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-rw-r--r--rust/Makefile6
-rw-r--r--rust/bindings/bindings_helper.h3
-rw-r--r--rust/helpers/helpers.c1
-rw-r--r--rust/helpers/jump_label.c14
-rw-r--r--rust/kernel/.gitignore3
-rw-r--r--rust/kernel/generated_arch_static_branch_asm.rs.S7
-rw-r--r--rust/kernel/jump_label.rs74
-rw-r--r--rust/kernel/lib.rs37
-rw-r--r--rust/kernel/tracepoint.rs49
9 files changed, 194 insertions, 0 deletions
diff --git a/rust/Makefile b/rust/Makefile
index b5e0a73b78f3..99db963637e6 100644
--- a/rust/Makefile
+++ b/rust/Makefile
@@ -36,6 +36,8 @@ always-$(CONFIG_RUST_KERNEL_DOCTESTS) += doctests_kernel_generated_kunit.c
obj-$(CONFIG_RUST_KERNEL_DOCTESTS) += doctests_kernel_generated.o
obj-$(CONFIG_RUST_KERNEL_DOCTESTS) += doctests_kernel_generated_kunit.o
+always-$(subst y,$(CONFIG_RUST),$(CONFIG_JUMP_LABEL)) += kernel/generated_arch_static_branch_asm.rs
+
# Avoids running `$(RUSTC)` for the sysroot when it may not be available.
ifdef CONFIG_RUST
@@ -424,4 +426,8 @@ $(obj)/kernel.o: $(src)/kernel/lib.rs $(obj)/alloc.o $(obj)/build_error.o \
$(obj)/libmacros.so $(obj)/bindings.o $(obj)/uapi.o FORCE
+$(call if_changed_rule,rustc_library)
+ifdef CONFIG_JUMP_LABEL
+$(obj)/kernel.o: $(obj)/kernel/generated_arch_static_branch_asm.rs
+endif
+
endif # CONFIG_RUST
diff --git a/rust/bindings/bindings_helper.h b/rust/bindings/bindings_helper.h
index ca13659ded4c..0e9fee0a4a27 100644
--- a/rust/bindings/bindings_helper.h
+++ b/rust/bindings/bindings_helper.h
@@ -17,6 +17,7 @@
#include <linux/firmware.h>
#include <linux/fs.h>
#include <linux/jiffies.h>
+#include <linux/jump_label.h>
#include <linux/mdio.h>
#include <linux/phy.h>
#include <linux/pid_namespace.h>
@@ -25,8 +26,10 @@
#include <linux/sched.h>
#include <linux/security.h>
#include <linux/slab.h>
+#include <linux/tracepoint.h>
#include <linux/wait.h>
#include <linux/workqueue.h>
+#include <trace/events/rust_sample.h>
/* `bindgen` gets confused at certain things. */
const size_t RUST_CONST_HELPER_ARCH_SLAB_MINALIGN = ARCH_SLAB_MINALIGN;
diff --git a/rust/helpers/helpers.c b/rust/helpers/helpers.c
index 62022b18caf5..463b970154de 100644
--- a/rust/helpers/helpers.c
+++ b/rust/helpers/helpers.c
@@ -14,6 +14,7 @@
#include "cred.c"
#include "err.c"
#include "fs.c"
+#include "jump_label.c"
#include "kunit.c"
#include "mutex.c"
#include "page.c"
diff --git a/rust/helpers/jump_label.c b/rust/helpers/jump_label.c
new file mode 100644
index 000000000000..fc1f1e0df08e
--- /dev/null
+++ b/rust/helpers/jump_label.c
@@ -0,0 +1,14 @@
+// SPDX-License-Identifier: GPL-2.0
+
+/*
+ * Copyright (C) 2024 Google LLC.
+ */
+
+#include <linux/jump_label.h>
+
+#ifndef CONFIG_JUMP_LABEL
+int rust_helper_static_key_count(struct static_key *key)
+{
+ return static_key_count(key);
+}
+#endif
diff --git a/rust/kernel/.gitignore b/rust/kernel/.gitignore
new file mode 100644
index 000000000000..6ba39a178f30
--- /dev/null
+++ b/rust/kernel/.gitignore
@@ -0,0 +1,3 @@
+# SPDX-License-Identifier: GPL-2.0
+
+/generated_arch_static_branch_asm.rs
diff --git a/rust/kernel/generated_arch_static_branch_asm.rs.S b/rust/kernel/generated_arch_static_branch_asm.rs.S
new file mode 100644
index 000000000000..2afb638708db
--- /dev/null
+++ b/rust/kernel/generated_arch_static_branch_asm.rs.S
@@ -0,0 +1,7 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#include <linux/jump_label.h>
+
+// Cut here.
+
+::kernel::concat_literals!(ARCH_STATIC_BRANCH_ASM("{symb} + {off} + {branch}", "{l_yes}"))
diff --git a/rust/kernel/jump_label.rs b/rust/kernel/jump_label.rs
new file mode 100644
index 000000000000..4e974c768dbd
--- /dev/null
+++ b/rust/kernel/jump_label.rs
@@ -0,0 +1,74 @@
+// SPDX-License-Identifier: GPL-2.0
+
+// Copyright (C) 2024 Google LLC.
