diff options
| author | Waiman Long <longman@redhat.com> | 2022-07-23 15:59:32 -0400 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2022-07-25 19:39:07 +0200 |
| commit | d295ad34f236c3518634fb6403d4c0160456e470 (patch) | |
| tree | b51bf57d16a2ba4af9295232ee6fa37f46a79f22 /drivers/idle | |
| parent | e0dccc3b76fb35bb257b4118367a883073d7390e (diff) | |
| download | lwn-d295ad34f236c3518634fb6403d4c0160456e470.tar.gz lwn-d295ad34f236c3518634fb6403d4c0160456e470.zip | |
intel_idle: Fix false positive RCU splats due to incorrect hardirqs state
Commit 32d4fd5751ea ("cpuidle,intel_idle: Fix CPUIDLE_FLAG_IRQ_ENABLE")
uses raw_local_irq_enable/local_irq_disable() around call to
__intel_idle() in intel_idle_irq().
With interrupt enabled, timer tick interrupt can happen and a
subsequently call to __do_softirq() may change the lockdep hardirqs state
of a debug kernel back to 'on'. This will result in a mismatch between
the cpu hardirqs state (off) and the lockdep hardirqs state (on) causing
a number of false positive "WARNING: suspicious RCU usage" splats.
Fix that by using local_irq_disable() to disable interrupt in
intel_idle_irq().
Fixes: 32d4fd5751ea ("cpuidle,intel_idle: Fix CPUIDLE_FLAG_IRQ_ENABLE")
Signed-off-by: Waiman Long <longman@redhat.com>
Cc: 5.16+ <stable@vger.kernel.org> # 5.16+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/idle')
| -rw-r--r-- | drivers/idle/intel_idle.c | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/drivers/idle/intel_idle.c b/drivers/idle/intel_idle.c index f5c6802aa6c3..907700d1e78e 100644 --- a/drivers/idle/intel_idle.c +++ b/drivers/idle/intel_idle.c @@ -162,7 +162,13 @@ static __cpuidle int intel_idle_irq(struct cpuidle_device *dev, raw_local_irq_enable(); ret = __intel_idle(dev, drv, index); - raw_local_irq_disable(); + + /* + * The lockdep hardirqs state may be changed to 'on' with timer + * tick interrupt followed by __do_softirq(). Use local_irq_disable() + * to keep the hardirqs state correct. + */ + local_irq_disable(); return ret; } |