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| author | Paul E. McKenney <paulmck@kernel.org> | 2022-01-04 10:34:34 -0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-04-08 13:58:36 +0200 |
| commit | 33884c907e6e5a1eb97aa1fa6983c8672850931b (patch) | |
| tree | 40be80b20211edd280ff2f217c0658b65d0b18fa | |
| parent | 77e2de05e5cd61e4e691a394f126645347684cec (diff) | |
| download | linux-rt-33884c907e6e5a1eb97aa1fa6983c8672850931b.tar.gz | |
rcu: Mark writes to the rcu_segcblist structure's ->flags field
[ Upstream commit c09929031018913b5783872a8b8cdddef4a543c7 ]
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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | kernel/rcu/rcu_segcblist.h | 4 |
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, |