delve/pkg/proc/bininfo.go
2023-11-06 07:55:44 -06:00

2767 lines
82 KiB
Go

package proc
import (
"bytes"
"debug/dwarf"
"debug/elf"
"debug/macho"
"debug/pe"
"encoding/binary"
"encoding/hex"
"errors"
"fmt"
"go/ast"
"go/token"
"hash/crc32"
"io"
"os"
"path/filepath"
"sort"
"strconv"
"strings"
"sync"
"time"
pdwarf "github.com/go-delve/delve/pkg/dwarf"
"github.com/go-delve/delve/pkg/dwarf/frame"
"github.com/go-delve/delve/pkg/dwarf/godwarf"
"github.com/go-delve/delve/pkg/dwarf/line"
"github.com/go-delve/delve/pkg/dwarf/loclist"
"github.com/go-delve/delve/pkg/dwarf/op"
"github.com/go-delve/delve/pkg/dwarf/reader"
"github.com/go-delve/delve/pkg/goversion"
"github.com/go-delve/delve/pkg/internal/gosym"
"github.com/go-delve/delve/pkg/internal/moduledata"
"github.com/go-delve/delve/pkg/logflags"
"github.com/go-delve/delve/pkg/proc/debuginfod"
"github.com/hashicorp/golang-lru/simplelru"
)
const (
dwarfGoLanguage = 22 // DW_LANG_Go (from DWARF v5, section 7.12, page 231)
dwarfAttrAddrBase = 0x74 // debug/dwarf.AttrAddrBase in Go 1.14, defined here for compatibility with Go < 1.14
dwarfTreeCacheSize = 512 // size of the dwarfTree cache of each image
)
// BinaryInfo holds information on the binaries being executed (this
// includes both the executable and also any loaded libraries).
type BinaryInfo struct {
// Architecture of this binary.
Arch *Arch
// GOOS operating system this binary is executing on.
GOOS string
DebugInfoDirectories []string
// BuildID of this binary.
BuildID string
// Functions is a list of all DW_TAG_subprogram entries in debug_info, sorted by entry point
Functions []Function
// Sources is a list of all source files found in debug_line.
Sources []string
// lookupFunc maps function names to a description of the function.
lookupFunc map[string][]*Function
// lookupGenericFunc maps function names, with their type parameters removed, to functions.
// Functions that are not generic are not added to this map.
lookupGenericFunc map[string][]*Function
// SymNames maps addr to a description *elf.Symbol of this addr.
SymNames map[uint64]*elf.Symbol
// Images is a list of loaded shared libraries (also known as
// shared objects on linux or DLLs on windows).
Images []*Image
ElfDynamicSection ElfDynamicSection
lastModified time.Time // Time the executable of this process was last modified
// PackageMap maps package names to package paths, needed to lookup types inside DWARF info.
// On Go1.12 this mapping is determined by using the last element of a package path, for example:
// github.com/go-delve/delve
// will map to 'delve' because it ends in '/delve'.
// Starting with Go1.13 debug_info will contain a special attribute
// (godwarf.AttrGoPackageName) containing the canonical package name for
// each package.
// If multiple packages have the same name the map entry will have more
// than one item in the slice.
PackageMap map[string][]string
frameEntries frame.FrameDescriptionEntries
types map[string]dwarfRef
packageVars []packageVar // packageVars is a list of all global/package variables in debug_info, sorted by address
gStructOffset uint64
gStructOffsetIsPtr bool
// consts[off] lists all the constants with the type defined at offset off.
consts constantsMap
// inlinedCallLines maps a file:line pair, corresponding to the header line
// of a function to a list of PC addresses where an inlined call to that
// function starts.
inlinedCallLines map[fileLine][]uint64
// dwrapUnwrapCache caches unwrapping of defer wrapper functions (dwrap)
dwrapUnwrapCache map[uint64]*Function
// Go 1.17 register ABI is enabled.
regabi bool
logger logflags.Logger
}
var (
// ErrCouldNotDetermineRelocation is an error returned when Delve could not determine the base address of a
// position independent executable.
ErrCouldNotDetermineRelocation = errors.New("could not determine the base address of a PIE")
// ErrNoDebugInfoFound is returned when Delve cannot open the debug_info
// section or find an external debug info file.
ErrNoDebugInfoFound = errors.New("could not open debug info")
)
var (
supportedLinuxArch = map[elf.Machine]bool{
elf.EM_X86_64: true,
elf.EM_AARCH64: true,
elf.EM_386: true,
elf.EM_PPC64: true,
}
supportedWindowsArch = map[_PEMachine]bool{
_IMAGE_FILE_MACHINE_AMD64: true,
_IMAGE_FILE_MACHINE_ARM64: true,
}
supportedDarwinArch = map[macho.Cpu]bool{
macho.CpuAmd64: true,
macho.CpuArm64: true,
}
)
// ErrFunctionNotFound is returned when failing to find the
// function named 'FuncName' within the binary.
type ErrFunctionNotFound struct {
FuncName string
}
func (err *ErrFunctionNotFound) Error() string {
return fmt.Sprintf("could not find function %s\n", err.FuncName)
}
// FindFileLocation returns the PC for a given file:line.
// Assumes that `file` is normalized to lower case and '/' on Windows.
func FindFileLocation(p Process, filename string, lineno int) ([]uint64, error) {
// A single file:line can appear in multiple concrete functions, because of
// generics instantiation as well as multiple inlined calls into other
// concrete functions.
// 1. Find all instructions assigned in debug_line to filename:lineno.
bi := p.BinInfo()
fileFound := false
pcs := []line.PCStmt{}
for _, image := range bi.Images {
for _, cu := range image.compileUnits {
if cu.lineInfo == nil || cu.lineInfo.Lookup[filename] == nil {
continue
}
fileFound = true
pcs = append(pcs, cu.lineInfo.LineToPCs(filename, lineno)...)
}
}
if len(pcs) == 0 {
// Check if the line contained a call to a function that was inlined, in
// that case it's possible for the line itself to not appear in debug_line
// at all, but it will still be in debug_info as the call site for an
// inlined subroutine entry.
for _, pc := range bi.inlinedCallLines[fileLine{filename, lineno}] {
pcs = append(pcs, line.PCStmt{PC: pc, Stmt: true})
}
}
if len(pcs) == 0 {
return nil, &ErrCouldNotFindLine{fileFound, filename, lineno}
}
// 2. assign all occurrences of filename:lineno to their containing function
pcByFunc := map[*Function][]line.PCStmt{}
sort.Slice(pcs, func(i, j int) bool { return pcs[i].PC < pcs[j].PC })
var fn *Function
for _, pcstmt := range pcs {
if fn == nil || (pcstmt.PC < fn.Entry) || (pcstmt.PC >= fn.End) {
fn = p.BinInfo().PCToFunc(pcstmt.PC)
}
if fn != nil {
pcByFunc[fn] = append(pcByFunc[fn], pcstmt)
}
}
selectedPCs := []uint64{}
for fn, pcs := range pcByFunc {
// 3. for each concrete function split instruction between the inlined functions it contains
if strings.Contains(fn.Name, "·dwrap·") || fn.trampoline {
// skip autogenerated functions
continue
}
dwtree, err := fn.cu.image.getDwarfTree(fn.offset)
if err != nil {
return nil, fmt.Errorf("loading DWARF for %s@%#x: %v", fn.Name, fn.offset, err)
}
inlrngs := allInlineCallRanges(dwtree)
// findInlRng returns the DWARF offset of the inlined call containing pc.
// If multiple nested inlined calls contain pc the deepest one is returned
// (since allInlineCallRanges returns inlined call by decreasing depth
// this is the first matching entry of the slice).
findInlRng := func(pc uint64) dwarf.Offset {
for _, inlrng := range inlrngs {
if inlrng.rng[0] <= pc && pc < inlrng.rng[1] {
return inlrng.off
}
}
return fn.offset
}
pcsByOff := map[dwarf.Offset][]line.PCStmt{}
for _, pc := range pcs {
off := findInlRng(pc.PC)
pcsByOff[off] = append(pcsByOff[off], pc)
}
// 4. pick the first instruction with stmt set for each inlined call as
// well as the main body of the concrete function. If nothing has
// is_stmt set pick the first instruction instead.
for off, pcs := range pcsByOff {
sort.Slice(pcs, func(i, j int) bool { return pcs[i].PC < pcs[j].PC })
var selectedPC uint64
for _, pc := range pcs {
if pc.Stmt {
selectedPC = pc.PC
break
}
}
if selectedPC == 0 && len(pcs) > 0 {
selectedPC = pcs[0].PC
}
if selectedPC == 0 {
continue
}
// 5. if we picked the entry point of the function, skip it
if off == fn.offset && fn.Entry == selectedPC {
selectedPC, _ = FirstPCAfterPrologue(p, fn, true)
}
selectedPCs = append(selectedPCs, selectedPC)
}
}
sort.Slice(selectedPCs, func(i, j int) bool { return selectedPCs[i] < selectedPCs[j] })
return selectedPCs, nil
}
// inlRange is the range of an inlined call
type inlRange struct {
off dwarf.Offset
depth uint32
rng [2]uint64
}
// allInlineCallRanges returns all inlined calls contained inside 'tree' in
// reverse nesting order (i.e. the most nested calls are returned first).
// Note that a single inlined call might not have a continuous range of
// addresses and therefore appear multiple times in the returned slice.
func allInlineCallRanges(tree *godwarf.Tree) []inlRange {
r := []inlRange{}
var visit func(*godwarf.Tree, uint32)
visit = func(n *godwarf.Tree, depth uint32) {
if n.Tag == dwarf.TagInlinedSubroutine {
for _, rng := range n.Ranges {
r = append(r, inlRange{off: n.Offset, depth: depth, rng: rng})
}
}
for _, child := range n.Children {
visit(child, depth+1)
}
}
visit(tree, 0)
sort.SliceStable(r, func(i, j int) bool { return r[i].depth > r[j].depth })
return r
}
// FindFunction returns the functions with name funcName.
func (bi *BinaryInfo) FindFunction(funcName string) ([]*Function, error) {
if fns := bi.LookupFunc()[funcName]; fns != nil {
return fns, nil
}
fns := bi.LookupGenericFunc()[funcName]
if len(fns) == 0 {
return nil, &ErrFunctionNotFound{funcName}
}
return fns, nil
}
// FindFunctionLocation finds address of a function's line
// If lineOffset is passed FindFunctionLocation will return the address of that line
func FindFunctionLocation(p Process, funcName string, lineOffset int) ([]uint64, error) {
bi := p.BinInfo()
origfns, err := bi.FindFunction(funcName)
if err != nil {
return nil, err
}
if lineOffset > 0 {
fn := origfns[0]
filename, lineno := bi.EntryLineForFunc(fn)
return FindFileLocation(p, filename, lineno+lineOffset)
}
r := make([]uint64, 0, len(origfns[0].InlinedCalls)+len(origfns))
for _, origfn := range origfns {
if origfn.Entry > 0 {
// add concrete implementation of the function
pc, err := FirstPCAfterPrologue(p, origfn, false)
if err != nil {
return nil, err
}
r = append(r, pc)
}
// add inlined calls to the function
for _, call := range origfn.InlinedCalls {
r = append(r, call.LowPC)
}
if len(r) == 0 {
return nil, &ErrFunctionNotFound{funcName}
}
}
sort.Slice(r, func(i, j int) bool { return r[i] < r[j] })
return r, nil
}
// FirstPCAfterPrologue returns the address of the first
// instruction after the prologue for function fn.
