CUBELinux.0.1: name the release, and build with this box's rustc

The tree is Linux 6.19.3 with the changes this machine's toolchain needs, and
nothing else. No CUBE code yet — this is the base the coordinate interface will
be built on, so it starts from a known-good bootable kernel.

Naming:
- VERSION/PATCHLEVEL/SUBLEVEL stay 6.19.3 (visible in `make kernelversion`),
  while the release string setlocalversion composes is CUBELinux.0.1, so
  `uname -r` and /lib/modules report this product rather than a Linux point
  release. The SCM suffix still applies: a dirty tree says so.

rustc compatibility (rustc 1.100.0-nightly, clang 19.1.7):
- scripts/generate_rust_target.rs emitted `"rustc-abi": "x86-softfloat"`, which
  this rustc rejects; it is `softfloat` now.
- rust/Makefile's cmd_rustc_library did not pass -Zunstable-options, so the
  custom target spec would not load at all.
- the generated bindings declare `strlen` with the kernel target's `c_char`
  (u8, from -funsigned-char) while rustc expects `*const i8`; the newer
  suspicious_runtime_symbol_definitions lint fires on that and -D warnings makes
  it fatal. Scoped to bindings.o and uapi.o, not to handwritten code.
- three `'static` bounds the abstractions now need (irq handlers).
- str.rs imported alloc::flags::* which prelude::* already provides, and
  `#![feature(used_with_arg)]` is stale now that the feature is stable; both are
  unused-feature/unused-import errors under -D warnings.

Gates: bzImage builds (14,697,472 bytes) with CONFIG_RUST=y, virtio-blk and a
serial console built in. Boot test in QEMU is next.

Makefile

@@ -3,7 +3,13 @@ VERSION = 6
 PATCHLEVEL = 19
 SUBLEVEL = 3
 EXTRAVERSION =
-NAME = Baby Opossum Posse
+NAME = CUBELinux
+
+# CUBELinux: the release string belongs to this product, not to a Linux point
+# release. The base version stays in VERSION/PATCHLEVEL/SUBLEVEL above (visible in
+# `make kernelversion`), while `uname -r` and /lib/modules report the CUBELinux
+# release, with any -dirty or SCM suffix still appended by setlocalversion.
+CUBELINUX_VERSION = CUBELinux.0.1
 
 # *DOCUMENTATION*
 # To see a list of typical targets execute "make help"
@@ -1280,7 +1286,7 @@ vmlinux: vmlinux.o $(KBUILD_LDS) modpost
 $(sort $(KBUILD_LDS) $(KBUILD_VMLINUX_OBJS) $(KBUILD_VMLINUX_LIBS)): . ;
 
 ifeq ($(origin KERNELRELEASE),file)
-filechk_kernel.release = $(srctree)/scripts/setlocalversion $(srctree)
+filechk_kernel.release = KERNELVERSION=$(CUBELINUX_VERSION) $(srctree)/scripts/setlocalversion $(srctree)
 else
 filechk_kernel.release = echo $(KERNELRELEASE)
 endif

rust/Makefile

@@ -556,6 +556,7 @@ quiet_cmd_rustc_library = $(if $(skip_clippy),RUSTC,$(RUSTC_OR_CLIPPY_QUIET)) L
       cmd_rustc_library = \
 	OBJTREE=$(abspath $(objtree)) \
 	$(if $(skip_clippy),$(RUSTC),$(RUSTC_OR_CLIPPY)) \
+		-Zunstable-options \
 		$(filter-out $(skip_flags),$(rust_flags)) $(rustc_target_flags) \
 		--emit=dep-info=$(depfile) --emit=obj=$@ \
 		--emit=metadata=$(dir $@)$(patsubst %.o,lib%.rmeta,$(notdir $@)) \
@@ -661,7 +662,9 @@ $(obj)/ffi.o: private skip_gendwarfksyms = 1
 $(obj)/ffi.o: $(src)/ffi.rs $(obj)/compiler_builtins.o FORCE
 	+$(call if_changed_rule,rustc_library)
 
