Linux kernel source tree
Go to file
Linus Torvalds 5572ad8fdd tracing fixes for v6.19:
- Remove useless assignment of soft_mode variable
 
   The function __ftrace_event_enable_disable() sets "soft_mode" in one of
   the branch paths but doesn't use it after that. Remove the setting of that
   variable.
 
 - Add a cond_resched() in ring_buffer_resize()
 
   The resize function that allocates all the pages for the ring buffer was
   causing a soft lockup on PREEMPT_NONE configs when allocating large
   buffers on machines with many CPUs. Hopefully this is the last
   cond_resched() needed to be added as PREEMPT_LAZY becomes the norm in the
   future.
 
 - Make ftrace_graph_ent depth field signed
 
   The "depth" field of struct ftrace_graph_ent was converted from "int" to
   "unsigned long" for alignment reasons to work with being embedded in other
   structures. The conversion from a signed to unsigned caused integrity
   checks to always pass as they were comparing "depth" to less than zero.
   Make the field signed long.
 
 - Add recursion protection to stack trace events
 
   A infinite recursion was triggered by a stack trace event calling RCU
   which internally called rcu_read_unlock_special(), which triggered an
   event that was also doing stacktraces which cause it to trigger the same
   RCU lock that called rcu_read_unlock_special() again.
 
   Update the trace_test_and_set_recursion() to add a set of context checks
   for events to use, and have the stack trace event use that for recursion
   protection.
 
 - Make the variable ftrace_dump_on_oops static
 
   The cleanup of sysctl that moved all the updates to the files that use
   them moved the reference of ftrace_dump_on_oops to where it is used.
   It is no longer used outside of the trace.c file. Make it static.
 -----BEGIN PGP SIGNATURE-----
 
 iIoEABYKADIWIQRRSw7ePDh/lE+zeZMp5XQQmuv6qgUCaV/2wRQccm9zdGVkdEBn
 b29kbWlzLm9yZwAKCRAp5XQQmuv6qmMqAQD+LyAOb7bKlgFjwRABjszg1yDhJPb0
 gQGSNPchQyq/7gD8Cu3/ze5UxrNV8cNNsbAPu0/xEg4eyozbRiP/VjzZ4gU=
 =uLUP
 -----END PGP SIGNATURE-----

Merge tag 'trace-v6.19-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull tracing fixes from Steven Rostedt:

 - Remove useless assignment of soft_mode variable

   The function __ftrace_event_enable_disable() sets "soft_mode" in one
   of the branch paths but doesn't use it after that. Remove the setting
   of that variable.

 - Add a cond_resched() in ring_buffer_resize()

   The resize function that allocates all the pages for the ring buffer
   was causing a soft lockup on PREEMPT_NONE configs when allocating
   large buffers on machines with many CPUs. Hopefully this is the last
   cond_resched() needed to be added as PREEMPT_LAZY becomes the norm in
   the future.

 - Make ftrace_graph_ent depth field signed

   The "depth" field of struct ftrace_graph_ent was converted from "int"
   to "unsigned long" for alignment reasons to work with being embedded
   in other structures. The conversion from a signed to unsigned caused
   integrity checks to always pass as they were comparing "depth" to
   less than zero. Make the field signed long.

 - Add recursion protection to stack trace events

   A infinite recursion was triggered by a stack trace event calling RCU
   which internally called rcu_read_unlock_special(), which triggered an
   event that was also doing stacktraces which cause it to trigger the
   same RCU lock that called rcu_read_unlock_special() again.

   Update the trace_test_and_set_recursion() to add a set of context
   checks for events to use, and have the stack trace event use that for
   recursion protection.

 - Make the variable ftrace_dump_on_oops static

   The cleanup of sysctl that moved all the updates to the files that
   use them moved the reference of ftrace_dump_on_oops to where it is
   used. It is no longer used outside of the trace.c file. Make it
   static.

