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 specification
generation script, the version detection script and a few
other bits.
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]>
Co-developed-by: David Gow <[email protected]>
Signed-off-by: David Gow <[email protected]>
Signed-off-by: Miguel Ojeda <[email protected]>
---
.gitignore | 5 +
.rustfmt.toml | 12 +
Makefile | 175 +++++++-
arch/Kconfig | 6 +
arch/arm/Kconfig | 1 +
arch/arm64/Kconfig | 1 +
arch/powerpc/Kconfig | 1 +
arch/riscv/Kconfig | 1 +
arch/riscv/Makefile | 5 +
arch/um/Kconfig | 1 +
arch/x86/Kconfig | 1 +
arch/x86/Makefile | 14 +
init/Kconfig | 45 ++-
lib/Kconfig.debug | 155 ++++++++
rust/.gitignore | 10 +
rust/Makefile | 398 +++++++++++++++++++
rust/bindgen_parameters | 17 +
scripts/.gitignore | 1 +
scripts/Kconfig.include | 6 +-
scripts/Makefile | 3 +
scripts/Makefile.build | 60 +++
scripts/Makefile.debug | 10 +
scripts/Makefile.host | 34 +-
scripts/Makefile.lib | 12 +
scripts/Makefile.modfinal | 8 +-
scripts/cc-version.sh | 12 +-
scripts/generate_rust_target.rs | 227 +++++++++++
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 ++++++++
32 files changed, 1452 insertions(+), 23 deletions(-)
create mode 100644 .rustfmt.toml
create mode 100644 rust/.gitignore
create mode 100644 rust/Makefile
create mode 100644 rust/bindgen_parameters
create mode 100644 scripts/generate_rust_target.rs
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 7d5b0bfe7960..ce17ec71f89b 100644
--- a/Makefile
+++ b/Makefile
@@ -120,6 +120,15 @@ 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 := $(CLIPPY)
+endif
+
+export KBUILD_CLIPPY
+
# Use make M=dir or set the environment variable KBUILD_EXTMOD to specify the
# directory of external module to build. Setting M= takes precedence.
ifeq ("$(origin M)", "command line")
@@ -267,7 +276,7 @@ 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 \
@@ -436,6 +445,7 @@ else
HOSTCC = gcc
HOSTCXX = g++
endif
+HOSTRUSTC = rustc
KBUILD_USERHOSTCFLAGS := -Wall -Wmissing-prototypes -Wstrict-prototypes \
-O2 -fomit-frame-pointer -std=gnu11 \
@@ -443,8 +453,26 @@ KBUILD_USERHOSTCFLAGS := -Wall -Wmissing-prototypes -Wstrict-prototypes \
KBUILD_USERCFLAGS := $(KBUILD_USERHOSTCFLAGS) $(USERCFLAGS)
KBUILD_USERLDFLAGS := $(USERLDFLAGS)
+# These flags apply to all Rust code in the tree, including the kernel and
+# host programs.
+export rust_common_flags := --edition=2021 \
+ -Zbinary_dep_depinfo=y \
+ -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::let_unit_value -Dclippy::mut_mut \
+ -Dclippy::needless_bitwise_bool \
+ -Dclippy::needless_continue \
+ -Wclippy::dbg_macro
+
KBUILD_HOSTCFLAGS := $(KBUILD_USERHOSTCFLAGS) $(HOST_LFS_CFLAGS) $(HOSTCFLAGS)
KBUILD_HOSTCXXFLAGS := -Wall -O2 $(HOST_LFS_CFLAGS) $(HOSTCXXFLAGS)
+KBUILD_HOSTRUSTFLAGS := $(rust_common_flags) -O -Cstrip=debuginfo \
+ -Zallow-features= $(HOSTRUSTFLAGS)
KBUILD_HOSTLDFLAGS := $(HOST_LFS_LDFLAGS) $(HOSTLDFLAGS)
KBUILD_HOSTLDLIBS := $(HOST_LFS_LIBS) $(HOSTLDLIBS)
@@ -469,6 +497,12 @@ 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
@@ -494,9 +528,11 @@ 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 =
@@ -525,15 +561,42 @@ KBUILD_CFLAGS := -Wall -Wundef -Werror=strict-prototypes -Wno-trigraphs \
-Werror=return-type -Wno-format-security \
-std=gnu11
KBUILD_CPPFLAGS := -D__KERNEL__
+KBUILD_RUSTFLAGS := $(rust_common_flags) \
+ --target=$(objtree)/rust/target.json \
+ -Cpanic=abort -Cembed-bitcode=n -Clto=n \
+ -Cforce-unwind-tables=n -Ccodegen-units=1 \
+ -Csymbol-mangling-version=v0 \
+ -Crelocation-model=static \
+ -Zfunction-sections=n \
+ -Dclippy::float_arithmetic
+
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 HOSTRUSTC KBUILD_HOSTRUSTFLAGS
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
@@ -542,9 +605,10 @@ export KBUILD_USERCFLAGS KBUILD_USERLDFLAGS
export KBUILD_CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS KBUILD_LDFLAGS
export KBUILD_CFLAGS CFLAGS_KERNEL CFLAGS_MODULE
+export 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
@@ -725,7 +789,7 @@ $(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
@@ -754,12 +818,28 @@ 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
@@ -789,6 +869,9 @@ 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=gnu11' so use of GNU extensions is acceptable.
