From: Sergej Proskurin <proskurin@sec.in.tum.de>
To: Julien Grall <julien.grall@arm.com>, xen-devel@lists.xenproject.org
Cc: Stefano Stabellini <sstabellini@kernel.org>
Subject: Re: [PATCH v5 10/12] arm/mem_access: Add long-descriptor based gpt
Date: Thu, 6 Jul 2017 13:18:41 +0200 [thread overview]
Message-ID: <c831d1e3-0d61-c342-503c-7adda30c6324@sec.in.tum.de> (raw)
In-Reply-To: <700fa37e-0d6e-1103-ab40-95769036d7b2@arm.com>
Hi Julien,
On 07/04/2017 07:06 PM, Julien Grall wrote:
> Hi Sergej,
>
>
>> + /*
>> + * According to to ARM DDI 0487B.a J1-5927, we return an error
>> if the found
>> + * PTE is invalid or holds a reserved entry (PTE<1:0> == x0)) or
>> if the PTE
>> + * maps a memory block at level 3 (PTE<1:0> == 01).
>> + */
>> + if ( !lpae_valid(pte) || ((level == 3) && !lpae_page(pte, level)) )
>
> NIT: What you want to check here is either the entry is a superpage or
> a page. So the below check would be easier to parse:
>
> if ( !lpae_is_superpage(pte, level) || !lpae_is_page(pte, level) )
Your suggested check is easier to parse, however introduces a bug
because as soon as the pte is not a superpage it will return an -EFAULT
at this point. I have changed the || into an && which makes it fine
again. The next patch series will follow shortly.
Cheers
~Sergej
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next prev parent reply other threads:[~2017-07-06 11:18 UTC|newest]
Thread overview: 46+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-06-27 11:52 [PATCH v5 00/12] arm/mem_access: Walk guest page tables in SW if mem_access is active Sergej Proskurin
2017-06-27 11:52 ` [PATCH v5 01/12] arm/mem_access: Add and cleanup (TCR_|TTBCR_)* defines Sergej Proskurin
2017-07-04 16:04 ` Julien Grall
2017-06-27 11:52 ` [PATCH v5 02/12] arm/mem_access: Move PAGE_SHIFT_* macros to lib.h Sergej Proskurin
2017-06-27 12:04 ` Jan Beulich
2017-07-03 8:40 ` Sergej Proskurin
2017-07-03 9:03 ` Sergej Proskurin
2017-07-03 9:16 ` Jan Beulich
2017-07-03 13:07 ` Sergej Proskurin
2017-07-03 13:25 ` Jan Beulich
2017-07-03 9:13 ` Jan Beulich
2017-07-03 13:17 ` Sergej Proskurin
2017-07-03 13:27 ` Jan Beulich
2017-06-27 11:52 ` [PATCH v5 03/12] arm/mem_access: Add defines supporting PTs with varying page sizes Sergej Proskurin
2017-07-04 16:15 ` Julien Grall
2017-07-04 21:33 ` Sergej Proskurin
2017-07-05 11:41 ` Julien Grall
2017-07-05 11:48 ` Sergej Proskurin
2017-06-27 11:52 ` [PATCH v5 04/12] arm/lpae: Introduce lpae_page helper Sergej Proskurin
2017-07-04 16:23 ` Julien Grall
2017-07-05 13:11 ` Sergej Proskurin
2017-07-05 13:12 ` Julien Grall
2017-06-27 11:52 ` [PATCH v5 05/12] arm/mem_access: Add short-descriptor pte typedefs and macros Sergej Proskurin
2017-07-04 16:25 ` Julien Grall
2017-06-27 11:52 ` [PATCH v5 06/12] arm/mem_access: Introduce GV2M_EXEC permission Sergej Proskurin
2017-06-27 11:52 ` [PATCH v5 07/12] arm/mem_access: Introduce BIT_ULL bit operation Sergej Proskurin
2017-07-04 16:26 ` Julien Grall
2017-06-27 11:52 ` [PATCH v5 08/12] arm/mem_access: Introduce GENMASK_ULL " Sergej Proskurin
2017-07-04 16:28 ` Julien Grall
2017-07-04 20:46 ` Sergej Proskurin
2017-07-04 21:44 ` Sergej Proskurin
2017-07-05 12:39 ` Julien Grall
2017-06-27 11:52 ` [PATCH v5 09/12] arm/mem_access: Add software guest-page-table walk Sergej Proskurin
2017-07-04 16:58 ` Julien Grall
2017-07-04 20:25 ` Sergej Proskurin
2017-07-05 12:36 ` Julien Grall
2017-07-05 12:46 ` Sergej Proskurin
2017-06-27 11:52 ` [PATCH v5 10/12] arm/mem_access: Add long-descriptor based gpt Sergej Proskurin
2017-07-04 17:06 ` Julien Grall
2017-07-05 14:37 ` Sergej Proskurin
2017-07-05 14:47 ` Julien Grall
2017-07-06 11:18 ` Sergej Proskurin [this message]
2017-07-06 11:21 ` Julien Grall
2017-06-27 11:52 ` [PATCH v5 11/12] arm/mem_access: Add short-descriptor " Sergej Proskurin
2017-07-05 13:35 ` Julien Grall
2017-06-27 11:52 ` [PATCH v5 12/12] arm/mem_access: Walk the guest's pt in software Sergej Proskurin
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