| Message ID | 20250121095739.986006-1-rppt@kernel.org (mailing list archive) |
|---|---|
| Headers | show |
| Series | x86/module: rework ROX cache to avoid writable copy | expand |
On Tue, Jan 21, 2025 at 11:57:29AM +0200, Mike Rapoport wrote: > Kirill A. Shutemov (1): > x86/mm/pat: restore large ROX pages after fragmentation The duplication between pmd and pud collapse is a bit annoying, but so be it. > Mike Rapoport (Microsoft) (9): > x86/mm/pat: cpa-test: fix length for CPA_ARRAY test > x86/mm/pat: drop duplicate variable in cpa_flush() > execmem: don't remove ROX cache from the direct map > execmem: add API for temporal remapping as RW and restoring ROX afterwards > module: introduce MODULE_STATE_GONE > module: 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() > x86: re-enable EXECMEM_ROX support All these look good on a first reading, let me go build and test the various options.
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_rox() capable of restoring large pages (more details are in patch 3). Since this is really about x86, I believe this should go in via tip tree. The patches also available in git https://git.kernel.org/rppt/h/execmem/x86-rox/v9 v2 changes: * only collapse large mappings in set_memory_rox() * simplify RW <-> ROX remapping * don't remove ROX cache pages from the direct map (patch 4) v1: https://lore.kernel.org/all/20241227072825.1288491-1-rppt@kernel.org [1] https://lore.kernel.org/all/20241209083818.GK8562@noisy.programming.kicks-ass.net Kirill A. Shutemov (1): x86/mm/pat: restore large ROX pages after fragmentation Mike Rapoport (Microsoft) (9): x86/mm/pat: cpa-test: fix length for CPA_ARRAY test x86/mm/pat: drop duplicate variable in cpa_flush() execmem: don't remove ROX cache from the direct map execmem: add API for temporal remapping as RW and restoring ROX afterwards module: introduce MODULE_STATE_GONE module: 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() x86: re-enable EXECMEM_ROX support arch/um/kernel/um_arch.c | 11 +- arch/x86/Kconfig | 1 + 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 | 220 +++++++++++++++++- include/linux/execmem.h | 31 +++ include/linux/module.h | 22 +- 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 | 39 ++-- 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 + 28 files changed, 442 insertions(+), 283 deletions(-) base-commit: ffd294d346d185b70e28b1a28abe367bbfe53c04