Most architectures current have a debugfs file for dumping the kernel page tables. Currently each architecture has to implement custom functions for walking the page tables because the generic walk_page_range() function is unable to walk the page tables used by the kernel. This series extends the capabilities of walk_page_range() so that it can deal with the page tables of the kernel (which have no VMAs and can contain larger huge pages than exist for user space). x86 and arm64 are then converted to make use of walk_page_range() removing the custom page table walkers. Potentially future changes could unify the implementations of the debugfs walkers further, moving the common functionality into common code. This would require a common way of handling the effective permissions (currently implemented only for x86) along with a per-arch way of formatting the page table information for debugfs. One immediate benefit would be getting the KASAN speed up optimisation in arm64 (and other arches) which is currently only implemented for x86. Changes since v1: * Added p4d_large() macro * Comments to explain p?d_large() macro semantics * Expanded comment for pte_hole() callback to explain mapping between depth and P?D * Handle folded page tables at all levels, so depth from pte_hole() ignores folding at any level (see real_depth() function in mm/pagewalk.c) James Morse (2): arm64: mm: Add p?d_large() definitions mm: Add generic p?d_large() macros Steven Price (11): x86/mm: Add p?d_large() definitions mm: pagewalk: Add p4d_entry() and pgd_entry() mm: pagewalk: Allow walking without vma mm: pagewalk: Add 'depth' parameter to pte_hole mm: pagewalk: Add test_p?d callbacks arm64: mm: Convert mm/dump.c to use walk_page_range() x86/mm: Point to struct seq_file from struct pg_state x86/mm+efi: Convert ptdump_walk_pgd_level() to take a mm_struct x86/mm: Convert ptdump_walk_pgd_level_debugfs() to take an mm_struct x86/mm: Convert ptdump_walk_pgd_level_core() to take an mm_struct x86: mm: Convert dump_pagetables to use walk_page_range arch/arm64/include/asm/pgtable.h | 2 + arch/arm64/mm/dump.c | 108 +++++----- arch/x86/include/asm/pgtable.h | 8 +- arch/x86/mm/debug_pagetables.c | 8 +- arch/x86/mm/dump_pagetables.c | 342 ++++++++++++++++--------------- arch/x86/platform/efi/efi_32.c | 2 +- arch/x86/platform/efi/efi_64.c | 4 +- fs/proc/task_mmu.c | 4 +- include/asm-generic/pgtable.h | 19 ++ include/linux/mm.h | 26 ++- mm/hmm.c | 2 +- mm/migrate.c | 1 + mm/mincore.c | 1 + mm/pagewalk.c | 107 +++++++--- 14 files changed, 375 insertions(+), 259 deletions(-) -- 2.20.1
