pid_t fork(struct trapframe *ptf, int *error)
{
struct trapframe *ctf = NULL;
ctf = kmalloc(sizeof(struct trapframe));
if(ctf == NULL){
*error = ENOMEM;
return -1;
}
memcpy(ctf, ptf, sizeof(struct trapframe));
struct addrspace *caddr = kmalloc(sizeof(struct addrspace));
*error = as_copy(curthread->t_addrspace, &caddr);
// new
if(*error > 0){
return -1;
}
struct thread *child_thread;
*error = thread_fork("fork",
child_fork_entry,
ctf,
(unsigned long)caddr,
&child_thread);
if(child_thread == NULL){
*error = ENOMEM;
return -1;
}
if(*error > 0){
return -1;
}
return child_thread->pid;
}
pid_t sys_fork(struct trapframe *tf)
{
struct trapframe *newtrapframe =kmalloc(sizeof(struct trapframe ));
*newtrapframe = *tf;
//memcpy(newtrapframe,tf ,sizeof(struct trapframe ));
int result ;
struct addrspace *newaddrspace;
result = as_copy(curthread->t_addrspace,&newaddrspace);
if(result)
{
return result;
}
struct thread *newthread ;
result = thread_fork("childthread", child_process_entry, newtrapframe,(unsigned long)newaddrspace,&newthread);
if (result)
{
return result ;
}
tf->tf_v0 = newthread->pid;
tf->tf_a3 = 0;
return -(newthread->pid) ;
}
pid_t sys_fork(struct trapframe * tf, int *retval)
{
struct trapframe *ntf;
int result;
ntf = (struct trapframe *)kmalloc(sizeof(struct trapframe));
if (ntf==NULL) {
return ENOMEM;
}
memcpy(ntf,tf,sizeof(struct trapframe));
struct thread * child;
struct fork_data * fork_data = (struct fork_data*) kmalloc(sizeof(struct fork_data));
fork_data->tf = ntf;
as_copy(curthread->t_vmspace, &fork_data->addr);
result = thread_fork(curthread->t_name, fork_data, 0, md_forkentry, &child);
*retval = child->pid;
return 0;
}
int sys_fork(struct trapframe* tf, pid_t* retval) {
int errcheck; //this is to check if there's error in some funcitons
//first creating a new proc
struct proc* child = proc_create_runprogram("child123");
//proctable_insert(child);
if(child == NULL) {
return ENOMEM;
}
curproc->child_pid = child->pid;
curproc->child = child; ///////////////
child->parent = curproc; //////////////
//now, copying the address space
struct addrspace* newas;
errcheck = as_copy(curproc_getas(), &newas);
if(errcheck != 0) { //there's an error
return errcheck;
}
child->p_addrspace = newas;
//now copying the trapframe to the child
struct trapframe* newtf = kmalloc(sizeof(struct trapframe));
if(newtf == NULL) {
return ENOMEM;
}
*newtf = *tf;
//now, do the thread_fork
errcheck = thread_fork("child2", child, enter_forked_process, newtf, 0);
if(errcheck != 0) {
return errcheck;
}
*retval = child->pid;
return(0);
}
int sys_fork(struct trapframe *tf, int * retval){
int spl = splhigh();
struct addrspace * child_vmspace;
// copy the parent's address space
int result = as_copy(curthread->t_vmspace, &child_vmspace);
if(result){
splx(spl);
return result;
}
struct thread *child_thread = NULL;
// duplicate the parent's trapframe, which is on this kernel thread's stack
// we need to copy the trapframe to kernel heap
struct trapframe* child_tf = kmalloc(sizeof(struct trapframe));
if (child_tf == NULL) {
splx(spl);
return ENOMEM;
}
*child_tf = *tf;
// create child thread/process
result = thread_fork("child_process",
(void*)child_tf, (unsigned long)child_vmspace,
md_forkentry,
&child_thread);
assert(child_thread != NULL);
// parent returns the child pID
*retval = child_thread->pID;
splx(spl);
return 0;
}
// -----------------------------------------------------------------
// Copy self-dual scalar fields in the site struct
void scalar_field_copy(field_offset src, field_offset dest) {
register int i;
register site *s;
FORALLSITES(i, s)
as_copy((antisym *)F_PT(s, src), (antisym *)F_PT(s, dest));
}
int sys_fork(struct trapframe *tf)
{
struct thread* newthread;
struct trapframe* newtf;
struct addrspace* newas;
int result;
newtf = (struct trapframe*) kmalloc(sizeof(struct trapframe));
if (newtf == NULL){
return ENOMEM;
}
*newtf = *tf;
int err;
err= as_copy(curthread->t_vmspace,&newas);
if (err){
return ENOMEM;
}
as_activate(curthread->t_vmspace);
result = thread_fork(curthread->t_name, newtf,(unsigned long)newas,
(void (*)(void *, unsigned long)) md_forkentry,&newthread);
if (result)
return -ENOMEM;
return newthread->t_pid;
}
void
md_forkentry(void * data1, unsigned long unused) {
//(void)unused;
struct fork_info * info = data1;
struct addrspace * new_as;
struct trapframe new_tf;
/* copy address space */
if (as_copy(info->parent->t_vmspace, &new_as)) {
info->child_pid = ENOMEM; // Means no memory for process
V(info->sem); // child is done, parent should resume.
