linux-kernel - [PATCH tip/core/rcu 6/9] doc: Update rcu_assign

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]

Date:   Wed, 12 Apr 2017 09:40:19 -0700
From:   "Paul E. McKenney" <paulmck@...ux.vnet.ibm.com>
To:     linux-kernel@...r.kernel.org
Cc:     mingo@...nel.org, jiangshanlai@...il.com, dipankar@...ibm.com,
        akpm@...ux-foundation.org, mathieu.desnoyers@...icios.com,
        josh@...htriplett.org, tglx@...utronix.de, peterz@...radead.org,
        rostedt@...dmis.org, dhowells@...hat.com, edumazet@...gle.com,
        dvhart@...ux.intel.com, fweisbec@...il.com, oleg@...hat.com,
        bobby.prani@...il.com,
        "Paul E. McKenney" <paulmck@...ux.vnet.ibm.com>
Subject: [PATCH tip/core/rcu 6/9] doc: Update rcu_assign_pointer() definition in whatisRCU.txt

The rcu_assign_pointer() macro has changed over time, and the version
in Documentation/RCU/whatisRCU.txt has not kept up.  This commit brings
it into 2017, albeit in a simplified fashion.

Reported-by: Andrea Parri <parri.andrea@...il.com>
Signed-off-by: Paul E. McKenney <paulmck@...ux.vnet.ibm.com>
---
 Documentation/RCU/whatisRCU.txt | 29 +++++++++++++++--------------
 1 file changed, 15 insertions(+), 14 deletions(-)

diff --git a/Documentation/RCU/whatisRCU.txt b/Documentation/RCU/whatisRCU.txt
index 5cbd8b2395b8..6b0337008f9c 100644
--- a/Documentation/RCU/whatisRCU.txt
+++ b/Documentation/RCU/whatisRCU.txt
@@ -587,20 +587,21 @@ It is extremely simple:
 		write_unlock(&rcu_gp_mutex);
 	}
 
-[You can ignore rcu_assign_pointer() and rcu_dereference() without
-missing much.  But here they are anyway.  And whatever you do, don't
-forget about them when submitting patches making use of RCU!]
-
-	#define rcu_assign_pointer(p, v)	({ \
-							smp_wmb(); \
-							(p) = (v); \
-						})
-
-	#define rcu_dereference(p)     ({ \
-					typeof(p) _________p1 = p; \
-					smp_read_barrier_depends(); \
-					(_________p1); \
-					})
+[You can ignore rcu_assign_pointer() and rcu_dereference() without missing
+much.  But here are simplified versions anyway.  And whatever you do,
+don't forget about them when submitting patches making use of RCU!]
+
+	#define rcu_assign_pointer(p, v) \
+	({ \
+		smp_store_release(&(p), (v)); \
+	})
+
+	#define rcu_dereference(p) \
+	({ \
+		typeof(p) _________p1 = p; \
+		smp_read_barrier_depends(); \
+		(_________p1); \
+	})
 
 
 The rcu_read_lock() and rcu_read_unlock() primitive read-acquire
-- 
2.5.2