debugfs access modes were added in Linux 5.10 (Dec 2020) [1], but the
no-mount mode has behaved effectively the same as the off mode since
Linux 5.12 (Apr 2021) [2]. The only difference is the specific error
code returned by the debugfs_create_* functions, which is -ENOENT in
no-mount mode and -EPERM in off mode.
Given that no-mount hasn't worked for several years with no complaints,
just remove it.
[1] a24c6f7bc9 ("debugfs: Add access restriction option")
[2] bc6de804d3 ("debugfs: be more robust at handling improper input in debugfs_lookup()")
56348560d4 ("debugfs: do not attempt to create a new file before the filesystem is initalized")
Signed-off-by: Aaron Thompson <dev@aaront.org>
Link: https://patch.msgid.link/20251120102222.18371-3-dev@null.aaront.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
debugfs_get_tree() can only be called if debugfs itself calls
simple_pin_fs() or register_filesystem(), and those call paths also
check the access mode.
debugfs_start_creating() checks the access mode so the checks in the
debugfs_create_* functions are unnecessary.
An upcoming change will affect debugfs_allow, so doing this cleanup
first will make that change simpler.
Signed-off-by: Aaron Thompson <dev@aaront.org>
Link: https://patch.msgid.link/20251120102222.18371-2-dev@null.aaront.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When a device is hot-plugged, the drivers_autoprobe sysfs attribute is
not checked (at least for PCI devices). This means that
drivers_autoprobe is not working as intended, e.g. hot-plugged PCI
devices will still be autoprobed and bound to drivers even with
drivers_autoprobe disabled.
The problem likely started when device_add() was removed from
pci_bus_add_device() in commit 4f535093cf ("PCI: Put pci_dev in device
tree as early as possible") which means that the check for
drivers_autoprobe which used to happen in bus_probe_device() is no
longer present (previously bus_add_device() calls bus_probe_device()).
Conveniently, in commit 9170304169 ("PCI: Allow built-in drivers to
use async initial probing") device_attach() was replaced with
device_initial_probe() which faciliates this change to push the check
for drivers_autoprobe into device_initial_probe().
Make sure all devices check drivers_autoprobe by pushing the
drivers_autoprobe check into device_initial_probe(). This will only
affect devices on the PCI bus for now as device_initial_probe() is only
called by pci_bus_add_device() and bus_probe_device(), but
bus_probe_device() already checks for autoprobe, so callers of
bus_probe_device() should not observe changes on autoprobing.
Note also that pushing this check into device_initial_probe() rather
than device_attach() makes it only affect automatic probing of
drivers (e.g. when a device is hot-plugged), userspace can still choose
to manually bind a driver by writing to drivers_probe sysfs attribute,
even with autoprobe disabled.
Any future callers of device_initial_probe() will respect the
drivers_autoprobe sysfs attribute, which is the intended purpose of
drivers_autoprobe.
Signed-off-by: Vincent Liu <vincent.liu@nutanix.com>
Link: https://patch.msgid.link/20251022120740.2476482-1-vincent.liu@nutanix.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Currently if a user enqueue a work item using schedule_delayed_work() the
used wq is "system_wq" (per-cpu wq) while queue_delayed_work() use
WORK_CPU_UNBOUND (used when a cpu is not specified). The same applies to
schedule_work() that is using system_wq and queue_work(), that makes use
again of WORK_CPU_UNBOUND.
This lack of consistency cannot be addressed without refactoring the API.
alloc_workqueue() treats all queues as per-CPU by default, while unbound
workqueues must opt-in via WQ_UNBOUND.
This default is suboptimal: most workloads benefit from unbound queues,
allowing the scheduler to place worker threads where they’re needed and
reducing noise when CPUs are isolated.
This continues the effort to refactor workqueue APIs, which began with
the introduction of new workqueues and a new alloc_workqueue flag in:
commit 128ea9f6cc ("workqueue: Add system_percpu_wq and system_dfl_wq")
commit 930c2ea566 ("workqueue: Add new WQ_PERCPU flag")
This change adds a new WQ_PERCPU flag to explicitly request
alloc_workqueue() to be per-cpu when WQ_UNBOUND has not been specified.
