From: Richard Weinberger <richard.weinberger@gmail.com>
To: Xenomai <xenomai@xenomai.org>
Subject: RTDM module ownership
Date: Thu, 2 Jul 2020 10:32:39 +0200 [thread overview]
Message-ID: <CAFLxGvxru2Y==qboUgwHdsQvOT5MEL2O8CexkhkQpKz0Qj+jqw@mail.gmail.com> (raw)
Hi!
I'm working on a kernel module which is used on plain Linux and
Xenomai (RTDM), while reviewing RTDM to understand refcounting I found
something that is not entirely clear to me.
Why does __rtdm_dev_open() not grab a reference on the RTDM module owner?
This leads to the case where one can rmmod the module while it is in use.
Unloading will block uninterruptible in rtdm_dev_unregister() in the
module's cleanup funktion.
In contrast, on regular Linux rmmod will refuse to unload the module
if the device node is still open because fops_get() or other helpers
gained a reference on the owner.
--
Thanks,
//richard
next reply other threads:[~2020-07-02 8:32 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-02 8:32 Richard Weinberger [this message]
2020-07-03 6:14 ` RTDM module ownership Jan Kiszka
2020-07-03 6:22 ` Richard Weinberger
2020-07-03 9:10 ` Jan Kiszka
2020-07-03 9:26 ` Richard Weinberger
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