[tip:timers/core] posix-timers: Make posix_clocks immutable

[tip-bot for Christoph Hellwig]

Commit-ID:  d346807445883732d530a62ebadb69af2f017e28
Gitweb:     http://git.kernel.org/tip/d346807445883732d530a62ebadb69af2f017e28
Author:     Christoph Hellwig <hch@xxxxxx>
AuthorDate: Fri, 26 May 2017 12:03:11 +0300
Committer:  Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitDate: Fri, 26 May 2017 14:35:06 +0200

posix-timers: Make posix_clocks immutable

There are no more modular users providing a posix clock. The register
function is now pointless so the posix clock array can be initialized
statically at compile time and the array including the various k_clock
structs can be marked 'const'.

Inspired by changes in the Grsecurity patch set, but done proper.

[ tglx: Massaged changelog and fixed the POSIX_TIMER=n case ]

Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Mike Travis <mike.travis@xxxxxxx>
Cc: Dimitri Sivanich <sivanich@xxxxxxx>
Link: http://lkml.kernel.org/r/20170526090311.3377-3-hch@xxxxxx
---
 kernel/time/alarmtimer.c | 64 ++++++++++++++++++++++++------------------------
 1 file changed, 32 insertions(+), 32 deletions(-)

diff --git a/kernel/time/alarmtimer.c b/kernel/time/alarmtimer.c
index 7b5b7bf..4f4cc35 100644
--- a/kernel/time/alarmtimer.c
+++ b/kernel/time/alarmtimer.c
@@ -307,38 +307,6 @@ static int alarmtimer_resume(struct device *dev)
 }
 #endif
 
-static void alarmtimer_freezerset(ktime_t absexp, enum alarmtimer_type type)
-{
-	struct alarm_base *base;
-	unsigned long flags;
-	ktime_t delta;
-
-	switch(type) {
-	case ALARM_REALTIME:
-		base = &alarm_bases[ALARM_REALTIME];
-		type = ALARM_REALTIME_FREEZER;
-		break;
-	case ALARM_BOOTTIME:
-		base = &alarm_bases[ALARM_BOOTTIME];
-		type = ALARM_BOOTTIME_FREEZER;
-		break;
-	default:
-		WARN_ONCE(1, "Invalid alarm type: %d\n", type);
-		return;
-	}
-
-	delta = ktime_sub(absexp, base->gettime());
-
-	spin_lock_irqsave(&freezer_delta_lock, flags);
-	if (!freezer_delta || (delta < freezer_delta)) {
-		freezer_delta = delta;
-		freezer_expires = absexp;
-		freezer_alarmtype = type;
-	}
-	spin_unlock_irqrestore(&freezer_delta_lock, flags);
-}
-
-
 /**
  * alarm_init - Initialize an alarm structure
  * @alarm: ptr to alarm to be initialized
@@ -489,6 +457,38 @@ u64 alarm_forward_now(struct alarm *alarm, ktime_t interval)
 EXPORT_SYMBOL_GPL(alarm_forward_now);
 
 #ifdef CONFIG_POSIX_TIMERS
+
+static void alarmtimer_freezerset(ktime_t absexp, enum alarmtimer_type type)
+{
+	struct alarm_base *base;
+	unsigned long flags;
+	ktime_t delta;
+
+	switch(type) {
+	case ALARM_REALTIME:
+		base = &alarm_bases[ALARM_REALTIME];
+		type = ALARM_REALTIME_FREEZER;
+		break;
+	case ALARM_BOOTTIME:
+		base = &alarm_bases[ALARM_BOOTTIME];
+		type = ALARM_BOOTTIME_FREEZER;
+		break;
+	default:
+		WARN_ONCE(1, "Invalid alarm type: %d\n", type);
+		return;
+	}
+
+	delta = ktime_sub(absexp, base->gettime());
+
+	spin_lock_irqsave(&freezer_delta_lock, flags);
+	if (!freezer_delta || (delta < freezer_delta)) {
+		freezer_delta = delta;
+		freezer_expires = absexp;
+		freezer_alarmtype = type;
+	}
+	spin_unlock_irqrestore(&freezer_delta_lock, flags);
+}
+
 /**
  * clock2alarm - helper that converts from clockid to alarmtypes
  * @clockid: clockid.