// If sameline is set FirstPCAfterPrologue will always return an
// address associated with the same line as fn.Entry.
func FirstPCAfterPrologue(p Process, fn *Function, sameline bool) (uint64, error) {
if fn.cu.lineInfo != nil {
pc, _, line, ok := fn.cu.lineInfo.PrologueEndPC(fn.Entry, fn.End)
if ok {
if !sameline {
return pc, nil
}
_, entryLine := p.BinInfo().EntryLineForFunc(fn)
if entryLine == line {
return pc, nil
}
}
}
pc, err := firstPCAfterPrologueDisassembly(p, fn, sameline)
if err != nil {
return fn.Entry, err
}
if pc == fn.Entry && fn.cu.lineInfo != nil {
// Look for the first instruction with the stmt flag set, so that setting a
// breakpoint with file:line and with the function name always result on
// the same instruction being selected.
if pc2, _, _, ok := fn.cu.lineInfo.FirstStmtForLine(fn.Entry, fn.End); ok {
return pc2, nil
}
}
return pc, nil
}
func findRetPC(t *Target, name string) ([]uint64, error) {
fn := t.BinInfo().lookupOneFunc(name)
if fn == nil {
return nil, fmt.Errorf("could not find %s", name)
}
text, err := Disassemble(t.Memory(), nil, t.Breakpoints(), t.BinInfo(), fn.Entry, fn.End)
if err != nil {
return nil, err
}
r := []uint64{}
for _, instr := range text {
if instr.IsRet() {
r = append(r, instr.Loc.PC)
}
}
if len(r) == 0 {
return nil, fmt.Errorf("could not find return instruction in %s", name)
}
return r, nil
}
// cpuArch is a stringer interface representing CPU architectures.
type cpuArch interface {
String() string
}
// ErrUnsupportedArch is returned when attempting to debug a binary compiled for an unsupported architecture.
type ErrUnsupportedArch struct {
os string
cpuArch cpuArch
}
func (e *ErrUnsupportedArch) Error() string {
var supportArchs []cpuArch
switch e.os {
case "linux":
for linuxArch := range supportedLinuxArch {
supportArchs = append(supportArchs, linuxArch)
}
case "windows":
for windowArch := range supportedWindowsArch {
supportArchs = append(supportArchs, windowArch)
}
case "darwin":
for darwinArch := range supportedDarwinArch {
supportArchs = append(supportArchs, darwinArch)
}
}
errStr := "unsupported architecture of " + e.os + "/" + e.cpuArch.String()
errStr += " - only"
for _, arch := range supportArchs {
errStr += " " + e.os + "/" + arch.String() + " "
}
if len(supportArchs) == 1 {
errStr += "is supported"
} else {
errStr += "are supported"
}
return errStr
}
type compileUnit struct {
name string // univocal name for non-go compile units
Version uint8 // DWARF version of this compile unit
lowPC uint64
ranges [][2]uint64
entry *dwarf.Entry // debug_info entry describing this compile unit
isgo bool // true if this is the go compile unit
lineInfo *line.DebugLineInfo // debug_line segment associated with this compile unit
optimized bool // this compile unit is optimized
producer string // producer attribute
offset dwarf.Offset // offset of the entry describing the compile unit
image *Image // parent image of this compilation unit.
}
type fileLine struct {
file string
line int
}
// dwarfRef is a reference to a Debug Info Entry inside a shared object.
type dwarfRef struct {
imageIndex int
offset dwarf.Offset
}
// InlinedCall represents a concrete inlined call to a function.
type InlinedCall struct {
cu *compileUnit
LowPC, HighPC uint64 // Address range of the generated inlined instructions
}
// Function describes a function in the target program.
type Function struct {
Name string
Entry, End uint64 // same as DW_AT_lowpc and DW_AT_highpc
offset dwarf.Offset
cu *compileUnit
trampoline bool // DW_AT_trampoline attribute set to true
// InlinedCalls lists all inlined calls to this function
InlinedCalls []InlinedCall
}
// instRange returns the indexes in fn.Name of the type parameter
// instantiation, which is the position of the outermost '[' and ']'.
// If fn is not an instantiated function both returned values will be len(fn.Name)
func (fn *Function) instRange() [2]int {
d := len(fn.Name)
inst := [2]int{d, d}
if strings.HasPrefix(fn.Name, "type..") {
return inst
}
inst[0] = strings.Index(fn.Name, "[")
if inst[0] < 0 {
inst[0] = d
return inst
}
inst[1] = strings.LastIndex(fn.Name, "]")
if inst[1] < 0 {
inst[0] = d
inst[1] = d
return inst
}
return inst
}
// PackageName returns the package part of the symbol name,
// or the empty string if there is none.
// Borrowed from $GOROOT/debug/gosym/symtab.go
func (fn *Function) PackageName() string {
inst := fn.instRange()
return packageName(fn.Name[:inst[0]])
}
func packageName(name string) string {
pathend := strings.LastIndex(name, "/")
if pathend < 0 {
pathend = 0
}
if i := strings.Index(name[pathend:], "."); i != -1 {
return name[:pathend+i]
}
return ""
}
// ReceiverName returns the receiver type name of this symbol,
// or the empty string if there is none.
// Borrowed from $GOROOT/debug/gosym/symtab.go
func (fn *Function) ReceiverName() string {
inst := fn.instRange()
pathend := strings.LastIndex(fn.Name[:inst[0]], "/")
if pathend < 0 {
pathend = 0
}
l := strings.Index(fn.Name[pathend:], ".")
if l == -1 {
return ""
}
if r := strings.LastIndex(fn.Name[inst[1]:], "."); r != -1 && pathend+l != inst[1]+r {
return fn.Name[pathend+l+1 : inst[1]+r]
} else if r := strings.LastIndex(fn.Name[pathend:inst[0]], "."); r != -1 && l != r {
return fn.Name[pathend+l+1 : pathend+r]
}
return ""
}
// BaseName returns the symbol name without the package or receiver name.
// Borrowed from $GOROOT/debug/gosym/symtab.go
func (fn *Function) BaseName() string {
inst := fn.instRange()
if i := strings.LastIndex(fn.Name[inst[1]:], "."); i != -1 {
return fn.Name[inst[1]+i+1:]
} else if i := strings.LastIndex(fn.Name[:inst[0]], "."); i != -1 {
return fn.Name[i+1:]
}
return fn.Name
}
// NameWithoutTypeParams returns the function name without instantiation parameters
func (fn *Function) NameWithoutTypeParams() string {
inst := fn.instRange()
if inst[0] == inst[1] {
return fn.Name
}
return fn.Name[:inst[0]] + fn.Name[inst[1]+1:]
}
// Optimized returns true if the function was optimized by the compiler.
func (fn *Function) Optimized() bool {
return fn.cu.optimized
}
// PrologueEndPC returns the PC just after the function prologue
func (fn *Function) PrologueEndPC() uint64 {
pc, _, _, ok := fn.cu.lineInfo.PrologueEndPC(fn.Entry, fn.End)
if !ok {
return fn.Entry
}
return pc
}
func (fn *Function) AllPCs(excludeFile string, excludeLine int) ([]uint64, error) {
if !fn.cu.image.Stripped() {
return fn.cu.lineInfo.AllPCsBetween(fn.Entry, fn.End-1, excludeFile, excludeLine)
}
var pcs []uint64
fnFile, lastLine, _ := fn.cu.image.symTable.PCToLine(fn.Entry - fn.cu.image.StaticBase)
for pc := fn.Entry - fn.cu.image.StaticBase; pc < fn.End-fn.cu.image.StaticBase; pc++ {
f, line, pcfn := fn.cu.image.symTable.PCToLine(pc)
if pcfn == nil {
continue
}
if f == fnFile && line > lastLine {
lastLine = line
pcs = append(pcs, pc+fn.cu.image.StaticBase)
}
}
return pcs, nil
}
// From $GOROOT/src/runtime/traceback.go:597
// exportedRuntime reports whether the function is an exported runtime function.
// It is only for runtime functions, so ASCII A-Z is fine.
func (fn *Function) exportedRuntime() bool {
name := fn.Name
const n = len("runtime.")
return len(name) > n && name[:n] == "runtime." && 'A' <= name[n] && name[n] <= 'Z'
}
// unexportedRuntime reports whether the function is a private runtime function.
func (fn *Function) privateRuntime() bool {
name := fn.Name
const n = len("runtime.")
return len(name) > n && name[:n] == "runtime." && !('A' <= name[n] && name[n] <= 'Z')
}
type constantsMap map[dwarfRef]*constantType
type constantType struct {
initialized bool
values []constantValue
}
type constantValue struct {
name string
fullName string
value int64
singleBit bool
}
// packageVar represents a package-level variable (or a C global variable).
// If a global variable does not have an address (for example it's stored in
// a register, or non-contiguously) addr will be 0.
type packageVar struct {
name string
cu *compileUnit
offset dwarf.Offset
addr uint64
}
type buildIDHeader struct {
Namesz uint32
Descsz uint32
Type uint32
}
// ElfDynamicSection describes the .dynamic section of an ELF executable.
type ElfDynamicSection struct {
Addr uint64 // relocated address of where the .dynamic section is mapped in memory
Size uint64 // size of the .dynamic section of the executable
}
// NewBinaryInfo returns an initialized but unloaded BinaryInfo struct.
func NewBinaryInfo(goos, goarch string) *BinaryInfo {
r := &BinaryInfo{GOOS: goos, logger: logflags.DebuggerLogger()}
// TODO: find better way to determine proc arch (perhaps use executable file info).
switch goarch {
case "386":
r.Arch = I386Arch(goos)
case "amd64":
r.Arch = AMD64Arch(goos)
case "arm64":
r.Arch = ARM64Arch(goos)
case "ppc64le":
r.Arch = PPC64LEArch(goos)
}
return r
}
// LoadBinaryInfo will load and store the information from the binary at 'path'.
func (bi *BinaryInfo) LoadBinaryInfo(path string, entryPoint uint64, debugInfoDirs []string) error {
fi, err := os.Stat(path)
if err == nil {
bi.lastModified = fi.ModTime()
}
bi.DebugInfoDirectories = debugInfoDirs
return bi.AddImage(path, entryPoint)
}
func loadBinaryInfo(bi *BinaryInfo, image *Image, path string, entryPoint uint64) error {
var wg sync.WaitGroup
defer wg.Wait()
switch bi.GOOS {
case "linux", "freebsd":
return loadBinaryInfoElf(bi, image, path, entryPoint, &wg)
case "windows":
return loadBinaryInfoPE(bi, image, path, entryPoint, &wg)
case "darwin":
return loadBinaryInfoMacho(bi, image, path, entryPoint, &wg)
}
return errors.New("unsupported operating system")
}
// GStructOffset returns the offset of the G
// struct in thread local storage.
func (bi *BinaryInfo) GStructOffset(mem MemoryReadWriter) (uint64, error) {
offset := bi.gStructOffset
if bi.gStructOffsetIsPtr {
// The G struct offset from the TLS section is a pointer
// and the address must be dereferenced to find to actual G struct offset.
var err error
offset, err = readUintRaw(mem, offset, int64(bi.Arch.PtrSize()))
if err != nil {
return 0, err
}
}
return offset, nil
}
// LastModified returns the last modified time of the binary.
func (bi *BinaryInfo) LastModified() time.Time {
return bi.lastModified
}
// DwarfReader returns a reader for the dwarf data
func (so *Image) DwarfReader() *reader.Reader {
if so.dwarf == nil {
return nil
}
return reader.New(so.dwarf)
}
// Types returns list of types present in the debugged program.
func (bi *BinaryInfo) Types() ([]string, error) {
types := make([]string, 0, len(bi.types))
for k := range bi.types {
types = append(types, k)
}
return types, nil
}
func (bi *BinaryInfo) EntryLineForFunc(fn *Function) (string, int) {
return bi.pcToLine(fn, fn.Entry)
}
func (bi *BinaryInfo) pcToLine(fn *Function, pc uint64) (string, int) {
if fn.cu.lineInfo == nil {
f, l, _ := fn.cu.image.symTable.PCToLine(pc - fn.cu.image.StaticBase)
return f, l
}
f, l := fn.cu.lineInfo.PCToLine(fn.Entry, pc)
return f, l
}
// PCToLine converts an instruction address to a file/line/function.
func (bi *BinaryInfo) PCToLine(pc uint64) (string, int, *Function) {
fn := bi.PCToFunc(pc)
if fn == nil {
return "", 0, nil
}
f, ln := bi.pcToLine(fn, pc)
return f, ln, fn
}
type ErrCouldNotFindLine struct {
fileFound bool
filename string
lineno int
}
func (err *ErrCouldNotFindLine) Error() string {
if err.fileFound {
return fmt.Sprintf("could not find statement at %s:%d, please use a line with a statement", err.filename, err.lineno)
}
return fmt.Sprintf("could not find file %s", err.filename)
}
// AllPCsForFileLines returns a map providing all PC addresses for filename and each line in linenos
func (bi *BinaryInfo) AllPCsForFileLines(filename string, linenos []int) map[int][]uint64 {
r := make(map[int][]uint64)
for _, line := range linenos {
r[line] = make([]uint64, 0, 1)
}
for _, image := range bi.Images {
for _, cu := range image.compileUnits {
if cu.lineInfo != nil && cu.lineInfo.Lookup[filename] != nil {
cu.lineInfo.AllPCsForFileLines(filename, r)
}
}
}
return r
}
// PCToFunc returns the concrete function containing the given PC address.
