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From: Arnd Bergmann <arnd@kernel.org>
To: Kalle Valo <kvalo@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>,
	"David S. Miller" <davem@davemloft.net>,
	Eric Dumazet <edumazet@google.com>,
	Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
	Nathan Chancellor <nathan@kernel.org>,
	Nick Desaulniers <ndesaulniers@google.com>,
	Tom Rix <trix@redhat.com>,
	linux-wireless@vger.kernel.org, b43-dev@lists.infradead.org,
	netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
	llvm@lists.linux.dev
Subject: [PATCH] wifi: b43: fix incorrect __packed annotation
Date: Tue, 16 May 2023 09:45:42 +0200	[thread overview]
Message-ID: <20230516074554.1674536-1-arnd@kernel.org> (raw)

From: Arnd Bergmann <arnd@arndb.de>

clang warns about an unpacked structure inside of a packed one:

drivers/net/wireless/broadcom/b43/b43.h:654:4: error: field data within 'struct b43_iv' is less aligned than 'union (unnamed union at /home/arnd/arm-soc/drivers/net/wireless/broadcom/b43/b43.h:651:2)' and is usually due to 'struct b43_iv' being packed, which can lead to unaligned accesses [-Werror,-Wunaligned-access]

The problem here is that the anonymous union has the default alignment
from its members, apparently because the original author mixed up the
placement of the __packed attribute by placing it next to the struct
member rather than the union definition. As the struct itself is
also marked as __packed, there is no need to mark its members, so just
move the annotation to the inner type instead.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 drivers/net/wireless/broadcom/b43/b43.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/wireless/broadcom/b43/b43.h b/drivers/net/wireless/broadcom/b43/b43.h
index 9fc7c088a539..67b4bac048e5 100644
--- a/drivers/net/wireless/broadcom/b43/b43.h
+++ b/drivers/net/wireless/broadcom/b43/b43.h
@@ -651,7 +651,7 @@ struct b43_iv {
 	union {
 		__be16 d16;
 		__be32 d32;
-	} data __packed;
+	} __packed data;
 } __packed;
 
 
-- 
2.39.2


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WARNING: multiple messages have this Message-ID (diff)
From: Arnd Bergmann <arnd@kernel.org>
To: Kalle Valo <kvalo@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>,
	"David S. Miller" <davem@davemloft.net>,
	Eric Dumazet <edumazet@google.com>,
	Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
	Nathan Chancellor <nathan@kernel.org>,
	Nick Desaulniers <ndesaulniers@google.com>,
	Tom Rix <trix@redhat.com>,
	linux-wireless@vger.kernel.org, b43-dev@lists.infradead.org,
	netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
	llvm@lists.linux.dev
Subject: [PATCH] wifi: b43: fix incorrect __packed annotation
Date: Tue, 16 May 2023 09:45:42 +0200	[thread overview]
Message-ID: <20230516074554.1674536-1-arnd@kernel.org> (raw)

From: Arnd Bergmann <arnd@arndb.de>

clang warns about an unpacked structure inside of a packed one:

drivers/net/wireless/broadcom/b43/b43.h:654:4: error: field data within 'struct b43_iv' is less aligned than 'union (unnamed union at /home/arnd/arm-soc/drivers/net/wireless/broadcom/b43/b43.h:651:2)' and is usually due to 'struct b43_iv' being packed, which can lead to unaligned accesses [-Werror,-Wunaligned-access]

The problem here is that the anonymous union has the default alignment
from its members, apparently because the original author mixed up the
placement of the __packed attribute by placing it next to the struct
member rather than the union definition. As the struct itself is
also marked as __packed, there is no need to mark its members, so just
move the annotation to the inner type instead.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 drivers/net/wireless/broadcom/b43/b43.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/wireless/broadcom/b43/b43.h b/drivers/net/wireless/broadcom/b43/b43.h
index 9fc7c088a539..67b4bac048e5 100644
--- a/drivers/net/wireless/broadcom/b43/b43.h
+++ b/drivers/net/wireless/broadcom/b43/b43.h
@@ -651,7 +651,7 @@ struct b43_iv {
 	union {
 		__be16 d16;
 		__be32 d32;
-	} data __packed;
+	} __packed data;
 } __packed;
 
 
-- 
2.39.2


             reply	other threads:[~2023-05-16  7:46 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-05-16  7:45 Arnd Bergmann [this message]
2023-05-16  7:45 ` [PATCH] wifi: b43: fix incorrect __packed annotation Arnd Bergmann
2023-05-16 11:00 ` Simon Horman
2023-05-16 11:00   ` Simon Horman
2023-05-16 17:12 ` Michael Büsch
2023-05-16 17:12   ` Michael Büsch
2023-05-16 17:45   ` Arnd Bergmann
2023-05-16 17:45     ` Arnd Bergmann
2023-05-16 17:47     ` Michael Büsch
2023-05-16 17:47       ` Michael Büsch
2023-05-16 17:53 ` Larry Finger
2023-05-16 17:53   ` Larry Finger

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