NetBSD Problem Report #48536
From paul@whooppee.com Mon Jan 20 15:01:49 2014
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for <gnats-bugs@gnats.NetBSD.org>; Mon, 20 Jan 2014 15:01:49 +0000 (UTC)
Message-Id: <20140120150147.7B910248472@screamer.whooppee.com>
Date: Mon, 20 Jan 2014 07:01:47 -0800 (PST)
From: paul@whooppee.com
Reply-To: paul@whooppee.com
To: gnats-bugs@NetBSD.org
Subject: Modules need a ref-count mechanism external to the module
X-Send-Pr-Version: 3.95
>Number: 48536
>Category: kern
>Synopsis: Modules need a ref-count mechanism external to the module
>Confidential: no
>Severity: serious
>Priority: high
>Responsible: kern-bug-people
>State: closed
>Class: sw-bug
>Submitter-Id: net
>Arrival-Date: Mon Jan 20 15:05:00 +0000 2014
>Closed-Date: Wed Jun 09 03:28:11 +0000 2021
>Last-Modified: Wed Jun 09 03:28:11 +0000 2021
>Originator: Paul Goyette
>Release: NetBSD 6.99.28
>Organization:
-------------------------------------------------------------------------
| Paul Goyette | PGP Key fingerprint: | E-mail addresses: |
| Customer Service | FA29 0E3B 35AF E8AE 6651 | paul at whooppee.com |
| Network Engineer | 0786 F758 55DE 53BA 7731 | pgoyette at juniper.net |
| Kernel Developer | | pgoyette at netbsd.org |
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>Environment:
System: NetBSD screamer.whooppee.com 6.99.28 NetBSD 6.99.28 (WHOOPPEE (shared) 2013-12-14 23:34:52) #13: Sat Dec 14 16:05:43 PST 2013 paul@screamer.whooppee.com:/build/netbsd-local/obj/amd64/sys/arch/amd64/compile/WHOOPPEE amd64
Architecture: x86_64
Machine: amd64
>Description:
Device driver modules in particular require a ref-count mechanism to
determine whether or not it is safe for the driver to be unloaded.
Without this mechanism, a driver can be unloaded while the device is still
being accessed from user-land. Additionally, the driver's detach code
can attempt to release other resources (memory, pools, mutex, etc.) which
are still in use.
See recent discussion on current-users and source-changes-d for more
context.
http://mail-index.netbsd.org/current-users/2014/01/19/msg024107.html
http://mail-index.netbsd.org/source-changes-d/2014/01/19/msg006440.html
>How-To-Repeat:
>Fix:
>Release-Note:
>Audit-Trail:
From: Paul Goyette <paul@whooppee.com>
To: gnats-bugs@NetBSD.org
Cc:
Subject: Re: kern/48536: Modules need a ref-count mechanism external to the
module
Date: Fri, 10 Jun 2016 14:32:16 +0800 (PHT)
Additionally see the following more recent discussion on this topic.
Perhaps Taylor's suggesetion could be implemented?
http://mail-index.netbsd.org/tech-kern/2016/06/07/msg020656.html
+------------------+--------------------------+------------------------+
| Paul Goyette | PGP Key fingerprint: | E-mail addresses: |
| (Retired) | FA29 0E3B 35AF E8AE 6651 | paul at whooppee.com |
| Kernel Developer | 0786 F758 55DE 53BA 7731 | pgoyette at netbsd.org |
+------------------+--------------------------+------------------------+
State-Changed-From-To: open->closed
State-Changed-By: pgoyette@NetBSD.org
State-Changed-When: Wed, 09 Jun 2021 03:28:11 +0000
State-Changed-Why:
This was fixed a couple years ago with the merge of the new compat code.
That work introduced localcount(9) reference counting for modules.
>Unformatted:
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