From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 33EE218A6B5 for ; Fri, 27 Sep 2024 08:48:50 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=193.142.43.55 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727426931; cv=none; b=roFUp1p/z5aeXR16Ueu7uSWDqk6Kv49iSUMAUullRxSYbX17rJw5ov0iybQ6TXJVc4nHjZe9elUTbu52Pxjgg3aSYCXbIJk8fCugz9Hvi+C654ET/3GrQWWQhj5yFkrAl8v9UoG4e/gK7Wf772KsJSiTECX02gSR9DWsIX3Y7og= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727426931; c=relaxed/simple; bh=MLbvTApDwcn4rh7emeTMGx1Q505+q6MoicWj4Jh2Yfg=; h=Message-ID:From:To:Cc:Subject:References:MIME-Version: Content-Type:Date; b=gUHrxWg1eXurPCZNm+3ulVHLt499JeWcJRgk0h9XNzlv2+fdYMtC2m1QS/EuJBImEk1T4G8IgsSN2pMtF26/ocWx1kbMxKL+W/YfZvKgzK4+k6HlVVTINpg8e6SlKHtJiPu5tnTCbBWrBe0l54WBgtr3lb1oV0lB4RpYD3h8fbQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de; spf=pass smtp.mailfrom=linutronix.de; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=qIO9m7jt; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=GueneQV6; arc=none smtp.client-ip=193.142.43.55 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linutronix.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="qIO9m7jt"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="GueneQV6" Message-ID: <20240927084817.261702549@linutronix.de> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1727426926; 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=RKLyvk4kjAmxUrZnWrBzTvZjowh6Tz3OdWzxp5LVw2k=; b=qIO9m7jt5/Rz4bIHOp4HoOrRUPdYRn1H/rflE/7ySnjJBJ2GFeyDVUeQE83pkNGT/NgBr7 28+dgzjEU3WR6hIm4OKx5JmmMp4jd8YE5CFYXnH3g3OuputP7i2rPGMm1bjIk/mGLHsM7J q8f3UkTh5moqRjB11UAk69Rq5Q7z+N5us4brmT2zO6b5EEf3DeVp3uJRGich3Puf7v9Eq9 nN+bonrPZBfiEv3kjPYKY5OOe9wapnC/o3O5pD7dw6LqVAQg5a4br1umR0IPHK1k2vcX9L F1VtKRN2oD66W5tzPtCu5ChFJ3UbGKMP+h6D1RMfuh197gI2ojJSZ6uA+DR+2Q== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1727426926; 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=RKLyvk4kjAmxUrZnWrBzTvZjowh6Tz3OdWzxp5LVw2k=; b=GueneQV6KCVq0cibTzXfN0LryZGhUik5kBmLoDGkTMjPHXccxJ+pjcHFyz5AzDDhKP1t4m /PajCjFQhSQnYCCQ== From: Thomas Gleixner To: LKML Cc: Anna-Maria Behnsen , Frederic Weisbecker , John Stultz , Peter Zijlstra , Ingo Molnar , Stephen Boyd , Eric Biederman , Oleg Nesterov Subject: [patch v4 06/27] posix-timers: Drop signal if timer has been deleted or reprogrammed References: <20240927083900.989915582@linutronix.de> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Date: Fri, 27 Sep 2024 10:48:46 +0200 (CEST) From: Thomas Gleixner No point in delivering a signal from the past. POSIX does not specify the behaviour here: - "The effect of disarming or resetting a timer with pending expiration notifications is unspecified." - "The disposition of pending signals for the deleted timer is unspecified." In both cases it is reasonable to expect that pending signals are discarded. Especially in the reprogramming case it does not make sense to account for previous overruns or to deliver a signal for a timer which has been disarmed. Drop the signal as that is conistent and understandable behaviour. Signed-off-by: Thomas Gleixner Acked-by: Peter Zijlstra (Intel) --- kernel/time/posix-timers.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) --- diff --git a/kernel/time/posix-timers.c b/kernel/time/posix-timers.c index d7ed7542f803..b5d7e71c10f2 100644 --- a/kernel/time/posix-timers.c +++ b/kernel/time/posix-timers.c @@ -250,14 +250,14 @@ static void common_hrtimer_rearm(struct k_itimer *timr) } /* - * This function is called from the signal delivery code if - * info::si_sys_private is not zero, which indicates that the timer has to - * be rearmed. Restart the timer and update info::si_overrun. + * This function is called from the signal delivery code. It decides + * whether the signal should be dropped and rearms interval timers. */ bool posixtimer_deliver_signal(struct kernel_siginfo *info) { struct k_itimer *timr; unsigned long flags; + bool ret = false; /* * Release siglock to ensure proper locking order versus @@ -279,6 +279,7 @@ bool posixtimer_deliver_signal(struct kernel_siginfo *info) info->si_overrun = timer_overrun_to_int(timr, info->si_overrun); } + ret = true; unlock_timer(timr, flags); out: @@ -286,7 +287,7 @@ bool posixtimer_deliver_signal(struct kernel_siginfo *info) /* Don't expose the si_sys_private value to userspace */ info->si_sys_private = 0; - return true; + return ret; } int posix_timer_queue_signal(struct k_itimer *timr)