With the introduction of the WQ_PERCPU flag (equivalent to !WQ_UNBOUND),
any alloc_workqueue() caller that doesn’t explicitly specify WQ_UNBOUND
must now use WQ_PERCPU.
Once migration is complete, WQ_UNBOUND can be removed and unbound will
become the implicit default.
Suggested-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Marco Crivellari <marco.crivellari@suse.com>
Link: https://patch.msgid.link/20251114141618.172154-3-marco.crivellari@suse.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Currently if a user enqueue a work item using schedule_delayed_work() the
used wq is "system_wq" (per-cpu wq) while queue_delayed_work() use
WORK_CPU_UNBOUND (used when a cpu is not specified). The same applies to
schedule_work() that is using system_wq and queue_work(), that makes use
again of WORK_CPU_UNBOUND.
This lack of consistentcy cannot be addressed without refactoring the API.
This continues the effort to refactor workqueue APIs, which began with
the introduction of new workqueues and a new alloc_workqueue flag in:
commit 128ea9f6cc ("workqueue: Add system_percpu_wq and system_dfl_wq")
commit 930c2ea566 ("workqueue: Add new WQ_PERCPU flag")
Switch to using system_dfl_wq because system_unbound_wq is going away as part of
a workqueue restructuring.
Suggested-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Marco Crivellari <marco.crivellari@suse.com>
Link: https://patch.msgid.link/20251114141618.172154-2-marco.crivellari@suse.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Expose the current system-defined list of housekeeping CPUs in a new
sysfs file: /sys/devices/system/cpu/housekeeping.
This provides userspace performance tuning tools and resource managers
with a canonical, reliable method to accurately identify the cores
responsible for essential kernel maintenance workloads (RCU, timer
callbacks, and unbound workqueues). Currently, tooling must manually
calculate the housekeeping set by parsing complex kernel boot parameters
(like isolcpus= and nohz_full=) and system topology, which is prone to
error. This dedicated file simplifies the configuration of low-latency
workloads.
Signed-off-by: Aaron Tomlin <atomlin@atomlin.com>
Link: https://patch.msgid.link/20251011012853.7539-2-atomlin@atomlin.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In the context of CONFIG_NO_HZ_FULL=y, tick_nohz_full_mask (of type
cpumask_var_t) is initialised to 0. Memory is only allocated to the cpumask
data structure, in tick_nohz_full_setup(), when Linux kernel boot-time
parameter "nohz_full=" is correctly specified (see housekeeping_setup()).
If "nohz_full=" is not set and an attempt is made to read
/sys/devices/system/cpu/nohz_full, '(null)' can be displayed:
❯ cat /sys/devices/system/cpu/nohz_full
(null)
This patch changes the output to print a newline (or 0x0A) instead of
'(null)', making it consistent with print_cpus_isolated() behaviour.
Signed-off-by: Aaron Tomlin <atomlin@atomlin.com>
Link: https://patch.msgid.link/20251011011830.6670-3-atomlin@atomlin.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The /sys/devices/system/cpu/nohz_full file is a read-only attribute that
reports the CPUs configured for tickless operation (CONFIG_NO_HZ_FULL=y).
The current definition uses the generic DEVICE_ATTR macro, which
unnecessarily requires specifying the file mode (0444) and a NULL
store operation pointer.
This patch converts the definition to use the dedicated DEVICE_ATTR_RO
macro. This correctly expresses the read-only nature of the attribute,
removes the redundant mode field, and simplifies the code. As a related
cleanup, rename the show function from print_cpus_nohz_full() to the
standard nohz_full_show() for consistency with common sysfs attribute
naming conventions.
Signed-off-by: Aaron Tomlin <atomlin@atomlin.com>
Link: https://patch.msgid.link/20251011011830.6670-2-atomlin@atomlin.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There exists a memory leak of kernfs_iattrs contained as an element
of kernfs_node allocated in __kernfs_new_node(). __kernfs_setattr()
allocates kernfs_iattrs as a sub-object, and the LSM security check
incorrectly errors out and does not free the kernfs_iattrs sub-object.
