[OpenAFS-devel] OpenAFS on FreeBSD 6.1-BETA (lwp and -fPIC problems)

[David G. Andersen]

I spent a bit of time trying to get the latest OpenAFS from CVS
to work under FreeBSD 6.1, and I've hit a small wall in the
amd64 process.s code in lwp.  A suggested fix from someone who 
knows amd64 better than I would be welcome. 

Changes required to get it to work this far:
  - The previously mentioned -mpreferred-stack-boundary=2 problem
     https://www.openafs.org/pipermail/openafs-info/2006-January/020946.html
     (but also added -fPIC to the MakefileProto.FBSD.in)
  - Created a param file and new SYS_NAME_ID in much the same way the
    above poster did:

#define SYS_NAME_ID_amd64_fbsd_60        3009
#define SYS_NAME_ID_amd64_fbsd_61        3010

  - Created a new amd64_fbsd_* subsection in osconf.m4 and
    added -fPIC to the CCOBJ and SHLIB_CFLAGS lines

And then hit the remaining problem:  When bundling liblwp.a into a
shared library, I get the error:

  /usr/bin/ld: process.o: relocation R_X86_64_32S can not be used when making a shared object; recompile with -fPIC

This comes from process.amd64.s.  The first problem in this file is the
references to the external PRE_Block variable:

        movl    $1,_C_LABEL(PRE_Block)  /* Do not allow any interrupts */
and
        movl    $0,_C_LABEL(PRE_Block)  /* clear it up... */

But this is where I've hit the end of what I know about amd64.  I
tried replacing these with GOT-relative references:

        movq    PRE_Block@GOTPCREL(%rip), %rax
        movl    $1,(%rax)  /* Do not allow any interrupts */

(moving the save of %rax appropriately).  This makes the file compile,
but then FreeBSD complains when I try to load the resulting module:

Feb 18 02:28:16 moo kernel: kldload: Unsupported file type
Feb 18 02:28:16 moo kernel: kldload: unexpected relocation type 7
Feb 18 02:28:16 moo kernel: link_elf: symbol copyinstr undefined

Clue or patch would be very welcome at this point.  I've kind of run
out of time to sink into getting it running.

  -Dave