// If the PC address belongs to an inlined call it will return the containing function.
func (bi *BinaryInfo) PCToFunc(pc uint64) *Function {
i := sort.Search(len(bi.Functions), func(i int) bool {
fn := bi.Functions[i]
return pc <= fn.Entry || (fn.Entry <= pc && pc < fn.End)
})
if i != len(bi.Functions) {
fn := &bi.Functions[i]
if fn.Entry <= pc && pc < fn.End {
return fn
}
}
return nil
}
// PCToImage returns the image containing the given PC address.
func (bi *BinaryInfo) PCToImage(pc uint64) *Image {
fn := bi.PCToFunc(pc)
return bi.funcToImage(fn)
}
// Image represents a loaded library file (shared object on linux, DLL on windows).
type Image struct {
Path string
StaticBase uint64
addr uint64
index int // index of this object in BinaryInfo.SharedObjects
closer io.Closer
sepDebugCloser io.Closer
dwarf *dwarf.Data
dwarfReader *dwarf.Reader
loclist2 *loclist.Dwarf2Reader
loclist5 *loclist.Dwarf5Reader
debugAddr *godwarf.DebugAddrSection
debugLineStr []byte
symTable *gosym.Table
typeCache map[dwarf.Offset]godwarf.Type
compileUnits []*compileUnit // compileUnits is sorted by increasing DWARF offset
dwarfTreeCache *simplelru.LRU
runtimeMallocgcTree *godwarf.Tree // patched version of runtime.mallocgc's DIE
// runtimeTypeToDIE maps between the offset of a runtime._type in
// runtime.moduledata.types and the offset of the DIE in debug_info. This
// map is filled by using the extended attribute godwarf.AttrGoRuntimeType
// which was added in go 1.11.
runtimeTypeToDIE map[uint64]runtimeTypeDIE
loadErrMu sync.Mutex
loadErr error
}
func (image *Image) registerRuntimeTypeToDIE(entry *dwarf.Entry, ardr *reader.Reader) {
if off, ok := entry.Val(godwarf.AttrGoRuntimeType).(uint64); ok {
if _, ok := image.runtimeTypeToDIE[off]; !ok {
image.runtimeTypeToDIE[off] = runtimeTypeDIE{entry.Offset, -1}
}
}
}
func (image *Image) Stripped() bool {
return image.dwarf == nil
}
// AddImage adds the specified image to bi, loading data asynchronously.
// Addr is the relocated entry point for the executable and staticBase (i.e.
// the relocation offset) for all other images.
// The first image added must be the executable file.
func (bi *BinaryInfo) AddImage(path string, addr uint64) error {
// Check if the image is already present.
if len(bi.Images) > 0 && !strings.HasPrefix(path, "/") {
return nil
}
for _, image := range bi.Images {
if image.Path == path && image.addr == addr {
return nil
}
}
// Actually add the image.
image := &Image{Path: path, addr: addr, typeCache: make(map[dwarf.Offset]godwarf.Type)}
image.dwarfTreeCache, _ = simplelru.NewLRU(dwarfTreeCacheSize, nil)
// add Image regardless of error so that we don't attempt to re-add it every time we stop
image.index = len(bi.Images)
bi.Images = append(bi.Images, image)
err := loadBinaryInfo(bi, image, path, addr)
if err != nil {
bi.Images[len(bi.Images)-1].loadErr = err
}
bi.macOSDebugFrameBugWorkaround()
return err
}
// moduleDataToImage finds the image corresponding to the given module data object.
func (bi *BinaryInfo) moduleDataToImage(md *moduleData) *Image {
fn := bi.PCToFunc(uint64(md.text))
if fn != nil {
return bi.funcToImage(fn)
}
// Try searching for the image with the closest address preceding md.text
var so *Image
for i := range bi.Images {
if int64(bi.Images[i].StaticBase) > int64(md.text) {
continue
}
if so == nil || int64(bi.Images[i].StaticBase) > int64(so.StaticBase) {
so = bi.Images[i]
}
}
return so
}
// imageToModuleData finds the module data in mds corresponding to the given image.
func (bi *BinaryInfo) imageToModuleData(image *Image, mds []moduleData) *moduleData {
for _, md := range mds {
im2 := bi.moduleDataToImage(&md)
if im2 != nil && im2.index == image.index {
return &md
}
}
return nil
}
// typeToImage returns the image containing the give type.
func (bi *BinaryInfo) typeToImage(typ godwarf.Type) *Image {
return bi.Images[typ.Common().Index]
}
func (bi *BinaryInfo) runtimeTypeTypename() string {
if goversion.ProducerAfterOrEqual(bi.Producer(), 1, 21) {
return "internal/abi.Type"
}
return "runtime._type"
}
var errBinaryInfoClose = errors.New("multiple errors closing executable files")
// Close closes all internal readers.
func (bi *BinaryInfo) Close() error {
var errs []error
for _, image := range bi.Images {
if err := image.Close(); err != nil {
errs = append(errs, err)
}
}
switch len(errs) {
case 0:
return nil
case 1:
return errs[0]
default:
return errBinaryInfoClose
}
}
func (image *Image) Close() error {
var err1, err2 error
if image.sepDebugCloser != nil {
err := image.sepDebugCloser.Close()
if err != nil {
err1 = fmt.Errorf("closing shared object %q (split dwarf): %v", image.Path, err)
}
}
if image.closer != nil {
err := image.closer.Close()
if err != nil {
err2 = fmt.Errorf("closing shared object %q: %v", image.Path, err)
}
}
if err1 != nil && err2 != nil {
return errBinaryInfoClose
}
if err1 != nil {
return err1
}
return err2
}
func (image *Image) setLoadError(logger logflags.Logger, fmtstr string, args ...interface{}) {
image.loadErrMu.Lock()
image.loadErr = fmt.Errorf(fmtstr, args...)
image.loadErrMu.Unlock()
if logger != nil {
logger.Errorf("error loading binary %q: %v", image.Path, image.loadErr)
}
}
// LoadError returns any error incurred while loading this image.
func (image *Image) LoadError() error {
return image.loadErr
}
func (image *Image) getDwarfTree(off dwarf.Offset) (*godwarf.Tree, error) {
if image.runtimeMallocgcTree != nil && off == image.runtimeMallocgcTree.Offset {
return image.runtimeMallocgcTree, nil
}
if r, ok := image.dwarfTreeCache.Get(off); ok {
return r.(*godwarf.Tree), nil
}
r, err := godwarf.LoadTree(off, image.dwarf, image.StaticBase)
if err != nil {
return nil, err
}
image.dwarfTreeCache.Add(off, r)
return r, nil
}
type nilCloser struct{}
func (c *nilCloser) Close() error { return nil }
// LoadImageFromData creates a new Image, using the specified data, and adds it to bi.
// This is used for debugging BinaryInfo, you should use LoadBinary instead.
func (bi *BinaryInfo) LoadImageFromData(dwdata *dwarf.Data, debugFrameBytes, debugLineBytes, debugLocBytes []byte) {
image := &Image{}
image.closer = (*nilCloser)(nil)
image.sepDebugCloser = (*nilCloser)(nil)
image.dwarf = dwdata
image.typeCache = make(map[dwarf.Offset]godwarf.Type)
image.dwarfTreeCache, _ = simplelru.NewLRU(dwarfTreeCacheSize, nil)
if debugFrameBytes != nil {
bi.frameEntries, _ = frame.Parse(debugFrameBytes, frame.DwarfEndian(debugFrameBytes), 0, bi.Arch.PtrSize(), 0)
}
image.loclist2 = loclist.NewDwarf2Reader(debugLocBytes, bi.Arch.PtrSize())
bi.loadDebugInfoMaps(image, nil, debugLineBytes, nil, nil)
bi.Images = append(bi.Images, image)
}
func (bi *BinaryInfo) locationExpr(entry godwarf.Entry, attr dwarf.Attr, pc uint64) ([]byte, *locationExpr, error) {
//TODO(aarzilli): handle DW_FORM_loclistx attribute form new in DWARFv5
a := entry.Val(attr)
if a == nil {
return nil, nil, fmt.Errorf("no location attribute %s", attr)
}
if instr, ok := a.([]byte); ok {
return instr, &locationExpr{isBlock: true, instr: instr, regnumToName: bi.Arch.RegnumToString}, nil
}
off, ok := a.(int64)
if !ok {
return nil, nil, fmt.Errorf("could not interpret location attribute %s", attr)
}
instr := bi.loclistEntry(off, pc)
if instr == nil {
return nil, nil, fmt.Errorf("could not find loclist entry at %#x for address %#x", off, pc)
}
return instr, &locationExpr{pc: pc, off: off, instr: instr, regnumToName: bi.Arch.RegnumToString}, nil
}
type locationExpr struct {
isBlock bool
isEscaped bool
off int64
pc uint64
instr []byte
regnumToName func(uint64) string
}
func (le *locationExpr) String() string {
if le == nil {
return ""
}
var descr bytes.Buffer
if le.isBlock {
fmt.Fprintf(&descr, "[block] ")
op.PrettyPrint(&descr, le.instr, le.regnumToName)
} else {
fmt.Fprintf(&descr, "[%#x:%#x] ", le.off, le.pc)
op.PrettyPrint(&descr, le.instr, le.regnumToName)
}
if le.isEscaped {
fmt.Fprintf(&descr, " (escaped)")
}
return descr.String()
}
// LocationCovers returns the list of PC addresses that is covered by the
// location attribute 'attr' of entry 'entry'.
func (bi *BinaryInfo) LocationCovers(entry *dwarf.Entry, attr dwarf.Attr) ([][2]uint64, error) {
a := entry.Val(attr)
if a == nil {
return nil, fmt.Errorf("attribute %s not found", attr)
}
if _, isblock := a.([]byte); isblock {
return [][2]uint64{{0, ^uint64(0)}}, nil
}
off, ok := a.(int64)
if !ok {
return nil, fmt.Errorf("attribute %s of unsupported type %T", attr, a)
}
cu := bi.Images[0].findCompileUnitForOffset(entry.Offset)
if cu == nil {
return nil, errors.New("could not find compile unit")
}
if cu.Version >= 5 && cu.image.loclist5 != nil {
return nil, errors.New("LocationCovers does not support DWARFv5")
}
image := cu.image
base := cu.lowPC
if image == nil || image.loclist2.Empty() {
return nil, errors.New("malformed executable")
}
r := [][2]uint64{}
var e loclist.Entry
image.loclist2.Seek(int(off))
for image.loclist2.Next(&e) {
if e.BaseAddressSelection() {
base = e.HighPC
continue
}
r = append(r, [2]uint64{e.LowPC + base, e.HighPC + base})
}
return r, nil
}
// Location returns the location described by attribute attr of entry.
