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| author | Paul E. McKenney <paulmck@kernel.org> | 2020-01-03 16:27:00 -0800 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@kernel.org> | 2020-02-20 16:03:31 -0800 |
| commit | f042a436c8dc9f9cfe8ed1ee5de372697269657d (patch) | |
| tree | f026309a51c6ff18e4e5f53a027f7977344dfca5 /kernel/rcu | |
| parent | 102c14d2f87976e8390d2cb892ccd14e3532e020 (diff) | |
| download | linux-f042a436c8dc9f9cfe8ed1ee5de372697269657d.tar.bz2 | |
rcutorture: Add READ_ONCE() to rcu_torture_count and rcu_torture_batch
The rcutorture rcu_torture_count and rcu_torture_batch per-CPU variables
are read locklessly, so this commit adds the READ_ONCE() to a load in
order to avoid various types of compiler vandalism^Woptimization.
This data race was reported by KCSAN. Not appropriate for backporting
due to failure being unlikely and due to this being rcutorture.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Diffstat (limited to 'kernel/rcu')
| -rw-r--r-- | kernel/rcu/rcutorture.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c index 124160a610fa..0b9ce9a00623 100644 --- a/kernel/rcu/rcutorture.c +++ b/kernel/rcu/rcutorture.c @@ -1413,8 +1413,8 @@ rcu_torture_stats_print(void) for_each_possible_cpu(cpu) { for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) { - pipesummary[i] += per_cpu(rcu_torture_count, cpu)[i]; - batchsummary[i] += per_cpu(rcu_torture_batch, cpu)[i]; + pipesummary[i] += READ_ONCE(per_cpu(rcu_torture_count, cpu)[i]); + batchsummary[i] += READ_ONCE(per_cpu(rcu_torture_batch, cpu)[i]); } } for (i = RCU_TORTURE_PIPE_LEN - 1; i >= 0; i--) { |