thread_exit();
}
curthread->t_vmspace = new_as;
as_activate(new_as);
/* copy trap frame */
memcpy(&new_tf, info->tf, sizeof(struct trapframe));
/* change tf's registers to return values for syscall */
new_tf.tf_v0 = 0;
new_tf.tf_a3 = 0;
new_tf.tf_epc += 4;
/* create process and get the pid */
struct thread *new_process = kmalloc(sizeof(struct thread));
new_process->parent_pid = curthread->t_pid;
proc_table++;
new_process->t_pid = create_tpid();
proc_table++;
V(info->sem);
mips_usermode(&new_tf);
/* mips_usermode does not return */
}
int sys_fork(struct trapframe *tf, pid_t *retval){
const char* name = "Anonymous student's process";
// create process struct for child
struct proc *childp = proc_create_runprogram(name);
if(childp == NULL){
return ENOMEM; //OUT OF MEMORY
}
// create and copy as to child
struct addrspace* childas = kmalloc(sizeof(struct addrspace));
if(childas == NULL){
proc_destroy(childp);
return ENOMEM;
}
if(as_copy(curproc->p_addrspace, &childas)){
kfree(childas);
as_destroy(childas);
proc_destroy(childp);
return ENOMEM;
}
// attach new as to child proc
childp->p_addrspace = childas;
// create parent child relationship
struct procinfo *pi = array_get(procinfotable, childp->pid - 1);
if(pi == NULL){
kfree(childas);
as_destroy(childas);
proc_destroy(childp);
return ECHILD; // NO SUCH CHILD IN THE INFO TABLE
}
pi->parent_pid = curproc->pid;
// create thread for child and pass it tf
struct trapframe *childtf = kmalloc(sizeof(struct trapframe));
memcpy(childtf,tf,sizeof(struct trapframe));
void ** data = kmalloc(2*sizeof(void*));
data[0] = (void*)childtf;
data[1] = (void*)childas;
int err = thread_fork(name, childp,(void *)enter_forked_process, data, 0);
if(err){
kfree(childas);
kfree(childtf);
as_destroy(childas);
proc_destroy(childp);
kfree(childtf);
return ENOMEM;
}
*retval = childp->pid;
return 0;
}
/*
Duplicates the currently running process
The two copies are identical except for the child having a new pid
*/
int
sys_fork(struct trapframe *tf, int32_t *retval) {
// Prevent interrupts so address space doesn't change before getting
// copied
int spl = splhigh();
// Store trapframe on the heap for copying to child
// thread later
struct trapframe *child_tf;
child_tf = kmalloc(sizeof(tf));
if (child_tf == NULL) {
splx(spl);
return ENOMEM;
}
//memcpy(child_tf, tf, sizeof(tf));
child_tf = tf;
// Copy parent address space
struct addrspace *original_as;
struct addrspace *new_as;
original_as = curproc_getas();
int result = as_copy(original_as, &new_as);
if (result) {
splx(spl);
return ENOMEM;
}
// Create new process
struct proc *new_proc = proc_create(curproc->p_name);
// Copy process fdlist
for (int i = 0; i < __OPEN_MAX; i++) {
if (curproc->p_fdlist[i] != NULL) {
new_proc->p_fdlist[i] = curproc->p_fdlist[i];
// Increment reference count
new_proc->p_fdlist[i]->fd_vfile->vn_refcount++;
}
}
//Child process needs to have parent pid attached to it
set_parent(curproc->pid, new_proc->pid);
// Fork new thread, attach to new proc
result = thread_fork("Child process", new_proc, enter_forked_process, (void *)child_tf, (unsigned long)new_as);
if (result) {
kfree(child_tf);
splx(spl);
return result; // Error code will be returned from thread_fork
}
// Set retval to child process pid
*retval = new_proc->pid;
splx(spl);
return 0;
}
t_status interface_as_copy(o_syscall* message)
{
t_status error;
error = as_copy(message->u.request.u.as_copy.arg1,
message->u.request.u.as_copy.arg2,
message->u.request.u.as_copy.arg3,
message->u.request.u.as_copy.arg4,
message->u.request.u.as_copy.arg5);
message->u.reply.error = error;
return (STATUS_OK);
}
int sys_fork(struct trapframe *tf, int *retval)
{
struct thread *child_thread;
struct trapframe *child_trapframe = kmalloc(sizeof(struct trapframe));
struct addrspace *child_space;
struct addrspace *parent_space;
if (child_trapframe == NULL)
{
kprintf("Out of memory, ENoMEM\n");
// No memory to allocate for child's trapframe, return error.
*retval = ENOMEM;
return -1;
}
memcpy(child_trapframe, tf, sizeof(struct trapframe));
// get the parent address space.
parent_space = curthread->t_vmspace;
assert(parent_space != NULL);
int copy_error = as_copy(parent_space, &child_space);
if(copy_error != 0)
{
// As written in dumbvm.c, as_copy will return either ENOMEM for error or 0 for success
*retval = ENOMEM;
//kprintf("Address space Out of Memory, ENoMEM\n");
kfree(child_trapframe);
return -1;
}
int thread_fork_error = thread_fork(curthread->t_name, child_trapframe, ( unsigned long )child_space, md_forkentry, &child_thread);
if (thread_fork_error != 0)
{
*retval = ENOMEM;
//kprintf("Thread_fork out of memory, ENoMEM \n");
kfree(child_trapframe);
return -1;
}
*retval = child_thread -> t_pid;
return 0;
}
int sys_fork(struct trapframe *tf, int* err)
{
int ret;
// copy the trapframe
struct trapframe *newtf = kmalloc(sizeof(struct trapframe));
if (newtf == NULL) {
*err = ENOMEM;
goto fail;
}
memmove(newtf, tf, sizeof(struct trapframe));
struct addrspace *t_vmspace;
/* Copy the address space. */
ret = as_copy(curthread->t_vmspace, &t_vmspace);
if (ret) {
*err = ENOMEM;
goto fail1;
}
int spl = splhigh();
// create a new thread
struct thread *newth;
ret = thread_fork("" /* thread name */,
newtf /* thread arg */, (unsigned long)t_vmspace /* thread arg */,
md_forkentry, &newth);
if (ret) {
*err = ENOMEM;
goto fail2;
}
newth->t_vmspace = NULL;
int newid = newth->t_miPCB->processID;
splx(spl);
// on success
return newid;
fail2:
as_destroy(t_vmspace);
fail1:
kfree(newtf);
fail:
splx(spl);
return -1;
}
pid_t sys_fork(struct trapframe *tf)
{
//int s;
//print_function_dbprint("sys_fork");
//sem_fork = sem_create ("sem_fork", 0);
struct thread *child_thread;
// copy address space of the parent to the child
struct addrspace *childaddrspace;
as_copy(curthread->t_vmspace, &childaddrspace);
// allocate space on heap for copy of parent's trapframe
struct trapframe *child_tf = kmalloc(sizeof(struct trapframe));
if (child_tf == NULL)
{
kfree (child_tf);
return (-1)*(ENOMEM);
}
//s = splhigh();
// copy parent's trapframe
memcpy(child_tf, tf, sizeof(struct trapframe));
//splx(s);
child_tf->tf_a0 = (u_int32_t) childaddrspace; // need this to pass to md_forkentry, we know that fork() takes 0 parameters, so we can use a0
//kprintf ("in Sysfork fm size: %d\n", filemanager_getsize((struct filemanager *)curthread->t_fm));
//splx(s);
// fork thread to do rest of bookkeeping etc...