+
+//! Logic for static keys.
+//!
+//! C header: [`include/linux/jump_label.h`](srctree/include/linux/jump_label.h).
+
+/// Branch based on a static key.
+///
+/// Takes three arguments:
+///
+/// * `key` - the path to the static variable containing the `static_key`.
+/// * `keytyp` - the type of `key`.
+/// * `field` - the name of the field of `key` that contains the `static_key`.
+///
+/// # Safety
+///
+/// The macro must be used with a real static key defined by C.
+#[macro_export]
+macro_rules! static_branch_unlikely {
+ ($key:path, $keytyp:ty, $field:ident) => {{
+ let _key: *const $keytyp = ::core::ptr::addr_of!($key);
+ let _key: *const $crate::bindings::static_key_false = ::core::ptr::addr_of!((*_key).$field);
+ let _key: *const $crate::bindings::static_key = _key.cast();
+
+ #[cfg(not(CONFIG_JUMP_LABEL))]
+ {
+ $crate::bindings::static_key_count(_key.cast_mut()) > 0
+ }
+
+ #[cfg(CONFIG_JUMP_LABEL)]
+ $crate::jump_label::arch_static_branch! { $key, $keytyp, $field, false }
+ }};
+}
+pub use static_branch_unlikely;
+
+/// Assert that the assembly block evaluates to a string literal.
+#[cfg(CONFIG_JUMP_LABEL)]
+const _: &str = include!(concat!(
+ env!("OBJTREE"),
+ "/rust/kernel/generated_arch_static_branch_asm.rs"
+));
+
+#[macro_export]
+#[doc(hidden)]
+#[cfg(CONFIG_JUMP_LABEL)]
+macro_rules! arch_static_branch {
+ ($key:path, $keytyp:ty, $field:ident, $branch:expr) => {'my_label: {
+ $crate::asm!(
+ include!(concat!(env!("OBJTREE"), "/rust/kernel/generated_arch_static_branch_asm.rs"));
+ l_yes = label {
+ break 'my_label true;
+ },
+ symb = sym $key,
+ off = const ::core::mem::offset_of!($keytyp, $field),
+ branch = const $crate::jump_label::bool_to_int($branch),
+ );
+
+ break 'my_label false;
+ }};
+}
+
+#[cfg(CONFIG_JUMP_LABEL)]
+pub use arch_static_branch;
+
+/// A helper used by inline assembly to pass a boolean to as a `const` parameter.
+///
+/// Using this function instead of a cast lets you assert that the input is a boolean, and not some
+/// other type that can also be cast to an integer.
+#[doc(hidden)]
+pub const fn bool_to_int(b: bool) -> i32 {
+ b as i32
+}
diff --git a/rust/kernel/lib.rs b/rust/kernel/lib.rs
index 9843eedd4293..29947bb8593b 100644
--- a/rust/kernel/lib.rs
+++ b/rust/kernel/lib.rs
@@ -38,6 +38,7 @@ pub mod firmware;
pub mod fs;
pub mod init;
pub mod ioctl;
+pub mod jump_label;
#[cfg(CONFIG_KUNIT)]
pub mod kunit;
pub mod list;
@@ -57,6 +58,7 @@ pub mod str;
pub mod sync;
pub mod task;
pub mod time;
+pub mod tracepoint;
pub mod types;
pub mod uaccess;
pub mod workqueue;
@@ -150,3 +152,38 @@ macro_rules! container_of {
ptr.sub(offset) as *const $type
}}
}
+
+/// Helper for `.rs.S` files.
+#[doc(hidden)]
+#[macro_export]
+macro_rules! concat_literals {
+ ($( $asm:literal )* ) => {
+ ::core::concat!($($asm),*)
+ };
+}
+
+/// Wrapper around `asm!` configured for use in the kernel.
+///
+/// Uses a semicolon to avoid parsing ambiguities, even though this does not match native `asm!`
+/// syntax.
+// For x86, `asm!` uses intel syntax by default, but we want to use at&t syntax in the kernel.
+#[cfg(any(target_arch = "x86", target_arch = "x86_64"))]
+#[macro_export]
+macro_rules! asm {
+ ($($asm:expr),* ; $($rest:tt)*) => {
+ ::core::arch::asm!( $($asm)*, options(att_syntax), $($rest)* )
+ };
+}
+
+/// Wrapper around `asm!` configured for use in the kernel.
+///
+/// Uses a semicolon to avoid parsing ambiguities, even though this does not match native `asm!`
+/// syntax.
+// For non-x86 arches we just pass through to `asm!`.
+#[cfg(not(any(target_arch = "x86", target_arch = "x86_64")))]
+#[macro_export]
+macro_rules! asm {
+ ($($asm:expr),* ; $($rest:tt)*) => {
+ ::core::arch::asm!( $($asm)*, $($rest)* )
+ };
+}
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;
generated by cgit v1.2.3 (git 2.39.1) at 2026-01-02 23:52:02 +0000