update github.com/opencontainers/runc to v1.2.0-rc.3

Signed-off-by: Paul Holzinger <pholzing@redhat.com>

vendor/github.com/opencontainers/runc/libcontainer/system/proc.go

@@ -0,0 +1,127 @@
+package system
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+	"strconv"
+	"strings"
+)
+
+// State is the status of a process.
+type State rune
+
+const ( // Only values for Linux 3.14 and later are listed here
+	Dead        State = 'X'
+	DiskSleep   State = 'D'
+	Running     State = 'R'
+	Sleeping    State = 'S'
+	Stopped     State = 'T'
+	TracingStop State = 't'
+	Zombie      State = 'Z'
+	Parked      State = 'P'
+	Idle        State = 'I'
+)
+
+// String forms of the state from proc(5)'s documentation for
+// /proc/[pid]/status' "State" field.
+func (s State) String() string {
+	switch s {
+	case Dead:
+		return "dead"
+	case DiskSleep:
+		return "disk sleep"
+	case Running:
+		return "running"
+	case Sleeping:
+		return "sleeping"
+	case Stopped:
+		return "stopped"
+	case TracingStop:
+		return "tracing stop"
+	case Zombie:
+		return "zombie"
+	case Parked:
+		return "parked"
+	case Idle:
+		return "idle" // kernel thread
+	default:
+		return fmt.Sprintf("unknown (%c)", s)
+	}
+}
+
+// Stat_t represents the information from /proc/[pid]/stat, as
+// described in proc(5) with names based on the /proc/[pid]/status
+// fields.
+type Stat_t struct {
+	// Name is the command run by the process.
+	Name string
+
+	// State is the state of the process.
+	State State
+
+	// StartTime is the number of clock ticks after system boot (since
+	// Linux 2.6).
+	StartTime uint64
+}
+
+// Stat returns a Stat_t instance for the specified process.
+func Stat(pid int) (stat Stat_t, err error) {
+	bytes, err := os.ReadFile(filepath.Join("/proc", strconv.Itoa(pid), "stat"))
+	if err != nil {
+		return stat, err
+	}
+	return parseStat(string(bytes))
+}
+
+func parseStat(data string) (stat Stat_t, err error) {
+	// Example:
+	// 89653 (gunicorn: maste) S 89630 89653 89653 0 -1 4194560 29689 28896 0 3 146 32 76 19 20 0 1 0 2971844 52965376 3920 18446744073709551615 1 1 0 0 0 0 0 16781312 137447943 0 0 0 17 1 0 0 0 0 0 0 0 0 0 0 0 0 0
+	// The fields are space-separated, see full description in proc(5).
+	//
+	// We are only interested in:
+	//  * field 2: process name. It is the only field enclosed into
+	//    parenthesis, as it can contain spaces (and parenthesis) inside.
+	//  * field 3: process state, a single character (%c)
+	//  * field 22: process start time, a long unsigned integer (%llu).
+
+	// 1. Look for the first '(' and the last ')' first, what's in between is Name.
+	//    We expect at least 20 fields and a space after the last one.
+
+	const minAfterName = 20*2 + 1 // the min field is '0 '.
+
+	first := strings.IndexByte(data, '(')
+	if first < 0 || first+minAfterName >= len(data) {
+		return stat, fmt.Errorf("invalid stat data (no comm or too short): %q", data)
+	}
+
+	last := strings.LastIndexByte(data, ')')
+	if last <= first || last+minAfterName >= len(data) {
+		return stat, fmt.Errorf("invalid stat data (no comm or too short): %q", data)
+	}
+
+	stat.Name = data[first+1 : last]
+
+	// 2. Remove fields 1 and 2 and a space after. State is right after.
+	data = data[last+2:]
+	stat.State = State(data[0])
+
+	// 3. StartTime is field 22, data is at field 3 now, so we need to skip 19 spaces.
+	skipSpaces := 22 - 3
+	for first = 0; skipSpaces > 0 && first < len(data); first++ {
+		if data[first] == ' ' {
+			skipSpaces--
+		}
+	}
+	// Now first points to StartTime; look for space right after.
+	i := strings.IndexByte(data[first:], ' ')
+	if i < 0 {
+		return stat, fmt.Errorf("invalid stat data (too short): %q", data)
+	}
+	stat.StartTime, err = strconv.ParseUint(data[first:first+i], 10, 64)
+	if err != nil {
+		return stat, fmt.Errorf("invalid stat data (bad start time): %w", err)
+	}
+
+	return stat, nil
+}