posix-clocks: Wire up clock_gettime() with timens offsets

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 when the namespace was created

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

Co-developed-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Andrei Vagin <avagin@gmail.com>
Signed-off-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20191112012724.250792-12-dima@arista.com

1 files changed, 5 insertions, 0 deletions

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;
 }