fuck that fork syscall

src/mm/paging.c

@@ -265,5 +265,5 @@ uint32_t* copy_page_dir(uint32_t* page_dir_virt)
     }
     debug_log("ENDENDENDEND\n");
 
-    return new_pagedir - 0xC0000000;
+    return new_pagedir;
 }

src/tasking/syscalls.c

@@ -58,9 +58,12 @@ int sys_exit(TrapFrame *tf)
     return error_code;
 }
 
+extern void trapret(void);
+
 int sys_fork(TrapFrame *tf)
 {
     debug_log("FORKFORKFORKFORK\n");
+    scheduler_lock();
 
     uint32_t* new_pd = copy_page_dir(current->pagedir);
     if (!new_pd) {
@@ -94,39 +97,42 @@ int sys_fork(TrapFrame *tf)
     map_page(kstack_physical, child->kstack, PAGE_PRESENT | PAGE_RW);
     debug_log("child->kstack: %X\n", child->kstack);
 
-    memcpy(child->kstack, current->kstack, KSTACKSIZE);
-    debug_log("Kernel stack copied\n");
+    uint8_t* sp = (uint8_t*)(child->kstack + KSTACKSIZE);
 
-    uint32_t tf_offset = (uint32_t)current->tf - (uint32_t)current->kstack;
-    child->tf = (TrapFrame*)((uint32_t)child->kstack + tf_offset);
-    debug_log("child->tf: %X\n", child->tf);
-
-    if (current->context) {
-        uint32_t context_offset = (uint32_t)current->context - (uint32_t)current->kstack;
-        child->context = (Context*)((uint32_t)child->kstack + context_offset);
-        debug_log("child->context: %X\n", child->context);
-    }
+    // 1. Place the TrapFrame on the child's stack.
+    sp -= sizeof(TrapFrame);
+    child->tf = (TrapFrame*)sp;
 
     *child->tf = *tf;
     child->tf->eax = 0;       // Child returns 0
     debug_log("Parent returns PID: %X, Child returns 0\n", child->pid);
 
+    sp -= sizeof(Context);
+    child->context = (Context*)sp;
+    memset(child->context, 0, sizeof(Context));
+
+    // 5. Set the child's starting instruction pointer to trapret.
+    // When the child is scheduled, it will execute trapret, which will
+    // restore the registers from the TrapFrame and iret to user mode.
+    child->context->eip = (uint32_t)trapret;
+
+    // 6. IMPORTANT: Set the child's kernel stack pointer for the scheduler.
+    child->kesp = (uint32_t)sp;
+
     for (int i = 0; i < MAX_OPEN_FILES; i++) {
         child->file_descriptors[i] = current->file_descriptors[i];
     }
     debug_log("File descriptors copied\n");
 
-    if (!queue) {
-        queue = child;
-        current = queue;
-    } else {
     Process* curr = queue;
-        while (curr->next)
+    while (curr->next) {
         curr = curr->next;
-        curr->next = child;
     }
+    curr->next = child;
     debug_log("Child added to queue\n");
     
+    scheduler_unlock(); // Release the lock
+
     return child->pid;
 }