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go.mod: runc v1.0.0

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Signed-off-by: Akihiro Suda <akihiro.suda.cz@hco.ntt.co.jp>
This commit is contained in:
Akihiro Suda
2021-06-22 15:35:10 +09:00
committed by Davanum Srinivas
parent 28bb59c080
commit f913a42755
107 changed files with 9760 additions and 1798 deletions
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28
vendor/github.com/cilium/ebpf/internal/btf/btf.go generated vendored
View File

@@ -35,7 +35,7 @@ type Spec struct {
namedTypes map[string][]namedType
funcInfos map[string]extInfo
lineInfos map[string]extInfo
coreRelos map[string]bpfCoreRelos
coreRelos map[string]coreRelos
byteOrder binary.ByteOrder
}
@@ -53,7 +53,7 @@ type btfHeader struct {
// LoadSpecFromReader reads BTF sections from an ELF.
//
// Returns a nil Spec and no error if no BTF was present.
// Returns ErrNotFound if the reader contains no BTF.
func LoadSpecFromReader(rd io.ReaderAt) (*Spec, error) {
file, err := internal.NewSafeELFFile(rd)
if err != nil {
@@ -67,7 +67,7 @@ func LoadSpecFromReader(rd io.ReaderAt) (*Spec, error) {
}
if btfSection == nil {
return nil, nil
return nil, fmt.Errorf("btf: %w", ErrNotFound)
}
symbols, err := file.Symbols()
@@ -438,13 +438,13 @@ func (s *Spec) Program(name string, length uint64) (*Program, error) {
funcInfos, funcOK := s.funcInfos[name]
lineInfos, lineOK := s.lineInfos[name]
coreRelos, coreOK := s.coreRelos[name]
relos, coreOK := s.coreRelos[name]
if !funcOK && !lineOK && !coreOK {
return nil, fmt.Errorf("no extended BTF info for section %s", name)
}
return &Program{s, length, funcInfos, lineInfos, coreRelos}, nil
return &Program{s, length, funcInfos, lineInfos, relos}, nil
}
// Datasec returns the BTF required to create maps which represent data sections.
@@ -491,7 +491,8 @@ func (s *Spec) FindType(name string, typ Type) error {
return fmt.Errorf("type %s: %w", name, ErrNotFound)
}
value := reflect.Indirect(reflect.ValueOf(copyType(candidate)))
cpy, _ := copyType(candidate, nil)
value := reflect.Indirect(reflect.ValueOf(cpy))
reflect.Indirect(reflect.ValueOf(typ)).Set(value)
return nil
}
@@ -606,7 +607,7 @@ type Program struct {
spec *Spec
length uint64
funcInfos, lineInfos extInfo
coreRelos bpfCoreRelos
coreRelos coreRelos
}
// ProgramSpec returns the Spec needed for loading function and line infos into the kernel.
@@ -665,16 +666,23 @@ func ProgramLineInfos(s *Program) (recordSize uint32, bytes []byte, err error) {
return s.lineInfos.recordSize, bytes, nil
}
// ProgramRelocations returns the CO-RE relocations required to adjust the
// program to the target.
// ProgramFixups returns the changes required to adjust the program to the target.
//
// This is a free function instead of a method to hide it from users
// of package ebpf.
func ProgramRelocations(s *Program, target *Spec) (map[uint64]Relocation, error) {
func ProgramFixups(s *Program, target *Spec) (COREFixups, error) {
if len(s.coreRelos) == 0 {
return nil, nil
}
if target == nil {
var err error
target, err = LoadKernelSpec()
if err != nil {
return nil, err
}
}
return coreRelocate(s.spec, target, s.coreRelos)
}

795
vendor/github.com/cilium/ebpf/internal/btf/core.go generated vendored
View File

@@ -3,43 +3,160 @@ package btf
import (
"errors"
"fmt"
"math"
"reflect"
"sort"
"strconv"
"strings"
"github.com/cilium/ebpf/asm"
)
// Code in this file is derived from libbpf, which is available under a BSD
// 2-Clause license.
// Relocation describes a CO-RE relocation.
type Relocation struct {
Current uint32
New uint32
// COREFixup is the result of computing a CO-RE relocation for a target.
