[PATCH v2 0/9] livepatch,module: Remove .klp.arch and module_disable_ro()

From: Josh Poimboeuf
Date: Fri Apr 17 2020 - 10:05:33 EST


v2:
- add vmlinux.ko check [peterz]
- remove 'klp_object' forward declaration [mbenes]
- use text_mutex [jeyu]
- fix documentation TOC [jeyu]
- fix s390 issues [mbenes]
- upstream kpatch-build now supports this
(though it's only enabled for Linux >= 5.8)

These patches add simplifications and improvements for some issues Peter
found six months ago, as part of his non-writable text code (W^X)
cleanups.

Highlights:

- Remove the livepatch arch-specific .klp.arch sections, which were used
to do paravirt patching and alternatives patching for livepatch
replacement code.

- Add support for jump labels in patched code.

- Remove the last module_disable_ro() usage.

For more background, see this thread:

https://lkml.kernel.org/r/20191021135312.jbbxsuipxldocdjk@treble

I've tested this with a modified kpatch-build:

https://github.com/jpoimboe/kpatch/tree/no-klp-arch

(I'm planning to submit a github PR for kpatch-build, once I get
the updated unit/integration tests sorted out.



Josh Poimboeuf (6):
livepatch: Disallow vmlinux.ko
livepatch: Apply vmlinux-specific KLP relocations early
livepatch: Prevent module-specific KLP rela sections from referencing
vmlinux symbols
s390: Change s390_kernel_write() return type to match memcpy()
livepatch: Remove module_disable_ro() usage
module: Remove module_disable_ro()

Peter Zijlstra (3):
livepatch: Remove .klp.arch
s390/module: Use s390_kernel_write() for late relocations
x86/module: Use text_poke() for late relocations

Documentation/livepatch/module-elf-format.rst | 15 +-
arch/s390/include/asm/uaccess.h | 2 +-
arch/s390/kernel/module.c | 125 ++++++++++------
arch/s390/mm/maccess.c | 9 +-
arch/um/kernel/um_arch.c | 16 +++
arch/x86/kernel/Makefile | 1 -
arch/x86/kernel/livepatch.c | 53 -------
arch/x86/kernel/module.c | 43 +++++-
include/linux/livepatch.h | 17 ++-
include/linux/module.h | 2 -
kernel/livepatch/core.c | 133 +++++++++++-------
kernel/module.c | 22 +--
12 files changed, 243 insertions(+), 195 deletions(-)
delete mode 100644 arch/x86/kernel/livepatch.c

--
2.21.1