Having all the new files in place, we now enable Rust support
in the build system, including `Kconfig` entries related to Rust,
the Rust configuration printer, the target definition files,
the version detection script and a few other bits.
In the future, we will likely want to generate the target files
on the fly via a script.
Co-developed-by: Alex Gaynor <[email protected]>
Signed-off-by: Alex Gaynor <[email protected]>
Co-developed-by: Finn Behrens <[email protected]>
Signed-off-by: Finn Behrens <[email protected]>
Co-developed-by: Adam Bratschi-Kaye <[email protected]>
Signed-off-by: Adam Bratschi-Kaye <[email protected]>
Co-developed-by: Wedson Almeida Filho <[email protected]>
Signed-off-by: Wedson Almeida Filho <[email protected]>
Co-developed-by: Michael Ellerman <[email protected]>
Signed-off-by: Michael Ellerman <[email protected]>
Co-developed-by: Sven Van Asbroeck <[email protected]>
Signed-off-by: Sven Van Asbroeck <[email protected]>
Co-developed-by: Gary Guo <[email protected]>
Signed-off-by: Gary Guo <[email protected]>
Co-developed-by: Boris-Chengbiao Zhou <[email protected]>
Signed-off-by: Boris-Chengbiao Zhou <[email protected]>
Co-developed-by: Boqun Feng <[email protected]>
Signed-off-by: Boqun Feng <[email protected]>
Co-developed-by: Douglas Su <[email protected]>
Signed-off-by: Douglas Su <[email protected]>
Co-developed-by: Dariusz Sosnowski <[email protected]>
Signed-off-by: Dariusz Sosnowski <[email protected]>
Co-developed-by: Antonio Terceiro <[email protected]>
Signed-off-by: Antonio Terceiro <[email protected]>
Co-developed-by: Daniel Xu <[email protected]>
Signed-off-by: Daniel Xu <[email protected]>
Co-developed-by: Miguel Cano <[email protected]>
Signed-off-by: Miguel Cano <[email protected]>
Signed-off-by: Miguel Ojeda <[email protected]>
---
.gitignore | 5 +
.rustfmt.toml | 12 +
Makefile | 154 +++++++-
arch/arm/rust/target.json | 27 ++
arch/arm64/rust/target.json | 34 ++
arch/powerpc/rust/target.json | 29 ++
arch/riscv/Makefile | 1 +
arch/riscv/rust/rv32ima.json | 36 ++
arch/riscv/rust/rv32imac.json | 36 ++
arch/riscv/rust/rv64ima.json | 36 ++
arch/riscv/rust/rv64imac.json | 36 ++
arch/x86/rust/target.json | 36 ++
init/Kconfig | 45 ++-
lib/Kconfig.debug | 144 +++++++
rust/.gitignore | 7 +
rust/Makefile | 374 +++++++++++++++++++
rust/bindgen_parameters | 13 +
scripts/Kconfig.include | 6 +-
scripts/Makefile.build | 65 ++++
scripts/Makefile.debug | 10 +
scripts/Makefile.lib | 12 +
scripts/Makefile.modfinal | 8 +-
scripts/cc-version.sh | 12 +-
scripts/is_rust_module.sh | 13 +
scripts/kconfig/confdata.c | 75 ++++
scripts/min-tool-version.sh | 6 +
scripts/rust-is-available-bindgen-libclang.h | 2 +
scripts/rust-is-available.sh | 158 ++++++++
28 files changed, 1372 insertions(+), 20 deletions(-)
create mode 100644 .rustfmt.toml
create mode 100644 arch/arm/rust/target.json
create mode 100644 arch/arm64/rust/target.json
create mode 100644 arch/powerpc/rust/target.json
create mode 100644 arch/riscv/rust/rv32ima.json
create mode 100644 arch/riscv/rust/rv32imac.json
create mode 100644 arch/riscv/rust/rv64ima.json
create mode 100644 arch/riscv/rust/rv64imac.json
create mode 100644 arch/x86/rust/target.json
create mode 100644 rust/.gitignore
create mode 100644 rust/Makefile
create mode 100644 rust/bindgen_parameters
create mode 100755 scripts/is_rust_module.sh
create mode 100644 scripts/rust-is-available-bindgen-libclang.h
create mode 100755 scripts/rust-is-available.sh
diff --git a/.gitignore b/.gitignore
index 7afd412dadd2..48c68948f476 100644
--- a/.gitignore
+++ b/.gitignore
@@ -37,6 +37,7 @@
*.o
*.o.*
*.patch
+*.rmeta
*.s
*.so
*.so.dbg
@@ -96,6 +97,7 @@ modules.order
!.gitattributes
!.gitignore
!.mailmap
+!.rustfmt.toml
#
# Generated include files
@@ -161,3 +163,6 @@ x509.genkey
# Documentation toolchain
sphinx_*/
+
+# Rust analyzer configuration
+/rust-project.json
diff --git a/.rustfmt.toml b/.rustfmt.toml
new file mode 100644
index 000000000000..3de5cc497465
--- /dev/null
+++ b/.rustfmt.toml
@@ -0,0 +1,12 @@
+edition = "2021"
+newline_style = "Unix"
+
+# Unstable options that help catching some mistakes in formatting and that we may want to enable
+# when they become stable.
+#
+# They are kept here since they are useful to run from time to time.
+#format_code_in_doc_comments = true
+#reorder_impl_items = true
+#comment_width = 100
+#wrap_comments = true
+#normalize_comments = true
diff --git a/Makefile b/Makefile
index ceb987e5c87b..1975d47e74e6 100644
--- a/Makefile
+++ b/Makefile
@@ -120,6 +120,13 @@ endif
export KBUILD_CHECKSRC
+# Enable "clippy" (a linter) as part of the Rust compilation.
+#
+# Use 'make CLIPPY=1' to enable it.
+ifeq ("$(origin CLIPPY)", "command line")
+ KBUILD_CLIPPY := $(CLIPPY)
+endif
+
# Use make M=dir or set the environment variable KBUILD_EXTMOD to specify the
# directory of external module to build. Setting M= takes precedence.
ifeq ("$(origin M)", "command line")
@@ -267,7 +274,7 @@ no-dot-config-targets := $(clean-targets) \
cscope gtags TAGS tags help% %docs check% coccicheck \
$(version_h) headers headers_% archheaders archscripts \
%asm-generic kernelversion %src-pkg dt_binding_check \
- outputmakefile
+ outputmakefile rustavailable rustfmt rustfmtcheck
# Installation targets should not require compiler. Unfortunately, vdso_install
# is an exception where build artifacts may be updated. This must be fixed.
no-compiler-targets := $(no-dot-config-targets) install dtbs_install \
@@ -461,6 +468,12 @@ OBJDUMP = $(CROSS_COMPILE)objdump
READELF = $(CROSS_COMPILE)readelf
STRIP = $(CROSS_COMPILE)strip
endif
+RUSTC = rustc
+RUSTDOC = rustdoc
+RUSTFMT = rustfmt
+CLIPPY_DRIVER = clippy-driver
+BINDGEN = bindgen
+CARGO = cargo
PAHOLE = pahole
RESOLVE_BTFIDS = $(objtree)/tools/bpf/resolve_btfids/resolve_btfids
LEX = flex
@@ -486,9 +499,11 @@ CHECKFLAGS := -D__linux__ -Dlinux -D__STDC__ -Dunix -D__unix__ \
-Wbitwise -Wno-return-void -Wno-unknown-attribute $(CF)
NOSTDINC_FLAGS :=
CFLAGS_MODULE =
+RUSTFLAGS_MODULE =
AFLAGS_MODULE =
LDFLAGS_MODULE =
CFLAGS_KERNEL =
+RUSTFLAGS_KERNEL =
AFLAGS_KERNEL =
LDFLAGS_vmlinux =
@@ -517,15 +532,46 @@ KBUILD_CFLAGS := -Wall -Wundef -Werror=strict-prototypes -Wno-trigraphs \
-Werror=return-type -Wno-format-security \
-std=gnu89
KBUILD_CPPFLAGS := -D__KERNEL__
+KBUILD_RUST_TARGET := $(srctree)/arch/$(SRCARCH)/rust/target.json
+KBUILD_RUSTFLAGS := --edition=2021 \
+ -Cpanic=abort -Cembed-bitcode=n -Clto=n -Crpath=n \
+ -Cforce-unwind-tables=n -Ccodegen-units=1 \
+ -Zbinary_dep_depinfo=y -Zsymbol-mangling-version=v0 \
+ -Dunsafe_op_in_unsafe_fn -Drust_2018_idioms \
+ -Dunreachable_pub -Dnon_ascii_idents \
+ -Wmissing_docs \
+ -Drustdoc::missing_crate_level_docs \
+ -Dclippy::correctness -Dclippy::style -Dclippy::suspicious \
+ -Dclippy::complexity -Dclippy::perf -Dclippy::float_arithmetic \
+ -Dclippy::let_unit_value -Dclippy::mut_mut \
+ -Dclippy::needless_bitwise_bool -Dclippy::needless_continue \
+ -Wclippy::dbg_macro
KBUILD_AFLAGS_KERNEL :=
KBUILD_CFLAGS_KERNEL :=
+KBUILD_RUSTFLAGS_KERNEL :=
KBUILD_AFLAGS_MODULE := -DMODULE
KBUILD_CFLAGS_MODULE := -DMODULE
+KBUILD_RUSTFLAGS_MODULE := --cfg MODULE
KBUILD_LDFLAGS_MODULE :=
KBUILD_LDFLAGS :=
CLANG_FLAGS :=
+ifeq ($(KBUILD_CLIPPY),1)
+ RUSTC_OR_CLIPPY_QUIET := CLIPPY
+ RUSTC_OR_CLIPPY = $(CLIPPY_DRIVER)
+else
+ RUSTC_OR_CLIPPY_QUIET := RUSTC
+ RUSTC_OR_CLIPPY = $(RUSTC)
+endif
+
+ifdef RUST_LIB_SRC
+ export RUST_LIB_SRC
+endif
+
+export RUSTC_BOOTSTRAP := 1
+
export ARCH SRCARCH CONFIG_SHELL BASH HOSTCC KBUILD_HOSTCFLAGS CROSS_COMPILE LD CC
+export RUSTC RUSTDOC RUSTFMT RUSTC_OR_CLIPPY_QUIET RUSTC_OR_CLIPPY BINDGEN CARGO
export CPP AR NM STRIP OBJCOPY OBJDUMP READELF PAHOLE RESOLVE_BTFIDS LEX YACC AWK INSTALLKERNEL
export PERL PYTHON3 CHECK CHECKFLAGS MAKE UTS_MACHINE HOSTCXX
export KGZIP KBZIP2 KLZOP LZMA LZ4 XZ ZSTD
@@ -533,9 +579,10 @@ export KBUILD_HOSTCXXFLAGS KBUILD_HOSTLDFLAGS KBUILD_HOSTLDLIBS LDFLAGS_MODULE
export KBUILD_CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS KBUILD_LDFLAGS
export KBUILD_CFLAGS CFLAGS_KERNEL CFLAGS_MODULE
+export KBUILD_RUST_TARGET KBUILD_RUSTFLAGS RUSTFLAGS_KERNEL RUSTFLAGS_MODULE
export KBUILD_AFLAGS AFLAGS_KERNEL AFLAGS_MODULE
-export KBUILD_AFLAGS_MODULE KBUILD_CFLAGS_MODULE KBUILD_LDFLAGS_MODULE
-export KBUILD_AFLAGS_KERNEL KBUILD_CFLAGS_KERNEL
+export KBUILD_AFLAGS_MODULE KBUILD_CFLAGS_MODULE KBUILD_RUSTFLAGS_MODULE KBUILD_LDFLAGS_MODULE
+export KBUILD_AFLAGS_KERNEL KBUILD_CFLAGS_KERNEL KBUILD_RUSTFLAGS_KERNEL
export PAHOLE_FLAGS
# Files to ignore in find ... statements
@@ -716,7 +763,7 @@ $(KCONFIG_CONFIG):
#
# Do not use $(call cmd,...) here. That would suppress prompts from syncconfig,
# so you cannot notice that Kconfig is waiting for the user input.
-%/config/auto.conf %/config/auto.conf.cmd %/generated/autoconf.h: $(KCONFIG_CONFIG)
+%/config/auto.conf %/config/auto.conf.cmd %/generated/autoconf.h %/generated/rustc_cfg: $(KCONFIG_CONFIG)
$(Q)$(kecho) " SYNC $@"
$(Q)$(MAKE) -f $(srctree)/Makefile syncconfig
else # !may-sync-config
@@ -745,12 +792,28 @@ KBUILD_CFLAGS += $(call cc-disable-warning, address-of-packed-member)
ifdef CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE
KBUILD_CFLAGS += -O2
+KBUILD_RUSTFLAGS_OPT_LEVEL_MAP := 2
else ifdef CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE_O3
KBUILD_CFLAGS += -O3
+KBUILD_RUSTFLAGS_OPT_LEVEL_MAP := 3
else ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE
KBUILD_CFLAGS += -Os
+KBUILD_RUSTFLAGS_OPT_LEVEL_MAP := s
endif
+# Always set `debug-assertions` and `overflow-checks` because their default
+# depends on `opt-level` and `debug-assertions`, respectively.
