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From: Arnd Bergmann <arnd@kernel.org>
To: Peter Zijlstra <peterz@infradead.org>,
	Ingo Molnar <mingo@redhat.com>, Will Deacon <will@kernel.org>,
	"Ahmed S. Darwish" <a.darwish@linutronix.de>
Cc: Arnd Bergmann <arnd@arndb.de>,
	"Paul E. McKenney" <paulmck@kernel.org>,
	Marco Elver <elver@google.com>,
	linux-kernel@vger.kernel.org
Subject: [PATCH] seqlock: avoid -Wshadow warnings
Date: Mon, 26 Oct 2020 17:50:38 +0100	[thread overview]
Message-ID: <20201026165044.3722931-1-arnd@kernel.org> (raw)

From: Arnd Bergmann <arnd@arndb.de>

When building with W=2, there is a flood of warnings about the seqlock
macros shadowing local variables:

  19806 linux/seqlock.h:331:11: warning: declaration of 'seq' shadows a previous local [-Wshadow]
     48 linux/seqlock.h:348:11: warning: declaration of 'seq' shadows a previous local [-Wshadow]
      8 linux/seqlock.h:379:11: warning: declaration of 'seq' shadows a previous local [-Wshadow]

Prefix the local variables to make the warning useful elsewhere again.

Fixes: 52ac39e5db51 ("seqlock: seqcount_t: Implement all read APIs as statement expressions")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 include/linux/seqlock.h | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/include/linux/seqlock.h b/include/linux/seqlock.h
index cbfc78b92b65..8d8552474c64 100644
--- a/include/linux/seqlock.h
+++ b/include/linux/seqlock.h
@@ -328,13 +328,13 @@ SEQCOUNT_LOCKNAME(ww_mutex,     struct ww_mutex, true,     &s->lock->base, ww_mu
  */
 #define __read_seqcount_begin(s)					\
 ({									\
-	unsigned seq;							\
+	unsigned __seq;							\
 									\
-	while ((seq = __seqcount_sequence(s)) & 1)			\
+	while ((__seq = __seqcount_sequence(s)) & 1)			\
 		cpu_relax();						\
 									\
 	kcsan_atomic_next(KCSAN_SEQLOCK_REGION_MAX);			\
-	seq;								\
+	__seq;								\
 })
 
 /**
@@ -345,10 +345,10 @@ SEQCOUNT_LOCKNAME(ww_mutex,     struct ww_mutex, true,     &s->lock->base, ww_mu
  */
 #define raw_read_seqcount_begin(s)					\
 ({									\
-	unsigned seq = __read_seqcount_begin(s);			\
+	unsigned _seq = __read_seqcount_begin(s);			\
 									\
 	smp_rmb();							\
-	seq;								\
+	_seq;								\
 })
 
 /**
@@ -376,11 +376,11 @@ SEQCOUNT_LOCKNAME(ww_mutex,     struct ww_mutex, true,     &s->lock->base, ww_mu
  */
 #define raw_read_seqcount(s)						\
 ({									\
-	unsigned seq = __seqcount_sequence(s);				\
+	unsigned __seq = __seqcount_sequence(s);			\
 									\
 	smp_rmb();							\
 	kcsan_atomic_next(KCSAN_SEQLOCK_REGION_MAX);			\
-	seq;								\
+	__seq;								\
 })
 
 /**
-- 
2.27.0


             reply	other threads:[~2020-10-26 16:52 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-10-26 16:50 Arnd Bergmann [this message]
2020-10-26 16:58 ` [PATCH] seqlock: avoid -Wshadow warnings Peter Zijlstra
2020-10-27 23:34   ` Arnd Bergmann
2020-10-28  7:51     ` Rasmus Villemoes
2020-10-28  8:51     ` Peter Zijlstra
2020-12-03 10:35 ` [tip: locking/core] " tip-bot2 for Arnd Bergmann

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