Re: [PATCH v6 00/10] kbuild: yet another series of cleanups (modpost, LTO, MODULE_REL_CRCS, export.h)

[matoro]

Hi Masahiro, I'm sorry to raise this after release but this seems to be 
broken on SOME architectures.  So far I have tested:

Affected - sparc, alpha
Unaffected - riscv, ia64

The affected systems are unable to load modules, similar to the 
previously reported issue.  All module loading fails with "disagrees 
about version of symbol module_layout".

Bisect blames 7b4537199a4a8480b8c3ba37a2d44765ce76cd9b, but this does 
not revert cleanly.  Presumably CONFIG_MODVERSIONS=n would fix, but this 
is a pretty core feature.

Unlike the issue Sedat reported, this is on a GNU toolchain, no clang 
involved.

Here are the configs I am using (with make olddefconfig on upgrade to 
5.19):

Broken - sparc - https://dpaste.com/5A8F2JD6U
Broken - alpha - https://dpaste.com/FYKK23L9X
Working - riscv - https://dpaste.com/HV6Y4V6NT
Working - ia64 - https://dpaste.com/HDLDNEAK4

Please let me know if there's anything I can do to help track down this 
regression.


-------- Original Message --------
Subject: Re: [PATCH v6 00/10] kbuild: yet another series of cleanups 
(modpost, LTO, MODULE_REL_CRCS, export.h)
Date: 2022-05-13 08:20
From: Masahiro Yamada <masahiroy@xxxxxxxxxx>
To: Linux Kbuild mailing list <linux-kbuild@xxxxxxxxxxxxxxx>

On Fri, May 13, 2022 at 8:42 PM Masahiro Yamada <masahiroy@xxxxxxxxxx> 
wrote:
> This is the third batch of cleanups in this development cycle.


This series is available at
git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild.git
 lto-cleanup-v6


> Changes in v6:
>   - Fix false-positive warnings when CONFIG_TRIM_UNUSED_KSYMS=y
>
> Changes in v5:
>   - Fix the build error when CONFIG_DEBUG_INFO_BTF=y (reported by 
> Nathan)
>   - Clean up arch/m68k/include/asm/export.h (Nick)
>   - Keep gen_symversions (and will be removed by a later patch)
>   - Add more comments in the script
>
> Changes in v4:
>   - Rename .vmlinux-symver.c to .vmlinux.export.c
>     because I notice this approach is useful for further cleanups,
>     not only for modversioning but also for overall EXPORT_SYMBOL.
>   - New patch
>   - New.
>     Resent of my previous submission.
>     
> https://lore.kernel.org/all/20210831074004.3195284-10-masahiroy@xxxxxxxxxx/
>   - New
>     Resent of my previous submission
>     
> https://lore.kernel.org/linux-kbuild/20210831074004.3195284-11-masahiroy@xxxxxxxxxx/
>
> Changes in v3:
>   - New patch
>
> Changes in v2:
>   - Simplify the implementation (parse .cmd files after ELF)
>   - New patch
>  - replace the chain of $(if ...) with $(and )
>   - New patch
>   - New patch
>
> Masahiro Yamada (10):
>   modpost: extract symbol versions from *.cmd files
>   kbuild: link symbol CRCs at final link, removing
>     CONFIG_MODULE_REL_CRCS
>   kbuild: stop merging *.symversions
>   genksyms: adjust the output format to modpost
>   kbuild: do not create *.prelink.o for Clang LTO or IBT
>   kbuild: check static EXPORT_SYMBOL* by script instead of modpost
>   kbuild: make built-in.a rule robust against too long argument error
>   kbuild: make *.mod rule robust against too long argument error
>   kbuild: add cmd_and_savecmd macro
>   kbuild: rebuild multi-object modules when objtool is updated
>
>  arch/m68k/include/asm/Kbuild    |   1 +
>  arch/m68k/include/asm/export.h  |   2 -
>  arch/powerpc/Kconfig            |   1 -
>  arch/s390/Kconfig               |   1 -
>  arch/um/Kconfig                 |   1 -
>  include/asm-generic/export.h    |  22 ++-
>  include/linux/export-internal.h |  16 +++
>  include/linux/export.h          |  30 ++--
>  init/Kconfig                    |   4 -
>  kernel/module.c                 |  10 +-
>  scripts/Kbuild.include          |  10 +-
>  scripts/Makefile.build          | 134 ++++++------------
>  scripts/Makefile.lib            |   7 -
>  scripts/Makefile.modfinal       |   5 +-
>  scripts/Makefile.modpost        |   9 +-
>  scripts/check-local-export      |  64 +++++++++
>  scripts/genksyms/genksyms.c     |  18 +--
>  scripts/link-vmlinux.sh         |  33 ++---
>  scripts/mod/modpost.c           | 236 +++++++++++++++++++++-----------
>  19 files changed, 320 insertions(+), 284 deletions(-)
>  delete mode 100644 arch/m68k/include/asm/export.h
>  create mode 100644 include/linux/export-internal.h
>  create mode 100755 scripts/check-local-export
>
> --
> 2.32.0