-$(obj)/bindings.o: private rustc_target_flags = --extern ffi --extern pin_init
+# bindgen's output trips a newer rustc lint over `c_char` width (see below), so the
+# declaration is allowed here rather than in the flags that cover handwritten code.
+$(obj)/bindings.o: private rustc_target_flags = --extern ffi --extern pin_init --allow=suspicious_runtime_symbol_definitions
 $(obj)/bindings.o: $(src)/bindings/lib.rs \
     $(obj)/ffi.o \
     $(obj)/pin_init.o \
@@ -669,7 +672,7 @@ $(obj)/bindings.o: $(src)/bindings/lib.rs \
     $(obj)/bindings/bindings_helpers_generated.rs FORCE
 	+$(call if_changed_rule,rustc_library)
 
-$(obj)/uapi.o: private rustc_target_flags = --extern ffi --extern pin_init
+$(obj)/uapi.o: private rustc_target_flags = --extern ffi --extern pin_init --allow=suspicious_runtime_symbol_definitions
 $(obj)/uapi.o: private skip_gendwarfksyms = 1
 $(obj)/uapi.o: $(src)/uapi/lib.rs \
     $(obj)/ffi.o \

rust/kernel/irq/request.rs

@@ -261,7 +261,7 @@ impl<T: Handler + 'static> Registration<T> {
 /// # Safety
 ///
 /// This function should be only used as the callback in `request_irq`.
-unsafe extern "C" fn handle_irq_callback<T: Handler>(_irq: i32, ptr: *mut c_void) -> c_uint {
+unsafe extern "C" fn handle_irq_callback<T: Handler + 'static>(_irq: i32, ptr: *mut c_void) -> c_uint {
     // SAFETY: `ptr` is a pointer to `Registration<T>` set in `Registration::new`
     let registration = unsafe { &*(ptr as *const Registration<T>) };
     // SAFETY: The irq callback is removed before the device is unbound, so the fact that the irq
@@ -480,7 +480,7 @@ impl<T: ThreadedHandler + 'static> ThreadedRegistration<T> {
 /// # Safety
 ///
 /// This function should be only used as the callback in `request_threaded_irq`.
-unsafe extern "C" fn handle_threaded_irq_callback<T: ThreadedHandler>(
+unsafe extern "C" fn handle_threaded_irq_callback<T: ThreadedHandler + 'static>(
     _irq: i32,
     ptr: *mut c_void,
 ) -> c_uint {
@@ -496,7 +496,7 @@ unsafe extern "C" fn handle_threaded_irq_callback<T: ThreadedHandler>(
 /// # Safety
 ///
 /// This function should be only used as the callback in `request_threaded_irq`.
-unsafe extern "C" fn thread_fn_callback<T: ThreadedHandler>(_irq: i32, ptr: *mut c_void) -> c_uint {
+unsafe extern "C" fn thread_fn_callback<T: ThreadedHandler + 'static>(_irq: i32, ptr: *mut c_void) -> c_uint {
     // SAFETY: `ptr` is a pointer to `ThreadedRegistration<T>` set in `ThreadedRegistration::new`
     let registration = unsafe { &*(ptr as *const ThreadedRegistration<T>) };
     // SAFETY: The irq callback is removed before the device is unbound, so the fact that the irq

rust/kernel/lib.rs

@@ -40,8 +40,8 @@
 // Expected to become stable.
 #![feature(arbitrary_self_types)]
 //
-// To be determined.
-#![feature(used_with_arg)]
+// `used_with_arg` was stabilised; the attribute below is used without a gate now, and a
+// stale `#![feature]` for it is an error under `-D warnings` on this rustc.
 //
 // `feature(derive_coerce_pointee)` is expected to become stable. Before Rust
 // 1.84.0, it did not exist, so enable the predecessor features.

rust/kernel/str.rs

@@ -3,7 +3,7 @@
 //! String representations.
 
 use crate::{
-    alloc::{flags::*, AllocError, KVec},
+    alloc::{AllocError, KVec},
     error::{to_result, Result},
     fmt::{self, Write},
     prelude::*,

scripts/generate_rust_target.rs

@@ -197,7 +197,7 @@ fn main() {
     } else if cfg.has("X86_64") {
         ts.push("arch", "x86_64");
         if cfg.rustc_version_atleast(1, 86, 0) {
-            ts.push("rustc-abi", "x86-softfloat");
+            ts.push("rustc-abi", "softfloat");
         }
         ts.push(
             "data-layout",
@@ -237,7 +237,7 @@ fn main() {
         }
         ts.push("arch", "x86");
         if cfg.rustc_version_atleast(1, 86, 0) {
-            ts.push("rustc-abi", "x86-softfloat");
+            ts.push("rustc-abi", "softfloat");
         }
         ts.push(
             "data-layout",