+KBUILD_RUSTFLAGS += -Cdebug-assertions=$(if $(CONFIG_RUST_DEBUG_ASSERTIONS),y,n)
+KBUILD_RUSTFLAGS += -Coverflow-checks=$(if $(CONFIG_RUST_OVERFLOW_CHECKS),y,n)
+KBUILD_RUSTFLAGS += -Copt-level=$\
+ $(if $(CONFIG_RUST_OPT_LEVEL_SIMILAR_AS_CHOSEN_FOR_C),$(KBUILD_RUSTFLAGS_OPT_LEVEL_MAP))$\
+ $(if $(CONFIG_RUST_OPT_LEVEL_0),0)$\
+ $(if $(CONFIG_RUST_OPT_LEVEL_1),1)$\
+ $(if $(CONFIG_RUST_OPT_LEVEL_2),2)$\
+ $(if $(CONFIG_RUST_OPT_LEVEL_3),3)$\
+ $(if $(CONFIG_RUST_OPT_LEVEL_S),s)$\
+ $(if $(CONFIG_RUST_OPT_LEVEL_Z),z)
+
# Tell gcc to never replace conditional load with a non-conditional one
ifdef CONFIG_CC_IS_GCC
# gcc-10 renamed --param=allow-store-data-races=0 to
@@ -780,6 +843,9 @@ KBUILD_CFLAGS += $(stackp-flags-y)
KBUILD_CFLAGS-$(CONFIG_WERROR) += -Werror
KBUILD_CFLAGS += $(KBUILD_CFLAGS-y) $(CONFIG_CC_IMPLICIT_FALLTHROUGH)
+KBUILD_RUSTFLAGS-$(CONFIG_WERROR) += -Dwarnings
+KBUILD_RUSTFLAGS += $(KBUILD_RUSTFLAGS-y)
+
ifdef CONFIG_CC_IS_CLANG
KBUILD_CPPFLAGS += -Qunused-arguments
# The kernel builds with '-std=gnu89' so use of GNU extensions is acceptable.
@@ -801,6 +867,7 @@ KBUILD_CFLAGS += $(call cc-disable-warning, unused-const-variable)
ifdef CONFIG_FRAME_POINTER
KBUILD_CFLAGS += -fno-omit-frame-pointer -fno-optimize-sibling-calls
+KBUILD_RUSTFLAGS += -Cforce-frame-pointers=y
else
# Some targets (ARM with Thumb2, for example), can't be built with frame
# pointers. For those, we don't have FUNCTION_TRACER automatically
@@ -1016,10 +1083,11 @@ include $(addprefix $(srctree)/, $(include-y))
# Do not add $(call cc-option,...) below this line. When you build the kernel
# from the clean source tree, the GCC plugins do not exist at this point.
-# Add user supplied CPPFLAGS, AFLAGS and CFLAGS as the last assignments
+# Add user supplied CPPFLAGS, AFLAGS, CFLAGS and RUSTFLAGS as the last assignments
KBUILD_CPPFLAGS += $(KCPPFLAGS)
KBUILD_AFLAGS += $(KAFLAGS)
KBUILD_CFLAGS += $(KCFLAGS)
+KBUILD_RUSTFLAGS += $(KRUSTFLAGS)
KBUILD_LDFLAGS_MODULE += --build-id=sha1
LDFLAGS_vmlinux += --build-id=sha1
@@ -1088,6 +1156,7 @@ export MODULES_NSDEPS := $(extmod_prefix)modules.nsdeps
ifeq ($(KBUILD_EXTMOD),)
core-y += kernel/ certs/ mm/ fs/ ipc/ security/ crypto/
core-$(CONFIG_BLOCK) += block/
+core-$(CONFIG_RUST) += rust/
vmlinux-dirs := $(patsubst %/,%,$(filter %/, \
$(core-y) $(core-m) $(drivers-y) $(drivers-m) \
@@ -1192,6 +1261,10 @@ prepare0: archprepare
# All the preparing..
prepare: prepare0
+ifdef CONFIG_RUST
+ $(Q)$(CONFIG_SHELL) $(srctree)/scripts/rust-is-available.sh -v
+ $(Q)$(MAKE) $(build)=rust
+endif
PHONY += remove-stale-files
remove-stale-files:
@@ -1480,7 +1553,7 @@ endif # CONFIG_MODULES
# Directories & files removed with 'make clean'
CLEAN_FILES += include/ksym vmlinux.symvers modules-only.symvers \
modules.builtin modules.builtin.modinfo modules.nsdeps \
- compile_commands.json .thinlto-cache
+ compile_commands.json .thinlto-cache rust/test rust/doc
# Directories & files removed with 'make mrproper'
MRPROPER_FILES += include/config include/generated \
@@ -1491,7 +1564,8 @@ MRPROPER_FILES += include/config include/generated \
certs/signing_key.pem \
certs/x509.genkey \
vmlinux-gdb.py \
- *.spec
+ *.spec \
+ rust/libmacros.so
# clean - Delete most, but leave enough to build external modules
#
@@ -1516,6 +1590,9 @@ $(mrproper-dirs):
mrproper: clean $(mrproper-dirs)
$(call cmd,rmfiles)
+ @find . $(RCS_FIND_IGNORE) \
+ \( -name '*.rmeta' \) \
+ -type f -print | xargs rm -f
# distclean
#
@@ -1603,6 +1680,23 @@ help:
@echo ' kselftest-merge - Merge all the config dependencies of'
@echo ' kselftest to existing .config.'
@echo ''
+ @echo 'Rust targets:'
+ @echo ' rustavailable - Checks whether the Rust toolchain is'
+ @echo ' available and, if not, explains why.'
+ @echo ' rustfmt - Reformat all the Rust code in the kernel'
+ @echo ' rustfmtcheck - Checks if all the Rust code in the kernel'
+ @echo ' is formatted, printing a diff otherwise.'
+ @echo ' rustdoc - Generate Rust documentation'
+ @echo ' (requires kernel .config)'
+ @echo ' rusttest - Runs the Rust tests'
+ @echo ' (requires kernel .config; downloads external repos)'
+ @echo ' rust-analyzer - Generate rust-project.json rust-analyzer support file'
+ @echo ' (requires kernel .config)'
+ @echo ' dir/file.[os] - Build specified target only'
+ @echo ' dir/file.i - Build macro expanded source, similar to C preprocessing'
+ @echo ' (run with RUSTFMT=n to skip reformatting if needed)'
+ @echo ' dir/file.ll - Build the LLVM assembly file'
+ @echo ''
@$(if $(dtstree), \
echo 'Devicetree:'; \
echo '* dtbs - Build device tree blobs for enabled boards'; \
@@ -1674,6 +1768,52 @@ PHONY += $(DOC_TARGETS)
$(DOC_TARGETS):
$(Q)$(MAKE) $(build)=Documentation $@
+
+# Rust targets
+# ---------------------------------------------------------------------------
+
+# "Is Rust available?" target
+PHONY += rustavailable
+rustavailable:
+ $(Q)$(CONFIG_SHELL) $(srctree)/scripts/rust-is-available.sh -v && echo >&2 "Rust is available!"
+
+# Documentation target
+#
+# Using the singular to avoid running afoul of `no-dot-config-targets`.
+PHONY += rustdoc
+rustdoc: prepare0
+ $(Q)$(MAKE) $(build)=rust $@
+
+# Testing target
+PHONY += rusttest
+rusttest: prepare0
+ $(Q)$(MAKE) $(build)=rust $@
+
+# Formatting targets
+PHONY += rustfmt rustfmtcheck
+
+# We skip `rust/alloc` since we want to minimize the diff w.r.t. upstream.
+#
+# We match using absolute paths since `find` does not resolve them
+# when matching, which is a problem when e.g. `srctree` is `..`.
+# We `grep` afterwards in order to remove the directory entry itself.
