Fail exec if called directly from a worker

dbd13d5c · Silas Boyd-Wickizer · e3f250b7 · dbd13d5c
--- a/kernel/exec.cc
+++ b/kernel/exec.cc
@@ -189,6 +189,9 @@ exec(const char *path, char **argv)
  if((ip = namei(myproc()->cwd, path)) == 0)
    return -1;

+  if(myproc()->worker != nullptr)
+    return -1;
+
  gc_begin_epoch();

  // Check ELF header