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Andrii Nakryiko 593fffb8bc Merge branch 'libbpf-fix-perm-errors-for-ldimm_64_full_range_off'
Emil Tsalapatis says:

====================
libbpf: Fix perm errors for LDIMM_64_FULL_RANGE_OFF

Commit 728ff16791 ("libbpf: Add gating for arena globals relocation feature")
adds a feature flag for testing whether the running kernel supports LDIMM64
instructions with large direct offsets. Fix two edge cases that can
cause unexpected -EPERM errors in two ways:

1) The probe program used for the feature has type TRACEPOINT, but it's
possible the caller does not have permission to load it, even if it is
able to do so for generic BPF programs. Use the SOCKET_FILTER type
instead that requires fewer permissions. This does not affect the check
itself, which will always fail verification anyway.

2) The probe is triggered during bpf_object__collect_relos(), itself
called in bpf_object_open(), to compute the arena relocation offsets of
arena variables. However, the caller may not have permissions to load
BPF programs. This is the case in some systems with the bpftool calls made
by the BPF selftests during compilation, e.g., for skeleton generation.
Move all uses of the feature check to bpf_object_prepare() time instead.

Fixes: 728ff16791 ("libbpf: Add gating for arena globals relocation feature")
Signed-off-by: Emil Tsalapatis <emil@etsalapatis.com>

v2 -> v3: https://lore.kernel.org/bpf/20260214021014.15670-1-emil@etsalapatis.com/

- Only zero out the first byte of the log buffer (Andrii)
- Minimize invocations of the feature gate (Andrii)

v1 -> v2: https://lore.kernel.org/bpf/20260213181752.505318-1-emil@etsalapatis.com/

- Adjust the hash of the original commit post-tree rebase
- Ensure close() is not called on invalid prog_fd in feature probe (Coverity)
====================

Link: https://patch.msgid.link/20260217204345.548648-1-emil@etsalapatis.com
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
2026-02-17 14:20:25 -08:00
arch bpf, riscv: add fsession support for trampolines 2026-02-13 14:14:27 -08:00
block mm.git review status for linus..mm-stable 2026-02-12 11:32:37 -08:00
certs mm.git review status for linus..mm-nonmm-stable 2026-02-12 12:13:01 -08:00
crypto mm.git review status for linus..mm-nonmm-stable 2026-02-12 12:13:01 -08:00
Documentation virtio,vhost,vdpa: features, fixes 2026-02-13 12:02:18 -08:00
drivers virtio,vhost,vdpa: features, fixes 2026-02-13 12:02:18 -08:00
fs Three MM hotfixes, all three are cc:stable. 2026-02-13 12:13:27 -08:00
include virtio,vhost,vdpa: features, fixes 2026-02-13 12:02:18 -08:00
init mm.git review status for linus..mm-nonmm-stable 2026-02-12 12:13:01 -08:00
io_uring for-7.0/io_uring-zcrx-large-buffers-20260206 2026-02-12 15:07:50 -08:00
ipc mm.git review status for linus..mm-nonmm-stable 2026-02-12 12:13:01 -08:00
kernel bpf: Add a map/btf from a fd array more consistently 2026-02-13 14:37:02 -08:00
lib mm.git review status for linus..mm-nonmm-stable 2026-02-12 12:13:01 -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 Three MM hotfixes, all three are cc:stable. 2026-02-13 12:13:27 -08:00
net virtio,vhost,vdpa: features, fixes 2026-02-13 12:02:18 -08:00
rust configfs changes for v7.0 2026-02-12 14:01:38 -08:00
samples configfs changes for v7.0 2026-02-12 14:01:38 -08:00
scripts virtio,vhost,vdpa: features, fixes 2026-02-13 12:02:18 -08:00
security mm.git review status for linus..mm-nonmm-stable 2026-02-12 12:13:01 -08:00
sound mm.git review status for linus..mm-nonmm-stable 2026-02-12 12:13:01 -08:00
tools libbpf: Delay feature gate check until object prepare time 2026-02-17 14:20:24 -08:00
usr kbuild: uapi: drop dependency on CC_CAN_LINK 2026-01-16 15:02:11 -07:00
virt Merge tag 'kvm-x86-pmu-6.20' of https://github.com/kvm-x86/linux into HEAD 2026-02-11 12:45:40 -05:00
.clang-format Devicetree updates for v7.0: 2026-02-11 18:27:08 -08:00
.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: add rst extension 2026-01-26 19:07:09 -08:00
.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 Landlock update for v7.0-rc1 2026-02-11 15:57:08 -08:00
.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 Networking changes for 7.0 2026-02-11 19:31:52 -08:00
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 Loongarch: 2026-02-13 11:31:15 -08:00
Makefile Devicetree updates for v7.0: 2026-02-11 18:27:08 -08:00
README docs: add AI Coding Assistants documentation 2026-01-06 14:55:06 -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
* AI Coding Assistant - LLMs and AI-powered development tools


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

AI Coding Assistant
-------------------

CRITICAL: If you are an LLM or AI-powered coding assistant, you MUST read and
follow the AI coding assistants documentation before contributing to the Linux
kernel:

* Documentation/process/coding-assistants.rst

This documentation contains essential requirements about licensing, attribution,
and the Developer Certificate of Origin that all AI tools must comply with.


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