Dear x86 maintainers, the series looks pretty mature now, any chance it can be considered for upstream? On Sun, Mar 12, 2023 at 12:26 PM Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx> wrote: > > Linear Address Masking[1] (LAM) modifies the checking that is applied to > 64-bit linear addresses, allowing software to use of the untranslated > address bits for metadata. > > The capability can be used for efficient address sanitizers (ASAN) > implementation and for optimizations in JITs and virtual machines. > > The patchset brings support for LAM for userspace addresses. Only LAM_U57 at > this time. > > Please review and consider applying. > > git://git.kernel.org/pub/scm/linux/kernel/git/kas/linux.git lam > > v16: > - Add #include <linux/mmu_context.h> into fs/proc/array.c; > - Whitespace fix; > - Add Alexander's Tested-bys; > v15: > - Replace static branch in untagged_addr() with alternative; > - Drop unneeded READ_ONCE(); > - Acks from Peter; > v14: > - Rework address range check in get_user() and put_user(); > - Introduce CONFIG_ADDRESS_MASKING; > - Cache untag masking in per-CPU variable; > - Reject LAM enabling via PTRACE_ARCH_PRCTL; > - Fix locking around untagged_addr_remote(); > - Fix typo in MM_CONTEXT_ conversion patch; > - Fix selftest; > v13: > - Fix race between untagged_addr() and LAM enabling: > + Do not allow to enable LAM after the process spawned the second thread; > + untagged_addr() untags the address according to rules of the current > process; > + untagged_addr_remote() can be used for untagging addresses for foreign > process. It requires mmap lock for the target process to be taken; > v12: > - Rebased onto tip/x86/mm; > - Drop VM_WARN_ON() that may produce false-positive on race between context > switch and LAM enabling; > - Adjust comments explain possible race; > - User READ_ONCE() in mm_lam_cr3_mask(); > - Do not assume &init_mm == mm in initialize_tlbstate_and_flush(); > - Ack by Andy; > v11: > - Move untag_mask to /proc/$PID/status; > - s/SVM/SVA/g; > - static inline arch_pgtable_dma_compat() instead of macros; > - Replace pasid_valid() with mm_valid_pasid(); > - Acks from Ashok and Jacob (forgot to apply from v9); > v10: > - Rebased to v6.1-rc1; > - Add selftest for SVM vs LAM; > v9: > - Fix race between LAM enabling and check that KVM memslot address doesn't > have any tags; > - Reduce untagged_addr() overhead until the first LAM user; > - Clarify SVM vs. LAM semantics; > - Use mmap_lock to serialize LAM enabling; > v8: > - Drop redundant smb_mb() in prctl_enable_tagged_addr(); > - Cleanup code around build_cr3(); > - Fix commit messages; > - Selftests updates; > - Acked/Reviewed/Tested-bys from Alexander and Peter; > v7: > - Drop redundant smb_mb() in prctl_enable_tagged_addr(); > - Cleanup code around build_cr3(); > - Fix commit message; > - Fix indentation; > v6: > - Rebased onto v6.0-rc1 > - LAM_U48 excluded from the patchet. Still available in the git tree; > - add ARCH_GET_MAX_TAG_BITS; > - Fix build without CONFIG_DEBUG_VM; > - Update comments; > - Reviewed/Tested-by from Alexander; > v5: > - Do not use switch_mm() in enable_lam_func() > - Use mb()/READ_ONCE() pair on LAM enabling; > - Add self-test by Weihong Zhang; > - Add comments; > v4: > - Fix untagged_addr() for LAM_U48; > - Remove no-threads restriction on LAM enabling; > - Fix