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
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devm_add_action_or_reset() already invokes the action on failure,
so the explicit put causes a double-put.
Fixes: 9b07cdf86a0b ("pinctrl: cirrus: Fix fwnode leak in cs42l43_pin_probe()")
Signed-off-by: Felix Gu <ustc.gu@gmail.com>
Reviewed-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Signed-off-by: Linus Walleij <linusw@kernel.org>
The of_get_parent() function returns a device_node with an incremented
reference count.
Use the __free(device_node) cleanup attribute to ensure of_node_put()
is automatically called when pnode goes out of scope, fixing a
reference leak.
Fixes: 6e9be3abb78c ("pinctrl: Add driver support for Amlogic SoCs")
Signed-off-by: Felix Gu <ustc.gu@gmail.com>
Signed-off-by: Linus Walleij <linusw@kernel.org>
File-scope 'sdm660_lpi_pinctrl_groups' and
'sdm660_lpi_pinctrl_functions' are not used outside of this unit, so
make them static to silence sparse warnings:
pinctrl-sdm660-lpass-lpi.c:79:27: warning: symbol 'sdm660_lpi_pinctrl_groups' was not declared. Should it be static?
pinctrl-sdm660-lpass-lpi.c:116:27: warning: symbol 'sdm660_lpi_pinctrl_functions' was not declared. Should it be static?
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>
Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Signed-off-by: Linus Walleij <linusw@kernel.org>
File-scope 'sky1_pinctrl_pm_ops' is not used outside of this unit (and
it should not be!), so unexport it and make it static to silence sparse
warning:
pinctrl-sky1.c:525:25: warning: symbol 'sky1_pinctrl_pm_ops' was not declared. Should it be static?
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>
Signed-off-by: Linus Walleij <linusw@kernel.org>
File-scope 'amdisp_pinctrl_ops' is not used outside of this unit, so
make it static to silence sparse warning:
pinctrl-amdisp.c:83:26: warning: symbol 'amdisp_pinctrl_ops' was not declared. Should it be static?
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>
Signed-off-by: Linus Walleij <linusw@kernel.org>
In pinconf_generic_parse_dt_config(), if parse_dt_cfg() fails, it returns
directly. This bypasses the cleanup logic and results in a memory leak of
the cfg buffer.
Fix this by jumping to the out label on failure, ensuring kfree(cfg) is
called before returning.
Fixes: 90a18c512884 ("pinctrl: pinconf-generic: Handle string values for generic properties")
Signed-off-by: Felix Gu <ustc.gu@gmail.com>
Reviewed-by: Antonio Borneo <antonio.borneo@foss.st.com>
Signed-off-by: Linus Walleij <linusw@kernel.org>
Wakeup capable GPIOs uses PDC as parent IRQ chip and PDC on qcs615 do not
support dual edge IRQs. Add missing wakeirq_dual_edge_errata configuration
to enable workaround for dual edge GPIO IRQs.
Fixes: b698f36a9d40 ("pinctrl: qcom: add the tlmm driver for QCS615 platform")
Signed-off-by: Maulik Shah <maulik.shah@oss.qualcomm.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Signed-off-by: Linus Walleij <linusw@kernel.org>
The callback functions 'eqbr_irq_mask()' and 'eqbr_irq_ack()' are also
called in the callback function 'eqbr_irq_mask_ack()'. This is done to
avoid source code duplication. The problem, is that in the function
'eqbr_irq_mask()' also calles the gpiolib function 'gpiochip_disable_irq()'
This generates the following warning trace in the log for every gpio on
load.
