Date: Mon, 17 Oct 2016 11:22:31 +0100
From: James Hogan <james.hogan@imgtec.com>
To: Matt Redfearn <matt.redfearn@imgtec.com>
CC: Ralf Baechle <ralf@linux-mips.org>, <linux-mips@linux-mips.org>,
        <linux-kernel@vger.kernel.org>, Paul Burton <paul.burton@imgtec.com>
Subject: Re: [PATCH] MIPS: generic: Fix KASLR for generic kernel.
Message-ID: <20161017102231.GB9443@jhogan-linux.le.imgtec.org>
References: <1476698709-6771-1-git-send-email-matt.redfearn@imgtec.com>
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Hi Matt,

On Mon, Oct 17, 2016 at 11:05:09AM +0100, Matt Redfearn wrote:
> The KASLR code requires that the plat_get_fdt() function return the
> address of the device tree, and it must be available early in the boot,
> before prom_init() is called. Move the code determining the address of
> the device tree into plat_get_fdt, and call that from prom_init().
>=20
> The fdt pointer will be set up by plat_get_fdt() called from
> relocate_kernel initially and once the relocated kernel has started,
> prom_init() will use it again to determine the address in the relocated
> image.
>=20
> Fixes: eed0eabd12ef

I believe this is the preferred form:

Fixes: eed0eabd12ef ("MIPS: generic: Introduce generic DT-based board suppo=
rt")

Otherwise looks good to me

Reviewed-by: James Hogan <james.hogan@imgtec.com>

Cheers
James

> Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com>
> ---
>=20
>  arch/mips/generic/init.c | 16 ++++++++++------
>  1 file changed, 10 insertions(+), 6 deletions(-)
>=20
> diff --git a/arch/mips/generic/init.c b/arch/mips/generic/init.c
> index 0ea73e845440..d493ccbf274a 100644
> --- a/arch/mips/generic/init.c
> +++ b/arch/mips/generic/init.c
> @@ -30,9 +30,19 @@ static __initdata const void *mach_match_data;
> =20
>  void __init prom_init(void)
>  {
> +	plat_get_fdt();
> +	BUG_ON(!fdt);
> +}
> +
> +void __init *plat_get_fdt(void)
> +{
>  	const struct mips_machine *check_mach;
>  	const struct of_device_id *match;
> =20
> +	if (fdt)
> +		/* Already set up */
> +		return (void *)fdt;
> +
>  	if ((fw_arg0 =3D=3D -2) && !fdt_check_header((void *)fw_arg1)) {
>  		/*
>  		 * We booted using the UHI boot protocol, so we have been
> @@ -75,12 +85,6 @@ void __init prom_init(void)
>  		/* Retrieve the machine's FDT */
>  		fdt =3D mach->fdt;
>  	}
> -
> -	BUG_ON(!fdt);
> -}
> -
> -void __init *plat_get_fdt(void)
> -{
>  	return (void *)fdt;
>  }
> =20
> --=20
> 2.7.4
>=20
>=20

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