On Tue, Nov 08, 2022 at 02:23:55PM -0600, Gustavo A. R. Silva wrote: > When built with Control Flow Integrity, function prototypes between > caller and function declaration must match. These mismatches are visible > at compile time with the new -Wcast-function-type-strict in Clang[1]. > > Fix a total of 73 warnings like these: > > drivers/net/wireless/intersil/orinoco/wext.c:1379:27: warning: cast from 'int (*)(struct net_device *, struct iw_request_info *, struct iw_param *, char *)' to 'iw_handler' (aka 'int (*)(struct net_device *, struct iw_request_info *, union iwreq_data *, char *)') converts to incompatible function type [-Wcast-function-type-strict] > IW_HANDLER(SIOCGIWPOWER, (iw_handler)orinoco_ioctl_getpower), > ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > > ../net/wireless/wext-compat.c:1607:33: warning: cast from 'int (*)(struct net_device *, struct iw_request_info *, struct iw_point *, char *)' to 'iw_handler' (aka 'int (*)(struct net_device *, struct iw_request_info *, union iwreq_data *, char *)') converts to incompatible function type [-Wcast-function-type-strict] > [IW_IOCTL_IDX(SIOCSIWGENIE)] = (iw_handler) cfg80211_wext_siwgenie, > ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > > ../drivers/net/wireless/intersil/orinoco/wext.c:1390:27: error: incompatible function pointer types initializing 'const iw_handler' (aka 'int (*const)(struct net_device *, struct iw_request_info *, union iwreq_data *, char *)') with an expression of type 'int (struct net_device *, struct iw_request_info *, struct iw_param *, char *)' [-Wincompatible-function-pointer-types] > IW_HANDLER(SIOCGIWRETRY, cfg80211_wext_giwretry), > ^~~~~~~~~~~~~~~~~~~~~~ > > The cfg80211 Wireless Extension handler callbacks (iw_handler) use a > union for the data argument. Actually use the union and perform explicit > member selection in the function body instead of having a function > prototype mismatch. There are no resulting binary differences > before/after changes. > > These changes were made partly manually and partly with the help of > Coccinelle. > > Link: https://github.com/KSPP/linux/issues/234 > Link: https://reviews.llvm.org/D134831 [1] > Signed-off-by: Gustavo A. R. Silva <gustavoars@xxxxxxxxxx> Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx> -- Kees Cook
