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

Change-Id: I5d8c8329ccc9d747bd81ade6b1cb7cb8ae2e94b2

13 files changed, 670 insertions, 124 deletions

diff --git a/src/debug/dwarf/const.go b/src/debug/dwarf/const.go
index b11bf90c37..c60709199b 100644
--- a/src/debug/dwarf/const.go
+++ b/src/debug/dwarf/const.go
@@ -461,3 +461,15 @@ const (
 	utSplitCompile = 0x05
 	utSplitType    = 0x06
 )
+
+// Opcodes for DWARFv5 debug_rnglists section.
+const (
+	rleEndOfList    = 0x0
+	rleBaseAddressx = 0x1
+	rleStartxEndx   = 0x2
+	rleStartxLength = 0x3
+	rleOffsetPair   = 0x4
+	rleBaseAddress  = 0x5
+	rleStartEnd     = 0x6
+	rleStartLength  = 0x7
+)
diff --git a/src/debug/dwarf/dwarf5ranges_test.go b/src/debug/dwarf/dwarf5ranges_test.go
new file mode 100644
index 0000000000..0ff1a55bc9
--- /dev/null
+++ b/src/debug/dwarf/dwarf5ranges_test.go
@@ -0,0 +1,36 @@
+// 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 dwarf
+
+import (
+	"encoding/binary"
+	"os"
+	"reflect"
+	"testing"
+)
+
+func TestDwarf5Ranges(t *testing.T) {
+	rngLists, err := os.ReadFile("testdata/debug_rnglists")
+	if err != nil {
+		t.Fatalf("could not read test data: %v", err)
+	}
+
+	d := &Data{}
+	d.order = binary.LittleEndian
+	if err := d.AddSection(".debug_rnglists", rngLists); err != nil {
+		t.Fatal(err)
+	}
+	ret, err := d.dwarf5Ranges(nil, 0x5fbd, 0xc, [][2]uint64{})
+	if err != nil {
+		t.Fatalf("could not read rnglist: %v", err)
+	}
+	t.Logf("%#v", ret)
+
+	tgt := [][2]uint64{{0x0000000000006712, 0x000000000000679f}, {0x00000000000067af}, {0x00000000000067b3}}
+
+	if reflect.DeepEqual(ret, tgt) {
+		t.Errorf("expected %#v got %#x", tgt, ret)
+	}
+}
diff --git a/src/debug/dwarf/entry.go b/src/debug/dwarf/entry.go
index 01f2190db7..bc05d7ef31 100644
--- a/src/debug/dwarf/entry.go
+++ b/src/debug/dwarf/entry.go
@@ -453,38 +453,28 @@ func (b *buf) entry(cu *Entry, atab abbrevTable, ubase Offset, vers int) *Entry
 			case formAddrx4:
 				off = uint64(b.uint32())
 			}
-			if len(b.dwarf.addr) == 0 {
+			if b.dwarf.addr == nil {
 				b.error("DW_FORM_addrx with no .debug_addr section")
 			}
 			if b.err != nil {
 				return nil
 			}
-			addrsize := b.format.addrsize()
-			if addrsize == 0 {
-				b.error("unknown address size for DW_FORM_addrx")
-			}
-			off *= uint64(addrsize)
 
 			// We have to adjust by the offset of the
 			// compilation unit. This won't work if the
 			// program uses Reader.Seek to skip over the
 			// unit. Not much we can do about that.
+			var addrBase int64
 			if cu != nil {
-				cuOff, ok := cu.Val(AttrAddrBase).(int64)
-				if ok {
-					off += uint64(cuOff)
-				}
-			}
-
-			if uint64(int(off)) != off {
-				b.error("DW_FORM_addrx offset out of range")
+				addrBase, _ = cu.Val(AttrAddrBase).(int64)
 			}
 
-			b1 := makeBuf(b.dwarf, b.format, "addr", 0, b.dwarf.addr)
-			b1.skip(int(off))
-			val = b1.addr()
-			if b1.err != nil {
-				b.err = b1.err
+			var err error
+			val, err = b.dwarf.debugAddr(uint64(addrBase), off)
+			if err != nil {
+				if b.err == nil {
+					b.err = err
+				}
 				return nil
 			}
 
@@ -717,6 +707,7 @@ type Reader struct {
 	d            *Data
 	err          error
 	unit         int
+	lastUnit     bool   // set if last entry returned by Next is TagCompileUnit/TagPartialUnit
 	lastChildren bool   // .Children of last entry returned by Next
 	lastSibling  Offset // .Val(AttrSibling) of last entry returned by Next
 	cu           *Entry // current compilation unit
@@ -774,13 +765,18 @@ func (r *Reader) Seek(off Offset) {
 // maybeNextUnit advances to the next unit if this one is finished.
 func (r *Reader) maybeNextUnit() {
 	for len(r.b.data) == 0 && r.unit+1 < len(r.d.unit) {
-		r.unit++
-		u := &r.d.unit[r.unit]
-		r.b = makeBuf(r.d, u, "info", u.off, u.data)
-		r.cu = nil
+		r.nextUnit()
 	}
 }
 
+// nextUnit advances to the next unit.
+func (r *Reader) nextUnit() {
+	r.unit++
+	u := &r.d.unit[r.unit]
+	r.b = makeBuf(r.d, u, "info", u.off, u.data)
+	r.cu = nil
+}
+
 // Next reads the next entry from the encoded entry stream.
 // It returns nil, nil when it reaches the end of the section.
 // It returns an error if the current offset is invalid or the data at the
@@ -799,12 +795,14 @@ func (r *Reader) Next() (*Entry, error) {
 		r.err = r.b.err
 		return nil, r.err
 	}
+	r.lastUnit = false
 	if e != nil {
 		r.lastChildren = e.Children
 		if r.lastChildren {
 			r.lastSibling, _ = e.Val(AttrSibling).(Offset)
 		}
 		if e.Tag == TagCompileUnit || e.Tag == TagPartialUnit {
+			r.lastUnit = true
 			r.cu = e
 		}
 	} else {
@@ -830,6 +828,11 @@ func (r *Reader) SkipChildren() {
 		return
 	}
 
+	if r.lastUnit && r.unit+1 < len(r.d.unit) {
+		r.nextUnit()
+		return
+	}
+
 	for {
 		e, err := r.Next()
 		if err != nil || e == nil || e.Tag == 0 {
@@ -922,53 +925,187 @@ func (d *Data) Ranges(e *Entry) ([][2]uint64, error) {
 		ret = append(ret, [2]uint64{low, high})
 	}
 
