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i2c: rust: mark I2cAdapter methods as inline
A single cleanup for the Rust I2C abstractions, targeting 7.3.
`I2cAdapter::get`, `inc_ref`, and `dec_ref` are trivial wrappers around
`i2c_get_adapter`/`i2c_put_adapter` and were showing up as their own
symbols in the build. Mark them `#[inline]` so they get folded into
their callers instead.
Signed-off-by: Igor Korotin <igor.korotin@linux.dev>
* tag 'rust-i2c-for-7.3':
i2c: rust: mark I2cAdapter methods as inline
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After commit dfc256dac54c ("calibrate: Rework delay timer calibration"),
certain ARM configurations (such as multi_v5_defconfig) hang during
boot. The use of read_current_timer() in arch/arm's get_cycles() was
improperly converted to delay_read_timer(), resulting in get_cycles()
returning 0 even when the timer has been read or an uninitialized stack
value when delay_read_timer() returns false.
Flip the branches of the ternary condition to fix get_cycles().
Fixes: dfc256dac54c ("calibrate: Rework delay timer calibration")
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Reviewed-by: Jinjie Ruan <ruanjinjie@huawei.com>
Cc: Thomas Gleixner <tglx@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org
Link: https://patch.msgid.link/20260819-fix-arm-get_cycles-v1-1-208bf07ac540@kernel.org
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bh_pool_kick_normal() and bh_pool_kick_highpri() are registered via
init_irq_work() without the IRQ_WORK_HARD_IRQ flag. On PREEMPT_RT, such
irq_work items are processed by the per-CPU irq_workd kthread in preemptible
task context with IRQs enabled. However, raise_softirq_irqoff() requires
IRQs to be disabled. Calling it from irq_workd trips the lockdep assertion
in __raise_softirq_irqoff() and the non-atomic update of the softirq pending
mask can lose bits raised by an interrupt on the same CPU. Replace
raise_softirq_irqoff() with raise_softirq() in the irq_work handlers.
Fixes: 2f34d7337d98 ("workqueue: Fix queue_work_on() with BH workqueues")
Cc: stable@vger.kernel.org # v6.9+
Signed-off-by: Zqiang <qiang.zhang@linux.dev>
Signed-off-by: Tejun Heo <tj@kernel.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/driver-core/driver-core
Pull driver core updates from Danilo Krummrich:
"container_of:
- Apply typeof_member(), remove the local __mptr variable to
eliminate variable shadowing warnings on nested container_of()
calls, and remove unnecessary parentheses
core:
- Add driver name to probe debug print for initcall_debug
- Avoid repeatedly printing the same 'Fixed dependency cycle' log
- Unwind device_add() on attribute creation failure in
attribute_container_add_class_device()
- Remove statistics group if encryption group creation fails in
transport_add_class_device()
debugfs:
- Fix lockdown check for mmap_prepare()
- Warn if file creation failed due to uninitialized debugfs
device property:
- Implement fw_devlink support for software nodes by adding
software_node_add_links(), which creates fwnode links from
DEV_PROP_REF properties to enable automatic probe ordering. Add
kunit-managed fwnode helpers and test coverage
- Fix infinite loop in fwnode_for_each_child_node() when the
secondary fwnode has more than one child. Add test cases
- Fix out-of-bounds access in software_node_get_reference_args() when
called with index -1 (UINT_MAX)
- Refactor to use RAII approach with __free()
- Add Bartosz Golaszewski as software node reviewer
firmware loader:
- Fix race where a sysfs fallback request can complete before being
queued as pending, leading to a use-after-free on the next fallback
request
- Reject 0-size built-in firmware and fail the build on empty
firmware files in CONFIG_EXTRA_FIRMWARE
kobject:
- Provide __KOBJ_ATTR() and __KOBJ_ATTR_RO/WO() initialization macros
and allow the constification of kobject attributes, enabling them
to reside in read-only memory
platform:
- Provide platform_device_set_of_node(), platform_device_set_fwnode(),
and platform_device_set_of_node_from_dev() helpers that encapsulate
firmware node reference counting for dynamically allocated platform
devices
Convert all in-tree users that manually assigned dev.of_node or
dev.fwnode, fixing a pre-existing refcount bug in powermac. Switch
to counting references of all firmware node types, not only OF
nodes
- Unify the release path for dynamically allocated platform devices
by removing platform_device_release_full(). Amend the fwnode setter
API contract to warn if a primary software node is overwritten. Add
KUnit tests for correct software node removal on device
unregistration
Rust:
- Auxiliary:
- Add registration_data_with() closure-based API for invariant
ForLt types
- Debugfs:
- Migrate BinaryWriter and BinaryReaderMut trait requirements
from kernel::transmute traits to zerocopy traits
- Device:
- Add BoundInternal device context and InternalBoundContext trait
for bus abstractions that need internal access to a bound
device.
