3 files changed, 80 insertions, 1 deletions
diff --git a/pkg/tcpip/link/rawfile/blockingpoll_arm64.s b/pkg/tcpip/link/rawfile/blockingpoll_arm64.s
new file mode 100644
index 000000000..b62888b93
--- /dev/null
+++ b/pkg/tcpip/link/rawfile/blockingpoll_arm64.s
@@ -0,0 +1,42 @@
+// Copyright 2018 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
diff --git a/pkg/tcpip/link/rawfile/blockingpoll_noyield_unsafe.go b/pkg/tcpip/link/rawfile/blockingpoll_noyield_unsafe.go
new file mode 100644
index 000000000..621ab8d29
--- /dev/null
+++ b/pkg/tcpip/link/rawfile/blockingpoll_noyield_unsafe.go
@@ -0,0 +1,31 @@
+// Copyright 2018 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.
+
+// +build linux,!amd64,!arm64
+
+package rawfile
+
+import (
+	"syscall"
+	"unsafe"
+)
+
+// BlockingPoll is just a stub function that forwards to the ppoll() system call
+// 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)
+
+	return int(n), e
+}
diff --git a/pkg/tcpip/link/rawfile/blockingpoll_amd64_unsafe.go b/pkg/tcpip/link/rawfile/blockingpoll_yield_unsafe.go
index 47039a446..dda3b10a6 100644
--- a/pkg/tcpip/link/rawfile/blockingpoll_amd64_unsafe.go
+++ b/pkg/tcpip/link/rawfile/blockingpoll_yield_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
 
@@ -25,6 +25,12 @@ import (
 	_ "unsafe" // for go:linkname
 )
 
+// BlockingPoll on amd64/arm64 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. On non amd64/arm64 platforms it just forwards to the ppoll() system
+// call.
+//
 //go:noescape
 func BlockingPoll(fds *PollEvent, nfds int, timeout *syscall.Timespec) (int, syscall.Errno)