From 2c15d097976907f4a233a4083823b4acc77638bc Mon Sep 17 00:00:00 2001
From: Bahadir Balban <bbalban@b-labs.co.uk>
Date: Mon, 10 Nov 2008 11:22:38 +0200
Subject: [PATCH] Towards finishing off clone()

Few minor changes in clone() syscall
---
 tasks/mm0/include/clone.h | 17 ++++++++++
 tasks/mm0/include/task.h  |  1 +
 tasks/mm0/src/clone.c     | 65 +++++++++++++++++++++++++++------------
 3 files changed, 64 insertions(+), 19 deletions(-)
 create mode 100644 tasks/mm0/include/clone.h

diff --git a/tasks/mm0/include/clone.h b/tasks/mm0/include/clone.h
new file mode 100644
index 0000000..c79768a
--- /dev/null
+++ b/tasks/mm0/include/clone.h
@@ -0,0 +1,17 @@
+#ifndef __CLONE_H__
+#define __CLONE_H__
+
+/* Linux clone() system call flags */
+#define CLONE_VM	0x100
+#define CLONE_FS	0x200
+#define CLONE_FILES	0x400
+#define CLONE_SIGHAND	0x800
+#define CLONE_VFORK	0x4000
+#define CLONE_PARENT	0x8000
+#define CLONE_THREAD	0x10000
+#define CLONE_NEWNS	0x20000
+#define CLONE_STOPPED	0x2000000
+
+#endif /* __CLONE_H__ */
+
+
diff --git a/tasks/mm0/include/task.h b/tasks/mm0/include/task.h
index 4783307..2932655 100644
--- a/tasks/mm0/include/task.h
+++ b/tasks/mm0/include/task.h
@@ -28,6 +28,7 @@
 #define	TCB_SHARED_VM				(1 << 0)
 #define	TCB_SHARED_FILES			(1 << 1)
 #define TCB_SHARED_FS				(1 << 2)
+#define TCB_SAME_GROUP				(1 << 3)
 
 struct vm_file;
 
diff --git a/tasks/mm0/src/clone.c b/tasks/mm0/src/clone.c
index c5227b8..2091e4d 100644
--- a/tasks/mm0/src/clone.c
+++ b/tasks/mm0/src/clone.c
@@ -3,17 +3,18 @@
  *
  * Copyright (C) 2008 Bahadir Balban
  */
-#include <syscalls.h>
-#include <vm_area.h>
-#include <task.h>
-#include <mmap.h>
 #include <l4lib/arch/syslib.h>
 #include <l4lib/ipcdefs.h>
 #include <l4lib/exregs.h>
 #include <l4/api/errno.h>
 #include <l4/api/thread.h>
+#include <syscalls.h>
+#include <vm_area.h>
+#include <task.h>
+#include <mmap.h>
 #include <utcb.h>
 #include <shm.h>
+#include <clone.h>
 
 /*
  * Sends vfs task information about forked child, and its utcb
@@ -58,7 +59,7 @@ int sys_fork(struct tcb *parent)
 	struct exregs_data exregs;
 	struct task_ids ids = {
 		.tid = TASK_ID_INVALID,
-		.spid = parent->spid,
+		.spid = parent->spid,		/* spid to copy from */
 		.tgid = TASK_ID_INVALID,	/* FIXME: !!! FIX THIS */
 	};
 
@@ -99,35 +100,48 @@ int sys_fork(struct tcb *parent)
 	return child->tid;
 }
 
-int do_clone(struct tcb *parent, void *child_stack, unsigned int flags)
+int do_clone(struct tcb *parent, unsigned long child_stack, unsigned int flags)
 {
+	struct exregs_data exregs;
 	struct task_ids ids;
 	struct tcb *child;
+	int err;
 
 	ids.tid = TASK_ID_INVALID;
 	ids.spid = parent->spid;
-	ids.tgid = parent->tgid;
 
-	if (IS_ERR(child = task_create(parent, &ids, THREAD_SAME_SPACE,
-			    	       TCB_SHARED_VM | TCB_SHARED_FILES)))
+	if (flags & TCB_SAME_GROUP)
+		ids.tgid = parent->tgid;
+	else
+		ids.tgid = TASK_ID_INVALID;
+
+	if (IS_ERR(child = task_create(parent, &ids, THREAD_SAME_SPACE, flags)))
 		return (int)child;
 
+	/* Set up child stack marks with given stack argument */
+	child->stack_end = child_stack;
+	child->stack_start = 0;
+
+	/* Set child's stack pointer */
+	memset(&exregs, 0, sizeof(exregs));
+	exregs_set_stack(&exregs, child_stack);
+
+	/* Do the actual exregs call to c0 */
+	if ((err = l4_exchange_registers(&exregs, child->tid)) < 0)
+		BUG();
+
 	/* Create and prefault a utcb for child and map it to vfs task */
 	utcb_map_to_task(child, find_task(VFS_TID),
 			 UTCB_NEW_ADDRESS | UTCB_NEW_SHM | UTCB_PREFAULT);
 
-	/* Set up child stack marks with given stack argument */
-	child->stack_end = (unsigned long)child_stack;
-	child->stack_start = 0;
-
 	/* We can now notify vfs about forked process */
-	vfs_notify_fork(child, parent, TCB_SHARED_FILES);
+	vfs_notify_fork(child, parent, flags);
 
 	/* Add child to global task list */
 	global_add_task(child);
 
-	/* Start forked child. */
-	printf("%s/%s: Starting forked child.\n", __TASKNAME__, __FUNCTION__);
+	/* Start cloned child. */
+	printf("%s/%s: Starting cloned child.\n", __TASKNAME__, __FUNCTION__);
 	l4_thread_control(THREAD_RUN, &ids);
 
 	/* Return child tid to parent */
@@ -135,9 +149,22 @@ int do_clone(struct tcb *parent, void *child_stack, unsigned int flags)
 }
 
 
-int sys_clone(struct tcb *parent, void *child_stack, unsigned int flags)
+int sys_clone(struct tcb *parent, void *child_stack, unsigned int clone_flags)
 {
+	unsigned int flags = 0;
+
+	if (!child_stack)
+		return -EINVAL;
+
+	if (clone_flags & CLONE_VM)
+		flags |= TCB_SHARED_VM;
+	if (clone_flags & CLONE_FS)
+		flags |= TCB_SHARED_FS;
+	if (clone_flags & CLONE_FILES)
+		flags |= TCB_SHARED_FILES;
+	if (clone_flags & CLONE_THREAD)
+		flags |= TCB_SAME_GROUP;
+
+	return do_clone(parent, (unsigned long)child_stack, flags);
 }
 
-
-