runsc/debug: add an option to list all processes

runsc debug --ps list all processes with all threads. This option is added to
the debug command but not to the ps command, because it is going to be used for
debug purposes and we want to add any useful information without thinking about
backward compatibility.

This will help to investigate syzkaller issues.

PiperOrigin-RevId: 285013668

1 files changed, 19 insertions, 15 deletions

diff --git a/pkg/sentry/control/proc.go b/pkg/sentry/control/proc.go
index a6f90b2bb..ced51c66c 100644
--- a/pkg/sentry/control/proc.go
+++ b/pkg/sentry/control/proc.go
@@ -272,7 +272,8 @@ type Process struct {
 	UID auth.KUID       `json:"uid"`
 	PID kernel.ThreadID `json:"pid"`
 	// Parent PID
-	PPID kernel.ThreadID `json:"ppid"`
+	PPID    kernel.ThreadID   `json:"ppid"`
+	Threads []kernel.ThreadID `json:"threads"`
 	// Processor utilization
 	C int32 `json:"c"`
 	// TTY name of the process. Will be of the form "pts/N" if there is a
@@ -310,7 +311,7 @@ func ProcessListToTable(pl []*Process) string {
 
 // ProcessListToJSON will return the JSON representation of ps.
 func ProcessListToJSON(pl []*Process) (string, error) {
-	b, err := json.Marshal(pl)
+	b, err := json.MarshalIndent(pl, "", "  ")
 	if err != nil {
 		return "", fmt.Errorf("couldn't marshal process list %v: %v", pl, err)
 	}
@@ -337,7 +338,9 @@ func Processes(k *kernel.Kernel, containerID string, out *[]*Process) error {
 	ts := k.TaskSet()
 	now := k.RealtimeClock().Now()
 	for _, tg := range ts.Root.ThreadGroups() {
-		pid := tg.PIDNamespace().IDOfThreadGroup(tg)
+		pidns := tg.PIDNamespace()
+		pid := pidns.IDOfThreadGroup(tg)
+
 		// If tg has already been reaped ignore it.
 		if pid == 0 {
 			continue
@@ -348,19 +351,20 @@ func Processes(k *kernel.Kernel, containerID string, out *[]*Process) error {
 
 		ppid := kernel.ThreadID(0)
 		if p := tg.Leader().Parent(); p != nil {
-			ppid = p.PIDNamespace().IDOfThreadGroup(p.ThreadGroup())
-		}
-		p := Process{
-			UID:   tg.Leader().Credentials().EffectiveKUID,
-			PID:   pid,
-			PPID:  ppid,
-			STime: formatStartTime(now, tg.Leader().StartTime()),
-			C:     percentCPU(tg.CPUStats(), tg.Leader().StartTime(), now),
-			Time:  tg.CPUStats().SysTime.String(),
-			Cmd:   tg.Leader().Name(),
-			TTY:   ttyName(tg.TTY()),
+			ppid = pidns.IDOfThreadGroup(p.ThreadGroup())
 		}
-		*out = append(*out, &p)
+		threads := tg.MemberIDs(pidns)
+		*out = append(*out, &Process{
+			UID:     tg.Leader().Credentials().EffectiveKUID,
+			PID:     pid,
+			PPID:    ppid,
+			Threads: threads,
+			STime:   formatStartTime(now, tg.Leader().StartTime()),
+			C:       percentCPU(tg.CPUStats(), tg.Leader().StartTime(), now),
+			Time:    tg.CPUStats().SysTime.String(),
+			Cmd:     tg.Leader().Name(),
+			TTY:     ttyName(tg.TTY()),
+		})
 	}
 	sort.Slice(*out, func(i, j int) bool { return (*out)[i].PID < (*out)[j].PID })
 	return nil