+rustfmt:
+ $(Q)find $(abs_srctree) -type f -name '*.rs' \
+ -o -path $(abs_srctree)/rust/alloc -prune \
+ -o -path $(abs_objtree)/rust/test -prune \
+ | grep -Fv $(abs_srctree)/rust/alloc \
+ | grep -Fv $(abs_objtree)/rust/test \
+ | grep -Fv generated \
+ | xargs $(RUSTFMT) $(rustfmt_flags)
+
+rustfmtcheck: rustfmt_flags = --check
+rustfmtcheck: rustfmt
+
+# IDE support targets
+PHONY += rust-analyzer
+rust-analyzer: prepare0
+ $(Q)$(MAKE) $(build)=rust $@
+
# Misc
# ---------------------------------------------------------------------------
diff --git a/arch/arm/rust/target.json b/arch/arm/rust/target.json
new file mode 100644
index 000000000000..3f845b8221dc
--- /dev/null
+++ b/arch/arm/rust/target.json
@@ -0,0 +1,27 @@
+{
+ "arch": "arm",
+ "crt-static-respected": true,
+ "data-layout": "e-m:e-p:32:32-Fi8-i64:64-v128:64:128-a:0:32-n32-S64",
+ "dynamic-linking": true,
+ "env": "gnu",
+ "executables": true,
+ "features": "+strict-align,+v6",
+ "function-sections": false,
+ "has-elf-tls": true,
+ "has-rpath": true,
+ "linker-is-gnu": true,
+ "llvm-target": "arm-unknown-linux-gnueabi",
+ "max-atomic-width": 64,
+ "os": "linux",
+ "position-independent-executables": true,
+ "pre-link-args": {
+ "gcc": [
+ "-Wl,--as-needed",
+ "-Wl,-z,noexecstack"
+ ]
+ },
+ "relocation-model": "static",
+ "target-family": "unix",
+ "target-mcount": "\u0001__gnu_mcount_nc",
+ "target-pointer-width": "32"
+}
diff --git a/arch/arm64/rust/target.json b/arch/arm64/rust/target.json
new file mode 100644
index 000000000000..09a264df26c7
--- /dev/null
+++ b/arch/arm64/rust/target.json
@@ -0,0 +1,34 @@
+{
+ "arch": "aarch64",
+ "data-layout": "e-m:e-i8:8:32-i16:16:32-i64:64-i128:128-n32:64-S128",
+ "disable-redzone": true,
+ "emit-debug-gdb-scripts": false,
+ "env": "gnu",
+ "features": "+strict-align,+neon,+fp-armv8",
+ "frame-pointer": "always",
+ "function-sections": false,
+ "linker-flavor": "gcc",
+ "linker-is-gnu": true,
+ "llvm-target": "aarch64-unknown-none",
+ "max-atomic-width": 128,
+ "needs-plt": true,
+ "os": "none",
+ "panic-strategy": "abort",
+ "position-independent-executables": true,
+ "pre-link-args": {
+ "gcc": [
+ "-Wl,--as-needed",
+ "-Wl,-z,noexecstack",
+ "-m64"
+ ]
+ },
+ "relocation-model": "static",
+ "relro-level": "full",
+ "stack-probes": {
+ "kind": "none"
+ },
+ "target-c-int-width": "32",
+ "target-endian": "little",
+ "target-pointer-width": "64",
+ "vendor": ""
+}
diff --git a/arch/powerpc/rust/target.json b/arch/powerpc/rust/target.json
new file mode 100644
index 000000000000..2420c8e6a520
--- /dev/null
+++ b/arch/powerpc/rust/target.json
@@ -0,0 +1,29 @@
+{
+ "arch": "powerpc64",
+ "code-model": "large",
+ "cpu": "ppc64le",
+ "data-layout": "e-m:e-i64:64-n32:64",
+ "env": "gnu",
+ "features": "-altivec,-vsx,-hard-float",
+ "function-sections": false,
+ "linker-flavor": "gcc",
+ "linker-is-gnu": true,
+ "llvm-target": "powerpc64le-elf",
+ "max-atomic-width": 64,
+ "os": "none",
+ "panic-strategy": "abort",
+ "position-independent-executables": true,
+ "pre-link-args": {
+ "gcc": [
+ "-Wl,--as-needed",
+ "-Wl,-z,noexecstack",
+ "-m64"
+ ]
+ },
+ "relocation-model": "static",
+ "relro-level": "full",
+ "target-family": "unix",
+ "target-mcount": "_mcount",
+ "target-endian": "little",
+ "target-pointer-width": "64"
+}
diff --git a/arch/riscv/Makefile b/arch/riscv/Makefile
index 8a107ed18b0d..0487db1e54c6 100644
--- a/arch/riscv/Makefile
+++ b/arch/riscv/Makefile
@@ -52,6 +52,7 @@ riscv-march-$(CONFIG_FPU) := $(riscv-march-y)fd
riscv-march-$(CONFIG_RISCV_ISA_C) := $(riscv-march-y)c
KBUILD_CFLAGS += -march=$(subst fd,,$(riscv-march-y))
KBUILD_AFLAGS += -march=$(riscv-march-y)
+KBUILD_RUST_TARGET := $(srctree)/arch/riscv/rust/$(subst fd,,$(riscv-march-y)).json
KBUILD_CFLAGS += -mno-save-restore
KBUILD_CFLAGS += -DCONFIG_PAGE_OFFSET=$(CONFIG_PAGE_OFFSET)
diff --git a/arch/riscv/rust/rv32ima.json b/arch/riscv/rust/rv32ima.json
new file mode 100644
index 000000000000..bcdda88c1604
--- /dev/null
+++ b/arch/riscv/rust/rv32ima.json
@@ -0,0 +1,36 @@
+{
+ "arch": "riscv32",
+ "code-model": "medium",
+ "cpu": "generic-rv32",
+ "data-layout": "e-m:e-p:32:32-i64:64-n32-S128",
+ "disable-redzone": true,
+ "emit-debug-gdb-scripts": false,
+ "env": "gnu",
+ "features": "+m,+a",
+ "frame-pointer": "always",
+ "function-sections": false,
+ "linker-flavor": "gcc",
+ "linker-is-gnu": true,
+ "llvm-target": "riscv32",
+ "max-atomic-width": 32,
+ "needs-plt": true,
+ "os": "none",
+ "panic-strategy": "abort",
+ "position-independent-executables": true,
+ "pre-link-args": {
+ "gcc": [
+ "-Wl,--as-needed",
+ "-Wl,-z,noexecstack",
+ "-m32"
+ ]
+ },
+ "relocation-model": "static",
+ "relro-level": "full",
+ "stack-probes": {
+ "kind": "none"
+ },
+ "target-c-int-width": "32",
+ "target-endian": "little",
+ "target-pointer-width": "32",
+ "vendor": ""
+}
diff --git a/arch/riscv/rust/rv32imac.json b/arch/riscv/rust/rv32imac.json
new file mode 100644
index 000000000000..45873c10a5c3
--- /dev/null
+++ b/arch/riscv/rust/rv32imac.json
@@ -0,0 +1,36 @@
+{
+ "arch": "riscv32",
+ "code-model": "medium",
+ "cpu": "generic-rv32",
+ "data-layout": "e-m:e-p:32:32-i64:64-n32-S128",
+ "disable-redzone": true,
+ "emit-debug-gdb-scripts": false,
+ "env": "gnu",
+ "features": "+m,+a,+c",
+ "frame-pointer": "always",
+ "function-sections": false,
+ "linker-flavor": "gcc",
+ "linker-is-gnu": true,
+ "llvm-target": "riscv32",
+ "max-atomic-width": 32,
+ "needs-plt": true,
+ "os": "none",
+ "panic-strategy": "abort",
+ "position-independent-executables": true,
+ "pre-link-args": {
+ "gcc": [
+ "-Wl,--as-needed",
+ "-Wl,-z,noexecstack",
+ "-m32"
+ ]
+ },
+ "relocation-model": "static",
+ "relro-level": "full",
+ "stack-probes": {
+ "kind": "none"
+ },
+ "target-c-int-width": "32",
+ "target-endian": "little",
+ "target-pointer-width": "32",
+ "vendor": ""
+}
diff --git a/arch/riscv/rust/rv64ima.json b/arch/riscv/rust/rv64ima.json
new file mode 100644
index 000000000000..853d758c5461
--- /dev/null
+++ b/arch/riscv/rust/rv64ima.json
@@ -0,0 +1,36 @@
+{
+ "arch": "riscv64",
+ "code-model": "medium",
+ "cpu": "generic-rv64",
+ "data-layout": "e-m:e-p:64:64-i64:64-i128:128-n64-S128",
+ "disable-redzone": true,
+ "emit-debug-gdb-scripts": false,
+ "env": "gnu",
+ "features": "+m,+a",
+ "frame-pointer": "always",
+ "function-sections": false,
+ "linker-flavor": "gcc",
+ "linker-is-gnu": true,
+ "llvm-target": "riscv64",
+ "max-atomic-width": 64,
+ "needs-plt": true,
+ "os": "none",
+ "panic-strategy": "abort",
+ "position-independent-executables": true,
+ "pre-link-args": {
+ "gcc": [
+ "-Wl,--as-needed",
+ "-Wl,-z,noexecstack",
+ "-m64"
+ ]
+ },
+ "relocation-model": "static",
+ "relro-level": "full",
+ "stack-probes": {
+ "kind": "none"
+ },
+ "target-c-int-width": "32",
+ "target-endian": "little",
+ "target-pointer-width": "64",
+ "vendor": ""
+}
diff --git a/arch/riscv/rust/rv64imac.json b/arch/riscv/rust/rv64imac.json
new file mode 100644
index 000000000000..ce50ee8e8c93
--- /dev/null
+++ b/arch/riscv/rust/rv64imac.json
@@ -0,0 +1,36 @@
+{
+ "arch": "riscv64",
+ "code-model": "medium",
+ "cpu": "generic-rv64",
+ "data-layout": "e-m:e-p:64:64-i64:64-i128:128-n64-S128",
+ "disable-redzone": true,
+ "emit-debug-gdb-scripts": false,
+ "env": "gnu",
+ "features": "+m,+a,+c",
+ "frame-pointer": "always",
+ "function-sections": false,
+ "linker-flavor": "gcc",
+ "linker-is-gnu": true,
+ "llvm-target": "riscv64",
+ "max-atomic-width": 64,
+ "needs-plt": true,
+ "os": "none",
+ "panic-strategy": "abort",
+ "position-independent-executables": true,
+ "pre-link-args": {
+ "gcc": [
+ "-Wl,--as-needed",
+ "-Wl,-z,noexecstack",
+ "-m64"
+ ]
+ },
+ "relocation-model": "static",
+ "relro-level": "full",
+ "stack-probes": {
+ "kind": "none"
+ },
+ "target-c-int-width": "32",
+ "target-endian": "little",
+ "target-pointer-width": "64",
+ "vendor": ""
+}
diff --git a/arch/x86/rust/target.json b/arch/x86/rust/target.json
new file mode 100644
index 000000000000..379cf39e8941
--- /dev/null
+++ b/arch/x86/rust/target.json
@@ -0,0 +1,36 @@
+{
+ "arch": "x86_64",
+ "code-model": "kernel",
+ "cpu": "x86-64",
+ "data-layout": "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128",
+ "disable-redzone": true,
+ "emit-debug-gdb-scripts": false,
+ "env": "gnu",
+ "features": "-mmx,-sse,-sse2,-sse3,-ssse3,-sse4.1,-sse4.2,-3dnow,-3dnowa,-avx,-avx2,+soft-float",
+ "frame-pointer": "always",
+ "function-sections": false,
+ "linker-flavor": "gcc",
+ "linker-is-gnu": true,
+ "llvm-target": "x86_64-elf",
+ "max-atomic-width": 64,
+ "needs-plt": true,
+ "os": "none",
+ "panic-strategy": "abort",
+ "position-independent-executables": true,
+ "pre-link-args": {
+ "gcc": [
+ "-Wl,--as-needed",
+ "-Wl,-z,noexecstack",
+ "-m64"
+ ]
+ },
+ "relocation-model": "static",
+ "relro-level": "full",
+ "stack-probes": {
+ "kind": "none"
+ },
+ "target-c-int-width": "32",
+ "target-endian": "little",
+ "target-pointer-width": "64",
+ "vendor": "unknown"
+}
diff --git a/init/Kconfig b/init/Kconfig
index e9119bf54b1f..6a9047318cb3 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -60,6 +60,17 @@ config LLD_VERSION
default $(ld-version) if LD_IS_LLD
default 0
+config RUST_IS_AVAILABLE
+ def_bool $(success,$(srctree)/scripts/rust-is-available.sh)
+ help
+ This shows whether a suitable Rust toolchain is available (found).
+
+ Please see Documentation/rust/quick-start.rst for instructions on how
+ to satify the build requirements of Rust support.
+
+ In particular, the Makefile target 'rustavailable' is useful to check
+ why the Rust toolchain is not being detected.
+
config CC_CAN_LINK
bool
default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(m64-flag)) if 64BIT
@@ -142,7 +153,8 @@ config WERROR
default COMPILE_TEST
help
A kernel build should not cause any compiler warnings, and this
- enables the '-Werror' flag to enforce that rule by default.
+ enables the '-Werror' (for C) and '-Dwarnings' (for Rust) flags
+ to enforce that rule by default.
However, if you have a new (or very old) compiler with odd and
unusual warnings, or you have some architecture with problems,
@@ -2041,6 +2053,37 @@ config PROFILING
Say Y here to enable the extended profiling support mechanisms used
by profilers.
+config RUST
+ bool "Rust support"
+ depends on RUST_IS_AVAILABLE
+ depends on ARM64 || CPU_32v6 || CPU_32v6K || (PPC64 && CPU_LITTLE_ENDIAN) || X86_64 || RISCV
+ depends on !MODVERSIONS
+ depends on !GCC_PLUGIN_RANDSTRUCT
+ select CONSTRUCTORS
+ default n
+ help
+ Enables Rust support in the kernel.
+
+ This allows other Rust-related options, like drivers written in Rust,
+ to be selected.
+
+ It is also required to be able to load external kernel modules
+ written in Rust.
+
+ See Documentation/rust/ for more information.
+
+ If unsure, say N.
+
+config RUSTC_VERSION_TEXT
+ string
+ depends on RUST
+ default $(shell,command -v $(RUSTC) >/dev/null 2>&1 && $(RUSTC) --version || echo n)
+
+config BINDGEN_VERSION_TEXT
+ string
+ depends on RUST
+ default $(shell,command -v $(BINDGEN) >/dev/null 2>&1 && $(BINDGEN) --version || echo n)
+
#
# Place an empty function call at each tracepoint site. Can be
# dynamically changed for a probe function.
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 14b89aa37c5c..048883dee5c9 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -2687,6 +2687,150 @@ config HYPERV_TESTING
endmenu # "Kernel Testing and Coverage"
+menu "Rust hacking"
+
+config RUST_DEBUG_ASSERTIONS
+ bool "Debug assertions"
+ default n
+ depends on RUST
+ help
+ Enables rustc's `-Cdebug-assertions` codegen option.
+
+ This flag lets you turn `cfg(debug_assertions)` conditional
+ compilation on or off. This can be used to enable extra debugging
+ code in development but not in production. For example, it controls
+ the behavior of the standard library's `debug_assert!` macro.
+
+ Note that this will apply to all Rust code, including `core`.
+
+ If unsure, say N.
+
+config RUST_OVERFLOW_CHECKS
+ bool "Overflow checks"
+ default y
+ depends on RUST
+ help
+ Enables rustc's `-Coverflow-checks` codegen option.
+
+ This flag allows you to control the behavior of runtime integer
+ overflow. When overflow-checks are enabled, a Rust panic will occur
+ on overflow.
+
+ Note that this will apply to all Rust code, including `core`.
+
+ If unsure, say Y.
