Re: [patch] 2.4.2-pre3: parport_pc init_module bug

[Jeff Garzik]

On Tue, 13 Feb 2001, Tim Waugh wrote:
> Here's a patch that fixes a bug that can cause PCI driver list
> corruption.  If parport_pc's init_module fails after it calls
> pci_register_driver, cleanup_module isn't called and so it's still
> registered when it gets unloaded.

> --- linux/drivers/parport/parport_pc.c.init	Tue Feb 13 23:31:25 2001
> +++ linux/drivers/parport/parport_pc.c	Tue Feb 13 23:35:56 2001
> @@ -89,6 +89,7 @@
>  } superios[NR_SUPERIOS] __devinitdata = { {0,},};
>  
>  static int user_specified __devinitdata = 0;
> +static int registered_parport;
>  
>  /* frob_control, but for ECR */
>  static void frob_econtrol (struct parport *pb, unsigned char m,
> @@ -2605,6 +2606,7 @@
>  	count += parport_pc_find_nonpci_ports (autoirq, autodma);
>  
>  	r = pci_register_driver (&parport_pc_pci_driver);
> +	registered_parport = 1;
>  	if (r > 0)
>  		count += r;

Bad patch.  It should be

	if (r >= 0) {
		registered_parport = 1;
		if (r > 0)
			count += r;
	}

If pci_register_driver returns < 0, the driver is not registered with
the system.

	Jeff