Linux kernel source tree
Go to file
Jani Nikula 78f1421dc3 Revert "drm/gma500: use drm_crtc_vblank_crtc()"
This reverts commit d930ffa5d6.

According to Thomas, commit d930ffa5d6 ("drm/gma500: use
drm_crtc_vblank_crtc()") breaks the driver with a NULL-ptr oops on
startup. This is because the IRQ initialization in gma_irq_install() now
uses CRTCs that are only allocated later in psb_modeset_init(). Stack
trace is below. Revert. Go back to the drawing board.

[   65.831766] Oops: general protection fault, probably for non-canonical address 0xdffffc0000000021: 0000 [#1] SMP KASAN NOPTI
[   65.832114] KASAN: null-ptr-deref in range [0x0000000000000108-0x000000000000010f]
[   65.832232] CPU: 1 UID: 0 PID: 296 Comm: (udev-worker) Tainted: G         E       6.19.0-rc6-1-default+ #4622 PREEMPT(voluntary)
[   65.832376] Tainted: [E]=UNSIGNED_MODULE
[   65.832448] Hardware name:  /DN2800MT, BIOS MTCDT10N.86A.0164.2012.1213.1024 12/13/2012
[   65.832543] RIP: 0010:drm_crtc_vblank_crtc+0x24/0xd0
[   65.832652] Code: 90 90 90 90 90 90 0f 1f 44 00 00 48 89 f8 48 81 c7
18 01 00 00 48 83 ec 10 48 ba 00 00 00 00 00 fc ff df 48 89 f9 48 c1 e9
03 <0f> b6 14 11 84 d2 74 05 80 fa 03 7e 58 48 89 c6 8b 90 18 01 00
00
[   65.832820] RSP: 0018:ffff88800c8f7688 EFLAGS: 00010006
[   65.832919] RAX: fffffffffffffff0 RBX: ffff88800fff4928 RCX: 0000000000000021
[   65.833011] RDX: dffffc0000000000 RSI: ffffc90000978130 RDI: 0000000000000108
[   65.833107] RBP: ffffed1001ffea03 R08: 0000000000000000 R09: ffffed100191eec7
[   65.833199] R10: 0000000000000001 R11: 0000000000000001 R12: ffff8880014480c8
[   65.833289] R13: dffffc0000000000 R14: fffffffffffffff0 R15: ffff88800fff4000
[   65.833380] FS:  00007fe53d4d5d80(0000) GS:ffff888148dd8000(0000) knlGS:0000000000000000
[   65.833488] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   65.833575] CR2: 00007fac707420b8 CR3: 000000000ebd1000 CR4: 00000000000006f0
[   65.833668] Call Trace:
[   65.833735]  <TASK>
[   65.833808]  gma_irq_preinstall+0x190/0x3e0 [gma500_gfx]
[   65.834054]  gma_irq_install+0xb2/0x240 [gma500_gfx]
[   65.834282]  psb_driver_load+0x7b2/0x1090 [gma500_gfx]
[   65.834516]  ? __pfx_psb_driver_load+0x10/0x10 [gma500_gfx]
[   65.834726]  ? ksize+0x1d/0x40
[   65.834817]  ? drmm_add_final_kfree+0x3b/0xb0
[   65.834935]  ? __pfx_psb_pci_probe+0x10/0x10 [gma500_gfx]
[   65.835164]  psb_pci_probe+0xc8/0x150 [gma500_gfx]
[   65.835384]  local_pci_probe+0xd5/0x190
[   65.835492]  pci_call_probe+0x167/0x4b0
[   65.835594]  ? __pfx_pci_call_probe+0x10/0x10
[   65.835693]  ? local_clock+0x11/0x30
[   65.835808]  ? __pfx___driver_attach+0x10/0x10
[   65.835915]  ? do_raw_spin_unlock+0x55/0x230
[   65.836014]  ? pci_match_device+0x303/0x790
[   65.836124]  ? pci_match_device+0x386/0x790
[   65.836226]  ? __pfx_pci_assign_irq+0x10/0x10
[   65.836320]  ? kernfs_create_link+0x16a/0x230
[   65.836418]  ? do_raw_spin_unlock+0x55/0x230
[   65.836526]  ? __pfx___driver_attach+0x10/0x10
[   65.836626]  pci_device_probe+0x175/0x2c0
[   65.836735]  call_driver_probe+0x64/0x1e0
[   65.836842]  really_probe+0x194/0x740
[   65.836951]  ? __pfx___driver_attach+0x10/0x10
[   65.837053]  __driver_probe_device+0x18c/0x3a0
[   65.837163]  ? __pfx___driver_attach+0x10/0x10
[   65.837262]  driver_probe_device+0x4a/0x120
[   65.837369]  __driver_attach+0x19c/0x550
[   65.837474]  ? __pfx___driver_attach+0x10/0x10
[   65.837575]  bus_for_each_dev+0xe6/0x150
[   65.837669]  ? local_clock+0x11/0x30
[   65.837770]  ? __pfx_bus_for_each_dev+0x10/0x10
[   65.837891]  bus_add_driver+0x2af/0x4f0
[   65.838000]  ? __pfx_psb_init+0x10/0x10 [gma500_gfx]
[   65.838236]  driver_register+0x19f/0x3a0
[   65.838342]  ? rcu_is_watching+0x11/0xb0
[   65.838446]  do_one_initcall+0xb5/0x3a0
[   65.838546]  ? __pfx_do_one_initcall+0x10/0x10
[   65.838644]  ? __kasan_slab_alloc+0x2c/0x70
[   65.838741]  ? rcu_is_watching+0x11/0xb0
[   65.838837]  ? __kmalloc_cache_noprof+0x3e8/0x6e0
[   65.838937]  ? klp_module_coming+0x1a0/0x2e0
[   65.839033]  ? do_init_module+0x85/0x7f0
[   65.839126]  ? kasan_unpoison+0x40/0x70
[   65.839230]  do_init_module+0x26e/0x7f0
[   65.839341]  ? __pfx_do_init_module+0x10/0x10
[   65.839450]  init_module_from_file+0x13f/0x160
[   65.839549]  ? __pfx_init_module_from_file+0x10/0x10
[   65.839651]  ? __lock_acquire+0x578/0xae0
[   65.839791]  ? do_raw_spin_unlock+0x55/0x230
[   65.839886]  ? idempotent_init_module+0x585/0x720
[   65.839993]  idempotent_init_module+0x1ff/0x720
[   65.840097]  ? __pfx_cred_has_capability.isra.0+0x10/0x10
[   65.840211]  ? __pfx_idempotent_init_module+0x10/0x10