+
+choice
+ prompt "Optimization level"
+ default RUST_OPT_LEVEL_SIMILAR_AS_CHOSEN_FOR_C
+ depends on RUST
+ help
+ Controls rustc's `-Copt-level` codegen option.
+
+ This flag controls the optimization level.
+
+ If unsure, say "Similar as chosen for C".
+
+config RUST_OPT_LEVEL_SIMILAR_AS_CHOSEN_FOR_C
+ bool "Similar as chosen for C"
+ help
+ This choice will pick a similar optimization level as chosen in
+ the "Compiler optimization level" for C:
+
+ -O2 is currently mapped to -Copt-level=2
+ -O3 is currently mapped to -Copt-level=3
+ -Os is currently mapped to -Copt-level=s
+
+ The mapping may change over time to follow the intended semantics
+ of the choice for C as sensibly as possible.
+
+ This is the default.
+
+config RUST_OPT_LEVEL_0
+ bool "No optimizations (-Copt-level=0)"
+ help
+ Not recommended for most purposes. It may come in handy for debugging
+ suspected optimizer bugs, unexpected undefined behavior, etc.
+
+ Note that this level will *not* enable debug assertions nor overflow
+ checks on its own (like it happens when interacting with rustc
+ directly). Use the corresponding configuration options to control
+ that instead, orthogonally.
+
+ Note this level may cause excessive stack usage, which can lead to stack
+ overflow and subsequent crashes.
+
+config RUST_OPT_LEVEL_1
+ bool "Basic optimizations (-Copt-level=1)"
+ help
+ Useful for debugging without getting too lost, but without
+ the overhead and boilerplate of no optimizations at all.
+
+ Note this level may cause excessive stack usage, which can lead to stack
+ overflow and subsequent crashes.
+
+config RUST_OPT_LEVEL_2
+ bool "Some optimizations (-Copt-level=2)"
+ help
+ The sensible choice in most cases.
+
+config RUST_OPT_LEVEL_3
+ bool "All optimizations (-Copt-level=3)"
+ help
+ Yet more performance (hopefully).
+
+config RUST_OPT_LEVEL_S
+ bool "Optimize for size (-Copt-level=s)"
+ help
+ Smaller kernel, ideally without too much performance loss.
+
+config RUST_OPT_LEVEL_Z
+ bool "Optimize for size, no loop vectorization (-Copt-level=z)"
+ help
+ Like the previous level, but also turn off loop vectorization.
+
+endchoice
+
+choice
+ prompt "Build-time assertions"
+ default RUST_BUILD_ASSERT_ALLOW if RUST_OPT_LEVEL_0
+ default RUST_BUILD_ASSERT_DENY if !RUST_OPT_LEVEL_0
+ depends on RUST
+ help
+ Controls how are `build_error!` and `build_assert!` handled during build.
+
+ If calls to them exist in the binary, it may indicate a violated invariant
+ or that the optimizer failed to verify the invariant during compilation.
+ You can choose to abort compilation or ignore them during build and let the
+ check be carried to runtime.
+
+ If optimizations are turned off, you cannot select "Deny".
+
+ If unsure, say "Deny".
+
+config RUST_BUILD_ASSERT_ALLOW
+ bool "Allow"
+ help
+ Unoptimized calls to `build_error!` will be converted to `panic!`
+ and checked at runtime.
+
+config RUST_BUILD_ASSERT_WARN
+ bool "Warn"
+ help
+ Unoptimized calls to `build_error!` will be converted to `panic!`
+ and checked at runtime, but warnings will be generated when building.
+
+config RUST_BUILD_ASSERT_DENY
+ bool "Deny"
+ depends on !RUST_OPT_LEVEL_0
+ help
+ Unoptimized calls to `build_error!` will abort compilation.
+
+endchoice
+
+
+endmenu # "Rust"
+
source "Documentation/Kconfig"
endmenu # Kernel hacking
diff --git a/rust/.gitignore b/rust/.gitignore
new file mode 100644
index 000000000000..168cb26a31b9
--- /dev/null
+++ b/rust/.gitignore
@@ -0,0 +1,7 @@
+# SPDX-License-Identifier: GPL-2.0
+
+bindings_generated.rs
+bindings_helpers_generated.rs
+exports_*_generated.h
+doc/
+test/
diff --git a/rust/Makefile b/rust/Makefile
new file mode 100644
index 000000000000..f78dba9b3db6
--- /dev/null
+++ b/rust/Makefile
@@ -0,0 +1,374 @@
+# SPDX-License-Identifier: GPL-2.0
+
+obj-$(CONFIG_RUST) += core.o compiler_builtins.o
+always-$(CONFIG_RUST) += exports_core_generated.h
+
+# Missing prototypes are expected in the helpers since these are exported
+# for Rust only, thus there is no header nor prototypes.
+obj-$(CONFIG_RUST) += helpers.o
+CFLAGS_REMOVE_helpers.o = -Wmissing-prototypes -Wmissing-declarations
+
+always-$(CONFIG_RUST) += libmacros.so
+no-clean-files += libmacros.so
+
+always-$(CONFIG_RUST) += bindings_generated.rs bindings_helpers_generated.rs
+obj-$(CONFIG_RUST) += alloc.o kernel.o
+always-$(CONFIG_RUST) += exports_alloc_generated.h exports_kernel_generated.h
+
+ifdef CONFIG_RUST_BUILD_ASSERT_DENY
+always-$(CONFIG_RUST) += build_error.o
+else
+obj-$(CONFIG_RUST) += build_error.o
+endif
+
+obj-$(CONFIG_RUST) += exports.o
+
+# Avoids running `$(RUSTC)` for the sysroot when it may not be available.
+ifdef CONFIG_RUST
+
+ifeq ($(quiet),silent_)
+cargo_quiet=-q
+rust_test_quiet=-q
+rustdoc_test_quiet=--test-args -q
+else ifeq ($(quiet),quiet_)
+rust_test_quiet=-q
+rustdoc_test_quiet=--test-args -q
+else
+cargo_quiet=--verbose
+endif
+
+core-cfgs = \
+ --cfg no_fp_fmt_parse
+
+alloc-cfgs = \
+ --cfg no_global_oom_handling \
+ --cfg no_rc \
+ --cfg no_sync
+
+quiet_cmd_rustdoc = RUSTDOC $(if $(rustdoc_host),H, ) $<
+ cmd_rustdoc = \
+ OBJTREE=$(abspath $(objtree)) \
+ $(RUSTDOC) $(if $(rustdoc_host),,$(rust_cross_flags)) \
+ $(filter-out -Cpanic=abort, $(rust_flags)) \
+ $(rustc_target_flags) -L $(objtree)/rust \
+ --output $(objtree)/rust/doc --crate-name $(subst rustdoc-,,$@) \
+ @$(objtree)/include/generated/rustc_cfg $<
+
+# The `html_logo_url` and `html_favicon_url` forms of the `doc` attribute
+# can be used to specify a custom logo. However:
+# - The given value is used as-is, thus it cannot be relative or a local file
+# (unlike the non-custom case) since the generated docs have subfolders.
+# - It requires adding it to every crate.
+# - It requires changing `core` which comes from the sysroot.
+#
+# Using `-Zcrate-attr` would solve the last two points, but not the first.
+# The https://github.com/rust-lang/rfcs/pull/3226 RFC suggests two new
+# command-like flags to solve the issue. Meanwhile, we use the non-custom case
+# and then retouch the generated files.
+rustdoc: rustdoc-core rustdoc-macros rustdoc-compiler_builtins rustdoc-alloc rustdoc-kernel
+ $(Q)cp $(srctree)/Documentation/rust/logo.svg $(objtree)/rust/doc
+ $(Q)find $(objtree)/rust/doc -name '*.html' -type f -print0 | xargs -0 sed -Ei \
+ -e 's:rust-logo\.png:logo.svg:g' \
+ -e 's:favicon\.svg:logo.svg:g' \
+ -e 's:<link rel="alternate icon" type="image/png" href="[./]*favicon-(16x16|32x32)\.png">::g'
+
+rustdoc-macros: private rustdoc_host = yes
+rustdoc-macros: private rustc_target_flags = --crate-type proc-macro \
+ --extern proc_macro
+rustdoc-macros: $(srctree)/rust/macros/lib.rs FORCE
+ $(call if_changed,rustdoc)
+
+rustdoc-compiler_builtins: $(srctree)/rust/compiler_builtins.rs rustdoc-core FORCE
+ $(call if_changed,rustdoc)
+
+# We need to allow `rustdoc::broken_intra_doc_links` because some
+# `no_global_oom_handling` functions refer to non-`no_global_oom_handling`
+# functions. Ideally `rustdoc` would have a way to distinguish broken links
+# due to things that are "configured out" vs. entirely non-existing ones.
+rustdoc-alloc: private rustc_target_flags = $(alloc-cfgs) \
+ -Arustdoc::broken_intra_doc_links
+rustdoc-alloc: $(srctree)/rust/alloc/lib.rs rustdoc-core \
+ rustdoc-compiler_builtins FORCE
+ $(call if_changed,rustdoc)
+
+rustdoc-kernel: private rustc_target_flags = --extern alloc \
+ --extern build_error \
+ --extern macros=$(objtree)/rust/libmacros.so
+rustdoc-kernel: $(srctree)/rust/kernel/lib.rs rustdoc-core \
+ rustdoc-macros rustdoc-compiler_builtins rustdoc-alloc \
+ $(objtree)/rust/libmacros.so $(objtree)/rust/bindings_generated.rs \
+ $(objtree)/rust/bindings_helpers_generated.rs FORCE
+ $(call if_changed,rustdoc)
+
+quiet_cmd_rustc_test_library = RUSTC TL $<
+ cmd_rustc_test_library = \
+ OBJTREE=$(abspath $(objtree)) \
+ $(RUSTC) $(filter-out --sysroot=%, $(filter-out -Cpanic=abort, $(rust_flags))) \
+ $(rustc_target_flags) --crate-type $(if $(rustc_test_library_proc),proc-macro,rlib) \
+ --out-dir $(objtree)/rust/test/ --cfg testlib \
+ --sysroot $(objtree)/rust/test/sysroot \
+ -L $(objtree)/rust/test/ --crate-name $(subst rusttest-,,$(subst rusttestlib-,,$@)) $<
+
+rusttestlib-build_error: $(srctree)/rust/build_error.rs rusttest-prepare FORCE
+ $(call if_changed,rustc_test_library)
+
+rusttestlib-macros: private rustc_target_flags = --extern proc_macro
+rusttestlib-macros: private rustc_test_library_proc = yes
+rusttestlib-macros: $(srctree)/rust/macros/lib.rs rusttest-prepare FORCE
+ $(call if_changed,rustc_test_library)
+
+quiet_cmd_rustdoc_test = RUSTDOC T $<
+ cmd_rustdoc_test = \
+ OBJTREE=$(abspath $(objtree)) \
+ $(RUSTDOC) --test $(filter-out --sysroot=%, $(filter-out -Cpanic=abort, $(rust_flags))) \
+ $(rustc_target_flags) $(rustdoc_test_target_flags) \
+ --sysroot $(objtree)/rust/test/sysroot $(rustdoc_test_quiet) \
+ -L $(objtree)/rust/test \
+ --output $(objtree)/rust/doc --crate-name $(subst rusttest-,,$@) \
+ @$(objtree)/include/generated/rustc_cfg $<
+
+# We cannot use `-Zpanic-abort-tests` because some tests are dynamic,
+# so for the moment we skip `-Cpanic=abort`.
+quiet_cmd_rustc_test = RUSTC T $<
+ cmd_rustc_test = \
+ OBJTREE=$(abspath $(objtree)) \
+ $(RUSTC) --test $(filter-out --sysroot=%, $(filter-out -Cpanic=abort, $(rust_flags))) \
+ $(rustc_target_flags) --out-dir $(objtree)/rust/test \
+ --sysroot $(objtree)/rust/test/sysroot \
+ -L $(objtree)/rust/test/ --crate-name $(subst rusttest-,,$@) $<; \
+ $(objtree)/rust/test/$(subst rusttest-,,$@) $(rust_test_quiet) \
+ $(rustc_test_run_flags)
+
+rusttest: rusttest-macros rusttest-kernel
+
+# This prepares a custom sysroot with our custom `alloc` instead of
+# the standard one.
+#
+# This requires several hacks:
+# - Unlike `core` and `alloc`, `std` depends on more than a dozen crates,
+# including third-party crates that need to be downloaded, plus custom
+# `build.rs` steps. Thus hardcoding things here is not maintainable.
