linux-kernel - Re: [PATCH v3 03/13] mm/execmem, arch: convert simple overrides of module

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Date:   Wed, 4 Oct 2023 00:29:58 +0000
From:   "Edgecombe, Rick P" <rick.p.edgecombe@...el.com>
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Subject: Re: [PATCH v3 03/13] mm/execmem, arch: convert simple overrides of
 module_alloc to execmem

On Mon, 2023-09-18 at 10:29 +0300, Mike Rapoport wrote:
> +
> +static void execmem_init_missing(struct execmem_params *p)
> +{
> +       struct execmem_range *default_range = &p-
> >ranges[EXECMEM_DEFAULT];
> +
> +       for (int i = EXECMEM_DEFAULT + 1; i < EXECMEM_TYPE_MAX; i++)
> {
> +               struct execmem_range *r = &p->ranges[i];
> +
> +               if (!r->start) {
> +                       r->pgprot = default_range->pgprot;
> +                       r->alignment = default_range->alignment;
> +                       r->start = default_range->start;
> +                       r->end = default_range->end;
> +               }
> +       }
> +}
> +

It seems a bit weird to copy all of this. Is it trying to be faster or
something?

Couldn't it just check r->start in execmem_text/data_alloc() path and
switch to EXECMEM_DEFAULT if needed then? The execmem_range_is_data()
part that comes later could be added to the logic there too. So this
seems like unnecessary complexity to me or I don't see the reason.