[PATCH v2 00/14] powerpc/objtool: uaccess validation for PPC32 (v2)

Christophe Leroy christophe.leroy at csgroup.eu
Thu Jun 22 20:54:22 AEST 2023


This series adds UACCESS validation for PPC32. It includes half
a dozen of changes to objtool core.

It is almost mature, performs code analysis for all PPC32, only
missing marking of UACCESS enable/disable for book3s/32.

Most object files are correctly decoded, only a few
'unreachable instruction' warnings remain due to more complex
switch table cases:
- Loading of table address after the dynamic jump
- Nested switches

It allowed to detect some UACCESS mess in a few files. They've been
fixed through other patches.

Christophe Leroy (14):
  powerpc/kuap: Avoid unnecessary reads of MD_AP
  powerpc/kuap: Avoid useless jump_label on empty function
  powerpc/kuap: Refactor static branch for disabling kuap
  powerpc/kuap: Make disabling KUAP at boottime impossible except on
    book3s/64
  powerpc/kuap: KUAP enabling/disabling functions must be
    __always_inline
  Revert "powerpc/bug: Provide better flexibility to
    WARN_ON/__WARN_FLAGS() with asm goto"
  objtool: Allow an architecture to disable objtool on ASM files
  objtool: Fix JUMP_ENTRY_SIZE for bi-arch like powerpc
  objtool: Add INSN_RETURN_CONDITIONAL
  objtool: Add support for relative switch tables
  objtool: Remove too strict constraint in jump table search
  objtool: Add support for more complex UACCESS control
  powerpc/bug: Annotate reachable after warning trap
  powerpc: Implement UACCESS validation on PPC32

 arch/Kconfig                                  |  5 ++
 arch/powerpc/Kconfig                          |  2 +
 arch/powerpc/include/asm/book3s/32/kup.h      | 39 ++++-----
 arch/powerpc/include/asm/book3s/64/kup.h      | 36 ++++----
 arch/powerpc/include/asm/bug.h                | 77 ++++-------------
 arch/powerpc/include/asm/kup.h                | 66 ++++++++++-----
 arch/powerpc/include/asm/nohash/32/kup-8xx.h  | 52 +++++-------
 arch/powerpc/include/asm/nohash/kup-booke.h   | 49 +++++------
 arch/powerpc/include/asm/uaccess.h            |  6 +-
 arch/powerpc/kernel/misc_32.S                 |  2 +-
 arch/powerpc/kernel/traps.c                   |  9 +-
 arch/powerpc/kexec/core_32.c                  |  4 +-
 arch/powerpc/mm/book3s32/kuap.c               | 18 ++--
 arch/powerpc/mm/init-common.c                 |  3 +
 arch/powerpc/mm/nohash/kup.c                  | 11 +--
 include/linux/objtool.h                       | 14 ++++
 scripts/Makefile.build                        |  4 +
 tools/objtool/arch/powerpc/decode.c           | 82 +++++++++++++++++--
 .../arch/powerpc/include/arch/special.h       |  2 +-
 tools/objtool/arch/powerpc/special.c          | 44 +++++++++-
 tools/objtool/arch/x86/special.c              |  3 +-
 tools/objtool/check.c                         | 79 ++++++++++++++----
 tools/objtool/include/objtool/arch.h          |  1 +
 tools/objtool/include/objtool/elf.h           |  1 +
 tools/objtool/include/objtool/special.h       |  2 +-
 tools/objtool/special.c                       | 55 ++++++-------
 26 files changed, 395 insertions(+), 271 deletions(-)

-- 
2.40.1



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