Merge release-20210408.0-32-g108410638 (automated)

6 files changed, 54 insertions, 4 deletions

diff --git a/pkg/sentry/platform/kvm/bluepill.go b/pkg/sentry/platform/kvm/bluepill.go
index fd1131638..bb9967b9f 100644
--- a/pkg/sentry/platform/kvm/bluepill.go
+++ b/pkg/sentry/platform/kvm/bluepill.go
@@ -16,7 +16,6 @@ package kvm
 
 import (
 	"fmt"
-	"reflect"
 
 	"golang.org/x/sys/unix"
 	"gvisor.dev/gvisor/pkg/ring0"
@@ -36,6 +35,14 @@ func sighandler()
 // dieArchSetup and the assembly implementation for dieTrampoline.
 func dieTrampoline()
 
+// Return the start address of the functions above.
+//
+// In Go 1.17+, Go references to assembly functions resolve to an ABIInternal
+// wrapper function rather than the function itself. We must reference from
+// assembly to get the ABI0 (i.e., primary) address.
+func addrOfSighandler() uintptr
+func addrOfDieTrampoline() uintptr
+
 var (
 	// bounceSignal is the signal used for bouncing KVM.
 	//
@@ -87,10 +94,10 @@ func (c *vCPU) die(context *arch.SignalContext64, msg string) {
 
 func init() {
 	// Install the handler.
-	if err := safecopy.ReplaceSignalHandler(bluepillSignal, reflect.ValueOf(sighandler).Pointer(), &savedHandler); err != nil {
+	if err := safecopy.ReplaceSignalHandler(bluepillSignal, addrOfSighandler(), &savedHandler); err != nil {
 		panic(fmt.Sprintf("Unable to set handler for signal %d: %v", bluepillSignal, err))
 	}
 
 	// Extract the address for the trampoline.
-	dieTrampolineAddr = reflect.ValueOf(dieTrampoline).Pointer()
+	dieTrampolineAddr = addrOfDieTrampoline()
 }
diff --git a/pkg/sentry/platform/kvm/bluepill_arm64.s b/pkg/sentry/platform/kvm/bluepill_arm64.s
index 09c7e88e5..308f2a951 100644
--- a/pkg/sentry/platform/kvm/bluepill_arm64.s
+++ b/pkg/sentry/platform/kvm/bluepill_arm64.s
@@ -92,6 +92,12 @@ fallback:
 	MOVD	·savedHandler(SB), R7
 	B	(R7)
 
+// func addrOfSighandler() uintptr
+TEXT ·addrOfSighandler(SB), $0-8
+	MOVD	$·sighandler(SB), R0
+	MOVD	R0, ret+0(FP)
+	RET
+
 // dieTrampoline: see bluepill.go, bluepill_arm64_unsafe.go for documentation.
 TEXT ·dieTrampoline(SB),NOSPLIT,$0
 	// R0: Fake the old PC as caller
@@ -99,3 +105,9 @@ TEXT ·dieTrampoline(SB),NOSPLIT,$0
 	MOVD.P R1, 8(RSP) // R1: First argument (vCPU)
 	MOVD.P R0, 8(RSP) // R0: Fake the old PC as caller
 	B ·dieHandler(SB)
+
+// func addrOfDieTrampoline() uintptr
+TEXT ·addrOfDieTrampoline(SB), $0-8
+	MOVD	$·dieTrampoline(SB), R0
+	MOVD	R0, ret+0(FP)
+	RET
diff --git a/pkg/sentry/platform/kvm/bluepill_impl_amd64.s b/pkg/sentry/platform/kvm/bluepill_impl_amd64.s
index 2bbf06b18..b7f1dd5ac 100644
--- a/pkg/sentry/platform/kvm/bluepill_impl_amd64.s
+++ b/pkg/sentry/platform/kvm/bluepill_impl_amd64.s
@@ -151,8 +151,20 @@ fallback:
 	MOVQ ·savedHandler(SB), AX
 	JMP AX
 
+// func addrOfSighandler() uintptr
+TEXT ·addrOfSighandler(SB), $0-8
+	MOVQ $·sighandler(SB), AX
+	MOVQ AX, ret+0(FP)
+	RET
+
 // dieTrampoline: see bluepill.go, bluepill_amd64_unsafe.go for documentation.
 TEXT ·dieTrampoline(SB),NOSPLIT,$0
 	PUSHQ BX // First argument (vCPU).
 	PUSHQ AX // Fake the old RIP as caller.
 	JMP ·dieHandler(SB)
+
+// func addrOfDieTrampoline() uintptr
+TEXT ·addrOfDieTrampoline(SB), $0-8
+	MOVQ $·dieTrampoline(SB), AX
+	MOVQ AX, ret+0(FP)
+	RET
diff --git a/pkg/sentry/platform/ptrace/stub_amd64.s b/pkg/sentry/platform/ptrace/stub_amd64.s
index 16f9c523e..d5c3f901f 100644
--- a/pkg/sentry/platform/ptrace/stub_amd64.s
+++ b/pkg/sentry/platform/ptrace/stub_amd64.s
@@ -109,6 +109,12 @@ parent_dead:
 	SYSCALL
 	HLT
 
+// func addrOfStub() uintptr
+TEXT ·addrOfStub(SB), $0-8
+	MOVQ $·stub(SB), AX
+	MOVQ AX, ret+0(FP)
+	RET
+
 // stubCall calls the stub function at the given address with the given PPID.
 //
 // This is a distinct function because stub, above, may be mapped at any
diff --git a/pkg/sentry/platform/ptrace/stub_arm64.s b/pkg/sentry/platform/ptrace/stub_arm64.s
index 6162df02a..4664cd4ad 100644
--- a/pkg/sentry/platform/ptrace/stub_arm64.s
+++ b/pkg/sentry/platform/ptrace/stub_arm64.s
@@ -102,6 +102,12 @@ parent_dead:
 	SVC
 	HLT
 
+// func addrOfStub() uintptr
+TEXT ·addrOfStub(SB), $0-8
+	MOVD	$·stub(SB), R0
+	MOVD	R0, ret+0(FP)
+	RET
+
 // stubCall calls the stub function at the given address with the given PPID.
 //
 // This is a distinct function because stub, above, may be mapped at any
diff --git a/pkg/sentry/platform/ptrace/stub_unsafe.go b/pkg/sentry/platform/ptrace/stub_unsafe.go
index 5c9b7784f..1fbdea898 100644
--- a/pkg/sentry/platform/ptrace/stub_unsafe.go
+++ b/pkg/sentry/platform/ptrace/stub_unsafe.go
@@ -26,6 +26,13 @@ import (
 // stub is defined in arch-specific assembly.
 func stub()
 
+// addrOfStub returns the start address of stub.
+//
+// In Go 1.17+, Go references to assembly functions resolve to an ABIInternal
+// wrapper function rather than the function itself. We must reference from
+// assembly to get the ABI0 (i.e., primary) address.
+func addrOfStub() uintptr
+
 // stubCall calls the stub at the given address with the given pid.
 func stubCall(addr, pid uintptr)
 
@@ -41,7 +48,7 @@ func unsafeSlice(addr uintptr, length int) (slice []byte) {
 // stubInit initializes the stub.
 func stubInit() {
 	// Grab the existing stub.
-	stubBegin := reflect.ValueOf(stub).Pointer()
+	stubBegin := addrOfStub()
 	stubLen := int(safecopy.FindEndAddress(stubBegin) - stubBegin)
 	stubSlice := unsafeSlice(stubBegin, stubLen)
 	mapLen := uintptr(stubLen)