[PATCH v3 0/1] Rust enablement for AArch64

[PATCH v3 0/1] Rust enablement for AArch64

[Jamie Cunliffe]

Enable Rust support for the AArch64 architecture.

The only change here since the v2 patch is the removal of the
fp-armv8 feature. rustc ties fp and Neon together. However due to a
bug in versions before 1.71 fp wasn't correctly being disabled. Now
the compiler version used is 1.71 we can drop this option which now
allows this to build without warnings.

Jamie Cunliffe (1):
  arm64: rust: Enable Rust support for AArch64

 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(-)

-- 
2.30.2

[PATCH v3 1/1] arm64: rust: Enable Rust support for AArch64

[Jamie Cunliffe]

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>
---
 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

Re: [PATCH v3 1/1] arm64: rust: Enable Rust support for AArch64

[Boqun Feng]

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@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@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
> 

Re: [PATCH v3 1/1] arm64: rust: Enable Rust support for AArch64

[Andrew Lunn]

> --- 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

It seems odd that adding arm64 support requires adding to the x86
Makefile.

Should this be moved into a patch of its own explaining why it is
needed? Do the refactoring first, then add support for a new
architecture?

	Andrew

Re: [PATCH v3 1/1] arm64: rust: Enable Rust support for AArch64

[Miguel Ojeda]

On Mon, Oct 16, 2023 at 11:47 PM Andrew Lunn <andrew@lunn.ch> wrote:
>
> It seems odd that adding arm64 support requires adding to the x86
> Makefile.

> Should this be moved into a patch of its own explaining why it is
> needed? Do the refactoring first, then add support for a new
> architecture?

That would be nice, yeah.

(It is needed because they are not using the target specification file
for arm64, which is something that an architecture should use only if
required. Eventually the goal is to not use it for any architecture).

Cheers,
Miguel

Re: [PATCH v3 1/1] arm64: rust: Enable Rust support for AArch64

[Miguel Ojeda]

On Mon, Oct 16, 2023 at 3:16 PM Jamie Cunliffe <Jamie.Cunliffe@arm.com> wrote:
>
>  BINDGEN_TARGET_x86     := x86_64-linux-gnu
> +BINDGEN_TARGET_arm64    := aarch64-linux-gnu

Tabs vs. spaces.

>  filechk_rust_target = $< < include/config/auto.conf
> -

Spurious removal?

Cheers,
Miguel

Re: [PATCH v3 1/1] arm64: rust: Enable Rust support for AArch64

[Miguel Ojeda]

On Mon, Oct 16, 2023 at 3:16 PM Jamie Cunliffe <Jamie.Cunliffe@arm.com> wrote:
>
> +KBUILD_RUSTFLAGS += --target aarch64-unknown-none -C target-feature="-neon"

For consistency with other flags we pass in Rust, please avoid the
space after `-C`.

By the way, perhaps we could already add others like (untested):

 ifeq ($(CONFIG_ARM64_USE_LSE_ATOMICS),y)
+KBUILD_RUSTFLAGS += -Ctarget-feature="+lse"
   ifneq ($(CONFIG_ARM64_LSE_ATOMICS),y)
        @echo "warning: LSE atomics not supported by binutils" >&2
   endif

This one in particular (LSE) came up in a Binder discussion yesterday.

Cheers,
Miguel

Re: [PATCH v3 1/1] arm64: rust: Enable Rust support for AArch64

[Miguel Ojeda]

On Tue, Oct 17, 2023 at 5:38 PM Miguel Ojeda
<miguel.ojeda.sandonis@gmail.com> wrote:
>
> By the way, perhaps we could already add others like (untested):
>
>  ifeq ($(CONFIG_ARM64_USE_LSE_ATOMICS),y)
> +KBUILD_RUSTFLAGS += -Ctarget-feature="+lse"
>    ifneq ($(CONFIG_ARM64_LSE_ATOMICS),y)
>         @echo "warning: LSE atomics not supported by binutils" >&2
>    endif

Ignore this, sorry -- as Boqun reminded me, this uses an
`ALTERNATIVE`, rather than enable it unconditionally. See
https://github.com/Rust-for-Linux/linux/issues/970.

Cheers,
Miguel

Re: [PATCH v3 1/1] arm64: rust: Enable Rust support for AArch64

[Will Deacon]

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@arm.com>
> ---
>  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(-)

Acked-by: Will Deacon <will@kernel.org>

Will