[PATCH v3 3/3] powerpc: mm: support page table check

[Russell Currey]

On Mon, 2022-10-24 at 11:35 +1100, Rohan McLure wrote:
> On creation and clearing of a page table mapping, instrument such
> calls
> by invoking page_table_check_pte_set and page_table_check_pte_clear
> respectively. These calls serve as a sanity check against illegal
> mappings.
> 
> Enable ARCH_SUPPORTS_PAGE_TABLE_CHECK for all ppc64, and 32-bit
> platforms implementing Book3S.
> 
> Change pud_pfn to be a runtime bug rather than a build bug as it is
> consumed by page_table_check_pud_{clear,set} which are not called.
> 
> See also:
> 
> riscv support in commit 3fee229a8eb9 ("riscv/mm: enable
> ARCH_SUPPORTS_PAGE_TABLE_CHECK")
> arm64 in commit 42b2547137f5 ("arm64/mm: enable
> ARCH_SUPPORTS_PAGE_TABLE_CHECK")
> x86_64 in commit d283d422c6c4 ("x86: mm: add x86_64 support for page
> table
> check")
> 
> Signed-off-by: Rohan McLure <rmclure at linux.ibm.com>

Reviewed-by: Russell Currey <ruscur at russell.cc>