368 Commits

Author SHA1 Message Date
Linus Torvalds
4793dae01f Merge tag 'driver-core-7.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/driver-core/driver-core
Pull driver core updates from Danilo Krummrich:
 "debugfs:
   - Fix NULL pointer dereference in debugfs_create_str()
   - Fix misplaced EXPORT_SYMBOL_GPL for debugfs_create_str()
   - Fix soundwire debugfs NULL pointer dereference from uninitialized
     firmware_file

  device property:
   - Make fwnode flags modifications thread safe; widen the field to
     unsigned long and use set_bit() / clear_bit() based accessors
   - Document how to check for the property presence

  devres:
   - Separate struct devres_node from its "subclasses" (struct devres,
     struct devres_group); give struct devres_node its own release and
     free callbacks for per-type dispatch
   - Introduce struct devres_action for devres actions, avoiding the
     ARCH_DMA_MINALIGN alignment overhead of struct devres
   - Export struct devres_node and its init/add/remove/dbginfo
     primitives for use by Rust Devres<T>
   - Fix missing node debug info in devm_krealloc()
   - Use guard(spinlock_irqsave) where applicable; consolidate unlock
     paths in devres_release_group()

  driver_override:
   - Convert PCI, WMI, vdpa, s390/cio, s390/ap, and fsl-mc to the
     generic driver_override infrastructure, replacing per-bus
     driver_override strings, sysfs attributes, and match logic; fixes a
     potential UAF from unsynchronized access to driver_override in bus
     match() callbacks
   - Simplify __device_set_driver_override() logic

  kernfs:
   - Send IN_DELETE_SELF and IN_IGNORED inotify events on kernfs file
     and directory removal
   - Add corresponding selftests for memcg

  platform:
   - Allow attaching software nodes when creating platform devices via a
     new 'swnode' field in struct platform_device_info
   - Add kerneldoc for struct platform_device_info

  software node:
   - Move software node initialization from postcore_initcall() to
     driver_init(), making it available early in the boot process
   - Move kernel_kobj initialization (ksysfs_init) earlier to support
     the above
   - Remove software_node_exit(); dead code in a built-in unit

  SoC:
   - Introduce of_machine_read_compatible() and of_machine_read_model()
     OF helpers and export soc_attr_read_machine() to replace direct
     accesses to of_root from SoC drivers; also enables
     CONFIG_COMPILE_TEST coverage for these drivers

  sysfs:
   - Constify attribute group array pointers to
     'const struct attribute_group *const *' in sysfs functions,
     device_add_groups() / device_remove_groups(), and struct class

  Rust:
   - Devres:
      - Embed struct devres_node directly in Devres<T> instead of going
        through devm_add_action(), avoiding the extra allocation and the
        unnecessary ARCH_DMA_MINALIGN alignment

   - I/O:
      - Turn IoCapable from a marker trait into a functional trait
        carrying the raw I/O accessor implementation (io_read /
        io_write), providing working defaults for the per-type Io
        methods
      - Add RelaxedMmio wrapper type, making relaxed accessors usable in
        code generic over the Io trait
      - Remove overloaded per-type Io methods and per-backend macros
        from Mmio and PCI ConfigSpace

   - I/O (Register):
      - Add IoLoc trait and generic read/write/update methods to the Io
        trait, making I/O operations parameterizable by typed locations
      - Add register! macro for defining hardware register types with
        typed bitfield accessors backed by Bounded values; supports
        direct, relative, and array register addressing
      - Add write_reg() / try_write_reg() and LocatedRegister trait
      - Update PCI sample driver to demonstrate the register! macro

         Example:

         ```
             register! {
                 /// UART control register.
                 CTRL(u32) @ 0x18 {
                     /// Receiver enable.
                     19:19   rx_enable => bool;
                     /// Parity configuration.
                     14:13   parity ?=> Parity;
                 }

                 /// FIFO watermark and counter register.
                 WATER(u32) @ 0x2c {
                     /// Number of datawords in the receive FIFO.
                     26:24   rx_count;
                     /// RX interrupt threshold.
                     17:16   rx_water;
                 }
             }

             impl WATER {
                 fn rx_above_watermark(&self) -> bool {
                     self.rx_count() > self.rx_water()
                 }
             }

             fn init(bar: &pci::Bar<BAR0_SIZE>) {
                 let water = WATER::zeroed()
                     .with_const_rx_water::<1>(); // > 3 would not compile
                 bar.write_reg(water);

                 let ctrl = CTRL::zeroed()
                     .with_parity(Parity::Even)
                     .with_rx_enable(true);
                 bar.write_reg(ctrl);
             }

             fn handle_rx(bar: &pci::Bar<BAR0_SIZE>) {
                 if bar.read(WATER).rx_above_watermark() {
                     // drain the FIFO
                 }
             }

             fn set_parity(bar: &pci::Bar<BAR0_SIZE>, parity: Parity) {
                 bar.update(CTRL, |r| r.with_parity(parity));
             }
         ```

   - IRQ:
      - Move 'static bounds from where clauses to trait declarations for
        IRQ handler traits

   - Misc:
      - Enable the generic_arg_infer Rust feature
      - Extend Bounded with shift operations, single-bit bool
        conversion, and const get()

  Misc:
   - Make deferred_probe_timeout default a Kconfig option
   - Drop auxiliary_dev_pm_ops; the PM core falls back to driver PM
     callbacks when no bus type PM ops are set
   - Add conditional guard support for device_lock()
   - Add ksysfs.c to the DRIVER CORE MAINTAINERS entry
   - Fix kernel-doc warnings in base.h
   - Fix stale reference to memory_block_add_nid() in documentation"

* tag 'driver-core-7.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/driver-core/driver-core: (67 commits)
  bus: fsl-mc: use generic driver_override infrastructure
  s390/ap: use generic driver_override infrastructure
  s390/cio: use generic driver_override infrastructure
  vdpa: use generic driver_override infrastructure
  platform/wmi: use generic driver_override infrastructure
  PCI: use generic driver_override infrastructure
  driver core: make software nodes available earlier
  software node: remove software_node_exit()
  kernel: ksysfs: initialize kernel_kobj earlier
  MAINTAINERS: add ksysfs.c to the DRIVER CORE entry
  drivers/base/memory: fix stale reference to memory_block_add_nid()
  device property: Document how to check for the property presence
  soundwire: debugfs: initialize firmware_file to empty string
  debugfs: fix placement of EXPORT_SYMBOL_GPL for debugfs_create_str()
  debugfs: check for NULL pointer in debugfs_create_str()
  driver core: Make deferred_probe_timeout default a Kconfig option
  driver core: simplify __device_set_driver_override() clearing logic
  driver core: auxiliary bus: Drop auxiliary_dev_pm_ops
  device property: Make modifications of fwnode "flags" thread safe
  rust: devres: embed struct devres_node directly
  ...
2026-04-13 19:03:11 -07:00
Miguel Ojeda
d1aa40daa7 rust: kbuild: remove feature(...)s that are now stable
Now that the Rust minimum version is 1.85.0, there is no need to enable
certain features that are stable.

Thus clean them up.

Reviewed-by: Tamir Duberstein <tamird@kernel.org>
Reviewed-by: Gary Guo <gary@garyguo.net>
Link: https://patch.msgid.link/20260405235309.418950-13-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2026-04-07 10:00:24 +02:00
Alice Ryhl
7e9535ebd0 rust: support overriding crate_name
Currently you cannot filter out the crate-name argument
RUSTFLAGS_REMOVE_stem.o because the Rust filter-out invocation does not
include that particular argument. Since --crate-name is an argument that
can't be passed multiple times, this means that it's currently not
possible to override the crate name. Thus, remove the --crate-name
argument for drivers. This allows them to override the crate name using
the #![crate_name] annotation.

This affects symbol names, but has no effect on the filenames of object
files and other things generated by the build, as we always use --emit
with a fixed output filename.

The --crate-name argument is kept for the crates under rust/ for
simplicity and to avoid changing many of them by adding #![crate_name].

The rust analyzer script is updated to use rustc to obtain the crate
name of the driver crates, which picks up the right name whether it is
configured via #![crate_name] or not. For readability, the logic to
invoke 'rustc' is extracted to its own function.

Note that the crate name in the python script is not actually that
important - the only place where the name actually affects anything is
in the 'deps' array which specifies an index and name for each
dependency, and determines what that dependency is called in *this*
crate. (The same crate may be called different things in each
dependency.) Since driver crates are leaf crates, this doesn't apply and
the rustc invocation only affects the 'display_name' parameter.

Acked-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Jesung Yang <y.jems.n@gmail.com>
Acked-by: Tamir Duberstein <tamird@kernel.org>
Link: https://patch.msgid.link/20260402-binder-crate-name-v4-1-ec3919b87909@google.com
[ Applied Python type hints. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2026-04-03 11:57:35 +02:00
Gary Guo
3a2486cc1d kbuild: rust: provide an option to inline C helpers into Rust
A new experimental Kconfig option, `RUST_INLINE_HELPERS` is added to
allow C helpers (which were created to allow Rust to call into
inline/macro C functions without having to re-implement the logic in
Rust) to be inlined into Rust crates without performing global LTO.

If the option is enabled, the following is performed:
* For helpers, instead of compiling them to an object file to be linked
  into vmlinux, they're compiled to LLVM IR bitcode. Two versions are
  generated: one for built-in code (`helpers.bc`) and one for modules
  (`helpers_module.bc`, with -DMODULE defined). This ensures that C
  macros/inlines that behave differently for modules (e.g. static calls)
  function correctly when inlined.
* When a Rust crate or object is compiled, instead of generating an
  object file, LLVM bitcode is generated.
* llvm-link is invoked with --internalize to combine the helper bitcode
  with the crate bitcode. This step is similar to LTO, but this is much
  faster since it only needs to inline the helpers.
* clang is invoked to turn the combined bitcode into a final object file.
* Since clang may produce LLVM bitcode when LTO is enabled, and objtool
  requires ELF input, $(cmd_ld_single) is invoked to ensure the object
  is converted to ELF before objtool runs.

The --internalize flag tells llvm-link to treat all symbols in
helpers.bc using `internal` linkage [1]. This matches the behavior of
`clang` on `static inline` functions, and avoids exporting the symbol
from the object file.

To ensure that RUST_INLINE_HELPERS is not incompatible with BTF, we pass
the -g0 flag when building helpers. See commit 5daa0c35a1 ("rust:
Disallow BTF generation with Rust + LTO") for details.

We have an intended triple mismatch of `aarch64-unknown-none` vs
`aarch64-unknown-linux-gnu`, so we pass --suppress-warnings to llvm-link
to suppress it.

I considered adding some sort of check that KBUILD_MODNAME is not
present in helpers_module.bc, but this is actually not so easy to carry
out because .bc files store strings in a weird binary format, so you
cannot just grep it for a string to check whether it ended up using
KBUILD_MODNAME anywhere.

[ Andreas writes:

    For the rnull driver, enabling helper inlining with this patch
    gives an average speedup of 2% over the set of 120 workloads that
    we publish on [2].

    Link: https://rust-for-linux.com/null-block-driver [2]

  This series also uncovered a pre-existing UB instance thanks to an
  `objtool` warning which I noticed while testing the series (details
  in the mailing list).

