[PATCH v1 4/5] mm: ptdump: Support hugepd table entries
Daniel Axtens
dja at axtens.net
Fri Apr 16 00:29:20 BST 2021
Hi Christophe,
> Which hugepd, page table entries can be at any level
> and can be of any size.
>
> Add support for them.
>
> Signed-off-by: Christophe Leroy <christophe.leroy at csgroup.eu>
> ---
> mm/ptdump.c | 17 +++++++++++++++--
> 1 file changed, 15 insertions(+), 2 deletions(-)
>
> diff --git a/mm/ptdump.c b/mm/ptdump.c
> index 61cd16afb1c8..6efdb8c15a7d 100644
> --- a/mm/ptdump.c
> +++ b/mm/ptdump.c
> @@ -112,11 +112,24 @@ static int ptdump_pte_entry(pte_t *pte, unsigned long addr,
> {
> struct ptdump_state *st = walk->private;
> pte_t val = ptep_get(pte);
> + unsigned long page_size = next - addr;
> + int level;
> +
> + if (page_size >= PGDIR_SIZE)
> + level = 0;
> + else if (page_size >= P4D_SIZE)
> + level = 1;
> + else if (page_size >= PUD_SIZE)
> + level = 2;
> + else if (page_size >= PMD_SIZE)
> + level = 3;
> + else
> + level = 4;
>
> if (st->effective_prot)
> - st->effective_prot(st, 4, pte_val(val));
> + st->effective_prot(st, level, pte_val(val));
>
> - st->note_page(st, addr, 4, pte_val(val), PAGE_SIZE);
> + st->note_page(st, addr, level, pte_val(val), page_size);
It seems to me that passing both level and page_size is a bit redundant,
but I guess it does reduce the impact on each arch's code?
Kind regards,
Daniel
>
> return 0;
> }
> --
> 2.25.0
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