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| author |   Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2018-04-19 12:23:34 -0700 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2018-05-15 10:30:48 -0700 |
| commit | 665f08f1ce9cf608a9435e11d66f55be4e72540a (patch) | |
| tree | a5f0c6e8d759ada2ed304bca07ae3fa49bc00995 /kernel | |
| parent | rcu: Add funnel locking to rcu_start_this_gp() (diff) | |
| download | linux-dev-665f08f1ce9cf608a9435e11d66f55be4e72540a.tar.xz linux-dev-665f08f1ce9cf608a9435e11d66f55be4e72540a.zip | |
rcu: Make rcu_start_this_gp() check for out-of-range requests
If rcu_start_this_gp() is invoked with a requested grace period more
than three in the future, then either the ->need_future_gp[] array
needs to be bigger or the caller needs to be repaired. This commit
therefore adds a WARN_ON_ONCE() checking for this condition.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Tested-by: Nicholas Piggin <npiggin@gmail.com>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/rcu/tree.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index d3c769502929..07bccb1f0c87 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -1698,6 +1698,8 @@ static bool rcu_start_this_gp(struct rcu_node *rnp, struct rcu_data *rdp, for (rnp_root = rnp; 1; rnp_root = rnp_root->parent) { if (rnp_root != rnp) raw_spin_lock_rcu_node(rnp_root); + WARN_ON_ONCE(ULONG_CMP_LT(rnp_root->gpnum + + need_future_gp_mask(), c)); if (need_future_gp_element(rnp_root, c) || ULONG_CMP_GE(rnp_root->gpnum, c) || (rnp != rnp_root && |