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Sebastian Andrzej Siewior 838e6dd8b5 module: Begin to move from RCU-sched to RCU.
The RCU usage in module was introduced in commit d72b37513c ("Remove
stop_machine during module load v2") and it claimed not to be RCU but
similar. Then there was another improvement in commit e91defa26c
("module: don't use stop_machine on module load"). It become a mix of
RCU and RCU-sched and was eventually fixed 0be964be0d ("module:
Sanitize RCU usage and locking"). Later RCU & RCU-sched was merged in
commit cb2f55369d ("modules: Replace synchronize_sched() and
call_rcu_sched()") so that was aligned.

Looking at it today, there is still leftovers. The preempt_disable() was
used instead rcu_read_lock_sched(). The RCU & RCU-sched merge was not
complete as there is still rcu_dereference_sched() for module::kallsyms.

The RCU-list modules and unloaded_tainted_modules are always accessed
under RCU protection or the module_mutex. The modules list iteration can
always happen safely because the module will not disappear.
Once the module is removed (free_module()) then after removing the
module from the list, there is a synchronize_rcu() which waits until
every RCU reader left the section. That means iterating over the list
within a RCU-read section is enough, there is no need to disable
preemption. module::kallsyms is first assigned in add_kallsyms() before
the module is added to the list. At this point, it points to init data.
This pointer is later updated and before the init code is removed there
is also synchronize_rcu() in do_free_init(). That means A RCU read lock
is enough for protection and rcu_dereference() can be safely used.

Convert module code and its users step by step. Update comments and
convert print_modules() to use RCU.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20250108090457.512198-3-bigeasy@linutronix.de
Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
2025-03-10 11:54:43 +01:00
arch KVM/arm64 fixes for 6.14, take #4 2025-03-09 09:04:08 -10:00
block block-6.14-20250306 2025-03-07 11:12:33 -10:00
certs sign-file,extract-cert: use pkcs11 provider for OPENSSL MAJOR >= 3 2024-09-20 19:52:48 +03:00
crypto treewide: const qualify ctl_tables where applicable 2025-01-28 13:48:37 +01:00
Documentation Kbuild fixes for v6.14 (3rd) 2025-03-09 09:23:14 -10:00
drivers USB fixes for 6.14-rc6 2025-03-09 09:14:07 -10:00
fs 33 hotfixes. 24 are cc:stable and the remainder address post-6.13 issues 2025-03-08 14:34:06 -10:00
include 33 hotfixes. 24 are cc:stable and the remainder address post-6.13 issues 2025-03-08 14:34:06 -10:00
init Kbuild updates for v6.14 2025-01-31 12:07:07 -08:00
io_uring io_uring-6.14-20250306 2025-03-07 11:09:33 -10:00
ipc treewide: const qualify ctl_tables where applicable 2025-01-28 13:48:37 +01:00
kernel module: Begin to move from RCU-sched to RCU. 2025-03-10 11:54:43 +01:00
lib tests/module: nix-ify 2025-03-10 11:54:13 +01:00
LICENSES LICENSES: add 0BSD license text 2024-09-01 20:43:24 -07:00
mm 33 hotfixes. 24 are cc:stable and the remainder address post-6.13 issues 2025-03-08 14:34:06 -10:00
net net: ipv6: fix missing dst ref drop in ila lwtunnel 2025-03-06 11:08:45 +01:00
rust Driver core api addition for 6.14-rc3 2025-02-16 12:54:42 -08:00
samples Driver core api addition for 6.14-rc3 2025-02-16 12:54:42 -08:00
scripts kbuild: install-extmod-build: Fix build when specifying KBUILD_OUTPUT 2025-03-06 20:32:30 +09:00
security Landlock fix for v6.14-rc5 2025-02-26 11:55:44 -08:00
sound ALSA: hda/realtek: Add support for ASUS Zenbook UM3406KA Laptops using CS35L41 HDA 2025-03-05 19:52:56 +01:00
tools KVM/arm64 fixes for 6.14, take #4 2025-03-09 09:04:08 -10:00
usr kbuild: hdrcheck: fix cross build with clang 2025-03-05 04:06:45 +09:00
virt KVM: remove kvm_arch_post_init_vm 2025-02-04 11:27:45 -05:00
.clang-format clang-format: Update with v6.11-rc1's for_each macro list 2024-08-02 13:20:31 +02:00
.clippy.toml rust: give Clippy the minimum supported Rust version 2025-01-10 00:17:25 +01:00
.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 MAINTAINERS: Retire Ralf Baechle 2024-11-12 15:48:59 +01:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore rust: use host dylib naming convention to support macOS 2025-01-10 01:01:24 +01:00
.mailmap 33 hotfixes. 24 are cc:stable and the remainder address post-6.13 issues 2025-03-08 14:34:06 -10:00
.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: Move Pavel to kernel.org address 2025-02-07 09:12:33 -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 Char/Misc/IIO driver fixes for 6.14-rc6 2025-03-09 09:07:54 -10:00
Makefile Linux 6.14-rc6 2025-03-09 13:45:25 -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.