Files
codezero/conts/posix/mm0/mm/clone.c
2010-03-25 01:12:40 +02:00

136 lines
3.0 KiB
C

/*
* Forking and cloning threads, processes
*
* Copyright (C) 2008 Bahadir Balban
*/
#include L4LIB_INC_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 <shm.h>
#include <test.h>
#include <clone.h>
int sys_fork(struct tcb *parent)
{
int err;
struct tcb *child;
struct exregs_data exregs;
struct task_ids ids;
/* Make all shadows in this task read-only */
vm_freeze_shadows(parent);
/*
* Create a new L4 thread with parent's page tables
* kernel stack and kernel-side tcb copied
*/
if (IS_ERR(child = task_create(parent, &ids,
TCB_NO_SHARING,
TC_COPY_SPACE)))
return (int)child;
/* Set child's fork return value to 0 */
memset(&exregs, 0, sizeof(exregs));
exregs_set_mr(&exregs, MR_RETURN, 0);
/* Set child's new utcb address set by task_create() */
BUG_ON(!child->utcb_address);
exregs_set_utcb(&exregs,
child->utcb_address);
/* Do the actual exregs call to c0 */
if ((err = l4_exchange_registers(&exregs,
child->tid)) < 0)
BUG();
/* Add child to global task list */
global_add_task(child);
/* Start forked child. */
l4_thread_control(THREAD_RUN, &ids);
/* Return child tid to parent */
return child->tid;
}
int do_clone(struct tcb *parent, unsigned long child_stack,
unsigned int flags, unsigned int sysflags)
{
struct exregs_data exregs;
struct task_ids ids;
struct tcb *child;
int err;
if (IS_ERR(child = task_create(parent, &ids,
flags,
sysflags)))
return (int)child;
/* Set up child stack marks with given stack argument */
child->stack_end = child_stack;
child->stack_start = 0;
memset(&exregs, 0, sizeof(exregs));
/* Set child's stack pointer */
exregs_set_stack(&exregs, child_stack);
/* Set child's clone return value to 0 */
exregs_set_mr(&exregs, MR_RETURN, 0);
BUG_ON(!child->utcb_address);
exregs_set_utcb(&exregs, child->utcb_address);
/* Do the actual exregs call to c0 */
if ((err = l4_exchange_registers(&exregs,
child->tid)) < 0)
BUG();
/* Add child to global task list */
global_add_task(child);
/* Start cloned child. */
l4_thread_control(THREAD_RUN, &ids);
/* Return child tid to parent */
return child->tid;
}
int sys_clone(struct tcb *parent,
void *child_stack,
unsigned int clone_flags)
{
unsigned int flags = 0;
unsigned int sysflags = 0;
if (!child_stack)
return -EINVAL;
BUG_ON((unsigned long)child_stack < 0x10000);
if (clone_flags & CLONE_VM) {
flags |= TCB_SHARED_VM;
sysflags |= TC_SHARE_SPACE;
}
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_SHARED_TGROUP;
sysflags |= TC_SHARE_GROUP;
}
if (clone_flags & CLONE_PARENT)
flags |= TCB_SHARED_PARENT;
return do_clone(parent,
(unsigned long)child_stack,
flags, sysflags);
}