+# - `cargo` knows how to build the standard library, but it is an unstable
+# feature so far (`-Zbuild-std`).
+# - `cargo` only considers the use case of building the standard library
+# to use it in a given package. Thus we need to create a dummy package
+# and pick the generated libraries from there.
+# - Since we only keep a subset of upstream `alloc` in-tree, we need
+# to recreate it on the fly by putting our sources on top.
+# - The usual ways of modifying the dependency graph in `cargo` do not seem
+# to apply for the `-Zbuild-std` steps, thus we have to mislead it
+# by modifying the sources in the sysroot.
+# - To avoid messing with the user's Rust installation, we create a clone
+# of the sysroot. However, `cargo` ignores `RUSTFLAGS` in the `-Zbuild-std`
+# steps, thus we use a wrapper binary passed via `RUSTC` to pass the flag.
+#
+# In the future, we hope to avoid the whole ordeal by either:
+# - Making the `test` crate not depend on `std` (either improving upstream
+# or having our own custom crate).
+# - Making the tests run in kernel space (requires the previous point).
+# - Making `std` and friends be more like a "normal" crate, so that
+# `-Zbuild-std` and related hacks are not needed.
+quiet_cmd_rustsysroot = RUSTSYSROOT
+ cmd_rustsysroot = \
+ rm -rf $(objtree)/rust/test; \
+ mkdir -p $(objtree)/rust/test; \
+ cp -a $(rustc_sysroot) $(objtree)/rust/test/sysroot; \
+ cp -r $(srctree)/rust/alloc/* \
+ $(objtree)/rust/test/sysroot/lib/rustlib/src/rust/library/alloc/src; \
+ echo '\#!/bin/sh' > $(objtree)/rust/test/rustc_sysroot; \
+ echo "$(RUSTC) --sysroot=$(abspath $(objtree)/rust/test/sysroot) \"\$$@\"" \
+ >> $(objtree)/rust/test/rustc_sysroot; \
+ chmod u+x $(objtree)/rust/test/rustc_sysroot; \
+ $(CARGO) -q new $(objtree)/rust/test/dummy; \
+ RUSTC=$(objtree)/rust/test/rustc_sysroot $(CARGO) $(cargo_quiet) \
+ test -Zbuild-std --target $(rustc_host_target) \
+ --manifest-path $(objtree)/rust/test/dummy/Cargo.toml; \
+ rm $(objtree)/rust/test/sysroot/lib/rustlib/$(rustc_host_target)/lib/*; \
+ cp $(objtree)/rust/test/dummy/target/$(rustc_host_target)/debug/deps/* \
+ $(objtree)/rust/test/sysroot/lib/rustlib/$(rustc_host_target)/lib
+
+rusttest-prepare: FORCE
+ $(call if_changed,rustsysroot)
+
+rusttest-macros: private rustc_target_flags = --extern proc_macro
+rusttest-macros: private rustdoc_test_target_flags = --crate-type proc-macro
+rusttest-macros: $(srctree)/rust/macros/lib.rs rusttest-prepare FORCE
+ $(call if_changed,rustc_test)
+ $(call if_changed,rustdoc_test)
+
+rusttest-kernel: private rustc_target_flags = --extern alloc \
+ --extern build_error --extern macros
+rusttest-kernel: private rustc_test_run_flags = \
+ --skip bindgen_test_layout_
+rusttest-kernel: $(srctree)/rust/kernel/lib.rs rusttest-prepare \
+ rusttestlib-build_error rusttestlib-macros FORCE
+ $(call if_changed,rustc_test)
+ $(call if_changed,rustc_test_library)
+ $(call if_changed,rustdoc_test)
+
+ifdef CONFIG_CC_IS_CLANG
+bindgen_c_flags = $(c_flags)
+else
+# bindgen relies on libclang to parse C. Ideally, bindgen would support a GCC
+# plugin backend and/or the Clang driver would be perfectly compatible with GCC.
+#
+# For the moment, here we are tweaking the flags on the fly. This is a hack,
+# and some kernel configurations may not work (e.g. `GCC_PLUGIN_RANDSTRUCT`
+# if we end up using one of those structs).
+bindgen_skip_c_flags := -mno-fp-ret-in-387 -mpreferred-stack-boundary=% \
+ -mskip-rax-setup -mgeneral-regs-only -msign-return-address=% \
+ -mindirect-branch=thunk-extern -mindirect-branch-register -mrecord-mcount \
+ -mabi=lp64 -mstack-protector-guard% -mtraceback=no \
+ -mno-pointers-to-nested-functions -mno-string -mno-strict-align \
+ -mstrict-align \
+ -fconserve-stack -falign-jumps=% -falign-loops=% \
+ -femit-struct-debug-baseonly -fno-ipa-cp-clone -fno-ipa-sra \
+ -fno-partial-inlining -fplugin-arg-arm_ssp_per_task_plugin-% \
+ -fno-reorder-blocks -fno-allow-store-data-races -fasan-shadow-offset=% \
+ -fzero-call-used-regs=% -fno-stack-clash-protection \
+ -fno-inline-functions-called-once \
+ --param=% --param asan-%
+
+# Derived from `scripts/Makefile.clang`
+BINDGEN_TARGET_arm := arm-linux-gnueabi
+BINDGEN_TARGET_arm64 := aarch64-linux-gnu
+BINDGEN_TARGET_powerpc := powerpc64le-linux-gnu
+BINDGEN_TARGET_riscv := riscv64-linux-gnu
+BINDGEN_TARGET_x86 := x86_64-linux-gnu
+BINDGEN_TARGET := $(BINDGEN_TARGET_$(SRCARCH))
+
+# All warnings are inhibited since GCC builds are very experimental,
+# many GCC warnings are not supported by Clang, they may only appear in
+# some configurations, with new GCC versions, etc.
+bindgen_extra_c_flags = -w --target=$(BINDGEN_TARGET)
+
+bindgen_c_flags = $(filter-out $(bindgen_skip_c_flags), $(c_flags)) \
+ $(bindgen_extra_c_flags)
+endif
+
+ifdef CONFIG_LTO
+bindgen_c_flags_lto = $(filter-out $(CC_FLAGS_LTO), $(bindgen_c_flags))
+else
+bindgen_c_flags_lto = $(bindgen_c_flags)
+endif
+
+bindgen_c_flags_final = $(bindgen_c_flags_lto)
+
+quiet_cmd_bindgen = BINDGEN $@
+ cmd_bindgen = \
+ $(BINDGEN) $< $(bindgen_target_flags) \
+ --use-core --with-derive-default --ctypes-prefix c_types \
+ --no-debug '.*' \
+ --size_t-is-usize -o $@ -- $(bindgen_c_flags_final) -DMODULE \
+ $(bindgen_target_cflags) $(bindgen_target_extra)
+
+$(objtree)/rust/bindings_generated.rs: private bindgen_target_flags = \
+ $(shell grep -v '^\#\|^$$' $(srctree)/rust/bindgen_parameters)
+$(objtree)/rust/bindings_generated.rs: $(srctree)/rust/kernel/bindings_helper.h \
+ $(srctree)/rust/bindgen_parameters FORCE
+ $(call if_changed_dep,bindgen)
+
+# See `CFLAGS_REMOVE_helpers.o` above. In addition, Clang on C does not warn
+# with `-Wmissing-declarations` (unlike GCC), so it is not strictly needed here
+# given it is `libclang`; but for consistency, future Clang changes and/or
+# a potential future GCC backend for `bindgen`, we disable it too.
+$(objtree)/rust/bindings_helpers_generated.rs: private bindgen_target_flags = \
+ --blacklist-type '.*' --whitelist-var '' --whitelist-function 'rust_helper_.*'
+$(objtree)/rust/bindings_helpers_generated.rs: private bindgen_target_cflags = \
+ -I$(objtree)/rust/ -Wno-missing-prototypes -Wno-missing-declarations
+$(objtree)/rust/bindings_helpers_generated.rs: private bindgen_target_extra = ; \
+ sed -Ei 's/pub fn rust_helper_([a-zA-Z0-9_]*)/#[link_name="rust_helper_\1"]\n pub fn \1/g' $@
+$(objtree)/rust/bindings_helpers_generated.rs: $(srctree)/rust/helpers.c FORCE
+ $(call if_changed_dep,bindgen)
+
+quiet_cmd_exports = EXPORTS $@
+ cmd_exports = \
+ $(NM) -p --defined-only $< \
+ | grep -E ' (T|R|D) ' | cut -d ' ' -f 3 \
+ | xargs -Isymbol \
+ echo 'EXPORT_SYMBOL_RUST_GPL(symbol);' > $@
+
+$(objtree)/rust/exports_core_generated.h: $(objtree)/rust/core.o FORCE
+ $(call if_changed,exports)
+
+$(objtree)/rust/exports_alloc_generated.h: $(objtree)/rust/alloc.o FORCE
+ $(call if_changed,exports)
+
+$(objtree)/rust/exports_kernel_generated.h: $(objtree)/rust/kernel.o FORCE
+ $(call if_changed,exports)
+
+# `-Cpanic=unwind -Cforce-unwind-tables=y` overrides `rust_flags` in order to
+# avoid the https://github.com/rust-lang/rust/issues/82320 rustc crash.
+quiet_cmd_rustc_procmacro = $(RUSTC_OR_CLIPPY_QUIET) P $@
+ cmd_rustc_procmacro = \
+ $(RUSTC_OR_CLIPPY) $(rust_flags) \
+ --emit=dep-info,link --extern proc_macro \
+ -Cpanic=unwind -Cforce-unwind-tables=y \
+ --crate-type proc-macro --out-dir $(objtree)/rust/ \
+ --crate-name $(patsubst lib%.so,%,$(notdir $@)) $<; \
+ mv $(objtree)/rust/$(patsubst lib%.so,%,$(notdir $@)).d $(depfile); \
+ sed -i '/^\#/d' $(depfile)
+
+# Procedural macros can only be used with the `rustc` that compiled it.
+# Therefore, to get `libmacros.so` automatically recompiled when the compiler
+# version changes, we add `core.o` as a dependency (even if it is not needed).
+$(objtree)/rust/libmacros.so: $(srctree)/rust/macros/lib.rs \
+ $(objtree)/rust/core.o FORCE
+ $(call if_changed_dep,rustc_procmacro)
+
+quiet_cmd_rustc_library = $(if $(skip_clippy),RUSTC,$(RUSTC_OR_CLIPPY_QUIET)) L $@
+ cmd_rustc_library = \
+ OBJTREE=$(abspath $(objtree)) \
+ $(if $(skip_clippy),$(RUSTC),$(RUSTC_OR_CLIPPY)) \
+ $(filter-out $(skip_flags),$(rust_flags) $(rust_cross_flags) $(rustc_target_flags)) \
+ --emit=dep-info,obj,metadata \
+ --crate-type rlib --out-dir $(objtree)/rust/ -L $(objtree)/rust/ \
+ --crate-name $(patsubst %.o,%,$(notdir $@)) $<; \
+ mv $(objtree)/rust/$(patsubst %.o,%,$(notdir $@)).d $(depfile); \
+ sed -i '/^\#/d' $(depfile) \
+ $(if $(rustc_objcopy),;$(OBJCOPY) $(rustc_objcopy) $@)
+
+# `$(rust_flags)` is passed in case the user added `--sysroot`.
