- DEBUGFS
- Remove unneeded debugfs_file_{get,put}() instances
- Remove last remnants of debugfs_real_fops()
- Allow storing non-const void * in struct debugfs_inode_info::aux
- SYSFS
- Switch back to attribute_group::bin_attrs (treewide)
- Switch back to bin_attribute::read()/write() (treewide)
- Constify internal references to 'struct bin_attribute'
- Support cache-ids for device-tree systems
- Add arch hook arch_compact_of_hwid()
- Use arch_compact_of_hwid() to compact MPIDR values on arm64
- Rust
- Device
- Introduce CoreInternal device context (for bus internal methods)
- Provide generic drvdata accessors for bus devices
- Provide Driver::unbind() callbacks
- Use the infrastructure above for auxiliary, PCI and platform
- Implement Device::as_bound()
- Rename Device::as_ref() to Device::from_raw() (treewide)
- Implement fwnode and device property abstractions
- Implement example usage in the Rust platform sample driver
- Devres
- Remove the inner reference count (Arc) and use pin-init instead
- Replace Devres::new_foreign_owned() with devres::register()
- Require T to be Send in Devres<T>
- Initialize the data kept inside a Devres last
- Provide an accessor for the Devres associated Device
- Device ID
- Add support for ACPI device IDs and driver match tables
- Split up generic device ID infrastructure
- Use generic device ID infrastructure in net::phy
- DMA
- Implement the dma::Device trait
- Add DMA mask accessors to dma::Device
- Implement dma::Device for PCI and platform devices
- Use DMA masks from the DMA sample module
- I/O
- Implement abstraction for resource regions (struct resource)
- Implement resource-based ioremap() abstractions
- Provide platform device accessors for I/O (remap) requests
- Misc
- Support fallible PinInit types in Revocable
- Implement Wrapper<T> for Opaque<T>
- Merge pin-init blanket dependencies (for Devres)
- Misc
- Fix OF node leak in auxiliary_device_create()
- Use util macros in device property iterators
- Improve kobject sample code
- Add device_link_test() for testing device link flags
- Fix typo in Documentation/ABI/testing/sysfs-kernel-address_bits
- Hint to prefer container_of_const() over container_of()
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Merge tag 'driver-core-6.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/driver-core/driver-core
Pull driver core updates from Danilo Krummrich:
"debugfs:
- Remove unneeded debugfs_file_{get,put}() instances
- Remove last remnants of debugfs_real_fops()
- Allow storing non-const void * in struct debugfs_inode_info::aux
sysfs:
- Switch back to attribute_group::bin_attrs (treewide)
- Switch back to bin_attribute::read()/write() (treewide)
- Constify internal references to 'struct bin_attribute'
Support cache-ids for device-tree systems:
- Add arch hook arch_compact_of_hwid()
- Use arch_compact_of_hwid() to compact MPIDR values on arm64
Rust:
- Device:
- Introduce CoreInternal device context (for bus internal methods)
- Provide generic drvdata accessors for bus devices
- Provide Driver::unbind() callbacks
- Use the infrastructure above for auxiliary, PCI and platform
- Implement Device::as_bound()
- Rename Device::as_ref() to Device::from_raw() (treewide)
- Implement fwnode and device property abstractions
- Implement example usage in the Rust platform sample driver
- Devres:
- Remove the inner reference count (Arc) and use pin-init instead
- Replace Devres::new_foreign_owned() with devres::register()
- Require T to be Send in Devres<T>
- Initialize the data kept inside a Devres last
- Provide an accessor for the Devres associated Device
- Device ID:
- Add support for ACPI device IDs and driver match tables
- Split up generic device ID infrastructure
- Use generic device ID infrastructure in net::phy
- DMA:
- Implement the dma::Device trait
- Add DMA mask accessors to dma::Device
- Implement dma::Device for PCI and platform devices
- Use DMA masks from the DMA sample module
- I/O:
- Implement abstraction for resource regions (struct resource)
- Implement resource-based ioremap() abstractions
- Provide platform device accessors for I/O (remap) requests
- Misc:
- Support fallible PinInit types in Revocable
- Implement Wrapper<T> for Opaque<T>
- Merge pin-init blanket dependencies (for Devres)
Misc:
- Fix OF node leak in auxiliary_device_create()
- Use util macros in device property iterators
- Improve kobject sample code
- Add device_link_test() for testing device link flags
- Fix typo in Documentation/ABI/testing/sysfs-kernel-address_bits
- Hint to prefer container_of_const() over container_of()"
* tag 'driver-core-6.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/driver-core/driver-core: (84 commits)
rust: io: fix broken intra-doc links to `platform::Device`
rust: io: fix broken intra-doc link to missing `flags` module
rust: io: mem: enable IoRequest doc-tests
rust: platform: add resource accessors
rust: io: mem: add a generic iomem abstraction
rust: io: add resource abstraction
rust: samples: dma: set DMA mask
rust: platform: implement the `dma::Device` trait
rust: pci: implement the `dma::Device` trait
rust: dma: add DMA addressing capabilities
rust: dma: implement `dma::Device` trait
rust: net::phy Change module_phy_driver macro to use module_device_table macro
rust: net::phy represent DeviceId as transparent wrapper over mdio_device_id
rust: device_id: split out index support into a separate trait
device: rust: rename Device::as_ref() to Device::from_raw()
arm64: cacheinfo: Provide helper to compress MPIDR value into u32
cacheinfo: Add arch hook to compress CPU h/w id into 32 bits for cache-id
cacheinfo: Set cache 'id' based on DT data
container_of: Document container_of() is not to be used in new code
driver core: auxiliary bus: fix OF node leak
...
Now that the driver core can properly handle constant struct bus_type,
move the nvmem_bus_type variable to be a constant structure as well,
placing it into read-only memory which can not be modified at runtime.
