[PATCHv8 11/34] posix-clocks: Wire up clock_gettime() with timens offsets

Dmitry Safonov
2019-11-12T01:27:00Z

From: Andrei Vagin <avagin@openvz.org>

Adjust monotonic and boottime clocks with per-timens offsets.
As the result a process inside time namespace will see timers and clocks
corrected to offsets that were set on creating namespace.

Note that applications usually go through vDSO to get time, which is not
yet adjusted. Further changes complete time namespace virtualisation
with vDSO support.

Signed-off-by: Andrei Vagin <avagin@gmail.com>
Co-developed-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Dmitry Safonov <dima@arista.com>
---
kernel/time/alarmtimer.c | 9 ++++++++-
kernel/time/posix-stubs.c | 3 +++
kernel/time/posix-timers.c | 5 +++++
3 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/kernel/time/alarmtimer.c b/kernel/time/alarmtimer.c
index 4d8c90546635..9a8e81bc4ec2 100644
--- a/kernel/time/alarmtimer.c
+++ b/kernel/time/alarmtimer.c
@@ -26,6 +26,7 @@
#include <linux/freezer.h>
#include <linux/compat.h>
#include <linux/module.h>
+#include <linux/time_namespace.h>

#include "posix-timers.h"

@@ -886,6 +887,12 @@ static struct platform_driver alarmtimer_driver = {
}
};

+static void get_boottime_timespec(struct timespec64 *tp)
+{
+ ktime_get_boottime_ts64(tp);
+ timens_add_boottime(tp);
+}
+
/**
* alarmtimer_init - Initialize alarm timer code
*
@@ -906,7 +913,7 @@ static int __init alarmtimer_init(void)
alarm_bases[ALARM_REALTIME].get_timespec = ktime_get_real_ts64,
alarm_bases[ALARM_BOOTTIME].base_clockid = CLOCK_BOOTTIME;
alarm_bases[ALARM_BOOTTIME].get_ktime = &ktime_get_boottime;
- alarm_bases[ALARM_BOOTTIME].get_timespec = ktime_get_boottime_ts64;
+ alarm_bases[ALARM_BOOTTIME].get_timespec = get_boottime_timespec;
for (i = 0; i < ALARM_NUMTYPE; i++) {
timerqueue_init_head(&alarm_bases[i].timerqueue);
spin_lock_init(&alarm_bases[i].lock);
diff --git a/kernel/time/posix-stubs.c b/kernel/time/posix-stubs.c
index 67df65f887ac..edaf075d1ee4 100644
--- a/kernel/time/posix-stubs.c
+++ b/kernel/time/posix-stubs.c
@@ -14,6 +14,7 @@
#include <linux/ktime.h>
#include <linux/timekeeping.h>
#include <linux/posix-timers.h>
+#include <linux/time_namespace.h>
#include <linux/compat.h>

#ifdef CONFIG_ARCH_HAS_SYSCALL_WRAPPER
@@ -77,9 +78,11 @@ int do_clock_gettime(clockid_t which_clock, struct timespec64 *tp)
break;
case CLOCK_MONOTONIC:
ktime_get_ts64(tp);
+ timens_add_monotonic(tp);
break;
case CLOCK_BOOTTIME:
ktime_get_boottime_ts64(tp);
+ timens_add_boottime(tp);
break;
default:
return -EINVAL;
diff --git a/kernel/time/posix-timers.c b/kernel/time/posix-timers.c
index fe1de4f71ace..d26b915b227a 100644
--- a/kernel/time/posix-timers.c
+++ b/kernel/time/posix-timers.c
@@ -30,6 +30,7 @@
#include <linux/hashtable.h>
#include <linux/compat.h>
#include <linux/nospec.h>
+#include <linux/time_namespace.h>

#include "timekeeping.h"
#include "posix-timers.h"
@@ -195,6 +196,7 @@ static int posix_clock_realtime_adj(const clockid_t which_clock,
static int posix_get_monotonic_timespec(clockid_t which_clock, struct timespec64 *tp)
{
ktime_get_ts64(tp);
+ timens_add_monotonic(tp);
return 0;
}

@@ -209,6 +211,7 @@ static ktime_t posix_get_monotonic_ktime(clockid_t which_clock)
static int posix_get_monotonic_raw(clockid_t which_clock, struct timespec64 *tp)
{
ktime_get_raw_ts64(tp);
+ timens_add_monotonic(tp);
return 0;
}

@@ -223,6 +226,7 @@ static int posix_get_monotonic_coarse(clockid_t which_clock,
struct timespec64 *tp)
{
ktime_get_coarse_ts64(tp);
+ timens_add_monotonic(tp);
return 0;
}

@@ -235,6 +239,7 @@ static int posix_get_coarse_res(const clockid_t which_clock, struct timespec64 *
static int posix_get_boottime_timespec(const clockid_t which_clock, struct timespec64 *tp)
{
ktime_get_boottime_ts64(tp);
+ timens_add_boottime(tp);
return 0;
}

--
2.24.0