linux-kernel - [tip: sched/core] cpuidle: Fix poll

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Date:   Tue, 31 Jan 2023 14:22:26 -0000
From:   "tip-bot2 for Peter Zijlstra" <tip-bot2@...utronix.de>
To:     linux-tip-commits@...r.kernel.org
Cc:     kernel test robot <oliver.sang@...el.com>,
        "Peter Zijlstra (Intel)" <peterz@...radead.org>,
        Ingo Molnar <mingo@...nel.org>,
        "Rafael J. Wysocki" <rafael.j.wysocki@...el.com>, x86@...nel.org,
        linux-kernel@...r.kernel.org
Subject: [tip: sched/core] cpuidle: Fix poll_idle() noinstr annotation

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

Commit-ID:     4d627628d7584f3d3add1d53342d0f01aa878e04
Gitweb:        https://git.kernel.org/tip/4d627628d7584f3d3add1d53342d0f01aa878e04
Author:        Peter Zijlstra <peterz@...radead.org>
AuthorDate:    Thu, 26 Jan 2023 16:08:38 +01:00
Committer:     Ingo Molnar <mingo@...nel.org>
CommitterDate: Tue, 31 Jan 2023 15:01:47 +01:00

cpuidle: Fix poll_idle() noinstr annotation

The instrumentation_begin()/end() annotations in poll_idle() were
complete nonsense. Specifically they caused tracing to happen in the
middle of noinstr code, resulting in RCU splats.

Now that local_clock() is noinstr, mark up the rest and let it rip.

Fixes: 00717eb8c955 ("cpuidle: Annotate poll_idle()")
Reported-by: kernel test robot <oliver.sang@...el.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@...radead.org>
Signed-off-by: Ingo Molnar <mingo@...nel.org>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
Link: https://lore.kernel.org/oe-lkp/202301192148.58ece903-oliver.sang@intel.com
Link: https://lore.kernel.org/r/20230126151323.819534689@infradead.org
---
 drivers/cpuidle/cpuidle.c    | 2 +-
 drivers/cpuidle/poll_state.c | 2 --
 2 files changed, 1 insertion(+), 3 deletions(-)

diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c
index 500d172..0b00f21 100644
--- a/drivers/cpuidle/cpuidle.c
+++ b/drivers/cpuidle/cpuidle.c
@@ -426,7 +426,7 @@ void cpuidle_reflect(struct cpuidle_device *dev, int index)
  * @dev:   the cpuidle device
  *
  */
-u64 cpuidle_poll_time(struct cpuidle_driver *drv,
+__cpuidle u64 cpuidle_poll_time(struct cpuidle_driver *drv,
 		      struct cpuidle_device *dev)
 {
 	int i;
diff --git a/drivers/cpuidle/poll_state.c b/drivers/cpuidle/poll_state.c
index d25ec52..bdcfeae 100644
--- a/drivers/cpuidle/poll_state.c
+++ b/drivers/cpuidle/poll_state.c
@@ -15,7 +15,6 @@ static int __cpuidle poll_idle(struct cpuidle_device *dev,
 {
 	u64 time_start;
 
-	instrumentation_begin();
 	time_start = local_clock();
 
 	dev->poll_time_limit = false;
@@ -42,7 +41,6 @@ static int __cpuidle poll_idle(struct cpuidle_device *dev,
 	raw_local_irq_disable();
 
 	current_clr_polling();
-	instrumentation_end();
 
 	return index;
 }