Linux kernel ============ The Linux kernel is the core of any Linux operating system. It manages hardware, system resources, and provides the fundamental services for all other software. Quick Start ----------- * Report a bug: See Documentation/admin-guide/reporting-issues.rst * Get the latest kernel: https://kernel.org * Build the kernel: See Documentation/admin-guide/quickly-build-trimmed-linux.rst * Join the community: https://lore.kernel.org/ Essential Documentation ----------------------- All users should be familiar with: * Building requirements: Documentation/process/changes.rst * Code of Conduct: Documentation/process/code-of-conduct.rst * License: See COPYING Documentation can be built with make htmldocs or viewed online at: https://www.kernel.org/doc/html/latest/ Who Are You? ============ Find your role below: * New Kernel Developer - Getting started with kernel development * Academic Researcher - Studying kernel internals and architecture * Security Expert - Hardening and vulnerability analysis * Backport/Maintenance Engineer - Maintaining stable kernels * System Administrator - Configuring and troubleshooting * Maintainer - Leading subsystems and reviewing patches * Hardware Vendor - Writing drivers for new hardware * Distribution Maintainer - Packaging kernels for distros For Specific Users ================== New Kernel Developer -------------------- Welcome! Start your kernel development journey here: * Getting Started: Documentation/process/development-process.rst * Your First Patch: Documentation/process/submitting-patches.rst * Coding Style: Documentation/process/coding-style.rst * Build System: Documentation/kbuild/index.rst * Development Tools: Documentation/dev-tools/index.rst * Kernel Hacking Guide: Documentation/kernel-hacking/hacking.rst * Core APIs: Documentation/core-api/index.rst Academic Researcher ------------------- Explore the kernel's architecture and internals: * Researcher Guidelines: Documentation/process/researcher-guidelines.rst * Memory Management: Documentation/mm/index.rst * Scheduler: Documentation/scheduler/index.rst * Networking Stack: Documentation/networking/index.rst * Filesystems: Documentation/filesystems/index.rst * RCU (Read-Copy Update): Documentation/RCU/index.rst * Locking Primitives: Documentation/locking/index.rst * Power Management: Documentation/power/index.rst Security Expert --------------- Security documentation and hardening guides: * Security Documentation: Documentation/security/index.rst * LSM Development: Documentation/security/lsm-development.rst * Self Protection: Documentation/security/self-protection.rst * Reporting Vulnerabilities: Documentation/process/security-bugs.rst * CVE Procedures: Documentation/process/cve.rst * Embargoed Hardware Issues: Documentation/process/embargoed-hardware-issues.rst * Security Features: Documentation/userspace-api/seccomp_filter.rst Backport/Maintenance Engineer ----------------------------- Maintain and stabilize kernel versions: * Stable Kernel Rules: Documentation/process/stable-kernel-rules.rst * Backporting Guide: Documentation/process/backporting.rst * Applying Patches: Documentation/process/applying-patches.rst * Subsystem Profile: Documentation/maintainer/maintainer-entry-profile.rst * Git for Maintainers: Documentation/maintainer/configure-git.rst System Administrator -------------------- Configure, tune, and troubleshoot Linux systems: * Admin Guide: Documentation/admin-guide/index.rst * Kernel Parameters: Documentation/admin-guide/kernel-parameters.rst * Sysctl Tuning: Documentation/admin-guide/sysctl/index.rst * Tracing/Debugging: Documentation/trace/index.rst * Performance Security: Documentation/admin-guide/perf-security.rst * Hardware Monitoring: Documentation/hwmon/index.rst Maintainer ---------- Lead kernel subsystems and manage contributions: * Maintainer Handbook: Documentation/maintainer/index.rst * Pull Requests: Documentation/maintainer/pull-requests.rst * Managing Patches: Documentation/maintainer/modifying-patches.rst * Rebasing and Merging: Documentation/maintainer/rebasing-and-merging.rst * Development Process: Documentation/process/maintainer-handbooks.rst * Maintainer Entry Profile: Documentation/maintainer/maintainer-entry-profile.rst * Git Configuration: Documentation/maintainer/configure-git.rst Hardware Vendor --------------- Write drivers and support new hardware: * Driver API Guide: Documentation/driver-api/index.rst * Driver Model: Documentation/driver-api/driver-model/driver.rst * Device Drivers: Documentation/driver-api/infrastructure.rst * Bus Types: Documentation/driver-api/driver-model/bus.rst * Device Tree Bindings: Documentation/devicetree/bindings/ * Power Management: Documentation/driver-api/pm/index.rst * DMA API: Documentation/core-api/dma-api.rst Distribution Maintainer ----------------------- Package and distribute the kernel: * Stable Kernel Rules: Documentation/process/stable-kernel-rules.rst * ABI Documentation: Documentation/ABI/README * Kernel Configuration: Documentation/kbuild/kconfig.rst * Module Signing: Documentation/admin-guide/module-signing.rst * Kernel Parameters: Documentation/admin-guide/kernel-parameters.rst * Tainted Kernels: Documentation/admin-guide/tainted-kernels.rst Communication and Support ========================= * Mailing Lists: https://lore.kernel.org/ * IRC: #kernelnewbies on irc.oftc.net * Bugzilla: https://bugzilla.kernel.org/ * MAINTAINERS file: Lists subsystem maintainers and mailing lists * Email Clients: Documentation/process/email-clients.rst
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The monitor container source files contained a declaration and a
definition for the rv_monitor variable. The former is superfluous and
can be removed.
