net: socket: add __sys_getsockopt() helper; remove in-kernel call to syscall
Using the net-internal helper __sys_getsockopt() allows us to avoid the
internal calls to the sys_getsockopt() 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>
diff --git a/net/socket.c b/net/socket.c
index 5dd2e39..a05289b 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -1918,8 +1918,8 @@ SYSCALL_DEFINE5(setsockopt, int, fd, int, level, int, optname,
* to pass a user mode parameter for the protocols to sort out.
*/
-SYSCALL_DEFINE5(getsockopt, int, fd, int, level, int, optname,
- char __user *, optval, int __user *, optlen)
+static int __sys_getsockopt(int fd, int level, int optname,
+ char __user *optval, int __user *optlen)
{
int err, fput_needed;
struct socket *sock;
@@ -1944,6 +1944,12 @@ SYSCALL_DEFINE5(getsockopt, int, fd, int, level, int, optname,
return err;
}
+SYSCALL_DEFINE5(getsockopt, int, fd, int, level, int, optname,
+ char __user *, optval, int __user *, optlen)
+{
+ return __sys_getsockopt(fd, level, optname, optval, optlen);
+}
+
/*
* Shutdown a socket.
*/
@@ -2563,8 +2569,8 @@ SYSCALL_DEFINE2(socketcall, int, call, unsigned long __user *, args)
break;
case SYS_GETSOCKOPT:
err =
- sys_getsockopt(a0, a1, a[2], (char __user *)a[3],
- (int __user *)a[4]);
+ __sys_getsockopt(a0, a1, a[2], (char __user *)a[3],
+ (int __user *)a[4]);
break;
case SYS_SENDMSG:
err = sys_sendmsg(a0, (struct user_msghdr __user *)a1, a[2]);