-	ranges, rangesOK := e.Val(AttrRanges).(int64)
-	if rangesOK && d.ranges != nil {
-		// The initial base address is the lowpc attribute
-		// of the enclosing compilation unit.
-		// Although DWARF specifies the lowpc attribute,
-		// comments in gdb/dwarf2read.c say that some versions
-		// of GCC use the entrypc attribute, so we check that too.
-		var cu *Entry
-		if e.Tag == TagCompileUnit {
-			cu = e
-		} else {
-			i := d.offsetToUnit(e.Offset)
-			if i == -1 {
-				return nil, errors.New("no unit for entry")
+	var u *unit
+	if uidx := d.offsetToUnit(e.Offset); uidx >= 0 && uidx < len(d.unit) {
+		u = &d.unit[uidx]
+	}
+
+	if u != nil && u.vers >= 5 && d.rngLists != nil {
+		// DWARF version 5 and later
+		field := e.AttrField(AttrRanges)
+		if field == nil {
+			return ret, nil
+		}
+		switch field.Class {
+		case ClassRangeListPtr:
+			ranges, rangesOK := field.Val.(int64)
+			if !rangesOK {
+				return ret, nil
 			}
-			u := &d.unit[i]
-			b := makeBuf(d, u, "info", u.off, u.data)
-			cu = b.entry(nil, u.atable, u.base, u.vers)
-			if b.err != nil {
-				return nil, b.err
+			cu, base, err := d.baseAddressForEntry(e)
+			if err != nil {
+				return nil, err
 			}
+			return d.dwarf5Ranges(cu, base, ranges, ret)
+
+		case ClassRngList:
+			// TODO: support DW_FORM_rnglistx
+			return ret, nil
+
+		default:
+			return ret, nil
 		}
+	}
 
-		var base uint64
-		if cuEntry, cuEntryOK := cu.Val(AttrEntrypc).(uint64); cuEntryOK {
-			base = cuEntry
-		} else if cuLow, cuLowOK := cu.Val(AttrLowpc).(uint64); cuLowOK {
-			base = cuLow
+	// DWARF version 2 through 4
+	ranges, rangesOK := e.Val(AttrRanges).(int64)
+	if rangesOK && d.ranges != nil {
+		_, base, err := d.baseAddressForEntry(e)
+		if err != nil {
+			return nil, err
 		}
+		return d.dwarf2Ranges(u, base, ranges, ret)
+	}
 
-		u := &d.unit[d.offsetToUnit(e.Offset)]
-		buf := makeBuf(d, u, "ranges", Offset(ranges), d.ranges[ranges:])
-		for len(buf.data) > 0 {
-			low = buf.addr()
-			high = buf.addr()
+	return ret, nil
+}
 
-			if low == 0 && high == 0 {
-				break
+// baseAddressForEntry returns the initial base address to be used when
+// looking up the range list of entry e.
+// DWARF specifies that this should be the lowpc attribute of the enclosing
+// compilation unit, however comments in gdb/dwarf2read.c say that some
+// versions of GCC use the entrypc attribute, so we check that too.
+func (d *Data) baseAddressForEntry(e *Entry) (*Entry, uint64, error) {
+	var cu *Entry
+	if e.Tag == TagCompileUnit {
+		cu = e
+	} else {
+		i := d.offsetToUnit(e.Offset)
+		if i == -1 {
+			return nil, 0, errors.New("no unit for entry")
+		}
+		u := &d.unit[i]
+		b := makeBuf(d, u, "info", u.off, u.data)
+		cu = b.entry(nil, u.atable, u.base, u.vers)
+		if b.err != nil {
+			return nil, 0, b.err
+		}
+	}
+
+	if cuEntry, cuEntryOK := cu.Val(AttrEntrypc).(uint64); cuEntryOK {
+		return cu, cuEntry, nil
+	} else if cuLow, cuLowOK := cu.Val(AttrLowpc).(uint64); cuLowOK {
+		return cu, cuLow, nil
+	}
+
+	return cu, 0, nil
+}
+
+func (d *Data) dwarf2Ranges(u *unit, base uint64, ranges int64, ret [][2]uint64) ([][2]uint64, error) {
+	buf := makeBuf(d, u, "ranges", Offset(ranges), d.ranges[ranges:])
+	for len(buf.data) > 0 {
+		low := buf.addr()
+		high := buf.addr()
+
+		if low == 0 && high == 0 {
+			break
+		}
+
+		if low == ^uint64(0)>>uint((8-u.addrsize())*8) {
+			base = high
+		} else {
+			ret = append(ret, [2]uint64{base + low, base + high})
+		}
+	}
+
+	return ret, nil
+}
+
+// dwarf5Ranges interpets a debug_rnglists sequence, see DWARFv5 section
+// 2.17.3 (page 53).
+func (d *Data) dwarf5Ranges(cu *Entry, base uint64, ranges int64, ret [][2]uint64) ([][2]uint64, error) {
+	var addrBase int64
+	if cu != nil {
+		addrBase, _ = cu.Val(AttrAddrBase).(int64)
+	}
+
+	buf := makeBuf(d, d.rngLists, "rnglists", 0, d.rngLists.data)
+	buf.skip(int(ranges))
+	for {
+		opcode := buf.uint8()
+		switch opcode {
+		case rleEndOfList:
+			if buf.err != nil {
+				return nil, buf.err
 			}
+			return ret, nil
 
-			if low == ^uint64(0)>>uint((8-u.addrsize())*8) {
-				base = high
-			} else {
-				ret = append(ret, [2]uint64{base + low, base + high})
+		case rleBaseAddressx:
+			baseIdx := buf.uint()
+			var err error
+			base, err = d.debugAddr(uint64(addrBase), baseIdx)
+			if err != nil {
+				return nil, err
+			}
+
+		case rleStartxEndx:
+			startIdx := buf.uint()
+			endIdx := buf.uint()
+
+			start, err := d.debugAddr(uint64(addrBase), startIdx)
+			if err != nil {
+				return nil, err
 			}
+			end, err := d.debugAddr(uint64(addrBase), endIdx)
+			if err != nil {
+				return nil, err
+			}
+			ret = append(ret, [2]uint64{start, end})
+
+		case rleStartxLength:
+			startIdx := buf.uint()
+			len := buf.uint()
+			start, err := d.debugAddr(uint64(addrBase), startIdx)
+			if err != nil {
+				return nil, err
+			}
+			ret = append(ret, [2]uint64{start, start + len})
+
+		case rleOffsetPair:
+			off1 := buf.uint()
+			off2 := buf.uint()
+			ret = append(ret, [2]uint64{base + off1, base + off2})
+
+		case rleBaseAddress:
+			base = buf.addr()
+
+		case rleStartEnd:
+			start := buf.addr()
+			end := buf.addr()
+			ret = append(ret, [2]uint64{start, end})
+
+		case rleStartLength:
+			start := buf.addr()
+			len := buf.uint()
+			ret = append(ret, [2]uint64{start, start + len})
 		}
 	}
+}
 
