[PATCH 04/10] rtlwifi: rtl8192cu: Remove uninitialized_var() usage

From: Kees Cook <keescook@chromium.org>
To: linux-kernel@vger.kernel.org
Cc: Kees Cook <keescook@chromium.org>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>,
	Alexander Potapenko <glider@google.com>,
	Joe Perches <joe@perches.com>, Andy Whitcroft <apw@canonical.com>,
	x86@kernel.org, drbd-dev@lists.linbit.com,
	linux-block@vger.kernel.org, b43-dev@lists.infradead.org,
	netdev@vger.kernel.org, linux-wireless@vger.kernel.org,
	linux-ide@vger.kernel.org, linux-clk@vger.kernel.org,
	linux-spi@vger.kernel.org, linux-mm@kvack.org,
	clang-built-linux@googlegroups.com
Subject: [PATCH 04/10] rtlwifi: rtl8192cu: Remove uninitialized_var() usage
Date: Wed,  3 Jun 2020 16:31:57 -0700	[thread overview]
Message-ID: <20200603233203.1695403-5-keescook@chromium.org> (raw)
In-Reply-To: <20200603233203.1695403-1-keescook@chromium.org>

Using uninitialized_var() is dangerous as it papers over real bugs[1]
(or can in the future), and suppresses unrelated compiler warnings (e.g.
"unused variable"). If the compiler thinks it is uninitialized, either
simply initialize the variable or make compiler changes. As a precursor
to removing[2] this[3] macro[4], just initialize this variable to NULL,
and avoid sending garbage by returning.

[1] https://lore.kernel.org/lkml/20200603174714.192027-1-glider@google.com/
[2] https://lore.kernel.org/lkml/CA+55aFw+Vbj0i=1TGqCR5vQkCzWJ0QxK6CernOU6eedsudAixw@mail.gmail.com/
[3] https://lore.kernel.org/lkml/CA+55aFwgbgqhbp1fkxvRKEpzyR5J8n1vKT1VZdz9knmPuXhOeg@mail.gmail.com/
[4] https://lore.kernel.org/lkml/CA+55aFz2500WfbKXAx8s67wrm9=yVJu65TpLgN_ybYNv0VEOKA@mail.gmail.com/

Signed-off-by: Kees Cook <keescook@chromium.org>
---
 drivers/net/wireless/realtek/rtlwifi/rtl8192cu/hw.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/wireless/realtek/rtlwifi/rtl8192cu/hw.c b/drivers/net/wireless/realtek/rtlwifi/rtl8192cu/hw.c
index f070f25bb735..5b071b70bc08 100644
--- a/drivers/net/wireless/realtek/rtlwifi/rtl8192cu/hw.c
+++ b/drivers/net/wireless/realtek/rtlwifi/rtl8192cu/hw.c
@@ -592,7 +592,7 @@ static void _rtl92cu_init_chipn_one_out_ep_priority(struct ieee80211_hw *hw,
 						    bool wmm_enable,
 						    u8 queue_sel)
 {
-	u16 uninitialized_var(value);
+	u16 value;
 
 	switch (queue_sel) {
 	case TX_SELE_HQ:
@@ -606,7 +606,7 @@ static void _rtl92cu_init_chipn_one_out_ep_priority(struct ieee80211_hw *hw,
 		break;
 	default:
 		WARN_ON(1); /* Shall not reach here! */
-		break;
+		return;
 	}
 	_rtl92c_init_chipn_reg_priority(hw, value, value, value, value,
 					value, value);
-- 
2.25.1