Remove the variable declaration from the template as well as the
existing monitor containers.
Reviewed-by: Nam Cao <namcao@linutronix.de>
Link: https://lore.kernel.org/r/20251126104241.291258-9-gmonaco@redhat.com
Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
The header files generated by dot2c currently create enums for states
and events assigning the first element to 0. This is superfluous as it
happens automatically if no value is specified.
Also it doesn't add a comma to the last enum elements, which slightly
complicates the diff if states or events are added.
Remove the assignment to 0 and add a comma to last elements, this
simplifies the logic for the code generator.
Reviewed-by: Nam Cao <namcao@linutronix.de>
Link: https://lore.kernel.org/r/20251126104241.291258-8-gmonaco@redhat.com
Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
str.join() can do what __buff_to_string() does. Therefore replace
__buff_to_string() to make the scripts more pythonic.
Also clean and remove some intermediate functions.
Reviewed-by: Nam Cao <namcao@linutronix.de>
Link: https://lore.kernel.org/r/20251126104241.291258-7-gmonaco@redhat.com
Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
Functions in automata.py, dot2c.py and dot2k.py don't have type
annotations and it can get complicated to remember how to use them.
Add minimal type annotations.
Reviewed-by: Nam Cao <namcao@linutronix.de>
Link: https://lore.kernel.org/r/20251126104241.291258-6-gmonaco@redhat.com
Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
Previous changes refactored the da_monitor header file to avoid using
macros. This implies a few changes in how to import and use da_monitor
helpers:
DECLARE_DA_MON_<TYPE>(name, type) is substituted by
#define RV_MON_TYPE RV_MON_<TYPE>
Update the rvgen templates to reflect the changes.
Reviewed-by: Nam Cao <namcao@linutronix.de>
Link: https://lore.kernel.org/r/20251126104241.291258-5-gmonaco@redhat.com
Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
Previous changes refactored the da_monitor header file to avoid using
macros. This implies a few changes in how to import and use da_monitor
helpers:
DECLARE_DA_MON_<TYPE>(name, type) is substituted by
#define RV_MON_TYPE RV_MON_<TYPE>
da_handle_event_<name>() is substituted by
da_handle_event()
Update the documentation to reflect the changes.
Reviewed-by: Nam Cao <namcao@linutronix.de>
Link: https://lore.kernel.org/r/20251126104241.291258-4-gmonaco@redhat.com
Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
Previous changes refactored the da_monitor header file to avoid using
macros, however empty macros (e.g. DECLARE_DA_FUNCTION) were left to
ease review with diff tools.
Most macros also get the argument type which doesn't really have a
purpose since states have their own enum and the storage in struct
da_monitor is fixed to unsigned int.
Remove empty and no longer required macros and substitute the type
parameter with the appropriate enum.
Additionally break long line and adjust the format overall.
Reviewed-by: Nam Cao <namcao@linutronix.de>
Link: https://lore.kernel.org/r/20251126104241.291258-3-gmonaco@redhat.com
Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
The da_monitor helper functions are generated from macros of the type:
DECLARE_DA_FUNCTION(name, type) \
static void da_func_x_##name(type arg) {} \
static void da_func_y_##name(type arg) {} \
This is good to minimise code duplication but the long macros made of
skipped end of lines is rather hard to parse. Since functions are
static, the advantage of naming them differently for each monitor is
minimal.
Refactor the da_monitor.h file to minimise macros, instead of declaring
functions from macros, we simply declare them with the same name for all
monitors (e.g. da_func_x) and for any remaining reference to the monitor
name (e.g. tracepoints, enums, global variables) we use the CONCATENATE
macro.
In this way the file is much easier to maintain while keeping the same
generality.