-	return ret, nil
+// debugAddr returns the address at idx in debug_addr
+func (d *Data) debugAddr(addrBase, idx uint64) (uint64, error) {
+	off := idx*uint64(d.addr.addrsize()) + addrBase
+
+	if uint64(int(off)) != off {
+		return 0, errors.New("offset out of range")
+	}
+
+	b := makeBuf(d, d.addr, "addr", 0, d.addr.data)
+	b.skip(int(off))
+	val := b.addr()
+	if b.err != nil {
+		return 0, b.err
+	}
+
+	return val, nil
 }
diff --git a/src/debug/dwarf/entry_test.go b/src/debug/dwarf/entry_test.go
index 4c9aad21f3..2e6ee048aa 100644
--- a/src/debug/dwarf/entry_test.go
+++ b/src/debug/dwarf/entry_test.go
@@ -7,6 +7,7 @@ package dwarf_test
 import (
 	. "debug/dwarf"
 	"encoding/binary"
+	"path/filepath"
 	"reflect"
 	"testing"
 )
@@ -209,3 +210,44 @@ func Test64Bit(t *testing.T) {
 		}
 	}
 }
+
+func TestUnitIteration(t *testing.T) {
+	// Iterate over all ELF test files we have and ensure that
+	// we get the same set of compilation units skipping (method 0)
+	// and not skipping (method 1) CU children.
+	files, err := filepath.Glob(filepath.Join("testdata", "*.elf"))
+	if err != nil {
+		t.Fatal(err)
+	}
+	for _, file := range files {
+		t.Run(file, func(t *testing.T) {
+			d := elfData(t, file)
+			var units [2][]interface{}
+			for method := range units {
+				for r := d.Reader(); ; {
+					ent, err := r.Next()
+					if err != nil {
+						t.Fatal(err)
+					}
+					if ent == nil {
+						break
+					}
+					if ent.Tag == TagCompileUnit {
+						units[method] = append(units[method], ent.Val(AttrName))
+					}
+					if method == 0 {
+						if ent.Tag != TagCompileUnit {
+							t.Fatalf("found unexpected tag %v on top level", ent.Tag)
+						}
+						r.SkipChildren()
+					}
+				}
+			}
+			t.Logf("skipping CUs:     %v", units[0])
+			t.Logf("not-skipping CUs: %v", units[1])
+			if !reflect.DeepEqual(units[0], units[1]) {
+				t.Fatal("set of CUs differ")
+			}
+		})
+	}
+}
diff --git a/src/debug/dwarf/line.go b/src/debug/dwarf/line.go
index 7692f05552..c4937ca7dd 100644
--- a/src/debug/dwarf/line.go
+++ b/src/debug/dwarf/line.go
@@ -814,7 +814,11 @@ func pathJoin(dirname, filename string) string {
 		// Drives are the same. Ignore drive on filename.
 	}
 	if !(strings.HasSuffix(dirname, "/") || strings.HasSuffix(dirname, `\`)) && dirname != "" {
-		dirname += `\`
+		sep := `\`
+		if strings.HasPrefix(dirname, "/") {
+			sep = `/`
+		}
+		dirname += sep
 	}
 	return drive + dirname + filename
 }
diff --git a/src/debug/dwarf/line_test.go b/src/debug/dwarf/line_test.go
index 1fd9b19b03..b13818e8b5 100644
--- a/src/debug/dwarf/line_test.go
+++ b/src/debug/dwarf/line_test.go
@@ -341,6 +341,14 @@ var joinTests = []joinTest{
 	{`\\host\share\`, `foo\bar`, `\\host\share\foo\bar`},
 	{`//host/share/`, `foo/bar`, `//host/share/foo/bar`},
 
+	// Note: the Go compiler currently emits DWARF line table paths
+	// with '/' instead of '\' (see issues #19784, #36495). These
+	// tests are to cover cases that might come up for Windows Go
+	// binaries.
+	{`c:/workdir/go/src/x`, `y.go`, `c:/workdir/go/src/x/y.go`},
+	{`d:/some/thing/`, `b.go`, `d:/some/thing/b.go`},
+	{`e:\blah\`, `foo.c`, `e:\blah\foo.c`},
+
 	// The following are "best effort". We shouldn't see relative
 	// base directories in DWARF, but these test that pathJoin
 	// doesn't fail miserably if it sees one.
diff --git a/src/debug/dwarf/open.go b/src/debug/dwarf/open.go
index 72ee64d558..617b8c56dd 100644
--- a/src/debug/dwarf/open.go
+++ b/src/debug/dwarf/open.go
@@ -7,7 +7,10 @@
 // http://dwarfstd.org/doc/dwarf-2.0.0.pdf
 package dwarf
 
-import "encoding/binary"
+import (
+	"encoding/binary"
+	"errors"
+)
 
 // Data represents the DWARF debugging information
 // loaded from an executable file (for example, an ELF or Mach-O executable).
@@ -23,9 +26,10 @@ type Data struct {
 	str      []byte
 
 	// New sections added in DWARF 5.
-	addr       []byte
+	addr       *debugAddr
 	lineStr    []byte
 	strOffsets []byte
+	rngLists   *rngLists
 
 	// parsed data
 	abbrevCache map[uint64]abbrevTable
@@ -36,6 +40,23 @@ type Data struct {
 	unit        []unit
 }
 
