Re: Stime/Settimeofday are still broken

[george anzinger <george@mvista.com>]

David S. Miller wrote:
> On Tue, 15 Jul 2003 00:40:49 -0700
> "B. D. Elliott" <bde@nwlink.com> wrote:
> 
> 
>>The problems described below still exist in -2.6.0-test1.
> 
> 
> Ignore my previous reply, not a Sparc problem obviously
> but a generic one, sorry.
> 
> Andrew, he's right, we need to fix this and his patch looks
> perfectly fine.

Looks good to me.

-g
> 
> 
>>>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
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>>>
>>>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
>>-
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-- 
George Anzinger   george@mvista.com
High-res-timers:  http://sourceforge.net/projects/high-res-timers/
Preemption patch: http://www.kernel.org/pub/linux/kernel/people/rml