Upgrade containerd/cgroups to remove github.com/cilium/ebpf's fuzzer

The fuzzer is broken and it breaks OSS-Fuzz according to #7288.

Signed-off-by: Kazuyoshi Kato <katokazu@amazon.com>
This commit is contained in:
Kazuyoshi Kato
2022-08-16 23:13:58 +00:00
parent f0e1a27cbd
commit 470d3ee057
89 changed files with 9362 additions and 5207 deletions

View File

@@ -6,14 +6,15 @@ import (
"fmt"
"os"
"path/filepath"
"regexp"
"runtime"
"strconv"
"strings"
"unsafe"
"github.com/cilium/ebpf"
"github.com/cilium/ebpf/asm"
"github.com/cilium/ebpf/internal"
"github.com/cilium/ebpf/internal/sys"
"github.com/cilium/ebpf/internal/unix"
)
@@ -43,11 +44,6 @@ import (
var (
tracefsPath = "/sys/kernel/debug/tracing"
// Trace event groups, names and kernel symbols must adhere to this set
// of characters. Non-empty, first character must not be a number, all
// characters must be alphanumeric or underscore.
rgxTraceEvent = regexp.MustCompile("^[a-zA-Z_][0-9a-zA-Z_]*$")
errInvalidInput = errors.New("invalid input")
)
@@ -69,6 +65,8 @@ const (
// can be attached to it. It is created based on a tracefs trace event or a
// Performance Monitoring Unit (PMU).
type perfEvent struct {
// The event type determines the types of programs that can be attached.
typ perfEventType
// Group and name of the tracepoint/kprobe/uprobe.
group string
@@ -79,53 +77,15 @@ type perfEvent struct {
// ID of the trace event read from tracefs. Valid IDs are non-zero.
tracefsID uint64
// The event type determines the types of programs that can be attached.
typ perfEventType
// User provided arbitrary value.
cookie uint64
fd *internal.FD
}
func (pe *perfEvent) isLink() {}
func (pe *perfEvent) Pin(string) error {
return fmt.Errorf("pin perf event: %w", ErrNotSupported)
}
func (pe *perfEvent) Unpin() error {
return fmt.Errorf("unpin perf event: %w", ErrNotSupported)
}
// Since 4.15 (e87c6bc3852b "bpf: permit multiple bpf attachments for a single perf event"),
// calling PERF_EVENT_IOC_SET_BPF appends the given program to a prog_array
// owned by the perf event, which means multiple programs can be attached
// simultaneously.
//
// Before 4.15, calling PERF_EVENT_IOC_SET_BPF more than once on a perf event
// returns EEXIST.
//
// Detaching a program from a perf event is currently not possible, so a
// program replacement mechanism cannot be implemented for perf events.
func (pe *perfEvent) Update(prog *ebpf.Program) error {
return fmt.Errorf("can't replace eBPF program in perf event: %w", ErrNotSupported)
// This is the perf event FD.
fd *sys.FD
}
func (pe *perfEvent) Close() error {
if pe.fd == nil {
return nil
}
pfd, err := pe.fd.Value()
if err != nil {
return fmt.Errorf("getting perf event fd: %w", err)
}
err = unix.IoctlSetInt(int(pfd), unix.PERF_EVENT_IOC_DISABLE, 0)
if err != nil {
return fmt.Errorf("disabling perf event: %w", err)
}
err = pe.fd.Close()
if err != nil {
if err := pe.fd.Close(); err != nil {
return fmt.Errorf("closing perf event fd: %w", err)
}
@@ -148,49 +108,150 @@ func (pe *perfEvent) Close() error {
return nil
}
// perfEventLink represents a bpf perf link.
type perfEventLink struct {
RawLink
pe *perfEvent
}
func (pl *perfEventLink) isLink() {}
// Pinning requires the underlying perf event FD to stay open.
//
// | PerfEvent FD | BpfLink FD | Works |
// |--------------|------------|-------|
// | Open | Open | Yes |
// | Closed | Open | No |
// | Open | Closed | No (Pin() -> EINVAL) |
// | Closed | Closed | No (Pin() -> EINVAL) |
//
// There is currently no pretty way to recover the perf event FD
// when loading a pinned link, so leave as not supported for now.
func (pl *perfEventLink) Pin(string) error {
return fmt.Errorf("perf event link pin: %w", ErrNotSupported)
}
func (pl *perfEventLink) Unpin() error {
return fmt.Errorf("perf event link unpin: %w", ErrNotSupported)
}
func (pl *perfEventLink) Close() error {
if err := pl.pe.Close(); err != nil {
return fmt.Errorf("perf event link close: %w", err)
}
return pl.fd.Close()
}
func (pl *perfEventLink) Update(prog *ebpf.Program) error {
return fmt.Errorf("perf event link update: %w", ErrNotSupported)
}
// perfEventIoctl implements Link and handles the perf event lifecycle
// via ioctl().
type perfEventIoctl struct {
*perfEvent
}
func (pi *perfEventIoctl) isLink() {}
// Since 4.15 (e87c6bc3852b "bpf: permit multiple bpf attachments for a single perf event"),
// calling PERF_EVENT_IOC_SET_BPF appends the given program to a prog_array
// owned by the perf event, which means multiple programs can be attached
// simultaneously.
