From:   Nathan Chancellor <natechancellor@gmail.com>
To:     Johannes Berg <johannes@sipsolutions.net>
Cc:     linux-wireless@vger.kernel.org,
        "David S. Miller" <davem@davemloft.net>, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org, clang-built-linux@googlegroups.com,
        Nick Desaulniers <ndesaulniers@google.com>,
        Nathan Chancellor <natechancellor@gmail.com>
Subject: [PATCH] cfg80211: Change an 'else if' into an 'else' in cfg80211_calculate_bitrate_he
Date:   Thu,  7 Mar 2019 16:57:35 -0700
Message-Id: <20190307235735.31487-1-natechancellor@gmail.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Sender: linux-wireless-owner@vger.kernel.org
Precedence: bulk

When building with -Wsometimes-uninitialized, Clang warns:

net/wireless/util.c:1223:11: warning: variable 'result' is used
uninitialized whenever 'if' condition is false
[-Wsometimes-uninitialized]

Clang can't evaluate at this point that WARN(1, ...) always returns true
because __ret_warn_on is defined as !!(condition), which isn't
immediately evaluated as 1. Change this branch to else so that it's
clear to Clang that we intend to bail out here.

Link: https://github.com/ClangBuiltLinux/linux/issues/382
Suggested-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
---
 net/wireless/util.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/net/wireless/util.c b/net/wireless/util.c
index e4b8db5e81ec..75899b62bdc9 100644
--- a/net/wireless/util.c
+++ b/net/wireless/util.c
@@ -1220,9 +1220,11 @@ static u32 cfg80211_calculate_bitrate_he(struct rate_info *rate)
 	else if (rate->bw == RATE_INFO_BW_HE_RU &&
 		 rate->he_ru_alloc == NL80211_RATE_INFO_HE_RU_ALLOC_26)
 		result = rates_26[rate->he_gi];
-	else if (WARN(1, "invalid HE MCS: bw:%d, ru:%d\n",
-		      rate->bw, rate->he_ru_alloc))
+	else {
+		WARN(1, "invalid HE MCS: bw:%d, ru:%d\n",
+		     rate->bw, rate->he_ru_alloc);
 		return 0;
+	}
 
 	/* now scale to the appropriate MCS */
 	tmp = result;
-- 
2.21.0