tjh.dev
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1444015
3
928
Clone this repository
https://tangled.org/tjh.dev/kernel
https://tangled.org/did:plc:65gha4t3avpfpzmvpbwovss7/kernel
git@gordian.tjh.dev:tjh.dev/kernel
git@gordian.tjh.dev:did:plc:65gha4t3avpfpzmvpbwovss7/kernel
For self-hosted knots, clone URLs may differ based on your setup.
Download tar.gz
This reverts commit 4900454b4f819e88e9c57ed93542bf9325d7e161.
Now that nobody relies of cfg->priv containing anything useful before the
.init() callback is used, restore the previous behaviour.
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://patch.msgid.link/20250625111806.4153773-4-maz@kernel.org
On MicroChip MPFS Icicle:
microchip-pcie 2000000000.pcie: host bridge /soc/pcie@2000000000 ranges:
microchip-pcie 2000000000.pcie: Parsing ranges property...
microchip-pcie 2000000000.pcie: MEM 0x2008000000..0x2087ffffff -> 0x0008000000
Unable to handle kernel NULL pointer dereference at virtual address 0000000000000368
Current swapper/0 pgtable: 4K pagesize, 39-bit VAs, pgdp=0x00000000814f1000
[0000000000000368] pgd=0000000000000000, p4d=0000000000000000, pud=0000000000000000
Oops [#1]
Modules linked in:
CPU: 0 UID: 0 PID: 1 Comm: swapper/0 Not tainted 6.15.0-rc1-icicle-00003-gafc0a570bb61 #232 NONE
Hardware name: Microchip PolarFire-SoC Icicle Kit (DT)
[...]
[<ffffffff803fb8a4>] plda_pcie_setup_iomems+0xe/0x78
[<ffffffff803fc246>] mc_platform_init+0x80/0x1d2
[<ffffffff803f9c88>] pci_ecam_create+0x104/0x1e2
[<ffffffff8000adbe>] pci_host_common_init+0x120/0x228
[<ffffffff8000af42>] pci_host_common_probe+0x7c/0x8a
The initialization of driver_data was moved after the call to
gen_pci_init(), while the pci_ecam_ops.init() callback
mc_platform_init() expects it has already been initialized.
Fix this by moving the initialization of driver_data up.
Fixes: afc0a570bb613871 ("PCI: host-generic: Extract an ECAM bridge creation helper from pci_host_common_probe()")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://lore.kernel.org/r/774290708a6f0f683711914fda110742c18a7fb2.1750787223.git.geert+renesas@glider.be
Link: https://patch.msgid.link/20250625111806.4153773-2-maz@kernel.org
The apple driver relies on being able to directly find the matching root
port structure from the platform device that represents this port.
A previous hack stashed a pointer to the root port structure in the config
window private pointer, but that ended up relying on assumptions that break
other drivers.
Instead, bite the bullet and track the association as part of the driver
itself as a list of probed root ports.
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://patch.msgid.link/20250625111806.4153773-3-maz@kernel.org
Pull turbostat updates from Len Brown:
- Add initial DMR support, which required smarter RAPL probe
- Fix AMD MSR RAPL energy reporting
- Add RAPL power limit configuration output
- Minor fixes
* tag 'turbostat-2025.06.08' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux:
tools/power turbostat: version 2025.06.08
tools/power turbostat: Add initial support for BartlettLake
tools/power turbostat: Add initial support for DMR
tools/power turbostat: Dump RAPL sysfs info
tools/power turbostat: Avoid probing the same perf counters
tools/power turbostat: Allow probing RAPL with platform_features->rapl_msrs cleared
tools/power turbostat: Clean up add perf/msr counter logic
tools/power turbostat: Introduce add_msr_counter()
tools/power turbostat: Remove add_msr_perf_counter_()
tools/power turbostat: Remove add_cstate_perf_counter_()
tools/power turbostat: Remove add_rapl_perf_counter_()
tools/power turbostat: Quit early for unsupported RAPL counters
tools/power turbostat: Always check rapl_joules flag
tools/power turbostat: Fix AMD package-energy reporting
tools/power turbostat: Fix RAPL_GFX_ALL typo
tools/power turbostat: Add Android support for MSR device handling
tools/power turbostat.8: pm_domain wording fix
tools/power turbostat.8: fix typo: idle_pct should be pct_idle
Pull timer cleanup from Thomas Gleixner:
"The delayed from_timer() API cleanup:
The renaming to the timer_*() namespace was delayed due massive
conflicts against Linux-next. Now that everything is upstream finish
the conversion"
* tag 'timers-cleanups-2025-06-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
treewide, timers: Rename from_timer() to timer_container_of()
Add initial DMR support, which required smarter RAPL probe
Fix AMD MSR RAPL energy reporting
Add RAPL power limit configuration output
Minor fixes
Signed-off-by: Len Brown <len.brown@intel.com>
Pull x86 fixes from Thomas Gleixner:
"A small set of x86 fixes:
- Cure IO bitmap inconsistencies
A failed fork cleans up all resources of the newly created thread
via exit_thread(). exit_thread() invokes io_bitmap_exit() which
does the IO bitmap cleanups, which unfortunately assume that the
cleanup is related to the current task, which is obviously bogus.
