From: liuwenliang@huawei.com (Liuwenliang (Abbott Liu))
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH 01/11] Initialize the mapping of KASan shadow memory
Date: Sat, 18 Nov 2017 10:40:08 +0000 [thread overview]
Message-ID: <B8AC3E80E903784988AB3003E3E97330C00638D4@dggemm510-mbs.china.huawei.com> (raw)
In-Reply-To: <20171117073556.GB28855@cbox>
On Nov 17, 2017 15:36 Christoffer Dall [mailto:cdall at linaro.org] wrote:
>If your processor does support LPAE (like a Cortex-A15 for example),
>then you have both the 32-bit accessors (MRC and MCR) and the 64-bit
>accessors (MRRC, MCRR), and using the 32-bit accessor will simply access
>the lower 32-bits of the 64-bit register.
>
>Hope this helps,
>-Christoffer
If you know the higher 32-bits of the 64-bits cp15's register is not useful for your system,
then you can use the 32-bit accessor to get or set the 64-bit cp15's register.
But if the higher 32-bits of the 64-bits cp15's register is useful for your system,
then you can't use the 32-bit accessor to get or set the 64-bit cp15's register.
TTBR0/TTBR1/PAR's higher 32-bits is useful for CPU supporting LPAE.
The following description which comes from ARM(r) Architecture Reference
Manual ARMv7-A and ARMv7-R edition tell us the reason:
64-bit TTBR0 and TTBR1 format:
...
BADDR, bits[39:x] :
Translation table base address, bits[39:x]. Defining the translation table base address width on
page B4-1698 describes how x is defined.
The value of x determines the required alignment of the translation table, which must be aligned to
2x bytes.
Abbott Liu: Because BADDR on CPU supporting LPAE may be bigger than max value of 32-bit, so bits[39:32] may
be valid value which is useful for the system.
64-bit PAR format
...
PA[39:12]
Physical Address. The physical address corresponding to the supplied virtual address. This field
returns address bits[39:12].
Abbott Liu: Because Physical Address on CPU supporting LPAE may be bigger than max value of 32-bit,
so bits[39:32] may be valid value which is useful for the system.
Conclusion: Don't use 32-bit accessor to get or set TTBR0/TTBR1/PAR on CPU supporting LPAE,
if you do that, your system may run error.
next prev parent reply other threads:[~2017-11-18 10:40 UTC|newest]
Thread overview: 85+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-10-11 8:22 [PATCH 00/11] KASan for arm Abbott Liu
2017-10-11 8:22 ` [PATCH 01/11] Initialize the mapping of KASan shadow memory Abbott Liu
2017-10-11 19:39 ` Florian Fainelli
2017-10-11 21:41 ` Russell King - ARM Linux
2017-10-17 13:28 ` Liuwenliang (Lamb)
2017-10-11 23:42 ` Dmitry Osipenko
2017-10-19 6:52 ` Liuwenliang (Lamb)
2017-10-19 12:01 ` Russell King - ARM Linux
2018-02-26 13:09 ` 答复: " Liuwenliang (Abbott Liu)
2017-10-12 7:58 ` Marc Zyngier
2017-11-09 7:46 ` Liuwenliang (Abbott Liu)
2017-11-09 10:10 ` Marc Zyngier
2017-11-15 10:20 ` Liuwenliang (Abbott Liu)
2017-11-15 10:35 ` Marc Zyngier
2017-11-15 13:16 ` Liuwenliang (Abbott Liu)
2017-11-15 13:54 ` Marc Zyngier
2017-11-16 3:07 ` Liuwenliang (Abbott Liu)
2017-11-16 9:54 ` Marc Zyngier
2017-11-16 14:24 ` Liuwenliang (Abbott Liu)
2017-11-16 14:40 ` Marc Zyngier
