[<prev] [next>] [day] [month] [year] [list]
Message-ID: <158923078565.390.9530533982000142424.tip-bot2@tip-bot2>
Date: Mon, 11 May 2020 20:59:45 -0000
From: "tip-bot2 for Paul E. McKenney" <tip-bot2@...utronix.de>
To: linux-tip-commits@...r.kernel.org
Cc: "Paul E. McKenney" <paulmck@...nel.org>, x86 <x86@...nel.org>,
LKML <linux-kernel@...r.kernel.org>
Subject: [tip: core/rcu] srcu: Add data_race() to ->srcu_lock_count and
->srcu_unlock_count arrays
The following commit has been merged into the core/rcu branch of tip:
Commit-ID: b68c6146512d92f6d570d26e1873497ade2cc4cb
Gitweb: https://git.kernel.org/tip/b68c6146512d92f6d570d26e1873497ade2cc4cb
Author: Paul E. McKenney <paulmck@...nel.org>
AuthorDate: Fri, 03 Jan 2020 16:36:59 -08:00
Committer: Paul E. McKenney <paulmck@...nel.org>
CommitterDate: Mon, 27 Apr 2020 11:01:16 -07:00
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@...nel.org>
---
kernel/rcu/srcutree.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/kernel/rcu/srcutree.c b/kernel/rcu/srcutree.c
index ba2b751..6d3ef70 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;
Powered by blists - more mailing lists