Cc: Srinivas Kandagatla <srini@kernel.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Srinivas Kandagatla <srini@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20250712181905.6738-6-srini@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch fixes minor typo issues for nvmem-core.c:
Corrects "form" to "from" in multiple function descriptions.
Fixes missing closing angle brackets in MODULE_AUTHOR entries.
These changes improve readability and formatting consistency.
Signed-off-by: Alok Tiwari <alok.a.tiwari@oracle.com>
Signed-off-by: Srinivas Kandagatla <srini@kernel.org>
Link: https://lore.kernel.org/r/20250712181905.6738-4-srini@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Board files are deprecated by DT, and the last user of
nvmem_add_cell_table() was removed by commit 2af4fcc0d3 ("ARM:
davinci: remove unused board support") in v6.3. Hence remove all
support for nvmem cell tables, and update the documentation.
Device drivers can still register a single cell using
nvmem_add_one_cell() (which was not documented before).
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Srinivas Kandagatla <srini@kernel.org>
Link: https://lore.kernel.org/r/20250509122452.11827-2-srini@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If NVMEM cell uses bit offset or specifies bit truncation, update
raw_len manually (following the cell->bytes update), ensuring that the
NVMEM access is still word-aligned.
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20250411112251.68002-11-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Check that the NVMEM cell's raw_len is a aligned to word_size. Otherwise
Otherwise drivers might face incomplete read while accessing the last
part of the NVMEM cell.
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20250411112251.68002-10-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If the NVMEM specifies a stride to access data, reading particular cell
might require bit offset that is bigger than one byte. Rework NVMEM core
code to support bit offsets of more than 8 bits.
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20250411112251.68002-9-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When __nvmem_cell_entry_write() is called for an nvmem cell that does
not need bit shifting, it requires that the len parameter exactly
matches the nvmem cell size. However, when the nvmem cell has a nonzero
bit_offset, it was skipping this check.
Accepting values of len larger than the cell size results in
nvmem_cell_prepare_write_buffer() trying to write past the end of a heap
buffer that it allocates. Add a check to avoid that problem and instead
return -EINVAL when len doesn't match the number of bits expected by the
nvmem cell when bit_offset is nonzero.
This check uses cell->nbits in order to allow providing the smaller size
to cells that are shifted into another byte by bit_offset. For example,
a cell with nbits=8 and nonzero bit_offset would have bytes=2 but should
accept a 1-byte write here, although no current callers depend on this.
Fixes: 69aba7948c ("nvmem: Add a simple NVMEM framework for consumers")
Cc: stable@vger.kernel.org
Signed-off-by: Jennifer Berringer <jberring@redhat.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20241230141901.263976-7-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The sysfs core now allows instances of 'struct bin_attribute' to be
moved into read-only memory. Make use of that to protect them against
accidental or malicious modifications.
Also adapt the dynamic sysfs cell logic to handle the const attributes.
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20241230143035.265518-2-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Here is the "big and hairy" char/misc/iio and other small driver
subsystem updates for 6.13-rc1. Sorry for doing this at the end of the
merge window, conference and holiday travel got in the way on my side
(hence the 5am pull request emails...)
Loads of things in here, and even a fun merge conflict!
- rust misc driver bindings and other rust changes to make misc
drivers actually possible. I think this is the tipping point,
expect to see way more rust drivers going forward now that these
bindings are present. Next merge window hopefully we will have pci
and platform drivers working, which will fully enable almost all
driver subsystems to start accepting (or at least getting) rust
drivers. This is the end result of a lot of work from a lot of
people, congrats to all of them for getting this far, you've proved
many of us wrong in the best way possible, working code :)
- IIO driver updates, too many to list individually, that subsystem
keeps growing and growing...
- Interconnect driver updates
- nvmem driver updates
- pwm driver updates
- platform_driver::remove() fixups, loads of them
- counter driver updates
- misc driver updates (keba?)
- binder driver updates and fixes
- loads of other small char/misc/etc driver updates and additions,
full details in the shortlog.
Note, there is a semi-hairy rust merge conflict when pulling this. The
resolution has been in linux-next for a while and can be seen here:
https://lore.kernel.org/all/20241111173459.2646d4af@canb.auug.org.au/
All of these have been in linux-next for a while, with no other reported
issues other than that merge conflict.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'char-misc-6.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc
Pull char/misc/IIO/whatever driver subsystem updates from Greg KH:
"Here is the 'big and hairy' char/misc/iio and other small driver
subsystem updates for 6.13-rc1.
Loads of things in here, and even a fun merge conflict!
- rust misc driver bindings and other rust changes to make misc
drivers actually possible.
I think this is the tipping point, expect to see way more rust
drivers going forward now that these bindings are present. Next
merge window hopefully we will have pci and platform drivers
working, which will fully enable almost all driver subsystems to
start accepting (or at least getting) rust drivers.
This is the end result of a lot of work from a lot of people,
congrats to all of them for getting this far, you've proved many of
us wrong in the best way possible, working code :)
- IIO driver updates, too many to list individually, that subsystem
keeps growing and growing...
- Interconnect driver updates
- nvmem driver updates
- pwm driver updates
- platform_driver::remove() fixups, loads of them
- counter driver updates
- misc driver updates (keba?)
- binder driver updates and fixes
- loads of other small char/misc/etc driver updates and additions,
full details in the shortlog.