Make it work correctly
- A lockdep fix in the resctrl code removed the clearing of the
command buffer in two places, which keeps stale error messages
around. Bring them back.
- Remove unused trace events"
* tag 'x86-urgent-2025-06-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
fs/resctrl: Restore the rdt_last_cmd_clear() calls after acquiring rdtgroup_mutex
x86/iopl: Cure TIF_IO_BITMAP inconsistencies
x86/fpu: Remove unused trace events
Move this API to the canonical timer_*() namespace.
[ tglx: Redone against pre rc1 ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/aB2X0jCKQO56WdMt@gmail.com
Add initial support for BartlettLake.
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Pull timer fix from Thomas Gleixner:
"Add the missing seq_file forward declaration in the timer namespace
header"
* tag 'timers-urgent-2025-06-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
timens: Add struct seq_file forward declaration
A lockdep fix removed two rdt_last_cmd_clear() calls that were used to
clear the last_cmd_status buffer but called without holding the required
rdtgroup_mutex.
The impacted resctrl commands are writing to the cpus or cpus_list files
and creating a new monitor or control group. With stale data in the
last_cmd_status buffer the impacted resctrl commands report the stale error
on success, or append its own failure message to the stale error on
failure.
Consequently, restore the rdt_last_cmd_clear() calls after acquiring
rdtgroup_mutex.
Fixes: c8eafe149530 ("x86/resctrl: Fix potential lockdep warning")
Signed-off-by: Zeng Heng <zengheng4@huawei.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Link: https://lore.kernel.org/all/20250603125828.1590067-1-zengheng4@huawei.com
Pull Kbuild updates from Masahiro Yamada:
- Add support for the EXPORT_SYMBOL_GPL_FOR_MODULES() macro, which
exports a symbol only to specified modules
- Improve ABI handling in gendwarfksyms
- Forcibly link lib-y objects to vmlinux even if CONFIG_MODULES=n
- Add checkers for redundant or missing <linux/export.h> inclusion
- Deprecate the extra-y syntax
- Fix a genksyms bug when including enum constants from *.symref files
* tag 'kbuild-v6.16' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (28 commits)
genksyms: Fix enum consts from a reference affecting new values
arch: use always-$(KBUILD_BUILTIN) for vmlinux.lds
kbuild: set y instead of 1 to KBUILD_{BUILTIN,MODULES}
efi/libstub: use 'targets' instead of extra-y in Makefile
module: make __mod_device_table__* symbols static
scripts/misc-check: check unnecessary #include <linux/export.h> when W=1
scripts/misc-check: check missing #include <linux/export.h> when W=1
scripts/misc-check: add double-quotes to satisfy shellcheck
kbuild: move W=1 check for scripts/misc-check to top-level Makefile
scripts/tags.sh: allow to use alternative ctags implementation
kconfig: introduce menu type enum
docs: symbol-namespaces: fix reST warning with literal block
kbuild: link lib-y objects to vmlinux forcibly even when CONFIG_MODULES=n
tinyconfig: enable CONFIG_LD_DEAD_CODE_DATA_ELIMINATION
docs/core-api/symbol-namespaces: drop table of contents and section numbering
modpost: check forbidden MODULE_IMPORT_NS("module:") at compile time
kbuild: move kbuild syntax processing to scripts/Makefile.build
Makefile: remove dependency on archscripts for header installation
Documentation/kbuild: Add new gendwarfksyms kABI rules
Documentation/kbuild: Drop section numbers
...
Add initial support for DMR.
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Pull x86 perf fix from Thomas Gleixner:
"A single fix for the x86 performance counters on Intel CPUs:
The MSR offset calculations for fixed performance counters are stored
at the wrong index in the configuration array causing the general
purpose counter MSR offset to be overwritten, so both the general
purpose and the fixed counters offsets are incorrect.
Correct the array index calculation to fix that"
* tag 'perf-urgent-2025-06-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf/x86/intel: Fix incorrect MSR index calculations in intel_pmu_config_acr()
Add forward declaration of struct seq_file before using it in a
function prototype.
Fixes: 04a8682a71be ("fs/proc: Introduce /proc/pid/timens_offsets")
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Andrei Vagin <avagin@gmail.com>
Link: https://lore.kernel.org/all/aDlskzKIAULMlwPj@gondor.apana.org.au
README