diff --git a/cmd/viewcore/main.go b/cmd/viewcore/main.go
index 26e2785..c5842ee 100644
--- a/cmd/viewcore/main.go
+++ b/cmd/viewcore/main.go
@@ -297,14 +297,14 @@
 		cmd.Usage()
 		return
 	}
+	// Interactive mode.
+	cfg.interactive = true
+
 	p, _, err := readCore()
 	if err != nil {
 		exitf("%v\n", err)
 	}
 
-	// Interactive mode.
-	cfg.interactive = true
-
 	// Create a dummy root to run in shell.
 	root := &cobra.Command{}
 	// Make all subcommands of viewcore available in the shell.
diff --git a/internal/gocore/dwarf.go b/internal/gocore/dwarf.go
index d185d34..c5cc173 100644
--- a/internal/gocore/dwarf.go
+++ b/internal/gocore/dwarf.go
@@ -7,6 +7,7 @@
 import (
 	"debug/dwarf"
 	"fmt"
+	"reflect"
 	"regexp"
 	"sort"
 	"strings"
@@ -58,6 +59,23 @@
 			t.Kind = KindStruct
 			for _, f := range x.Field {
 				fType := p.dwarfMap[f.Type]
+				if fType == nil {
+					// Weird case: arrays of size 0 in structs, like
+					// Sysinfo_t.X_f. Synthesize a type so things later don't
+					// get sad.
+					if arr, ok := f.Type.(*dwarf.ArrayType); ok && arr.Count == 0 {
+						fType = &Type{
+							Name:  f.Type.String(),
+							Kind:  KindArray,
+							Count: arr.Count,
+							Elem:  p.dwarfMap[arr.Type],
+						}
+					} else {
+						panic(fmt.Sprintf(
+							"found a nil ftype for field %s.%s, type %s (%s) on ",
+							x.StructName, f.Name, f.Type, reflect.TypeOf(f.Type)))
+					}
+				}
 
 				// Work around issue 21094. There's no guarantee that the
 				// pointer type is in the DWARF, so just invent a Type.
diff --git a/internal/gocore/gocore_test.go b/internal/gocore/gocore_test.go
index 0b33ca6..d233296 100644
--- a/internal/gocore/gocore_test.go
+++ b/internal/gocore/gocore_test.go
@@ -272,4 +272,6 @@
 	loadExampleVersion(t, "1.13.zip")
 	loadExampleVersion(t, "1.13.3.zip")
 	loadExampleVersion(t, "1.14.zip")
+	loadExampleVersion(t, "1.16.zip")
+	loadExampleVersion(t, "1.17.zip")
 }
diff --git a/internal/gocore/module.go b/internal/gocore/module.go
index 2f5e632..aacbd0c 100644
--- a/internal/gocore/module.go
+++ b/internal/gocore/module.go
@@ -14,6 +14,7 @@
 type module struct {
 	r             region       // inferior region holding a runtime.moduledata
 	types, etypes core.Address // range that holds all the runtime._type data in this module
+	p             *Process     // The parent process of this module.
 }
 
 func (p *Process) readModules() {
@@ -29,12 +30,18 @@
 }
 
 func (p *Process) readModule(r region) *module {
-	m := &module{r: r}
+	m := &module{p: p, r: r}
 	m.types = core.Address(r.Field("types").Uintptr())
 	m.etypes = core.Address(r.Field("etypes").Uintptr())
 
