From: "Bjørn Mork" <bjorn-yOkvZcmFvRU@public.gmane.org>
To: Alan Stern <stern-nwvwT67g6+6dFdvTe/nMLpVzexx5G7lz@public.gmane.org>
Cc: "Emilio López"
<emilio.lopez-ZGY8ohtN/8pPYcu2f3hruQ@public.gmane.org>,
gregkh-hQyY1W1yCW8ekmWlsbkhG0B+6BGkLq7r@public.gmane.org,
kborer-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org,
k.opasiak-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org,
reillyg-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org,
keescook-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org,
linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
linux-usb-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
jorgelo-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org,
dan.carpenter-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org
Subject: Re: [PATCH v2] usb: devio: Add ioctl to disallow detaching kernel USB drivers.
Date: Mon, 25 Jan 2016 16:32:14 +0100 [thread overview]
Message-ID: <8737tln08x.fsf@nemi.mork.no> (raw)
In-Reply-To: <Pine.LNX.4.44L0.1601251016490.1849-100000-IYeN2dnnYyZXsRXLowluHWD2FQJk+8+b@public.gmane.org> (Alan Stern's message of "Mon, 25 Jan 2016 10:21:21 -0500 (EST)")
Alan Stern <stern-nwvwT67g6+6dFdvTe/nMLpVzexx5G7lz@public.gmane.org> writes:
> On Mon, 25 Jan 2016, Bjørn Mork wrote:
>
>> I don't feel much like an expert here, but I can certainly make up an
>> opinion anyway :)
>>
>> Since 64bits kernels allow usb devio with interface numbers up to 63, I
>> guess you need __u64 to avoid limiting the range? Limiting will create
>> all sorts of followup problems, so it's definitely easiest to just go
>> with __u64.
>
> But the Linux USB stack only allows up to 32 interfaces (see
> include/linux/usb.h):
>
> /* this maximum is arbitrary */
> #define USB_MAXINTERFACES 32
Ah, I totally missed that. Thanks
> So there's no point using a 64-bit value.
>
> On the other hand, this value is supposed to be the same size as
> ps->ifclaimed, which is used as an argument to clear_bit(), set_bit(),
> and test_bit(). Those routines require unsigned long.
Maybe the input to these should be clamped to USB_MAXINTERFACES?
Bjørn
WARNING: multiple messages have this Message-ID (diff)
From: "Bjørn Mork" <bjorn@mork.no>
To: Alan Stern <stern@rowland.harvard.edu>
Cc: "Emilio López" <emilio.lopez@collabora.co.uk>,
gregkh@linuxfoundation.org, kborer@gmail.com,
k.opasiak@samsung.com, reillyg@chromium.org,
keescook@chromium.org, linux-api@vger.kernel.org,
linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org,
jorgelo@chromium.org, dan.carpenter@oracle.com
Subject: Re: [PATCH v2] usb: devio: Add ioctl to disallow detaching kernel USB drivers.
Date: Mon, 25 Jan 2016 16:32:14 +0100 [thread overview]
Message-ID: <8737tln08x.fsf@nemi.mork.no> (raw)
In-Reply-To: <Pine.LNX.4.44L0.1601251016490.1849-100000@iolanthe.rowland.org> (Alan Stern's message of "Mon, 25 Jan 2016 10:21:21 -0500 (EST)")
Alan Stern <stern@rowland.harvard.edu> writes:
> On Mon, 25 Jan 2016, Bjørn Mork wrote:
>
>> I don't feel much like an expert here, but I can certainly make up an
>> opinion anyway :)
>>
>> Since 64bits kernels allow usb devio with interface numbers up to 63, I
>> guess you need __u64 to avoid limiting the range? Limiting will create
>> all sorts of followup problems, so it's definitely easiest to just go
>> with __u64.
>
> But the Linux USB stack only allows up to 32 interfaces (see
> include/linux/usb.h):
>
> /* this maximum is arbitrary */
> #define USB_MAXINTERFACES 32
Ah, I totally missed that. Thanks
> So there's no point using a 64-bit value.
>
> On the other hand, this value is supposed to be the same size as
> ps->ifclaimed, which is used as an argument to clear_bit(), set_bit(),
> and test_bit(). Those routines require unsigned long.
Maybe the input to these should be clamped to USB_MAXINTERFACES?