- Make the lifetime on Core and CoreInternal invariant to prevent
coercion to shorter lifetimes
- Devres:
- Fix race between concurrent revokers where the losing revoker
could return before the winning revoker finished dropping the
inner data, causing use-after-free.
- Ensure revocation is complete before the device finishes
unbinding by making the synchronization bidirectional.
- Add DevresLt<F: ForLt>, a wrapper around Devres that shortens
'static back to the caller's borrow scope. Implement ForLt and
CovariantForLt for Bar, IoMem, and ExclusiveIoMem
- Driver:
- Switch from index-based to pointer-based device ID info lookup,
storing static references in driver_data. Centralize device ID
handling in device_id.rs, removing the open-coded ACPI/OF
matching logic and duplicate ID table from driver.rs
- I/O:
- Make I/O regions typed (with a dynamically-sized Region type
for the existing untyped case), create view types representing
subregions of a mapped I/O region, and add io_project!() for
safely creating subviews.
- Split Io into a base trait (IoBase) and an extension trait (Io)
with a blanket implementation, preventing implementers from
overriding provided methods that unsafe code relies on.
- Add a SysMem backend for shared system memory with volatile
access, and make Coherent implement Io via an I/O view type.
Add IoSysMap as sum type of Mmio and SysMem. Add copying
methods (memcpy_{from,to}io()) and read_val()/write_val() for
typed access.
- Replace dma_read!()/dma_write!() with io_read!()/io_write!()
for primitives and copying methods for aggregates; drop the old
macros. Convert nova-core to use I/O projection.
- Fix internal shortcut rule dispatch in the register!() macro,
remove unused rule arguments, and use path fragments for alias
destinations
- IRQ:
- Make irq::Registration compatible with lifetime-bound drivers
by removing the 'static bound on Handler/ThreadedHandler and
replacing Devres<RegistrationInner> with direct
request_irq()/free_irq() calls. Handlers can now directly own
lifetime-bound device resources
- PCI:
- Convert IrqVectorRegistration to a lifetime-annotated owning
type, giving drivers explicit control over the allocation
lifetime. IrqVector embeds a resolved IrqRequest, making the
conversion infallible. Remove the redundant
request_irq()/request_threaded_irq() wrappers from pci::Device.
- Add pci_irq_type() C helper and expose it via irq_type() on
IrqVectorRegistration and IrqVector, returning PCI_IRQ_MSIX,
PCI_IRQ_MSI, or PCI_IRQ_INTX.
- Mark pci::Device refcount methods inline
- Serdev:
- Add Rust abstractions for the serial device bus, including
serdev::Driver trait, serdev::Device wrapping struct
serdev_device, and serdev::Adapter implementing
RegistrationOps. Includes a sample driver. Markus Probst takes
over as serdev maintainer for both C and Rust code
- Misc:
- Split ForLt into a base trait (providing the Of<'a> GAT) and an
unsafe CovariantForLt subtrait guaranteeing covariance,
enabling invariant types (e.g. those containing Mutex<&'bound T>)
to participate in the ForLt abstraction.
- Fix Coherent read past EOF returning -ERANGE instead of zero.
- Fix firmware example UB by avoiding null-pointer ARef
misc:
- Avoid iattr allocation in kernfs listxattr by using
kernfs_iattrs_noalloc().
- Unregister SoC bus on early device registration failure.
- Remove unused DMA_FENCE_TRACE Kconfig symbol.
- Fix /sys/module path in comment.
- Refactor ISA bus init to remove nested blocks.
- Remove redundant nodemask clears in numa_init().
- Add kernel-doc for fwnode_operations and sys_soc.h, mark
internal property data as private for kernel-doc, and add
property.h/fwnode.h to driver-api infrastructure docs.