      - Miguel ]

Link: https://github.com/llvm/llvm-project/pull/170397 [1]
Co-developed-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Co-developed-by: Matthew Maurer <mmaurer@google.com>
Signed-off-by: Matthew Maurer <mmaurer@google.com>
Signed-off-by: Gary Guo <gary@garyguo.net>
Co-developed-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Andreas Hindborg <a.hindborg@kernel.org>
Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org>
Link: https://patch.msgid.link/20260203-inline-helpers-v2-3-beb8547a03c9@google.com
[ Some changes, apart from the rebase:

  - Added "(EXPERIMENTAL)" to Kconfig as the commit mentions.

  - Added `depends on ARM64 || X86_64` and `!UML` for now, since this is
    experimental, other architectures may require other changes (e.g.
    the issues I mentioned in the mailing list for ARM and UML) and they
    are not really tested so far. So let arch maintainers pick this up
    if they think it is worth it.

  - Gated the `cmd_ld_single` step also into the new mode, which also
    means that any possible future `objcopy` step is done after the
    translation, as expected.

  - Added `.gitignore` for `.bc` with exception for existing script.

  - Added `part-of-*` for helpers bitcode files as discussed, and
    dropped `$(if $(filter %_module.bc,$@),-DMODULE)` since `-DMODULE`
    is already there (would be duplicated otherwise).

  - Moved `LLVM_LINK` to keep binutils list alphabetized.

  - Fixed typo in title.

  - Dropped second `cmd_ld_single` commit message paragraph.

      - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2026-03-30 02:03:52 +02:00
Gary Guo
560a7a9b92 rust: add const_assert! macro
The macro is a more powerful version of `static_assert!` for use inside
function contexts. This is powered by inline consts, so enable the feature
for old compiler versions that does not have it stably.

While it is possible already to write `const { assert!(...) }`, this
provides a short hand that is more uniform with other assertions. It also
formats nicer with rustfmt where it will not be formatted into multiple
lines.

Two users that would route via the Rust tree are converted.

Reviewed-by: Yury Norov <ynorov@nvidia.com>
Signed-off-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Danilo Krummrich <dakr@kernel.org>
Link: https://patch.msgid.link/20260319121653.2975748-3-gary@kernel.org
[ Rebased. Fixed period typo. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2026-03-30 02:03:49 +02:00
Alexandre Courbot
3cc319d5f4 rust: enable the generic_arg_infer feature
This feature is stable since 1.89, and used in subsequent patches.

Reviewed-by: Gary Guo <gary@garyguo.net>
Tested-by: Dirk Behme <dirk.behme@de.bosch.com>
Acked-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Link: https://patch.msgid.link/20260314-register-v9-1-86805b2f7e9d@nvidia.com
[ Resolve merge conflict. - Danilo ]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2026-03-17 20:03:45 +01:00
Gary Guo
f41941aab3 rust: ptr: add projection infrastructure
Add a generic infrastructure for performing field and index projections on
raw pointers. This will form the basis of performing I/O projections.

Pointers manipulations are intentionally using the safe wrapping variants
instead of the unsafe variants, as the latter requires pointers to be
inside an allocation which is not necessarily true for I/O pointers.

This projection macro protects against rogue `Deref` implementation, which
can causes the projected pointer to be outside the bounds of starting
pointer. This is extremely unlikely and Rust has a lint to catch this, but
is unsoundness regardless. The protection works by inducing type inference
ambiguity when `Deref` is implemented.

This projection macro also stops projecting into unaligned fields (i.e.
fields of `#[repr(packed)]` structs), as misaligned pointers require
special handling. This is implemented by attempting to create reference to
projected field inside a `if false` block. Despite being unreachable, Rust
still checks that they're not unaligned fields.

The projection macro supports both fallible and infallible index
projections. These are described in detail inside the documentation.

Signed-off-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Benno Lossin <lossin@kernel.org>
Acked-by: Miguel Ojeda <ojeda@kernel.org>
Link: https://patch.msgid.link/20260302164239.284084-3-gary@kernel.org
[ * Add intro-doc links where possible,
  * Fix typos and slightly improve wording, e.g. "as documentation
    describes" -> "as the documentation of [`Self::proj`] describes",
  * Add an empty line between regular and safety comments, before
    examples, and between logically independent comments,
  * Capitalize various safety comments.

    - Danilo ]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2026-03-07 23:06:17 +01:00
Linus Torvalds
44f4119c7c Merge tag 'kbuild-fixes-6.19-3' of git://git.kernel.org/pub/scm/linux/kernel/git/kbuild/linux
Pull Kbuild fixes from Nicolas Schier:

 - Generate rpm-pkg debuginfo package manually, allowing signed kernel
   modules in rpm package, again

 - Fix permissions of modules.builtin.modinfo

 - Do not run kernel-doc when building external modules

* tag 'kbuild-fixes-6.19-3' of git://git.kernel.org/pub/scm/linux/kernel/git/kbuild/linux:
  kbuild: Do not run kernel-doc when building external modules
  kbuild: Fix permissions of modules.builtin.modinfo
  kbuild: rpm-pkg: Generate debuginfo package manually
2026-01-31 08:21:32 -08:00
Nathan Chancellor
8e24994872 kbuild: Do not run kernel-doc when building external modules
After commit 778b8ebe51 ("docs: Move the python libraries to
tools/lib/python"), building an external module with any value of W=
against the output of install-extmod-build fails with:

  $ make -C /usr/lib/modules/6.19.0-rc7-00108-g4d310797262f/build M=$PWD W=1
  make: Entering directory '/usr/lib/modules/6.19.0-rc7-00108-g4d310797262f/build'
  make[1]: Entering directory '...'
    CC [M] ...
  Traceback (most recent call last):
    File "/usr/lib/modules/6.19.0-rc7-00108-g4d310797262f/build/scripts/kernel-doc.py", line 339, in <module>
      main()
      ~~~~^^
    File "/usr/lib/modules/6.19.0-rc7-00108-g4d310797262f/build/scripts/kernel-doc.py", line 295, in main
      from kdoc.kdoc_files import KernelFiles             # pylint: disable=C0415
      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  ModuleNotFoundError: No module named 'kdoc'

scripts/lib was included in the build directory from find_in_scripts but
after the move to tools/lib/python, it is no longer included, breaking
kernel-doc.py.

Commit eba6ffd126 ("docs: kdoc: move kernel-doc to tools/docs") breaks
this even further by moving kernel-doc outside of scripts as well, so it
cannot be found when called by cmd_checkdoc.

  $ make -C /usr/lib/modules/6.19.0-rc7-next-20260130/build M=$PWD W=1
  make: Entering directory '/usr/lib/modules/6.19.0-rc7-next-20260130/build'
  make[1]: Entering directory '...'
    CC [M]  ...
  python3: can't open file '/usr/lib/modules/6.19.0-rc7-next-20260130/build/tools/docs/kernel-doc': [Errno 2] No such file or directory

While kernel-doc could be useful for external modules, it is more useful
for in-tree documentation that will be build and included in htmldocs.
Rather than including it in install-extmod-build, just skip running
kernel-doc for the external module build.

Cc: stable@vger.kernel.org
Fixes: 778b8ebe51 ("docs: Move the python libraries to tools/lib/python")
Reported-by: Rong Zhang <i@rong.moe>
Closes: https://lore.kernel.org/20260129175321.415295-1-i@rong.moe/
Reviewed-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Link: https://patch.msgid.link/20260130-kbuild-skip-kernel-doc-extmod-v1-1-58443d60131a@kernel.org
Reviewed-by: Nicolas Schier <nsc@kernel.org>
Signed-off-by: Nicolas Schier <nsc@kernel.org>
2026-01-31 16:12:01 +01:00
Miguel Ojeda
af20ae33e7 rust: kbuild: give --config-path to rustfmt in .rsi target
`rustfmt` is configured via the `.rustfmt.toml` file in the source tree,
and we apply `rustfmt` to the macro expanded sources generated by the
`.rsi` target.

However, under an `O=` pointing to an external folder (i.e. not just
a subdir), `rustfmt` will not find the file when checking the parent
folders. Since the edition is configured in this file, this can lead to
errors when it encounters newer syntax, e.g.

    error: expected one of `!`, `.`, `::`, `;`, `?`, `where`, `{`, or an operator, found `"rust_minimal"`
      --> samples/rust/rust_minimal.rsi:29:49
       |
    28 | impl ::kernel::ModuleMetadata for RustMinimal {
       |                                               - while parsing this item list starting here
    29 |     const NAME: &'static ::kernel::str::CStr = c"rust_minimal";
       |                                                 ^^^^^^^^^^^^^^ expected one of 8 possible tokens
    30 | }
       | - the item list ends here
       |
       = note: you may be trying to write a c-string literal
       = note: c-string literals require Rust 2021 or later
       = help: pass `--edition 2024` to `rustc`
       = note: for more on editions, read https://doc.rust-lang.org/edition-guide

A workaround is to use `RUSTFMT=n`, which is documented in the `Makefile`
help for cases where macro expanded source may happen to break `rustfmt`
for other reasons, but this is not one of those cases.

One solution would be to pass `--edition`, but we want `rustfmt` to
use the entire configuration, even if currently we essentially use the
default configuration.

Thus explicitly give the path to the config file to `rustfmt` instead.

Reported-by: Alice Ryhl <aliceryhl@google.com>
Fixes: 2f7ab1267d ("Kbuild: add Rust support")
Cc: stable@vger.kernel.org
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Gary Guo <gary@garyguo.net>
Link: https://patch.msgid.link/20260115183832.46595-1-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2026-01-18 20:24:15 +01:00
Thomas De Schampheleire
b08fc4d0ec kbuild: fix compilation of dtb specified on command-line without make rule
Since commit e7e2941300 ("kbuild: split device tree build rules into
scripts/Makefile.dtbs"), it is no longer possible to compile a device tree
blob that is not specified in a make rule
like:
    dtb-$(CONFIG_FOO) += foo.dtb

Before the mentioned commit, one could copy a dts file to e.g.
arch/arm64/boot/dts/ (or a new subdirectory) and then convert it to a dtb
file using:
    make ARCH=arm64 foo.dtb

In this scenario, both 'dtb-y' and 'dtb-' are empty, and the inclusion of
scripts/Makefile.dtbs relies on 'targets' to contain the MAKECMDGOALS. The
value of 'targets', however, is only final later in the code.

Move the conditional include of scripts/Makefile.dtbs down to where the
value of 'targets' is final. Since Makefile.dtbs updates 'always-y' which is
used as a prerequisite in the build rule, the build rule also needs to move
down.

Fixes: e7e2941300 ("kbuild: split device tree build rules into scripts/Makefile.dtbs")
Signed-off-by: Thomas De Schampheleire <thomas.de_schampheleire@nokia.com>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Acked-by: Rob Herring (Arm) <robh@kernel.org>
Link: https://patch.msgid.link/20251126100017.1162330-1-thomas.de_schampheleire@nokia.com
Signed-off-by: Nicolas Schier <nsc@kernel.org>
2025-12-27 20:48:01 +01:00
Jean Delvare
002621a4df kbuild: Let kernel-doc.py use PYTHON3 override
It is possible to force a specific version of python to be used when
building the kernel by passing PYTHON3= on the make command line.
However kernel-doc.py is currently called with python3 hard-coded and
thus ignores this setting.

