Merge tag 'locking-urgent-2025-03-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull misc locking fixes from Ingo Molnar:

 - Restrict the Rust runtime from unintended access to dynamically
   allocated LockClassKeys

 - KernelDoc annotation fix

 - Fix a lock ordering bug in semaphore::up(), related to trying to
   printk() and wake up the console within critical sections

* tag 'locking-urgent-2025-03-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  locking/semaphore: Use wake_q to wake up processes outside lock critical section
  locking/rtmutex: Use the 'struct' keyword in kernel-doc comment
  rust: lockdep: Remove support for dynamically allocated LockClassKeys

2 files changed, 11 insertions, 6 deletions

diff --git a/kernel/locking/rtmutex_common.h b/kernel/locking/rtmutex_common.h
index c38a2d2d4a7e..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
  */
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);
 }