Enable automated marshalling for signals and the arch package.

PiperOrigin-RevId: 308472331

32 files changed, 203 insertions, 175 deletions

diff --git a/pkg/abi/linux/BUILD b/pkg/abi/linux/BUILD
index 59b0e138a..114b516e2 100644
--- a/pkg/abi/linux/BUILD
+++ b/pkg/abi/linux/BUILD
@@ -44,6 +44,8 @@ go_library(
         "poll.go",
         "prctl.go",
         "ptrace.go",
+        "ptrace_amd64.go",
+        "ptrace_arm64.go",
         "rseq.go",
         "rusage.go",
         "sched.go",
diff --git a/pkg/abi/linux/ptrace_amd64.go b/pkg/abi/linux/ptrace_amd64.go
new file mode 100644
index 000000000..ed3881e27
--- /dev/null
+++ b/pkg/abi/linux/ptrace_amd64.go
@@ -0,0 +1,52 @@
+// Copyright 2020 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 amd64
+
+package linux
+
+// PtraceRegs is the set of CPU registers exposed by ptrace. Source:
+// syscall.PtraceRegs.
+//
+// +marshal
+// +stateify savable
+type PtraceRegs struct {
+	R15      uint64
+	R14      uint64
+	R13      uint64
+	R12      uint64
+	Rbp      uint64
+	Rbx      uint64
+	R11      uint64
+	R10      uint64
+	R9       uint64
+	R8       uint64
+	Rax      uint64
+	Rcx      uint64
+	Rdx      uint64
+	Rsi      uint64
+	Rdi      uint64
+	Orig_rax uint64
+	Rip      uint64
+	Cs       uint64
+	Eflags   uint64
+	Rsp      uint64
+	Ss       uint64
+	Fs_base  uint64
+	Gs_base  uint64
+	Ds       uint64
+	Es       uint64
+	Fs       uint64
+	Gs       uint64
+}
diff --git a/pkg/sentry/arch/arch_state_aarch64.go b/pkg/abi/linux/ptrace_arm64.go
index 0136a85ad..6147738b3 100644
--- a/pkg/sentry/arch/arch_state_aarch64.go
+++ b/pkg/abi/linux/ptrace_arm64.go
@@ -1,4 +1,4 @@
-// Copyright 2020 The gVisor Authors.
+// 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.
@@ -14,25 +14,16 @@
 
 // +build arm64
 
-package arch
+package linux
 
-import (
-	"syscall"
-)
-
-type syscallPtraceRegs struct {
+// PtraceRegs is the set of CPU registers exposed by ptrace. Source:
+// syscall.PtraceRegs.
+//
+// +marshal
+// +stateify savable
+type PtraceRegs struct {
 	Regs   [31]uint64
 	Sp     uint64
 	Pc     uint64
 	Pstate uint64
 }
-
-// saveRegs is invoked by stateify.
-func (s *State) saveRegs() syscallPtraceRegs {
-	return syscallPtraceRegs(s.Regs)
-}
-
-// loadRegs is invoked by stateify.
-func (s *State) loadRegs(r syscallPtraceRegs) {
-	s.Regs = syscall.PtraceRegs(r)
-}
diff --git a/pkg/sentry/arch/BUILD b/pkg/sentry/arch/BUILD
index e27f21e5e..901e0f320 100644
--- a/pkg/sentry/arch/BUILD
+++ b/pkg/sentry/arch/BUILD
@@ -11,7 +11,6 @@ go_library(
         "arch_amd64.go",
         "arch_amd64.s",
         "arch_arm64.go",
-        "arch_state_aarch64.go",
         "arch_state_x86.go",
         "arch_x86.go",
         "arch_x86_impl.go",
@@ -26,11 +25,11 @@ go_library(
         "syscalls_amd64.go",
         "syscalls_arm64.go",
     ],
+    marshal = True,
     visibility = ["//:sandbox"],
     deps = [
         ":registers_go_proto",
         "//pkg/abi/linux",
-        "//pkg/binary",
         "//pkg/context",
         "//pkg/cpuid",
         "//pkg/log",
@@ -38,6 +37,7 @@ go_library(
         "//pkg/sync",
         "//pkg/syserror",
         "//pkg/usermem",
+        "//tools/go_marshal/marshal",
     ],
 )
 
diff --git a/pkg/sentry/arch/arch_aarch64.go b/pkg/sentry/arch/arch_aarch64.go
index c29e1b841..529980267 100644
--- a/pkg/sentry/arch/arch_aarch64.go
+++ b/pkg/sentry/arch/arch_aarch64.go
@@ -17,18 +17,20 @@
 package arch
 
 import (
+	"encoding/binary"
 	"fmt"
 	"io"
-	"syscall"
 
-	"gvisor.dev/gvisor/pkg/binary"
+	"gvisor.dev/gvisor/pkg/abi/linux"
 	"gvisor.dev/gvisor/pkg/cpuid"
 	"gvisor.dev/gvisor/pkg/log"
 	rpb "gvisor.dev/gvisor/pkg/sentry/arch/registers_go_proto"
 	"gvisor.dev/gvisor/pkg/syserror"
-	"gvisor.dev/gvisor/pkg/usermem"
 )
 
+// Registers represents the CPU registers for this architecture.
+type Registers = linux.PtraceRegs
+
 const (
 	// SyscallWidth is the width of insturctions.
 	SyscallWidth = 4
@@ -90,7 +92,7 @@ func NewFloatingPointData() *FloatingPointData {
 // file ensures it's only built on aarch64).
 type State struct {
 	// The system registers.
-	Regs syscall.PtraceRegs `state:".(syscallPtraceRegs)"`
+	Regs Registers
 
 	// Our floating point state.
 	aarch64FPState `state:"wait"`
@@ -226,25 +228,27 @@ func (s *State) RegisterMap() (map[string]uintptr, error) {
 
 // PtraceGetRegs implements Context.PtraceGetRegs.
 func (s *State) PtraceGetRegs(dst io.Writer) (int, error) {
-	return dst.Write(binary.Marshal(nil, usermem.ByteOrder, s.ptraceGetRegs()))
+	regs := s.ptraceGetRegs()
+	n, err := regs.WriteTo(dst)
+	return int(n), err
 }
 
-func (s *State) ptraceGetRegs() syscall.PtraceRegs {
+func (s *State) ptraceGetRegs() Registers {
 	return s.Regs
 }
 
-var ptraceRegsSize = int(binary.Size(syscall.PtraceRegs{}))
+var registersSize = (*Registers)(nil).SizeBytes()
 
 // PtraceSetRegs implements Context.PtraceSetRegs.
 func (s *State) PtraceSetRegs(src io.Reader) (int, error) {
-	var regs syscall.PtraceRegs
-	buf := make([]byte, ptraceRegsSize)
+	var regs Registers
+	buf := make([]byte, registersSize)
 	if _, err := io.ReadFull(src, buf); err != nil {
 		return 0, err
 	}
-	binary.Unmarshal(buf, usermem.ByteOrder, &regs)
+	regs.UnmarshalUnsafe(buf)
 	s.Regs = regs
-	return ptraceRegsSize, nil
+	return registersSize, nil
 }
 
 // PtraceGetFPRegs implements Context.PtraceGetFPRegs.
diff --git a/pkg/sentry/arch/arch_amd64.go b/pkg/sentry/arch/arch_amd64.go
index 85d6acc0f..3b3a0a272 100644
--- a/pkg/sentry/arch/arch_amd64.go
+++ b/pkg/sentry/arch/arch_amd64.go
@@ -22,7 +22,6 @@ import (
 	"math/rand"
 	"syscall"
 
