The patch titled
Fix discrepancy between VDSO based gettimeofday() and sys_gettimeofday().
has been removed from the -mm tree. Its filename was
fix-discrepancy-between-vdso-based-gettimeofday-and-sys_gettimeofday.patch
This patch was dropped because it was merged into mainline or a subsystem tree
------------------------------------------------------
Subject: Fix discrepancy between VDSO based gettimeofday() and sys_gettimeofday().
From: Tony Breeds <tony@xxxxxxxxxxxxxxxxxx>
On platforms that copy sys_tz into the vdso (currently only x86_64, soon to
include powerpc), it is possible for the vdso to get out of sync if a user
calls (admittedly unusual) settimeofday(NULL, ptr).
This patch adds a hook for architectures that set
CONFIG_GENERIC_TIME_VSYSCALL to ensure when sys_tz is updated they can also
updatee their copy in the vdso.
Signed-off-by: Tony Breeds <tony@xxxxxxxxxxxxxxxxxx>
Cc: Andi Kleen <ak@xxxxxxx>
Cc: Tony Luck <tony.luck@xxxxxxxxx>
Acked-by: John Stultz <johnstul@xxxxxxxxxx>
Cc: Paul Mackerras <paulus@xxxxxxxxx>
Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
arch/ia64/kernel/time.c | 5 +++++
arch/x86/kernel/vsyscall_64.c | 11 ++++++++++-
include/linux/clocksource.h | 5 +++++
kernel/time.c | 2 ++
4 files changed, 22 insertions(+), 1 deletion(-)
diff -puN arch/ia64/kernel/time.c~fix-discrepancy-between-vdso-based-gettimeofday-and-sys_gettimeofday arch/ia64/kernel/time.c
--- a/arch/ia64/kernel/time.c~fix-discrepancy-between-vdso-based-gettimeofday-and-sys_gettimeofday
+++ a/arch/ia64/kernel/time.c
@@ -371,6 +371,11 @@ ia64_setup_printk_clock(void)
ia64_printk_clock = ia64_itc_printk_clock;
}
+/* IA64 doesn't cache the timezone */
+void update_vsyscall_tz(void)
+{
+}
+
void update_vsyscall(struct timespec *wall, struct clocksource *c)
{
unsigned long flags;
diff -puN arch/x86/kernel/vsyscall_64.c~fix-discrepancy-between-vdso-based-gettimeofday-and-sys_gettimeofday arch/x86/kernel/vsyscall_64.c
--- a/arch/x86/kernel/vsyscall_64.c~fix-discrepancy-between-vdso-based-gettimeofday-and-sys_gettimeofday
+++ a/arch/x86/kernel/vsyscall_64.c
@@ -64,6 +64,16 @@ struct vsyscall_gtod_data __vsyscall_gto
.sysctl_enabled = 1,
};
+void update_vsyscall_tz(void)
+{
+ unsigned long flags;
+
+ write_seqlock_irqsave(&vsyscall_gtod_data.lock, flags);
+ /* sys_tz has changed */
+ vsyscall_gtod_data.sys_tz = sys_tz;
+ write_sequnlock_irqrestore(&vsyscall_gtod_data.lock, flags);
+}
+
void update_vsyscall(struct timespec *wall_time, struct clocksource *clock)
{
unsigned long flags;
@@ -77,7 +87,6 @@ void update_vsyscall(struct timespec *wa
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;
- vsyscall_gtod_data.sys_tz = sys_tz;
vsyscall_gtod_data.wall_to_monotonic = wall_to_monotonic;
write_sequnlock_irqrestore(&vsyscall_gtod_data.lock, flags);
}
diff -puN include/linux/clocksource.h~fix-discrepancy-between-vdso-based-gettimeofday-and-sys_gettimeofday include/linux/clocksource.h
--- a/include/linux/clocksource.h~fix-discrepancy-between-vdso-based-gettimeofday-and-sys_gettimeofday
+++ a/include/linux/clocksource.h
@@ -221,10 +221,15 @@ extern void clocksource_resume(void);
#ifdef CONFIG_GENERIC_TIME_VSYSCALL
extern void update_vsyscall(struct timespec *ts, struct clocksource *c);
+extern void update_vsyscall_tz(void);
#else
static inline void update_vsyscall(struct timespec *ts, struct clocksource *c)
{
}
+
+static inline void update_vsyscall_tz(void)
+{
+}
#endif
#endif /* _LINUX_CLOCKSOURCE_H */
diff -puN kernel/time.c~fix-discrepancy-between-vdso-based-gettimeofday-and-sys_gettimeofday kernel/time.c
--- a/kernel/time.c~fix-discrepancy-between-vdso-based-gettimeofday-and-sys_gettimeofday
+++ a/kernel/time.c
@@ -30,6 +30,7 @@
#include <linux/module.h>
#include <linux/timex.h>
#include <linux/capability.h>
+#include <linux/clocksource.h>
#include <linux/errno.h>
#include <linux/syscalls.h>
#include <linux/security.h>
@@ -158,6 +159,7 @@ int do_sys_settimeofday(struct timespec
if (tz) {
/* SMP safe, global irq locking makes it work. */
sys_tz = *tz;
+ update_vsyscall_tz();
if (firsttime) {
firsttime = 0;
if (!tv)
_
Patches currently in -mm which might be from tony@xxxxxxxxxxxxxxxxxx are
origin.patch
-
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