Re: [PATCH 5/5] ptdump: add state parameter for non-leaf callback

From: Andrew Morton
Date: Tue Apr 16 2024 - 16:11:37 EST


On Mon, 15 Apr 2024 14:51:32 -0500 Maxwell Bland <mbland@xxxxxxxxxxxx> wrote:

> ptdump can now note non-leaf descriptor entries, a useful addition for
> debugging table descriptor permissions when working on related code
>
> Signed-off-by: Maxwell Bland <mbland@xxxxxxxxxxxx>
> ---
> arch/arm64/mm/ptdump.c | 6 ++++--
> arch/powerpc/mm/ptdump/ptdump.c | 2 ++
> arch/riscv/mm/ptdump.c | 6 ++++--
> arch/s390/mm/dump_pagetables.c | 6 ++++--
> arch/x86/mm/dump_pagetables.c | 3 ++-
> include/linux/ptdump.h | 1 +
> mm/ptdump.c | 13 +++++++++++++
> 7 files changed, 30 insertions(+), 7 deletions(-)
>
> diff --git a/arch/arm64/mm/ptdump.c b/arch/arm64/mm/ptdump.c
> index 796231a4fd63..1a6f4a3513e5 100644
> --- a/arch/arm64/mm/ptdump.c
> +++ b/arch/arm64/mm/ptdump.c
> @@ -299,7 +299,8 @@ void ptdump_walk(struct seq_file *s, struct ptdump_info *info)
> .range = (struct ptdump_range[]){
> {info->base_addr, end},
> {0, 0}
> - }
> + },
> + .note_non_leaf = false
> }

It would be acceptable to omit all of these and rely upon the runtime
zeroing which the compiler will emit.

Documentation/arch/arm64/ptdump.rst might need updating.

Please include sample output in the changelog so we can better
understand the user's view of this change.