+// rngLists represents the contents of a debug_rnglists section (DWARFv5).
+type rngLists struct {
+	is64  bool
+	asize uint8
+	data  []byte
+	ver   uint16
+}
+
+// debugAddr represents the contents of a debug_addr section (DWARFv5).
+type debugAddr struct {
+	is64  bool
+	asize uint8
+	data  []byte
+}
+
+var errSegmentSelector = errors.New("non-zero segment_selector size not supported")
+
 // New returns a new Data object initialized from the given parameters.
 // Rather than calling this function directly, clients should typically use
 // the DWARF method of the File type of the appropriate package debug/elf,
@@ -108,14 +129,79 @@ func (d *Data) AddTypes(name string, types []byte) error {
 // so forth. This approach is used for new DWARF sections added in
 // DWARF 5 and later.
 func (d *Data) AddSection(name string, contents []byte) error {
+	var err error
 	switch name {
 	case ".debug_addr":
-		d.addr = contents
+		d.addr, err = d.parseAddrHeader(contents)
 	case ".debug_line_str":
 		d.lineStr = contents
 	case ".debug_str_offsets":
 		d.strOffsets = contents
+	case ".debug_rnglists":
+		d.rngLists, err = d.parseRngListsHeader(contents)
 	}
 	// Just ignore names that we don't yet support.
-	return nil
+	return err
+}
+
+// parseRngListsHeader reads the header of a debug_rnglists section, see
+// DWARFv5 section 7.28 (page 242).
+func (d *Data) parseRngListsHeader(bytes []byte) (*rngLists, error) {
+	rngLists := &rngLists{data: bytes}
+
+	buf := makeBuf(d, unknownFormat{}, "rnglists", 0, bytes)
+	_, rngLists.is64 = buf.unitLength()
+
+	rngLists.ver = buf.uint16() // version
+
+	rngLists.asize = buf.uint8()
+	segsize := buf.uint8()
+	if segsize != 0 {
+		return nil, errSegmentSelector
+	}
+
+	// Header fields not read: offset_entry_count, offset table
+
+	return rngLists, nil
+}
+
+func (rngLists *rngLists) version() int {
+	return int(rngLists.ver)
+}
+
+func (rngLists *rngLists) dwarf64() (bool, bool) {
+	return rngLists.is64, true
+}
+
+func (rngLists *rngLists) addrsize() int {
+	return int(rngLists.asize)
+}
+
+// parseAddrHeader reads the header of a debug_addr section, see DWARFv5
+// section 7.27 (page 241).
+func (d *Data) parseAddrHeader(bytes []byte) (*debugAddr, error) {
+	addr := &debugAddr{data: bytes}
+
+	buf := makeBuf(d, unknownFormat{}, "addr", 0, bytes)
+	_, addr.is64 = buf.unitLength()
+
+	addr.asize = buf.uint8()
+	segsize := buf.uint8()
+	if segsize != 0 {
+		return nil, errSegmentSelector
+	}
+
+	return addr, nil
+}
+
+func (addr *debugAddr) version() int {
+	return 5
+}
+
+func (addr *debugAddr) dwarf64() (bool, bool) {
+	return addr.is64, true
+}
+
+func (addr *debugAddr) addrsize() int {
+	return int(addr.asize)
 }
diff --git a/src/debug/dwarf/testdata/debug_rnglists b/src/debug/dwarf/testdata/debug_rnglists
new file mode 100644
index 0000000000..985ec6c9f2
--- /dev/null
+++ b/src/debug/dwarf/testdata/debug_rnglists
diff --git a/src/debug/elf/elf.go b/src/debug/elf/elf.go
index 96a67ce732..2b777eabac 100644
--- a/src/debug/elf/elf.go
+++ b/src/debug/elf/elf.go
@@ -745,18 +745,51 @@ func (i CompressionType) GoString() string { return stringName(uint32(i), compre
 type ProgType int
 
 const (
-	PT_NULL    ProgType = 0          /* Unused entry. */
-	PT_LOAD    ProgType = 1          /* Loadable segment. */
-	PT_DYNAMIC ProgType = 2          /* Dynamic linking information segment. */
-	PT_INTERP  ProgType = 3          /* Pathname of interpreter. */
-	PT_NOTE    ProgType = 4          /* Auxiliary information. */
-	PT_SHLIB   ProgType = 5          /* Reserved (not used). */
-	PT_PHDR    ProgType = 6          /* Location of program header itself. */
-	PT_TLS     ProgType = 7          /* Thread local storage segment */
-	PT_LOOS    ProgType = 0x60000000 /* First OS-specific. */
-	PT_HIOS    ProgType = 0x6fffffff /* Last OS-specific. */
-	PT_LOPROC  ProgType = 0x70000000 /* First processor-specific type. */
-	PT_HIPROC  ProgType = 0x7fffffff /* Last processor-specific type. */
+	PT_NULL    ProgType = 0 /* Unused entry. */
+	PT_LOAD    ProgType = 1 /* Loadable segment. */
+	PT_DYNAMIC ProgType = 2 /* Dynamic linking information segment. */
+	PT_INTERP  ProgType = 3 /* Pathname of interpreter. */
+	PT_NOTE    ProgType = 4 /* Auxiliary information. */
+	PT_SHLIB   ProgType = 5 /* Reserved (not used). */
+	PT_PHDR    ProgType = 6 /* Location of program header itself. */
+	PT_TLS     ProgType = 7 /* Thread local storage segment */
+
+	PT_LOOS ProgType = 0x60000000 /* First OS-specific. */
+
+	PT_GNU_EH_FRAME ProgType = 0x6474e550 /* Frame unwind information */
+	PT_GNU_STACK    ProgType = 0x6474e551 /* Stack flags */
+	PT_GNU_RELRO    ProgType = 0x6474e552 /* Read only after relocs */
+	PT_GNU_PROPERTY ProgType = 0x6474e553 /* GNU property */
+	PT_GNU_MBIND_LO ProgType = 0x6474e555 /* Mbind segments start */
+	PT_GNU_MBIND_HI ProgType = 0x6474f554 /* Mbind segments finish */
+
+	PT_PAX_FLAGS ProgType = 0x65041580 /* PAX flags */
+
+	PT_OPENBSD_RANDOMIZE ProgType = 0x65a3dbe6 /* Random data */
+	PT_OPENBSD_WXNEEDED  ProgType = 0x65a3dbe7 /* W^X violations */
+	PT_OPENBSD_BOOTDATA  ProgType = 0x65a41be6 /* Boot arguments */
+
+	PT_SUNW_EH_FRAME ProgType = 0x6474e550 /* Frame unwind information */
+	PT_SUNWSTACK     ProgType = 0x6ffffffb /* Stack segment */
+
+	PT_HIOS ProgType = 0x6fffffff /* Last OS-specific. */
+
+	PT_LOPROC ProgType = 0x70000000 /* First processor-specific type. */
+
+	PT_ARM_ARCHEXT ProgType = 0x70000000 /* Architecture compatibility */
+	PT_ARM_EXIDX   ProgType = 0x70000001 /* Exception unwind tables */
+
+	PT_AARCH64_ARCHEXT ProgType = 0x70000000 /* Architecture compatibility */
+	PT_AARCH64_UNWIND  ProgType = 0x70000001 /* Exception unwind tables */
+
+	PT_MIPS_REGINFO  ProgType = 0x70000000 /* Register usage */
+	PT_MIPS_RTPROC   ProgType = 0x70000001 /* Runtime procedures */
+	PT_MIPS_OPTIONS  ProgType = 0x70000002 /* Options */
+	PT_MIPS_ABIFLAGS ProgType = 0x70000003 /* ABI flags */
+
+	PT_S390_PGSTE ProgType = 0x70000000 /* 4k page table size */
+
+	PT_HIPROC ProgType = 0x7fffffff /* Last processor-specific type. */
 )
 
 var ptStrings = []intName{
@@ -769,8 +802,19 @@ var ptStrings = []intName{
 	{6, "PT_PHDR"},
 	{7, "PT_TLS"},
 	{0x60000000, "PT_LOOS"},
+	{0x6474e550, "PT_GNU_EH_FRAME"},
+	{0x6474e551, "PT_GNU_STACK"},
+	{0x6474e552, "PT_GNU_RELRO"},
+	{0x6474e553, "PT_GNU_PROPERTY"},
+	{0x65041580, "PT_PAX_FLAGS"},
+	{0x65a3dbe6, "PT_OPENBSD_RANDOMIZE"},
+	{0x65a3dbe7, "PT_OPENBSD_WXNEEDED"},
+	{0x65a41be6, "PT_OPENBSD_BOOTDATA"},
+	{0x6ffffffb, "PT_SUNWSTACK"},
 	{0x6fffffff, "PT_HIOS"},
 	{0x70000000, "PT_LOPROC"},
+	// We don't list the processor-dependent ProgTypes,
+	// as the values overlap.
 	{0x7fffffff, "PT_HIPROC"},
 }
 