@@ -806,12 +889,15 @@ 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
# select FRAME_POINTER. However, FUNCTION_TRACER adds -pg, and this is
# incompatible with -fomit-frame-pointer with current GCC, so we don't use
# -fomit-frame-pointer with FUNCTION_TRACER.
+# In the Rust target specification, "frame-pointer" is set explicitly
+# to "may-omit".
ifndef CONFIG_FUNCTION_TRACER
KBUILD_CFLAGS += -fomit-frame-pointer
endif
@@ -876,8 +962,10 @@ ifdef CONFIG_DEBUG_SECTION_MISMATCH
KBUILD_CFLAGS += -fno-inline-functions-called-once
endif
+# `rustc`'s `-Zfunction-sections` applies to data too (as of 1.59.0).
ifdef CONFIG_LD_DEAD_CODE_DATA_ELIMINATION
KBUILD_CFLAGS_KERNEL += -ffunction-sections -fdata-sections
+KBUILD_RUSTFLAGS_KERNEL += -Zfunction-sections=y
LDFLAGS_vmlinux += --gc-sections
endif
@@ -1019,10 +1107,11 @@ 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
@@ -1091,6 +1180,7 @@ 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) \
@@ -1195,6 +1285,10 @@ 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:
@@ -1483,7 +1577,7 @@ 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 \
@@ -1494,7 +1588,8 @@ MRPROPER_FILES += include/config include/generated \
certs/signing_key.pem \
certs/x509.genkey \
vmlinux-gdb.py \
- *.spec
+ *.spec \
+ rust/target.json rust/libmacros.so
# clean - Delete most, but leave enough to build external modules
#
@@ -1519,6 +1614,9 @@ $(mrproper-dirs):
mrproper: clean $(mrproper-dirs)
$(call cmd,rmfiles)
+ @find . $(RCS_FIND_IGNORE) \
+ \( -name '*.rmeta' \) \
+ -type f -print | xargs rm -f
# distclean
#
@@ -1606,6 +1704,23 @@ 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'; \
@@ -1677,6 +1792,52 @@ 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: prepare
+ $(Q)$(MAKE) $(build)=rust $@
+
+# Testing target
+PHONY += rusttest
+rusttest: prepare
+ $(Q)$(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:
+ $(Q)$(MAKE) $(build)=rust $@
+
# Misc
# ---------------------------------------------------------------------------
diff --git a/arch/Kconfig b/arch/Kconfig
index 31c4fdc4a4ba..89d27b2a86dd 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -344,6 +344,12 @@ config HAVE_RSEQ
This symbol should be selected by an architecture if it
supports an implementation of restartable sequences.
+config HAVE_RUST
+ bool
+ help
+ This symbol should be selected by an architecture if it
+ supports Rust.
