[PATCH v4 00/11] livepatch,module: Remove .klp.arch and module_disable_ro()

Josh Poimboeuf
2020-04-29T15:25:16Z

v4:
- Fixed rebase bisection regression [Miroslav]
- Made module_enable_ro() static [Jessica]
- Added Acked-by's

v3:
- klp: split klp_write_relocations() into object/section specific
functions [joe]
- s390: fix plt/got writes [joe]
- s390: remove text_mutex usage [mbenes]
- x86: do text_poke_sync() before releasing text_mutex [peterz]
- split x86 text_mutex changes into separate patch [mbenes]

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 (only for static keys
which live in vmlinux).

- Remove the last module_disable_ro() usage.

For more background, see this thread:

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

This has been tested with kpatch-build integration tests and klp-convert
selftests.

Josh Poimboeuf (8):
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()
x86/module: Use text_mutex in apply_relocate_add()
module: Make module_enable_ro() static again

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 | 147 +++++++++------
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 | 8 -
kernel/livepatch/core.c | 177 +++++++++++-------
kernel/module.c | 27 +--
12 files changed, 279 insertions(+), 236 deletions(-)
delete mode 100644 arch/x86/kernel/livepatch.c

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2.21.1