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[221.188.16.207]) by smtp.gmail.com with ESMTPSA id d2e1a72fcca58-72918ad5bc5sm7987806b3a.69.2024.12.17.22.21.27 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 17 Dec 2024 22:21:33 -0800 (PST) From: FUJITA Tomonori To: linux-kernel@vger.kernel.org, rust-for-linux@vger.kernel.org Cc: x86@kernel.org, linux-riscv@lists.infradead.org, linux-arm-kernel@lists.infradead.org, loongarch@lists.linux.dev, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, peterz@infradead.org, hpa@zytor.com, paul.walmsley@sifive.com, palmer@dabbelt.com, aou@eecs.berkeley.edu, catalin.marinas@arm.com, will@kernel.org, chenhuacai@kernel.org, kernel@xen0n.name, tangyouling@loongson.cn, hejinyang@loongson.cn, yangtiezhu@loongson.cn, ojeda@kernel.org, alex.gaynor@gmail.com, boqun.feng@gmail.com, gary@garyguo.net, bjorn3_gh@protonmail.com, benno.lossin@proton.me, a.hindborg@kernel.org, aliceryhl@google.com, tmgross@umich.edu Subject: [PATCH v2 5/5] rust: Add warn_on and warn_on_once Date: Wed, 18 Dec 2024 15:20:09 +0900 Message-ID: <20241218062009.2402650-6-fujita.tomonori@gmail.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20241218062009.2402650-1-fujita.tomonori@gmail.com> References: <20241218062009.2402650-1-fujita.tomonori@gmail.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" 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 --- 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 diff --git a/rust/Makefile b/rust/Makefile index a40a3936126d..633b2c28605c 100644 --- a/rust/Makefile +++ b/rust/Makefile @@ -37,6 +37,9 @@ obj-$(CONFIG_RUST_KERNEL_DOCTESTS) +=3D doctests_kernel_g= enerated.o obj-$(CONFIG_RUST_KERNEL_DOCTESTS) +=3D doctests_kernel_generated_kunit.o =20 always-$(subst y,$(CONFIG_RUST),$(CONFIG_JUMP_LABEL)) +=3D kernel/generate= d_arch_static_branch_asm.rs +ifndef CONFIG_UML +always-$(subst y,$(CONFIG_RUST),$(CONFIG_BUG)) +=3D kernel/generated_arch_= warn_asm.rs kernel/generated_arch_reachable_asm.rs +endif =20 # 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_err= or.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 $(obj)/kernel/ge= nerated_arch_reachable_asm.rs +endif +endif =20 endif # CONFIG_RUST diff --git a/rust/kernel/.gitignore b/rust/kernel/.gitignore index 6ba39a178f30..f1d7f4225332 100644 --- a/rust/kernel/.gitignore +++ b/rust/kernel/.gitignore @@ -1,3 +1,5 @@ # SPDX-License-Identifier: GPL-2.0 =20 /generated_arch_static_branch_asm.rs +/generated_arch_warn_asm.rs +/generated_arch_reachable_asm.rs \ No newline at end of file diff --git a/rust/kernel/bug.rs b/rust/kernel/bug.rs new file mode 100644 index 000000000000..7ffd9cb1ad75 --- /dev/null +++ b/rust/kernel/bug.rs @@ -0,0 +1,100 @@ +// SPDX-License-Identifier: GPL-2.0 + +// Copyright (C) 2024 FUJITA Tomonori + +//! Support for BUG_* and WARN_* functionality. +//! +//! C header: [`include/asm-generic/bug.h`](srctree/include/asm-generic/bu= g.h) + +#[macro_export] +#[doc(hidden)] +#[cfg(all(CONFIG_BUG, not(CONFIG_UML)))] +macro_rules! warn_flags { + ($flags:expr) =3D> { + const FLAGS: u32 =3D $crate::bindings::BUGFLAG_WARNING | $flags; + // SAFETY: Just an FFI call. + #[cfg(CONFIG_DEBUG_BUGVERBOSE)] + unsafe { + $crate::asm!(concat!( + "/* {size} */", + ".pushsection .rodata.str1.1, \"aMS\",@progbits, 1\n", + "111:\t .string ", "\"", file!(), "\"\n", + ".popsection\n", + include!(concat!(env!("OBJTREE"), "/rust/kernel/generated_= arch_warn_asm.rs")), + include!(concat!(env!("OBJTREE"), "/rust/kernel/generated_= arch_reachable_asm.rs"))); + line =3D const line!(), + flags =3D const FLAGS, + size =3D const ::core::mem::size_of::<$crate::bindings::bug_en= try>(), + ); + } + // SAFETY: Just an FFI call. + #[cfg(not(CONFIG_DEBUG_BUGVERBOSE))] + unsafe { + $crate::asm!( + concat!( + "/* {size} */", + include!(concat!(env!("OBJTREE"), "/rust/kernel/generated_= arch_warn_asm.rs")), + include!(concat!(env!("OBJTREE"), "/rust/kernel/generated_= arch_reachable_asm.rs"))); + flags =3D const FLAGS, + size =3D const ::core::mem::size_of::<$crate::bindings::bug_en= try>(), + ); + } + } +} + +#[macro_export] +#[doc(hidden)] +#[cfg(all(CONFIG_BUG, CONFIG_UML))] +macro_rules! warn_flags { + ($flags:expr) =3D> { + // 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) =3D> {}; +} + +#[doc(hidden)] +#[macro_export] +macro_rules! bugflag_taint { + ($taint:expr) =3D> { + $taint << 8 + }; +} + +/// Report a warning only once. +#[macro_export] +macro_rules! warn_on_once { + ($cond:expr) =3D> { + 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) =3D> { + if $cond { + $crate::warn_flags!($crate::bugflag_taint!($crate::bindings::T= AINT_WARN)); + } + $cond + }; +} diff --git a/rust/kernel/generated_arch_reachable_asm.rs.S b/rust/kernel/ge= nerated_arch_reachable_asm.rs.S new file mode 100644 index 000000000000..4e65525e4464 --- /dev/null +++ b/rust/kernel/generated_arch_reachable_asm.rs.S @@ -0,0 +1,7 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#include + +// Cut here. + +::kernel::concat_literals!(ASM_REACHABLE) diff --git a/rust/kernel/generated_arch_warn_asm.rs.S b/rust/kernel/generat= ed_arch_warn_asm.rs.S new file mode 100644 index 000000000000..8f239b431aa4 --- /dev/null +++ b/rust/kernel/generated_arch_warn_asm.rs.S @@ -0,0 +1,7 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#include + +// Cut here. + +::kernel::concat_literals!(ARCH_WARN_ASM("111b", "{line}", "{flags}", "{s= ize}")) diff --git a/rust/kernel/lib.rs b/rust/kernel/lib.rs index e1065a7551a3..913f3a5b2a98 100644 --- a/rust/kernel/lib.rs +++ b/rust/kernel/lib.rs @@ -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; --=20 2.43.0