+
config HAVE_FUNCTION_ARG_ACCESS_API
bool
help
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 2e8091e2d8a8..1d0005080aeb 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -116,6 +116,7 @@ config ARM
select MMU_GATHER_RCU_TABLE_FREE if SMP && ARM_LPAE
select HAVE_REGS_AND_STACK_ACCESS_API
select HAVE_RSEQ
+ select HAVE_RUST if CPU_32v6 || CPU_32v6K
select HAVE_STACKPROTECTOR
select HAVE_SYSCALL_TRACEPOINTS
select HAVE_UID16
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 20ea89d9ac2f..308cff85f5cb 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -198,6 +198,7 @@ config ARM64
select HAVE_FUNCTION_ARG_ACCESS_API
select MMU_GATHER_RCU_TABLE_FREE
select HAVE_RSEQ
+ select HAVE_RUST
select HAVE_STACKPROTECTOR
select HAVE_SYSCALL_TRACEPOINTS
select HAVE_KPROBES
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 174edabb74fa..ffbad38204b9 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -239,6 +239,7 @@ config PPC
select HAVE_REGS_AND_STACK_ACCESS_API
select HAVE_RELIABLE_STACKTRACE
select HAVE_RSEQ
+ select HAVE_RUST if PPC64 && CPU_LITTLE_ENDIAN
select HAVE_SETUP_PER_CPU_AREA if PPC64
select HAVE_SOFTIRQ_ON_OWN_STACK
select HAVE_STACKPROTECTOR if PPC32 && $(cc-option,-mstack-protector-guard=tls -mstack-protector-guard-reg=r2)
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index 00fd9c548f26..63f7258984f3 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -101,6 +101,7 @@ config RISCV
select HAVE_PERF_REGS
select HAVE_PERF_USER_STACK_DUMP
select HAVE_REGS_AND_STACK_ACCESS_API
+ select HAVE_RUST if 64BIT
select HAVE_FUNCTION_ARG_ACCESS_API
select HAVE_STACKPROTECTOR
select HAVE_SYSCALL_TRACEPOINTS
diff --git a/arch/riscv/Makefile b/arch/riscv/Makefile
index 7d81102cffd4..663ae53b5597 100644
--- a/arch/riscv/Makefile
+++ b/arch/riscv/Makefile
@@ -26,6 +26,8 @@ ifeq ($(CONFIG_ARCH_RV64I),y)
KBUILD_CFLAGS += -mabi=lp64
KBUILD_AFLAGS += -mabi=lp64
+ KBUILD_RUSTFLAGS += -Ctarget-cpu=generic-rv64
+
KBUILD_LDFLAGS += -melf64lriscv
else
BITS := 32
@@ -33,6 +35,9 @@ else
KBUILD_CFLAGS += -mabi=ilp32
KBUILD_AFLAGS += -mabi=ilp32
+
+ KBUILD_RUSTFLAGS += -Ctarget-cpu=generic-rv32
+
KBUILD_LDFLAGS += -melf32lriscv
endif
diff --git a/arch/um/Kconfig b/arch/um/Kconfig
index 4d398b80aea8..c9e76243c0b9 100644
--- a/arch/um/Kconfig
+++ b/arch/um/Kconfig
@@ -24,6 +24,7 @@ config UML
select TRACE_IRQFLAGS_SUPPORT
select TTY # Needed for line.c
select HAVE_ARCH_VMAP_STACK
+ select HAVE_RUST if X86_64
config MMU
bool
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 4bed3abf444d..8d4e30f07a7d 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -252,6 +252,7 @@ config X86
select HAVE_STATIC_CALL_INLINE if HAVE_STACK_VALIDATION
select HAVE_PREEMPT_DYNAMIC_CALL
select HAVE_RSEQ
+ select HAVE_RUST if X86_64
select HAVE_SYSCALL_TRACEPOINTS
select HAVE_UNSTABLE_SCHED_CLOCK
select HAVE_USER_RETURN_NOTIFIER
diff --git a/arch/x86/Makefile b/arch/x86/Makefile
index 63d50f65b828..5ac9b324751d 100644
--- a/arch/x86/Makefile
+++ b/arch/x86/Makefile
@@ -21,6 +21,8 @@ ifdef CONFIG_CC_IS_CLANG
RETPOLINE_CFLAGS := -mretpoline-external-thunk
RETPOLINE_VDSO_CFLAGS := -mretpoline
endif
+RETPOLINE_RUSTFLAGS := -Ctarget-feature=+retpoline-external-thunk
+
export RETPOLINE_CFLAGS
export RETPOLINE_VDSO_CFLAGS