//
// Before 4.15, calling PERF_EVENT_IOC_SET_BPF more than once on a perf event
// returns EEXIST.
//
// Detaching a program from a perf event is currently not possible, so a
// program replacement mechanism cannot be implemented for perf events.
func (pi *perfEventIoctl) Update(prog *ebpf.Program) error {
return fmt.Errorf("perf event ioctl update: %w", ErrNotSupported)
}
func (pi *perfEventIoctl) Pin(string) error {
return fmt.Errorf("perf event ioctl pin: %w", ErrNotSupported)
}
func (pi *perfEventIoctl) Unpin() error {
return fmt.Errorf("perf event ioctl unpin: %w", ErrNotSupported)
}
func (pi *perfEventIoctl) Info() (*Info, error) {
return nil, fmt.Errorf("perf event ioctl info: %w", ErrNotSupported)
}
// attach the given eBPF prog to the perf event stored in pe.
// pe must contain a valid perf event fd.
// prog's type must match the program type stored in pe.
func (pe *perfEvent) attach(prog *ebpf.Program) error {
func attachPerfEvent(pe *perfEvent, prog *ebpf.Program) (Link, error) {
if prog == nil {
return errors.New("cannot attach a nil program")
}
if pe.fd == nil {
return errors.New("cannot attach to nil perf event")
return nil, errors.New("cannot attach a nil program")
}
if prog.FD() < 0 {
return fmt.Errorf("invalid program: %w", internal.ErrClosedFd)
return nil, fmt.Errorf("invalid program: %w", sys.ErrClosedFd)
}
switch pe.typ {
case kprobeEvent, kretprobeEvent, uprobeEvent, uretprobeEvent:
if t := prog.Type(); t != ebpf.Kprobe {
return fmt.Errorf("invalid program type (expected %s): %s", ebpf.Kprobe, t)
return nil, fmt.Errorf("invalid program type (expected %s): %s", ebpf.Kprobe, t)
}
case tracepointEvent:
if t := prog.Type(); t != ebpf.TracePoint {
return fmt.Errorf("invalid program type (expected %s): %s", ebpf.TracePoint, t)
return nil, fmt.Errorf("invalid program type (expected %s): %s", ebpf.TracePoint, t)
}
default:
return fmt.Errorf("unknown perf event type: %d", pe.typ)
return nil, fmt.Errorf("unknown perf event type: %d", pe.typ)
}
// The ioctl below will fail when the fd is invalid.
kfd, _ := pe.fd.Value()
if err := haveBPFLinkPerfEvent(); err == nil {
return attachPerfEventLink(pe, prog)
}
return attachPerfEventIoctl(pe, prog)
}
func attachPerfEventIoctl(pe *perfEvent, prog *ebpf.Program) (*perfEventIoctl, error) {
if pe.cookie != 0 {
return nil, fmt.Errorf("cookies are not supported: %w", ErrNotSupported)
}
// Assign the eBPF program to the perf event.
err := unix.IoctlSetInt(int(kfd), unix.PERF_EVENT_IOC_SET_BPF, prog.FD())
err := unix.IoctlSetInt(pe.fd.Int(), unix.PERF_EVENT_IOC_SET_BPF, prog.FD())
if err != nil {
return fmt.Errorf("setting perf event bpf program: %w", err)
return nil, fmt.Errorf("setting perf event bpf program: %w", err)
}
// PERF_EVENT_IOC_ENABLE and _DISABLE ignore their given values.
if err := unix.IoctlSetInt(int(kfd), unix.PERF_EVENT_IOC_ENABLE, 0); err != nil {
return fmt.Errorf("enable perf event: %s", err)
if err := unix.IoctlSetInt(pe.fd.Int(), unix.PERF_EVENT_IOC_ENABLE, 0); err != nil {
return nil, fmt.Errorf("enable perf event: %s", err)
}
pi := &perfEventIoctl{pe}
// Close the perf event when its reference is lost to avoid leaking system resources.
runtime.SetFinalizer(pe, (*perfEvent).Close)
return nil
runtime.SetFinalizer(pi, (*perfEventIoctl).Close)
return pi, nil
}
// Use the bpf api to attach the perf event (BPF_LINK_TYPE_PERF_EVENT, 5.15+).
