Merge release-20191210.0-30-g6b42453 (automated)

1 files changed, 87 insertions, 0 deletions

diff --git a/pkg/sentry/platform/kvm/bluepill_arm64.s b/pkg/sentry/platform/kvm/bluepill_arm64.s
new file mode 100755
index 000000000..c61700892
--- /dev/null
+++ b/pkg/sentry/platform/kvm/bluepill_arm64.s
@@ -0,0 +1,87 @@
+// 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"
+
+// VCPU_CPU is the location of the CPU in the vCPU struct.
+//
+// This is guaranteed to be zero.
+#define VCPU_CPU 0x0
+
+// CPU_SELF is the self reference in ring0's percpu.
+//
+// This is guaranteed to be zero.
+#define CPU_SELF 0x0
+
+// Context offsets.
+//
+// Only limited use of the context is done in the assembly stub below, most is
+// done in the Go handlers.
+#define SIGINFO_SIGNO 0x0
+#define CONTEXT_PC  0x1B8
+#define CONTEXT_R0 0xB8
+
+// See bluepill.go.
+TEXT ·bluepill(SB),NOSPLIT,$0
+begin:
+	MOVD	vcpu+0(FP), R8
+	MOVD	$VCPU_CPU(R8), R9
+	ORR	$0xffff000000000000, R9, R9
+	// Trigger sigill.
+	// In ring0.Start(), the value of R8 will be stored into tpidr_el1.
+	// When the context was loaded into vcpu successfully,
+	// we will check if the value of R10 and R9 are the same.
+	WORD	$0xd538d08a // MRS TPIDR_EL1, R10
+check_vcpu:
+	CMP	R10, R9
+	BEQ	right_vCPU
+wrong_vcpu:
+	CALL	·redpill(SB)
+	B	begin
+right_vCPU:
+	RET
+
+// sighandler: see bluepill.go for documentation.
+//
+// The arguments are the following:
+//
+// 	R0 - The signal number.
+// 	R1 - Pointer to siginfo_t structure.
+// 	R2 - Pointer to ucontext structure.
+//
+TEXT ·sighandler(SB),NOSPLIT,$0
+	// si_signo should be sigill.
+	MOVD	SIGINFO_SIGNO(R1), R7
+	CMPW	$4, R7
+	BNE	fallback
+
+	MOVD	CONTEXT_PC(R2), R7
+	CMPW	$0, R7
+	BEQ	fallback
+
+	MOVD	R2, 8(RSP)
+	BL	·bluepillHandler(SB)   // Call the handler.
+
+	RET
+
+fallback:
+	// Jump to the previous signal handler.
+	MOVD	·savedHandler(SB), R7
+	B	(R7)
+
+// dieTrampoline: see bluepill.go, bluepill_arm64_unsafe.go for documentation.
+TEXT ·dieTrampoline(SB),NOSPLIT,$0
+	// TODO(gvisor.dev/issue/1249): dieTrampoline supporting for Arm64.
+	MOVD	R9, 8(RSP)
+	BL	·dieHandler(SB)