type COREFixup struct {
Kind COREKind
Local uint32
Target uint32
Poison bool
}
func (r Relocation) equal(other Relocation) bool {
return r.Current == other.Current && r.New == other.New
func (f COREFixup) equal(other COREFixup) bool {
return f.Local == other.Local && f.Target == other.Target
}
// coreReloKind is the type of CO-RE relocation
type coreReloKind uint32
func (f COREFixup) String() string {
if f.Poison {
return fmt.Sprintf("%s=poison", f.Kind)
}
return fmt.Sprintf("%s=%d->%d", f.Kind, f.Local, f.Target)
}
func (f COREFixup) apply(ins *asm.Instruction) error {
if f.Poison {
return errors.New("can't poison individual instruction")
}
switch class := ins.OpCode.Class(); class {
case asm.LdXClass, asm.StClass, asm.StXClass:
if want := int16(f.Local); want != ins.Offset {
return fmt.Errorf("invalid offset %d, expected %d", ins.Offset, want)
}
if f.Target > math.MaxInt16 {
return fmt.Errorf("offset %d exceeds MaxInt16", f.Target)
}
ins.Offset = int16(f.Target)
case asm.LdClass:
if !ins.IsConstantLoad(asm.DWord) {
return fmt.Errorf("not a dword-sized immediate load")
}
if want := int64(f.Local); want != ins.Constant {
return fmt.Errorf("invalid immediate %d, expected %d", ins.Constant, want)
}
ins.Constant = int64(f.Target)
case asm.ALUClass:
if ins.OpCode.ALUOp() == asm.Swap {
return fmt.Errorf("relocation against swap")
}
fallthrough
case asm.ALU64Class:
if src := ins.OpCode.Source(); src != asm.ImmSource {
return fmt.Errorf("invalid source %s", src)
}
if want := int64(f.Local); want != ins.Constant {
return fmt.Errorf("invalid immediate %d, expected %d", ins.Constant, want)
}
if f.Target > math.MaxInt32 {
return fmt.Errorf("immediate %d exceeds MaxInt32", f.Target)
}
ins.Constant = int64(f.Target)
default:
return fmt.Errorf("invalid class %s", class)
}
return nil
}
func (f COREFixup) isNonExistant() bool {
return f.Kind.checksForExistence() && f.Target == 0
}
type COREFixups map[uint64]COREFixup
// Apply a set of CO-RE relocations to a BPF program.
func (fs COREFixups) Apply(insns asm.Instructions) (asm.Instructions, error) {
if len(fs) == 0 {
cpy := make(asm.Instructions, len(insns))
copy(cpy, insns)
return insns, nil
}
cpy := make(asm.Instructions, 0, len(insns))
iter := insns.Iterate()
for iter.Next() {
fixup, ok := fs[iter.Offset.Bytes()]
if !ok {
cpy = append(cpy, *iter.Ins)
continue
}
ins := *iter.Ins
if fixup.Poison {
const badRelo = asm.BuiltinFunc(0xbad2310)
cpy = append(cpy, badRelo.Call())
if ins.OpCode.IsDWordLoad() {
// 64 bit constant loads occupy two raw bpf instructions, so
// we need to add another instruction as padding.
cpy = append(cpy, badRelo.Call())
}
continue
}
if err := fixup.apply(&ins); err != nil {
return nil, fmt.Errorf("instruction %d, offset %d: %s: %w", iter.Index, iter.Offset.Bytes(), fixup.Kind, err)
}
cpy = append(cpy, ins)
}
return cpy, nil
}
// COREKind is the type of CO-RE relocation
type COREKind uint32
const (
reloFieldByteOffset coreReloKind = iota /* field byte offset */
reloFieldByteSize /* field size in bytes */
reloFieldExists /* field existence in target kernel */
reloFieldSigned /* field signedness (0 - unsigned, 1 - signed) */
reloFieldLShiftU64 /* bitfield-specific left bitshift */
reloFieldRShiftU64 /* bitfield-specific right bitshift */
reloTypeIDLocal /* type ID in local BPF object */
reloTypeIDTarget /* type ID in target kernel */
reloTypeExists /* type existence in target kernel */
reloTypeSize /* type size in bytes */
reloEnumvalExists /* enum value existence in target kernel */
reloEnumvalValue /* enum value integer value */
reloFieldByteOffset COREKind = iota /* field byte offset */
reloFieldByteSize /* field size in bytes */
reloFieldExists /* field existence in target kernel */
reloFieldSigned /* field signedness (0 - unsigned, 1 - signed) */
reloFieldLShiftU64 /* bitfield-specific left bitshift */
reloFieldRShiftU64 /* bitfield-specific right bitshift */
reloTypeIDLocal /* type ID in local BPF object */
reloTypeIDTarget /* type ID in target kernel */
reloTypeExists /* type existence in target kernel */
reloTypeSize /* type size in bytes */
reloEnumvalExists /* enum value existence in target kernel */
reloEnumvalValue /* enum value integer value */
)
func (k coreReloKind) String() string {
func (k COREKind) String() string {
switch k {
case reloFieldByteOffset:
return "byte_off"
@@ -70,103 +187,249 @@ func (k coreReloKind) String() string {
}
}
func coreRelocate(local, target *Spec, coreRelos bpfCoreRelos) (map[uint64]Relocation, error) {
if target == nil {
var err error
target, err = loadKernelSpec()
if err != nil {
return nil, err
}
}
func (k COREKind) checksForExistence() bool {
return k == reloEnumvalExists || k == reloTypeExists || k == reloFieldExists
}
func coreRelocate(local, target *Spec, relos coreRelos) (COREFixups, error) {
if local.byteOrder != target.byteOrder {
return nil, fmt.Errorf("can't relocate %s against %s", local.byteOrder, target.byteOrder)
}
relocations := make(map[uint64]Relocation, len(coreRelos))
for _, relo := range coreRelos {
accessorStr, err := local.strings.Lookup(relo.AccessStrOff)
if err != nil {
return nil, err
}
var ids []TypeID
relosByID := make(map[TypeID]coreRelos)
result := make(COREFixups, len(relos))
for _, relo := range relos {
if relo.kind == reloTypeIDLocal {
// Filtering out reloTypeIDLocal here makes our lives a lot easier
// down the line, since it doesn't have a target at all.
