This is a note to let you know that I've just added the patch titled wifi: rtlwifi: add calculate_bit_shift() to the 5.10-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: wifi-rtlwifi-add-calculate_bit_shift.patch and it can be found in the queue-5.10 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit fe77939f82f119749a4de8bb03f4c8cc255a60e3 Author: Su Hui <suhui@xxxxxxxxxxxx> Date: Tue Dec 19 14:57:29 2023 +0800 wifi: rtlwifi: add calculate_bit_shift() [ Upstream commit 52221dfddbbfb5b4e029bb2efe9bb7da33ec1e46 ] There are many same functions like _rtl88e_phy_calculate_bit_shift(), _rtl92c_phy_calculate_bit_shift() and so on. And these functions can cause undefined bitwise shift behavior. Add calculate_bit_shift() to replace them and fix undefined behavior in subsequent patches. Signed-off-by: Su Hui <suhui@xxxxxxxxxxxx> Acked-by: Ping-Ke Shih <pkshih@xxxxxxxxxxx> Signed-off-by: Kalle Valo <kvalo@xxxxxxxxxx> Link: https://msgid.link/20231219065739.1895666-2-suhui@xxxxxxxxxxxx Stable-dep-of: 969bc926f04b ("wifi: rtlwifi: rtl8188ee: phy: using calculate_bit_shift()") Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/net/wireless/realtek/rtlwifi/wifi.h b/drivers/net/wireless/realtek/rtlwifi/wifi.h index fdccfd29fd61..a89e232d6963 100644 --- a/drivers/net/wireless/realtek/rtlwifi/wifi.h +++ b/drivers/net/wireless/realtek/rtlwifi/wifi.h @@ -3111,4 +3111,11 @@ static inline struct ieee80211_sta *rtl_find_sta(struct ieee80211_hw *hw, return ieee80211_find_sta(mac->vif, mac_addr); } +static inline u32 calculate_bit_shift(u32 bitmask) +{ + if (WARN_ON_ONCE(!bitmask)) + return 0; + + return __ffs(bitmask); +} #endif