4.1: fixed last issues

kernel/exec.c

@@ -38,6 +38,11 @@ exec(char *path, char **argv)
   begin_op(ROOTDEV);
 
   if((ip = namei(path)) == 0){
+    acquire(&p->vma_lock);
+  p->stack_vma = svma;
+  p->heap_vma = hvma;
+  p->memory_areas = mem_areas;
+  release(&p->vma_lock);
     end_op(ROOTDEV);
     return -1;
   }
@@ -95,13 +100,11 @@ exec(char *path, char **argv)
   uint64 oldsz = p->sz;
 
   // Allocate two pages at the next page boundary.
-  // Use the second as the   stack.
+  // Use the second as the user stack.
   sz = PGROUNDUP(sz);
   // Add VMA for stack and save it in process
-  // acquire(&p->vma_lock);
   p->stack_vma = add_memory_area(p, sz + PGSIZE, sz + 2 * PGSIZE);
   if((sz = uvmalloc(pagetable, sz, sz + 2*PGSIZE)) == 0){
-    // release(&p->vma_lock);
     printf("exec: uvmalloc failed for the stack\n");
     goto bad;
   }
@@ -111,7 +114,6 @@ exec(char *path, char **argv)
 
   // Add VMA for heap and save it in process
   p->heap_vma = add_memory_area(p, sz, sz);
-  // release(&p->vma_lock);
 
   // Push argument strings, prepare rest of stack in ustack.
   for(argc = 0; argv[argc]; argc++) {