// This will either be an int64 address or a slice of Pieces for locations
// that don't correspond to a single memory address (registers, composite
// locations).
func (bi *BinaryInfo) Location(entry godwarf.Entry, attr dwarf.Attr, pc uint64, regs op.DwarfRegisters, mem MemoryReadWriter) (int64, []op.Piece, *locationExpr, error) {
instr, descr, err := bi.locationExpr(entry, attr, pc)
if err != nil {
return 0, nil, nil, err
}
readMemory := op.ReadMemoryFunc(nil)
if mem != nil {
readMemory = mem.ReadMemory
}
addr, pieces, err := op.ExecuteStackProgram(regs, instr, bi.Arch.PtrSize(), readMemory)
return addr, pieces, descr, err
}
// loclistEntry returns the loclist entry in the loclist starting at off,
// for address pc.
func (bi *BinaryInfo) loclistEntry(off int64, pc uint64) []byte {
var base uint64
image := bi.Images[0]
cu := bi.findCompileUnit(pc)
if cu != nil {
base = cu.lowPC
image = cu.image
}
if image == nil {
return nil
}
var loclist loclist.Reader = image.loclist2
var debugAddr *godwarf.DebugAddr
if cu != nil && cu.Version >= 5 && image.loclist5 != nil {
loclist = image.loclist5
if addrBase, ok := cu.entry.Val(dwarfAttrAddrBase).(int64); ok {
debugAddr = image.debugAddr.GetSubsection(uint64(addrBase))
}
}
if loclist.Empty() {
return nil
}
e, err := loclist.Find(int(off), image.StaticBase, base, pc, debugAddr)
if err != nil {
bi.logger.Errorf("error reading loclist section: %v", err)
return nil
}
if e != nil {
return e.Instr
}
return nil
}
// findCompileUnit returns the compile unit containing address pc.
func (bi *BinaryInfo) findCompileUnit(pc uint64) *compileUnit {
for _, image := range bi.Images {
for _, cu := range image.compileUnits {
for _, rng := range cu.ranges {
if pc >= rng[0] && pc < rng[1] {
return cu
}
}
}
}
return nil
}
func (bi *Image) findCompileUnitForOffset(off dwarf.Offset) *compileUnit {
i := sort.Search(len(bi.compileUnits), func(i int) bool {
return bi.compileUnits[i].offset >= off
})
if i > 0 {
i--
}
return bi.compileUnits[i]
}
// Producer returns the value of DW_AT_producer.
func (bi *BinaryInfo) Producer() string {
for _, cu := range bi.Images[0].compileUnits {
if cu.isgo && cu.producer != "" {
return cu.producer
}
}
return ""
}
// Type returns the Dwarf type entry at `offset`.
func (image *Image) Type(offset dwarf.Offset) (godwarf.Type, error) {
return godwarf.ReadType(image.dwarf, image.index, offset, image.typeCache)
}
// funcToImage returns the Image containing function fn, or the
// executable file as a fallback.
func (bi *BinaryInfo) funcToImage(fn *Function) *Image {
if fn == nil {
return bi.Images[0]
}
return fn.cu.image
}
// parseDebugFrameGeneral parses a debug_frame and a eh_frame section.
// At least one of the two must be present and parsed correctly, if
// debug_frame is present it must be parsable correctly.
func (bi *BinaryInfo) parseDebugFrameGeneral(image *Image, debugFrameBytes []byte, debugFrameName string, debugFrameErr error, ehFrameBytes []byte, ehFrameAddr uint64, ehFrameName string, byteOrder binary.ByteOrder) {
if debugFrameBytes == nil && ehFrameBytes == nil {
image.setLoadError(bi.logger, "could not get %s section: %v", debugFrameName, debugFrameErr)
return
}
if debugFrameBytes != nil {
fe, err := frame.Parse(debugFrameBytes, byteOrder, image.StaticBase, bi.Arch.PtrSize(), 0)
if err != nil {
image.setLoadError(bi.logger, "could not parse %s section: %v", debugFrameName, err)
return
}
bi.frameEntries = bi.frameEntries.Append(fe)
}
if ehFrameBytes != nil && ehFrameAddr > 0 {
fe, err := frame.Parse(ehFrameBytes, byteOrder, image.StaticBase, bi.Arch.PtrSize(), ehFrameAddr)
if err != nil {
if debugFrameBytes == nil {
image.setLoadError(bi.logger, "could not parse %s section: %v", ehFrameName, err)
return
}
bi.logger.Warnf("could not parse %s section: %v", ehFrameName, err)
return
}
bi.frameEntries = bi.frameEntries.Append(fe)
}
}
// ELF ///////////////////////////////////////////////////////////////
// openSeparateDebugInfo searches for a file containing the separate
// debug info for the binary using the "build ID" method as described
// in GDB's documentation [1], and if found returns two handles, one
// for the bare file, and another for its corresponding elf.File.
// [1] https://sourceware.org/gdb/onlinedocs/gdb/Separate-Debug-Files.html
//
// Alternatively, if the debug file cannot be found be the build-id, Delve
// will look in directories specified by the debug-info-directories config value.
func (bi *BinaryInfo) openSeparateDebugInfo(image *Image, exe *elf.File, debugInfoDirectories []string) (*os.File, *elf.File, error) {
exePath := image.Path
exeName := filepath.Base(image.Path)
if strings.HasPrefix(image.Path, "/proc") {
var err error
exePath, err = filepath.EvalSymlinks(image.Path)
if err == nil {
exeName = filepath.Base(exePath)
}
}
var debugFilePath string
check := func(potentialDebugFilePath string) bool {
_, err := os.Stat(potentialDebugFilePath)
if err == nil {
debugFilePath = potentialDebugFilePath
return true
}
return false
}
find := func(f func(string) bool, suffix string) {
for _, dir := range debugInfoDirectories {
if f != nil && !f(dir) {
continue
}
if check(fmt.Sprintf("%s/%s", dir, suffix)) {
break
}
}
}
if debugFilePath == "" && len(bi.BuildID) > 2 {
// Build ID method: look for a file named .build-id/nn/nnnnnnnn.debug in
// every debug info directory.
find(nil, fmt.Sprintf(".build-id/%s/%s.debug", bi.BuildID[:2], bi.BuildID[2:]))
}
if debugFilePath == "" {
// Debug link: method if the executable contains a .gnu_debuglink section
// it will look for the file named in the same directory of the
// executable, then in a subdirectory named .debug and finally in each
// debug info directory in a subdirectory with the same path as the
// directory of the executable
debugLink, crc := bi.getDebugLink(exe)
if debugLink != "" {
check(filepath.Join(filepath.Dir(exePath), debugLink))
if debugFilePath == "" {
check(filepath.Join(filepath.Dir(exePath), ".debug", debugLink))
}
if debugFilePath == "" {
suffix := filepath.Join(filepath.Dir(exePath)[1:], debugLink)
find(nil, suffix)
}
if debugFilePath == "" {
bi.logger.Warnf("gnu_debuglink link %q not found in any debug info directory", debugLink)
}
}
if debugFilePath != "" {
// CRC check
buf, err := os.ReadFile(debugFilePath)
if err == nil {
computedCRC := crc32.ChecksumIEEE(buf)
if crc != computedCRC {
bi.logger.Errorf("gnu_debuglink CRC check failed for %s (want %x got %x)", debugFilePath, crc, computedCRC)
debugFilePath = ""
}
}
}
}
if debugFilePath == "" && len(bi.BuildID) > 2 {
// Previous versions of delve looked for the build id in every debug info
// directory that contained the build-id substring. This behavior deviates
// from the ones specified by GDB but we keep it for backwards compatibility.
find(func(dir string) bool { return strings.Contains(dir, "build-id") }, fmt.Sprintf("%s/%s.debug", bi.BuildID[:2], bi.BuildID[2:]))
}
if debugFilePath == "" {
// Previous versions of delve looked for the executable filename (with
// .debug extension) in every debug info directory. This behavior also
// deviates from the ones specified by GDB, but we keep it for backwards
// compatibility.
find(func(dir string) bool { return !strings.Contains(dir, "build-id") }, fmt.Sprintf("%s.debug", exeName))
}
// We cannot find the debug information locally on the system. Try and see if we're on a system that
// has debuginfod so that we can use that in order to find any relevant debug information.
if debugFilePath == "" {
var err error
debugFilePath, err = debuginfod.GetDebuginfo(bi.BuildID)
if err != nil {
return nil, nil, ErrNoDebugInfoFound
}
}
sepFile, err := os.OpenFile(debugFilePath, 0, os.ModePerm)
if err != nil {
return nil, nil, errors.New("can't open separate debug file: " + err.Error())
}
elfFile, err := elf.NewFile(sepFile)
if err != nil {
sepFile.Close()
return nil, nil, fmt.Errorf("can't open separate debug file %q: %v", debugFilePath, err.Error())
}
if !supportedLinuxArch[elfFile.Machine] {
sepFile.Close()
return nil, nil, fmt.Errorf("can't open separate debug file %q: %v", debugFilePath, &ErrUnsupportedArch{os: "linux", cpuArch: elfFile.Machine})
}
return sepFile, elfFile, nil
}
// loadBinaryInfoElf specifically loads information from an ELF binary.
func loadBinaryInfoElf(bi *BinaryInfo, image *Image, path string, addr uint64, wg *sync.WaitGroup) error {
exe, err := os.OpenFile(path, 0, os.ModePerm)
if err != nil {
return err
}
image.closer = exe
elfFile, err := elf.NewFile(exe)
if err != nil {
return err
}
if !supportedLinuxArch[elfFile.Machine] {
return &ErrUnsupportedArch{os: "linux", cpuArch: elfFile.Machine}
}
if image.index == 0 {
// adding executable file:
// - addr is entryPoint therefore staticBase needs to be calculated by
// subtracting the entry point specified in the executable file from addr.
// - memory address of the .dynamic section needs to be recorded in
// BinaryInfo so that we can find loaded libraries.
if addr != 0 {
image.StaticBase = addr - elfFile.Entry
} else if elfFile.Type == elf.ET_DYN {
return ErrCouldNotDetermineRelocation
}
if dynsec := elfFile.Section(".dynamic"); dynsec != nil {
bi.ElfDynamicSection.Addr = dynsec.Addr + image.StaticBase
bi.ElfDynamicSection.Size = dynsec.Size
}
} else {
image.StaticBase = addr
}
dwarfFile := elfFile
bi.loadBuildID(image, elfFile)
var debugInfoBytes []byte
var dwerr error
image.dwarf, dwerr = elfFile.DWARF()
if dwerr != nil {
var sepFile *os.File
var serr error
sepFile, dwarfFile, serr = bi.openSeparateDebugInfo(image, elfFile, bi.DebugInfoDirectories)
if serr != nil {
if len(bi.Images) <= 1 {
fmt.Fprintln(os.Stderr, "Warning: no debug info found, some functionality will be missing such as stack traces and variable evaluation.")
