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.ga17...@light.dominikbrodowski.net Cc: David S. Miller <da...@davemloft.net> Cc: netdev@vger.kernel.org Signed-off-by: Dominik Brodowski <li...@dominikbrodowski.net> --- net/compat.c | 23 ++++++++++++++++------- 1 file changed, 16 insertions(+), 7 deletions(-) diff --git a/net/compat.c b/net/compat.c index 9e0d030063ad..513adc8d0e0f 100644 --- a/net/compat.c +++ b/net/compat.c @@ -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); -- 2.16.3