diff options
| author | Sebastian Andrzej Siewior <bigeasy@linutronix.de> | 2025-02-12 11:36:18 +0100 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2025-03-14 21:13:20 +0100 |
| commit | 87886b32d669abc11c7be95ef44099215e4f5788 (patch) | |
| tree | e12e120fe20ac5184899f28ef716d15cde3520ff | |
| parent | f73ca66f0d7f4371d172d6f5b1f9a00e367ba921 (diff) | |
lockdep: Don't disable interrupts on RT in disable_irq_nosync_lockdep.*()
disable_irq_nosync_lockdep() disables interrupts with lockdep enabled to
avoid false positive reports by lockdep that a certain lock has not been
acquired with disabled interrupts. The user of this macros expects that
a lock can be acquried without disabling interrupts because the IRQ line
triggering the interrupt is disabled.
This triggers a warning on PREEMPT_RT because after
disable_irq_nosync_lockdep.*() the following spinlock_t now is acquired
with disabled interrupts.
On PREEMPT_RT there is no difference between spin_lock() and
spin_lock_irq() so avoiding disabling interrupts in this case works for
the two remaining callers as of today.
Don't disable interrupts on PREEMPT_RT in disable_irq_nosync_lockdep.*().
Closes: https://lore.kernel.org/760e34f9-6034-40e0-82a5-ee9becd24438@roeck-us.net
Fixes: e8106b941ceab ("[PATCH] lockdep: core, add enable/disable_irq_irqsave/irqrestore() APIs")
Reported-by: Guenter Roeck <linux@roeck-us.net>
Suggested-by: "Steven Rostedt (Google)" <rostedt@goodmis.org>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20250212103619.2560503-2-bigeasy@linutronix.de
| -rw-r--r-- | include/linux/interrupt.h | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h index 8cd9327e4e78..a1b1be9bf73b 100644 --- a/include/linux/interrupt.h +++ b/include/linux/interrupt.h @@ -448,7 +448,7 @@ irq_calc_affinity_vectors(unsigned int minvec, unsigned int maxvec, static inline void disable_irq_nosync_lockdep(unsigned int irq) { disable_irq_nosync(irq); -#ifdef CONFIG_LOCKDEP +#if defined(CONFIG_LOCKDEP) && !defined(CONFIG_PREEMPT_RT) local_irq_disable(); #endif } @@ -456,7 +456,7 @@ static inline void disable_irq_nosync_lockdep(unsigned int irq) static inline void disable_irq_nosync_lockdep_irqsave(unsigned int irq, unsigned long *flags) { disable_irq_nosync(irq); -#ifdef CONFIG_LOCKDEP +#if defined(CONFIG_LOCKDEP) && !defined(CONFIG_PREEMPT_RT) local_irq_save(*flags); #endif } @@ -471,7 +471,7 @@ static inline void disable_irq_lockdep(unsigned int irq) static inline void enable_irq_lockdep(unsigned int irq) { -#ifdef CONFIG_LOCKDEP +#if defined(CONFIG_LOCKDEP) && !defined(CONFIG_PREEMPT_RT) local_irq_enable(); #endif enable_irq(irq); @@ -479,7 +479,7 @@ static inline void enable_irq_lockdep(unsigned int irq) static inline void enable_irq_lockdep_irqrestore(unsigned int irq, unsigned long *flags) { -#ifdef CONFIG_LOCKDEP +#if defined(CONFIG_LOCKDEP) && !defined(CONFIG_PREEMPT_RT) local_irq_restore(*flags); #endif enable_irq(irq); |