linux-kernel - [PATCH 4/4] rcu: Name internal polling flag

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20220316144255.336021-5-frederic@kernel.org>
Date:   Wed, 16 Mar 2022 15:42:55 +0100
From:   Frederic Weisbecker <frederic@...nel.org>
To:     "Paul E . McKenney" <paulmck@...nel.org>
Cc:     LKML <linux-kernel@...r.kernel.org>,
        Frederic Weisbecker <frederic@...nel.org>,
        Uladzislau Rezki <uladzislau.rezki@...y.com>,
        Boqun Feng <boqun.feng@...il.com>,
        Neeraj Upadhyay <quic_neeraju@...cinc.com>,
        Joel Fernandes <joel@...lfernandes.org>
Subject: [PATCH 4/4] rcu: Name internal polling flag

Give a proper self-explanatory name to the expedited grace period
internal polling flag.

Signed-off-by: Frederic Weisbecker <frederic@...nel.org>
Cc: Neeraj Upadhyay <quic_neeraju@...cinc.com>
Cc: Boqun Feng <boqun.feng@...il.com>
Cc: Uladzislau Rezki <uladzislau.rezki@...y.com>
Cc: Joel Fernandes <joel@...lfernandes.org>
---
 kernel/rcu/rcu.h      | 5 +++++
 kernel/rcu/tree.c     | 2 +-
 kernel/rcu/tree_exp.h | 9 +++++----
 3 files changed, 11 insertions(+), 5 deletions(-)

diff --git a/kernel/rcu/rcu.h b/kernel/rcu/rcu.h
index eccbdbdaa02e..8a62bb416ba4 100644
--- a/kernel/rcu/rcu.h
+++ b/kernel/rcu/rcu.h
@@ -30,6 +30,11 @@
 #define RCU_GET_STATE_USE_NORMAL	0x2
 #define RCU_GET_STATE_BAD_FOR_NORMAL	(RCU_GET_STATE_FROM_EXPEDITED | RCU_GET_STATE_USE_NORMAL)
 
+/*
+ * Low-order bit definitions for polled grace-period internals.
+ */
+#define RCU_EXP_SEQ_POLL_DONE 0x1
+
 /*
  * Return the counter portion of a sequence number previously returned
  * by rcu_seq_snap() or rcu_seq_current().
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 5da381a3cbe5..b3223b365f9f 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -4679,7 +4679,7 @@ static void __init rcu_init_one(void)
 			spin_lock_init(&rnp->exp_lock);
 			mutex_init(&rnp->boost_kthread_mutex);
 			raw_spin_lock_init(&rnp->exp_poll_lock);
-			rnp->exp_seq_poll_rq = 0x1;
+			rnp->exp_seq_poll_rq = RCU_EXP_SEQ_POLL_DONE;
 			INIT_WORK(&rnp->exp_poll_wq, sync_rcu_do_polled_gp);
 		}
 	}
diff --git a/kernel/rcu/tree_exp.h b/kernel/rcu/tree_exp.h
index c4a19c6a83cf..7ccb909d6355 100644
--- a/kernel/rcu/tree_exp.h
+++ b/kernel/rcu/tree_exp.h
@@ -910,14 +910,14 @@ static void sync_rcu_do_polled_gp(struct work_struct *wp)
 	unsigned long s;
 
 	s = READ_ONCE(rnp->exp_seq_poll_rq);
-	if (s & 0x1)
+	if (s & RCU_EXP_SEQ_POLL_DONE)
 		return;
 	while (!sync_exp_work_done(s))
 		__synchronize_rcu_expedited(true);
 	raw_spin_lock_irqsave(&rnp->exp_poll_lock, flags);
 	s = rnp->exp_seq_poll_rq;
-	if (!(s & 0x1) && sync_exp_work_done(s))
-		WRITE_ONCE(rnp->exp_seq_poll_rq, s | 0x1);
+	if (!(s & RCU_EXP_SEQ_POLL_DONE) && sync_exp_work_done(s))
+		WRITE_ONCE(rnp->exp_seq_poll_rq, s | RCU_EXP_SEQ_POLL_DONE);
 	raw_spin_unlock_irqrestore(&rnp->exp_poll_lock, flags);
 }
 
@@ -946,7 +946,8 @@ unsigned long start_poll_synchronize_rcu_expedited(void)
 	rnp = rdp->mynode;
 	if (rcu_init_invoked())
 		raw_spin_lock_irqsave(&rnp->exp_poll_lock, flags);
-	if ((rnp->exp_seq_poll_rq & 0x1) || ULONG_CMP_LT(rnp->exp_seq_poll_rq, s)) {
+	if ((rnp->exp_seq_poll_rq & RCU_EXP_SEQ_POLL_DONE) ||
+	    ULONG_CMP_LT(rnp->exp_seq_poll_rq, s)) {
 		WRITE_ONCE(rnp->exp_seq_poll_rq, s);
 		if (rcu_init_invoked())
 			queue_work(rcu_gp_wq, &rnp->exp_poll_wq);
-- 
2.25.1