 	// Read the pc->function table
 	pcln := r.Field("pclntable")
+	var pctab, funcnametab region
+	if p.minorVersion >= 16 {
+		// In 1.16, pclntable was split up into pctab and funcnametab.
+		pctab = r.Field("pctab")
+		funcnametab = r.Field("funcnametab")
+	}
 	ftab := r.Field("ftab")
 	n := ftab.SliceLen() - 1 // last slot is a dummy, just holds entry
 	for i := int64(0); i < n; i++ {
@@ -42,7 +49,12 @@
 		min := core.Address(ft.Field("entry").Uintptr())
 		max := core.Address(ftab.SliceIndex(i + 1).Field("entry").Uintptr())
 		fr := pcln.SliceIndex(int64(ft.Field("funcoff").Uintptr())).Cast("runtime._func")
-		f := m.readFunc(fr, pcln)
+		var f *Func
+		if p.minorVersion >= 16 {
+			f = m.readFunc(fr, pctab, funcnametab)
+		} else {
+			f = m.readFunc(fr, pcln, pcln)
+		}
 		if f.entry != min {
 			panic(fmt.Errorf("entry %x and min %x don't match for %s", f.entry, min, f.name))
 		}
@@ -55,34 +67,52 @@
 // readFunc parses a runtime._func and returns a *Func.
 // r must have type runtime._func.
 // pcln must have type []byte and represent the module's pcln table region.
-func (m *module) readFunc(r region, pcln region) *Func {
+func (m *module) readFunc(r region, pctab region, funcnametab region) *Func {
 	f := &Func{module: m, r: r}
 	f.entry = core.Address(r.Field("entry").Uintptr())
-	f.name = r.p.proc.ReadCString(pcln.SliceIndex(int64(r.Field("nameoff").Int32())).a)
-	f.frameSize.read(r.p.proc, pcln.SliceIndex(int64(r.Field("pcsp").Int32())).a)
+	f.name = r.p.proc.ReadCString(funcnametab.SliceIndex(int64(r.Field("nameoff").Int32())).a)
+	pcsp := r.Field("pcsp")
+	var pcspIdx int64
+	if m.p.minorVersion >= 16 {
+		// In 1.16, pcsp changed to be a uint32 from an int32.
+		pcspIdx = int64(pcsp.Uint32())
+	} else {
+		pcspIdx = int64(pcsp.Int32())
+	}
+	f.frameSize.read(r.p.proc, pctab.SliceIndex(pcspIdx).a)
 
 	// Parse pcdata and funcdata, which are laid out beyond the end of the _func.
-	a := r.a.Add(int64(r.p.findType("runtime._func").Size))
-	n := r.Field("npcdata").Int32()
-	for i := int32(0); i < n; i++ {
+	// In 1.16, npcdata changed to be a uint32 from an int32.
+	npcdata := r.Field("npcdata")
+	var n uint32
+	if m.p.minorVersion >= 16 {
+		// In 1.16, pcsp changed to be a uint32 from an int32.
+		n = uint32(npcdata.Uint32())
+	} else {
+		n = uint32(npcdata.Int32())
+	}
+	nfd := r.Field("nfuncdata")
+	a := nfd.a.Add(nfd.typ.Size)
+
+	for i := uint32(0); i < n; i++ {
 		f.pcdata = append(f.pcdata, r.p.proc.ReadInt32(a))
 		a = a.Add(4)
 	}
 	a = a.Align(r.p.proc.PtrSize())
 
-	if nfd := r.Field("nfuncdata"); nfd.typ.Size == 1 { // go 1.12 and beyond, this is a uint8
-		n = int32(nfd.Uint8())
+	if nfd.typ.Size == 1 { // go 1.12 and beyond, this is a uint8
+		n = uint32(nfd.Uint8())
 	} else { // go 1.11 and earlier, this is an int32
-		n = nfd.Int32()
+		n = uint32(nfd.Int32())
 	}
-	for i := int32(0); i < n; i++ {
+	for i := uint32(0); i < n; i++ {
 		f.funcdata = append(f.funcdata, r.p.proc.ReadPtr(a))
 		a = a.Add(r.p.proc.PtrSize())
 	}
 
