From: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com> stable inclusion from stable-v5.10.253 commit 3e84116d45a2f35c6de5aef09e8f305d258fef08 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 4b6d9904cec7..83af15f77f66 100644 --- a/drivers/cpuidle/cpuidle.c +++ b/drivers/cpuidle/cpuidle.c @@ -319,16 +319,6 @@ int cpuidle_enter_state(struct cpuidle_device *dev, struct cpuidle_driver *drv, 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 b6537524c035..9ab5c46b07c8 100644 --- a/kernel/sched/idle.c +++ b/kernel/sched/idle.c @@ -223,7 +223,7 @@ 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; /* @@ -241,6 +241,15 @@ 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