tasking: make jump_usermode2 lock the scheduler & test the second user task

src/tasking/task.c

@@ -160,6 +160,7 @@ extern void test_user_function(void);
 extern void second_user_function(void);
 
 void jump_usermode2(void) {
+    scheduler_lock();
     void* code_phys = alloc_page();
     if (!code_phys) {
         printf("No memory for user code\n");
@@ -193,7 +194,9 @@ void jump_usermode2(void) {
            (uint32_t)code_phys, kernel_temp_virt);
 
     uint32_t* proc_pd = (uint32_t*)create_page_dir();
+    uint32_t* proc2_pd = (uint32_t*)create_page_dir();
     Process* p_task1 = task_create(0x400000, NULL, 0, 3, proc_pd);
+    Process* p_task2 = task_create(0x400000, NULL, 0, 3, proc2_pd);
 
     if (map_page_in_directory(p_task1->page_directory, 
         code_phys, 
@@ -204,4 +207,15 @@ void jump_usermode2(void) {
         // TODO: Terminate/cleanup p_task1, free code_phys_task1
         return;
     }
+
+    if (map_page_in_directory(p_task2->page_directory, 
+        second_code_phys, 
+        (void*)0x400000, 
+        PAGE_PRESENT | PAGE_RW | PAGE_USER) != 0) { // PAGE_USER is critical, PAGE_RW for now, can be R-X
+
+        printf("jump_usermode2: Failed to map user code into task's PD for PID %d\n", p_task2->pid);
+        // TODO: Terminate/cleanup p_task1, free code_phys_task1
+        return;
+    }
+    scheduler_unlock();
 }