From nobody Thu Nov 28 16:39:23 2024 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 41BC41BE87C for ; Tue, 1 Oct 2024 08:42:30 +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=1727772155; cv=none; b=G0rLHXOWJPY66LP3LTZABIkKZMYrM/uryRT7FdoVpxTqKe64k9OgYq5Sjfe2FvDskGONECvxke1ht4qCwDWzygoTzOi8LnedsKS3gy2uP5vZVOo63W11YlggDlAEMH/LtJvLPCn21G16TOT1Cgeo7NrFkiJYe4dRkKSPUjYZhmE= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727772155; c=relaxed/simple; bh=ugm1bDvC3jut/vMuR/KbvcyMOYDJMmXjOVhnIPLEVhY=; h=Message-ID:From:To:Cc:Subject:References:MIME-Version: Content-Type:Date; b=EBre4hZngpiY27S0eNKZZ9SYLIrUFBGrgPZmtS8pRALV85lze3vIePPtgWKAJDGG3vBGdpOVgz7g3BT1b7A0jiKmdodVOax0iBPVp7eGMWWR1kHBF2RlVVeK5OVNLMAK4tw/nsGBsvI/uwTmWup5cbZ4GUg/y4yqFvnHDkcqYyo= 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=hKYz36kI; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=LGvqb0J/; 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="hKYz36kI"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="LGvqb0J/" Message-ID: <20241001083836.514196709@linutronix.de> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1727772149; 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=c6Y96xN0JlBMa7/gJ/CnZwn5sY28IT7kPPBfheQu2l4=; b=hKYz36kI2iyfXQ3c1cMeN4pPdtTLIZR87pn4Fo9u30PmcmzeaOHZOb+hP3TT98DhnvypOv xKEnTnFsbabOWPOWrFLX87FUtu6wroeaIM73Pyre8wtthy68nEGexQlOBsjRjvotsIUq7R DWOzB8OySBNz3GI7g1NqsQmd2jXwnBMwgMSsdiv/4mHwErzXV89By5hR9jfd3/iO9rVSqO 10QH4UZb5rFpt54/AkB+9JxYyRhODLHEf1bELTDq3X77c1YbruqmDSY4Iobeqegm5fBPNm N+2sFEl0tmeW1SBIAfQIGBX6wor3VPkbgB7kGYzQZP+1in9DzLdpQLz6uJe5+w== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1727772149; 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=c6Y96xN0JlBMa7/gJ/CnZwn5sY28IT7kPPBfheQu2l4=; b=LGvqb0J/ea7/g7G34YLpcs07FMEivcCoRFm6d4pAFGTYsW3IEJpZkgTdS5tmB8rw82S1ek QLQcRzJXCP4D4LCw== 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 21/26] posix-timers: Handle ignored list on delete and exit 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 Date: Tue, 1 Oct 2024 10:42:29 +0200 (CEST) Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: Thomas Gleixner To handle posix timer signals on sigaction(SIG_IGN) properly, the timers will be queued on a separate ignored list. Add the necessary cleanup code for timer_delete() and exit_itimers(). Signed-off-by: Thomas Gleixner Acked-by: Peter Zijlstra (Intel) --- include/linux/posix-timers.h | 4 +++- kernel/time/posix-timers.c | 20 ++++++++++++++++++++ 2 files changed, 23 insertions(+), 1 deletion(-) --- --- a/include/linux/posix-timers.h +++ b/include/linux/posix-timers.h @@ -152,7 +152,8 @@ static inline void posix_cputimers_init_ =20 /** * struct k_itimer - POSIX.1b interval timer structure. - * @list: List head for binding the timer to signals->posix_timers + * @list: List node for binding the timer to tsk::signal::posix_timers + * @ignored_list: List node for tracking ignored timers in tsk::signal::ig= nored_posix_timers * @t_hash: Entry in the posix timer hash table * @it_lock: Lock protecting the timer * @kclock: Pointer to the k_clock struct handling this timer @@ -176,6 +177,7 @@ static inline void posix_cputimers_init_ */ struct k_itimer { struct hlist_node list; + struct hlist_node ignored_list; struct hlist_node t_hash; spinlock_t it_lock; const struct k_clock *kclock; --- a/kernel/time/posix-timers.c +++ b/kernel/time/posix-timers.c @@ -1031,6 +1031,18 @@ int common_timer_del(struct k_itimer *ti return 0; } =20 +/* + * If the deleted timer is on the ignored list, remove it and + * drop the associated reference. + */ +static inline void posix_timer_cleanup_ignored(struct k_itimer *tmr) +{ + if (!hlist_unhashed(&tmr->ignored_list)) { + hlist_del_init(&tmr->ignored_list); + posixtimer_putref(tmr); + } +} + static inline int timer_delete_hook(struct k_itimer *timer) { const struct k_clock *kc =3D timer->kclock; @@ -1063,6 +1075,7 @@ SYSCALL_DEFINE1(timer_delete, timer_t, t =20 spin_lock(¤t->sighand->siglock); hlist_del(&timer->list); + posix_timer_cleanup_ignored(timer); spin_unlock(¤t->sighand->siglock); /* * A concurrent lookup could check timer::it_signal lockless. It @@ -1114,6 +1127,8 @@ static void itimer_delete(struct k_itime } hlist_del(&timer->list); =20 + posix_timer_cleanup_ignored(timer); + /* * Setting timer::it_signal to NULL is technically not required * here as nothing can access the timer anymore legitimately via @@ -1146,6 +1161,11 @@ void exit_itimers(struct task_struct *ts /* The timers are not longer accessible via tsk::signal */ while (!hlist_empty(&timers)) itimer_delete(hlist_entry(timers.first, struct k_itimer, list)); + + /* Mop up timers which are on the ignored list */ + hlist_move_list(&tsk->signal->ignored_posix_timers, &timers); + while (!hlist_empty(&timers)) + posix_timer_cleanup_ignored(hlist_entry(timers.first, struct k_itimer, l= ist)); } =20 SYSCALL_DEFINE2(clock_settime, const clockid_t, which_clock,