[ 6.088111] ------------[ cut here ]------------
[ 6.092440] WARNING: CPU: 3 PID: 1 at drivers/gpio/gpiolib.c:3810 gpiochip_disable_irq+0x39/0x50
[ 6.097847] Modules linked in:
[ 6.097847] CPU: 3 UID: 0 PID: 1 Comm: swapper/0 Tainted: G W 6.12.59+ #0
[ 6.097847] Tainted: [W]=WARN
[ 6.097847] RIP: 0010:gpiochip_disable_irq+0x39/0x50
[ 6.097847] Code: 39 c6 48 19 c0 21 c6 48 c1 e6 05 48 03 b2 38 03 00 00 48 81 fe 00 f0 ff ff 77 11 48 8b 46 08 f6 c4 02 74 06 f0 80 66 09 fb c3 <0f> 0b 90 0f 1f 40 00 c3 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40
[ 6.097847] RSP: 0000:ffffc9000000b830 EFLAGS: 00010046
[ 6.097847] RAX: 0000000000000045 RBX: ffff888001be02a0 RCX: 0000000000000008
[ 6.097847] RDX: ffff888001be9000 RSI: ffff888001b2dd00 RDI: ffff888001be02a0
[ 6.097847] RBP: ffffc9000000b860 R08: 0000000000000000 R09: 0000000000000000
[ 6.097847] R10: 0000000000000001 R11: ffff888001b2a154 R12: ffff888001be0514
[ 6.097847] R13: ffff888001be02a0 R14: 0000000000000008 R15: 0000000000000000
[ 6.097847] FS: 0000000000000000(0000) GS:ffff888041d80000(0000) knlGS:0000000000000000
[ 6.097847] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 6.097847] CR2: 0000000000000000 CR3: 0000000003030000 CR4: 00000000001026b0
[ 6.097847] Call Trace:
[ 6.097847] <TASK>
[ 6.097847] ? eqbr_irq_mask+0x63/0x70
[ 6.097847] ? no_action+0x10/0x10
[ 6.097847] eqbr_irq_mask_ack+0x11/0x60
In an other driver (drivers/pinctrl/starfive/pinctrl-starfive-jh7100.c) the
interrupt is not disabled here.
To fix this, do not call the 'eqbr_irq_mask()' and 'eqbr_irq_ack()'
function. Implement instead this directly without disabling the interrupts.
Fixes: 52066a53bd11 ("pinctrl: equilibrium: Convert to immutable irq_chip")
Signed-off-by: Florian Eckert <fe@dev.tdt.de>
Signed-off-by: Linus Walleij <linusw@kernel.org>
Renaming of the irq_chip callback functions to improve clarity.
Signed-off-by: Florian Eckert <fe@dev.tdt.de>
Signed-off-by: Linus Walleij <linusw@kernel.org>
Pull fsverity fixes from Eric Biggers:
- Fix a build error on parisc
- Remove the non-large-folio-aware function fsverity_verify_page()
* tag 'fsverity-for-linus' of git://git.kernel.org/pub/scm/fs/fsverity/linux:
fsverity: fix build error by adding fsverity_readahead() stub
fsverity: remove fsverity_verify_page()
f2fs: make f2fs_verify_cluster() partially large-folio-aware
f2fs: remove unnecessary ClearPageUptodate in f2fs_verify_cluster()
Pull crypto library fix from Eric Biggers:
"Fix a big endian specific issue in the PPC64-optimized AES code"
* tag 'libcrypto-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiggers/linux:
lib/crypto: powerpc/aes: Fix rndkey_from_vsx() on big endian CPUs
hppa-linux-gcc 9.5.0 generates a call to fsverity_readahead() in
f2fs_readahead() when CONFIG_FS_VERITY=n, because it fails to do the
expected dead code elimination based on vi always being NULL. Fix the
build error by adding an inline stub for fsverity_readahead(). Since
it's just for opportunistic readahead, just make it a no-op.
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202602180838.pwICdY2r-lkp@intel.com/
Fixes: 45dcb3ac9832 ("f2fs: consolidate fsverity_info lookup")
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20260218012244.18536-1-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@kernel.org>
Stephen retired and stepped back from -next maintainership, update his
entry in CREDITS to recognise his 18 years of hard work making it what
it is today and all the impact it's had on our development process.
Also update to his current GnuPG key while we're here.
Acked-by: Stephen Rothwell <sfr@canb.auug.org.au>
Acked-by: SeongJae Park <sj@kernel.org>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
Acked-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
I finally got a big endian PPC64 kernel to boot in QEMU. The PPC64 VSX
optimized AES library code does work in that case, with the exception of
rndkey_from_vsx() which doesn't take into account that the order in
which the VSX code stores the round key words depends on the endianness.
So fix rndkey_from_vsx() to do the right thing on big endian CPUs.
Fixes: 7cf2082e74ce ("lib/crypto: powerpc/aes: Migrate POWER8 optimized code into library")
Link: https://lore.kernel.org/r/20260216022104.332991-1-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@kernel.org>
Now that fsverity_verify_page() has no callers, remove it.
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20260218010630.7407-4-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@kernel.org>