Linux kernel source tree
Go to file
Linus Torvalds 8f7537efbe pwm: Two fixes and a maintainer update
Included here are three changes:
 
  - pwm: Ensure ioctl() returns a negative errno on error
    This affects two ioctls on /dev/pwmchipX where the return value of
    copy_to_user() was passed to userspace. This is fixed to return
    -EFAULT now instead.
    You might argue that this is an ABI change, but I still think it's
    sensible to be fixed because a) other exit paths already return
    -EFAULT so userspace must be aware of this return value; b) the
    interface is somewhat new (commit v6.17-rc1~181^2~35 ("pwm: Add
    support for pwmchip devices for faster and easier userspace access"))
    and the only known user is libpwm which relies on the fixed
    semantics (and uses the ioctl correctly and thus doesn't trigger that
    problematic error path); and c) it's very unlikely that
    copy_to_user() fails if a moment before copy_from_user() on the same
    memory chunk succeeded.
 
  - pwm: max7360: Populate missing .sizeof_wfhw in max7360_pwm_ops
    This fixes an oversight in commit v6.18-rc1~168^2~3^2~6 which added
    support for the max7360 driver. There is no user-visible effect
    because the .sizeof_wfhw member is just a safe guard that the memory
    provided by the core is big enough. While it currently is big enough
    and there is no reason to assume that will change, doing that
    correctly is necessary.
 
  - MAINTAINERS: Add myself as reviewer for PWM rust drivers
    "Myself" here is Michal Wilczynski who cares for the Rust parts of
    the pwm subsystem. Several of the patches sent recently for the (for
    now) only Rust pwm driver did not add Michal to Cc which resulted in
    the patches waiting for review as I thought Michal would care but he
    wasn't aware of them.
 -----BEGIN PGP SIGNATURE-----
 
 iQEzBAABCgAdFiEEP4GsaTp6HlmJrf7Tj4D7WH0S/k4FAmlvR/AACgkQj4D7WH0S
 /k6KoQgAmUmnCVrIcqdzSlC1drxdzhV9kAqTaVUi317xC3AtSquuUojrfwEiGnBq
 v/p9we57m4jcRjt56Qrg6g23bt8U7F4OSiFKifXgCDrpoX5qdN/iCchOQ1SfR7fA
 o0F4KSBZHCOCHBwUgfEQmXPMkEj5VaJ20xh6yLlyrIgkTlaMQ3TMyD39+uHk68Pm
 hyaiCyYNOfu+UkYX2BbjNCCzAxTmdZim1vQ6iZsRrSY97+Fp+WDKvAErZUuPgzJQ
 aqvBleJXMCS+y0w6hcoTAuf/g8YXAeNo+kYNANfzO1UKoXsyG0+feHbohKFA46L7
 xKi/5Y1vd058EiNh12AW7MJ/u1GNwg==
 =txwU
 -----END PGP SIGNATURE-----

Merge tag 'pwm/for-6.19-rc7-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/ukleinek/linux

Pull pwm fixes and a maintainer update from Uwe Kleine-König:

 - pwm: Ensure ioctl() returns a negative errno on error

   This affects two ioctls on /dev/pwmchipX where the return value of
   copy_to_user() was passed to userspace. This is fixed to return
   -EFAULT now instead.

 - pwm: max7360: Populate missing .sizeof_wfhw in max7360_pwm_ops

   This fixes an oversight in the original commit that added support for
   the max7360 driver (d93a75d94b79: "pwm: max7360: Add MAX7360 PWM
   support"). There is no user-visible effect because the .sizeof_wfhw
   member is just a safe guard that the memory provided by the core is
   big enough. While it currently is big enough and there is no reason
   to assume that will change, doing that correctly is necessary.

 - MAINTAINERS: Add Michal Wilczynski as reviewer for PWM rust drivers

   Michal cares for the Rust parts of the pwm subsystem. Several of the
   patches sent recently for the (for now) only Rust pwm driver did not
   add Michal to Cc which resulted in the patches waiting for review as
   I thought Michal would care but he wasn't aware of them.

* tag 'pwm/for-6.19-rc7-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/ukleinek/linux:
  MAINTAINERS: Add myself as reviewer for PWM rust drivers
  pwm: max7360: Populate missing .sizeof_wfhw in max7360_pwm_ops
  pwm: Ensure ioctl() returns a negative errno on error
2026-01-20 09:46:29 -08:00
Documentation phy fixes for 6.19 2026-01-18 13:18:40 -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
arch Misc x86 fixes: 2026-01-18 11:34:11 -08:00
block block-6.19-20260116 2026-01-16 20:59:46 -08:00
certs
crypto crypto: seqiv - Do not use req->iv after crypto_aead_encrypt 2025-12-19 14:47:06 +08:00
drivers pwm: Two fixes and a maintainer update 2026-01-20 09:46:29 -08:00
fs Ext4 bug fixes for 6.19: 2026-01-18 14:01:20 -08:00
include Landlock fix for v6.19-rc6 2026-01-18 15:15:47 -08:00
init Significant patch series in this pull request: 2025-12-06 14:01:20 -08:00
io_uring io_uring-6.19-20260116 2026-01-16 20:56:56 -08:00
ipc Significant patch series in this pull request: 2025-12-06 14:01:20 -08:00
kernel cgroup: Another fix for v6.19-rc5 2026-01-18 14:30:27 -08:00
lib lib/buildid: use __kernel_read() for sleepable context 2026-01-14 22:16:21 -08:00
mm cxl fixes for v6.19-rc6 2026-01-16 13:09:28 -08:00
net Including fixes from bluetooth, can and IPsec. 2026-01-15 10:11:11 -08:00
rust rust: bitops: fix missing _find_* functions on 32-bit ARM 2026-01-13 22:16:39 -05:00
samples samples/ftrace: Adjust LoongArch register restore order in direct calls 2025-12-31 15:19:25 +08:00
scripts Crypto library fixes for v6.19-rc5 2026-01-11 15:07:56 -10:00
security Landlock fix for v6.19-rc6 2026-01-18 15:15:47 -08:00
sound ALSA: hda/tas2781: Add newly-released HP laptop 2026-01-15 15:04:27 +01:00
tools Landlock fix for v6.19-rc6 2026-01-18 15:15:47 -08:00
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
.cocciconfig
.editorconfig
.get_maintainer.ignore MAINTAINERS: remove Alyssa Rosenzweig 2025-09-18 21:17:31 +02:00
.gitattributes
.gitignore rust: kbuild: add proc macro library support 2025-11-24 17:15:36 +01:00
.mailmap mailmap: add entry for Daniel Thompson 2026-01-14 22:16:26 -08:00
.pylintrc docs: Move the python libraries to tools/lib/python 2025-11-18 09:22:40 -07:00
.rustfmt.toml
COPYING
CREDITS treewide: Update email address 2026-01-11 06:09:11 -10:00
Kbuild sched: Make migrate_{en,dis}able() inline 2025-09-25 09:57:16 +02:00
Kconfig
MAINTAINERS pwm: Two fixes and a maintainer update 2026-01-20 09:46:29 -08:00
Makefile Linux 6.19-rc6 2026-01-18 15:42:45 -08:00
README README: restructure with role-based documentation and guidelines 2025-11-29 08:40:33 -07:00

README

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