lkml.org 
[lkml]   [2015]   [Mar]   [2]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: gadgetfs broken since 7f7f25e8
Am 02.03.2015 um 11:20 schrieb Al Viro:
> On Mon, Mar 02, 2015 at 10:13:27AM +0100, Richard Weinberger wrote:
>> On Mon, Mar 2, 2015 at 9:28 AM, Alexander Holler <holler@ahsoftware.de> wrote:
>>> Hello.
>>>
>>> Commit 7f7f25e82d54870df24d415a7007fbd327da027b (introduced with 3.16) broke
>>> dynamic changing of file_operations->[read|write].
>>>
>>> At least gadgetfs is a victim.
>>>
>>> Feel free to ask me off-list for a patch as I don't want to end up in
>>> annoying discussions on Linux kernel lists anymore.
>>>
>>> Alexander Holler
>>
>> CC'ing Al.
>
> I know. FWIW, gadgetfs is one of the very few places that tried to pull that
> crap off and it had always been seriously racy. I've posted a partial analysis
> about a month ago (<20150204190645.GJ29656@ZenIV.linux.org.uk>).
>
> If Alexander (or anybody else) has a patch that really fixes that thing,
> I would certainly like to see it. If not, I'll try to cook something,
> but I'm not very familiar with that code. I really hope that this patch
> isn't "modify ->f_mode to match ->f_op change" - that's too racy.
> We'll obviously need to fix the userland-visible breakage in that one,
> but that's not the way to go...

I exactly did what you've assumed, I've just fixed f_mode but not the
already existing races which I haven't introduced. So I was right in not
sending a patch as would have been blamed for not rewriting everything
as so often.






\
 
 \ /
  Last update: 2015-03-02 13:01    [W:0.066 / U:0.888 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site