linux-kernel - [PATCH v2] staging: rtl8188eu: remove dead code/vestigial do..while loop

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-Id: <20190924142819.5243-1-connor.kuehl@canonical.com>
Date:   Tue, 24 Sep 2019 07:28:19 -0700
From:   Connor Kuehl <connor.kuehl@...onical.com>
To:     Larry.Finger@...inger.net, gregkh@...uxfoundation.org,
        straube.linux@...il.com, devel@...verdev.osuosl.org,
        dan.carpenter@...cle.com
Cc:     linux-kernel@...r.kernel.org, kernel-janitors@...r.kernel.org
Subject: [PATCH v2] staging: rtl8188eu: remove dead code/vestigial do..while loop

The local variable 'bcmd_down' is always set to true almost immediately
before the do-while's condition is checked. As a result, !bcmd_down
evaluates to false which short circuits the logical AND operator meaning
that the second operand is never reached and is therefore dead code.

Furthermore, the do..while loop may be removed since it will always only
execute once because 'bcmd_down' is always set to true, so the
!bcmd_down evaluates to false and the loop exits immediately after the
first pass.

Fix this by removing the loop and its condition variables 'bcmd_down'
and 'retry_cnts'

While we're in there, also fix some checkpatch.pl suggestions regarding
spaces around arithmetic operators like '+'

Addresses-Coverity: ("Logically dead code")

Signed-off-by: Connor Kuehl <connor.kuehl@...onical.com>
---
v1 -> v2:
 - remove the loop and its condition variable bcmd_down
 - address some non-invasive checkpatch.pl suggestions as a result of
   deleting the loop

 drivers/staging/rtl8188eu/hal/rtl8188e_cmd.c | 55 +++++++++-----------
 1 file changed, 24 insertions(+), 31 deletions(-)

diff --git a/drivers/staging/rtl8188eu/hal/rtl8188e_cmd.c b/drivers/staging/rtl8188eu/hal/rtl8188e_cmd.c
index 47352f210c0b..7646167a0b36 100644
--- a/drivers/staging/rtl8188eu/hal/rtl8188e_cmd.c
+++ b/drivers/staging/rtl8188eu/hal/rtl8188e_cmd.c
@@ -47,8 +47,6 @@ static u8 _is_fw_read_cmd_down(struct adapter *adapt, u8 msgbox_num)
 ******************************************/
 static s32 FillH2CCmd_88E(struct adapter *adapt, u8 ElementID, u32 CmdLen, u8 *pCmdBuffer)
 {
-	u8 bcmd_down = false;
-	s32 retry_cnts = 100;
 	u8 h2c_box_num;
 	u32 msgbox_addr;
 	u32 msgbox_ex_addr;
@@ -71,39 +69,34 @@ static s32 FillH2CCmd_88E(struct adapter *adapt, u8 ElementID, u32 CmdLen, u8 *p
 		goto exit;
 
 	/* pay attention to if  race condition happened in  H2C cmd setting. */
-	do {
-		h2c_box_num = adapt->HalData->LastHMEBoxNum;
-
-		if (!_is_fw_read_cmd_down(adapt, h2c_box_num)) {
-			DBG_88E(" fw read cmd failed...\n");
-			goto exit;
-		}
-
-		*(u8 *)(&h2c_cmd) = ElementID;
-
-		if (CmdLen <= 3) {
-			memcpy((u8 *)(&h2c_cmd)+1, pCmdBuffer, CmdLen);
-		} else {
-			memcpy((u8 *)(&h2c_cmd)+1, pCmdBuffer, 3);
-			ext_cmd_len = CmdLen-3;
-			memcpy((u8 *)(&h2c_cmd_ex), pCmdBuffer+3, ext_cmd_len);
+	h2c_box_num = adapt->HalData->LastHMEBoxNum;
 
-			/* Write Ext command */
-			msgbox_ex_addr = REG_HMEBOX_EXT_0 + (h2c_box_num * RTL88E_EX_MESSAGE_BOX_SIZE);
-			for (cmd_idx = 0; cmd_idx < ext_cmd_len; cmd_idx++)
-				usb_write8(adapt, msgbox_ex_addr+cmd_idx, *((u8 *)(&h2c_cmd_ex)+cmd_idx));
-		}
-		/*  Write command */
-		msgbox_addr = REG_HMEBOX_0 + (h2c_box_num * RTL88E_MESSAGE_BOX_SIZE);
-		for (cmd_idx = 0; cmd_idx < RTL88E_MESSAGE_BOX_SIZE; cmd_idx++)
-			usb_write8(adapt, msgbox_addr+cmd_idx, *((u8 *)(&h2c_cmd)+cmd_idx));
+	if (!_is_fw_read_cmd_down(adapt, h2c_box_num)) {
+		DBG_88E(" fw read cmd failed...\n");
+		goto exit;
+	}
 
-		bcmd_down = true;
+	*(u8 *)(&h2c_cmd) = ElementID;
 
-		adapt->HalData->LastHMEBoxNum =
-			(h2c_box_num+1) % RTL88E_MAX_H2C_BOX_NUMS;
+	if (CmdLen <= 3) {
+		memcpy((u8 *)(&h2c_cmd) + 1, pCmdBuffer, CmdLen);
+	} else {
+		memcpy((u8 *)(&h2c_cmd) + 1, pCmdBuffer, 3);
+		ext_cmd_len = CmdLen - 3;
+		memcpy((u8 *)(&h2c_cmd_ex), pCmdBuffer + 3, ext_cmd_len);
+
+		/* Write Ext command */
+		msgbox_ex_addr = REG_HMEBOX_EXT_0 + (h2c_box_num * RTL88E_EX_MESSAGE_BOX_SIZE);
+		for (cmd_idx = 0; cmd_idx < ext_cmd_len; cmd_idx++)
+			usb_write8(adapt, msgbox_ex_addr + cmd_idx, *((u8 *)(&h2c_cmd_ex) + cmd_idx));
+	}
+	/*  Write command */
+	msgbox_addr = REG_HMEBOX_0 + (h2c_box_num * RTL88E_MESSAGE_BOX_SIZE);
+	for (cmd_idx = 0; cmd_idx < RTL88E_MESSAGE_BOX_SIZE; cmd_idx++)
+		usb_write8(adapt, msgbox_addr + cmd_idx, *((u8 *)(&h2c_cmd) + cmd_idx));
 
-	} while ((!bcmd_down) && (retry_cnts--));
+	adapt->HalData->LastHMEBoxNum =
+		(h2c_box_num + 1) % RTL88E_MAX_H2C_BOX_NUMS;
 
 	ret = _SUCCESS;
 
-- 
2.17.1