diff options
Diffstat (limited to 'vendor/github.com/cilium/ebpf/btf/btf.go')
| -rw-r--r-- | vendor/github.com/cilium/ebpf/btf/btf.go | 897 |
1 files changed, 0 insertions, 897 deletions
diff --git a/vendor/github.com/cilium/ebpf/btf/btf.go b/vendor/github.com/cilium/ebpf/btf/btf.go deleted file mode 100644 index a5969332a..000000000 --- a/vendor/github.com/cilium/ebpf/btf/btf.go +++ /dev/null @@ -1,897 +0,0 @@ -package btf - -import ( - "bufio" - "bytes" - "debug/elf" - "encoding/binary" - "errors" - "fmt" - "io" - "math" - "os" - "reflect" - - "github.com/cilium/ebpf/internal" - "github.com/cilium/ebpf/internal/sys" - "github.com/cilium/ebpf/internal/unix" -) - -const btfMagic = 0xeB9F - -// Errors returned by BTF functions. -var ( - ErrNotSupported = internal.ErrNotSupported - ErrNotFound = errors.New("not found") - ErrNoExtendedInfo = errors.New("no extended info") -) - -// ID represents the unique ID of a BTF object. -type ID = sys.BTFID - -// Spec represents decoded BTF. -type Spec struct { - // Data from .BTF. - rawTypes []rawType - strings *stringTable - - // All types contained by the spec. For the base type, the position of - // a type in the slice is its ID. - types types - - // Type IDs indexed by type. - typeIDs map[Type]TypeID - - // Types indexed by essential name. - // Includes all struct flavors and types with the same name. - namedTypes map[essentialName][]Type - - byteOrder binary.ByteOrder -} - -type btfHeader struct { - Magic uint16 - Version uint8 - Flags uint8 - HdrLen uint32 - - TypeOff uint32 - TypeLen uint32 - StringOff uint32 - StringLen uint32 -} - -// typeStart returns the offset from the beginning of the .BTF section -// to the start of its type entries. -func (h *btfHeader) typeStart() int64 { - return int64(h.HdrLen + h.TypeOff) -} - -// stringStart returns the offset from the beginning of the .BTF section -// to the start of its string table. -func (h *btfHeader) stringStart() int64 { - return int64(h.HdrLen + h.StringOff) -} - -// LoadSpec opens file and calls LoadSpecFromReader on it. -func LoadSpec(file string) (*Spec, error) { - fh, err := os.Open(file) - if err != nil { - return nil, err - } - defer fh.Close() - - return LoadSpecFromReader(fh) -} - -// LoadSpecFromReader reads from an ELF or a raw BTF blob. -// -// Returns ErrNotFound if reading from an ELF which contains no BTF. ExtInfos -// may be nil. -func LoadSpecFromReader(rd io.ReaderAt) (*Spec, error) { - file, err := internal.NewSafeELFFile(rd) - if err != nil { - if bo := guessRawBTFByteOrder(rd); bo != nil { - // Try to parse a naked BTF blob. This will return an error if - // we encounter a Datasec, since we can't fix it up. - spec, err := loadRawSpec(io.NewSectionReader(rd, 0, math.MaxInt64), bo, nil, nil) - return spec, err - } - - return nil, err - } - - return loadSpecFromELF(file) -} - -// LoadSpecAndExtInfosFromReader reads from an ELF. -// -// ExtInfos may be nil if the ELF doesn't contain section metadta. -// Returns ErrNotFound if the ELF contains no BTF. -func LoadSpecAndExtInfosFromReader(rd io.ReaderAt) (*Spec, *ExtInfos, error) { - file, err := internal.NewSafeELFFile(rd) - if err != nil { - return nil, nil, err - } - - spec, err := loadSpecFromELF(file) - if err != nil { - return nil, nil, err - } - - extInfos, err := loadExtInfosFromELF(file, spec.types, spec.strings) - if err != nil && !errors.Is(err, ErrNotFound) { - return nil, nil, err - } - - return spec, extInfos, nil -} - -// variableOffsets extracts all symbols offsets from an ELF and indexes them by -// section and variable name. -// -// References to variables in BTF data sections carry unsigned 32-bit offsets. -// Some ELF symbols (e.g. in vmlinux) may point to virtual memory that is well -// beyond this range. Since these symbols cannot be described by BTF info, -// ignore them here. -func variableOffsets(file *internal.SafeELFFile) (map[variable]uint32, error) { - symbols, err := file.Symbols() - if err != nil { - return nil, fmt.Errorf("can't read symbols: %v", err) - } - - variableOffsets := make(map[variable]uint32) - for _, symbol := range symbols { - if idx := symbol.Section; idx >= elf.SHN_LORESERVE && idx <= elf.SHN_HIRESERVE { - // Ignore things like SHN_ABS - continue - } - - if symbol.Value > math.MaxUint32 { - // VarSecinfo offset is u32, cannot reference symbols in higher regions. - continue - } - - if int(symbol.Section) >= len(file.Sections) { - return nil, fmt.Errorf("symbol %s: invalid section %d", symbol.Name, symbol.Section) - } - - secName := file.Sections[symbol.Section].Name - variableOffsets[variable{secName, symbol.Name}] = uint32(symbol.Value) - } - - return variableOffsets, nil -} - -func loadSpecFromELF(file *internal.SafeELFFile) (*Spec, error) { - var ( - btfSection *elf.Section - sectionSizes = make(map[string]uint32) - ) - - for _, sec := range file.Sections { - switch sec.Name { - case ".BTF": - btfSection = sec - default: - if sec.Type != elf.SHT_PROGBITS && sec.Type != elf.SHT_NOBITS { - break - } - - if sec.Size > math.MaxUint32 { - return nil, fmt.Errorf("section %s exceeds maximum size", sec.Name) - } - - sectionSizes[sec.Name] = uint32(sec.Size) - } - } - - if btfSection == nil { - return nil, fmt.Errorf("btf: %w", ErrNotFound) - } - - vars, err := variableOffsets(file) - if err != nil { - return nil, err - } - - if btfSection.ReaderAt == nil { - return nil, fmt.Errorf("compressed BTF is not supported") - } - - rawTypes, rawStrings, err := parseBTF(btfSection.ReaderAt, file.ByteOrder, nil) - if err != nil { - return nil, err - } - - err = fixupDatasec(rawTypes, rawStrings, sectionSizes, vars) - if err != nil { - return nil, err - } - - return inflateSpec(rawTypes, rawStrings, file.ByteOrder, nil) -} - -func loadRawSpec(btf io.ReaderAt, bo binary.ByteOrder, - baseTypes types, baseStrings *stringTable) (*Spec, error) { - - rawTypes, rawStrings, err := parseBTF(btf, bo, baseStrings) - if err != nil { - return nil, err - } - - return inflateSpec(rawTypes, rawStrings, bo, baseTypes) -} - -func inflateSpec(rawTypes []rawType, rawStrings *stringTable, bo binary.ByteOrder, - baseTypes types) (*Spec, error) { - - types, err := inflateRawTypes(rawTypes, baseTypes, rawStrings) - if err != nil { - return nil, err - } - - typeIDs, typesByName := indexTypes(types, TypeID(len(baseTypes))) - - return &Spec{ - rawTypes: rawTypes, - namedTypes: typesByName, - typeIDs: typeIDs, - types: types, - strings: rawStrings, - byteOrder: bo, - }, nil -} - -func indexTypes(types []Type, typeIDOffset TypeID) (map[Type]TypeID, map[essentialName][]Type) { - namedTypes := 0 - for _, typ := range types { - if typ.TypeName() != "" { - // Do a pre-pass to figure out how big types by name has to be. - // Most types have unique names, so it's OK to ignore essentialName - // here. - namedTypes++ - } - } - - typeIDs := make(map[Type]TypeID, len(types)) - typesByName := make(map[essentialName][]Type, namedTypes) - - for i, typ := range types { - if name := newEssentialName(typ.TypeName()); name != "" { - typesByName[name] = append(typesByName[name], typ) - } - typeIDs[typ] = TypeID(i) + typeIDOffset - } - - return typeIDs, typesByName -} - -// LoadKernelSpec returns the current kernel's BTF information. -// -// Defaults to /sys/kernel/btf/vmlinux and falls back to scanning the file system -// for vmlinux ELFs. Returns an error wrapping ErrNotSupported if BTF is not enabled. -func LoadKernelSpec() (*Spec, error) { - fh, err := os.Open("/sys/kernel/btf/vmlinux") - if err == nil { - defer fh.Close() - - return loadRawSpec(fh, internal.NativeEndian, nil, nil) - } - - file, err := findVMLinux() - if err != nil { - return nil, err - } - defer file.Close() - - return loadSpecFromELF(file) -} - -// findVMLinux scans multiple well-known paths for