[dev.fuzz] all: merge master into dev.fuzz

Change-Id: I5d8c8329ccc9d747bd81ade6b1cb7cb8ae2e94b2

66 files changed, 1050 insertions, 522 deletions

diff --git a/src/internal/bytealg/bytealg.go b/src/internal/bytealg/bytealg.go
index 6fd9308369..b30c234436 100644
--- a/src/internal/bytealg/bytealg.go
+++ b/src/internal/bytealg/bytealg.go
@@ -99,7 +99,7 @@ func HashStrRev(sep string) (uint32, uint32) {
 }
 
 // IndexRabinKarpBytes uses the Rabin-Karp search algorithm to return the index of the
-// first occurence of substr in s, or -1 if not present.
+// first occurrence of substr in s, or -1 if not present.
 func IndexRabinKarpBytes(s, sep []byte) int {
 	// Rabin-Karp search
 	hashsep, pow := HashStrBytes(sep)
@@ -124,7 +124,7 @@ func IndexRabinKarpBytes(s, sep []byte) int {
 }
 
 // IndexRabinKarp uses the Rabin-Karp search algorithm to return the index of the
-// first occurence of substr in s, or -1 if not present.
+// first occurrence of substr in s, or -1 if not present.
 func IndexRabinKarp(s, substr string) int {
 	// Rabin-Karp search
 	hashss, pow := HashStr(substr)
diff --git a/src/internal/bytealg/count_generic.go b/src/internal/bytealg/count_generic.go
index 7cc1d50312..5575e81ab8 100644
--- a/src/internal/bytealg/count_generic.go
+++ b/src/internal/bytealg/count_generic.go
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build !amd64,!arm,!arm64,!ppc64le,!ppc64,!s390x
+// +build !amd64,!arm,!arm64,!ppc64le,!ppc64,!riscv64,!s390x
 
 package bytealg
 
diff --git a/src/internal/bytealg/count_native.go b/src/internal/bytealg/count_native.go
index 0448fca9e8..b1ff1d265a 100644
--- a/src/internal/bytealg/count_native.go
+++ b/src/internal/bytealg/count_native.go
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build amd64 arm arm64 ppc64le ppc64 s390x
+// +build amd64 arm arm64 ppc64le ppc64 riscv64 s390x
 
 package bytealg
 
diff --git a/src/internal/bytealg/count_riscv64.s b/src/internal/bytealg/count_riscv64.s
new file mode 100644
index 0000000000..3f4eb23286
--- /dev/null
+++ b/src/internal/bytealg/count_riscv64.s
@@ -0,0 +1,44 @@
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#include "go_asm.h"
+#include "textflag.h"
+
+TEXT ·Count(SB),NOSPLIT,$0-40
+	MOV	b_base+0(FP), A1
+	MOV	b_len+8(FP), A2
+	MOVBU	c+24(FP), A3	// byte to count
+	MOV	ZERO, A4	// count
+	ADD	A1, A2		// end
+
+loop:
+	BEQ	A1, A2, done
+	MOVBU	(A1), A5
+	ADD	$1, A1
+	BNE	A3, A5, loop
+	ADD	$1, A4
+	JMP	loop
+
+done:
+	MOV	A4, ret+32(FP)
+	RET
+
+TEXT ·CountString(SB),NOSPLIT,$0-32
+	MOV	s_base+0(FP), A1
+	MOV	s_len+8(FP), A2
+	MOVBU	c+16(FP), A3	// byte to count
+	MOV	ZERO, A4	// count
+	ADD	A1, A2		// end
+
+loop:
+	BEQ	A1, A2, done
+	MOVBU	(A1), A5
+	ADD	$1, A1
+	BNE	A3, A5, loop
+	ADD	$1, A4
+	JMP	loop
+
+done:
+	MOV	A4, ret+24(FP)
+	RET
diff --git a/src/internal/bytealg/equal_mips64x.s b/src/internal/bytealg/equal_mips64x.s
index 58dc4303b4..641e3ff06c 100644
--- a/src/internal/bytealg/equal_mips64x.s
+++ b/src/internal/bytealg/equal_mips64x.s
@@ -16,18 +16,82 @@ TEXT runtime·memequal(SB),NOSPLIT|NOFRAME,$0-25
 	BEQ	R1, R2, eq
 	MOVV	size+16(FP), R3
 	ADDV	R1, R3, R4
-loop:
-	BNE	R1, R4, test
+
+	// chunk size is 16
+	SGTU	$16, R3, R8
+	BEQ	R0, R8, chunk_entry
+
+byte_loop:
+	BNE	R1, R4, byte_test
 	MOVV	$1, R1
 	MOVB	R1, ret+24(FP)
 	RET
-test:
+byte_test:
 	MOVBU	(R1), R6
 	ADDV	$1, R1
 	MOVBU	(R2), R7
 	ADDV	$1, R2
-	BEQ	R6, R7, loop
+	BEQ	R6, R7, byte_loop
+	JMP	not_eq
+
+chunk_entry:
+	// make sure both a and b are aligned
+	OR	R1, R2, R9
+	AND	$0x7, R9
+	BNE	R0, R9, byte_loop
+	JMP	chunk_loop_1
+
+chunk_loop:
+	// chunk size is 16
+	SGTU	$16, R3, R8
+	BNE	R0, R8, chunk_tail_8
+chunk_loop_1:
+	MOVV	(R1), R6
+	MOVV	(R2), R7
+	BNE	R6, R7, not_eq
+	MOVV	8(R1), R12
+	MOVV	8(R2), R13
+	ADDV	$16, R1
+	ADDV	$16, R2
+	SUBV	$16, R3
+	BEQ	R12, R13, chunk_loop
+	JMP	not_eq
+
+chunk_tail_8:
+	AND	$8, R3, R14
+	BEQ	R0, R14, chunk_tail_4
+	MOVV	(R1), R6
+	MOVV	(R2), R7
+	BNE	R6, R7, not_eq
+	ADDV	$8, R1
+	ADDV	$8, R2
+
+chunk_tail_4:
+	AND	$4, R3, R14
+	BEQ	R0, R14, chunk_tail_2
+	MOVWU	(R1), R6
+	MOVWU	(R2), R7
+	BNE	R6, R7, not_eq
+	ADDV	$4, R1
+	ADDV	$4, R2
+
+chunk_tail_2:
+	AND	$2, R3, R14
+	BEQ	R0, R14, chunk_tail_1
+	MOVHU	(R1), R6
+	MOVHU	(R2), R7
+	BNE	R6, R7, not_eq
+	ADDV	$2, R1
+	ADDV	$2, R2
+
+chunk_tail_1:
+	AND	$1, R3, R14
+	BEQ	R0, R14, eq
+	MOVBU	(R1), R6
+	MOVBU	(R2), R7
+	BEQ	R6, R7, eq
 
+not_eq:
 	MOVB	R0, ret+24(FP)
 	RET
 eq:
diff --git a/src/internal/bytealg/index_generic.go b/src/internal/bytealg/index_generic.go
index 83345f1013..98e859f925 100644
--- a/src/internal/bytealg/index_generic.go
+++ b/src/internal/bytealg/index_generic.go
@@ -16,42 +16,8 @@ func Index(a, b []byte) int {
 
 // IndexString returns the index of the first instance of b in a, or -1 if b is not present in a.
 // Requires 2 <= len(b) <= MaxLen.
-func IndexString(s, substr string) int {
-	// This is a partial copy of strings.Index, here because bytes.IndexAny and bytes.LastIndexAny
-	// call bytealg.IndexString. Some platforms have an optimized assembly version of this function.
-	// This implementation is used for those that do not. Although the pure Go implementation here
-	// works for the case of len(b) > MaxLen, we do not require that its assembly implementation also
-	// supports the case of len(b) > MaxLen. And we do not guarantee that this function supports the
-	// case of len(b) > MaxLen.
-	n := len(substr)
-	c0 := substr[0]
-	c1 := substr[1]
-	i := 0
-	t := len(s) - n + 1
-	fails := 0
-	for i < t {
-		if s[i] != c0 {
-			o := IndexByteString(s[i:t], c0)
-			if o < 0 {
-				return -1
-			}
-			i += o
-		}
-		if s[i+1] == c1 && s[i:i+n] == substr {
-			return i
-		}
-		i++
-		fails++
-		if fails >= 4+i>>4 && i < t {
-			// See comment in src/bytes/bytes.go.
-			j := IndexRabinKarp(s[i:], substr)
-			if j < 0 {
-				return -1
-			}
-			return i + j
-		}
-	}
-	return -1
+func IndexString(a, b string) int {
+	panic("unimplemented")
 }
 
 // Cutover reports the number of failures of IndexByte we should tolerate
diff --git a/src/internal/cfg/cfg.go b/src/internal/cfg/cfg.go
index bdbe9df3e7..553021374d 100644
--- a/src/internal/cfg/cfg.go
+++ b/src/internal/cfg/cfg.go
@@ -58,6 +58,7 @@ const KnownEnv = `
 	GOSUMDB
 	GOTMPDIR
 	GOTOOLDIR
+	GOVCS
 	GOWASM
 	GO_EXTLINK_ENABLED
 	PKG_CONFIG
diff --git a/src/internal/cpu/cpu.go b/src/internal/cpu/cpu.go
index 2829945af0..dab5d068ef 100644
--- a/src/internal/cpu/cpu.go
+++ b/src/internal/cpu/cpu.go
@@ -56,32 +56,17 @@ var ARM struct {
 // The booleans in ARM64 contain the correspondingly named cpu feature bit.
 // The struct is padded to avoid false sharing.
 var ARM64 struct {
-	_           CacheLinePad
-	HasFP       bool
-	HasASIMD    bool
-	HasEVTSTRM  bool
-	HasAES      bool
-	HasPMULL    bool
-	HasSHA1     bool
-	HasSHA2     bool
-	HasCRC32    bool
-	HasATOMICS  bool
-	HasFPHP     bool
-	HasASIMDHP  bool
-	HasCPUID    bool
-	HasASIMDRDM bool
-	HasJSCVT    bool
-	HasFCMA     bool
-	HasLRCPC    bool
-	HasDCPOP    bool
-	HasSHA3     bool
-	HasSM3      bool
-	HasSM4      bool
-	HasASIMDDP  bool
-	HasSHA512   bool
-	HasSVE      bool
-	HasASIMDFHM bool
-	_           CacheLinePad
+	_            CacheLinePad
+	HasAES       bool
+	HasPMULL     bool
+	HasSHA1      bool
+	HasSHA2      bool
+	HasCRC32     bool
+	HasATOMICS   bool
+	HasCPUID     bool
+	IsNeoverseN1 bool
+	IsZeus       bool
+	_            CacheLinePad
 }
 
 var MIPS64X struct {
diff --git a/src/internal/cpu/cpu.s b/src/internal/cpu/cpu.s
new file mode 100644
index 0000000000..3c770c132d
--- /dev/null
+++ b/src/internal/cpu/cpu.s
@@ -0,0 +1,6 @@
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// This assembly file exists to allow internal/cpu to call
+// non-exported runtime functions that use "go:linkname".
\ No newline at end of file
diff --git a/src/internal/cpu/cpu_arm64.go b/src/internal/cpu/cpu_arm64.go
index efdb3b9e33..f64d9e4dd3 100644
--- a/src/internal/cpu/cpu_arm64.go
+++ b/src/internal/cpu/cpu_arm64.go
@@ -6,97 +6,23 @@ package cpu
 
 const CacheLinePadSize = 64
 
-// arm64 doesn't have a 'cpuid' equivalent, so we rely on HWCAP/HWCAP2.
-// These are initialized by archauxv and should not be changed after they are
-// initialized.
-var HWCap uint
-var HWCap2 uint
-
-// HWCAP/HWCAP2 bits. These are exposed by Linux.
-const (
-	hwcap_FP       = 1 << 0
-	hwcap_ASIMD    = 1 << 1
-	hwcap_EVTSTRM  = 1 << 2
-	hwcap_AES      = 1 << 3
-	hwcap_PMULL    = 1 << 4
-	hwcap_SHA1     = 1 << 5
-	hwcap_SHA2     = 1 << 6
-	hwcap_CRC32    = 1 << 7
-	hwcap_ATOMICS  = 1 << 8
-	hwcap_FPHP     = 1 << 9
-	hwcap_ASIMDHP  = 1 << 10
-	hwcap_CPUID    = 1 << 11
-	hwcap_ASIMDRDM = 1 << 12
-	hwcap_JSCVT    = 1 << 13
-	hwcap_FCMA     = 1 << 14
-	hwcap_LRCPC    = 1 << 15
-	hwcap_DCPOP    = 1 << 16
-	hwcap_SHA3     = 1 << 17
-	hwcap_SM3      = 1 << 18
-	hwcap_SM4      = 1 << 19
-	hwcap_ASIMDDP  = 1 << 20
-	hwcap_SHA512   = 1 << 21
-	hwcap_SVE      = 1 << 22
-	hwcap_ASIMDFHM = 1 << 23
-)
-
 func doinit() {
 	options = []option{
-		{Name: "evtstrm", Feature: &ARM64.HasEVTSTRM},
 		{Name: "aes", Feature: &ARM64.HasAES},
 		{Name: "pmull", Feature: &ARM64.HasPMULL},
 		{Name: "sha1", Feature: &ARM64.HasSHA1},
 		{Name: "sha2", Feature: &ARM64.HasSHA2},
 		{Name: "crc32", Feature: &ARM64.HasCRC32},
 		{Name: "atomics", Feature: &ARM64.HasATOMICS},
-		{Name: "fphp", Feature: &ARM64.HasFPHP},
-		{Name: "asimdhp", Feature: &ARM64.HasASIMDHP},
 		{Name: "cpuid", Feature: &ARM64.HasCPUID},
-		{Name: "asimdrdm", Feature: &ARM64.HasASIMDRDM},
-		{Name: "jscvt", Feature: &ARM64.HasJSCVT},
-		{Name: "fcma", Feature: &ARM64.HasFCMA},
-		{Name: "lrcpc", Feature: &ARM64.HasLRCPC},
-		{Name: "dcpop", Feature: &ARM64.HasDCPOP},
-		{Name: "sha3", Feature: &ARM64.HasSHA3},
-		{Name: "sm3", Feature: &ARM64.HasSM3},
-		{Name: "sm4", Feature: &ARM64.HasSM4},
-		{Name: "asimddp", Feature: &ARM64.HasASIMDDP},
-		{Name: "sha512", Feature: &ARM64.HasSHA512},
-		{Name: "sve", Feature: &ARM64.HasSVE},
-		{Name: "asimdfhm", Feature: &ARM64.HasASIMDFHM},
-
-		// These capabilities should always be enabled on arm64:
-		{Name: "fp", Feature: &ARM64.HasFP, Required: true},
-		{Name: "asimd", Feature: &ARM64.HasASIMD, Required: true},
+		{Name: "isNeoverseN1", Feature: &ARM64.IsNeoverseN1},
+		{Name: "isZeus", Feature: &ARM64.IsZeus},
 	}
 
