From: "Mike Rapoport (Microsoft)" rppt@kernel.org
Hi,
Following Peter's comments [1] these patches rework handling of ROX caches for module text allocations.
Instead of using a writable copy that really complicates alternatives patching, temporarily remap parts of a large ROX page as RW for the time of module formation and then restore it's ROX protections when the module is ready.
To keep the ROX memory mapped with large pages, make set_memory code capable of restoring large pages (more details are in patch 3).
The patches also available in git https://git.kernel.org/rppt/h/execmem/x86-rox/v8
[1] https://lore.kernel.org/all/20241209083818.GK8562@noisy.programming.kicks-as...
Kirill A. Shutemov (1): x86/mm/pat: Restore large pages after fragmentation
Mike Rapoport (Microsoft) (7): x86/mm/pat: cpa-test: fix length for CPA_ARRAY test x86/mm/pat: drop duplicate variable in cpa_flush() execmem: add API for temporal remapping as RW and restoring ROX afterwards module: introduce MODULE_STATE_GONE modules: switch to execmem API for remapping as RW and restoring ROX Revert "x86/module: prepare module loading for ROX allocations of text" module: drop unused module_writable_address()
arch/um/kernel/um_arch.c | 11 +- arch/x86/entry/vdso/vma.c | 3 +- arch/x86/include/asm/alternative.h | 14 +- arch/x86/include/asm/pgtable_types.h | 2 + arch/x86/kernel/alternative.c | 181 ++++++--------- arch/x86/kernel/ftrace.c | 30 ++- arch/x86/kernel/module.c | 45 ++-- arch/x86/mm/pat/cpa-test.c | 2 +- arch/x86/mm/pat/set_memory.c | 216 +++++++++++++++++- include/linux/execmem.h | 31 +++ include/linux/module.h | 21 +- include/linux/moduleloader.h | 4 - include/linux/vm_event_item.h | 2 + kernel/module/kallsyms.c | 8 +- kernel/module/kdb.c | 2 +- kernel/module/main.c | 86 ++----- kernel/module/procfs.c | 2 +- kernel/module/strict_rwx.c | 9 +- kernel/tracepoint.c | 2 + lib/kunit/test.c | 2 + mm/execmem.c | 118 ++++++++-- mm/vmstat.c | 2 + samples/livepatch/livepatch-callbacks-demo.c | 1 + .../test_modules/test_klp_callbacks_demo.c | 1 + .../test_modules/test_klp_callbacks_demo2.c | 1 + .../livepatch/test_modules/test_klp_state.c | 1 + .../livepatch/test_modules/test_klp_state2.c | 1 + 27 files changed, 511 insertions(+), 287 deletions(-)