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authorWaiman Long <longman@redhat.com>2022-07-23 22:59:32 +0300
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2022-07-25 20:39:07 +0300
commitd295ad34f236c3518634fb6403d4c0160456e470 (patch)
treeb51bf57d16a2ba4af9295232ee6fa37f46a79f22 /drivers/idle
parente0dccc3b76fb35bb257b4118367a883073d7390e (diff)
downloadlinux-d295ad34f236c3518634fb6403d4c0160456e470.tar.xz
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.c8
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;
}