thread_fork(curthread->t_name, child_tf, 0, (void *)md_forkentry, &child_thread);
//kprintf ("sys_fork pid: %d\n", curthread->t_pid);
//child_thread->t_fm = filemanager_clone((struct filemanager *)curthread->t_fm);
//s = splhigh();
//kprintf ("WAITING: %d\n", curthread->t_pid);
//splx(s);
P(child_thread->t_sem_fork);
//s = splhigh();
//kprintf ("DONE: %d\n", curthread->t_pid);
//splx(s);
return (child_thread->t_pid);
}
pid_t sys_fork(struct trapframe * tf, int *retval)
{
struct trapframe *ntf;
int result, asret;
ntf = (struct trapframe *)kmalloc(sizeof(struct trapframe));
if(ntf == NULL)
return ENOMEM;
assert(ntf>0);
memcpy(ntf,tf,sizeof(struct trapframe));
struct thread* child;
child = (struct thread*) kmalloc(sizeof(struct thread*));
if(child == NULL)
return ENOMEM;
struct fork_data * fork_data = (struct fork_data*) kmalloc(sizeof(struct fork_data));
if(fork_data == NULL)
return ENOMEM;
assert(fork_data > 0);
fork_data->tf = ntf;
asret = as_copy(curthread->t_vmspace, &fork_data->addr);
if(asret != 0)
return asret;
result = thread_fork(curthread->t_name, fork_data, 0, md_forkentry, &child);
if(result != 0)
return result;
*retval = child->pid;
return result;
}
int
sys_fork(struct trapframe* tf, int *err) {
struct trapframe* childtf = NULL;
struct proc* childproc = NULL;
struct addrspace* childaddr = NULL;
int result;
childtf = kmalloc(sizeof(struct trapframe));
if(childtf == NULL){
*err = ENOMEM;
return -1;
}
memcpy(childtf, tf, sizeof(struct trapframe));
result = as_copy(curproc->p_addrspace, &childaddr);
if(childaddr == NULL){
kfree(childtf);
*err = ENOMEM;
return -1;
}
childproc = proc_create_child("child");
if(childproc == NULL){
kfree(childtf);
*err = ENOMEM;
return -1;
}
result = thread_fork("process", childproc, child_forkentry, childtf,
(unsigned long) childaddr);
if(result) {
return result;
}
result = childproc->pid;
childproc->p_cwd = curproc->p_cwd;
VOP_INCREF(curproc->p_cwd);
curproc->p_numthreads++;
return result;
}
pid_t sys_fork(struct trapframe * tf,int *retval)
{
int res = 0;
int index = 0;
char *forkedName = kmalloc(sizeof(char) *NAME_MAX);
strcpy(forkedName, curproc->p_name);
strcat(forkedName, "_fork");
struct proc * childProc = proc_create_runprogram(forkedName);
struct addrspace * childsSpace = kmalloc(sizeof(struct addrspace));
res = as_copy(curproc->p_addrspace, &childsSpace);
//kprintf("curproc->pid = %d\n", (int)curproc->pid);
if(res) {
kprintf(" WE ARE FORKING ");
}
childProc-> p_addrspace = childsSpace;
struct trapframe *tf_child = kmalloc(sizeof(struct trapframe));
if(tf_child == NULL){
kprintf(" trapframe PROBLEM ");
}
memcpy(tf_child, tf, sizeof(struct trapframe));
//*tf_child = *tf;
//kprintf("cant copy mem ");
for(int i = 0; i < 65536; i++)
{
if(!process_table[i])
{
childProc->pid = i;
index = i;
break;
}
}
//kprintf("cant set pid ");
childProc->ppid = curproc->pid;
struct proc_entry * pentry = proc_entry_create(childProc);
process_table[index] = pentry;
res = thread_fork(forkedName, childProc, entrypoint, (struct trapframe *) tf_child, (unsigned long)childsSpace);
*retval = childProc->pid;
return(0);
}
int sys_fork(struct trapframe *tf,struct addrspace *parent_addr_space){
//kprintf("\n in sys_fork");
struct thread *child_thread=NULL;
struct thread *test;
struct addrspace *parent_addr_space_copy;
//create a new address space
//kprintf("\n in sys_fork:creating new addr space");
parent_addr_space_copy=as_create();
if(parent_addr_space_copy==NULL)
return ENOMEM;
//make a copy of the parent's address space
//kprintf("\n in sys_fork:copying to the addr space %x",parent_addr_space);
as_copy(parent_addr_space,&parent_addr_space_copy);
//kprintf("\n in sys_fork:copying to the addr space %x",*(parent_addr_space_copy));
//make a copy of the parent`s trapframe on kernel heap
//kprintf("\n in sys_fork:copying trap frame");
struct trapframe *tf_temp=kmalloc(sizeof(struct trapframe));
if(tf_temp==NULL){
kfree(tf_temp);
return ENOMEM;
}
memcpy(tf_temp,tf,sizeof(struct trapframe));
//call thread_fork
//pass the trapframe and the address space of the parent to the child`s thread_fork
//kprintf("\n in sys_fork:forking");
thread_fork("child thread",tf_temp,(unsigned long)parent_addr_space_copy,md_forkentry,&child_thread);
//kprintf("\nchild_thread::%x",*(child_thread));
//copy other required stuff and return with child`s pid
//test=(child_thread);
return child_thread->pid;
}
int sys_fork(struct trapframe *tf, pid_t *retval) {
int result;
char* name;
(void) result;
(void) tf;
(void) retval;
struct trapframe *temp_tf = kmalloc(sizeof(*temp_tf));
*temp_tf = *tf;
struct proc *newproc = proc_create("forked_process");
// TODO: concurrency issue?