-	// HWCAP feature bits
-	ARM64.HasFP = isSet(HWCap, hwcap_FP)
-	ARM64.HasASIMD = isSet(HWCap, hwcap_ASIMD)
-	ARM64.HasEVTSTRM = isSet(HWCap, hwcap_EVTSTRM)
-	ARM64.HasAES = isSet(HWCap, hwcap_AES)
-	ARM64.HasPMULL = isSet(HWCap, hwcap_PMULL)
-	ARM64.HasSHA1 = isSet(HWCap, hwcap_SHA1)
-	ARM64.HasSHA2 = isSet(HWCap, hwcap_SHA2)
-	ARM64.HasCRC32 = isSet(HWCap, hwcap_CRC32)
-	ARM64.HasATOMICS = isSet(HWCap, hwcap_ATOMICS)
-	ARM64.HasFPHP = isSet(HWCap, hwcap_FPHP)
-	ARM64.HasASIMDHP = isSet(HWCap, hwcap_ASIMDHP)
-	ARM64.HasCPUID = isSet(HWCap, hwcap_CPUID)
-	ARM64.HasASIMDRDM = isSet(HWCap, hwcap_ASIMDRDM)
-	ARM64.HasJSCVT = isSet(HWCap, hwcap_JSCVT)
-	ARM64.HasFCMA = isSet(HWCap, hwcap_FCMA)
-	ARM64.HasLRCPC = isSet(HWCap, hwcap_LRCPC)
-	ARM64.HasDCPOP = isSet(HWCap, hwcap_DCPOP)
-	ARM64.HasSHA3 = isSet(HWCap, hwcap_SHA3)
-	ARM64.HasSM3 = isSet(HWCap, hwcap_SM3)
-	ARM64.HasSM4 = isSet(HWCap, hwcap_SM4)
-	ARM64.HasASIMDDP = isSet(HWCap, hwcap_ASIMDDP)
-	ARM64.HasSHA512 = isSet(HWCap, hwcap_SHA512)
-	ARM64.HasSVE = isSet(HWCap, hwcap_SVE)
-	ARM64.HasASIMDFHM = isSet(HWCap, hwcap_ASIMDFHM)
+	// arm64 uses different ways to detect CPU features at runtime depending on the operating system.
+	osInit()
 }
 
-func isSet(hwc uint, value uint) bool {
-	return hwc&value != 0
-}
+func getisar0() uint64
+
+func getMIDR() uint64
diff --git a/src/internal/cpu/cpu_arm64.s b/src/internal/cpu/cpu_arm64.s
new file mode 100644
index 0000000000..d6e7f44373
--- /dev/null
+++ b/src/internal/cpu/cpu_arm64.s
@@ -0,0 +1,18 @@
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#include "textflag.h"
+
+// func getisar0() uint64
+TEXT ·getisar0(SB),NOSPLIT,$0
+	// get Instruction Set Attributes 0 into R0
+	MRS	ID_AA64ISAR0_EL1, R0
+	MOVD	R0, ret+0(FP)
+	RET
+
+// func getMIDR() uint64
+TEXT ·getMIDR(SB), NOSPLIT, $0-8
+	MRS	MIDR_EL1, R0
+	MOVD	R0, ret+0(FP)
+	RET
diff --git a/src/internal/cpu/cpu_arm64_android.go b/src/internal/cpu/cpu_arm64_android.go
new file mode 100644
index 0000000000..3c9e57c52a
--- /dev/null
+++ b/src/internal/cpu/cpu_arm64_android.go
@@ -0,0 +1,11 @@
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build arm64
+
+package cpu
+
+func osInit() {
+	hwcapInit("android")
+}
diff --git a/src/internal/cpu/cpu_arm64_darwin.go b/src/internal/cpu/cpu_arm64_darwin.go
new file mode 100644
index 0000000000..e094b97f97
--- /dev/null
+++ b/src/internal/cpu/cpu_arm64_darwin.go
@@ -0,0 +1,34 @@
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build arm64
+// +build darwin
+// +build !ios
+
+package cpu
+
+func osInit() {
+	ARM64.HasATOMICS = sysctlEnabled([]byte("hw.optional.armv8_1_atomics\x00"))
+	ARM64.HasCRC32 = sysctlEnabled([]byte("hw.optional.armv8_crc32\x00"))
+
+	// There are no hw.optional sysctl values for the below features on Mac OS 11.0
+	// to detect their supported state dynamically. Assume the CPU features that
+	// Apple Silicon M1 supports to be available as a minimal set of features
+	// to all Go programs running on darwin/arm64.
+	ARM64.HasAES = true
+	ARM64.HasPMULL = true
+	ARM64.HasSHA1 = true
+	ARM64.HasSHA2 = true
+}
+
+//go:noescape
+func getsysctlbyname(name []byte) (int32, int32)
+
+func sysctlEnabled(name []byte) bool {
+	ret, value := getsysctlbyname(name)
+	if ret < 0 {
+		return false
+	}
+	return value > 0
+}
diff --git a/src/internal/cpu/cpu_arm64_freebsd.go b/src/internal/cpu/cpu_arm64_freebsd.go
new file mode 100644
index 0000000000..9de2005c2e
--- /dev/null
+++ b/src/internal/cpu/cpu_arm64_freebsd.go
@@ -0,0 +1,45 @@
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build arm64
+
+package cpu
+
+func osInit() {
+	// Retrieve info from system register ID_AA64ISAR0_EL1.
+	isar0 := getisar0()
+
+	// ID_AA64ISAR0_EL1
+	switch extractBits(isar0, 4, 7) {
+	case 1:
+		ARM64.HasAES = true
+	case 2:
+		ARM64.HasAES = true
+		ARM64.HasPMULL = true
+	}
+
+	switch extractBits(isar0, 8, 11) {
+	case 1:
+		ARM64.HasSHA1 = true
+	}
+
+	switch extractBits(isar0, 12, 15) {
+	case 1, 2:
+		ARM64.HasSHA2 = true
+	}
+
+	switch extractBits(isar0, 16, 19) {
+	case 1:
+		ARM64.HasCRC32 = true
+	}
+
+	switch extractBits(isar0, 20, 23) {
+	case 2:
+		ARM64.HasATOMICS = true
+	}
+}
+
+func extractBits(data uint64, start, end uint) uint {
+	return (uint)(data>>start) & ((1 << (end - start + 1)) - 1)
+}
diff --git a/src/internal/cpu/cpu_arm64_hwcap.go b/src/internal/cpu/cpu_arm64_hwcap.go
new file mode 100644
index 0000000000..fdaf43e1a2
--- /dev/null
+++ b/src/internal/cpu/cpu_arm64_hwcap.go
@@ -0,0 +1,63 @@
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build arm64
+// +build linux
+
+package cpu
+
+// HWCap may be initialized by archauxv and
+// should not be changed after it was initialized.
+var HWCap uint
+
+// HWCAP bits. These are exposed by Linux.
+const (
+	hwcap_AES     = 1 << 3
+	hwcap_PMULL   = 1 << 4
+	hwcap_SHA1    = 1 << 5
+	hwcap_SHA2    = 1 << 6
+	hwcap_CRC32   = 1 << 7
+	hwcap_ATOMICS = 1 << 8
+	hwcap_CPUID   = 1 << 11
+)
+
+func hwcapInit(os string) {
+	// HWCap was populated by the runtime from the auxiliary vector.
+	// Use HWCap information since reading aarch64 system registers
+	// is not supported in user space on older linux kernels.
+	ARM64.HasAES = isSet(HWCap, hwcap_AES)
+	ARM64.HasPMULL = isSet(HWCap, hwcap_PMULL)
+	ARM64.HasSHA1 = isSet(HWCap, hwcap_SHA1)
+	ARM64.HasSHA2 = isSet(HWCap, hwcap_SHA2)
+	ARM64.HasCRC32 = isSet(HWCap, hwcap_CRC32)
+	ARM64.HasCPUID = isSet(HWCap, hwcap_CPUID)
+
+	// The Samsung S9+ kernel reports support for atomics, but not all cores
+	// actually support them, resulting in SIGILL. See issue #28431.
+	// TODO(elias.naur): Only disable the optimization on bad chipsets on android.
+	ARM64.HasATOMICS = isSet(HWCap, hwcap_ATOMICS) && os != "android"
+
+	// Check to see if executing on a NeoverseN1 and in order to do that,
+	// check the AUXV for the CPUID bit. The getMIDR function executes an
+	// instruction which would normally be an illegal instruction, but it's
+	// trapped by the kernel, the value sanitized and then returned. Without
+	// the CPUID bit the kernel will not trap the instruction and the process
+	// will be terminated with SIGILL.
+	if ARM64.HasCPUID {
+		midr := getMIDR()
+		part_num := uint16((midr >> 4) & 0xfff)
+		implementor := byte((midr >> 24) & 0xff)
+
+		if implementor == 'A' && part_num == 0xd0c {
+			ARM64.IsNeoverseN1 = true
+		}
+		if implementor == 'A' && part_num == 0xd40 {
+			ARM64.IsZeus = true
+		}
+	}
+}
+
+func isSet(hwc uint, value uint) bool {
+	return hwc&value != 0
+}
diff --git a/src/internal/cpu/cpu_arm64_linux.go b/src/internal/cpu/cpu_arm64_linux.go
new file mode 100644
index 0000000000..2f7411ff1e
--- /dev/null
+++ b/src/internal/cpu/cpu_arm64_linux.go
@@ -0,0 +1,13 @@
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build arm64
+// +build linux
+// +build !android
+
+package cpu
+
+func osInit() {
+	hwcapInit("linux")
+}
diff --git a/src/internal/cpu/cpu_arm64_other.go b/src/internal/cpu/cpu_arm64_other.go
new file mode 100644
index 0000000000..f191db28d2
--- /dev/null
+++ b/src/internal/cpu/cpu_arm64_other.go
@@ -0,0 +1,17 @@
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build arm64
+// +build !linux
+// +build !freebsd
+// +build !android
+// +build !darwin ios
+
+package cpu
+
+func osInit() {
+	// Other operating systems do not support reading HWCap from auxiliary vector,
+	// reading privileged aarch64 system registers or sysctl in user space to detect
+	// CPU features at runtime.
+}
diff --git a/src/internal/cpu/cpu_mips.go b/src/internal/cpu/cpu_mips.go
index 0f821e44e7..14a9c975ea 100644
--- a/src/internal/cpu/cpu_mips.go
+++ b/src/internal/cpu/cpu_mips.go
@@ -5,3 +5,6 @@
 package cpu
 
 const CacheLinePadSize = 32
+
+func doinit() {
+}
diff --git a/src/internal/cpu/cpu_mipsle.go b/src/internal/cpu/cpu_mipsle.go
index 0f821e44e7..14a9c975ea 100644
--- a/src/internal/cpu/cpu_mipsle.go
+++ b/src/internal/cpu/cpu_mipsle.go
@@ -5,3 +5,6 @@
 package cpu
 
 const CacheLinePadSize = 32
+
+func doinit() {
+}
diff --git a/src/internal/cpu/cpu_no_init.go b/src/internal/cpu/cpu_no_init.go
deleted file mode 100644
index fb381e1ce2..0000000000
--- a/src/internal/cpu/cpu_no_init.go
+++ /dev/null
@@ -1,18 +0,0 @@
-// Copyright 2018 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-// +build !386
-// +build !amd64
-// +build !arm
-// +build !arm64
-// +build !ppc64
-// +build !ppc64le
-// +build !s390x
-// +build !mips64
-// +build !mips64le
-
-package cpu
-
-func doinit() {
-}
diff --git a/src/internal/cpu/cpu_no_name.go b/src/internal/cpu/cpu_no_name.go
new file mode 100644
index 0000000000..ce1c37a3c7
--- /dev/null
+++ b/src/internal/cpu/cpu_no_name.go
@@ -0,0 +1,19 @@
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build !386
+// +build !amd64
+
+package cpu
+
+// Name returns the CPU name given by the vendor
+// if it can be read directly from memory or by CPU instructions.
+// If the CPU name can not be determined an empty string is returned.
+//
+// Implementations that use the Operating System (e.g. sysctl or /sys/)
+// to gather CPU information for display should be placed in internal/sysinfo.
+func Name() string {
+	// "A CPU has no name".
+	return ""
+}
diff --git a/src/internal/cpu/cpu_ppc64x.go b/src/internal/cpu/cpu_ppc64x.go
index 2487879c46..beb1765427 100644
--- a/src/internal/cpu/cpu_ppc64x.go
+++ b/src/internal/cpu/cpu_ppc64x.go
@@ -8,39 +8,14 @@ package cpu
 
 const CacheLinePadSize = 128
 
-// ppc64x doesn't have a 'cpuid' equivalent, so we rely on HWCAP/HWCAP2.
-// These are initialized by archauxv and should not be changed after they are
-// initialized.
-// On aix/ppc64, these values are initialized early in the runtime in runtime/os_aix.go.
-var HWCap uint
-var HWCap2 uint
-
-// HWCAP/HWCAP2 bits. These are exposed by the kernel.
-const (
-	// ISA Level
-	PPC_FEATURE2_ARCH_2_07 = 0x80000000
-	PPC_FEATURE2_ARCH_3_00 = 0x00800000
-
-	// CPU features
-	PPC_FEATURE2_DARN = 0x00200000
-	PPC_FEATURE2_SCV  = 0x00100000
-)
-
 func doinit() {
 	options = []option{
 		{Name: "darn", Feature: &PPC64.HasDARN},
 		{Name: "scv", Feature: &PPC64.HasSCV},
 		{Name: "power9", Feature: &PPC64.IsPOWER9},
-
-		// These capabilities should always be enabled on ppc64 and ppc64le:
-		{Name: "power8", Feature: &PPC64.IsPOWER8, Required: true},
 	}
 