Make an additional error out case that properly frees kernfs_iattrs if
security_kernfs_init_security() fails.
Fixes: e19dfdc83b ("kernfs: initialize security of newly created nodes")
Co-developed-by: Oliver Rosenberg <olrose55@gmail.com>
Signed-off-by: Oliver Rosenberg <olrose55@gmail.com>
Signed-off-by: Will Rosenberg <whrosenb@asu.edu>
Link: https://patch.msgid.link/20251125151332.2010687-1-whrosenb@asu.edu
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
On an ARM64 A1 system, it's possible to have physical memory span
up to the 64T boundary, like below
$ lsmem -b -r -n -o range,size
0x0000000080000000-0x00000000bfffffff 1073741824
0x0000080000000000-0x000008007fffffff 2147483648
0x00000800c0000000-0x0000087fffffffff 546534588416
0x0000400000000000-0x00004000bfffffff 3221225472
0x0000400100000000-0x0000407fffffffff 545460846592
So it's time to extend /sys/kernel/mm/page_idle/bitmap to be able
to account for >2G number of pages, by raising the kernfs file size
limit.
Signed-off-by: Jane Chu <jane.chu@oracle.com>
Link: https://patch.msgid.link/20251111202606.1505437-1-jane.chu@oracle.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We have an upcoming driver named "intel_ehl_pse_io". This creates an
auxiliary child device for it's GPIO sub-functionality, which matches
against "intel_ehl_pse_io.gpio-elkhartlake" and overshoots the current
maximum limit of 32 bytes for auxiliary device id string. Bump the size
to 40 bytes to satisfy such cases.
Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Raag Jadav <raag.jadav@intel.com>
Link: https://patch.msgid.link/20251106052838.433673-1-raag.jadav@intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Define the macros in terms of each other.
This makes them easier to understand and also will make it easier to
implement the transition machinery for 'const struct attribute'.
__ATTR_RO_MODE() can't be implemented in terms of __ATTR() as not all
attributes have a .store callback. The same issue theoretically exists
for __ATTR_WO(), but practically that does not occur today.
Reorder __ATTR_RO() below __ATTR_RO_MODE() to keep the order of the
macro definition consistent with respect to each other.
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Link: https://patch.msgid.link/20251029-sysfs-const-attr-prep-v5-7-ea7d745acff4@weissschuh.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There was no example for the is_visible() callback so far.
It will also become an example and test for the constification of
'struct attribute' later.
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Link: https://patch.msgid.link/20251029-sysfs-const-attr-prep-v5-5-ea7d745acff4@weissschuh.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When constifying instances of struct attribute, for consistency the
corresponding .is_visible() callback should be adapted, too.
Introduce a temporary transition mechanism until all callbacks are
converted.
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Link: https://patch.msgid.link/20251029-sysfs-const-attr-prep-v5-4-ea7d745acff4@weissschuh.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
For the constification phase of 'struct attribute' various callback
struct members will need to exist in both const and non-const variants.
Keeping both members in a union avoids memory and CPU overhead but will
be detected and trapped by Control Flow Integrity (CFI). By deciding
between a struct and a union depending whether CFI is enabled, most
configurations can avoid this overhead. Code using these callbacks will
still need to be updated to handle both members explicitly.
In the union case the compiler will recognize that testing for one union
member is enough and optimize away the code for the other one.
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Link: https://patch.msgid.link/20251029-sysfs-const-attr-prep-v5-3-ea7d745acff4@weissschuh.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To ease the constification process of 'struct attribute', transparently
handle the const pointers in ATTRIBUTE_GROUPS(). A cast is used instead
of assigning to .attrs_new as it keeps the macro smaller. As both
members are aliased to each other the result is identical.
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Link: https://patch.msgid.link/20251029-sysfs-const-attr-prep-v5-2-ea7d745acff4@weissschuh.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To be able to constify instances of struct attribute it has to be
possible to add them to struct attribute_group. The current type of the
attrs member however is not compatible with that. Introduce a union that
allows registration of both const and non-const attributes to enable a
piecewise transition. As both union member types are compatible no
logic needs to be adapted.
