[PATCH -next 08/22] net: socket: add __sys_getsockname() helper; remove in-kernel call to syscall

From: Dominik Brodowski
Date: Fri Mar 16 2018 - 13:10:51 EST


Using the net-internal helper __sys_getsockname() allows us to avoid the
internal calls to the sys_getsockname() syscall.

Cc: David S. Miller <davem@xxxxxxxxxxxxx>
Cc: netdev@xxxxxxxxxxxxxxx
Signed-off-by: Dominik Brodowski <linux@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/socket.h | 2 ++
net/compat.c | 2 +-
net/socket.c | 14 ++++++++++----
3 files changed, 13 insertions(+), 5 deletions(-)

diff --git a/include/linux/socket.h b/include/linux/socket.h
index 7e37af25509d..ef0226a61b03 100644
--- a/include/linux/socket.h
+++ b/include/linux/socket.h
@@ -368,5 +368,7 @@ extern int __sys_bind(int fd, struct sockaddr __user *umyaddr, int addrlen);
extern int __sys_connect(int fd, struct sockaddr __user *uservaddr,
int addrlen);
extern int __sys_listen(int fd, int backlog);
+extern int __sys_getsockname(int fd, struct sockaddr __user *usockaddr,
+ int __user *usockaddr_len);

#endif /* _LINUX_SOCKET_H */
diff --git a/net/compat.c b/net/compat.c
index c80cb973f383..efd28d02608c 100644
--- a/net/compat.c
+++ b/net/compat.c
@@ -826,7 +826,7 @@ COMPAT_SYSCALL_DEFINE2(socketcall, int, call, u32 __user *, args)
ret = __sys_accept4(a0, compat_ptr(a1), compat_ptr(a[2]), 0);
break;
case SYS_GETSOCKNAME:
- ret = sys_getsockname(a0, compat_ptr(a1), compat_ptr(a[2]));
+ ret = __sys_getsockname(a0, compat_ptr(a1), compat_ptr(a[2]));
break;
case SYS_GETPEERNAME:
ret = sys_getpeername(a0, compat_ptr(a1), compat_ptr(a[2]));
diff --git a/net/socket.c b/net/socket.c
index 67d9d70a4734..b61e0d20f37b 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -1675,8 +1675,8 @@ SYSCALL_DEFINE3(connect, int, fd, struct sockaddr __user *, uservaddr,
* name to user space.
*/

-SYSCALL_DEFINE3(getsockname, int, fd, struct sockaddr __user *, usockaddr,
- int __user *, usockaddr_len)
+int __sys_getsockname(int fd, struct sockaddr __user *usockaddr,
+ int __user *usockaddr_len)
{
struct socket *sock;
struct sockaddr_storage address;
@@ -1701,6 +1701,12 @@ SYSCALL_DEFINE3(getsockname, int, fd, struct sockaddr __user *, usockaddr,
return err;
}

+SYSCALL_DEFINE3(getsockname, int, fd, struct sockaddr __user *, usockaddr,
+ int __user *, usockaddr_len)
+{
+ return __sys_getsockname(fd, usockaddr, usockaddr_len);
+}
+
/*
* Get the remote address ('name') of a socket object. Move the obtained
* name to user space.
@@ -2500,8 +2506,8 @@ SYSCALL_DEFINE2(socketcall, int, call, unsigned long __user *, args)
break;
case SYS_GETSOCKNAME:
err =
- sys_getsockname(a0, (struct sockaddr __user *)a1,
- (int __user *)a[2]);
+ __sys_getsockname(a0, (struct sockaddr __user *)a1,
+ (int __user *)a[2]);
break;
case SYS_GETPEERNAME:
err =
--
2.16.2