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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API Fixes:
- Add missing pad and extensions check (Jonathan)
- Reject unsafe PAT indices for CPU cached memory (Jia)
Driver Fixes:
- Drop registration of guc_submit_wedged_fini from xe_guc_submit_wedge (Brost)
- Xe3p tuning and workaround fixes (Roper, Gustavo)
- USE drm mm instead of drm SA for CCS read/write (Satya)
- Fix leaks and null derefs (Shuicheng)
- Fix Wa_18022495364 (Tvrtko)
Signed-off-by: Dave Airlie <airlied@redhat.com>
From: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patch.msgid.link/afO05KvmFMn_7qcY@intel.com
amd-drm-fixes-7.1-2026-04-30:
amdgpu:
- GFX12 fix for CONFIG_DRM_DEBUG_MM configs
- Fix DC analog support
- Userq fixes
- GART placement fix
- Aldebaran SMU fixes
- AMDGPU_INFO_READ_MMR_REG fix
- UVD 3.1 fix
- GC 6 TCC fix
- Fix root reservation in amdgpu_vm_handle_fault()
- RAS fix
- Module reload fix for APUs
- Fix build for CONFIG_DRM_FBDEV_EMULATION=n
- IGT DWB regression fix
- GC 11.5.4 fix
- VCN user fence fixes
- JPEG user fence fixes
- SMU 13.0.6 fix
- VCN 3/4 IB parser fixes
- NV3x+ dGPU vblank fix
- DCE6/8 fixes for LVDS/eDP panels without an EDID
amdkfd:
- Fix for when CONFIG_HSA_AMD is not set
- SVM fixes
Signed-off-by: Dave Airlie <airlied@redhat.com>
From: Alex Deucher <alexander.deucher@amd.com>
Link: https://patch.msgid.link/20260430135619.3929877-1-alexander.deucher@amd.com
Add validation in xe_vm_bind_ioctl() to reject PAT indices
with XE_COH_NONE coherency mode when used with
DRM_XE_VM_BIND_FLAG_CPU_ADDR_MIRROR.
CPU address mirror mappings use system memory that is CPU
cached, which makes them incompatible with COH_NONE PAT
indices. Allowing COH_NONE with CPU cached buffers is a
security risk, as the GPU may bypass CPU caches and read
stale sensitive data from DRAM.
Although CPU_ADDR_MIRROR does not create an immediate
mapping, the backing system memory is still CPU cached.
Apply the same PAT coherency restrictions as
DRM_XE_VM_BIND_OP_MAP_USERPTR.
v2:
- Correct fix tag
v6:
- No change
v7:
- Correct fix tag
v8:
- Rebase
v9:
- Limit the restrictions to iGPU
v10:
- Just add the iGPU logic but keep dGPU logic
Fixes: b43e864af0d4 ("drm/xe/uapi: Add DRM_XE_VM_BIND_FLAG_CPU_ADDR_MIRROR")
Cc: <stable@vger.kernel.org> # v6.15+
Cc: Shuicheng Lin <shuicheng.lin@intel.com>
Cc: Mathew Alwin <alwin.mathew@intel.com>
Cc: Michal Mrozek <michal.mrozek@intel.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Cc: Matthew Auld <matthew.auld@intel.com>
Signed-off-by: Jia Yao <jia.yao@intel.com>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Acked-by: Michal Mrozek <michal.mrozek@intel.com>
Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patch.msgid.link/20260417055917.2027459-3-jia.yao@intel.com
(cherry picked from commit 4d58d7535e826a3175527b6174502f0db319d7f6)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Short summary of fixes pull:
DRM core and helpers:
- calculate framebuffer geometry with format helpers
- fix docs
appletbdrm:
- allocate protocol buffers with kvzalloc()
dma-buf:
- fix docs
imagination:
- avoid segfault in debugfs
ofdrm:
- put PCI device reference on errors
udl:
- increase USB timeout
Signed-off-by: Dave Airlie <airlied@redhat.com>
From: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patch.msgid.link/20260430064521.GA14957@linux.fritz.box
When an embedded panel has no DDC, read the EDID from
the VBIOS embedded panel info and use that.
Fixes: 7c7f5b15be65 ("drm/amd/display: Refactor edid read.")
Link: https://gitlab.freedesktop.org/drm/amd/-/work_items/5192
Signed-off-by: Timur Kristóf <timur.kristof@gmail.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit 399b9abc353c62f6e37d38325edbdb6c2c00411c)
Add validation in xe_vm_madvise_ioctl() to reject PAT indices with
XE_COH_NONE coherency mode when applied to CPU cached memory.
Using coh_none with CPU cached buffers is a security issue. When the
kernel clears pages before reallocation, the clear operation stays in
CPU cache (dirty). GPU with coh_none can bypass CPU caches and read
stale sensitive data directly from DRAM, potentially leaking data from
previously freed pages of other processes.
