demos/sgrep/dangerous_GFP_KERNEL.sgrep

   1
   2 // note that need -sgrep options otherwise don't detect
   3 // every situation as for instance:
   4
   5 // static int start_command_port(struct usb_serial *serial)
   6 // {
   7 //      spin_lock_irqsave(&command_info->lock, flags);
   8 //      if (!command_info->port_running) {
   9 //              retval = usb_submit_urb(command_port->read_urb, GFP_KERNEL);
  10 //              if (retval) {
  11 //                      err("%s - failed submitting read urb, error %d", __FUNCTION__, retval);
  12 //                      goto exit;
  13 //              }
  14 //      }
  15 //      command_info->port_running++;
  16 //
  17 // exit:
  18 //      spin_unlock_irqrestore(&command_info->lock, flags);
  19 //      return retval;
  20 // }
  21
  22 // note that better to send a .sgrep than a .cocci, that is
  23 // to not do the fix because sometimes the correct fix is not to replace
  24 // the use of GFP_KERNEL but instead to move the function call outside
  25 // the spin_locked region.
  26
  27 @@
  28 //expression E;
  29 identifier fn;
  30 @@
  31
  32 (
  33 spin_lock_irqsave(...)
  34 |
  35 spin_lock(...)
  36 )
  37 ... when != \(spin_unlock_irqrestore(...)\|spin_unlock(...)\)
  38 //- usb_submit_urb(E, GFP_KERNEL)
  39 fn(...,
  40 - GFP_KERNEL
  41 //+ GFP_ATOMIC
  42   ,...
  43   )
  44