_lock_common(lock, TASK_UNINTERRUPTIBLE,
-			    0, nest, _RET_IP_, NULL);
+			    0, nest, _RET_IP_, NULL, 0);
 }
 
 EXPORT_SYMBOL_GPL(_mutex_lock_nest_lock);
@@ -635,7 +635,7 @@ mutex_lock_killable_nested(struct mutex *lock, unsigned int subclass)
 {
 	might_sleep();
 	return __mutex_lock_common(lock, TASK_KILLABLE,
-				   subclass, NULL, _RET_IP_, NULL);
+				   subclass, NULL, _RET_IP_, NULL, 0);
 }
 EXPORT_SYMBOL_GPL(mutex_lock_killable_nested);
 
@@ -644,7 +644,7 @@ mutex_lock_interruptible_nested(struct mutex *lock, unsigned int subclass)
 {
 	might_sleep();
 	return __mutex_lock_common(lock, TASK_INTERRUPTIBLE,
-				   subclass, NULL, _RET_IP_, NULL);
+				   subclass, NULL, _RET_IP_, NULL, 0);
 }
 
 EXPORT_SYMBOL_GPL(mutex_lock_interruptible_nested);
@@ -682,7 +682,7 @@ __ww_mutex_lock(struct ww_mutex *lock, struct ww_acquire_ctx *ctx)
 
 	might_sleep();
 	ret =  __mutex_lock_common(&lock->base, TASK_UNINTERRUPTIBLE,
-				   0, &ctx->dep_map, _RET_IP_, ctx);
+				   0, &ctx->dep_map, _RET_IP_, ctx, 1);
 	if (!ret && ctx->acquired > 1)
 		return ww_mutex_deadlock_injection(lock, ctx);
 
@@ -697,7 +697,7 @@ __ww_mutex_lock_interruptible(struct ww_mutex *lock, struct ww_acquire_ctx *ctx)
 
 	might_sleep();
 	ret = __mutex_lock_common(&lock->base, TASK_INTERRUPTIBLE,
-				  0, &ctx->dep_map, _RET_IP_, ctx);
+				  0, &ctx->dep_map, _RET_IP_, ctx, 1);
 
 	if (!ret && ctx->acquired > 1)
 		return ww_mutex_deadlock_injection(lock, ctx);
@@ -809,28 +809,28 @@ __mutex_lock_slowpath(atomic_t *lock_count)
 	struct mutex *lock = container_of(lock_count, struct mutex, count);
 
 	__mutex_lock_common(lock, TASK_UNINTERRUPTIBLE, 0,
-			    NULL, _RET_IP_, NULL);
+			    NULL, _RET_IP_, NULL, 0);
 }
 
 static noinline int __sched
 __mutex_lock_killable_slowpath(struct mutex *lock)
 {
 	return __mutex_lock_common(lock, TASK_KILLABLE, 0,
-				   NULL, _RET_IP_, NULL);
+				   NULL, _RET_IP_, NULL, 0);
 }
 
 static noinline int __sched
 __mutex_lock_interruptible_slowpath(struct mutex *lock)
 {
 	return __mutex_lock_common(lock, TASK_INTERRUPTIBLE, 0,
-				   NULL, _RET_IP_, NULL);
+				   NULL, _RET_IP_, NULL, 0);
 }
 
 static noinline int __sched
 __ww_mutex_lock_slowpath(struct ww_mutex *lock, struct ww_acquire_ctx *ctx)
 {
 	return __mutex_lock_common(&lock->base, TASK_UNINTERRUPTIBLE, 0,
-				   NULL, _RET_IP_, ctx);
+				   NULL, _RET_IP_, ctx, 1);
 }
 
 static noinline int __sched
@@ -838,7 +838,7 @@ __ww_mutex_lock_interruptible_slowpath(struct ww_mutex *lock,
 					    struct ww_acquire_ctx *ctx)
 {
 	return __mutex_lock_common(&lock->base, TASK_INTERRUPTIBLE, 0,
-				   NULL, _RET_IP_, ctx);
+				   NULL, _RET_IP_, ctx, 1);
 }
 