if len(relo.accessor) > 1 || relo.accessor[0] != 0 {
return nil, fmt.Errorf("%s: unexpected accessor %v", relo.kind, relo.accessor)
}
accessor, err := parseCoreAccessor(accessorStr)
if err != nil {
return nil, fmt.Errorf("accessor %q: %s", accessorStr, err)
}
if int(relo.TypeID) >= len(local.types) {
return nil, fmt.Errorf("invalid type id %d", relo.TypeID)
}
typ := local.types[relo.TypeID]
if relo.ReloKind == reloTypeIDLocal {
relocations[uint64(relo.InsnOff)] = Relocation{
uint32(typ.ID()),
uint32(typ.ID()),
result[uint64(relo.insnOff)] = COREFixup{
relo.kind,
uint32(relo.typeID),
uint32(relo.typeID),
false,
}
continue
}
named, ok := typ.(namedType)
if !ok || named.name() == "" {
return nil, fmt.Errorf("relocate anonymous type %s: %w", typ.String(), ErrNotSupported)
relos, ok := relosByID[relo.typeID]
if !ok {
ids = append(ids, relo.typeID)
}
name := essentialName(named.name())
res, err := coreCalculateRelocation(typ, target.namedTypes[name], relo.ReloKind, accessor)
if err != nil {
return nil, fmt.Errorf("relocate %s: %w", name, err)
}
relocations[uint64(relo.InsnOff)] = res
relosByID[relo.typeID] = append(relos, relo)
}
return relocations, nil
// Ensure we work on relocations in a deterministic order.
sort.Slice(ids, func(i, j int) bool {
return ids[i] < ids[j]
})
for _, id := range ids {
if int(id) >= len(local.types) {
return nil, fmt.Errorf("invalid type id %d", id)
}
localType := local.types[id]
named, ok := localType.(namedType)
if !ok || named.name() == "" {
return nil, fmt.Errorf("relocate unnamed or anonymous type %s: %w", localType, ErrNotSupported)
}
relos := relosByID[id]
targets := target.namedTypes[named.essentialName()]
fixups, err := coreCalculateFixups(localType, targets, relos)
if err != nil {
return nil, fmt.Errorf("relocate %s: %w", localType, err)
}
for i, relo := range relos {
result[uint64(relo.insnOff)] = fixups[i]
}
}
return result, nil
}
var errAmbiguousRelocation = errors.New("ambiguous relocation")
var errImpossibleRelocation = errors.New("impossible relocation")
// coreCalculateFixups calculates the fixups for the given relocations using
// the "best" target.
//
// The best target is determined by scoring: the less poisoning we have to do
// the better the target is.
func coreCalculateFixups(local Type, targets []namedType, relos coreRelos) ([]COREFixup, error) {
localID := local.ID()
local, err := copyType(local, skipQualifierAndTypedef)
if err != nil {
return nil, err
}
bestScore := len(relos)
var bestFixups []COREFixup
for i := range targets {
targetID := targets[i].ID()
target, err := copyType(targets[i], skipQualifierAndTypedef)
if err != nil {
return nil, err
}
score := 0 // lower is better
fixups := make([]COREFixup, 0, len(relos))
for _, relo := range relos {
fixup, err := coreCalculateFixup(local, localID, target, targetID, relo)
if err != nil {
return nil, fmt.Errorf("target %s: %w", target, err)
}
if fixup.Poison || fixup.isNonExistant() {
score++
}
fixups = append(fixups, fixup)
}
if score > bestScore {
// We have a better target already, ignore this one.
continue
}
if score < bestScore {
// This is the best target yet, use it.
bestScore = score
bestFixups = fixups
continue
}
// Some other target has the same score as the current one. Make sure
// the fixups agree with each other.
for i, fixup := range bestFixups {
if !fixup.equal(fixups[i]) {
return nil, fmt.Errorf("%s: multiple types match: %w", fixup.Kind, errAmbiguousRelocation)
}
}
}
if bestFixups == nil {
// Nothing at all matched, probably because there are no suitable
// targets at all. Poison everything!
bestFixups = make([]COREFixup, len(relos))
for i, relo := range relos {
bestFixups[i] = COREFixup{Kind: relo.kind, Poison: true}
}
}
return bestFixups, nil
}
// coreCalculateFixup calculates the fixup for a single local type, target type
// and relocation.