Reported-by: Thomas Zimmermann <tzimmermann@suse.de>
Closes: https://lore.kernel.org/r/5aec1964-072c-4335-8f37-35e6efb4910e@suse.de
Fixes: d930ffa5d6 ("drm/gma500: use drm_crtc_vblank_crtc()")
Cc: Patrik Jakobsson <patrik.r.jakobsson@gmail.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Tested-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Patrik Jakobsson <patrik.r.jakobsson@gmail.com>
Link: https://patch.msgid.link/20260130151319.31264-1-jani.nikula@intel.com
2026-02-02 10:10:15 +01:00
arch Disable GCOV instrumentation in the SEV noinstr.c collection 2026-01-11 07:19:43 -10:00
block block-6.19-20260109 2026-01-09 15:42:46 -10:00
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 treewide: Update email address 2026-01-11 06:09:11 -10:00
drivers Revert "drm/gma500: use drm_crtc_vblank_crtc()" 2026-02-02 10:10:15 +01:00
fs treewide: Update email address 2026-01-11 06:09:11 -10:00
include drm-misc-fixes for v6.19-rc6: 2026-01-16 20:27:21 +01:00
init Significant patch series in this pull request: 2025-12-06 14:01:20 -08:00
io_uring io_uring-6.19-20260109 2026-01-09 15:21:15 -10:00
ipc Significant patch series in this pull request: 2025-12-06 14:01:20 -08:00
kernel Fix a crash in sched_mm_cid_after_execve(). 2026-01-11 07:11:53 -10:00
lib Crypto library fixes for v6.19-rc5 2026-01-11 15:07:56 -10:00
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 A bunch of libceph fixes split evenly between memory safety and 2026-01-09 15:05:19 -10:00
rust Driver core fixes for 6.19-rc5 2026-01-10 15:04:04 -10:00
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 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 treewide: Update email address 2026-01-11 06:09:11 -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
.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 treewide: Update email address 2026-01-11 06:09:11 -10:00
.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 io_uring: Rename KConfig to Kconfig 2025-02-19 14:53:27 -07:00
MAINTAINERS Crypto library fixes for v6.19-rc5 2026-01-11 15:07:56 -10:00
Makefile Linux 6.19-rc5 2026-01-11 17:03:14 -10:00
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