 #endif

^ permalink raw reply related	[flat|nested] 48+ messages in thread
* [GIT PULL] locking fix
@ 2011-02-15 17:02 Ingo Molnar
  0 siblings, 0 replies; 48+ messages in thread
From: Ingo Molnar @ 2011-02-15 17:02 UTC (permalink / raw)
  To: Linus Torvalds
  Cc: linux-kernel, Peter Zijlstra, Thomas Gleixner, Andrew Morton

Linus,

Please pull the latest core-fixes-for-linus git tree from:

   git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip.git core-fixes-for-linus

 Thanks,

	Ingo

------------------>
Peter Zijlstra (1):
      Revert "lockdep, timer: Fix del_timer_sync() annotation"


 kernel/timer.c |    8 +++-----
 1 files changed, 3 insertions(+), 5 deletions(-)

diff --git a/kernel/timer.c b/kernel/timer.c
index d53ce66..d645992 100644
--- a/kernel/timer.c
+++ b/kernel/timer.c
@@ -959,7 +959,7 @@ EXPORT_SYMBOL(try_to_del_timer_sync);
  *
  * Synchronization rules: Callers must prevent restarting of the timer,
  * otherwise this function is meaningless. It must not be called from
- * hardirq contexts. The caller must not hold locks which would prevent
+ * interrupt contexts. The caller must not hold locks which would prevent
  * completion of the timer's handler. The timer's handler must not call
  * add_timer_on(). Upon exit the timer is not queued and the handler is
  * not running on any CPU.
@@ -971,12 +971,10 @@ int del_timer_sync(struct timer_list *timer)
 #ifdef CONFIG_LOCKDEP
 	unsigned long flags;
 
-	raw_local_irq_save(flags);
-	local_bh_disable();
+	local_irq_save(flags);
 	lock_map_acquire(&timer->lockdep_map);
 	lock_map_release(&timer->lockdep_map);
-	_local_bh_enable();
-	raw_local_irq_restore(flags);
+	local_irq_restore(flags);
 #endif
 	/*
 	 * don't use it in hardirq context, because it

^ permalink raw reply related	[flat|nested] 48+ messages in thread
end of thread, other threads:[~2025-11-08 17:15 UTC | newest]

Thread overview: 48+ messages (download: mbox.gz follow: Atom feed
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2015-03-28 10:07 [GIT PULL] locking fix Ingo Molnar
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2025-11-08 13:04 Ingo Molnar
2025-11-08 17:15 ` pr-tracker-bot
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2025-02-28 19:02 Ingo Molnar
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2024-12-29 18:22 ` pr-tracker-bot
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2024-06-08 16:50 ` pr-tracker-bot
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2024-04-14 18:48 ` pr-tracker-bot
2023-11-26  9:39 Ingo Molnar
2023-11-26 17:16 ` pr-tracker-bot
2023-02-11  8:54 Ingo Molnar
2023-02-11 19:24 ` pr-tracker-bot
2021-03-28 10:28 Ingo Molnar
2021-03-28 19:22 ` pr-tracker-bot
2019-07-14 11:36 Ingo Molnar
2019-07-14 18:45 ` pr-tracker-bot
2019-05-16 16:01 Ingo Molnar
2019-05-16 17:57 ` Linus Torvalds
2019-05-16 18:39   ` Greg KH
2019-05-16 18:42     ` Linus Torvalds
2019-05-16 23:55       ` Sasha Levin
2019-05-17 12:16         ` Greg KH
2019-05-16 18:20 ` pr-tracker-bot
2019-04-12 11:53 Ingo Molnar
2019-04-13  4:05 ` pr-tracker-bot
2017-07-21 10:11 Ingo Molnar
2016-09-13 18:11 Ingo Molnar
2016-04-16  9:16 Ingo Molnar
2015-08-14  7:08 Ingo Molnar
2015-03-01 16:57 Ingo Molnar
2013-10-26 12:19 Ingo Molnar
2013-10-27 17:28 ` Linus Torvalds
2013-10-27 19:00   ` Maarten Lankhorst
2013-10-27 19:23     ` Linus Torvalds
2013-10-27 19:35       ` Linus Torvalds
2013-10-27 19:37       ` Maarten Lankhorst
2013-10-27 19:51         ` Linus Torvalds
2013-10-27 19:56           ` Maarten Lankhorst
2013-10-27 19:59             ` Linus Torvalds
2013-10-28  8:47               ` Ingo Molnar
2011-02-15 17:02 Ingo Molnar

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