public inbox for linuxppc-dev@ozlabs.org 
 help / color / mirror / Atom feed
From: Christopher Covington <cov@codeaurora•org>
To: Laurent Dufour <ldufour@linux•vnet.ibm.com>
Cc: Benjamin Herrenschmidt <benh@kernel•crashing.org>,
	Paul Mackerras <paulus@samba•org>,
	Michael Ellerman <mpe@ellerman•id.au>,
	Jeff Dike <jdike@addtoit•com>,
	Richard Weinberger <richard@nod•at>,
	Guan Xuetao <gxt@mprc•pku.edu.cn>,
	Thomas Gleixner <tglx@linutronix•de>,
	Ingo Molnar <mingo@redhat•com>, "H. Peter Anvin" <hpa@zytor•com>,
	x86@kernel•org, Arnd Bergmann <arnd@arndb•de>,
	linuxppc-dev@lists•ozlabs.org, linux-kernel@vger•kernel.org,
	linux-s390@vger•kernel.org,
	user-mode-linux-devel@lists•sourceforge.net,
	user-mode-linux-user@lists•sourceforge.net,
	linux-arch@vger•kernel.org, linux-mm@kvack•org, criu@openvz•org,
	"linux-arm-kernel@lists•infradead.org"
	<linux-arm-kernel@lists•infradead.org>,
	Will Deacon <Will.Deacon@arm•com>,
	Laura Abbott <labbott@fedoraproject•org>,
	David Brown <david.brown@linaro•org>
Subject: Re: [PATCH 0/2] Tracking user space vDSO remaping
Date: Wed, 2 Mar 2016 07:13:10 -0500	[thread overview]
Message-ID: <56D6D8D6.6060306@codeaurora.org> (raw)
In-Reply-To: <cover.1426866405.git.ldufour@linux.vnet.ibm.com>

Hi,

On 03/20/2015 11:53 AM, Laurent Dufour wrote:
> CRIU is recreating the process memory layout by remapping the checkpointee
> memory area on top of the current process (criu). This includes remapping
> the vDSO to the place it has at checkpoint time.
> 
> However some architectures like powerpc are keeping a reference to the vDSO
> base address to build the signal return stack frame by calling the vDSO
> sigreturn service. So once the vDSO has been moved, this reference is no
> more valid and the signal frame built later are not usable.
> 
> This patch serie is introducing a new mm hook 'arch_remap' which is called
> when mremap is done and the mm lock still hold. The next patch is adding the
> vDSO remap and unmap tracking to the powerpc architecture.
> 
> Laurent Dufour (2):
>   mm: Introducing arch_remap hook
>   powerpc/mm: Tracking vDSO remap
> 
>  arch/powerpc/include/asm/mmu_context.h   | 35 +++++++++++++++++++++++++++++++-
>  arch/s390/include/asm/mmu_context.h      |  6 ++++++
>  arch/um/include/asm/mmu_context.h        |  5 +++++
>  arch/unicore32/include/asm/mmu_context.h |  6 ++++++
>  arch/x86/include/asm/mmu_context.h       |  6 ++++++
>  include/asm-generic/mm_hooks.h           |  6 ++++++
>  mm/mremap.c                              |  9 ++++++--
>  7 files changed, 70 insertions(+), 3 deletions(-)

We would like to be able to remap/unmap the VDSO on arm and arm64 as
well. When I proposed a patch with mmu_context.h and mmu-arch-hooks.h
changes to arm64 that were nearly identical to those done to powerpc,
Will Deacon reasonably suggested [1] attempting to combine the code and
provide generic VDSO accessors. Unfortunately, I no prior experience
with generic MM code. Can anyone advise on how to get started with that?