Bjørn
next prev parent reply other threads:[~2016-01-25 15:32 UTC|newest]
Thread overview: 54+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-11-25 15:45 [PATCH v1 0/1] ioctl to disallow detaching kernel USB drivers Emilio López
2015-11-25 15:45 ` Emilio López
2015-11-25 15:45 ` [PATCH v1] usb: devio: Add " Emilio López
2015-11-26 8:59 ` Peter Chen
2015-11-26 8:59 ` Peter Chen
2015-11-26 9:20 ` Dan Carpenter
[not found] ` <1448466334-21346-1-git-send-email-emilio.lopez-ZGY8ohtN/8pPYcu2f3hruQ@public.gmane.org>
2015-11-26 9:19 ` [PATCH v1 0/1] " Krzysztof Opasiak
2015-11-26 9:19 ` Krzysztof Opasiak
2015-11-26 17:29 ` Greg KH
[not found] ` <20151126172914.GA8671-U8xfFu+wG4EAvxtiuMwx3w@public.gmane.org>
2015-11-27 8:44 ` Krzysztof Opasiak
2015-11-27 8:44 ` Krzysztof Opasiak
[not found] ` <565817FD.3090409-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org>
2015-11-28 2:39 ` Greg KH
2015-11-28 2:39 ` Greg KH
[not found] ` <20151128023925.GA5177-U8xfFu+wG4EAvxtiuMwx3w@public.gmane.org>
2015-11-30 9:08 ` Oliver Neukum
2015-11-30 9:08 ` Oliver Neukum
2015-11-30 16:16 ` Alan Stern
[not found] ` <Pine.LNX.4.44L0.1511301113120.1938-100000-IYeN2dnnYyZXsRXLowluHWD2FQJk+8+b@public.gmane.org>
2015-11-30 17:12 ` Krzysztof Opasiak
2015-11-30 17:12 ` Krzysztof Opasiak
[not found] ` <565C8376.6070505-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org>
2015-11-30 17:20 ` Greg KH
2015-11-30 17:20 ` Greg KH
[not found] ` <20151130172028.GA1088-U8xfFu+wG4EAvxtiuMwx3w@public.gmane.org>
2015-11-30 18:48 ` Krzysztof Opasiak
2015-11-30 18:48 ` Krzysztof Opasiak
[not found] ` <565C9A18.6000006-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org>
2016-01-19 16:39 ` Emilio López
2016-01-19 16:39 ` Emilio López
[not found] ` <569E66DF.3050004-ZGY8ohtN/8pPYcu2f3hruQ@public.gmane.org>
2016-01-19 18:07 ` Greg KH
2016-01-19 18:07 ` Greg KH
[not found] ` <20160119180752.GA10487-U8xfFu+wG4EAvxtiuMwx3w@public.gmane.org>
2016-01-21 23:54 ` [PATCH v2] usb: devio: Add " Emilio López
2016-01-21 23:54 ` Emilio López
[not found] ` <1453420476-26125-1-git-send-email-emilio.lopez-ZGY8ohtN/8pPYcu2f3hruQ@public.gmane.org>
2016-01-22 9:41 ` Bjørn Mork
2016-01-22 9:41 ` Bjørn Mork
[not found] ` <8760ymdk94.fsf-lbf33ChDnrE/G1V5fR+Y7Q@public.gmane.org>
2016-01-25 1:40 ` Emilio López
2016-01-25 1:40 ` Emilio López
2016-01-25 8:39 ` Bjørn Mork
[not found] ` <87powqrr1s.fsf-lbf33ChDnrE/G1V5fR+Y7Q@public.gmane.org>
2016-01-25 15:21 ` Alan Stern
2016-01-25 15:21 ` Alan Stern
[not found] ` <Pine.LNX.4.44L0.1601251016490.1849-100000-IYeN2dnnYyZXsRXLowluHWD2FQJk+8+b@public.gmane.org>
2016-01-25 15:32 ` Bjørn Mork [this message]
2016-01-25 15:32 ` Bjørn Mork
[not found] ` <8737tln08x.fsf-lbf33ChDnrE/G1V5fR+Y7Q@public.gmane.org>
2016-01-25 15:46 ` Alan Stern
2016-01-25 15:46 ` Alan Stern
2016-01-22 16:10 ` Alan Stern
2016-01-22 16:10 ` Alan Stern
2016-01-25 2:01 ` Emilio López
2016-02-04 3:20 ` [PATCH v3] " Emilio López
2016-02-04 3:20 ` Emilio López
2016-02-04 16:27 ` Alan Stern
2016-02-04 16:27 ` Alan Stern
[not found] ` <Pine.LNX.4.44L0.1602041122340.1515-100000-IYeN2dnnYyZXsRXLowluHWD2FQJk+8+b@public.gmane.org>
2016-02-08 1:56 ` Emilio López
2016-02-08 1:56 ` Emilio López
[not found] ` <1454556057-18956-1-git-send-email-emilio.lopez-ZGY8ohtN/8pPYcu2f3hruQ@public.gmane.org>
2016-02-04 3:46 ` Greg KH
2016-02-04 3:46 ` Greg KH
2016-02-15 1:41 ` [PATCH v4] " Emilio López
2016-02-15 1:41 ` Emilio López
[not found] ` <1455500516-21590-1-git-send-email-emilio.lopez-ZGY8ohtN/8pPYcu2f3hruQ@public.gmane.org>
2016-02-18 18:44 ` Alan Stern
2016-02-18 18:44 ` Alan Stern
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