/* * linux/kernel/exit.c * * (C) 1991 Linus Torvalds */ #include <errno.h> #include <signal.h> #include <sys/wait.h> #include <linux/sched.h> #include <linux/kernel.h> #include <linux/tty.h> #include <asm/segment.h> int sys_pause(void); int sys_close(int fd); void release(struct task_struct * p) { int i; if (!p) return; for (i=1 ; i<NR_TASKS ; i++) if (task[i]==p) { task[i]=NULL; free_page((long)p); schedule(); return; } panic("trying to release non-existent task"); } static inline void send_sig(long sig,struct task_struct * p,int priv) { if (!p || sig<1 || sig>32) return; if (priv || current->uid==p->uid || current->euid==p->uid || current->uid==p->euid || current->euid==p->euid) p->signal |= (1<<(sig-1)); } static void kill_session(void) { struct task_struct **p = NR_TASKS + task; while (--p > &FIRST_TASK) { if (*p && (*p)->session == current->session) (*p)->signal |= 1<<(SIGHUP-1); } } void do_kill(long pid,long sig,int priv) { struct task_struct **p = NR_TASKS + task; if (!pid) while (--p > &FIRST_TASK) { if (*p && (*p)->pgrp == current->pid) send_sig(sig,*p,priv); } else if (pid>0) while (--p > &FIRST_TASK) { if (*p && (*p)->pid == pid) send_sig(sig,*p,priv); } else if (pid == -1) while (--p > &FIRST_TASK) send_sig(sig,*p,priv); else while (--p > &FIRST_TASK) if (*p && (*p)->pgrp == -pid) send_sig(sig,*p,priv); } int sys_kill(int pid,int sig) { do_kill(pid,sig,!(current->uid || current->euid)); return 0; } static void tell_father(int pid) { int i; if (pid) for (i=0;i<NR_TASKS;i++) { if (!task[i]) continue; if (task[i]->pid != pid) continue; task[i]->signal |= (1<<(SIGCHLD-1)); return; } /* if we don't find any fathers, we just release ourselves */ release(current); } int do_exit(long code) { int i; free_page_tables(get_base(current->ldt[1]),get_limit(0x0f)); free_page_tables(get_base(current->ldt[2]),get_limit(0x17)); for (i=0 ; i<NR_TASKS ; i++) if (task[i] && task[i]->father == current->pid) task[i]->father = 0; for (i=0 ; i<NR_OPEN ; i++) if (current->filp[i]) sys_close(i); iput(current->pwd); current->pwd=NULL; iput(current->root); current->root=NULL; if (current->leader && current->tty >= 0) tty_table[current->tty].pgrp = 0; if (last_task_used_math == current) last_task_used_math = NULL; if (current->leader) kill_session(); current->state = TASK_ZOMBIE; current->exit_code = code; tell_father(current->father); schedule(); return (-1); /* just to suppress warnings */ } int sys_exit(int error_code) { return do_exit((error_code&0xff)<<8); } int sys_waitpid(pid_t pid,unsigned long * stat_addr, int options) { int flag; struct task_struct ** p; verify_area(stat_addr,4); repeat: flag=0; for(p = &LAST_TASK ; p > &FIRST_TASK ; --p) { if (!*p || *p == current) continue; if ((*p)->father != current->pid) continue; if (pid>0) { if ((*p)->pid != pid) continue; } else if (!pid) { if ((*p)->pgrp != current->pgrp) continue; } else if (pid != -1) { if ((*p)->pgrp != -pid) continue; } switch ((*p)->state) { case TASK_STOPPED: if (!(options & WUNTRACED)) continue; put_fs_long(0x7f,stat_addr); return (*p)->pid; case TASK_ZOMBIE: current->cutime += (*p)->utime; current->cstime += (*p)->stime; flag = (*p)->pid; put_fs_long((*p)->exit_code,stat_addr); release(*p); return flag; default: flag=1; continue; } } if (flag) { if (options & WNOHANG) return 0; current->state=TASK_INTERRUPTIBLE; schedule(); if (!(current->signal &= ~(1<<(SIGCHLD-1)))) goto repeat; else return -EINTR; } return -ECHILD; }