+rustc_sysroot := $(shell $(RUSTC) $(rust_flags) --print sysroot)
+rustc_host_target := $(shell $(RUSTC) --version --verbose | grep -F 'host: ' | cut -d' ' -f2)
+RUST_LIB_SRC ?= $(rustc_sysroot)/lib/rustlib/src/rust/library
+
+rust-analyzer:
+ $(Q)$(srctree)/scripts/generate_rust_analyzer.py $(srctree) $(objtree) $(RUST_LIB_SRC) > $(objtree)/rust-project.json
+
+$(objtree)/rust/compiler_builtins.o: private rustc_objcopy = -w -W '__*'
+$(objtree)/rust/compiler_builtins.o: $(srctree)/rust/compiler_builtins.rs \
+ $(objtree)/rust/core.o FORCE
+ $(call if_changed_dep,rustc_library)
+
+$(objtree)/rust/alloc.o: private skip_clippy = 1
+$(objtree)/rust/alloc.o: private skip_flags = -Dunreachable_pub
+$(objtree)/rust/alloc.o: private rustc_target_flags = $(alloc-cfgs)
+$(objtree)/rust/alloc.o: $(srctree)/rust/alloc/lib.rs \
+ $(objtree)/rust/compiler_builtins.o FORCE
+ $(call if_changed_dep,rustc_library)
+
+$(objtree)/rust/build_error.o: $(srctree)/rust/build_error.rs \
+ $(objtree)/rust/compiler_builtins.o FORCE
+ $(call if_changed_dep,rustc_library)
+
+$(objtree)/rust/kernel.o: private rustc_target_flags = --extern alloc \
+ --extern build_error \
+ --extern macros
+$(objtree)/rust/kernel.o: $(srctree)/rust/kernel/lib.rs $(objtree)/rust/alloc.o \
+ $(objtree)/rust/build_error.o \
+ $(objtree)/rust/libmacros.so $(objtree)/rust/bindings_generated.rs \
+ $(objtree)/rust/bindings_helpers_generated.rs FORCE
+ $(call if_changed_dep,rustc_library)
+
+$(objtree)/rust/core.o: private skip_clippy = 1
+$(objtree)/rust/core.o: private skip_flags = -Dunreachable_pub --edition=2021
+$(objtree)/rust/core.o: private rustc_target_flags = $(core-cfgs) --edition=2018
+$(objtree)/rust/core.o: $(RUST_LIB_SRC)/core/src/lib.rs FORCE
+ $(call if_changed_dep,rustc_library)
+
+rustdoc-core: private rustc_target_flags = $(core-cfgs)
+rustdoc-core: $(RUST_LIB_SRC)/core/src/lib.rs FORCE
+ $(call if_changed,rustdoc)
+
+endif # CONFIG_RUST
diff --git a/rust/bindgen_parameters b/rust/bindgen_parameters
new file mode 100644
index 000000000000..c2cc4a88234e
--- /dev/null
+++ b/rust/bindgen_parameters
@@ -0,0 +1,13 @@
+# SPDX-License-Identifier: GPL-2.0
+
+--opaque-type xregs_state
+--opaque-type desc_struct
+--opaque-type arch_lbr_state
+--opaque-type local_apic
+
+# If SMP is disabled, `arch_spinlock_t` is defined as a ZST which triggers a Rust
+# warning. We don't need to peek into it anyway.
+--opaque-type spinlock
+
+# `seccomp`'s comment gets understood as a doctest
+--no-doc-comments
diff --git a/scripts/Kconfig.include b/scripts/Kconfig.include
index 0496efd6e117..83e850321eb6 100644
--- a/scripts/Kconfig.include
+++ b/scripts/Kconfig.include
@@ -36,12 +36,12 @@ ld-option = $(success,$(LD) -v $(1))
as-instr = $(success,printf "%b\n" "$(1)" | $(CC) $(CLANG_FLAGS) -c -x assembler -o /dev/null -)
# check if $(CC) and $(LD) exist
-$(error-if,$(failure,command -v $(CC)),compiler '$(CC)' not found)
+$(error-if,$(failure,command -v $(CC)),C compiler '$(CC)' not found)
$(error-if,$(failure,command -v $(LD)),linker '$(LD)' not found)
-# Get the compiler name, version, and error out if it is not supported.
+# Get the C compiler name, version, and error out if it is not supported.
cc-info := $(shell,$(srctree)/scripts/cc-version.sh $(CC))
-$(error-if,$(success,test -z "$(cc-info)"),Sorry$(comma) this compiler is not supported.)
+$(error-if,$(success,test -z "$(cc-info)"),Sorry$(comma) this C compiler is not supported.)
cc-name := $(shell,set -- $(cc-info) && echo $1)
cc-version := $(shell,set -- $(cc-info) && echo $2)
diff --git a/scripts/Makefile.build b/scripts/Makefile.build
index a4b89b757287..a461b34cabe7 100644
--- a/scripts/Makefile.build
+++ b/scripts/Makefile.build
@@ -26,6 +26,7 @@ EXTRA_CPPFLAGS :=
EXTRA_LDFLAGS :=
asflags-y :=
ccflags-y :=
+rustflags-y :=
cppflags-y :=
ldflags-y :=
@@ -324,6 +325,70 @@ quiet_cmd_cc_lst_c = MKLST $@
$(obj)/%.lst: $(src)/%.c FORCE
$(call if_changed_dep,cc_lst_c)
+# Compile Rust sources (.rs)
+# ---------------------------------------------------------------------------
+
+# Need to use absolute path here and have symbolic links resolved;
+# otherwise rustdoc and rustc compute different hashes for the target.
+rust_cross_flags := --target=$(realpath $(KBUILD_RUST_TARGET))
+
+rust_allowed_features := allocator_api,bench_black_box,concat_idents,generic_associated_types,global_asm
+
+rust_common_cmd = \
+ RUST_MODFILE=$(modfile) $(RUSTC_OR_CLIPPY) \
+ $(rust_flags) $(rust_cross_flags) \
+ -Zallow-features=$(rust_allowed_features) \
+ -Zcrate-attr=no_std \
+ -Zcrate-attr='feature($(rust_allowed_features))' \
+ --extern alloc --extern kernel \
+ --crate-type rlib --out-dir $(obj) -L $(objtree)/rust/ \
+ --crate-name $(basename $(notdir $@))
+
+rust_handle_depfile = \
+ mv $(obj)/$(basename $(notdir $@)).d $(depfile); \
+ sed -i '/^\#/d' $(depfile)
+
+# `--emit=obj`, `--emit=asm` and `--emit=llvm-ir` imply a single codegen unit
+# will be used. We explicitly request `-Ccodegen-units=1` in any case, and
+# the compiler shows a warning if it is not 1. However, if we ever stop
+# requesting it explicitly and we start using some other `--emit` that does not
+# imply it (and for which codegen is performed), then we would be out of sync,
+# i.e. the outputs we would get for the different single targets (e.g. `.ll`)
+# would not match each other.
+
+quiet_cmd_rustc_o_rs = $(RUSTC_OR_CLIPPY_QUIET) $(quiet_modtag) $@
+ cmd_rustc_o_rs = \
+ $(rust_common_cmd) --emit=dep-info,obj $<; \
+ $(rust_handle_depfile)
+
+$(obj)/%.o: $(src)/%.rs FORCE
+ $(call if_changed_dep,rustc_o_rs)
+
+quiet_cmd_rustc_i_rs = $(RUSTC_OR_CLIPPY_QUIET) $(quiet_modtag) $@
+ cmd_rustc_i_rs = \
+ $(rust_common_cmd) --emit=dep-info -Zunpretty=expanded $< >$@; \
+ command -v $(RUSTFMT) >/dev/null && $(RUSTFMT) $@; \
+ $(rust_handle_depfile)
+
+$(obj)/%.i: $(src)/%.rs FORCE
+ $(call if_changed_dep,rustc_i_rs)
+
+quiet_cmd_rustc_s_rs = $(RUSTC_OR_CLIPPY_QUIET) $(quiet_modtag) $@
+ cmd_rustc_s_rs = \
+ $(rust_common_cmd) --emit=dep-info,asm $<; \
+ $(rust_handle_depfile)
+
+$(obj)/%.s: $(src)/%.rs FORCE
+ $(call if_changed_dep,rustc_s_rs)
+
+quiet_cmd_rustc_ll_rs = $(RUSTC_OR_CLIPPY_QUIET) $(quiet_modtag) $@
+ cmd_rustc_ll_rs = \
+ $(rust_common_cmd) --emit=dep-info,llvm-ir $<; \
+ $(rust_handle_depfile)
+
+$(obj)/%.ll: $(src)/%.rs FORCE
+ $(call if_changed_dep,rustc_ll_rs)
+
# Compile assembler sources (.S)
# ---------------------------------------------------------------------------
diff --git a/scripts/Makefile.debug b/scripts/Makefile.debug
index 9f39b0130551..fe87389d52c0 100644
--- a/scripts/Makefile.debug
+++ b/scripts/Makefile.debug
@@ -1,4 +1,5 @@
DEBUG_CFLAGS :=
+DEBUG_RUSTFLAGS :=
ifdef CONFIG_DEBUG_INFO_SPLIT
DEBUG_CFLAGS += -gsplit-dwarf
@@ -10,6 +11,12 @@ ifndef CONFIG_AS_IS_LLVM
KBUILD_AFLAGS += -Wa,-gdwarf-2
endif
+ifdef CONFIG_DEBUG_INFO_REDUCED
+DEBUG_RUSTFLAGS += -Cdebuginfo=1
+else
+DEBUG_RUSTFLAGS += -Cdebuginfo=2
+endif
+
ifndef CONFIG_DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT
dwarf-version-$(CONFIG_DEBUG_INFO_DWARF4) := 4
dwarf-version-$(CONFIG_DEBUG_INFO_DWARF5) := 5
@@ -31,3 +38,6 @@ endif
KBUILD_CFLAGS += $(DEBUG_CFLAGS)
export DEBUG_CFLAGS
+
+KBUILD_RUSTFLAGS += $(DEBUG_RUSTFLAGS)
+export DEBUG_RUSTFLAGS
diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
index 79be57fdd32a..6ac8ae2fc3b6 100644
--- a/scripts/Makefile.lib
+++ b/scripts/Makefile.lib
@@ -8,6 +8,7 @@ ldflags-y += $(EXTRA_LDFLAGS)
# flags that take effect in current and sub directories
KBUILD_AFLAGS += $(subdir-asflags-y)
KBUILD_CFLAGS += $(subdir-ccflags-y)
+KBUILD_RUSTFLAGS += $(subdir-rustflags-y)
# Figure out what we need to build from the various variables
# ===========================================================================
@@ -133,6 +134,10 @@ _c_flags = $(filter-out $(CFLAGS_REMOVE_$(target-stem).o), \
$(filter-out $(ccflags-remove-y), \
$(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) $(ccflags-y)) \
$(CFLAGS_$(target-stem).o))
+_rust_flags = $(filter-out $(RUSTFLAGS_REMOVE_$(target-stem).o), \
+ $(filter-out $(rustflags-remove-y), \
+ $(KBUILD_RUSTFLAGS) $(rustflags-y)) \
+ $(RUSTFLAGS_$(target-stem).o))
_a_flags = $(filter-out $(AFLAGS_REMOVE_$(target-stem).o), \
$(filter-out $(asflags-remove-y), \
$(KBUILD_CPPFLAGS) $(KBUILD_AFLAGS) $(asflags-y)) \
@@ -207,6 +212,11 @@ modkern_cflags = \
$(KBUILD_CFLAGS_MODULE) $(CFLAGS_MODULE), \
$(KBUILD_CFLAGS_KERNEL) $(CFLAGS_KERNEL) $(modfile_flags))
+modkern_rustflags = \
+ $(if $(part-of-module), \
+ $(KBUILD_RUSTFLAGS_MODULE) $(RUSTFLAGS_MODULE), \
+ $(KBUILD_RUSTFLAGS_KERNEL) $(RUSTFLAGS_KERNEL))
+
modkern_aflags = $(if $(part-of-module), \
$(KBUILD_AFLAGS_MODULE) $(AFLAGS_MODULE), \
$(KBUILD_AFLAGS_KERNEL) $(AFLAGS_KERNEL))
@@ -216,6 +226,8 @@ c_flags = -Wp,-MMD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE) \
$(_c_flags) $(modkern_cflags) \
$(basename_flags) $(modname_flags)
+rust_flags = $(_rust_flags) $(modkern_rustflags) @$(objtree)/include/generated/rustc_cfg
+
a_flags = -Wp,-MMD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE) \
$(_a_flags) $(modkern_aflags)
diff --git a/scripts/Makefile.modfinal b/scripts/Makefile.modfinal
index 7f39599e9fae..670d7997a38b 100644
--- a/scripts/Makefile.modfinal
+++ b/scripts/Makefile.modfinal
@@ -39,11 +39,13 @@ quiet_cmd_ld_ko_o = LD [M] $@
quiet_cmd_btf_ko = BTF [M] $@
cmd_btf_ko = \
- if [ -f vmlinux ]; then \
+ if [ ! -f vmlinux ]; then \
+ printf "Skipping BTF generation for %s due to unavailability of vmlinux\n" $@ 1>&2; \
+ elif [ -n "$(CONFIG_RUST)" ] && $(srctree)/scripts/is_rust_module.sh $@; then \
+ printf "Skipping BTF generation for %s because it's a Rust module\n" $@ 1>&2; \
+ else \
LLVM_OBJCOPY="$(OBJCOPY)" $(PAHOLE) -J $(PAHOLE_FLAGS) --btf_base vmlinux $@; \
$(RESOLVE_BTFIDS) -b vmlinux $@; \
- else \
- printf "Skipping BTF generation for %s due to unavailability of vmlinux\n" $@ 1>&2; \
fi;
# Same as newer-prereqs, but allows to exclude specified extra dependencies
diff --git a/scripts/cc-version.sh b/scripts/cc-version.sh
index f1952c522466..2401c86fcf53 100755
--- a/scripts/cc-version.sh
+++ b/scripts/cc-version.sh
@@ -1,13 +1,13 @@
#!/bin/sh
# SPDX-License-Identifier: GPL-2.0
#
-# Print the compiler name and its version in a 5 or 6-digit form.
