1999-05-29 Roland McGrath <roland@baalperazim.frob.com>

	* mgt.c (add_tasks): Skip invalid (null) rights in tasks array.
	* info.c (S_proc_pid2task): Add assert for p_task right validity.

2 files changed, 10 insertions, 3 deletions

diff --git a/proc/info.c b/proc/info.c
index 1a398461..a53df08a 100644
--- a/proc/info.c
+++ b/proc/info.c
@@ -1,5 +1,5 @@
 /* Process information queries
-   Copyright (C) 1992, 1993, 1994, 1995, 1996 Free Software Foundation
+   Copyright (C) 1992,93,94,95,96,99 Free Software Foundation, Inc.
 
 This file is part of the GNU Hurd.
 
@@ -55,6 +55,7 @@ S_proc_pid2task (struct proc *callerp,
   if (! check_owner (callerp, p))
     return EPERM;
 
+  assert (MACH_PORT_VALID (p->p_task));
   *t = p->p_task;
 
   return 0;
@@ -426,7 +427,7 @@ S_proc_getprocinfo (struct proc *callerp,
     assert (tp);
   pi->logincollection = tp->p_pid;
   if (p->p_dead || p->p_stopped)
-    {    
+    {
       pi->exitstatus = p->p_status;
       pi->sigcode = p->p_sigcode;
     }
diff --git a/proc/mgt.c b/proc/mgt.c
index 3f4f5f3b..cde05cd0 100644
--- a/proc/mgt.c
+++ b/proc/mgt.c
@@ -238,7 +238,7 @@ S_proc_reassign (struct proc *p,
   p->p_envp = stubp->p_envp;
 
   /* Destroy stubp */
-  stubp->p_task = 0;		/* block deallocation */
+  stubp->p_task = MACH_PORT_NULL;/* block deallocation */
   process_has_exited (stubp);
   stubp->p_waited = 1;		/* fake out complete_exit */
   complete_exit (stubp);
@@ -750,6 +750,12 @@ add_tasks (task_t task)
 	  for (j = 0; j < ntasks; j++)
 	    {
 	      int set = 0;
+
+	      /* The kernel can deliver us an array with null slots in the
+		 middle, e.g. if a task died during the call.  */
+	      if (! MACH_PORT_VALID (tasks[j]))
+		continue;
+
 	      if (!foundp)
 		{
 		  struct proc *p = task_find_nocreate (tasks[j]);