On Fri, Jun 28, 2024 at 01:23:31PM +0000, Alice Ryhl wrote: > rust/kernel/arch/arm64/jump_label.rs | 34 ++++++++++++++++++++++++++++ > rust/kernel/arch/loongarch/jump_label.rs | 35 +++++++++++++++++++++++++++++ > rust/kernel/arch/mod.rs | 24 ++++++++++++++++++++ > rust/kernel/arch/riscv/jump_label.rs | 38 ++++++++++++++++++++++++++++++++ > rust/kernel/arch/x86/jump_label.rs | 35 +++++++++++++++++++++++++++++ > rust/kernel/lib.rs | 2 ++ > rust/kernel/static_key.rs | 32 +++++++++++++++++++++++++++ > scripts/Makefile.build | 2 +- > 8 files changed, 201 insertions(+), 1 deletion(-) So I really find the amount of duplicated asm offensive. Is is far too easy for any of this to get out of sync. > diff --git a/rust/kernel/arch/x86/jump_label.rs b/rust/kernel/arch/x86/jump_label.rs > new file mode 100644 > index 000000000000..383bed273c50 > --- /dev/null > +++ b/rust/kernel/arch/x86/jump_label.rs > @@ -0,0 +1,35 @@ > +// SPDX-License-Identifier: GPL-2.0 > + > +// Copyright (C) 2024 Google LLC. > + > +//! X86 Rust implementation of jump_label.h > + > +/// x86 implementation of arch_static_branch > +#[macro_export] > +#[cfg(target_arch = "x86_64")] > +macro_rules! arch_static_branch { > + ($key:path, $keytyp:ty, $field:ident, $branch:expr) => {'my_label: { > + core::arch::asm!( > + r#" > + 1: .byte 0x0f,0x1f,0x44,0x00,0x00 > + > + .pushsection __jump_table, "aw" > + .balign 8 > + .long 1b - . > + .long {0} - . > + .quad {1} + {2} + {3} - . > + .popsection > + "#, > + label { > + break 'my_label true; > + }, > + sym $key, > + const ::core::mem::offset_of!($keytyp, $field), > + const $crate::arch::bool_to_int($branch), > + ); > + > + break 'my_label false; > + }}; > +} Note that this uses the forced 5 byte version, and not the dynamic sized one. On top of that it hard-codes the nop5 string :/ Please work harder to not have to duplicate stuff like this. NAK.