[PATCH v3 1/7] wifi: orinoco: Avoid clashing function prototypes

From: Gustavo A. R. Silva
Date: Tue Nov 08 2022 - 15:21:52 EST


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 43 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),
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

The orinoco 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. No significant binary differences were seen
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>
---
Changes in v3:
- Split patch out of cfg80211.
- Remove iw_handler casts from orinoco_private_handler[].
- Update changelog text.

Changes in v2:
- Use IW_HANDLER in cfg80211_handlers instead of open-coded
[IW_IOCTL_IDX(SIOCGIWRETRY)] = cfg80211_wext_giwretry, ...
- This patch was merged into cfg80211.
- Link: https://lore.kernel.org/linux-hardening/c8239f5813dec6e5cfb554ca92b1783a18ac5537.1666894751.git.gustavoars@xxxxxxxxxx/

v1:
- Link: https://lore.kernel.org/linux-hardening/2387e02ae7f31388f24041cae8d02d5e12151708.1666038048.git.gustavoars@xxxxxxxxxx/

drivers/net/wireless/intersil/orinoco/wext.c | 109 +++++++++++--------
1 file changed, 62 insertions(+), 47 deletions(-)

diff --git a/drivers/net/wireless/intersil/orinoco/wext.c b/drivers/net/wireless/intersil/orinoco/wext.c
index 4a01260027bc..b8eb5d60192f 100644
--- a/drivers/net/wireless/intersil/orinoco/wext.c
+++ b/drivers/net/wireless/intersil/orinoco/wext.c
@@ -154,9 +154,10 @@ static struct iw_statistics *orinoco_get_wireless_stats(struct net_device *dev)

static int orinoco_ioctl_setwap(struct net_device *dev,
struct iw_request_info *info,
- struct sockaddr *ap_addr,
+ union iwreq_data *wrqu,
char *extra)
{
+ struct sockaddr *ap_addr = &wrqu->ap_addr;
struct orinoco_private *priv = ndev_priv(dev);
int err = -EINPROGRESS; /* Call commit handler */
unsigned long flags;
@@ -213,9 +214,10 @@ static int orinoco_ioctl_setwap(struct net_device *dev,

static int orinoco_ioctl_getwap(struct net_device *dev,
struct iw_request_info *info,
- struct sockaddr *ap_addr,
+ union iwreq_data *wrqu,
char *extra)
{
+ struct sockaddr *ap_addr = &wrqu->ap_addr;
struct orinoco_private *priv = ndev_priv(dev);

int err = 0;
@@ -234,9 +236,10 @@ static int orinoco_ioctl_getwap(struct net_device *dev,

static int orinoco_ioctl_setiwencode(struct net_device *dev,
struct iw_request_info *info,
- struct iw_point *erq,
+ union iwreq_data *wrqu,
char *keybuf)
{
+ struct iw_point *erq = &wrqu->encoding;
struct orinoco_private *priv = ndev_priv(dev);
int index = (erq->flags & IW_ENCODE_INDEX) - 1;
int setindex = priv->tx_key;
@@ -325,9 +328,10 @@ static int orinoco_ioctl_setiwencode(struct net_device *dev,

static int orinoco_ioctl_getiwencode(struct net_device *dev,
struct iw_request_info *info,
- struct iw_point *erq,
+ union iwreq_data *wrqu,
char *keybuf)
{
+ struct iw_point *erq = &wrqu->encoding;
struct orinoco_private *priv = ndev_priv(dev);
int index = (erq->flags & IW_ENCODE_INDEX) - 1;
unsigned long flags;
@@ -361,9 +365,10 @@ static int orinoco_ioctl_getiwencode(struct net_device *dev,

static int orinoco_ioctl_setessid(struct net_device *dev,
struct iw_request_info *info,
- struct iw_point *erq,
+ union iwreq_data *wrqu,
char *essidbuf)
{
+ struct iw_point *erq = &wrqu->essid;
struct orinoco_private *priv = ndev_priv(dev);
unsigned long flags;

