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authorPaul E. McKenney <paulmck@kernel.org>2019-12-21 11:23:50 -0800
committerPaul E. McKenney <paulmck@kernel.org>2020-02-20 16:03:31 -0800
commit102c14d2f87976e8390d2cb892ccd14e3532e020 (patch)
tree0db30da090f575b92d3082e570419783a129675b /kernel/rcu
parent202489101f2e6cee3f6dffc087a4abd5fdfcebda (diff)
rcutorture: Fix stray access to rcu_fwd_cb_nodelay
The rcu_fwd_cb_nodelay variable suppresses excessively long read-side delays while carrying out an rcutorture forward-progress test. As such, it is accessed both by readers and updaters, and most of the accesses therefore use *_ONCE(). Except for one in rcu_read_delay(), which this commit fixes. This data race was reported by KCSAN. Not appropriate for backporting 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.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c
index edd97465a0f7..124160a610fa 100644
--- a/kernel/rcu/rcutorture.c
+++ b/kernel/rcu/rcutorture.c
@@ -339,7 +339,7 @@ rcu_read_delay(struct torture_random_state *rrsp, struct rt_read_seg *rtrsp)
* period, and we want a long delay occasionally to trigger
* force_quiescent_state. */
- if (!rcu_fwd_cb_nodelay &&
+ if (!READ_ONCE(rcu_fwd_cb_nodelay) &&
!(torture_random(rrsp) % (nrealreaders * 2000 * longdelay_ms))) {
started = cur_ops->get_gp_seq();
ts = rcu_trace_clock_local();