rcu: Add assertions verifying blocked-tasks list

This commit adds assertions verifying the consistency of the rcu_node
structure's ->blkd_tasks list and its ->gp_tasks, ->exp_tasks, and
->boost_tasks pointers.  In particular, the ->blkd_tasks lists must be
empty except for leaf rcu_node structures.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 2b37f1a8e235..ac2617d857a3 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -2410,6 +2410,8 @@ rcu_report_qs_rnp(unsigned long mask, struct rcu_state *rsp,
                         return;
                 }
                 WARN_ON_ONCE(oldmask); /* Any child must be all zeroed! */
+                WARN_ON_ONCE(rnp->level != rcu_num_lvls - 1 &&
+                             rcu_preempt_blocked_readers_cgp(rnp));
                 rnp->qsmask &= ~mask;
                 trace_rcu_quiescent_state_report(rsp->name, rnp->gpnum,
                                                  mask, rnp->qsmask, rnp->level,