net: socket: add __sys_accept4() helper; remove in-kernel call to syscall

Using the net-internal helper __sys_accept4() allows us to avoid the
internal calls to the sys_accept4() 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 19:24:23 +01:00
parent 211b634b7f
commit 4541e80560
3 changed files with 17 additions and 9 deletions

View File

@ -361,5 +361,7 @@ extern int __sys_recvfrom(int fd, void __user *ubuf, size_t size,
extern int __sys_sendto(int fd, void __user *buff, size_t len,
unsigned int flags, struct sockaddr __user *addr,
int addr_len);
extern int __sys_accept4(int fd, struct sockaddr __user *upeer_sockaddr,
int __user *upeer_addrlen, int flags);
#endif /* _LINUX_SOCKET_H */

View File

@ -823,7 +823,7 @@ COMPAT_SYSCALL_DEFINE2(socketcall, int, call, u32 __user *, args)
ret = sys_listen(a0, a1);
break;
case SYS_ACCEPT:
ret = sys_accept4(a0, compat_ptr(a1), compat_ptr(a[2]), 0);
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]));
@ -873,7 +873,7 @@ COMPAT_SYSCALL_DEFINE2(socketcall, int, call, u32 __user *, args)
compat_ptr(a[4]));
break;
case SYS_ACCEPT4:
ret = sys_accept4(a0, compat_ptr(a1), compat_ptr(a[2]), a[3]);
ret = __sys_accept4(a0, compat_ptr(a1), compat_ptr(a[2]), a[3]);
break;
default:
ret = -EINVAL;

View File

@ -1519,8 +1519,8 @@ SYSCALL_DEFINE2(listen, int, fd, int, backlog)
* clean when we restucture accept also.
*/
SYSCALL_DEFINE4(accept4, int, fd, struct sockaddr __user *, upeer_sockaddr,
int __user *, upeer_addrlen, int, flags)
int __sys_accept4(int fd, struct sockaddr __user *upeer_sockaddr,
int __user *upeer_addrlen, int flags)
{
struct socket *sock, *newsock;
struct file *newfile;
@ -1599,10 +1599,16 @@ out_fd:
goto out_put;
}
SYSCALL_DEFINE4(accept4, int, fd, struct sockaddr __user *, upeer_sockaddr,
int __user *, upeer_addrlen, int, flags)
{
return __sys_accept4(fd, upeer_sockaddr, upeer_addrlen, flags);
}
SYSCALL_DEFINE3(accept, int, fd, struct sockaddr __user *, upeer_sockaddr,
int __user *, upeer_addrlen)
{
return sys_accept4(fd, upeer_sockaddr, upeer_addrlen, 0);
return __sys_accept4(fd, upeer_sockaddr, upeer_addrlen, 0);
}
/*
@ -2469,7 +2475,7 @@ SYSCALL_DEFINE2(socketcall, int, call, unsigned long __user *, args)
err = sys_listen(a0, a1);
break;
case SYS_ACCEPT:
err = sys_accept4(a0, (struct sockaddr __user *)a1,
err = __sys_accept4(a0, (struct sockaddr __user *)a1,
(int __user *)a[2], 0);
break;
case SYS_GETSOCKNAME:
@ -2525,7 +2531,7 @@ SYSCALL_DEFINE2(socketcall, int, call, unsigned long __user *, args)
(struct timespec __user *)a[4]);
break;
case SYS_ACCEPT4:
err = sys_accept4(a0, (struct sockaddr __user *)a1,
err = __sys_accept4(a0, (struct sockaddr __user *)a1,
(int __user *)a[2], a[3]);
break;
default: