From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755405AbZBIXbf (ORCPT ); Mon, 9 Feb 2009 18:31:35 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751786AbZBIXb0 (ORCPT ); Mon, 9 Feb 2009 18:31:26 -0500 Received: from x35.xmailserver.org ([64.71.152.41]:58103 "EHLO x35.xmailserver.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750933AbZBIXb0 (ORCPT ); Mon, 9 Feb 2009 18:31:26 -0500 X-AuthUser: davidel@xmailserver.org Date: Mon, 9 Feb 2009 15:31:24 -0800 (PST) From: Davide Libenzi X-X-Sender: davide@alien.or.mcafeemobile.com To: Linux Kernel Mailing List cc: Michael Kerrisk , Greg KH , Andrew Morton Subject: [patch] timerfd add flags check Message-ID: 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 Like Michael requested, this patch adds a missing check for valid flags in timerfd_settime(), and make it return EINVAL in case some extra bits are set. Michael said: If this is to be any use to userland apps that want to check flag support (perhaps it is too late already), then the sooner we get it into the kernel the better: 2.6.29 would be good; earlier stables as well would be even better. Acked-by: Michael Kerrisk Signed-off-by: Davide Libenzi - Davide --- fs/timerfd.c | 12 ++++++------ include/linux/timerfd.h | 17 ++++++++++++++--- 2 files changed, 20 insertions(+), 9 deletions(-) Index: linux-2.6.mod/fs/timerfd.c =================================================================== --- linux-2.6.mod.orig/fs/timerfd.c 2009-02-08 18:36:45.000000000 -0800 +++ linux-2.6.mod/fs/timerfd.c 2009-02-08 18:53:32.000000000 -0800 @@ -186,10 +186,9 @@ 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)) - return -EINVAL; - if (clockid != CLOCK_MONOTONIC && - clockid != CLOCK_REALTIME) + if ((flags & ~TFD_CREATE_FLAGS) || + (clockid != CLOCK_MONOTONIC && + clockid != CLOCK_REALTIME)) return -EINVAL; ctx = kzalloc(sizeof(*ctx), GFP_KERNEL); @@ -201,7 +200,7 @@ 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 +218,8 @@ 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/timerfd.h =================================================================== --- linux-2.6.mod.orig/include/linux/timerfd.h 2009-02-08 18:36:45.000000000 -0800 +++ linux-2.6.mod/include/linux/timerfd.h 2009-02-08 18:41:22.000000000 -0800 @@ -11,13 +11,24 @@ /* 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) +/* Flags for timerfd_create. */ +#define TFD_CREATE_FLAGS TFD_SHARED_FCNTL_FLAGS +/* Flags for timerfd_settime. */ +#define TFD_SETTIME_FLAGS TFD_TIMER_ABSTIME +#define TFD_FLAGS_SET (TFD_SHARED_FCNTL_FLAGS | TFD_TIMER_ABSTIME) + #endif /* _LINUX_TIMERFD_H */