@@ -392,9 +397,10 @@ static int orinoco_ioctl_setessid(struct net_device *dev,

static int orinoco_ioctl_getessid(struct net_device *dev,
struct iw_request_info *info,
- struct iw_point *erq,
+ union iwreq_data *wrqu,
char *essidbuf)
{
+ struct iw_point *erq = &wrqu->essid;
struct orinoco_private *priv = ndev_priv(dev);
int active;
int err = 0;
@@ -420,9 +426,10 @@ static int orinoco_ioctl_getessid(struct net_device *dev,

static int orinoco_ioctl_setfreq(struct net_device *dev,
struct iw_request_info *info,
- struct iw_freq *frq,
+ union iwreq_data *wrqu,
char *extra)
{
+ struct iw_freq *frq = &wrqu->freq;
struct orinoco_private *priv = ndev_priv(dev);
int chan = -1;
unsigned long flags;
@@ -469,9 +476,10 @@ static int orinoco_ioctl_setfreq(struct net_device *dev,

static int orinoco_ioctl_getfreq(struct net_device *dev,
struct iw_request_info *info,
- struct iw_freq *frq,
+ union iwreq_data *wrqu,
char *extra)
{
+ struct iw_freq *frq = &wrqu->freq;
struct orinoco_private *priv = ndev_priv(dev);
int tmp;

@@ -488,9 +496,10 @@ static int orinoco_ioctl_getfreq(struct net_device *dev,

static int orinoco_ioctl_getsens(struct net_device *dev,
struct iw_request_info *info,
- struct iw_param *srq,
+ union iwreq_data *wrqu,
char *extra)
{
+ struct iw_param *srq = &wrqu->sens;
struct orinoco_private *priv = ndev_priv(dev);
struct hermes *hw = &priv->hw;
u16 val;
@@ -517,9 +526,10 @@ static int orinoco_ioctl_getsens(struct net_device *dev,

static int orinoco_ioctl_setsens(struct net_device *dev,
struct iw_request_info *info,
- struct iw_param *srq,
+ union iwreq_data *wrqu,
char *extra)
{
+ struct iw_param *srq = &wrqu->sens;
struct orinoco_private *priv = ndev_priv(dev);
int val = srq->value;
unsigned long flags;
@@ -540,9 +550,10 @@ static int orinoco_ioctl_setsens(struct net_device *dev,

static int orinoco_ioctl_setrate(struct net_device *dev,
struct iw_request_info *info,
- struct iw_param *rrq,
+ union iwreq_data *wrqu,
char *extra)
{
+ struct iw_param *rrq = &wrqu->bitrate;
struct orinoco_private *priv = ndev_priv(dev);
int ratemode;
int bitrate; /* 100s of kilobits */
@@ -574,9 +585,10 @@ static int orinoco_ioctl_setrate(struct net_device *dev,

static int orinoco_ioctl_getrate(struct net_device *dev,
struct iw_request_info *info,
- struct iw_param *rrq,
+ union iwreq_data *wrqu,
char *extra)
{
+ struct iw_param *rrq = &wrqu->bitrate;
struct orinoco_private *priv = ndev_priv(dev);
int err = 0;
int bitrate, automatic;
@@ -610,9 +622,10 @@ static int orinoco_ioctl_getrate(struct net_device *dev,

static int orinoco_ioctl_setpower(struct net_device *dev,
struct iw_request_info *info,
- struct iw_param *prq,
+ union iwreq_data *wrqu,
char *extra)
{
+ struct iw_param *prq = &wrqu->power;
struct orinoco_private *priv = ndev_priv(dev);
int err = -EINPROGRESS; /* Call commit handler */
unsigned long flags;
@@ -664,9 +677,10 @@ static int orinoco_ioctl_setpower(struct net_device *dev,

static int orinoco_ioctl_getpower(struct net_device *dev,
struct iw_request_info *info,
- struct iw_param *prq,
+ union iwreq_data *wrqu,
char *extra)
{
+ struct iw_param *prq = &wrqu->power;
struct orinoco_private *priv = ndev_priv(dev);
struct hermes *hw = &priv->hw;
int err = 0;
@@ -1097,7 +1111,7 @@ static int orinoco_ioctl_set_mlme(struct net_device *dev,

static int orinoco_ioctl_reset(struct net_device *dev,
struct iw_request_info *info,
- void *wrqu,
+ union iwreq_data *wrqu,
char *extra)
{
struct orinoco_private *priv = ndev_priv(dev);
@@ -1121,7 +1135,7 @@ static int orinoco_ioctl_reset(struct net_device *dev,

static int orinoco_ioctl_setibssport(struct net_device *dev,
struct iw_request_info *info,
- void *wrqu,
+ union iwreq_data *wrqu,
char *extra)

