The current implementation creates a 4K array and move it into the box.
Klint reports that this causes excesssive stack usage:
warning: stack size of `create_file_write` is 4472 bytes, exceeds the 2048-byte limit
--> samples/rust/rust_debugfs_scoped.rs:54:1
|
54 | / fn create_file_write(
55 | | mod_data: &ModuleData,
56 | | reader: &mut kernel::uaccess::UserSliceReader,
57 | | ) -> Result {
| |___________^
|
= note: the stack size is inferred from instruction `sub $0x1178,%rsp` at .text+2205
Use pin-init to create the array in-place instead.
Fixes: f656279afd ("samples: rust: debugfs_scoped: add example for blobs")
Signed-off-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Link: https://patch.msgid.link/20260716144144.3665719-1-gary@kernel.org
[ Make the patch rustfmtcheck complient. - Danilo ]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Currently the lifetime on `Core` and `CoreInternal` is covariant. This
means that they can be coerced into shorter living lifetimes. On `probe`
function, signature has `&'bound Device<Core<'a>>`; the type's wellformness
would imply `'a: 'bound` and thus the type can be coerced `&'bound
Device<Core<'bound>>`, defeating the purpose of having the lifetime bound
to prevent users of the `Core` type to escape the function.
Fix this by making the lifetime invariant, so the coercion is impossible.
The lifetime here only needs to be "branded" so it does not coerce or unify
with other lifetimes, so we do not need to ensure `'bound: 'a`.
This requires modifying `nova-core` which relies on this implied bound due
to pre-2024 capture rule. The "use" bound can be removed if built with
edition 2024.
Fixes: 24799831d6 ("rust: device: make Core and CoreInternal lifetime-parameterized")
Signed-off-by: Gary Guo <gary@garyguo.net>
Link: https://patch.msgid.link/20260713201455.640151-1-gary@kernel.org
[ Fixup the debugfs sample to use an explicit lifetime instead of
Core<'_>. - Danilo ]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
I/O type generalization and projection
This series presents a major rework of I/O types, as a summary:
- Make I/O regions typed. The existing untyped region still exists
with a dynamically sized `Region` type.
- Create I/O view types to represent subregion of a full I/O region mapped.
A projection macro is added to allow safely create such subviews.
- Split I/O traits, make I/O views play a central role, avoid
duplicate monomorphization and less `unsafe` code.
- Add a `SysMem` backend, and make `Coherent` implement `Io`.
- Add copying methods (memcpy_{from,to}io and friends).
This series generalize `Mmio` type from just an untyped region to typed
representations (so `MmioRaw<T>` is `__iomem *T`). This allows us to remove
the `IoKnownSize` trait; the information is sourced from just the pointer
from the `KnownSize` trait instead.
Building on top of that, `Mmio` and `ConfigSpace` have been converted to
typed views of I/O regions rather than just a big chunk of untyped I/O
memory. These changes made it possible to implement `Io` trait for
`Coherent<T>`.
Shared system memory, `SysMem` is also added to the series, given it
similarity in implementation compared to `Coherent`. In fact, the series
use `SysMem` to implement `Coherent`'s I/O methods.
Built on these generalization, this series add `io_project!()`.
`io_project!()` performs a safe way to project a bigger view to a small
subviews, and some Nova code has been converted in this series to
demonstrate cleanups possible with this addition.
New `io_read!()`, `io_write!()` has been added that supersedes
`dma_read!()`, `dma_write!()` macro. Although, they work for primitives
only (to be exact, types that the backend is `IoCapable` of).
One feature that was lost from the old `dma_read!()` and `dma_write!()`
series was the ability to read/write a large structs. However, the
semantics was unclear to begin with, as there was no guarantee about their
atomicity even for structs that were small enough to fit in u32.
Suggested-by: Danilo Krummrich <dakr@kernel.org>
Link: https://rust-for-linux.zulipchat.com/#narrow/channel/288089-General/topic/Generic.20I.2FO.20backends/near/571198078
This is a stable tag for other trees to merge.
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Gary Guo <gary@garyguo.net> says:
This series presents a major rework of I/O types, as a summary:
- Make I/O regions typed. The existing untyped region still exists
with a dynamically sized `Region` type.
- Create I/O view types to represent subregion of a full I/O region mapped.
A projection macro is added to allow safely create such subviews.
- Split I/O traits, make I/O views play a central role, avoid
duplicate monomorphization and less `unsafe` code.
