3 files changed, 65 insertions, 21 deletions
diff --git a/pkg/sentry/arch/arch_aarch64.go b/pkg/sentry/arch/arch_aarch64.go
index d7794db63..b998f84fc 100644
--- a/pkg/sentry/arch/arch_aarch64.go
+++ b/pkg/sentry/arch/arch_aarch64.go
@@ -32,6 +32,12 @@ import (
 const (
 	// SyscallWidth is the width of insturctions.
 	SyscallWidth = 4
+
+	// fpsimdMagic is the magic number which is used in fpsimd_context.
+	fpsimdMagic = 0x46508001
+
+	// fpsimdContextSize is the size of fpsimd_context.
+	fpsimdContextSize = 0x210
 )
 
 // ARMTrapFlag is the mask for the trap flag.
@@ -40,24 +46,24 @@ const ARMTrapFlag = uint64(1) << 21
 // aarch64FPState is aarch64 floating point state.
 type aarch64FPState []byte
 
-// initAarch64FPState (defined in asm files) sets up initial state.
-func initAarch64FPState(data *FloatingPointData) {
-	// TODO(gvisor.dev/issue/1238): floating-point is not supported.
+// initAarch64FPState sets up initial state.
+func initAarch64FPState(data aarch64FPState) {
+	binary.LittleEndian.PutUint32(data, fpsimdMagic)
+	binary.LittleEndian.PutUint32(data[4:], fpsimdContextSize)
 }
 
 func newAarch64FPStateSlice() []byte {
-	return alignedBytes(4096, 32)[:4096]
+	return alignedBytes(4096, 16)[:fpsimdContextSize]
 }
 
 // newAarch64FPState returns an initialized floating point state.
 //
 // The returned state is large enough to store all floating point state
 // supported by host, even if the app won't use much of it due to a restricted
-// FeatureSet. Since they may still be able to see state not advertised by
-// CPUID we must ensure it does not contain any sentry state.
+// FeatureSet.
 func newAarch64FPState() aarch64FPState {
 	f := aarch64FPState(newAarch64FPStateSlice())
-	initAarch64FPState(f.FloatingPointData())
+	initAarch64FPState(f)
 	return f
 }
 
@@ -89,6 +95,9 @@ type State struct {
 	// Our floating point state.
 	aarch64FPState `state:"wait"`
 
+	// TLS pointer
+	TPValue uint64
+
 	// FeatureSet is a pointer to the currently active feature set.
 	FeatureSet *cpuid.FeatureSet
 }
@@ -136,10 +145,11 @@ func (s State) Proto() *rpb.Registers {
 
 // Fork creates and returns an identical copy of the state.
 func (s *State) Fork() State {
-	// TODO(gvisor.dev/issue/1238): floating-point is not supported.
 	return State{
-		Regs:       s.Regs,
-		FeatureSet: s.FeatureSet,
+		Regs:           s.Regs,
+		aarch64FPState: s.aarch64FPState.fork(),
+		TPValue:        s.TPValue,
+		FeatureSet:     s.FeatureSet,
 	}
 }
 
@@ -249,6 +259,7 @@ func (s *State) PtraceSetFPRegs(src io.Reader) (int, error) {
 const (
 	_NT_PRSTATUS = 1
 	_NT_PRFPREG  = 2
+	_NT_ARM_TLS  = 0x401
 )
 
 // PtraceGetRegSet implements Context.PtraceGetRegSet.
@@ -288,8 +299,10 @@ func New(arch Arch, fs *cpuid.FeatureSet) Context {
 	case ARM64:
 		return &context64{
 			State{
-				FeatureSet: fs,
+				aarch64FPState: newAarch64FPState(),
+				FeatureSet:     fs,
 			},
+			[]aarch64FPState(nil),
 		}
 	}
 	panic(fmt.Sprintf("unknown architecture %v", arch))
diff --git a/pkg/sentry/arch/arch_arm64.go b/pkg/sentry/arch/arch_arm64.go
index ac98897b5..db99c5acb 100644
--- a/pkg/sentry/arch/arch_arm64.go
+++ b/pkg/sentry/arch/arch_arm64.go
@@ -53,6 +53,11 @@ const (
 	preferredPIELoadAddr usermem.Addr = maxAddr64 / 6 * 5
 )
 