{
@@ -1143,7 +1157,7 @@ static int orinoco_ioctl_setibssport(struct net_device *dev,

static int orinoco_ioctl_getibssport(struct net_device *dev,
struct iw_request_info *info,
- void *wrqu,
+ union iwreq_data *wrqu,
char *extra)
{
struct orinoco_private *priv = ndev_priv(dev);
@@ -1155,7 +1169,7 @@ static int orinoco_ioctl_getibssport(struct net_device *dev,

static int orinoco_ioctl_setport3(struct net_device *dev,
struct iw_request_info *info,
- void *wrqu,
+ union iwreq_data *wrqu,
char *extra)
{
struct orinoco_private *priv = ndev_priv(dev);
@@ -1201,7 +1215,7 @@ static int orinoco_ioctl_setport3(struct net_device *dev,

static int orinoco_ioctl_getport3(struct net_device *dev,
struct iw_request_info *info,
- void *wrqu,
+ union iwreq_data *wrqu,
char *extra)
{
struct orinoco_private *priv = ndev_priv(dev);
@@ -1213,7 +1227,7 @@ static int orinoco_ioctl_getport3(struct net_device *dev,

static int orinoco_ioctl_setpreamble(struct net_device *dev,
struct iw_request_info *info,
- void *wrqu,
+ union iwreq_data *wrqu,
char *extra)
{
struct orinoco_private *priv = ndev_priv(dev);
@@ -1245,7 +1259,7 @@ static int orinoco_ioctl_setpreamble(struct net_device *dev,

static int orinoco_ioctl_getpreamble(struct net_device *dev,
struct iw_request_info *info,
- void *wrqu,
+ union iwreq_data *wrqu,
char *extra)
{
struct orinoco_private *priv = ndev_priv(dev);
@@ -1265,9 +1279,10 @@ static int orinoco_ioctl_getpreamble(struct net_device *dev,
* For Wireless Tools 25 and 26 append "dummy" are the end. */
static int orinoco_ioctl_getrid(struct net_device *dev,
struct iw_request_info *info,
- struct iw_point *data,
+ union iwreq_data *wrqu,
char *extra)
{
+ struct iw_point *data = &wrqu->data;
struct orinoco_private *priv = ndev_priv(dev);
struct hermes *hw = &priv->hw;
int rid = data->flags;
@@ -1303,7 +1318,7 @@ static int orinoco_ioctl_getrid(struct net_device *dev,
/* Commit handler, called after set operations */
static int orinoco_ioctl_commit(struct net_device *dev,
struct iw_request_info *info,
- void *wrqu,
+ union iwreq_data *wrqu,
char *extra)
{
struct orinoco_private *priv = ndev_priv(dev);
@@ -1347,36 +1362,36 @@ static const struct iw_priv_args orinoco_privtab[] = {
*/

