From: Dave Hansen <dave.hansen@intel.com>
To: Matt Fleming <matt@codeblueprint.co.uk>,
Ingo Molnar <mingo@kernel.org>,
Thomas Gleixner <tglx@linutronix.de>,
"H . Peter Anvin" <hpa@zytor.com>
Cc: Toshi Kani <toshi.kani@hp.com>,
linux-kernel@vger.kernel.org, linux-efi@vger.kernel.org,
Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>,
Borislav Petkov <bp@suse.de>
Subject: Re: [PATCH v2 1/5] x86/mm/pageattr: Ensure cpa->pfn only contains page frame numbers
Date: Mon, 16 Nov 2015 07:56:17 -0800 [thread overview]
Message-ID: <5649FCA1.1000600@intel.com> (raw)
In-Reply-To: <1447538451-5793-2-git-send-email-matt@codeblueprint.co.uk>
I'm glad you're looking at this. It obviously needed some love. :)
On 11/14/2015 02:00 PM, Matt Fleming wrote:
> + npages = (_end - _text) >> PAGE_SHIFT;
> + text = __pa(_text);
> + pfn = text >> PAGE_SHIFT;
> +
> + if (kernel_map_pages_in_pgd(pgd, pfn, text, npages, 0)) {
> + pr_err("Failed to map kernel text 1:1\n");
> + return 1;
> + }
Are _end and _text guaranteed to be aligned? If not, I think the
calculation might be wrong. Just for fun, imagine that _end=0xfff and
_text=0x1001. npages would be 0.
Some other code like set_kernel_text_rw() does alignment on _text.
One nit is that there's quite a bit going on here, like rearranging the
phys_stack arithmetic ordering that is far beyond just simplifying the
paddr vs. pfn issue, but that isn't called out in the changelog at all.
Your fixes all look correct to me, fwiw.
next prev parent reply other threads:[~2015-11-16 15:56 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-11-14 22:00 [GIT PULL v2 0/5] EFI page table isolation Matt Fleming
2015-11-14 22:00 ` [PATCH v2 1/5] x86/mm/pageattr: Ensure cpa->pfn only contains page frame numbers Matt Fleming
2015-11-16 15:56 ` Dave Hansen [this message]
2015-11-17 9:44 ` Matt Fleming
2015-11-16 20:19 ` Thomas Gleixner
2015-11-16 21:20 ` Borislav Petkov
2015-11-16 21:48 ` Thomas Gleixner
2015-11-17 8:50 ` Thomas Gleixner
2015-11-17 9:45 ` Matt Fleming
2015-11-18 8:14 ` Ingo Molnar
2015-11-20 12:01 ` Matt Fleming
2015-11-14 22:00 ` [PATCH 2/5] x86/efi: Map RAM into the identity page table for mixed mode Matt Fleming
2015-11-14 22:00 ` [PATCH v2 3/5] x86/efi: Hoist page table switching code into efi_call_virt() Matt Fleming
2015-11-14 22:00 ` [PATCH v2 4/5] x86/efi: Build our own page table structures Matt Fleming
2015-11-14 22:00 ` [PATCH 5/5] Documentation/x86: Update EFI memory region description Matt Fleming
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