@@ -61,6 +63,8 @@ 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 += -Ctarget-feature=-mmx,-sse,-sse2,-sse3,-ssse3,-sse4.1,-sse4.2
+KBUILD_RUSTFLAGS += -Ctarget-feature=-3dnow,-3dnowa,-avx,-avx2,+soft-float
ifeq ($(CONFIG_X86_KERNEL_IBT),y)
#
@@ -148,8 +152,17 @@ else
cflags-$(CONFIG_GENERIC_CPU) += -mtune=generic
KBUILD_CFLAGS += $(cflags-y)
+ rustflags-$(CONFIG_MK8) += -Ctarget-cpu=k8
+ rustflags-$(CONFIG_MPSC) += -Ctarget-cpu=nocona
+ rustflags-$(CONFIG_MCORE2) += -Ctarget-cpu=core2
+ rustflags-$(CONFIG_MATOM) += -Ctarget-cpu=atom
+ rustflags-$(CONFIG_GENERIC_CPU) += -Ztune-cpu=generic
+ KBUILD_RUSTFLAGS += $(rustflags-y)
+
KBUILD_CFLAGS += -mno-red-zone
KBUILD_CFLAGS += -mcmodel=kernel
+ KBUILD_RUSTFLAGS += -Cno-redzone=y
+ KBUILD_RUSTFLAGS += -Ccode-model=kernel
endif
#
@@ -185,6 +198,7 @@ ifdef CONFIG_RETPOLINE
ifndef CONFIG_CC_IS_CLANG
KBUILD_CFLAGS += -fno-jump-tables
endif
+ KBUILD_RUSTFLAGS += $(RETPOLINE_RUSTFLAGS)
endif
ifdef CONFIG_SLS
diff --git a/init/Kconfig b/init/Kconfig
index ddcbefe535e9..3457cf596588 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) $(USERCFLAGS) $(USERLDFLAGS) $(m64-flag)) if 64BIT
@@ -146,7 +157,8 @@ 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,
@@ -2045,6 +2057,37 @@ config PROFILING
Say Y here to enable the extended profiling support mechanisms used
by profilers.
+config RUST
+ bool "Rust support"
+ depends on HAVE_RUST
+ depends on RUST_IS_AVAILABLE
+ depends on !MODVERSIONS
+ depends on !GCC_PLUGINS
+ depends on !DEBUG_INFO_BTF
+ select CONSTRUCTORS
+ 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 075cd25363ac..bfc28f52b603 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -2760,6 +2760,161 @@ config HYPERV_TESTING
endmenu # "Kernel Testing and Coverage"
+menu "Rust hacking"
+
+config RUST_DEBUG_ASSERTIONS
+ bool "Debug assertions"
+ 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
+
+config RUST_KERNEL_KUNIT_TEST
+ bool "KUnit test for the `kernel` crate" if !KUNIT_ALL_TESTS
+ depends on RUST && KUNIT=y
+ default KUNIT_ALL_TESTS
+ help
+ This builds the documentation tests of the `kernel` crate
+ as KUnit tests.
+
+ For more information on KUnit and unit tests in general,
+ please refer to the KUnit documentation in Documentation/dev-tools/kunit/.
+
+ If unsure, say N.
+
+endmenu # "Rust"
+
source "Documentation/Kconfig"
endmenu # Kernel hacking
diff --git a/rust/.gitignore b/rust/.gitignore
new file mode 100644
index 000000000000..89b602d91109
--- /dev/null
+++ b/rust/.gitignore
@@ -0,0 +1,10 @@
+# SPDX-License-Identifier: GPL-2.0
+
+target.json
+bindings_generated.rs
+bindings_helpers_generated.rs
+exports_*_generated.h
+doctests_kernel_generated.rs
+doctests_kernel_generated_kunit.c
+doc/
+test/
diff --git a/rust/Makefile b/rust/Makefile
new file mode 100644
index 000000000000..a7dc37027fe2
--- /dev/null
+++ b/rust/Makefile
@@ -0,0 +1,398 @@
+# SPDX-License-Identifier: GPL-2.0
+
+always-$(CONFIG_RUST) += target.json
+no-clean-files += target.json
+
+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
+
+obj-$(CONFIG_RUST_KERNEL_KUNIT_TEST) += doctests_kernel_generated.o
+obj-$(CONFIG_RUST_KERNEL_KUNIT_TEST) += doctests_kernel_generated_kunit.o
+
+# Avoids running `$(RUSTC)` for the sysroot when it may not be available.
