sched/clock: Disable interrupts when calling generic_sched_clock_init()

Pavel Tatashin · KAGA-KOKO · commit bd9f943e5d2a · 2018-07-30T19:33:35.000+02:00
sched_clock_init() used be called early during boot when interrupts were still disabled. After the recent changes to utilize sched clock early the sched_clock_init() call happens when interrupts are already enabled, which triggers the following warning: WARNING: CPU: 0 PID: 0 at kernel/time/sched_clock.c:180 sched_clock_register+0x44/0x278 [<c001a13c>] (warn_slowpath_null) from [<c052367c>] (sched_clock_register+0x44/0x278) [<c052367c>] (sched_clock_register) from [<c05238d8>] (generic_sched_clock_init+0x28/0x88) [<c05238d8>] (generic_sched_clock_init) from [<c0521a00>] (sched_clock_init+0x54/0x74) [<c0521a00>] (sched_clock_init) from [<c0519c18>] (start_kernel+0x310/0x3e4) [<c0519c18>] (start_kernel) from [<00000000>] ( (null)) Disable IRQs for the duration of generic_sched_clock_init(). Fixes: 857baa8 ("sched/clock: Enable sched clock early") Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com> Reported-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: steven.sistare@oracle.com Cc: daniel.m.jordan@oracle.com Link: https://lkml.kernel.org/r/20180730135252.24599-1-pasha.tatashin@oracle.com
diff --git a/kernel/sched/clock.c b/kernel/sched/clock.c
@@ -452,7 +452,9 @@ EXPORT_SYMBOL_GPL(sched_clock_idle_wakeup_event);
 void __init sched_clock_init(void)
 {
 	static_branch_inc(&sched_clock_running);
+	local_irq_disable();
 	generic_sched_clock_init();
+	local_irq_enable();
 }
 
 u64 sched_clock_cpu(int cpu)

Original file line number	Diff line number	Diff line change
`@@ -452,7 +452,9 @@ EXPORT_SYMBOL_GPL(sched_clock_idle_wakeup_event);`
`452`	`452`	`void __init sched_clock_init(void)`
`453`	`453`	`{`
`454`	`454`	`static_branch_inc(&sched_clock_running);`
	`455`	`+ local_irq_disable();`
`455`	`456`	`generic_sched_clock_init();`
	`457`	`+ local_irq_enable();`
`456`	`458`	`}`
`457`	`459`
`458`	`460`	`u64 sched_clock_cpu(int cpu)`