@@ -37,6 +37,9 @@ obj-$(CONFIG_RUST_KERNEL_DOCTESTS) += doctests_kernel_generated.o
obj-$(CONFIG_RUST_KERNEL_DOCTESTS) += doctests_kernel_generated_kunit.o
always-$(subst y,$(CONFIG_RUST),$(CONFIG_JUMP_LABEL)) += kernel/generated_arch_static_branch_asm.rs
+ifndef CONFIG_UML
+always-$(subst y,$(CONFIG_RUST),$(CONFIG_BUG)) += kernel/generated_arch_warn_asm.rs kernel/generated_arch_reachable_asm.rs
+endif
# Avoids running `$(RUSTC)` for the sysroot when it may not be available.
ifdef CONFIG_RUST
@@ -449,5 +452,10 @@ $(obj)/kernel.o: $(src)/kernel/lib.rs $(obj)/build_error.o \
ifdef CONFIG_JUMP_LABEL
$(obj)/kernel.o: $(obj)/kernel/generated_arch_static_branch_asm.rs
endif
+ifndef CONFIG_UML
+ifdef CONFIG_BUG
+$(obj)/kernel.o: $(obj)/kernel/generated_arch_warn_asm.rs $(obj)/kernel/generated_arch_reachable_asm.rs
+endif
+endif
endif # CONFIG_RUST
@@ -1,3 +1,5 @@
# SPDX-License-Identifier: GPL-2.0
/generated_arch_static_branch_asm.rs
+/generated_arch_warn_asm.rs
+/generated_arch_reachable_asm.rs
\ No newline at end of file
new file mode 100644
@@ -0,0 +1,100 @@
+// SPDX-License-Identifier: GPL-2.0
+
+// Copyright (C) 2024 FUJITA Tomonori
+
+//! Support for BUG_* and WARN_* functionality.
+//!
+//! C header: [`include/asm-generic/bug.h`](srctree/include/asm-generic/bug.h)
+
+#[macro_export]
+#[doc(hidden)]
+#[cfg(all(CONFIG_BUG, not(CONFIG_UML)))]
+macro_rules! warn_flags {
+ ($flags:expr) => {
+ const FLAGS: u32 = $crate::bindings::BUGFLAG_WARNING | $flags;
+ // SAFETY: Just an FFI call.
+ #[cfg(CONFIG_DEBUG_BUGVERBOSE)]
+ unsafe {
+ $crate::asm!(concat!(
+ "/* {size} */",
+ ".pushsection .rodata.str1.1, \"aMS\",@progbits, 1\n",
+ "111:\t .string ", "\"", file!(), "\"\n",
+ ".popsection\n",
+ include!(concat!(env!("OBJTREE"), "/rust/kernel/generated_arch_warn_asm.rs")),
+ include!(concat!(env!("OBJTREE"), "/rust/kernel/generated_arch_reachable_asm.rs")));
+ line = const line!(),
+ flags = const FLAGS,
+ size = const ::core::mem::size_of::<$crate::bindings::bug_entry>(),
+ );
+ }
+ // SAFETY: Just an FFI call.
+ #[cfg(not(CONFIG_DEBUG_BUGVERBOSE))]
+ unsafe {
+ $crate::asm!(
+ concat!(
+ "/* {size} */",
+ include!(concat!(env!("OBJTREE"), "/rust/kernel/generated_arch_warn_asm.rs")),
+ include!(concat!(env!("OBJTREE"), "/rust/kernel/generated_arch_reachable_asm.rs")));
+ flags = const FLAGS,
+ size = const ::core::mem::size_of::<$crate::bindings::bug_entry>(),
+ );
+ }
+ }
+}
+
+#[macro_export]
+#[doc(hidden)]
+#[cfg(all(CONFIG_BUG, CONFIG_UML))]
+macro_rules! warn_flags {
+ ($flags:expr) => {
+ // SAFETY: Just an FFI call.
+ unsafe {
+ $crate::bindings::warn_slowpath_fmt(
+ $crate::c_str!(::core::file!()).as_ptr() as *const ::core::ffi::c_char,
+ line!() as i32,
+ $flags as u32,
+ ::core::ptr::null() as *const ::core::ffi::c_char,
+ );
+ }
+ };
+}
+
+#[macro_export]
+#[doc(hidden)]
+#[cfg(not(CONFIG_BUG))]
+macro_rules! warn_flags {
+ ($flags:expr) => {};
+}
+
+#[doc(hidden)]
+#[macro_export]
+macro_rules! bugflag_taint {
+ ($taint:expr) => {
+ $taint << 8
+ };
+}
+
+/// Report a warning only once.
+#[macro_export]
+macro_rules! warn_on_once {
+ ($cond:expr) => {
+ if $cond {
+ $crate::warn_flags!(
+ $crate::bindings::BUGFLAG_ONCE
+ | $crate::bugflag_taint!($crate::bindings::TAINT_WARN)
+ );
+ }
+ $cond
+ };
+}
+
+/// Report a warning.
+#[macro_export]
+macro_rules! warn_on {
+ ($cond:expr) => {
+ if $cond {
+ $crate::warn_flags!($crate::bugflag_taint!($crate::bindings::TAINT_WARN));
+ }
+ $cond
+ };
+}
new file mode 100644
@@ -0,0 +1,7 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#include <linux/objtool.h>
+
+// Cut here.
+
+::kernel::concat_literals!(ASM_REACHABLE)
new file mode 100644
@@ -0,0 +1,7 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#include <linux/bug.h>
+
+// Cut here.
+
+::kernel::concat_literals!(ARCH_WARN_ASM("111b", "{line}", "{flags}", "{size}"))
@@ -32,6 +32,7 @@
pub mod alloc;
#[cfg(CONFIG_BLOCK)]
pub mod block;
+pub mod bug;
mod build_assert;
pub mod cred;
pub mod device;
Add warn_on and warn_on_once macros. Wrapping the C's WARN_* and BUG_* macros doesn't work so this uses the assembly code exported by the C side via ARCH_WARN_ASM macro. Like the static branch code, this generates the assembly code for rust dynamically by using the C preprocessor. file()! macro doesn't work for the Rust inline assembly in the same way as __FILE__ for the C inline assembly. So the code to handle a file name is different from the C assembly code (similar to the arm64/loongarch assembly). ASM_REACHABLE definition works in the same way to get objtool's reachable asm code. The architectures which use objtool (x86 and loongarch) needs it. Signed-off-by: FUJITA Tomonori <fujita.tomonori@gmail.com> --- rust/Makefile | 8 ++ rust/kernel/.gitignore | 2 + rust/kernel/bug.rs | 100 ++++++++++++++++++ rust/kernel/generated_arch_reachable_asm.rs.S | 7 ++ rust/kernel/generated_arch_warn_asm.rs.S | 7 ++ rust/kernel/lib.rs | 1 + 6 files changed, 125 insertions(+) create mode 100644 rust/kernel/bug.rs create mode 100644 rust/kernel/generated_arch_reachable_asm.rs.S create mode 100644 rust/kernel/generated_arch_warn_asm.rs.S