- Add a `SysMem` backend, and make `Coherent` implement `Io`.
- Add copying methods (memcpy_{from,to}io and friends).
This series generalize `Mmio` type from just an untyped region to typed
representations (so `MmioRaw<T>` is `__iomem *T`). This allows us to remove
the `IoKnownSize` trait; the information is sourced from just the pointer
from the `KnownSize` trait instead.
Building on top of that, `Mmio` and `ConfigSpace` have been converted to
typed views of I/O regions rather than just a big chunk of untyped I/O
memory. These changes made it possible to implement `Io` trait for
`Coherent<T>`.
Shared system memory, `SysMem` is also added to the series, given it
similarity in implementation compared to `Coherent`. In fact, the series
use `SysMem` to implement `Coherent`'s I/O methods.
Built on these generalization, this series add `io_project!()`.
`io_project!()` performs a safe way to project a bigger view to a small
subviews, and some Nova code has been converted in this series to
demonstrate cleanups possible with this addition.
New `io_read!()`, `io_write!()` has been added that supersedes
`dma_read!()`, `dma_write!()` macro. Although, they work for primitives
only (to be exact, types that the backend is `IoCapable` of).
One feature that was lost from the old `dma_read!()` and `dma_write!()`
series was the ability to read/write a large structs. However, the
semantics was unclear to begin with, as there was no guarantee about their
atomicity even for structs that were small enough to fit in u32.
Suggested-by: Danilo Krummrich <dakr@kernel.org>
Link: https://rust-for-linux.zulipchat.com/#narrow/channel/288089-General/topic/Generic.20I.2FO.20backends/near/571198078
Link: https://patch.msgid.link/20260706-io_projection-v6-0-72cd5d055d54@garyguo.net
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Add a faux::Device type that wraps struct faux_device and implements
AsBusDevice, enabling faux devices to be used as parent devices for
subsystems that require a bus device, such as DRM.
Update Registration to return &faux::Device<Bound> via AsRef.
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Tested-by: Deborah Brouwer <deborah.brouwer@collabora.com>
Link: https://patch.msgid.link/20260628145406.2107056-4-dakr@kernel.org
[ Drop redundant 'struct device' invariant; implied by valid
struct faux_device. - Danilo ]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Extend the auxiliary driver sample to demonstrate both access patterns:
- registration_data() with CovariantForLt!(Data<'_>) for the covariant
data type that holds a plain &'bound reference.
- registration_data_with() with ForLt!(MutexData<'_>) for an invariant
data type that wraps a Mutex<&'bound Device>. Since Mutex<T> is
invariant over T, MutexData cannot implement CovariantForLt and must
use the closure-based accessor.
Reviewed-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Link: https://patch.msgid.link/20260626183630.2585057-5-dakr@kernel.org
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Rename ForLt to CovariantForLt to prepare for the introduction of a new
ForLt base trait that does not require covariance.
The existing ForLt trait requires covariance, which enables the safe
cast_ref() method. This rename preserves the same semantics under a more
precise name, making room for a weaker ForLt trait in a subsequent
commit.
No functional change.
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Acked-by: Miguel Ojeda <ojeda@kernel.org>
Link: https://patch.msgid.link/20260626183630.2585057-2-dakr@kernel.org
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
One feature that was lost from the old `dma_read!` and `dma_write!` when
moving to `io_read!` and `io_write!` was the ability to read/write a large
structs. However, the semantics was unclear to begin with, as there was no
guarantee about their atomicity even for structs that were small enough to
fit in u32. Re-introduce the capability in the form of copying methods.
dma_read!(foo, bar) -> io_project!(foo, bar).copy_read()
dma_write!(foo, bar, baz) -> io_project!(foo, bar).copy_write(baz)
Model these semantics after memcpy so user has clear expectation of lack of
atomicity. As an additional benefit of this change, this now works for MMIO
as well by mapping them to `memcpy_{from,to}io`.
For slices which is DST so the `copy_read` and `copy_write` API above can't
work, add `copy_from_slice` and `copy_to_slice` to copy from/to normal
memory.
Signed-off-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Link: https://patch.msgid.link/20260706-io_projection-v6-19-72cd5d055d54@garyguo.net
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Add support for parsing boolean module parameters in the Rust
module! macro.
