From 724a75ac9542fe1f8aaa587da4d3863d8ea292fc Mon Sep 17 00:00:00 2001
From: Jamie Cunliffe <Jamie.Cunliffe@arm.com>
Date: Fri, 20 Oct 2023 16:50:56 +0100
Subject: [PATCH] arm64: rust: Enable Rust support for AArch64
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@arm.com>
Acked-by: Will Deacon <will@kernel.org>
Tested-by: Dirk Behme <dirk.behme@de.bosch.com>
Tested-by: Boqun Feng <boqun.feng@gmail.com>
Acked-by: Miguel Ojeda <ojeda@kernel.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: Alice Ryhl <aliceryhl@google.com>
Tested-by: Fabien Parent <fabien.parent@linaro.org>
Link: https://lore.kernel.org/r/20231020155056.3495121-3-Jamie.Cunliffe@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
---
Documentation/rust/arch-support.rst | 1 +
arch/arm64/Kconfig | 1 +
arch/arm64/Makefile | 4 ++++
rust/Makefile | 1 +
scripts/generate_rust_target.rs | 4 +++-
5 files changed, 10 insertions(+), 1 deletion(-)
diff --git a/Documentation/rust/arch-support.rst b/Documentation/rust/arch-support.rst
index 73203ba1e9011..5c4fa9f5d1cdb 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.
``loongarch`` Maintained -
``um`` Maintained ``x86_64`` only.
``x86`` Maintained ``x86_64`` only.
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index aa7c1d4351396..8a5f3823242c8 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -229,6 +229,7 @@ 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 a88cdf9106871..0e075d3c546b4 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 -Ctarget-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 += -Zbranch-protection=bti,pac-ret
else ifeq ($(CONFIG_ARM64_PTR_AUTH_KERNEL),y)
+ KBUILD_RUSTFLAGS += -Zbranch-protection=pac-ret
ifeq ($(CONFIG_CC_HAS_BRANCH_PROT_PAC_RET),y)
KBUILD_CFLAGS += -mbranch-protection=pac-ret
else
diff --git a/rust/Makefile b/rust/Makefile
index 88f88a26e5032..fe045dbc701ea 100644
--- a/rust/Makefile
+++ b/rust/Makefile
@@ -297,6 +297,7 @@ 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,
diff --git a/scripts/generate_rust_target.rs b/scripts/generate_rust_target.rs
index 0da52b548ba50..9e117957ea7ba 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",
--
GitLab