All of these have been in linux-next for a while, with no other
reported issues other than that merge conflict"
* tag 'char-misc-6.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (401 commits)
mei: vsc: Fix typo "maintstepping" -> "mainstepping"
firmware: Switch back to struct platform_driver::remove()
misc: isl29020: Fix the wrong format specifier
scripts/tags.sh: Don't tag usages of DEFINE_MUTEX
fpga: Switch back to struct platform_driver::remove()
mei: vsc: Improve error logging in vsc_identify_silicon()
mei: vsc: Do not re-enable interrupt from vsc_tp_reset()
dt-bindings: spmi: qcom,x1e80100-spmi-pmic-arb: Add SAR2130P compatible
dt-bindings: spmi: spmi-mtk-pmif: Add compatible for MT8188
spmi: pmic-arb: fix return path in for_each_available_child_of_node()
iio: Move __private marking before struct element priv in struct iio_dev
docs: iio: ad7380: add adaq4370-4 and adaq4380-4
iio: adc: ad7380: add support for adaq4370-4 and adaq4380-4
iio: adc: ad7380: use local dev variable to shorten long lines
iio: adc: ad7380: fix oversampling formula
dt-bindings: iio: adc: ad7380: add adaq4370-4 and adaq4380-4 compatible parts
bus: mhi: host: pci_generic: Use pcim_iomap_region() to request and map MHI BAR
bus: mhi: host: Switch trace_mhi_gen_tre fields to native endian
misc: atmel-ssc: Use of_property_present() for non-boolean properties
misc: keba: Add hardware dependency
...
The bin_attr_nvmem_write() must check the read_only flag and block
writes on read-only devices, now that a nvmem device can be switched
between read-write and read-only mode at runtime using the force_ro
attribute. Add the missing check.
Fixes: 9d7eb234ac ("nvmem: core: Implement force_ro sysfs attribute")
Cc: Stable@vger.kernel.org
Signed-off-by: Marek Vasut <marex@denx.de>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20241030140253.40445-2-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The is_bin_visible() callbacks should not modify the struct
bin_attribute passed as argument.
Enforce this by marking the argument as const.
As there are not many callback implementers perform this change
throughout the tree at once.
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Acked-by: Martin K. Petersen <martin.petersen@oracle.com>
Acked-by: Jason Gunthorpe <jgg@nvidia.com>
Acked-by: Ira Weiny <ira.weiny@intel.com>
Acked-by: Krzysztof Wilczyński <kw@linux.com>
Link: https://lore.kernel.org/r/20241103-sysfs-const-bin_attr-v2-5-71110628844c@weissschuh.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Stop abusing the is_bin_visible() callback to calculate the attribute
size. Instead use the new, dedicated bin_size() one.
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Acked-by: Krzysztof Wilczyński <kw@linux.com>
Link: https://lore.kernel.org/r/20241103-sysfs-const-bin_attr-v2-4-71110628844c@weissschuh.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Here is the "big" set of char/misc and other driver subsystem changes
for 6.11-rc1. Nothing major in here, just loads of new drivers and
updates. Included in here are:
- IIO api updates and new drivers added
- wait_interruptable_timeout() api cleanups for some drivers
- MODULE_DESCRIPTION() additions for loads of drivers
- parport out-of-bounds fix
- interconnect driver updates and additions
- mhi driver updates and additions
- w1 driver fixes
- binder speedups and fixes
- eeprom driver updates
- coresight driver updates
- counter driver update
- new misc driver additions
- other minor api updates
All of these, EXCEPT for the final Kconfig build fix for 32bit systems,
have been in linux-next for a while with no reported issues. The
Kconfig fixup went in 29 hours ago, so might have missed the latest
linux-next, but was acked by everyone involved.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'char-misc-6.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc
Pull char / misc and other driver updates from Greg KH:
"Here is the "big" set of char/misc and other driver subsystem changes
for 6.11-rc1. Nothing major in here, just loads of new drivers and
updates. Included in here are:
- IIO api updates and new drivers added
- wait_interruptable_timeout() api cleanups for some drivers
- MODULE_DESCRIPTION() additions for loads of drivers
- parport out-of-bounds fix
- interconnect driver updates and additions
- mhi driver updates and additions
- w1 driver fixes
- binder speedups and fixes
- eeprom driver updates
- coresight driver updates
- counter driver update
- new misc driver additions
- other minor api updates
All of these, EXCEPT for the final Kconfig build fix for 32bit
systems, have been in linux-next for a while with no reported issues.
The Kconfig fixup went in 29 hours ago, so might have missed the
latest linux-next, but was acked by everyone involved"
* tag 'char-misc-6.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (330 commits)
misc: Kconfig: exclude mrvl-cn10k-dpi compilation for 32-bit systems
misc: delete Makefile.rej
binder: fix hang of unregistered readers
misc: Kconfig: add a new dependency for MARVELL_CN10K_DPI
virtio: add missing MODULE_DESCRIPTION() macro
agp: uninorth: add missing MODULE_DESCRIPTION() macro
spmi: add missing MODULE_DESCRIPTION() macros
dev/parport: fix the array out-of-bounds risk
samples: configfs: add missing MODULE_DESCRIPTION() macro
misc: mrvl-cn10k-dpi: add Octeon CN10K DPI administrative driver
misc: keba: Fix missing AUXILIARY_BUS dependency
slimbus: Fix struct and documentation alignment in stream.c
MAINTAINERS: CC dri-devel list on Qualcomm FastRPC patches
misc: fastrpc: use coherent pool for untranslated Compute Banks
misc: fastrpc: support complete DMA pool access to the DSP
misc: fastrpc: add missing MODULE_DESCRIPTION() macro
misc: fastrpc: Add missing dev_err newlines
misc: fastrpc: Use memdup_user()
nvmem: core: Implement force_ro sysfs attribute
nvmem: Use sysfs_emit() for type attribute
...
Implement "force_ro" sysfs attribute to allow users to set read-write
devices as read-only and back to read-write from userspace. The choice
of the name is based on MMC core 'force_ro' attribute.
This solves a situation where an AT24 I2C EEPROM with GPIO based nWP
signal may have to be occasionally updated. Such I2C EEPROM device is
usually set as read-only during most of the regular system operation,
but in case it has to be updated in a controlled manner, it could be
unlocked using this new "force_ro" sysfs attribute and then re-locked
again.
The "read-only" DT property and config->read_only configuration is
respected and is used to set default state of the device, read-only
or read-write, for devices which do implement .reg_write function.
