Re: [PATCH] epca: privent from panic on tty_register_driver()failure

From: Randy Dunlap
Date: Mon Oct 09 2006 - 11:44:39 EST


On Mon, 9 Oct 2006 18:06:03 +0900 Akinobu Mita wrote:

> This patch makes epca fail on initialization failure instead of panic.
>
> Cc: "Digi International, Inc" <Eng.Linux@xxxxxxxx>
> Signed-off-by: Akinobu Mita <akinobu.mita@xxxxxxxxx>
>
> drivers/char/epca.c | 32 +++++++++++++++++++++++---------
> 1 file changed, 23 insertions(+), 9 deletions(-)
>
> Index: work-fault-inject/drivers/char/epca.c
> ===================================================================
> --- work-fault-inject.orig/drivers/char/epca.c 2006-10-09 15:06:32.000000000 +0900
> +++ work-fault-inject/drivers/char/epca.c 2006-10-09 15:09:14.000000000 +0900
> @@ -1160,6 +1160,7 @@ static int __init pc_init(void)
> int crd;
> struct board_info *bd;
> unsigned char board_id = 0;
> + int err = -ENOMEM;
>
> int pci_boards_found, pci_count;
>
> @@ -1167,13 +1168,11 @@ static int __init pc_init(void)
>
> pc_driver = alloc_tty_driver(MAX_ALLOC);
> if (!pc_driver)
> - return -ENOMEM;
> + goto out1;
>
> pc_info = alloc_tty_driver(MAX_ALLOC);
> - if (!pc_info) {
> - put_tty_driver(pc_driver);
> - return -ENOMEM;
> - }
> + if (!pc_info)
> + goto out2;

and then out2: uses pc_info, if it's NULL. Is that OK?

>
> /* -----------------------------------------------------------------------
> If epca_setup has not been ran by LILO set num_cards to defaults; copy
> @@ -1373,11 +1372,17 @@ static int __init pc_init(void)
>
> } /* End for each card */
>
> - if (tty_register_driver(pc_driver))
> - panic("Couldn't register Digi PC/ driver");
> + err = tty_register_driver(pc_driver);
> + if (err) {
> + printk(KERN_ERR "Couldn't register Digi PC/ driver");
> + goto out3;
> + }
>
> - if (tty_register_driver(pc_info))
> - panic("Couldn't register Digi PC/ info ");
> + err = tty_register_driver(pc_info);
> + if (err) {
> + printk(KERN_ERR "Couldn't register Digi PC/ info ");
> + goto out4;
> + }
>
> /* -------------------------------------------------------------------
> Start up the poller to check for events on all enabled boards
> @@ -1388,6 +1393,15 @@ static int __init pc_init(void)
> mod_timer(&epca_timer, jiffies + HZ/25);
> return 0;
>
> +out4:
> + tty_unregister_driver(pc_driver);
> +out3:
> + put_tty_driver(pc_driver);
> +out2:
> + put_tty_driver(pc_info);
> +out1:
> + return err;
> +
> } /* End pc_init */
>
> /* ------------------ Begin post_fep_init ---------------------- */
> -

---
~Randy
-
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