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authorPaul E. McKenney <paulmck@kernel.org>2020-01-03 16:36:59 -0800
committerPaul E. McKenney <paulmck@kernel.org>2020-04-27 11:01:16 -0700
commitb68c6146512d92f6d570d26e1873497ade2cc4cb (patch)
tree26d7970096a5f2b92f7cf6df9af687edc3315721 /kernel/rcu
parentrcu: Add READ_ONCE and data_race() to rcu_node ->boost_tasks (diff)
downloadlinux-dev-b68c6146512d92f6d570d26e1873497ade2cc4cb.tar.xz
linux-dev-b68c6146512d92f6d570d26e1873497ade2cc4cb.zip
srcu: Add data_race() to ->srcu_lock_count and ->srcu_unlock_count arrays
The srcu_data structure's ->srcu_lock_count and ->srcu_unlock_count arrays are read and written locklessly, so this commit adds the data_race() to the diagnostic-print loads from these arrays in order mark them as known and approved data-racy accesses. This data race was reported by KCSAN. Not appropriate for backporting due to failure being unlikely and due to this being used only by rcutorture. Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Diffstat (limited to 'kernel/rcu')
-rw-r--r--kernel/rcu/srcutree.c8
1 files changed, 4 insertions, 4 deletions
diff --git a/kernel/rcu/srcutree.c b/kernel/rcu/srcutree.c
index ba2b751e9168..6d3ef700fb0e 100644
--- a/kernel/rcu/srcutree.c
+++ b/kernel/rcu/srcutree.c
@@ -1281,8 +1281,8 @@ void srcu_torture_stats_print(struct srcu_struct *ssp, char *tt, char *tf)
struct srcu_data *sdp;
sdp = per_cpu_ptr(ssp->sda, cpu);
- u0 = sdp->srcu_unlock_count[!idx];
- u1 = sdp->srcu_unlock_count[idx];
+ u0 = data_race(sdp->srcu_unlock_count[!idx]);
+ u1 = data_race(sdp->srcu_unlock_count[idx]);
/*
* Make sure that a lock is always counted if the corresponding
@@ -1290,8 +1290,8 @@ void srcu_torture_stats_print(struct srcu_struct *ssp, char *tt, char *tf)
*/
smp_rmb();
- l0 = sdp->srcu_lock_count[!idx];
- l1 = sdp->srcu_lock_count[idx];
+ l0 = data_race(sdp->srcu_lock_count[!idx]);
+ l1 = data_race(sdp->srcu_lock_count[idx]);
c0 = l0 - u0;
c1 = l1 - u1;