-	// HWCAP2 feature bits
-	PPC64.IsPOWER8 = isSet(HWCap2, PPC_FEATURE2_ARCH_2_07)
-	PPC64.IsPOWER9 = isSet(HWCap2, PPC_FEATURE2_ARCH_3_00)
-	PPC64.HasDARN = isSet(HWCap2, PPC_FEATURE2_DARN)
-	PPC64.HasSCV = isSet(HWCap2, PPC_FEATURE2_SCV)
+	osinit()
 }
 
 func isSet(hwc uint, value uint) bool {
diff --git a/src/internal/cpu/cpu_ppc64x_aix.go b/src/internal/cpu/cpu_ppc64x_aix.go
new file mode 100644
index 0000000000..b840b823ba
--- /dev/null
+++ b/src/internal/cpu/cpu_ppc64x_aix.go
@@ -0,0 +1,21 @@
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build ppc64 ppc64le
+
+package cpu
+
+const (
+	// getsystemcfg constants
+	_SC_IMPL     = 2
+	_IMPL_POWER9 = 0x20000
+)
+
+func osinit() {
+	impl := getsystemcfg(_SC_IMPL)
+	PPC64.IsPOWER9 = isSet(impl, _IMPL_POWER9)
+}
+
+// getsystemcfg is defined in runtime/os2_aix.go
+func getsystemcfg(label uint) uint
diff --git a/src/internal/cpu/cpu_ppc64x_linux.go b/src/internal/cpu/cpu_ppc64x_linux.go
new file mode 100644
index 0000000000..73b191436d
--- /dev/null
+++ b/src/internal/cpu/cpu_ppc64x_linux.go
@@ -0,0 +1,29 @@
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build ppc64 ppc64le
+
+package cpu
+
+// ppc64 doesn't have a 'cpuid' equivalent, so we rely on HWCAP/HWCAP2.
+// These are initialized by archauxv and should not be changed after they are
+// initialized.
+var HWCap uint
+var HWCap2 uint
+
+// HWCAP bits. These are exposed by Linux.
+const (
+	// ISA Level
+	hwcap2_ARCH_3_00 = 0x00800000
+
+	// CPU features
+	hwcap2_DARN = 0x00200000
+	hwcap2_SCV  = 0x00100000
+)
+
+func osinit() {
+	PPC64.IsPOWER9 = isSet(HWCap2, hwcap2_ARCH_3_00)
+	PPC64.HasDARN = isSet(HWCap2, hwcap2_DARN)
+	PPC64.HasSCV = isSet(HWCap2, hwcap2_SCV)
+}
diff --git a/src/internal/cpu/cpu_riscv64.go b/src/internal/cpu/cpu_riscv64.go
index c49cab79fd..54b8c3378b 100644
--- a/src/internal/cpu/cpu_riscv64.go
+++ b/src/internal/cpu/cpu_riscv64.go
@@ -5,3 +5,6 @@
 package cpu
 
 const CacheLinePadSize = 32
+
+func doinit() {
+}
diff --git a/src/internal/cpu/cpu_s390x.go b/src/internal/cpu/cpu_s390x.go
index 526e074225..45d8ed27f0 100644
--- a/src/internal/cpu/cpu_s390x.go
+++ b/src/internal/cpu/cpu_s390x.go
@@ -6,6 +6,8 @@ package cpu
 
 const CacheLinePadSize = 256
 
+var HWCap uint
+
 // bitIsSet reports whether the bit at index is set. The bit index
 // is in big endian order, so bit index 0 is the leftmost bit.
 func bitIsSet(bits []uint64, index uint) bool {
@@ -95,8 +97,10 @@ const (
 	// vector facilities
 	vxe facility = 135 // vector-enhancements 1
 
-	// Note: vx and highgprs are excluded because they require
-	// kernel support and so must be fetched from HWCAP.
+	// Note: vx requires kernel support
+	// and so must be fetched from HWCAP.
+
+	hwcap_VX = 1 << 11 // vector facility
 )
 
 // facilityList contains the result of an STFLE call.
@@ -188,7 +192,14 @@ func doinit() {
 			S390X.HasEDDSA = kdsa.Has(eddsaVerifyEd25519, eddsaSignEd25519, eddsaVerifyEd448, eddsaSignEd448)
 		}
 	}
+
+	S390X.HasVX = isSet(HWCap, hwcap_VX)
+
 	if S390X.HasVX {
 		S390X.HasVXE = facilities.Has(vxe)
 	}
 }
+
+func isSet(hwc uint, value uint) bool {
+	return hwc&value != 0
+}
diff --git a/src/internal/cpu/cpu_s390x_test.go b/src/internal/cpu/cpu_s390x_test.go
index d910bbe695..ad86858db0 100644
--- a/src/internal/cpu/cpu_s390x_test.go
+++ b/src/internal/cpu/cpu_s390x_test.go
@@ -7,13 +7,13 @@ package cpu_test
 import (
 	"errors"
 	. "internal/cpu"
-	"io/ioutil"
+	"os"
 	"regexp"
 	"testing"
 )
 
 func getFeatureList() ([]string, error) {
-	cpuinfo, err := ioutil.ReadFile("/proc/cpuinfo")
+	cpuinfo, err := os.ReadFile("/proc/cpuinfo")
 	if err != nil {
 		return nil, err
 	}
diff --git a/src/internal/cpu/cpu_test.go b/src/internal/cpu/cpu_test.go
index e09bd2d8b9..2de7365732 100644
--- a/src/internal/cpu/cpu_test.go
+++ b/src/internal/cpu/cpu_test.go
@@ -15,9 +15,10 @@ import (
 )
 
 func TestMinimalFeatures(t *testing.T) {
+	// TODO: maybe do MustSupportFeatureDectection(t) ?
 	if runtime.GOARCH == "arm64" {
 		switch runtime.GOOS {
-		case "linux", "android":
+		case "linux", "android", "darwin":
 		default:
 			t.Skipf("%s/%s is not supported", runtime.GOOS, runtime.GOARCH)
 		}
@@ -36,6 +37,10 @@ func MustHaveDebugOptionsSupport(t *testing.T) {
 	}
 }
 
+func MustSupportFeatureDectection(t *testing.T) {
+	// TODO: add platforms that do not have CPU feature detection support.
+}
+
 func runDebugOptionsTest(t *testing.T, test string, options string) {
 	MustHaveDebugOptionsSupport(t)
 
@@ -58,6 +63,7 @@ func runDebugOptionsTest(t *testing.T, test string, options string) {
 }
 
 func TestDisableAllCapabilities(t *testing.T) {
+	MustSupportFeatureDectection(t)
 	runDebugOptionsTest(t, "TestAllCapabilitiesDisabled", "cpu.all=off")
 }
 
diff --git a/src/internal/cpu/cpu_wasm.go b/src/internal/cpu/cpu_wasm.go
index b459738770..2310ad6a48 100644
--- a/src/internal/cpu/cpu_wasm.go
+++ b/src/internal/cpu/cpu_wasm.go
@@ -5,3 +5,6 @@
 package cpu
 
 const CacheLinePadSize = 64
+
+func doinit() {
+}
diff --git a/src/internal/cpu/cpu_x86.go b/src/internal/cpu/cpu_x86.go
index da6cf67258..ba6bf69034 100644
--- a/src/internal/cpu/cpu_x86.go
+++ b/src/internal/cpu/cpu_x86.go
@@ -38,6 +38,8 @@ const (
 	cpuid_ADX  = 1 << 19
 )
 
+var maxExtendedFunctionInformation uint32
+
 func doinit() {
 	options = []option{
 		{Name: "adx", Feature: &X86.HasADX},
@@ -65,19 +67,30 @@ func doinit() {
 		return
 	}
 
+	maxExtendedFunctionInformation, _, _, _ = cpuid(0x80000000, 0)
+
 	_, _, ecx1, edx1 := cpuid(1, 0)
 	X86.HasSSE2 = isSet(edx1, cpuid_SSE2)
 
 	X86.HasSSE3 = isSet(ecx1, cpuid_SSE3)
 	X86.HasPCLMULQDQ = isSet(ecx1, cpuid_PCLMULQDQ)
 	X86.HasSSSE3 = isSet(ecx1, cpuid_SSSE3)
-	X86.HasFMA = isSet(ecx1, cpuid_FMA)
 	X86.HasSSE41 = isSet(ecx1, cpuid_SSE41)
 	X86.HasSSE42 = isSet(ecx1, cpuid_SSE42)
 	X86.HasPOPCNT = isSet(ecx1, cpuid_POPCNT)
 	X86.HasAES = isSet(ecx1, cpuid_AES)
+
+	// OSXSAVE can be false when using older Operating Systems
+	// or when explicitly disabled on newer Operating Systems by
+	// e.g. setting the xsavedisable boot option on Windows 10.
 	X86.HasOSXSAVE = isSet(ecx1, cpuid_OSXSAVE)
 
+	// The FMA instruction set extension only has VEX prefixed instructions.
+	// VEX prefixed instructions require OSXSAVE to be enabled.
+	// See Intel 64 and IA-32 Architecture Software Developer’s Manual Volume 2
+	// Section 2.4 "AVX and SSE Instruction Exception Specification"
+	X86.HasFMA = isSet(ecx1, cpuid_FMA) && X86.HasOSXSAVE
+
 	osSupportsAVX := false
 	// For XGETBV, OSXSAVE bit is required and sufficient.
 	if X86.HasOSXSAVE {
@@ -103,3 +116,48 @@ func doinit() {
 func isSet(hwc uint32, value uint32) bool {
 	return hwc&value != 0
 }
+
+// Name returns the CPU name given by the vendor.
+// If the CPU name can not be determined an
+// empty string is returned.
+func Name() string {
+	if maxExtendedFunctionInformation < 0x80000004 {
+		return ""
+	}
+
+	data := make([]byte, 0, 3*4*4)
+
+	var eax, ebx, ecx, edx uint32
+	eax, ebx, ecx, edx = cpuid(0x80000002, 0)
+	data = appendBytes(data, eax, ebx, ecx, edx)
+	eax, ebx, ecx, edx = cpuid(0x80000003, 0)
+	data = appendBytes(data, eax, ebx, ecx, edx)
+	eax, ebx, ecx, edx = cpuid(0x80000004, 0)
+	data = appendBytes(data, eax, ebx, ecx, edx)
+
+	// Trim leading spaces.
+	for len(data) > 0 && data[0] == ' ' {
+		data = data[1:]
+	}
+
+	// Trim tail after and including the first null byte.
+	for i, c := range data {
+		if c == '\x00' {
+			data = data[:i]
+			break
+		}
+	}
+
+	return string(data)
+}
+
+func appendBytes(b []byte, args ...uint32) []byte {
+	for _, arg := range args {
+		b = append(b,
+			byte((arg >> 0)),
+			byte((arg >> 8)),
+			byte((arg >> 16)),
+			byte((arg >> 24)))
+	}
+	return b
+}
diff --git a/src/internal/fmtsort/sort.go b/src/internal/fmtsort/sort.go
index b01229bd06..7127ba6ac3 100644
--- a/src/internal/fmtsort/sort.go
+++ b/src/internal/fmtsort/sort.go
@@ -130,7 +130,7 @@ func compare(aVal, bVal reflect.Value) int {
 		default:
 			return -1
 		}
-	case reflect.Ptr:
+	case reflect.Ptr, reflect.UnsafePointer:
 		a, b := aVal.Pointer(), bVal.Pointer()
 		switch {
 		case a < b:
diff --git a/src/internal/fmtsort/sort_test.go b/src/internal/fmtsort/sort_test.go
index aaa0004666..5c4db1c5fa 100644
--- a/src/internal/fmtsort/sort_test.go
+++ b/src/internal/fmtsort/sort_test.go
@@ -11,6 +11,7 @@ import (
 	"reflect"
 	"strings"
 	"testing"
+	"unsafe"
 )
 
 var compareTests = [][]reflect.Value{
@@ -32,6 +33,7 @@ var compareTests = [][]reflect.Value{
 	ct(reflect.TypeOf(complex128(0+1i)), -1-1i, -1+0i, -1+1i, 0-1i, 0+0i, 0+1i, 1-1i, 1+0i, 1+1i),
 	ct(reflect.TypeOf(false), false, true),
 	ct(reflect.TypeOf(&ints[0]), &ints[0], &ints[1], &ints[2]),
+	ct(reflect.TypeOf(unsafe.Pointer(&ints[0])), unsafe.Pointer(&ints[0]), unsafe.Pointer(&ints[1]), unsafe.Pointer(&ints[2])),
 	ct(reflect.TypeOf(chans[0]), chans[0], chans[1], chans[2]),
 	ct(reflect.TypeOf(toy{}), toy{0, 1}, toy{0, 2}, toy{1, -1}, toy{1, 1}),
 	ct(reflect.TypeOf([2]int{}), [2]int{1, 1}, [2]int{1, 2}, [2]int{2, 0}),
@@ -119,6 +121,10 @@ var sortTests = []sortTest{
 		"PTR0:0 PTR1:1 PTR2:2",
 	},
 	{
+		unsafePointerMap(),
+		"UNSAFEPTR0:0 UNSAFEPTR1:1 UNSAFEPTR2:2",
+	},
+	{
 		map[toy]string{{7, 2}: "72", {7, 1}: "71", {3, 4}: "34"},
 		"{3 4}:34 {7 1}:71 {7 2}:72",
 	},
@@ -159,6 +165,14 @@ func sprintKey(key reflect.Value) string {
 			}
 		}
 		return "PTR???"
+	case "unsafe.Pointer":
+		ptr := key.Interface().(unsafe.Pointer)
+		for i := range ints {
+			if ptr == unsafe.Pointer(&ints[i]) {
+				return fmt.Sprintf("UNSAFEPTR%d", i)
+			}
+		}
+		return "UNSAFEPTR???"
 	case "chan int":
 		c := key.Interface().(chan int)
 		for i := range chans {
@@ -185,6 +199,14 @@ func pointerMap() map[*int]string {
 	return m
 }
 
+func unsafePointerMap() map[unsafe.Pointer]string {
+	m := make(map[unsafe.Pointer]string)
+	for i := 2; i >= 0; i-- {
+		m[unsafe.Pointer(&ints[i])] = fmt.Sprint(i)
+	}
+	return m
+}
+
 func chanMap() map[chan int]string {
 	m := make(map[chan int]string)
 	for i := 2; i >= 0; i-- {
diff --git a/src/internal/obscuretestdata/obscuretestdata.go b/src/internal/obscuretestdata/obscuretestdata.go
index 512f3759b4..5ea2cdf5d1 100644
--- a/src/internal/obscuretestdata/obscuretestdata.go
+++ b/src/internal/obscuretestdata/obscuretestdata.go
@@ -10,7 +10,6 @@ package obscuretestdata
 import (
 	"encoding/base64"
 	"io"
-	"io/ioutil"
 	"os"
 )
 
