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

From: Christophe Leroy
Date: Thu Jun 22 2023 - 06:55:14 EST


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