-	"gvisor.dev/gvisor/pkg/binary"
 	"gvisor.dev/gvisor/pkg/cpuid"
 	"gvisor.dev/gvisor/pkg/sentry/limits"
 	"gvisor.dev/gvisor/pkg/usermem"
@@ -301,8 +300,10 @@ func (c *context64) PtracePeekUser(addr uintptr) (interface{}, error) {
 	// PTRACE_PEEKUSER and PTRACE_POKEUSER are only effective on regs and
 	// u_debugreg, returning 0 or silently no-oping for other fields
 	// respectively.
-	if addr < uintptr(ptraceRegsSize) {
-		buf := binary.Marshal(nil, usermem.ByteOrder, c.ptraceGetRegs())
+	if addr < uintptr(registersSize) {
+		regs := c.ptraceGetRegs()
+		buf := make([]byte, regs.SizeBytes())
+		regs.MarshalUnsafe(buf)
 		return c.Native(uintptr(usermem.ByteOrder.Uint64(buf[addr:]))), nil
 	}
 	// Note: x86 debug registers are missing.
@@ -314,8 +315,10 @@ func (c *context64) PtracePokeUser(addr, data uintptr) error {
 	if addr&7 != 0 || addr >= userStructSize {
 		return syscall.EIO
 	}
-	if addr < uintptr(ptraceRegsSize) {
-		buf := binary.Marshal(nil, usermem.ByteOrder, c.ptraceGetRegs())
+	if addr < uintptr(registersSize) {
+		regs := c.ptraceGetRegs()
+		buf := make([]byte, regs.SizeBytes())
+		regs.MarshalUnsafe(buf)
 		usermem.ByteOrder.PutUint64(buf[addr:], uint64(data))
 		_, err := c.PtraceSetRegs(bytes.NewBuffer(buf))
 		return err
diff --git a/pkg/sentry/arch/arch_arm64.go b/pkg/sentry/arch/arch_arm64.go
index db99c5acb..ada7ac7b8 100644
--- a/pkg/sentry/arch/arch_arm64.go
+++ b/pkg/sentry/arch/arch_arm64.go
@@ -12,6 +12,8 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+// +build arm64
+
 package arch
 
 import (
diff --git a/pkg/sentry/arch/arch_state_x86.go b/pkg/sentry/arch/arch_state_x86.go
index aa31169e0..19ce99d25 100644
--- a/pkg/sentry/arch/arch_state_x86.go
+++ b/pkg/sentry/arch/arch_state_x86.go
@@ -18,7 +18,6 @@ package arch
 
 import (
 	"fmt"
-	"syscall"
 
 	"gvisor.dev/gvisor/pkg/cpuid"
 	"gvisor.dev/gvisor/pkg/usermem"
@@ -90,44 +89,3 @@ func (s *State) afterLoadFPState() {
 	// Copy to the new, aligned location.
 	copy(s.x86FPState, old)
 }
-
-// +stateify savable
-type syscallPtraceRegs struct {
-	R15      uint64
-	R14      uint64
-	R13      uint64
-	R12      uint64
-	Rbp      uint64
-	Rbx      uint64
-	R11      uint64
-	R10      uint64
-	R9       uint64
-	R8       uint64
-	Rax      uint64
-	Rcx      uint64
-	Rdx      uint64
-	Rsi      uint64
-	Rdi      uint64
-	Orig_rax uint64
-	Rip      uint64
-	Cs       uint64
-	Eflags   uint64
-	Rsp      uint64
-	Ss       uint64
-	Fs_base  uint64
-	Gs_base  uint64
-	Ds       uint64
-	Es       uint64
-	Fs       uint64
-	Gs       uint64
-}
-
-// saveRegs is invoked by stateify.
-func (s *State) saveRegs() syscallPtraceRegs {
-	return syscallPtraceRegs(s.Regs)
-}
-
-// loadRegs is invoked by stateify.
-func (s *State) loadRegs(r syscallPtraceRegs) {
-	s.Regs = syscall.PtraceRegs(r)
-}
diff --git a/pkg/sentry/arch/arch_x86.go b/pkg/sentry/arch/arch_x86.go
index 7fc4c0473..dc458b37f 100644
--- a/pkg/sentry/arch/arch_x86.go
+++ b/pkg/sentry/arch/arch_x86.go
@@ -21,7 +21,7 @@ import (
 	"io"
 	"syscall"
 
-	"gvisor.dev/gvisor/pkg/binary"
+	"gvisor.dev/gvisor/pkg/abi/linux"
 	"gvisor.dev/gvisor/pkg/cpuid"
 	"gvisor.dev/gvisor/pkg/log"
 	rpb "gvisor.dev/gvisor/pkg/sentry/arch/registers_go_proto"
@@ -30,6 +30,9 @@ import (
 	"gvisor.dev/gvisor/pkg/usermem"
 )
 
+// Registers represents the CPU registers for this architecture.
+type Registers = linux.PtraceRegs
+
 // System-related constants for x86.
 const (
 	// SyscallWidth is the width of syscall, sysenter, and int 80 insturctions.
@@ -267,10 +270,12 @@ func (s *State) RegisterMap() (map[string]uintptr, error) {
 
 // PtraceGetRegs implements Context.PtraceGetRegs.
 func (s *State) PtraceGetRegs(dst io.Writer) (int, error) {
-	return dst.Write(binary.Marshal(nil, usermem.ByteOrder, s.ptraceGetRegs()))
+	regs := s.ptraceGetRegs()
+	n, err := regs.WriteTo(dst)
+	return int(n), err
 }
 
-func (s *State) ptraceGetRegs() syscall.PtraceRegs {
+func (s *State) ptraceGetRegs() Registers {
 	regs := s.Regs
 	// These may not be initialized.
 	if regs.Cs == 0 || regs.Ss == 0 || regs.Eflags == 0 {
@@ -306,16 +311,16 @@ func (s *State) ptraceGetRegs() syscall.PtraceRegs {
 	return regs
 }
 
-var ptraceRegsSize = int(binary.Size(syscall.PtraceRegs{}))
+var registersSize = (*Registers)(nil).SizeBytes()
 
 // PtraceSetRegs implements Context.PtraceSetRegs.
 func (s *State) PtraceSetRegs(src io.Reader) (int, error) {
-	var regs syscall.PtraceRegs
-	buf := make([]byte, ptraceRegsSize)
+	var regs Registers
+	buf := make([]byte, registersSize)
 	if _, err := io.ReadFull(src, buf); err != nil {
 		return 0, err
 	}
-	binary.Unmarshal(buf, usermem.ByteOrder, &regs)
+	regs.UnmarshalUnsafe(buf)
 	// Truncate segment registers to 16 bits.
 	regs.Cs = uint64(uint16(regs.Cs))
 	regs.Ds = uint64(uint16(regs.Ds))
@@ -369,7 +374,7 @@ func (s *State) PtraceSetRegs(src io.Reader) (int, error) {
 	}
 	regs.Eflags = (s.Regs.Eflags &^ eflagsPtraceMutable) | (regs.Eflags & eflagsPtraceMutable)
 	s.Regs = regs
-	return ptraceRegsSize, nil
+	return registersSize, nil
 }
 
