task2 finished

kernel/proc.h

@@ -94,11 +94,12 @@ struct proc {
 
   // wait_lock must be held when using this:
   struct proc *parent;         // Parent process
-
-  // these are private to the process, so p->lock need not be held.
+ // these are private to the process, so p->lock need not be held.
   uint64 kstack;               // Virtual address of kernel stack
   uint64 sz;                   // Size of process memory (bytes)
   pagetable_t pagetable;       // User page table
+  // 进程的结构体中需要加上usyscall字段
+  struct usyscall *usyscall;   // data page for usyscall
   struct trapframe *trapframe; // data page for trampoline.S
   struct context context;      // swtch() here to run process
   struct file *ofile[NOFILE];  // Open files