Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754180AbYLTRuR (ORCPT ); Sat, 20 Dec 2008 12:50:17 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753046AbYLTRuD (ORCPT ); Sat, 20 Dec 2008 12:50:03 -0500 Received: from mx2.redhat.com ([66.187.237.31]:39473 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752959AbYLTRuC (ORCPT ); Sat, 20 Dec 2008 12:50:02 -0500 Date: Sat, 20 Dec 2008 18:48:17 +0100 From: Oleg Nesterov To: Thomas Gleixner Cc: Eric Sesterhenn , LKML Subject: [PATCH] posix-timers: CLOCK_MONOTONIC_RAW: fix the usage of ->it_clock Message-ID: <20081220174817.GA5273@redhat.com> References: <20081219172549.GA25722@alice> <20081220161457.GA26499@redhat.com> <20081220163033.GB26499@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20081220163033.GB26499@redhat.com> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1886 Lines: 52 (compile tested) common_timer_create() and common_timer_set() blindly pass ->it_clock to hrtimer_init() as clock_id. This used to work until CLOCK_MONOTONIC_RAW was introduced, now we should be careful. Perhaps it makes sense to add BUG_ON(clock_id >= HRTIMER_MAX_CLOCK_BASES) to __hrtimer_init(), the wrong clock_id leads to catastrophe. Reported-by: Eric Sesterhenn Signed-off-by: Oleg Nesterov --- K-28/kernel/posix-timers.c~CLOCK_MONOTONIC_RAW 2008-12-02 17:12:40.000000000 +0100 +++ K-28/kernel/posix-timers.c 2008-12-20 18:23:28.000000000 +0100 @@ -191,12 +191,20 @@ static inline int common_clock_set(const return do_sys_settimeofday(tp, NULL); } -static int common_timer_create(struct k_itimer *new_timer) +static inline int +__common_timer_init(struct k_itimer *timer, enum hrtimer_mode mode) { - hrtimer_init(&new_timer->it.real.timer, new_timer->it_clock, 0); + clockid_t clock_id = timer->it_clock ? + CLOCK_MONOTONIC : CLOCK_REALTIME; + hrtimer_init(&timer->it.real.timer, clock_id, mode); return 0; } +static int common_timer_create(struct k_itimer *new_timer) +{ + return __common_timer_init(new_timer, HRTIMER_MODE_ABS); +} + /* * Return nonzero if we know a priori this clockid_t value is bogus. */ @@ -730,7 +738,7 @@ common_timer_set(struct k_itimer *timr, return 0; mode = flags & TIMER_ABSTIME ? HRTIMER_MODE_ABS : HRTIMER_MODE_REL; - hrtimer_init(&timr->it.real.timer, timr->it_clock, mode); + __common_timer_init(timr, mode); timr->it.real.timer.function = posix_timer_fn; hrtimer_set_expires(timer, timespec_to_ktime(new_setting->it_value)); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/