Use $(PYTHON3) to run $(KERNELDOC) so that the desired version of
python is used.

Signed-off-by: Jean Delvare <jdelvare@suse.de>
Reviewed-by: Nicolas Schier <nsc@kernel.org>
Reviewed-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://patch.msgid.link/20251107192933.2bfe9e57@endymion
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
2025-11-08 19:42:22 -07:00
Linus Torvalds
352af6a011 Merge tag 'rust-6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux
Pull Rust updates from Miguel Ojeda:
 "Toolchain and infrastructure:

   - Enable a set of Clippy lints: 'ptr_as_ptr', 'ptr_cast_constness',
     'as_ptr_cast_mut', 'as_underscore', 'cast_lossless' and
     'ref_as_ptr'

     These are intended to avoid type casts with the 'as' operator,
     which are quite powerful, into restricted variants that are less
     powerful and thus should help to avoid mistakes

   - Remove the 'author' key now that most instances were moved to the
     plural one in the previous cycle

  'kernel' crate:

   - New 'bug' module: add 'warn_on!' macro which reuses the existing
     'BUG'/'WARN' infrastructure, i.e. it respects the usual sysctls and
     kernel parameters:

         warn_on!(value == 42);

     To avoid duplicating the assembly code, the same strategy is
     followed as for the static branch code in order to share the
     assembly between both C and Rust

     This required a few rearrangements on C arch headers -- the
     existing C macros should still generate the same outputs, thus no
     functional change expected there

   - 'workqueue' module: add delayed work items, including a
     'DelayedWork' struct, a 'impl_has_delayed_work!' macro and an
     'enqueue_delayed' method, e.g.:

         /// Enqueue the struct for execution on the system workqueue,
         /// where its value will be printed 42 jiffies later.
         fn print_later(value: Arc<MyStruct>) {
             let _ = workqueue::system().enqueue_delayed(value, 42);
         }

   - New 'bits' module: add support for 'bit' and 'genmask' functions,
     with runtime- and compile-time variants, e.g.:

         static_assert!(0b00010000 == bit_u8(4));
         static_assert!(0b00011110 == genmask_u8(1..=4));

         assert!(checked_bit_u32(u32::BITS).is_none());

   - 'uaccess' module: add 'UserSliceReader::strcpy_into_buf', which
     reads NUL-terminated strings from userspace into a '&CStr'

     Introduce 'UserPtr' newtype, similar in purpose to '__user' in C,
     to minimize mistakes handling userspace pointers, including mixing
     them up with integers and leaking them via the 'Debug' trait. Add
     it to the prelude, too

   - Start preparations for the replacement of our custom 'CStr' type
     with the analogous type in the 'core' standard library. This will
     take place across several cycles to make it easier. For this one,
     it includes a new 'fmt' module, using upstream method names and
     some other cleanups

     Replace 'fmt!' with a re-export, which helps Clippy lint properly,
     and clean up the found 'uninlined-format-args' instances

   - 'dma' module:

      - Clarify wording and be consistent in 'coherent' nomenclature

      - Convert the 'read!()' and 'write!()' macros to return a 'Result'

      - Add 'as_slice()', 'write()' methods in 'CoherentAllocation'

      - Expose 'count()' and 'size()' in 'CoherentAllocation' and add
        the corresponding type invariants

      - Implement 'CoherentAllocation::dma_handle_with_offset()'

   - 'time' module:

      - Make 'Instant' generic over clock source. This allows the
        compiler to assert that arithmetic expressions involving the
        'Instant' use 'Instants' based on the same clock source

      - Make 'HrTimer' generic over the timer mode. 'HrTimer' timers
        take a 'Duration' or an 'Instant' when setting the expiry time,
        depending on the timer mode. With this change, the compiler can
        check the type matches the timer mode

      - Add an abstraction for 'fsleep'. 'fsleep' is a flexible sleep
        function that will select an appropriate sleep method depending
        on the requested sleep time

      - Avoid 64-bit divisions on 32-bit hardware when calculating
        timestamps

      - Seal the 'HrTimerMode' trait. This prevents users of the
        'HrTimerMode' from implementing the trait on their own types

      - Pass the correct timer mode ID to 'hrtimer_start_range_ns()'

   - 'list' module: remove 'OFFSET' constants, allowing to remove
     pointer arithmetic; now 'impl_list_item!' invokes
     'impl_has_list_links!' or 'impl_has_list_links_self_ptr!'. Other
     simplifications too

   - 'types' module: remove 'ForeignOwnable::PointedTo' in favor of a
     constant, which avoids exposing the type of the opaque pointer, and
     require 'into_foreign' to return non-null

     Remove the 'Either<L, R>' type as well. It is unused, and we want
     to encourage the use of custom enums for concrete use cases

   - 'sync' module: implement 'Borrow' and 'BorrowMut' for 'Arc' types
     to allow them to be used in generic APIs

   - 'alloc' module: implement 'Borrow' and 'BorrowMut' for 'Box<T, A>';
     and 'Borrow', 'BorrowMut' and 'Default' for 'Vec<T, A>'

   - 'Opaque' type: add 'cast_from' method to perform a restricted cast
     that cannot change the inner type and use it in callers of
     'container_of!'. Rename 'raw_get' to 'cast_into' to match it

   - 'rbtree' module: add 'is_empty' method

   - 'sync' module: new 'aref' submodule to hold 'AlwaysRefCounted' and
     'ARef', which are moved from the too general 'types' module which
     we want to reduce or eventually remove. Also fix a safety comment
     in 'static_lock_class'

  'pin-init' crate:

   - Add 'impl<T, E> [Pin]Init<T, E> for Result<T, E>', so results are
     now (pin-)initializers

   - Add 'Zeroable::init_zeroed()' that delegates to 'init_zeroed()'

   - New 'zeroed()', a safe version of 'mem::zeroed()' and also provide
     it via 'Zeroable::zeroed()'

   - Implement 'Zeroable' for 'Option<&T>', 'Option<&mut T>' and for
     'Option<[unsafe] [extern "abi"] fn(...args...) -> ret>' for
     '"Rust"' and '"C"' ABIs and up to 20 arguments

   - Changed blanket impls of 'Init' and 'PinInit' from 'impl<T, E>
     [Pin]Init<T, E> for T' to 'impl<T> [Pin]Init<T> for T'

   - Renamed 'zeroed()' to 'init_zeroed()'

   - Upstream dev news: improve CI more to deny warnings, use
     '--all-targets'. Check the synchronization status of the two
     '-next' branches in upstream and the kernel

  MAINTAINERS:

   - Add Vlastimil Babka, Liam R. Howlett, Uladzislau Rezki and Lorenzo
     Stoakes as reviewers (thanks everyone)

  And a few other cleanups and improvements"

* tag 'rust-6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux: (76 commits)
  rust: Add warn_on macro
  arm64/bug: Add ARCH_WARN_ASM macro for BUG/WARN asm code sharing with Rust
  riscv/bug: Add ARCH_WARN_ASM macro for BUG/WARN asm code sharing with Rust
  x86/bug: Add ARCH_WARN_ASM macro for BUG/WARN asm code sharing with Rust
  rust: kernel: move ARef and AlwaysRefCounted to sync::aref
  rust: sync: fix safety comment for `static_lock_class`
  rust: types: remove `Either<L, R>`
  rust: kernel: use `core::ffi::CStr` method names
  rust: str: add `CStr` methods matching `core::ffi::CStr`
  rust: str: remove unnecessary qualification
  rust: use `kernel::{fmt,prelude::fmt!}`
  rust: kernel: add `fmt` module
  rust: kernel: remove `fmt!`, fix clippy::uninlined-format-args
  scripts: rust: emit path candidates in panic message
  scripts: rust: replace length checks with match
  rust: list: remove nonexistent generic parameter in link
  rust: bits: add support for bits/genmask macros
  rust: list: remove OFFSET constants
  rust: list: add `impl_list_item!` examples
  rust: list: use fully qualified path
  ...
2025-08-03 13:49:10 -07:00
Tamir Duberstein
5d840b4c49 rust: list: add impl_list_item! examples
There's a comprehensive example in `rust/kernel/list.rs` but it doesn't
exercise the `using ListLinksSelfPtr` variant nor the generic cases. Add
that here. Generalize `impl_has_list_links_self_ptr` to handle nested
fields in the same manner as `impl_has_list_links`.

Tested-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: Tamir Duberstein <tamird@gmail.com>
Link: https://lore.kernel.org/r/20250709-list-no-offset-v4-5-a429e75840a9@gmail.com
[ Fixed Rust < 1.82 build by enabling the `offset_of_nested`
  feature. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-07-19 23:18:18 +02:00
Miguel Ojeda
7498159226 rust: use #[used(compiler)] to fix build and modpost with Rust >= 1.89.0
Starting with Rust 1.89.0 (expected 2025-08-07), the Rust compiler fails
to build the `rusttest` target due to undefined references such as:

    kernel...-cgu.0:(.text....+0x116): undefined reference to
    `rust_helper_kunit_get_current_test'

Moreover, tooling like `modpost` gets confused:

    WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/gpu/drm/nova/nova.o
    ERROR: modpost: missing MODULE_LICENSE() in drivers/gpu/nova-core/nova_core.o

The reason behind both issues is that the Rust compiler will now [1]
treat `#[used]` as `#[used(linker)]` instead of `#[used(compiler)]`
for our targets. This means that the retain section flag (`R`,
`SHF_GNU_RETAIN`) will be used and that they will be marked as `unique`
too, with different IDs. In turn, that means we end up with undefined
references that did not get discarded in `rusttest` and that multiple
`.modinfo` sections are generated, which confuse tooling like `modpost`
because they only expect one.

Thus start using `#[used(compiler)]` to keep the previous behavior
and to be explicit about what we want. Sadly, it is an unstable feature
(`used_with_arg`) [2] -- we will talk to upstream Rust about it. The good
news is that it has been available for a long time (Rust >= 1.60) [3].

The changes should also be fine for previous Rust versions, since they
behave the same way as before [4].

Alternatively, we could use `#[no_mangle]` or `#[export_name = ...]`
since those still behave like `#[used(compiler)]`, but of course it is
not really what we want to express, and it requires other changes to
avoid symbol conflicts.

