Enabling pkg/tcpip/link support on arm64.

Signed-off-by: Haibo Xu haibo.xu@arm.com
Change-Id: Ib6b4aa2db19032e58bf0395f714e6883caee460a

pkg/tcpip/link/fdbased/BUILD

@@ -7,9 +7,9 @@ go_library(
     srcs = [
         "endpoint.go",
         "endpoint_unsafe.go",
-        "mmap_amd64.go",
-        "mmap_amd64_unsafe.go",
+        "mmap.go",
         "mmap_stub.go",
+        "mmap_unsafe.go",
         "packet_dispatchers.go",
     ],
     importpath = "gvisor.dev/gvisor/pkg/tcpip/link/fdbased",

pkg/tcpip/link/fdbased/mmap.go

@@ -12,7 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-// +build linux,amd64
+// +build linux,amd64 linux,arm64
 
 package fdbased
 

pkg/tcpip/link/fdbased/mmap_stub.go

@@ -12,11 +12,11 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-// +build !linux !amd64
+// +build !linux !amd64,!arm64
 
 package fdbased
 
-// Stubbed out version for non-linux/non-amd64 platforms.
+// Stubbed out version for non-linux/non-amd64/non-arm64 platforms.
 
 func newPacketMMapDispatcher(fd int, e *endpoint) (linkDispatcher, error) {
 	return nil, nil

pkg/tcpip/link/fdbased/mmap_unsafe.go

@@ -12,7 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-// +build linux,amd64
+// +build linux,amd64 linux,arm64
 
 package fdbased
 

pkg/tcpip/link/rawfile/BUILD

@@ -6,7 +6,8 @@ go_library(
     name = "rawfile",
     srcs = [
         "blockingpoll_amd64.s",
-        "blockingpoll_amd64_unsafe.go",
+        "blockingpoll_arm64.s",
+        "blockingpoll_unsafe.go",
         "blockingpoll_stub_unsafe.go",
         "errors.go",
         "rawfile_unsafe.go",

pkg/tcpip/link/rawfile/blockingpoll_arm64.s

@@ -0,0 +1,42 @@
+// Copyright 2019 The gVisor Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "textflag.h"
+
+// BlockingPoll makes the ppoll() syscall while calling the version of
+// entersyscall that relinquishes the P so that other Gs can run. This is meant
+// to be called in cases when the syscall is expected to block.
+//
+// func BlockingPoll(fds *PollEvent, nfds int, timeout *syscall.Timespec) (n int, err syscall.Errno)
+TEXT ·BlockingPoll(SB),NOSPLIT,$0-40
+	BL	·callEntersyscallblock(SB)
+	MOVD	fds+0(FP), R0
+	MOVD	nfds+8(FP), R1
+	MOVD	timeout+16(FP), R2
+	MOVD	$0x0, R3  // sigmask parameter which isn't used here
+	MOVD	$0x49, R8 // SYS_PPOLL
+	SVC
+	CMP	$0xfffffffffffff001, R0
+	BLS	ok
+	MOVD	$-1, R1
+	MOVD	R1, n+24(FP)
+	NEG	R0, R0
+	MOVD	R0, err+32(FP)
+	BL	·callExitsyscall(SB)
+	RET
+ok:
+	MOVD	R0, n+24(FP)
+	MOVD	$0, err+32(FP)
+	BL	·callExitsyscall(SB)
+	RET

pkg/tcpip/link/rawfile/blockingpoll_stub_unsafe.go

@@ -12,7 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-// +build linux,!amd64
+// +build linux,!amd64,!arm64
 
 package rawfile
 
@@ -22,7 +22,7 @@ import (
 )
 
 // BlockingPoll is just a stub function that forwards to the ppoll() system call
-// on non-amd64 platforms.
+// on non-amd64 and non-arm64 platforms.
 func BlockingPoll(fds *PollEvent, nfds int, timeout *syscall.Timespec) (int, syscall.Errno) {
 	n, _, e := syscall.Syscall6(syscall.SYS_PPOLL, uintptr(unsafe.Pointer(fds)),
 		uintptr(nfds), uintptr(unsafe.Pointer(timeout)), 0, 0, 0)

pkg/tcpip/link/rawfile/blockingpoll_unsafe.go

@@ -12,7 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-// +build linux,amd64
+// +build linux,amd64 linux,arm64
 // +build go1.12
 // +build !go1.14