//
// https://github.com/torvalds/linux/commit/b89fbfbb854c9afc3047e8273cc3a694650b802e
func attachPerfEventLink(pe *perfEvent, prog *ebpf.Program) (*perfEventLink, error) {
fd, err := sys.LinkCreatePerfEvent(&sys.LinkCreatePerfEventAttr{
ProgFd: uint32(prog.FD()),
TargetFd: pe.fd.Uint(),
AttachType: sys.BPF_PERF_EVENT,
BpfCookie: pe.cookie,
})
if err != nil {
return nil, fmt.Errorf("cannot create bpf perf link: %v", err)
}
pl := &perfEventLink{RawLink{fd: fd}, pe}
// Close the perf event when its reference is lost to avoid leaking system resources.
runtime.SetFinalizer(pl, (*perfEventLink).Close)
return pl, nil
}
// unsafeStringPtr returns an unsafe.Pointer to a NUL-terminated copy of str.
@@ -203,8 +264,12 @@ func unsafeStringPtr(str string) (unsafe.Pointer, error) {
}
// getTraceEventID reads a trace event's ID from tracefs given its group and name.
// group and name must be alphanumeric or underscore, as required by the kernel.
// The kernel requires group and name to be alphanumeric or underscore.
//
// name automatically has its invalid symbols converted to underscores so the caller
// can pass a raw symbol name, e.g. a kernel symbol containing dots.
func getTraceEventID(group, name string) (uint64, error) {
name = sanitizeSymbol(name)
tid, err := uint64FromFile(tracefsPath, "events", group, name, "id")
if errors.Is(err, os.ErrNotExist) {
return 0, fmt.Errorf("trace event %s/%s: %w", group, name, os.ErrNotExist)
@@ -235,7 +300,7 @@ func getPMUEventType(typ probeType) (uint64, error) {
// openTracepointPerfEvent opens a tracepoint-type perf event. System-wide
// [k,u]probes created by writing to <tracefs>/[k,u]probe_events are tracepoints
// behind the scenes, and can be attached to using these perf events.
func openTracepointPerfEvent(tid uint64, pid int) (*internal.FD, error) {
func openTracepointPerfEvent(tid uint64, pid int) (*sys.FD, error) {
attr := unix.PerfEventAttr{
Type: unix.PERF_TYPE_TRACEPOINT,
Config: tid,
@@ -249,7 +314,7 @@ func openTracepointPerfEvent(tid uint64, pid int) (*internal.FD, error) {
return nil, fmt.Errorf("opening tracepoint perf event: %w", err)
}
return internal.NewFD(uint32(fd)), nil
return sys.NewFD(fd)
}
// uint64FromFile reads a uint64 from a file. All elements of path are sanitized
@@ -270,3 +335,60 @@ func uint64FromFile(base string, path ...string) (uint64, error) {
et := bytes.TrimSpace(data)
return strconv.ParseUint(string(et), 10, 64)
}
// Probe BPF perf link.
//
// https://elixir.bootlin.com/linux/v5.16.8/source/kernel/bpf/syscall.c#L4307
// https://github.com/torvalds/linux/commit/b89fbfbb854c9afc3047e8273cc3a694650b802e
var haveBPFLinkPerfEvent = internal.FeatureTest("bpf_link_perf_event", "5.15", func() error {
prog, err := ebpf.NewProgram(&ebpf.ProgramSpec{
Name: "probe_bpf_perf_link",
Type: ebpf.Kprobe,
Instructions: asm.Instructions{
asm.Mov.Imm(asm.R0, 0),
asm.Return(),
},
License: "MIT",
})
if err != nil {
return err
}
defer prog.Close()
_, err = sys.LinkCreatePerfEvent(&sys.LinkCreatePerfEventAttr{
ProgFd: uint32(prog.FD()),
AttachType: sys.BPF_PERF_EVENT,
})
if errors.Is(err, unix.EINVAL) {
return internal.ErrNotSupported
}
if errors.Is(err, unix.EBADF) {
return nil
}
return err
})
// isValidTraceID implements the equivalent of a regex match
// against "^[a-zA-Z_][0-9a-zA-Z_]*$".
//
// Trace event groups, names and kernel symbols must adhere to this set
// of characters. Non-empty, first character must not be a number, all
// characters must be alphanumeric or underscore.
func isValidTraceID(s string) bool {
if len(s) < 1 {
return false
}
for i, c := range []byte(s) {
switch {
case c >= 'a' && c <= 'z':
case c >= 'A' && c <= 'Z':
case c == '_':
case i > 0 && c >= '0' && c <= '9':
default:
return false
}
}
return true
}