Cc: David Wood <david@davidtw.co>
Cc: Wesley Wiser <wwiser@gmail.com>
Cc: stable@vger.kernel.org # Needed in 6.12.y and later (Rust is pinned in older LTSs).
Link: https://github.com/rust-lang/rust/pull/140872 [1]
Link: https://github.com/rust-lang/rust/issues/93798 [2]
Link: https://github.com/rust-lang/rust/pull/91504 [3]
Link: https://godbolt.org/z/sxzWTMfzW [4]
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Acked-by: Björn Roy Baron <bjorn3_gh@protonmail.com>
Link: https://lore.kernel.org/r/20250712160103.1244945-3-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-07-14 23:30:44 +02:00
Linus Torvalds
8630c59e99 Merge tag 'kbuild-v6.16' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild
Pull Kbuild updates from Masahiro Yamada:

 - Add support for the EXPORT_SYMBOL_GPL_FOR_MODULES() macro, which
   exports a symbol only to specified modules

 - Improve ABI handling in gendwarfksyms

 - Forcibly link lib-y objects to vmlinux even if CONFIG_MODULES=n

 - Add checkers for redundant or missing <linux/export.h> inclusion

 - Deprecate the extra-y syntax

 - Fix a genksyms bug when including enum constants from *.symref files

* tag 'kbuild-v6.16' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (28 commits)
  genksyms: Fix enum consts from a reference affecting new values
  arch: use always-$(KBUILD_BUILTIN) for vmlinux.lds
  kbuild: set y instead of 1 to KBUILD_{BUILTIN,MODULES}
  efi/libstub: use 'targets' instead of extra-y in Makefile
  module: make __mod_device_table__* symbols static
  scripts/misc-check: check unnecessary #include <linux/export.h> when W=1
  scripts/misc-check: check missing #include <linux/export.h> when W=1
  scripts/misc-check: add double-quotes to satisfy shellcheck
  kbuild: move W=1 check for scripts/misc-check to top-level Makefile
  scripts/tags.sh: allow to use alternative ctags implementation
  kconfig: introduce menu type enum
  docs: symbol-namespaces: fix reST warning with literal block
  kbuild: link lib-y objects to vmlinux forcibly even when CONFIG_MODULES=n
  tinyconfig: enable CONFIG_LD_DEAD_CODE_DATA_ELIMINATION
  docs/core-api/symbol-namespaces: drop table of contents and section numbering
  modpost: check forbidden MODULE_IMPORT_NS("module:") at compile time
  kbuild: move kbuild syntax processing to scripts/Makefile.build
  Makefile: remove dependency on archscripts for header installation
  Documentation/kbuild: Add new gendwarfksyms kABI rules
  Documentation/kbuild: Drop section numbers
  ...
2025-06-07 10:05:35 -07:00
Linus Torvalds
ec7714e494 Merge tag 'rust-6.16' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux
Pull Rust updates from Miguel Ojeda:
 "Toolchain and infrastructure:

   - KUnit '#[test]'s:

      - Support KUnit-mapped 'assert!' macros.

        The support that landed last cycle was very basic, and the
        'assert!' macros panicked since they were the standard library
        ones. Now, they are mapped to the KUnit ones in a similar way to
        how is done for doctests, reusing the infrastructure there.

        With this, a failing test like:

            #[test]
            fn my_first_test() {
                assert_eq!(42, 43);
            }

        will report:

            # my_first_test: ASSERTION FAILED at rust/kernel/lib.rs:251
            Expected 42 == 43 to be true, but is false
            # my_first_test.speed: normal
            not ok 1 my_first_test

      - Support tests with checked 'Result' return types.

        The return value of test functions that return a 'Result' will
        be checked, thus one can now easily catch errors when e.g. using
        the '?' operator in tests.

        With this, a failing test like:

            #[test]
            fn my_test() -> Result {
                f()?;
                Ok(())
            }

        will report:

            # my_test: ASSERTION FAILED at rust/kernel/lib.rs:321
            Expected is_test_result_ok(my_test()) to be true, but is false
            # my_test.speed: normal
            not ok 1 my_test

      - Add 'kunit_tests' to the prelude.

   - Clarify the remaining language unstable features in use.

   - Compile 'core' with edition 2024 for Rust >= 1.87.

   - Workaround 'bindgen' issue with forward references to 'enum' types.

   - objtool: relax slice condition to cover more 'noreturn' functions.

   - Use absolute paths in macros referencing 'core' and 'kernel'
     crates.

   - Skip '-mno-fdpic' flag for bindgen in GCC 32-bit arm builds.

   - Clean some 'doc_markdown' lint hits -- we may enable it later on.

  'kernel' crate:

   - 'alloc' module:

      - 'Box': support for type coercion, e.g. 'Box<T>' to 'Box<dyn U>'
        if 'T' implements 'U'.

      - 'Vec': implement new methods (prerequisites for nova-core and
        binder): 'truncate', 'resize', 'clear', 'pop',
        'push_within_capacity' (with new error type 'PushError'),
        'drain_all', 'retain', 'remove' (with new error type
        'RemoveError'), insert_within_capacity' (with new error type
        'InsertError').

        In addition, simplify 'push' using 'spare_capacity_mut', split
        'set_len' into 'inc_len' and 'dec_len', add type invariant 'len
        <= capacity' and simplify 'truncate' using 'dec_len'.

   - 'time' module:

      - Morph the Rust hrtimer subsystem into the Rust timekeeping
        subsystem, covering delay, sleep, timekeeping, timers. This new
        subsystem has all the relevant timekeeping C maintainers listed
        in the entry.

      - Replace 'Ktime' with 'Delta' and 'Instant' types to represent a
        duration of time and a point in time.

      - Temporarily add 'Ktime' to 'hrtimer' module to allow 'hrtimer'
        to delay converting to 'Instant' and 'Delta'.

   - 'xarray' module:

      - Add a Rust abstraction for the 'xarray' data structure. This
        abstraction allows Rust code to leverage the 'xarray' to store
        types that implement 'ForeignOwnable'. This support is a
        dependency for memory backing feature of the Rust null block
        driver, which is waiting to be merged.

      - Set up an entry in 'MAINTAINERS' for the XArray Rust support.
        Patches will go to the new Rust XArray tree and then via the
        Rust subsystem tree for now.

      - Allow 'ForeignOwnable' to carry information about the pointed-to
        type. This helps asserting alignment requirements for the
        pointer passed to the foreign language.

   - 'container_of!': retain pointer mut-ness and add a compile-time
     check of the type of the first parameter ('$field_ptr').

   - Support optional message in 'static_assert!'.

   - Add C FFI types (e.g. 'c_int') to the prelude.

   - 'str' module: simplify KUnit tests 'format!' macro, convert
     'rusttest' tests into KUnit, take advantage of the '-> Result'
     support in KUnit '#[test]'s.

   - 'list' module: add examples for 'List', fix path of
     'assert_pinned!' (so far unused macro rule).

   - 'workqueue' module: remove 'HasWork::OFFSET'.

   - 'page' module: add 'inline' attribute.

  'macros' crate:

   - 'module' macro: place 'cleanup_module()' in '.exit.text' section.

  'pin-init' crate:

   - Add 'Wrapper<T>' trait for creating pin-initializers for wrapper
     structs with a structurally pinned value such as 'UnsafeCell<T>' or
     'MaybeUninit<T>'.

   - Add 'MaybeZeroable' derive macro to try to derive 'Zeroable', but
     not error if not all fields implement it. This is needed to derive
     'Zeroable' for all bindgen-generated structs.

   - Add 'unsafe fn cast_[pin_]init()' functions to unsafely change the
     initialized type of an initializer. These are utilized by the
     'Wrapper<T>' implementations.

   - Add support for visibility in 'Zeroable' derive macro.

   - Add support for 'union's in 'Zeroable' derive macro.

   - Upstream dev news: streamline CI, fix some bugs. Add new workflows
     to check if the user-space version and the one in the kernel tree
     have diverged. Use the issues tab [1] to track them, which should
     help folks report and diagnose issues w.r.t. 'pin-init' better.

       [1] https://github.com/rust-for-linux/pin-init/issues

  Documentation:

   - Testing: add docs on the new KUnit '#[test]' tests.

   - Coding guidelines: explain that '///' vs. '//' applies to private
     items too. Add section on C FFI types.

   - Quick Start guide: update Ubuntu instructions and split them into
     "25.04" and "24.04 LTS and older".

  And a few other cleanups and improvements"

* tag 'rust-6.16' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux: (78 commits)
  rust: list: Fix typo `much` in arc.rs
  rust: check type of `$ptr` in `container_of!`
  rust: workqueue: remove HasWork::OFFSET
  rust: retain pointer mut-ness in `container_of!`
  Documentation: rust: testing: add docs on the new KUnit `#[test]` tests
  Documentation: rust: rename `#[test]`s to "`rusttest` host tests"
  rust: str: take advantage of the `-> Result` support in KUnit `#[test]`'s
  rust: str: simplify KUnit tests `format!` macro
  rust: str: convert `rusttest` tests into KUnit
  rust: add `kunit_tests` to the prelude
  rust: kunit: support checked `-> Result`s in KUnit `#[test]`s
  rust: kunit: support KUnit-mapped `assert!` macros in `#[test]`s
  rust: make section names plural
  rust: list: fix path of `assert_pinned!`
  rust: compile libcore with edition 2024 for 1.87+
  rust: dma: add missing Markdown code span
  rust: task: add missing Markdown code spans and intra-doc links
  rust: pci: fix docs related to missing Markdown code spans
  rust: alloc: add missing Markdown code span
  rust: alloc: add missing Markdown code spans
  ...
2025-06-04 21:18:37 -07:00
Masahiro Yamada
8f81d8529e kbuild: move kbuild syntax processing to scripts/Makefile.build
scripts/Makefile.lib is included by the following Makefiles:

  scripts/Makefile.build
  scripts/Makefile.modfinal
  scripts/Makefile.package
  scripts/Makefile.vmlinux
  scripts/Makefile.vmlinux_o

However, the last four do not need to process Kbuild syntax such as
obj-*, lib-*, subdir-*, etc.

Move the relevant code to scripts/Makefile.build.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <nicolas.schier@linux.dev>
2025-05-25 18:15:31 +09:00
Miguel Ojeda
b9b701fce4 rust: clarify the language unstable features in use
We track the details of which Rust features we use at our usual "live
list" [1] (and its sub-lists), but in light of a discussion in the LWN
article [2], it would help to clarify it in the source code.

In particular, we are very close to rely only on stable Rust language-wise
-- essentially only two language features remain (including the `kernel`
crate).

Thus add some details in both the feature list of the `kernel` crate as
well as the list of allowed features.

This does not over every single feature, and there are quite a few
non-language features that we use too. To have the full picture, please
refer to [1].

Link: https://github.com/Rust-for-Linux/linux/issues/2 [1]
Link: https://lwn.net/Articles/1015409/ [2]
Suggested-by: Andreas Hindborg <a.hindborg@kernel.org>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Link: https://lore.kernel.org/r/20250327211302.286313-1-ojeda@kernel.org
[ Improved comments with suggestions from the list. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-05-12 00:20:25 +02:00
Mauro Carvalho Chehab
5c5c32d7ab scripts/kernel-doc.py: don't create *.pyc files
As reported by Andy, kernel-doc.py is creating a __pycache__
directory at build time.

Disable creation of __pycache__ for the libraries used by
kernel-doc.py, when excecuted via the build system or via
scripts/find-unused-docs.sh.

