xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

net: separate SIOCGIFCONF handling from dev_ioctl()

Browse Source 
Only two of dev_ioctl() callers may pass SIOCGIFCONF to it.
Separating that codepath from the rest of dev_ioctl() allows both
to simplify dev_ioctl() itself (all other cases work with struct ifreq *)
*and* seriously simplify the compat side of that beast: all it takes
is passing to inet_gifconf() an extra argument - the size of individual
records (sizeof(struct ifreq) or sizeof(struct compat_ifreq)).  With
dev_ifconf() called directly from sock_do_ioctl()/compat_dev_ifconf()
that's easy to arrange.

As the result, compat side of SIOCGIFCONF doesn't need any
allocations, copy_in_user() back and forth, etc.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro
2017-06-26 13:19:16 -04:00
parent be1b6e8b54
commit 36fd633ec9
4 changed files with 42 additions and 86 deletions
Download Patch File Download Diff File Expand all files Collapse all files

4
include/linux/netdevice.h
View File

@@ -2761,7 +2761,8 @@ static inline bool dev_validate_header(const struct net_device *dev,
return false;
}
typedef int gifconf_func_t(struct net_device * dev, char __user * bufptr, int len);
typedef int gifconf_func_t(struct net_device * dev, char __user * bufptr,
int len, int size);
int register_gifconf(unsigned int family, gifconf_func_t *gifconf);
static inline int unregister_gifconf(unsigned int family)
{
@@ -3315,6 +3316,7 @@ void netdev_rx_handler_unregister(struct net_device *dev);
bool dev_valid_name(const char *name);
int dev_ioctl(struct net *net, unsigned int cmd, void __user *);
int dev_ifconf(struct net *net, struct ifconf *, int);
int dev_ethtool(struct net *net, struct ifreq *);
unsigned int dev_get_flags(const struct net_device *);
int __dev_change_flags(struct net_device *, unsigned int flags);