uprobes: Use DEFINE_STATIC_PERCPU_RWSEM() to initialize dup_mmap_sem

Use DEFINE_STATIC_PERCPU_RWSEM() to initialize dup_mmap_sem.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>

kernel/events/uprobes.c

@@ -46,7 +46,7 @@ static DEFINE_SPINLOCK(uprobes_treelock);	/* serialize rbtree access */
 static struct mutex uprobes_mmap_mutex[UPROBES_HASH_SZ];
 #define uprobes_mmap_hash(v)	(&uprobes_mmap_mutex[((unsigned long)(v)) % UPROBES_HASH_SZ])
 
-static struct percpu_rw_semaphore dup_mmap_sem;
+DEFINE_STATIC_PERCPU_RWSEM(dup_mmap_sem);
 
 /* Have a copy of original instruction */
 #define UPROBE_COPY_INSN	0
@@ -2302,7 +2302,5 @@ void __init uprobes_init(void)
 	for (i = 0; i < UPROBES_HASH_SZ; i++)
 		mutex_init(&uprobes_mmap_mutex[i]);
 
-	BUG_ON(percpu_init_rwsem(&dup_mmap_sem));
-
 	BUG_ON(register_die_notifier(&uprobe_exception_nb));
 }