kernel/system/do_exit.c

   1 /* The kernel call implemented in this file:
   2  *   m_type:    SYS_EXIT
   3  *
   4  * The parameters for this kernel call are:
   5  *    m1_i1:    PR_ENDPT                (slot number of exiting process)
   6  */
   7
   8 #include "../system.h"
   9
  10 #include <minix/endpoint.h>
  11
  12 #if USE_EXIT
  13
  14 FORWARD _PROTOTYPE( void clear_proc, (register struct proc *rc));
  15
  16 /*===========================================================================*
  17  *                              do_exit                                      *
  18  *===========================================================================*/
  19 PUBLIC int do_exit(struct proc * caller, message * m_ptr)
  20 {
  21 /* Handle sys_exit. A user process has exited or a system process requests
  22  * to exit. Only the PM can request other process slots to be cleared.
  23  * The routine to clean up a process table slot cancels outstanding timers,
  24  * possibly removes the process from the message queues, and resets certain
  25  * process table fields to the default values.
  26  */
  27   int exit_e;
  28
  29   /* Determine what process exited. User processes are handled here. */
  30   if (PM_PROC_NR == caller->p_endpoint) {
  31       if (m_ptr->PR_ENDPT != SELF) {            /* PM tries to exit self */
  32           if(!isokendpt(m_ptr->PR_ENDPT, &exit_e)) /* get exiting process */
  33              return EINVAL;
  34           clear_proc(proc_addr(exit_e));        /* exit a user process */
  35           return(OK);                           /* report back to PM */
  36       }
  37   }
  38
  39   /* The PM or some other system process requested to be exited. */
  40   clear_proc(caller);
  41   return(EDONTREPLY);
  42 }
  43
  44 /*===========================================================================*
  45  *                               clear_proc                                  *
  46  *===========================================================================*/
  47 PRIVATE void clear_proc(rc)
  48 register struct proc *rc;               /* slot of process to clean up */
  49 {
  50   int i;
  51
  52   /* Don't clear if already cleared. */
  53   if(isemptyp(rc)) return;
  54
  55   /* Check the table with IRQ hooks to see if hooks should be released. */
  56   for (i=0; i < NR_IRQ_HOOKS; i++) {
  57       if (rc->p_endpoint == irq_hooks[i].proc_nr_e) {
  58         rm_irq_handler(&irq_hooks[i]);  /* remove interrupt handler */
  59         irq_hooks[i].proc_nr_e = NONE;  /* mark hook as free */
  60       }
  61   }
  62
  63   /* Remove the process' ability to send and receive messages */
  64   clear_endpoint(rc);
  65
  66
  67   /* Turn off any alarm timers at the clock. */
  68   reset_timer(&priv(rc)->s_alarm_timer);
  69
  70   /* Make sure that the exiting process is no longer scheduled,
  71    * and mark slot as FREE. Also mark saved fpu contents as not significant.
  72    */
  73   RTS_LOCK_SETFLAGS(rc, RTS_SLOT_FREE);
  74   rc->p_misc_flags &= ~MF_FPU_INITIALIZED;
  75
  76   /* Release the process table slot. If this is a system process, also
  77    * release its privilege structure.  Further cleanup is not needed at
  78    * this point. All important fields are reinitialized when the
  79    * slots are assigned to another, new process.
  80    */
  81   if (priv(rc)->s_flags & SYS_PROC) priv(rc)->s_proc_nr = NONE;
  82
  83 #if 0
  84   /* Clean up virtual memory */
  85   if (rc->p_misc_flags & MF_VM) {
  86         vm_map_default(rc);
  87   }
  88 #endif
  89 }
  90
  91 #endif /* USE_EXIT */
  92