}
cu := &compileUnit{}
cu.image = image
symTable, pcLnTabAddr, err := readPcLnTableElf(elfFile, path)
if err != nil {
return fmt.Errorf("could not read debug info (%v) and could not read go symbol table (%v)", dwerr, err)
}
image.symTable = symTable
goFuncVal, err := moduledata.GetGoFuncValue(elfFile, pcLnTabAddr)
if err != nil {
return err
}
prog := gosym.ProgContaining(elfFile, goFuncVal)
inlFuncs := make(map[string]*Function)
for _, f := range image.symTable.Funcs {
fnEntry := f.Entry + image.StaticBase
if prog != nil {
inlCalls, err := image.symTable.GetInlineTree(&f, goFuncVal, prog.Vaddr, prog.ReaderAt)
if err != nil {
return err
}
for _, inlfn := range inlCalls {
newInlinedCall := InlinedCall{cu: cu, LowPC: fnEntry + uint64(inlfn.ParentPC)}
if fn, ok := inlFuncs[inlfn.Name]; ok {
fn.InlinedCalls = append(fn.InlinedCalls, newInlinedCall)
continue
}
inlFuncs[inlfn.Name] = &Function{
Name: inlfn.Name,
Entry: 0, End: 0,
cu: cu,
InlinedCalls: []InlinedCall{
newInlinedCall,
},
}
}
}
fn := Function{Name: f.Name, Entry: fnEntry, End: f.End + image.StaticBase, cu: cu}
bi.Functions = append(bi.Functions, fn)
}
for i := range inlFuncs {
bi.Functions = append(bi.Functions, *inlFuncs[i])
}
sort.Sort(functionsDebugInfoByEntry(bi.Functions))
for f := range image.symTable.Files {
bi.Sources = append(bi.Sources, f)
}
sort.Strings(bi.Sources)
bi.Sources = uniq(bi.Sources)
return nil
}
image.sepDebugCloser = sepFile
image.dwarf, err = dwarfFile.DWARF()
if err != nil {
return err
}
}
debugInfoBytes, err = godwarf.GetDebugSectionElf(dwarfFile, "info")
if err != nil {
return err
}
image.dwarfReader = image.dwarf.Reader()
debugLineBytes, err := godwarf.GetDebugSectionElf(dwarfFile, "line")
if err != nil {
return err
}
debugLocBytes, _ := godwarf.GetDebugSectionElf(dwarfFile, "loc")
image.loclist2 = loclist.NewDwarf2Reader(debugLocBytes, bi.Arch.PtrSize())
debugLoclistBytes, _ := godwarf.GetDebugSectionElf(dwarfFile, "loclists")
image.loclist5 = loclist.NewDwarf5Reader(debugLoclistBytes)
debugAddrBytes, _ := godwarf.GetDebugSectionElf(dwarfFile, "addr")
image.debugAddr = godwarf.ParseAddr(debugAddrBytes)
debugLineStrBytes, _ := godwarf.GetDebugSectionElf(dwarfFile, "line_str")
image.debugLineStr = debugLineStrBytes
wg.Add(3)
go bi.parseDebugFrameElf(image, dwarfFile, elfFile, debugInfoBytes, wg)
go bi.loadDebugInfoMaps(image, debugInfoBytes, debugLineBytes, wg, nil)
go bi.loadSymbolName(image, elfFile, wg)
if image.index == 0 {
// determine g struct offset only when loading the executable file
wg.Add(1)
go bi.setGStructOffsetElf(image, dwarfFile, wg)
}
return nil
}
// _STT_FUNC is a code object, see /usr/include/elf.h for a full definition.
const _STT_FUNC = 2
func (bi *BinaryInfo) loadSymbolName(image *Image, file *elf.File, wg *sync.WaitGroup) {
defer wg.Done()
if bi.SymNames == nil {
bi.SymNames = make(map[uint64]*elf.Symbol)
}
symSecs, _ := file.Symbols()
for _, symSec := range symSecs {
if symSec.Info == _STT_FUNC { // TODO(chainhelen), need to parse others types.
s := symSec
bi.SymNames[symSec.Value+image.StaticBase] = &s
}
}
}
func (bi *BinaryInfo) loadBuildID(image *Image, file *elf.File) {
buildid := file.Section(".note.gnu.build-id")
if buildid == nil {
return
}
br := buildid.Open()
bh := new(buildIDHeader)
if err := binary.Read(br, binary.LittleEndian, bh); err != nil {
bi.logger.Warnf("can't read build-id header: %v", err)
return
}
name := make([]byte, bh.Namesz)
if err := binary.Read(br, binary.LittleEndian, name); err != nil {
bi.logger.Warnf("can't read build-id name: %v", err)
return
}
if strings.TrimSpace(string(name)) != "GNU\x00" {
bi.logger.Warn("invalid build-id signature")
return
}
descBinary := make([]byte, bh.Descsz)
if err := binary.Read(br, binary.LittleEndian, descBinary); err != nil {
bi.logger.Warnf("can't read build-id desc: %v", err)
return
}
bi.BuildID = hex.EncodeToString(descBinary)
}
func (bi *BinaryInfo) getDebugLink(exe *elf.File) (debugLink string, crc uint32) {
gnuDebugLink := exe.Section(".gnu_debuglink")
if gnuDebugLink == nil {
return
}
br := gnuDebugLink.Open()
buf, err := io.ReadAll(br)
if err != nil {
bi.logger.Warnf("can't read .gnu_debuglink: %v", err)
return
}
zero := bytes.Index(buf, []byte{0})
if zero <= 0 || len(buf[zero+1:]) < 4 {
bi.logger.Warnf("wrong .gnu_debuglink format: %q", buf)
return
}
debugLink = string(buf[:zero])
crc = binary.LittleEndian.Uint32(buf[len(buf)-4:])
return
}
func (bi *BinaryInfo) parseDebugFrameElf(image *Image, dwarfFile, exeFile *elf.File, debugInfoBytes []byte, wg *sync.WaitGroup) {
defer wg.Done()
debugFrameData, debugFrameErr := godwarf.GetDebugSectionElf(dwarfFile, "frame")
ehFrameSection := exeFile.Section(".eh_frame")
var ehFrameData []byte
var ehFrameAddr uint64
if ehFrameSection != nil {
ehFrameAddr = ehFrameSection.Addr
// Workaround for go.dev/cl/429601
if ehFrameSection.Type == elf.SHT_NOBITS {
ehFrameData = make([]byte, ehFrameSection.Size)
} else {
ehFrameData, _ = ehFrameSection.Data()
}
}
bi.parseDebugFrameGeneral(image, debugFrameData, ".debug_frame", debugFrameErr, ehFrameData, ehFrameAddr, ".eh_frame", frame.DwarfEndian(debugInfoBytes))
}
func (bi *BinaryInfo) setGStructOffsetElf(image *Image, exe *elf.File, wg *sync.WaitGroup) {
defer wg.Done()
// This is a bit arcane. Essentially:
// - If the program is pure Go, it can do whatever it wants, and puts the G
// pointer at %fs-8 on 64 bit.
// - %Gs is the index of private storage in GDT on 32 bit, and puts the G
// pointer at -4(tls).
// - Otherwise, Go asks the external linker to place the G pointer by
// emitting runtime.tlsg, a TLS symbol, which is relocated to the chosen
// offset in libc's TLS block.
// - On ARM64 (but really, any architecture other than i386 and 86x64) the
// offset is calculated using runtime.tls_g and the formula is different.
var tls *elf.Prog
for _, prog := range exe.Progs {
if prog.Type == elf.PT_TLS {
tls = prog
break
}
}
switch exe.Machine {
case elf.EM_X86_64, elf.EM_386:
tlsg := getSymbol(image, bi.logger, exe, "runtime.tlsg")
if tlsg == nil || tls == nil {
bi.gStructOffset = ^uint64(bi.Arch.PtrSize()) + 1 //-ptrSize
return
}
// According to https://reviews.llvm.org/D61824, linkers must pad the actual
// size of the TLS segment to ensure that (tlsoffset%align) == (vaddr%align).
// This formula, copied from the lld code, matches that.
// https://github.com/llvm-mirror/lld/blob/9aef969544981d76bea8e4d1961d3a6980980ef9/ELF/InputSection.cpp#L643
memsz := tls.Memsz + (-tls.Vaddr-tls.Memsz)&(tls.Align-1)
// The TLS register points to the end of the TLS block, which is
// tls.Memsz long. runtime.tlsg is an offset from the beginning of that block.
bi.gStructOffset = ^(memsz) + 1 + tlsg.Value // -tls.Memsz + tlsg.Value
case elf.EM_AARCH64:
tlsg := getSymbol(image, bi.logger, exe, "runtime.tls_g")
if tlsg == nil || tls == nil {
bi.gStructOffset = 2 * uint64(bi.Arch.PtrSize())
return
}
bi.gStructOffset = tlsg.Value + uint64(bi.Arch.PtrSize()*2) + ((tls.Vaddr - uint64(bi.Arch.PtrSize()*2)) & (tls.Align - 1))
case elf.EM_PPC64:
_ = getSymbol(image, bi.logger, exe, "runtime.tls_g")
default:
// we should never get here
panic("architecture not supported")
}
}
func getSymbol(image *Image, logger logflags.Logger, exe *elf.File, name string) *elf.Symbol {
symbols, err := exe.Symbols()
if err != nil {
image.setLoadError(logger, "could not parse ELF symbols: %v", err)
return nil
}
for _, symbol := range symbols {
if symbol.Name == name {
s := symbol
return &s
}
}
return nil
}
// PE ////////////////////////////////////////////////////////////////
const _IMAGE_DLLCHARACTERISTICS_DYNAMIC_BASE = 0x0040
// loadBinaryInfoPE specifically loads information from a PE binary.
func loadBinaryInfoPE(bi *BinaryInfo, image *Image, path string, entryPoint uint64, wg *sync.WaitGroup) error {
peFile, closer, err := openExecutablePathPE(path)
if err != nil {
return err
}
image.closer = closer
cpuArch := _PEMachine(peFile.Machine)
if !supportedWindowsArch[cpuArch] {
return &ErrUnsupportedArch{os: "windows", cpuArch: cpuArch}
}
image.dwarf, err = peFile.DWARF()
if err != nil {
return err
}
debugInfoBytes, err := godwarf.GetDebugSectionPE(peFile, "info")
if err != nil {
return err
}
opth := peFile.OptionalHeader.(*pe.OptionalHeader64)
if entryPoint != 0 {
image.StaticBase = entryPoint - opth.ImageBase
} else {
if opth.DllCharacteristics&_IMAGE_DLLCHARACTERISTICS_DYNAMIC_BASE != 0 {
return ErrCouldNotDetermineRelocation
}
}
image.dwarfReader = image.dwarf.Reader()
debugLineBytes, err := godwarf.GetDebugSectionPE(peFile, "line")
if err != nil {
return err
}
debugLocBytes, _ := godwarf.GetDebugSectionPE(peFile, "loc")
image.loclist2 = loclist.NewDwarf2Reader(debugLocBytes, bi.Arch.PtrSize())
debugLoclistBytes, _ := godwarf.GetDebugSectionPE(peFile, "loclists")
image.loclist5 = loclist.NewDwarf5Reader(debugLoclistBytes)
debugAddrBytes, _ := godwarf.GetDebugSectionPE(peFile, "addr")
image.debugAddr = godwarf.ParseAddr(debugAddrBytes)
debugLineStrBytes, _ := godwarf.GetDebugSectionPE(peFile, "line_str")
image.debugLineStr = debugLineStrBytes
wg.Add(2)
go bi.parseDebugFramePE(image, peFile, debugInfoBytes, wg)
go bi.loadDebugInfoMaps(image, debugInfoBytes, debugLineBytes, wg, func() {
// setGStructOffsetPE requires the image compile units to be loaded,
// so it can't be called concurrently with loadDebugInfoMaps.
if image.index == 0 {
// determine g struct offset only when loading the executable file.