func coreCalculateFixup(local Type, localID TypeID, target Type, targetID TypeID, relo coreRelo) (COREFixup, error) {
fixup := func(local, target uint32) (COREFixup, error) {
return COREFixup{relo.kind, local, target, false}, nil
}
poison := func() (COREFixup, error) {
if relo.kind.checksForExistence() {
return fixup(1, 0)
}
return COREFixup{relo.kind, 0, 0, true}, nil
}
zero := COREFixup{}
switch relo.kind {
case reloTypeIDTarget, reloTypeSize, reloTypeExists:
if len(relo.accessor) > 1 || relo.accessor[0] != 0 {
return zero, fmt.Errorf("%s: unexpected accessor %v", relo.kind, relo.accessor)
}
err := coreAreTypesCompatible(local, target)
if errors.Is(err, errImpossibleRelocation) {
return poison()
}
if err != nil {
return zero, fmt.Errorf("relocation %s: %w", relo.kind, err)
}
switch relo.kind {
case reloTypeExists:
return fixup(1, 1)
func coreCalculateRelocation(local Type, targets []namedType, kind coreReloKind, localAccessor coreAccessor) (Relocation, error) {
var relos []Relocation
var matches []Type
for _, target := range targets {
switch kind {
case reloTypeIDTarget:
if localAccessor[0] != 0 {
return Relocation{}, fmt.Errorf("%s: unexpected non-zero accessor", kind)
return fixup(uint32(localID), uint32(targetID))
case reloTypeSize:
localSize, err := Sizeof(local)
if err != nil {
return zero, err
}
if compat, err := coreAreTypesCompatible(local, target); err != nil {
return Relocation{}, fmt.Errorf("%s: %s", kind, err)
} else if !compat {
continue
targetSize, err := Sizeof(target)
if err != nil {
return zero, err
}
relos = append(relos, Relocation{uint32(target.ID()), uint32(target.ID())})
default:
return Relocation{}, fmt.Errorf("relocation %s: %w", kind, ErrNotSupported)
return fixup(uint32(localSize), uint32(targetSize))
}
matches = append(matches, target)
}
if len(relos) == 0 {
// TODO: Add switch for existence checks like reloEnumvalExists here.
case reloEnumvalValue, reloEnumvalExists:
localValue, targetValue, err := coreFindEnumValue(local, relo.accessor, target)
if errors.Is(err, errImpossibleRelocation) {
return poison()
}
if err != nil {
return zero, fmt.Errorf("relocation %s: %w", relo.kind, err)
}
// TODO: This might have to be poisoned.
return Relocation{}, fmt.Errorf("no relocation found, tried %v", targets)
}
switch relo.kind {
case reloEnumvalExists:
return fixup(1, 1)
case reloEnumvalValue:
return fixup(uint32(localValue.Value), uint32(targetValue.Value))
}
case reloFieldByteOffset, reloFieldByteSize, reloFieldExists:
if _, ok := target.(*Fwd); ok {
// We can't relocate fields using a forward declaration, so
// skip it. If a non-forward declaration is present in the BTF
// we'll find it in one of the other iterations.
return poison()
}
localField, targetField, err := coreFindField(local, relo.accessor, target)
if errors.Is(err, errImpossibleRelocation) {
return poison()
}
if err != nil {
return zero, fmt.Errorf("target %s: %w", target, err)
}
switch relo.kind {
case reloFieldExists:
return fixup(1, 1)
case reloFieldByteOffset:
return fixup(localField.offset/8, targetField.offset/8)
case reloFieldByteSize:
localSize, err := Sizeof(localField.Type)
if err != nil {
return zero, err
}
targetSize, err := Sizeof(targetField.Type)
if err != nil {
return zero, err
}
return fixup(uint32(localSize), uint32(targetSize))
relo := relos[0]
for _, altRelo := range relos[1:] {
if !altRelo.equal(relo) {
return Relocation{}, fmt.Errorf("multiple types %v match: %w", matches, errAmbiguousRelocation)
}
}
return relo, nil
return zero, fmt.Errorf("relocation %s: %w", relo.kind, ErrNotSupported)
}
/* coreAccessor contains a path through a struct. It contains at least one index.
@@ -219,6 +482,240 @@ func parseCoreAccessor(accessor string) (coreAccessor, error) {
return result, nil
}
func (ca coreAccessor) String() string {
strs := make([]string, 0, len(ca))
for _, i := range ca {
strs = append(strs, strconv.Itoa(i))
}
return strings.Join(strs, ":")
}
func (ca coreAccessor) enumValue(t Type) (*EnumValue, error) {
e, ok := t.(*Enum)
if !ok {
return nil, fmt.Errorf("not an enum: %s", t)
}
if len(ca) > 1 {
return nil, fmt.Errorf("invalid accessor %s for enum", ca)
}
i := ca[0]
if i >= len(e.Values) {
return nil, fmt.Errorf("invalid index %d for %s", i, e)
}
return &e.Values[i], nil
}
type coreField struct {
Type Type
offset uint32
}
func adjustOffset(base uint32, t Type, n int) (uint32, error) {
size, err := Sizeof(t)
if err != nil {
return 0, err
}
return base + (uint32(n) * uint32(size) * 8), nil
}
// coreFindField descends into the local type using the accessor and tries to
// find an equivalent field in target at each step.
