argint32 bug fix.

d00a87f6 · Silas Boyd-Wickizer · 455c6a88 · d00a87f6
--- a/syscall.c
+++ b/syscall.c
@@ -64,7 +64,7 @@ argint32(int n, int *ip)
  u64 i;

  r = fetchint64(myproc()->tf->rsp + 8 + 8*n, &i);
-  if (r > 0)
+  if (r >= 0)
    *ip = i;
  return r;
 }