1. http://www.spinics.net/lists/linux-arm-msm/msg18441.html

Thanks,
Christopher Covington

-- 
Qualcomm Innovation Center, Inc.
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
a Linux Foundation Collaborative Project

      parent reply	other threads:[~2016-03-02 12:20 UTC|newest]

Thread overview: 31+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-03-20 15:53 [PATCH 0/2] Tracking user space vDSO remaping Laurent Dufour
2015-03-20 15:53 ` [PATCH 1/2] mm: Introducing arch_remap hook Laurent Dufour
2015-03-20 23:19   ` Richard Weinberger
2015-03-23  8:52   ` Ingo Molnar
2015-03-23  9:11     ` Laurent Dufour
2015-03-25 11:06     ` [PATCH v2 0/2] Tracking user space vDSO remaping Laurent Dufour
2015-03-25 11:06       ` [PATCH v2 1/2] mm: Introducing arch_remap hook Laurent Dufour
2015-03-25 11:06       ` [PATCH v2 2/2] powerpc/mm: Tracking vDSO remap Laurent Dufour
2015-03-25 12:11         ` Ingo Molnar
2015-03-25 13:25           ` Laurent Dufour
2015-03-25 13:53           ` [PATCH v3 0/2] Tracking user space vDSO remaping Laurent Dufour
2015-03-25 13:53             ` [PATCH v3 1/2] mm: Introducing arch_remap hook Laurent Dufour
2015-03-25 13:53             ` [PATCH v3 2/2] powerpc/mm: Tracking vDSO remap Laurent Dufour
2015-03-25 18:33               ` Ingo Molnar
2015-03-25 18:36                 ` Ingo Molnar
2015-03-25 21:11                   ` Benjamin Herrenschmidt
2015-03-26  9:43                     ` Ingo Molnar
2015-03-26 10:37                       ` Laurent Dufour
2015-03-26 14:17                         ` Ingo Molnar
2015-03-26 14:32                           ` Laurent Dufour
2015-03-26 17:37                           ` [PATCH v4 0/2] Tracking user space vDSO remaping Laurent Dufour
2015-03-26 17:37                             ` [PATCH v4 1/2] mm: Introducing arch_remap hook Laurent Dufour
2015-03-26 17:37                             ` [PATCH v4 2/2] powerpc/mm: Tracking vDSO remap Laurent Dufour
2015-03-26 18:55                               ` Ingo Molnar
2015-03-27 11:02                                 ` Laurent Dufour
2015-03-26 23:23                       ` [PATCH v3 " Benjamin Herrenschmidt
2015-03-25 21:09                 ` Benjamin Herrenschmidt
2015-03-26  9:48                   ` Ingo Molnar
2015-03-26 10:13                     ` Laurent Dufour
2015-03-20 15:53 ` [PATCH " Laurent Dufour
2016-03-02 12:13 ` Christopher Covington [this message]

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=56D6D8D6.6060306@codeaurora.org \
    --to=cov@codeaurora$(echo .)org \
    --cc=Will.Deacon@arm$(echo .)com \
    --cc=arnd@arndb$(echo .)de \
    --cc=benh@kernel$(echo .)crashing.org \
    --cc=criu@openvz$(echo .)org \
    --cc=david.brown@linaro$(echo .)org \
    --cc=gxt@mprc$(echo .)pku.edu.cn \
    --cc=hpa@zytor$(echo .)com \
    --cc=jdike@addtoit$(echo .)com \
    --cc=labbott@fedoraproject$(echo .)org \
    --cc=ldufour@linux$(echo .)vnet.ibm.com \
    --cc=linux-arch@vger$(echo .)kernel.org \
    --cc=linux-arm-kernel@lists$(echo .)infradead.org \
    --cc=linux-kernel@vger$(echo .)kernel.org \
    --cc=linux-mm@kvack$(echo .)org \
    --cc=linux-s390@vger$(echo .)kernel.org \
    --cc=linuxppc-dev@lists$(echo .)ozlabs.org \
    --cc=mingo@redhat$(echo .)com \
    --cc=mpe@ellerman$(echo .)id.au \
    --cc=paulus@samba$(echo .)org \
    --cc=richard@nod$(echo .)at \
    --cc=tglx@linutronix$(echo .)de \
    --cc=user-mode-linux-devel@lists$(echo .)sourceforge.net \
    --cc=user-mode-linux-user@lists$(echo .)sourceforge.net \
    --cc=x86@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