core: refactor fork function

src/multitasking/fork.c

@@ -4,21 +4,6 @@
 #include "string.h"
 #include "thread.h"
 
-static struct tcb *thread_clone(struct tcb *thread)
-{
-	struct tcb *new_tcb = umalloc(sizeof(struct tcb));
-	if (!new_tcb)
-		return NULL;
-	new_tcb->tid = thread->tid;
-	new_tcb->esp0 = kalloc_pages(STACK_SIZE);
-	if (!new_tcb->esp0) {
-		delete_thread(new_tcb);
-		return NULL;
-	}
-	memcpy(new_tcb->esp0, thread->esp0, STACK_SIZE);
-	return new_tcb;
-}
-
 static void free_pts(void)
 {
 	for (size_t i = USER_PT_END / 2; PD[i]; i++) {
@@ -49,6 +34,32 @@ static int copy_pt(uint32_t *pt_src, uint32_t *pt_dest, size_t pd_index)
 	return 0;
 }
 
+static int copy_thread_list(struct pcb *new_pcb)
+{
+	struct list *e;
+	struct list *prev = NULL;
+	for (struct list *it = current_pcb->thread_list; it; it = it->next) {
+		e = kmalloc(sizeof(struct list));
+		if (!e)
+			return -1;
+		if (prev)
+			prev->next = e;
+		else
+			new_pcb->thread_list = e;
+		struct tcb *new_content = kmalloc(sizeof(struct tcb));
+		if (!new_content) {
+			kfree(e);
+			return -1;
+		}
+		memcpy(new_content, it->content, sizeof(struct tcb));
+		new_content->process = new_pcb;
+		e->next = NULL;
+		e->content = new_content;
+		prev = e;
+	}
+	return 0;
+}
+
 static int deep_copy(struct pcb *new_pcb)
 {
 	if (PD[USER_PT_END / 2])
@@ -69,6 +80,8 @@ static int deep_copy(struct pcb *new_pcb)
 		new_pcb->heap[i] = (uint32_t)new_pt | INIT_FLAGS;
 	}
 	bzero(PD + USER_PT_END / 2, i * sizeof(uint32_t));
+	if (copy_thread_list(new_pcb) < 0)
+		return -1;
 	return 0;
 }
 
@@ -85,32 +98,10 @@ pid_t fork(void)
 	new_pcb->daddy = current_pcb;
 	lst_add_back(&current_pcb->children, new_node);
 
-	if (deep_copy(new_pcb) < 0)
+	if (deep_copy(new_pcb) < 0) {
-		goto error;
-	struct list *e;
-	struct list *prev = NULL;
-	for (struct list *it = current_pcb->thread_list; it; it = it->next) {
-		e = kmalloc(sizeof(struct list));
-		if (!e)
-			goto error;
-		if (prev)
-			prev->next = e;
-		else
-			new_pcb->thread_list = e;
-		struct tcb *new_content = kmalloc(sizeof(struct tcb));
-		if (!new_content) {
-			kfree(e);
-			goto error;
-		}
-		memcpy(new_content, it->content, sizeof(struct tcb));
-		new_content->process = new_pcb;
-		e->next = NULL;
-		e->content = new_content;
-		prev = e;
-	}
-
-	return current_pcb == new_pcb ? 0 : new_pcb->pid;
-error:
 		remove_process(new_pcb);
 		return -1;
 	}
+
+	return current_pcb == new_pcb ? 0 : new_pcb->pid;
+}