From 7d3705e6ccb61479685fc02d542bc7b66f1d7294 Mon Sep 17 00:00:00 2001
From: Al Viro <viro@ZenIV.linux.org.uk>
Date: Wed, 7 Jun 2017 09:42:28 +0100
Subject: [PATCH 1/3] hrtimer_nanosleep(): Pass rmtp in restart_block

Git-commit: 192a82f9003fe8fabd6088aa646e829225a94c55
Patch-mainline: v4.13-rc1
References: bsc#1191713

Store the pointer to the timespec which gets updated with the remaining
time in the restart block and remove the function argument.

[ tglx: Added changelog ]

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20170607084241.28657-3-viro@ZenIV.linux.org.uk

Signed-off-by: Firo Yang <firo.yang@suse.com>
---
 include/linux/hrtimer.h    |  1 -
 kernel/compat.c            |  6 +++---
 kernel/time/hrtimer.c      | 11 ++++++-----
 kernel/time/posix-stubs.c  |  5 ++++-
 kernel/time/posix-timers.c |  5 ++++-
 5 files changed, 17 insertions(+), 11 deletions(-)

diff --git a/include/linux/hrtimer.h b/include/linux/hrtimer.h
index a1d1a966eeaa..f9753ac8d483 100644
--- a/include/linux/hrtimer.h
+++ b/include/linux/hrtimer.h
@@ -459,7 +459,6 @@ static inline u64 hrtimer_forward_now(struct hrtimer *timer,
 
 /* Precise sleep: */
 extern long hrtimer_nanosleep(struct timespec64 *rqtp,
-			      struct timespec __user *rmtp,
 			      const enum hrtimer_mode mode,
 			      const clockid_t clockid);
 extern long hrtimer_nanosleep_restart(struct restart_block *restart_block);
diff --git a/kernel/compat.c b/kernel/compat.c
index 933bcb31ae10..cc9ba9d29b47 100644
--- a/kernel/compat.c
+++ b/kernel/compat.c
@@ -253,9 +253,9 @@ COMPAT_SYSCALL_DEFINE2(nanosleep, struct compat_timespec __user *, rqtp,
 
 	oldfs = get_fs();
 	set_fs(KERNEL_DS);
-	ret = hrtimer_nanosleep(&tu64,
-				rmtp ? (struct timespec __user *)&rmt : NULL,
-				HRTIMER_MODE_REL, CLOCK_MONOTONIC);
+	current->restart_block.nanosleep.rmtp =
+				rmtp ? (struct timespec __user *)&rmt : NULL;
+	ret = hrtimer_nanosleep(&tu64, HRTIMER_MODE_REL, CLOCK_MONOTONIC);
 	set_fs(oldfs);
 
 	/*
diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c
index 0f9dda89d45c..4f34200ab588 100644
--- a/kernel/time/hrtimer.c
+++ b/kernel/time/hrtimer.c
@@ -1511,10 +1511,11 @@ long __sched hrtimer_nanosleep_restart(struct restart_block *restart)
 	return ret;
 }
 
-long hrtimer_nanosleep(struct timespec64 *rqtp, struct timespec __user *rmtp,
+long hrtimer_nanosleep(struct timespec64 *rqtp,
 		       const enum hrtimer_mode mode, const clockid_t clockid)
 {
-	struct restart_block *restart;
+	struct restart_block *restart = &current->restart_block;
+	struct timespec __user *rmtp;
 	struct hrtimer_sleeper t;
 	int ret = 0;
 	u64 slack;
@@ -1534,16 +1535,15 @@ long hrtimer_nanosleep(struct timespec64 *rqtp, struct timespec __user *rmtp,
 		goto out;
 	}
 
+	rmtp = restart->nanosleep.rmtp;
 	if (rmtp) {
 		ret = update_rmtp(&t.timer, rmtp);
 		if (ret <= 0)
 			goto out;
 	}
 
-	restart = &current->restart_block;
 	restart->fn = hrtimer_nanosleep_restart;
 	restart->nanosleep.clockid = t.timer.base->clockid;
-	restart->nanosleep.rmtp = rmtp;
 	restart->nanosleep.expires = hrtimer_get_expires_tv64(&t.timer);
 
 	ret = -ERESTART_RESTARTBLOCK;
@@ -1565,7 +1565,8 @@ SYSCALL_DEFINE2(nanosleep, struct timespec __user *, rqtp,
 	if (!timespec64_valid(&tu64))
 		return -EINVAL;
 
-	return hrtimer_nanosleep(&tu64, rmtp, HRTIMER_MODE_REL, CLOCK_MONOTONIC);
+	current->restart_block.nanosleep.rmtp = rmtp;
+	return hrtimer_nanosleep(&tu64, HRTIMER_MODE_REL, CLOCK_MONOTONIC);
 }
 
 /*
diff --git a/kernel/time/posix-stubs.c b/kernel/time/posix-stubs.c
index c0cd53eb018a..156a5e6f3bd2 100644
--- a/kernel/time/posix-stubs.c
+++ b/kernel/time/posix-stubs.c
@@ -115,7 +115,10 @@ SYSCALL_DEFINE4(clock_nanosleep, const clockid_t, which_clock, int, flags,
 		t64 = timespec_to_timespec64(t);
 		if (!timespec64_valid(&t64))
 			return -EINVAL;
-		return hrtimer_nanosleep(&t64, rmtp, flags & TIMER_ABSTIME ?
+		if (flags & TIMER_ABSTIME)
+			rmtp = NULL;
+		current->restart_block.nanosleep.rmtp = rmtp;
+		return hrtimer_nanosleep(&t64, flags & TIMER_ABSTIME ?
 					 HRTIMER_MODE_ABS : HRTIMER_MODE_REL,
 					 which_clock);
 	default:
diff --git a/kernel/time/posix-timers.c b/kernel/time/posix-timers.c
index 9f3398a11a53..895be31f6514 100644
--- a/kernel/time/posix-timers.c
+++ b/kernel/time/posix-timers.c
@@ -1124,7 +1124,10 @@ SYSCALL_DEFINE2(clock_getres, const clockid_t, which_clock,
 static int common_nsleep(const clockid_t which_clock, int flags,
 			 struct timespec64 *tsave, struct timespec __user *rmtp)
 {
-	return hrtimer_nanosleep(tsave, rmtp, flags & TIMER_ABSTIME ?
+	if (flags & TIMER_ABSTIME)
+		rmtp = NULL;
+	current->restart_block.nanosleep.rmtp = rmtp;
+	return hrtimer_nanosleep(tsave, flags & TIMER_ABSTIME ?
 				 HRTIMER_MODE_ABS : HRTIMER_MODE_REL,
 				 which_clock);
 }
-- 
2.26.2