[PATCH v2 00/13] Fix LKDTM for PPC64/IA64/PARISC

Christophe Leroy
2021-10-14T05:49:49Z

PPC64/IA64/PARISC have function descriptors. LKDTM doesn't work
on those three architectures because LKDTM messes up function
descriptors with functions.

This series does some cleanup in the three architectures and
refactors function descriptors so that it can then easily use it
in a generic way in LKDTM.

Patch 8 is not absolutely necessary but it is a good trivial cleanup.

Changes in v2:
- Addressed received comments
- Moved dereference_[kernel]_function_descriptor() out of line
- Added patches to remove func_descr_t and func_desc_t in powerpc
- Using func_desc_t instead of funct_descr_t
- Renamed HAVE_DEREFERENCE_FUNCTION_DESCRIPTOR to HAVE_FUNCTION_DESCRIPTORS
- Added a new lkdtm test to check protection of function descriptors

Christophe Leroy (13):
powerpc: Move 'struct ppc64_opd_entry' back into asm/elf.h
powerpc: Rename 'funcaddr' to 'addr' in 'struct ppc64_opd_entry'
powerpc: Remove func_descr_t
powerpc: Prepare func_desc_t for refactorisation
ia64: Rename 'ip' to 'addr' in 'struct fdesc'
asm-generic: Use HAVE_FUNCTION_DESCRIPTORS to define associated stubs
asm-generic: Define 'func_desc_t' to commonly describe function
descriptors
asm-generic: Refactor dereference_[kernel]_function_descriptor()
lkdtm: Force do_nothing() out of line
lkdtm: Really write into kernel text in WRITE_KERN
lkdtm: Fix lkdtm_EXEC_RODATA()
lkdtm: Fix execute_[user]_location()
lkdtm: Add a test for function descriptors protection

arch/ia64/include/asm/elf.h | 2 +-
arch/ia64/include/asm/sections.h | 25 ++-------
arch/ia64/kernel/module.c | 6 +--
arch/parisc/include/asm/sections.h | 17 +++---
arch/parisc/kernel/process.c | 21 --------
arch/powerpc/include/asm/code-patching.h | 2 +-
arch/powerpc/include/asm/elf.h | 6 +++
arch/powerpc/include/asm/sections.h | 30 ++---------
arch/powerpc/include/asm/types.h | 6 ---
arch/powerpc/include/uapi/asm/elf.h | 8 ---
arch/powerpc/kernel/module_64.c | 38 +++++--------
arch/powerpc/kernel/signal_64.c | 8 +--
drivers/misc/lkdtm/core.c | 1 +
drivers/misc/lkdtm/lkdtm.h | 1 +
drivers/misc/lkdtm/perms.c | 68 ++++++++++++++++++++----
include/asm-generic/sections.h | 13 ++++-
include/linux/kallsyms.h | 2 +-
kernel/extable.c | 23 +++++++-
18 files changed, 138 insertions(+), 139 deletions(-)

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2.31.1