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From: Vinay Sridhar <vinay@linux.vnet.ibm.com>
To: linux-kernel@vger.kernel.org
Cc: jstultz@us.ibm.com
Subject: [Patch] Fix sys_time to handle intra-tick correction
Date: Tue, 09 Dec 2008 17:28:58 +0530	[thread overview]
Message-ID: <1228823938.11639.7.camel@localhost.localdomain> (raw)

Hi All,

This fix changes sys_time to use do_gettimeofday instead of get_seconds.
Running the stime01 test from LTP triggers this error. Calling sys_stime
and then calling sys_time causes this. "do_settimeofday" subtracts the
nsec offset from the nsec value(0 in this case) passed to it.
Subsequently, "set_normalized_timespec" modifies sec and nsec
accordingly. This compensation is handled in the do_gettimeofday path.
However, sys_time does not handle this case and reports an incorrect
seconds value.


signed-off by : Vinay Sridhar <vinay@linux.vnet.ibm.com>

--- time.c.orig	2008-12-04 06:30:12.000000000 -0600
+++ time.c	2008-12-04 06:31:25.000000000 -0600
@@ -61,7 +61,12 @@ EXPORT_SYMBOL(sys_tz);
  */
 asmlinkage long sys_time(time_t __user * tloc)
 {
-	time_t i = get_seconds();
+	struct timeval t;	
+	time_t i;
+
+	do_gettimeofday(&t);
+
+	i = t.tv_sec;
 
 	if (tloc) {
 		if (put_user(i,tloc))



             reply	other threads:[~2008-12-09 12:00 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-12-09 11:58 Vinay Sridhar [this message]
2008-12-10  0:24 ` john stultz
2008-12-10  2:25   ` john stultz

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