Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
From:   Arnd Bergmann <arnd@kernel.org>
To:     Chas Williams <3chas3@gmail.com>
Cc:     Arnd Bergmann <arnd@arndb.de>,
        Nathan Chancellor <natechancellor@gmail.com>,
        Nick Desaulniers <ndesaulniers@google.com>,
        "David S. Miller" <davem@davemloft.net>,
        linux-atm-general@lists.sourceforge.net, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org, clang-built-linux@googlegroups.com
Subject: [PATCH net-next 01/11] atm: horizon: shut up clang null pointer arithmetic warning
Date:   Mon, 26 Oct 2020 22:29:48 +0100
Message-Id: <20201026213040.3889546-1-arnd@kernel.org>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

From: Arnd Bergmann <arnd@arndb.de>

Building a "W=1" kernel with clang produces a warning about
suspicous pointer arithmetic:

drivers/atm/horizon.c:1844:52: warning: performing pointer arithmetic
on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
  for (mem = (HDW *) memmap; mem < (HDW *) (memmap + 1); ++mem)

The way that the addresses are handled is very obscure, and
rewriting it to be more conventional seems fairly pointless, given
that this driver probably has no users.
Shut up this warning by adding a cast to uintptr_t.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 drivers/atm/horizon.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/atm/horizon.c b/drivers/atm/horizon.c
index 4f2951cbe69c..cd368786b216 100644
--- a/drivers/atm/horizon.c
+++ b/drivers/atm/horizon.c
@@ -1841,7 +1841,7 @@ static int hrz_init(hrz_dev *dev)
   
   printk (" clearing memory");
   
-  for (mem = (HDW *) memmap; mem < (HDW *) (memmap + 1); ++mem)
+  for (mem = (HDW *) memmap; mem < (HDW *) ((uintptr_t)memmap + 1); ++mem)
     wr_mem (dev, mem, 0);
   
   printk (" tx channels");
-- 
2.27.0