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

Using the net-internal helper __compat_sys_recvfrom() allows us to avoid
the internal calls to the compat_sys_recvfrom() 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 2018-03-16 16:48:34 +01:00
parent d27e9afc64
commit fd4e82f5b8

View File

@ -753,18 +753,25 @@ COMPAT_SYSCALL_DEFINE3(recvmsg, int, fd, struct compat_msghdr __user *, msg, uns
flags | MSG_CMSG_COMPAT, false);
}
static inline long __compat_sys_recvfrom(int fd, void __user *buf,
compat_size_t len, unsigned int flags,
struct sockaddr __user *addr,
int __user *addrlen)
{
return __sys_recvfrom(fd, buf, len, flags | MSG_CMSG_COMPAT, addr,
addrlen);
}
COMPAT_SYSCALL_DEFINE4(recv, int, fd, void __user *, buf, compat_size_t, len, unsigned int, flags)
{
return __sys_recvfrom(fd, buf, len, flags | MSG_CMSG_COMPAT, NULL,
NULL);
return __compat_sys_recvfrom(fd, buf, len, flags, NULL, NULL);
}
COMPAT_SYSCALL_DEFINE6(recvfrom, int, fd, void __user *, buf, compat_size_t, len,
unsigned int, flags, struct sockaddr __user *, addr,
int __user *, addrlen)
{
return __sys_recvfrom(fd, buf, len, flags | MSG_CMSG_COMPAT, addr,
addrlen);
return __compat_sys_recvfrom(fd, buf, len, flags, addr, addrlen);
}
COMPAT_SYSCALL_DEFINE5(recvmmsg, int, fd, struct compat_mmsghdr __user *, mmsg,
@ -845,11 +852,13 @@ COMPAT_SYSCALL_DEFINE2(socketcall, int, call, u32 __user *, args)
compat_ptr(a[4]), a[5]);
break;
case SYS_RECV:
ret = compat_sys_recv(a0, compat_ptr(a1), a[2], a[3]);
ret = __compat_sys_recvfrom(a0, compat_ptr(a1), a[2], a[3],
NULL, NULL);
break;
case SYS_RECVFROM:
ret = compat_sys_recvfrom(a0, compat_ptr(a1), a[2], a[3],
compat_ptr(a[4]), compat_ptr(a[5]));
ret = __compat_sys_recvfrom(a0, compat_ptr(a1), a[2], a[3],
compat_ptr(a[4]),
compat_ptr(a[5]));
break;
case SYS_SHUTDOWN:
ret = __sys_shutdown(a0, a1);