Currently, only integer types are supported by the `module_param!`
macros. This patch implements the `ModuleParam` trait for `bool`
by delegating the string parsing to the existing C implementation
via `kstrtobool_bytes()`. It also wires up `PARAM_OPS_BOOL` so that
the Rust parameter system correctly links to the C `param_ops_bool`
structure.
For demonstration and verification, a boolean parameter is added
to `samples/rust/rust_minimal.rs`.
Support for boolean parameters will initially be used by the Rust
null block driver [1].
Link: https://lore.kernel.org/all/20260609-rnull-v6-19-rc5-send-v2-4-82c7404542e2@kernel.org/ [1]
Assisted-by: Codex:GPT-5
Signed-off-by: Wenzhao Liao <wenzhaoliao@ruc.edu.cn>
Tested-by: Andreas Hindborg <a.hindborg@kernel.org>
Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org>
Link: https://lore.kernel.org/linux-modules/20260411130254.3510128-1-wenzhaoliao@ruc.edu.cn/
[ppavlu: add motivation to the commit message and rebase the patch]
Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
For `Copy` parameter types it is more ergonomic to retrieve the
parameter value by copy than through a shared reference. Change
`ModuleParamAccess::value` to return `T` by copy when `T: Copy`,
and rename the previous reference-returning accessor to
`value_ref`. Update the in-tree caller in `rust_minimal`.
Suggested-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: Andreas Hindborg <a.hindborg@kernel.org>
Reviewed-by: Petr Pavlu <petr.pavlu@suse.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
Pull misc driver updates from Greg KH:
"Here is the big set of char, misc, iio, fpga, and other small driver
subsystems changes for 7.2-rc1.
Lots of little stuff in here, the majority being of course the IIO
driver updates, as a list they are:
- IIO driver updates and additions
- GPIB driver bugfixes and cleanups
- Android binder driver updates (rust and C version)
- counter driver updates
- MHI driver updates
- mei driver updates
- w1 driver updates
- interconnect driver updates
- Comedi driver fixes and updates
- some obsolete char drivers removed (applicom and dtlk)
- hwtracing driver updates
- other tiny driver updates
All of these have been in linux-next for a while with no reported
issues"
* tag 'char-misc-7.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (406 commits)
w1: ds2482: Use named initializers for arrays of i2c_device_data
firmware: stratix10-svc: Add support to query Arm Trusted Firmware (ATF) version
firmware: stratix10-rsu: avoid blocking reboot_image sysfs when busy
coresight: ultrasoc-smb: Fix OOB write in smb_sync_perf_buffer()
iio: adc: nxp-sar-adc: harden buffer ISR against per-channel read failure
iio: chemical: scd30: Replace manual locking with RAII locking
iio: light: tsl2591: remove unneeded tsl2591_compatible_als_persist_cycle()
iio: dac: ad5686: create bus ops struct
iio: dac: ad5686: cleanup doc header of local structs
iio: dac: ad5686: add control_sync() for single-channel devices
iio: dac: ad5686: add helpers to handle powerdown masks
iio: dac: ad5686: add of_match table to the spi driver
iio: dac: ad5686: drop enum id
iio: dac: ad5686: remove redundant register definition
iio: dac: ad5686: refactor include headers
iio: adc: ad4080: fix AD4880 chip ID
iio: light: veml3328: add support for new device
dt-bindings: iio: light: veml6030: add veml3328
fpga: microchip-spi: fix zero header_size OOB read in mpf_ops_parse_header()
fpga: dfl-afu: validate DMA mapping length in afu_dma_map_region()
...
