linux-kernel - Re: [PATCH] tty: synclink_gt: unwind actions in error path of net device open

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Message-ID: <Y3PSTmUD37e0hsyr@kroah.com>
Date:   Tue, 15 Nov 2022 18:54:22 +0100
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     Paul Fulghum <paulkf@...rogate.com>
Cc:     Zhengchao Shao <shaozhengchao@...wei.com>,
        "linux-kernel@...r.kernel.org Mailing List" 
        <linux-kernel@...r.kernel.org>, Jiri Slaby <jirislaby@...nel.org>,
        akpm@...ux-foundation.org, weiyongjun1@...wei.com,
        yuehaibing@...wei.com
Subject: Re: [PATCH] tty: synclink_gt: unwind actions in error path of net
 device open

On Tue, Nov 15, 2022 at 09:38:32AM -0800, Paul Fulghum wrote:
> Resent again, last attempt still altered the plain text.
> 

Please send a v2 patch, and this is not needed as it would show up in
the commit log if we were to apply it, right?

> 
> Zhengchao Shao <shaozhengchao@...wei.com> identified by inspection bugs in the error path of hdlcdev_open() in synclink_gt.c

Properly wrap your lines at 72 columns please.

> 
> The function did not fully unwind actions in the error path. The use of try_module_get()/module_put() is unnecessary, potentially hazardous and is removed. The synclink_gt driver is already pinned any point the net device is registered, a requirement for calling this entry point.
> 
> The call hdlc_open() to init the generic HDLC layer is moved to after driver level init/checks and proper rollback of previous actions is added. This is a more sensible ordering as the most common error paths are at the driver level and the driver level rollbacks require less processing than hdlc_open()/hdlc_close().
> 
> This has been tested with supported hardware.
> 
> Signed-off-by:Paul Fulghum <paulkf@...rogate.com>

You need a Suggested-by: tag here.

And a space after the ':' character.

> 
> diff --git a/drivers/tty/synclink_gt.c b/drivers/tty/synclink_gt.c
> index 25e9befdda3a..72b76cdde534 100644
> --- a/drivers/tty/synclink_gt.c
> +++ b/drivers/tty/synclink_gt.c
> @@ -1433,16 +1433,8 @@ static int hdlcdev_open(struct net_device *dev)
>  	int rc;
>  	unsigned long flags;
>  
> -	if (!try_module_get(THIS_MODULE))
> -		return -EBUSY;

Thank you for removing this, this code pattern is always wrong :)

thanks,

greg k-h