From: greg@kroah.com (Greg Kroah-Hartman)
To: kernelnewbies@lists.kernelnewbies.org
Subject: User space <==> kernel space for device wakeups.
Date: Wed, 8 Oct 2014 09:25:45 -0700 [thread overview]
Message-ID: <20141008162545.GA22573@kroah.com> (raw)
In-Reply-To: <20141008155750.GF2017@vega.codepro.be>
On Wed, Oct 08, 2014 at 05:57:50PM +0200, Kristof Provost wrote:
> On 2014-10-08 21:14:43 (+0530), Jeshwanth Kumar N K <jeshkumar555@gmail.com> wrote:
> > Wayback when I was working on some project to wake up userspace program for
> > every rising edge in GPIO pin (hall sensor), I use to send signal to the
> > PID from kernel, before that userspace has to register its PID with kernel
> > module.
> >
> I've seen a certain vendor[1] do something similar. They saved the task
> pointer for whichever process made the magical ioctl() call and used it
> to send signals from the interrupt handler. It worked, right up to the
> point where the process went away and then the kernel panicked.
Exactly, don't do that :)
Finding out the real problem that is attempting to be solved would be
good...
greg k-h
next prev parent reply other threads:[~2014-10-08 16:25 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-10-08 7:39 User space <==> kernel space for device wakeups manty kuma
2014-10-08 13:29 ` Greg KH
2014-10-08 15:44 ` Jeshwanth Kumar N K
2014-10-08 15:57 ` Kristof Provost
2014-10-08 16:25 ` Greg Kroah-Hartman [this message]
2014-10-08 16:31 ` Jeshwanth Kumar N K
2014-10-08 16:38 ` Greg Kroah-Hartman
2014-10-08 16:53 ` Jeshwanth Kumar N K
2014-10-08 17:32 ` Greg Kroah-Hartman
2014-10-08 17:47 ` Jeshwanth Kumar N K
2014-10-09 15:18 ` buyitian
2014-10-08 18:30 ` Jinqiang Zeng
2014-10-09 1:38 ` manty kuma
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