as_copy(curproc->p_addrspace, &newproc->p_addrspace);
newproc->p_filetable = kmalloc(sizeof(struct filetable));
newproc->p_filetable->filetable_lock = lock_create("filetable_lock");
filetable_copy(newproc->p_filetable);
// copied from proc.c init p_cwd
spinlock_acquire(&curproc->p_lock);
if (curproc->p_cwd != NULL) {
VOP_INCREF(curproc->p_cwd);
newproc->p_cwd = curproc->p_cwd;
}
spinlock_release(&curproc->p_lock);
newproc->parent_pid = curproc->pid;
name = kstrdup(curproc->p_name);
*retval = newproc->pid;
thread_fork(name, newproc ,run_forked_proc, (void *)temp_tf, 0);
return 0;
}
/*
* Create a new thread based on an existing one.
* The new thread has name NAME, and starts executing in function FUNC.
* DATA1 and DATA2 are passed to FUNC.
*/
int
thread_fork(const char *name,
void *data1, unsigned long data2,
void (*func)(void *, unsigned long),
pid_t *ret)
{
struct thread *newguy;
int s, result;
/* Allocate a thread */
newguy = thread_create(name);
if (newguy==NULL) {
return ENOMEM;
}
/* ASST1: Allocate a pid */
result = pid_alloc(&newguy->t_pid);
if (result != 0) {
kfree(newguy->t_name);
kfree(newguy);
return result;
}
/* Allocate a stack */
newguy->t_stack = kmalloc(STACK_SIZE);
if (newguy->t_stack==NULL) {
pid_unalloc(newguy->t_pid); /* ASST1: cleanup pid on fail */
kfree(newguy->t_name);
kfree(newguy);
return ENOMEM;
}
/* stick a magic number on the bottom end of the stack */
newguy->t_stack[0] = 0xae;
newguy->t_stack[1] = 0x11;
newguy->t_stack[2] = 0xda;
newguy->t_stack[3] = 0x33;
/* Inherit the current directory */
if (curthread->t_cwd != NULL) {
VOP_INCREF(curthread->t_cwd);
newguy->t_cwd = curthread->t_cwd;
}
/* ASST1: copy address space if there is one */
if (curthread->t_vmspace != NULL) {
result = as_copy(curthread->t_vmspace, &newguy->t_vmspace);
if (result) {
pid_unalloc(newguy->t_pid);
kfree(newguy->t_name);
kfree(newguy->t_stack);
kfree(newguy);
return ENOMEM;
}
}
/* Set up the pcb (this arranges for func to be called) */
md_initpcb(&newguy->t_pcb, newguy->t_stack, data1, data2, func);
/* Interrupts off for atomicity */
s = splhigh();
/*
* Make sure our data structures have enough space, so we won't
* run out later at an inconvenient time.
*/
result = array_preallocate(sleepers, numthreads+1);
if (result) {
goto fail;
}
result = array_preallocate(zombies, numthreads+1);
if (result) {
goto fail;
}
/* Do the same for the scheduler. */
result = scheduler_preallocate(numthreads+1);
if (result) {
goto fail;
}
/* Make the new thread runnable */
result = make_runnable(newguy);
if (result != 0) {
goto fail;
}
/*
* Increment the thread counter. This must be done atomically
* with the preallocate calls; otherwise the count can be
* temporarily too low, which would obviate its reason for
* existence.
*/
numthreads++;
/* Done with stuff that needs to be atomic */
splx(s);
/*
* Return new thread structure if it's wanted. Note that
* using the thread structure from the parent thread should be
* done only with caution, because in general the child thread
* might exit at any time.