Pull driver core updates from Danilo Krummrich:
"Deferred probe:
- Fix race where deferred probe timeout work could be permanently
canceled by using mod_delayed_work()
- Fix missing jiffies conversion in deferred_probe_extend_timeout()
- Guard timeout extension with delayed_work_pending() to prevent
premature firing
- Use system_percpu_wq instead of the deprecated system_wq
- Update deferred_probe_timeout documentation
device:
- Replace direct struct device bitfield access (can_match, dma_iommu,
dma_skip_sync, dma_ops_bypass, state_synced, dma_coherent,
of_node_reused, offline, offline_disabled) with flag-based
accessors using bit operations
- Reject devices with unregistered buses
- Delete unused DEVICE_ATTR_PREALLOC()
- Add low-level device attribute macros with const show/store
callbacks, allowing device attributes to reside in read-only memory
- Move core device attributes to read-only memory
- Constify group array pointers in driver_add_groups() /
driver_remove_groups(), struct bus_type, and struct device_driver
device property:
- Fix fwnode reference leak in fwnode_graph_get_endpoint_by_id()
- Initialize all fields of fwnode_handle in fwnode_init()
- Provide swnode_get()/swnode_put() wrappers around kobject_get/put()
- Allow passing struct software_node_ref_args pointers directly to
PROPERTY_ENTRY_REF()
driver_override:
- Migrate amba, cdx, vmbus, and rpmsg to the generic driver_override
infrastructure, fixing a UAF from unsynchronized access to
driver_override in bus match() callbacks
- Remove the now-unused driver_set_override()
firmware loader:
- Fix recursive lock deadlock in device_cache_fw_images() when async
work falls back to synchronous execution
- Fix device reference leak in firmware_upload_register()
platform:
- Pass KBUILD_MODNAME through the platform driver registration macro
to create module symlinks in sysfs for built-in drivers; move
module_kset initialization to a pure_initcall and tegra cbb
registration to core_initcall to ensure correct ordering
- Pass THIS_MODULE implicitly through a coresight_init_driver() macro
sysfs:
- Upgrade OOB write detection in sysfs_kf_seq_show() from printk to
WARN
- Add return value clamping to sysfs_kf_read()
Rust:
- ACPI:
Fix missing match data for PRP0001 by exporting
acpi_of_match_device()
- Auxiliary:
Replace drvdata() with dedicated registration data on
auxiliary_device. drvdata() exposed the driver's bus device private
data beyond the driver's own scope, creating ordering constraints
and forcing the data to outlive all registrations that access it.
Registration data is instead scoped structurally to the
Registration object, making lifecycle ordering enforced by
construction rather than convention.
- Rust-native device driver lifetimes (HRT):
Allow Rust device drivers to carry a lifetime parameter on their
bus device private data, tied to the device binding scope -- the
interval during which a bus device is bound to a driver. Device
resources like pci::Bar<'a> and IoMem<'a> can be stored directly in
the driver's bus device private data with a lifetime bounded by the
binding scope, so the compiler enforces at build time that they do
not outlive the binding. This removes Devres indirection from every
access site and eliminates try_access() failure paths in
destructors.
Bus driver traits use a Generic Associated Type (GAT) Data<'bound>
to introduce the lifetime on the private data, rather than
parameterizing the Driver trait itself. Auxiliary registration
data, where the lifetime is not introduced by a trait callback but
must be threaded through Registration, uses the ForLt trait (a
type-level abstraction for types generic over a lifetime).
Misc:
- Fix DT overlayed devices not probing by reverting the broken
treewide overlay fix and re-running fw_devlink consumer pickup when
an overlay is applied to a bound device
- Use root_device_register() for faux bus root device; add sanity
check for failed bus init
- Fix dev_has_sync_state() data race with READ_ONCE() and move it to
base.h
- Avoid spurious device_links warning when removing a device while
its supplier is unbinding
- Switch ISA bus to dynamic root device
- Fix suspicious RCU usage in kernfs_put()
- Remove devcoredump exit callback
- Constify devfreq_event_class"
* tag 'driver-core-7.2-rc1' of gitolite.kernel.org:pub/scm/linux/kernel/git/driver-core/driver-core: (81 commits)
software node: allow passing reference args to PROPERTY_ENTRY_REF()
driver core: platform: set mod_name in driver registration
coresight: pass THIS_MODULE implicitly through a macro
kernel: param: initialize module_kset in a pure_initcall
soc/tegra: cbb: Move driver registration from pure_initcall to core_initcall
firmware_loader: Fix recursive lock in device_cache_fw_images()
driver core: Use system_percpu_wq instead of system_wq
driver core: remove driver_set_override()
rpmsg: use generic driver_override infrastructure
Drivers: hv: vmbus: use generic driver_override infrastructure
cdx: use generic driver_override infrastructure
amba: use generic driver_override infrastructure
rust: devres: add 'static bound to Devres<T>
samples: rust: rust_driver_auxiliary: showcase lifetime-bound registration data
rust: auxiliary: generalize Registration over ForLt
rust: types: add `ForLt` trait for higher-ranked lifetime support
gpu: nova-core: separate driver type from driver data
samples: rust: rust_driver_pci: use HRT lifetime for Bar
rust: io: make IoMem and ExclusiveIoMem lifetime-parameterized
rust: pci: make Bar lifetime-parameterized
...
