linux-kernel - Re: [PATCH v6 02/18] kasan: Unpoison vms[area] addresses with a common tag

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Message-ID: <CAG_fn=V6pbNdN3w0Jr5rCL=M27-bOBt4AK8rB7UvvwT=3g4m7g@mail.gmail.com>
Date: Mon, 10 Nov 2025 17:40:19 +0100
From: Alexander Potapenko <glider@...gle.com>
To: Maciej Wieczor-Retman <m.wieczorretman@...me>
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	Baoquan He <bhe@...hat.com>
Subject: Re: [PATCH v6 02/18] kasan: Unpoison vms[area] addresses with a
 common tag

>  void __kasan_unpoison_vmap_areas(struct vm_struct **vms, int nr_vms)
>  {
>         int area;
>
>         for (area = 0 ; area < nr_vms ; area++) {
>                 kasan_poison(vms[area]->addr, vms[area]->size,
> -                            arch_kasan_get_tag(vms[area]->addr), false);
> +                            arch_kasan_get_tag(vms[0]->addr), false);
> +               arch_kasan_set_tag(vms[area]->addr, arch_kasan_get_tag(vms[0]->addr));

Like set_tag(), arch_kasan_set_tag() does not set the tag value in
place, so this line is a no-op.