*/
if (ret != NULL) {
*ret = newguy->t_pid; /* ASST1 return pid, not thread struct */
} else {
/* Not returning the pid... better detach the new thread */
result = thread_detach(newguy->t_pid);
assert(result == 0); /* can't fail. */
}
return 0;
fail:
splx(s);
/* ASST1: cleanup pid and vmspace on fail */
pid_unalloc(newguy->t_pid);
if (newguy->t_vmspace) {
as_destroy(newguy->t_vmspace);
}
if (newguy->t_cwd != NULL) {
VOP_DECREF(newguy->t_cwd);
}
kfree(newguy->t_stack);
kfree(newguy->t_name);
kfree(newguy);
return result;
}
int sysfork(int32_t *retval, struct trapframe *tf){
int s=splhigh();
DEBUG(1,"sysfork\n");
if(errsuperflag==1){
*retval=-1;
splx(s);
//thread_exit();
return ENOMEM;
}
int ret=0;
struct thread *child_thread;
struct trapframe *child_tf;
int pid = my_get_pid();
if(pid==-1){
splx(s);
//errno=11;
*retval=-1;
return 11; // EAGAIN too many processes exist
}else{
*retval = pid;
}
parent_array[pid]=curthread->ppid; //initalize ur parent;
DEBUG(1,"I am %d and my mommy is %d,I love her\n",pid,parent_array[pid]);
child_tf = (struct trapframe *)kmalloc(sizeof(struct trapframe));
if(child_tf==NULL){
DEBUG(1,"tf messed %d\n",curthread->ppid);
errsuperflag=1;
splx(s);
//thread_exit();
*retval=-1;
return ENOMEM;
}
memcpy(child_tf,tf, sizeof(struct trapframe));
ret = thread_fork("child", child_tf, 0, forkentry, &child_thread);
/*kprintf("copying stack\n");
kfree(child_thread->t_stack);
int act;
child_thread->t_stack = kmalloc(STACK_SIZE);
//memcpy(child_thread->t_stack,curthread->t_stack,sizeof(curthread->t_stack));
copyoutstr(curthread->t_stack,(userptr_t)(child_thread->t_stack),sizeof(curthread->t_stack),&act);*/
child_thread->my_parent=curthread;
(curthread->counter)++;
if(ret!=0) {
pid_array[pid]=NULL;
DEBUG(1,"thread_fork messed %d\n",curthread->ppid);
//int *temp;
//sysexit(temp,child_tf);
//kfree(child_thread);
//errno = ret;
child_thread->errflag=1;
//as_activate(child_thread->t_vmspace);
errsuperflag=1;
*retval=-1;
splx(s);
//thread_exit();
return ret;
}
pid_array[pid] = child_thread;
ret = as_copy((curthread->t_vmspace), &(child_thread->t_vmspace));
if(ret!=0){
DEBUG(1,"as_copy messed mommy: %d child: %d\n",curthread->ppid,pid);
//int *temp;
//sysexit(temp,child_tf);
//kfree(child_thread);
child_thread->errflag=1;
as_activate(child_thread->t_vmspace);
errsuperflag=1;
*retval=-1;
//as_destroy((child_thread->t_vmspace));
splx(s);
//thread_exit();
return ret;
}
as_activate(child_thread->t_vmspace);
((child_thread))->ppid = pid;
//DEBUG(1,"Pid Set %d\n", ((child_thread))->ppid);
splx(s);
return 0;
}
int sys_execv(char* progname, char** args){
struct vnode *v;
vaddr_t stackptr, entrypoint;
int result;
int string_size = 0; //s_size
int kargc = 0; //kargc
int err;
char ** kernel_args; //kargs
size_t check; //tt
//CHECKS BEFORE WE BEGIN!!
if(args == NULL)
return EFAULT;
if(progname == NULL)
return ENOEXEC;
struct addrspace* temp =(struct addrspace*)kmalloc(sizeof(struct addrspace));
if(temp == NULL)
return ENOMEM;
while(args[kargc] != NULL){
kargc++;
}
//Copy the address space to the one on the kernel heap.
err = as_copy(curthread->t_vmspace, &(temp));
//If there is an error on copy.
if(err){
kfree(temp);
return ENOMEM;
}
//make a copy of the kernel args on the heap.
kernel_args = (char **)kmalloc((kargc)*sizeof(char*));
if(kernel_args == NULL){
kfree(kernel_args);
return ENOMEM;
}
int i,j;
//Transfer the items passed in to the kernel heap array.
for(i = 0; i<kargc; i++){
string_size = strlen(args[i]);
kernel_args[i] =(char *)kmalloc(string_size * sizeof(char));
//If there is not enough memory...
if(kernel_args[i]== NULL){
kfree(temp);
for(j =0; j<i; j++){
kfree(kernel_args[j]);
}
kfree(kernel_args);
return ENOMEM;
}
//If we get here, we have successfully copied the arguments. Copy in now.
err = copyinstr(args[i], kernel_args[i], string_size+1, &check);
//Check if copyinstr Success/Fail
if(err){
for(i = 0; i<kargc; i++){
kfree(kernel_args[i]);
}
kfree(temp);
kfree(kernel_args);
return err;
}
}
kernel_args[kargc]= NULL;
//NOW, WE FOLLOW THE SAME PROCEDURE AS RUNPROGRAM!!
/* Open the file. */
result = vfs_open(progname, O_RDONLY, &v);
if (result) {
kfree(temp);
for(i = 0; i<kargc; i++)
kfree(kernel_args[i]);
kfree(kernel_args);
return result;
}
//Destroy the old address space, and setup the new one!
as_destroy(curthread->t_vmspace);
curthread->t_vmspace = NULL;
//Setup new vmspace.
curthread->t_vmspace = as_create();
if (curthread->t_vmspace==NULL) {
curthread->t_vmspace = temp;
for(i = 0; i<kargc; i++)
kfree(kernel_args[i]);
kfree(kernel_args);
vfs_close(v);
return ENOMEM;
}
/* Activate vmspace */
as_activate(curthread->t_vmspace);
/* Load the executable. */
result = load_elf(v, &entrypoint);
if (result) {
as_destroy(curthread->t_vmspace);
curthread->t_vmspace = temp;
for(i = 0; i<kargc; i++)
kfree(kernel_args[i]);
kfree(kernel_args);
vfs_close(v);
return result;
}
/* Done with the file now. */
vfs_close(v);
//We now prepare the user stack by placing the arguments on it, like we did in runprogram.
result = as_define_stack(curthread->t_vmspace, &stackptr);
//If error:
if (result) {
as_destroy(curthread->t_vmspace);
curthread->t_vmspace = temp;
for(i = 0; i<kargc; i++)
kfree(kernel_args[i]);
kfree(kernel_args);
return result;
}
// new addr space user stack
vaddr_t new_args[kargc];
int padding;
/*place all the strings on the stack*/
for(i = (kargc-1); i>=0 ; i--){
string_size = strlen(kernel_args[i]);
padding = ((string_size / 4 ) + 1)*4;
stackptr = stackptr - padding;
//Do a copyout and check if success/fail
err = copyoutstr(kernel_args[i], stackptr, string_size+1, &check);
if(err){
return err;
}
//Success!