For devices which do not implement .reg_write function, the device
is unconditionally read-only and the "force_ro" attribute is not
visible.
Signed-off-by: Marek Vasut <marex@denx.de>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20240705074852.423202-16-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Use sysfs_emit() instead of sprintf() to follow best practice per
Documentation/filesystems/sysfs.rst
"
show() should only use sysfs_emit()...
"
Signed-off-by: Marek Vasut <marex@denx.de>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20240705074852.423202-15-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The same checks have already been done in sysfs_kf_bin_write() and
sysfs_kf_bin_read() just before the callbacks are invoked.
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20240705074852.423202-12-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
nvmem_cells_groups is a global variable that is also mutated.
This is complicated and error-prone.
Instead use a normal stack variable.
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20240705074852.423202-11-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The sysfs core provides a function to easily register a single group.
Use it and remove the now unnecessary nvmem_cells_groups array.
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20240705074852.423202-10-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The cell sysfs attribute should not provide more access to the nvmem
data than the main attribute itself.
For example if nvme_config::root_only was set, the cell attribute
would still provide read access to everybody.
Mask out permissions not available on the main attribute.
Fixes: 0331c61194 ("nvmem: core: Expose cells through sysfs")
Cc: stable@vger.kernel.org
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20240628113704.13742-5-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
bin_attr_nvmem_eeprom_compat is the template from which all future
compat attributes are created.
Changing it means to change all subsquent compat attributes, too.
Instead only use the "fram" name for the currently registered attribute.
Fixes: fd307a4ad3 ("nvmem: prepare basics for FRAM support")
Cc: stable@vger.kernel.org
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20240628113704.13742-4-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
devm_device_add_groups() is being removed from the kernel, so move the
nvmem driver to use device_add_groups() instead. The logic is
identical, when the device is removed the driver core will properly
clean up and remove the groups, and the memory used by the attribute
groups will be freed because it was created with dev_* calls, so this is
functionally identical overall.
Cc: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20240430084921.33387-7-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The algorithms in nvmem core are built with the constraint that
bit_offset < 8. If bit_offset is greater the results are wrong. Print an
error if the devicetree 'bits' property is outside of the valid range
and abort parsing.
Signed-off-by: Markus Schneider-Pargmann <msp@baylibre.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20240224114516.86365-12-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Creating sysfs files for all Cells caused a boot failure for linux-6.8-rc1 on
Apple M1, which (in downstream dts files) has multiple nvmem cells that use the
same byte address. This causes the device probe to fail with
[ 0.605336] sysfs: cannot create duplicate filename '/devices/platform/soc@200000000/2922bc000.efuse/apple_efuses_nvmem0/cells/efuse@a10'
[ 0.605347] CPU: 7 PID: 1 Comm: swapper/0 Tainted: G S 6.8.0-rc1-arnd-5+ #133
[ 0.605355] Hardware name: Apple Mac Studio (M1 Ultra, 2022) (DT)
[ 0.605362] Call trace:
[ 0.605365] show_stack+0x18/0x2c
[ 0.605374] dump_stack_lvl+0x60/0x80
[ 0.605383] dump_stack+0x18/0x24
[ 0.605388] sysfs_warn_dup+0x64/0x80
[ 0.605395] sysfs_add_bin_file_mode_ns+0xb0/0xd4
[ 0.605402] internal_create_group+0x268/0x404
[ 0.605409] sysfs_create_groups+0x38/0x94
[ 0.605415] devm_device_add_groups+0x50/0x94
[ 0.605572] nvmem_populate_sysfs_cells+0x180/0x1b0
[ 0.605682] nvmem_register+0x38c/0x470
[ 0.605789] devm_nvmem_register+0x1c/0x6c
[ 0.605895] apple_efuses_probe+0xe4/0x120
[ 0.606000] platform_probe+0xa8/0xd0
As far as I can tell, this is a problem for any device with multiple cells on
different bits of the same address. Avoid the issue by changing the file name
to include the first bit number.
Fixes: 0331c61194 ("nvmem: core: Expose cells through sysfs")
Link: https://github.com/AsahiLinux/linux/blob/bd0a1a7d4/arch/arm64/boot/dts/apple/t600x-dieX.dtsi#L156
Cc: <regressions@lists.linux.dev>
Cc: Miquel Raynal <miquel.raynal@bootlin.com>
Cc: Rafał Miłecki <rafal@milecki.pl>
Cc: Chen-Yu Tsai <wenst@chromium.org>
Cc: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: <asahi@lists.linux.dev>
Cc: Sven Peter <sven@svenpeter.dev>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Reviewed-by: Eric Curtin <ecurtin@redhat.com>
Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/r/20240209163454.98051-1-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This is required by layouts that need to read whole NVMEM content. It's
especially useful for NVMEM devices without hardcoded layout (like
U-Boot environment data block).
Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/r/20231221173421.13737-2-zajec5@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Thanks for layouts refactoring we now have "struct device" associated
with layout. Also its OF pointer points directly to the "nvmem-layout"
DT node.
All it takes to get match data is a generic of_device_get_match_data().
Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Michael Walle <michael@walle.cc>
Link: https://lore.kernel.org/r/20231219120104.3422-2-zajec5@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Simply pass whole "struct nvmem_layout" instead of single variables.
There is nothing in "struct nvmem_layout" that we have to hide from
layout drivers. They also access it during .probe() and .remove().
Thanks to this change:
1. API gets more consistent
All layouts drivers callbacks get the same argument
2. Layouts get correct device
Before this change NVMEM core code was passing NVMEM device instead
of layout device. That resulted in:
* Confusing prints
* Calling devm_*() helpers on wrong device
* Helpers like of_device_get_match_data() dereferencing NULLs
3. It gets possible to get match data
First of all nvmem_layout_get_match_data() requires passing "struct
nvmem_layout" which .add_cells() callback didn't have before this. It
doesn't matter much as it's rather useless now anyway (and will be
dropped).
