From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: Nathan Chancellor <natechancellor@gmail.com>
Cc: devel@driverdev.osuosl.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] staging: rtl8188eu: Simplify memcmp logical checks
Date: Tue, 25 Sep 2018 21:07:11 +0200 [thread overview]
Message-ID: <20180925190711.GA31631@kroah.com> (raw)
In-Reply-To: <20180921002221.14424-1-natechancellor@gmail.com>
On Thu, Sep 20, 2018 at 05:22:21PM -0700, Nathan Chancellor wrote:
> Clang generates a warning when it sees a logical not followed by a
> conditional operator like ==, >, or < because it thinks that the logical
> not should be applied to the whole statement:
>
> drivers/staging/rtl8188eu/core/rtw_ieee80211.c:293:8: warning: logical
> not is only applied to the left hand side of this comparison
> [-Wlogical-not-parentheses]
>
> It assumes the author might have made a mistake in their logic:
>
> if (!a == b) -> if (!(a == b))
>
> Sometimes that is the case; other times, it's just a super convoluted
> way of saying 'if (a)' when b = 0:
>
> if (!1 == 0) -> if (0 == 0) -> if (true)
>
> Alternatively:
>
> if (!1 == 0) -> if (!!1) -> if (1)
>
> Simplify these comparisons so that Clang doesn't complain.
>
> Link: https://github.com/ClangBuiltLinux/linux/issues/161
> Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
> ---
> drivers/staging/rtl8188eu/core/rtw_ieee80211.c | 2 +-
> drivers/staging/rtl8188eu/core/rtw_mlme.c | 2 +-
> drivers/staging/rtl8188eu/core/rtw_recv.c | 4 ++--
> drivers/staging/rtl8188eu/core/rtw_wlan_util.c | 2 +-
> 4 files changed, 5 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/staging/rtl8188eu/core/rtw_ieee80211.c b/drivers/staging/rtl8188eu/core/rtw_ieee80211.c
> index 9e5c7e62d26f..20f34d25c369 100644
> --- a/drivers/staging/rtl8188eu/core/rtw_ieee80211.c
> +++ b/drivers/staging/rtl8188eu/core/rtw_ieee80211.c
> @@ -284,7 +284,7 @@ unsigned char *rtw_get_wpa_ie(unsigned char *pie, uint *wpa_ie_len, int limit)
>
> if (pbuf) {
> /* check if oui matches... */
> - if (!memcmp((pbuf + 2), wpa_oui_type, sizeof(wpa_oui_type)) == false)
> + if (memcmp((pbuf + 2), wpa_oui_type, sizeof(wpa_oui_type)))
> goto check_next_ie;
>
> /* check version... */
> diff --git a/drivers/staging/rtl8188eu/core/rtw_mlme.c b/drivers/staging/rtl8188eu/core/rtw_mlme.c
> index ef8a7dc4bd34..43d6513484c5 100644
> --- a/drivers/staging/rtl8188eu/core/rtw_mlme.c
> +++ b/drivers/staging/rtl8188eu/core/rtw_mlme.c
> @@ -1437,7 +1437,7 @@ static int rtw_check_join_candidate(struct mlme_priv *pmlmepriv
> /* check ssid, if needed */
> if (pmlmepriv->assoc_ssid.SsidLength) {
> if (competitor->network.Ssid.SsidLength != pmlmepriv->assoc_ssid.SsidLength ||
> - !memcmp(competitor->network.Ssid.Ssid, pmlmepriv->assoc_ssid.Ssid, pmlmepriv->assoc_ssid.SsidLength) == false)
> + memcmp(competitor->network.Ssid.Ssid, pmlmepriv->assoc_ssid.Ssid, pmlmepriv->assoc_ssid.SsidLength))
> goto exit;
> }
>
> diff --git a/drivers/staging/rtl8188eu/core/rtw_recv.c b/drivers/staging/rtl8188eu/core/rtw_recv.c
> index ab9638d618a9..f3eb63f8cf0b 100644
> --- a/drivers/staging/rtl8188eu/core/rtw_recv.c
> +++ b/drivers/staging/rtl8188eu/core/rtw_recv.c
> @@ -1283,8 +1283,8 @@ static int wlanhdr_to_ethhdr(struct recv_frame *precvframe)
> psnap_type = ptr+pattrib->hdrlen + pattrib->iv_len+SNAP_SIZE;
> /* convert hdr + possible LLC headers into Ethernet header */
> if ((!memcmp(psnap, rtw_rfc1042_header, SNAP_SIZE) &&
> - (!memcmp(psnap_type, SNAP_ETH_TYPE_IPX, 2) == false) &&
> - (!memcmp(psnap_type, SNAP_ETH_TYPE_APPLETALK_AARP, 2) == false)) ||
> + memcmp(psnap_type, SNAP_ETH_TYPE_IPX, 2) &&
> + memcmp(psnap_type, SNAP_ETH_TYPE_APPLETALK_AARP, 2)) ||
> !memcmp(psnap, rtw_bridge_tunnel_header, SNAP_SIZE)) {
> /* remove RFC1042 or Bridge-Tunnel encapsulation and replace EtherType */
> bsnaphdr = true;
> diff --git a/drivers/staging/rtl8188eu/core/rtw_wlan_util.c b/drivers/staging/rtl8188eu/core/rtw_wlan_util.c
> index fb496ab5a862..51cf78150168 100644
> --- a/drivers/staging/rtl8188eu/core/rtw_wlan_util.c
> +++ b/drivers/staging/rtl8188eu/core/rtw_wlan_util.c
> @@ -856,7 +856,7 @@ int rtw_check_bcn_info(struct adapter *Adapter, u8 *pframe, u32 packet_len)
> return _FAIL;
> }
>
> - if (!memcmp(cur_network->network.MacAddress, pbssid, 6) == false) {
> + if (memcmp(cur_network->network.MacAddress, pbssid, 6) {
> DBG_88E("Oops: rtw_check_network_encrypt linked but recv other bssid bcn\n%pM %pM\n",
> (pbssid), (cur_network->network.MacAddress));
> return true;
Always test-build your patches before sending them off so you do not get
a grumpy maintainer upset at you for breaking their build system...
Hint, it's the last chunk here...
greg k-h
next prev parent reply other threads:[~2018-09-25 19:07 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-09-21 0:22 [PATCH] staging: rtl8188eu: Simplify memcmp logical checks Nathan Chancellor
2018-09-25 19:07 ` Greg Kroah-Hartman [this message]
2018-09-25 19:15 ` Nathan Chancellor
2018-09-25 19:13 ` [PATCH v2] " Nathan Chancellor
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