- Add MAINTAINERS entry for sys_soc.h"
* tag 'driver-core-7.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/driver-core/driver-core: (129 commits)
rust: pci: expose the allocated interrupt type
PCI: Add pci_irq_type() to query the allocated interrupt type
rust: pci: remove request_irq() and request_threaded_irq() from Device
rust: pci: resolve IRQ in index() and embed IrqRequest in IrqVector
rust: pci: convert IrqVectorRegistration to a lifetime-managed owning type
kernfs: avoid iattr allocation in listxattr
rust: serdev: use ThisModule::as_ptr() instead of field access
ACPI/IORT: use platform_device_set_fwnode()
ACPI/APMT: use platform_device_set_fwnode()
firmware_loader: do not queue completed sysfs fallback requests
rust: pci: Mark Device refcount methods inline
rust: irq: make Registration compatible with lifetime-bound drivers
rust: net/phy: remove expansion from doc
rust: dma: return zero for Coherent reads past EOF
rust: io: register: use path fragment for alias destination
rust: io: register: remove unused rule arguments
rust: io: register: dispatch shortcut rules internally
MAINTAINERS: add sys_soc.h to DRIVER CORE
rust: debugfs: remove unsafe blocks from traits impl for Vec
rust: debugfs: migrate debugfs traits requirements to zerocopy
...
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git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux
Pull devicetree updates from Rob Herring:
- Add a DT maintainer profile document
- Various dt-check-style improvements
- Add a devres managed reserved memory region init function
- Print node name on any skipped reserved memory regions
- Correctly handle optional argument in
of_parse_phandle_with_args_map()
- Convert ti,keystone-reset, ti,da850-vpif, TI L4 interconnect, TI
SmartReflex, microchip,pic32mzda-dmt, microchip,pic32mzda-wdt, TI
DA8XX MSTPRI bus, and Xen VM bindings to DT schema format
- Add bindings for StarFive JHB100 plic, Allwinner A733 NMI controller,
MediaTek MT8173 GPU, QCom Shikra, Eliza, and Maili cpu-bwmon, and
QCom Shikra SCM firmware
- A couple of syntax fixes found using PoC Rust implementation of
dtschema tools
- Clean-ups for typos, brackets, incorrect "::" usages, and
white-space style
* tag 'devicetree-for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux: (40 commits)
dt-bindings: interconnect: qcom-bwmon: Add Maili cpu-bwmon compatible
dtc: dt-check-style: Simplify setting depth of DtsLine
dtc: dt-check-style: Add missing /dts-v1/ to few test cases
dt-bindings: power: reset: ti,keystone-reset: Convert to DT schema
media: dt-bindings: ti,da850-vpif: Convert to dt-schema
dt-bindings: devfreq: samsung,exynos-ppmu: Use standard regex syntax
dt-bindings: interrupt-controller: mediatek,mt6577-sysirq: Drop invalid JSON pointer
dt-bindings: arm: omap: Convert L4 interconnect to DT schema
dt-bindings: power: Convert TI SmartReflex to DT schema
of: reserved_mem: Introduce devres-managed initialization function
dt-bindings: interrupt-controller: Add StarFive JHB100 plic
dt-bindings: irq: sun7i-nmi: Document the Allwinner A733 NMI controller
dt-bindings: Correct white-space style
dt-bindings: fix typos and brackets
docs: dt: submitting-patches: Mention expectation about dt-check-style
docs: dt: maintainer: Add Devicetree and OF maintainer profile document
docs: dt: writing-schema: Extend expectations about example part of binding
dt-bindings: gpu: powervr-rogue: Add MediaTek MT8173 GPU
of: base: Handle optional argument in of_parse_phandle_with_args_map()
dt-bindings: update Sudeep Holla's email address
...