+var (
+	// CPUIDInstruction doesn't exist on ARM64.
+	CPUIDInstruction = []byte{}
+)
+
 // These constants are selected as heuristics to help make the Platform's
 // potentially limited address space conform as closely to Linux as possible.
 const (
@@ -68,6 +73,7 @@ const (
 // context64 represents an ARM64 context.
 type context64 struct {
 	State
+	sigFPState []aarch64FPState // fpstate to be restored on sigreturn.
 }
 
 // Arch implements Context.Arch.
@@ -75,10 +81,19 @@ func (c *context64) Arch() Arch {
 	return ARM64
 }
 
+func (c *context64) copySigFPState() []aarch64FPState {
+	var sigfps []aarch64FPState
+	for _, s := range c.sigFPState {
+		sigfps = append(sigfps, s.fork())
+	}
+	return sigfps
+}
+
 // Fork returns an exact copy of this context.
 func (c *context64) Fork() Context {
 	return &context64{
-		State: c.State.Fork(),
+		State:      c.State.Fork(),
+		sigFPState: c.copySigFPState(),
 	}
 }
 
@@ -125,16 +140,17 @@ func (c *context64) SetStack(value uintptr) {
 
 // TLS returns the current TLS pointer.
 func (c *context64) TLS() uintptr {
-	// TODO(gvisor.dev/issue/1238): TLS is not supported.
-	// MRS_TPIDR_EL0
-	return 0
+	return uintptr(c.TPValue)
 }
 
 // SetTLS sets the current TLS pointer. Returns false if value is invalid.
 func (c *context64) SetTLS(value uintptr) bool {
-	// TODO(gvisor.dev/issue/1238): TLS is not supported.
-	// MSR_TPIDR_EL0
-	return false
+	if value >= uintptr(maxAddr64) {
+		return false
+	}
+
+	c.TPValue = uint64(value)
+	return true
 }
 
 // SetOldRSeqInterruptedIP implements Context.SetOldRSeqInterruptedIP.
diff --git a/pkg/sentry/arch/signal_arm64.go b/pkg/sentry/arch/signal_arm64.go
index 4f4cc46a8..0c1db4b13 100644
--- a/pkg/sentry/arch/signal_arm64.go
+++ b/pkg/sentry/arch/signal_arm64.go
@@ -30,14 +30,29 @@ type SignalContext64 struct {
 	Sp        uint64
 	Pc        uint64
 	Pstate    uint64
-	_pad      [8]byte // __attribute__((__aligned__(16)))
-	Reserved  [4096]uint8
+	_pad      [8]byte       // __attribute__((__aligned__(16)))
+	Fpsimd64  FpsimdContext // size = 528
+	Reserved  [3568]uint8
+}
+
+type aarch64Ctx struct {
+	Magic uint32
+	Size  uint32
+}
+
+// FpsimdContext is equivalent to struct fpsimd_context on arm64
+// (arch/arm64/include/uapi/asm/sigcontext.h).
+type FpsimdContext struct {
+	Head  aarch64Ctx
+	Fpsr  uint32
+	Fpcr  uint32
+	Vregs [64]uint64 // actually [32]uint128
 }
 
 // UContext64 is equivalent to ucontext on arm64(arch/arm64/include/uapi/asm/ucontext.h).
 type UContext64 struct {
 	Flags  uint64
-	Link   *UContext64
+	Link   uint64
 	Stack  SignalStack
 	Sigset linux.SignalSet
 	// glibc uses a 1024-bit sigset_t