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From:   Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
To:     Andrew Morton <akpm@linux-foundation.org>
Cc:     linux-kernel@vger.kernel.org,
        Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
        Alexei Starovoitov <ast@kernel.org>,
        "Paul E. McKenney" <paulmck@kernel.org>,
        Frederic Weisbecker <frederic@kernel.org>,
        Neeraj Upadhyay <quic_neeraju@quicinc.com>,
        Joel Fernandes <joel@joelfernandes.org>,
        Josh Triplett <josh@joshtriplett.org>,
        Boqun Feng <boqun.feng@gmail.com>,
        Steven Rostedt <rostedt@goodmis.org>,
        Lai Jiangshan <jiangshanlai@gmail.com>,
        Zqiang <qiang1.zhang@intel.com>, rcu@vger.kernel.org
Subject: [RFC PATCH 03/13] rculist_nulls.h: Add parentheses around macro pointer parameter use
Date:   Thu,  4 May 2023 16:05:17 -0400
Message-Id: <20230504200527.1935944-4-mathieu.desnoyers@efficios.com>
In-Reply-To: <20230504200527.1935944-1-mathieu.desnoyers@efficios.com>
References: <20230504200527.1935944-1-mathieu.desnoyers@efficios.com>
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Add parentheses around use of macro argument "tpos" in those patterns to
ensure operator precedence behaves as expected:

- typeof(*tpos)

The typeof(*tpos) lack of parentheses around "tpos" is not an issue per se
in the specific macros modified here because "tpos" is used as an lvalue,
which should prevent use of any operator causing issue. Still add the
extra parentheses for consistency with other list iteration code across
the kernel tree.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Frederic Weisbecker <frederic@kernel.org>
Cc: Neeraj Upadhyay <quic_neeraju@quicinc.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Zqiang <qiang1.zhang@intel.com>
Cc: rcu@vger.kernel.org
---
 include/linux/rculist_nulls.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/include/linux/rculist_nulls.h b/include/linux/rculist_nulls.h
index ba4c00dd8005..6e56dd2daecf 100644
--- a/include/linux/rculist_nulls.h
+++ b/include/linux/rculist_nulls.h
@@ -168,7 +168,7 @@ static inline void hlist_nulls_add_fake(struct hlist_nulls_node *n)
 	for (({barrier();}),							\
 	     pos = rcu_dereference_raw(hlist_nulls_first_rcu(head));		\
 		(!is_a_nulls(pos)) &&						\
-		({ tpos = hlist_nulls_entry(pos, typeof(*tpos), member); 1; }); \
+		({ tpos = hlist_nulls_entry(pos, typeof(*(tpos)), member); 1; }); \
 		pos = rcu_dereference_raw(hlist_nulls_next_rcu(pos)))
 
 /**
@@ -183,7 +183,7 @@ static inline void hlist_nulls_add_fake(struct hlist_nulls_node *n)
 	for (({barrier();}),							\
 	     pos = rcu_dereference_raw(hlist_nulls_first_rcu(head));		\
 		(!is_a_nulls(pos)) &&						\
-		({ tpos = hlist_nulls_entry(pos, typeof(*tpos), member);	\
+		({ tpos = hlist_nulls_entry(pos, typeof(*(tpos)), member);	\
 		   pos = rcu_dereference_raw(hlist_nulls_next_rcu(pos)); 1; });)
 #endif
 #endif
-- 
2.25.1