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git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media
Pull media updates from Mauro Carvalho Chehab:
- v4l2-core: added ISP statistics support and per-block validation
- v4l2-core: Allow unknown HDR10 white point and luminance
- New camera sensors: Sony IMX678 and IMX471m, Himax HM1092 IR sensor
- New codec: Milos: VPU v2.0 codec support
- isp driver: gained support for Dreamchip RPPX1 ISP framework
- vsp1 driver: gained support for RZ/T2H and RZ/N2H
- Novalake driver: gained CVS support for new NVL hardware
- dvb-core: fix feed leak on failed DMX_ADD_PID
- several driver fixes, cleanups and minor improvements
* tag 'media/v7.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media: (308 commits)
media: ipu-bridge: check all DMI entries when overriding sensor rotation
media: v4l2-async: avoid deleting unlinked ASC entry on link error
media: rzg2l-cru: Align bytesperline to hardware DMA stride requirement
media: intel/ipu6: fix async notifier cleanup leak on parse error
media: staging/ipu7: fix async notifier UAF on probe error path
media: amd: isp4: fix self-deadlock in isp4sd_pwron_and_init() error path
media: amd: isp4: release partial allocations in isp4if_alloc_fw_gpumem()
media: rcar-isp: Fix VSPX reference leaks
media: rcar-isp: Release ISPCORE resources
media: i2c: imx415: Release runtime PM reference on VBLANK error
media: i2c: imx415: Return test pattern write errors
media: renesas: vsp1: Declare index variables in for loop statement
media: renesas: vsp1: Make reset control optional to support platforms without a reset line
media: dt-bindings: media: renesas,vsp1: Document RZ/T2H and RZ/N2H SoCs
media: dt-bindings: media: renesas,fcp: Document RZ/T2H and RZ/N2H SoCs
media: nxp: imx8-isi: Add additional 32-bit RGB format support
media: nxp: imx8-isi: Add 16-bit raw Bayer format support
media: nxp: imx8-isi: Implement per-stream reference counting for multiplexed streams
media: nxp: imx8-isi: Use BIT_ULL() for 64-bit stream masks
media: nxp: imx8-isi: Correct color map between V4L2 and ISI
...
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On PREEMPT_RT, bh_worker() wraps work item execution in pool->cb_lock to
provide a handshake for canceling BH work items. When a CPU goes down,
drain_dead_softirq_workfn() runs the dead pool's bh_worker() nested inside
the local pool's bh_worker(), acquiring the cb_locks of two different pools
without a nesting annotation. lockdep reports possible recursive locking:
============================================
WARNING: possible recursive locking detected
--------------------------------------------
ktimers/0/16 is trying to acquire lock:
ffff8880b873a990 (&pool->cb_lock){+...}-{3:3}, at: bh_worker+0x7d/0x880
but task is already holding lock:
ffff8880b863a990 (&pool->cb_lock){+...}-{3:3}, at: bh_worker+0x7d/0x880
Call Trace:
bh_worker+0x7d/0x880 kernel/workqueue.c:3688
drain_dead_softirq_workfn+0x95/0x220 kernel/workqueue.c:3763
process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3405
bh_worker+0x46a/0x880 kernel/workqueue.c:3708
tasklet_action+0xc/0x70 kernel/softirq.c:965
The nesting can't deadlock. A pool's bh_worker() runs nested only while the
pool's CPU is dead, entered from a live pool's bh_worker() on the draining
CPU, so the ordering is always live to dead. CPU hotplug operations are
serialized and the drain is synchronous, so the nesting depth never exceeds
two. Annotate the inner acquisition with SINGLE_DEPTH_NESTING.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: syzbot+1bd20115328f8254ed62@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=1bd20115328f8254ed62
Fixes: ad7c7f4b9c6c ("workqueue: Provide a handshake for canceling BH workers")
Cc: stable@vger.kernel.org # v6.18+
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Add irq_type() on IrqVectorRegistration and IrqVector, wrapping the new
pci_irq_type() C function. A driver whose interrupt acknowledgment
depends on the type (MSI-X vs MSI vs INTx) queries it here rather than
assuming which type the PCI core selected.
Tested-by: John Hubbard <jhubbard@nvidia.com>
Suggested-by: John Hubbard <jhubbard@nvidia.com>
Link: https://lore.kernel.org/all/20260808031120.363869-4-jhubbard@nvidia.com/
Reviewed-by: Gary Guo <gary@garyguo.net>
Link: https://patch.msgid.link/20260813165234.620555-6-dakr@kernel.org
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
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Add a helper that returns PCI_IRQ_MSIX, PCI_IRQ_MSI, or PCI_IRQ_INTX
based on the interrupt type the PCI core selected after
pci_alloc_irq_vectors().
Several drivers already open-code this check against pdev->msix_enabled
and pdev->msi_enabled, or even open code this helper [1].
A common helper avoids the duplication and keeps drivers from accessing
the bitfield directly (see also [2]).
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Tested-by: John Hubbard <jhubbard@nvidia.com>
Link: https://elixir.bootlin.com/linux/v7.1/source/drivers/net/ethernet/aquantia/atlantic/aq_pci_func.c#L196 [1]
Inspired-by: John Hubbard <jhubbard@nvidia.com>
Link: https://lore.kernel.org/all/DKKG2QM3YJYB.Z2H2B2UXJ75N@kernel.org/ [2]
Reviewed-by: Gary Guo <gary@garyguo.net>
Link: https://patch.msgid.link/20260813165234.620555-5-dakr@kernel.org
[ Add missing pci_irq_type() stub for CONFIG_PCI=n. ]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
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Add the Qualcomm Maili SoC compatible string for the CPU bandwidth
monitor (BWMONv4). This falls back to the sdm845-bwmon compatible,
consistent with the existing pattern used by other recent SoCs such as
sm8750 and kaanapali.