@@ -837,15 +881,114 @@ const (
 	   the interpretation of the d_un union
 	   as follows: even == 'd_ptr', even == 'd_val'
 	   or none */
-	DT_PREINIT_ARRAY   DynTag = 32         /* Address of the array of pointers to pre-initialization functions. */
-	DT_PREINIT_ARRAYSZ DynTag = 33         /* Size in bytes of the array of pre-initialization functions. */
-	DT_LOOS            DynTag = 0x6000000d /* First OS-specific */
-	DT_HIOS            DynTag = 0x6ffff000 /* Last OS-specific */
-	DT_VERSYM          DynTag = 0x6ffffff0
-	DT_VERNEED         DynTag = 0x6ffffffe
-	DT_VERNEEDNUM      DynTag = 0x6fffffff
-	DT_LOPROC          DynTag = 0x70000000 /* First processor-specific type. */
-	DT_HIPROC          DynTag = 0x7fffffff /* Last processor-specific type. */
+	DT_PREINIT_ARRAY   DynTag = 32 /* Address of the array of pointers to pre-initialization functions. */
+	DT_PREINIT_ARRAYSZ DynTag = 33 /* Size in bytes of the array of pre-initialization functions. */
+	DT_SYMTAB_SHNDX    DynTag = 34 /* Address of SHT_SYMTAB_SHNDX section. */
+
+	DT_LOOS DynTag = 0x6000000d /* First OS-specific */
+	DT_HIOS DynTag = 0x6ffff000 /* Last OS-specific */
+
+	DT_VALRNGLO       DynTag = 0x6ffffd00
+	DT_GNU_PRELINKED  DynTag = 0x6ffffdf5
+	DT_GNU_CONFLICTSZ DynTag = 0x6ffffdf6
+	DT_GNU_LIBLISTSZ  DynTag = 0x6ffffdf7
+	DT_CHECKSUM       DynTag = 0x6ffffdf8
+	DT_PLTPADSZ       DynTag = 0x6ffffdf9
+	DT_MOVEENT        DynTag = 0x6ffffdfa
+	DT_MOVESZ         DynTag = 0x6ffffdfb
+	DT_FEATURE        DynTag = 0x6ffffdfc
+	DT_POSFLAG_1      DynTag = 0x6ffffdfd
+	DT_SYMINSZ        DynTag = 0x6ffffdfe
+	DT_SYMINENT       DynTag = 0x6ffffdff
+	DT_VALRNGHI       DynTag = 0x6ffffdff
+
+	DT_ADDRRNGLO    DynTag = 0x6ffffe00
+	DT_GNU_HASH     DynTag = 0x6ffffef5
+	DT_TLSDESC_PLT  DynTag = 0x6ffffef6
+	DT_TLSDESC_GOT  DynTag = 0x6ffffef7
+	DT_GNU_CONFLICT DynTag = 0x6ffffef8
+	DT_GNU_LIBLIST  DynTag = 0x6ffffef9
+	DT_CONFIG       DynTag = 0x6ffffefa
+	DT_DEPAUDIT     DynTag = 0x6ffffefb
+	DT_AUDIT        DynTag = 0x6ffffefc
+	DT_PLTPAD       DynTag = 0x6ffffefd
+	DT_MOVETAB      DynTag = 0x6ffffefe
+	DT_SYMINFO      DynTag = 0x6ffffeff
+	DT_ADDRRNGHI    DynTag = 0x6ffffeff
+
+	DT_VERSYM     DynTag = 0x6ffffff0
+	DT_RELACOUNT  DynTag = 0x6ffffff9
+	DT_RELCOUNT   DynTag = 0x6ffffffa
+	DT_FLAGS_1    DynTag = 0x6ffffffb
+	DT_VERDEF     DynTag = 0x6ffffffc
+	DT_VERDEFNUM  DynTag = 0x6ffffffd
+	DT_VERNEED    DynTag = 0x6ffffffe
+	DT_VERNEEDNUM DynTag = 0x6fffffff
+
+	DT_LOPROC DynTag = 0x70000000 /* First processor-specific type. */
+
+	DT_MIPS_RLD_VERSION           DynTag = 0x70000001
+	DT_MIPS_TIME_STAMP            DynTag = 0x70000002
+	DT_MIPS_ICHECKSUM             DynTag = 0x70000003
+	DT_MIPS_IVERSION              DynTag = 0x70000004
+	DT_MIPS_FLAGS                 DynTag = 0x70000005
+	DT_MIPS_BASE_ADDRESS          DynTag = 0x70000006
+	DT_MIPS_MSYM                  DynTag = 0x70000007
+	DT_MIPS_CONFLICT              DynTag = 0x70000008
+	DT_MIPS_LIBLIST               DynTag = 0x70000009
+	DT_MIPS_LOCAL_GOTNO           DynTag = 0x7000000a
+	DT_MIPS_CONFLICTNO            DynTag = 0x7000000b
+	DT_MIPS_LIBLISTNO             DynTag = 0x70000010
+	DT_MIPS_SYMTABNO              DynTag = 0x70000011
+	DT_MIPS_UNREFEXTNO            DynTag = 0x70000012
+	DT_MIPS_GOTSYM                DynTag = 0x70000013
+	DT_MIPS_HIPAGENO              DynTag = 0x70000014
+	DT_MIPS_RLD_MAP               DynTag = 0x70000016
+	DT_MIPS_DELTA_CLASS           DynTag = 0x70000017
+	DT_MIPS_DELTA_CLASS_NO        DynTag = 0x70000018
+	DT_MIPS_DELTA_INSTANCE        DynTag = 0x70000019
+	DT_MIPS_DELTA_INSTANCE_NO     DynTag = 0x7000001a
+	DT_MIPS_DELTA_RELOC           DynTag = 0x7000001b
+	DT_MIPS_DELTA_RELOC_NO        DynTag = 0x7000001c
+	DT_MIPS_DELTA_SYM             DynTag = 0x7000001d
+	DT_MIPS_DELTA_SYM_NO          DynTag = 0x7000001e
+	DT_MIPS_DELTA_CLASSSYM        DynTag = 0x70000020
+	DT_MIPS_DELTA_CLASSSYM_NO     DynTag = 0x70000021
+	DT_MIPS_CXX_FLAGS             DynTag = 0x70000022
+	DT_MIPS_PIXIE_INIT            DynTag = 0x70000023
+	DT_MIPS_SYMBOL_LIB            DynTag = 0x70000024
+	DT_MIPS_LOCALPAGE_GOTIDX      DynTag = 0x70000025
+	DT_MIPS_LOCAL_GOTIDX          DynTag = 0x70000026
+	DT_MIPS_HIDDEN_GOTIDX         DynTag = 0x70000027
+	DT_MIPS_PROTECTED_GOTIDX      DynTag = 0x70000028
+	DT_MIPS_OPTIONS               DynTag = 0x70000029
+	DT_MIPS_INTERFACE             DynTag = 0x7000002a
+	DT_MIPS_DYNSTR_ALIGN          DynTag = 0x7000002b
+	DT_MIPS_INTERFACE_SIZE        DynTag = 0x7000002c
+	DT_MIPS_RLD_TEXT_RESOLVE_ADDR DynTag = 0x7000002d
+	DT_MIPS_PERF_SUFFIX           DynTag = 0x7000002e
+	DT_MIPS_COMPACT_SIZE          DynTag = 0x7000002f
+	DT_MIPS_GP_VALUE              DynTag = 0x70000030
+	DT_MIPS_AUX_DYNAMIC           DynTag = 0x70000031
+	DT_MIPS_PLTGOT                DynTag = 0x70000032
+	DT_MIPS_RWPLT                 DynTag = 0x70000034
+	DT_MIPS_RLD_MAP_REL           DynTag = 0x70000035
+
+	DT_PPC_GOT DynTag = 0x70000000
+	DT_PPC_OPT DynTag = 0x70000001
+
+	DT_PPC64_GLINK DynTag = 0x70000000
+	DT_PPC64_OPD   DynTag = 0x70000001
+	DT_PPC64_OPDSZ DynTag = 0x70000002
+	DT_PPC64_OPT   DynTag = 0x70000003
+
+	DT_SPARC_REGISTER DynTag = 0x70000001
+
+	DT_AUXILIARY DynTag = 0x7ffffffd
+	DT_USED      DynTag = 0x7ffffffe
+	DT_FILTER    DynTag = 0x7fffffff
+
+	DT_HIPROC DynTag = 0x7fffffff /* Last processor-specific type. */
 )
 
