Date: Sun, 28 Oct 2018 12:00:10 -0700 From: John-Mark Gurney <jmg@funkthat.com> To: Mark Johnston <markj@freebsd.org> Cc: Andreas Longwitz <longwitz@incore.de>, "freebsd-dtrace@freebsd.org" <freebsd-dtrace@freebsd.org> Subject: Re: Why my DTrace script does not work after installing a new kernel without reboot Message-ID: <20181028190010.GF75530@funkthat.com> In-Reply-To: <20181027225339.GA4191@spy> References: <5BD4E965.9040006@incore.de> <20181027225339.GA4191@spy>
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Mark Johnston wrote this message on Sat, Oct 27, 2018 at 18:53 -0400:
> On Sun, Oct 28, 2018 at 12:40:37AM +0200, Andreas Longwitz wrote:
> > I have a simple, probably stupid question. I run FreeBSD 10.4 Stable
> > r338093 and use the script
> >
> > #!/usr/sbin/dtrace -s
> >
> > dtrace:::BEGIN
> > {
> > printf("pf_default_rule.timeout[2/16/17]=%d/%d/%d\n",
> > kernel`pf_default_rule.timeout[2], kernel`pf_default_rule.timeout[16],
> > kernel`pf_default_rule.timeout[17]);
> > }
> >
> > The output normally is
> > pf_default_rule.timeout[2/16/17]=86400/6000/12000
> >
> > But when I change the sourcefile /sys/netpfil/pf/pf.c trying a patch and
> > build and install the new kernel but without reboot, then the output of
> > the script is wrong:
> >
> > pf_default_rule.timeout[2/16/17]=3237216124/0/0
> >
> > After reboot everything works again.
>
> Does your patch change the layout of the timeout structure? If so, the
> problem is that dtrace(1) is using the CTF from kern.bootfile, but that
> doesn't match the layout of the structures used by the running kernel.
Except that the default make installkernel will adjust kern.bootfile to
point to the correct old location..
--
John-Mark Gurney Voice: +1 415 225 5579
"All that I will do, has been done, All that I have, has not."
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