What's more important however is that of_device_get_match_data() can
be used now thanks to owning a proper device pointer.
Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Michael Walle <michael@walle.cc>
Link: https://lore.kernel.org/r/20231219120104.3422-1-zajec5@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The binary content of nvmem devices is available to the user so in the
easiest cases, finding the content of a cell is rather easy as it is
just a matter of looking at a known and fixed offset. However, nvmem
layouts have been recently introduced to cope with more advanced
situations, where the offset and size of the cells is not known in
advance or is dynamic. When using layouts, more advanced parsers are
used by the kernel in order to give direct access to the content of each
cell, regardless of its position/size in the underlying
device. Unfortunately, these information are not accessible by users,
unless by fully re-implementing the parser logic in userland.
Let's expose the cells and their content through sysfs to avoid these
situations. Of course the relevant NVMEM sysfs Kconfig option must be
enabled for this support to be available.
Not all nvmem devices expose cells. Indeed, the .bin_attrs attribute
group member will be filled at runtime only when relevant and will
remain empty otherwise. In this case, as the cells attribute group will
be empty, it will not lead to any additional folder/file creation.
Exposed cells are read-only. There is, in practice, everything in the
core to support a write path, but as I don't see any need for that, I
prefer to keep the interface simple (and probably safer). The interface
is documented as being in the "testing" state which means we can later
add a write attribute if though relevant.
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Tested-by: Rafał Miłecki <rafal@milecki.pl>
Tested-by: Chen-Yu Tsai <wenst@chromium.org>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20231215111536.316972-9-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Current layout support was initially written without modules support in
mind. When the requirement for module support rose, the existing base
was improved to adopt modularization support, but kind of a design flaw
was introduced. With the existing implementation, when a storage device
registers into NVMEM, the core tries to hook a layout (if any) and
populates its cells immediately. This means, if the hardware description
expects a layout to be hooked up, but no driver was provided for that,
the storage medium will fail to probe and try later from
scratch. Even if we consider that the hardware description shall be
correct, we could still probe the storage device (especially if it
contains the rootfs).
One way to overcome this situation is to consider the layouts as
devices, and leverage the native notifier mechanism. When a new NVMEM
device is registered, we can populate its nvmem-layout child, if any,
and wait for the matching to be done in order to get the cells (the
waiting can be easily done with the NVMEM notifiers). If the layout
driver is compiled as a module, it should automatically be loaded. This
way, there is no strong order to enforce, any NVMEM device creation
or NVMEM layout driver insertion will be observed as a new event which
may lead to the creation of additional cells, without disturbing the
probes with costly (and sometimes endless) deferrals.
In order to achieve that goal we create a new bus for the nvmem-layouts
with minimal logic to match nvmem-layout devices with nvmem-layout
drivers. All this infrastructure code is created in the layouts.c file.
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Tested-by: Rafał Miłecki <rafal@milecki.pl>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20231215111536.316972-7-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This hook is meant to be used by any provider and instantiating a layout
just for this is useless. Let's instead move this hook to the nvmem
device and add it to the config structure to be easily shared by the
providers.
While at moving this hook, rename it ->fixup_dt_cell_info() to clarify
its main intended purpose.
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20231215111536.316972-6-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The layout entry is not used and will anyway be made useless by the new
layout bus infrastructure coming next, so drop it. While at it, clarify
the kdoc entry.
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20231215111536.316972-5-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Before adding all the NVMEM layout bus infrastructure to the core, let's
move the main nvmem_device structure in an internal header, only
available to the core. This way all the additional code can be added in
a dedicated file in order to keep the current core file tidy.
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20231215111536.316972-4-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
nvmem-consumer.h is included by consumer devices, extracting data from
NVMEM devices whereas nvmem-provider.h is included by devices providing
NVMEM content.
The only users of of_nvmem_layout_get_container() outside of the core
are layout drivers, so better move its prototype to nvmem-provider.h.
While we do so, we also move the kdoc associated with the function to
the header rather than the .c file.
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20231215111536.316972-3-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Two series lived in parallel for some time, which led to this situation:
- The nvmem-layout container is used for dynamic layouts
- We now expect fixed layouts to also use the nvmem-layout container but
this does not require any additional driver, the support is built-in the
nvmem core.
Ensure we don't refuse to probe for wrong reasons.
Fixes: 27f699e578 ("nvmem: core: add support for fixed cells *layout*")
Cc: stable@vger.kernel.org
Reported-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Tested-by: Rafał Miłecki <rafal@milecki.pl>
Tested-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
Reviewed-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
Link: https://lore.kernel.org/r/20231124193814.360552-1-miquel.raynal@bootlin.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This reverts commit 517f14d9cf.
Config option "no_of_node" is no longer needed since adding a more
explicit and targeted option "add_legacy_fixed_of_cells".
That "no_of_node" config option was needed *earlier* to help mtd's case.
DT nodes of MTD partitions (that are also NVMEM devices) may contain
subnodes. Those SHOULD NOT be treated as NVMEM fixed cells.
To prevent NVMEM core code from parsing subnodes a "no_of_node" option
was added (and set to true in mtd) to make for_each_child_of_node() in
NVMEM a no-op. That was a bit hacky because it was messing with
"of_node" pointer to achieve some side-effect.
With the introduction of "add_legacy_fixed_of_cells" config option
things got more explicit. MTD subsystem simply tells NVMEM when to look
for fixed cells and there is no need to hack "of_node" pointer anymore.
Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20231023102759.31529-1-zajec5@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Binding for fixed NVMEM cells defined directly as NVMEM device subnodes
has been deprecated. It has been replaced by the "fixed-layout" NVMEM
layout binding.
New syntax is meant to be clearer and should help avoiding imprecise
bindings.
