[PATCH v2 5.2] rsi: Properly initialize data in rsi_sdio_ta_reset

From: Nathan Chancellor <natechancellor@gmail.com>
To: Amitkumar Karwar <amitkarwar@gmail.com>,
	Siva Rebbagondla <siva8118@gmail.com>,
	Kalle Valo <kvalo@codeaurora.org>
Cc: linux-wireless@vger.kernel.org, netdev@vger.kernel.org,
	linux-kernel@vger.kernel.org, Arnd Bergmann <arnd@arndb.de>,
	Nick Desaulniers <ndesaulniers@google.com>,
	clang-built-linux@googlegroups.com,
	Nathan Chancellor <natechancellor@gmail.com>
Subject: [PATCH v2 5.2] rsi: Properly initialize data in rsi_sdio_ta_reset
Date: Thu, 23 May 2019 08:30:08 -0700	[thread overview]
Message-ID: <20190523153007.112231-1-natechancellor@gmail.com> (raw)
In-Reply-To: <20190502151548.11143-1-natechancellor@gmail.com>

When building with -Wuninitialized, Clang warns:

drivers/net/wireless/rsi/rsi_91x_sdio.c:940:43: warning: variable 'data'
is uninitialized when used here [-Wuninitialized]
        put_unaligned_le32(TA_HOLD_THREAD_VALUE, data);
                                                 ^~~~
drivers/net/wireless/rsi/rsi_91x_sdio.c:930:10: note: initialize the
variable 'data' to silence this warning
        u8 *data;
                ^
                 = NULL
1 warning generated.

Using Clang's suggestion of initializing data to NULL wouldn't work out
because data will be dereferenced by put_unaligned_le32. Use kzalloc to
properly initialize data, which matches a couple of other places in this
driver.

Fixes: e5a1ecc97e5f ("rsi: add firmware loading for 9116 device")
Link: https://github.com/ClangBuiltLinux/linux/issues/464
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
---

v1 -> v2:

* Use RSI_9116_REG_SIZE instead of sizeof(u32) for kzalloc thanks to
  review from Arnd.

 drivers/net/wireless/rsi/rsi_91x_sdio.c | 21 ++++++++++++++-------
 1 file changed, 14 insertions(+), 7 deletions(-)

diff --git a/drivers/net/wireless/rsi/rsi_91x_sdio.c b/drivers/net/wireless/rsi/rsi_91x_sdio.c
index f9c67ed473d1..b42cd50b837e 100644
--- a/drivers/net/wireless/rsi/rsi_91x_sdio.c
+++ b/drivers/net/wireless/rsi/rsi_91x_sdio.c
@@ -929,11 +929,15 @@ static int rsi_sdio_ta_reset(struct rsi_hw *adapter)
 	u32 addr;
 	u8 *data;
 
+	data = kzalloc(RSI_9116_REG_SIZE, GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
 	status = rsi_sdio_master_access_msword(adapter, TA_BASE_ADDR);
 	if (status < 0) {
 		rsi_dbg(ERR_ZONE,
 			"Unable to set ms word to common reg\n");
-		return status;
+		goto err;
 	}
 
 	rsi_dbg(INIT_ZONE, "%s: Bring TA out of reset\n", __func__);
@@ -944,7 +948,7 @@ static int rsi_sdio_ta_reset(struct rsi_hw *adapter)
 						  RSI_9116_REG_SIZE);
 	if (status < 0) {
 		rsi_dbg(ERR_ZONE, "Unable to hold TA threads\n");
-		return status;
+		goto err;
 	}
 
 	put_unaligned_le32(TA_SOFT_RST_CLR, data);
@@ -954,7 +958,7 @@ static int rsi_sdio_ta_reset(struct rsi_hw *adapter)
 						  RSI_9116_REG_SIZE);
 	if (status < 0) {
 		rsi_dbg(ERR_ZONE, "Unable to get TA out of reset\n");
-		return status;
+		goto err;
 	}
 
 	put_unaligned_le32(TA_PC_ZERO, data);
@@ -964,7 +968,8 @@ static int rsi_sdio_ta_reset(struct rsi_hw *adapter)
 						  RSI_9116_REG_SIZE);
 	if (status < 0) {
 		rsi_dbg(ERR_ZONE, "Unable to Reset TA PC value\n");
-		return -EINVAL;
+		status = -EINVAL;
+		goto err;
 	}
 
 	put_unaligned_le32(TA_RELEASE_THREAD_VALUE, data);
@@ -974,17 +979,19 @@ static int rsi_sdio_ta_reset(struct rsi_hw *adapter)
 						  RSI_9116_REG_SIZE);
 	if (status < 0) {
 		rsi_dbg(ERR_ZONE, "Unable to release TA threads\n");
-		return status;
+		goto err;
 	}
 
 	status = rsi_sdio_master_access_msword(adapter, MISC_CFG_BASE_ADDR);
 	if (status < 0) {
 		rsi_dbg(ERR_ZONE, "Unable to set ms word to common reg\n");
-		return status;
+		goto err;
 	}
 	rsi_dbg(INIT_ZONE, "***** TA Reset done *****\n");
 
-	return 0;
+err:
+	kfree(data);
+	return status;
 }
 
 static struct rsi_host_intf_ops sdio_host_intf_ops = {
-- 
2.22.0.rc1

