Stime/Settimeofday are still broken

B. D. Elliott (bde@nwlink.com)
Tue, 15 Jul 2003 00:40:49 -0700


The problems described below still exist in -2.6.0-test1.

>Date: Wed, 18 Jun 2003 00:57:12 -0700
>From: "B. D. Elliott" <bde@nwlink.com>
>To: linux-kernel@vger.kernel.org
>Subject: Sparc64-2.5.72: A Serious Time Problem
>Mail-Followup-To: linux-kernel@vger.kernel.org
>Mime-Version: 1.0
>Content-Type: text/plain; charset=us-ascii
>Content-Disposition: inline
>User-Agent: Mutt/1.5.4i
>Message-Id: <20030618073556.94E966A4FC@smtp4.pacifier.net>
>Status: RO
>Content-Length: 1651
>Lines: 47
>
>There is a serious bug in setting time on 64-bit sparcs (and probably other
>64-bit systems). The symptom is that ntpdate or date set the time back to
>1969 or 1970. The underlying problems are that stime is broken, and any
>settimeofday call fails with a bad fractional value. Ntpdate falls back to
>stime when settimeofday fails.
>
>The settimeofday problem is that the timeval and timespec structures are not
>the same size. In particular, the fractional part is an int in timeval, and
>a long in timespec. The stime problem is that the argument is not an int,
>but a time_t, which is long on at least some 64-bit systems.
>
>The following patch appears to fix this on my sparc64.
>
>===================================================================
>--- ./kernel/time.c.orig 2003-06-16 22:36:04.000000000 -0700
>+++ ./kernel/time.c 2003-06-18 00:00:43.000000000 -0700
>@@ -66,7 +66,7 @@
> * architectures that need it).
> */
>
>-asmlinkage long sys_stime(int * tptr)
>+asmlinkage long sys_stime(time_t * tptr)
> {
> struct timespec tv;
>
>@@ -162,13 +162,15 @@
>
> asmlinkage long sys_settimeofday(struct timeval __user *tv, struct timezone __user *tz)
> {
>+ struct timeval user_tv;
> struct timespec new_tv;
> struct timezone new_tz;
>
> if (tv) {
>- if (copy_from_user(&new_tv, tv, sizeof(*tv)))
>+ if (copy_from_user(&user_tv, tv, sizeof(*tv)))
> return -EFAULT;
>- new_tv.tv_nsec *= NSEC_PER_USEC;
>+ new_tv.tv_sec = user_tv.tv_sec;
>+ new_tv.tv_nsec = user_tv.tv_usec * NSEC_PER_USEC;
> }
> if (tz) {
> if (copy_from_user(&new_tz, tz, sizeof(*tz)))
>===================================================================

-- 
B. D. Elliott   bde@nwlink.com
-
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/