From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794048910; b=iRaXqnKUF51xjucWVYCaznwsHWkBmqiVAdnpQHqMpYx1CMRBRlmsPQGv03TKXtb47MXk VVZS9PKSMenYrLiwp6JqNjXbt8dXiB80JfxLPxzxz7qtCo4FlvV1ppVGUd2Yx4xfueRgB LzVohE7jbyeiZz+eZFCl1ZmLfFwEH3yxlfpM62ZAWObp+DX1Wn4tQRgSFSHwAZkYqq10T Sh6zCv3W86MOpf3OSMt1jJCtSHGpk6nbMiiROmIdlqSmxTnu8a8gW4rPANlwJhuXgpuBR SmHOUKO8uONwwsM6VPbFKIqUfQ/GATwpRF+Qjk1HrU38hvkEX3bpDnSK+EzOsofz4Zg== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794048910; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: MIME-Version:Content-Type:Content-Transfer-Encoding; bh=fwpOQhAimF5ziXikdm3POLCngehf7SatwgxQftECijo=; b=w5crTgaBb/s0XuC1C+9Q7pNu2z/cAmqYHENE1RGZoPrOYhPmb3tDlnCKq3dlaxbqxyks J3IDjK0AnC7n/+bHmrOM4WW4jLcreJ+6wfYQKUp2bCfSnkYyp4CDN5uV7YTqzJmNT+Xnm Bzm46BLyE2Y+oChBpgWNYxEaqQkJIrTdZ8tER2tKDuYN0sbsDg+6yXaujkmib3T3XBm/1 M6faOje/L2lE+XRAKBMC1+k5I0/tB9useqe84OFYI+j4tPImLCR2auFyL8VOnZqv6wZ9h RM0lVhUUc7VMSCq7mz40oDmbleTjwwDPRv4wL6hLqp5IEmKigW9XXjk0rolofGBYdFA== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=BC3x2Wv6; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A71FA606A326 for ; Sat, 7 Nov 2026 10:55:09 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=BC3x2Wv6 Received: by smtp.kernel.org (Postfix) with ESMTPSA id 233011F0089F; Sat, 7 Nov 2026 10:55:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794048909; bh=fwpOQhAimF5ziXikdm3POLCngehf7SatwgxQftECijo=; h=From:To:Cc:Subject:Date; b=BC3x2Wv6TzJX+hKZihP8i6yamegn0aqpVPRKXrsYlaVuQyTsWSVq7mNc+gKqzUaoa ecccDE7KatqZaGX/4UlONpUpwdV5ONvQOmwCGXO41kbSeqNKbBFFBAajIhJ1RIPuEn Lr4DxOVrncnKDUPFs5JkIswrVoFVUX6dL8K3xc384CdAUijkTgwltCBuKyvSNPybTj amgR0HYPrEbbfWJRdowHlj7vsoPCV9EWtKBQXI9g8vcSdZ/OMO4YFtVRICbwyXaf3V ud/+UuGTg/Dg8vZnmdIq2ruXOJYVu9deut/vcirsojJJ9+fNozqStZLPLHbXxWeBSO KqJO9zvRJNX5Q== From: Sasha Levin To: alex.lin.programmer@gmail.com, tglx@kernel.org Cc: stable@vger.kernel.org Subject: FAILED: patch "[PATCH] posix-timers: Report zero remaining time for disarmed SIGEV_NONE timers" failed to apply to 6.1-stable tree Date: Sat, 7 Nov 2026 05:55:07 -0500 Message-ID: <20261107055507-failed-6.1-141a27750ec3@kernel.org> X-Mailer: git-send-email 2.53.0 X-Mailing-List: stable@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The patch below does not apply to the 6.1-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.1.y git checkout FETCH_HEAD git cherry-pick -x 141a27750ec3d91ad9d1ad1764ebb5e51b963478 # git commit -s git send-email --to '' --in-reply-to '20261107055507-failed-6.1-141a27750ec3@kernel.org' --subject-prefix 'PATCH 6.1.y' 'HEAD^..' Thanks, Sasha ------------------ original commit in Linus's tree ------------------ >From 141a27750ec3d91ad9d1ad1764ebb5e51b963478 Mon Sep 17 00:00:00 2001 From: Hung-Jui Lin Date: Fri, 23 Oct 2026 23:14:10 +0800 Subject: [PATCH] posix-timers: Report zero remaining time for disarmed SIGEV_NONE timers SIGEV_NONE timers are never queued. common_timer_get() emulates their expiry by computing the remaining time from the stored expiry value. Because an armed SIGEV_NONE oneshot timer is not queued, its it_status stays POSIX_TIMER_DISARMED. So common_timer_get() cannot use it_status to skip a disarmed SIGEV_NONE timer and evaluates the stored expiry value for all SIGEV_NONE timers. Disarming a timer with timer_settime() and a zero it_value cancels the timer and sets it_status