Revert "Merge pull request 101888 from kolyshkin/update-runc-rc94"

This reverts commit b1b06fe0a4, reversing
changes made to 382a33986b.

vendor/github.com/cilium/ebpf/internal/version.go

@@ -1,163 +0,0 @@
-package internal
-
-import (
-	"fmt"
-	"io/ioutil"
-	"regexp"
-	"sync"
-
-	"github.com/cilium/ebpf/internal/unix"
-)
-
-const (
-	// Version constant used in ELF binaries indicating that the loader needs to
-	// substitute the eBPF program's version with the value of the kernel's
-	// KERNEL_VERSION compile-time macro. Used for compatibility with BCC, gobpf
-	// and RedSift.
-	MagicKernelVersion = 0xFFFFFFFE
-)
-
-var (
-	// Match between one and three decimals separated by dots, with the last
-	// segment (patch level) being optional on some kernels.
-	// The x.y.z string must appear at the start of a string or right after
-	// whitespace to prevent sequences like 'x.y.z-a.b.c' from matching 'a.b.c'.
-	rgxKernelVersion = regexp.MustCompile(`(?:\A|\s)\d{1,3}\.\d{1,3}(?:\.\d{1,3})?`)
-
-	kernelVersion = struct {
-		once    sync.Once
-		version Version
-		err     error
-	}{}
-)
-
-// A Version in the form Major.Minor.Patch.
-type Version [3]uint16
-
-// NewVersion creates a version from a string like "Major.Minor.Patch".
-//
-// Patch is optional.
-func NewVersion(ver string) (Version, error) {
-	var major, minor, patch uint16
-	n, _ := fmt.Sscanf(ver, "%d.%d.%d", &major, &minor, &patch)
-	if n < 2 {
-		return Version{}, fmt.Errorf("invalid version: %s", ver)
-	}
-	return Version{major, minor, patch}, nil
-}
-
-func (v Version) String() string {
-	if v[2] == 0 {
-		return fmt.Sprintf("v%d.%d", v[0], v[1])
-	}
-	return fmt.Sprintf("v%d.%d.%d", v[0], v[1], v[2])
-}
-
-// Less returns true if the version is less than another version.
-func (v Version) Less(other Version) bool {
-	for i, a := range v {
-		if a == other[i] {
-			continue
-		}
-		return a < other[i]
-	}
-	return false
-}
-
-// Unspecified returns true if the version is all zero.
-func (v Version) Unspecified() bool {
-	return v[0] == 0 && v[1] == 0 && v[2] == 0
-}
-
-// Kernel implements the kernel's KERNEL_VERSION macro from linux/version.h.
-// It represents the kernel version and patch level as a single value.
-func (v Version) Kernel() uint32 {
-
-	// Kernels 4.4 and 4.9 have their SUBLEVEL clamped to 255 to avoid
-	// overflowing into PATCHLEVEL.
-	// See kernel commit 9b82f13e7ef3 ("kbuild: clamp SUBLEVEL to 255").
-	s := v[2]
-	if s > 255 {
-		s = 255
-	}
-
-	// Truncate members to uint8 to prevent them from spilling over into
-	// each other when overflowing 8 bits.
-	return uint32(uint8(v[0]))<<16 | uint32(uint8(v[1]))<<8 | uint32(uint8(s))
-}
-
-// KernelVersion returns the version of the currently running kernel.
-func KernelVersion() (Version, error) {
-	kernelVersion.once.Do(func() {
-		kernelVersion.version, kernelVersion.err = detectKernelVersion()
-	})
-
-	if kernelVersion.err != nil {
-		return Version{}, kernelVersion.err
-	}
-	return kernelVersion.version, nil
-}
-
-// detectKernelVersion returns the version of the running kernel. It scans the
-// following sources in order: /proc/version_signature, uname -v, uname -r.
-// In each of those locations, the last-appearing x.y(.z) value is selected
-// for parsing. The first location that yields a usable version number is
-// returned.
-func detectKernelVersion() (Version, error) {
-
-	// Try reading /proc/version_signature for Ubuntu compatibility.
-	// Example format: Ubuntu 4.15.0-91.92-generic 4.15.18
-	// This method exists in the kernel itself, see d18acd15c
-	// ("perf tools: Fix kernel version error in ubuntu").
-	if pvs, err := ioutil.ReadFile("/proc/version_signature"); err == nil {
-		// If /proc/version_signature exists, failing to parse it is an error.
-		// It only exists on Ubuntu, where the real patch level is not obtainable
-		// through any other method.
-		v, err := findKernelVersion(string(pvs))
-		if err != nil {
-			return Version{}, err
-		}
-		return v, nil
-	}
-
-	var uname unix.Utsname
-	if err := unix.Uname(&uname); err != nil {
-		return Version{}, fmt.Errorf("calling uname: %w", err)
-	}
-
-	// Debian puts the version including the patch level in uname.Version.
-	// It is not an error if there's no version number in uname.Version,
-	// as most distributions don't use it. Parsing can continue on uname.Release.
-	// Example format: #1 SMP Debian 4.19.37-5+deb10u2 (2019-08-08)
-	if v, err := findKernelVersion(unix.ByteSliceToString(uname.Version[:])); err == nil {
-		return v, nil
-	}
-
-	// Most other distributions have the full kernel version including patch
-	// level in uname.Release.
-	// Example format: 4.19.0-5-amd64, 5.5.10-arch1-1
-	v, err := findKernelVersion(unix.ByteSliceToString(uname.Release[:]))
-	if err != nil {
-		return Version{}, err
-	}
-
-	return v, nil
-}
-
-// findKernelVersion matches s against rgxKernelVersion and parses the result
-// into a Version. If s contains multiple matches, the last entry is selected.
-func findKernelVersion(s string) (Version, error) {
-	m := rgxKernelVersion.FindAllString(s, -1)
-	if m == nil {
-		return Version{}, fmt.Errorf("no kernel version in string: %s", s)
-	}
-	// Pick the last match of the string in case there are multiple.
-	s = m[len(m)-1]
-
-	v, err := NewVersion(s)
-	if err != nil {
-		return Version{}, fmt.Errorf("parsing version string %s: %w", s, err)
-	}
-
-	return v, nil
-}