linux-kernel - [RFC PATCH 0/2] Providing mount for memfd

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: Windows password security audit tool. GUI, reports in PDF.

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

Date:   Thu, 16 Feb 2023 00:41:15 +0000
From:   Ackerley Tng <ackerleytng@...gle.com>
To:     kvm@...r.kernel.org, linux-api@...r.kernel.org,
        linux-arch@...r.kernel.org, linux-doc@...r.kernel.org,
        linux-fsdevel@...r.kernel.org, linux-kernel@...r.kernel.org,
        linux-mm@...ck.org, qemu-devel@...gnu.org
Cc:     chao.p.peng@...ux.intel.com, aarcange@...hat.com,
        ak@...ux.intel.com, akpm@...ux-foundation.org, arnd@...db.de,
        bfields@...ldses.org, bp@...en8.de, corbet@....net,
        dave.hansen@...el.com, david@...hat.com, ddutile@...hat.com,
        dhildenb@...hat.com, hpa@...or.com, hughd@...gle.com,
        jlayton@...nel.org, jmattson@...gle.com, joro@...tes.org,
        jun.nakajima@...el.com, kirill.shutemov@...ux.intel.com,
        linmiaohe@...wei.com, luto@...nel.org, mail@...iej.szmigiero.name,
        mhocko@...e.com, michael.roth@....com, mingo@...hat.com,
        naoya.horiguchi@....com, pbonzini@...hat.com, qperret@...gle.com,
        rppt@...nel.org, seanjc@...gle.com, shuah@...nel.org,
        steven.price@....com, tabba@...gle.com, tglx@...utronix.de,
        vannapurve@...gle.com, vbabka@...e.cz, vkuznets@...hat.com,
        wanpengli@...cent.com, wei.w.wang@...el.com, x86@...nel.org,
        yu.c.zhang@...ux.intel.com, Ackerley Tng <ackerleytng@...gle.com>
Subject: [RFC PATCH 0/2] Providing mount for memfd_restricted() syscall

Hello,

This patchset builds upon the memfd_restricted() system call that has
been discussed in the ‘KVM: mm: fd-based approach for supporting KVM’
patch series, at
https://lore.kernel.org/lkml/20221202061347.1070246-1-chao.p.peng@linux.intel.com/T/#m7e944d7892afdd1d62a03a287bd488c56e377b0c

The tree can be found at:
https://github.com/googleprodkernel/linux-cc/tree/restrictedmem-provide-mount-path

In this patchset, a modification to the memfd_restricted() syscall is
proposed, which allows userspace to provide a mount, on which the file
will be created and returned from the memfd_restricted().

Allowing userspace to provide a mount allows userspace to control
various memory binding policies via tmpfs mount options, such as
Transparent HugePage memory allocation policy through
‘huge=always/never’ and NUMA memory allocation policy through
‘mpol=local/bind:*’.

Dependencies:
+ Sean’s iteration of the ‘KVM: mm: fd-based approach for supporting
  KVM’ patch series at
  https://github.com/sean-jc/linux/tree/x86/upm_base_support
+ Proposed fixes for these issues mentioned on the mailing list:
    + https://lore.kernel.org/lkml/diqzzga0fv96.fsf@ackerleytng-cloudtop-sg.c.googlers.com/

Future work/TODOs:
+ man page for the memfd_restricted() syscall
+ Support for per file Transparent HugePage allocation hints
+ Support for per file NUMA binding hints

Ackerley Tng (2):
  mm: restrictedmem: Allow userspace to specify mount_path for
    memfd_restricted
  selftests: restrictedmem: Check hugepage-ness of shmem file backing
    restrictedmem fd

 include/linux/syscalls.h                      |   2 +-
 include/uapi/linux/restrictedmem.h            |   8 +
 mm/restrictedmem.c                            |  63 +++-
 tools/testing/selftests/Makefile              |   1 +
 .../selftests/restrictedmem/.gitignore        |   3 +
 .../testing/selftests/restrictedmem/Makefile  |  14 +
 .../testing/selftests/restrictedmem/common.c  |   9 +
 .../testing/selftests/restrictedmem/common.h  |   8 +
 .../restrictedmem_hugepage_test.c             | 344 ++++++++++++++++++
 9 files changed, 445 insertions(+), 7 deletions(-)
 create mode 100644 include/uapi/linux/restrictedmem.h
 create mode 100644 tools/testing/selftests/restrictedmem/.gitignore
 create mode 100644 tools/testing/selftests/restrictedmem/Makefile
 create mode 100644 tools/testing/selftests/restrictedmem/common.c
 create mode 100644 tools/testing/selftests/restrictedmem/common.h
 create mode 100644 tools/testing/selftests/restrictedmem/restrictedmem_hugepage_test.c

--
2.39.1.637.g21b0678d19-goog