to POSIX_TIMER_DISARMED, but leaves the expiry value unchanged. As a consequence, timer_gettime() on a disarmed SIGEV_NONE timer reports the remaining time of the previous arming until that time has passed, instead of zero as POSIX requires for a disarmed timer. Example with a CLOCK_MONOTONIC timer armed with it_value = 10ms and it_interval = 100ms, then disarmed with an all-zero itimerspec: armed: it_value = 0.009999000 it_interval = 0.100000000 disarmed: it_value = 0.008700792 it_interval = 0.000000000 SIGEV_SIGNAL timers and SIGEV_NONE CPU timers report zero in the same situation. All clocks which use common_timer_get() are affected, including the alarm timer clocks. Mark SIGEV_NONE timers as POSIX_TIMER_ARMED when they are armed, so that common_timer_get() returns early for every disarmed timer. Forward SIGEV_NONE interval timers in common_timer_get() regardless of it_status, as they are never queued and therefore never forwarded by the expiry code. After the change the disarmed timer above reports zero. Armed SIGEV_NONE oneshot and interval timers on CLOCK_MONOTONIC, CLOCK_REALTIME, CLOCK_BOOTTIME and CLOCK_BOOTTIME_ALARM still report their remaining time, and the posix_timers selftest passes. Fixes: becf8b5d00f4 ("[PATCH] hrtimer: convert posix timers completely") Signed-off-by: Hung-Jui Lin Signed-off-by: Thomas Gleixner Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20261023151411.28685-1-alex.lin.programmer@gmail.com --- kernel/time/posix-timers.c | 25 ++++++++++++------------- 1 file changed, 12 insertions(+), 13 deletions(-) diff --git a/kernel/time/posix-timers.c b/kernel/time/posix-timers.c index 436ba794cc0b5..4c80c2dada9d3 100644 --- a/kernel/time/posix-timers.c +++ b/kernel/time/posix-timers.c @@ -694,16 +694,8 @@ void common_timer_get(struct k_itimer *timr, struct itimerspec64 *cur_setting) if (iv) { cur_setting->it_interval = ktime_to_timespec64(iv); } else if (timr->it_status == POSIX_TIMER_DISARMED) { - /* - * SIGEV_NONE oneshot timers are never queued and therefore - * 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 - * return. - */ - if (!sig_none) - return; + /* Nothing to update for a disarmed timer */ + return; } now = kc->clock_get_ktime(timr->it_clock); @@ -713,7 +705,7 @@ void common_timer_get(struct k_itimer *timr, struct itimerspec64 *cur_setting) * is a SIGEV_NONE timer move the expiry time forward by intervals, * so expiry is > now. */ - if (iv && timr->it_status != POSIX_TIMER_ARMED) + if (iv && (sig_none || timr->it_status != POSIX_TIMER_ARMED)) timr->it_overrun += kc->timer_forward(timr, now); remaining = kc->timer_remaining(timr, now); @@ -915,8 +907,15 @@ int common_timer_set(struct k_itimer *timr, int flags, sigev_none = timr->it_sigev_notify == SIGEV_NONE; if (kc->timer_arm(timr, expires, flags & TIMER_ABSTIME, sigev_none)) { - if (!sigev_none) - timr->it_status = POSIX_TIMER_ARMED; + /* + * SIGEV_NONE timers are not queued, but mark them armed + * so that common_timer_get() can tell them apart from + * disarmed timers. An expired SIGEV_NONE timer stays + * armed, which is harmless: common_timer_get() reports + * zero remaining time for it and it never reaches the + * signal delivery code. + */ + timr->it_status = POSIX_TIMER_ARMED; } else { /* Timer was already expired, queue the signal */ posix_timer_queue_signal(timr); -- 2.53.0