Technically it is now possible register a const struct attribute and
receive it as mutable pointer in the callbacks. This is a soundness
issue. But this same soundness issue already exists today in
sysfs_create_file(). Also the struct definition and callback
implementation are always closely linked and are meant to be moved to
const in lockstep.
Similar to commit 906c508afd ("sysfs: attribute_group: allow
registration of const bin_attribute")
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Link: https://patch.msgid.link/20251029-sysfs-const-attr-prep-v5-1-ea7d745acff4@weissschuh.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The rust-next tree contains commit:
3b83f5d5e7 ("rust: replace `CStr` with `core::ffi::CStr`")
which, when merged together with commits:
57c5bd9aee ("rust: i2c: add basic I2C device and driver abstractions")
f3cc26a417 ("rust: i2c: add manual I2C device creation abstractions")
from this tree (driver-core), produces errors like the following:
error[E0599]: no method named `len_with_nul` found for reference `&'static ffi::CStr` in the current scope
--> rust/kernel/i2c.rs:48:16
|
48 | id.len_with_nul() <= Self::I2C_NAME_SIZE,
| ^^^^^^^^^^^^ method not found in `&CStr`
error[E0599]: no method named `as_bytes_with_nul` found for reference `&'static ffi::CStr` in the current scope
--> rust/kernel/i2c.rs:51:22
|
51 | let src = id.as_bytes_with_nul();
| ^^^^^^^^^^^^^^^^^
|
help: there is a method `to_bytes_with_nul` with a similar name
|
51 | let src = id.to_bytes_with_nul();
| ~~~~~~~~~~~~~~~~~
which were detected in linux-next by Stephen [1].
The `i2c` code can be independently prepared to be ready for the change,
thus do so.
The change is similar to the one done by Tamir in commit 657403637f
("rust: acpi: use `core::ffi::CStr` method names").
Link: https://lore.kernel.org/all/20251120181111.65ce75a0@canb.auug.org.au/ [1]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Link: https://patch.msgid.link/20251123163536.1771801-1-ojeda@kernel.org
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Implement the `AsBusDevice` trait for converting a `Device` reference to a
bus device reference for all bus devices.
The `AsBusDevice` trait allows abstractions to provide the bus device in
class device callbacks. It must not be used by drivers and is intended for
bus and class device abstractions only.
Signed-off-by: Markus Probst <markus.probst@posteo.de>
Link: https://patch.msgid.link/20251027200547.1038967-2-markus.probst@posteo.de
[ * Remove unused import.
* Change visibility of AsBusDevice to public.
* Fix build for USB.
* Add impl for I2cClient.
- Danilo ]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Add a new `rust_i2c_client` sample, showing how to create a new
i2c client using `i2c::Registration`
Acked-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Igor Korotin <igor.korotin.linux@gmail.com>
Link: https://patch.msgid.link/20251116162210.171542-1-igor.korotin.linux@gmail.com
[ * Remove dependency to I2C_CHARDEV, depend on I2C=y.
* Remove unnecessary impl Drop for SampleDriver.
* Rename i2c::Registration, import Devres.
* Fixup module description.
* Add new source file to MAINTAINERS.
- Danilo ]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Add a new `rust_driver_i2c` sample, showing how to create a new
i2c driver using ACPI/OF/Legacy ID tables.
Acked-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Igor Korotin <igor.korotin.linux@gmail.com>
Link: https://patch.msgid.link/20251116162204.171518-1-igor.korotin.linux@gmail.com
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
In addition to the basic I2C device support, add rust abstractions
upon `i2c_new_client_device`/`i2c_unregister_device` C functions.
