From: =?UTF-8?q?Patryk=20Gawro=C5=84ski?= <gawronski1.6@gmail.com>
To: gregkh@linuxfoundation.org
Cc: =?UTF-8?q?Patryk=20Gawro=C5=84ski?= <gawronski1.6@gmail.com>,
	Dan Carpenter <error27@gmail.com>,
	Ethan Tidmore <ethantidmore06@gmail.com>,
	Lin YuChen <starpt.official@gmail.com>,
	Maksym Pikhotskyi <mpikhotskyi@gmail.com>,
	Michael Straube <straube.linux@gmail.com>,
	Sameeksha Sankpal <sameekshasankpal@gmail.com>,
	Artur Stupa <arthur.stupa@gmail.com>,
	linux-staging@lists.linux.dev,
	linux-kernel@vger.kernel.org
Subject: [PATCH] staging: rtl8723bs: Replace custom RotR1 macro with ror16
Date: Wed, 22 Jul 2026 23:53:25 +0200
Message-ID: <20260722215327.62791-1-gawronski1.6@gmail.com>
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The custom RotR1 macro reuses its argument, which throws a checkpatch
warning and can lead to unexpected side-effects if called with an
expression that has side-effects.

Remove the custom macro and replace its usages with the standard
kernel ror16() function from <linux/bitops.h> to clean up the code.

Signed-off-by: Patryk Gawroński <gawronski1.6@gmail.com>
---
 drivers/staging/rtl8723bs/core/rtw_security.c | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/drivers/staging/rtl8723bs/core/rtw_security.c b/drivers/staging/rtl8723bs/core/rtw_security.c
index 29e2a5a771dd..2217cffac5f2 100644
--- a/drivers/staging/rtl8723bs/core/rtw_security.c
+++ b/drivers/staging/rtl8723bs/core/rtw_security.c
@@ -6,6 +6,7 @@
  ******************************************************************************/
 #include <linux/crc32.h>
 #include <linux/unaligned.h>
+#include <linux/bitops.h>
 #include <drv_types.h>
 #include <crypto/aes.h>
 #include <crypto/utils.h>
@@ -225,7 +226,6 @@ void rtw_seccalctkipmic(u8 *key, u8 *header, u8 *data, u32 data_len, u8 *mic_cod
 }
 
 /* macros for extraction/creation of unsigned char/unsigned short values  */
-#define RotR1(v16)   ((((v16) >> 1) & 0x7FFF) ^ (((v16) & 1) << 15))
 #define   Lo8(v16)   ((u8)((v16)       & 0x00FF))
 #define   Hi8(v16)   ((u8)(((v16) >> 8) & 0x00FF))
 #define  Lo16(v32)   ((u16)((v32)       & 0xFFFF))
@@ -392,12 +392,12 @@ static void phase2(u8 *rc4key, const u8 *tk, const u16 *p1k, u16 iv16)
 	PPK[5] +=    _S_(PPK[4] ^ TK16(5));   /* Total # S-box lookups == 6  */
 
 	/* Final sweep: bijective, "linear". Rotates kill LSB correlations   */
-	PPK[0] +=  RotR1(PPK[5] ^ TK16(6));
-	PPK[1] +=  RotR1(PPK[0] ^ TK16(7));   /* Use all of TK[] in Phase2   */
-	PPK[2] +=  RotR1(PPK[1]);
-	PPK[3] +=  RotR1(PPK[2]);
-	PPK[4] +=  RotR1(PPK[3]);
-	PPK[5] +=  RotR1(PPK[4]);
+	PPK[0] +=  ror16(PPK[5] ^ TK16(6), 1);
+	PPK[1] +=  ror16(PPK[0] ^ TK16(7), 1);   /* Use all of TK[] in Phase2   */
+	PPK[2] +=  ror16(PPK[1], 1);
+	PPK[3] +=  ror16(PPK[2], 1);
+	PPK[4] +=  ror16(PPK[3], 1);
+	PPK[5] +=  ror16(PPK[4], 1);
 	/* Note: At this point, for a given key TK[0..15], the 96-bit output */
 	/*       value PPK[0..5] is guaranteed to be unique, as a function   */
 	/*       of the 96-bit "input" value   {TA, IV32, IV16}. That is, P1K  */
-- 
2.55.0