From dea1bf38143f8505747c19b953ef12fb809d5d77 Mon Sep 17 00:00:00 2001 From: FUJITA Tomonori Date: Sun, 9 Aug 2026 22:48:58 +0900 Subject: rust: jump_label: skip arch-specific asm in `testlib` builds Running `make rusttest` with `ARCH=` set to an architecture other than the host's may fail in the future, e.g. `ARCH=arm64` on an x86_64 host: error: alignment must be a power of 2 --> rust/kernel/jump_label.rs:51:13 | 51 | include!(concat!(env!("OBJTREE"), "/rust/kernel/generated_arch_static_branch_asm.rs")); | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ | note: instantiated into assembly here --> :3:10 | 3 | .align 3 | ^ The reason is that `rusttest` builds the kernel crate as a host library: it passes the `CONFIG_*` cfgs of the configured architecture, but not `--target`, so code generation happens for the host. `arch_static_branch!` then selects the arch-specific inline asm arm based on CONFIG_*, and the host assembler rejects it. This does not happen with the current master because `arch_static_branch!` has no user inside the kernel crate itself yet, but fix it now to avoid surprises later. Signed-off-by: FUJITA Tomonori Link: https://patch.msgid.link/20260809134858.1219036-1-tomo@flapping.org [ Reworded slightly to clarify it "may fail in the future". - Miguel ] Signed-off-by: Miguel Ojeda --- rust/kernel/jump_label.rs | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/rust/kernel/jump_label.rs b/rust/kernel/jump_label.rs index 4e974c768dbd..f54cedcb6fd5 100644 --- a/rust/kernel/jump_label.rs +++ b/rust/kernel/jump_label.rs @@ -44,6 +44,7 @@ const _: &str = include!(concat!( #[macro_export] #[doc(hidden)] +#[cfg(not(testlib))] #[cfg(CONFIG_JUMP_LABEL)] macro_rules! arch_static_branch { ($key:path, $keytyp:ty, $field:ident, $branch:expr) => {'my_label: { @@ -61,6 +62,17 @@ macro_rules! arch_static_branch { }}; } +#[macro_export] +#[doc(hidden)] +#[cfg(testlib)] +#[cfg(CONFIG_JUMP_LABEL)] +macro_rules! arch_static_branch { + ($key:path, $keytyp:ty, $field:ident, $branch:expr) => { + // The asm falls through until patched, which never happens on the host. + false + }; +} + #[cfg(CONFIG_JUMP_LABEL)] pub use arch_static_branch; -- cgit v1.2.3