bi.setGStructOffsetPE(entryPoint, peFile)
}
})
return nil
}
func (bi *BinaryInfo) setGStructOffsetPE(entryPoint uint64, peFile *pe.File) {
readtls_g := func() uint64 {
for _, s := range peFile.Symbols {
if s.Name == "runtime.tls_g" {
i := int(s.SectionNumber) - 1
if 0 <= i && i < len(peFile.Sections) {
sect := peFile.Sections[i]
if s.Value < sect.VirtualSize {
return entryPoint + uint64(sect.VirtualAddress) + uint64(s.Value)
}
}
break
}
}
return 0
}
switch _PEMachine(peFile.Machine) {
case _IMAGE_FILE_MACHINE_AMD64:
producer := bi.Producer()
if producer != "" && goversion.ProducerAfterOrEqual(producer, 1, 20) {
// Use runtime.tls_g as pointer to offset from GS to G struct:
// https://golang.org/src/runtime/sys_windows_amd64.s
bi.gStructOffset = readtls_g()
bi.gStructOffsetIsPtr = true
} else {
// Use ArbitraryUserPointer (0x28) as pointer to pointer
// to G struct per:
// https://golang.org/src/runtime/cgo/gcc_windows_amd64.c
bi.gStructOffset = 0x28
}
case _IMAGE_FILE_MACHINE_ARM64:
// Use runtime.tls_g as pointer to offset from R18 to G struct:
// https://golang.org/src/runtime/sys_windows_arm64.s
bi.gStructOffset = readtls_g()
bi.gStructOffsetIsPtr = true
}
}
func openExecutablePathPE(path string) (*pe.File, io.Closer, error) {
f, err := os.OpenFile(path, 0, os.ModePerm)
if err != nil {
return nil, nil, err
}
peFile, err := pe.NewFile(f)
if err != nil {
f.Close()
return nil, nil, err
}
return peFile, f, nil
}
func (bi *BinaryInfo) parseDebugFramePE(image *Image, exe *pe.File, debugInfoBytes []byte, wg *sync.WaitGroup) {
defer wg.Done()
debugFrameBytes, err := godwarf.GetDebugSectionPE(exe, "frame")
bi.parseDebugFrameGeneral(image, debugFrameBytes, ".debug_frame", err, nil, 0, "", frame.DwarfEndian(debugInfoBytes))
}
// MACH-O ////////////////////////////////////////////////////////////
// loadBinaryInfoMacho specifically loads information from a Mach-O binary.
func loadBinaryInfoMacho(bi *BinaryInfo, image *Image, path string, entryPoint uint64, wg *sync.WaitGroup) error {
exe, err := macho.Open(path)
if err != nil {
return err
}
if entryPoint != 0 {
machoOff := uint64(0x100000000)
for _, ld := range exe.Loads {
if seg, _ := ld.(*macho.Segment); seg != nil {
if seg.Name == "__TEXT" {
machoOff = seg.Addr
break
}
}
}
logflags.DebuggerLogger().Debugf("entryPoint %#x machoOff %#x", entryPoint, machoOff)
image.StaticBase = entryPoint - machoOff
}
image.closer = exe
if !supportedDarwinArch[exe.Cpu] {
return &ErrUnsupportedArch{os: "darwin", cpuArch: exe.Cpu}
}
var dwerr error
image.dwarf, dwerr = exe.DWARF()
if dwerr != nil {
if len(bi.Images) <= 1 {
fmt.Fprintln(os.Stderr, "Warning: no debug info found, some functionality will be missing such as stack traces and variable evaluation.")
}
symTable, err := readPcLnTableMacho(exe, path)
if err != nil {
return fmt.Errorf("could not read debug info (%v) and could not read go symbol table (%v)", dwerr, err)
}
image.symTable = symTable
for _, f := range image.symTable.Funcs {
cu := &compileUnit{}
cu.image = image
fn := Function{Name: f.Name, Entry: f.Entry + image.StaticBase, End: f.End + image.StaticBase, cu: cu}
bi.Functions = append(bi.Functions, fn)
}
for f := range image.symTable.Files {
bi.Sources = append(bi.Sources, f)
}
return nil
}
debugInfoBytes, err := godwarf.GetDebugSectionMacho(exe, "info")
if err != nil {
return err
}
image.dwarfReader = image.dwarf.Reader()
debugLineBytes, err := godwarf.GetDebugSectionMacho(exe, "line")
if err != nil {
return err
}
debugLocBytes, _ := godwarf.GetDebugSectionMacho(exe, "loc")
image.loclist2 = loclist.NewDwarf2Reader(debugLocBytes, bi.Arch.PtrSize())
debugLoclistBytes, _ := godwarf.GetDebugSectionMacho(exe, "loclists")
image.loclist5 = loclist.NewDwarf5Reader(debugLoclistBytes)
debugAddrBytes, _ := godwarf.GetDebugSectionMacho(exe, "addr")
image.debugAddr = godwarf.ParseAddr(debugAddrBytes)
debugLineStrBytes, _ := godwarf.GetDebugSectionMacho(exe, "line_str")
image.debugLineStr = debugLineStrBytes
wg.Add(2)
go bi.parseDebugFrameMacho(image, exe, debugInfoBytes, wg)
go bi.loadDebugInfoMaps(image, debugInfoBytes, debugLineBytes, wg, bi.setGStructOffsetMacho)
return nil
}
func (bi *BinaryInfo) setGStructOffsetMacho() {
// In go1.11 it's 0x30, before 0x8a0, see:
// https://github.com/golang/go/issues/23617
// and go commit b3a854c733257c5249c3435ffcee194f8439676a
producer := bi.Producer()
if producer != "" && goversion.ProducerAfterOrEqual(producer, 1, 11) {
bi.gStructOffset = 0x30
return
}
bi.gStructOffset = 0x8a0
}
func (bi *BinaryInfo) parseDebugFrameMacho(image *Image, exe *macho.File, debugInfoBytes []byte, wg *sync.WaitGroup) {
defer wg.Done()
debugFrameBytes, debugFrameErr := godwarf.GetDebugSectionMacho(exe, "frame")
ehFrameSection := exe.Section("__eh_frame")
var ehFrameBytes []byte
var ehFrameAddr uint64
if ehFrameSection != nil {
ehFrameAddr = ehFrameSection.Addr
ehFrameBytes, _ = ehFrameSection.Data()
}
bi.parseDebugFrameGeneral(image, debugFrameBytes, "__debug_frame", debugFrameErr, ehFrameBytes, ehFrameAddr, "__eh_frame", frame.DwarfEndian(debugInfoBytes))
}
// macOSDebugFrameBugWorkaround applies a workaround for [golang/go#25841]
//
// It finds the Go function with the lowest entry point and the first
// debug_frame FDE, calculates the difference between the start of the
// function and the start of the FDE and sums it to all debug_frame FDEs.
// A number of additional checks are performed to make sure we don't ruin
// executables unaffected by this bug.
//
// [golang/go#25841]: https://github.com/golang/go/issues/25841
func (bi *BinaryInfo) macOSDebugFrameBugWorkaround() {
if bi.GOOS != "darwin" {
return
}
if len(bi.Images) > 1 {
// Only do this for the first executable, but it might work for plugins as
// well if we had a way to distinguish where entries in bi.frameEntries
// come from
return
}
exe, ok := bi.Images[0].closer.(*macho.File)
if !ok {
return
}
if bi.Arch.Name == "arm64" {
if exe.Flags&macho.FlagPIE == 0 {
bi.logger.Infof("debug_frame workaround not needed: not a PIE (%#x)", exe.Flags)
return
}
} else {
prod := goversion.ParseProducer(bi.Producer())
if !prod.AfterOrEqual(goversion.GoVersion{Major: 1, Minor: 19, Rev: 3}) && !prod.IsDevel() {
bi.logger.Infof("debug_frame workaround not needed (version %q on %s)", bi.Producer(), bi.Arch.Name)
return
}
found := false
for i := range bi.frameEntries {
if bi.frameEntries[i].CIE.CIE_id == ^uint32(0) && bi.frameEntries[i].Begin() < 0x4000000 {
found = true
break
}
}
if !found {
bi.logger.Infof("debug_frame workaround not needed (all FDEs above 0x4000000)")
return
}
}
// Find first Go function (first = lowest entry point)
var fn *Function
for i := range bi.Functions {
if bi.Functions[i].cu.isgo && bi.Functions[i].Entry > 0 {
fn = &bi.Functions[i]
break
}
}
if fn == nil {
bi.logger.Warn("debug_frame workaround not applied: could not find a Go function")
return
}
if fde, _ := bi.frameEntries.FDEForPC(fn.Entry); fde != nil {
// Function is covered, no need to apply workaround
bi.logger.Warnf("debug_frame workaround not applied: function %s (at %#x) covered by %#x-%#x", fn.Name, fn.Entry, fde.Begin(), fde.End())
return
}
// Find lowest FDE in debug_frame
var fde *frame.FrameDescriptionEntry
for i := range bi.frameEntries {
if bi.frameEntries[i].CIE.CIE_id == ^uint32(0) {
fde = bi.frameEntries[i]
break
}
}
if fde == nil {
bi.logger.Warnf("debug_frame workaround not applied because there are no debug_frame entries (%d)", len(bi.frameEntries))
return
}
fnsize := fn.End - fn.Entry
if fde.End()-fde.Begin() != fnsize || fde.Begin() > fn.Entry {
bi.logger.Warnf("debug_frame workaround not applied: function %s (at %#x-%#x) has a different size than the first FDE (%#x-%#x) (or the FDE starts after the function)", fn.Name, fn.Entry, fn.End, fde.Begin(), fde.End())
return
}
delta := fn.Entry - fde.Begin()
bi.logger.Infof("applying debug_frame workaround +%#x: function %s (at %#x-%#x) and FDE %#x-%#x", delta, fn.Name, fn.Entry, fn.End, fde.Begin(), fde.End())
for i := range bi.frameEntries {
if bi.frameEntries[i].CIE.CIE_id == ^uint32(0) {
bi.frameEntries[i].Translate(delta)
}
}
}
// Do not call this function directly it isn't able to deal correctly with package paths
func (bi *BinaryInfo) findType(name string) (godwarf.Type, error) {
name = strings.ReplaceAll(name, "interface{", "interface {")
name = strings.ReplaceAll(name, "struct{", "struct {")
ref, found := bi.types[name]
if !found {
return nil, reader.ErrTypeNotFound
}
image := bi.Images[ref.imageIndex]
return godwarf.ReadType(image.dwarf, ref.imageIndex, ref.offset, image.typeCache)
}
func (bi *BinaryInfo) findTypeExpr(expr ast.Expr) (godwarf.Type, error) {
if lit, islit := expr.(*ast.BasicLit); islit && lit.Kind == token.STRING {
// Allow users to specify type names verbatim as quoted
// string. Useful as a catch-all workaround for cases where we don't
// parse/serialize types correctly or can not resolve package paths.
typn, _ := strconv.Unquote(lit.Value)
// Check if the type in question is an array type, in which case we try to
// fake it.
if len(typn) > 0 && typn[0] == '[' {
closedBrace := strings.Index(typn, "]")
if closedBrace > 1 {
n, err := strconv.Atoi(typn[1:closedBrace])
if err == nil {
return bi.findArrayType(n, typn[closedBrace+1:])
}
}
}
return bi.findType(typn)
}
bi.expandPackagesInType(expr)
if snode, ok := expr.(*ast.StarExpr); ok {
// Pointer types only appear in the dwarf information when
// a pointer to the type is used in the target program, here
// we create a pointer type on the fly so that the user can
// specify a pointer to any variable used in the target program
ptyp, err := bi.findTypeExpr(snode.X)
if err != nil {
return nil, err
}
return pointerTo(ptyp, bi.Arch), nil
}
if anode, ok := expr.(*ast.ArrayType); ok {
// Array types (for example [N]byte) are only present in DWARF if they are
// used by the program, but it's convenient to make all of them available
// to the user for two reasons:
// 1. to allow reading arbitrary memory byte-by-byte (by casting an
// address to an array of bytes).
