[PATCH v3 1/1] arm64: rust: Enable Rust support for AArch64
Boqun Feng
boqun.feng at gmail.com
Mon Oct 16 11:14:11 PDT 2023
On Mon, Oct 16, 2023 at 02:15:23PM +0100, Jamie Cunliffe wrote:
> This commit provides the build flags for Rust for AArch64. The core Rust
> support already in the kernel does the rest. This enables the PAC ret
> and BTI options in the Rust build flags to match the options that are
> used when building C.
>
> The Rust samples have been tested with this commit.
>
> Signed-off-by: Jamie Cunliffe <Jamie.Cunliffe at arm.com>
Like I post previouly, the following is needed upon this to make the
command "make LLVM=1" still work on x86:
(the reason is https://lore.kernel.org/rust-for-linux/ZNu9JhYlsFWmliQE@boqun-archlinux/)
diff --git a/rust/Makefile b/rust/Makefile
index 3a784aa3a8a9..ac2ae21b830f 100644
--- a/rust/Makefile
+++ b/rust/Makefile
@@ -429,7 +429,7 @@ $(obj)/core.o: private rustc_objcopy = $(foreach sym,$(redirect-intrinsics),--re
$(obj)/core.o: private rustc_target_flags = $(core-cfgs)
$(obj)/core.o: $(RUST_LIB_SRC)/core/src/lib.rs FORCE
$(call if_changed_dep,rustc_library)
-ifeq ($(ARCH),x86_64)
+ifdef CONFIG_X86_64
$(obj)/core.o: scripts/target.json
endif
diff --git a/scripts/Makefile b/scripts/Makefile
index 0aa78339128c..a1b01c16688d 100644
--- a/scripts/Makefile
+++ b/scripts/Makefile
@@ -12,7 +12,7 @@ hostprogs-always-$(CONFIG_SYSTEM_EXTRA_CERTIFICATE) += insert-sys-cert
hostprogs-always-$(CONFIG_RUST_KERNEL_DOCTESTS) += rustdoc_test_builder
hostprogs-always-$(CONFIG_RUST_KERNEL_DOCTESTS) += rustdoc_test_gen
-ifeq ($(ARCH),x86_64)
+ifdef CONFIG_X86_64
always-$(CONFIG_RUST) += target.json
filechk_rust_target = $< < include/config/auto.conf
$(obj)/target.json: scripts/generate_rust_target include/config/auto.conf FORCE
I put an updated version in the rust-dev branch:
https://github.com/Rust-for-Linux/linux/commits/rust-dev
and have tested it (with kunit), so feel free to add:
Tested-by: Boqun Feng <boqun.feng at gmail.com>
More information for ARM64 maintainers, I have queued the previous
version for a while and tested with it whenever I updated the rust-dev,
so far no problem. I also have accesses to some ARM64 VMs (on Microsoft
Azure), if you want to see more testing, feel free to let me know.
Regards,
Boqun
> ---
> Documentation/rust/arch-support.rst | 1 +
> Makefile | 1 -
> arch/arm64/Kconfig | 1 +
> arch/arm64/Makefile | 4 ++++
> arch/x86/Makefile | 1 +
> rust/Makefile | 6 +++++-
> scripts/Makefile | 5 +++--
> scripts/generate_rust_target.rs | 4 +++-
> 8 files changed, 18 insertions(+), 5 deletions(-)
>
> diff --git a/Documentation/rust/arch-support.rst b/Documentation/rust/arch-support.rst
> index b91e9ef4d0c2..6bcb3b97c5b6 100644
> --- a/Documentation/rust/arch-support.rst
> +++ b/Documentation/rust/arch-support.rst
> @@ -15,6 +15,7 @@ support corresponds to ``S`` values in the ``MAINTAINERS`` file.
> ============ ================ ==============================================
> Architecture Level of support Constraints
> ============ ================ ==============================================
> +``arm64`` Maintained Little Endian only.
> ``um`` Maintained ``x86_64`` only.
> ``x86`` Maintained ``x86_64`` only.
