Re: [PATCH v1 0/6] objtool: Fixup alternate feature relative addresses

Le 05/05/2026 à 10:46, Sathvika Vasireddy a écrit :

This patch series implements build-time fixup of alternate feature
relative addresses for powerpc.

Previously, Nicholas Piggin proposed a build-time solution using a
custom PowerPC tool [1], which provided the foundation for this approach.
The current implementation leverages objtool's existing ELF parsing
infrastructure to do the same.

What are the changes since last RFC 
https://lore.kernel.org/linuxppc-dev/20260316062237.30948-1-sv@linux.ibm.com/ (local)

This patchset applies atop powerpc/merge branch.

[1] Original PowerPC tool approach:
     http://patchwork.ozlabs.org/project/linuxppc-dev/patch/20170521010130.13552-1-npiggin@gmail.com/

Testing:
Build and Boot tested on ppc64le, ppc64be, and ppc32be configs.

Sathvika Vasireddy (6):
   objtool/powerpc: Add build-time fixup of alternate feature branch
     targets
   objtool: Set ELF_F_LAYOUT flag to preserve vmlinux segment layout
   objtool: Fix "can't find starting instruction" warnings on vmlinux
   objtool/powerpc: Skip jump destination analysis and unnanotated
     intra-function call warnings for --ftr-fixup
   kbuild: Add objtool integration for PowerPC feature fixups
   powerpc: Enable build-time feature fixup processing by default

  Makefile                                  |   7 +
  arch/powerpc/Kconfig                      |   3 +
  arch/powerpc/Makefile                     |   5 +
  arch/powerpc/include/asm/feature-fixups.h |   2 +-
  arch/powerpc/kernel/vmlinux.lds.S         |   8 +-
  arch/powerpc/lib/feature-fixups.c         |  12 -
  scripts/Makefile.lib                      |   4 +-
  scripts/Makefile.vmlinux                  |  11 +-
  tools/objtool/arch/powerpc/decode.c       |  15 +-
  tools/objtool/arch/powerpc/special.c      | 451 ++++++++++++++++++++++
  tools/objtool/builtin-check.c             |   2 +
  tools/objtool/check.c                     |  57 ++-
  tools/objtool/elf.c                       |   4 +
  tools/objtool/include/objtool/builtin.h   |   1 +
  tools/objtool/include/objtool/special.h   |  56 +++
  tools/objtool/special.c                   |  29 ++
  16 files changed, 637 insertions(+), 30 deletions(-)