Reported-by: Andy Shevchenko <andriy.shevchenko@intel.com>
Closes: https://lore.kernel.org/linux-doc/Z_zYXAJcTD-c3xTe@black.fi.intel.com/
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Tested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Message-ID: <158b962ed7cd104f7bbfe69f499ec1cc378864db.1745453655.git.mchehab+huawei@kernel.org>
2025-04-24 10:12:46 -06:00
Linus Torvalds
f4d2ef4825 Merge tag 'kbuild-v6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild
Pull Kbuild updates from Masahiro Yamada:

 - Improve performance in gendwarfksyms

 - Remove deprecated EXTRA_*FLAGS and KBUILD_ENABLE_EXTRA_GCC_CHECKS

 - Support CONFIG_HEADERS_INSTALL for ARCH=um

 - Use more relative paths to sources files for better reproducibility

 - Support the loong64 Debian architecture

 - Add Kbuild bash completion

 - Introduce intermediate vmlinux.unstripped for architectures that need
   static relocations to be stripped from the final vmlinux

 - Fix versioning in Debian packages for -rc releases

 - Treat missing MODULE_DESCRIPTION() as an error

 - Convert Nios2 Makefiles to use the generic rule for built-in DTB

 - Add debuginfo support to the RPM package

* tag 'kbuild-v6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (40 commits)
  kbuild: rpm-pkg: build a debuginfo RPM
  kconfig: merge_config: use an empty file as initfile
  nios2: migrate to the generic rule for built-in DTB
  rust: kbuild: skip `--remap-path-prefix` for `rustdoc`
  kbuild: pacman-pkg: hardcode module installation path
  kbuild: deb-pkg: don't set KBUILD_BUILD_VERSION unconditionally
  modpost: require a MODULE_DESCRIPTION()
  kbuild: make all file references relative to source root
  x86: drop unnecessary prefix map configuration
  kbuild: deb-pkg: add comment about future removal of KDEB_COMPRESS
  kbuild: Add a help message for "headers"
  kbuild: deb-pkg: remove "version" variable in mkdebian
  kbuild: deb-pkg: fix versioning for -rc releases
  Documentation/kbuild: Fix indentation in modules.rst example
  x86: Get rid of Makefile.postlink
  kbuild: Create intermediate vmlinux build with relocations preserved
  kbuild: Introduce Kconfig symbol for linking vmlinux with relocations
  kbuild: link-vmlinux.sh: Make output file name configurable
  kbuild: do not generate .tmp_vmlinux*.map when CONFIG_VMLINUX_MAP=y
  Revert "kheaders: Ignore silly-rename files"
  ...
2025-04-05 15:46:50 -07:00
Antonio Hickey
e1dfaa33fd rust: enable raw_ref_op feature
Since Rust 1.82.0 the `raw_ref_op` feature is stable [1].

By enabling this feature we can use `&raw const place` and
`&raw mut place` instead of using `addr_of!(place)` and
`addr_of_mut!(place)` macros.

Allowing us to reduce macro complexity, and improve consistency
with existing reference syntax as `&raw const`, `&raw mut` are
similar to `&`, `&mut` making it fit more naturally with other
existing code.

Suggested-by: Benno Lossin <benno.lossin@proton.me>
Link: https://github.com/Rust-for-Linux/linux/issues/1148
Link: https://blog.rust-lang.org/2024/10/17/Rust-1.82.0.html#native-syntax-for-creating-a-raw-pointer [1]
Signed-off-by: Antonio Hickey <contact@antoniohickey.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org>
Reviewed-by: Tamir Duberstein <tamird@gmail.com>
Link: https://lore.kernel.org/r/20250320020740.1631171-2-contact@antoniohickey.com
[ Removed dashed line change as discussed. Added Link to the explanation
  of the feature in the Rust 1.82.0 release blog post. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-03-23 19:56:45 +01:00
Miguel Ojeda
d7659acca7 rust: add pin-init crate build infrastructure
Add infrastructure for moving the initialization API to its own crate.
Covers all make targets such as `rust-analyzer` and `rustdoc`. The tests
of pin-init are not added to `rusttest`, as they are already tested in
the user-space repository [1].

Link: https://github.com/Rust-for-Linux/pin-init [1]
Co-developed-by: Benno Lossin <benno.lossin@proton.me>
Signed-off-by: Benno Lossin <benno.lossin@proton.me>
Tested-by: Andreas Hindborg <a.hindborg@kernel.org>
Link: https://lore.kernel.org/r/20250308110339.2997091-15-benno.lossin@proton.me
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-03-16 21:59:19 +01:00
Masahiro Yamada
e966ad0edd kbuild: remove EXTRA_*FLAGS support
Commit f77bf01425 ("kbuild: introduce ccflags-y, asflags-y and
ldflags-y") deprecated these in 2007. The migration should have been
completed by now.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Kees Cook <kees@kernel.org>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
2025-03-15 21:16:21 +09:00
Masahiro Yamada
695ed93bb3 kbuild: fix Clang LTO with CONFIG_OBJTOOL=n
Since commit bede169618 ("kbuild: enable objtool for *.mod.o and
additional kernel objects"), Clang LTO builds do not perform any
optimizations when CONFIG_OBJTOOL is disabled (e.g., for ARCH=arm64).
This is because every LLVM bitcode file is immediately converted to
ELF format before the object files are linked together.

This commit fixes the breakage.

Fixes: bede169618 ("kbuild: enable objtool for *.mod.o and additional kernel objects")
Reported-by: Yonghong Song <yonghong.song@linux.dev>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Tested-by: Yonghong Song <yonghong.song@linux.dev>
2025-02-01 04:28:05 +09:00
Sami Tolvanen
9c3681f9b9 kbuild: Add gendwarfksyms as an alternative to genksyms
When MODVERSIONS is enabled, allow selecting gendwarfksyms as the
implementation, but default to genksyms.

Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2025-01-11 01:25:26 +09:00
Linus Torvalds
6a34dfa15d Merge tag 'kbuild-v6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild
Pull Kbuild updates from Masahiro Yamada:

 - Add generic support for built-in boot DTB files

 - Enable TAB cycling for dialog buttons in nconfig

 - Fix issues in streamline_config.pl

 - Refactor Kconfig

 - Add support for Clang's AutoFDO (Automatic Feedback-Directed
   Optimization)

 - Add support for Clang's Propeller, a profile-guided optimization.

 - Change the working directory to the external module directory for M=
   builds

 - Support building external modules in a separate output directory

 - Enable objtool for *.mod.o and additional kernel objects

 - Use lz4 instead of deprecated lz4c

 - Work around a performance issue with "git describe"

 - Refactor modpost

* tag 'kbuild-v6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (85 commits)
  kbuild: rename .tmp_vmlinux.kallsyms0.syms to .tmp_vmlinux0.syms
  gitignore: Don't ignore 'tags' directory
  kbuild: add dependency from vmlinux to resolve_btfids
  modpost: replace tdb_hash() with hash_str()
  kbuild: deb-pkg: add python3:native to build dependency
  genksyms: reduce indentation in export_symbol()
  modpost: improve error messages in device_id_check()
  modpost: rename alias symbol for MODULE_DEVICE_TABLE()
  modpost: rename variables in handle_moddevtable()
  modpost: move strstarts() to modpost.h
  modpost: convert do_usb_table() to a generic handler
  modpost: convert do_of_table() to a generic handler
  modpost: convert do_pnp_device_entry() to a generic handler
  modpost: convert do_pnp_card_entries() to a generic handler
  modpost: call module_alias_printf() from all do_*_entry() functions
  modpost: pass (struct module *) to do_*_entry() functions
  modpost: remove DEF_FIELD_ADDR_VAR() macro
  modpost: deduplicate MODULE_ALIAS() for all drivers
  modpost: introduce module_alias_printf() helper
  modpost: remove unnecessary check in do_acpi_entry()
  ...
2024-11-30 13:41:50 -08:00
Masahiro Yamada
bede169618 kbuild: enable objtool for *.mod.o and additional kernel objects
Currently, objtool is disabled in scripts/Makefile.{modfinal,vmlinux}.

This commit moves rule_cc_o_c and rule_as_o_S to scripts/Makefile.lib
and set objtool-enabled to y there.

With this change, *.mod.o, .module-common.o,  builtin-dtb.o, and
vmlinux.export.o will now be covered by objtool.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2024-11-28 08:11:55 +09:00
Masahiro Yamada
000e22a80d kbuild: move cmd_cc_o_c and cmd_as_o_S to scripts/Malefile.lib
The cmd_cc_o_c and cmd_as_o_S macros are duplicated in
scripts/Makefile.{build,modfinal,vmlinux}.

This commit factors them out to scripts/Makefile.lib.

No functional changes are intended.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2024-11-28 08:11:55 +09:00
Masahiro Yamada
91ca8be3c4 kbuild: remove support for single %.symtypes build rule
This rule is unnecessary because you can generate foo/bar.symtypes
as a side effect using:

  $ make KBUILD_SYMTYPES=1 foo/bar.o

While compiling *.o is slower than preprocessing, the impact is
negligible. I prioritize keeping the code simpler.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
2024-11-28 08:11:55 +09:00
Masahiro Yamada
c2386abf55 kbuild: do not pass -r to genksyms when *.symref does not exist
There is no need to pass '-r /dev/null', which is no-op.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
2024-11-28 08:11:55 +09:00
Masahiro Yamada
13b25489b6 kbuild: change working directory to external module directory with M=
Currently, Kbuild always operates in the output directory of the kernel,
even when building external modules. This increases the risk of external
module Makefiles attempting to write to the kernel directory.

This commit switches the working directory to the external module
directory, allowing the removal of the $(KBUILD_EXTMOD)/ prefix from
some build artifacts.

The command for building external modules maintains backward
compatibility, but Makefiles that rely on working in the kernel
directory may break. In such cases, $(objtree) and $(srctree) should
be used to refer to the output and source directories of the kernel.

The appearance of the build log will change as follows:

[Before]

  $ make -C /path/to/my/linux M=/path/to/my/externel/module
  make: Entering directory '/path/to/my/linux'
    CC [M]  /path/to/my/externel/module/helloworld.o
    MODPOST /path/to/my/externel/module/Module.symvers
    CC [M]  /path/to/my/externel/module/helloworld.mod.o
    CC [M]  /path/to/my/externel/module/.module-common.o
    LD [M]  /path/to/my/externel/module/helloworld.ko
  make: Leaving directory '/path/to/my/linux'

[After]

  $ make -C /path/to/my/linux M=/path/to/my/externel/module
  make: Entering directory '/path/to/my/linux'
  make[1]: Entering directory '/path/to/my/externel/module'
    CC [M]  helloworld.o
    MODPOST Module.symvers
    CC [M]  helloworld.mod.o
    CC [M]  .module-common.o
    LD [M]  helloworld.ko
  make[1]: Leaving directory '/path/to/my/externel/module'
  make: Leaving directory '/path/to/my/linux'

Printing "Entering directory" twice is cumbersome. This will be
addressed later.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <n.schier@avm.de>
2024-11-28 08:10:23 +09:00
Masahiro Yamada
214c0eea43 kbuild: add $(objtree)/ prefix to some in-kernel build artifacts
$(objtree) refers to the top of the output directory of kernel builds.

This commit adds the explicit $(objtree)/ prefix to build artifacts
needed for building external modules.

This change has no immediate impact, as the top-level Makefile
currently defines:

  objtree         := .