 // isUserSegmentSelector returns true if the given segment selector specifies a
@@ -538,7 +543,7 @@ const (
 func (s *State) PtraceGetRegSet(regset uintptr, dst io.Writer, maxlen int) (int, error) {
 	switch regset {
 	case _NT_PRSTATUS:
-		if maxlen < ptraceRegsSize {
+		if maxlen < registersSize {
 			return 0, syserror.EFAULT
 		}
 		return s.PtraceGetRegs(dst)
@@ -558,7 +563,7 @@ func (s *State) PtraceGetRegSet(regset uintptr, dst io.Writer, maxlen int) (int,
 func (s *State) PtraceSetRegSet(regset uintptr, src io.Reader, maxlen int) (int, error) {
 	switch regset {
 	case _NT_PRSTATUS:
-		if maxlen < ptraceRegsSize {
+		if maxlen < registersSize {
 			return 0, syserror.EFAULT
 		}
 		return s.PtraceSetRegs(src)
diff --git a/pkg/sentry/arch/arch_x86_impl.go b/pkg/sentry/arch/arch_x86_impl.go
index 3edf40764..0c73fcbfb 100644
--- a/pkg/sentry/arch/arch_x86_impl.go
+++ b/pkg/sentry/arch/arch_x86_impl.go
@@ -17,8 +17,6 @@
 package arch
 
 import (
-	"syscall"
-
 	"gvisor.dev/gvisor/pkg/cpuid"
 )
 
@@ -28,7 +26,7 @@ import (
 // +stateify savable
 type State struct {
 	// The system registers.
-	Regs syscall.PtraceRegs `state:".(syscallPtraceRegs)"`
+	Regs Registers
 
 	// Our floating point state.
 	x86FPState `state:"wait"`
diff --git a/pkg/sentry/arch/signal.go b/pkg/sentry/arch/signal.go
index 8b03d0187..c9fb55d00 100644
--- a/pkg/sentry/arch/signal.go
+++ b/pkg/sentry/arch/signal.go
@@ -22,6 +22,7 @@ import (
 // SignalAct represents the action that should be taken when a signal is
 // delivered, and is equivalent to struct sigaction.
 //
+// +marshal
 // +stateify savable
 type SignalAct struct {
 	Handler  uint64
@@ -43,6 +44,7 @@ func (s *SignalAct) DeserializeTo(other *SignalAct) {
 // SignalStack represents information about a user stack, and is equivalent to
 // stack_t.
 //
+// +marshal
 // +stateify savable
 type SignalStack struct {
 	Addr  uint64
@@ -64,6 +66,7 @@ func (s *SignalStack) DeserializeTo(other *SignalStack) {
 // SignalInfo represents information about a signal being delivered, and is
 // equivalent to struct siginfo in linux kernel(linux/include/uapi/asm-generic/siginfo.h).
 //
+// +marshal
 // +stateify savable
 type SignalInfo struct {
 	Signo int32 // Signal number
diff --git a/pkg/sentry/arch/signal_act.go b/pkg/sentry/arch/signal_act.go
index f9ca2e74e..32173aa20 100644
--- a/pkg/sentry/arch/signal_act.go
+++ b/pkg/sentry/arch/signal_act.go
@@ -14,6 +14,8 @@
 
 package arch
 
+import "gvisor.dev/gvisor/tools/go_marshal/marshal"
+
 // Special values for SignalAct.Handler.
 const (
 	// SignalActDefault is SIG_DFL and specifies that the default behavior for
@@ -71,6 +73,8 @@ func (s SignalAct) HasRestorer() bool {
 // NativeSignalAct is a type that is equivalent to struct sigaction in the
 // guest architecture.
 type NativeSignalAct interface {
+	marshal.Marshallable
+
 	// SerializeFrom copies the data in the host SignalAct s into this object.
 	SerializeFrom(s *SignalAct)
 
diff --git a/pkg/sentry/arch/signal_stack.go b/pkg/sentry/arch/signal_stack.go
index e58f055c7..0fa738a1d 100644
--- a/pkg/sentry/arch/signal_stack.go
+++ b/pkg/sentry/arch/signal_stack.go
@@ -18,6 +18,7 @@ package arch
 
 import (
 	"gvisor.dev/gvisor/pkg/usermem"
+	"gvisor.dev/gvisor/tools/go_marshal/marshal"
 )
 
 const (
@@ -55,6 +56,8 @@ func (s *SignalStack) Contains(sp usermem.Addr) bool {
 // NativeSignalStack is a type that is equivalent to stack_t in the guest
 // architecture.
 type NativeSignalStack interface {
+	marshal.Marshallable
+
 	// SerializeFrom copies the data in the host SignalStack s into this
 	// object.
 	SerializeFrom(s *SignalStack)
diff --git a/pkg/sentry/kernel/task_signals.go b/pkg/sentry/kernel/task_signals.go
index 7d25e98f7..79766cafe 100644
--- a/pkg/sentry/kernel/task_signals.go
+++ b/pkg/sentry/kernel/task_signals.go
@@ -716,7 +716,7 @@ func (tg *ThreadGroup) SetSignalAct(sig linux.Signal, actptr *arch.SignalAct) (a
 func (t *Task) CopyOutSignalAct(addr usermem.Addr, s *arch.SignalAct) error {
 	n := t.Arch().NewSignalAct()
 	n.SerializeFrom(s)
-	_, err := t.CopyOut(addr, n)
+	_, err := n.CopyOut(t, addr)
 	return err
 }
 
@@ -725,7 +725,7 @@ func (t *Task) CopyOutSignalAct(addr usermem.Addr, s *arch.SignalAct) error {
 func (t *Task) CopyInSignalAct(addr usermem.Addr) (arch.SignalAct, error) {
 	n := t.Arch().NewSignalAct()
 	var s arch.SignalAct
-	if _, err := t.CopyIn(addr, n); err != nil {
+	if _, err := n.CopyIn(t, addr); err != nil {
 		return s, err
 	}
 	n.DeserializeTo(&s)
@@ -737,7 +737,7 @@ func (t *Task) CopyInSignalAct(addr usermem.Addr) (arch.SignalAct, error) {
 func (t *Task) CopyOutSignalStack(addr usermem.Addr, s *arch.SignalStack) error {
 	n := t.Arch().NewSignalStack()
 	n.SerializeFrom(s)
-	_, err := t.CopyOut(addr, n)
+	_, err := n.CopyOut(t, addr)
 	return err
 }
 
@@ -746,7 +746,7 @@ func (t *Task) CopyOutSignalStack(addr usermem.Addr, s *arch.SignalStack) error
 func (t *Task) CopyInSignalStack(addr usermem.Addr) (arch.SignalStack, error) {
 	n := t.Arch().NewSignalStack()
 	var s arch.SignalStack
-	if _, err := t.CopyIn(addr, n); err != nil {
+	if _, err := n.CopyIn(t, addr); err != nil {
 		return s, err
 	}
 	n.DeserializeTo(&s)
diff --git a/pkg/sentry/platform/kvm/kvm_arm64.go b/pkg/sentry/platform/kvm/kvm_arm64.go
index 716198712..29d457a7e 100644
--- a/pkg/sentry/platform/kvm/kvm_arm64.go
+++ b/pkg/sentry/platform/kvm/kvm_arm64.go
@@ -17,8 +17,7 @@
 package kvm
 
 import (
-	"syscall"
-
+	"gvisor.dev/gvisor/pkg/sentry/arch"
 	"gvisor.dev/gvisor/pkg/sentry/platform/ring0"
 )
 
@@ -37,7 +36,7 @@ type userFpsimdState struct {
 }
 
 type userRegs struct {
-	Regs    syscall.PtraceRegs
+	Regs    arch.Registers
 	sp_el1  uint64
 	elr_el1 uint64
 	spsr    [KVM_NR_SPSR]uint64
diff --git a/pkg/sentry/platform/kvm/kvm_test.go b/pkg/sentry/platform/kvm/kvm_test.go
index c42752d50..6c8f4fa28 100644
--- a/pkg/sentry/platform/kvm/kvm_test.go
+++ b/pkg/sentry/platform/kvm/kvm_test.go
@@ -117,10 +117,10 @@ func TestKernelFloatingPoint(t *testing.T) {
 	})
 }
 
