lab syscall: finish

Conflicts:
	kernel/syscall.c
	kernel/syscall.h
	user/user.h
	user/usys.pl

1 files changed, 20 insertions, 0 deletions

diff --git a/kernel/proc.c b/kernel/proc.c
index 58a8a0b..5aa616f 100644
--- a/kernel/proc.c
+++ b/kernel/proc.c
@@ -299,6 +299,9 @@ fork(void)
   // copy saved user registers.
   *(np->trapframe) = *(p->trapframe);
 
+  // inherit trace_mask
+  np->trace_mask = p->trace_mask;
+
   // Cause fork to return 0 in the child.
   np->trapframe->a0 = 0;
 
@@ -686,3 +689,20 @@ procdump(void)
     printf("\n");
   }
 }
+
+int
+get_nproc(void)
+{
+  int n = 0;
+  struct proc *p;
+
+  for(int i = 0; i < NPROC; i++) {
+    p = &proc[i];
+    acquire(&p->lock);
+    if(p->state != UNUSED)
+      n++;
+    release(&p->lock);
+  }
+
+  return n;
+}