@@ -24,7 +23,7 @@ func DecodeToTempFile(name string) (path string, err error) {
 	}
 	defer f.Close()
 
-	tmp, err := ioutil.TempFile("", "obscuretestdata-decoded-")
+	tmp, err := os.CreateTemp("", "obscuretestdata-decoded-")
 	if err != nil {
 		return "", err
 	}
@@ -47,5 +46,5 @@ func ReadFile(name string) ([]byte, error) {
 		return nil, err
 	}
 	defer f.Close()
-	return ioutil.ReadAll(base64.NewDecoder(base64.StdEncoding, f))
+	return io.ReadAll(base64.NewDecoder(base64.StdEncoding, f))
 }
diff --git a/src/internal/poll/copy_file_range_linux.go b/src/internal/poll/copy_file_range_linux.go
index 09de299ff7..fc34aef4cb 100644
--- a/src/internal/poll/copy_file_range_linux.go
+++ b/src/internal/poll/copy_file_range_linux.go
@@ -10,15 +10,61 @@ import (
 	"syscall"
 )
 
-var copyFileRangeSupported int32 = 1 // accessed atomically
+var copyFileRangeSupported int32 = -1 // accessed atomically
 
 const maxCopyFileRangeRound = 1 << 30
 
+func kernelVersion() (major int, minor int) {
+	var uname syscall.Utsname
+	if err := syscall.Uname(&uname); err != nil {
+		return
+	}
+
+	rl := uname.Release
+	var values [2]int
+	vi := 0
+	value := 0
+	for _, c := range rl {
+		if '0' <= c && c <= '9' {
+			value = (value * 10) + int(c-'0')
+		} else {
+			// Note that we're assuming N.N.N here.  If we see anything else we are likely to
+			// mis-parse it.
+			values[vi] = value
+			vi++
+			if vi >= len(values) {
+				break
+			}
+			value = 0
+		}
+	}
+	switch vi {
+	case 0:
+		return 0, 0
+	case 1:
+		return values[0], 0
+	case 2:
+		return values[0], values[1]
+	}
+	return
+}
+
 // CopyFileRange copies at most remain bytes of data from src to dst, using
 // the copy_file_range system call. dst and src must refer to regular files.
 func CopyFileRange(dst, src *FD, remain int64) (written int64, handled bool, err error) {
-	if atomic.LoadInt32(&copyFileRangeSupported) == 0 {
+	if supported := atomic.LoadInt32(&copyFileRangeSupported); supported == 0 {
 		return 0, false, nil
+	} else if supported == -1 {
+		major, minor := kernelVersion()
+		if major > 5 || (major == 5 && minor >= 3) {
+			atomic.StoreInt32(&copyFileRangeSupported, 1)
+		} else {
+			// copy_file_range(2) is broken in various ways on kernels older than 5.3,
+			// see issue #42400 and
+			// https://man7.org/linux/man-pages/man2/copy_file_range.2.html#VERSIONS
+			atomic.StoreInt32(&copyFileRangeSupported, 0)
+			return 0, false, nil
+		}
 	}
 	for remain > 0 {
 		max := remain
@@ -41,7 +87,7 @@ func CopyFileRange(dst, src *FD, remain int64) (written int64, handled bool, err
 			// use copy_file_range(2) again.
 			atomic.StoreInt32(&copyFileRangeSupported, 0)
 			return 0, false, nil
-		case syscall.EXDEV, syscall.EINVAL, syscall.EOPNOTSUPP, syscall.EPERM:
+		case syscall.EXDEV, syscall.EINVAL, syscall.EIO, syscall.EOPNOTSUPP, syscall.EPERM:
 			// Prior to Linux 5.3, it was not possible to
 			// copy_file_range across file systems. Similarly to
 			// the ENOSYS case above, if we see EXDEV, we have
@@ -53,6 +99,9 @@ func CopyFileRange(dst, src *FD, remain int64) (written int64, handled bool, err
 			// file. This is another case where no data has been
 			// transfered, so we consider it unhandled.
 			//
+			// If src and dst are on CIFS, we can see EIO.
+			// See issue #42334.
+			//
 			// If the file is on NFS, we can see EOPNOTSUPP.
 			// See issue #40731.
 			//
diff --git a/src/internal/poll/error_test.go b/src/internal/poll/error_test.go
index 06b96f635a..abc8b1684f 100644
--- a/src/internal/poll/error_test.go
+++ b/src/internal/poll/error_test.go
@@ -6,6 +6,7 @@ package poll_test
 
 import (
 	"fmt"
+	"io/fs"
 	"net"
 	"os"
 	"testing"
@@ -37,7 +38,7 @@ func parseReadError(nestedErr error, verify func(error) (string, bool)) error {
 	if nerr, ok := err.(*net.OpError); ok {
 		err = nerr.Err
 	}
-	if nerr, ok := err.(*os.PathError); ok {
+	if nerr, ok := err.(*fs.PathError); ok {
 		err = nerr.Err
 	}
 	if nerr, ok := err.(*os.SyscallError); ok {
diff --git a/src/internal/poll/fd_fsync_darwin.go b/src/internal/poll/fd_fsync_darwin.go
index 91751496a4..48e7596922 100644
--- a/src/internal/poll/fd_fsync_darwin.go
+++ b/src/internal/poll/fd_fsync_darwin.go
@@ -14,7 +14,8 @@ func (fd *FD) Fsync() error {
 		return err
 	}
 	defer fd.decref()
-
-	_, e1 := fcntl(fd.Sysfd, syscall.F_FULLFSYNC, 0)
-	return e1
+	return ignoringEINTR(func() error {
+		_, err := fcntl(fd.Sysfd, syscall.F_FULLFSYNC, 0)
+		return err
+	})
 }
diff --git a/src/internal/poll/fd_posix.go b/src/internal/poll/fd_posix.go
index e5fb05c9c2..4edfa953a4 100644
--- a/src/internal/poll/fd_posix.go
+++ b/src/internal/poll/fd_posix.go
@@ -29,17 +29,6 @@ func (fd *FD) Shutdown(how int) error {
 	return syscall.Shutdown(fd.Sysfd, how)
 }
 
-// Fchmod wraps syscall.Fchmod.
-func (fd *FD) Fchmod(mode uint32) error {
-	if err := fd.incref(); err != nil {
-		return err
-	}
-	defer fd.decref()
-	return ignoringEINTR(func() error {
-		return syscall.Fchmod(fd.Sysfd, mode)
-	})
-}
-
 // Fchown wraps syscall.Fchown.
 func (fd *FD) Fchown(uid, gid int) error {
 	if err := fd.incref(); err != nil {
diff --git a/src/internal/poll/fd_unix.go b/src/internal/poll/fd_unix.go
index 1d5101eac3..2e77e76c87 100644
--- a/src/internal/poll/fd_unix.go
+++ b/src/internal/poll/fd_unix.go
@@ -74,7 +74,14 @@ func (fd *FD) destroy() error {
 	// Poller may want to unregister fd in readiness notification mechanism,
 	// so this must be executed before CloseFunc.
 	fd.pd.close()
+
+	// We don't use ignoringEINTR here because POSIX does not define
+	// whether the descriptor is closed if close returns EINTR.
+	// If the descriptor is indeed closed, using a loop would race
+	// with some other goroutine opening a new descriptor.
+	// (The Linux kernel guarantees that it is closed on an EINTR error.)
 	err := CloseFunc(fd.Sysfd)
+
 	fd.Sysfd = -1
 	runtime_Semrelease(&fd.csema)
 	return err
@@ -437,6 +444,17 @@ func (fd *FD) ReadDirent(buf []byte) (int, error) {
 	}
 }
 
+// Fchmod wraps syscall.Fchmod.
+func (fd *FD) Fchmod(mode uint32) error {
+	if err := fd.incref(); err != nil {
+		return err
+	}
+	defer fd.decref()
+	return ignoringEINTR(func() error {
+		return syscall.Fchmod(fd.Sysfd, mode)
+	})
+}
+
 // Fchdir wraps syscall.Fchdir.
 func (fd *FD) Fchdir() error {
 	if err := fd.incref(); err != nil {
diff --git a/src/internal/poll/fd_windows.go b/src/internal/poll/fd_windows.go
index e1ef6199b3..d8c834f929 100644
--- a/src/internal/poll/fd_windows.go
+++ b/src/internal/poll/fd_windows.go
@@ -886,6 +886,33 @@ func (fd *FD) FindNextFile(data *syscall.Win32finddata) error {
 	return syscall.FindNextFile(fd.Sysfd, data)
 }
 
+// Fchmod updates syscall.ByHandleFileInformation.Fileattributes when needed.
+func (fd *FD) Fchmod(mode uint32) error {
+	if err := fd.incref(); err != nil {
+		return err
+	}
+	defer fd.decref()
+
+	var d syscall.ByHandleFileInformation
+	if err := syscall.GetFileInformationByHandle(fd.Sysfd, &d); err != nil {
+		return err
+	}
+	attrs := d.FileAttributes
+	if mode&syscall.S_IWRITE != 0 {
+		attrs &^= syscall.FILE_ATTRIBUTE_READONLY
+	} else {
+		attrs |= syscall.FILE_ATTRIBUTE_READONLY
+	}
+	if attrs == d.FileAttributes {
+		return nil
+	}
+
+	var du windows.FILE_BASIC_INFO
+	du.FileAttributes = attrs
+	l := uint32(unsafe.Sizeof(d))
+	return windows.SetFileInformationByHandle(fd.Sysfd, windows.FileBasicInfo, uintptr(unsafe.Pointer(&du)), l)
+}
+
 // Fchdir wraps syscall.Fchdir.
 func (fd *FD) Fchdir() error {
 	if err := fd.incref(); err != nil {
diff --git a/src/internal/poll/fd_writev_illumos.go b/src/internal/poll/fd_writev_illumos.go
new file mode 100644
index 0000000000..1fa47ab1a3
--- /dev/null
+++ b/src/internal/poll/fd_writev_illumos.go
@@ -0,0 +1,16 @@
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build illumos
+
+package poll
+
+import (
+	"internal/syscall/unix"
+	"syscall"
+)
+
+func writev(fd int, iovecs []syscall.Iovec) (uintptr, error) {
+	return unix.Writev(fd, iovecs)
+}
diff --git a/src/internal/poll/hook_cloexec.go b/src/internal/poll/hook_cloexec.go
index 5c93bdaf6c..5fd5449bb0 100644
--- a/src/internal/poll/hook_cloexec.go
+++ b/src/internal/poll/hook_cloexec.go
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build dragonfly freebsd linux netbsd openbsd
+// +build dragonfly freebsd illumos linux netbsd openbsd
 
 package poll
 
diff --git a/src/internal/poll/iovec_illumos.go b/src/internal/poll/iovec_illumos.go
new file mode 100644
index 0000000000..057067465b
--- /dev/null
+++ b/src/internal/poll/iovec_illumos.go
@@ -0,0 +1,16 @@
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build illumos
+
+package poll
+
+import (
+	"syscall"
+	"unsafe"
+)
+
+func newIovecWithBase(base *byte) syscall.Iovec {
+	return syscall.Iovec{Base: (*int8)(unsafe.Pointer(base))}
+}
diff --git a/src/internal/poll/iovec_unix.go b/src/internal/poll/iovec_unix.go
new file mode 100644
index 0000000000..6f98947866
--- /dev/null
+++ b/src/internal/poll/iovec_unix.go
@@ -0,0 +1,13 @@
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build darwin dragonfly freebsd linux netbsd openbsd
+
+package poll
+
+import "syscall"
+
+func newIovecWithBase(base *byte) syscall.Iovec {
+	return syscall.Iovec{Base: base}
+}
diff --git a/src/internal/poll/read_test.go b/src/internal/poll/read_test.go
index b4f5236d3e..598a52ee44 100644
--- a/src/internal/poll/read_test.go
+++ b/src/internal/poll/read_test.go
@@ -5,7 +5,6 @@
 package poll_test
 
 import (
-	"io/ioutil"
 	"os"
 	"runtime"
 	"sync"
@@ -22,7 +21,7 @@ func TestRead(t *testing.T) {
 				go func(p string) {
 					defer wg.Done()
 					for i := 0; i < 100; i++ {
-						if _, err := ioutil.ReadFile(p); err != nil {
+						if _, err := os.ReadFile(p); err != nil {
 							t.Error(err)
 							return
 						}
@@ -38,7 +37,7 @@ func TestRead(t *testing.T) {
 func specialFiles() []string {
 	var ps []string
 	switch runtime.GOOS {
-	case "darwin", "dragonfly", "freebsd", "netbsd", "openbsd":
+	case "darwin", "ios", "dragonfly", "freebsd", "netbsd", "openbsd":
 		ps = []string{
 			"/dev/null",
 		}
diff --git a/src/internal/poll/sock_cloexec.go b/src/internal/poll/sock_cloexec.go
index 691cb8e36f..ff7982ca9e 100644
--- a/src/internal/poll/sock_cloexec.go
+++ b/src/internal/poll/sock_cloexec.go
@@ -5,7 +5,7 @@
 // This file implements sysSocket and accept for platforms that
 // provide a fast path for setting SetNonblock and CloseOnExec.
 
-// +build dragonfly freebsd linux netbsd openbsd
+// +build dragonfly freebsd illumos linux netbsd openbsd
 
 package poll
 
diff --git a/src/internal/poll/sys_cloexec.go b/src/internal/poll/sys_cloexec.go
index 7b87f136df..4b3c642173 100644
--- a/src/internal/poll/sys_cloexec.go
+++ b/src/internal/poll/sys_cloexec.go
@@ -5,7 +5,7 @@
 // This file implements sysSocket and accept for platforms that do not
 // provide a fast path for setting SetNonblock and CloseOnExec.
 