-func applicationTest(t testHarness, useHostMappings bool, target func(), fn func(*vCPU, *syscall.PtraceRegs, *pagetables.PageTables) bool) {
+func applicationTest(t testHarness, useHostMappings bool, target func(), fn func(*vCPU, *arch.Registers, *pagetables.PageTables) bool) {
 	// Initialize registers & page tables.
 	var (
-		regs syscall.PtraceRegs
+		regs arch.Registers
 		pt   *pagetables.PageTables
 	)
 	testutil.SetTestTarget(&regs, target)
@@ -154,7 +154,7 @@ func applicationTest(t testHarness, useHostMappings bool, target func(), fn func
 }
 
 func TestApplicationSyscall(t *testing.T) {
-	applicationTest(t, true, testutil.SyscallLoop, func(c *vCPU, regs *syscall.PtraceRegs, pt *pagetables.PageTables) bool {
+	applicationTest(t, true, testutil.SyscallLoop, func(c *vCPU, regs *arch.Registers, pt *pagetables.PageTables) bool {
 		var si arch.SignalInfo
 		if _, err := c.SwitchToUser(ring0.SwitchOpts{
 			Registers:          regs,
@@ -168,7 +168,7 @@ func TestApplicationSyscall(t *testing.T) {
 		}
 		return false
 	})
-	applicationTest(t, true, testutil.SyscallLoop, func(c *vCPU, regs *syscall.PtraceRegs, pt *pagetables.PageTables) bool {
+	applicationTest(t, true, testutil.SyscallLoop, func(c *vCPU, regs *arch.Registers, pt *pagetables.PageTables) bool {
 		var si arch.SignalInfo
 		if _, err := c.SwitchToUser(ring0.SwitchOpts{
 			Registers:          regs,
@@ -184,7 +184,7 @@ func TestApplicationSyscall(t *testing.T) {
 }
 
 func TestApplicationFault(t *testing.T) {
-	applicationTest(t, true, testutil.Touch, func(c *vCPU, regs *syscall.PtraceRegs, pt *pagetables.PageTables) bool {
+	applicationTest(t, true, testutil.Touch, func(c *vCPU, regs *arch.Registers, pt *pagetables.PageTables) bool {
 		testutil.SetTouchTarget(regs, nil) // Cause fault.
 		var si arch.SignalInfo
 		if _, err := c.SwitchToUser(ring0.SwitchOpts{
@@ -199,7 +199,7 @@ func TestApplicationFault(t *testing.T) {
 		}
 		return false
 	})
-	applicationTest(t, true, testutil.Touch, func(c *vCPU, regs *syscall.PtraceRegs, pt *pagetables.PageTables) bool {
+	applicationTest(t, true, testutil.Touch, func(c *vCPU, regs *arch.Registers, pt *pagetables.PageTables) bool {
 		testutil.SetTouchTarget(regs, nil) // Cause fault.
 		var si arch.SignalInfo
 		if _, err := c.SwitchToUser(ring0.SwitchOpts{
@@ -216,7 +216,7 @@ func TestApplicationFault(t *testing.T) {
 }
 
 func TestRegistersSyscall(t *testing.T) {
-	applicationTest(t, true, testutil.TwiddleRegsSyscall, func(c *vCPU, regs *syscall.PtraceRegs, pt *pagetables.PageTables) bool {
+	applicationTest(t, true, testutil.TwiddleRegsSyscall, func(c *vCPU, regs *arch.Registers, pt *pagetables.PageTables) bool {
 		testutil.SetTestRegs(regs) // Fill values for all registers.
 		for {
 			var si arch.SignalInfo
@@ -239,7 +239,7 @@ func TestRegistersSyscall(t *testing.T) {
 }
 
 func TestRegistersFault(t *testing.T) {
-	applicationTest(t, true, testutil.TwiddleRegsFault, func(c *vCPU, regs *syscall.PtraceRegs, pt *pagetables.PageTables) bool {
+	applicationTest(t, true, testutil.TwiddleRegsFault, func(c *vCPU, regs *arch.Registers, pt *pagetables.PageTables) bool {
 		testutil.SetTestRegs(regs) // Fill values for all registers.
 		for {
 			var si arch.SignalInfo
@@ -263,7 +263,7 @@ func TestRegistersFault(t *testing.T) {
 }
 
 func TestSegments(t *testing.T) {
-	applicationTest(t, true, testutil.TwiddleSegments, func(c *vCPU, regs *syscall.PtraceRegs, pt *pagetables.PageTables) bool {
+	applicationTest(t, true, testutil.TwiddleSegments, func(c *vCPU, regs *arch.Registers, pt *pagetables.PageTables) bool {
 		testutil.SetTestSegments(regs)
 		for {
 			var si arch.SignalInfo
@@ -287,7 +287,7 @@ func TestSegments(t *testing.T) {
 }
 
 func TestBounce(t *testing.T) {
-	applicationTest(t, true, testutil.SpinLoop, func(c *vCPU, regs *syscall.PtraceRegs, pt *pagetables.PageTables) bool {
+	applicationTest(t, true, testutil.SpinLoop, func(c *vCPU, regs *arch.Registers, pt *pagetables.PageTables) bool {
 		go func() {
 			time.Sleep(time.Millisecond)
 			c.BounceToKernel()
@@ -302,7 +302,7 @@ func TestBounce(t *testing.T) {
 		}
 		return false
 	})
-	applicationTest(t, true, testutil.SpinLoop, func(c *vCPU, regs *syscall.PtraceRegs, pt *pagetables.PageTables) bool {
+	applicationTest(t, true, testutil.SpinLoop, func(c *vCPU, regs *arch.Registers, pt *pagetables.PageTables) bool {
 		go func() {
 			time.Sleep(time.Millisecond)
 			c.BounceToKernel()
@@ -321,7 +321,7 @@ func TestBounce(t *testing.T) {
 }
 
 func TestBounceStress(t *testing.T) {
-	applicationTest(t, true, testutil.SpinLoop, func(c *vCPU, regs *syscall.PtraceRegs, pt *pagetables.PageTables) bool {
+	applicationTest(t, true, testutil.SpinLoop, func(c *vCPU, regs *arch.Registers, pt *pagetables.PageTables) bool {
 		randomSleep := func() {
 			// O(hundreds of microseconds) is appropriate to ensure
 			// different overlaps and different schedules.
@@ -357,7 +357,7 @@ func TestBounceStress(t *testing.T) {
 
 func TestInvalidate(t *testing.T) {
 	var data uintptr // Used below.
-	applicationTest(t, true, testutil.Touch, func(c *vCPU, regs *syscall.PtraceRegs, pt *pagetables.PageTables) bool {
+	applicationTest(t, true, testutil.Touch, func(c *vCPU, regs *arch.Registers, pt *pagetables.PageTables) bool {
 		testutil.SetTouchTarget(regs, &data) // Read legitimate value.
 		for {
 			var si arch.SignalInfo
@@ -398,7 +398,7 @@ func IsFault(err error, si *arch.SignalInfo) bool {
 }
 
