Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Date:   Thu, 14 Nov 2019 16:16:38 +0800
From:   Baoquan He <bhe@redhat.com>
To:     Masayoshi Mizuma <msys.mizuma@gmail.com>
Cc:     Borislav Petkov <bp@alien8.de>,
        Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>,
        "H. Peter Anvin" <hpa@zytor.com>, x86@kernel.org,
        Masayoshi Mizuma <m.mizuma@jp.fujitsu.com>,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH v4 4/4] x86/mm/KASLR: Adjust the padding size for the
 direct  mapping.
Message-ID: <20191114081638.GH30906@MiWiFi-R3L-srv>
References: <20191102010911.21460-1-msys.mizuma@gmail.com>
 <20191102010911.21460-5-msys.mizuma@gmail.com>
 <20191104004825.GK7616@MiWiFi-R3L-srv>
 <20191112204707.jyruwkb4pbdj3jvv@gabell>
MIME-Version: 1.0
In-Reply-To: <20191112204707.jyruwkb4pbdj3jvv@gabell>
User-Agent: Mutt/1.10.1 (2018-07-13)
Content-Type: text/plain; charset=WINDOWS-1252
Content-Transfer-Encoding: quoted-printable
Content-Disposition: inline
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On 11/12/19 at 03:47pm, Masayoshi Mizuma wrote:
> Your suggesion makes it simpler, thanks!
> So I'll modify calc_direct_mapping_size() as following.
> Does it make sense?

Yeah, it looks good to me. Thanks.

>=20
> static inline unsigned long calc_direct_mapping_size(void)
> {
>        unsigned long size_tb, memory_tb;
>=20
>        memory_tb =3D DIV_ROUND_UP(max_pfn << PAGE_SHIFT, 1UL << TB_SHIFT)=
 +
>                CONFIG_RANDOMIZE_MEMORY_PHYSICAL_PADDING;
>=20
> #ifdef CONFIG_MEMORY_HOTPLUG
>        if (boot_params.max_addr) {
>                unsigned long maximum_tb;
>=20
>                maximum_tb =3D DIV_ROUND_UP(boot_params.max_addr,
>                                1UL << TB_SHIFT);
>=20
>                if (maximum_tb > memory_tb)
>                        memory_tb =3D maximum_tb;
>        }
> #endif
>        size_tb =3D 1 << (MAX_PHYSMEM_BITS - TB_SHIFT);
>=20
>        /*
>         * Adapt physical memory region size based on available memory
>         */
>        if (memory_tb < size_tb)
>                size_tb =3D memory_tb;
>=20
>        return size_tb;
> }