locking/lockdep: Only call init_rcu_head() after RCU has been initialized

init_data_structures_once() is called for the first time before RCU has
been initialized. Make sure that init_rcu_head() is called before the
RCU head is used and after RCU has been initialized.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@surriel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Cc: longman@redhat.com
Link: https://lkml.kernel.org/r/c20aa0f0-42ab-a884-d931-7d4ec2bf0cdc@acm.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
index 35a144d..34cdcbe 100644 (file)
--- a/kernel/locking/lockdep.c
+++ b/kernel/locking/lockdep.c
@@ -982,15 +982,22 @@ static inline void check_data_structures(void) { }
  */
 static void init_data_structures_once(void)
 {
-       static bool initialization_happened;
+       static bool ds_initialized, rcu_head_initialized;
        int i;
 
-       if (likely(initialization_happened))
+       if (likely(rcu_head_initialized))
                return;
 
-       initialization_happened = true;
+       if (system_state >= SYSTEM_SCHEDULING) {
+               init_rcu_head(&delayed_free.rcu_head);
+               rcu_head_initialized = true;
+       }
+
+       if (ds_initialized)
+               return;
+
+       ds_initialized = true;
 
-       init_rcu_head(&delayed_free.rcu_head);
        INIT_LIST_HEAD(&delayed_free.pf[0].zapped);
        INIT_LIST_HEAD(&delayed_free.pf[1].zapped);