linux-kernel - Re: [PATCH 5/7] arm64/efi: do not enter virtual mode in case booting with efi=noruntime or noefi

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Date:	Fri, 15 Aug 2014 16:09:52 +0100
From:	Will Deacon <will.deacon@....com>
To:	Dave Young <dyoung@...hat.com>
Cc:	Matt Fleming <matt.fleming@...el.com>,
	Catalin Marinas <Catalin.Marinas@....com>,
	Thomas Gleixner <tglx@...utronix.de>,
	Ingo Molnar <mingo@...hat.com>,
	"hpa@...or.com" <hpa@...or.com>,
	Alessandro Zummo <a.zummo@...ertech.it>,
	Leif Lindholm <leif.lindholm@...aro.org>,
	Ard Biesheuvel <ard.biesheuvel@...aro.org>,
	"msalter@...hat.com" <msalter@...hat.com>,
	Randy Dunlap <rdunlap@...radead.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	"linux-arm-kernel@...ts.infradead.org" 
	<linux-arm-kernel@...ts.infradead.org>,
	"linux-efi@...r.kernel.org" <linux-efi@...r.kernel.org>,
	Daniel Kiper <daniel.kiper@...cle.com>,
	Russ Anderson <rja@....com>
Subject: Re: [PATCH 5/7] arm64/efi: do not enter virtual mode in case booting
 with efi=noruntime or noefi

On Thu, Aug 14, 2014 at 10:15:30AM +0100, Dave Young wrote:
> In case efi runtime disabled via noefi kernel cmdline arm64_enter_virtual_mode
> should error out.
> 
> At the same time move early_memunmap(memmap.map, mapsize) to the beginning of
> the function or it will leak early mem.
> 
> Signed-off-by: Dave Young <dyoung@...hat.com>
> ---
>  arch/arm64/kernel/efi.c | 9 +++++++--
>  1 file changed, 7 insertions(+), 2 deletions(-)
> 
> diff --git a/arch/arm64/kernel/efi.c b/arch/arm64/kernel/efi.c
> index 6ed0362..309fab1 100644
> --- a/arch/arm64/kernel/efi.c
> +++ b/arch/arm64/kernel/efi.c
> @@ -392,11 +392,16 @@ static int __init arm64_enter_virtual_mode(void)
>  		return -1;
>  	}
>  
> +	mapsize = memmap.map_end - memmap.map;
> +	if (efi_runtime_disabled()) {
> +		early_memunmap(memmap.map, mapsize);

Should this early_memunmap really be conditional? With this change, we no
longer unmap it before setting up the permanent mapping below.

Will

> +		pr_info("EFI runtime services will be disabled.\n");
> +		return -1;
> +	}
> +
>  	pr_info("Remapping and enabling EFI services.\n");
>  
>  	/* replace early memmap mapping with permanent mapping */
> -	mapsize = memmap.map_end - memmap.map;
> -	early_memunmap(memmap.map, mapsize);
>  	memmap.map = (__force void *)ioremap_cache((phys_addr_t)memmap.phys_map,
>  						   mapsize);
>  	memmap.map_end = memmap.map + mapsize;
> -- 
> 1.8.3.1
> 
> 
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