linux-kernel - Re: [PATCH v2 2/4] usb: gadget: mass_storage: Store lun_opts in fsg

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <Pine.LNX.4.44L0.1504081012240.1384-100000@iolanthe.rowland.org>
Date:	Wed, 8 Apr 2015 10:15:32 -0400 (EDT)
From:	Alan Stern <stern@...land.harvard.edu>
To:	Krzysztof Opasiak <k.opasiak@...sung.com>
cc:	balbi@...com, <gregkh@...uxfoundation.org>, <jlbec@...lplan.org>,
	<andrzej.p@...sung.com>, <m.szyprowski@...sung.com>,
	<linux-api@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
	<linux-usb@...r.kernel.org>
Subject: Re: [PATCH v2 2/4] usb: gadget: mass_storage: Store lun_opts in
 fsg_opts

On Wed, 8 Apr 2015, Krzysztof Opasiak wrote:

> Signed-off-by: Krzysztof Opasiak <k.opasiak@...sung.com>
> ---
>  drivers/usb/gadget/function/f_mass_storage.c |    5 +++++
>  drivers/usb/gadget/function/f_mass_storage.h |    1 +
>  2 files changed, 6 insertions(+)
> 
> diff --git a/drivers/usb/gadget/function/f_mass_storage.c b/drivers/usb/gadget/function/f_mass_storage.c
> index 811929c..095b618 100644
> --- a/drivers/usb/gadget/function/f_mass_storage.c
> +++ b/drivers/usb/gadget/function/f_mass_storage.c
> @@ -3372,6 +3372,8 @@ static struct config_group *fsg_lun_make(struct config_group *group,
>  	}
>  	opts->lun = fsg_opts->common->luns[num];
>  	opts->lun_id = num;
> +	BUG_ON(fsg_opts->lun_opts[num]);

This is not a good idea.  BUG_ON should hardly ever be used.  In fact,
Linus has said that the only time BUG_ON should be used is when things
are so badly messed up that it is better to crash the computer than to
let it continue.

What's wrong with using WARN_ON instead?

> diff --git a/drivers/usb/gadget/function/f_mass_storage.h b/drivers/usb/gadget/function/f_mass_storage.h
> index b4866fc..0a7c656 100644
> --- a/drivers/usb/gadget/function/f_mass_storage.h
> +++ b/drivers/usb/gadget/function/f_mass_storage.h
> @@ -81,6 +81,7 @@ struct fsg_opts {
>  	struct fsg_common *common;
>  	struct usb_function_instance func_inst;
>  	struct fsg_lun_opts lun0;
> +	struct fsg_lun_opts *lun_opts[FSG_MAX_LUNS];

This looks strange.  Why is the entry for LUN 0 duplicated?

Alan Stern

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/