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Wei Yang 04dafdd208 maple_tree: print empty for an empty tree on mt_dump()
Patch series "refine storing null", v5.

When overwriting the whole range with NULL, current behavior is not
correct.

An empty tree is represented by having the tree point to NULL directly. 
An empty tree indicates the entire range (0-ULONG_MAX) is NULL.

A store operation into an existing node that causes 0 - ULONG_MAX to be
equal to NULL may not be restored to an empty state - a node is used to
store the single range instead.  This is wasteful and different from the
initial setup of the tree.

Once the tree is using a single node to store 0 - ULONG_MAX, problems may
arise when storing more values into a tree with the unexpected state of 0
- ULONG being a single range in a node.

User visible issues may mean a corrupt tree and incorrect storage of
information within the tree.  This would be limited to users who create
and then empty a tree by overwriting all values, then try to store more
NULLs into the empty tree.

I cannot come up with an example of any user doing this (users usually
destroy the tree and generally don't keep trying to store NULLs over
NULLs), but patch 4/5 "maple_tree: refine mas_store_root() on storing
NULL" should be backported just in case.


This patch (of 5):

Currently for an empty tree, it would print:

  maple_tree(0x7ffcd02c6ee0) flags 1, height 0 root (nil)
  0: (nil)

This is a little misleading.

Let's print (empty) for an empty tree.

Link: https://lkml.kernel.org/r/20241031231627.14316-1-richard.weiyang@gmail.com
Link: https://lkml.kernel.org/r/20241031231627.14316-2-richard.weiyang@gmail.com
Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
Reviewed-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Cc: Liam R. Howlett <Liam.Howlett@Oracle.com>
Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
History 2024-11-11 13:09:42 -08:00
arch mm: madvise: implement lightweight guard page mechanism 2024-11-11 00:26:45 -08:00
block block-6.12-20241101 2024-11-01 13:41:55 -10:00
certs sign-file,extract-cert: use pkcs11 provider for OPENSSL MAJOR >= 3 2024-09-20 19:52:48 +03:00
crypto This push fixes the following issues: 2024-10-16 08:42:54 -07:00
Documentation kasan: delete CONFIG_KASAN_MODULE_TEST 2024-11-11 00:26:44 -08:00
drivers zram: clear IDLE flag in mark_idle() 2024-11-11 13:09:35 -08:00
fs mm: zswap: modify zswap_stored_pages to be atomic_long_t 2024-11-11 00:26:42 -08:00
include memcg: add flush tracepoint 2024-11-11 00:26:46 -08:00
init cfi: fix conditions for HAVE_CFI_ICALL_NORMALIZE_INTEGERS 2024-10-13 22:23:13 +02:00
io_uring io_uring/rw: fix missing NOWAIT check for O_DIRECT start write 2024-10-31 08:21:02 -06:00
ipc struct fd layout change (and conversion to accessor helpers) 2024-09-23 09:35:36 -07:00
kernel Merge branch 'mm-hotfixes-stable' into mm-stable 2024-11-11 00:04:10 -08:00
lib maple_tree: print empty for an empty tree on mt_dump() 2024-11-11 13:09:42 -08:00
LICENSES LICENSES: add 0BSD license text 2024-09-01 20:43:24 -07:00
mm vma: detect infinite loop in vma tree 2024-11-11 13:09:42 -08:00
net nfsd-6.12 fixes: 2024-11-02 09:27:11 -10:00
rust Driver core fix for 6.12-rc3 2024-10-13 09:10:52 -07:00
samples [tree-wide] finally take no_llseek out 2024-09-27 08:18:43 -07:00
scripts alloc_tag: load module tags into separate contiguous memory 2024-11-07 14:25:16 -08:00
security ipe: fallback to platform keyring also if key in trusted keyring is rejected 2024-10-18 12:14:53 -07:00
sound ALSA: hda/realtek: Fix headset mic on TUXEDO Stellaris 16 Gen6 mb1 2024-10-30 14:46:59 +01:00
tools selftests/mm: skip virtual_address_range tests on riscv 2024-11-11 13:09:42 -08:00
usr initramfs: shorten cmd_initfs in usr/Makefile 2024-07-16 01:07:52 +09:00
virt ARM64: 2024-10-21 11:22:04 -07:00
.clang-format clang-format: Update with v6.11-rc1's for_each macro list 2024-08-02 13:20:31 +02:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.editorconfig .editorconfig: remove trim_trailing_whitespace option 2024-06-13 16:47:52 +02:00
.get_maintainer.ignore Add Jeff Kirsher to .get_maintainer.ignore 2024-03-08 11:36:54 +00:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore Kbuild updates for v6.12 2024-09-24 13:02:06 -07:00
.mailmap Merge branch 'mm-hotfixes-stable' into mm-stable 2024-11-11 00:04:10 -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 CREDITS: sort alphabetically by name 2024-10-09 12:47:19 -07:00
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 MAINTAINERS: mailmap: update Alexey Klimov's email address 2024-11-06 20:11:11 -08:00
Makefile Linux 6.12-rc6 2024-11-03 14:05:52 -10:00
README README: Fix spelling 2024-03-18 03:36:32 -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 reStructuredText 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.