From: Lin Ming <ming.m.lin@intel.com>
Subject: timekeeping: Fix clock_gettime vsyscall time warp
Patch-mainline: 0696b711e4be45fa104c12329f617beb29c03f78
References: bnc#569238

commit 0696b711e4be45fa104c12329f617beb29c03f78
Author: Lin Ming <ming.m.lin@intel.com>
Date:   Tue Nov 17 13:49:50 2009 +0800

    timekeeping: Fix clock_gettime vsyscall time warp
    
    Since commit 0a544198 "timekeeping: Move NTP adjusted clock multiplier
    to struct timekeeper" the clock multiplier of vsyscall is updated with
    the unmodified clock multiplier of the clock source and not with the
    NTP adjusted multiplier of the timekeeper.
    
    This causes user space observerable time warps:
    new CLOCK-warp maximum: 120 nsecs,  00000025c337c537 -> 00000025c337c4bf
    
    Add a new argument "mult" to update_vsyscall() and hand in the
    timekeeping internal NTP adjusted multiplier.
    
    Signed-off-by: Lin Ming <ming.m.lin@intel.com>
    Cc: "Zhang Yanmin" <yanmin_zhang@linux.intel.com>
    Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
    Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
    Cc: Tony Luck <tony.luck@intel.com>
    LKML-Reference: <1258436990.17765.83.camel@minggr.sh.intel.com>
    Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

Signed-off-by: Kurt Garloff <garloff@suse.de>

Automatically created from "patches.fixes/fix_clock_gettime_vsyscall_time_warp.diff" by xen-port-patches.py

--- sle11sp1-2010-03-01.orig/arch/x86/kernel/vsyscall_64-xen.c	2009-11-06 10:52:23.000000000 +0100
+++ sle11sp1-2010-03-01/arch/x86/kernel/vsyscall_64-xen.c	2010-03-01 14:44:50.000000000 +0100
@@ -73,7 +73,8 @@ void update_vsyscall_tz(void)
 	write_sequnlock_irqrestore(&vsyscall_gtod_data.lock, flags);
 }
 
-void update_vsyscall(struct timespec *wall_time, struct clocksource *clock)
+void update_vsyscall(struct timespec *wall_time, struct clocksource *clock,
+		     u32 mult)
 {
 	unsigned long flags;
 
@@ -82,7 +83,7 @@ void update_vsyscall(struct timespec *wa
 	vsyscall_gtod_data.clock.vread = clock->vread;
 	vsyscall_gtod_data.clock.cycle_last = clock->cycle_last;
 	vsyscall_gtod_data.clock.mask = clock->mask;
-	vsyscall_gtod_data.clock.mult = clock->mult;
+	vsyscall_gtod_data.clock.mult = mult;
 	vsyscall_gtod_data.clock.shift = clock->shift;
 	vsyscall_gtod_data.wall_time_sec = wall_time->tv_sec;
 	vsyscall_gtod_data.wall_time_nsec = wall_time->tv_nsec;