From: Russell King <rmk+lkml@arm.linux.org.uk>
To: Rusty Russell <rusty@rustcorp.com.au>
Cc: Karsten Keil <kkeil@suse.de>,
linux-kernel@vger.kernel.org, Michal Hocko <mhocko@suse.cz>,
richard kennedy <richard@rsk.demon.co.uk>,
Dan Williams <dan.j.williams@intel.com>,
Dmitry Torokhov <dmitry.torokhov@gmail.com>,
dwmw2@infradead.org, Scott Wood <scottwood@freescale.com>,
netdev@vger.kernel.org, Al Viro <viro@zeniv.linux.org.uk>
Subject: Re: [RFC] Suspicious bug in module refcounting
Date: Wed, 4 Feb 2009 10:11:30 +0000 [thread overview]
Message-ID: <20090204101130.GB19498@flint.arm.linux.org.uk> (raw)
In-Reply-To: <200902041418.09630.rusty@rustcorp.com.au>
On Wed, Feb 04, 2009 at 02:18:08PM +1030, Rusty Russell wrote:
> gameport.c, serio.c and input.c increment their own refcount, but to get
> into those init functions someone must be holding a refcount already (ie. a
> module depends on this module). Ditto cyber2000fb.c, and MTD.
Err, wrong. cyber2000fb.c does it in its module initialization function
to prevent the module (when built for Shark) from being unloaded. It
does this because it's from the days of 2.2 kernels and no one bothered
writing the module unload support for Shark. I'm certainly not in a
position to do that.
Since you can't unload a module while its initialization function is
running, so someone else must be holding a refcount (the insmod process).
I'm not saying that it's the right solution, I'm saying that this is how
it's evolved.
If someone has an idea on what to do about it then patches will be given
due consideration.
--
Russell King
Linux kernel 2.6 ARM Linux - http://www.arm.linux.org.uk/
maintainer of:
next prev parent reply other threads:[~2009-02-04 10:12 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-02-03 13:47 [RFC] Suspicious bug in module refcounting Karsten Keil
2009-02-03 15:02 ` richard kennedy
2009-02-04 3:48 ` Rusty Russell
2009-02-04 10:11 ` Russell King [this message]
2009-02-04 10:55 ` Rusty Russell
2009-02-04 10:59 ` Russell King
2009-02-04 16:33 ` Dan Williams
2009-02-06 22:41 ` Karsten Keil
2009-02-09 15:18 ` Michal Hocko
2009-02-10 3:15 ` Rusty Russell
2009-02-10 3:42 ` Karsten Keil
2009-02-10 10:31 ` Michal Hocko
2009-02-10 13:36 ` Rusty Russell
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=20090204101130.GB19498@flint.arm.linux.org.uk \
--to=rmk+lkml@arm.linux.org.uk \
--cc=dan.j.williams@intel.com \
--cc=dmitry.torokhov@gmail.com \
--cc=dwmw2@infradead.org \
--cc=kkeil@suse.de \
--cc=linux-kernel@vger.kernel.org \
--cc=mhocko@suse.cz \
--cc=netdev@vger.kernel.org \
--cc=richard@rsk.demon.co.uk \
--cc=rusty@rustcorp.com.au \
--cc=scottwood@freescale.com \
--cc=viro@zeniv.linux.org.uk \
/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