//
// Returns the field and the offset of the field from the start of
// target in bits.
func coreFindField(local Type, localAcc coreAccessor, target Type) (_, _ coreField, _ error) {
// The first index is used to offset a pointer of the base type like
// when accessing an array.
localOffset, err := adjustOffset(0, local, localAcc[0])
if err != nil {
return coreField{}, coreField{}, err
}
targetOffset, err := adjustOffset(0, target, localAcc[0])
if err != nil {
return coreField{}, coreField{}, err
}
if err := coreAreMembersCompatible(local, target); err != nil {
return coreField{}, coreField{}, fmt.Errorf("fields: %w", err)
}
var localMaybeFlex, targetMaybeFlex bool
for _, acc := range localAcc[1:] {
switch localType := local.(type) {
case composite:
// For composite types acc is used to find the field in the local type,
// and then we try to find a field in target with the same name.
localMembers := localType.members()
if acc >= len(localMembers) {
return coreField{}, coreField{}, fmt.Errorf("invalid accessor %d for %s", acc, local)
}
localMember := localMembers[acc]
if localMember.Name == "" {
_, ok := localMember.Type.(composite)
if !ok {
return coreField{}, coreField{}, fmt.Errorf("unnamed field with type %s: %s", localMember.Type, ErrNotSupported)
}
// This is an anonymous struct or union, ignore it.
local = localMember.Type
localOffset += localMember.Offset
localMaybeFlex = false
continue
}
targetType, ok := target.(composite)
if !ok {
return coreField{}, coreField{}, fmt.Errorf("target not composite: %w", errImpossibleRelocation)
}
targetMember, last, err := coreFindMember(targetType, localMember.Name)
if err != nil {
return coreField{}, coreField{}, err
}
if targetMember.BitfieldSize > 0 {
return coreField{}, coreField{}, fmt.Errorf("field %q is a bitfield: %w", targetMember.Name, ErrNotSupported)
}
local = localMember.Type
localMaybeFlex = acc == len(localMembers)-1
localOffset += localMember.Offset
target = targetMember.Type
targetMaybeFlex = last
targetOffset += targetMember.Offset
case *Array:
// For arrays, acc is the index in the target.
targetType, ok := target.(*Array)
if !ok {
return coreField{}, coreField{}, fmt.Errorf("target not array: %w", errImpossibleRelocation)
}
if localType.Nelems == 0 && !localMaybeFlex {
return coreField{}, coreField{}, fmt.Errorf("local type has invalid flexible array")
}
if targetType.Nelems == 0 && !targetMaybeFlex {
return coreField{}, coreField{}, fmt.Errorf("target type has invalid flexible array")
}
if localType.Nelems > 0 && acc >= int(localType.Nelems) {
return coreField{}, coreField{}, fmt.Errorf("invalid access of %s at index %d", localType, acc)
}
if targetType.Nelems > 0 && acc >= int(targetType.Nelems) {
return coreField{}, coreField{}, fmt.Errorf("out of bounds access of target: %w", errImpossibleRelocation)
}
local = localType.Type
localMaybeFlex = false
localOffset, err = adjustOffset(localOffset, local, acc)
if err != nil {
return coreField{}, coreField{}, err
}
target = targetType.Type
targetMaybeFlex = false
targetOffset, err = adjustOffset(targetOffset, target, acc)
if err != nil {
return coreField{}, coreField{}, err
}
default:
return coreField{}, coreField{}, fmt.Errorf("relocate field of %T: %w", localType, ErrNotSupported)
}
if err := coreAreMembersCompatible(local, target); err != nil {
return coreField{}, coreField{}, err
}
}
return coreField{local, localOffset}, coreField{target, targetOffset}, nil
}
// coreFindMember finds a member in a composite type while handling anonymous
// structs and unions.
func coreFindMember(typ composite, name Name) (Member, bool, error) {
if name == "" {
return Member{}, false, errors.New("can't search for anonymous member")
}
type offsetTarget struct {
composite
offset uint32
}
targets := []offsetTarget{{typ, 0}}
visited := make(map[composite]bool)
for i := 0; i < len(targets); i++ {
target := targets[i]
// Only visit targets once to prevent infinite recursion.
if visited[target] {
continue
}
if len(visited) >= maxTypeDepth {
// This check is different than libbpf, which restricts the entire
// path to BPF_CORE_SPEC_MAX_LEN items.
return Member{}, false, fmt.Errorf("type is nested too deep")
}
visited[target] = true
members := target.members()
for j, member := range members {
if member.Name == name {
// NB: This is safe because member is a copy.
member.Offset += target.offset
return member, j == len(members)-1, nil
}
// The names don't match, but this member could be an anonymous struct
// or union.
if member.Name != "" {
continue
}
comp, ok := member.Type.(composite)
if !ok {
return Member{}, false, fmt.Errorf("anonymous non-composite type %T not allowed", member.Type)
}
targets = append(targets, offsetTarget{comp, target.offset + member.Offset})
}
}
return Member{}, false, fmt.Errorf("no matching member: %w", errImpossibleRelocation)
}
// coreFindEnumValue follows localAcc to find the equivalent enum value in target.
