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authorPaul E. McKenney <paulmck@kernel.org>2022-01-04 10:34:34 -0800
committerPaul E. McKenney <paulmck@kernel.org>2022-02-14 10:36:58 -0800
commitc09929031018913b5783872a8b8cdddef4a543c7 (patch)
tree1a5534653c6131cdada887ca30c16ffb2d22f1e5 /kernel/rcu
parentd818cc76e2b4d5f6cebf8c7ce1160d652d7e572b (diff)
rcu: Mark writes to the rcu_segcblist structure's ->flags field
KCSAN reports data races between the rcu_segcblist_clear_flags() and rcu_segcblist_set_flags() functions, though misreporting the latter as a call to rcu_segcblist_is_enabled() from call_rcu(). This commit converts the updates of this field to WRITE_ONCE(), relying on the resulting unmarked reads to continue to detect buggy concurrent writes to this field. Reported-by: Zhouyi Zhou <zhouzhouyi@gmail.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Cc: Frederic Weisbecker <frederic@kernel.org>
Diffstat (limited to 'kernel/rcu')
-rw-r--r--kernel/rcu/rcu_segcblist.h4
1 files changed, 2 insertions, 2 deletions
diff --git a/kernel/rcu/rcu_segcblist.h b/kernel/rcu/rcu_segcblist.h
index e373fbe44da5..431cee212467 100644
--- a/kernel/rcu/rcu_segcblist.h
+++ b/kernel/rcu/rcu_segcblist.h
@@ -56,13 +56,13 @@ static inline long rcu_segcblist_n_cbs(struct rcu_segcblist *rsclp)
static inline void rcu_segcblist_set_flags(struct rcu_segcblist *rsclp,
int flags)
{
- rsclp->flags |= flags;
+ WRITE_ONCE(rsclp->flags, rsclp->flags | flags);
}
static inline void rcu_segcblist_clear_flags(struct rcu_segcblist *rsclp,
int flags)
{
- rsclp->flags &= ~flags;
+ WRITE_ONCE(rsclp->flags, rsclp->flags & ~flags);
}
static inline bool rcu_segcblist_test_flags(struct rcu_segcblist *rsclp,