From 34a94ce86b1bada9c0768f631540735d44f41100 Mon Sep 17 00:00:00 2001
From: Justus Winter <justus@gnupg.org>
Date: Thu, 9 Mar 2017 23:55:12 +0100
Subject: proc: Hierarchical proc servers.

Previously, a Subhurd's tasks were shown as weird processes in the
Motherhurd.  This change connects the proc server in the Motherhurd
with the proc server in the Subhurd, embedding the Subhurd's process
hierarchy.  Subhurd's processes can now be inspected and debugged like
any other process.

* NEWS: Update.
* boot/boot.c (mach_msg_forward): New function.
(boot_demuxer): Forward messages arriving on the new task notification
port from the proc server, and forward them to the proc server inside
the Subhurd via the notification port.
* proc/info.c (S_proc_task2proc): Relay request for processes in a task
namespace to the Subhurd's proc server.
(S_proc_pid2proc): Likewise.
(S_proc_getprocargs): Likewise.
(S_proc_getprocenv): Likewise.
(S_proc_getprocinfo): Likewise.  Translate PIDs.
(S_proc_getloginid): Likewise.
(S_proc_getloginpids): Likewise.
* proc/mgt.c (namespace_is_subprocess): New function.
(namespace_translate_pids): Likewise.
* proc/msg.c (S_proc_getmsgport): Relay request for processes in a task
namespace to the Subhurd's proc server.
* proc/pgrp.c (S_proc_getsid): Likewise.  Translate PIDs.
(S_proc_getsessionpids): Likewise.
(S_proc_getsessionpgids): Likewise.
(S_proc_getpgrppids): Likewise.
* proc/proc.h (namespace_is_subprocess): New prototype.
(namespace_translate_pids): Likewise.
---
 proc/pgrp.c | 100 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 100 insertions(+)

(limited to 'proc/pgrp.c')

diff --git a/proc/pgrp.c b/proc/pgrp.c
index d7c562fa..9db1dba6 100644
--- a/proc/pgrp.c
+++ b/proc/pgrp.c
@@ -147,6 +147,30 @@ S_proc_getsid (struct proc *callerp,
 
   /* No need to check CALLERP; we don't use it. */
 
+  if (namespace_is_subprocess (p))
+    {
+      /* Relay it to the Subhurd's proc server (if any).  */
+      error_t err;
+      pid_t pid_sub;
+
+      /* Release global lock while talking to the other proc server.  */
+      pthread_mutex_unlock (&global_lock);
+
+      err = proc_task2pid (p->p_task_namespace, p->p_task, &pid_sub);
+      if (! err)
+        err = proc_getsid (p->p_task_namespace, pid_sub, sid);
+      if (! err)
+	/* Acquires global_lock.  */
+	err = namespace_translate_pids (p->p_task_namespace, sid, 1);
+      else
+	pthread_mutex_lock (&global_lock);
+
+      if (! err)
+	return 0;
+
+      /* Fallback.  */
+    }
+
   *sid = p->p_pgrp->pg_session->s_sid;
   return 0;
 }
@@ -167,6 +191,31 @@ S_proc_getsessionpids (struct proc *callerp,
 
   /* No need to check CALLERP; we don't use it. */
 
+  p = pid_find (sid);
+  if (namespace_is_subprocess (p))
+    {
+      /* Relay it to the Subhurd's proc server (if any).  */
+      error_t err;
+      pid_t pid_sub;
+
+      /* Release global lock while talking to the other proc server.  */
+      pthread_mutex_unlock (&global_lock);
+
+      err = proc_task2pid (p->p_task_namespace, p->p_task, &pid_sub);
+      if (! err)
+        err = proc_getsessionpids (p->p_task_namespace, pid_sub, pids, npidsp);
+      if (! err)
+	/* Acquires global_lock.  */
+	err = namespace_translate_pids (p->p_task_namespace, *pids, *npidsp);
+      else
+	pthread_mutex_lock (&global_lock);
+
+      if (! err)
+	return 0;
+
+      /* Fallback.  */
+    }
+
   s = session_find (sid);
   if (!s)
     return ESRCH;
@@ -206,6 +255,7 @@ S_proc_getsessionpgids (struct proc *callerp,
 			size_t *npgidsp)
 {
   int count;
+  struct proc *p;
   struct pgrp *pg;
   struct session *s;
   pid_t *pp = *pgids;
@@ -213,6 +263,31 @@ S_proc_getsessionpgids (struct proc *callerp,
 
   /* No need to check CALLERP; we don't use it. */
 
+  p = pid_find (sid);
+  if (namespace_is_subprocess (p))
+    {
+      /* Relay it to the Subhurd's proc server (if any).  */
+      error_t err;
+      pid_t pid_sub;
+
+      /* Release global lock while talking to the other proc server.  */
+      pthread_mutex_unlock (&global_lock);
+
+      err = proc_task2pid (p->p_task_namespace, p->p_task, &pid_sub);
+      if (! err)
+        err = proc_getsessionpgids (p->p_task_namespace, pid_sub, pgids, npgidsp);
+      if (! err)
+	/* Acquires global_lock.  */
+	err = namespace_translate_pids (p->p_task_namespace, *pgids, *npgidsp);
+      else
+	pthread_mutex_lock (&global_lock);
+
+      if (! err)
+	return 0;
+
+      /* Fallback.  */
+    }
+
   s = session_find (sid);
   if (!s)
     return ESRCH;
@@ -254,6 +329,31 @@ S_proc_getpgrppids (struct proc *callerp,
 
   /* No need to check CALLERP; we don't use it. */
 
+  p = pid_find (pgid);
+  if (namespace_is_subprocess (p))
+    {
+      /* Relay it to the Subhurd's proc server (if any).  */
+      error_t err;
+      pid_t pid_sub;
+
+      /* Release global lock while talking to the other proc server.  */
+      pthread_mutex_unlock (&global_lock);
+
+      err = proc_task2pid (p->p_task_namespace, p->p_task, &pid_sub);
+      if (! err)
+        err = proc_getpgrppids (p->p_task_namespace, pid_sub, pids, npidsp);
+      if (! err)
+	/* Acquires global_lock.  */
+	err = namespace_translate_pids (p->p_task_namespace, *pids, *npidsp);
+      else
+	pthread_mutex_lock (&global_lock);
+
+      if (! err)
+	return 0;
+
+      /* Fallback.  */
+    }
+
   if (pgid == 0)
     pg = callerp->p_pgrp;
   else
-- 
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