+# Print the C compiler name and its version in a 5 or 6-digit form.
# Also, perform the minimum version check.
set -e
-# Print the compiler name and some version components.
-get_compiler_info()
+# Print the C compiler name and some version components.
+get_c_compiler_info()
{
cat <<- EOF | "$@" -E -P -x c - 2>/dev/null
#if defined(__clang__)
@@ -32,7 +32,7 @@ get_canonical_version()
# $@ instead of $1 because multiple words might be given, e.g. CC="ccache gcc".
orig_args="$@"
-set -- $(get_compiler_info "$@")
+set -- $(get_c_compiler_info "$@")
name=$1
@@ -52,7 +52,7 @@ ICC)
min_version=$($min_tool_version icc)
;;
*)
- echo "$orig_args: unknown compiler" >&2
+ echo "$orig_args: unknown C compiler" >&2
exit 1
;;
esac
@@ -62,7 +62,7 @@ min_cversion=$(get_canonical_version $min_version)
if [ "$cversion" -lt "$min_cversion" ]; then
echo >&2 "***"
- echo >&2 "*** Compiler is too old."
+ echo >&2 "*** C compiler is too old."
echo >&2 "*** Your $name version: $version"
echo >&2 "*** Minimum $name version: $min_version"
echo >&2 "***"
diff --git a/scripts/is_rust_module.sh b/scripts/is_rust_module.sh
new file mode 100755
index 000000000000..277a64d07f22
--- /dev/null
+++ b/scripts/is_rust_module.sh
@@ -0,0 +1,13 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0
+#
+# is_rust_module.sh module.ko
+#
+# Returns `0` if `module.ko` is a Rust module, `1` otherwise.
+
+set -e
+
+# Using the `16_` prefix ensures other symbols with the same substring
+# are not picked up (even if it would be unlikely). The last part is
+# used just in case LLVM decides to use the `.` suffix.
+${NM} "$*" | grep -qE '^[0-9a-fA-F]+ r _R[^[:space:]]+16___IS_RUST_MODULE[^[:space:]]*$'
diff --git a/scripts/kconfig/confdata.c b/scripts/kconfig/confdata.c
index 59717be31210..ae54319cdde4 100644
--- a/scripts/kconfig/confdata.c
+++ b/scripts/kconfig/confdata.c
@@ -216,6 +216,13 @@ static const char *conf_get_autoheader_name(void)
return name ? name : "include/generated/autoconf.h";
}
+static const char *conf_get_rustccfg_name(void)
+{
+ char *name = getenv("KCONFIG_RUSTCCFG");
+
+ return name ? name : "include/generated/rustc_cfg";
+}
+
static int conf_set_sym_val(struct symbol *sym, int def, int def_flags, char *p)
{
char *p2;
@@ -605,6 +612,9 @@ static const struct comment_style comment_style_c = {
static void conf_write_heading(FILE *fp, const struct comment_style *cs)
{
+ if (!cs)
+ return;
+
fprintf(fp, "%s\n", cs->prefix);
fprintf(fp, "%s Automatically generated file; DO NOT EDIT.\n",
@@ -752,6 +762,65 @@ static void print_symbol_for_c(FILE *fp, struct symbol *sym)
free(escaped);
}
+static void print_symbol_for_rustccfg(FILE *fp, struct symbol *sym)
+{
+ const char *val;
+ const char *val_prefix = "";
+ char *val_prefixed = NULL;
+ size_t val_prefixed_len;
+ char *escaped = NULL;
+
+ if (sym->type == S_UNKNOWN)
+ return;
+
+ val = sym_get_string_value(sym);
+
+ switch (sym->type) {
+ case S_BOOLEAN:
+ case S_TRISTATE:
+ /*
+ * We do not care about disabled ones, i.e. no need for
+ * what otherwise are "comments" in other printers.
+ */
+ if (*val == 'n')
+ return;
+
+ /*
+ * To have similar functionality to the C macro `IS_ENABLED()`
+ * we provide an empty `--cfg CONFIG_X` here in both `y`
+ * and `m` cases.
+ *
+ * Then, the common `fprintf()` below will also give us
+ * a `--cfg CONFIG_X="y"` or `--cfg CONFIG_X="m"`, which can
+ * be used as the equivalent of `IS_BUILTIN()`/`IS_MODULE()`.
+ */
+ fprintf(fp, "--cfg=%s%s\n", CONFIG_, sym->name);
+ break;
+ case S_HEX:
+ if (val[0] != '0' || (val[1] != 'x' && val[1] != 'X'))
+ val_prefix = "0x";
+ break;
+ default:
+ break;
+ }
+
+ if (strlen(val_prefix) > 0) {
+ val_prefixed_len = strlen(val) + strlen(val_prefix) + 1;
+ val_prefixed = xmalloc(val_prefixed_len);
+ snprintf(val_prefixed, val_prefixed_len, "%s%s", val_prefix, val);
+ val = val_prefixed;
+ }
+
+ /* All values get escaped: the `--cfg` option only takes strings */
+ escaped = escape_string_value(val);
+ val = escaped;
+
+ fprintf(fp, "--cfg=%s%s=%s\n", CONFIG_, sym->name, val);
+
+ free(escaped);
+ free(val_prefixed);
+}
+
/*
* Write out a minimal config.
* All values that has default values are skipped as this is redundant.
@@ -1131,6 +1200,12 @@ int conf_write_autoconf(int overwrite)
if (ret)
return ret;
+ ret = __conf_write_autoconf(conf_get_rustccfg_name(),
+ print_symbol_for_rustccfg,
+ NULL);
+ if (ret)
+ return ret;
+
/*
* Create include/config/auto.conf. This must be the last step because
* Kbuild has a dependency on auto.conf and this marks the successful
diff --git a/scripts/min-tool-version.sh b/scripts/min-tool-version.sh
index 7c20252a90c6..117797d7e0c7 100755
--- a/scripts/min-tool-version.sh
+++ b/scripts/min-tool-version.sh
@@ -31,6 +31,12 @@ llvm)
echo 11.0.0
fi
;;
+rustc)
+ echo 1.58.0
+ ;;
+bindgen)
+ echo 0.56.0
+ ;;
*)
echo "$1: unknown tool" >&2
exit 1
diff --git a/scripts/rust-is-available-bindgen-libclang.h b/scripts/rust-is-available-bindgen-libclang.h
new file mode 100644
index 000000000000..0ef6db10d674
--- /dev/null
+++ b/scripts/rust-is-available-bindgen-libclang.h
@@ -0,0 +1,2 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#pragma message("clang version " __clang_version__)
diff --git a/scripts/rust-is-available.sh b/scripts/rust-is-available.sh
new file mode 100755
index 000000000000..6bd395167d0f
--- /dev/null
+++ b/scripts/rust-is-available.sh
@@ -0,0 +1,158 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0
+#
+# Tests whether a suitable Rust toolchain is available.
+#
+# Pass `-v` for human output and more checks (as warnings).
+
+set -e
+
+min_tool_version=$(dirname $0)/min-tool-version.sh
+
+# Convert the version string x.y.z to a canonical up-to-7-digits form.
+#
+# Note that this function uses one more digit (compared to other
+# instances in other version scripts) to give a bit more space to
+# `rustc` since it will reach 1.100.0 in late 2026.
+get_canonical_version()
+{
+ IFS=.
+ set -- $1
+ echo $((100000 * $1 + 100 * $2 + $3))
+}
+
+# Check that the Rust compiler exists.
+if ! command -v "$RUSTC" >/dev/null; then
+ if [ "$1" = -v ]; then
+ echo >&2 "***"
+ echo >&2 "*** Rust compiler '$RUSTC' could not be found."
+ echo >&2 "***"
+ fi
+ exit 1
+fi
+
+# Check that the Rust bindings generator exists.
+if ! command -v "$BINDGEN" >/dev/null; then
+ if [ "$1" = -v ]; then
+ echo >&2 "***"
+ echo >&2 "*** Rust bindings generator '$BINDGEN' could not be found."
+ echo >&2 "***"
+ fi
+ exit 1
+fi
+
+# Check that the Rust compiler version is suitable.
+#
+# Non-stable and distributions' versions may have a version suffix, e.g. `-dev`.
+rust_compiler_version=$( \
+ LC_ALL=C "$RUSTC" --version 2>/dev/null \
+ | head -n 1 \
+ | grep -oE '[0-9]+\.[0-9]+\.[0-9]+' \
+)
+rust_compiler_min_version=$($min_tool_version rustc)
+rust_compiler_cversion=$(get_canonical_version $rust_compiler_version)
+rust_compiler_min_cversion=$(get_canonical_version $rust_compiler_min_version)
+if [ "$rust_compiler_cversion" -lt "$rust_compiler_min_cversion" ]; then
+ if [ "$1" = -v ]; then
+ echo >&2 "***"
+ echo >&2 "*** Rust compiler '$RUSTC' is too old."
+ echo >&2 "*** Your version: $rust_compiler_version"
+ echo >&2 "*** Minimum version: $rust_compiler_min_version"
+ echo >&2 "***"
+ fi
+ exit 1
+fi
+if [ "$1" = -v ] && [ "$rust_compiler_cversion" -gt "$rust_compiler_min_cversion" ]; then
+ echo >&2 "***"
+ echo >&2 "*** Rust compiler '$RUSTC' is too new. This may or may not work."
+ echo >&2 "*** Your version: $rust_compiler_version"
+ echo >&2 "*** Expected version: $rust_compiler_min_version"
+ echo >&2 "***"
+fi
+
+# Check that the Rust bindings generator is suitable.
+#
+# Non-stable and distributions' versions may have a version suffix, e.g. `-dev`.
+rust_bindings_generator_version=$( \
+ LC_ALL=C "$BINDGEN" --version 2>/dev/null \
+ | head -n 1 \
+ | grep -oE '[0-9]+\.[0-9]+\.[0-9]+' \
+)
+rust_bindings_generator_min_version=$($min_tool_version bindgen)
+rust_bindings_generator_cversion=$(get_canonical_version $rust_bindings_generator_version)
+rust_bindings_generator_min_cversion=$(get_canonical_version $rust_bindings_generator_min_version)
+if [ "$rust_bindings_generator_cversion" -lt "$rust_bindings_generator_min_cversion" ]; then
+ if [ "$1" = -v ]; then
+ echo >&2 "***"
+ echo >&2 "*** Rust bindings generator '$BINDGEN' is too old."
+ echo >&2 "*** Your version: $rust_bindings_generator_version"
+ echo >&2 "*** Minimum version: $rust_bindings_generator_min_version"
+ echo >&2 "***"
+ fi
+ exit 1
+fi
+if [ "$1" = -v ] && [ "$rust_bindings_generator_cversion" -gt "$rust_bindings_generator_min_cversion" ]; then
+ echo >&2 "***"
+ echo >&2 "*** Rust bindings generator '$BINDGEN' is too new. This may or may not work."
+ echo >&2 "*** Your version: $rust_bindings_generator_version"
+ echo >&2 "*** Expected version: $rust_bindings_generator_min_version"
+ echo >&2 "***"
+fi
+
+# Check that the `libclang` used by the Rust bindings generator is suitable.