mm_struct access from /proc/$PID/arch_status > - Fix LAM handling in initialize_tlbstate_and_flush() > - Pack tlb_state better; > - Comments and commit messages; > v3: > - Rebased onto v5.19-rc1 > - Per-process enabling; > - API overhaul (again); > - Avoid branches and costly computations in the fast path; > - LAM_U48 is in optional patch. > v2: > - Rebased onto v5.18-rc1 > - New arch_prctl(2)-based API > - Expose status of LAM (or other thread features) in > /proc/$PID/arch_status > > [1] ISE, Chapter 10. https://cdrdv2.intel.com/v1/dl/getContent/671368 > > Kirill A. Shutemov (12): > x86/mm: Rework address range check in get_user() and put_user() > x86: Allow atomic MM_CONTEXT flags setting > x86: CPUID and CR3/CR4 flags for Linear Address Masking > x86/mm: Handle LAM on context switch > mm: Introduce untagged_addr_remote() > x86/uaccess: Provide untagged_addr() and remove tags before address > check > x86/mm: Reduce untagged_addr() overhead for systems without LAM > x86/mm: Provide arch_prctl() interface for LAM > mm: Expose untagging mask in /proc/$PID/status > iommu/sva: Replace pasid_valid() helper with mm_valid_pasid() > x86/mm/iommu/sva: Make LAM and SVA mutually exclusive > selftests/x86/lam: Add test cases for LAM vs thread creation > > Weihong Zhang (5): > selftests/x86/lam: Add malloc and tag-bits test cases for > linear-address masking > selftests/x86/lam: Add mmap and SYSCALL test cases for linear-address > masking > selftests/x86/lam: Add io_uring test cases for linear-address masking > selftests/x86/lam: Add inherit test cases for linear-address masking > selftests/x86/lam: Add ARCH_FORCE_TAGGED_SVA test cases for > linear-address masking > > arch/arm64/include/asm/mmu_context.h | 6 + > arch/sparc/include/asm/mmu_context_64.h | 6 + > arch/sparc/include/asm/uaccess_64.h | 2 + > arch/x86/Kconfig | 11 + > arch/x86/entry/vsyscall/vsyscall_64.c | 2 +- > arch/x86/include/asm/cpufeatures.h | 1 + > arch/x86/include/asm/disabled-features.h | 8 +- > arch/x86/include/asm/mmu.h | 18 +- > arch/x86/include/asm/mmu_context.h | 49 +- > arch/x86/include/asm/processor-flags.h | 2 + > arch/x86/include/asm/tlbflush.h | 48 +- > arch/x86/include/asm/uaccess.h | 58 +- > arch/x86/include/uapi/asm/prctl.h | 5 + > arch/x86/include/uapi/asm/processor-flags.h | 6 + > arch/x86/kernel/process.c | 6 + > arch/x86/kernel/process_64.c | 66 +- > arch/x86/kernel/traps.c | 6 +- > arch/x86/lib/getuser.S | 83 +- > arch/x86/lib/putuser.S | 54 +- > arch/x86/mm/init.c | 5 + > arch/x86/mm/tlb.c | 53 +- > drivers/iommu/iommu-sva.c | 8 +- > drivers/vfio/vfio_iommu_type1.c | 2 +- > fs/proc/array.c | 7 + > fs/proc/task_mmu.c | 9 +- > include/linux/ioasid.h | 9 - > include/linux/mm.h | 11 - > include/linux/mmu_context.h | 14 + > include/linux/sched/mm.h | 8 +- > include/linux/uaccess.h | 22 + > mm/gup.c | 4 +- > mm/madvise.c | 5 +- > mm/migrate.c | 11 +- > tools/testing/selftests/x86/Makefile | 2 +- > tools/testing/selftests/x86/lam.c | 1241 +++++++++++++++++++ > 35 files changed, 1699 insertions(+), 149 deletions(-) > create mode 100644 tools/testing/selftests/x86/lam.c > > -- > 2.39.2 > -- Alexander Potapenko Software Engineer Google Germany GmbH Erika-Mann-Straße, 33 80636 München Geschäftsführer: Paul Manicle, Liana Sebastian Registergericht und -nummer: Hamburg, HRB 86891 Sitz der Gesellschaft: Hamburg