This aligns with the existing validation in vm_bind path
(xe_vm_bind_ioctl_validate_bo).
v2(Matthew brost)
- Add fixes
- Move one debug print to better place
v3(Matthew Auld)
- Should be drm/xe/uapi
- More Cc
v4(Shuicheng Lin)
- Fix kmem leak issues by the way
v5
- Remove kmem leak because it has been merged by another patch
v6
- Remove the fix which is not related to current fix
v7
- No change
v8
- Rebase
v9
- Limit the restrictions to iGPU
v10
- No change
Fixes: ada7486c5668 ("drm/xe: Implement madvise ioctl for xe")
Cc: <stable@vger.kernel.org> # v6.18+
Cc: Shuicheng Lin <shuicheng.lin@intel.com>
Cc: Mathew Alwin <alwin.mathew@intel.com>
Cc: Michal Mrozek <michal.mrozek@intel.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Cc: Matthew Auld <matthew.auld@intel.com>
Signed-off-by: Jia Yao <jia.yao@intel.com>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Acked-by: Michal Mrozek <michal.mrozek@intel.com>
Acked-by: José Roberto de Souza <jose.souza@intel.com>
Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patch.msgid.link/20260417055917.2027459-2-jia.yao@intel.com
(cherry picked from commit 016ccdb674b8c899940b3944952c96a6a490d10a)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
[WHY]
A situation has occurred where udl_handle_damage() executed successfully
and the kernel log appears normal, but the display fails to show any output.
This is because the call to udl_get_urb() in udl_crtc_helper_atomic_enable()
failed without generating any error message.
[HOW]
1. Increase timeout of getting urb.
2. Add error messages when calling udl_get_urb() failed in
udl_crtc_helper_atomic_enable().
Signed-off-by: Shixiong Ou <oushixiong@kylinos.cn>
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Fixes: 5320918b9a87 ("drm/udl: initial UDL driver (v4)")
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Cc: <stable@vger.kernel.org> # v3.4+
Link: https://patch.msgid.link/20260424124427.657-1-oushixiong1025@163.com
Some board manufacturers hardcode the EDID for the embedded
panel in the VBIOS. This EDID should be used when the panel
doesn't have a DDC.
For reference, see the legacy non-DC display code:
amdgpu_atombios_encoder_get_lcd_info()
This is necessary to support embedded connectors without DDC.
Fixes: 4562236b3bc0 ("drm/amd/dc: Add dc display driver (v2)")
Link: https://gitlab.freedesktop.org/drm/amd/-/work_items/5192
Signed-off-by: Timur Kristóf <timur.kristof@gmail.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit eb105e63b474c11ef6a84a1c6b18100d851ff364)
Command parser relative MMIO addressing needs to be enabled when writing
to the register.
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@igalia.com>
Fixes: ca33cd271ef9 ("drm/xe/xelp: Add Wa_18022495364")
Cc: Matt Roper <matthew.d.roper@intel.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Link: https://patch.msgid.link/20260420131603.70357-1-tvrtko.ursulin@igalia.com
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
(cherry picked from commit 5627392001802a98ed6cf8cf79a303abd00d1c0f)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Pull clk fix from Stephen Boyd:
"One more fix for the merge window to avoid a boot hang on
Raspberry Pi 3B by marking the VEC clk critical so that it
doesn't get turned off and hang the bus"
* tag 'clk-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux:
clk: bcm: rpi: Mark VEC clock as CLK_IGNORE_UNUSED
Fix invalid data access by passing right data for debugfs entry.
[ 171.549793] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000
[ 171.559248] Mem abort info:
[ 171.562173] ESR = 0x0000000096000044
[ 171.566227] EC = 0x25: DABT (current EL), IL = 32 bits
[ 171.573108] SET = 0, FnV = 0
[ 171.576448] EA = 0, S1PTW = 0
[ 171.579745] FSC = 0x04: level 0 translation fault
[ 171.584760] Data abort info:
[ 171.588012] ISV = 0, ISS = 0x00000044, ISS2 = 0x00000000
[ 171.593734] CM = 0, WnR = 1, TnD = 0, TagAccess = 0
[ 171.598962] GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
[ 171.604471] user pgtable: 4k pages, 48-bit VAs, pgdp=0000000083837000
[ 171.611358] [0000000000000000] pgd=0000000000000000, p4d=0000000000000000
[ 171.618500] Internal error: Oops: 0000000096000044 [#1] SMP
[ 171.624222] Modules linked in: powervr drm_shmem_helper drm_gpuvm...
