linux-kernel - [PATCH v2 0/3] Create 'old' ptes for faultaround mappings on arm64 with hardware access flag

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Date:   Fri,  8 Jan 2021 17:15:14 +0000
From:   Will Deacon <will@...nel.org>
To:     linux-kernel@...r.kernel.org
Cc:     linux-mm@...ck.org, linux-arm-kernel@...ts.infradead.org,
        Will Deacon <will@...nel.org>,
        Catalin Marinas <catalin.marinas@....com>,
        Jan Kara <jack@...e.cz>, Minchan Kim <minchan@...nel.org>,
        Andrew Morton <akpm@...ux-foundation.org>,
        "Kirill A . Shutemov" <kirill.shutemov@...ux.intel.com>,
        Linus Torvalds <torvalds@...ux-foundation.org>,
        Vinayak Menon <vinmenon@...eaurora.org>,
        Hugh Dickins <hughd@...gle.com>, kernel-team@...roid.com
Subject: [PATCH v2 0/3] Create 'old' ptes for faultaround mappings on arm64 with hardware access flag

Hi all,

This is version two of the series I originally posted here:

  https://lore.kernel.org/r/20201209163950.8494-1-will@kernel.org

The patches allow architectures to opt-in at runtime for faultaround
mappings to be created as 'old' instead of 'young'. Although there have
been previous attempts at this, they failed either because the decision
was deferred to userspace [1] or because it was done unconditionally and
shown to regress benchmarks for particular architectures [2].

The big difference in this version is that I have reworked it based on
Kirill's patch which he posted as a follow-up to the original. However,
I can't tell where we've landed on that -- Linus seemed to like it, but
Hugh was less enthusiastic. I think that my subsequent patches are an
awful lot cleaner after the rework, but I don't think I necessarily
depend on everything in there so if that patch is likely to be a
sticking point then I can try to extract the parts I need.

Feedback welcome.

Cheers,

Will

[1] https://www.spinics.net/lists/linux-mm/msg143831.html
[2] 315d09bf30c2 ("Revert "mm: make faultaround produce old ptes"")

Cc: Catalin Marinas <catalin.marinas@....com>
Cc: Jan Kara <jack@...e.cz>
Cc: Minchan Kim <minchan@...nel.org>
Cc: Andrew Morton <akpm@...ux-foundation.org>
Cc: Kirill A. Shutemov <kirill.shutemov@...ux.intel.com>
Cc: Linus Torvalds <torvalds@...ux-foundation.org>
Cc: Vinayak Menon <vinmenon@...eaurora.org>
Cc: Andrew Morton <akpm@...ux-foundation.org>
Cc: Hugh Dickins <hughd@...gle.com>
Cc: <kernel-team@...roid.com>

--->8

Kirill A. Shutemov (1):
  mm: Cleanup faultaround and finish_fault() codepaths

Will Deacon (2):
  mm: Allow architectures to request 'old' entries when prefaulting
  arm64: mm: Implement arch_wants_old_prefaulted_pte()

 arch/arm64/include/asm/pgtable.h |  12 +-
 fs/xfs/xfs_file.c                |   6 +-
 include/linux/mm.h               |  17 ++-
 include/linux/pgtable.h          |  11 ++
 mm/filemap.c                     | 181 +++++++++++++++++++------
 mm/memory.c                      | 219 +++++++++++--------------------
 6 files changed, 251 insertions(+), 195 deletions(-)

-- 
2.29.2.729.g45daf8777d-goog