Re: [PATCH v4 1/5] mm: add ARCH_SUPPORTS_NON_LEAF_PTDUMP

[LEROY Christophe <christophe.leroy2@cs-soprasteria.com>]

Le 18/06/2024 à 16:40, Maxwell Bland a écrit :
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> 
> Provide a Kconfig option indicating if note_page can be called for
> intermediate page directories during ptdump.
> 
> Signed-off-by: Maxwell Bland <mbland@motorola.com>
> ---
>   mm/Kconfig.debug |  9 +++++++++
>   mm/ptdump.c      | 21 +++++++++++++--------
>   2 files changed, 22 insertions(+), 8 deletions(-)
> 
> diff --git a/mm/Kconfig.debug b/mm/Kconfig.debug
> index afc72fde0f03..6af5ecfdef93 100644
> --- a/mm/Kconfig.debug
> +++ b/mm/Kconfig.debug
> @@ -201,6 +201,15 @@ config PTDUMP_DEBUGFS
> 
>            If in doubt, say N.
> 
> +config ARCH_SUPPORTS_NON_LEAF_PTDUMP
> +       bool "Include intermediate directory entries in pagetable dumps"
> +       default n
> +       help
> +         Enable the inclusion of intermediate page directory entries in calls
> +         to the ptdump API. Once an architecture defines correct ptdump
> +         behavior for PGD, PUD, P4D, and PMD entries, this config can be
> +         selected.
> +
>   config HAVE_DEBUG_KMEMLEAK
>          bool
> 
> diff --git a/mm/ptdump.c b/mm/ptdump.c
> index 106e1d66e9f9..6180708669fe 100644
> --- a/mm/ptdump.c
> +++ b/mm/ptdump.c
> @@ -41,10 +41,11 @@ static int ptdump_pgd_entry(pgd_t *pgd, unsigned long addr,
>          if (st->effective_prot)
>                  st->effective_prot(st, 0, pgd_val(val));
> 
> -       if (pgd_leaf(val)) {
> +       if (IS_ENABLED(CONFIG_ARCH_SUPPORTS_NON_LEAF_PTDUMP) || pgd_leaf(val))
>                  st->note_page(st, addr, 0, pgd_val(val));
> +
> +       if (pgd_leaf(val))
>                  walk->action = ACTION_CONTINUE;
> -       }
> 
>          return 0;
>   }
> @@ -64,10 +65,11 @@ static int ptdump_p4d_entry(p4d_t *p4d, unsigned long addr,
>          if (st->effective_prot)
>                  st->effective_prot(st, 1, p4d_val(val));
> 
> -       if (p4d_leaf(val)) {
> +       if (IS_ENABLED(CONFIG_ARCH_SUPPORTS_NON_LEAF_PTDUMP) || pgd_leaf(val))

Don't you mean p4d_leaf() here instead of pgd_leaf() ?

>                  st->note_page(st, addr, 1, p4d_val(val));
> +
> +       if (p4d_leaf(val))
>                  walk->action = ACTION_CONTINUE;
> -       }
> 
>          return 0;
>   }
> @@ -87,10 +89,11 @@ static int ptdump_pud_entry(pud_t *pud, unsigned long addr,
>          if (st->effective_prot)
>                  st->effective_prot(st, 2, pud_val(val));
> 
> -       if (pud_leaf(val)) {
> +       if (IS_ENABLED(CONFIG_ARCH_SUPPORTS_NON_LEAF_PTDUMP) || pgd_leaf(val))

Don't you mean pud_leaf() here instead of pgd_leaf() ?

>                  st->note_page(st, addr, 2, pud_val(val));
> +
> +       if (pud_leaf(val))
>                  walk->action = ACTION_CONTINUE;
> -       }
> 
>          return 0;
>   }
> @@ -108,10 +111,12 @@ static int ptdump_pmd_entry(pmd_t *pmd, unsigned long addr,
> 
>          if (st->effective_prot)
>                  st->effective_prot(st, 3, pmd_val(val));
> -       if (pmd_leaf(val)) {
> +
> +       if (IS_ENABLED(CONFIG_ARCH_SUPPORTS_NON_LEAF_PTDUMP) || pgd_leaf(val))

Don't you mean pmd_leaf() here instead of pgd_leaf() ?

>                  st->note_page(st, addr, 3, pmd_val(val));
> +
> +       if (pmd_leaf(val))
>                  walk->action = ACTION_CONTINUE;
> -       }
> 
>          return 0;
>   }
> --
> 2.39.2
> 
>