> ============ ================ ==============================================
> diff --git a/Makefile b/Makefile
> index 88ebf6547964..23100f193da3 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -566,7 +566,6 @@ KBUILD_CFLAGS += -fno-strict-aliasing
>
> KBUILD_CPPFLAGS := -D__KERNEL__
> KBUILD_RUSTFLAGS := $(rust_common_flags) \
> - --target=$(objtree)/scripts/target.json \
> -Cpanic=abort -Cembed-bitcode=n -Clto=n \
> -Cforce-unwind-tables=n -Ccodegen-units=1 \
> -Csymbol-mangling-version=v0 \
> diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
> index 78f20e632712..d72618433521 100644
> --- a/arch/arm64/Kconfig
> +++ b/arch/arm64/Kconfig
> @@ -227,6 +227,7 @@ config ARM64
> select HAVE_FUNCTION_ARG_ACCESS_API
> select MMU_GATHER_RCU_TABLE_FREE
> select HAVE_RSEQ
> + select HAVE_RUST if CPU_LITTLE_ENDIAN
> select HAVE_STACKPROTECTOR
> select HAVE_SYSCALL_TRACEPOINTS
> select HAVE_KPROBES
> diff --git a/arch/arm64/Makefile b/arch/arm64/Makefile
> index 2d49aea0ff67..4562a8173e90 100644
> --- a/arch/arm64/Makefile
> +++ b/arch/arm64/Makefile
> @@ -41,6 +41,8 @@ KBUILD_CFLAGS += -mgeneral-regs-only \
> KBUILD_CFLAGS += $(call cc-disable-warning, psabi)
> KBUILD_AFLAGS += $(compat_vdso)
>
> +KBUILD_RUSTFLAGS += --target aarch64-unknown-none -C target-feature="-neon"
> +
> KBUILD_CFLAGS += $(call cc-option,-mabi=lp64)
> KBUILD_AFLAGS += $(call cc-option,-mabi=lp64)
>
> @@ -65,7 +67,9 @@ endif
>
> ifeq ($(CONFIG_ARM64_BTI_KERNEL),y)
> KBUILD_CFLAGS += -mbranch-protection=pac-ret+bti
> + KBUILD_RUSTFLAGS += -Z branch-protection=bti,pac-ret
> else ifeq ($(CONFIG_ARM64_PTR_AUTH_KERNEL),y)
> + KBUILD_RUSTFLAGS += -Z branch-protection=pac-ret
> ifeq ($(CONFIG_CC_HAS_BRANCH_PROT_PAC_RET),y)
> KBUILD_CFLAGS += -mbranch-protection=pac-ret
> else
> diff --git a/arch/x86/Makefile b/arch/x86/Makefile
> index 5bfe5caaa444..0f339d4abd40 100644
> --- a/arch/x86/Makefile
> +++ b/arch/x86/Makefile
> @@ -68,6 +68,7 @@ export BITS
> # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=53383
> #
> KBUILD_CFLAGS += -mno-sse -mno-mmx -mno-sse2 -mno-3dnow -mno-avx
> +KBUILD_RUSTFLAGS += --target=$(objtree)/scripts/target.json
> KBUILD_RUSTFLAGS += -Ctarget-feature=-sse,-sse2,-sse3,-ssse3,-sse4.1,-sse4.2,-avx,-avx2
>
> ifeq ($(CONFIG_X86_KERNEL_IBT),y)
> diff --git a/rust/Makefile b/rust/Makefile
> index 87958e864be0..b3127501e0e1 100644
> --- a/rust/Makefile
> +++ b/rust/Makefile
> @@ -294,6 +294,7 @@ bindgen_skip_c_flags := -mno-fp-ret-in-387 -mpreferred-stack-boundary=% \
>
> # Derived from `scripts/Makefile.clang`.
> BINDGEN_TARGET_x86 := x86_64-linux-gnu
> +BINDGEN_TARGET_arm64 := aarch64-linux-gnu
> BINDGEN_TARGET := $(BINDGEN_TARGET_$(SRCARCH))
>
> # All warnings are inhibited since GCC builds are very experimental,
> @@ -428,8 +429,11 @@ $(obj)/core.o: private skip_clippy = 1
> $(obj)/core.o: private skip_flags = -Dunreachable_pub
> $(obj)/core.o: private rustc_objcopy = $(foreach sym,$(redirect-intrinsics),--redefine-sym $(sym)=__rust$(sym))
> $(obj)/core.o: private rustc_target_flags = $(core-cfgs)
> -$(obj)/core.o: $(RUST_LIB_SRC)/core/src/lib.rs scripts/target.json FORCE
> +$(obj)/core.o: $(RUST_LIB_SRC)/core/src/lib.rs FORCE
> $(call if_changed_dep,rustc_library)
> +ifeq ($(ARCH),x86_64)
> +$(obj)/core.o: scripts/target.json
> +endif
>
> $(obj)/compiler_builtins.o: private rustc_objcopy = -w -W '__*'
> $(obj)/compiler_builtins.o: $(src)/compiler_builtins.rs $(obj)/core.o FORCE
> diff --git a/scripts/Makefile b/scripts/Makefile
> index 576cf64be667..0aa78339128c 100644
> --- a/scripts/Makefile
> +++ b/scripts/Makefile
> @@ -11,12 +11,13 @@ hostprogs-always-$(CONFIG_MODULE_SIG_FORMAT) += sign-file
> hostprogs-always-$(CONFIG_SYSTEM_EXTRA_CERTIFICATE) += insert-sys-cert
> hostprogs-always-$(CONFIG_RUST_KERNEL_DOCTESTS) += rustdoc_test_builder
> hostprogs-always-$(CONFIG_RUST_KERNEL_DOCTESTS) += rustdoc_test_gen
> -always-$(CONFIG_RUST) += target.json
>
> +ifeq ($(ARCH),x86_64)
> +always-$(CONFIG_RUST) += target.json
> filechk_rust_target = $< < include/config/auto.conf
> -
> $(obj)/target.json: scripts/generate_rust_target include/config/auto.conf FORCE
> $(call filechk,rust_target)
> +endif
>
> hostprogs += generate_rust_target
> generate_rust_target-rust := y
> diff --git a/scripts/generate_rust_target.rs b/scripts/generate_rust_target.rs
> index 3c6cbe2b278d..ec5ef35dbe52 100644
> --- a/scripts/generate_rust_target.rs
> +++ b/scripts/generate_rust_target.rs
> @@ -148,7 +148,9 @@ fn main() {
> let mut ts = TargetSpec::new();
>
> // `llvm-target`s are taken from `scripts/Makefile.clang`.
> - if cfg.has("X86_64") {
> + if cfg.has("ARM64") {
> + panic!("arm64 uses the builtin rustc aarch64-unknown-none target");
> + } else if cfg.has("X86_64") {
> ts.push("arch", "x86_64");
> ts.push(
> "data-layout",
> --
> 2.30.2
>
More information about the linux-arm-kernel
mailing list