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

Using the net-internal helper __sys_shutdown() allows us to avoid the
internal calls to the sys_shutdown() 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 20:07:05 +01:00
parent 6debc8d834
commit 005a1aeac4
3 changed files with 9 additions and 3 deletions

View File

@ -374,5 +374,6 @@ extern int __sys_getpeername(int fd, struct sockaddr __user *usockaddr,
int __user *usockaddr_len);
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

@ -849,7 +849,7 @@ COMPAT_SYSCALL_DEFINE2(socketcall, int, call, u32 __user *, args)
compat_ptr(a[4]), compat_ptr(a[5]));
break;
case SYS_SHUTDOWN:
ret = sys_shutdown(a0, a1);
ret = __sys_shutdown(a0, a1);
break;
case SYS_SETSOCKOPT:
ret = compat_sys_setsockopt(a0, a1, a[2],

View File

@ -1942,7 +1942,7 @@ SYSCALL_DEFINE5(getsockopt, int, fd, int, level, int, optname,
* Shutdown a socket.
*/
SYSCALL_DEFINE2(shutdown, int, fd, int, how)
int __sys_shutdown(int fd, int how)
{
int err, fput_needed;
struct socket *sock;
@ -1957,6 +1957,11 @@ SYSCALL_DEFINE2(shutdown, int, fd, int, how)
return err;
}
SYSCALL_DEFINE2(shutdown, int, fd, int, how)
{
return __sys_shutdown(fd, how);
}
/* A couple of helpful macros for getting the address of the 32/64 bit
* fields which are the same type (int / unsigned) on our platforms.
*/
@ -2544,7 +2549,7 @@ SYSCALL_DEFINE2(socketcall, int, call, unsigned long __user *, args)
(int __user *)a[5]);
break;
case SYS_SHUTDOWN:
err = sys_shutdown(a0, a1);
err = __sys_shutdown(a0, a1);
break;
case SYS_SETSOCKOPT:
err = sys_setsockopt(a0, a1, a[2], (char __user *)a[3], a[4]);