new_args[i] = stackptr;
}
new_args[kargc] = NULL;
for(i = kargc-1; i>=0 ; i--){
stackptr= stackptr- 4;
err = copyout(&(new_args[i]), stackptr, 4);
if(err){
return err;
}
}
for(i =0; i<kargc; i++){
kfree(kernel_args[i]);
}
kfree(temp);
kfree(kernel_args);
/* Warp to user mode. */
md_usermode(kargc, stackptr, stackptr, entrypoint);
}
// The parent copies the appropriate data from itself to its child in this function
void start_child(void * data1, unsigned long unused) {
(void)unused;
struct fork_info * info = data1;
struct addrspace * new_as;
struct trapframe new_tf;
/* copy address space */
if (as_copy(info->parent->t_vmspace, &new_as)) {
info->child_pid = ENOMEM; // Means no memory for process
V(info->sem); // child is done, parent should resume.
thread_exit();
}
curthread->t_vmspace = new_as;
as_activate(new_as);
/* copy trap frame to new curkstack */
memcpy(&new_tf, info->tf, sizeof(struct trapframe));
/* change tf's registers to return values for syscall */
new_tf.tf_v0 = 0;
new_tf.tf_a3 = 0;
new_tf.tf_epc += 4;
/* create process and get the pid */
struct process *new_process = proctable_add_child_process(curthread->t_process);
if (new_process == NULL) {
info->child_pid = EAGAIN; // Means no more processes available in process table
V(info->sem); // child is done, parent should resume.
thread_exit();
}
info->child_pid = new_process->pid;
new_process->parent = info->parent->t_process;
// Attach new process to our thread
curthread->t_process = new_process;
// Initalize new file table
int result = fdtable_create();
if (result)
{
// Error occured
info->child_pid = result;
result = proctable_remove_process(new_process->pid);
// We're already exiting, so if there's an error with the line above, then it doesn't matter that much
V(info->sem); // child is done, parent should resume.
thread_exit();
}
struct process * parent_process = info->parent->t_process;
lock_acquire(parent_process->t_fdtable_lock);
// Copy file table
// This requires the filetable to be locked and the refcounts of each file to be increased.
int i;
for (i = 0; i < OPEN_MAX ; i++) {
new_process->t_fdtable->entries[i] = parent_process->t_fdtable->entries[i];
if (new_process->t_fdtable->entries[i] != NULL) new_process->t_fdtable->entries[i]->refcount++; // Increases the number of references to a file
}
lock_release(parent_process->t_fdtable_lock);
// child is done, parent should resume.
V(info->sem);
mips_usermode(&new_tf);
/* mips_usermode does not return */
panic("start_child returned\n");
}
void test_core_as_copy_01(void)
{
i_task task1;
i_task task2;
i_as as1;
i_as as2;
i_segment seg1;
i_segment seg2;
i_segment seg3;
i_segment seg4;
i_segment seg5;
i_segment seg6;
i_segment useless;
i_region reg;
t_uint32 i;
t_uint8 buff[4 * ___kaneton$pagesz];
TEST_ENTER();
/*
* first address space
*/
if (task_reserve(TASK_CLASS_GUEST,
TASK_BEHAVIOUR_INTERACTIVE,
TASK_PRIORITY_INTERACTIVE,
&task1) != STATUS_OK)
TEST_ERROR("[task_reserve] error");
if (as_reserve(task1, &as1) != STATUS_OK)
TEST_ERROR("[as_reserve] error");
if (segment_reserve(as1,
2 * ___kaneton$pagesz,
PERMISSION_READ | PERMISSION_WRITE,
SEGMENT_OPTION_NONE,
&seg1) != STATUS_OK)
TEST_ERROR("[segment_reserve] error");
if (segment_reserve(as1,
___kaneton$pagesz,
PERMISSION_READ | PERMISSION_WRITE,
SEGMENT_OPTION_NONE,
&useless) != STATUS_OK)
TEST_ERROR("[segment_reserve] error");
if (segment_reserve(as1,
4 * ___kaneton$pagesz,
PERMISSION_READ | PERMISSION_WRITE,
SEGMENT_OPTION_NONE,
&seg2) != STATUS_OK)
TEST_ERROR("[segment_reserve] error");
if (segment_reserve(as1,
___kaneton$pagesz,
PERMISSION_READ | PERMISSION_WRITE,
SEGMENT_OPTION_NONE,
&useless) != STATUS_OK)
TEST_ERROR("[segment_reserve] error");
if (segment_reserve(as1,
2 * ___kaneton$pagesz,
PERMISSION_READ | PERMISSION_WRITE,
SEGMENT_OPTION_NONE,
&seg3) != STATUS_OK)
TEST_ERROR("[segment_reserve] error");
if (region_reserve(as1,
seg1,
___kaneton$pagesz,
REGION_OPTION_FORCE,
0x20000000,
___kaneton$pagesz,
®) != STATUS_OK)
TEST_ERROR("[region_reserve] error");
if (region_reserve(as1,
seg2,
___kaneton$pagesz,
REGION_OPTION_FORCE,
0x20001000,
2 * ___kaneton$pagesz,
®) != STATUS_OK)
TEST_ERROR("[region_reserve] error");
if (region_reserve(as1,
seg3,
0,
REGION_OPTION_FORCE,
0x20003000,
___kaneton$pagesz,
®) != STATUS_OK)
