void trap(struct trapframe *tf)
{
// used for previous projects
if (pls_read(current) == NULL) {
trap_dispatch(tf);
} else {
// keep a trapframe chain in stack
struct trapframe *otf = pls_read(current)->tf;
pls_read(current)->tf = tf;
bool in_kernel = trap_in_kernel(tf);
trap_dispatch(tf);
pls_read(current)->tf = otf;
if (!in_kernel) {
may_killed();
if (pls_read(current)->need_resched) {
schedule();
}
}
}
}
int
do_linux_waitpid(int pid, int *code_store) {
struct mm_struct *mm = current->mm;
if (code_store != NULL) {
if (!user_mem_check(mm, (uintptr_t)code_store, sizeof(int), 1)) {
return -E_INVAL;
}
}
struct proc_struct *proc, *cproc;
bool intr_flag, haskid;
repeat:
cproc = current;
haskid = 0;
if (pid > 0) {
proc = find_proc(pid);
if (proc != NULL) {
do {
if (proc->parent == cproc) {
haskid = 1;
if (proc->state == PROC_ZOMBIE) {
goto found;
}
break;
}
cproc = next_thread(cproc);
} while (cproc != current);
}
}
/* we do NOT have group id, so..*/
else if(pid==0 || pid==-1){ /* pid == 0 */
do {
proc = cproc->cptr;
for (; proc != NULL; proc = proc->optr) {
haskid = 1;
if (proc->state == PROC_ZOMBIE) {
goto found;
}
}
cproc = next_thread(cproc);
} while (cproc != current);
}else{ //pid<-1
//TODO
return -E_INVAL;
}
if (haskid) {
current->state = PROC_SLEEPING;
current->wait_state = WT_CHILD;
schedule();
may_killed();
goto repeat;
}
return -E_BAD_PROC;
found:
if (proc == idleproc || proc == initproc) {
panic("wait idleproc or initproc.\n");
}
int exit_code = proc->exit_code;
int return_pid = proc->pid;
local_intr_save(intr_flag);
{
unhash_proc(proc);
remove_links(proc);
}
local_intr_restore(intr_flag);
put_kstack(proc);
kfree(proc);
int ret = 0;
if (code_store != NULL) {
lock_mm(mm);
{
int status = exit_code << 8;
if (!copy_to_user(mm, code_store, &status, sizeof(int))) {
ret = -E_INVAL;
}
}
unlock_mm(mm);
}
return (ret == 0) ? return_pid : ret;
}
// do_wait - wait one OR any children with PROC_ZOMBIE state, and free memory space of kernel stack
// - proc struct of this child.
// NOTE: only after do_wait function, all resources of the child proces are free.
int do_wait(int pid, int *code_store)
{
struct mm_struct *mm = current->mm;
if (code_store != NULL) {
if (!user_mem_check(mm, (uintptr_t) code_store, sizeof(int), 1)) {
return -E_INVAL;
}
}
struct proc_struct *proc, *cproc;
bool intr_flag, haskid;
repeat:
cproc = current;
haskid = 0;
if (pid != 0) {
proc = find_proc(pid);
if (proc != NULL) {
do {
if (proc->parent == cproc) {
haskid = 1;
if (proc->state == PROC_ZOMBIE) {
goto found;
}
break;
}
cproc = next_thread(cproc);
} while (cproc != current);
}
} else {
do {
proc = cproc->cptr;
for (; proc != NULL; proc = proc->optr) {
haskid = 1;
if (proc->state == PROC_ZOMBIE) {
goto found;
}
}
cproc = next_thread(cproc);
} while (cproc != current);
}
if (haskid) {
current->state = PROC_SLEEPING;
current->wait_state = WT_CHILD;
schedule();
may_killed();
goto repeat;
}
return -E_BAD_PROC;
found:
if (proc == idleproc || proc == initproc) {
panic("wait idleproc or initproc.\n");
}
int exit_code = proc->exit_code;
spin_lock_irqsave(&proc_lock, intr_flag);
{
unhash_proc(proc);
remove_links(proc);
}
spin_unlock_irqrestore(&proc_lock, intr_flag);
put_kstack(proc);
kfree(proc);
int ret = 0;
if (code_store != NULL) {
lock_mm(mm);
{
if (!copy_to_user
(mm, code_store, &exit_code, sizeof(int))) {
ret = -E_INVAL;
}
}
unlock_mm(mm);
}
return ret;
}
