From: Arnd Bergmann <arnd@kernel.org>
To: Amitkumar Karwar <amitkarwar@gmail.com>,
Ganapathi Bhat <ganapathi017@gmail.com>,
Sharvari Harisangam <sharvari.harisangam@nxp.com>,
Xinming Hu <huxinming820@gmail.com>,
Kalle Valo <kvalo@codeaurora.org>
Cc: Arnd Bergmann <arnd@arndb.de>,
"David S. Miller" <davem@davemloft.net>,
Jakub Kicinski <kuba@kernel.org>,
Nathan Chancellor <nathan@kernel.org>,
Nick Desaulniers <ndesaulniers@google.com>,
linux-wireless@vger.kernel.org, netdev@vger.kernel.org,
linux-kernel@vger.kernel.org, llvm@lists.linux.dev
Subject: [PATCH] mwifiex: avoid null-pointer-subtraction warning
Date: Mon, 27 Sep 2021 14:16:35 +0200 [thread overview]
Message-ID: <20210927121656.940304-1-arnd@kernel.org> (raw)
From: Arnd Bergmann <arnd@arndb.de>
clang complains about some NULL pointer arithmetic in this driver:
drivers/net/wireless/marvell/mwifiex/sta_tx.c:65:59: error: performing pointer subtraction with a null pointer has undefined behavior [-Werror,-Wnull-pointer-subtraction]
pad = ((void *)skb->data - (sizeof(*local_tx_pd) + hroom)-
^
drivers/net/wireless/marvell/mwifiex/uap_txrx.c:478:53: error: performing pointer subtraction with a null pointer has undefined behavior [-Werror,-Wnull-pointer-subtraction]
pad = ((void *)skb->data - (sizeof(*txpd) + hroom) - NULL) &
Rework that expression to do the same thing using a uintptr_t.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
drivers/net/wireless/marvell/mwifiex/sta_tx.c | 4 ++--
drivers/net/wireless/marvell/mwifiex/uap_txrx.c | 4 ++--
2 files changed, 4 insertions(+), 4 deletions(-)
diff --git a/drivers/net/wireless/marvell/mwifiex/sta_tx.c b/drivers/net/wireless/marvell/mwifiex/sta_tx.c
index 241305377e20..a9b5eb992220 100644
--- a/drivers/net/wireless/marvell/mwifiex/sta_tx.c
+++ b/drivers/net/wireless/marvell/mwifiex/sta_tx.c
@@ -62,8 +62,8 @@ void *mwifiex_process_sta_txpd(struct mwifiex_private *priv,
pkt_type = mwifiex_is_skb_mgmt_frame(skb) ? PKT_TYPE_MGMT : 0;
- pad = ((void *)skb->data - (sizeof(*local_tx_pd) + hroom)-
- NULL) & (MWIFIEX_DMA_ALIGN_SZ - 1);
+ pad = ((uintptr_t)skb->data - (sizeof(*local_tx_pd) + hroom)) &
+ (MWIFIEX_DMA_ALIGN_SZ - 1);
skb_push(skb, sizeof(*local_tx_pd) + pad);
local_tx_pd = (struct txpd *) skb->data;
diff --git a/drivers/net/wireless/marvell/mwifiex/uap_txrx.c b/drivers/net/wireless/marvell/mwifiex/uap_txrx.c
index 9bbdb8dfce62..245ff644f81e 100644
--- a/drivers/net/wireless/marvell/mwifiex/uap_txrx.c
+++ b/drivers/net/wireless/marvell/mwifiex/uap_txrx.c
@@ -475,8 +475,8 @@ void *mwifiex_process_uap_txpd(struct mwifiex_private *priv,
pkt_type = mwifiex_is_skb_mgmt_frame(skb) ? PKT_TYPE_MGMT : 0;
- pad = ((void *)skb->data - (sizeof(*txpd) + hroom) - NULL) &
- (MWIFIEX_DMA_ALIGN_SZ - 1);
+ pad = ((uintptr_t)skb->data - (sizeof(*txpd) + hroom)) &
+ (MWIFIEX_DMA_ALIGN_SZ - 1);
skb_push(skb, sizeof(*txpd) + pad);
--
2.29.2
next reply other threads:[~2021-09-27 12:17 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-27 12:16 Arnd Bergmann [this message]
2021-09-28 6:43 ` [PATCH] mwifiex: avoid null-pointer-subtraction warning Kalle Valo
2021-09-28 14:42 ` Kalle Valo
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