Re: git: 349cc55c9796 - main - Merge llvm-project main llvmorg-14-init-10186-gff7f2cfa959b

On 5/16/22 8:09 PM, Charlie Li wrote:
> Brooks Davis wrote:
>> On Mon, May 16, 2022 at 10:47:49AM -0400, Charlie Li wrote:
>>> Dimitry Andric wrote:
>>>> This was also reported by another user, and it turned out they were
>>>> using WITHOUT_CROSS_COMPILER= in src.conf. If you also have that, try
>>>> removing it and rebuilding.
>>>>
>>> Yeah I eventually figured that part out. Worked around (first attempt)
>>> by building with devel/llvm14 CROSS_TOOLCHAIN, but resulted in certain
>>> kernel modules (zfs and a few more) with malformed relocations.
>>> Subsequent rebuild with the new world's toolchain corrected that.
>>
>> Does that mean we're missing patches in the port?  Hopefully anything
>> this critical can be merged into LLVM 14.0.3.
>>
> Probably:
> 
> May 15 22:34:08 current-builder kernel: ---<<BOOT>>---
> May 15 22:34:08 current-builder kernel: Copyright (c) 1992-2022 The
> FreeBSD Project.
> May 15 22:34:08 current-builder kernel: Copyright (c) 1979, 1980, 1983,
> 1986, 1988, 1989, 1991, 1992, 1993, 1994
> May 15 22:34:08 current-builder kernel:         The Regents of the
> University of California. All rights reserved.
> May 15 22:34:08 current-builder kernel: FreeBSD is a registered
> trademark of The FreeBSD Foundation.
> May 15 22:34:08 current-builder kernel: FreeBSD 14.0-CURRENT #121
> main-n255657-48a1a6be196: Sun May 15 21:59:12 EDT 2022
> May 15 22:34:08 current-builder kernel:
> root@current-builder:/usr/obj/usr/src/amd64.amd64/sys/GENERIC-NODEBUG amd64
> May 15 22:34:08 current-builder kernel: clang version 14.0.2
> [...]
> May 15 22:34:08 current-builder kernel: kldload: unexpected relocation
> type 42, symbol index 8321

These are all type 42:

#define	R_X86_64_REX_GOTPCRELX	42

It's not a LLVM bug so much as it is probably missing support in the kernel and/or
loader for this type of relocation.  kldxref might also need updating.

I suspect due to a mismatch of old lld with new clang or some such that the old
lld failed to resolve these relocations to some other type or something weird like
that?

-- 
John Baldwin