Functions depending on the monitor types are now conditionally compiled
according to the value of RV_MON_TYPE, which must be defined in the
monitor source.
The monitor type can be specified as in the original implementation,
although it's best to keep the default implementation (unsigned char) as
not all parts of code support larger data types, and likely there's no
need.
We keep the empty macro definitions to ease review of this change with
diff tools, but cleanup is required.
Also adapt existing monitors to keep the build working.
Reviewed-by: Nam Cao <namcao@linutronix.de>
Link: https://lore.kernel.org/r/20251126104241.291258-2-gmonaco@redhat.com
Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
Pull crypto library fixes from Eric Biggers:
- A couple more fixes for the lib/crypto KUnit tests
- Fix missing MMU protection for the AES S-box
* tag 'libcrypto-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiggers/linux:
lib/crypto: aes: Fix missing MMU protection for AES S-box
MAINTAINERS: add test vector generation scripts to "CRYPTO LIBRARY"
lib/crypto: tests: Fix syntax error for old python versions
lib/crypto: tests: polyval_kunit: Increase iterations for preparekey in IRQs
Pull char/misc driver fixes from Greg KH:
"Here are some small char/misc driver fixes for some reported issues.
Included in here is:
- much reported rust_binder fix
- counter driver fixes
- new device ids for the mei driver
All of these have been in linux-next for a while with no reported
issues"
* tag 'char-misc-6.19-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
rust_binder: remove spin_lock() in rust_shrink_free_page()
mei: me: add nova lake point S DID
counter: 104-quad-8: Fix incorrect return value in IRQ handler
counter: interrupt-cnt: Drop IRQF_NO_THREAD flag
__cacheline_aligned puts the data in the ".data..cacheline_aligned"
section, which isn't marked read-only i.e. it doesn't receive MMU
protection. Replace it with ____cacheline_aligned which does the right
thing and just aligns the data while keeping it in ".rodata".
Fixes: b5e0b032b6c3 ("crypto: aes - add generic time invariant AES cipher")
Cc: stable@vger.kernel.org
Reported-by: Qingfang Deng <dqfext@gmail.com>
Closes: https://lore.kernel.org/r/20260105074712.498-1-dqfext@gmail.com/
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20260107052023.174620-1-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@kernel.org>
Pull x86 fix from Ingo Molnar:
"Disable GCOV instrumentation in the SEV noinstr.c collection of SEV
noinstr methods, to further robustify the code"
* tag 'x86-urgent-2026-01-11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/sev: Disable GCOV on noinstr object
When forward-porting Rust Binder to 6.18, I neglected to take commit
fb56fdf8b9a2 ("mm/list_lru: split the lock to per-cgroup scope") into
account, and apparently I did not end up running the shrinker callback
when I sanity tested the driver before submission. This leads to crashes
like the following:
============================================
WARNING: possible recursive locking detected
6.18.0-mainline-maybe-dirty #1 Tainted: G IO
--------------------------------------------
kswapd0/68 is trying to acquire lock:
ffff956000fa18b0 (&l->lock){+.+.}-{2:2}, at: lock_list_lru_of_memcg+0x128/0x230
but task is already holding lock:
ffff956000fa18b0 (&l->lock){+.+.}-{2:2}, at: rust_helper_spin_lock+0xd/0x20
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(&l->lock);
lock(&l->lock);
*** DEADLOCK ***
May be due to missing lock nesting notation
3 locks held by kswapd0/68:
#0: ffffffff90d2e260 (fs_reclaim){+.+.}-{0:0}, at: kswapd+0x597/0x1160
#1: ffff956000fa18b0 (&l->lock){+.+.}-{2:2}, at: rust_helper_spin_lock+0xd/0x20
#2: ffffffff90cf3680 (rcu_read_lock){....}-{1:2}, at: lock_list_lru_of_memcg+0x2d/0x230
To fix this, remove the spin_lock() call from rust_shrink_free_page().
Cc: stable <stable@kernel.org>
Fixes: eafedbc7c050 ("rust_binder: add Rust Binder driver")
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Link: https://patch.msgid.link/20251202-binder-shrink-unspin-v1-1-263efb9ad625@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The scripts in scripts/crypto/ are used to generate files in
lib/crypto/, so they should be included in "CRYPTO LIBRARY".
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20260107033948.29368-1-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@kernel.org>
Pull scheduler fix from Ingo Molnar:
"Fix a crash in sched_mm_cid_after_execve()"
* tag 'sched-urgent-2026-01-11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched/mm_cid: Prevent NULL mm dereference in sched_mm_cid_after_execve()