Implement the core abstractions needed for manual creation/deletion
of I2C devices, including:
* `i2c::Registration` — a NonNull pointer created by the function
`i2c_new_client_device`
* `i2c::I2cAdapter` — a ref counted wrapper around `struct i2c_adapter`
* `i2c::I2cBoardInfo` — a safe wrapper around `struct i2c_board_info`
Acked-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Igor Korotin <igor.korotin.linux@gmail.com>
Link: https://patch.msgid.link/20251116162154.171493-1-igor.korotin.linux@gmail.com
[ Remove unnecessary safety comment. - Danilo ]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Now that ResourceSize has been moved to kernel::io, import it from the
io module instead of the io::resource sub-module. It makes sense in this
case since the dma_len isn't really related to the Resource type even
though both are sizes of allocations in physical ram.
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Link: https://patch.msgid.link/20251112-resource-phys-typedefs-v2-3-538307384f82@google.com
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Resource sizes are a general concept for dealing with physical
addresses, and not specific to the Resource type, which is just one way
to access physical addresses. Thus, move the typedef to the io module.
Still keep a re-export under resource. This avoids this commit from
being a flag-day, but I also think it's a useful re-export in general so
that you can import
use kernel::io::resource::{Resource, ResourceSize};
instead of having to write
use kernel::io::{
resource::Resource,
ResourceSize,
};
in the specific cases where you need ResourceSize because you are using
the Resource type. Therefore I think it makes sense to keep this
re-export indefinitely and it is *not* intended as a temporary re-export
for migration purposes.
Cc: stable@vger.kernel.org # for v6.18 [1]
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Link: https://patch.msgid.link/20251112-resource-phys-typedefs-v2-2-538307384f82@google.com
Link: https://lore.kernel.org/all/20251112-resource-phys-typedefs-v2-0-538307384f82@google.com/ [1]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
In struct CoherentAllocation, use NonNull<T> instead of a raw *mut T for
the CPU address; the CPU address of a valid CoherentAllocation won't
ever be NULL.
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://patch.msgid.link/20251103190655.2326191-2-dakr@kernel.org
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Using start_ptr() and start_ptr_mut() has the advantage that we inherit
the requirements the a mutable or immutable reference from those
methods.
Hence, use them instead of self.cpu_addr.
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://patch.msgid.link/20251103190655.2326191-1-dakr@kernel.org
[ Keep using self.cpu_addr in item_from_index(). - Danilo ]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Commit 46f045db5a ("rust: Add read_poll_timeout_atomic function")
initiated the first import change in the I/O module using the agreed
"kernel vertical" import style [1].
For consistency throughout the module, adjust all other imports
accordingly.
While at it, drop unnecessary imports covered by prelude::*.
Link: https://docs.kernel.org/rust/coding-guidelines.html#imports [1]
Reviewed-by: Zhi Wang <zhiw@nvidia.com>
Link: https://patch.msgid.link/20251104133301.59402-1-dakr@kernel.org
[ Use prelude::* in io/poll.rs. - Danilo ]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Currently request_irq_by_index() returns
Result<impl PinInit<irq::Registration<T>, Error> + 'a>
which may carry an error in the Result or the initializer; the same is
true for the other IRQ methods.
Use pin_init::pin_init_scope() to get rid of this redundancy.
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://patch.msgid.link/20251103203053.2348783-2-dakr@kernel.org
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Currently request_irq() returns
Result<impl PinInit<irq::Registration<T>, Error> + 'a>
which may carry an error in the Result or the initializer; the same is
true for request_threaded_irq().
Use pin_init::pin_init_scope() to get rid of this redundancy.
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://patch.msgid.link/20251103203053.2348783-1-dakr@kernel.org
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Some older (yet supported) versions of clippy throw a false positive
warning for missing a safety comment when the safety comment is on a
multiline statement.
warning: unsafe block missing a safety comment
--> rust/kernel/auxiliary.rs:351:22
|
351 | Self(unsafe { NonNull::new_unchecked(adev) }),
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= help: consider adding a safety comment on the preceding line
= help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#undocumented_unsafe_blocks
= note: requested on the command line with `-W clippy::undocumented-unsafe-blocks`
warning: 1 warning emitted
Fix this by placing the safety comment right on top of the same line
introducing the unsafe block.