-// +build aix darwin js,wasm solaris
+// +build aix darwin js,wasm solaris,!illumos
 
 package poll
 
diff --git a/src/internal/poll/writev.go b/src/internal/poll/writev.go
index 305e2fd209..0123fc33de 100644
--- a/src/internal/poll/writev.go
+++ b/src/internal/poll/writev.go
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build darwin dragonfly freebsd linux netbsd openbsd
+// +build darwin dragonfly freebsd illumos linux netbsd openbsd
 
 package poll
 
@@ -38,7 +38,7 @@ func (fd *FD) Writev(v *[][]byte) (int64, error) {
 			if len(chunk) == 0 {
 				continue
 			}
-			iovecs = append(iovecs, syscall.Iovec{Base: &chunk[0]})
+			iovecs = append(iovecs, newIovecWithBase(&chunk[0]))
 			if fd.IsStream && len(chunk) > 1<<30 {
 				iovecs[len(iovecs)-1].SetLen(1 << 30)
 				break // continue chunk on next writev
diff --git a/src/internal/profile/profile.go b/src/internal/profile/profile.go
index a6275bc6de..29568aa4b5 100644
--- a/src/internal/profile/profile.go
+++ b/src/internal/profile/profile.go
@@ -12,7 +12,6 @@ import (
 	"compress/gzip"
 	"fmt"
 	"io"
-	"io/ioutil"
 	"regexp"
 	"strings"
 	"time"
@@ -125,7 +124,7 @@ type Function struct {
 // may be a gzip-compressed encoded protobuf or one of many legacy
 // profile formats which may be unsupported in the future.
 func Parse(r io.Reader) (*Profile, error) {
-	orig, err := ioutil.ReadAll(r)
+	orig, err := io.ReadAll(r)
 	if err != nil {
 		return nil, err
 	}
@@ -136,7 +135,7 @@ func Parse(r io.Reader) (*Profile, error) {
 		if err != nil {
 			return nil, fmt.Errorf("decompressing profile: %v", err)
 		}
-		data, err := ioutil.ReadAll(gz)
+		data, err := io.ReadAll(gz)
 		if err != nil {
 			return nil, fmt.Errorf("decompressing profile: %v", err)
 		}
diff --git a/src/internal/reflectlite/reflect_mirror_test.go b/src/internal/reflectlite/reflect_mirror_test.go
index fbb6fb397e..9b28b13550 100644
--- a/src/internal/reflectlite/reflect_mirror_test.go
+++ b/src/internal/reflectlite/reflect_mirror_test.go
@@ -9,6 +9,7 @@ import (
 	"go/ast"
 	"go/parser"
 	"go/token"
+	"io/fs"
 	"os"
 	"path/filepath"
 	"runtime"
@@ -71,7 +72,7 @@ func (v visitor) Visit(n ast.Node) ast.Visitor {
 func loadTypes(path, pkgName string, v visitor) {
 	fset := token.NewFileSet()
 
-	filter := func(fi os.FileInfo) bool {
+	filter := func(fi fs.FileInfo) bool {
 		return strings.HasSuffix(fi.Name(), ".go")
 	}
 	pkgs, err := parser.ParseDir(fset, path, filter, 0)
diff --git a/src/internal/reflectlite/type.go b/src/internal/reflectlite/type.go
index eb7f1a4b78..15ba30da36 100644
--- a/src/internal/reflectlite/type.go
+++ b/src/internal/reflectlite/type.go
@@ -384,6 +384,44 @@ const (
 	kindMask        = (1 << 5) - 1
 )
 
+// String returns the name of k.
+func (k Kind) String() string {
+	if int(k) < len(kindNames) {
+		return kindNames[k]
+	}
+	return kindNames[0]
+}
+
+var kindNames = []string{
+	Invalid:       "invalid",
+	Bool:          "bool",
+	Int:           "int",
+	Int8:          "int8",
+	Int16:         "int16",
+	Int32:         "int32",
+	Int64:         "int64",
+	Uint:          "uint",
+	Uint8:         "uint8",
+	Uint16:        "uint16",
+	Uint32:        "uint32",
+	Uint64:        "uint64",
+	Uintptr:       "uintptr",
+	Float32:       "float32",
+	Float64:       "float64",
+	Complex64:     "complex64",
+	Complex128:    "complex128",
+	Array:         "array",
+	Chan:          "chan",
+	Func:          "func",
+	Interface:     "interface",
+	Map:           "map",
+	Ptr:           "ptr",
+	Slice:         "slice",
+	String:        "string",
+	Struct:        "struct",
+	UnsafePointer: "unsafe.Pointer",
+}
+
 func (t *uncommonType) methods() []method {
 	if t.mcount == 0 {
 		return nil
diff --git a/src/internal/reflectlite/value.go b/src/internal/reflectlite/value.go
index 85beea606c..0365eeeabf 100644
--- a/src/internal/reflectlite/value.go
+++ b/src/internal/reflectlite/value.go
@@ -160,7 +160,10 @@ type ValueError struct {
 }
 
 func (e *ValueError) Error() string {
-	return "reflect: call of " + e.Method + " on zero Value"
+	if e.Kind == 0 {
+		return "reflect: call of " + e.Method + " on zero Value"
+	}
+	return "reflect: call of " + e.Method + " on " + e.Kind.String() + " Value"
 }
 
 // methodName returns the name of the calling method,
diff --git a/src/internal/syscall/unix/pipe2_illumos.go b/src/internal/syscall/unix/pipe2_illumos.go
new file mode 100644
index 0000000000..f3ac8d29df
--- /dev/null
+++ b/src/internal/syscall/unix/pipe2_illumos.go
@@ -0,0 +1,34 @@
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build illumos
+
+package unix
+
+import (
+	"syscall"
+	"unsafe"
+)
+
+//go:cgo_import_dynamic libc_pipe2 pipe2 "libc.so"
+
+//go:linkname procpipe2 libc_pipe2
+
+var procpipe2 uintptr
+
+type _C_int int32
+
+func Pipe2(p []int, flags int) error {
+	if len(p) != 2 {
+		return syscall.EINVAL
+	}
+	var pp [2]_C_int
+	_, _, errno := syscall6(uintptr(unsafe.Pointer(&procpipe2)), 2, uintptr(unsafe.Pointer(&pp)), uintptr(flags), 0, 0, 0, 0)
+	if errno != 0 {
+		return errno
+	}
+	p[0] = int(pp[0])
+	p[1] = int(pp[1])
+	return nil
+}
diff --git a/src/internal/syscall/unix/writev_illumos.go b/src/internal/syscall/unix/writev_illumos.go
new file mode 100644
index 0000000000..eb7973d65b
--- /dev/null
+++ b/src/internal/syscall/unix/writev_illumos.go
@@ -0,0 +1,30 @@
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build illumos
+
+package unix
+
+import (
+	"syscall"
+	"unsafe"
+)
+
+//go:cgo_import_dynamic libc_writev writev "libc.so"
+
+//go:linkname procwritev libc_writev
+
+var procwritev uintptr
+
+func Writev(fd int, iovs []syscall.Iovec) (uintptr, error) {
+	var p *syscall.Iovec
+	if len(iovs) > 0 {
+		p = &iovs[0]
+	}
+	n, _, errno := syscall6(uintptr(unsafe.Pointer(&procwritev)), 3, uintptr(fd), uintptr(unsafe.Pointer(p)), uintptr(len(iovs)), 0, 0, 0)
+	if errno != 0 {
+		return 0, errno
+	}
+	return n, nil
+}
diff --git a/src/internal/syscall/windows/mksyscall.go b/src/internal/syscall/windows/mksyscall.go
index 95e36f7aa3..599f07601b 100644
--- a/src/internal/syscall/windows/mksyscall.go
+++ b/src/internal/syscall/windows/mksyscall.go
@@ -6,4 +6,4 @@
 
 package windows
 
-//go:generate go run golang.org/x/sys/windows/mkwinsyscall -output zsyscall_windows.go syscall_windows.go security_windows.go psapi_windows.go symlink_windows.go
+//go:generate go run ../../../syscall/mksyscall_windows.go -output zsyscall_windows.go syscall_windows.go security_windows.go psapi_windows.go symlink_windows.go
diff --git a/src/internal/syscall/windows/registry/key.go b/src/internal/syscall/windows/registry/key.go
index cc3d0c774b..612c48f084 100644
--- a/src/internal/syscall/windows/registry/key.go
+++ b/src/internal/syscall/windows/registry/key.go
@@ -25,10 +25,7 @@
 //
 package registry
 
-import (
-	"io"
-	"syscall"
-)
+import "syscall"
 
 const (
 	// Registry key security and access rights.
@@ -90,20 +87,13 @@ func OpenKey(k Key, path string, access uint32) (Key, error) {
 }
 
 // ReadSubKeyNames returns the names of subkeys of key k.
-// The parameter n controls the number of returned names,
-// analogous to the way os.File.Readdirnames works.
-func (k Key) ReadSubKeyNames(n int) ([]string, error) {
+func (k Key) ReadSubKeyNames() ([]string, error) {
 	names := make([]string, 0)
 	// Registry key size limit is 255 bytes and described there:
 	// https://msdn.microsoft.com/library/windows/desktop/ms724872.aspx
 	buf := make([]uint16, 256) //plus extra room for terminating zero byte
 loopItems:
 	for i := uint32(0); ; i++ {
-		if n > 0 {
-			if len(names) == n {
-				return names, nil
-			}
-		}
 		l := uint32(len(buf))
 		for {
 			err := syscall.RegEnumKeyEx(syscall.Handle(k), i, &buf[0], &l, nil, nil, nil, nil)
@@ -123,9 +113,6 @@ loopItems:
 		}
 		names = append(names, syscall.UTF16ToString(buf[:l]))
 	}
-	if n > len(names) {
-		return names, io.EOF
-	}
 	return names, nil
 }
 
diff --git a/src/internal/syscall/windows/registry/mksyscall.go b/src/internal/syscall/windows/registry/mksyscall.go
index cb4906a7b2..320abf7fc6 100644
--- a/src/internal/syscall/windows/registry/mksyscall.go
+++ b/src/internal/syscall/windows/registry/mksyscall.go
@@ -6,4 +6,4 @@
 
 package registry
 
-//go:generate go run golang.org/x/sys/windows/mkwinsyscall -output zsyscall_windows.go syscall.go
+//go:generate go run ../../../../syscall/mksyscall_windows.go -output zsyscall_windows.go syscall.go
diff --git a/src/internal/syscall/windows/registry/registry_test.go b/src/internal/syscall/windows/registry/registry_test.go
index 8227232c70..5797162900 100644
--- a/src/internal/syscall/windows/registry/registry_test.go
+++ b/src/internal/syscall/windows/registry/registry_test.go
@@ -34,7 +34,7 @@ func TestReadSubKeyNames(t *testing.T) {
 	}
 	defer k.Close()
 
-	names, err := k.ReadSubKeyNames(-1)
+	names, err := k.ReadSubKeyNames()
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -190,7 +190,7 @@ func setValues(t *testing.T, k registry.Key) {
 }
 
 func enumerateValues(t *testing.T, k registry.Key) {
-	names, err := k.ReadValueNames(-1)
+	names, err := k.ReadValueNames()
 	if err != nil {
 		t.Error(err)
 		return
@@ -480,7 +480,7 @@ func deleteValues(t *testing.T, k registry.Key) {
 			continue
 		}
 	}
-	names, err := k.ReadValueNames(-1)
+	names, err := k.ReadValueNames()
 	if err != nil {
 		t.Error(err)
 		return
diff --git a/src/internal/syscall/windows/registry/value.go b/src/internal/syscall/windows/registry/value.go
index bf8ab00759..dc3930a6bc 100644
--- a/src/internal/syscall/windows/registry/value.go
+++ b/src/internal/syscall/windows/registry/value.go
@@ -8,7 +8,6 @@ package registry
 
 import (
 	"errors"
-	"io"
 	"syscall"
 	"unicode/utf16"
 	"unsafe"
@@ -341,9 +340,7 @@ func (k Key) DeleteValue(name string) error {
 }
 
 // ReadValueNames returns the value names of key k.
-// The parameter n controls the number of returned names,
-// analogous to the way os.File.Readdirnames works.
-func (k Key) ReadValueNames(n int) ([]string, error) {
+func (k Key) ReadValueNames() ([]string, error) {
 	ki, err := k.Stat()
 	if err != nil {
 		return nil, err
@@ -352,11 +349,6 @@ func (k Key) ReadValueNames(n int) ([]string, error) {
 	buf := make([]uint16, ki.MaxValueNameLen+1) // extra room for terminating null character
 loopItems:
 	for i := uint32(0); ; i++ {
-		if n > 0 {
-			if len(names) == n {
-				return names, nil
-			}
-		}
 		l := uint32(len(buf))
 		for {
 			err := regEnumValue(syscall.Handle(k), i, &buf[0], &l, nil, nil, nil, nil)
@@ -376,8 +368,5 @@ loopItems:
 		}
 		names = append(names, syscall.UTF16ToString(buf[:l]))
 	}
-	if n > len(names) {
-		return names, io.EOF
-	}
 	return names, nil
 }
diff --git a/src/internal/syscall/windows/registry/zsyscall_windows.go b/src/internal/syscall/windows/registry/zsyscall_windows.go
index c3f3a8a215..cab1319374 100644
--- a/src/internal/syscall/windows/registry/zsyscall_windows.go
+++ b/src/internal/syscall/windows/registry/zsyscall_windows.go
@@ -18,6 +18,7 @@ const (
 
 var (
 	errERROR_IO_PENDING error = syscall.Errno(errnoERROR_IO_PENDING)
+	errERROR_EINVAL     error = syscall.EINVAL
 )
 
 // errnoErr returns common boxed Errno values, to prevent
@@ -25,7 +26,7 @@ var (
 func errnoErr(e syscall.Errno) error {
 	switch e {
 	case 0:
-		return nil
+		return errERROR_EINVAL
 	case errnoERROR_IO_PENDING:
 		return errERROR_IO_PENDING
 	}
@@ -41,10 +42,10 @@ var (
 
 	procRegCreateKeyExW           = modadvapi32.NewProc("RegCreateKeyExW")
 	procRegDeleteKeyW             = modadvapi32.NewProc("RegDeleteKeyW")
-	procRegSetValueExW            = modadvapi32.NewProc("RegSetValueExW")
-	procRegEnumValueW             = modadvapi32.NewProc("RegEnumValueW")
 	procRegDeleteValueW           = modadvapi32.NewProc("RegDeleteValueW")
+	procRegEnumValueW             = modadvapi32.NewProc("RegEnumValueW")
 	procRegLoadMUIStringW         = modadvapi32.NewProc("RegLoadMUIStringW")
+	procRegSetValueExW            = modadvapi32.NewProc("RegSetValueExW")
 	procExpandEnvironmentStringsW = modkernel32.NewProc("ExpandEnvironmentStringsW")
 )
 
@@ -64,8 +65,8 @@ func regDeleteKey(key syscall.Handle, subkey *uint16) (regerrno error) {
 	return
 }
 
-func regSetValueEx(key syscall.Handle, valueName *uint16, reserved uint32, vtype uint32, buf *byte, bufsize uint32) (regerrno error) {
-	r0, _, _ := syscall.Syscall6(procRegSetValueExW.Addr(), 6, uintptr(key), uintptr(unsafe.Pointer(valueName)), uintptr(reserved), uintptr(vtype), uintptr(unsafe.Pointer(buf)), uintptr(bufsize))
+func regDeleteValue(key syscall.Handle, name *uint16) (regerrno error) {
+	r0, _, _ := syscall.Syscall(procRegDeleteValueW.Addr(), 2, uintptr(key), uintptr(unsafe.Pointer(name)), 0)
 	if r0 != 0 {
 		regerrno = syscall.Errno(r0)
 	}
@@ -80,16 +81,16 @@ func regEnumValue(key syscall.Handle, index uint32, name *uint16, nameLen *uint3
 	return
 }
 
-func regDeleteValue(key syscall.Handle, name *uint16) (regerrno error) {
-	r0, _, _ := syscall.Syscall(procRegDeleteValueW.Addr(), 2, uintptr(key), uintptr(unsafe.Pointer(name)), 0)
+func regLoadMUIString(key syscall.Handle, name *uint16, buf *uint16, buflen uint32, buflenCopied *uint32, flags uint32, dir *uint16) (regerrno error) {
+	r0, _, _ := syscall.Syscall9(procRegLoadMUIStringW.Addr(), 7, uintptr(key), uintptr(unsafe.Pointer(name)), uintptr(unsafe.Pointer(buf)), uintptr(buflen), uintptr(unsafe.Pointer(buflenCopied)), uintptr(flags), uintptr(unsafe.Pointer(dir)), 0, 0)
 	if r0 != 0 {
 		regerrno = syscall.Errno(r0)
 	}
 	return
 }
 
-func regLoadMUIString(key syscall.Handle, name *uint16, buf *uint16, buflen uint32, buflenCopied *uint32, flags uint32, dir *uint16) (regerrno error) {
-	r0, _, _ := syscall.Syscall9(procRegLoadMUIStringW.Addr(), 7, uintptr(key), uintptr(unsafe.Pointer(name)), uintptr(unsafe.Pointer(buf)), uintptr(buflen), uintptr(unsafe.Pointer(buflenCopied)), uintptr(flags), uintptr(unsafe.Pointer(dir)), 0, 0)
+func regSetValueEx(key syscall.Handle, valueName *uint16, reserved uint32, vtype uint32, buf *byte, bufsize uint32) (regerrno error) {
+	r0, _, _ := syscall.Syscall6(procRegSetValueExW.Addr(), 6, uintptr(key), uintptr(unsafe.Pointer(valueName)), uintptr(reserved), uintptr(vtype), uintptr(unsafe.Pointer(buf)), uintptr(bufsize))
 	if r0 != 0 {
 		regerrno = syscall.Errno(r0)
 	}
@@ -100,11 +101,7 @@ func expandEnvironmentStrings(src *uint16, dst *uint16, size uint32) (n uint32,
 	r0, _, e1 := syscall.Syscall(procExpandEnvironmentStringsW.Addr(), 3, uintptr(unsafe.Pointer(src)), uintptr(unsafe.Pointer(dst)), uintptr(size))
 	n = uint32(r0)
 	if n == 0 {
-		if e1 != 0 {
-			err = errnoErr(e1)
-		} else {
-			err = syscall.EINVAL
-		}
+		err = errnoErr(e1)
 	}
 	return
 }
diff --git a/src/internal/syscall/windows/syscall_windows.go b/src/internal/syscall/windows/syscall_windows.go
index edf0b5a40b..1f40c11820 100644
--- a/src/internal/syscall/windows/syscall_windows.go
+++ b/src/internal/syscall/windows/syscall_windows.go
@@ -131,6 +131,14 @@ type IpAdapterAddresses struct {
 	/* more fields might be present here. */
 }
 
+type FILE_BASIC_INFO struct {
+	CreationTime   syscall.Filetime
+	LastAccessTime syscall.Filetime
+	LastWriteTime  syscall.Filetime
+	ChangedTime    syscall.Filetime
+	FileAttributes uint32
+}
+
 const (
 	IfOperStatusUp             = 1
 	IfOperStatusDown           = 2
@@ -145,6 +153,7 @@ const (
 //sys	GetComputerNameEx(nameformat uint32, buf *uint16, n *uint32) (err error) = GetComputerNameExW
 //sys	MoveFileEx(from *uint16, to *uint16, flags uint32) (err error) = MoveFileExW
 //sys	GetModuleFileName(module syscall.Handle, fn *uint16, len uint32) (n uint32, err error) = kernel32.GetModuleFileNameW
+//sys	SetFileInformationByHandle(handle syscall.Handle, fileInformationClass uint32, buf uintptr, bufsize uint32) (err error) = kernel32.SetFileInformationByHandle
 
 const (
 	WSA_FLAG_OVERLAPPED        = 0x01
diff --git a/src/internal/syscall/windows/zsyscall_windows.go b/src/internal/syscall/windows/zsyscall_windows.go
index ca5b4e6f16..170b239486 100644
--- a/src/internal/syscall/windows/zsyscall_windows.go
+++ b/src/internal/syscall/windows/zsyscall_windows.go
@@ -18,6 +18,7 @@ const (
 
 var (
 	errERROR_IO_PENDING error = syscall.Errno(errnoERROR_IO_PENDING)
+	errERROR_EINVAL     error = syscall.EINVAL
 )
 
 // errnoErr returns common boxed Errno values, to prevent
@@ -25,7 +26,7 @@ var (
 func errnoErr(e syscall.Errno) error {
 	switch e {
 	case 0:
-		return nil
+		return errERROR_EINVAL
 	case errnoERROR_IO_PENDING:
 		return errERROR_IO_PENDING
 	}
@@ -36,121 +37,113 @@ func errnoErr(e syscall.Errno) error {
 }
 
 var (
+	modadvapi32 = syscall.NewLazyDLL(sysdll.Add("advapi32.dll"))
 	modiphlpapi = syscall.NewLazyDLL(sysdll.Add("iphlpapi.dll"))
 	modkernel32 = syscall.NewLazyDLL(sysdll.Add("kernel32.dll"))
-	modws2_32   = syscall.NewLazyDLL(sysdll.Add("ws2_32.dll"))
 	modnetapi32 = syscall.NewLazyDLL(sysdll.Add("netapi32.dll"))
-	modadvapi32 = syscall.NewLazyDLL(sysdll.Add("advapi32.dll"))
-	moduserenv  = syscall.NewLazyDLL(sysdll.Add("userenv.dll"))
 	modpsapi    = syscall.NewLazyDLL(sysdll.Add("psapi.dll"))
+	moduserenv  = syscall.NewLazyDLL(sysdll.Add("userenv.dll"))
+	modws2_32   = syscall.NewLazyDLL(sysdll.Add("ws2_32.dll"))
 
+	procAdjustTokenPrivileges        = modadvapi32.NewProc("AdjustTokenPrivileges")
+	procDuplicateTokenEx             = modadvapi32.NewProc("DuplicateTokenEx")
+	procImpersonateSelf              = modadvapi32.NewProc("ImpersonateSelf")
+	procLookupPrivilegeValueW        = modadvapi32.NewProc("LookupPrivilegeValueW")
+	procOpenThreadToken              = modadvapi32.NewProc("OpenThreadToken")
+	procRevertToSelf                 = modadvapi32.NewProc("RevertToSelf")
+	procSetTokenInformation          = modadvapi32.NewProc("SetTokenInformation")
 	procGetAdaptersAddresses         = modiphlpapi.NewProc("GetAdaptersAddresses")
+	procGetACP                       = modkernel32.NewProc("GetACP")
 	procGetComputerNameExW           = modkernel32.NewProc("GetComputerNameExW")
-	procMoveFileExW                  = modkernel32.NewProc("MoveFileExW")
+	procGetConsoleCP                 = modkernel32.NewProc("GetConsoleCP")
+	procGetCurrentThread             = modkernel32.NewProc("GetCurrentThread")
+	procGetFileInformationByHandleEx = modkernel32.NewProc("GetFileInformationByHandleEx")
+	procGetFinalPathNameByHandleW    = modkernel32.NewProc("GetFinalPathNameByHandleW")
 	procGetModuleFileNameW           = modkernel32.NewProc("GetModuleFileNameW")
-	procWSASocketW                   = modws2_32.NewProc("WSASocketW")
 	procLockFileEx                   = modkernel32.NewProc("LockFileEx")
-	procUnlockFileEx                 = modkernel32.NewProc("UnlockFileEx")
-	procGetACP                       = modkernel32.NewProc("GetACP")
-	procGetConsoleCP                 = modkernel32.NewProc("GetConsoleCP")
+	procMoveFileExW                  = modkernel32.NewProc("MoveFileExW")
 	procMultiByteToWideChar          = modkernel32.NewProc("MultiByteToWideChar")
-	procGetCurrentThread             = modkernel32.NewProc("GetCurrentThread")
+	procSetFileInformationByHandle   = modkernel32.NewProc("SetFileInformationByHandle")
+	procUnlockFileEx                 = modkernel32.NewProc("UnlockFileEx")
 	procNetShareAdd                  = modnetapi32.NewProc("NetShareAdd")
 	procNetShareDel                  = modnetapi32.NewProc("NetShareDel")
-	procGetFinalPathNameByHandleW    = modkernel32.NewProc("GetFinalPathNameByHandleW")
+	procNetUserGetLocalGroups        = modnetapi32.NewProc("NetUserGetLocalGroups")
+	procGetProcessMemoryInfo         = modpsapi.NewProc("GetProcessMemoryInfo")
 	procCreateEnvironmentBlock       = moduserenv.NewProc("CreateEnvironmentBlock")
 	procDestroyEnvironmentBlock      = moduserenv.NewProc("DestroyEnvironmentBlock")
-	procImpersonateSelf              = modadvapi32.NewProc("ImpersonateSelf")
-	procRevertToSelf                 = modadvapi32.NewProc("RevertToSelf")
-	procOpenThreadToken              = modadvapi32.NewProc("OpenThreadToken")
-	procLookupPrivilegeValueW        = modadvapi32.NewProc("LookupPrivilegeValueW")
-	procAdjustTokenPrivileges        = modadvapi32.NewProc("AdjustTokenPrivileges")
-	procDuplicateTokenEx             = modadvapi32.NewProc("DuplicateTokenEx")
-	procSetTokenInformation          = modadvapi32.NewProc("SetTokenInformation")
 	procGetProfilesDirectoryW        = moduserenv.NewProc("GetProfilesDirectoryW")
-	procNetUserGetLocalGroups        = modnetapi32.NewProc("NetUserGetLocalGroups")
-	procGetProcessMemoryInfo         = modpsapi.NewProc("GetProcessMemoryInfo")
-	procGetFileInformationByHandleEx = modkernel32.NewProc("GetFileInformationByHandleEx")
+	procWSASocketW                   = modws2_32.NewProc("WSASocketW")
 )
 
-func GetAdaptersAddresses(family uint32, flags uint32, reserved uintptr, adapterAddresses *IpAdapterAddresses, sizePointer *uint32) (errcode error) {
-	r0, _, _ := syscall.Syscall6(procGetAdaptersAddresses.Addr(), 5, uintptr(family), uintptr(flags), uintptr(reserved), uintptr(unsafe.Pointer(adapterAddresses)), uintptr(unsafe.Pointer(sizePointer)), 0)
-	if r0 != 0 {
-		errcode = syscall.Errno(r0)
+func adjustTokenPrivileges(token syscall.Token, disableAllPrivileges bool, newstate *TOKEN_PRIVILEGES, buflen uint32, prevstate *TOKEN_PRIVILEGES, returnlen *uint32) (ret uint32, err error) {
+	var _p0 uint32
+	if disableAllPrivileges {
+		_p0 = 1
+	}
+	r0, _, e1 := syscall.Syscall6(procAdjustTokenPrivileges.Addr(), 6, uintptr(token), uintptr(_p0), uintptr(unsafe.Pointer(newstate)), uintptr(buflen), uintptr(unsafe.Pointer(prevstate)), uintptr(unsafe.Pointer(returnlen)))
+	ret = uint32(r0)
+	if true {
+		err = errnoErr(e1)
 	}
 	return
 }
 
-func GetComputerNameEx(nameformat uint32, buf *uint16, n *uint32) (err error) {
-	r1, _, e1 := syscall.Syscall(procGetComputerNameExW.Addr(), 3, uintptr(nameformat), uintptr(unsafe.Pointer(buf)), uintptr(unsafe.Pointer(n)))
+func DuplicateTokenEx(hExistingToken syscall.Token, dwDesiredAccess uint32, lpTokenAttributes *syscall.SecurityAttributes, impersonationLevel uint32, tokenType TokenType, phNewToken *syscall.Token) (err error) {
+	r1, _, e1 := syscall.Syscall6(procDuplicateTokenEx.Addr(), 6, uintptr(hExistingToken), uintptr(dwDesiredAccess), uintptr(unsafe.Pointer(lpTokenAttributes)), uintptr(impersonationLevel), uintptr(tokenType), uintptr(unsafe.Pointer(phNewToken)))
 	if r1 == 0 {
-		if e1 != 0 {
-			err = errnoErr(e1)
-		} else {
-			err = syscall.EINVAL
-		}
+		err = errnoErr(e1)
 	}
 	return
 }
 
-func MoveFileEx(from *uint16, to *uint16, flags uint32) (err error) {
-	r1, _, e1 := syscall.Syscall(procMoveFileExW.Addr(), 3, uintptr(unsafe.Pointer(from)), uintptr(unsafe.Pointer(to)), uintptr(flags))
+func ImpersonateSelf(impersonationlevel uint32) (err error) {
+	r1, _, e1 := syscall.Syscall(procImpersonateSelf.Addr(), 1, uintptr(impersonationlevel), 0, 0)
 	if r1 == 0 {
-		if e1 != 0 {
-			err = errnoErr(e1)
-		} else {
-			err = syscall.EINVAL
-		}
+		err = errnoErr(e1)
 	}
 	return
 }
 
-func GetModuleFileName(module syscall.Handle, fn *uint16, len uint32) (n uint32, err error) {
-	r0, _, e1 := syscall.Syscall(procGetModuleFileNameW.Addr(), 3, uintptr(module), uintptr(unsafe.Pointer(fn)), uintptr(len))
-	n = uint32(r0)
-	if n == 0 {
-		if e1 != 0 {
-			err = errnoErr(e1)
-		} else {
-			err = syscall.EINVAL
-		}
+func LookupPrivilegeValue(systemname *uint16, name *uint16, luid *LUID) (err error) {
+	r1, _, e1 := syscall.Syscall(procLookupPrivilegeValueW.Addr(), 3, uintptr(unsafe.Pointer(systemname)), uintptr(unsafe.Pointer(name)), uintptr(unsafe.Pointer(luid)))
+	if r1 == 0 {
+		err = errnoErr(e1)
 	}
 	return
 }
 
