[PATCHv5 10/37] posix-clocks: Introduce CLOCK_BOOTTIME time namespace offset

From: Dmitry Safonov <dima@arista.com>
To: linux-kernel@vger.kernel.org
Cc: Dmitry Safonov <0x7f454c46@gmail.com>,
	Andrei Vagin <avagin@gmail.com>, Dmitry Safonov <dima@arista.com>,
	Adrian Reber <adrian@lisas.de>, Andrei Vagin <avagin@openvz.org>,
	Andy Lutomirski <luto@kernel.org>, Arnd Bergmann <arnd@arndb.de>,
	Christian Brauner <christian.brauner@ubuntu.com>,
	Cyrill Gorcunov <gorcunov@openvz.org>,
	"Eric W. Biederman" <ebiederm@xmission.com>,
	"H. Peter Anvin" <hpa@zytor.com>, Ingo Molnar <mingo@redhat.com>,
	Jann Horn <jannh@google.com>, Jeff Dike <jdike@addtoit.com>,
	Oleg Nesterov <oleg@redhat.com>,
	Pavel Emelyanov <xemul@virtuozzo.com>,
	Shuah Khan <shuah@kernel.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	Vincenzo Frascino <vincenzo.frascino@arm.com>,
	containers@lists.linux-foundation.org, criu@openvz.org,
	linux-api@vger.kernel.org, x86@kernel.org
Subject: [PATCHv5 10/37] posix-clocks: Introduce CLOCK_BOOTTIME time namespace offset
Date: Mon, 29 Jul 2019 22:57:30 +0100	[thread overview]
Message-ID: <20190729215758.28405-49-dima@arista.com> (raw)
In-Reply-To: <20190729215758.28405-1-dima@arista.com>

From: Andrei Vagin <avagin@gmail.com>

Adds boottime virtualisation for time namespace.
Introduce timespec for boottime clock into timens offsets and wire
clock_gettime() syscall.

Signed-off-by: Andrei Vagin <avagin@gmail.com>
Co-developed-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Dmitry Safonov <dima@arista.com>
---
 include/linux/time_namespace.h | 9 +++++++++
 include/linux/timens_offsets.h | 1 +
 kernel/time/alarmtimer.c       | 1 +
 kernel/time/posix-stubs.c      | 1 +
 kernel/time/posix-timers.c     | 1 +
 5 files changed, 13 insertions(+)

diff --git a/include/linux/time_namespace.h b/include/linux/time_namespace.h
index 186c134fe222..334c1a1c6607 100644
--- a/include/linux/time_namespace.h
+++ b/include/linux/time_namespace.h
@@ -48,6 +48,14 @@ static inline void timens_add_monotonic(struct timespec64 *ts)
 		*ts = timespec64_add(*ts, ns_offsets->monotonic);
 }
 
+static inline void timens_add_boottime(struct timespec64 *ts)
+{
+	struct timens_offsets *ns_offsets = current->nsproxy->time_ns->offsets;
+
+	if (ns_offsets)
+		*ts = timespec64_add(*ts, ns_offsets->boottime);
+}
+
 #else
 static inline struct time_namespace *get_time_ns(struct time_namespace *ns)
 {
@@ -73,6 +81,7 @@ static inline int timens_on_fork(struct nsproxy *nsproxy, struct task_struct *ts
 }
 
 static inline void timens_add_monotonic(struct timespec64 *ts) {}
+static inline void timens_add_boottime(struct timespec64 *ts) {}
 #endif
 
 #endif /* _LINUX_TIMENS_H */
diff --git a/include/linux/timens_offsets.h b/include/linux/timens_offsets.h
index eaac2c82be5c..e93aabaa5e45 100644
--- a/include/linux/timens_offsets.h
+++ b/include/linux/timens_offsets.h
@@ -4,6 +4,7 @@
 
 struct timens_offsets {
 	struct timespec64 monotonic;
+	struct timespec64 boottime;
 };
 
 #endif
diff --git a/kernel/time/alarmtimer.c b/kernel/time/alarmtimer.c
index 55cb6e78d082..b1e82bb6cc6b 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"
 
diff --git a/kernel/time/posix-stubs.c b/kernel/time/posix-stubs.c
index 17c67e0aecd8..edaf075d1ee4 100644
--- a/kernel/time/posix-stubs.c
+++ b/kernel/time/posix-stubs.c
@@ -82,6 +82,7 @@ int do_clock_gettime(clockid_t which_clock, struct timespec64 *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 cfeb0477d1f9..265fbc816520 100644
--- a/kernel/time/posix-timers.c
+++ b/kernel/time/posix-timers.c
@@ -240,6 +240,7 @@ static int posix_get_coarse_res(const clockid_t which_clock, struct timespec64 *
 int posix_get_boottime_timespec(const clockid_t which_clock, struct timespec64 *tp)
 {
 	ktime_get_boottime_ts64(tp);
+	timens_add_boottime(tp);
 	return 0;
 }
 
-- 
2.22.0

