[PATCH 00/13] Convert x86 & arm64 to use generic page walk

Steven Price
2019-02-15T17:03:06Z

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.

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 | 10 +
include/linux/mm.h | 25 ++-
mm/hmm.c | 2 +-
mm/migrate.c | 1 +
mm/mincore.c | 1 +
mm/pagewalk.c | 92 ++++++---
14 files changed, 350 insertions(+), 259 deletions(-)

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2.20.1