TEST_ERROR("[region_reserve] error");
/*
* second address space
*/
if (task_reserve(TASK_CLASS_GUEST,
TASK_BEHAVIOUR_INTERACTIVE,
TASK_PRIORITY_INTERACTIVE,
&task2) != STATUS_OK)
TEST_ERROR("[task_reserve] error");
if (as_reserve(task2, &as2) != STATUS_OK)
TEST_ERROR("[as_reserve] error");
if (segment_reserve(as2,
2 * ___kaneton$pagesz,
PERMISSION_READ | PERMISSION_WRITE,
SEGMENT_OPTION_NONE,
&seg4) != STATUS_OK)
TEST_ERROR("[segment_reserve] error");
if (segment_reserve(as2,
___kaneton$pagesz,
PERMISSION_READ | PERMISSION_WRITE,
SEGMENT_OPTION_NONE,
&useless) != STATUS_OK)
TEST_ERROR("[segment_reserve] error");
if (segment_reserve(as2,
4 * ___kaneton$pagesz,
PERMISSION_READ | PERMISSION_WRITE,
SEGMENT_OPTION_NONE,
&seg5) != STATUS_OK)
TEST_ERROR("[segment_reserve] error");
if (segment_reserve(as2,
___kaneton$pagesz,
PERMISSION_READ | PERMISSION_WRITE,
SEGMENT_OPTION_NONE,
&useless) != STATUS_OK)
TEST_ERROR("[segment_reserve] error");
if (segment_reserve(as2,
2 * ___kaneton$pagesz,
PERMISSION_READ | PERMISSION_WRITE,
SEGMENT_OPTION_NONE,
&seg6) != STATUS_OK)
TEST_ERROR("[segment_reserve] error");
if (region_reserve(as2,
seg4,
0,
REGION_OPTION_FORCE,
0x40000000,
___kaneton$pagesz,
®) != STATUS_OK)
TEST_ERROR("[region_reserve] error");
if (region_reserve(as2,
seg5,
2 * ___kaneton$pagesz,
REGION_OPTION_FORCE,
0x40001000,
___kaneton$pagesz,
®) != STATUS_OK)
TEST_ERROR("[region_reserve] error");
if (region_reserve(as2,
seg6,
0,
REGION_OPTION_FORCE,
0x40002000,
2 * ___kaneton$pagesz,
®) != STATUS_OK)
TEST_ERROR("[region_reserve] error");
/*
* operations
*/
for (i = 0; i < 4 * ___kaneton$pagesz; i++)
buff[i] = (i * 2 + 4) % 256;
if (as_write(as1, buff, 4 * ___kaneton$pagesz, 0x20000000) != STATUS_OK)
TEST_ERROR("[as_write] error");
for (i = 0; i < 4 * ___kaneton$pagesz; i++)
buff[i] = 0;
if (as_copy(as1, 0x20000000, as2, 0x40000000, 4 * ___kaneton$pagesz) != STATUS_OK)
TEST_ERROR("[as_copy] error");
if (as_read(as2, 0x40000000, 4 * ___kaneton$pagesz, buff) != STATUS_OK)
TEST_ERROR("[as_read] error");
for (i = 0; i < 4 * ___kaneton$pagesz; i++)
if (buff[i] != (i * 2 + 4) % 256)
TEST_ERROR("the data appears invalid once read from the "
"address space\n");
TEST_SIGNATURE(rr3fiw3w20aafi9gre9g);
TEST_LEAVE();
}
pid_t
sys_fork(const struct trapframe *parent_tf, int *err)
{
struct process *parent = curthread->t_proc;
// set up new process structure
struct process *child = process_create(parent->ps_name);
if (child == NULL)
{
*err = ENOMEM;
return -1;
}
// Get a PID for the child. ENPROC is
// the error code for "no more processes allowed
// in the system."
pid_t child_pid = process_identify(child);
if (child_pid == 0)
{
*err = ENPROC;
process_cleanup(child);
return -1;
}
// copy the file descriptor table of the parent
child->ps_fdt = fdt_copy(parent->ps_fdt);
if (child->ps_fdt == NULL)
{
*err = ENOMEM;
process_destroy(child_pid);
return -1;
}
// copy the address space of the parent
*err = as_copy(parent->ps_addrspace,
&child->ps_addrspace);
if (*err)
{
process_destroy(child_pid);
return -1;
}
// add PID to children now. That way, if we fail to
// allocate memory, we have not yet forked a thread
*err = pid_set_add(parent->ps_children, child_pid);
if (*err)
{
process_destroy(child_pid);
return -1;
}
// allocate space for child trapframe in the kernel heap
struct trapframe *child_tf = kmalloc(sizeof(struct trapframe));
if (child_tf == NULL)
{
process_destroy(child_pid);
pid_set_remove(parent->ps_children, child_pid);
*err = ENOMEM;
return -1;
}
// copy trapframe
memcpy(child_tf, parent_tf, sizeof(struct trapframe));
// abuse child_tf->TF_RET (which will be set to 0)
// to pass the process struct to the child thread
// this cast and assignment will always work,
// as pointers always fit in machine registers
child_tf->TF_RET = (uintptr_t)child;
// child thread sets up child return value
// and ps_thread/t_proc
*err = thread_fork("user process",
enter_forked_process,
child_tf, 0,
NULL);
if (*err)
{
process_destroy(child_pid);
kfree(child_tf);
pid_set_remove(parent->ps_children, child_pid);
return -1;
}
return child_pid;
}
/*
* Create a new thread based on an existing one.
* The new thread has name NAME, and starts executing in function FUNC.
* DATA1 and DATA2 are passed to FUNC.
