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 0E7FB19D896 for ; Tue, 1 Oct 2024 08:42:08 +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=1727772129; cv=none; b=h8ez9+UkVsHfxq9dXoqre3puN/c5fecHgz4uv6OepnGs3Lc5J5o5FSdDO89cqWIzYpq3VqHPFRxr4KI6ZtfTwmq9DkK79uGjlYBM7almoh2GvhIWwa2RK22yyLa7moPQp2oo1m9azJynZC1gFDzBHquOAIEc4NjmLgVA+UTf1RQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727772129; c=relaxed/simple; bh=lbAJsxEIBuEi5j1fxs6XlVgx5F/bE/5BIwwAUQBVOy8=; h=Message-ID:From:To:Cc:Subject:References:MIME-Version: Content-Type:Date; b=HzMNtPMVPMo8zroJd92Capt8h3xD26f/fEihbkmn2JXNELSmuzMDbjOM4fJEBEkV00P3gJfCv1RJKUbL315HgP8CofdSFSfe51mUD/np3myaqS3Z7ve5o7BeMWPt33G0B7a/nbFetzAY9OChzfvCQrT6zYy7g1NmRj94MkFgyRs= 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=DPQjWPZl; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=6Fzl19jD; 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="DPQjWPZl"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="6Fzl19jD" Message-ID: <20241001083835.553646280@linutronix.de> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1727772126; 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=5PUBsJTvJ1KFQG92jonGbwEiSpgHpeT/5KITtDrmIx4=; b=DPQjWPZlLfZ1hi4UA+/Q0yu35uFVsLCUcvqKvlebPnATvGhm+6M6P7ejGlPfmFkT7lTyGR DcVj0jGfPxyVp4jVxQw6bII6cTawGbXEKH2VoYgD6g2daNDGe5aQ9NWKBhHs6+NUtBPSpg YoC+AeeHquPJSZleHFyjQ7+YO36wD0k2u80xu139TDarhXzIAQEbjHK1i0MFLVcsGBOVpI DK2XVYglM/8tly+xdwpiryMh2f5efKuO2WAyspZmJgu8Tb0YSMnRrK0vCIBP7FZ4cR193W jooTeUQQjM7mJIDAZUFQ6i553mus2ZP0dWzgtEtH6+G1wSshxQFP83vKWM/M2Q== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1727772126; 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=5PUBsJTvJ1KFQG92jonGbwEiSpgHpeT/5KITtDrmIx4=; b=6Fzl19jDE8EcZl/Lgh9d6HVkLI8SNke7RvmP4BXJ3asN2+L2wyCOmynufUFiNf6TKLb6M2 Ci8J8hUGSRcUqMDA== 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 V5 05/26] posix-timers: Drop signal if timer has been deleted or reprogrammed References: <20241001083138.922192481@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: Tue, 1 Oct 2024 10:42:06 +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)