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Juntong Deng a5989d4ed4 kasan: improve free meta storage in Generic KASAN
Currently free meta can only be stored in object if the object is not
smaller than free meta.

After the improvement, when the object is smaller than free meta and SLUB
DEBUG is not enabled, it is possible to store part of the free meta in the
object, reducing the increased size of the red zone.

Example:

free meta size: 16 bytes
alloc meta size: 16 bytes
object size: 8 bytes
optimal redzone size (object_size <= 64): 16 bytes

Before improvement:
actual redzone size = alloc meta size + free meta size = 32 bytes

After improvement:
actual redzone size = alloc meta size + (free meta size - object size)
                    = 24 bytes

[juntong.deng@outlook.com: make kasan_metadata_size() adapt to the improved free meta storage]
  Link: https://lkml.kernel.org/r/VI1P193MB0752675D6E0A2D16CE656F8299BAA@VI1P193MB0752.EURP193.PROD.OUTLOOK.COM
Link: https://lkml.kernel.org/r/VI1P193MB0752DE2CCD9046B5FED0AA8E99B5A@VI1P193MB0752.EURP193.PROD.OUTLOOK.COM
Signed-off-by: Juntong Deng <juntong.deng@outlook.com>
Suggested-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-10 16:51:50 -08:00
arch NUMA: optimize detection of memory with no node id assigned by firmware 2023-12-10 16:51:34 -08:00
block fs: convert error_remove_page to error_remove_folio 2023-12-10 16:51:42 -08:00
certs This update includes the following changes: 2023-11-02 16:15:30 -10:00
crypto This push fixes a regression in ahash and hides the Kconfig sub-options for the jitter RNG. 2023-11-09 17:04:58 -08:00
Documentation fs: convert error_remove_page to error_remove_folio 2023-12-10 16:51:42 -08:00
drivers zram: tweak writeback config help 2023-12-10 16:51:41 -08:00
fs fs: convert error_remove_page to error_remove_folio 2023-12-10 16:51:42 -08:00
include mm: use vmem_altmap code without CONFIG_ZONE_DEVICE 2023-12-10 16:51:48 -08:00
init As usual, lots of singleton and doubleton patches all over the tree and 2023-11-02 20:53:31 -10:00
io_uring io_uring: use fget/fput consistently 2023-11-28 11:56:29 -07:00
ipc Many singleton patches against the MM code. The patch series which are 2023-11-02 19:38:47 -10:00
kernel fork: use __mt_dup() to duplicate maple tree in dup_mmap() 2023-12-10 16:51:34 -08:00
lib lib/stackdepot: adjust DEPOT_POOLS_CAP for KMSAN 2023-12-10 16:51:48 -08:00
LICENSES LICENSES: Add the copyleft-next-0.3.1 license 2022-11-08 15:44:01 +01:00
mm kasan: improve free meta storage in Generic KASAN 2023-12-10 16:51:50 -08:00
net wireless fixes: 2023-11-29 19:43:34 -08:00
rust Kbuild updates for v6.7 2023-11-04 08:07:19 -10:00
samples Landlock updates for v6.7-rc1 2023-11-03 09:28:53 -10:00
scripts Merge branch 'master' into mm-hotfixes-stable 2023-12-06 17:03:50 -08:00
security + Features 2023-11-03 09:48:17 -10:00
sound ALSA: hda: Disable power-save on KONTRON SinglePC 2023-11-30 16:14:21 +01:00
tools selftests/mm: check that PAGEMAP_SCAN returns correct categories 2023-12-10 16:51:35 -08:00
usr arch: Remove Itanium (IA-64) architecture 2023-09-11 08:13:17 +00:00
virt ARM: 2023-09-07 13:52:20 -07:00
.clang-format iommu: Add for_each_group_device() 2023-05-23 08:15:51 +02:00
.cocciconfig
.get_maintainer.ignore get_maintainer: add Alan to .get_maintainer.ignore 2022-08-20 15:17:44 -07:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore kbuild: rpm-pkg: generate kernel.spec in rpmbuild/SPECS/ 2023-10-03 20:49:09 +09:00
.mailmap .mailmap: add a new address mapping for Chester Lin 2023-12-06 16:12:45 -08:00
.rustfmt.toml rust: add .rustfmt.toml 2022-09-28 09:02:20 +02:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: drop Antti Palosaari 2023-12-06 16:12:49 -08:00
Kbuild Kbuild updates for v6.1 2022-10-10 12:00:45 -07:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS Merge branch 'master' into mm-hotfixes-stable 2023-12-06 17:03:50 -08:00
Makefile Linux 6.7-rc4 2023-12-03 18:52:56 +09:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.