[PATCH Makedumpfile 0/4] x86_64: Fix page_offset for randomized base enabled

Louis Bouchard louis.bouchard at canonical.com
Tue Oct 25 02:17:00 PDT 2016


Le 24/10/2016 à 18:48, Pratyush Anand a écrit :
> Patch 1/4 fixes page_offset calculation, so that it is correctly calculated
> on KASLR enabled kernel as well.
> Patch 2/4 simplifies VA to PA translation. New code has been benchmarked
> against old code on a 4T system.
> Patch 3/4 and 4/4 is removal of (now) unnecessary code.
> I think, we should find a way to kill find_vememmap() as well, so that
> VMEMMAP_START can be removed. I have very limited idea about x86, so unable
> to do that as of now.
> Pratyush Anand (4):
>   x86_64: Calculate page_offset from pt_load
>   x86_64: translate all VA to PA using page table values
>   x86_64: kill is_vmalloc_addr_x86_64()
>   x86_64: kill some unused initialization
>  arch/x86_64.c  | 84 ++++++++++++++++++++--------------------------------------
>  makedumpfile.h |  9 +++----
>  2 files changed, 32 insertions(+), 61 deletions(-)

Cross-posting but FYI, this patch fixes the issue reported in the following
thread : makedumpfile issues many readpage_elf: Attempt to read non-existent page[1]

It corresponds to the commit identified by my kernel bisection.

I will wait until it is accepted in Kumagai-san's tree to include it in

Kind regards,


[1] https://www.mail-archive.com/kexec@lists.infradead.org/msg16434.html
Louis Bouchard
Software engineer, Cloud & Sustaining eng.
Canonical Ltd
Ubuntu developer                       Debian Maintainer
GPG : 429D 7A3B DD05 B6F8 AF63  B9C4 8B3D 867C 823E 7A61

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