-func WSASocket(af int32, typ int32, protocol int32, protinfo *syscall.WSAProtocolInfo, group uint32, flags uint32) (handle syscall.Handle, err error) {
-	r0, _, e1 := syscall.Syscall6(procWSASocketW.Addr(), 6, uintptr(af), uintptr(typ), uintptr(protocol), uintptr(unsafe.Pointer(protinfo)), uintptr(group), uintptr(flags))
-	handle = syscall.Handle(r0)
-	if handle == syscall.InvalidHandle {
-		if e1 != 0 {
-			err = errnoErr(e1)
-		} else {
-			err = syscall.EINVAL
-		}
+func OpenThreadToken(h syscall.Handle, access uint32, openasself bool, token *syscall.Token) (err error) {
+	var _p0 uint32
+	if openasself {
+		_p0 = 1
+	}
+	r1, _, e1 := syscall.Syscall6(procOpenThreadToken.Addr(), 4, uintptr(h), uintptr(access), uintptr(_p0), uintptr(unsafe.Pointer(token)), 0, 0)
+	if r1 == 0 {
+		err = errnoErr(e1)
 	}
 	return
 }
 
-func LockFileEx(file syscall.Handle, flags uint32, reserved uint32, bytesLow uint32, bytesHigh uint32, overlapped *syscall.Overlapped) (err error) {
-	r1, _, e1 := syscall.Syscall6(procLockFileEx.Addr(), 6, uintptr(file), uintptr(flags), uintptr(reserved), uintptr(bytesLow), uintptr(bytesHigh), uintptr(unsafe.Pointer(overlapped)))
+func RevertToSelf() (err error) {
+	r1, _, e1 := syscall.Syscall(procRevertToSelf.Addr(), 0, 0, 0, 0)
 	if r1 == 0 {
-		if e1 != 0 {
-			err = errnoErr(e1)
-		} else {
-			err = syscall.EINVAL
-		}
+		err = errnoErr(e1)
 	}
 	return
 }
 
-func UnlockFileEx(file syscall.Handle, reserved uint32, bytesLow uint32, bytesHigh uint32, overlapped *syscall.Overlapped) (err error) {
-	r1, _, e1 := syscall.Syscall6(procUnlockFileEx.Addr(), 5, uintptr(file), uintptr(reserved), uintptr(bytesLow), uintptr(bytesHigh), uintptr(unsafe.Pointer(overlapped)), 0)
+func SetTokenInformation(tokenHandle syscall.Token, tokenInformationClass uint32, tokenInformation uintptr, tokenInformationLength uint32) (err error) {
+	r1, _, e1 := syscall.Syscall6(procSetTokenInformation.Addr(), 4, uintptr(tokenHandle), uintptr(tokenInformationClass), uintptr(tokenInformation), uintptr(tokenInformationLength), 0, 0)
 	if r1 == 0 {
-		if e1 != 0 {
-			err = errnoErr(e1)
-		} else {
-			err = syscall.EINVAL
-		}
+		err = errnoErr(e1)
+	}
+	return
+}
+
+func GetAdaptersAddresses(family uint32, flags uint32, reserved uintptr, adapterAddresses *IpAdapterAddresses, sizePointer *uint32) (errcode error) {
+	r0, _, _ := syscall.Syscall6(procGetAdaptersAddresses.Addr(), 5, uintptr(family), uintptr(flags), uintptr(reserved), uintptr(unsafe.Pointer(adapterAddresses)), uintptr(unsafe.Pointer(sizePointer)), 0)
+	if r0 != 0 {
+		errcode = syscall.Errno(r0)
 	}
 	return
 }
@@ -161,22 +154,17 @@ func GetACP() (acp uint32) {
 	return
 }
 
-func GetConsoleCP() (ccp uint32) {
-	r0, _, _ := syscall.Syscall(procGetConsoleCP.Addr(), 0, 0, 0, 0)
-	ccp = uint32(r0)
+func GetComputerNameEx(nameformat uint32, buf *uint16, n *uint32) (err error) {
+	r1, _, e1 := syscall.Syscall(procGetComputerNameExW.Addr(), 3, uintptr(nameformat), uintptr(unsafe.Pointer(buf)), uintptr(unsafe.Pointer(n)))
+	if r1 == 0 {
+		err = errnoErr(e1)
+	}
 	return
 }
 
-func MultiByteToWideChar(codePage uint32, dwFlags uint32, str *byte, nstr int32, wchar *uint16, nwchar int32) (nwrite int32, err error) {
-	r0, _, e1 := syscall.Syscall6(procMultiByteToWideChar.Addr(), 6, uintptr(codePage), uintptr(dwFlags), uintptr(unsafe.Pointer(str)), uintptr(nstr), uintptr(unsafe.Pointer(wchar)), uintptr(nwchar))
-	nwrite = int32(r0)
-	if nwrite == 0 {
-		if e1 != 0 {
-			err = errnoErr(e1)
-		} else {
-			err = syscall.EINVAL
-		}
-	}
+func GetConsoleCP() (ccp uint32) {
+	r0, _, _ := syscall.Syscall(procGetConsoleCP.Addr(), 0, 0, 0, 0)
+	ccp = uint32(r0)
 	return
 }
 
@@ -184,211 +172,143 @@ func GetCurrentThread() (pseudoHandle syscall.Handle, err error) {
 	r0, _, e1 := syscall.Syscall(procGetCurrentThread.Addr(), 0, 0, 0, 0)
 	pseudoHandle = syscall.Handle(r0)
 	if pseudoHandle == 0 {
-		if e1 != 0 {
-			err = errnoErr(e1)
-		} else {
-			err = syscall.EINVAL
-		}
+		err = errnoErr(e1)
 	}
 	return
 }
 
-func NetShareAdd(serverName *uint16, level uint32, buf *byte, parmErr *uint16) (neterr error) {
-	r0, _, _ := syscall.Syscall6(procNetShareAdd.Addr(), 4, uintptr(unsafe.Pointer(serverName)), uintptr(level), uintptr(unsafe.Pointer(buf)), uintptr(unsafe.Pointer(parmErr)), 0, 0)
-	if r0 != 0 {
-		neterr = syscall.Errno(r0)
+func GetFileInformationByHandleEx(handle syscall.Handle, class uint32, info *byte, bufsize uint32) (err error) {
+	r1, _, e1 := syscall.Syscall6(procGetFileInformationByHandleEx.Addr(), 4, uintptr(handle), uintptr(class), uintptr(unsafe.Pointer(info)), uintptr(bufsize), 0, 0)
+	if r1 == 0 {
+		err = errnoErr(e1)
 	}
 	return
 }
 
-func NetShareDel(serverName *uint16, netName *uint16, reserved uint32) (neterr error) {
-	r0, _, _ := syscall.Syscall(procNetShareDel.Addr(), 3, uintptr(unsafe.Pointer(serverName)), uintptr(unsafe.Pointer(netName)), uintptr(reserved))
-	if r0 != 0 {
-		neterr = syscall.Errno(r0)
+func GetFinalPathNameByHandle(file syscall.Handle, filePath *uint16, filePathSize uint32, flags uint32) (n uint32, err error) {
+	r0, _, e1 := syscall.Syscall6(procGetFinalPathNameByHandleW.Addr(), 4, uintptr(file), uintptr(unsafe.Pointer(filePath)), uintptr(filePathSize), uintptr(flags), 0, 0)
+	n = uint32(r0)
+	if n == 0 {
+		err = errnoErr(e1)
 	}
 	return
 }
 
-func GetFinalPathNameByHandle(file syscall.Handle, filePath *uint16, filePathSize uint32, flags uint32) (n uint32, err error) {
-	r0, _, e1 := syscall.Syscall6(procGetFinalPathNameByHandleW.Addr(), 4, uintptr(file), uintptr(unsafe.Pointer(filePath)), uintptr(filePathSize), uintptr(flags), 0, 0)
+func GetModuleFileName(module syscall.Handle, fn *uint16, len uint32) (n uint32, err error) {
+	r0, _, e1 := syscall.Syscall(procGetModuleFileNameW.Addr(), 3, uintptr(module), uintptr(unsafe.Pointer(fn)), uintptr(len))
 	n = uint32(r0)
 	if n == 0 {
-		if e1 != 0 {
-			err = errnoErr(e1)
-		} else {
-			err = syscall.EINVAL
-		}
+		err = errnoErr(e1)
 	}
 	return
 }
 
-func CreateEnvironmentBlock(block **uint16, token syscall.Token, inheritExisting bool) (err error) {
-	var _p0 uint32
-	if inheritExisting {
-		_p0 = 1
-	} else {
-		_p0 = 0
-	}
-	r1, _, e1 := syscall.Syscall(procCreateEnvironmentBlock.Addr(), 3, uintptr(unsafe.Pointer(block)), uintptr(token), uintptr(_p0))
+func LockFileEx(file syscall.Handle, flags uint32, reserved uint32, bytesLow uint32, bytesHigh uint32, overlapped *syscall.Overlapped) (err error) {
+	r1, _, e1 := syscall.Syscall6(procLockFileEx.Addr(), 6, uintptr(file), uintptr(flags), uintptr(reserved), uintptr(bytesLow), uintptr(bytesHigh), uintptr(unsafe.Pointer(overlapped)))
 	if r1 == 0 {
-		if e1 != 0 {
-			err = errnoErr(e1)
-		} else {
-			err = syscall.EINVAL
-		}
+		err = errnoErr(e1)
 	}
 	return
 }
 
-func DestroyEnvironmentBlock(block *uint16) (err error) {
-	r1, _, e1 := syscall.Syscall(procDestroyEnvironmentBlock.Addr(), 1, uintptr(unsafe.Pointer(block)), 0, 0)
+func MoveFileEx(from *uint16, to *uint16, flags uint32) (err error) {
+	r1, _, e1 := syscall.Syscall(procMoveFileExW.Addr(), 3, uintptr(unsafe.Pointer(from)), uintptr(unsafe.Pointer(to)), uintptr(flags))
 	if r1 == 0 {
-		if e1 != 0 {
-			err = errnoErr(e1)
-		} else {
-			err = syscall.EINVAL
-		}
+		err = errnoErr(e1)
 	}
 	return
 }
 
-func ImpersonateSelf(impersonationlevel uint32) (err error) {
-	r1, _, e1 := syscall.Syscall(procImpersonateSelf.Addr(), 1, uintptr(impersonationlevel), 0, 0)
-	if r1 == 0 {
-		if e1 != 0 {
-			err = errnoErr(e1)
-		} else {
-			err = syscall.EINVAL
-		}
+func MultiByteToWideChar(codePage uint32, dwFlags uint32, str *byte, nstr int32, wchar *uint16, nwchar int32) (nwrite int32, err error) {
+	r0, _, e1 := syscall.Syscall6(procMultiByteToWideChar.Addr(), 6, uintptr(codePage), uintptr(dwFlags), uintptr(unsafe.Pointer(str)), uintptr(nstr), uintptr(unsafe.Pointer(wchar)), uintptr(nwchar))
+	nwrite = int32(r0)
+	if nwrite == 0 {
+		err = errnoErr(e1)
 	}
 	return
 }
 
-func RevertToSelf() (err error) {
-	r1, _, e1 := syscall.Syscall(procRevertToSelf.Addr(), 0, 0, 0, 0)
+func SetFileInformationByHandle(handle syscall.Handle, fileInformationClass uint32, buf uintptr, bufsize uint32) (err error) {
+	r1, _, e1 := syscall.Syscall6(procSetFileInformationByHandle.Addr(), 4, uintptr(handle), uintptr(fileInformationClass), uintptr(buf), uintptr(bufsize), 0, 0)
 	if r1 == 0 {
-		if e1 != 0 {
-			err = errnoErr(e1)
-		} else {
-			err = syscall.EINVAL
-		}
+		err = errnoErr(e1)
 	}
 	return
 }
 
-func OpenThreadToken(h syscall.Handle, access uint32, openasself bool, token *syscall.Token) (err error) {
-	var _p0 uint32
-	if openasself {
-		_p0 = 1
-	} else {
-		_p0 = 0
-	}
-	r1, _, e1 := syscall.Syscall6(procOpenThreadToken.Addr(), 4, uintptr(h), uintptr(access), uintptr(_p0), uintptr(unsafe.Pointer(token)), 0, 0)
+func UnlockFileEx(file syscall.Handle, reserved uint32, bytesLow uint32, bytesHigh uint32, overlapped *syscall.Overlapped) (err error) {
+	r1, _, e1 := syscall.Syscall6(procUnlockFileEx.Addr(), 5, uintptr(file), uintptr(reserved), uintptr(bytesLow), uintptr(bytesHigh), uintptr(unsafe.Pointer(overlapped)), 0)
 	if r1 == 0 {
-		if e1 != 0 {
-			err = errnoErr(e1)
-		} else {
-			err = syscall.EINVAL
-		}
+		err = errnoErr(e1)
 	}
 	return
 }
 
-func LookupPrivilegeValue(systemname *uint16, name *uint16, luid *LUID) (err error) {
-	r1, _, e1 := syscall.Syscall(procLookupPrivilegeValueW.Addr(), 3, uintptr(unsafe.Pointer(systemname)), uintptr(unsafe.Pointer(name)), uintptr(unsafe.Pointer(luid)))
-	if r1 == 0 {
-		if e1 != 0 {
-			err = errnoErr(e1)
-		} else {
-			err = syscall.EINVAL
-		}
+func NetShareAdd(serverName *uint16, level uint32, buf *byte, parmErr *uint16) (neterr error) {
+	r0, _, _ := syscall.Syscall6(procNetShareAdd.Addr(), 4, uintptr(unsafe.Pointer(serverName)), uintptr(level), uintptr(unsafe.Pointer(buf)), uintptr(unsafe.Pointer(parmErr)), 0, 0)
+	if r0 != 0 {
+		neterr = syscall.Errno(r0)
 	}
 	return
 }
 