// 2. to read the contents of a channel's buffer (we create fake array
// types for them)
alen, litlen := anode.Len.(*ast.BasicLit)
if litlen && alen.Kind == token.INT {
n, _ := strconv.Atoi(alen.Value)
return bi.findArrayType(n, exprToString(anode.Elt))
}
}
return bi.findType(exprToString(expr))
}
func (bi *BinaryInfo) findArrayType(n int, etyp string) (godwarf.Type, error) {
switch etyp {
case "byte", "uint8":
etyp = "uint8"
fallthrough
default:
btyp, err := bi.findType(etyp)
if err != nil {
return nil, err
}
return fakeArrayType(uint64(n), btyp), nil
}
}
func complexType(typename string) bool {
for _, ch := range typename {
switch ch {
case '*', '[', '<', '{', '(', ' ':
return true
}
}
return false
}
func (bi *BinaryInfo) registerTypeToPackageMap(entry *dwarf.Entry) {
if entry.Tag != dwarf.TagTypedef && entry.Tag != dwarf.TagBaseType && entry.Tag != dwarf.TagClassType && entry.Tag != dwarf.TagStructType {
return
}
typename, ok := entry.Val(dwarf.AttrName).(string)
if !ok || complexType(typename) {
return
}
dot := strings.LastIndex(typename, ".")
if dot < 0 {
return
}
path := typename[:dot]
slash := strings.LastIndex(path, "/")
if slash < 0 || slash+1 >= len(path) {
return
}
name := path[slash+1:]
bi.PackageMap[name] = []string{path}
}
func (bi *BinaryInfo) loadDebugInfoMaps(image *Image, debugInfoBytes, debugLineBytes []byte, wg *sync.WaitGroup, cont func()) {
if wg != nil {
defer wg.Done()
}
if bi.types == nil {
bi.types = make(map[string]dwarfRef)
}
if bi.consts == nil {
bi.consts = make(map[dwarfRef]*constantType)
}
if bi.PackageMap == nil {
bi.PackageMap = make(map[string][]string)
}
if bi.inlinedCallLines == nil {
bi.inlinedCallLines = make(map[fileLine][]uint64)
}
if bi.dwrapUnwrapCache == nil {
bi.dwrapUnwrapCache = make(map[uint64]*Function)
}
image.runtimeTypeToDIE = make(map[uint64]runtimeTypeDIE)
ctxt := newLoadDebugInfoMapsContext(bi, image, pdwarf.ReadUnitVersions(debugInfoBytes))
reader := image.DwarfReader()
for {
entry, err := reader.Next()
if err != nil {
image.setLoadError(bi.logger, "error reading debug_info: %v", err)
break
}
if entry == nil {
break
}
switch entry.Tag {
case dwarf.TagCompileUnit:
cu := &compileUnit{}
cu.image = image
cu.entry = entry
cu.offset = entry.Offset
cu.Version = ctxt.offsetToVersion[cu.offset]
if lang, _ := entry.Val(dwarf.AttrLanguage).(int64); lang == dwarfGoLanguage {
cu.isgo = true
}
cu.name, _ = entry.Val(dwarf.AttrName).(string)
compdir, _ := entry.Val(dwarf.AttrCompDir).(string)
if compdir != "" {
cu.name = filepath.Join(compdir, cu.name)
}
cu.ranges, _ = image.dwarf.Ranges(entry)
for i := range cu.ranges {
cu.ranges[i][0] += image.StaticBase
cu.ranges[i][1] += image.StaticBase
}
if len(cu.ranges) >= 1 {
cu.lowPC = cu.ranges[0][0]
}
lineInfoOffset, hasLineInfo := entry.Val(dwarf.AttrStmtList).(int64)
if hasLineInfo && lineInfoOffset >= 0 && lineInfoOffset < int64(len(debugLineBytes)) {
var logfn func(string, ...interface{})
if logflags.DebugLineErrors() {
logfn = logflags.DebugLineLogger().Debugf
}
cu.lineInfo = line.Parse(compdir, bytes.NewBuffer(debugLineBytes[lineInfoOffset:]), image.debugLineStr, logfn, image.StaticBase, bi.GOOS == "windows", bi.Arch.PtrSize())
}
cu.producer, _ = entry.Val(dwarf.AttrProducer).(string)
if cu.isgo && cu.producer != "" {
semicolon := strings.Index(cu.producer, ";")
if semicolon < 0 {
cu.optimized = goversion.ProducerAfterOrEqual(cu.producer, 1, 10)
} else {
cu.optimized = !strings.Contains(cu.producer[semicolon:], "-N") || !strings.Contains(cu.producer[semicolon:], "-l")
const regabi = " regabi"
if i := strings.Index(cu.producer[semicolon:], regabi); i > 0 {
i += semicolon
if i+len(regabi) >= len(cu.producer) || cu.producer[i+len(regabi)] == ' ' {
bi.regabi = true
}
}
cu.producer = cu.producer[:semicolon]
}
}
gopkg, _ := entry.Val(godwarf.AttrGoPackageName).(string)
if cu.isgo && gopkg != "" {
bi.PackageMap[gopkg] = append(bi.PackageMap[gopkg], escapePackagePath(strings.ReplaceAll(cu.name, "\\", "/")))
}
image.compileUnits = append(image.compileUnits, cu)
if entry.Children {
bi.loadDebugInfoMapsCompileUnit(ctxt, image, reader, cu)
}
case dwarf.TagPartialUnit:
reader.SkipChildren()
default:
// ignore unknown tags
reader.SkipChildren()
}
}
sort.Sort(compileUnitsByOffset(image.compileUnits))
sort.Sort(functionsDebugInfoByEntry(bi.Functions))
sort.Sort(packageVarsByAddr(bi.packageVars))
bi.lookupFunc = nil
bi.lookupGenericFunc = nil
for _, cu := range image.compileUnits {
if cu.lineInfo != nil {
for _, fileEntry := range cu.lineInfo.FileNames {
bi.Sources = append(bi.Sources, fileEntry.Path)
}
}
}
sort.Strings(bi.Sources)
bi.Sources = uniq(bi.Sources)
if bi.regabi {
// prepare patch for runtime.mallocgc's DIE
fn := bi.lookupOneFunc("runtime.mallocgc")
if fn != nil && fn.cu.image == image {
tree, err := image.getDwarfTree(fn.offset)
if err == nil {
children, err := regabiMallocgcWorkaround(bi)
if err != nil {
bi.logger.Errorf("could not patch runtime.mallocgc: %v", err)
} else {
tree.Children = children
image.runtimeMallocgcTree = tree
}
}
}
}
if cont != nil {
cont()
}
}
// LookupGenericFunc returns a map that allows searching for instantiations of generic function by specifying a function name without type parameters.
// For example the key "pkg.(*Receiver).Amethod" will find all instantiations of Amethod:
// - pkg.(*Receiver[.shape.int]).Amethod
// - pkg.(*Receiver[.shape.*uint8]).Amethod
// - etc.
func (bi *BinaryInfo) LookupGenericFunc() map[string][]*Function {
if bi.lookupGenericFunc == nil {
bi.lookupGenericFunc = make(map[string][]*Function)
for i := range bi.Functions {
dn := bi.Functions[i].NameWithoutTypeParams()
if dn != bi.Functions[i].Name {
bi.lookupGenericFunc[dn] = append(bi.lookupGenericFunc[dn], &bi.Functions[i])
}
}
}
return bi.lookupGenericFunc
}
func (bi *BinaryInfo) LookupFunc() map[string][]*Function {
if bi.lookupFunc == nil {
bi.lookupFunc = make(map[string][]*Function)
for i := range bi.Functions {
name := bi.Functions[i].Name
bi.lookupFunc[name] = append(bi.lookupFunc[name], &bi.Functions[i])
}
}
return bi.lookupFunc
}
func (bi *BinaryInfo) lookupOneFunc(name string) *Function {
fns := bi.LookupFunc()[name]
if fns == nil {
return nil
}
return fns[0]
}
// loadDebugInfoMapsCompileUnit loads entry from a single compile unit.
func (bi *BinaryInfo) loadDebugInfoMapsCompileUnit(ctxt *loadDebugInfoMapsContext, image *Image, reader *reader.Reader, cu *compileUnit) {
hasAttrGoPkgName := goversion.ProducerAfterOrEqual(cu.producer, 1, 13)
depth := 0
for {
entry, err := reader.Next()
if err != nil {
image.setLoadError(bi.logger, "error reading debug_info: %v", err)
return
}
if entry == nil {
break
}
switch entry.Tag {
case 0:
if depth == 0 {
return
} else {
depth--
}
case dwarf.TagImportedUnit:
bi.loadDebugInfoMapsImportedUnit(entry, ctxt, image, cu)
reader.SkipChildren()
case dwarf.TagArrayType, dwarf.TagBaseType, dwarf.TagClassType, dwarf.TagStructType, dwarf.TagUnionType, dwarf.TagConstType, dwarf.TagVolatileType, dwarf.TagRestrictType, dwarf.TagEnumerationType, dwarf.TagPointerType, dwarf.TagSubroutineType, dwarf.TagTypedef, dwarf.TagUnspecifiedType:
if name, ok := entry.Val(dwarf.AttrName).(string); ok {
if !cu.isgo {
name = "C." + name
}
if _, exists := bi.types[name]; !exists {
bi.types[name] = dwarfRef{image.index, entry.Offset}
}
}
if cu != nil && cu.isgo && !hasAttrGoPkgName {
bi.registerTypeToPackageMap(entry)
}
image.registerRuntimeTypeToDIE(entry, ctxt.ardr)
reader.SkipChildren()
case dwarf.TagVariable:
if n, ok := entry.Val(dwarf.AttrName).(string); ok {
var addr uint64
if loc, ok := entry.Val(dwarf.AttrLocation).([]byte); ok {
if len(loc) == bi.Arch.PtrSize()+1 && op.Opcode(loc[0]) == op.DW_OP_addr {
addr, _ = pdwarf.ReadUintRaw(bytes.NewReader(loc[1:]), binary.LittleEndian, bi.Arch.PtrSize())
}
}
if !cu.isgo {
n = "C." + n
}
if _, known := ctxt.knownPackageVars[n]; !known {
bi.packageVars = append(bi.packageVars, packageVar{n, cu, entry.Offset, addr + image.StaticBase})
}
}
reader.SkipChildren()
case dwarf.TagConstant:
name, okName := entry.Val(dwarf.AttrName).(string)
typ, okType := entry.Val(dwarf.AttrType).(dwarf.Offset)
val, okVal := entry.Val(dwarf.AttrConstValue).(int64)
if okName && okType && okVal {
if !cu.isgo {
name = "C." + name
}
ct := bi.consts[dwarfRef{image.index, typ}]
if ct == nil {
ct = &constantType{}
bi.consts[dwarfRef{image.index, typ}] = ct
}
ct.values = append(ct.values, constantValue{name: name, fullName: name, value: val})
}
reader.SkipChildren()
case dwarf.TagSubprogram:
inlined := false
if inval, ok := entry.Val(dwarf.AttrInline).(int64); ok {
inlined = inval >= 1
}
if inlined {
bi.addAbstractSubprogram(entry, ctxt, reader, image, cu)
} else {
originOffset, hasAbstractOrigin := entry.Val(dwarf.AttrAbstractOrigin).(dwarf.Offset)
if hasAbstractOrigin {
bi.addConcreteInlinedSubprogram(entry, originOffset, ctxt, reader, cu)
} else {
bi.addConcreteSubprogram(entry, ctxt, reader, cu)
}
}
default:
if entry.Children {
depth++
}
}
}
}
// loadDebugInfoMapsImportedUnit loads entries into cu from the partial unit
// referenced in a DW_TAG_imported_unit entry.
func (bi *BinaryInfo) loadDebugInfoMapsImportedUnit(entry *dwarf.Entry, ctxt *loadDebugInfoMapsContext, image *Image, cu *compileUnit) {
off, ok := entry.Val(dwarf.AttrImport).(dwarf.Offset)
if !ok {
return
}
reader := image.DwarfReader()
reader.Seek(off)
imentry, err := reader.Next()
if err != nil {
return
}
if imentry.Tag != dwarf.TagPartialUnit {
return
}
bi.loadDebugInfoMapsCompileUnit(ctxt, image, reader, cu)
}
// addAbstractSubprogram adds the abstract entry for an inlined function.
func (bi *BinaryInfo) addAbstractSubprogram(entry *dwarf.Entry, ctxt *loadDebugInfoMapsContext, reader *reader.Reader, image *Image, cu *compileUnit) {
name, ok := subprogramEntryName(entry, cu)
if !ok {
bi.logger.Warnf("reading debug_info: abstract subprogram without name at %#x", entry.Offset)
// In some cases clang produces abstract subprograms that do not have a
// name, but we should process them anyway.