 var dtStrings = []intName{
@@ -883,13 +1026,49 @@ var dtStrings = []intName{
 	{32, "DT_ENCODING"},
 	{32, "DT_PREINIT_ARRAY"},
 	{33, "DT_PREINIT_ARRAYSZ"},
+	{34, "DT_SYMTAB_SHNDX"},
 	{0x6000000d, "DT_LOOS"},
 	{0x6ffff000, "DT_HIOS"},
+	{0x6ffffd00, "DT_VALRNGLO"},
+	{0x6ffffdf5, "DT_GNU_PRELINKED"},
+	{0x6ffffdf6, "DT_GNU_CONFLICTSZ"},
+	{0x6ffffdf7, "DT_GNU_LIBLISTSZ"},
+	{0x6ffffdf8, "DT_CHECKSUM"},
+	{0x6ffffdf9, "DT_PLTPADSZ"},
+	{0x6ffffdfa, "DT_MOVEENT"},
+	{0x6ffffdfb, "DT_MOVESZ"},
+	{0x6ffffdfc, "DT_FEATURE"},
+	{0x6ffffdfd, "DT_POSFLAG_1"},
+	{0x6ffffdfe, "DT_SYMINSZ"},
+	{0x6ffffdff, "DT_SYMINENT"},
+	{0x6ffffdff, "DT_VALRNGHI"},
+	{0x6ffffe00, "DT_ADDRRNGLO"},
+	{0x6ffffef5, "DT_GNU_HASH"},
+	{0x6ffffef6, "DT_TLSDESC_PLT"},
+	{0x6ffffef7, "DT_TLSDESC_GOT"},
+	{0x6ffffef8, "DT_GNU_CONFLICT"},
+	{0x6ffffef9, "DT_GNU_LIBLIST"},
+	{0x6ffffefa, "DT_CONFIG"},
+	{0x6ffffefb, "DT_DEPAUDIT"},
+	{0x6ffffefc, "DT_AUDIT"},
+	{0x6ffffefd, "DT_PLTPAD"},
+	{0x6ffffefe, "DT_MOVETAB"},
+	{0x6ffffeff, "DT_SYMINFO"},
+	{0x6ffffeff, "DT_ADDRRNGHI"},
 	{0x6ffffff0, "DT_VERSYM"},
+	{0x6ffffff9, "DT_RELACOUNT"},
+	{0x6ffffffa, "DT_RELCOUNT"},
+	{0x6ffffffb, "DT_FLAGS_1"},
+	{0x6ffffffc, "DT_VERDEF"},
+	{0x6ffffffd, "DT_VERDEFNUM"},
 	{0x6ffffffe, "DT_VERNEED"},
 	{0x6fffffff, "DT_VERNEEDNUM"},
 	{0x70000000, "DT_LOPROC"},
-	{0x7fffffff, "DT_HIPROC"},
+	// We don't list the processor-dependent DynTags,
+	// as the values overlap.
+	{0x7ffffffd, "DT_AUXILIARY"},
+	{0x7ffffffe, "DT_USED"},
+	{0x7fffffff, "DT_FILTER"},
 }
 
 func (i DynTag) String() string   { return stringName(uint32(i), dtStrings, false) }
diff --git a/src/debug/elf/file_test.go b/src/debug/elf/file_test.go
index 24948e696a..4c6fdeece9 100644
--- a/src/debug/elf/file_test.go
+++ b/src/debug/elf/file_test.go
@@ -899,7 +899,7 @@ func TestCompressedSection(t *testing.T) {
 func TestNoSectionOverlaps(t *testing.T) {
 	// Ensure cmd/link outputs sections without overlaps.
 	switch runtime.GOOS {
-	case "aix", "android", "darwin", "js", "plan9", "windows":
+	case "aix", "android", "darwin", "ios", "js", "plan9", "windows":
 		t.Skipf("cmd/link doesn't produce ELF binaries on %s", runtime.GOOS)
 	}
 	_ = net.ResolveIPAddr // force dynamic linkage
diff --git a/src/debug/gosym/pclntab.go b/src/debug/gosym/pclntab.go
index e5c50520fc..a72f9847d7 100644
--- a/src/debug/gosym/pclntab.go
+++ b/src/debug/gosym/pclntab.go
@@ -53,14 +53,19 @@ type LineTable struct {
 	quantum     uint32
 	ptrsize     uint32
 	funcnametab []byte
+	cutab       []byte
 	funcdata    []byte
 	functab     []byte
 	nfunctab    uint32
 	filetab     []byte
+	pctab       []byte // points to the pctables.
 	nfiletab    uint32
-	fileMap     map[string]uint32
 	funcNames   map[uint32]string // cache the function names
 	strings     map[uint32]string // interned substrings of Data, keyed by offset
+	// fileMap varies depending on the version of the object file.
+	// For ver12, it maps the name to the index in the file table.
+	// For ver116, it maps the name to the offset in filetab.
+	fileMap map[string]uint32
 }
 