-func adjustTokenPrivileges(token syscall.Token, disableAllPrivileges bool, newstate *TOKEN_PRIVILEGES, buflen uint32, prevstate *TOKEN_PRIVILEGES, returnlen *uint32) (ret uint32, err error) {
-	var _p0 uint32
-	if disableAllPrivileges {
-		_p0 = 1
-	} else {
-		_p0 = 0
-	}
-	r0, _, e1 := syscall.Syscall6(procAdjustTokenPrivileges.Addr(), 6, uintptr(token), uintptr(_p0), uintptr(unsafe.Pointer(newstate)), uintptr(buflen), uintptr(unsafe.Pointer(prevstate)), uintptr(unsafe.Pointer(returnlen)))
-	ret = uint32(r0)
-	if true {
-		if e1 != 0 {
-			err = errnoErr(e1)
-		} else {
-			err = syscall.EINVAL
-		}
+func NetShareDel(serverName *uint16, netName *uint16, reserved uint32) (neterr error) {
+	r0, _, _ := syscall.Syscall(procNetShareDel.Addr(), 3, uintptr(unsafe.Pointer(serverName)), uintptr(unsafe.Pointer(netName)), uintptr(reserved))
+	if r0 != 0 {
+		neterr = syscall.Errno(r0)
 	}
 	return
 }
 
-func DuplicateTokenEx(hExistingToken syscall.Token, dwDesiredAccess uint32, lpTokenAttributes *syscall.SecurityAttributes, impersonationLevel uint32, tokenType TokenType, phNewToken *syscall.Token) (err error) {
-	r1, _, e1 := syscall.Syscall6(procDuplicateTokenEx.Addr(), 6, uintptr(hExistingToken), uintptr(dwDesiredAccess), uintptr(unsafe.Pointer(lpTokenAttributes)), uintptr(impersonationLevel), uintptr(tokenType), uintptr(unsafe.Pointer(phNewToken)))
-	if r1 == 0 {
-		if e1 != 0 {
-			err = errnoErr(e1)
-		} else {
-			err = syscall.EINVAL
-		}
+func NetUserGetLocalGroups(serverName *uint16, userName *uint16, level uint32, flags uint32, buf **byte, prefMaxLen uint32, entriesRead *uint32, totalEntries *uint32) (neterr error) {
+	r0, _, _ := syscall.Syscall9(procNetUserGetLocalGroups.Addr(), 8, uintptr(unsafe.Pointer(serverName)), uintptr(unsafe.Pointer(userName)), uintptr(level), uintptr(flags), uintptr(unsafe.Pointer(buf)), uintptr(prefMaxLen), uintptr(unsafe.Pointer(entriesRead)), uintptr(unsafe.Pointer(totalEntries)), 0)
+	if r0 != 0 {
+		neterr = syscall.Errno(r0)
 	}
 	return
 }
 
-func SetTokenInformation(tokenHandle syscall.Token, tokenInformationClass uint32, tokenInformation uintptr, tokenInformationLength uint32) (err error) {
-	r1, _, e1 := syscall.Syscall6(procSetTokenInformation.Addr(), 4, uintptr(tokenHandle), uintptr(tokenInformationClass), uintptr(tokenInformation), uintptr(tokenInformationLength), 0, 0)
+func GetProcessMemoryInfo(handle syscall.Handle, memCounters *PROCESS_MEMORY_COUNTERS, cb uint32) (err error) {
+	r1, _, e1 := syscall.Syscall(procGetProcessMemoryInfo.Addr(), 3, uintptr(handle), uintptr(unsafe.Pointer(memCounters)), uintptr(cb))
 	if r1 == 0 {
-		if e1 != 0 {
-			err = errnoErr(e1)
-		} else {
-			err = syscall.EINVAL
-		}
+		err = errnoErr(e1)
 	}
 	return
 }
 
-func GetProfilesDirectory(dir *uint16, dirLen *uint32) (err error) {
-	r1, _, e1 := syscall.Syscall(procGetProfilesDirectoryW.Addr(), 2, uintptr(unsafe.Pointer(dir)), uintptr(unsafe.Pointer(dirLen)), 0)
+func CreateEnvironmentBlock(block **uint16, token syscall.Token, inheritExisting bool) (err error) {
+	var _p0 uint32
+	if inheritExisting {
+		_p0 = 1
+	}
+	r1, _, e1 := syscall.Syscall(procCreateEnvironmentBlock.Addr(), 3, uintptr(unsafe.Pointer(block)), uintptr(token), uintptr(_p0))
 	if r1 == 0 {
-		if e1 != 0 {
-			err = errnoErr(e1)
-		} else {
-			err = syscall.EINVAL
-		}
+		err = errnoErr(e1)
 	}
 	return
 }
 
-func NetUserGetLocalGroups(serverName *uint16, userName *uint16, level uint32, flags uint32, buf **byte, prefMaxLen uint32, entriesRead *uint32, totalEntries *uint32) (neterr error) {
-	r0, _, _ := syscall.Syscall9(procNetUserGetLocalGroups.Addr(), 8, uintptr(unsafe.Pointer(serverName)), uintptr(unsafe.Pointer(userName)), uintptr(level), uintptr(flags), uintptr(unsafe.Pointer(buf)), uintptr(prefMaxLen), uintptr(unsafe.Pointer(entriesRead)), uintptr(unsafe.Pointer(totalEntries)), 0)
-	if r0 != 0 {
-		neterr = syscall.Errno(r0)
+func DestroyEnvironmentBlock(block *uint16) (err error) {
+	r1, _, e1 := syscall.Syscall(procDestroyEnvironmentBlock.Addr(), 1, uintptr(unsafe.Pointer(block)), 0, 0)
+	if r1 == 0 {
+		err = errnoErr(e1)
 	}
 	return
 }
 
-func GetProcessMemoryInfo(handle syscall.Handle, memCounters *PROCESS_MEMORY_COUNTERS, cb uint32) (err error) {
-	r1, _, e1 := syscall.Syscall(procGetProcessMemoryInfo.Addr(), 3, uintptr(handle), uintptr(unsafe.Pointer(memCounters)), uintptr(cb))
+func GetProfilesDirectory(dir *uint16, dirLen *uint32) (err error) {
+	r1, _, e1 := syscall.Syscall(procGetProfilesDirectoryW.Addr(), 2, uintptr(unsafe.Pointer(dir)), uintptr(unsafe.Pointer(dirLen)), 0)
 	if r1 == 0 {
-		if e1 != 0 {
-			err = errnoErr(e1)
-		} else {
-			err = syscall.EINVAL
-		}
+		err = errnoErr(e1)
 	}
 	return
 }
 
-func GetFileInformationByHandleEx(handle syscall.Handle, class uint32, info *byte, bufsize uint32) (err error) {
-	r1, _, e1 := syscall.Syscall6(procGetFileInformationByHandleEx.Addr(), 4, uintptr(handle), uintptr(class), uintptr(unsafe.Pointer(info)), uintptr(bufsize), 0, 0)
-	if r1 == 0 {
-		if e1 != 0 {
-			err = errnoErr(e1)
-		} else {
-			err = syscall.EINVAL
-		}
+func WSASocket(af int32, typ int32, protocol int32, protinfo *syscall.WSAProtocolInfo, group uint32, flags uint32) (handle syscall.Handle, err error) {
+	r0, _, e1 := syscall.Syscall6(procWSASocketW.Addr(), 6, uintptr(af), uintptr(typ), uintptr(protocol), uintptr(unsafe.Pointer(protinfo)), uintptr(group), uintptr(flags))
+	handle = syscall.Handle(r0)
+	if handle == syscall.InvalidHandle {
+		err = errnoErr(e1)
 	}
 	return
 }
diff --git a/src/internal/sysinfo/sysinfo.go b/src/internal/sysinfo/sysinfo.go
new file mode 100644
index 0000000000..961be7abae
--- /dev/null
+++ b/src/internal/sysinfo/sysinfo.go
@@ -0,0 +1,31 @@
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package sysinfo implements high level hardware information gathering
+// that can be used for debugging or information purposes.
+package sysinfo
+
+import (
+	internalcpu "internal/cpu"
+	"sync"
+)
+
+type cpuInfo struct {
+	once sync.Once
+	name string
+}
+
+var CPU cpuInfo
+
+func (cpu *cpuInfo) Name() string {
+	cpu.once.Do(func() {
+		// Try to get the information from internal/cpu.
+		if name := internalcpu.Name(); name != "" {
+			cpu.name = name
+			return
+		}
+		// TODO(martisch): use /proc/cpuinfo and /sys/devices/system/cpu/ on Linux as fallback.
+	})
+	return cpu.name
+}
diff --git a/src/internal/testenv/testenv.go b/src/internal/testenv/testenv.go
index 309b2702ed..c902b1404f 100644
--- a/src/internal/testenv/testenv.go
+++ b/src/internal/testenv/testenv.go
@@ -43,12 +43,8 @@ func HasGoBuild() bool {
 		return false
 	}
 	switch runtime.GOOS {
-	case "android", "js":
+	case "android", "js", "ios":
 		return false
-	case "darwin":
-		if runtime.GOARCH == "arm64" {
-			return false
-		}
 	}
 	return true
 }
@@ -122,12 +118,8 @@ func GoTool() (string, error) {
 // using os.StartProcess or (more commonly) exec.Command.
 func HasExec() bool {
 	switch runtime.GOOS {
-	case "js":
+	case "js", "ios":
 		return false
-	case "darwin":
-		if runtime.GOARCH == "arm64" {
-			return false
-		}
 	}
 	return true
 }
@@ -135,10 +127,8 @@ func HasExec() bool {
 // HasSrc reports whether the entire source tree is available under GOROOT.
 func HasSrc() bool {
 	switch runtime.GOOS {
-	case "darwin":
-		if runtime.GOARCH == "arm64" {
-			return false
-		}
+	case "ios":
+		return false
 	}
 	return true
 }
@@ -202,6 +192,32 @@ func MustHaveCGO(t testing.TB) {
 	}
 }
 
+// CanInternalLink reports whether the current system can link programs with
+// internal linking.
+// (This is the opposite of cmd/internal/sys.MustLinkExternal. Keep them in sync.)
+func CanInternalLink() bool {
+	switch runtime.GOOS {
+	case "android":
+		if runtime.GOARCH != "arm64" {
+			return false
+		}
+	case "ios":
+		if runtime.GOARCH == "arm64" {
+			return false
+		}
+	}
+	return true
+}
+
+// MustInternalLink checks that the current system can link programs with internal
+// linking.
+// If not, MustInternalLink calls t.Skip with an explanation.
+func MustInternalLink(t testing.TB) {
+	if !CanInternalLink() {
+		t.Skipf("skipping test: internal linking on %s/%s is not supported", runtime.GOOS, runtime.GOARCH)
+	}
+}
+
 // HasSymlink reports whether the current system can use os.Symlink.
 func HasSymlink() bool {
 	ok, _ := hasSymlink()
@@ -270,3 +286,23 @@ func CleanCmdEnv(cmd *exec.Cmd) *exec.Cmd {
 	}
 	return cmd
 }
+
+// CPUIsSlow reports whether the CPU running the test is suspected to be slow.
+func CPUIsSlow() bool {
+	switch runtime.GOARCH {
+	case "arm", "mips", "mipsle", "mips64", "mips64le":
+		return true
+	}
+	return false
+}
+
+// SkipIfShortAndSlow skips t if -short is set and the CPU running the test is
+// suspected to be slow.
+//
+// (This is useful for CPU-intensive tests that otherwise complete quickly.)
+func SkipIfShortAndSlow(t testing.TB) {
+	if testing.Short() && CPUIsSlow() {
+		t.Helper()
+		t.Skipf("skipping test in -short mode on %s", runtime.GOARCH)
+	}
+}
diff --git a/src/internal/testenv/testenv_windows.go b/src/internal/testenv/testenv_windows.go
index eb8d6ac165..4802b13951 100644
--- a/src/internal/testenv/testenv_windows.go
+++ b/src/internal/testenv/testenv_windows.go
@@ -5,7 +5,6 @@
 package testenv
 
 import (
-	"io/ioutil"
 	"os"
 	"path/filepath"
 	"sync"
@@ -16,7 +15,7 @@ var symlinkOnce sync.Once
 var winSymlinkErr error
 
 func initWinHasSymlink() {
-	tmpdir, err := ioutil.TempDir("", "symtest")
+	tmpdir, err := os.MkdirTemp("", "symtest")
 	if err != nil {
 		panic("failed to create temp directory: " + err.Error())
 	}
diff --git a/src/internal/trace/gc_test.go b/src/internal/trace/gc_test.go
index 4f9c77041a..9b9771e7b0 100644
--- a/src/internal/trace/gc_test.go
+++ b/src/internal/trace/gc_test.go
@@ -6,8 +6,8 @@ package trace
 
 import (
 	"bytes"
-	"io/ioutil"
 	"math"
+	"os"
 	"testing"
 	"time"
 )
@@ -84,7 +84,7 @@ func TestMMUTrace(t *testing.T) {
 		t.Skip("skipping in -short mode")
 	}
 
-	data, err := ioutil.ReadFile("testdata/stress_1_10_good")
+	data, err := os.ReadFile("testdata/stress_1_10_good")
 	if err != nil {
 		t.Fatalf("failed to read input file: %v", err)
 	}
@@ -126,7 +126,7 @@ func TestMMUTrace(t *testing.T) {
 }
 
 func BenchmarkMMU(b *testing.B) {
-	data, err := ioutil.ReadFile("testdata/stress_1_10_good")
+	data, err := os.ReadFile("testdata/stress_1_10_good")
 	if err != nil {
 		b.Fatalf("failed to read input file: %v", err)
 	}
diff --git a/src/internal/trace/parser_test.go b/src/internal/trace/parser_test.go
index 6d87970157..cdab95a59e 100644
--- a/src/internal/trace/parser_test.go
+++ b/src/internal/trace/parser_test.go
@@ -6,7 +6,6 @@ package trace
 
 import (
 	"bytes"
-	"io/ioutil"
 	"os"
 	"path/filepath"
 	"strings"
@@ -34,20 +33,20 @@ func TestCorruptedInputs(t *testing.T) {
 }
 
 func TestParseCanned(t *testing.T) {
-	files, err := ioutil.ReadDir("./testdata")
+	files, err := os.ReadDir("./testdata")
 	if err != nil {
 		t.Fatalf("failed to read ./testdata: %v", err)
 	}
 	for _, f := range files {
-		name := filepath.Join("./testdata", f.Name())
-		info, err := os.Stat(name)
+		info, err := f.Info()
 		if err != nil {
 			t.Fatal(err)
 		}
 		if testing.Short() && info.Size() > 10000 {
 			continue
 		}
-		data, err := ioutil.ReadFile(name)
+		name := filepath.Join("./testdata", f.Name())
+		data, err := os.ReadFile(name)
 		if err != nil {
 			t.Fatal(err)
 		}