From nobody Mon Feb 9 21:18:40 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E4995C7EE24 for ; Tue, 6 Jun 2023 14:40:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238285AbjFFOka (ORCPT ); Tue, 6 Jun 2023 10:40:30 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41988 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238279AbjFFOjU (ORCPT ); Tue, 6 Jun 2023 10:39:20 -0400 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 576E31FCE for ; Tue, 6 Jun 2023 07:38:17 -0700 (PDT) Message-ID: <20230606142032.544511403@linutronix.de> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1686062282; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: references:references; bh=5ed1VkOh2UBEVrURDClugUqs9wtwWx9MqD/9qEBm3z4=; b=SuKcaX/uHCB7zYDh0doxbGCGrsnwgsbNatkptPv4YN63eB3SI+fQBRMq82+9X4EFM3OX+d Q2aLgkzG3HLJ7+D5/bvQlaB3bL11ESuo19w8/hYUiZwt3mSp9TWAVxafl60oWkz7+H91+E srSXZRI5FUVOyQZuK7uC1Dh6dvQv2dVY+hCX4zLHmot+wvuHplX074nrPq1EBsUUzloub4 5EoleiXrscDNFk0Zw5vecrIt8UcSs1Xmb97R/1dbfj7p5XD9tF2Wh+oD0K55ogMLQFKhVX 18GxPs8IylsMWpmnDC16vZ9T6wOB5amVLNUae6Xz3YALjUdzr+pxOezVnRgyFw== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1686062282; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: references:references; bh=5ed1VkOh2UBEVrURDClugUqs9wtwWx9MqD/9qEBm3z4=; b=pva/uGMhqiSbwG4R61C+hTFA66LNiX0FDV8a7t7kF753w3k3Uv6gPo7UxGDBcSDwoBDWN0 SFtTkR5NoQ/IgiCQ== From: Thomas Gleixner To: LKML Cc: Frederic Weisbecker , Anna-Maria Behnsen , John Stultz , Peter Zijlstra , Ingo Molnar , Stephen Boyd , Eric Biederman , Oleg Nesterov Subject: [patch 27/45] posix-timers: Add proper state tracking References: <20230606132949.068951363@linutronix.de> MIME-Version: 1.0 Date: Tue, 6 Jun 2023 16:38:01 +0200 (CEST) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Right now the state tracking is done by two struct members: - it_active: A boolean which tracks armed/disarmed state - it_signal_seq: A sequence counter which is used to invalidate settings and prevent rearming Replace it_active with it_status and keep properly track about the states in one place. This allows to reuse it_signal_seq to track reprogramming, disarm and delete operations in order to drop signals which are related to the state previous of those operations. Signed-off-by: Thomas Gleixner --- include/linux/posix-timers.h | 4 ++-- kernel/time/alarmtimer.c | 2 +- kernel/time/posix-cpu-timers.c | 14 +++++++------- kernel/time/posix-timers.c | 22 +++++++++++++--------- kernel/time/posix-timers.h | 6 ++++++ 5 files changed, 29 insertions(+), 19 deletions(-) --- a/include/linux/posix-timers.h +++ b/include/linux/posix-timers.h @@ -210,7 +210,7 @@ static inline void posix_cputimers_init_ * @kclock: Pointer to the k_clock struct handling this timer * @it_clock: The posix timer clock id * @it_id: The posix timer id for identifying the timer - * @it_active: Marker that timer is active + * @it_status: The status of the timer * @it_overrun: The overrun counter for pending signals * @it_overrun_last: The overrun at the time of the last delivered signal * @it_signal_seq: Sequence count to control signal delivery @@ -231,7 +231,7 @@ struct k_itimer { const struct k_clock *kclock; clockid_t it_clock; timer_t it_id; - int it_active; + int it_status; s64 it_overrun; s64 it_overrun_last; unsigned int it_signal_seq; --- a/kernel/time/alarmtimer.c +++ b/kernel/time/alarmtimer.c @@ -574,7 +574,7 @@ static enum alarmtimer_restart alarm_han */ ptr->it_overrun +=3D __alarm_forward_now(alarm, ptr->it_interval, true); ++ptr->it_signal_seq; - ptr->it_active =3D 1; + ptr->it_status =3D POSIX_TIMER_ARMED; result =3D ALARMTIMER_RESTART; } spin_unlock_irqrestore(&ptr->it_lock, flags); --- a/kernel/time/posix-cpu-timers.c +++ b/kernel/time/posix-cpu-timers.c @@ -453,7 +453,6 @@ static void disarm_timer(struct k_itimer struct cpu_timer *ctmr =3D &timer->it.cpu; struct posix_cputimer_base *base; =20 - timer->it_active =3D 0; if (!cpu_timer_dequeue(ctmr)) return; =20 @@ -494,11 +493,12 @@ static int