*/
int
thread_fork(const char *name,
void *data1, unsigned long data2,
void (*func)(void *, unsigned long),
struct thread **ret)
{
struct thread *newguy;
int s, result;
/* Allocate a thread */
newguy = thread_create(name);
if (newguy==NULL) {
return ENOMEM;
}
/* Allocate a stack */
newguy->t_stack = kmalloc(STACK_SIZE);
if (newguy->t_stack==NULL) {
kfree(newguy->t_name);
kfree(newguy);
return ENOMEM;
}
/* stick a magic number on the bottom end of the stack */
newguy->t_stack[0] = 0xae;
newguy->t_stack[1] = 0x11;
newguy->t_stack[2] = 0xda;
newguy->t_stack[3] = 0x33;
/* Inherit the current directory */
if (curthread->t_cwd != NULL) {
VOP_INCREF(curthread->t_cwd);
newguy->t_cwd = curthread->t_cwd;
}
#if OPT_A2
if(curthread->forkcalled) {
int i, res, spl;
//copy address space
res = as_copy(curthread->t_vmspace,&newguy->t_vmspace);
if (res) {
//kprintf("as_copy failed in thread_fork, curthread_vmspace_addr: %p, newguy_vmspace_addr: %p\n", curthread->t_vmspace, newguy->t_vmspace);
return res;
}
as_activate(curthread->t_vmspace); /* FIXME if wrong comment this out and retry */
//copy vnodes
// spl = splhigh();
for(i=3;i<MAX_OPENED_FILES;i++) {
if(curthread->files[i]!=NULL) {
newguy->files[i] = files_create(kstrdup(curthread->files[i]->filename), curthread->files[i]->vn, curthread->files[i]->flags);
VOP_INCOPEN(newguy->files[i]->vn);
VOP_INCREF(newguy->files[i]->vn);
} else {
break;
}
}
// splx(spl);
curthread->forkcalled = 0;
}
#endif
/* Set up the pcb (this arranges for func to be called) */
md_initpcb(&newguy->t_pcb, newguy->t_stack, data1, data2, func);
/* Interrupts off for atomicity */
s = splhigh();
/*
* Make sure our data structures have enough space, so we won't
* run out later at an inconvenient time.
*/
result = array_preallocate(sleepers, numthreads+1);
if (result) {
goto fail;
}
result = array_preallocate(zombies, numthreads+1);
if (result) {
goto fail;
}
/* Do the same for the scheduler. */
result = scheduler_preallocate(numthreads+1);
if (result) {
goto fail;
}
/* Make the new thread runnable */
result = make_runnable(newguy);
if (result != 0) {
goto fail;
}
/*
* Increment the thread counter. This must be done atomically
* with the preallocate calls; otherwise the count can be
* temporarily too low, which would obviate its reason for
* existence.
*/
numthreads++;
/* Done with stuff that needs to be atomic */
splx(s);
/*
* Return new thread structure if it's wanted. Note that
* using the thread structure from the parent thread should be
* done only with caution, because in general the child thread
* might exit at any time.
*/
if (ret != NULL) {
*ret = newguy;
}
return 0;
fail:
splx(s);
if (newguy->t_cwd != NULL) {
VOP_DECREF(newguy->t_cwd);
}
kfree(newguy->t_stack);
kfree(newguy->t_name);
kfree(newguy);
return result;
}
int
sys_fork(struct trapframe* tf, pid_t* retval)
{
DEBUG(DB_EXEC,"sys_fork(): entering\n");
KASSERT(curproc != NULL);
KASSERT(sizeof(struct trapframe)==(37*4));
char* child_name = kmalloc(sizeof(char)* NAME_MAX);
strcpy(child_name, curproc->p_name);
strcat(child_name, "_c");
// create PCB for child
struct proc* child_proc = NULL;
proc_fork(&child_proc);
if (child_proc == NULL)
{
return ENOMEM;
}
strcpy(child_proc->p_name, child_name);
KASSERT(child_proc->p_pid > 0);
// copy address space and registers from this process to child
struct addrspace* child_as = kmalloc(sizeof(struct addrspace));
if (child_as == NULL)
{
kfree(child_name);
proc_destroy(child_proc);
return ENOMEM;
}
struct trapframe* child_tf = kmalloc(sizeof(struct trapframe));
if (child_tf == NULL)
{
kfree(child_name);
as_destroy(child_as);
proc_destroy(child_proc);
return ENOMEM;
}
DEBUG(DB_EXEC,"sys_fork(): copying address space...\n");
// copy the address space just created into the child process's
// PCB structure
int result = as_copy(curproc->p_addrspace, &child_as);
if (result)
{
kfree(child_name);
as_destroy(child_as);
proc_destroy(child_proc);
return result;
}
child_proc->p_addrspace = child_as;
DEBUG(DB_EXEC,"sys_fork(): copying trapframe space...\n");
// copy this process's trapframe to the child process
memcpy(child_tf, tf, sizeof(struct trapframe));
DEBUG(DB_EXEC, "sys_fork(): copying filetable...\n");
filetable_copy(curproc->p_filetable,&child_proc->p_filetable);
DEBUG(DB_EXEC,"sys_fork(): assigning child process's parent as this process...\n");
// assign child processes parent as this process
child_proc->p_parent = curproc;
DEBUG(DB_EXEC,"sys_fork(): adding child to children procarray...\n");
result = procarray_add(&curproc->p_children, child_proc, NULL);
if (result)
{
DEBUG(DB_EXEC, "sys_fork(): failed to add child process to proc_table...\n");
}
DEBUG(DB_EXEC,"sys_fork(): allocating data...\n");
void **data = kmalloc(2*sizeof(void*));
data[0] = (void*)child_tf;
data[1] = (void*)child_as;
result = thread_fork(child_name, child_proc, &enter_forked_process, data, 0);
if (result)
{
kfree(child_name);
kfree(child_tf);
as_destroy(child_as);
proc_destroy(child_proc);
return ENOMEM;
}
*retval = child_proc->p_pid;
DEBUG(DB_EXEC, "sys_fork(): thread_fork returned: curproc=%u, child_proc=%u\n",curproc->p_pid,child_proc->p_pid);
return 0;
}
struct addrspace* copy_parent_addrspace(struct addrspace *padrs)
{
struct addrspace *cadrs;
as_copy(padrs, &cadrs);
return cadrs;
}