vmlinux kernel images. -func findVMLinux() (*internal.SafeELFFile, error) { - release, err := internal.KernelRelease() - if err != nil { - return nil, err - } - - // use same list of locations as libbpf - // https://github.com/libbpf/libbpf/blob/9a3a42608dbe3731256a5682a125ac1e23bced8f/src/btf.c#L3114-L3122 - locations := []string{ - "/boot/vmlinux-%s", - "/lib/modules/%s/vmlinux-%[1]s", - "/lib/modules/%s/build/vmlinux", - "/usr/lib/modules/%s/kernel/vmlinux", - "/usr/lib/debug/boot/vmlinux-%s", - "/usr/lib/debug/boot/vmlinux-%s.debug", - "/usr/lib/debug/lib/modules/%s/vmlinux", - } - - for _, loc := range locations { - file, err := internal.OpenSafeELFFile(fmt.Sprintf(loc, release)) - if errors.Is(err, os.ErrNotExist) { - continue - } - return file, err - } - - return nil, fmt.Errorf("no BTF found for kernel version %s: %w", release, internal.ErrNotSupported) -} - -// parseBTFHeader parses the header of the .BTF section. -func parseBTFHeader(r io.Reader, bo binary.ByteOrder) (*btfHeader, error) { - var header btfHeader - if err := binary.Read(r, bo, &header); err != nil { - return nil, fmt.Errorf("can't read header: %v", err) - } - - if header.Magic != btfMagic { - return nil, fmt.Errorf("incorrect magic value %v", header.Magic) - } - - if header.Version != 1 { - return nil, fmt.Errorf("unexpected version %v", header.Version) - } - - if header.Flags != 0 { - return nil, fmt.Errorf("unsupported flags %v", header.Flags) - } - - remainder := int64(header.HdrLen) - int64(binary.Size(&header)) - if remainder < 0 { - return nil, errors.New("header length shorter than btfHeader size") - } - - if _, err := io.CopyN(internal.DiscardZeroes{}, r, remainder); err != nil { - return nil, fmt.Errorf("header padding: %v", err) - } - - return &header, nil -} - -func guessRawBTFByteOrder(r io.ReaderAt) binary.ByteOrder { - buf := new(bufio.Reader) - for _, bo := range []binary.ByteOrder{ - binary.LittleEndian, - binary.BigEndian, - } { - buf.Reset(io.NewSectionReader(r, 0, math.MaxInt64)) - if _, err := parseBTFHeader(buf, bo); err == nil { - return bo - } - } - - return nil -} - -// parseBTF reads a .BTF section into memory and parses it into a list of -// raw types and a string table. -func parseBTF(btf io.ReaderAt, bo binary.ByteOrder, baseStrings *stringTable) ([]rawType, *stringTable, error) { - buf := internal.NewBufferedSectionReader(btf, 0, math.MaxInt64) - header, err := parseBTFHeader(buf, bo) - if err != nil { - return nil, nil, fmt.Errorf("parsing .BTF header: %v", err) - } - - rawStrings, err := readStringTable(io.NewSectionReader(btf, header.stringStart(), int64(header.StringLen)), - baseStrings) - if err != nil { - return nil, nil, fmt.Errorf("can't read type names: %w", err) - } - - buf.Reset(io.NewSectionReader(btf, header.typeStart(), int64(header.TypeLen))) - rawTypes, err := readTypes(buf, bo, header.TypeLen) - if err != nil { - return nil, nil, fmt.Errorf("can't read types: %w", err) - } - - return rawTypes, rawStrings, nil -} - -type variable struct { - section string - name string -} - -func fixupDatasec(rawTypes []rawType, rawStrings *stringTable, sectionSizes map[string]uint32, variableOffsets map[variable]uint32) error { - for i, rawType := range rawTypes { - if rawType.Kind() != kindDatasec { - continue - } - - name, err := rawStrings.Lookup(rawType.NameOff) - if err != nil { - return err - } - - if name == ".kconfig" || name == ".ksyms" { - return fmt.Errorf("reference to %s: %w", name, ErrNotSupported) - } - - if rawTypes[i].SizeType != 0 { - continue - } - - size, ok := sectionSizes[name] - if !ok { - return fmt.Errorf("data section %s: missing size", name) - } - - rawTypes[i].SizeType = size - - secinfos := rawType.data.