}
if entry.Children {
bi.loadDebugInfoMapsInlinedCalls(ctxt, reader, cu)
}
originIdx := ctxt.lookupAbstractOrigin(bi, entry.Offset)
fn := &bi.Functions[originIdx]
fn.Name = name
fn.offset = entry.Offset
fn.cu = cu
}
// addConcreteInlinedSubprogram adds the concrete entry of a subprogram that was also inlined.
func (bi *BinaryInfo) addConcreteInlinedSubprogram(entry *dwarf.Entry, originOffset dwarf.Offset, ctxt *loadDebugInfoMapsContext, reader *reader.Reader, cu *compileUnit) {
lowpc, highpc, ok := subprogramEntryRange(entry, cu.image)
if !ok {
bi.logger.Warnf("reading debug_info: concrete inlined subprogram without address range at %#x", entry.Offset)
if entry.Children {
reader.SkipChildren()
}
return
}
originIdx := ctxt.lookupAbstractOrigin(bi, originOffset)
fn := &bi.Functions[originIdx]
fn.offset = entry.Offset
fn.Entry = lowpc
fn.End = highpc
fn.cu = cu
if entry.Children {
bi.loadDebugInfoMapsInlinedCalls(ctxt, reader, cu)
}
}
// addConcreteSubprogram adds a concrete subprogram (a normal subprogram
// that doesn't have abstract or inlined entries)
func (bi *BinaryInfo) addConcreteSubprogram(entry *dwarf.Entry, ctxt *loadDebugInfoMapsContext, reader *reader.Reader, cu *compileUnit) {
lowpc, highpc, ok := subprogramEntryRange(entry, cu.image)
if !ok {
bi.logger.Warnf("reading debug_info: concrete subprogram without address range at %#x", entry.Offset)
// When clang inlines a function, in some cases, it produces a concrete
// subprogram without address range and then inlined calls that reference
// it, instead of producing an abstract subprogram.
// It is unclear if this behavior is standard.
}
name, ok := subprogramEntryName(entry, cu)
if !ok {
bi.logger.Warnf("reading debug_info: concrete subprogram without name at %#x", entry.Offset)
}
trampoline, _ := entry.Val(dwarf.AttrTrampoline).(bool)
originIdx := ctxt.lookupAbstractOrigin(bi, entry.Offset)
fn := &bi.Functions[originIdx]
fn.Name = name
fn.Entry = lowpc
fn.End = highpc
fn.offset = entry.Offset
fn.cu = cu
fn.trampoline = trampoline
if entry.Children {
bi.loadDebugInfoMapsInlinedCalls(ctxt, reader, cu)
}
}
func subprogramEntryName(entry *dwarf.Entry, cu *compileUnit) (string, bool) {
name, ok := entry.Val(dwarf.AttrName).(string)
if !ok {
return "", false
}
if !cu.isgo {
name = "C." + name
}
return name, true
}
func subprogramEntryRange(entry *dwarf.Entry, image *Image) (lowpc, highpc uint64, ok bool) {
ok = false
if ranges, _ := image.dwarf.Ranges(entry); len(ranges) >= 1 {
ok = true
lowpc = ranges[0][0] + image.StaticBase
highpc = ranges[0][1] + image.StaticBase
}
return lowpc, highpc, ok
}
func (bi *BinaryInfo) loadDebugInfoMapsInlinedCalls(ctxt *loadDebugInfoMapsContext, reader *reader.Reader, cu *compileUnit) {
for {
entry, err := reader.Next()
if err != nil {
cu.image.setLoadError(bi.logger, "error reading debug_info: %v", err)
return
}
switch entry.Tag {
case 0:
return
case dwarf.TagInlinedSubroutine:
originOffset, ok := entry.Val(dwarf.AttrAbstractOrigin).(dwarf.Offset)
if !ok {
bi.logger.Warnf("reading debug_info: inlined call without origin offset at %#x", entry.Offset)
reader.SkipChildren()
continue
}
lowpc, highpc, ok := subprogramEntryRange(entry, cu.image)
if !ok {
bi.logger.Warnf("reading debug_info: inlined call without address range at %#x", entry.Offset)
reader.SkipChildren()
continue
}
callfileidx, ok1 := entry.Val(dwarf.AttrCallFile).(int64)
callline, ok2 := entry.Val(dwarf.AttrCallLine).(int64)
if !ok1 || !ok2 {
bi.logger.Warnf("reading debug_info: inlined call without CallFile/CallLine at %#x", entry.Offset)
reader.SkipChildren()
continue
}
callfile, cferr := cu.filePath(int(callfileidx), entry)
if cferr != nil {
bi.logger.Warnf("%v", cferr)
reader.SkipChildren()
continue
}
originIdx := ctxt.lookupAbstractOrigin(bi, originOffset)
fn := &bi.Functions[originIdx]
fn.InlinedCalls = append(fn.InlinedCalls, InlinedCall{
cu: cu,
LowPC: lowpc,
HighPC: highpc,
})
if fn.cu == nil {
fn.cu = cu
}
fl := fileLine{callfile, int(callline)}
bi.inlinedCallLines[fl] = append(bi.inlinedCallLines[fl], lowpc)
if entry.Children {
bi.loadDebugInfoMapsInlinedCalls(ctxt, reader, cu)
}
}
reader.SkipChildren()
}
}
func uniq(s []string) []string {
if len(s) == 0 {
return s
}
src, dst := 1, 1
for src < len(s) {
if s[src] != s[dst-1] {
s[dst] = s[src]
dst++
}
src++
}
return s[:dst]
}
func (bi *BinaryInfo) expandPackagesInType(expr ast.Expr) {
switch e := expr.(type) {
case *ast.ArrayType:
bi.expandPackagesInType(e.Elt)
case *ast.ChanType:
bi.expandPackagesInType(e.Value)
case *ast.FuncType:
for i := range e.Params.List {
bi.expandPackagesInType(e.Params.List[i].Type)
}
if e.Results != nil {
for i := range e.Results.List {
bi.expandPackagesInType(e.Results.List[i].Type)
}
}
case *ast.MapType:
bi.expandPackagesInType(e.Key)
bi.expandPackagesInType(e.Value)
case *ast.ParenExpr:
bi.expandPackagesInType(e.X)
case *ast.SelectorExpr:
switch x := e.X.(type) {
case *ast.Ident:
if len(bi.PackageMap[x.Name]) > 0 {
// There's no particular reason to expect the first entry to be the
// correct one if the package name is ambiguous, but trying all possible
// expansions of all types mentioned in the expression is complicated
// and, besides type assertions, users can always specify the type they
// want exactly, using a string.
x.Name = bi.PackageMap[x.Name][0]
}
default:
bi.expandPackagesInType(e.X)
}
case *ast.StarExpr:
bi.expandPackagesInType(e.X)
default:
// nothing to do
}
}
// escapePackagePath returns pkg with '.' replaced with '%2e' (in all
// elements of the path except the first one) like Go does in variable and
// type names.
func escapePackagePath(pkg string) string {
slash := strings.Index(pkg, "/")
if slash < 0 {
slash = 0
}
return pkg[:slash] + strings.ReplaceAll(pkg[slash:], ".", "%2e")
}
// Looks up symbol (either functions or global variables) at address addr.
// Used by disassembly formatter.
func (bi *BinaryInfo) symLookup(addr uint64) (string, uint64) {
fn := bi.PCToFunc(addr)
if fn != nil {
if fn.Entry == addr {
// only report the function name if it's the exact address because it's
// easier to read the absolute address than function_name+offset.
return fn.Name, fn.Entry
}
return "", 0
}
if sym, ok := bi.SymNames[addr]; ok {
return sym.Name, addr
}
i := sort.Search(len(bi.packageVars), func(i int) bool {
return bi.packageVars[i].addr >= addr
})
if i >= len(bi.packageVars) {
return "", 0
}
if bi.packageVars[i].addr > addr {
// report previous variable + offset if i-th variable starts after addr
i--
}
if i >= 0 && bi.packageVars[i].addr != 0 {
return bi.packageVars[i].name, bi.packageVars[i].addr
}
return "", 0
}
type PackageBuildInfo struct {
ImportPath string
DirectoryPath string
Files map[string]struct{}
}
// ListPackagesBuildInfo returns the list of packages used by the program along with
// the directory where each package was compiled and optionally the list of
// files constituting the package.
func (bi *BinaryInfo) ListPackagesBuildInfo(includeFiles bool) []*PackageBuildInfo {
m := make(map[string]*PackageBuildInfo)
for _, cu := range bi.Images[0].compileUnits {
if cu.image != bi.Images[0] || !cu.isgo || cu.lineInfo == nil {
//TODO(aarzilli): what's the correct thing to do for plugins?
continue
}
ip := strings.ReplaceAll(cu.name, "\\", "/")
if _, ok := m[ip]; !ok {
path := cu.lineInfo.FirstFile()
if ext := filepath.Ext(path); ext != ".go" && ext != ".s" {
continue
}
dp := filepath.Dir(path)
m[ip] = &PackageBuildInfo{
ImportPath: ip,
DirectoryPath: dp,
Files: make(map[string]struct{}),
}
}
if includeFiles {
pbi := m[ip]
for _, file := range cu.lineInfo.FileNames {
pbi.Files[file.Path] = struct{}{}
}
}
}
r := make([]*PackageBuildInfo, 0, len(m))
for _, pbi := range m {
r = append(r, pbi)
}
sort.Slice(r, func(i, j int) bool { return r[i].ImportPath < r[j].ImportPath })
return r
}
// cuFilePath takes a compilation unit "cu" and a file index reference
// "fileidx" and returns the corresponding file name entry from the
// DWARF line table associated with the unit; "entry" is the offset of
// the attribute where the file reference originated, for logging
// purposes. Return value is the file string and an error value; error
// will be non-nil if the file could not be recovered, perhaps due to
// malformed DWARF.
func (cu *compileUnit) filePath(fileidx int, entry *dwarf.Entry) (string, error) {
if cu.lineInfo == nil {
return "", fmt.Errorf("reading debug_info: file reference within a compilation unit without debug_line section at %#x", entry.Offset)
}
// File numbering is slightly different before and after DWARF 5;
// account for this here. See section 6.2.4 of the DWARF 5 spec.
if cu.Version < 5 {
fileidx--
}
if fileidx < 0 || fileidx >= len(cu.lineInfo.FileNames) {
return "", fmt.Errorf("reading debug_info: file index (%d) out of range in compile unit file table at %#x", fileidx, entry.Offset)
}
return cu.lineInfo.FileNames[fileidx].Path, nil
}