From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755853AbZBHWCO (ORCPT ); Sun, 8 Feb 2009 17:02:14 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753931AbZBHVuT (ORCPT ); Sun, 8 Feb 2009 16:50:19 -0500 Received: from x35.xmailserver.org ([64.71.152.41]:47209 "EHLO x35.xmailserver.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754820AbZBHVuP (ORCPT ); Sun, 8 Feb 2009 16:50:15 -0500 X-AuthUser: davidel@xmailserver.org Date: Sun, 8 Feb 2009 13:50:11 -0800 (PST) From: Davide Libenzi X-X-Sender: davide@alien.or.mcafeemobile.com To: Michael Kerrisk cc: "linux-man@vger.kernel.org" , lkml , Thomas Gleixner Subject: Re: Why does timerfd() only support CLOCK_REALTIME and CLOCK_MONOTONIC? In-Reply-To: Message-ID: References: User-Agent: Alpine 1.10 (DEB 962 2008-03-14) X-GPG-FINGRPRINT: CFAE 5BEE FD36 F65E E640 56FE 0974 BF23 270F 474E X-GPG-PUBLIC_KEY: http://www.xmailserver.org/davidel.asc MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 9 Feb 2009, Michael Kerrisk wrote: > > @@ -186,12 +187,9 @@ SYSCALL_DEFINE2(timerfd_create, int, clo > > BUILD_BUG_ON(TFD_CLOEXEC != O_CLOEXEC); > > BUILD_BUG_ON(TFD_NONBLOCK != O_NONBLOCK); > > > > - if (flags & ~(TFD_CLOEXEC | TFD_NONBLOCK)) > > + if ((flags & ~TFD_FLAGS_SET) || > > + invalid_clockid(clockid)) > > return -EINVAL; > > Oh! Does this mean that in 2.6.2[789] it wasn't possible to use > TFD_TIMER_ABSTIME? No, sorry, my fault. Patch is wrong. In "create" ATM we accept only FCNTL-like flags. In "settime" we get TFD_TIMER_ABSTIME (that needs a check too for EINVAL). - Davide --- fs/timerfd.c | 13 ++++++------- include/linux/posix-timers.h | 1 + include/linux/timerfd.h | 15 ++++++++++++--- kernel/posix-timers.c | 2 +- 4 files changed, 20 insertions(+), 11 deletions(-) Index: linux-2.6.mod/fs/timerfd.c =================================================================== --- linux-2.6.mod.orig/fs/timerfd.c 2009-02-08 12:32:25.000000000 -0800 +++ linux-2.6.mod/fs/timerfd.c 2009-02-08 13:44:47.000000000 -0800 @@ -18,6 +18,7 @@ #include #include #include +#include #include #include #include @@ -186,12 +187,9 @@ SYSCALL_DEFINE2(timerfd_create, int, clo BUILD_BUG_ON(TFD_CLOEXEC != O_CLOEXEC); BUILD_BUG_ON(TFD_NONBLOCK != O_NONBLOCK); - if (flags & ~(TFD_CLOEXEC | TFD_NONBLOCK)) + if ((flags & ~TFD_CREATE_FLAGS) || + invalid_clockid(clockid)) return -EINVAL; - if (clockid != CLOCK_MONOTONIC && - clockid != CLOCK_REALTIME) - return -EINVAL; - ctx = kzalloc(sizeof(*ctx), GFP_KERNEL); if (!ctx) return -ENOMEM; @@ -201,7 +199,7 @@ SYSCALL_DEFINE2(timerfd_create, int, clo hrtimer_init(&ctx->tmr, clockid, HRTIMER_MODE_ABS); ufd = anon_inode_getfd("[timerfd]", &timerfd_fops, ctx, - flags & (O_CLOEXEC | O_NONBLOCK)); + flags & TFD_SHARED_FCNTL_FLAGS); if (ufd < 0) kfree(ctx); @@ -219,7 +217,8 @@ SYSCALL_DEFINE4(timerfd_settime, int, uf if (copy_from_user(&ktmr, utmr, sizeof(ktmr))) return -EFAULT; - if (!timespec_valid(&ktmr.it_value) || + if ((flags & ~TFD_SETTIME_FLAGS) || + !timespec_valid(&ktmr.it_value) || !timespec_valid(&ktmr.it_interval)) return -EINVAL; Index: linux-2.6.mod/include/linux/posix-timers.h =================================================================== --- linux-2.6.mod.orig/include/linux/posix-timers.h 2009-02-08 12:32:25.000000000 -0800 +++ linux-2.6.mod/include/linux/posix-timers.h 2009-02-08 12:33:12.000000000 -0800 @@ -84,6 +84,7 @@ struct k_clock { struct itimerspec * cur_setting); }; +int invalid_clockid(const clockid_t which_clock); void register_posix_clock(const clockid_t clock_id, struct k_clock *new_clock); /* error handlers for timer_create, nanosleep and settime */ Index: linux-2.6.mod/kernel/posix-timers.c =================================================================== --- linux-2.6.mod.orig/kernel/posix-timers.c 2009-02-08 12:32:25.000000000 -0800 +++ linux-2.6.mod/kernel/posix-timers.c 2009-02-08 12:32:57.000000000 -0800 @@ -205,7 +205,7 @@ static int no_timer_create(struct k_itim /* * Return nonzero if we know a priori this clockid_t value is bogus. */ -static inline int invalid_clockid(const clockid_t which_clock) +int invalid_clockid(const clockid_t which_clock) { if (which_clock < 0) /* CPU clock, posix_cpu_* will check it */ return 0; Index: linux-2.6.mod/include/linux/timerfd.h =================================================================== --- linux-2.6.mod.orig/include/linux/timerfd.h 2009-02-08 12:34:25.000000000 -0800 +++ linux-2.6.mod/include/linux/timerfd.h 2009-02-08 13:47:57.000000000 -0800 @@ -11,13 +11,22 @@ /* For O_CLOEXEC and O_NONBLOCK */ #include -/* Flags for timerfd_settime. */ +/* + * CAREFUL: Check include/asm-generic/fcntl.h when defining + * new flags, since they might collide with O_* ones. We want + * to re-use O_* flags that couldn't possibly have a meaning + * from eventfd, in order to leave a free define-space for + * shared O_* flags. + */ #define TFD_TIMER_ABSTIME (1 << 0) - -/* Flags for timerfd_create. */ #define TFD_CLOEXEC O_CLOEXEC #define TFD_NONBLOCK O_NONBLOCK +#define TFD_SHARED_FCNTL_FLAGS (TFD_CLOEXEC | TFD_NONBLOCK) +#define TFD_CREATE_FLAGS TFD_SHARED_FCNTL_FLAGS +#define TFD_SETTIME_FLAGS TFD_TIMER_ABSTIME +#define TFD_FLAGS_SET (TFD_SHARED_FCNTL_FLAGS | TFD_TIMER_ABSTIME) + #endif /* _LINUX_TIMERFD_H */