 func TestEmptyAddressSpace(t *testing.T) {
-	applicationTest(t, false, testutil.SyscallLoop, func(c *vCPU, regs *syscall.PtraceRegs, pt *pagetables.PageTables) bool {
+	applicationTest(t, false, testutil.SyscallLoop, func(c *vCPU, regs *arch.Registers, pt *pagetables.PageTables) bool {
 		var si arch.SignalInfo
 		if _, err := c.SwitchToUser(ring0.SwitchOpts{
 			Registers:          regs,
@@ -412,7 +412,7 @@ func TestEmptyAddressSpace(t *testing.T) {
 		}
 		return false
 	})
-	applicationTest(t, false, testutil.SyscallLoop, func(c *vCPU, regs *syscall.PtraceRegs, pt *pagetables.PageTables) bool {
+	applicationTest(t, false, testutil.SyscallLoop, func(c *vCPU, regs *arch.Registers, pt *pagetables.PageTables) bool {
 		var si arch.SignalInfo
 		if _, err := c.SwitchToUser(ring0.SwitchOpts{
 			Registers:          regs,
@@ -471,7 +471,7 @@ func BenchmarkApplicationSyscall(b *testing.B) {
 		i int // Iteration includes machine.Get() / machine.Put().
 		a int // Count for ErrContextInterrupt.
 	)
-	applicationTest(b, true, testutil.SyscallLoop, func(c *vCPU, regs *syscall.PtraceRegs, pt *pagetables.PageTables) bool {
+	applicationTest(b, true, testutil.SyscallLoop, func(c *vCPU, regs *arch.Registers, pt *pagetables.PageTables) bool {
 		var si arch.SignalInfo
 		if _, err := c.SwitchToUser(ring0.SwitchOpts{
 			Registers:          regs,
@@ -493,7 +493,7 @@ func BenchmarkApplicationSyscall(b *testing.B) {
 
 func BenchmarkKernelSyscall(b *testing.B) {
 	// Note that the target passed here is irrelevant, we never execute SwitchToUser.
-	applicationTest(b, true, testutil.Getpid, func(c *vCPU, regs *syscall.PtraceRegs, pt *pagetables.PageTables) bool {
+	applicationTest(b, true, testutil.Getpid, func(c *vCPU, regs *arch.Registers, pt *pagetables.PageTables) bool {
 		// iteration does not include machine.Get() / machine.Put().
 		for i := 0; i < b.N; i++ {
 			testutil.Getpid()
@@ -508,7 +508,7 @@ func BenchmarkWorldSwitchToUserRoundtrip(b *testing.B) {
 		i int
 		a int
 	)
-	applicationTest(b, true, testutil.SyscallLoop, func(c *vCPU, regs *syscall.PtraceRegs, pt *pagetables.PageTables) bool {
+	applicationTest(b, true, testutil.SyscallLoop, func(c *vCPU, regs *arch.Registers, pt *pagetables.PageTables) bool {
 		var si arch.SignalInfo
 		if _, err := c.SwitchToUser(ring0.SwitchOpts{
 			Registers:          regs,
diff --git a/pkg/sentry/platform/kvm/testutil/BUILD b/pkg/sentry/platform/kvm/testutil/BUILD
index f7605df8a..f7feb8683 100644
--- a/pkg/sentry/platform/kvm/testutil/BUILD
+++ b/pkg/sentry/platform/kvm/testutil/BUILD
@@ -13,4 +13,5 @@ go_library(
         "testutil_arm64.s",
     ],
     visibility = ["//pkg/sentry/platform/kvm:__pkg__"],
+    deps = ["//pkg/sentry/arch"],
 )
diff --git a/pkg/sentry/platform/kvm/testutil/testutil_amd64.go b/pkg/sentry/platform/kvm/testutil/testutil_amd64.go
index 4c108abbf..8048eedec 100644
--- a/pkg/sentry/platform/kvm/testutil/testutil_amd64.go
+++ b/pkg/sentry/platform/kvm/testutil/testutil_amd64.go
@@ -18,19 +18,20 @@ package testutil
 
 import (
 	"reflect"
-	"syscall"
+
+	"gvisor.dev/gvisor/pkg/sentry/arch"
 )
 
 // TwiddleSegments reads segments into known registers.
 func TwiddleSegments()
 
 // SetTestTarget sets the rip appropriately.
-func SetTestTarget(regs *syscall.PtraceRegs, fn func()) {
+func SetTestTarget(regs *arch.Registers, fn func()) {
 	regs.Rip = uint64(reflect.ValueOf(fn).Pointer())
 }
 
 // SetTouchTarget sets rax appropriately.
-func SetTouchTarget(regs *syscall.PtraceRegs, target *uintptr) {
+func SetTouchTarget(regs *arch.Registers, target *uintptr) {
 	if target != nil {
 		regs.Rax = uint64(reflect.ValueOf(target).Pointer())
 	} else {
@@ -39,12 +40,12 @@ func SetTouchTarget(regs *syscall.PtraceRegs, target *uintptr) {
 }
 
 // RewindSyscall rewinds a syscall RIP.
-func RewindSyscall(regs *syscall.PtraceRegs) {
+func RewindSyscall(regs *arch.Registers) {
 	regs.Rip -= 2
 }
 
 // SetTestRegs initializes registers to known values.
-func SetTestRegs(regs *syscall.PtraceRegs) {
+func SetTestRegs(regs *arch.Registers) {
 	regs.R15 = 0x15
 	regs.R14 = 0x14
 	regs.R13 = 0x13
@@ -64,7 +65,7 @@ func SetTestRegs(regs *syscall.PtraceRegs) {
 }
 
 // CheckTestRegs checks that registers were twiddled per TwiddleRegs.
-func CheckTestRegs(regs *syscall.PtraceRegs, full bool) (err error) {
+func CheckTestRegs(regs *arch.Registers, full bool) (err error) {
 	if need := ^uint64(0x15); regs.R15 != need {
 		err = addRegisterMismatch(err, "R15", regs.R15, need)
 	}
@@ -121,13 +122,13 @@ var fsData uint64 = 0x55
 var gsData uint64 = 0x85
 
 // SetTestSegments initializes segments to known values.
-func SetTestSegments(regs *syscall.PtraceRegs) {
+func SetTestSegments(regs *arch.Registers) {
 	regs.Fs_base = uint64(reflect.ValueOf(&fsData).Pointer())
 	regs.Gs_base = uint64(reflect.ValueOf(&gsData).Pointer())
 }
 
 // CheckTestSegments checks that registers were twiddled per TwiddleSegments.
-func CheckTestSegments(regs *syscall.PtraceRegs) (err error) {
+func CheckTestSegments(regs *arch.Registers) (err error) {
 	if regs.Rax != fsData {
 		err = addRegisterMismatch(err, "Rax", regs.Rax, fsData)
 	}
diff --git a/pkg/sentry/platform/kvm/testutil/testutil_arm64.go b/pkg/sentry/platform/kvm/testutil/testutil_arm64.go
index 40b2e4acc..ca902c8c1 100644
--- a/pkg/sentry/platform/kvm/testutil/testutil_arm64.go
+++ b/pkg/sentry/platform/kvm/testutil/testutil_arm64.go
@@ -19,16 +19,17 @@ package testutil
 import (
 	"fmt"
 	"reflect"
-	"syscall"
+
+	"gvisor.dev/gvisor/pkg/sentry/arch"
 )
 
 // SetTestTarget sets the rip appropriately.
-func SetTestTarget(regs *syscall.PtraceRegs, fn func()) {
+func SetTestTarget(regs *arch.Registers, fn func()) {
 	regs.Pc = uint64(reflect.ValueOf(fn).Pointer())
 }
 
 // SetTouchTarget sets rax appropriately.
-func SetTouchTarget(regs *syscall.PtraceRegs, target *uintptr) {
+func SetTouchTarget(regs *arch.Registers, target *uintptr) {
 	if target != nil {
 		regs.Regs[8] = uint64(reflect.ValueOf(target).Pointer())
 	} else {
@@ -37,19 +38,19 @@ func SetTouchTarget(regs *syscall.PtraceRegs, target *uintptr) {
 }
 
 // RewindSyscall rewinds a syscall RIP.
-func RewindSyscall(regs *syscall.PtraceRegs) {
+func RewindSyscall(regs *arch.Registers) {
 	regs.Pc -= 4
 }
 