 // NOTE(rsc): This is wrong for GOARCH=arm, which uses a quantum of 4,
@@ -223,22 +228,26 @@ func (t *LineTable) parsePclnTab() {
 	switch possibleVersion {
 	case ver116:
 		t.nfunctab = uint32(t.uintptr(t.Data[8:]))
-		offset := t.uintptr(t.Data[8+t.ptrsize:])
+		t.nfiletab = uint32(t.uintptr(t.Data[8+t.ptrsize:]))
+		offset := t.uintptr(t.Data[8+2*t.ptrsize:])
 		t.funcnametab = t.Data[offset:]
-		offset = t.uintptr(t.Data[8+2*t.ptrsize:])
+		offset = t.uintptr(t.Data[8+3*t.ptrsize:])
+		t.cutab = t.Data[offset:]
+		offset = t.uintptr(t.Data[8+4*t.ptrsize:])
+		t.filetab = t.Data[offset:]
+		offset = t.uintptr(t.Data[8+5*t.ptrsize:])
+		t.pctab = t.Data[offset:]
+		offset = t.uintptr(t.Data[8+6*t.ptrsize:])
 		t.funcdata = t.Data[offset:]
 		t.functab = t.Data[offset:]
 		functabsize := t.nfunctab*2*t.ptrsize + t.ptrsize
-		fileoff := t.binary.Uint32(t.functab[functabsize:])
-		t.filetab = t.functab[fileoff:]
 		t.functab = t.functab[:functabsize]
-		t.nfiletab = t.binary.Uint32(t.filetab)
-		t.filetab = t.filetab[:t.nfiletab*4]
 	case ver12:
 		t.nfunctab = uint32(t.uintptr(t.Data[8:]))
 		t.funcdata = t.Data
 		t.funcnametab = t.Data
 		t.functab = t.Data[8+t.ptrsize:]
+		t.pctab = t.Data
 		functabsize := t.nfunctab*2*t.ptrsize + t.ptrsize
 		fileoff := t.binary.Uint32(t.functab[functabsize:])
 		t.functab = t.functab[:functabsize]
@@ -330,17 +339,22 @@ func (t *LineTable) funcName(off uint32) string {
 	return s
 }
 
-// string returns a Go string found at off.
-func (t *LineTable) string(off uint32) string {
+// stringFrom returns a Go string found at off from a position.
+func (t *LineTable) stringFrom(arr []byte, off uint32) string {
 	if s, ok := t.strings[off]; ok {
 		return s
 	}
-	i := bytes.IndexByte(t.funcdata[off:], 0)
-	s := string(t.funcdata[off : off+uint32(i)])
+	i := bytes.IndexByte(arr[off:], 0)
+	s := string(arr[off : off+uint32(i)])
 	t.strings[off] = s
 	return s
 }
 
+// string returns a Go string found at off.
+func (t *LineTable) string(off uint32) string {
+	return t.stringFrom(t.funcdata, off)
+}
+
 // step advances to the next pc, value pair in the encoded table.
 func (t *LineTable) step(p *[]byte, pc *uint64, val *int32, first bool) bool {
 	uvdelta := t.readvarint(p)
@@ -363,7 +377,7 @@ func (t *LineTable) step(p *[]byte, pc *uint64, val *int32, first bool) bool {
 // off is the offset to the beginning of the pc-value table,
 // and entry is the start PC for the corresponding function.
 func (t *LineTable) pcvalue(off uint32, entry, targetpc uint64) int32 {
-	p := t.funcdata[off:]
+	p := t.pctab[off:]
 
 	val := int32(-1)
 	pc := entry
@@ -381,21 +395,25 @@ func (t *LineTable) pcvalue(off uint32, entry, targetpc uint64) int32 {
 // to file number. Since most functions come from a single file, these
 // are usually short and quick to scan. If a file match is found, then the
 // code goes to the expense of looking for a simultaneous line number match.
-func (t *LineTable) findFileLine(entry uint64, filetab, linetab uint32, filenum, line int32) uint64 {
+func (t *LineTable) findFileLine(entry uint64, filetab, linetab uint32, filenum, line int32, cutab []byte) uint64 {
 	if filetab == 0 || linetab == 0 {
 		return 0
 	}
 
-	fp := t.funcdata[filetab:]
-	fl := t.funcdata[linetab:]
+	fp := t.pctab[filetab:]
+	fl := t.pctab[linetab:]
 	fileVal := int32(-1)
 	filePC := entry
 	lineVal := int32(-1)
 	linePC := entry
 	fileStartPC := filePC
 	for t.step(&fp, &filePC, &fileVal, filePC == entry) {
-		if fileVal == filenum && fileStartPC < filePC {
-			// fileVal is in effect starting at fileStartPC up to
+		fileIndex := fileVal
+		if t.version == ver116 {
+			fileIndex = int32(t.binary.Uint32(cutab[fileVal*4:]))
+		}
+		if fileIndex == filenum && fileStartPC < filePC {
+			// fileIndex is in effect starting at fileStartPC up to
 			// but not including filePC, and it's the file we want.
 			// Run the PC table looking for a matching line number
 			// or until we reach filePC.
@@ -450,13 +468,24 @@ func (t *LineTable) go12PCToFile(pc uint64) (file string) {
 	entry := t.uintptr(f)
 	filetab := t.binary.Uint32(f[t.ptrsize+4*4:])
 	fno := t.pcvalue(filetab, entry, pc)
-	if fno <= 0 {
+	if t.version == ver12 {
+		if fno <= 0 {
+			return ""
+		}
+		return t.string(t.binary.Uint32(t.filetab[4*fno:]))
+	}
+	// Go ≥ 1.16
+	if fno < 0 { // 0 is valid for ≥ 1.16
 		return ""
 	}
-	return t.string(t.binary.Uint32(t.filetab[4*fno:]))
+	cuoff := t.binary.Uint32(f[t.ptrsize+7*4:])
+	if fnoff := t.binary.Uint32(t.cutab[(cuoff+uint32(fno))*4:]); fnoff != ^uint32(0) {
+		return t.stringFrom(t.filetab, fnoff)
+	}
+	return ""
 }
 