NVMEM subsystem already supports the new binding. It should be a good
idea to limit support for old syntax to existing drivers that actually
support & use it (we can't break backward compatibility!). That way we
additionally encourage new bindings & drivers to ignore deprecated
binding.
It wasn't clear (to me) if rtc and w1 code actually uses old syntax
fixed cells. I enabled them to don't risk any breakage.
Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
[for meson-{efuse,mx-efuse}.c]
Acked-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
[for mtk-efuse.c, nvmem/core.c, nvmem-provider.h]
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
[MT8192, MT8195 Chromebooks]
Tested-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
[for microchip-otpc.c]
Reviewed-by: Claudiu Beznea <claudiu.beznea@microchip.com>
[SAMA7G5-EK]
Tested-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Acked-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20231020105545.216052-3-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Tell listeners a new layout was introduced and is now available.
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20230823132744.350618-23-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Let's pack all the cells creation in one place, so they are all created
before we add the nvmem device.
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Michael Walle <michael@walle.cc>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20230823132744.350618-20-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The DT of_device.h and of_platform.h date back to the separate
of_platform_bus_type before it as merged into the regular platform bus.
As part of that merge prepping Arm DT support 13 years ago, they
"temporarily" include each other. They also include platform_device.h
and of.h. As a result, there's a pretty much random mix of those include
files used throughout the tree. In order to detangle these headers and
replace the implicit includes with struct declarations, users need to
explicitly include the correct includes.
Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20230823132744.350618-14-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This adds support for the "fixed-layout" NVMEM layout binding. It allows
defining NVMEM cells in a layout DT node named "nvmem-layout".
While NVMEM subsystem supports layout drivers it has been discussed that
"fixed-layout" may actually be supperted internally. It's because:
1. It's a very basic layout
2. It allows sharing code with legacy syntax parsing
3. It's safer for soc_device_match() due to -EPROBE_DEFER
4. This will make the syntax transition easier
Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Reviewed-by: Michael Walle <michael@walle.cc>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Message-ID: <20230611140330.154222-26-srinivas.kandagatla@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The summary of the changes for this pull requests is:
* Song Liu's new struct module_memory replacement
* Nick Alcock's MODULE_LICENSE() removal for non-modules
* My cleanups and enhancements to reduce the areas where we vmalloc
module memory for duplicates, and the respective debug code which
proves the remaining vmalloc pressure comes from userspace.
Most of the changes have been in linux-next for quite some time except
the minor fixes I made to check if a module was already loaded
prior to allocating the final module memory with vmalloc and the
respective debug code it introduces to help clarify the issue. Although
the functional change is small it is rather safe as it can only *help*
reduce vmalloc space for duplicates and is confirmed to fix a bootup
issue with over 400 CPUs with KASAN enabled. I don't expect stable
kernels to pick up that fix as the cleanups would have also had to have
been picked up. Folks on larger CPU systems with modules will want to
just upgrade if vmalloc space has been an issue on bootup.
Given the size of this request, here's some more elaborate details
on this pull request.
The functional change change in this pull request is the very first
patch from Song Liu which replaces the struct module_layout with a new
struct module memory. The old data structure tried to put together all
types of supported module memory types in one data structure, the new
one abstracts the differences in memory types in a module to allow each
one to provide their own set of details. This paves the way in the
future so we can deal with them in a cleaner way. If you look at changes
they also provide a nice cleanup of how we handle these different memory
areas in a module. This change has been in linux-next since before the
merge window opened for v6.3 so to provide more than a full kernel cycle
of testing. It's a good thing as quite a bit of fixes have been found
for it.
Jason Baron then made dynamic debug a first class citizen module user by
using module notifier callbacks to allocate / remove module specific
dynamic debug information.
Nick Alcock has done quite a bit of work cross-tree to remove module
license tags from things which cannot possibly be module at my request
so to:
a) help him with his longer term tooling goals which require a
deterministic evaluation if a piece a symbol code could ever be
part of a module or not. But quite recently it is has been made
clear that tooling is not the only one that would benefit.
Disambiguating symbols also helps efforts such as live patching,
kprobes and BPF, but for other reasons and R&D on this area
is active with no clear solution in sight.
b) help us inch closer to the now generally accepted long term goal
of automating all the MODULE_LICENSE() tags from SPDX license tags
In so far as a) is concerned, although module license tags are a no-op
for non-modules, tools which would want create a mapping of possible
modules can only rely on the module license tag after the commit
8b41fc4454 ("kbuild: create modules.builtin without Makefile.modbuiltin
or tristate.conf"). Nick has been working on this *for years* and
AFAICT I was the only one to suggest two alternatives to this approach
for tooling. The complexity in one of my suggested approaches lies in
that we'd need a possible-obj-m and a could-be-module which would check
if the object being built is part of any kconfig build which could ever
lead to it being part of a module, and if so define a new define
-DPOSSIBLE_MODULE [0]. A more obvious yet theoretical approach I've
suggested would be to have a tristate in kconfig imply the same new
-DPOSSIBLE_MODULE as well but that means getting kconfig symbol names
mapping to modules always, and I don't think that's the case today. I am
not aware of Nick or anyone exploring either of these options. Quite
recently Josh Poimboeuf has pointed out that live patching, kprobes and
BPF would benefit from resolving some part of the disambiguation as
well but for other reasons. The function granularity KASLR (fgkaslr)
patches were mentioned but Joe Lawrence has clarified this effort has
been dropped with no clear solution in sight [1].