2017-11-17 1:39 ` 答复: " Liuwenliang (Abbott Liu)
2017-11-17 7:18 ` Liuwenliang (Abbott Liu)
2017-11-17 7:35 ` Christoffer Dall
2017-11-18 10:40 ` Liuwenliang (Abbott Liu) [this message]
2017-11-18 13:48 ` Marc Zyngier
2017-11-21 7:59 ` 答复: " Liuwenliang (Abbott Liu)
2017-11-21 9:40 ` Russell King - ARM Linux
2017-11-21 9:46 ` Marc Zyngier
2017-11-21 12:29 ` Mark Rutland
2017-11-22 12:56 ` Liuwenliang (Abbott Liu)
2017-11-22 13:06 ` Marc Zyngier
2017-11-23 1:54 ` Liuwenliang (Abbott Liu)
2017-11-23 15:22 ` Russell King - ARM Linux
2017-11-27 1:23 ` Liuwenliang (Abbott Liu)
2017-11-23 15:31 ` Mark Rutland
2017-11-27 1:26 ` 答复: " Liuwenliang (Abbott Liu)
2017-10-19 11:09 ` Russell King - ARM Linux
2018-02-24 14:28 ` Liuwenliang (Abbott Liu)
2017-10-11 8:22 ` [PATCH 02/11] replace memory function Abbott Liu
2017-10-19 12:05 ` Russell King - ARM Linux
2017-10-22 12:42 ` 答复: " Liuwenliang (Lamb)
2017-10-11 8:22 ` [PATCH 03/11] arm: Kconfig: enable KASan Abbott Liu
2017-10-11 19:15 ` Florian Fainelli
2017-10-19 12:34 ` Russell King - ARM Linux
2017-10-22 12:27 ` Liuwenliang (Lamb)
2017-10-11 8:22 ` [PATCH 04/11] Define the virtual space of KASan's shadow region Abbott Liu
2017-10-14 11:41 ` kbuild test robot
2017-10-16 11:42 ` Liuwenliang (Lamb)
2017-10-16 12:14 ` Ard Biesheuvel
2017-10-17 11:27 ` Liuwenliang (Lamb)
2017-10-17 11:52 ` Ard Biesheuvel
2017-10-17 13:02 ` Liuwenliang (Lamb)
2017-10-19 12:43 ` Russell King - ARM Linux
2017-10-22 12:12 ` Liuwenliang (Lamb)
2017-10-19 12:41 ` Russell King - ARM Linux
2017-10-19 12:40 ` Russell King - ARM Linux
2017-10-11 8:22 ` [PATCH 05/11] Disable kasan's instrumentation Abbott Liu
2017-10-11 19:16 ` Florian Fainelli
2017-10-19 12:47 ` Russell King - ARM Linux
2017-11-15 10:19 ` Liuwenliang (Abbott Liu)
2017-10-11 8:22 ` [PATCH 06/11] change memory_is_poisoned_16 for aligned error Abbott Liu
2017-10-11 23:23 ` Andrew Morton
2017-10-12 7:16 ` Dmitry Vyukov
2017-10-12 11:27 ` Liuwenliang (Lamb)
2017-10-19 12:51 ` Russell King - ARM Linux
2017-12-05 14:19 ` Liuwenliang (Abbott Liu)
2017-12-05 17:08 ` Ard Biesheuvel
2017-10-11 8:22 ` [PATCH 07/11] Avoid cleaning the KASan shadow area's mapping table Abbott Liu
2017-10-11 8:22 ` [PATCH 08/11] Add support arm LPAE Abbott Liu
2017-10-11 8:22 ` [PATCH 09/11] Don't need to map the shadow of KASan's shadow memory Abbott Liu
2017-10-19 12:55 ` Russell King - ARM Linux
2017-10-22 12:31 ` Liuwenliang (Lamb)
2017-10-11 8:22 ` [PATCH 10/11] Change mapping of kasan_zero_page int readonly Abbott Liu
2017-10-11 19:19 ` Florian Fainelli
2017-10-11 8:22 ` [PATCH 11/11] Add KASan layout Abbott Liu
2017-10-11 19:13 ` [PATCH 00/11] KASan for arm Florian Fainelli
2017-10-11 19:50 ` Florian Fainelli
[not found] ` <44c86924-930b-3eff-55b8-b02c9060ebe3@gmail.com>
2017-10-11 22:10 ` Laura Abbott
2017-10-11 22:58 ` Russell King - ARM Linux
2017-10-17 12:41 ` Liuwenliang (Lamb)
2017-10-12 4:55 ` Liuwenliang (Lamb)
2017-10-12 7:38 ` Arnd Bergmann
2017-10-17 1:04 ` 答复: " Liuwenliang (Lamb)
2018-02-13 18:40 ` Florian Fainelli
2018-02-23 2:10 ` Liuwenliang (Abbott Liu)
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