-// go12LineToPC maps a (file, line) pair to a program counter for the Go 1.2 pcln table.
+// go12LineToPC maps a (file, line) pair to a program counter for the Go 1.2/1.16 pcln table.
 func (t *LineTable) go12LineToPC(file string, line int) (pc uint64) {
 	defer func() {
 		if recover() != nil {
@@ -465,20 +494,25 @@ func (t *LineTable) go12LineToPC(file string, line int) (pc uint64) {
 	}()
 
 	t.initFileMap()
-	filenum := t.fileMap[file]
-	if filenum == 0 {
+	filenum, ok := t.fileMap[file]
+	if !ok {
 		return 0
 	}
 
 	// Scan all functions.
 	// If this turns out to be a bottleneck, we could build a map[int32][]int32
 	// mapping file number to a list of functions with code from that file.
+	var cutab []byte
 	for i := uint32(0); i < t.nfunctab; i++ {
 		f := t.funcdata[t.uintptr(t.functab[2*t.ptrsize*i+t.ptrsize:]):]
 		entry := t.uintptr(f)
 		filetab := t.binary.Uint32(f[t.ptrsize+4*4:])
 		linetab := t.binary.Uint32(f[t.ptrsize+5*4:])
-		pc := t.findFileLine(entry, filetab, linetab, int32(filenum), int32(line))
+		if t.version == ver116 {
+			cuoff := t.binary.Uint32(f[t.ptrsize+7*4:]) * 4
+			cutab = t.cutab[cuoff:]
+		}
+		pc := t.findFileLine(entry, filetab, linetab, int32(filenum), int32(line), cutab)
 		if pc != 0 {
 			return pc
 		}
@@ -496,9 +530,18 @@ func (t *LineTable) initFileMap() {
 	}
 	m := make(map[string]uint32)
 
-	for i := uint32(1); i < t.nfiletab; i++ {
-		s := t.string(t.binary.Uint32(t.filetab[4*i:]))
-		m[s] = i
+	if t.version == ver12 {
+		for i := uint32(1); i < t.nfiletab; i++ {
+			s := t.string(t.binary.Uint32(t.filetab[4*i:]))
+			m[s] = i
+		}
+	} else {
+		var pos uint32
+		for i := uint32(0); i < t.nfiletab; i++ {
+			s := t.stringFrom(t.filetab, pos)
+			m[s] = pos
+			pos += uint32(len(s) + 1)
+		}
 	}
 	t.fileMap = m
 }
diff --git a/src/debug/gosym/pclntab_test.go b/src/debug/gosym/pclntab_test.go
index 33772c7813..7347139b5d 100644
--- a/src/debug/gosym/pclntab_test.go
+++ b/src/debug/gosym/pclntab_test.go
@@ -9,7 +9,7 @@ import (
 	"compress/gzip"
 	"debug/elf"
 	"internal/testenv"
-	"io/ioutil"
+	"io"
 	"os"
 	"os/exec"
 	"path/filepath"
@@ -30,7 +30,7 @@ func dotest(t *testing.T) {
 		t.Skipf("skipping on non-AMD64 system %s", runtime.GOARCH)
 	}
 	var err error
-	pclineTempDir, err = ioutil.TempDir("", "pclinetest")
+	pclineTempDir, err = os.MkdirTemp("", "pclinetest")
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -277,7 +277,7 @@ func TestPCLine(t *testing.T) {
 // }
 // [END]
 func Test115PclnParsing(t *testing.T) {
-	zippedDat, err := ioutil.ReadFile("testdata/pcln115.gz")
+	zippedDat, err := os.ReadFile("testdata/pcln115.gz")
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -287,7 +287,7 @@ func Test115PclnParsing(t *testing.T) {
 		t.Fatal(err)
 	}
 	var dat []byte
-	dat, err = ioutil.ReadAll(gzReader)
+	dat, err = io.ReadAll(gzReader)
 	if err != nil {
 		t.Fatal(err)
 	}
diff --git a/src/debug/pe/file_test.go b/src/debug/pe/file_test.go
index d96cd30904..58deff1450 100644
--- a/src/debug/pe/file_test.go
+++ b/src/debug/pe/file_test.go
@@ -8,7 +8,6 @@ import (
 	"bytes"
 	"debug/dwarf"
 	"internal/testenv"
-	"io/ioutil"
 	"os"
 	"os/exec"
 	"path/filepath"
@@ -354,7 +353,7 @@ func testDWARF(t *testing.T, linktype int) {
 	}
 	testenv.MustHaveGoRun(t)
 
-	tmpdir, err := ioutil.TempDir("", "TestDWARF")
+	tmpdir, err := os.MkdirTemp("", "TestDWARF")
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -473,7 +472,7 @@ func TestBSSHasZeros(t *testing.T) {
 		t.Skip("skipping test: gcc is missing")
 	}
 
-	tmpdir, err := ioutil.TempDir("", "TestBSSHasZeros")
+	tmpdir, err := os.MkdirTemp("", "TestBSSHasZeros")
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -492,7 +491,7 @@ main(void)
 	return 0;
 }
 `
-	err = ioutil.WriteFile(srcpath, []byte(src), 0644)
+	err = os.WriteFile(srcpath, []byte(src), 0644)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -597,14 +596,14 @@ func TestBuildingWindowsGUI(t *testing.T) {
 	if runtime.GOOS != "windows" {
 		t.Skip("skipping windows only test")
 	}
-	tmpdir, err := ioutil.TempDir("", "TestBuildingWindowsGUI")
+	tmpdir, err := os.MkdirTemp("", "TestBuildingWindowsGUI")
 	if err != nil {
 		t.Fatal(err)
 	}
 	defer os.RemoveAll(tmpdir)
 
 	src := filepath.Join(tmpdir, "a.go")
-	err = ioutil.WriteFile(src, []byte(`package main; func main() {}`), 0644)
+	err = os.WriteFile(src, []byte(`package main; func main() {}`), 0644)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -684,7 +683,7 @@ func TestInvalidOptionalHeaderMagic(t *testing.T) {
 func TestImportedSymbolsNoPanicMissingOptionalHeader(t *testing.T) {
 	// https://golang.org/issue/30250
 	// ImportedSymbols shouldn't panic if optional headers is missing
-	data, err := ioutil.ReadFile("testdata/gcc-amd64-mingw-obj")
+	data, err := os.ReadFile("testdata/gcc-amd64-mingw-obj")
 	if err != nil {
 		t.Fatal(err)
 	}