In the meantime removing module license tags from code which could never
be modules is welcomed for both objectives mentioned above. Some
developers have also welcomed these changes as it has helped clarify
when a module was never possible and they forgot to clean this up,
and so you'll see quite a bit of Nick's patches in other pull
requests for this merge window. I just picked up the stragglers after
rc3. LWN has good coverage on the motivation behind this work [2] and
the typical cross-tree issues he ran into along the way. The only
concrete blocker issue he ran into was that we should not remove the
MODULE_LICENSE() tags from files which have no SPDX tags yet, even if
they can never be modules. Nick ended up giving up on his efforts due
to having to do this vetting and backlash he ran into from folks who
really did *not understand* the core of the issue nor were providing
any alternative / guidance. I've gone through his changes and dropped
the patches which dropped the module license tags where an SPDX
license tag was missing, it only consisted of 11 drivers. To see
if a pull request deals with a file which lacks SPDX tags you
can just use:
./scripts/spdxcheck.py -f \
$(git diff --name-only commid-id | xargs echo)
You'll see a core module file in this pull request for the above,
but that's not related to his changes. WE just need to add the SPDX
license tag for the kernel/module/kmod.c file in the future but
it demonstrates the effectiveness of the script.
Most of Nick's changes were spread out through different trees,
and I just picked up the slack after rc3 for the last kernel was out.
Those changes have been in linux-next for over two weeks.
The cleanups, debug code I added and final fix I added for modules
were motivated by David Hildenbrand's report of boot failing on
a systems with over 400 CPUs when KASAN was enabled due to running
out of virtual memory space. Although the functional change only
consists of 3 lines in the patch "module: avoid allocation if module is
already present and ready", proving that this was the best we can
do on the modules side took quite a bit of effort and new debug code.
The initial cleanups I did on the modules side of things has been
in linux-next since around rc3 of the last kernel, the actual final
fix for and debug code however have only been in linux-next for about a
week or so but I think it is worth getting that code in for this merge
window as it does help fix / prove / evaluate the issues reported
with larger number of CPUs. Userspace is not yet fixed as it is taking
a bit of time for folks to understand the crux of the issue and find a
proper resolution. Worst come to worst, I have a kludge-of-concept [3]
of how to make kernel_read*() calls for modules unique / converge them,
but I'm currently inclined to just see if userspace can fix this
instead.
[0] https://lore.kernel.org/all/Y/kXDqW+7d71C4wz@bombadil.infradead.org/
[1] https://lkml.kernel.org/r/025f2151-ce7c-5630-9b90-98742c97ac65@redhat.com
[2] https://lwn.net/Articles/927569/
[3] https://lkml.kernel.org/r/20230414052840.1994456-3-mcgrof@kernel.org
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Merge tag 'modules-6.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux
Pull module updates from Luis Chamberlain:
"The summary of the changes for this pull requests is:
- Song Liu's new struct module_memory replacement
- Nick Alcock's MODULE_LICENSE() removal for non-modules
- My cleanups and enhancements to reduce the areas where we vmalloc
module memory for duplicates, and the respective debug code which
proves the remaining vmalloc pressure comes from userspace.
Most of the changes have been in linux-next for quite some time except
the minor fixes I made to check if a module was already loaded prior
to allocating the final module memory with vmalloc and the respective
debug code it introduces to help clarify the issue. Although the
functional change is small it is rather safe as it can only *help*
reduce vmalloc space for duplicates and is confirmed to fix a bootup
issue with over 400 CPUs with KASAN enabled. I don't expect stable
kernels to pick up that fix as the cleanups would have also had to
have been picked up. Folks on larger CPU systems with modules will
want to just upgrade if vmalloc space has been an issue on bootup.
Given the size of this request, here's some more elaborate details:
The functional change change in this pull request is the very first
patch from Song Liu which replaces the 'struct module_layout' with a
new 'struct module_memory'. The old data structure tried to put
together all types of supported module memory types in one data
structure, the new one abstracts the differences in memory types in a
module to allow each one to provide their own set of details. This
paves the way in the future so we can deal with them in a cleaner way.
If you look at changes they also provide a nice cleanup of how we
handle these different memory areas in a module. This change has been
in linux-next since before the merge window opened for v6.3 so to
provide more than a full kernel cycle of testing. It's a good thing as
quite a bit of fixes have been found for it.
Jason Baron then made dynamic debug a first class citizen module user
by using module notifier callbacks to allocate / remove module
specific dynamic debug information.
Nick Alcock has done quite a bit of work cross-tree to remove module
license tags from things which cannot possibly be module at my request
so to:
a) help him with his longer term tooling goals which require a
deterministic evaluation if a piece a symbol code could ever be
part of a module or not. But quite recently it is has been made
clear that tooling is not the only one that would benefit.
Disambiguating symbols also helps efforts such as live patching,
kprobes and BPF, but for other reasons and R&D on this area is
active with no clear solution in sight.
b) help us inch closer to the now generally accepted long term goal
of automating all the MODULE_LICENSE() tags from SPDX license tags
In so far as a) is concerned, although module license tags are a no-op
for non-modules, tools which would want create a mapping of possible
modules can only rely on the module license tag after the commit
8b41fc4454 ("kbuild: create modules.builtin without
Makefile.modbuiltin or tristate.conf").
Nick has been working on this *for years* and AFAICT I was the only
one to suggest two alternatives to this approach for tooling. The
complexity in one of my suggested approaches lies in that we'd need a
possible-obj-m and a could-be-module which would check if the object
being built is part of any kconfig build which could ever lead to it
being part of a module, and if so define a new define
-DPOSSIBLE_MODULE [0].
A more obvious yet theoretical approach I've suggested would be to
have a tristate in kconfig imply the same new -DPOSSIBLE_MODULE as
well but that means getting kconfig symbol names mapping to modules
always, and I don't think that's the case today. I am not aware of
Nick or anyone exploring either of these options. Quite recently Josh
Poimboeuf has pointed out that live patching, kprobes and BPF would
benefit from resolving some part of the disambiguation as well but for
other reasons. The function granularity KASLR (fgkaslr) patches were
mentioned but Joe Lawrence has clarified this effort has been dropped
with no clear solution in sight [1].
