linux-kernel - [tip: sched/core] cpuidle, intel_idle: Fix CPUIDLE_FLAG_IRQ

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Date:   Fri, 13 Jan 2023 12:31:12 -0000
From:   "tip-bot2 for Peter Zijlstra" <tip-bot2@...utronix.de>
To:     linux-tip-commits@...r.kernel.org
Cc:     "Peter Zijlstra (Intel)" <peterz@...radead.org>,
        Ingo Molnar <mingo@...nel.org>,
        Tony Lindgren <tony@...mide.com>,
        Ulf Hansson <ulf.hansson@...aro.org>,
        "Rafael J. Wysocki" <rafael.j.wysocki@...el.com>,
        Frederic Weisbecker <frederic@...nel.org>, x86@...nel.org,
        linux-kernel@...r.kernel.org
Subject: [tip: sched/core] cpuidle, intel_idle: Fix CPUIDLE_FLAG_IRQ_ENABLE *again*

The following commit has been merged into the sched/core branch of tip:

Commit-ID:     6d9c7f51b1d9179bf7c3542267c656a934e8af23
Gitweb:        https://git.kernel.org/tip/6d9c7f51b1d9179bf7c3542267c656a934e8af23
Author:        Peter Zijlstra <peterz@...radead.org>
AuthorDate:    Thu, 12 Jan 2023 20:43:32 +01:00
Committer:     Ingo Molnar <mingo@...nel.org>
CommitterDate: Fri, 13 Jan 2023 11:48:15 +01:00

cpuidle, intel_idle: Fix CPUIDLE_FLAG_IRQ_ENABLE *again*

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@...radead.org>
Signed-off-by: Ingo Molnar <mingo@...nel.org>
Tested-by: Tony Lindgren <tony@...mide.com>
Tested-by: Ulf Hansson <ulf.hansson@...aro.org>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
Acked-by: Frederic Weisbecker <frederic@...nel.org>
Link: https://lore.kernel.org/r/20230112195540.434302128@infradead.org
---
 drivers/idle/intel_idle.c | 8 +-------
 1 file changed, 1 insertion(+), 7 deletions(-)

diff --git a/drivers/idle/intel_idle.c b/drivers/idle/intel_idle.c
index cfeb24d..f060ac7 100644
--- a/drivers/idle/intel_idle.c
+++ b/drivers/idle/intel_idle.c
@@ -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;
 }