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From: Arnd Bergmann <arnd@kernel.org>
To: "David S. Miller" <davem@davemloft.net>,
	Jakub Kicinski <kuba@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>,
	Nathan Chancellor <nathan@kernel.org>,
	Nick Desaulniers <ndesaulniers@google.com>,
	netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
	llvm@lists.linux.dev
Subject: [PATCH] cxgb: avoid open-coded offsetof()
Date: Mon, 27 Sep 2021 14:16:04 +0200	[thread overview]
Message-ID: <20210927121611.940046-1-arnd@kernel.org> (raw)

From: Arnd Bergmann <arnd@arndb.de>

clang-14 does not like the custom offsetof() macro in vsc7326:

drivers/net/ethernet/chelsio/cxgb/vsc7326.c:597:3: error: performing pointer subtraction with a null pointer has undefined behavior [-Werror,-Wnull-pointer-subtraction]
                HW_STAT(RxUnicast, RxUnicastFramesOK),
                ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/net/ethernet/chelsio/cxgb/vsc7326.c:594:56: note: expanded from macro 'HW_STAT'
        { reg, (&((struct cmac_statistics *)NULL)->stat_name) - (u64 *)NULL }

Rewrite this to use the version provided by the kernel.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 drivers/net/ethernet/chelsio/cxgb/vsc7326.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/chelsio/cxgb/vsc7326.c b/drivers/net/ethernet/chelsio/cxgb/vsc7326.c
index 873c1c7b4ca0..a19284bdb80e 100644
--- a/drivers/net/ethernet/chelsio/cxgb/vsc7326.c
+++ b/drivers/net/ethernet/chelsio/cxgb/vsc7326.c
@@ -591,7 +591,7 @@ static void port_stats_update(struct cmac *mac)
 	} hw_stats[] = {
 
 #define HW_STAT(reg, stat_name) \
-	{ reg, (&((struct cmac_statistics *)NULL)->stat_name) - (u64 *)NULL }
+	{ reg, offsetof(struct cmac_statistics, stat_name) / sizeof(u64) }
 
 		/* Rx stats */
 		HW_STAT(RxUnicast, RxUnicastFramesOK),
-- 
2.29.2


             reply	other threads:[~2021-09-27 12:16 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-09-27 12:16 Arnd Bergmann [this message]
2021-09-27 13:10 ` [PATCH] cxgb: avoid open-coded offsetof() patchwork-bot+netdevbpf

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