 // SetTestRegs initializes registers to known values.
-func SetTestRegs(regs *syscall.PtraceRegs) {
+func SetTestRegs(regs *arch.Registers) {
 	for i := 0; i <= 30; i++ {
 		regs.Regs[i] = uint64(i) + 1
 	}
 }
 
 // CheckTestRegs checks that registers were twiddled per TwiddleRegs.
-func CheckTestRegs(regs *syscall.PtraceRegs, full bool) (err error) {
+func CheckTestRegs(regs *arch.Registers, full bool) (err error) {
 	for i := 0; i <= 30; i++ {
 		if need := ^uint64(i + 1); regs.Regs[i] != need {
 			err = addRegisterMismatch(err, fmt.Sprintf("R%d", i), regs.Regs[i], need)
diff --git a/pkg/sentry/platform/ptrace/ptrace_amd64.go b/pkg/sentry/platform/ptrace/ptrace_amd64.go
index 24fc5dc62..3b9a870a5 100644
--- a/pkg/sentry/platform/ptrace/ptrace_amd64.go
+++ b/pkg/sentry/platform/ptrace/ptrace_amd64.go
@@ -15,9 +15,8 @@
 package ptrace
 
 import (
-	"syscall"
-
 	"gvisor.dev/gvisor/pkg/abi/linux"
+	"gvisor.dev/gvisor/pkg/sentry/arch"
 )
 
 // fpRegSet returns the GETREGSET/SETREGSET register set type to be used.
@@ -28,12 +27,12 @@ func fpRegSet(useXsave bool) uintptr {
 	return linux.NT_PRFPREG
 }
 
-func stackPointer(r *syscall.PtraceRegs) uintptr {
+func stackPointer(r *arch.Registers) uintptr {
 	return uintptr(r.Rsp)
 }
 
 // x86 use the fs_base register to store the TLS pointer which can be
-// get/set in "func (t *thread) get/setRegs(regs *syscall.PtraceRegs)".
+// get/set in "func (t *thread) get/setRegs(regs *arch.Registers)".
 // So both of the get/setTLS() operations are noop here.
 
 // getTLS gets the thread local storage register.
diff --git a/pkg/sentry/platform/ptrace/ptrace_arm64.go b/pkg/sentry/platform/ptrace/ptrace_arm64.go
index 4db28c534..5c869926a 100644
--- a/pkg/sentry/platform/ptrace/ptrace_arm64.go
+++ b/pkg/sentry/platform/ptrace/ptrace_arm64.go
@@ -15,9 +15,8 @@
 package ptrace
 
 import (
-	"syscall"
-
 	"gvisor.dev/gvisor/pkg/abi/linux"
+	"gvisor.dev/gvisor/pkg/sentry/arch"
 )
 
 // fpRegSet returns the GETREGSET/SETREGSET register set type to be used.
@@ -25,6 +24,6 @@ func fpRegSet(_ bool) uintptr {
 	return linux.NT_PRFPREG
 }
 
-func stackPointer(r *syscall.PtraceRegs) uintptr {
+func stackPointer(r *arch.Registers) uintptr {
 	return uintptr(r.Sp)
 }
diff --git a/pkg/sentry/platform/ptrace/ptrace_unsafe.go b/pkg/sentry/platform/ptrace/ptrace_unsafe.go
index 6c0ed7b3e..8b72d24e8 100644
--- a/pkg/sentry/platform/ptrace/ptrace_unsafe.go
+++ b/pkg/sentry/platform/ptrace/ptrace_unsafe.go
@@ -24,7 +24,7 @@ import (
 )
 
 // getRegs gets the general purpose register set.
-func (t *thread) getRegs(regs *syscall.PtraceRegs) error {
+func (t *thread) getRegs(regs *arch.Registers) error {
 	iovec := syscall.Iovec{
 		Base: (*byte)(unsafe.Pointer(regs)),
 		Len:  uint64(unsafe.Sizeof(*regs)),
@@ -43,7 +43,7 @@ func (t *thread) getRegs(regs *syscall.PtraceRegs) error {
 }
 
 // setRegs sets the general purpose register set.
-func (t *thread) setRegs(regs *syscall.PtraceRegs) error {
+func (t *thread) setRegs(regs *arch.Registers) error {
 	iovec := syscall.Iovec{
 		Base: (*byte)(unsafe.Pointer(regs)),
 		Len:  uint64(unsafe.Sizeof(*regs)),
diff --git a/pkg/sentry/platform/ptrace/subprocess.go b/pkg/sentry/platform/ptrace/subprocess.go
index 773ddb1ed..2389423b0 100644
--- a/pkg/sentry/platform/ptrace/subprocess.go
+++ b/pkg/sentry/platform/ptrace/subprocess.go
@@ -63,7 +63,7 @@ type thread struct {
 	// initRegs are the initial registers for the first thread.
 	//
 	// These are used for the register set for system calls.
-	initRegs syscall.PtraceRegs
+	initRegs arch.Registers
 }
 
 // threadPool is a collection of threads.
@@ -317,7 +317,7 @@ const (
 )
 
 func (t *thread) dumpAndPanic(message string) {
-	var regs syscall.PtraceRegs
+	var regs arch.Registers
 	message += "\n"
 	if err := t.getRegs(&regs); err == nil {
 		message += dumpRegs(&regs)
@@ -423,7 +423,7 @@ func (t *thread) init() {
 // This is _not_ for use by application system calls, rather it is for use when
 // a system call must be injected into the remote context (e.g. mmap, munmap).
 // Note that clones are handled separately.
-func (t *thread) syscall(regs *syscall.PtraceRegs) (uintptr, error) {
+func (t *thread) syscall(regs *arch.Registers) (uintptr, error) {
 	// Set registers.
 	if err := t.setRegs(regs); err != nil {
 		panic(fmt.Sprintf("ptrace set regs failed: %v", err))
@@ -461,7 +461,7 @@ func (t *thread) syscall(regs *syscall.PtraceRegs) (uintptr, error) {
 // syscallIgnoreInterrupt ignores interrupts on the system call thread and
 // restarts the syscall if the kernel indicates that should happen.
 func (t *thread) syscallIgnoreInterrupt(
-	initRegs *syscall.PtraceRegs,
+	initRegs *arch.Registers,
 	sysno uintptr,
 	args ...arch.SyscallArgument) (uintptr, error) {
 	for {
diff --git a/pkg/sentry/platform/ptrace/subprocess_amd64.go b/pkg/sentry/platform/ptrace/subprocess_amd64.go
index cd74945e7..84b699f0d 100644
--- a/pkg/sentry/platform/ptrace/subprocess_amd64.go
+++ b/pkg/sentry/platform/ptrace/subprocess_amd64.go
@@ -41,7 +41,7 @@ const (
 // resetSysemuRegs sets up emulation registers.
 //
 // This should be called prior to calling sysemu.
-func (t *thread) resetSysemuRegs(regs *syscall.PtraceRegs) {
+func (t *thread) resetSysemuRegs(regs *arch.Registers) {
 	regs.Cs = t.initRegs.Cs
 	regs.Ss = t.initRegs.Ss
 	regs.Ds = t.initRegs.Ds
@@ -53,7 +53,7 @@ func (t *thread) resetSysemuRegs(regs *syscall.PtraceRegs) {
 // createSyscallRegs sets up syscall registers.
 //
 // This should be called to generate registers for a system call.
-func createSyscallRegs(initRegs *syscall.PtraceRegs, sysno uintptr, args ...arch.SyscallArgument) syscall.PtraceRegs {
+func createSyscallRegs(initRegs *arch.Registers, sysno uintptr, args ...arch.SyscallArgument) arch.Registers {
 	// Copy initial registers.
 	regs := *initRegs
 
