[PATCH 00/10] arm64: mm: Use __create_pgd_mapping_locked() in

[Ard Biesheuvel]

Hello Pingfan,

On Wed, 13 Mar 2024 at 13:57, Pingfan Liu <piliu at redhat.com> wrote:
>
> Hi everybody, I tried this stuff again.

Tried what again? Frankly, I have no idea what the purpose of this
patch series is, and this is v1.

Could you please explain?

Also, the early arm64 startup code is changing substantially - please refer to

https://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git/log/?h=for-next/stage1-lpa2

for details.

> Last time when I tried this,
> Catalin raised concern about the intrumentation, and Ard doubted this
> way due to alignement issue with mmu-off.
>
> Last time, the alignment issue looked unsoluable and I gave up.  But
> nowadays, when I looked at it, I think it is partially resovable.  (for
> detail, please see the commit log in [PATCH 08/10] arm64: mm: Enforce
> memory alignment in mmu_head)
>
> Overall, at this very early stage, the using of C routines faces three
> challenge:
>   PIC
>   instrumentation
>   alignment
>
> [2/10] resolves instrumentation issue
>
> [3/10] makes mmu_head self-contained and prevent the outside
> PIC/ instrumentation/ alignment issues from seeping in. And check the code PIC.
>
> [PATCH 08/10] explains the alignement issue, in theory, it can be
> checked and resolved. And in this patch, it is partially resolved.
>
>
> Cc: Ard Biesheuvel <ardb at kernel.org>
> Cc: Catalin Marinas <catalin.marinas at arm.com>
> Cc: Will Deacon <will at kernel.org>
> Cc: Mark Rutland <mark.rutland at arm.com>
> To: linux-arm-kernel at lists.infradead.org
> ---
>
> Pingfan Liu (10):
>   arm64: mm: Split out routines for code reuse
>   arm64: mm: Introduce mmu_head routines without instrumentation
>   arm64: mm: Use if-conditon to truncate external dependency
>   arm64: head: Enable __create_pgd_mapping() to handle pgtable's paddr
>   arm64: mm: Force early mapping aligned on SWAPPER_BLOCK_SIZE
>   arm64: mm: Handle scope beyond the capacity of kernel pgtable in
>     mmu_head_create_pgd_mapping()
>   arm64: mm: Introduce head_pool routines to enable pgtabl allocation
>   arm64: mm: Enforce memory alignment in mmu_head
>   arm64: head: Use __create_pgd_mapping_locked() to serve the creation
>     of pgtable
>   arm64: head: Clean up unneeded routines
>
>  arch/arm64/include/asm/kernel-pgtable.h |   1 +
>  arch/arm64/include/asm/mmu.h            |   4 +
>  arch/arm64/include/asm/pgtable.h        |  11 +-
>  arch/arm64/kernel/head.S                | 314 +++++++-----------------
>  arch/arm64/mm/Makefile                  |  22 +-
>  arch/arm64/mm/mmu.c                     | 289 +---------------------
>  arch/arm64/mm/mmu_head.c                | 134 ++++++++++
>  arch/arm64/mm/mmu_inc.c                 | 292 ++++++++++++++++++++++
>  8 files changed, 558 insertions(+), 509 deletions(-)
>  create mode 100644 arch/arm64/mm/mmu_head.c
>  create mode 100644 arch/arm64/mm/mmu_inc.c
>
> --
> 2.41.0
>