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| author | Paul E. McKenney <paulmck@kernel.org> | 2019-10-07 18:53:18 -0700 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@kernel.org> | 2019-12-09 12:24:56 -0800 |
| commit | 15c7c972cd26d89a26788e609c53b5a465324a6c (patch) | |
| tree | a974bdc151ac35db62b8b5bf9c5fff7a05a7a190 /kernel/cpu.c | |
| parent | e42617b825f8073569da76dc4510bfa019b1c35a (diff) | |
rcu: Use *_ONCE() to protect lockless ->expmask accesses
The rcu_node structure's ->expmask field is accessed locklessly when
starting a new expedited grace period and when reporting an expedited
RCU CPU stall warning. This commit therefore handles the former by
taking a snapshot of ->expmask while the lock is held and the latter
by applying READ_ONCE() to lockless reads and WRITE_ONCE() to the
corresponding updates.
Link: https://lore.kernel.org/lkml/CANpmjNNmSOagbTpffHr4=Yedckx9Rm2NuGqC9UqE+AOz5f1-ZQ@mail.gmail.com
Reported-by: syzbot+134336b86f728d6e55a0@syzkaller.appspotmail.com
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Acked-by: Marco Elver <elver@google.com>
Diffstat (limited to 'kernel/cpu.c')
0 files changed, 0 insertions, 0 deletions