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]
Message-Id: <cover.1679209395.git.lstoakes@gmail.com>
Date:   Sun, 19 Mar 2023 07:09:29 +0000
From:   Lorenzo Stoakes <lstoakes@...il.com>
To:     linux-mm@...ck.org, linux-kernel@...r.kernel.org,
        linux-fsdevel@...r.kernel.org,
        Andrew Morton <akpm@...ux-foundation.org>
Cc:     Baoquan He <bhe@...hat.com>, Uladzislau Rezki <urezki@...il.com>,
        Matthew Wilcox <willy@...radead.org>,
        David Hildenbrand <david@...hat.com>,
        Liu Shixin <liushixin2@...wei.com>,
        Jiri Olsa <jolsa@...nel.org>,
        Lorenzo Stoakes <lstoakes@...il.com>
Subject: [PATCH v2 0/4] convert read_kcore(), vread() to use iterators

While reviewing Baoquan's recent changes to permit vread() access to
vm_map_ram regions of vmalloc allocations, Willy pointed out [1] that it
would be nice to refactor vread() as a whole, since its only user is
read_kcore() and the existing form of vread() necessitates the use of a
bounce buffer.

This patch series does exactly that, as well as adjusting how we read the
kernel text section to avoid the use of a bounce buffer in this case as
well.

This patch series necessarily changes the locking used in vmalloc, however
tests indicate that this has very little impact on allocation performance
(test results are shown in the relevant patch).

This has been tested against the test case which motivated Baoquan's
changes in the first place [2] which continues to function correctly, as
do the vmalloc self tests.

[1] https://lore.kernel.org/all/Y8WfDSRkc%2FOHP3oD@casper.infradead.org/
[2] https://lore.kernel.org/all/87ilk6gos2.fsf@oracle.com/T/#u

v2:
- Fix ordering of vread_iter() parameters
- Fix nommu vread() -> vread_iter()

v1:
https://lore.kernel.org/all/cover.1679183626.git.lstoakes@gmail.com/

Lorenzo Stoakes (4):
  fs/proc/kcore: Avoid bounce buffer for ktext data
  mm: vmalloc: use rwsem, mutex for vmap_area_lock and vmap_block->lock
  fs/proc/kcore: convert read_kcore() to read_kcore_iter()
  mm: vmalloc: convert vread() to vread_iter()

 fs/proc/kcore.c         |  84 +++++++------------
 include/linux/vmalloc.h |   3 +-
 mm/nommu.c              |  10 +--
 mm/vmalloc.c            | 178 +++++++++++++++++++++-------------------
 4 files changed, 130 insertions(+), 145 deletions(-)


base-commit: 4018ab1f7cec061b8425737328edefebdc0ab832
--
2.39.2

Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