linux-kernel - Re: [PATCH v7u1 21/31] x86, kexec: only set ident mapping for ram.

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Message-ID: <20130113125653.GA17200@liondog.tnic>
Date:	Sun, 13 Jan 2013 13:56:53 +0100
From:	Borislav Petkov <bp@...en8.de>
To:	Yinghai Lu <yinghai@...nel.org>
Cc:	Thomas Gleixner <tglx@...utronix.de>, Ingo Molnar <mingo@...e.hu>,
	"H. Peter Anvin" <hpa@...or.com>,
	"Eric W. Biederman" <ebiederm@...ssion.com>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Jan Kiszka <jan.kiszka@....de>,
	Jason Wessel <jason.wessel@...driver.com>,
	linux-kernel@...r.kernel.org,
	Alexander Duyck <alexander.h.duyck@...el.com>
Subject: Re: [PATCH v7u1 21/31] x86, kexec: only set ident mapping for ram.

On Thu, Jan 03, 2013 at 04:48:41PM -0800, Yinghai Lu wrote:
> We should not set mapping for all under max_pfn.

"We should not establish mappings for all memory under max_pfn."

> That causes same problem that is fixed by

"Otherwise, it causes the same ..."

> 
> 	x86, mm: Only direct map addresses that are marked as E820_RAM

You could add this patch's commit id since it is in tip:x86/mm2 and it
shouldn't change: 66520ebc2df3.

Ditto for patch 09/31, "x86, 64bit: #PF handler set page to cover 2M only".

> 
> This patch expose pfn_mapped array, and only set ident mapping for ranges

	     exposes the...		       sets

> in that array.
> 
> This patch rely on new ident_mapping_init that could handle existing

	     relies on the new

> pgd/pud between different calling.

			    calls.

> 
> Signed-off-by: Yinghai Lu <yinghai@...nel.org>
> Cc: Alexander Duyck <alexander.h.duyck@...el.com>

[ … ]

> diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c
> index ab26a158b5a8..d704b369fd70 100644
> --- a/arch/x86/mm/init.c
> +++ b/arch/x86/mm/init.c
> @@ -300,8 +300,8 @@ static int __meminit split_mem_range(struct map_range *mr, int nr_range,
>         return nr_range;
>  }
>  
> -static struct range pfn_mapped[E820_X_MAX];
> -static int nr_pfn_mapped;

This could use a comment saying that this is an array of all mapped
memory ranges or something like that.

> +struct range pfn_mapped[E820_X_MAX];
> +int nr_pfn_mapped;
>  
>  static void add_pfn_range_mapped(unsigned long start_pfn, unsigned long end_pfn)
>  {

Thanks.

-- 
Regards/Gruss,
    Boris.

Sent from a fat crate under my desk. Formatting is fine.
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