locking: Revert switching guards to _irq_{disable,enable}()

Revert commit 1b0866874833 ("locking: Switch to _irq_{disable,enable}()
variants in cleanup guards").

While the guards are properly nested, not all wrapped code is nice, as already
highlighted by that fair.c hunk.

Syzbot found another instance of this pattern in posix_timer_delete(), which
does spin_unlock_irq()+spin_lock_irq() inside scoped_guard(spinlock_irq).
Combined with this patch, that goes sideways most spectacular.

Undo this until we've developed stronger tools / debug for such issues.

Fixes: 1b0866874833 ("locking: Switch to _irq_{disable,enable}() variants in cleanup guards")
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://patch.msgid.link/20260824105523.GA4121620%40noisy.programming.kicks-ass.net

1 files changed, 14 insertions, 12 deletions

diff --git a/include/linux/spinlock.h b/include/linux/spinlock.h
index 799a8f7d2741..3d405cc4c121 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)