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From: Al Viro <viro@ZenIV.linux.org.uk>
To: Alan Stern <stern@rowland.harvard.edu>
Cc: Alexander Holler <holler@ahsoftware.de>,
	Richard Weinberger <richard.weinberger@gmail.com>,
	USB list <linux-usb@vger.kernel.org>,
	LKML <linux-kernel@vger.kernel.org>, Felipe Balbi <balbi@ti.com>
Subject: Re: gadgetfs broken since 7f7f25e8
Date: Tue, 3 Mar 2015 21:42:49 +0000	[thread overview]
Message-ID: <20150303214249.GS29656@ZenIV.linux.org.uk> (raw)
In-Reply-To: <Pine.LNX.4.44L0.1503031042200.1655-100000@iolanthe.rowland.org>

On Tue, Mar 03, 2015 at 10:47:14AM -0500, Alan Stern wrote:
> On Tue, 3 Mar 2015, Al Viro wrote:
> 
> > Looking at that thing again...  why do they need to be dummy?  After all,
> > those methods start with get_ready_ep(), which will fail unless we have
> > ->state == STATE_EP_ENABLED.  So they'd be failing just fine until that
> > first write() anyway.  Let's do the following:
> 
> In addition to the changes you made, it looks like you will need the 
> following or something similar (also untested).  I'm not sure if this 
> is race-free, but it's better than before.

Right, ep0 has the same kind of problem...


> @@ -1240,6 +1241,10 @@ static int
>  ep0_fasync (int f, struct file *fd, int on)
>  {
>  	struct dev_data		*dev = fd->private_data;
> +
> +	if (dev->state <= STATE_DEV_OPENED)
> +		return -ENODEV;
> +

Er...  What is protecting dev->state here?  Matter of fact, what's the
point of that check at all?  Right now you have .fasync = ep0_fasync
both in ep0_io_operations and in dev_init_operations, so your delta
changes the existing semantics...

  reply	other threads:[~2015-03-03 21:42 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
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 [this message]
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

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