Signed-off-by: Yijie Yang <yijie.yang@oss.qualcomm.com>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>
Reviewed-by: Jingyi Wang <jingyi.wang@oss.qualcomm.com>
Link: https://patch.msgid.link/20260811-bwmon-v2-1-80f7f150ab9e@oss.qualcomm.com
Signed-off-by: Rob Herring (Arm) <robh@kernel.org>
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'rcu-tasks.2026.07.30a', 'srcu.2026.08.11a' and 'torture.2026.08.14a' into HEAD
Changes:
Make expedited grace periods expedite normal RCU callbacks
Miscellaneous fixes:
* Improve diagnostic output with character task states.
* Mark accesses to inform KCSAN of concurrency design.
* Move from kmalloc() to kmalloc_obj().
* Documentation updates.
* Improve handling of RCU deferred quiescent states.
* Clean up unused function arguments and structure fields.
* Reduce show_rcu_gp_kthreads() stack space.
Tasks RCU updates:
* Clean up after SRCU re-implementation of Tasks Trace RCU.
* Mark accesses to inform KCSAN of concurrency design.
* Add ->lazy_timer status to diagnostic output.
* Remove an unnecessary memory barrier.
* Fix a data race, courtesy of KCSAN.
* Documentation updates.
* Convert cond_resched_tasks_rcu_qs() from macro to static inline
function.
SRCU updates:
* Add Rust helpers for SRCU.
* Avoid losing queued work at cleanup_srcu_struct() time.
Torture-test updates:
* Preparation work for immediate RCU priority deboosting.
* Test RCU readers from real interrupt handlers (as opposed to softirq).
* Simplify code through use of cpumask_next_wrap().
* Improve diagnostic output with character task states.
* Add rcutorture.nwriters parameter to allow lightweight stall testing,
and rcutorture.stall_only to make doing so easier.
* Test an RCU Tasks Trace grace period implying an RCU grace period.
* Make RCU Tasks Trace torturing track reader batches.
* Fix a data race, courtesy of KCSAN.
* Plug a shuffle_tmp_mask memory leak on kthread spawn failure.
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kick_pool_pick() reads and writes p->wake_cpu while the scheduler can
update it concurrently. KCSAN reports:
BUG: KCSAN: data-race in kick_pool_pick+0xf8/0x2d8
race at unknown origin, with read to 0xffff000663229da4 of 4 bytes by
task 1817002 on cpu 40:
kick_pool_pick+0xf8/0x2d8
process_scheduled_works+0x2bc/0x888
worker_thread+0x394/0x548
kthread+0x1b8/0x1f0
ret_from_fork+0x10/0x20
value changed: 0x0000002b -> 0x0000002f
The race is harmless. wake_cpu is a best-effort placement hint: every
writer stores a valid CPU id and the wakeup path validates it through
select_task_rq(), so a stale value only affects which CPU the worker
wakes up on.
Mark both accesses with READ_ONCE() and WRITE_ONCE() to document that
they are intentionally racy and to stop the compiler from reloading or
tearing them.
Signed-off-by: Breno Leitao <leitao@debian.org>
Reviewed-by: Bradley Morgan <include@grrlz.net>
Signed-off-by: Tejun Heo <tj@kernel.org>
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wq_node_nr_active() warns and returns NULL when @wq is not unbound, but
every caller dereferences the result right away, so the WARN_ON_ONCE()
only moves the oops one frame up, as raised by Tejun.
Fix it by BUGing_ON() instead of this silly WARN_ON_ONCE();
Fixes: b72fdc651056 ("workqueue: account nr_active by the backing pool")
Suggested-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Breno Leitao <leitao@debian.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
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wq->cpu_pwq holds RCU-protected pwq pointers, but the percpu allocation
path fills it in with plain loads and stores, which sparse flags:
kernel/workqueue.c:5682:57: sparse: incorrect type in initializer (different address spaces) @@ expected struct pool_workqueue **pwq_p @@ got struct pool_workqueue [noderef] __rcu ** @@
Allocate the array as __rcu pointers and publish each pwq with
rcu_assign_pointer() once it is initialized and linked, the order
install_unbound_pwq() uses.
