Commit 157b334a authored by Dominik Brodowski's avatar Dominik Brodowski
Browse files

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

Using the net-internal helper __compat_sys_recvmmsg() allows us to avoid
the internal calls to the compat_sys_recvmmsg() 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: default avatarDominik Brodowski <linux@dominikbrodowski.net>
parent 8770cf4a

net/compat.c

+12 −5
Original line number Diff line number Diff line
@@ -787,9 +787,9 @@ COMPAT_SYSCALL_DEFINE6(recvfrom, int, fd, void __user *, buf, compat_size_t, len 
	return __compat_sys_recvfrom(fd, buf, len, flags, addr, addrlen);

}



COMPAT_SYSCALL_DEFINE5(recvmmsg, int, fd, struct compat_mmsghdr __user *, mmsg,

		       unsigned int, vlen, unsigned int, flags,

		       struct compat_timespec __user *, timeout)

static int __compat_sys_recvmmsg(int fd, struct compat_mmsghdr __user *mmsg,

				 unsigned int vlen, unsigned int flags,

				 struct compat_timespec __user *timeout)

{

	int datagrams;

	struct timespec ktspec;
@@ -809,6 +809,13 @@ COMPAT_SYSCALL_DEFINE5(recvmmsg, int, fd, struct compat_mmsghdr __user *, mmsg, 
	return datagrams;

}



COMPAT_SYSCALL_DEFINE5(recvmmsg, int, fd, struct compat_mmsghdr __user *, mmsg,

		       unsigned int, vlen, unsigned int, flags,

		       struct compat_timespec __user *, timeout)

{

	return __compat_sys_recvmmsg(fd, mmsg, vlen, flags, timeout);

}



COMPAT_SYSCALL_DEFINE2(socketcall, int, call, u32 __user *, args)

{

	u32 a[AUDITSC_ARGS];
@@ -895,7 +902,7 @@ COMPAT_SYSCALL_DEFINE2(socketcall, int, call, u32 __user *, args) 
		ret = compat_sys_recvmsg(a0, compat_ptr(a1), a[2]);

		break;

	case SYS_RECVMMSG:

		ret = compat_sys_recvmmsg(a0, compat_ptr(a1), a[2], a[3],

		ret = __compat_sys_recvmmsg(a0, compat_ptr(a1), a[2], a[3],

					    compat_ptr(a[4]));

		break;

	case SYS_ACCEPT4: