Merge tag 'locking-urgent-2026-08-30' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

63783656 · Linus Torvalds <[email protected]> · 2026-08-30 09:57:35 -07:00

Pull locking fix from Ingo Molnar:

 - Revert a commit to spinlock cleanup guards that got caught up
   in the subtle limitations & fragility of guards (again...) and
   caused a regression (Peter Zijlstra)

* tag 'locking-urgent-2026-08-30' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  locking: Revert switching guards to _irq_{disable,enable}()

Commit: 637836563deb95f4338decf2d2d832c4deef022a
Parents: f59c074e · 46094a77

Merge commit. Changes below are compared with the first parent: f59c074e.

Changes

2 files changed · +20 −18

File	Status	Add	Del	Content
include/linux/spinlock.h	modified	+14	−12	View file
kernel/sched/fair.c	modified	+6	−6	View file

include/linux/spinlock.h

View file

diff --git a/include/linux/spinlock.h b/include/linux/spinlock.h
index 799a8f7..3d405cc 100644
--- a/include/linux/spinlock.h
+++ b/include/linux/spinlock.h
@@ -572,12 +572,12 @@ DECLARE_LOCK_GUARD_1_ATTRS(raw_spinlock_nested, __acquires(_T), __releases(*(raw
 #define class_raw_spinlock_nested_constructor(_T) WITH_LOCK_GUARD_1_ATTRS(raw_spinlock_nested, _T)
 
 DEFINE_LOCK_GUARD_1(raw_spinlock_irq, raw_spinlock_t,
-		    raw_spin_lock_irq_disable(_T->lock),
-		    raw_spin_unlock_irq_enable(_T->lock))
+		    raw_spin_lock_irq(_T->lock),
+		    raw_spin_unlock_irq(_T->lock))
 DECLARE_LOCK_GUARD_1_ATTRS(raw_spinlock_irq, __acquires(_T), __releases(*(raw_spinlock_t **)_T))
 #define class_raw_spinlock_irq_constructor(_T) WITH_LOCK_GUARD_1_ATTRS(raw_spinlock_irq, _T)
 
-DEFINE_LOCK_GUARD_1_COND(raw_spinlock_irq, _try, raw_spin_trylock_irq_disable(_T->lock))
+DEFINE_LOCK_GUARD_1_COND(raw_spinlock_irq, _try, raw_spin_trylock_irq(_T->lock))
 DECLARE_LOCK_GUARD_1_ATTRS(raw_spinlock_irq_try, __acquires(_T), __releases(*(raw_spinlock_t **)_T))
 #define class_raw_spinlock_irq_try_constructor(_T) WITH_LOCK_GUARD_1_ATTRS(raw_spinlock_irq_try, _T)
 
@@ -592,13 +592,14 @@ DECLARE_LOCK_GUARD_1_ATTRS(raw_spinlock_bh_try, __acquires(_T), __releases(*(raw
 #define class_raw_spinlock_bh_try_constructor(_T) WITH_LOCK_GUARD_1_ATTRS(raw_spinlock_bh_try, _T)
 
 DEFINE_LOCK_GUARD_1(raw_spinlock_irqsave, raw_spinlock_t,
-		    raw_spin_lock_irq_disable(_T->lock),
-		    raw_spin_unlock_irq_enable(_T->lock))
+		    raw_spin_lock_irqsave(_T->lock, _T->flags),
+		    raw_spin_unlock_irqrestore(_T->lock, _T->flags),
+		    unsigned long flags)
 DECLARE_LOCK_GUARD_1_ATTRS(raw_spinlock_irqsave, __acquires(_T), __releases(*(raw_spinlock_t **)_T))
 #define class_raw_spinlock_irqsave_constructor(_T) WITH_LOCK_GUARD_1_ATTRS(raw_spinlock_irqsave, _T)
 
 DEFINE_LOCK_GUARD_1_COND(raw_spinlock_irqsave, _try,
-			 raw_spin_trylock_irq_disable(_T->lock))
+			 raw_spin_trylock_irqsave(_T->lock, _T->flags))
 DECLARE_LOCK_GUARD_1_ATTRS(raw_spinlock_irqsave_try, __acquires(_T), __releases(*(raw_spinlock_t **)_T))
 #define class_raw_spinlock_irqsave_try_constructor(_T) WITH_LOCK_GUARD_1_ATTRS(raw_spinlock_irqsave_try, _T)
 
@@ -617,13 +618,13 @@ DECLARE_LOCK_GUARD_1_ATTRS(spinlock_try, __acquires(_T), __releases(*(spinlock_t
 #define class_spinlock_try_constructor(_T) WITH_LOCK_GUARD_1_ATTRS(spinlock_try, _T)
 
 DEFINE_LOCK_GUARD_1(spinlock_irq, spinlock_t,
-		    spin_lock_irq_disable(_T->lock),
-		    spin_unlock_irq_enable(_T->lock))
+		    spin_lock_irq(_T->lock),
+		    spin_unlock_irq(_T->lock))
 DECLARE_LOCK_GUARD_1_ATTRS(spinlock_irq, __acquires(_T), __releases(*(spinlock_t **)_T))
 #define class_spinlock_irq_constructor(_T) WITH_LOCK_GUARD_1_ATTRS(spinlock_irq, _T)
 
