diff options
Diffstat (limited to 'rust/kernel')
| -rw-r--r-- | rust/kernel/lib.rs | 1 | ||||
| -rw-r--r-- | rust/kernel/tracepoint.rs | 49 |
2 files changed, 50 insertions, 0 deletions
diff --git a/rust/kernel/lib.rs b/rust/kernel/lib.rs index 708ff817ccc3..55f81f49024e 100644 --- a/rust/kernel/lib.rs +++ b/rust/kernel/lib.rs @@ -54,6 +54,7 @@ pub mod str; pub mod sync; pub mod task; pub mod time; +pub mod tracepoint; pub mod types; pub mod uaccess; pub mod workqueue; diff --git a/rust/kernel/tracepoint.rs b/rust/kernel/tracepoint.rs new file mode 100644 index 000000000000..c6e80aa99e8e --- /dev/null +++ b/rust/kernel/tracepoint.rs @@ -0,0 +1,49 @@ +// SPDX-License-Identifier: GPL-2.0 + +// Copyright (C) 2024 Google LLC. + +//! Logic for tracepoints. + +/// Declare the Rust entry point for a tracepoint. +/// +/// This macro generates an unsafe function that calls into C, and its safety requirements will be +/// whatever the relevant C code requires. To document these safety requirements, you may add +/// doc-comments when invoking the macro. +#[macro_export] +macro_rules! declare_trace { + ($($(#[$attr:meta])* $pub:vis unsafe fn $name:ident($($argname:ident : $argtyp:ty),* $(,)?);)*) => {$( + $( #[$attr] )* + #[inline(always)] + $pub unsafe fn $name($($argname : $argtyp),*) { + #[cfg(CONFIG_TRACEPOINTS)] + { + // SAFETY: It's always okay to query the static key for a tracepoint. + let should_trace = unsafe { + $crate::macros::paste! { + $crate::jump_label::static_branch_unlikely!( + $crate::bindings::[< __tracepoint_ $name >], + $crate::bindings::tracepoint, + key + ) + } + }; + + if should_trace { + $crate::macros::paste! { + // SAFETY: The caller guarantees that it is okay to call this tracepoint. + unsafe { $crate::bindings::[< rust_do_trace_ $name >]($($argname),*) }; + } + } + } + + #[cfg(not(CONFIG_TRACEPOINTS))] + { + // If tracepoints are disabled, insert a trivial use of each argument + // to avoid unused argument warnings. + $( let _unused = $argname; )* + } + } + )*} +} + +pub use declare_trace; |