From 513d5aaac86da67e1361b4c9792a5f3889439c19 Mon Sep 17 00:00:00 2001
From: Bahadir Balban <bbalban@b-labs.co.uk>
Date: Sun, 9 Nov 2008 11:42:10 +0200
Subject: [PATCH] Added exit.c that seemed to be out of tree.

---
 tasks/mm0/src/exit.c | 102 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 102 insertions(+)
 create mode 100644 tasks/mm0/src/exit.c

diff --git a/tasks/mm0/src/exit.c b/tasks/mm0/src/exit.c
new file mode 100644
index 0000000..ee70f24
--- /dev/null
+++ b/tasks/mm0/src/exit.c
@@ -0,0 +1,102 @@
+/*
+ * exit()
+ *
+ * Copyright (C) 2008 Bahadir Balban
+ */
+#include <task.h>
+#include <file.h>
+#include <utcb.h>
+#include <vm_area.h>
+#include <syscalls.h>
+#include <l4lib/arch/syslib.h>
+#include <l4lib/arch/syscalls.h>
+#include <l4lib/exregs.h>
+#include <l4lib/ipcdefs.h>
+#include <lib/malloc.h>
+
+/*
+ * Sends vfs task information about forked child, and its utcb
+ */
+int vfs_notify_exit(struct tcb *task, int status)
+{
+	int err = 0;
+
+	// printf("%s/%s\n", __TASKNAME__, __FUNCTION__);
+
+	l4_save_ipcregs();
+
+	/* Write parent and child information */
+	write_mr(L4SYS_ARG0, task->tid);
+	write_mr(L4SYS_ARG1, status);
+
+	if ((err = l4_sendrecv(VFS_TID, VFS_TID,
+			       L4_IPC_TAG_NOTIFY_EXIT)) < 0) {
+		printf("%s: L4 IPC Error: %d.\n", __FUNCTION__, err);
+		goto out;
+	}
+
+	/* Check if syscall was successful */
+	if ((err = l4_get_retval()) < 0) {
+		printf("%s: VFS returned ipc error: %d.\n",
+		       __FUNCTION__, err);
+		goto out;
+	}
+
+out:
+	l4_restore_ipcregs();
+	return err;
+}
+
+
+/* Closes all file descriptors of a task */
+int task_close_files(struct tcb *task)
+{
+	int err = 0;
+
+	/* Flush all file descriptors */
+	for (int fd = 0; fd < TASK_FILES_MAX; fd++)
+		if (task->files->fd[fd].vmfile)
+			if ((err = sys_close(task, fd)) < 0) {
+				printf("File close error. Tid: %d,"
+				       " fd: %d, error: %d\n",
+				       task->tid, fd, err);
+				break;
+			}
+	return err;
+}
+
+void sys_exit(struct tcb *task, int status)
+{
+	struct task_ids ids = {
+		.tid = task->tid,
+		.spid = task->spid,
+		.tgid = task->tgid,
+	};
+
+	/* Flush all IO on task's files and close fds */
+	task_close_files(task);
+
+	/* Tell vfs that task is exiting */
+	vfs_notify_exit(task, status);
+
+	/* Remove utcb shm areas from vfs */
+	// printf("Unmapping 0x%p from vfs as utcb of %d\n", task->utcb, task->tid);
+	utcb_unmap_from_task(task, find_task(VFS_TID));
+
+	/* Free task's local tcb */
+	tcb_destroy(task);
+
+	/* Ask the kernel to delete it from its records */
+	l4_thread_control(THREAD_DESTROY, &ids);
+
+	/* TODO: Wake up any waiters about task's destruction */
+#if 0
+	struct tcb *parent = find_task(task->parentid);
+	if (parent->waiting) {
+		exregs_set_mr_return(status);
+		l4_exchange_registers(parent->tid);
+		l4_thread_control(THREAD_RUN, parent->tid);
+	}
+#endif
+}
+