@@ -82,18 +82,18 @@ func createSyscallRegs(initRegs *syscall.PtraceRegs, sysno uintptr, args ...arch
 }
 
 // isSingleStepping determines if the registers indicate single-stepping.
-func isSingleStepping(regs *syscall.PtraceRegs) bool {
+func isSingleStepping(regs *arch.Registers) bool {
 	return (regs.Eflags & arch.X86TrapFlag) != 0
 }
 
 // updateSyscallRegs updates registers after finishing sysemu.
-func updateSyscallRegs(regs *syscall.PtraceRegs) {
+func updateSyscallRegs(regs *arch.Registers) {
 	// Ptrace puts -ENOSYS in rax on syscall-enter-stop.
 	regs.Rax = regs.Orig_rax
 }
 
 // syscallReturnValue extracts a sensible return from registers.
-func syscallReturnValue(regs *syscall.PtraceRegs) (uintptr, error) {
+func syscallReturnValue(regs *arch.Registers) (uintptr, error) {
 	rval := int64(regs.Rax)
 	if rval < 0 {
 		return 0, syscall.Errno(-rval)
@@ -101,7 +101,7 @@ func syscallReturnValue(regs *syscall.PtraceRegs) (uintptr, error) {
 	return uintptr(rval), nil
 }
 
-func dumpRegs(regs *syscall.PtraceRegs) string {
+func dumpRegs(regs *arch.Registers) string {
 	var m strings.Builder
 
 	fmt.Fprintf(&m, "Registers:\n")
@@ -143,7 +143,7 @@ func (t *thread) adjustInitRegsRip() {
 }
 
 // Pass the expected PPID to the child via R15 when creating stub process.
-func initChildProcessPPID(initregs *syscall.PtraceRegs, ppid int32) {
+func initChildProcessPPID(initregs *arch.Registers, ppid int32) {
 	initregs.R15 = uint64(ppid)
 	// Rbx has to be set to 1 when creating stub process.
 	initregs.Rbx = 1
@@ -156,7 +156,7 @@ func initChildProcessPPID(initregs *syscall.PtraceRegs, ppid int32) {
 //
 // Note that this should only be called after verifying that the signalInfo has
 // been generated by the kernel.
-func patchSignalInfo(regs *syscall.PtraceRegs, signalInfo *arch.SignalInfo) {
+func patchSignalInfo(regs *arch.Registers, signalInfo *arch.SignalInfo) {
 	if linux.Signal(signalInfo.Signo) == linux.SIGSYS {
 		signalInfo.Signo = int32(linux.SIGSEGV)
 
diff --git a/pkg/sentry/platform/ptrace/subprocess_arm64.go b/pkg/sentry/platform/ptrace/subprocess_arm64.go
index 7f5c393f0..bd618fae8 100644
--- a/pkg/sentry/platform/ptrace/subprocess_arm64.go
+++ b/pkg/sentry/platform/ptrace/subprocess_arm64.go
@@ -41,13 +41,13 @@ const (
 // resetSysemuRegs sets up emulation registers.
 //
 // This should be called prior to calling sysemu.
-func (t *thread) resetSysemuRegs(regs *syscall.PtraceRegs) {
+func (t *thread) resetSysemuRegs(regs *arch.Registers) {
 }
 
 // createSyscallRegs sets up syscall registers.
 //
 // This should be called to generate registers for a system call.
-func createSyscallRegs(initRegs *syscall.PtraceRegs, sysno uintptr, args ...arch.SyscallArgument) syscall.PtraceRegs {
+func createSyscallRegs(initRegs *arch.Registers, sysno uintptr, args ...arch.SyscallArgument) arch.Registers {
 	// Copy initial registers (Pc, Sp, etc.).
 	regs := *initRegs
 
@@ -78,7 +78,7 @@ func createSyscallRegs(initRegs *syscall.PtraceRegs, sysno uintptr, args ...arch
 }
 
 // isSingleStepping determines if the registers indicate single-stepping.
-func isSingleStepping(regs *syscall.PtraceRegs) bool {
+func isSingleStepping(regs *arch.Registers) bool {
 	// Refer to the ARM SDM D2.12.3: software step state machine
 	// return (regs.Pstate.SS == 1) && (MDSCR_EL1.SS == 1).
 	//
@@ -89,13 +89,13 @@ func isSingleStepping(regs *syscall.PtraceRegs) bool {
 }
 
 // updateSyscallRegs updates registers after finishing sysemu.
-func updateSyscallRegs(regs *syscall.PtraceRegs) {
+func updateSyscallRegs(regs *arch.Registers) {
 	// No special work is necessary.
 	return
 }
 
 // syscallReturnValue extracts a sensible return from registers.
-func syscallReturnValue(regs *syscall.PtraceRegs) (uintptr, error) {
+func syscallReturnValue(regs *arch.Registers) (uintptr, error) {
 	rval := int64(regs.Regs[0])
 	if rval < 0 {
 		return 0, syscall.Errno(-rval)
@@ -103,7 +103,7 @@ func syscallReturnValue(regs *syscall.PtraceRegs) (uintptr, error) {
 	return uintptr(rval), nil
 }
 
-func dumpRegs(regs *syscall.PtraceRegs) string {
+func dumpRegs(regs *arch.Registers) string {
 	var m strings.Builder
 
 	fmt.Fprintf(&m, "Registers:\n")
@@ -125,7 +125,7 @@ func (t *thread) adjustInitRegsRip() {
 }
 
 // Pass the expected PPID to the child via X7 when creating stub process
-func initChildProcessPPID(initregs *syscall.PtraceRegs, ppid int32) {
+func initChildProcessPPID(initregs *arch.Registers, ppid int32) {
 	initregs.Regs[7] = uint64(ppid)
 	// R9 has to be set to 1 when creating stub process.
 	initregs.Regs[9] = 1
@@ -138,7 +138,7 @@ func initChildProcessPPID(initregs *syscall.PtraceRegs, ppid int32) {
 //
 // Note that this should only be called after verifying that the signalInfo has
 // been generated by the kernel.
-func patchSignalInfo(regs *syscall.PtraceRegs, signalInfo *arch.SignalInfo) {
+func patchSignalInfo(regs *arch.Registers, signalInfo *arch.SignalInfo) {
 	if linux.Signal(signalInfo.Signo) == linux.SIGSYS {
 		signalInfo.Signo = int32(linux.SIGSEGV)
 
diff --git a/pkg/sentry/platform/ring0/BUILD b/pkg/sentry/platform/ring0/BUILD
index b69520030..679b287c3 100644
--- a/pkg/sentry/platform/ring0/BUILD
+++ b/pkg/sentry/platform/ring0/BUILD
@@ -79,6 +79,7 @@ go_library(
     deps = [
         "//pkg/cpuid",
         "//pkg/safecopy",
+        "//pkg/sentry/arch",
         "//pkg/sentry/platform/ring0/pagetables",
         "//pkg/usermem",
     ],
diff --git a/pkg/sentry/platform/ring0/defs.go b/pkg/sentry/platform/ring0/defs.go
index 86fd5ed58..e6daf24df 100644
--- a/pkg/sentry/platform/ring0/defs.go
+++ b/pkg/sentry/platform/ring0/defs.go
@@ -15,8 +15,7 @@
 package ring0
 
 import (
-	"syscall"
-
+	"gvisor.dev/gvisor/pkg/sentry/arch"
 	"gvisor.dev/gvisor/pkg/sentry/platform/ring0/pagetables"
 )
 
@@ -72,7 +71,7 @@ type CPU struct {
 
 	// registers is a set of registers; these may be used on kernel system
 	// calls and exceptions via the Registers function.
-	registers syscall.PtraceRegs
+	registers arch.Registers
 
