RCU needs to check if the cpu hotplug lock is held, in the middle of other conditions to check the sanity of RCU-nocb. Provide a helper for that.
Signed-off-by: Frederic Weisbecker <[email protected]> Cc: Paul E. McKenney <[email protected]> Cc: Josh Triplett <[email protected]> Cc: Steven Rostedt <[email protected]> Cc: Mathieu Desnoyers <[email protected]> Cc: Lai Jiangshan <[email protected]> Cc: Joel Fernandes <[email protected]> Cc: Neeraj Upadhyay <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Boqun Feng <[email protected]> --- include/linux/cpu.h | 1 + kernel/cpu.c | 7 +++++++ 2 files changed, 8 insertions(+) diff --git a/include/linux/cpu.h b/include/linux/cpu.h index d6428aaf67e7..27eb3875e45a 100644 --- a/include/linux/cpu.h +++ b/include/linux/cpu.h @@ -118,6 +118,7 @@ extern void cpus_read_lock(void); extern void cpus_read_unlock(void); extern int cpus_read_trylock(void); extern void lockdep_assert_cpus_held(void); +extern int lockdep_is_cpus_held(void); extern void cpu_hotplug_disable(void); extern void cpu_hotplug_enable(void); void clear_tasks_mm_cpumask(int cpu); diff --git a/kernel/cpu.c b/kernel/cpu.c index 6ff2578ecf17..3cca5b27de25 100644 --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -330,6 +330,13 @@ void lockdep_assert_cpus_held(void) percpu_rwsem_assert_held(&cpu_hotplug_lock); } +#ifdef CONFIG_LOCKDEP +int lockdep_is_cpus_held(void) +{ + return percpu_rwsem_is_held(&cpu_hotplug_lock); +} +#endif + static void lockdep_acquire_cpus_lock(void) { rwsem_acquire(&cpu_hotplug_lock.dep_map, 0, 0, _THIS_IP_); -- 2.25.1