static const iw_handler orinoco_handler[] = {
- IW_HANDLER(SIOCSIWCOMMIT, (iw_handler)orinoco_ioctl_commit),
+ IW_HANDLER(SIOCSIWCOMMIT, orinoco_ioctl_commit),
IW_HANDLER(SIOCGIWNAME, (iw_handler)cfg80211_wext_giwname),
- IW_HANDLER(SIOCSIWFREQ, (iw_handler)orinoco_ioctl_setfreq),
- IW_HANDLER(SIOCGIWFREQ, (iw_handler)orinoco_ioctl_getfreq),
+ IW_HANDLER(SIOCSIWFREQ, orinoco_ioctl_setfreq),
+ IW_HANDLER(SIOCGIWFREQ, orinoco_ioctl_getfreq),
IW_HANDLER(SIOCSIWMODE, (iw_handler)cfg80211_wext_siwmode),
IW_HANDLER(SIOCGIWMODE, (iw_handler)cfg80211_wext_giwmode),
- IW_HANDLER(SIOCSIWSENS, (iw_handler)orinoco_ioctl_setsens),
- IW_HANDLER(SIOCGIWSENS, (iw_handler)orinoco_ioctl_getsens),
+ IW_HANDLER(SIOCSIWSENS, orinoco_ioctl_setsens),
+ IW_HANDLER(SIOCGIWSENS, orinoco_ioctl_getsens),
IW_HANDLER(SIOCGIWRANGE, (iw_handler)cfg80211_wext_giwrange),
IW_HANDLER(SIOCSIWSPY, iw_handler_set_spy),
IW_HANDLER(SIOCGIWSPY, iw_handler_get_spy),
IW_HANDLER(SIOCSIWTHRSPY, iw_handler_set_thrspy),
IW_HANDLER(SIOCGIWTHRSPY, iw_handler_get_thrspy),
- IW_HANDLER(SIOCSIWAP, (iw_handler)orinoco_ioctl_setwap),
- IW_HANDLER(SIOCGIWAP, (iw_handler)orinoco_ioctl_getwap),
+ IW_HANDLER(SIOCSIWAP, orinoco_ioctl_setwap),
+ IW_HANDLER(SIOCGIWAP, orinoco_ioctl_getwap),
IW_HANDLER(SIOCSIWSCAN, (iw_handler)cfg80211_wext_siwscan),
IW_HANDLER(SIOCGIWSCAN, (iw_handler)cfg80211_wext_giwscan),
- IW_HANDLER(SIOCSIWESSID, (iw_handler)orinoco_ioctl_setessid),
- IW_HANDLER(SIOCGIWESSID, (iw_handler)orinoco_ioctl_getessid),
- IW_HANDLER(SIOCSIWRATE, (iw_handler)orinoco_ioctl_setrate),
- IW_HANDLER(SIOCGIWRATE, (iw_handler)orinoco_ioctl_getrate),
+ IW_HANDLER(SIOCSIWESSID, orinoco_ioctl_setessid),
+ IW_HANDLER(SIOCGIWESSID, orinoco_ioctl_getessid),
+ IW_HANDLER(SIOCSIWRATE, orinoco_ioctl_setrate),
+ IW_HANDLER(SIOCGIWRATE, orinoco_ioctl_getrate),
IW_HANDLER(SIOCSIWRTS, (iw_handler)cfg80211_wext_siwrts),
IW_HANDLER(SIOCGIWRTS, (iw_handler)cfg80211_wext_giwrts),
IW_HANDLER(SIOCSIWFRAG, (iw_handler)cfg80211_wext_siwfrag),
IW_HANDLER(SIOCGIWFRAG, (iw_handler)cfg80211_wext_giwfrag),
IW_HANDLER(SIOCGIWRETRY, (iw_handler)cfg80211_wext_giwretry),
- IW_HANDLER(SIOCSIWENCODE, (iw_handler)orinoco_ioctl_setiwencode),
- IW_HANDLER(SIOCGIWENCODE, (iw_handler)orinoco_ioctl_getiwencode),
- IW_HANDLER(SIOCSIWPOWER, (iw_handler)orinoco_ioctl_setpower),
- IW_HANDLER(SIOCGIWPOWER, (iw_handler)orinoco_ioctl_getpower),
+ IW_HANDLER(SIOCSIWENCODE, orinoco_ioctl_setiwencode),
+ IW_HANDLER(SIOCGIWENCODE, orinoco_ioctl_getiwencode),
+ IW_HANDLER(SIOCSIWPOWER, orinoco_ioctl_setpower),
+ IW_HANDLER(SIOCGIWPOWER, orinoco_ioctl_getpower),
IW_HANDLER(SIOCSIWGENIE, orinoco_ioctl_set_genie),
IW_HANDLER(SIOCGIWGENIE, orinoco_ioctl_get_genie),
IW_HANDLER(SIOCSIWMLME, orinoco_ioctl_set_mlme),
@@ -1391,15 +1406,15 @@ static const iw_handler orinoco_handler[] = {
Added typecasting since we no longer use iwreq_data -- Moustafa
*/
static const iw_handler orinoco_private_handler[] = {
- [0] = (iw_handler)orinoco_ioctl_reset,
- [1] = (iw_handler)orinoco_ioctl_reset,
- [2] = (iw_handler)orinoco_ioctl_setport3,
- [3] = (iw_handler)orinoco_ioctl_getport3,
- [4] = (iw_handler)orinoco_ioctl_setpreamble,
- [5] = (iw_handler)orinoco_ioctl_getpreamble,
- [6] = (iw_handler)orinoco_ioctl_setibssport,
- [7] = (iw_handler)orinoco_ioctl_getibssport,
- [9] = (iw_handler)orinoco_ioctl_getrid,
+ [0] = orinoco_ioctl_reset,
+ [1] = orinoco_ioctl_reset,
+ [2] = orinoco_ioctl_setport3,
+ [3] = orinoco_ioctl_getport3,
+ [4] = orinoco_ioctl_setpreamble,
+ [5] = orinoco_ioctl_getpreamble,
+ [6] = orinoco_ioctl_setibssport,
+ [7] = orinoco_ioctl_getibssport,
+ [9] = orinoco_ioctl_getrid,
};

const struct iw_handler_def orinoco_handler_def = {
--
2.34.1