Files
codezero/tasks/mm0/src/clone.c
2008-11-09 12:22:48 +02:00

144 lines
3.4 KiB
C

/*
* Forking and cloning threads, processes
*
* 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 <utcb.h>
#include <shm.h>
/*
* Sends vfs task information about forked child, and its utcb
*/
int vfs_notify_fork(struct tcb *child, struct tcb *parent, unsigned int flags)
{
int err = 0;
// printf("%s/%s\n", __TASKNAME__, __FUNCTION__);
l4_save_ipcregs();
/* Write parent and child information */
write_mr(L4SYS_ARG0, parent->tid);
write_mr(L4SYS_ARG1, child->tid);
write_mr(L4SYS_ARG2, (unsigned int)child->utcb);
write_mr(L4SYS_ARG3, flags);
if ((err = l4_sendrecv(VFS_TID, VFS_TID,
L4_IPC_TAG_NOTIFY_FORK)) < 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: Pager from VFS read error: %d.\n",
__FUNCTION__, err);
goto out;
}
out:
l4_restore_ipcregs();
return err;
}
int sys_fork(struct tcb *parent)
{
int err;
struct tcb *child;
struct exregs_data exregs;
struct task_ids ids = {
.tid = TASK_ID_INVALID,
.spid = parent->spid,
.tgid = TASK_ID_INVALID, /* FIXME: !!! FIX THIS */
};
/* 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, THREAD_COPY_SPACE,
TCB_NO_SHARING)))
return (int)child;
/* Set child's fork return value to 0 */
memset(&exregs, 0, sizeof(exregs));
exregs_set_mr(&exregs, MR_RETURN, 0);
/* 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);
// printf("Mapped 0x%p to vfs as utcb of %d\n", child->utcb, child->tid);
/* We can now notify vfs about forked process */
vfs_notify_fork(child, parent, TCB_NO_SHARING);
/* 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, void *child_stack, unsigned int flags)
{
struct task_ids ids;
struct tcb *child;
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)))
return (int)child;
/* 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);
/* Add child to global task list */
global_add_task(child);
/* Start forked child. */
printf("%s/%s: Starting forked child.\n", __TASKNAME__, __FUNCTION__);
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 flags)
{
}