From: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com> stable inclusion from stable-v6.6.130 commit f691272c3e8cfb2a333ad33ffad9a3edba625e52 category: bugfix bugzilla: https://atomgit.com/src-openeuler/kernel/issues/15208 CVE: CVE-2026-45968 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- [ Upstream commit d557640e4ce589a24dca5ca7ce3b9680f471325f ] If the cpuidle governor .select() callback is skipped because there is only one idle state in the cpuidle driver, the .reflect() callback should be skipped as well, at least for consistency (if not for correctness), so do it. Fixes: e5c9ffc6ae1b ("cpuidle: Skip governor when only one idle state is available") Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Christian Loehle <christian.loehle@arm.com> Reviewed-by: Aboorva Devarajan <aboorvad@linux.ibm.com> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Link: https://patch.msgid.link/12857700.O9o76ZdvQC@rafael.j.wysocki Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com> --- drivers/cpuidle/cpuidle.c | 10 ---------- kernel/sched/idle.c | 11 ++++++++++- 2 files changed, 10 insertions(+), 11 deletions(-) diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c index aa117f2967fd..6704d610573a 100644 --- a/drivers/cpuidle/cpuidle.c +++ b/drivers/cpuidle/cpuidle.c @@ -356,16 +356,6 @@ noinstr int cpuidle_enter_state(struct cpuidle_device *dev, int cpuidle_select(struct cpuidle_driver *drv, struct cpuidle_device *dev, bool *stop_tick) { - /* - * If there is only a single idle state (or none), there is nothing - * meaningful for the governor to choose. Skip the governor and - * always use state 0 with the tick running. - */ - if (drv->state_count <= 1) { - *stop_tick = false; - return 0; - } - return cpuidle_curr_governor->select(drv, dev, stop_tick); } diff --git a/kernel/sched/idle.c b/kernel/sched/idle.c index 1a130e505ec8..e4be21e26a73 100644 --- a/kernel/sched/idle.c +++ b/kernel/sched/idle.c @@ -203,7 +203,7 @@ static void cpuidle_idle_call(void) next_state = cpuidle_find_deepest_state(drv, dev, max_latency_ns); call_cpuidle(drv, dev, next_state); - } else { + } else if (drv->state_count > 1) { bool stop_tick = true; /* @@ -221,6 +221,15 @@ static void cpuidle_idle_call(void) * Give the governor an opportunity to reflect on the outcome */ cpuidle_reflect(dev, entered_state); + } else { + tick_nohz_idle_retain_tick(); + + /* + * If there is only a single idle state (or none), there is + * nothing meaningful for the governor to choose. Skip the + * governor and always use state 0. + */ + call_cpuidle(drv, dev, 0); } exit_idle: -- 2.34.1