posix_cpu_timer_del(struct k_ */ WARN_ON_ONCE(ctmr->head || timerqueue_node_queued(&ctmr->node)); } else { - if (timer->it.cpu.firing) + if (timer->it.cpu.firing) { ret =3D TIMER_RETRY; - else + } else { disarm_timer(timer, p); - + timer->it_status =3D POSIX_TIMER_DISARMED; + } unlock_task_sighand(p, &flags); } =20 @@ -560,7 +560,7 @@ static void arm_timer(struct k_itimer *t struct cpu_timer *ctmr =3D &timer->it.cpu; u64 newexp =3D cpu_timer_getexpires(ctmr); =20 - timer->it_active =3D 1; + timer->it_status =3D POSIX_TIMER_ARMED; if (!cpu_timer_enqueue(&base->tqhead, ctmr)) return; =20 @@ -670,7 +670,7 @@ static int posix_cpu_timer_set(struct k_ ret =3D TIMER_RETRY; } else { cpu_timer_dequeue(ctmr); - timer->it_active =3D 0; + timer->it_status =3D POSIX_TIMER_DISARMED; } =20 /* @@ -804,7 +804,7 @@ static u64 collect_timerqueue(struct tim rcu_assign_pointer(ctmr->handling, current); cpu_timer_dequeue(ctmr); ktmr =3D container_of(ctmr, struct k_itimer, it.cpu); - ktmr->it_active =3D 0; + ktmr->it_status =3D POSIX_TIMER_DISARMED; list_add_tail(&ctmr->elist, firing); } =20 --- a/kernel/time/posix-timers.c +++ b/kernel/time/posix-timers.c @@ -272,7 +272,7 @@ bool posixtimer_deliver_signal(struct ke if (timr->it_interval && timr->it_signal_seq =3D=3D info->si_sys_private)= { timr->kclock->timer_rearm(timr); =20 - timr->it_active =3D 1; + timr->it_status =3D POSIX_TIMER_ARMED; timr->it_overrun_last =3D timr->it_overrun; timr->it_overrun =3D -1LL; ++timr->it_signal_seq; @@ -292,14 +292,17 @@ bool posixtimer_deliver_signal(struct ke =20 int posix_timer_queue_signal(struct k_itimer *timr) { + enum posix_timer_state state =3D POSIX_TIMER_DISARMED; int ret, si_private =3D 0; enum pid_type type; =20 lockdep_assert_held(&timr->it_lock); =20 - timr->it_active =3D 0; - if (timr->it_interval) + if (timr->it_interval) { + state =3D POSIX_TIMER_REQUEUE_PENDING; si_private =3D ++timr->it_signal_seq; + } + timr->it_status =3D state; =20 type =3D !(timr->it_sigev_notify & SIGEV_THREAD_ID) ? PIDTYPE_TGID : PIDT= YPE_PID; ret =3D send_sigqueue(timr->sigq, timr->it_pid, type, si_private); @@ -367,7 +370,7 @@ static enum hrtimer_restart posix_timer_ timr->it_overrun +=3D hrtimer_forward(timer, now, timr->it_interval); ret =3D HRTIMER_RESTART; ++timr->it_signal_seq; - timr->it_active =3D 1; + timr->it_status =3D POSIX_TIMER_ARMED; } } =20 @@ -642,10 +645,10 @@ void common_timer_get(struct k_itimer *t bool iv =3D !!timr->it_interval; ktime_t now, remaining; =20 - if (!iv && !timr->it_active) { + if (!iv && timr->it_status =3D=3D POSIX_TIMER_DISARMED) { /* * SIGEV_NONE oneshot timers are never queued and therefore - * timr->it_active is always false. The check below + * timr->it_status is always DISARMED. The check below * vs. remaining time will handle this case. * * For all other timers there is nothing to update here, so @@ -890,7 +893,7 @@ int common_timer_set(struct k_itimer *ti if (kc->timer_try_to_cancel(timr) < 0) return TIMER_RETRY; =20 - timr->it_active =3D 0; + timr->it_status =3D POSIX_TIMER_DISARMED; posix_timer_set_common(timr, new_setting); =20 /* Keep timer disarmed when it_value is zero */ @@ -903,7 +906,8 @@ int common_timer_set(struct k_itimer *ti sigev_none =3D timr->it_sigev_notify =3D=3D SIGEV_NONE; =20 kc->timer_arm(timr, expires, flags & TIMER_ABSTIME, sigev_none); - timr->it_active =3D !sigev_none; + if (!sigev_none) + timr->it_status =3D POSIX_TIMER_ARMED; return 0; } =20 @@ -1002,7 +1006,7 @@ int common_timer_del(struct k_itimer *ti timer->it_interval =3D 0; if (kc->timer_try_to_cancel(timer) < 0) return TIMER_RETRY; - timer->it_active =3D 0; + timer->it_status =3D POSIX_TIMER_DISARMED; return 0; } =20 --- a/kernel/time/posix-timers.h +++ b/kernel/time/posix-timers.h @@ -1,6 +1,12 @@ /* SPDX-License-Identifier: GPL-2.0 */ #define TIMER_RETRY 1 =20 +enum posix_timer_state { + POSIX_TIMER_DISARMED, + POSIX_TIMER_ARMED, + POSIX_TIMER_REQUEUE_PENDING, +}; + struct k_clock { int (*clock_getres)(const clockid_t which_clock, struct timespec64 *tp);