This commit prepares for supporting the building of external modules
in a different directory.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
2024-11-27 09:38:27 +09:00
Linus Torvalds
798bb342e0 Merge tag 'rust-6.13' of https://github.com/Rust-for-Linux/linux
Pull rust updates from Miguel Ojeda:
 "Toolchain and infrastructure:

   - Enable a series of lints, including safety-related ones, e.g. the
     compiler will now warn about missing safety comments, as well as
     unnecessary ones. How safety documentation is organized is a
     frequent source of review comments, thus having the compiler guide
     new developers on where they are expected (and where not) is very
     nice.

   - Start using '#[expect]': an interesting feature in Rust (stabilized
     in 1.81.0) that makes the compiler warn if an expected warning was
     _not_ emitted. This is useful to avoid forgetting cleaning up
     locally ignored diagnostics ('#[allow]'s).

   - Introduce '.clippy.toml' configuration file for Clippy, the Rust
     linter, which will allow us to tweak its behaviour. For instance,
     our first use cases are declaring a disallowed macro and, more
     importantly, enabling the checking of private items.

   - Lints-related fixes and cleanups related to the items above.

   - Migrate from 'receiver_trait' to 'arbitrary_self_types': to get the
     kernel into stable Rust, one of the major pieces of the puzzle is
     the support to write custom types that can be used as 'self', i.e.
     as receivers, since the kernel needs to write types such as 'Arc'
     that common userspace Rust would not. 'arbitrary_self_types' has
     been accepted to become stable, and this is one of the steps
     required to get there.

   - Remove usage of the 'new_uninit' unstable feature.

   - Use custom C FFI types. Includes a new 'ffi' crate to contain our
     custom mapping, instead of using the standard library 'core::ffi'
     one. The actual remapping will be introduced in a later cycle.

   - Map '__kernel_{size_t,ssize_t,ptrdiff_t}' to 'usize'/'isize'
     instead of 32/64-bit integers.

   - Fix 'size_t' in bindgen generated prototypes of C builtins.

   - Warn on bindgen < 0.69.5 and libclang >= 19.1 due to a double issue
     in the projects, which we managed to trigger with the upcoming
     tracepoint support. It includes a build test since some
     distributions backported the fix (e.g. Debian -- thanks!). All
     major distributions we list should be now OK except Ubuntu non-LTS.

  'macros' crate:

   - Adapt the build system to be able run the doctests there too; and
     clean up and enable the corresponding doctests.

  'kernel' crate:

   - Add 'alloc' module with generic kernel allocator support and remove
     the dependency on the Rust standard library 'alloc' and the
     extension traits we used to provide fallible methods with flags.

     Add the 'Allocator' trait and its implementations '{K,V,KV}malloc'.
     Add the 'Box' type (a heap allocation for a single value of type
     'T' that is also generic over an allocator and considers the
     kernel's GFP flags) and its shorthand aliases '{K,V,KV}Box'. Add
     'ArrayLayout' type. Add 'Vec' (a contiguous growable array type)
     and its shorthand aliases '{K,V,KV}Vec', including iterator
     support.

     For instance, now we may write code such as:

         let mut v = KVec::new();
         v.push(1, GFP_KERNEL)?;
         assert_eq!(&v, &[1]);

     Treewide, move as well old users to these new types.

   - 'sync' module: add global lock support, including the
     'GlobalLockBackend' trait; the 'Global{Lock,Guard,LockedBy}' types
     and the 'global_lock!' macro. Add the 'Lock::try_lock' method.

   - 'error' module: optimize 'Error' type to use 'NonZeroI32' and make
     conversion functions public.

   - 'page' module: add 'page_align' function.

   - Add 'transmute' module with the existing 'FromBytes' and 'AsBytes'
     traits.

   - 'block::mq::request' module: improve rendered documentation.

   - 'types' module: extend 'Opaque' type documentation and add simple
     examples for the 'Either' types.

  drm/panic:

   - Clean up a series of Clippy warnings.

  Documentation:

   - Add coding guidelines for lints and the '#[expect]' feature.

   - Add Ubuntu to the list of distributions in the Quick Start guide.

  MAINTAINERS:

   - Add Danilo Krummrich as maintainer of the new 'alloc' module.

  And a few other small cleanups and fixes"

* tag 'rust-6.13' of https://github.com/Rust-for-Linux/linux: (82 commits)
  rust: alloc: Fix `ArrayLayout` allocations
  docs: rust: remove spurious item in `expect` list
  rust: allow `clippy::needless_lifetimes`
  rust: warn on bindgen < 0.69.5 and libclang >= 19.1
  rust: use custom FFI integer types
  rust: map `__kernel_size_t` and friends also to usize/isize
  rust: fix size_t in bindgen prototypes of C builtins
  rust: sync: add global lock support
  rust: macros: enable the rest of the tests
  rust: macros: enable paste! use from macro_rules!
  rust: enable macros::module! tests
  rust: kbuild: expand rusttest target for macros
  rust: types: extend `Opaque` documentation
  rust: block: fix formatting of `kernel::block::mq::request` module
  rust: macros: fix documentation of the paste! macro
  rust: kernel: fix THIS_MODULE header path in ThisModule doc comment
  rust: page: add Rust version of PAGE_ALIGN
  rust: helpers: remove unnecessary header includes
  rust: exports: improve grammar in commentary
  drm/panic: allow verbose version check
  ...
2024-11-26 14:00:26 -08:00
Alice Ryhl
169484ab66 rust: add arch_static_branch
To allow the Rust implementation of static_key_false to use runtime code
patching instead of the generic implementation, pull in the relevant
inline assembly from the jump_label.h header by running the C
preprocessor on a .rs.S file. Build rules are added for .rs.S files.

Since the relevant inline asm has been adjusted to export the inline asm
via the ARCH_STATIC_BRANCH_ASM macro in a consistent way, the Rust side
does not need architecture specific code to pull in the asm.

It is not possible to use the existing C implementation of
arch_static_branch via a Rust helper because it passes the argument
`key` to inline assembly as an 'i' parameter. Any attempt to add a C
helper for this function will fail to compile because the value of `key`
must be known at compile-time.

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Josh Poimboeuf <jpoimboe@kernel.org>
Cc: Jason Baron <jbaron@akamai.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Alex Gaynor <alex.gaynor@gmail.com>
Cc: Wedson Almeida Filho <wedsonaf@gmail.com>
Cc: Gary Guo <gary@garyguo.net>
Cc: " =?utf-8?q?Bj=C3=B6rn_Roy_Baron?= " <bjorn3_gh@protonmail.com>
Cc: Benno Lossin <benno.lossin@proton.me>
Cc: Andreas Hindborg <a.hindborg@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Sean Christopherson <seanjc@google.com>
Cc: Uros Bizjak <ubizjak@gmail.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Oliver Upton <oliver.upton@linux.dev>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Fuad Tabba <tabba@google.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Anup Patel <apatel@ventanamicro.com>
Cc: Andrew Jones <ajones@ventanamicro.com>
Cc: Alexandre Ghiti <alexghiti@rivosinc.com>
Cc: Conor Dooley <conor.dooley@microchip.com>
Cc: Samuel Holland <samuel.holland@sifive.com>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: WANG Xuerui <kernel@xen0n.name>
Cc: Bibo Mao <maobibo@loongson.cn>
Cc: Tiezhu Yang <yangtiezhu@loongson.cn>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Tianrui Zhao <zhaotianrui@loongson.cn>
Link: https://lore.kernel.org/20241030-tracepoint-v12-5-eec7f0f8ad22@google.com
Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Co-developed-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-11-04 16:21:45 -05:00
Danilo Krummrich
392e34b6bc kbuild: rust: remove the alloc crate and GlobalAlloc
Now that we have our own `Allocator`, `Box` and `Vec` types we can remove
Rust's `alloc` crate and the `new_uninit` unstable feature.

Also remove `Kmalloc`'s `GlobalAlloc` implementation -- we can't remove
this in a separate patch, since the `alloc` crate requires a
`#[global_allocator]` to set, that implements `GlobalAlloc`.

Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Link: https://lore.kernel.org/r/20241004154149.93856-29-dakr@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-10-15 23:10:32 +02:00
Gary Guo
c95bbb59a9 rust: enable arbitrary_self_types and remove Receiver
The term "receiver" means that a type can be used as the type of `self`,
and thus enables method call syntax `foo.bar()` instead of
`Foo::bar(foo)`. Stable Rust as of today (1.81) enables a limited
selection of types (primitives and types in std, e.g. `Box` and `Arc`)
to be used as receivers, while custom types cannot.

We want the kernel `Arc` type to have the same functionality as the Rust
std `Arc`, so we use the `Receiver` trait (gated behind `receiver_trait`
unstable feature) to gain the functionality.

The `arbitrary_self_types` RFC [1] (tracking issue [2]) is accepted and
it will allow all types that implement a new `Receiver` trait (different
from today's unstable trait) to be used as receivers. This trait will be
automatically implemented for all `Deref` types, which include our `Arc`
type, so we no longer have to opt-in to be used as receiver. To prepare
us for the change, remove the `Receiver` implementation and the
associated feature. To still allow `Arc` and others to be used as method
receivers, turn on `arbitrary_self_types` feature instead.

This feature gate is introduced in 1.23.0. It used to enable both
`Deref` types and raw pointer types to be used as receivers, but the
latter is now split into a different feature gate in Rust 1.83 nightly.
We do not need receivers on raw pointers so this change would not affect
us and usage of `arbitrary_self_types` feature would work for all Rust
versions that we support (>=1.78).

Cc: Adrian Taylor <ade@hohum.me.uk>
Link: https://github.com/rust-lang/rfcs/pull/3519 [1]
Link: https://github.com/rust-lang/rust/issues/44874 [2]
Signed-off-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20240915132734.1653004-1-gary@garyguo.net
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-10-07 21:39:57 +02:00
Miguel Ojeda
1f9ed17254 rust: start using the #[expect(...)] attribute
In Rust, it is possible to `allow` particular warnings (diagnostics,
lints) locally, making the compiler ignore instances of a given warning
within a given function, module, block, etc.

It is similar to `#pragma GCC diagnostic push` + `ignored` + `pop` in C:

    #pragma GCC diagnostic push
    #pragma GCC diagnostic ignored "-Wunused-function"
    static void f(void) {}
    #pragma GCC diagnostic pop

But way less verbose:

    #[allow(dead_code)]
    fn f() {}

By that virtue, it makes it possible to comfortably enable more
diagnostics by default (i.e. outside `W=` levels) that may have some
false positives but that are otherwise quite useful to keep enabled to
catch potential mistakes.

The `#[expect(...)]` attribute [1] takes this further, and makes the
compiler warn if the diagnostic was _not_ produced. For instance, the
following will ensure that, when `f()` is called somewhere, we will have
to remove the attribute:

    #[expect(dead_code)]
    fn f() {}

If we do not, we get a warning from the compiler:

    warning: this lint expectation is unfulfilled
     --> x.rs:3:10
      |
    3 | #[expect(dead_code)]
      |          ^^^^^^^^^
      |
      = note: `#[warn(unfulfilled_lint_expectations)]` on by default

This means that `expect`s do not get forgotten when they are not needed.