The warnings are not new: commit 79f23600bc7b ("workqueue: factor out
get_percpu_pool()") only turned the flagged assignment into an
initializer.
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202608120931.tvTzq1gD-lkp@intel.com/
Signed-off-by: Breno Leitao <leitao@debian.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
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workqueue_congested() fetches the pwq out of wq->cpu_pwq with a plain
load, so sparse complains about the dropped __rcu:
kernel/workqueue.c:6304:13: sparse: incorrect type in assignment (different address spaces) @@ expected struct pool_workqueue *pwq @@ got struct pool_workqueue [noderef] __rcu * @@
A pwq is released with kfree_rcu() and the read is protected by the
surrounding preempt_disable(), which is what
commit fd5081f4ef33 ("workqueue: Remove redundant rcu_read_lock/unlock() in
workqueue_congested()") relied on when it dropped the rcu_read_lock()
here.
Use the rcu_dereference_sched() helper to make that explicit.
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202608120931.tvTzq1gD-lkp@intel.com/
Signed-off-by: Breno Leitao <leitao@debian.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
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apply_wqattrs_commit() updates node_nr_active->max unconditionally.
wq->node_nr_active[] is only allocated for unbound workqueues, so guard
the call before per-cpu workqueues start using this path.
No functional change: only unbound workqueues reach apply_wqattrs_*()
today.
Signed-off-by: Breno Leitao <leitao@debian.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
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As per discussion between the developers in the mail thread
linked, expand the comment in __switch_to so that readers
of the code understand what is going on.
Suggested-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Linus Walleij <linusw@kernel.org>>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
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When CONFIG_DEBUG_USER=y, and cmdline "user_debug=31" is set,
a user fault may trigger show_pte() without any lock.
If another thread in the same process concurrently calls munmap(),
the page table pages may be freed while show_pte() is still traversing
them, causing a use-after-free in show_pte().
If CONFIG_ARM_LPAE=y, this may cause a kernel panic if the pages table
of PMD are freed when show_pte() is running.
Acquire mmap_write_lock() around show_pte() for user faults to fix the
contention.
For user faults, additionally restrict that show_pte() is called only
when the addr is a user-space address (addr < TASK_SIZE). This is because
the lock of tsk->mm only protects the virtual memory of user address space,
furthermore, dumping the page tables of a kernel-space address for user
faults is unnecessary and may have security implications.
Keep everything unchanged for kernel faults, because the kernel is
already in the "oops" state, acquiring a lock may risk a deadlock.
Co-developed-by: Qi Xi <xiqi2@huawei.com>
Fixes: 6d021b724481 ("ARM: dump pgd, pmd and pte states on unhandled data abort faults")
Link: https://lore.kernel.org/20260716014022.2823-1-xieyuanbin1@huawei.com
Acked-by: Lorenzo Stoakes (ARM) <ljs@kernel.org>
Reviewed-by: Linus Walleij <linusw@kernel.org>
Signed-off-by: Qi Xi <xiqi2@huawei.com>
Signed-off-by: Xie Yuanbin <xieyuanbin1@huawei.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
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Each scftorture_invoker() thread decrements n_started, which is
initialized to the number of threads, and is then supposed to wait
until all of its siblings have also checked in before starting the
test proper. However, the wait loop is guarded by
!atomic_dec_return(&n_started), which is true only for the final
thread to arrive, and by then n_started is already zero, so the
final thread does not wait either. The side-effect (possibly positive)
is that no thread ever waits and the start-synchronization barrier is
dead code, with early threads beginning to hammer smp_call_function*()
while later threads are still being spawned.
Invert the test so that every thread other than the last spins until
n_started reaches zero, making the threads start testing together as
intended. The existing torture_must_stop() check in the wait loop
continues to bound the wait during shutdown.
We can also drop the spinning entirely if the intent is to leave it as
dead code, however for the current intent, this patches fixes the code.
Signed-off-by: Joel Fernandes <joelagnelf@nvidia.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
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scf_torture_stats_print() aggregates each invoker thread's counters
into a local scf_statistics structure before printing, but the
n_single_rpc_ofl field is missing from the aggregation loop. As a
result, the "single_rpc_ofl" value printed in the statistics line is
always zero, even when smp_call_function_single() invocations for the
RPC test have failed due to offline CPUs and been counted by the
invoker threads.
Add the missing accumulation so that the printed value reflects the
actual counts.
Signed-off-by: Joel Fernandes <joelagnelf@nvidia.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
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