linux/net/wireless/wext-compat.h
Gustavo A. R. Silva 02ae6a7034 wifi: cfg80211: Avoid clashing function prototypes
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@kernel.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/a68822bf8dd587988131bb6a295280cb4293f05d.1667934775.git.gustavoars@kernel.org
2022-11-16 11:31:47 +02:00

65 lines
2.3 KiB
C

/* SPDX-License-Identifier: GPL-2.0-only */
#ifndef __WEXT_COMPAT
#define __WEXT_COMPAT
#include <net/iw_handler.h>
#include <linux/wireless.h>
#ifdef CONFIG_CFG80211_WEXT_EXPORT
#define EXPORT_WEXT_HANDLER(h) EXPORT_SYMBOL_GPL(h)
#else
#define EXPORT_WEXT_HANDLER(h)
#endif /* CONFIG_CFG80211_WEXT_EXPORT */
int cfg80211_ibss_wext_siwfreq(struct net_device *dev,
struct iw_request_info *info,
struct iw_freq *wextfreq, char *extra);
int cfg80211_ibss_wext_giwfreq(struct net_device *dev,
struct iw_request_info *info,
struct iw_freq *freq, char *extra);
int cfg80211_ibss_wext_siwap(struct net_device *dev,
struct iw_request_info *info,
struct sockaddr *ap_addr, char *extra);
int cfg80211_ibss_wext_giwap(struct net_device *dev,
struct iw_request_info *info,
struct sockaddr *ap_addr, char *extra);
int cfg80211_ibss_wext_siwessid(struct net_device *dev,
struct iw_request_info *info,
struct iw_point *data, char *ssid);
int cfg80211_ibss_wext_giwessid(struct net_device *dev,
struct iw_request_info *info,
struct iw_point *data, char *ssid);
int cfg80211_mgd_wext_siwfreq(struct net_device *dev,
struct iw_request_info *info,
struct iw_freq *wextfreq, char *extra);
int cfg80211_mgd_wext_giwfreq(struct net_device *dev,
struct iw_request_info *info,
struct iw_freq *freq, char *extra);
int cfg80211_mgd_wext_siwap(struct net_device *dev,
struct iw_request_info *info,
struct sockaddr *ap_addr, char *extra);
int cfg80211_mgd_wext_giwap(struct net_device *dev,
struct iw_request_info *info,
struct sockaddr *ap_addr, char *extra);
int cfg80211_mgd_wext_siwessid(struct net_device *dev,
struct iw_request_info *info,
struct iw_point *data, char *ssid);
int cfg80211_mgd_wext_giwessid(struct net_device *dev,
struct iw_request_info *info,
struct iw_point *data, char *ssid);
int cfg80211_wext_siwmlme(struct net_device *dev,
struct iw_request_info *info,
union iwreq_data *wrqu, char *extra);
int cfg80211_wext_siwgenie(struct net_device *dev,
struct iw_request_info *info,
union iwreq_data *wrqu, char *extra);
int cfg80211_wext_freq(struct iw_freq *freq);
extern const struct iw_handler_def cfg80211_wext_handler;
#endif /* __WEXT_COMPAT */