See the next commit for more details, nuances on its usage and
documentation on the feature.

The attribute requires the `lint_reasons` [2] unstable feature, but it
is becoming stable in 1.81.0 (to be released on 2024-09-05) and it has
already been useful to clean things up in this patch series, finding
cases where the `allow`s should not have been there.

Thus, enable `lint_reasons` and convert some of our `allow`s to `expect`s
where possible.

This feature was also an example of the ongoing collaboration between
Rust and the kernel -- we tested it in the kernel early on and found an
issue that was quickly resolved [3].

Cc: Fridtjof Stoldt <xfrednet@gmail.com>
Cc: Urgau <urgau@numericable.fr>
Link: https://rust-lang.github.io/rfcs/2383-lint-reasons.html#expect-lint-attribute [1]
Link: https://github.com/rust-lang/rust/issues/54503 [2]
Link: https://github.com/rust-lang/rust/issues/114557 [3]
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Trevor Gross <tmgross@umich.edu>
Tested-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Gary Guo <gary@garyguo.net>
Link: https://lore.kernel.org/r/20240904204347.168520-18-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-10-07 21:39:57 +02:00
Linus Torvalds
5701725692 Merge tag 'rust-6.12' of https://github.com/Rust-for-Linux/linux
Pull Rust updates from Miguel Ojeda:
 "Toolchain and infrastructure:

   - Support 'MITIGATION_{RETHUNK,RETPOLINE,SLS}' (which cleans up
     objtool warnings), teach objtool about 'noreturn' Rust symbols and
     mimic '___ADDRESSABLE()' for 'module_{init,exit}'. With that, we
     should be objtool-warning-free, so enable it to run for all Rust
     object files.

   - KASAN (no 'SW_TAGS'), KCFI and shadow call sanitizer support.

   - Support 'RUSTC_VERSION', including re-config and re-build on
     change.

   - Split helpers file into several files in a folder, to avoid
     conflicts in it. Eventually those files will be moved to the right
     places with the new build system. In addition, remove the need to
     manually export the symbols defined there, reusing existing
     machinery for that.

   - Relax restriction on configurations with Rust + GCC plugins to just
     the RANDSTRUCT plugin.

  'kernel' crate:

   - New 'list' module: doubly-linked linked list for use with reference
     counted values, which is heavily used by the upcoming Rust Binder.

     This includes 'ListArc' (a wrapper around 'Arc' that is guaranteed
     unique for the given ID), 'AtomicTracker' (tracks whether a
     'ListArc' exists using an atomic), 'ListLinks' (the prev/next
     pointers for an item in a linked list), 'List' (the linked list
     itself), 'Iter' (an iterator over a 'List'), 'Cursor' (a cursor
     into a 'List' that allows to remove elements), 'ListArcField' (a
     field exclusively owned by a 'ListArc'), as well as support for
     heterogeneous lists.

   - New 'rbtree' module: red-black tree abstractions used by the
     upcoming Rust Binder.

     This includes 'RBTree' (the red-black tree itself), 'RBTreeNode' (a
     node), 'RBTreeNodeReservation' (a memory reservation for a node),
     'Iter' and 'IterMut' (immutable and mutable iterators), 'Cursor'
     (bidirectional cursor that allows to remove elements), as well as
     an entry API similar to the Rust standard library one.

   - 'init' module: add 'write_[pin_]init' methods and the
     'InPlaceWrite' trait. Add the 'assert_pinned!' macro.

   - 'sync' module: implement the 'InPlaceInit' trait for 'Arc' by
     introducing an associated type in the trait.

   - 'alloc' module: add 'drop_contents' method to 'BoxExt'.

   - 'types' module: implement the 'ForeignOwnable' trait for
     'Pin<Box<T>>' and improve the trait's documentation. In addition,
     add the 'into_raw' method to the 'ARef' type.

   - 'error' module: in preparation for the upcoming Rust support for
     32-bit architectures, like arm, locally allow Clippy lint for
     those.

  Documentation:

   - https://rust.docs.kernel.org has been announced, so link to it.

   - Enable rustdoc's "jump to definition" feature, making its output a
     bit closer to the experience in a cross-referencer.

   - Debian Testing now also provides recent Rust releases (outside of
     the freeze period), so add it to the list.

  MAINTAINERS:

   - Trevor is joining as reviewer of the "RUST" entry.

  And a few other small bits"

* tag 'rust-6.12' of https://github.com/Rust-for-Linux/linux: (54 commits)
  kasan: rust: Add KASAN smoke test via UAF
  kbuild: rust: Enable KASAN support
  rust: kasan: Rust does not support KHWASAN
  kbuild: rust: Define probing macros for rustc
  kasan: simplify and clarify Makefile
  rust: cfi: add support for CFI_CLANG with Rust
  cfi: add CONFIG_CFI_ICALL_NORMALIZE_INTEGERS
  rust: support for shadow call stack sanitizer
  docs: rust: include other expressions in conditional compilation section
  kbuild: rust: replace proc macros dependency on `core.o` with the version text
  kbuild: rust: rebuild if the version text changes
  kbuild: rust: re-run Kconfig if the version text changes
  kbuild: rust: add `CONFIG_RUSTC_VERSION`
  rust: avoid `box_uninit_write` feature
  MAINTAINERS: add Trevor Gross as Rust reviewer
  rust: rbtree: add `RBTree::entry`
  rust: rbtree: add cursor
  rust: rbtree: add mutable iterator
  rust: rbtree: add iterator
  rust: rbtree: add red-black tree implementation backed by the C version
  ...
2024-09-25 10:25:40 -07:00
Masahiro Yamada
e7e2941300 kbuild: split device tree build rules into scripts/Makefile.dtbs
scripts/Makefile.lib is included not only from scripts/Makefile.build
but also from scripts/Makefile.{modfinal,package,vmlinux,vmlinux_o},
where DT build rules are not required.

Split the DT build rules out to scripts/Makefile.dtbs, and include it
only when necessary.

While I was here, I added $(DT_TMP_SCHEMA) as a prerequisite of
$(multi-dtb-y).

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
2024-09-09 23:42:13 +09:00
Masahiro Yamada
fc41a0a749 kbuild: add intermediate targets for Flex/Bison in scripts/Makefile.host
Flex and Bison are used only for host programs. Move their intermediate
target processing from scripts/Makefile.build to scripts/Makefile.host.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2024-09-08 12:15:46 +09:00
Masahiro Yamada
8fb4ac1cee kbuild: fix typos "prequisites" to "prerequisites"
This typo in scripts/Makefile.build has been present for more than 20
years. It was accidentally copy-pasted to other scripts/Makefile.* files.
Fix them all.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
2024-08-23 02:41:02 +09:00
Miguel Ojeda
c4d7f546dd objtool/kbuild/rust: enable objtool for Rust
Now that we should be `objtool`-warning free, enable `objtool` for
Rust too.

Before this patch series, we were already getting warnings under e.g. IBT
builds, since those would see Rust code via `vmlinux.o`.

Tested-by: Alice Ryhl <aliceryhl@google.com>
Tested-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Gary Guo <gary@garyguo.net>
Link: https://lore.kernel.org/r/20240725183325.122827-7-ojeda@kernel.org
[ Solved trivial conflict. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-08-18 23:34:37 +02:00
Linus Torvalds
ff9a79307f Merge tag 'kbuild-v6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild
Pull Kbuild updates from Masahiro Yamada:

 - Avoid 'constexpr', which is a keyword in C23

 - Allow 'dtbs_check' and 'dt_compatible_check' run independently of
   'dt_binding_check'

 - Fix weak references to avoid GOT entries in position-independent code
   generation

 - Convert the last use of 'optional' property in arch/sh/Kconfig

 - Remove support for the 'optional' property in Kconfig

 - Remove support for Clang's ThinLTO caching, which does not work with
   the .incbin directive

 - Change the semantics of $(src) so it always points to the source
   directory, which fixes Makefile inconsistencies between upstream and
   downstream

 - Fix 'make tar-pkg' for RISC-V to produce a consistent package

 - Provide reasonable default coverage for objtool, sanitizers, and
   profilers

 - Remove redundant OBJECT_FILES_NON_STANDARD, KASAN_SANITIZE, etc.

 - Remove the last use of tristate choice in drivers/rapidio/Kconfig

 - Various cleanups and fixes in Kconfig

* tag 'kbuild-v6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (46 commits)
  kconfig: use sym_get_choice_menu() in sym_check_prop()
  rapidio: remove choice for enumeration
  kconfig: lxdialog: remove initialization with A_NORMAL
  kconfig: m/nconf: merge two item_add_str() calls
  kconfig: m/nconf: remove dead code to display value of bool choice
  kconfig: m/nconf: remove dead code to display children of choice members
  kconfig: gconf: show checkbox for choice correctly
  kbuild: use GCOV_PROFILE and KCSAN_SANITIZE in scripts/Makefile.modfinal
  Makefile: remove redundant tool coverage variables
  kbuild: provide reasonable defaults for tool coverage
  modules: Drop the .export_symbol section from the final modules
  kconfig: use menu_list_for_each_sym() in sym_check_choice_deps()
  kconfig: use sym_get_choice_menu() in conf_write_defconfig()
  kconfig: add sym_get_choice_menu() helper
  kconfig: turn defaults and additional prompt for choice members into error
  kconfig: turn missing prompt for choice members into error
  kconfig: turn conf_choice() into void function
  kconfig: use linked list in sym_set_changed()
  kconfig: gconf: use MENU_CHANGED instead of SYMBOL_CHANGED
  kconfig: gconf: remove debug code
  ...
2024-05-18 12:39:20 -07:00
Masahiro Yamada
9c2d1328f8 kbuild: provide reasonable defaults for tool coverage
The objtool, sanitizers (KASAN, UBSAN, etc.), and profilers (GCOV, etc.)
are intended only for kernel space objects.

For instance, the following are not kernel objects, and therefore should
opt out of coverage:

  - vDSO
  - purgatory
  - bootloader (arch/*/boot/)

However, to exclude these from coverage, you need to explicitly set
OBJECT_FILES_NON_STNDARD=y, KASAN_SANITIZE=n, etc.

Kbuild can achieve this without relying on such variables because
objects not directly linked to vmlinux or modules are considered
"non-standard objects".

Detecting standard objects is straightforward:

  - objects added to obj-y or lib-y are linked to vmlinux
  - objects added to obj-m are linked to modules

There are some exceptional Makefiles (e.g., arch/s390/boot/Makefile,
arch/xtensa/boot/lib/Makefile) that use obj-y or lib-y for non-kernel
space objects, but they can be fixed later if necessary.

Going forward, objects that are not listed in obj-y, lib-y, or obj-m
will opt out of objtool, sanitizers, and profilers by default.

You can still override the Kbuild decision by explicitly specifying
OBJECT_FILES_NON_STANDARD, KASAN_SANITIZE, etc. but most of such Make
variables can be removed.

The next commit will clean up redundant variables.