([]btfVarSecinfo) - for j, secInfo := range secinfos { - id := int(secInfo.Type - 1) - if id >= len(rawTypes) { - return fmt.Errorf("data section %s: invalid type id %d for variable %d", name, id, j) - } - - varName, err := rawStrings.Lookup(rawTypes[id].NameOff) - if err != nil { - return fmt.Errorf("data section %s: can't get name for type %d: %w", name, id, err) - } - - offset, ok := variableOffsets[variable{name, varName}] - if !ok { - return fmt.Errorf("data section %s: missing offset for variable %s", name, varName) - } - - secinfos[j].Offset = offset - } - } - - return nil -} - -// Copy creates a copy of Spec. -func (s *Spec) Copy() *Spec { - types := copyTypes(s.types, nil) - - typeIDOffset := TypeID(0) - if len(s.types) != 0 { - typeIDOffset = s.typeIDs[s.types[0]] - } - typeIDs, typesByName := indexTypes(types, typeIDOffset) - - // NB: Other parts of spec are not copied since they are immutable. - return &Spec{ - s.rawTypes, - s.strings, - types, - typeIDs, - typesByName, - s.byteOrder, - } -} - -type marshalOpts struct { - ByteOrder binary.ByteOrder - StripFuncLinkage bool -} - -func (s *Spec) marshal(opts marshalOpts) ([]byte, error) { - var ( - buf bytes.Buffer - header = new(btfHeader) - headerLen = binary.Size(header) - ) - - // Reserve space for the header. We have to write it last since - // we don't know the size of the type section yet. - _, _ = buf.Write(make([]byte, headerLen)) - - // Write type section, just after the header. - for _, raw := range s.rawTypes { - switch { - case opts.StripFuncLinkage && raw.Kind() == kindFunc: - raw.SetLinkage(StaticFunc) - } - - if err := raw.Marshal(&buf, opts.ByteOrder); err != nil { - return nil, fmt.Errorf("can't marshal BTF: %w", err) - } - } - - typeLen := uint32(buf.Len() - headerLen) - - // Write string section after type section. - stringsLen := s.strings.Length() - buf.Grow(stringsLen) - if err := s.strings.Marshal(&buf); err != nil { - return nil, err - } - - // Fill out the header, and write it out. - header = &btfHeader{ - Magic: btfMagic, - Version: 1, - Flags: 0, - HdrLen: uint32(headerLen), - TypeOff: 0, - TypeLen: typeLen, - StringOff: typeLen, - StringLen: uint32(stringsLen), - } - - raw := buf.Bytes() - err := binary.Write(sliceWriter(raw[:headerLen]), opts.ByteOrder, header) - if err != nil { - return nil, fmt.Errorf("can't write header: %v", err) - } - - return raw, nil -} - -type sliceWriter []byte - -func (sw sliceWriter) Write(p []byte) (int, error) { - if len(p) != len(sw) { - return 0, errors.New("size doesn't match") - } - - return copy(sw, p), nil -} - -// TypeByID returns the BTF Type with the given type ID. -// -// Returns an error wrapping ErrNotFound if a Type with the given ID -// does not exist in the Spec. -func (s *Spec) TypeByID(id TypeID) (Type, error) { - return s.types.ByID(id) -} - -// TypeID returns the ID for a given Type. -// -// Returns an error wrapping ErrNoFound if the type isn't part of the Spec. -func (s *Spec) TypeID(typ Type) (TypeID, error) { - if _, ok := typ.(*Void); ok { - // Equality is weird for void, since it is a zero sized type. - return 0, nil - } - - id, ok := s.typeIDs[typ] - if !ok { - return 0, fmt.Errorf("no ID for type %s: %w", typ, ErrNotFound) - } - - return id, nil -} - -// AnyTypesByName returns a list of BTF Types with the given name. -// -// If the BTF blob describes multiple compilation units like vmlinux, multiple -// Types with the same name and kind can exist, but might not describe the same -// data structure. -// -// Returns an error wrapping ErrNotFound if no matching Type exists in the Spec. -func (s *Spec) AnyTypesByName(name string) ([]Type, error) { - types := s.namedTypes[newEssentialName(name)] - if len(types) == 0 { - return nil, fmt.Errorf("type name %s: %w", name, ErrNotFound) - } - - // Return a copy to prevent changes to namedTypes. - result := make([]Type, 0, len(types)) - for _, t := range types { - // Match against the full name, not just the essential one - // in case the type being looked up is a struct flavor. - if t.TypeName() == name { - result = append(result, t) - } - } - return result, nil -} - -// AnyTypeByName returns a Type with the given name. -// -// Returns an error if multiple types of that name exist. -func (s *Spec) AnyTypeByName(name string) (Type, error) { - types, err := s.AnyTypesByName(name) - if err != nil { - return nil, err - } - - if len(types) > 1 { - return nil, fmt.Errorf("found multiple types: %v", types) - } - - return types[0], nil -} - -// TypeByName searches for a Type with a specific name. Since multiple -// Types with the same name can exist, the parameter typ is taken to -// narrow down the search in case of a clash. -// -// typ must be a non-nil pointer to an implementation of a Type. -// On success, the address of the found Type will be copied to typ. -// -// Returns an error wrapping ErrNotFound if no matching -// Type exists in the Spec. If multiple candidates are found, -// an error is returned. -func (s *Spec) TypeByName(name string, typ interface{}) error { - typValue := reflect.ValueOf(typ) - if typValue.Kind() != reflect.Ptr { - return fmt.Errorf("%T is not a pointer", typ) - } - - typPtr := typValue.Elem() - if !typPtr.CanSet() { - return fmt.Errorf("%T cannot be set", typ) - } - - wanted := typPtr.Type() - if !wanted.AssignableTo(reflect.TypeOf((*Type)(nil)).Elem()) { - return fmt.Errorf("%T does not satisfy Type interface", typ) - } - - types, err := s.AnyTypesByName(name) - if err != nil { - return err - } - - var candidate Type - for _, typ := range types { - if reflect.TypeOf(typ) != wanted { - continue - } - - if candidate != nil { - return fmt.Errorf("type %s: multiple candidates for %T", name, typ) - } - - candidate = typ - } - - if candidate == nil { - return fmt.Errorf("type %s: %w", name, ErrNotFound) - } - - typPtr.Set(reflect.ValueOf(candidate)) - - return nil -} - -// LoadSplitSpecFromReader loads split BTF from a reader. -// -// Types from base are used to resolve references in the split BTF. -// The returned Spec only contains types from the split BTF, not from the base. -func LoadSplitSpecFromReader(r io.ReaderAt, base *Spec) (*Spec, error) { - return loadRawSpec(r, internal.NativeEndian, base.types, base.strings) -} - -// TypesIterator iterates over types of a given spec. -type TypesIterator struct { - spec *Spec - index int - // The last visited type in the spec. - Type Type -} - -// Iterate returns the types iterator. -func (s *Spec) Iterate() *TypesIterator { - return &TypesIterator{spec: s, index: 0} -} - -// Next returns true as long as there are any remaining types. -func (iter *TypesIterator) Next() bool { - if len(iter.spec.types) <= iter.index { - return false - } - - iter.Type = iter.spec.types[iter.index] - iter.index++ - return true -} - -// Handle is a reference to BTF loaded into the kernel. -type Handle struct { - fd *sys.FD - - // Size of the raw BTF in bytes. - size uint32 -} - -// NewHandle loads BTF into the kernel. -// -// Returns ErrNotSupported if BTF is not supported. -func NewHandle(spec *Spec) (*Handle, error) { - if err := haveBTF(); err != nil { - return nil, err - } - - if spec.byteOrder != internal.NativeEndian { - return nil, fmt.Errorf("can't load %s BTF on %s", spec.byteOrder, internal.NativeEndian) - } - - btf, err := spec.marshal(marshalOpts{ - ByteOrder: internal.NativeEndian, - StripFuncLinkage: haveFuncLinkage() != nil, - }) - if err != nil { - return nil, fmt.Errorf("can't marshal BTF: %w", err) - } - - if uint64(len(btf)) > math.MaxUint32 { - return nil, errors.New("BTF exceeds the maximum size") - } - - attr := &sys.BtfLoadAttr{ - Btf: sys.NewSlicePointer(btf), - BtfSize: uint32(len(btf)), - } - - fd, err := sys.BtfLoad(attr) - if err != nil { - logBuf := make([]byte, 64*1024) - attr.BtfLogBuf = sys.NewSlicePointer(logBuf) - attr.BtfLogSize = uint32(len(logBuf)) - attr.BtfLogLevel = 1 - // NB: The syscall will never return ENOSPC