[PATCH 6.0 0302/1073] wifi: rtw89: use u32_encode_bits() to fill MAC quota value

Greg Kroah-Hartman
2022-12-28T15:33:32Z

From: Ping-Ke Shih <pkshih@realtek.com>

[ Upstream commit 525c06c81d75690a9b795cc62a758838c1a6b6fe ]

Coverity reported shift 16 bits could cause sign extension and might get
an unexpected value. Since the input values are predefined and no this
kind of case, original code is safe so far. But, still changing them to
use u32_encode_bits() will be more clear and prevent mistakes in the
future.

The original message of Coverity is:
Suspicious implicit sign extension: "max_cfg->cma0_dma" with type "u16"
(16 bits, unsigned) is promoted in "max_cfg->cma0_dma << 16" to type
"int" (32 bits, signed), then sign-extended to type "unsigned long"
(64 bits, unsigned). If "max_cfg->cma0_dma << 16" is greater than
0x7FFFFFFF, the upper bits of the result will all be 1."

Reported-by: coverity-bot <keescook+coverity-bot@chromium.org>
Addresses-Coverity-ID: 1527095 ("Integer handling issues")
Fixes: e3ec7017f6a2 ("rtw89: add Realtek 802.11ax driver")
Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/20221108013858.10806-1-pkshih@realtek.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/wireless/realtek/rtw89/mac.c | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/drivers/net/wireless/realtek/rtw89/mac.c b/drivers/net/wireless/realtek/rtw89/mac.c
index 93124b815825..1afc14531194 100644
--- a/drivers/net/wireless/realtek/rtw89/mac.c
+++ b/drivers/net/wireless/realtek/rtw89/mac.c
@@ -1387,10 +1387,8 @@ static int dle_mix_cfg(struct rtw89_dev *rtwdev, const struct rtw89_dle_mem *cfg
#define INVALID_QT_WCPU U16_MAX
#define SET_QUOTA_VAL(_min_x, _max_x, _module, _idx) \
do { \
- val = ((_min_x) & \
- B_AX_ ## _module ## _MIN_SIZE_MASK) | \
- (((_max_x) << 16) & \
- B_AX_ ## _module ## _MAX_SIZE_MASK); \
+ val = u32_encode_bits(_min_x, B_AX_ ## _module ## _MIN_SIZE_MASK) | \
+ u32_encode_bits(_max_x, B_AX_ ## _module ## _MAX_SIZE_MASK); \
rtw89_write32(rtwdev, \
R_AX_ ## _module ## _QTA ## _idx ## _CFG, \
val); \
--
2.35.1