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Subject[PATCH v9 00/21] Generic page walk and ptdump
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This is a slight reworking and extension of my previous patch set
(Convert x86 & arm64 to use generic page walk), but I've continued the
version numbering as most of the changes are the same. In particular
this series ends with a generic PTDUMP implemention for arm64 and x86.

Many architectures current have a debugfs file for dumping the kernel
page tables. Currently each architecture has to implement custom
functions for this because the details of walking the page tables used
by the kernel are different between architectures.

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). A generic PTDUMP
implementation is the implemented making use of the new functionality of
walk_page_range() and finally arm64 and x86 are switch to using it,
removing the custom table walkers.

To enable a generic page table walker to walk the unusual mappings of
the kernel we need to implement a set of functions which let us know
when the walker has reached the leaf entry. After a suggestion from Will
Deacon I've chosen the name p?d_leaf() as this (hopefully) describes
the purpose (and is a new name so has no historic baggage). Some
architectures have p?d_large macros but this is easily confused with
"large pages".

Mostly this is a clean up and there should be very little functional
change. The exceptions are:

* x86 PTDUMP debugfs output no longer display pages which aren't
present (patch 14).

* arm64 has the ability to efficiently process KASAN pages (which
previously only x86 implemented). This means that the combination of
KASAN and DEBUG_WX is now useable.

Also available as a git tree:
git://linux-arm.org/linux-sp.git walk_page_range/v9

Changes since v8:
https://lore.kernel.org/lkml/20190403141627.11664-1-steven.price@arm.com/
* Rename from p?d_large() to p?d_leaf()
* Dropped patches migrating arm64/x86 custom walkers to
walk_page_range() in favour of adding a generic PTDUMP implementation
and migrating arm64/x86 to that instead.
* Rebased to v5.3-rc1

Steven Price (21):
arc: mm: Add p?d_leaf() definitions
arm: mm: Add p?d_leaf() definitions
arm64: mm: Add p?d_leaf() definitions
mips: mm: Add p?d_leaf() definitions
powerpc: mm: Add p?d_leaf() definitions
riscv: mm: Add p?d_leaf() definitions
s390: mm: Add p?d_leaf() definitions
sparc: mm: Add p?d_leaf() definitions
x86: mm: Add p?d_leaf() definitions
mm: Add generic p?d_leaf() macros
mm: pagewalk: Add p4d_entry() and pgd_entry()
mm: pagewalk: Allow walking without vma
mm: pagewalk: Add test_p?d callbacks
x86: mm: Don't display pages which aren't present in debugfs
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
mm: Add generic ptdump
x86: mm: Convert dump_pagetables to use walk_page_range
arm64: mm: Convert mm/dump.c to use walk_page_range()

arch/arc/include/asm/pgtable.h | 1 +
arch/arm/include/asm/pgtable-2level.h | 1 +
arch/arm/include/asm/pgtable-3level.h | 1 +
arch/arm64/Kconfig | 1 +
arch/arm64/Kconfig.debug | 19 +-
arch/arm64/include/asm/pgtable.h | 2 +
arch/arm64/include/asm/ptdump.h | 8 +-
arch/arm64/mm/Makefile | 4 +-
arch/arm64/mm/dump.c | 117 +++----
arch/arm64/mm/ptdump_debugfs.c | 2 +-
arch/mips/include/asm/pgtable-64.h | 8 +
arch/powerpc/include/asm/book3s/64/pgtable.h | 30 +-
arch/riscv/include/asm/pgtable-64.h | 7 +
arch/riscv/include/asm/pgtable.h | 7 +
arch/s390/include/asm/pgtable.h | 2 +
arch/sparc/include/asm/pgtable_64.h | 2 +
arch/x86/Kconfig | 1 +
arch/x86/Kconfig.debug | 20 +-
arch/x86/include/asm/pgtable.h | 10 +-
arch/x86/mm/Makefile | 4 +-
arch/x86/mm/debug_pagetables.c | 8 +-
arch/x86/mm/dump_pagetables.c | 339 +++++--------------
arch/x86/platform/efi/efi_32.c | 2 +-
arch/x86/platform/efi/efi_64.c | 4 +-
drivers/firmware/efi/arm-runtime.c | 2 +-
include/asm-generic/pgtable.h | 19 ++
include/linux/mm.h | 26 +-
include/linux/ptdump.h | 19 ++
mm/Kconfig.debug | 21 ++
mm/Makefile | 1 +
mm/pagewalk.c | 76 +++--
mm/ptdump.c | 161 +++++++++
32 files changed, 507 insertions(+), 418 deletions(-)
create mode 100644 include/linux/ptdump.h
create mode 100644 mm/ptdump.c

--
2.20.1

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