as of 5.18-rc4. - _, _ = sys.BtfLoad(attr) - return nil, internal.ErrorWithLog(err, logBuf) - } - - return &Handle{fd, attr.BtfSize}, nil -} - -// NewHandleFromID returns the BTF handle for a given id. -// -// Prefer calling [ebpf.Program.Handle] or [ebpf.Map.Handle] if possible. -// -// Returns ErrNotExist, if there is no BTF with the given id. -// -// Requires CAP_SYS_ADMIN. -func NewHandleFromID(id ID) (*Handle, error) { - fd, err := sys.BtfGetFdById(&sys.BtfGetFdByIdAttr{ - Id: uint32(id), - }) - if err != nil { - return nil, fmt.Errorf("get FD for ID %d: %w", id, err) - } - - info, err := newHandleInfoFromFD(fd) - if err != nil { - _ = fd.Close() - return nil, err - } - - return &Handle{fd, info.size}, nil -} - -// Spec parses the kernel BTF into Go types. -// -// base is used to decode split BTF and may be nil. -func (h *Handle) Spec(base *Spec) (*Spec, error) { - var btfInfo sys.BtfInfo - btfBuffer := make([]byte, h.size) - btfInfo.Btf, btfInfo.BtfSize = sys.NewSlicePointerLen(btfBuffer) - - if err := sys.ObjInfo(h.fd, &btfInfo); err != nil { - return nil, err - } - - var baseTypes types - var baseStrings *stringTable - if base != nil { - baseTypes = base.types - baseStrings = base.strings - } - - return loadRawSpec(bytes.NewReader(btfBuffer), internal.NativeEndian, baseTypes, baseStrings) -} - -// Close destroys the handle. -// -// Subsequent calls to FD will return an invalid value. -func (h *Handle) Close() error { - if h == nil { - return nil - } - - return h.fd.Close() -} - -// FD returns the file descriptor for the handle. -func (h *Handle) FD() int { - return h.fd.Int() -} - -// Info returns metadata about the handle. -func (h *Handle) Info() (*HandleInfo, error) { - return newHandleInfoFromFD(h.fd) -} - -func marshalBTF(types interface{}, strings []byte, bo binary.ByteOrder) []byte { - const minHeaderLength = 24 - - typesLen := uint32(binary.Size(types)) - header := btfHeader{ - Magic: btfMagic, - Version: 1, - HdrLen: minHeaderLength, - TypeOff: 0, - TypeLen: typesLen, - StringOff: typesLen, - StringLen: uint32(len(strings)), - } - - buf := new(bytes.Buffer) - _ = binary.Write(buf, bo, &header) - _ = binary.Write(buf, bo, types) - buf.Write(strings) - - return buf.Bytes() -} - -var haveBTF = internal.FeatureTest("BTF", "5.1", func() error { - var ( - types struct { - Integer btfType - Var btfType - btfVar struct{ Linkage uint32 } - } - strings = []byte{0, 'a', 0} - ) - - // We use a BTF_KIND_VAR here, to make sure that - // the kernel understands BTF at least as well as we - // do. BTF_KIND_VAR was introduced ~5.1. - types.Integer.SetKind(kindPointer) - types.Var.NameOff = 1 - types.Var.SetKind(kindVar) - types.Var.SizeType = 1 - - btf := marshalBTF(&types, strings, internal.NativeEndian) - - fd, err := sys.BtfLoad(&sys.BtfLoadAttr{ - Btf: sys.NewSlicePointer(btf), - BtfSize: uint32(len(btf)), - }) - if errors.Is(err, unix.EINVAL) || errors.Is(err, unix.EPERM) { - // Treat both EINVAL and EPERM as not supported: loading the program - // might still succeed without BTF. - return internal.ErrNotSupported - } - if err != nil { - return err - } - - fd.Close() - return nil -}) - -var haveFuncLinkage = internal.FeatureTest("BTF func linkage", "5.6", func() error { - if err := haveBTF(); err != nil { - return err - } - - var ( - types struct { - FuncProto btfType - Func btfType - } - strings = []byte{0, 'a', 0} - ) - - types.FuncProto.SetKind(kindFuncProto) - types.Func.SetKind(kindFunc) - types.Func.SizeType = 1 // aka FuncProto - types.Func.NameOff = 1 - types.Func.SetLinkage(GlobalFunc) - - btf := marshalBTF(&types, strings, internal.NativeEndian) - - fd, err := sys.BtfLoad(&sys.BtfLoadAttr{ - Btf: sys.NewSlicePointer(btf), - BtfSize: uint32(len(btf)), - }) - if errors.Is(err, unix.EINVAL) { - return internal.ErrNotSupported - } - if err != nil { - return err - } - - fd.Close() - return nil -}) |