From: Andrei Vagin <ava...@openvz.org>
Add monotonic time virtualisation for time namespace.
Introduce timespec for monotionic clock into timens offsets and wire
clock_gettime() syscall.
Signed-off-by: Andrei Vagin <ava...@openvz.org>
Co-developed-by: Dmitry Safonov <d...@arista.com>
Signed-off-by: Dmitry Safonov <d...@arista.com>
---
include/linux/time_namespace.h | 11 ++++++++++
include/linux/timens_offsets.h | 1 +
kernel/time/posix-timers.c | 10 +++++++++
kernel/time/posix-timers.h | 1 +
kernel/time_namespace.c | 38 ++++++++++++++++++++++++++++++++++
5 files changed, 61 insertions(+)
diff --git a/include/linux/time_namespace.h b/include/linux/time_namespace.h
index b6985aa87479..f1807d7f524d 100644
--- a/include/linux/time_namespace.h
+++ b/include/linux/time_namespace.h
@@ -41,6 +41,9 @@ static inline void put_time_ns(struct time_namespace *ns)
}
+extern void timens_clock_to_host(int clockid, struct timespec64 *val);
+extern void timens_clock_from_host(int clockid, struct timespec64 *val);
+
#else
static inline struct time_namespace *get_time_ns(struct time_namespace *ns)
{
@@ -65,6 +68,14 @@ static inline int timens_on_fork(struct nsproxy *nsproxy,
struct task_struct *ts
return 0;
}
+static inline void timens_clock_to_host(int clockid, struct timespec64 *val)
+{
+}
+
+static inline void timens_clock_from_host(int clockid, struct timespec64 *val)
+{
+}
+
#endif
#endif /* _LINUX_TIMENS_H */
diff --git a/include/linux/timens_offsets.h b/include/linux/timens_offsets.h
index 7d7cb68ea778..248b0c0bb92a 100644
--- a/include/linux/timens_offsets.h
+++ b/include/linux/timens_offsets.h
@@ -3,6 +3,7 @@
#define _LINUX_TIME_OFFSETS_H
struct timens_offsets {
+ struct timespec64 monotonic_time_offset;
};
#endif
diff --git a/kernel/time/posix-timers.c b/kernel/time/posix-timers.c
index 0e84bb72a3da..b6d5145858a3 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"
@@ -1041,6 +1042,9 @@ SYSCALL_DEFINE2(clock_gettime, const clockid_t,
which_clock,
error = kc->clock_get(which_clock, &kernel_tp);
+ if (!error && kc->clock_timens_adjust)
+ timens_clock_from_host(which_clock, &kernel_tp);
+
if (!error && put_timespec64(&kernel_tp, tp))
error = -EFAULT;
@@ -1117,6 +1121,9 @@ COMPAT_SYSCALL_DEFINE2(clock_gettime, clockid_t,
which_clock,
err = kc->clock_get(which_clock, &ts);
+ if (!err && kc->clock_timens_adjust)
+ timens_clock_from_host(which_clock, &ts);
+
if (!err && put_old_timespec32(&ts, tp))
err = -EFAULT;
@@ -1259,6 +1266,7 @@ static const struct k_clock clock_realtime = {
static const struct k_clock clock_monotonic = {
.clock_getres = posix_get_hrtimer_res,
.clock_get = posix_ktime_get_ts,
+ .clock_timens_adjust = true,
.nsleep = common_nsleep,
.timer_create = common_timer_create,
.timer_set = common_timer_set,
@@ -1274,6 +1282,7 @@ static const struct k_clock clock_monotonic = {
static const struct k_clock clock_monotonic_raw = {
.clock_getres = posix_get_hrtimer_res,
.clock_get = posix_get_monotonic_raw,
+ .clock_timens_adjust = true,
};
static const struct k_clock clock_realtime_coarse = {
@@ -1284,6 +1293,7 @@ static const struct k_clock clock_realtime_coarse = {
static const struct k_clock clock_monotonic_coarse = {
.clock_getres = posix_get_coarse_res,
.clock_get = posix_get_monotonic_coarse,
+ .clock_timens_adjust = true,
};
static const struct k_clock clock_tai = {
diff --git a/kernel/time/posix-timers.h b/kernel/time/posix-timers.h
index ddb21145211a..1cf306bde639 100644
--- a/kernel/time/posix-timers.h
+++ b/kernel/time/posix-timers.h
@@ -24,6 +24,7 @@ struct k_clock {
int (*timer_try_to_cancel)(struct k_itimer *timr);
void (*timer_arm)(struct k_itimer *timr, ktime_t expires,
bool absolute, bool sigev_none);
+ bool clock_timens_adjust;
};
extern const struct k_clock clock_posix_cpu;
diff --git a/kernel/time_namespace.c b/kernel/time_namespace.c
index 4828447721ec..57694be9e9db 100644
--- a/kernel/time_namespace.c
+++ b/kernel/time_namespace.c
@@ -191,6 +191,44 @@ static struct user_namespace *timens_owner(struct
ns_common *ns)
return to_time_ns(ns)->user_ns;
}
+static void clock_timens_fixup(int clockid, struct timespec64 *val, bool to_ns)
+{
+ struct timens_offsets *ns_offsets = current->nsproxy->time_ns->offsets;
+ struct timespec64 *offsets = NULL;
+
+ if (!ns_offsets)
+ return;
+
+ if (val->tv_sec == 0 && val->tv_nsec == 0)
+ return;
+
+ switch (clockid) {
+ case CLOCK_MONOTONIC:
+ case CLOCK_MONOTONIC_RAW:
+ case CLOCK_MONOTONIC_COARSE:
+ offsets = &ns_offsets->monotonic_time_offset;
+ break;
+ }
+
+ if (!offsets)
+ return;
+
+ if (to_ns)
+ *val = timespec64_add(*val, *offsets);
+ else
+ *val = timespec64_sub(*val, *offsets);
+}
+
+void timens_clock_to_host(int clockid, struct timespec64 *val)
+{
+ clock_timens_fixup(clockid, val, false);
+}
+
+void timens_clock_from_host(int clockid, struct timespec64 *val)
+{
+ clock_timens_fixup(clockid, val, true);
+}
+
const struct proc_ns_operations timens_operations = {
.name = "time",
.type = CLONE_NEWTIME,
--
2.20.1