 DEFINE_LOCK_GUARD_1_COND(spinlock_irq, _try,
-			 spin_trylock_irq_disable(_T->lock))
+			 spin_trylock_irq(_T->lock))
 DECLARE_LOCK_GUARD_1_ATTRS(spinlock_irq_try, __acquires(_T), __releases(*(spinlock_t **)_T))
 #define class_spinlock_irq_try_constructor(_T) WITH_LOCK_GUARD_1_ATTRS(spinlock_irq_try, _T)
 
@@ -639,13 +640,14 @@ DECLARE_LOCK_GUARD_1_ATTRS(spinlock_bh_try, __acquires(_T), __releases(*(spinloc
 #define class_spinlock_bh_try_constructor(_T) WITH_LOCK_GUARD_1_ATTRS(spinlock_bh_try, _T)
 
 DEFINE_LOCK_GUARD_1(spinlock_irqsave, spinlock_t,
-		    spin_lock_irq_disable(_T->lock),
-		    spin_unlock_irq_enable(_T->lock))
+		    spin_lock_irqsave(_T->lock, _T->flags),
+		    spin_unlock_irqrestore(_T->lock, _T->flags),
+		    unsigned long flags)
 DECLARE_LOCK_GUARD_1_ATTRS(spinlock_irqsave, __acquires(_T), __releases(*(spinlock_t **)_T))
 #define class_spinlock_irqsave_constructor(_T) WITH_LOCK_GUARD_1_ATTRS(spinlock_irqsave, _T)
 
 DEFINE_LOCK_GUARD_1_COND(spinlock_irqsave, _try,
-			 spin_trylock_irq_disable(_T->lock))
+			 spin_trylock_irqsave(_T->lock, _T->flags))
 DECLARE_LOCK_GUARD_1_ATTRS(spinlock_irqsave_try, __acquires(_T), __releases(*(spinlock_t **)_T))
 #define class_spinlock_irqsave_try_constructor(_T) WITH_LOCK_GUARD_1_ATTRS(spinlock_irqsave_try, _T)
 

kernel/sched/fair.c

View file

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 6d881e5..8dff370 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -7253,7 +7253,7 @@ static bool distribute_cfs_runtime(struct cfs_bandwidth *cfs_b)
  * period the timer is deactivated until scheduling resumes; cfs_b->idle is
  * used to track this state.
  */
-static int do_sched_cfs_period_timer(struct cfs_bandwidth *cfs_b, int overrun)
+static int do_sched_cfs_period_timer(struct cfs_bandwidth *cfs_b, int overrun, unsigned long flags)
 	__must_hold(&cfs_b->lock)
 {
 	int throttled;
@@ -7288,10 +7288,10 @@ static int do_sched_cfs_period_timer(struct cfs_bandwidth *cfs_b, int overrun)
 	 * This check is repeated as we release cfs_b->lock while we unthrottle.
 	 */
 	while (throttled && cfs_b->runtime > 0) {
-		raw_spin_unlock_irq_enable(&cfs_b->lock);
+		raw_spin_unlock_irqrestore(&cfs_b->lock, flags);
 		/* we can't nest cfs_b->lock while distributing bandwidth */
 		throttled = distribute_cfs_runtime(cfs_b);
-		raw_spin_lock_irq_disable(&cfs_b->lock);
+		raw_spin_lock_irqsave(&cfs_b->lock, flags);
 	}
 
 	/*
@@ -7399,7 +7399,7 @@ static __always_inline void return_cfs_rq_runtime(struct cfs_rq *cfs_rq)
 static void do_sched_cfs_slack_timer(struct cfs_bandwidth *cfs_b)
 {
 	/* confirm we're still not at a refresh boundary */
-	scoped_guard(raw_spinlock_irq, &cfs_b->lock) {
+	scoped_guard(raw_spinlock_irqsave, &cfs_b->lock) {
 		u64 runtime = 0, slice = sched_cfs_bandwidth_slice();
 
 		cfs_b->slack_started = false;
@@ -7484,14 +7484,14 @@ static enum hrtimer_restart sched_cfs_period_timer(struct hrtimer *timer)
 	int idle = 0;
 	int count = 0;
 
-	guard(raw_spinlock_irq)(&cfs_b->lock);
+	CLASS(raw_spinlock_irqsave, cfsb_guard)(&cfs_b->lock);
 
 	for (;;) {
 		overrun = hrtimer_forward_now(timer, cfs_b->period);
 		if (!overrun)
 			break;
 
-		idle = do_sched_cfs_period_timer(cfs_b, overrun);
+		idle = do_sched_cfs_period_timer(cfs_b, overrun, cfsb_guard.flags);
 
 		if (++count > 3) {
 			u64 new, old = ktime_to_ns(cfs_b->period);