Re: 12.3-RC1 fails to compile perl,tcl86 (ipfw dtrace issue)

On Mon, Nov 22, 2021 at 10:45:09AM -0500, Mark Johnston wrote:
! On Sun, Nov 21, 2021 at 10:46:30PM +0100, Peter wrote:
! > ## this seems not have arrived on the list at first send ##
! > 
! > > dtrace: failed to establish error handler: "/usr/lib/dtrace/ipfw.d",
! > > line 106: failed to copy type of 'inp': Conflicting type is already defined
! > 
! > > That file ipfw.d appears to be new in 12.3, but I'm clueless what
! > > the error means (and why it happens only to me).
! > 
! > 
! > I figured out why - I have "device dtraceall" in my kernel. This is
! > reproducible: 
! > 
! > > root@y12y:/ # dtrace -h
! > > dtrace: -h requires one or more scripts or enabling options
! > > root@y12y:/ # kldload dtraceall
! > > root@y12y:/ # dtrace -h
! > > dtrace: failed to establish error handler: "/usr/lib/dtrace/ipfw.d", line 106: failed to copy type of 'inp': Conflicting type is already defined
! > > root@y12y:/ # kldunload dtraceall
! > > root@y12y:/ # dtrace -h
! > > dtrace: -h requires one or more scripts or enabling options
! > 
! > 
! > But we do already have a bug (#254483) for this error.
! > 
! > This bug was closed as duplicate to bug #258763, and the latter one
! > was closed as solved with a fix as stated here:
! > https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=258763#c7
! > 
! > 
! > But the fancy is:
! > 
! >  1. that fix appears to have missed the releng/12.3 branch by three
! >     days, so it is not in the code. But also 
! > 
! >  2. if applied, (*surprize*) that fix does NOT help!
! 
! Hmm, that is indeed surprising.  I'm able to reproduce the problem
! locally.
! 
! > More than one thing is wrong here, and bug #254483 is *not* a
! > duplicate to #258763.
! > 
! > The failure does NOT come from code covered by Mark Johnstons fix.
! > 
! > It comes from a neighboring section where Integers are compared, and
! > it fails with a type conflict 8bit vs. 32bit.
! > 
! > 
! > The problem must be within /usr/lib/dtrace/ipfw.d  - and indeed
! > it is (irrelevant parts stripped away):
! > 
! > > typedef struct ipfw_match_info {
! > >        struct mbuf     *m;
! > > } ipfw_match_info_t;
! > > 
! > > translator ipfw_match_info_t < struct ip_fw_args *p > {
! > >        m =             p->m;
! > > };
! > 
! > This does not work. Within the 'struct mbuf' definition is a
! > construct, that looks like this:
! > 
! > >        uint32_t         m_type:8,      /* type of data in this mbuf */
! > >                         m_flags:24;    /* flags; see below */
! > 
! > And it seems that is somehow the cause for the integer size conflict
! > (not implemented?)
! 
! How did you come to that conclusion?

Well, that's my trade secret :)

| Indeed, the problem had to do with handling of bitfield types in libctf.
| The problem you found is fixed by
| https://cgit.freebsd.org/src/commit/?id=3cbb4cc200f8a0ad7ed08233425ea54524a21f1c
| but that change was not merged to 12.  I just merged it to stable/12 and
| will try to get both libctf changes into 12.3, as both are required for
| dtrace to work properly while ipfw.ko is loaded.         

That would be great, but ... I gave that patch a quick try, and
doesn't yet seem to work, it is now a different error message:

> dtrace: failed to establish error handler: "/usr/lib/dtrace/ipfw.d", line 106: failed to copy type of 'inp': Invalid type identifier


Cheerio,
PMc