[ 171.656580] CPU: 0 UID: 0 PID: 549 Comm: bash Not tainted 7.0.0-rc2-g730b257ba723-dirty #13 PREEMPT
[ 171.665773] Hardware name: BeagleBoard.org BeaglePlay (DT)
[ 171.671296] pstate: 20000005 (nzCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[ 171.678306] pc : pvr_fw_trace_mask_set+0x78/0x154 [powervr]
[ 171.683959] lr : pvr_fw_trace_mask_set+0x4c/0x154 [powervr]
[ 171.689593] sp : ffff8000835ebb90
[ 171.692929] x29: ffff8000835ebc00 x28: ffff000005c60f80 x27: 0000000000000000
[ 171.700130] x26: 0000000000000000 x25: ffff00000504af28 x24: 0000000000000000
[ 171.707324] x23: ffff00000504af50 x22: 0000000000000203 x21: 0000000000000000
[ 171.714518] x20: ffff000005c44a80 x19: ffff000005c457b8 x18: 0000000000000000
[ 171.721715] x17: 0000000000000000 x16: 0000000000000000 x15: 0000aaaae8887580
[ 171.728908] x14: 0000000000000000 x13: 0000000000000000 x12: ffff8000835ebc30
[ 171.736095] x11: ffff00000504af2a x10: ffff00008504af29 x9 : 0fffffffffffffff
[ 171.743286] x8 : ffff8000835ebbf8 x7 : 0000000000000000 x6 : 000000000000002a
[ 171.750479] x5 : ffff00000504af2e x4 : 0000000000000000 x3 : 0000000000000010
[ 171.757674] x2 : 0000000000000203 x1 : 0000000000000000 x0 : ffff8000835ebba0
[ 171.764871] Call trace:
[ 171.767342] pvr_fw_trace_mask_set+0x78/0x154 [powervr] (P)
[ 171.772984] simple_attr_write_xsigned.isra.0+0xe0/0x19c
[ 171.778341] simple_attr_write+0x18/0x24
[ 171.782296] debugfs_attr_write+0x50/0x98
[ 171.786341] full_proxy_write+0x6c/0xa8
[ 171.790208] vfs_write+0xd4/0x350
[ 171.793561] ksys_write+0x70/0x108
[ 171.796995] __arm64_sys_write+0x1c/0x28
[ 171.800952] invoke_syscall+0x48/0x10c
[ 171.804740] el0_svc_common.constprop.0+0x40/0xe0
[ 171.809487] do_el0_svc+0x1c/0x28
[ 171.812834] el0_svc+0x34/0x108
[ 171.816013] el0t_64_sync_handler+0xa0/0xe4
[ 171.820237] el0t_64_sync+0x198/0x19c
[ 171.823939] Code: 32000262 b90ac293 1a931056 9134e293 (b9000036)
[ 171.830073] ---[ end trace 0000000000000000 ]---
Fixes: a331631496a0 ("drm/imagination: Simplify module parameters")
Signed-off-by: Brajesh Gupta <brajesh.gupta@imgtec.com>
Reviewed-by: Alessio Belle <alessio.belle@imgtec.com>
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20260427-ftrace_fix-v3-1-e081530759a8@imgtec.com
Signed-off-by: Matt Coster <matt.coster@imgtec.com>
When the DDC channel ID is set to CHANNEL_ID_UNKNOWN,
pass NULL to the AUX regs array.
This is necessary to support embedded connectors without DDC.
Fixes: 4562236b3bc0 ("drm/amd/dc: Add dc display driver (v2)")
Link: https://gitlab.freedesktop.org/drm/amd/-/work_items/5192
Signed-off-by: Timur Kristóf <timur.kristof@gmail.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit 155baf3038c1af50b602723022ed869b38e86a99)
When xe_gsc_read_out_header() fails, query_compatibility_version()
returns directly instead of jumping to the out_bo label. This skips
the xe_bo_unpin_map_no_vm() call, leaving the BO pinned and mapped
with no remaining reference to free it.
Fix by using goto out_bo so the error path properly cleans up the BO,
consistent with the other error handling in the same function.
Fixes: 0881cbe04077 ("drm/xe/gsc: Query GSC compatibility version")
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Reviewed-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Link: https://patch.msgid.link/20260417163308.3416147-1-shuicheng.lin@intel.com
Signed-off-by: Shuicheng Lin <shuicheng.lin@intel.com>
(cherry picked from commit 8de86d0a843c32ca9d36864bdb92f0376a830bce)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Pull PCIe TSP update from Dan Williams:
"A small update for the TSM core. It is arguably a fix and coming in
late as I have been offline the past few weeks:
- Drop class_create() for the 'tsm' class"
* tag 'tsm-for-7.1' of git://git.kernel.org/pub/scm/linux/kernel/git/devsec/tsm:
virt: coco: change tsm_class to a const struct
On Raspberry Pi 3B, the VEC clock is used by the VideoCore firmware
display driver, which remains active until the vc4 driver loads and
sends NOTIFY_DISPLAY_DONE. If this clock is disabled during boot, a bus
lockup happens and the firmware becomes unresponsive, causing a complete
system lockup.
Mark the VEC clock with CLK_IGNORE_UNUSED so it survives the unused
clock disablement and remains available until the vc4 driver takes over
display management.
Fixes: 672299736af6 ("clk: bcm: rpi: Manage clock rate in prepare/unprepare callbacks")
Reported-by: Mark Brown <broonie@kernel.org>
Closes: https://lore.kernel.org/r/5f0bec08-f458-4fba-8bf3-06817a100c4c@sirena.org.uk
Signed-off-by: Maíra Canal <mcanal@igalia.com>
Link: https://patch.msgid.link/20260401111416.562279-2-mcanal@igalia.com
Tested-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
Acked-by: Brian Masney <bmasney@redhat.com> # Active contributor to clk
Reviewed-by: Stefan Wahren <wahrenst@gmx.net>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>