cpuidle, intel_idle: Fix CPUIDLE_FLAG_IRQ_ENABLE *again*
authorPeter Zijlstra <peterz@infradead.org>
Thu, 12 Jan 2023 19:43:32 +0000 (20:43 +0100)
committerIngo Molnar <mingo@kernel.org>
Fri, 13 Jan 2023 10:48:15 +0000 (11:48 +0100)
So objtool found this bug:

  vmlinux.o: warning: objtool: intel_idle_irq+0x10c: call to trace_hardirqs_off() leaves .noinstr.text section

As per commit 32d4fd5751ea ("cpuidle,intel_idle: Fix CPUIDLE_FLAG_IRQ_ENABLE"):

  "must not have tracing in idle functions"

Clearly people can't read and tinker along until splat dissapears.
This straight up reverts commit d295ad34f236 ("intel_idle: Fix false
positive RCU splats due to incorrect hardirqs state").

It doesn't re-introduce the problem because preceding patches fixed it
properly.

Fixes: d295ad34f236 ("intel_idle: Fix false positive RCU splats due to incorrect hardirqs state")
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Tony Lindgren <tony@atomide.com>
Tested-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/r/20230112195540.434302128@infradead.org
drivers/idle/intel_idle.c

index cfeb24d..f060ac7 100644 (file)
@@ -168,13 +168,7 @@ static __cpuidle int intel_idle_irq(struct cpuidle_device *dev,
 
        raw_local_irq_enable();
        ret = __intel_idle(dev, drv, index);
-
-       /*
-        * 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();
+       raw_local_irq_disable();
 
        return ret;
 }