Re: Bug in VM pages protection handling.

From: Pawel Jakub Dawidek (nick_at_garage.freebsd.pl)
Date: 07/15/03

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    Date: Tue, 15 Jul 2003 11:47:08 +0200
To: "Alan L. Cox" <alc@imimic.com>

    On Tue, Jul 15, 2003 at 04:06:18AM -0500, Alan L. Cox wrote:
    +> Could you post a pointer to the kernel module's source code?

    It is hard to reproduce, you need majordomo for this:)
    Here is discussion about this:

            https://sourceforge.net/mailarchive/forum.php?thread_id=2722479&forum_id=7642

    And here is procedure that should handle everything:

            # cd /usr/ports/mail/majordomo
            # make install clean
            # cd /tmp
            # cvs -d:pserver:anonymous@cvs.sf.net:/cvsroot/cerb-ng co -D "July 11, 2003" cerb-ng
            # cd cerb-ng
            # make; make install
            # kldload cerb
            # /sbin/cbctl -f /path/to/majordomo-test.cb
            and:
            # echo test | /usr/local/majordomo/wrapper resend -l test-l test-l-outgoing
            Here you should have 'Bus error'.

    Policy majordomo-test.cb is attached. Look into logs for PIDs of processes
    that was monitored by cerb, they got read-only pages and look at PID
    of process exiting with SIGBUS.

    I've spend two days(?) on tracking this down in cerb, so good luck!

    PS. Note that we're talking about FreeBSD 4.x here. 

    -- 
Pawel Jakub Dawidek                       pawel@dawidek.net
UNIX Systems Programmer/Administrator     http://garage.freebsd.pl
Am I Evil? Yes, I Am!                     http://cerber.sourceforge.net

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