This is version 6 (5th version here [1]) of the series adding user-space support for the ARMv8.5 Memory Tagging Extension ([2], [3]). The patches are also available on this branch: git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux for-next/mte There are no ABI changes since v4/v5. I'll push these patches into linux-next for wider coverage, aiming for merging into 5.9. There are still some acks needed on the core mm and fs patches in the series. Thanks for the review/acks on v5. An important note, patch 7 introduces a core mm change to __split_huge_page_tail() so that it transfers the PG_arch_* flags from the head page to the tail ones. My understanding is that it shouldn't break anything but a more informed opinion from the mm folk is needed. Changes in this version: - __split_huge_page_tail() function update to preserve the PG_arch_* flags. - copy_mount_options() simplified with a fall-back to byte-by-byte copying. It turns out we arm64 can't guarantee an exact copy_from_user() with intra-page (tag) faults. - Dropped CONFIG_ARCH_USES_PG_ARCH_2 in favour of simply guarding PG_arch_2 by CONFIG_64BIT. - Added comments on where the new arch_swap_* and __HAVE_ARCH_SWAP_* macros should be defined by the arch code if they need to be overridden. - Fixed broken rebase conflict resolution in v5 re-introducing asm-generic/pgtable.h. - Added the acks received so far. [1] https://lore.kernel.org/linux-arm-kernel/20200624175244.25837-1-catalin.marinas@xxxxxxx/ [2] https://community.arm.com/developer/ip-products/processors/b/processors-ip-blog/posts/enhancing-memory-safety [3] https://developer.arm.com/-/media/Arm%20Developer%20Community/PDF/Arm_Memory_Tagging_Extension_Whitepaper.pdf [4] https://sourceware.org/pipermail/libc-alpha/2020-June/115039.html Catalin Marinas (14): arm64: mte: Use Normal Tagged attributes for the linear map mm: Preserve the PG_arch_* flags in __split_huge_page_tail() arm64: mte: Clear the tags when a page is mapped in user-space with PROT_MTE arm64: Avoid unnecessary clear_user_page() indirection arm64: mte: Tags-aware aware memcmp_pages() implementation arm64: mte: Add PROT_MTE support to mmap() and mprotect() mm: Introduce arch_validate_flags() arm64: mte: Validate the PROT_MTE request via arch_validate_flags() mm: Allow arm64 mmap(PROT_MTE) on RAM-based files arm64: mte: Allow user control of the tag check mode via prctl() arm64: mte: Allow user control of the generated random tags via prctl() arm64: mte: Restore the GCR_EL1 register after a suspend arm64: mte: Add PTRACE_{PEEK,POKE}MTETAGS support fs: Handle intra-page faults in copy_mount_options() Kevin Brodsky (1): mm: Introduce arch_calc_vm_flag_bits() Steven Price (4): mm: Add PG_arch_2 page flag mm: Add arch hooks for saving/restoring tags arm64: mte: Enable swap of tagged pages arm64: mte: Save tags when hibernating Vincenzo Frascino (7): arm64: mte: system register definitions arm64: mte: CPU feature detection and initial sysreg configuration arm64: mte: Add specific SIGSEGV codes arm64: mte: Handle synchronous and asynchronous tag check faults arm64: mte: Tags-aware copy_{user_,}highpage() implementations arm64: mte: Kconfig entry arm64: mte: Add Memory Tagging Extension documentation Documentation/arm64/cpu-feature-registers.rst | 2 + Documentation/arm64/elf_hwcaps.rst | 4 + Documentation/arm64/index.rst | 1 + .../arm64/memory-tagging-extension.rst | 297 ++++++++++++++++ arch/arm64/Kconfig | 28 ++ arch/arm64/include/asm/cpucaps.h | 3 +- arch/arm64/include/asm/cpufeature.h | 6 + arch/arm64/include/asm/hwcap.h | 1 + arch/arm64/include/asm/kvm_arm.h | 3 +- arch/arm64/include/asm/memory.h | 17 +- arch/arm64/include/asm/mman.h | 56 ++- arch/arm64/include/asm/mte.h | 86 +++++ arch/arm64/include/asm/page.h | 19 +- arch/arm64/include/asm/pgtable-prot.h | 2 + arch/arm64/include/asm/pgtable.h | 46 ++- arch/arm64/include/asm/processor.h | 4 + arch/arm64/include/asm/sysreg.h | 61 ++++ arch/arm64/include/asm/thread_info.h | 4 +- arch/arm64/include/uapi/asm/hwcap.h | 1 + arch/arm64/include/uapi/asm/mman.h | 1 + arch/arm64/include/uapi/asm/ptrace.h | 4 + arch/arm64/kernel/Makefile | 1 + arch/arm64/kernel/cpufeature.c | 61 ++++ arch/arm64/kernel/cpuinfo.c | 1 + arch/arm64/kernel/entry.S | 37 ++ arch/arm64/kernel/hibernate.c | 118 +++++++ arch/arm64/kernel/mte.c | 331 ++++++++++++++++++ arch/arm64/kernel/process.c | 31 +- arch/arm64/kernel/ptrace.c | 9 +- arch/arm64/kernel/signal.c | 9 + arch/arm64/kernel/suspend.c | 4 + arch/arm64/kernel/syscall.c | 10 + arch/arm64/lib/Makefile | 2 + arch/arm64/lib/mte.S | 151 ++++++++ arch/arm64/mm/Makefile | 1 + arch/arm64/mm/copypage.c | 25 +- arch/arm64/mm/dump.c | 4 + arch/arm64/mm/fault.c | 9 +- arch/arm64/mm/mmu.c | 22 +- arch/arm64/mm/mteswap.c | 83 +++++ arch/arm64/mm/proc.S | 8 +- arch/x86/kernel/signal_compat.c | 2 +- fs/namespace.c | 25 +- fs/proc/page.c | 3 + fs/proc/task_mmu.c | 4 + include/linux/kernel-page-flags.h | 1 + include/linux/mm.h | 8 + include/linux/mman.h | 23 +- include/linux/page-flags.h | 3 + include/linux/pgtable.h | 28 ++ include/trace/events/mmflags.h | 9 +- include/uapi/asm-generic/siginfo.h | 4 +- include/uapi/linux/prctl.h | 9 + mm/huge_memory.c | 4 + mm/mmap.c | 9 + mm/mprotect.c | 6 + mm/page_io.c | 10 + mm/shmem.c | 9 + mm/swapfile.c | 2 + mm/util.c | 2 +- tools/vm/page-types.c | 2 + 61 files changed, 1678 insertions(+), 48 deletions(-) create mode 100644 Documentation/arm64/memory-tagging-extension.rst create mode 100644 arch/arm64/include/asm/mte.h create mode 100644 arch/arm64/kernel/mte.c create mode 100644 arch/arm64/lib/mte.S create mode 100644 arch/arm64/mm/mteswap.c
