[PATCH v3 0/5] Rust dynamic debug support for pr_debug! and dev_dbg!

[Zhi Wang]

Add runtime dynamic debug control to Rust pr_debug! and dev_dbg!, using
the existing C control file, boot/module parameters, prefixes and jump
labels. Callsite flags and static keys always start disabled. Users enable
messages with dyndbg queries; Rust debug assertions do not affect whether
a debug message is printed.

This continues Andrew Ballance's RFC v2:
https://lore.kernel.org/rust-for-linux/20250620210533.400889-1-andrewjballance@xxxxxxxxx/

This revision retains RFC v2's nested-field static-branch macros and
static mut descriptors addressed through raw pointers.

Changes since RFC v2:

- Make debug logging independent of Rust's debug_assertions setting.
  Both pr_debug! and dev_dbg! start disabled and are enabled through
  dyndbg; without dynamic debug support, both remain disabled.
- Keep caller expressions outside unsafe blocks and avoid implicit Rust
  references when reading descriptor flags without jump labels.
- Correct big-endian bitfield layout and keep module descriptors writable
  with #[used(compiler)]. This fixes the kernel write fault when
  static_key_enable_cpuslocked() tries to write the static key.
- Use Kbuild module names and actual format strings for filtering, preserve
  the crate log prefix, and support +d stack output.
- Complete DYNAMIC_DEBUG_CORE-only support with per-crate opt-in.
- Port to driver-core-testing and preserve Nova's firmware validation when
  debug logging is disabled.

Limitations:

- Function metadata deliberately remains <unknown>;

Andrew Ballance (3):
  rust: jump label: add support for nested arguments
  rust: print: add dynamic debug support to pr_debug!
  rust: device: add dynamic debug support to dev_dbg!

Zhi Wang (2):
  gpu: nova-core: validate firmware versions before debug logging
  dynamic_debug: expose printing declarations with the core enabled

 .../admin-guide/dynamic-debug-howto.rst       |  41 ++++
 MAINTAINERS                                   |   2 +
 drivers/gpu/nova-core/firmware/booter.rs      |   8 +-
 drivers/gpu/nova-core/firmware/fsp.rs         |   3 +-
 .../nova-core/firmware/fwsec/bootloader.rs    |   7 +-
 drivers/gpu/nova-core/firmware/gsp.rs         |   3 +-
 drivers/gpu/nova-core/firmware/riscv.rs       |   7 +-
 include/linux/dynamic_debug.h                 |  16 +-
 rust/Makefile                                 |   3 +
 rust/bindings/bindings_helper.h               |   1 +
 rust/helpers/dynamic_debug.c                  |  33 +++
 rust/helpers/helpers.c                        |   1 +
 rust/kernel/device.rs                         |  42 +++-
 rust/kernel/jump_label.rs                     |  17 +-
 rust/kernel/print.rs                          |  53 ++++-
 rust/kernel/print/dynamic_debug.rs            | 192 ++++++++++++++++++
 scripts/Makefile.build                        |   1 +
 scripts/generate_rust_analyzer.py             |   1 +
 18 files changed, 386 insertions(+), 45 deletions(-)
 create mode 100644 rust/helpers/dynamic_debug.c
 create mode 100644 rust/kernel/print/dynamic_debug.rs


base-commit: f1850e443b0e4f2429ddf42a8d5033ea54ae8a90
-- 
2.53.0