Make the Data struct lifetime-parameterized, storing a reference to the
parent pci::Device<Bound>. This demonstrates that registration data can
hold device resources tied to the parent driver's lifetime.
In connect(), retrieve the parent PCI device from the registration data
rather than casting through adev.parent().
Reviewed-by: Eliot Courtney <ecourtney@nvidia.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Link: https://patch.msgid.link/20260525202921.124698-25-dakr@kernel.org
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Generalize Registration<T> to Registration<F: ForLt> and
Device::registration_data<F: ForLt>() to return Pin<&F::Of<'_>>.
The stored 'static lifetime is shortened to the borrow lifetime of &self
via ForLt::cast_ref; ForLt's covariance guarantee makes this sound.
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Reviewed-by: Eliot Courtney <ecourtney@nvidia.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Link: https://patch.msgid.link/20260525202921.124698-24-dakr@kernel.org
[ Use PhantomData<F::Of<'a>> instead of
PhantomData<(fn(&'a ()) -> &'a (), F)>], which also gets us rid of
#[allow(clippy::type_complexity)]. - Danilo ]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Convert the sample driver to SampleDriver<'bound>, taking advantage of
the lifetime-parameterized Driver trait.
The driver struct holds &'bound pci::Device directly instead of
ARef<pci::Device>, and pci::Bar<'bound> directly instead of
Devres<pci::Bar>. This removes PinnedDrop, pin_init_scope, and runtime
revocation checks on BAR access.
Reviewed-by: Eliot Courtney <ecourtney@nvidia.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Link: https://patch.msgid.link/20260525202921.124698-21-dakr@kernel.org
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Convert pci::Bar<SIZE> to pci::Bar<'a, SIZE>, storing &'a Device<Bound>
to tie the BAR mapping lifetime to the device.
iomap_region_sized() now returns Result<Bar<'a, SIZE>> directly instead
of impl PinInit<Devres<Bar<SIZE>>, Error>.
Since the lifetime ties the mapping to the device's bound state, callers
no longer need Devres for the common case where the Bar lives in the
driver's private data.
Add Bar::into_devres() to consume the bar and register it as a
device-managed resource, returning Devres<Bar<'static, SIZE>>. The
lifetime is erased to 'static because Devres guarantees the bar does not
actually outlive the device -- access is revoked on unbind.
Reviewed-by: Eliot Courtney <ecourtney@nvidia.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Link: https://patch.msgid.link/20260525202921.124698-19-dakr@kernel.org
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Add a 'bound lifetime to the associated Data, changing type Data to type
Data<'bound>.
This allows the driver's bus device private data to capture the device /
driver bound lifetime; device resources can be stored directly by
reference rather than requiring Devres.
The probe() and unbind() callbacks thus gain a 'bound lifetime parameter
on the methods themselves; avoiding a global lifetime on the trait impl.
Existing drivers set type Data<'bound> = Self, preserving the current
behavior.
Acked-by: Igor Korotin <igor.korotin@linux.dev>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Gary Guo <gary@garyguo.net>
Link: https://patch.msgid.link/20260525202921.124698-17-dakr@kernel.org
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Add a 'bound lifetime to the associated Data, changing type Data to type
Data<'bound>.
This allows the driver's bus device private data to capture the device /
driver bound lifetime; device resources can be stored directly by
reference rather than requiring Devres.
The probe() and disconnect() callbacks thus gain a 'bound lifetime
parameter on the methods themselves; avoiding a global lifetime on the
trait impl.
Existing drivers set type Data<'bound> = Self, preserving the current
behavior.
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Eliot Courtney <ecourtney@nvidia.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Daniel Almeida <daniel.almeida@collabora.com>
Link: https://patch.msgid.link/20260525202921.124698-16-dakr@kernel.org
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Add a 'bound lifetime to the associated Data, changing type Data to type
Data<'bound>.
This allows the driver's bus device private data to capture the device /
driver bound lifetime; device resources can be stored directly by
reference rather than requiring Devres.
The probe() and unbind() callbacks thus gain a 'bound lifetime parameter
on the methods themselves; avoiding a global lifetime on the trait impl.
Existing drivers set type Data<'bound> = Self, preserving the current
behavior.
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Gary Guo <gary@garyguo.net>
Link: https://patch.msgid.link/20260525202921.124698-15-dakr@kernel.org
Signed-off-by: Danilo Krummrich <dakr@kernel.org>