Page table check performs extra verifications at the time when new pages become accessible from the userspace by getting their page table entries (PTEs PMDs etc.) added into the table. It is supported on X86[1]. This patchset made some simple changes and make it easier to support new architecture, then we support this feature on ARM64 and RISCV. [1]https://lore.kernel.org/lkml/20211123214814.3756047-1-pasha.tatashin@xxxxxxxxxx/ v5 -> v6: According to Anshuman's suggestion, optimized partial implementation and commit message: 1. Remove redundant IS_ENABLED() in ptep_clear(). 2. Remove redundant __HAVE_ARCH_PTEP_CLEAR usage in pgtable.h. 3. Remove redundant __ptep_get_and_clear() on arm64 and riscv. v4 -> v5: According to Anshuman's suggestion, using PxD_SIZE instead of PxD_PAGE_SIZE in mm/page_table_check.c and it is checked by Pasha. v3 -> v4: Adapt to next-20220414 v2 -> v3: Modify ptep_clear() in include/linux/pgtable.h, using IS_ENABLED according to the suggestions of Pasha. v1 -> v2: 1. Fix arm64's pte/pmd/pud_user_accessible_page() according to the suggestions of Catalin. 2. Also fix riscv's pte_pmd_pud_user_accessible_page(). Kefeng Wang (2): mm: page_table_check: move pxx_user_accessible_page into x86 arm64/mm: Enable ARCH_SUPPORTS_PAGE_TABLE_CHECK Tong Tiangen (4): mm: page_table_check: using PxD_SIZE instead of PxD_PAGE_SIZE mm: page_table_check: add hooks to public helpers mm: remove __HAVE_ARCH_PTEP_CLEAR in pgtable.h riscv/mm: Enable ARCH_SUPPORTS_PAGE_TABLE_CHECK arch/arm64/Kconfig | 1 + arch/arm64/include/asm/pgtable.h | 59 +++++++++++++++++++++++--- arch/riscv/Kconfig | 1 + arch/riscv/include/asm/pgtable.h | 71 +++++++++++++++++++++++++++++--- arch/x86/include/asm/pgtable.h | 27 +++++++----- include/linux/pgtable.h | 21 ++++++---- mm/page_table_check.c | 25 ++--------- 7 files changed, 155 insertions(+), 50 deletions(-) -- 2.25.1
