1 files changed, 135 insertions, 0 deletions
diff --git a/linux/kernel/exit.c b/linux/kernel/exit.c
new file mode 100644
index 0000000..3402c33
--- /dev/null
+++ b/linux/kernel/exit.c
@@ -0,0 +1,135 @@
+#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));
+}
+
+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;
+}
+
+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->father) {
+		current->state = TASK_ZOMBIE;
+		do_kill(current->father,SIGCHLD,1);
+		current->exit_code = code;
+	} else
+		release(current);
+	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,int * stat_addr, int options)
+{
+	int flag=0;
+	struct task_struct ** p;
+
+	verify_area(stat_addr,4);
+repeat:
+	for(p = &LAST_TASK ; p > &FIRST_TASK ; --p)
+		if (*p && *p != current &&
+		   (pid==-1 || (*p)->pid==pid ||
+		   (pid==0 && (*p)->pgrp==current->pgrp) ||
+		   (pid<0 && (*p)->pgrp==-pid)))
+			if ((*p)->father == current->pid) {
+				flag=1;
+				if ((*p)->state==TASK_ZOMBIE) {
+					put_fs_long((*p)->exit_code,
+						(unsigned long *) stat_addr);
+					current->cutime += (*p)->utime;
+					current->cstime += (*p)->stime;
+					flag = (*p)->pid;
+					release(*p);
+					return flag;
+				}
+			}
+	if (flag) {
+		if (options & WNOHANG)
+			return 0;
+		sys_pause();
+		if (!(current->signal &= ~(1<<(SIGCHLD-1))))
+			goto repeat;
+		else
+			return -EINTR;
+	}
+	return -ECHILD;
+}
+
+