func coreFindEnumValue(local Type, localAcc coreAccessor, target Type) (localValue, targetValue *EnumValue, _ error) {
localValue, err := localAcc.enumValue(local)
if err != nil {
return nil, nil, err
}
targetEnum, ok := target.(*Enum)
if !ok {
return nil, nil, errImpossibleRelocation
}
localName := localValue.Name.essentialName()
for i, targetValue := range targetEnum.Values {
if targetValue.Name.essentialName() != localName {
continue
}
return localValue, &targetEnum.Values[i], nil
}
return nil, nil, errImpossibleRelocation
}
/* The comment below is from bpf_core_types_are_compat in libbpf.c:
*
* Check local and target types for compatibility. This check is used for
@@ -239,8 +736,10 @@ func parseCoreAccessor(accessor string) (coreAccessor, error) {
* number of input args and compatible return and argument types.
* These rules are not set in stone and probably will be adjusted as we get
* more experience with using BPF CO-RE relocations.
*
* Returns errImpossibleRelocation if types are not compatible.
*/
func coreAreTypesCompatible(localType Type, targetType Type) (bool, error) {
func coreAreTypesCompatible(localType Type, targetType Type) error {
var (
localTs, targetTs typeDeque
l, t = &localType, &targetType
@@ -249,14 +748,14 @@ func coreAreTypesCompatible(localType Type, targetType Type) (bool, error) {
for ; l != nil && t != nil; l, t = localTs.shift(), targetTs.shift() {
if depth >= maxTypeDepth {
return false, errors.New("types are nested too deep")
return errors.New("types are nested too deep")
}
localType = skipQualifierAndTypedef(*l)
targetType = skipQualifierAndTypedef(*t)
localType = *l
targetType = *t
if reflect.TypeOf(localType) != reflect.TypeOf(targetType) {
return false, nil
return fmt.Errorf("type mismatch: %w", errImpossibleRelocation)
}
switch lv := (localType).(type) {
@@ -266,7 +765,7 @@ func coreAreTypesCompatible(localType Type, targetType Type) (bool, error) {
case *Int:
tv := targetType.(*Int)
if lv.isBitfield() || tv.isBitfield() {
return false, nil
return fmt.Errorf("bitfield: %w", errImpossibleRelocation)
}
case *Pointer, *Array:
@@ -277,7 +776,7 @@ func coreAreTypesCompatible(localType Type, targetType Type) (bool, error) {
case *FuncProto:
tv := targetType.(*FuncProto)
if len(lv.Params) != len(tv.Params) {
return false, nil
return fmt.Errorf("function param mismatch: %w", errImpossibleRelocation)
}
depth++
@@ -285,22 +784,24 @@ func coreAreTypesCompatible(localType Type, targetType Type) (bool, error) {
targetType.walk(&targetTs)
default:
return false, fmt.Errorf("unsupported type %T", localType)
return fmt.Errorf("unsupported type %T", localType)
}
}
if l != nil {
return false, fmt.Errorf("dangling local type %T", *l)
return fmt.Errorf("dangling local type %T", *l)
}
if t != nil {
return false, fmt.Errorf("dangling target type %T", *t)
return fmt.Errorf("dangling target type %T", *t)
}
return true, nil
return nil
}
/* The comment below is from bpf_core_fields_are_compat in libbpf.c:
/* coreAreMembersCompatible checks two types for field-based relocation compatibility.
*
* The comment below is from bpf_core_fields_are_compat in libbpf.c:
*
* Check two types for compatibility for the purpose of field access
* relocation. const/volatile/restrict and typedefs are skipped to ensure we
@@ -314,65 +815,63 @@ func coreAreTypesCompatible(localType Type, targetType Type) (bool, error) {
* - for INT, size and signedness are ignored;
* - for ARRAY, dimensionality is ignored, element types are checked for
* compatibility recursively;
* [ NB: coreAreMembersCompatible doesn't recurse, this check is done
* by coreFindField. ]
* - everything else shouldn't be ever a target of relocation.
* These rules are not set in stone and probably will be adjusted as we get
* more experience with using BPF CO-RE relocations.
*
* Returns errImpossibleRelocation if the members are not compatible.