 	// hooks are kernel hooks.
 	hooks Hooks
@@ -83,14 +82,14 @@ type CPU struct {
 // This is explicitly safe to call during KernelException and KernelSyscall.
 //
 //go:nosplit
-func (c *CPU) Registers() *syscall.PtraceRegs {
+func (c *CPU) Registers() *arch.Registers {
 	return &c.registers
 }
 
 // SwitchOpts are passed to the Switch function.
 type SwitchOpts struct {
 	// Registers are the user register state.
-	Registers *syscall.PtraceRegs
+	Registers *arch.Registers
 
 	// FloatingPointState is a byte pointer where floating point state is
 	// saved and restored.
diff --git a/pkg/sentry/platform/ring0/entry_amd64.go b/pkg/sentry/platform/ring0/entry_amd64.go
index a5ce67885..7fa43c2f5 100644
--- a/pkg/sentry/platform/ring0/entry_amd64.go
+++ b/pkg/sentry/platform/ring0/entry_amd64.go
@@ -17,7 +17,7 @@
 package ring0
 
 import (
-	"syscall"
+	"gvisor.dev/gvisor/pkg/sentry/arch"
 )
 
 // This is an assembly function.
@@ -41,7 +41,7 @@ func swapgs()
 // The return code is the vector that interrupted execution.
 //
 // See stubs.go for a note regarding the frame size of this function.
-func sysret(*CPU, *syscall.PtraceRegs) Vector
+func sysret(*CPU, *arch.Registers) Vector
 
 // "iret is the cadillac of CPL switching."
 //
@@ -50,7 +50,7 @@ func sysret(*CPU, *syscall.PtraceRegs) Vector
 // iret is nearly identical to sysret, except an iret is used to fully restore
 // all user state. This must be called in cases where all registers need to be
 // restored.
-func iret(*CPU, *syscall.PtraceRegs) Vector
+func iret(*CPU, *arch.Registers) Vector
 
 // exception is the generic exception entry.
 //
diff --git a/pkg/sentry/platform/ring0/gen_offsets/BUILD b/pkg/sentry/platform/ring0/gen_offsets/BUILD
index 4cae10459..549f3d228 100644
--- a/pkg/sentry/platform/ring0/gen_offsets/BUILD
+++ b/pkg/sentry/platform/ring0/gen_offsets/BUILD
@@ -27,6 +27,7 @@ go_binary(
     visibility = ["//pkg/sentry/platform/ring0:__pkg__"],
     deps = [
         "//pkg/cpuid",
+        "//pkg/sentry/arch",
         "//pkg/sentry/platform/ring0/pagetables",
         "//pkg/usermem",
     ],
diff --git a/pkg/sentry/platform/ring0/offsets_amd64.go b/pkg/sentry/platform/ring0/offsets_amd64.go
index 85cc3fdad..b8ab120a0 100644
--- a/pkg/sentry/platform/ring0/offsets_amd64.go
+++ b/pkg/sentry/platform/ring0/offsets_amd64.go
@@ -20,7 +20,8 @@ import (
 	"fmt"
 	"io"
 	"reflect"
-	"syscall"
+
+	"gvisor.dev/gvisor/pkg/sentry/arch"
 )
 
 // Emit prints architecture-specific offsets.
@@ -64,7 +65,7 @@ func Emit(w io.Writer) {
 	fmt.Fprintf(w, "#define SyscallInt80               0x%02x\n", SyscallInt80)
 	fmt.Fprintf(w, "#define Syscall                    0x%02x\n", Syscall)
 
-	p := &syscall.PtraceRegs{}
+	p := &arch.Registers{}
 	fmt.Fprintf(w, "\n// Ptrace registers.\n")
 	fmt.Fprintf(w, "#define PTRACE_R15      0x%02x\n", reflect.ValueOf(&p.R15).Pointer()-reflect.ValueOf(p).Pointer())
 	fmt.Fprintf(w, "#define PTRACE_R14      0x%02x\n", reflect.ValueOf(&p.R14).Pointer()-reflect.ValueOf(p).Pointer())
diff --git a/pkg/sentry/platform/ring0/offsets_arm64.go b/pkg/sentry/platform/ring0/offsets_arm64.go
index 057fb5c69..f3de962f0 100644
--- a/pkg/sentry/platform/ring0/offsets_arm64.go
+++ b/pkg/sentry/platform/ring0/offsets_arm64.go
@@ -20,7 +20,8 @@ import (
 	"fmt"
 	"io"
 	"reflect"
-	"syscall"
+
+	"gvisor.dev/gvisor/pkg/sentry/arch"
 )
 
 // Emit prints architecture-specific offsets.
@@ -87,7 +88,7 @@ func Emit(w io.Writer) {
 	fmt.Fprintf(w, "#define Syscall 0x%02x\n", Syscall)
 	fmt.Fprintf(w, "#define VirtualizationException 0x%02x\n", VirtualizationException)
 
-	p := &syscall.PtraceRegs{}
+	p := &arch.Registers{}
 	fmt.Fprintf(w, "\n// Ptrace registers.\n")
 	fmt.Fprintf(w, "#define PTRACE_R0       0x%02x\n", reflect.ValueOf(&p.Regs[0]).Pointer()-reflect.ValueOf(p).Pointer())
 	fmt.Fprintf(w, "#define PTRACE_R1       0x%02x\n", reflect.ValueOf(&p.Regs[1]).Pointer()-reflect.ValueOf(p).Pointer())
diff --git a/pkg/sentry/syscalls/linux/sys_signal.go b/pkg/sentry/syscalls/linux/sys_signal.go
index 7e1747a0c..582d37e03 100644
--- a/pkg/sentry/syscalls/linux/sys_signal.go
+++ b/pkg/sentry/syscalls/linux/sys_signal.go
@@ -355,7 +355,7 @@ func Pause(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Syscall
 func RtSigpending(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
 	addr := args[0].Pointer()
 	pending := t.PendingSignals()
-	_, err := t.CopyOut(addr, pending)
+	_, err := pending.CopyOut(t, addr)
 	return 0, nil, err
 }
 
@@ -392,7 +392,7 @@ func RtSigtimedwait(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kerne
 
 	if siginfo != 0 {
 		si.FixSignalCodeForUser()
-		if _, err := t.CopyOut(siginfo, si); err != nil {
+		if _, err := si.CopyOut(t, siginfo); err != nil {
 			return 0, nil, err
 		}
 	}
@@ -411,7 +411,7 @@ func RtSigqueueinfo(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kerne
 	// same way), and that the code is in the allowed set. This same logic
 	// appears below in RtSigtgqueueinfo and should be kept in sync.
 	var info arch.SignalInfo
-	if _, err := t.CopyIn(infoAddr, &info); err != nil {
+	if _, err := info.CopyIn(t, infoAddr); err != nil {
 		return 0, nil, err
 	}
 	info.Signo = int32(sig)
@@ -455,7 +455,7 @@ func RtTgsigqueueinfo(t *kernel.Task, args arch.SyscallArguments) (uintptr, *ker
 
 	// Copy in the info. See RtSigqueueinfo above.
 	var info arch.SignalInfo
-	if _, err := t.CopyIn(infoAddr, &info); err != nil {
+	if _, err := info.CopyIn(t, infoAddr); err != nil {
 		return 0, nil, err
 	}
 	info.Signo = int32(sig)
@@ -485,7 +485,7 @@ func RtSigsuspend(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.
 
 	// Copy in the signal mask.
 	var mask linux.SignalSet
-	if _, err := t.CopyIn(sigset, &mask); err != nil {
+	if _, err := mask.CopyIn(t, sigset); err != nil {
 		return 0, nil, err
 	}
 	mask &^= kernel.UnblockableSignals