+bindgen_libclang_version=$( \
+ LC_ALL=C "$BINDGEN" $(dirname $0)/rust-is-available-bindgen-libclang.h 2>&1 >/dev/null \
+ | grep -F 'clang version ' \
+ | grep -oE '[0-9]+\.[0-9]+\.[0-9]+' \
+)
+bindgen_libclang_min_version=$($min_tool_version llvm)
+bindgen_libclang_cversion=$(get_canonical_version $bindgen_libclang_version)
+bindgen_libclang_min_cversion=$(get_canonical_version $bindgen_libclang_min_version)
+if [ "$bindgen_libclang_cversion" -lt "$bindgen_libclang_min_cversion" ]; then
+ if [ "$1" = -v ]; then
+ echo >&2 "***"
+ echo >&2 "*** libclang (used by the Rust bindings generator '$BINDGEN') is too old."
+ echo >&2 "*** Your version: $bindgen_libclang_version"
+ echo >&2 "*** Minimum version: $bindgen_libclang_min_version"
+ echo >&2 "***"
+ fi
+ exit 1
+fi
+
+# If the C compiler is Clang, then we can also check whether its version
+# matches the `libclang` version used by the Rust bindings generator.
+#
+# In the future, we might be able to perform a full version check, see
+# https://github.com/rust-lang/rust-bindgen/issues/2138.
+if [ "$1" = -v ]; then
+ cc_name=$($(dirname $0)/cc-version.sh "$CC" | cut -f1 -d' ')
+ if [ "$cc_name" = Clang ]; then
+ clang_version=$( \
+ LC_ALL=C "$CC" --version 2>/dev/null \
+ | sed -nE '1s:.*version ([0-9]+\.[0-9]+\.[0-9]+).*:\1:p'
+ )
+ if [ "$clang_version" != "$bindgen_libclang_version" ]; then
+ echo >&2 "***"
+ echo >&2 "*** libclang (used by the Rust bindings generator '$BINDGEN') version does not match Clang's. This may be a problem."
+ echo >&2 "*** libclang version: $bindgen_libclang_version"
+ echo >&2 "*** Clang version: $clang_version"
+ echo >&2 "***"
+ fi
+ fi
+fi
+
+# Check that the source code for the `core` standard library exists.
+#
+# `$KRUSTFLAGS` is passed in case the user added `--sysroot`.
+rustc_sysroot=$("$RUSTC" $KRUSTFLAGS --print sysroot)
+rustc_src=${RUST_LIB_SRC:-"$rustc_sysroot/lib/rustlib/src/rust/library"}
+rustc_src_core="$rustc_src/core/src/lib.rs"
+if [ ! -e "$rustc_src_core" ]; then
+ if [ "$1" = -v ]; then
+ echo >&2 "***"
+ echo >&2 "*** Source code for the 'core' standard library could not be found"
+ echo >&2 "*** at '$rustc_src_core'."
+ echo >&2 "***"
+ fi
+ exit 1
+fi
--
2.35.1
Hi!
On Sat, Feb 12, 2022 at 02:03:42PM +0100, Miguel Ojeda wrote:
> +config RUST
> + bool "Rust support"
> + depends on RUST_IS_AVAILABLE
> + depends on ARM64 || CPU_32v6 || CPU_32v6K || (PPC64 && CPU_LITTLE_ENDIAN) || X86_64 || RISCV
Is there any particular reason why this list excludes MIPS*, i386, big-endian
PowerPC and SPARC targets which are already supported by the Rust programming
language?
Are the arch/$ARCH/rust/target.json files everything that's needed for supporting
the other targets?
Thanks,
Adrian
--
.''`. John Paul Adrian Glaubitz
: :' : Debian Developer - [email protected]
`. `' Freie Universitaet Berlin - [email protected]
`- GPG: 62FF 8A75 84E0 2956 9546 0006 7426 3B37 F5B5 F913
Hi Russell,
On Sat, Feb 12, 2022 at 3:17 PM Russell King (Oracle)
<[email protected]> wrote:
>
> Please don't use CPU_32v6* here.
>
> It probably makes more sense to add a symbol "HAVE_RUST" and have the
> appropriate architecture Kconfig files select HAVE_RUST.
We can do it whatever way arch maintainers prefer, of course. Why
would you prefer one over the other?
> Does Rust support Thumb on ARMv6 and ARMv7 architectures?
Yes, the main backend is LLVM. Some built-in targets and their support
level are listed here, if you want to take a look:
https://doc.rust-lang.org/nightly/rustc/platform-support.html
There is also a GCC backend in `rustc` [1], which is making good
progress and may eventually give us access to architectures supported
by GCC. Furthermore, a from-scratch Rust frontend for GCC [2] is being
worked on, though this effort will likely take more time to reach a
point where it may be used for the kernel.
[1] https://github.com/rust-lang/rust/tree/master/compiler/rustc_codegen_gcc
[2] https://github.com/Rust-GCC/gccrs
> Please remove every utterance of "default n" from your patch; n is the
> default default which default defaults to, so you don't need to specify
> default n to make the option default to n. It will default to n purely
> because n is the default when no default is specified.
Certainly. I am curious, though: is there a reason for most of the
other 500+ instances in the kernel tree?
> As Rust doesn't support all the architectures that the kernel supports,
> Rust must not be used for core infrastructure.
Yeah, although I am not sure I understand what you are getting at here.
Cheers,
Miguel
On Sat, Feb 12, 2022 at 04:47:33PM +0100, Miguel Ojeda wrote:
> Hi Russell,
>
> On Sat, Feb 12, 2022 at 3:17 PM Russell King (Oracle)
> <[email protected]> wrote:
> >
> > Please don't use CPU_32v6* here.
> >
> > It probably makes more sense to add a symbol "HAVE_RUST" and have the
> > appropriate architecture Kconfig files select HAVE_RUST.
>
> We can do it whatever way arch maintainers prefer, of course. Why
> would you prefer one over the other?
It would be cleaner, rather than the "depends" line getting longer
and longer over time - and if different architecture maintainers
change it, it will lead to conflicts.
> > Does Rust support Thumb on ARMv6 and ARMv7 architectures?
>
> Yes, the main backend is LLVM. Some built-in targets and their support
> level are listed here, if you want to take a look:
Right, so why made it dependent on CPU_32v6 || CPU_32v6K if ARMv7 is
supported? What about CPU_32v7? What about CPU_32v7M?
I think it would be saner to use the CPU_V6, CPU_V6K, CPU_V7 and maybe
CPU_V7M here - even bettern to select "HAVE_RUST" from these symbols,
since I'm sure you'd start to see the issue behind my "HAVE_RUST"
suggestion as it means having four symbols just for 32-bit ARM on your
dependency line.
> https://doc.rust-lang.org/nightly/rustc/platform-support.html
Interestingly, it does not list arm-unknown-linux-gnueabihf, which
is the "tuple" commonly used to build 32-bit ARM kernels.
> > Please remove every utterance of "default n" from your patch; n is the
> > default default which default defaults to, so you don't need to specify
> > default n to make the option default to n. It will default to n purely
> > because n is the default when no default is specified.
>
> Certainly. I am curious, though: is there a reason for most of the
> other 500+ instances in the kernel tree?
Probably because people incorrectly think it's required or some other
minor reason. As I say:
config FOO
bool/tristate ...
always defaults to 'n' without needing "default n" to be specified.
Let's do some proper research on this. There are 19148 "config"
statements in the kernel tree, 521 "default n" and 4818 that
specify any kind of "default". That means there are about 14330
config statements that do not specify any kind of default.
So, there are about 27 times more config statements that specify no
default than those that specify "default n", so using the argument
that there are "500+ instances" and therefore should be seen as
correct is completely misguided.
> > As Rust doesn't support all the architectures that the kernel supports,
> > Rust must not be used for core infrastructure.
>
> Yeah, although I am not sure I understand what you are getting at here.
I mean, if we end up with, e.g. a filesystem coded in Rust, that
filesystem will not be available on architectures that the kernel
supports until either (a) Rust gains support for that architecture
or (b) someone re-codes the filesystem in C - at which point, what
is the point of having Rust in the kernel?
--
RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
FTTP is here! 40Mbps down 10Mbps up. Decent connectivity at last!
On Sat, Feb 12, 2022 at 5:19 PM Russell King (Oracle)
<[email protected]> wrote:
>
> Right, so why made it dependent on CPU_32v6 || CPU_32v6K if ARMv7 is
> supported? What about CPU_32v7? What about CPU_32v7M?
>
> I think it would be saner to use the CPU_V6, CPU_V6K, CPU_V7 and maybe
> CPU_V7M here - even bettern to select "HAVE_RUST" from these symbols,
> since I'm sure you'd start to see the issue behind my "HAVE_RUST"
> suggestion as it means having four symbols just for 32-bit ARM on your
> dependency line.
To support arch variations properly we also have to configure the
compiler via filling a target spec on the fly, but so far we only have
a few static variations as an example. This is one of the missing
parts of the arch support. I will let you know when we have something
ready.
> Interestingly, it does not list arm-unknown-linux-gnueabihf, which
> is the "tuple" commonly used to build 32-bit ARM kernels.
I see it there (Tier 2).
> Probably because people incorrectly think it's required or some other
> minor reason. As I say:
In that case, we should remove them and warn about those instances,
assuming the preferred style is to not have it.
> so using the argument
> that there are "500+ instances" and therefore should be seen as
> correct is completely misguided.
I did not use any such argument.
> I mean, if we end up with, e.g. a filesystem coded in Rust, that
> filesystem will not be available on architectures that the kernel
As long as that filesystem is an optional feature (or as long as there
is a C version), it should be fine.
> supports until either (a) Rust gains support for that architecture
For this, it would be ideal if entities behind some of the
architectures could support LLVM & ClangBuiltLinux, or the GCC Rust
frontend, or the GCC backend for `rustc`.
For instance, Arm is supporting both LLVM and the Rust project.
> or (b) someone re-codes the filesystem in C - at which point, what
> is the point of having Rust in the kernel?
Having a C version of some system does not mean a Rust version would
not offer advantages. In fact, we are adding Rust precisely because we
believe it offers some advantages over C, for both end users and
maintainers.
(Please see the RFC [1], previous discussions, etc.)
[1] https://lore.kernel.org/lkml/[email protected]/
Cheers,
Miguel
Hi John Paul,
On Sat, Feb 12, 2022 at 7:27 PM John Paul Adrian Glaubitz
<[email protected]> wrote:
>
> Is there any particular reason why this list excludes MIPS*, i386, big-endian
> PowerPC and SPARC targets which are already supported by the Rust programming
> language?
The variations we have so far were intended to showcase the Rust
support in several major architectures, rather than cover everything.
But as long as LLVM (& the kernel, i.e. ClangBuiltLinux) supports the
target (and as long there are no compiler/toolchain issues), you
should be able to try it.
> Are the arch/$ARCH/rust/target.json files everything that's needed for supporting
> the other targets?
Mostly -- there is also `rust/kernel/c_types.rs` and you may need to
tweak `rust/compiler_builtins.rs`, but not much more.
Note that for the target spec files, the short-term plan is to
generate dynamically the target spec file according to what the
architecture requests, instead of using these static files. Longer
term, we need a Rust-stable way to setup custom targets from upstream
`rustc` (though it is not clear yet how it will look, e.g. it could be
via command-line flags).
Cheers,
Miguel
On Sat, Feb 12, 2022 at 02:03:42PM +0100, Miguel Ojeda wrote:
> +config RUST
> + bool "Rust support"
> + depends on RUST_IS_AVAILABLE
> + depends on ARM64 || CPU_32v6 || CPU_32v6K || (PPC64 && CPU_LITTLE_ENDIAN) || X86_64 || RISCV
Please don't use CPU_32v6* here.
It probably makes more sense to add a symbol "HAVE_RUST" and have the
appropriate architecture Kconfig files select HAVE_RUST.
Does Rust support Thumb on ARMv6 and ARMv7 architectures?
> + depends on !MODVERSIONS
> + depends on !GCC_PLUGIN_RANDSTRUCT
> + select CONSTRUCTORS
> + default n
Please remove every utterance of "default n" from your patch; n is the
default default which default defaults to, so you don't need to specify
default n to make the option default to n. It will default to n purely
because n is the default when no default is specified.
> + help
> + Enables Rust support in the kernel.
> +
> + This allows other Rust-related options, like drivers written in Rust,
> + to be selected.
As Rust doesn't support all the architectures that the kernel supports,
Rust must not be used for core infrastructure.
--
RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
FTTP is here! 40Mbps down 10Mbps up. Decent connectivity at last!