[tip:timers/urgent] clocksource: Initialize cs->wd_list

[tip-bot for Peter Zijlstra <tipbot@zytor.com>]

Commit-ID:  5b9e886a4af97574ca3ce1147f35545da0e7afc7
Gitweb:     https://git.kernel.org/tip/5b9e886a4af97574ca3ce1147f35545da0e7afc7
Author:     Peter Zijlstra <peterz@infradead.org>
AuthorDate: Mon, 30 Apr 2018 12:00:11 +0200
Committer:  Thomas Gleixner <tglx@linutronix.de>
CommitDate: Wed, 2 May 2018 16:10:40 +0200

clocksource: Initialize cs->wd_list

A number of places relies on list_empty(&cs->wd_list), however the
list_head does not get initialized. Do so upon registration, such that
thereafter it is possible to rely on list_empty() correctly reflecting
the list membership status.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Diego Viola <diego.viola@gmail.com>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: stable@vger.kernel.org
Cc: len.brown@intel.com
Cc: rjw@rjwysocki.net
Cc: rui.zhang@intel.com
Link: https://lkml.kernel.org/r/20180430100344.472662715@infradead.org

---
 kernel/time/clocksource.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c
index c3d2b94723dc..935f39eb8aac 100644
--- a/kernel/time/clocksource.c
+++ b/kernel/time/clocksource.c
@@ -332,6 +332,8 @@ static void clocksource_resume_watchdog(void)
 
 static void clocksource_enqueue_watchdog(struct clocksource *cs)
 {
+	INIT_LIST_HEAD(&cs->wd_list);
+
 	if (cs->flags & CLOCK_SOURCE_MUST_VERIFY) {
 		/* cs is a clocksource to be watched. */
 		list_add(&cs->wd_list, &watchdog_list);