linux-kernel - [PATCHv5 16/37] posix-timers: Make clock

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Message-Id: <20190729215758.28405-17-dima@arista.com>
Date:   Mon, 29 Jul 2019 22:56:58 +0100
From:   Dmitry Safonov <dima@...sta.com>
To:     linux-kernel@...r.kernel.org
Cc:     Dmitry Safonov <0x7f454c46@...il.com>,
        Andrei Vagin <avagin@...il.com>,
        Dmitry Safonov <dima@...sta.com>,
        Adrian Reber <adrian@...as.de>,
        Andrei Vagin <avagin@...nvz.org>,
        Andy Lutomirski <luto@...nel.org>,
        Arnd Bergmann <arnd@...db.de>,
        Christian Brauner <christian.brauner@...ntu.com>,
        Cyrill Gorcunov <gorcunov@...nvz.org>,
        "Eric W. Biederman" <ebiederm@...ssion.com>,
        "H. Peter Anvin" <hpa@...or.com>, Ingo Molnar <mingo@...hat.com>,
        Jann Horn <jannh@...gle.com>, Jeff Dike <jdike@...toit.com>,
        Oleg Nesterov <oleg@...hat.com>,
        Pavel Emelyanov <xemul@...tuozzo.com>,
        Shuah Khan <shuah@...nel.org>,
        Thomas Gleixner <tglx@...utronix.de>,
        Vincenzo Frascino <vincenzo.frascino@....com>,
        containers@...ts.linux-foundation.org, criu@...nvz.org,
        linux-api@...r.kernel.org, x86@...nel.org
Subject: [PATCHv5 16/37] posix-timers: Make clock_nanosleep() time namespace aware

From: Andrei Vagin <avagin@...il.com>

clock_nanosleep() accepts absolute values of expiration time, if the
TIMER_ABSTIME flag is set. This value is in the task time namespace,
which has to be converted to the host time namespace.

Signed-off-by: Andrei Vagin <avagin@...nvz.org>
Co-developed-by: Dmitry Safonov <dima@...sta.com>
Signed-off-by: Dmitry Safonov <dima@...sta.com>
---
 kernel/time/posix-stubs.c  | 12 ++++++++++--
 kernel/time/posix-timers.c | 21 ++++++++++++++++++---
 2 files changed, 28 insertions(+), 5 deletions(-)

diff --git a/kernel/time/posix-stubs.c b/kernel/time/posix-stubs.c
index 2ccefc9ce184..47ee2684d250 100644
--- a/kernel/time/posix-stubs.c
+++ b/kernel/time/posix-stubs.c
@@ -129,6 +129,7 @@ SYSCALL_DEFINE4(clock_nanosleep, const clockid_t, which_clock, int, flags,
 		struct __kernel_timespec __user *, rmtp)
 {
 	struct timespec64 t;
+	ktime_t texp;
 
 	switch (which_clock) {
 	case CLOCK_REALTIME:
@@ -147,7 +148,10 @@ SYSCALL_DEFINE4(clock_nanosleep, const clockid_t, which_clock, int, flags,
 		rmtp = NULL;
 	current->restart_block.nanosleep.type = rmtp ? TT_NATIVE : TT_NONE;
 	current->restart_block.nanosleep.rmtp = rmtp;
-	return hrtimer_nanosleep(timespec64_to_ktime(t), flags & TIMER_ABSTIME ?
+	texp = timespec64_to_ktime(t);
+	if (flags & TIMER_ABSTIME)
+		texp = timens_ktime_to_host(clockid, texp);
+	return hrtimer_nanosleep(texp, flags & TIMER_ABSTIME ?
 				 HRTIMER_MODE_ABS : HRTIMER_MODE_REL,
 				 which_clock);
 }
@@ -215,6 +219,7 @@ SYSCALL_DEFINE4(clock_nanosleep_time32, clockid_t, which_clock, int, flags,
 		struct old_timespec32 __user *, rmtp)
 {
 	struct timespec64 t;
+	ktime texp;
 
 	switch (which_clock) {
 	case CLOCK_REALTIME:
@@ -233,7 +238,10 @@ SYSCALL_DEFINE4(clock_nanosleep_time32, clockid_t, which_clock, int, flags,
 		rmtp = NULL;
 	current->restart_block.nanosleep.type = rmtp ? TT_COMPAT : TT_NONE;
 	current->restart_block.nanosleep.compat_rmtp = rmtp;
-	return hrtimer_nanosleep(timespec64_to_ktime(t), flags & TIMER_ABSTIME ?
+	texp = timespec64_to_ktime(t);
+	if (flags & TIMER_ABSTIME)
+		texp = timens_ktime_to_host(clockid, texp);
+	return hrtimer_nanosleep(texp, flags & TIMER_ABSTIME ?
 				 HRTIMER_MODE_ABS : HRTIMER_MODE_REL,
 				 which_clock);
 }
diff --git a/kernel/time/posix-timers.c b/kernel/time/posix-timers.c
index c979e720a5a1..4dc46d697144 100644
--- a/kernel/time/posix-timers.c
+++ b/kernel/time/posix-timers.c
@@ -1187,7 +1187,22 @@ SYSCALL_DEFINE2(clock_getres_time32, clockid_t, which_clock,
 static int common_nsleep(const clockid_t which_clock, int flags,
 			 const struct timespec64 *rqtp)
 {
-	return hrtimer_nanosleep(rqtp, flags & TIMER_ABSTIME ?
+	ktime_t texp = timespec64_to_ktime(*rqtp);
+
+	return hrtimer_nanosleep(texp, flags & TIMER_ABSTIME ?
+				 HRTIMER_MODE_ABS : HRTIMER_MODE_REL,
+				 which_clock);
+}
+
+static int common_nsleep_timens(const clockid_t which_clock, int flags,
+			 const struct timespec64 *rqtp)
+{
+	ktime_t texp = timespec64_to_ktime(*rqtp);
+
+	if (flags & TIMER_ABSTIME)
+		texp = timens_ktime_to_host(which_clock, texp);
+
+	return hrtimer_nanosleep(texp, flags & TIMER_ABSTIME ?
 				 HRTIMER_MODE_ABS : HRTIMER_MODE_REL,
 				 which_clock);
 }
@@ -1268,7 +1283,7 @@ static const struct k_clock clock_monotonic = {
 	.clock_getres		= posix_get_hrtimer_res,
 	.clock_get_timespec	= posix_get_timespec,
 	.clock_get_ktime	= posix_get_ktime,
-	.nsleep			= common_nsleep,
+	.nsleep			= common_nsleep_timens,
 	.timer_create		= common_timer_create,
 	.timer_set		= common_timer_set,
 	.timer_get		= common_timer_get,
@@ -1315,7 +1330,7 @@ static const struct k_clock clock_boottime = {
 	.clock_getres		= posix_get_hrtimer_res,
 	.clock_get_ktime	= posix_get_boottime_ktime,
 	.clock_get_timespec	= posix_get_boottime_timespec,
-	.nsleep			= common_nsleep,
+	.nsleep			= common_nsleep_timens,
 	.timer_create		= common_timer_create,
 	.timer_set		= common_timer_set,
 	.timer_get		= common_timer_get,
-- 
2.22.0