* tag 'trace-v6.19-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  trace: ftrace_dump_on_oops[] is not exported, make it static
  tracing: Add recursion protection in kernel stack trace recording
  ftrace: Make ftrace_graph_ent depth field signed
  ring-buffer: Avoid softlockup in ring_buffer_resize() during memory free
  tracing: Drop unneeded assignment to soft_mode
2026-01-08 08:47:05 -10:00
arch Fix the AMD microcode Entrysign signature checking code to include more 2026-01-02 12:04:51 -08:00
block block-6.19-20260102 2026-01-02 12:15:59 -08:00
certs sign-file,extract-cert: use pkcs11 provider for OPENSSL MAJOR >= 3 2024-09-20 19:52:48 +03:00
crypto crypto: seqiv - Do not use req->iv after crypto_aead_encrypt 2025-12-19 14:47:06 +08:00
Documentation netlink: specs: netdev: clarify the page pool API a little 2026-01-05 16:49:54 -08:00
drivers Including fixes from netfilter and wireless. 2026-01-08 08:40:35 -10:00
fs nfsd-6.19 fixes: 2026-01-06 09:12:52 -08:00
include tracing fixes for v6.19: 2026-01-08 08:47:05 -10:00
init Significant patch series in this pull request: 2025-12-06 14:01:20 -08:00
io_uring io_uring-6.19-20260102 2026-01-02 12:07:55 -08:00
ipc Significant patch series in this pull request: 2025-12-06 14:01:20 -08:00
kernel trace: ftrace_dump_on_oops[] is not exported, make it static 2026-01-07 14:52:22 -05:00
lib idr: fix idr_alloc() returning an ID out of range 2025-12-23 11:23:11 -08:00
LICENSES LICENSES: Add modern form of the LGPL-2.1 tags to the usage guide section 2025-10-22 07:58:19 +02:00
mm mm/ksm: fix pte_unmap_unlock of wrong address in break_ksm_pmd_entry 2025-12-23 11:23:17 -08:00
net arp: do not assume dev_hard_header() does not change skb->head 2026-01-08 09:04:24 -08:00
rust 27 hotfixes. 12 are cc:stable, 18 are MM. 2025-12-29 11:40:38 -08:00
samples samples/ftrace: Adjust LoongArch register restore order in direct calls 2025-12-31 15:19:25 +08:00
scripts mcb: Add missing modpost build support 2025-12-27 20:48:01 +01:00
security kernel/kexec: change the prototype of kimage_map_segment() 2025-12-23 11:23:13 -08:00
sound ALSA: hda/realtek: add HP Laptop 15s-eq1xxx mute LED quirk 2026-01-02 14:34:23 +01:00
tools Including fixes from netfilter and wireless. 2026-01-08 08:40:35 -10:00
usr initramfs: add gen_init_cpio to hostprogs unconditionally 2025-11-26 21:55:40 +01:00
virt KVM fixes for 6.19-rc1 2025-12-18 18:38:45 +01:00
.clang-format s390/pci: Fix cyclic dead-lock in zpci_zdev_put() and zpci_scan_devices() 2025-12-14 11:03:58 +01:00
.clippy.toml rust: clean Rust 1.88.0's warning about clippy::disallowed_macros configuration 2025-05-07 00:11:47 +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 MAINTAINERS: remove Alyssa Rosenzweig 2025-09-18 21:17:31 +02:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore rust: kbuild: add proc macro library support 2025-11-24 17:15:36 +01:00
.mailmap Including fixes from netfilter and wireless. 2026-01-08 08:40:35 -10:00
.pylintrc docs: Move the python libraries to tools/lib/python 2025-11-18 09:22:40 -07:00
.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 Including fixes from netfilter and CAN. 2025-12-19 07:55:35 +12:00
Kbuild sched: Make migrate_{en,dis}able() inline 2025-09-25 09:57:16 +02:00
Kconfig io_uring: Rename KConfig to Kconfig 2025-02-19 14:53:27 -07:00
MAINTAINERS Including fixes from netfilter and wireless. 2026-01-08 08:40:35 -10:00
Makefile Linux 6.19-rc4 2026-01-04 14:41:55 -08:00
README README: restructure with role-based documentation and guidelines 2025-11-29 08:40:33 -07:00

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