*/
func coreAreMembersCompatible(localType Type, targetType Type) (bool, error) {
doNamesMatch := func(a, b string) bool {
func coreAreMembersCompatible(localType Type, targetType Type) error {
doNamesMatch := func(a, b string) error {
if a == "" || b == "" {
// allow anonymous and named type to match
return true
return nil
}
return essentialName(a) == essentialName(b)
if essentialName(a) == essentialName(b) {
return nil
}
return fmt.Errorf("names don't match: %w", errImpossibleRelocation)
}
for depth := 0; depth <= maxTypeDepth; depth++ {
localType = skipQualifierAndTypedef(localType)
targetType = skipQualifierAndTypedef(targetType)
_, lok := localType.(composite)
_, tok := targetType.(composite)
if lok && tok {
return true, nil
}
if reflect.TypeOf(localType) != reflect.TypeOf(targetType) {
return false, nil
}
switch lv := localType.(type) {
case *Pointer:
return true, nil
case *Enum:
tv := targetType.(*Enum)
return doNamesMatch(lv.name(), tv.name()), nil
case *Fwd:
tv := targetType.(*Fwd)
return doNamesMatch(lv.name(), tv.name()), nil
case *Int:
tv := targetType.(*Int)
return !lv.isBitfield() && !tv.isBitfield(), nil
case *Array:
tv := targetType.(*Array)
localType = lv.Type
targetType = tv.Type
default:
return false, fmt.Errorf("unsupported type %T", localType)
}
_, lok := localType.(composite)
_, tok := targetType.(composite)
if lok && tok {
return nil
}
return false, errors.New("types are nested too deep")
if reflect.TypeOf(localType) != reflect.TypeOf(targetType) {
return fmt.Errorf("type mismatch: %w", errImpossibleRelocation)
}
switch lv := localType.(type) {
case *Array, *Pointer:
return nil
case *Enum:
tv := targetType.(*Enum)
return doNamesMatch(lv.name(), tv.name())
case *Fwd:
tv := targetType.(*Fwd)
return doNamesMatch(lv.name(), tv.name())
case *Int:
tv := targetType.(*Int)
if lv.isBitfield() || tv.isBitfield() {
return fmt.Errorf("bitfield: %w", errImpossibleRelocation)
}
return nil
default:
return fmt.Errorf("type %s: %w", localType, ErrNotSupported)
}
}
func skipQualifierAndTypedef(typ Type) Type {
func skipQualifierAndTypedef(typ Type) (Type, error) {
result := typ
for depth := 0; depth <= maxTypeDepth; depth++ {
switch v := (result).(type) {
@@ -381,8 +880,8 @@ func skipQualifierAndTypedef(typ Type) Type {
case *Typedef:
result = v.Type
default:
return result
return result, nil
}
}
return typ
return nil, errors.New("exceeded type depth")
}

46
vendor/github.com/cilium/ebpf/internal/btf/ext_info.go generated vendored
View File

@@ -30,7 +30,7 @@ type btfExtCoreHeader struct {
CoreReloLen uint32
}
func parseExtInfos(r io.ReadSeeker, bo binary.ByteOrder, strings stringTable) (funcInfo, lineInfo map[string]extInfo, coreRelos map[string]bpfCoreRelos, err error) {
func parseExtInfos(r io.ReadSeeker, bo binary.ByteOrder, strings stringTable) (funcInfo, lineInfo map[string]extInfo, relos map[string]coreRelos, err error) {
var header btfExtHeader
var coreHeader btfExtCoreHeader
if err := binary.Read(r, bo, &header); err != nil {
@@ -94,13 +94,13 @@ func parseExtInfos(r io.ReadSeeker, bo binary.ByteOrder, strings stringTable) (f
return nil, nil, nil, fmt.Errorf("can't seek to CO-RE relocation section: %v", err)
}
coreRelos, err = parseExtInfoRelos(io.LimitReader(r, int64(coreHeader.CoreReloLen)), bo, strings)
relos, err = parseExtInfoRelos(io.LimitReader(r, int64(coreHeader.CoreReloLen)), bo, strings)
if err != nil {
return nil, nil, nil, fmt.Errorf("CO-RE relocation info: %w", err)
}
}
return funcInfo, lineInfo, coreRelos, nil
return funcInfo, lineInfo, relos, nil
}
type btfExtInfoSec struct {
@@ -208,18 +208,25 @@ type bpfCoreRelo struct {
InsnOff uint32
TypeID TypeID
AccessStrOff uint32
ReloKind coreReloKind
Kind COREKind
}
type bpfCoreRelos []bpfCoreRelo
type coreRelo struct {
insnOff uint32
typeID TypeID
accessor coreAccessor
kind COREKind
}
type coreRelos []coreRelo
// append two slices of extInfoRelo to each other. The InsnOff of b are adjusted
// by offset.
func (r bpfCoreRelos) append(other bpfCoreRelos, offset uint64) bpfCoreRelos {
result := make([]bpfCoreRelo, 0, len(r)+len(other))
func (r coreRelos) append(other coreRelos, offset uint64) coreRelos {
result := make([]coreRelo, 0, len(r)+len(other))
result = append(result, r...)
