net: socket: add __sys_setsockopt() helper; remove in-kernel call to syscall

Using the net-internal helper __sys_setsockopt() allows us to avoid the
internal calls to the sys_setsockopt() syscall.

This patch is part of a series which removes in-kernel calls to syscalls.
On this basis, the syscall entry path can be streamlined. For details, see
http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net

Cc: David S. Miller <davem@davemloft.net>
Cc: netdev@vger.kernel.org
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
This commit is contained in:
Dominik Brodowski 2018-03-13 20:10:59 +01:00
parent 005a1aeac4
commit cc36dca0df
2 changed files with 11 additions and 3 deletions

View File

@ -376,4 +376,5 @@ extern int __sys_socketpair(int family, int type, int protocol,
int __user *usockvec);
extern int __sys_shutdown(int fd, int how);
#endif /* _LINUX_SOCKET_H */

View File

@ -1878,8 +1878,8 @@ SYSCALL_DEFINE4(recv, int, fd, void __user *, ubuf, size_t, size,
* to pass the user mode parameter for the protocols to sort out.
*/
SYSCALL_DEFINE5(setsockopt, int, fd, int, level, int, optname,
char __user *, optval, int, optlen)
static int __sys_setsockopt(int fd, int level, int optname,
char __user *optval, int optlen)
{
int err, fput_needed;
struct socket *sock;
@ -1907,6 +1907,12 @@ SYSCALL_DEFINE5(setsockopt, int, fd, int, level, int, optname,
return err;
}
SYSCALL_DEFINE5(setsockopt, int, fd, int, level, int, optname,
char __user *, optval, int, optlen)
{
return __sys_setsockopt(fd, level, optname, optval, optlen);
}
/*
* Get a socket option. Because we don't know the option lengths we have
* to pass a user mode parameter for the protocols to sort out.
@ -2552,7 +2558,8 @@ SYSCALL_DEFINE2(socketcall, int, call, unsigned long __user *, args)
err = __sys_shutdown(a0, a1);
break;
case SYS_SETSOCKOPT:
err = sys_setsockopt(a0, a1, a[2], (char __user *)a[3], a[4]);
err = __sys_setsockopt(a0, a1, a[2], (char __user *)a[3],
a[4]);
break;
case SYS_GETSOCKOPT:
err =