projects/linux·commit cbaa1576

Merge branch 'smp-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

cbaa1576 · Linus Torvalds <[email protected]> · 2016-12-12 12:53:54 -08:00

Pull hotplug API fix from Ingo Molnar:
 "Late breaking fix from the v4.9 cycle: fix a hotplug register/
  unregister notifier API asymmetry bug that can cause kernel warnings
  (and worse) with certain Kconfig combinations"

* 'smp-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  hotplug: Make register and unregister notifier API symmetric
Commit
cbaa1576c4547b97cd7064469dcb5f7752def99f
Parents
92c020d0 · 777c6e0d

Merge commit. Changes below are compared with the first parent: 92c020d0.

Changes

2 files changed · +5 −12

FileStatusAddDelContent
include/linux/cpu.hmodified+4−11View file
kernel/cpu.cmodified+1−1View file

include/linux/cpu.h

View file
diff --git a/include/linux/cpu.h b/include/linux/cpu.h
index b886dc1..e571128 100644
--- a/include/linux/cpu.h
+++ b/include/linux/cpu.h
@@ -93,22 +93,16 @@ extern bool cpuhp_tasks_frozen;
{ .notifier_call = fn, .priority = pri }; \
__register_cpu_notifier(&fn##_nb); \
}
-#else /* #if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE) */
-#define cpu_notifier(fn, pri) do { (void)(fn); } while (0)
-#define __cpu_notifier(fn, pri) do { (void)(fn); } while (0)
-#endif /* #else #if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE) */
-#ifdef CONFIG_HOTPLUG_CPU
extern int register_cpu_notifier(struct notifier_block *nb);
extern int __register_cpu_notifier(struct notifier_block *nb);
extern void unregister_cpu_notifier(struct notifier_block *nb);
extern void __unregister_cpu_notifier(struct notifier_block *nb);
-#else
-#ifndef MODULE
-extern int register_cpu_notifier(struct notifier_block *nb);
-extern int __register_cpu_notifier(struct notifier_block *nb);
-#else
+#else /* #if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE) */
+#define cpu_notifier(fn, pri) do { (void)(fn); } while (0)
+#define __cpu_notifier(fn, pri) do { (void)(fn); } while (0)
+
static inline int register_cpu_notifier(struct notifier_block *nb)
{
return 0;
@@ -118,7 +112,6 @@ static inline int __register_cpu_notifier(struct notifier_block *nb)
{
return 0;
}
-#endif
static inline void unregister_cpu_notifier(struct notifier_block *nb)
{

kernel/cpu.c

View file
diff --git a/kernel/cpu.c b/kernel/cpu.c
index 29de1a9..217fd2e 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -659,7 +659,6 @@ void __init cpuhp_threads_init(void)
kthread_unpark(this_cpu_read(cpuhp_state.thread));
}
-#ifdef CONFIG_HOTPLUG_CPU
EXPORT_SYMBOL(register_cpu_notifier);
EXPORT_SYMBOL(__register_cpu_notifier);
void unregister_cpu_notifier(struct notifier_block *nb)
@@ -676,6 +675,7 @@ void __unregister_cpu_notifier(struct notifier_block *nb)
}
EXPORT_SYMBOL(__unregister_cpu_notifier);
+#ifdef CONFIG_HOTPLUG_CPU
/**
* clear_tasks_mm_cpumask - Safely clear tasks' mm_cpumask for a CPU
* @cpu: a CPU id