From: Catalin Marinas <catalin.marinas@arm•com>
To: Steve Capper <steve.capper@arm•com>
Cc: crecklin@redhat•com, ard.biesheuvel@linaro•org, maz@kernel•org,
bhsharma@redhat•com, will@kernel•org,
linux-arm-kernel@lists•infradead.org
Subject: Re: [PATCH V5 02/12] arm64: mm: Flip kernel VA space
Date: Wed, 7 Aug 2019 17:12:02 +0100 [thread overview]
Message-ID: <20190807161202.GA1766@arrakis.emea.arm.com> (raw)
In-Reply-To: <20190807155524.5112-3-steve.capper@arm.com>
On Wed, Aug 07, 2019 at 04:55:14PM +0100, Steve Capper wrote:
> In order to allow for a KASAN shadow that changes size at boot time, one
> must fix the KASAN_SHADOW_END for both 48 & 52-bit VAs and "grow" the
> start address. Also, it is highly desirable to maintain the same
> function addresses in the kernel .text between VA sizes. Both of these
> requirements necessitate us to flip the kernel address space halves s.t.
> the direct linear map occupies the lower addresses.
>
> This patch puts the direct linear map in the lower addresses of the
> kernel VA range and everything else in the higher ranges.
>
> We need to adjust:
> *) KASAN shadow region placement logic,
> *) KASAN_SHADOW_OFFSET computation logic,
> *) virt_to_phys, phys_to_virt checks,
> *) page table dumper.
>
> These are all small changes, that need to take place atomically, so they
> are bundled into this commit.
>
> As part of the re-arrangement, a guard region of 2MB (to preserve
> alignment for fixed map) is added after the vmemmap. Otherwise the
> vmemmap could intersect with IS_ERR pointers.
>
> Signed-off-by: Steve Capper <steve.capper@arm•com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm•com>
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists•infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2019-08-07 16:12 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-07 15:55 [PATCH V5 00/12] 52-bit kernel + user VAs Steve Capper
2019-08-07 15:55 ` [PATCH V5 01/12] arm64: mm: Remove bit-masking optimisations for PAGE_OFFSET and VMEMMAP_START Steve Capper
2019-08-07 15:55 ` [PATCH V5 02/12] arm64: mm: Flip kernel VA space Steve Capper
2019-08-07 16:12 ` Catalin Marinas [this message]
2019-08-07 15:55 ` [PATCH V5 03/12] arm64: kasan: Switch to using KASAN_SHADOW_OFFSET Steve Capper
2019-08-07 16:12 ` Catalin Marinas
2019-08-14 15:20 ` [PATCH] arm64: fix CONFIG_KASAN_SW_TAGS && CONFIG_KASAN_INLINE (was: Re: [PATCH V5 03/12] arm64: kasan: Switch to using) KASAN_SHADOW_OFFSET Mark Rutland
2019-08-14 15:57 ` Will Deacon
2019-08-14 16:03 ` Mark Rutland
2019-08-14 17:53 ` Steve Capper
2019-08-15 12:09 ` Will Deacon
2019-08-15 12:21 ` [PATCH] arm64: fix CONFIG_KASAN_SW_TAGS && CONFIG_KASAN_INLINE Andrey Ryabinin
2019-08-15 12:22 ` Will Deacon
2019-08-20 6:02 ` [PATCH] arm64: fix CONFIG_KASAN_SW_TAGS && CONFIG_KASAN_INLINE (was: Re: [PATCH V5 03/12] arm64: kasan: Switch to using) KASAN_SHADOW_OFFSET Bhupesh Sharma
2019-08-14 16:07 ` Steve Capper
2019-08-14 16:14 ` Steve Capper
2019-08-07 15:55 ` [PATCH V5 04/12] arm64: dump: De-constify VA_START and KASAN_SHADOW_START Steve Capper
2019-08-07 15:55 ` [PATCH V5 05/12] arm64: mm: Introduce VA_BITS_MIN Steve Capper
2019-08-07 16:14 ` Catalin Marinas
2019-08-07 15:55 ` [PATCH V5 06/12] arm64: mm: Introduce vabits_actual Steve Capper
2019-08-07 16:16 ` Catalin Marinas
2019-08-07 15:55 ` [PATCH V5 07/12] arm64: mm: Logic to make offset_ttbr1 conditional Steve Capper
2019-08-07 15:55 ` [PATCH V5 08/12] arm64: mm: Separate out vmemmap Steve Capper
2019-08-07 15:55 ` [PATCH V5 09/12] arm64: mm: Modify calculation of VMEMMAP_SIZE Steve Capper
2019-08-07 15:55 ` [PATCH V5 10/12] arm64: mm: Introduce 52-bit Kernel VAs Steve Capper
2019-08-07 15:55 ` [PATCH V5 11/12] arm64: mm: Remove vabits_user Steve Capper
2019-08-07 16:17 ` Catalin Marinas
2019-08-07 15:55 ` [PATCH V5 12/12] docs: arm64: Add layout and 52-bit info to memory document Steve Capper
2019-08-09 16:47 ` [PATCH V5 00/12] 52-bit kernel + user VAs Will Deacon
2019-08-13 11:23 ` Steve Capper
2019-08-13 11:59 ` Will Deacon
2019-08-13 12:43 ` Geert Uytterhoeven
2019-08-13 13:10 ` Will Deacon
2019-08-13 13:36 ` Geert Uytterhoeven
2019-08-14 8:04 ` Bhupesh Sharma
2019-08-14 8:21 ` Will Deacon
2019-08-14 11:59 ` Bhupesh Sharma
2019-08-14 12:24 ` Will Deacon
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20190807161202.GA1766@arrakis.emea.arm.com \
--to=catalin.marinas@arm$(echo .)com \
--cc=ard.biesheuvel@linaro$(echo .)org \
--cc=bhsharma@redhat$(echo .)com \
--cc=crecklin@redhat$(echo .)com \
--cc=linux-arm-kernel@lists$(echo .)infradead.org \
--cc=maz@kernel$(echo .)org \
--cc=steve.capper@arm$(echo .)com \
--cc=will@kernel$(echo .)org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox