root/kernel/syscalls/exit.c

/* */

DEFINITIONS

1. do_exit
2. sys_exit

   1 /*
   2  * fiwix/kernel/syscalls/exit.c
   3  *
   4  * Copyright 2018-2021, Jordi Sanfeliu. All rights reserved.
   5  * Distributed under the terms of the Fiwix License.
   6  */
   7 
   8 #include <fiwix/asm.h>
   9 #include <fiwix/kernel.h>
  10 #include <fiwix/syscalls.h>
  11 #include <fiwix/process.h>
  12 #include <fiwix/sched.h>
  13 #include <fiwix/mman.h>
  14 #include <fiwix/sleep.h>
  15 #include <fiwix/stdio.h>
  16 #include <fiwix/string.h>
  17 
  18 void do_exit(int exit_code)
  19 {
  20         int n;
  21         struct proc *p, *init;
  22 
  23 #ifdef __DEBUG__
  24         printk("\n");
  25         printk("sys_exit(pid %d, ppid %d)\n", current->pid, current->ppid);
  26         printk("------------------------------\n");
  27 #endif /*__DEBUG__ */
  28 
  29         release_binary();
  30         current->argv = NULL;
  31         current->envp = NULL;
  32 
  33         init = get_proc_by_pid(INIT);
  34         FOR_EACH_PROCESS(p) {
  35                 if(SESS_LEADER(current)) {
  36                         if(p->sid == current->sid && p->state != PROC_ZOMBIE) {
  37                                 p->pgid = 0;
  38                                 p->sid = 0;
  39                                 p->ctty = NULL;
  40                                 send_sig(p, SIGHUP);
  41                                 send_sig(p, SIGCONT);
  42                         }
  43                 }
  44 
  45                 /* make INIT inherit the children of this exiting process */
  46                 if(p->ppid == current->pid) {
  47                         p->ppid = INIT;
  48                         init->children++;
  49                         current->children--;
  50                         if(p->state == PROC_ZOMBIE) {
  51                                 send_sig(init, SIGCHLD);
  52                                 if(init->sleep_address == &sys_wait4) {
  53                                         wakeup_proc(init);
  54                                 }
  55                         }
  56                 }
  57                 p = p->next;
  58         }
  59 
  60         if(SESS_LEADER(current)) {
  61                 disassociate_ctty(current->ctty);
  62         }
  63 
  64         for(n = 0; n < OPEN_MAX; n++) {
  65                 if(current->fd[n]) {
  66                         sys_close(n);
  67                 }
  68         }
  69 
  70         iput(current->root);
  71         current->root = NULL;
  72         iput(current->pwd);
  73         current->pwd = NULL;
  74         current->exit_code = exit_code;
  75         if(!--nr_processes) {
  76                 printk("\n");
  77                 printk("WARNING: the last user process has exited. The kernel will stop itself.\n");
  78                 stop_kernel();
  79         }
  80 
  81         /* notify the parent about the child's death */
  82         if((p = get_proc_by_pid(current->ppid))) {
  83                 send_sig(p, SIGCHLD);
  84                 if(p->sleep_address == &sys_wait4) {
  85                         wakeup_proc(p);
  86                 }
  87         }
  88 
  89         current->sigpending = 0;
  90         current->sigblocked = 0;
  91         current->sigexecuting = 0;
  92         for(n = 0; n < NSIG; n++) {
  93                 current->sigaction[n].sa_mask = 0;
  94                 current->sigaction[n].sa_flags = 0;
  95                 current->sigaction[n].sa_handler = SIG_IGN;
  96         }
  97 
  98         not_runnable(current, PROC_ZOMBIE);
  99         need_resched = 1;
 100         do_sched();
 101 }
 102 
 103 int sys_exit(int exit_code)
 104 {
 105 #ifdef __DEBUG__
 106         printk("(pid %d) sys_exit()\n", current->pid);
 107 #endif /*__DEBUG__ */
 108 
 109         /* exit code in the second byte.
 110          *  15                8 7                 0
 111          * +-------------------+-------------------+
 112          * | exit code (0-255) |         0         |
 113          * +-------------------+-------------------+
 114          */
 115         do_exit((exit_code & 0xFF) << 8);
 116         return 0;
 117 }

/* */