访问不正确地址的指针OS161

Question

我使用的是OS161，在process.c中有一段如下所示的代码：

void
process_exit(int exit_code)
{
   splhigh(); 
    curthread->p_process->exited_flag = 1; // Process exited
    curthread->p_process->exit_code = exit_code;
    struct process * process;

    // Now all the child process will be orphant, we need to adopt them
    // Search through the process table, change all children's ppid

    for (int i = 0; i < array_getnum(process_table); i++) {
        *process = array_getguy(process_table, i);
        if (process != NULL && process->ppid == curthread->p_process->pid) { // We found a child here, it should be a orphant now
            process->ppid = 1; // Now the init(boot/menu) process should adopt the child process
            process->adopted_flag = 1;
        }
    }

    V(curthread->p_process->sem_exit); // Now signal processes which are waiting

    // Now exit the thread
    thread_exit();


}

process结构的定义：

struct process{

char* process_name;

struct addrspace *process_vmspace;


struct vnode *process_cwd;

pid_t pid;
pid_t ppid;
int adopted_flag;
int exited_flag;
int exit_code;
struct thread *p_thread;
struct semaphore *sem_exit;
};

我收到了一个END OF FILE错误，GDB告诉我这是定义process_exit的地方。我对操作系统编程不是很熟悉，有人知道为什么会发生这种情况吗？

编辑:这是GDB消息：

panic: Fatal exception 3 (TLB miss on store) in kernel mode
panic: EPC 0x8001a008, exception vaddr 0x18
sleep: Dropping thread <boot/menu>
panic: I can't handle this... I think I'll just die now...

我做了gdb list *0x8001a008，它指向curthread->p_process->exited_flag = 1;。

Answer 1

根据@ctx的分析，尝试以下代码来证明我们是否在正确的轨道上：

void
process_exit(int exit_code)
{
    splhigh();
    if (curthread  &&  curthread->p_process)
    {
        curthread->p_process->exited_flag = 1; // Process exited
        curthread->p_process->exit_code = exit_code;
    }
    // same code as before below here ...