Note:

This commit changes the coverage for some objects:

  - exclude .vmlinux.export.o from UBSAN, KCOV
  - exclude arch/csky/kernel/vdso/vgettimeofday.o from UBSAN
  - exclude arch/parisc/kernel/vdso32/vdso32.so from UBSAN
  - exclude arch/parisc/kernel/vdso64/vdso64.so from UBSAN
  - exclude arch/x86/um/vdso/um_vdso.o from UBSAN
  - exclude drivers/misc/lkdtm/rodata.o from UBSAN, KCOV
  - exclude init/version-timestamp.o from UBSAN, KCOV
  - exclude lib/test_fortify/*.o from all santizers and profilers

I believe these are positive effects.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Tested-by: Roberto Sassu <roberto.sassu@huawei.com>
2024-05-14 23:33:51 +09:00
Linus Torvalds
8f5b5f7811 Merge tag 'rust-6.10' of https://github.com/Rust-for-Linux/linux
Pull Rust updates from Miguel Ojeda:
 "The most notable change is the drop of the 'alloc' in-tree fork. This
  is nicely reflected in the diffstat as a ~10k lines drop. In turn,
  this makes the version upgrades way simpler and smaller in the future,
  e.g. the latest one in commit 56f64b3706 ("rust: upgrade to Rust
  1.78.0").

  More importantly, this increases the chances that a newer compiler
  version just works, which in turn means supporting several compiler
  versions is easier now. Thus we will look into finally setting a
  minimum version in the near future.

  Toolchain and infrastructure:

   - Upgrade to Rust 1.78.0

     This time around, due to how the kernel and Rust schedules have
     aligned, there are two upgrades in fact. These allow us to remove
     one more unstable feature ('offset_of') from the list, among other
     improvements

   - Drop 'alloc' in-tree fork of the standard library crate, which
     means all the unstable features used by 'alloc' (~30 language ones,
     ~60 library ones) are not a concern anymore

   - Support DWARFv5 via the '-Zdwarf-version' flag

   - Support zlib and zstd debuginfo compression via the
     '-Zdebuginfo-compression' flag

  'kernel' crate:

   - Support allocation flags ('GFP_*'), particularly in 'Box' (via
     'BoxExt'), 'Vec' (via 'VecExt'), 'Arc' and 'UniqueArc', as well as
     in the 'init' module APIs

   - Remove usage of the 'allocator_api' unstable feature

   - Remove 'try_' prefix in allocation APIs' names

   - Add 'VecExt' (an extension trait) to be able to drop the 'alloc'
     fork

   - Add the '{make,to}_{upper,lower}case()' methods to 'CStr'/'CString'

   - Add the 'as_ptr' method to 'ThisModule'

   - Add the 'from_raw' method to 'ArcBorrow'

   - Add the 'into_unique_or_drop' method to 'Arc'

   - Display column number in the 'dbg!' macro output by applying the
     equivalent change done to the standard library one

   - Migrate 'Work' to '#[pin_data]' thanks to the changes in the
     'macros' crate, which allows to remove an unsafe call in its 'new'
     associated function

   - Prevent namespacing issues when using the '[try_][pin_]init!'
     macros by changing the generated name of guard variables

   - Make the 'get' method in 'Opaque' const

   - Implement the 'Default' trait for 'LockClassKey'

   - Remove unneeded 'kernel::prelude' imports from doctests

   - Remove redundant imports

  'macros' crate:

   - Add 'decl_generics' to 'parse_generics()' to support default
     values, and use that to allow them in '#[pin_data]'

  Helpers:

   - Trivial English grammar fix

  Documentation:

   - Add section on Rust Kselftests to the 'Testing' document

   - Expand the 'Abstractions vs. bindings' section of the 'General
     Information' document"

* tag 'rust-6.10' of https://github.com/Rust-for-Linux/linux: (31 commits)
  rust: alloc: fix dangling pointer in VecExt<T>::reserve()
  rust: upgrade to Rust 1.78.0
  rust: kernel: remove redundant imports
  rust: sync: implement `Default` for `LockClassKey`
  docs: rust: extend abstraction and binding documentation
  docs: rust: Add instructions for the Rust kselftest
  rust: remove unneeded `kernel::prelude` imports from doctests
  rust: update `dbg!()` to format column number
  rust: helpers: Fix grammar in comment
  rust: init: change the generated name of guard variables
  rust: sync: add `Arc::into_unique_or_drop`
  rust: sync: add `ArcBorrow::from_raw`
  rust: types: Make Opaque::get const
  rust: kernel: remove usage of `allocator_api` unstable feature
  rust: init: update `init` module to take allocation flags
  rust: sync: update `Arc` and `UniqueArc` to take allocation flags
  rust: alloc: update `VecExt` to take allocation flags
  rust: alloc: introduce the `BoxExt` trait
  rust: alloc: introduce allocation flags
  rust: alloc: remove our fork of the `alloc` crate
  ...
2024-05-13 15:13:54 -07:00
Masahiro Yamada
d98dba8852 kbuild: add 'private' to target-specific variables
Currently, Kbuild produces inconsistent results in some cases.

You can do an interesting experiment using the --shuffle option, which
is supported by GNU Make 4.4 or later.

Set CONFIG_KVM_INTEL=y and CONFIG_KVM_AMD=m (or vice versa), and repeat
incremental builds w/wo --shuffle=reverse.

  $ make
    [ snip ]
    CC      arch/x86/kvm/kvm-asm-offsets.s

  $ make --shuffle=reverse
    [ snip ]
    CC [M]  arch/x86/kvm/kvm-asm-offsets.s

  $ make
    [ snip ]
    CC      arch/x86/kvm/kvm-asm-offsets.s

arch/x86/kvm/kvm-asm-offsets.s is rebuilt every time w/wo the [M] marker.

arch/x86/kvm/kvm-asm-offsets.s is built as built-in when it is built as
a prerequisite of arch/x86/kvm/kvm-intel.o, which is built-in.

arch/x86/kvm/kvm-asm-offsets.s is built as modular when it is built as
a prerequisite of arch/x86/kvm/kvm-amd.o, which is a module.

Another odd example is single target builds.

When CONFIG_LKDTM=m, drivers/misc/lkdtm/rodata.o can be built as
built-in or modular, depending on how it is built.

  $ make drivers/misc/lkdtm/lkdtm.o
    [ snip ]
    CC [M]  drivers/misc/lkdtm/rodata.o

  $ make drivers/misc/lkdtm/rodata.o
    [ snip ]
    CC      drivers/misc/lkdtm/rodata.o

drivers/misc/lkdtm/rodata.o is built as modular when it is built as a
prerequisite of another, but built as built-in when it is a final
target.

The same thing happens to drivers/memory/emif-asm-offsets.s when
CONFIG_TI_EMIF_SRAM=m.

  $ make drivers/memory/ti-emif-sram.o
    [ snip ]
    CC [M]  drivers/memory/emif-asm-offsets.s

  $ make drivers/memory/emif-asm-offsets.s
    [ snip ]
    CC      drivers/memory/emif-asm-offsets.s

This is because the part-of-module=y flag defined for the modules is
inherited by its prerequisites.

Target-specific variables are likely intended only for local use.
This commit adds 'private' to them.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <n.schier@avm.de>
2024-05-10 04:34:52 +09:00
Masahiro Yamada
b1992c3772 kbuild: use $(src) instead of $(srctree)/$(src) for source directory
Kbuild conventionally uses $(obj)/ for generated files, and $(src)/ for
checked-in source files. It is merely a convention without any functional
difference. In fact, $(obj) and $(src) are exactly the same, as defined
in scripts/Makefile.build:

    src := $(obj)

When the kernel is built in a separate output directory, $(src) does
not accurately reflect the source directory location. While Kbuild
resolves this discrepancy by specifying VPATH=$(srctree) to search for
source files, it does not cover all cases. For example, when adding a
header search path for local headers, -I$(srctree)/$(src) is typically
passed to the compiler.

This introduces inconsistency between upstream and downstream Makefiles
because $(src) is used instead of $(srctree)/$(src) for the latter.

To address this inconsistency, this commit changes the semantics of
$(src) so that it always points to the directory in the source tree.

Going forward, the variables used in Makefiles will have the following
meanings:

  $(obj)     - directory in the object tree
  $(src)     - directory in the source tree  (changed by this commit)
  $(objtree) - the top of the kernel object tree
  $(srctree) - the top of the kernel source tree

Consequently, $(srctree)/$(src) in upstream Makefiles need to be replaced
with $(src).

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
2024-05-10 04:34:52 +09:00
Masahiro Yamada
9a0ebe5011 kbuild: use $(obj)/ instead of $(src)/ for common pattern rules
Kbuild conventionally uses $(obj)/ for generated files, and $(src)/ for
checked-in source files. It is merely a convention without any functional
difference. In fact, $(obj) and $(src) are exactly the same, as defined
in scripts/Makefile.build:

  src := $(obj)

Before changing the semantics of $(src) in the next commit, this commit
replaces $(obj)/ with $(src)/ in pattern rules where the prerequisite
might be a generated file.

C, assembly, Rust, and DTS files are sometimes generated by tools, so
they could be either generated files or real sources. The $(obj)/ prefix
works for both cases with the help of VPATH.

As mentioned above, $(obj) and $(src) are the same at this point, hence
this commit has no functional change.

I did not modify scripts/Makefile.userprogs because there is no use
case where userspace C files are generated.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
2024-05-10 04:33:45 +09:00
Miguel Ojeda
ded103c7eb kbuild: rust: force alloc extern to allow "empty" Rust files
If one attempts to build an essentially empty file somewhere in the
kernel tree, it leads to a build error because the compiler does not
recognize the `new_uninit` unstable feature:

    error[E0635]: unknown feature `new_uninit`
     --> <crate attribute>:1:9
      |
    1 | feature(new_uninit)
      |         ^^^^^^^^^^

The reason is that we pass `-Zcrate-attr='feature(new_uninit)'` (together
with `-Zallow-features=new_uninit`) to let non-`rust/` code use that
unstable feature.

However, the compiler only recognizes the feature if the `alloc` crate
is resolved (the feature is an `alloc` one). `--extern alloc`, which we
pass, is not enough to resolve the crate.

Introducing a reference like `use alloc;` or `extern crate alloc;`
solves the issue, thus this is not seen in normal files. For instance,
`use`ing the `kernel` prelude introduces such a reference, since `alloc`
is used inside.

While normal use of the build system is not impacted by this, it can still
be fairly confusing for kernel developers [1], thus use the unstable
`force` option of `--extern` [2] (added in Rust 1.71 [3]) to force the
compiler to resolve `alloc`.

This new unstable feature is only needed meanwhile we use the other
unstable feature, since then we will not need `-Zcrate-attr`.

Cc: stable@vger.kernel.org # v6.6+
Reported-by: Daniel Almeida <daniel.almeida@collabora.com>
Reported-by: Julian Stecklina <julian.stecklina@cyberus-technology.de>
Closes: https://rust-for-linux.zulipchat.com/#narrow/stream/288089-General/topic/x/near/424096982 [1]
Fixes: 2f7ab1267d ("Kbuild: add Rust support")
Link: https://github.com/rust-lang/rust/issues/111302 [2]
Link: https://github.com/rust-lang/rust/pull/109421 [3]
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Link: https://lore.kernel.org/r/20240422090644.525520-1-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-04-25 17:34:22 +02:00