 	// Read pcln tables we need.
 	if stackmap := int(r.p.rtConstants["_PCDATA_StackMapIndex"]); stackmap < len(f.pcdata) {
-		f.stackMap.read(r.p.proc, pcln.SliceIndex(int64(f.pcdata[stackmap])).a)
+		f.stackMap.read(r.p.proc, pctab.SliceIndex(int64(f.pcdata[stackmap])).a)
 	} else {
 		f.stackMap.setEmpty()
 	}
diff --git a/internal/gocore/process.go b/internal/gocore/process.go
index 25d083b..c46a731 100644
--- a/internal/gocore/process.go
+++ b/internal/gocore/process.go
@@ -8,6 +8,7 @@
 	"debug/dwarf"
 	"fmt"
 	"math/bits"
+	"strconv"
 	"strings"
 	"sync"
 
@@ -54,6 +55,7 @@
 	stats *Stats
 
 	buildVersion string
+	minorVersion int
 
 	globals []*Root
 
@@ -153,6 +155,15 @@
 
 	// Read all the data that depend on runtime globals.
 	p.buildVersion = p.rtGlobals["buildVersion"].String()
+	versionComponents := strings.Split(p.buildVersion, ".")
+	if len(versionComponents) < 2 {
+		panic("malformed version " + p.buildVersion)
+	}
+	p.minorVersion, err = strconv.Atoi(versionComponents[1])
+	if err != nil {
+		panic("malformed version " + p.buildVersion)
+	}
+
 	p.readModules()
 	p.readHeap()
 	p.readGs()
@@ -258,10 +269,16 @@
 				// Copy out ptr/nonptr bits
 				n := bitmap.ArrayLen()
 				for i := int64(0); i < n; i++ {
+					// The nth byte is composed of 4 object bits and 4 live/dead
+					// bits. We ignore the 4 live/dead bits, which are on the
+					// high order side of the byte.
+					//
+					// See mbitmap.go for more information on the format of
+					// the bitmap field of heapArena.
 					m := bitmap.ArrayIndex(i).Uint8()
-					for j := int64(0); j < 8; j++ {
+					for j := int64(0); j < 4; j++ {
 						if m>>uint(j)&1 != 0 {
-							p.setHeapPtr(min.Add((i*8 + j) * ptrSize))
+							p.setHeapPtr(min.Add((i*4 + j) * ptrSize))
 						}
 					}
 				}
@@ -316,7 +333,10 @@
 			panic("weird mapping " + m.Perm().String())
 		}
 	}
-	if mheap.HasField("curArena") { // go1.13.3 and up
+	if p.minorVersion < 17 && mheap.HasField("curArena") {
+		// go1.13.3 and up has curArena.
+		// In Go 1.17, we ... don't need to do this any longer. See patch
+		// bd6aeca9686d5e672ffda1ea0cfeac7a3e7a20a4
 		// Subtract from the heap unallocated space
 		// in the current arena.
 		ca := mheap.Field("curArena")
diff --git a/internal/gocore/testdata/1.16.zip b/internal/gocore/testdata/1.16.zip
new file mode 100644
index 0000000..05fb11a
--- /dev/null
+++ b/internal/gocore/testdata/1.16.zip
Binary files differ
diff --git a/internal/gocore/testdata/1.17.zip b/internal/gocore/testdata/1.17.zip
new file mode 100644
index 0000000..f96ee79
--- /dev/null
+++ b/internal/gocore/testdata/1.17.zip
Binary files differ
diff --git a/internal/gocore/type.go b/internal/gocore/type.go
index 4f564fc..4d1b8a5 100644
--- a/internal/gocore/type.go
+++ b/internal/gocore/type.go
@@ -466,6 +466,11 @@
 		for len(work) > 0 {
 			c := work[len(work)-1]
 			work = work[:len(work)-1]
+			switch c.t.Kind {
+			case KindBool, KindInt, KindUint, KindFloat, KindComplex:
+				// Don't do O(n) function calls for big primitive slices
+				continue
+			}
 			for i := int64(0); i < c.r; i++ {
 				p.typeObject(c.a.Add(i*c.t.Size), c.t, p.proc, add)
 			}