Return-path: Received: from smtprelay0158.hostedemail.com ([216.40.44.158]:49471 "EHLO smtprelay.hostedemail.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752292AbeBIQYv (ORCPT ); Fri, 9 Feb 2018 11:24:51 -0500 Received: from smtprelay.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by smtpgrave08.hostedemail.com (Postfix) with ESMTP id 1C44B1802B41C for ; Fri, 9 Feb 2018 16:16:54 +0000 (UTC) Message-ID: <1518193009.14014.6.camel@perches.com> (sfid-20180209_172458_561118_9554322B) Subject: Re: [PATCH] rtlwifi: rtl8192cu: remove pointless memcpy From: Joe Perches To: Arnd Bergmann , Ping-Ke Shih Cc: Kalle Valo , Johannes Berg , linux-wireless@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Date: Fri, 09 Feb 2018 08:16:49 -0800 In-Reply-To: <20180209132531.2755482-1-arnd@arndb.de> References: <20180209132531.2755482-1-arnd@arndb.de> Content-Type: text/plain; charset="ISO-8859-1" Mime-Version: 1.0 Sender: linux-wireless-owner@vger.kernel.org List-ID: On Fri, 2018-02-09 at 14:24 +0100, Arnd Bergmann wrote: > gcc-8 points out that source and destination of the memcpy() are > always the same pointer, so the effect of memcpy() is undefined > here (its arguments must not overlap): > > drivers/net/wireless/realtek/rtlwifi/rtl8192cu/trx.c: In function '_rtl_rx_process': > drivers/net/wireless/realtek/rtlwifi/rtl8192cu/trx.c:430:2: error: 'memcpy' source argument is the same as destination [-Werror=restrict] > > Most likely this is harmless, but it's easy to just remove the > line and get rid of the warning. > > Signed-off-by: Arnd Bergmann > --- > drivers/net/wireless/realtek/rtlwifi/rtl8192cu/trx.c | 1 - > 1 file changed, 1 deletion(-) > > diff --git a/drivers/net/wireless/realtek/rtlwifi/rtl8192cu/trx.c b/drivers/net/wireless/realtek/rtlwifi/rtl8192cu/trx.c > index ac4a82de40c7..9ab56827124e 100644 > --- a/drivers/net/wireless/realtek/rtlwifi/rtl8192cu/trx.c > +++ b/drivers/net/wireless/realtek/rtlwifi/rtl8192cu/trx.c > @@ -427,7 +427,6 @@ static void _rtl_rx_process(struct ieee80211_hw *hw, struct sk_buff *skb) > (u32)hdr->addr1[0], (u32)hdr->addr1[1], > (u32)hdr->addr1[2], (u32)hdr->addr1[3], > (u32)hdr->addr1[4], (u32)hdr->addr1[5]); > - memcpy(IEEE80211_SKB_RXCB(skb), rx_status, sizeof(*rx_status)); > ieee80211_rx(hw, skb); > } trivia: The RT_TRACE above this should probably use %pM too. Not submitted as it would just cause a conflict. --- drivers/net/wireless/realtek/rtlwifi/rtl8192cu/trx.c | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-) diff --git a/drivers/net/wireless/realtek/rtlwifi/rtl8192cu/trx.c b/drivers/net/wireless/realtek/rtlwifi/rtl8192cu/trx.c index ac4a82de40c7..61da667ed8ba 100644 --- a/drivers/net/wireless/realtek/rtlwifi/rtl8192cu/trx.c +++ b/drivers/net/wireless/realtek/rtlwifi/rtl8192cu/trx.c @@ -422,11 +422,8 @@ static void _rtl_rx_process(struct ieee80211_hw *hw, struct sk_buff *skb) if (ieee80211_is_data(fc)) RT_TRACE(rtlpriv, COMP_INIT, DBG_DMESG, "Got data frame\n"); RT_TRACE(rtlpriv, COMP_INIT, DBG_DMESG, - "Fram: fc = 0x%X addr1 = 0x%02X:0x%02X:0x%02X:0x%02X:0x%02X:0x%02X\n", - fc, - (u32)hdr->addr1[0], (u32)hdr->addr1[1], - (u32)hdr->addr1[2], (u32)hdr->addr1[3], - (u32)hdr->addr1[4], (u32)hdr->addr1[5]); + "Fram: fc = 0x%X addr1 = %pM\n", + fc, hdr->addr1); memcpy(IEEE80211_SKB_RXCB(skb), rx_status, sizeof(*rx_status)); ieee80211_rx(hw, skb); }