for _, relo := range other {
relo.InsnOff += uint32(offset)
relo.insnOff += uint32(offset)
result = append(result, relo)
}
return result
@@ -227,7 +234,7 @@ func (r bpfCoreRelos) append(other bpfCoreRelos, offset uint64) bpfCoreRelos {
var extInfoReloSize = binary.Size(bpfCoreRelo{})
func parseExtInfoRelos(r io.Reader, bo binary.ByteOrder, strings stringTable) (map[string]bpfCoreRelos, error) {
func parseExtInfoRelos(r io.Reader, bo binary.ByteOrder, strings stringTable) (map[string]coreRelos, error) {
var recordSize uint32
if err := binary.Read(r, bo, &recordSize); err != nil {
return nil, fmt.Errorf("read record size: %v", err)
@@ -237,14 +244,14 @@ func parseExtInfoRelos(r io.Reader, bo binary.ByteOrder, strings stringTable) (m
return nil, fmt.Errorf("expected record size %d, got %d", extInfoReloSize, recordSize)
}
result := make(map[string]bpfCoreRelos)
result := make(map[string]coreRelos)
for {
secName, infoHeader, err := parseExtInfoHeader(r, bo, strings)
if errors.Is(err, io.EOF) {
return result, nil
}
var relos []bpfCoreRelo
var relos coreRelos
for i := uint32(0); i < infoHeader.NumInfo; i++ {
var relo bpfCoreRelo
if err := binary.Read(r, bo, &relo); err != nil {
@@ -255,7 +262,22 @@ func parseExtInfoRelos(r io.Reader, bo binary.ByteOrder, strings stringTable) (m
return nil, fmt.Errorf("section %v: offset %v is not aligned with instruction size", secName, relo.InsnOff)
}
relos = append(relos, relo)
accessorStr, err := strings.Lookup(relo.AccessStrOff)
if err != nil {
return nil, err
}
accessor, err := parseCoreAccessor(accessorStr)
if err != nil {
return nil, fmt.Errorf("accessor %q: %s", accessorStr, err)
}
relos = append(relos, coreRelo{
relo.InsnOff,
relo.TypeID,
accessor,
relo.Kind,
})
}
result[secName] = relos

46
vendor/github.com/cilium/ebpf/internal/btf/types.go generated vendored
View File

@@ -1,7 +1,6 @@
package btf
import (
"errors"
"fmt"
"math"
"strings"
@@ -37,6 +36,7 @@ type Type interface {
type namedType interface {
Type
name() string
essentialName() string
}
// Name identifies a type.
@@ -48,6 +48,10 @@ func (n Name) name() string {
return string(n)
}
func (n Name) essentialName() string {
return essentialName(string(n))
}
// Void is the unit type of BTF.
type Void struct{}
@@ -174,8 +178,7 @@ func (s *Struct) walk(tdq *typeDeque) {
func (s *Struct) copy() Type {
cpy := *s
cpy.Members = make([]Member, len(s.Members))
copy(cpy.Members, s.Members)
cpy.Members = copyMembers(s.Members)
return &cpy
}
@@ -206,8 +209,7 @@ func (u *Union) walk(tdq *typeDeque) {
func (u *Union) copy() Type {
cpy := *u
cpy.Members = make([]Member, len(u.Members))
copy(cpy.Members, u.Members)
cpy.Members = copyMembers(u.Members)
return &cpy
}
@@ -215,6 +217,12 @@ func (u *Union) members() []Member {
return u.Members
}
func copyMembers(orig []Member) []Member {
cpy := make([]Member, len(orig))
copy(cpy, orig)
return cpy
}
type composite interface {
members() []Member
}
@@ -511,7 +519,7 @@ func Sizeof(typ Type) (int, error) {
switch v := typ.(type) {
case *Array:
if n > 0 && int64(v.Nelems) > math.MaxInt64/n {
return 0, errors.New("overflow")
return 0, fmt.Errorf("type %s: overflow", typ)
}
// Arrays may be of zero length, which allows
@@ -532,28 +540,30 @@ func Sizeof(typ Type) (int, error) {
continue
default:
return 0, fmt.Errorf("unrecognized type %T", typ)
return 0, fmt.Errorf("unsized type %T", typ)
}
if n > 0 && elem > math.MaxInt64/n {
return 0, errors.New("overflow")
return 0, fmt.Errorf("type %s: overflow", typ)
}
size := n * elem
if int64(int(size)) != size {
return 0, errors.New("overflow")
return 0, fmt.Errorf("type %s: overflow", typ)
}
return int(size), nil
}
return 0, errors.New("exceeded type depth")
return 0, fmt.Errorf("type %s: exceeded type depth", typ)
}
// copy a Type recursively.
//
// typ may form a cycle.
func copyType(typ Type) Type {
//
// Returns any errors from transform verbatim.
func copyType(typ Type, transform func(Type) (Type, error)) (Type, error) {
var (
copies = make(map[Type]Type)
work typeDeque
@@ -566,7 +576,17 @@ func copyType(typ Type) Type {
continue
}
cpy := (*t).copy()
var cpy Type
if transform != nil {
tf, err := transform(*t)
if err != nil {
return nil, fmt.Errorf("copy %s: %w", typ, err)
}
cpy = tf.copy()
} else {
cpy = (*t).copy()
}
copies[*t] = cpy
*t = cpy
@@ -574,7 +594,7 @@ func copyType(typ Type) Type {
cpy.walk(&work)
}
return typ
return typ, nil
}
// typeDeque keeps track of pointers to types which still