Fixes: e4e679c860 ("rust: auxiliary: unregister on parent device unbind")
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://patch.msgid.link/20251103203932.2361660-1-dakr@kernel.org
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Extend the rust_debugfs_scoped sample to demonstrate how to export a
large binary object through a ScopedDir.
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Matthew Maurer <mmaurer@google.com>
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Add support for creating binary debugfs files via ScopedDir. This
mirrors the existing functionality for Dir, but without producing an
owning handle -- files are automatically removed when the associated
Scope is dropped.
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Matthew Maurer <mmaurer@google.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Extend the Rust debugfs sample to demonstrate usage of binary file
support. The example now shows how to expose both fixed-size arrays
and dynamically sized vectors as binary blobs in debugfs.
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Matthew Maurer <mmaurer@google.com>
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Extend Rust debugfs binary support to allow exposing data stored in
common smart pointers and heap-allocated collections.
- Implement BinaryWriter for Box<T>, Pin<Box<T>>, Arc<T>, and Vec<T>.
- Introduce BinaryReaderMut for mutable binary access with outer locks.
- Implement BinaryReaderMut for Box<T>, Vec<T>, and base types.
- Update BinaryReader to delegate to BinaryReaderMut for Mutex<T>,
Box<T>, Pin<Box<T>> and Arc<T>.
This enables debugfs files to directly expose or update data stored
inside heap-allocated, reference-counted, or lock-protected containers
without manual dereferencing or locking.
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Matthew Maurer <mmaurer@google.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Introduce support for read-only, write-only, and read-write binary files
in Rust debugfs. This adds:
- BinaryWriter and BinaryReader traits for writing to and reading from
user slices in binary form.
- New Dir methods: read_binary_file(), write_binary_file(),
`read_write_binary_file`.
- Corresponding FileOps implementations: BinaryReadFile,
BinaryWriteFile, BinaryReadWriteFile.
This allows kernel modules to expose arbitrary binary data through
debugfs, with proper support for offsets and partial reads/writes.
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Matthew Maurer <mmaurer@google.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Add UserSliceWriter::write_slice_file(), which is the same as
UserSliceWriter::write_slice_partial() but updates the given
file::Offset by the number of bytes written.
This is equivalent to C's `simple_read_from_buffer()` and useful when
dealing with file offsets from file operations.
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Acked-by: Miguel Ojeda <ojeda@kernel.org>
[ Replace saturating_add() with the raw operator and a corresponding
OVERFLOW comment. - Danilo ]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
The existing write_slice() method is a wrapper around copy_to_user() and
expects the user buffer to be larger than the source buffer.
However, userspace may split up reads in multiple partial operations
providing an offset into the source buffer and a smaller user buffer.
In order to support this common case, provide a helper for partial
writes.
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Matthew Maurer <mmaurer@google.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Acked-by: Miguel Ojeda <ojeda@kernel.org>
[ Replace map_or() with let-else; use saturating_add(). - Danilo ]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Add UserSliceReader::read_slice_file(), which is the same as
UserSliceReader::read_slice_partial() but updates the given file::Offset
by the number of bytes read.
This is equivalent to C's `simple_write_to_buffer()` and useful when
dealing with file offsets from file operations.
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Acked-by: Miguel Ojeda <ojeda@kernel.org>
[ Replace saturating_add() with the raw operator and a corresponding
OVERFLOW comment. - Danilo ]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
The existing read_slice() method is a wrapper around copy_from_user()
and expects the user buffer to be larger than the destination buffer.
However, userspace may split up writes in multiple partial operations
providing an offset into the destination buffer and a smaller user
buffer.
In order to support this common case, provide a helper for partial
reads.
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Matthew Maurer <mmaurer@google.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Acked-by: Miguel Ojeda <ojeda@kernel.org>
[ Replace map_or() with let-else; use saturating_add(). - Danilo ]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Add a type alias for file offsets, i.e. bindings::loff_t. Trying to
avoid using raw bindings types, this seems to be the better alternative
compared to just using i64.
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Jan Kara <jack@suse.cz>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Christian Brauner <brauner@kernel.org>
Link: https://patch.msgid.link/20251020222722.240473-2-dakr@kernel.org
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
