linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Al Viro <viro@ZenIV.linux.org.uk>
To: Richard Weinberger <richard.weinberger@gmail.com>
Cc: Alexander Holler <holler@ahsoftware.de>,
	USB list <linux-usb@vger.kernel.org>,
	LKML <linux-kernel@vger.kernel.org>
Subject: Re: gadgetfs broken since 7f7f25e8
Date: Mon, 2 Mar 2015 10:20:32 +0000	[thread overview]
Message-ID: <20150302102032.GP29656@ZenIV.linux.org.uk> (raw)
In-Reply-To: <CAFLxGvwbwhN7QAe-1og+=8_wg=f2WXq7wCUWvcgO8NkFZT5k=g@mail.gmail.com>

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...

  reply	other threads:[~2015-03-02 10:20 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-03-02  8:28 gadgetfs broken since 7f7f25e8 Alexander Holler
2015-03-02  9:13 ` Richard Weinberger
2015-03-02 10:20   ` Al Viro [this message]
2015-03-02 11:39     ` Alexander Holler
2015-03-02 13:02       ` Alexander Holler
2015-03-02 14:31         ` Alexander Holler
2015-03-03  8:39         ` Al Viro
2015-03-03 15:47           ` Alan Stern
2015-03-03 21:42             ` Al Viro
2015-03-04 15:31               ` Alan Stern
2015-03-07 11:23                 ` Alexander Holler
2015-03-07 20:03                   ` Alexander Holler
2015-03-07 20:51                     ` Al Viro
2015-03-07 20:59                       ` Alexander Holler
2015-03-07 21:08                     ` Alan Stern
2015-03-08 17:38                       ` Al Viro
2015-03-08 18:35                         ` Alan Stern
2015-03-08 19:20                           ` Al Viro
2015-03-10 21:07                           ` Felipe Balbi
2015-03-11 10:29                   ` Alexander Holler
2015-03-11 10:37                     ` Alexander Holler
2015-03-03 22:20             ` Al Viro

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20150302102032.GP29656@ZenIV.linux.org.uk \
    --to=viro@zeniv.linux.org.uk \
    --cc=holler@ahsoftware.de \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-usb@vger.kernel.org \
    --cc=richard.weinberger@gmail.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).