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References: <20230404084308.813-1-zhangqing@loongson.cn> <20230404084308.813-2-zhangqing@loongson.cn>
In-Reply-To: <20230404084308.813-2-zhangqing@loongson.cn>
From:   Andrey Konovalov <andreyknvl@gmail.com>
Date:   Wed, 5 Apr 2023 00:09:19 +0200
Message-ID: <CA+fCnZf-segLxa3QxStd6v15ZCge=3=3rOL-9Q_eMc-y2j1nhg@mail.gmail.com>
Subject: Re: [PATCH v2 5/6] kasan: Add (pmd|pud)_init for LoongArch
 zero_(pud|p4d)_populate process
To:     Qing Zhang <zhangqing@loongson.cn>
Cc:     Andrey Ryabinin <ryabinin.a.a@gmail.com>,
        Jonathan Corbet <corbet@lwn.net>,
        Huacai Chen <chenhuacai@kernel.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        Alexander Potapenko <glider@google.com>,
        Dmitry Vyukov <dvyukov@google.com>,
        Vincenzo Frascino <vincenzo.frascino@arm.com>,
        WANG Xuerui <kernel@xen0n.name>,
        Jiaxun Yang <jiaxun.yang@flygoat.com>,
        kasan-dev@googlegroups.com, linux-doc@vger.kernel.org,
        linux-mm@kvack.org, loongarch@lists.linux.dev,
        linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org
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On Tue, Apr 4, 2023 at 10:43=E2=80=AFAM Qing Zhang <zhangqing@loongson.cn> =
wrote:
>
> Loongarch populate pmd/pud with invalid_pmd_table/invalid_pud_table in
> pagetable_init, So pmd_init/pud_init(p) is required, define them as __wea=
k
> in mm/kasan/init.c, like mm/sparse-vmemmap.c.
>
> Signed-off-by: Qing Zhang <zhangqing@loongson.cn>
> ---
>  mm/kasan/init.c | 18 ++++++++++++++----
>  1 file changed, 14 insertions(+), 4 deletions(-)
>
> diff --git a/mm/kasan/init.c b/mm/kasan/init.c
> index cc64ed6858c6..a7fa223b96e4 100644
> --- a/mm/kasan/init.c
> +++ b/mm/kasan/init.c
> @@ -139,6 +139,10 @@ static int __ref zero_pmd_populate(pud_t *pud, unsig=
ned long addr,
>         return 0;
>  }
>
> +void __weak __meminit pmd_init(void *addr)
> +{
> +}
> +
>  static int __ref zero_pud_populate(p4d_t *p4d, unsigned long addr,
>                                 unsigned long end)
>  {
> @@ -166,8 +170,9 @@ static int __ref zero_pud_populate(p4d_t *p4d, unsign=
ed long addr,
>                                 if (!p)
>                                         return -ENOMEM;
>                         } else {
> -                               pud_populate(&init_mm, pud,
> -                                       early_alloc(PAGE_SIZE, NUMA_NO_NO=
DE));
> +                               p =3D early_alloc(PAGE_SIZE, NUMA_NO_NODE=
);
> +                               pmd_init(p);
> +                               pud_populate(&init_mm, pud, p);
>                         }
>                 }
>                 zero_pmd_populate(pud, addr, next);
> @@ -176,6 +181,10 @@ static int __ref zero_pud_populate(p4d_t *p4d, unsig=
ned long addr,
>         return 0;
>  }
>
> +void __weak __meminit pud_init(void *addr)
> +{
> +}
> +
>  static int __ref zero_p4d_populate(pgd_t *pgd, unsigned long addr,
>                                 unsigned long end)
>  {
> @@ -207,8 +216,9 @@ static int __ref zero_p4d_populate(pgd_t *pgd, unsign=
ed long addr,
>                                 if (!p)
>                                         return -ENOMEM;
>                         } else {
> -                               p4d_populate(&init_mm, p4d,
> -                                       early_alloc(PAGE_SIZE, NUMA_NO_NO=
DE));
> +                               p =3D early_alloc(PAGE_SIZE, NUMA_NO_NODE=
);
> +                               pud_init(p);
> +                               p4d_populate(&init_mm, p4d, p);
>                         }
>                 }
>                 zero_pud_populate(p4d, addr, next);
> --
> 2.20.1
>

Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>

Thanks!