Commit-ID:  0126574fca2ce0f0d5beb9dade6efb823ff7407b
Gitweb:     https://git.kernel.org/tip/0126574fca2ce0f0d5beb9dade6efb823ff7407b
Author:     Bart Van Assche <bvanass...@acm.org>
AuthorDate: Sun, 3 Mar 2019 10:19:01 -0800
Committer:  Ingo Molnar <mi...@kernel.org>
CommitDate: Sat, 9 Mar 2019 14:15:51 +0100

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 <bvanass...@acm.org>
Signed-off-by: Peter Zijlstra (Intel) <pet...@infradead.org>
Cc: Andrew Morton <a...@linux-foundation.org>
Cc: Andy Lutomirski <l...@kernel.org>
Cc: Borislav Petkov <b...@alien8.de>
Cc: Dave Hansen <dave.han...@linux.intel.com>
Cc: H. Peter Anvin <h...@zytor.com>
Cc: Linus Torvalds <torva...@linux-foundation.org>
Cc: Paul E. McKenney <paul...@linux.vnet.ibm.com>
Cc: Peter Zijlstra <pet...@infradead.org>
Cc: Rik van Riel <r...@surriel.com>
Cc: Thomas Gleixner <t...@linutronix.de>
Cc: Will Deacon <will.dea...@arm.com>
Cc: long...@redhat.com
Link: https://lkml.kernel.org/r/c20aa0f0-42ab-a884-d931-7d4ec2bf0...@acm.org
Signed-off-by: Ingo Molnar <mi...@kernel.org>
---
 kernel/locking/lockdep.c | 15 +++++++++++----
 1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
index 35a144dfddf5..34cdcbedda49 100644
--- 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);
 

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