In the meantime removing module license tags from code which could
never be modules is welcomed for both objectives mentioned above. Some
developers have also welcomed these changes as it has helped clarify
when a module was never possible and they forgot to clean this up, and
so you'll see quite a bit of Nick's patches in other pull requests for
this merge window. I just picked up the stragglers after rc3. LWN has
good coverage on the motivation behind this work [2] and the typical
cross-tree issues he ran into along the way. The only concrete blocker
issue he ran into was that we should not remove the MODULE_LICENSE()
tags from files which have no SPDX tags yet, even if they can never be
modules. Nick ended up giving up on his efforts due to having to do
this vetting and backlash he ran into from folks who really did *not
understand* the core of the issue nor were providing any alternative /
guidance. I've gone through his changes and dropped the patches which
dropped the module license tags where an SPDX license tag was missing,
it only consisted of 11 drivers. To see if a pull request deals with a
file which lacks SPDX tags you can just use:
./scripts/spdxcheck.py -f \
$(git diff --name-only commid-id | xargs echo)
You'll see a core module file in this pull request for the above, but
that's not related to his changes. WE just need to add the SPDX
license tag for the kernel/module/kmod.c file in the future but it
demonstrates the effectiveness of the script.
Most of Nick's changes were spread out through different trees, and I
just picked up the slack after rc3 for the last kernel was out. Those
changes have been in linux-next for over two weeks.
The cleanups, debug code I added and final fix I added for modules
were motivated by David Hildenbrand's report of boot failing on a
systems with over 400 CPUs when KASAN was enabled due to running out
of virtual memory space. Although the functional change only consists
of 3 lines in the patch "module: avoid allocation if module is already
present and ready", proving that this was the best we can do on the
modules side took quite a bit of effort and new debug code.
The initial cleanups I did on the modules side of things has been in
linux-next since around rc3 of the last kernel, the actual final fix
for and debug code however have only been in linux-next for about a
week or so but I think it is worth getting that code in for this merge
window as it does help fix / prove / evaluate the issues reported with
larger number of CPUs. Userspace is not yet fixed as it is taking a
bit of time for folks to understand the crux of the issue and find a
proper resolution. Worst come to worst, I have a kludge-of-concept [3]
of how to make kernel_read*() calls for modules unique / converge
them, but I'm currently inclined to just see if userspace can fix this
instead"
Link: https://lore.kernel.org/all/Y/kXDqW+7d71C4wz@bombadil.infradead.org/ [0]
Link: https://lkml.kernel.org/r/025f2151-ce7c-5630-9b90-98742c97ac65@redhat.com [1]
Link: https://lwn.net/Articles/927569/ [2]
Link: https://lkml.kernel.org/r/20230414052840.1994456-3-mcgrof@kernel.org [3]
* tag 'modules-6.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux: (121 commits)
module: add debugging auto-load duplicate module support
module: stats: fix invalid_mod_bytes typo
module: remove use of uninitialized variable len
module: fix building stats for 32-bit targets
module: stats: include uapi/linux/module.h
module: avoid allocation if module is already present and ready
module: add debug stats to help identify memory pressure
module: extract patient module check into helper
modules/kmod: replace implementation with a semaphore
Change DEFINE_SEMAPHORE() to take a number argument
module: fix kmemleak annotations for non init ELF sections
module: Ignore L0 and rename is_arm_mapping_symbol()
module: Move is_arm_mapping_symbol() to module_symbol.h
module: Sync code of is_arm_mapping_symbol()
scripts/gdb: use mem instead of core_layout to get the module address
interconnect: remove module-related code
interconnect: remove MODULE_LICENSE in non-modules
zswap: remove MODULE_LICENSE in non-modules
zpool: remove MODULE_LICENSE in non-modules
x86/mm/dump_pagetables: remove MODULE_LICENSE in non-modules
...
Since commit 8b41fc4454 ("kbuild: create modules.builtin without
Makefile.modbuiltin or tristate.conf"), MODULE_LICENSE declarations
are used to identify modules. As a consequence, uses of the macro
in non-modules will cause modprobe to misidentify their containing
object file as a module when it is not (false positives), and modprobe
might succeed rather than failing with a suitable error message.
So remove it in the files in this commit, none of which can be built as
modules.
Signed-off-by: Nick Alcock <nick.alcock@oracle.com>
Suggested-by: Luis Chamberlain <mcgrof@kernel.org>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: linux-modules@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: Hitomi Hasegawa <hasegawa-hitomi@fujitsu.com>
Cc: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Callback .read_post_process() is designed to modify raw cell content
before providing it to the consumer. So far we were dealing with
modifications that didn't affect cell size (length). In some cases
however cell content needs to be reformatted and resized.
It's required e.g. to provide properly formatted MAC address in case
it's stored in a non-binary format (e.g. using ASCII).
There were few discussions how to optimally handle that. Following
possible solutions were considered:
1. Allow .read_post_process() to realloc (resize) content buffer
2. Allow .read_post_process() to adjust (decrease) just buffer length
3. Register NVMEM cells using post-read sizes
The preferred solution was the last one. The problem is that simply
adjusting "bytes" in NVMEM providers would result in core code NOT
passing whole raw data to .read_post_process() callbacks. It means
callback functions couldn't do their job without somehow manually
reading original cell content on their own.
This patch deals with that by registering NVMEM cells with both lengths:
raw content one and post read one. It allows:
1. Core code to read whole raw cell content
2. Callbacks to return content they want
Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20230404172148.82422-35-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
It doesn't make any more sense to have a opaque pointer set up by the
nvmem device. Usually, the layout isn't associated with a particular
nvmem device. Instead, let the caller who set the post process callback
provide the priv pointer.
Signed-off-by: Michael Walle <michael@walle.cc>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20230404172148.82422-21-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There are no users anymore for the global cell_post_process callback
anymore. New users should use proper nvmem layouts.
Signed-off-by: Michael Walle <michael@walle.cc>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20230404172148.82422-20-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
