From: Greg KH <gregkh@linuxfoundation.org>
To: pp <mnipxh@gmail.com>
Cc: jslaby@suse.cz, linux-kernel@vger.kernel.org,
yanmin_zhang@linux.intel.com, xinhuix.pan@intel.com
Subject: Re: [PATCH] tty/tty_io.c: make a check before reuse cdev
Date: Mon, 21 Jul 2014 08:38:40 -0700 [thread overview]
Message-ID: <20140721153840.GA6802@kroah.com> (raw)
In-Reply-To: <53CD0BD4.4050007@gmail.com>
On Mon, Jul 21, 2014 at 08:47:16PM +0800, pp wrote:
> As reuse the cdev may cause panic. After we unregister the tty device, we may use tty_hangup() o
> other similar function to send a signal(SIGHUP) to process which has opend our device. But that
> not succeed if the process couldn't get the signal. for example, a process forked
> but his parent quited never get SIGHUP.
>
> Here is our scence.
> tty driver register its device and init the cdevs, then process "A" open one cdev.
> tty driver unregister its device and cdev_del the cdevs, call tty_hangup to (S)send signal SIGHUP to process A.
> But that step(S) fails.
How can that fail? What driver does this fail for?
> tty driver register its device and (D)init the cdevs again.
What driver does this with an "old" device, it should have created a new
one, otherwise, as you have pointed out, it's a bug.
thanks,
greg k-h
next prev parent reply other threads:[~2014-07-21 15:39 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-07-21 12:47 [PATCH] tty/tty_io.c: make a check before reuse cdev pp
2014-07-21 15:38 ` Greg KH [this message]
2014-07-22 11:52 ` xinhui.pan
2014-07-22 16:40 ` Peter Hurley
2014-07-22 17:38 ` Greg KH
2014-07-23 9:21 ` xinhui.pan
2014-07-23 16:04 ` Peter Hurley
2014-07-24 10:23 ` xinhui.pan
2014-07-25 15:24 ` xinhui
2014-07-23 16:07 ` One Thousand Gnomes
2014-07-24 11:01 ` xinhui.pan
2014-07-24 11:03 ` xinhui.pan
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