+ifdef CONFIG_RUST
+
+# `$(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 ?= $(rustc_sysroot)/lib/rustlib/src/rust/library
+
+ifeq ($(quiet),silent_)
+cargo_quiet=-q
+rust_test_quiet=-q
+rustdoc_test_quiet=--test-args -q
+rustdoc_test_kernel_quiet=>/dev/null
+else ifeq ($(quiet),quiet_)
+rust_test_quiet=-q
+rustdoc_test_quiet=--test-args -q
+rustdoc_test_kernel_quiet=>/dev/null
+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_common_flags),$(rust_flags)) \
+ $(rustc_target_flags) -L$(objtree)/$(obj) \
+ --output $(objtree)/$(obj)/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/logo.gif $(objtree)/$(obj)/doc
+ $(Q)find $(objtree)/$(obj)/doc -name '*.html' -type f -print0 | xargs -0 sed -Ei \
+ -e 's:rust-logo\.svg:logo.gif:g' \
+ -e 's:rust-logo\.png:logo.gif:g' \
+ -e 's:favicon\.svg:logo.gif: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: $(src)/macros/lib.rs FORCE
+ $(call if_changed,rustdoc)
+
+rustdoc-core: private rustc_target_flags = $(core-cfgs)
+rustdoc-core: $(RUST_LIB_SRC)/core/src/lib.rs FORCE
+ $(call if_changed,rustdoc)
+
+rustdoc-compiler_builtins: $(src)/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: $(src)/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)/$(obj)/libmacros.so
+rustdoc-kernel: $(src)/kernel/lib.rs rustdoc-core rustdoc-macros \
+ rustdoc-compiler_builtins rustdoc-alloc $(obj)/libmacros.so \
+ $(obj)/bindings_generated.rs $(obj)/bindings_helpers_generated.rs FORCE
+ $(call if_changed,rustdoc)
+
+quiet_cmd_rustc_test_library = RUSTC TL $<
+ cmd_rustc_test_library = \
+ OBJTREE=$(abspath $(objtree)) \
+ $(RUSTC) $(rust_common_flags) \
+ @$(objtree)/include/generated/rustc_cfg $(rustc_target_flags) \
+ --crate-type $(if $(rustc_test_library_proc),proc-macro,rlib) \
+ --out-dir $(objtree)/$(obj)/test --cfg testlib \
+ --sysroot $(objtree)/$(obj)/test/sysroot \
+ -L$(objtree)/$(obj)/test \
+ --crate-name $(subst rusttest-,,$(subst rusttestlib-,,$@)) $<
+
+rusttestlib-build_error: $(src)/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: $(src)/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 $(rust_common_flags) \
+ @$(objtree)/include/generated/rustc_cfg \
+ $(rustc_target_flags) $(rustdoc_test_target_flags) \
+ --sysroot $(objtree)/$(obj)/test/sysroot $(rustdoc_test_quiet) \
+ -L$(objtree)/$(obj)/test --output $(objtree)/$(obj)/doc \
+ --crate-name $(subst rusttest-,,$@) $<
+
+quiet_cmd_rustdoc_test_kernel = RUSTDOC TK $<
+ cmd_rustdoc_test_kernel = \
+ rm -rf $(objtree)/$(obj)/test/doctests/kernel; \
+ mkdir -p $(objtree)/$(obj)/test/doctests/kernel; \
+ OBJTREE=$(abspath $(objtree)) \
+ $(RUSTDOC) --test $(rust_flags) \
+ @$(objtree)/include/generated/rustc_cfg \
+ -L$(objtree)/$(obj) --extern alloc --extern kernel \
+ --extern build_error --extern macros \
+ --no-run --crate-name kernel -Zunstable-options \
+ --test-builder $(srctree)/scripts/rustdoc_test_builder.py \
+ $< $(rustdoc_test_kernel_quiet); \
+ $(srctree)/scripts/rustdoc_test_gen.py
+
+%/doctests_kernel_generated.rs %/doctests_kernel_generated_kunit.c: $(src)/kernel/lib.rs $(obj)/kernel.o FORCE
+ $(call if_changed,rustdoc_test_kernel)
+
+# 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 $(rust_common_flags) \
+ @$(objtree)/include/generated/rustc_cfg \
+ $(rustc_target_flags) --out-dir $(objtree)/$(obj)/test \
+ --sysroot $(objtree)/$(obj)/test/sysroot \
+ -L$(objtree)/$(obj)/test \
+ --crate-name $(subst rusttest-,,$@) $<; \
+ $(objtree)/$(obj)/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 $(objtree)/$(obj)/test; \
+ mkdir -p $(objtree)/$(obj)/test; \
+ cp -a $(rustc_sysroot) $(objtree)/$(obj)/test/sysroot; \
+ cp -r $(srctree)/$(src)/alloc/* \
+ $(objtree)/$(obj)/test/sysroot/lib/rustlib/src/rust/library/alloc/src; \
+ echo '\#!/bin/sh' > $(objtree)/$(obj)/test/rustc_sysroot; \
+ echo "$(RUSTC) --sysroot=$(abspath $(objtree)/$(obj)/test/sysroot) \"\$$@\"" \
+ >> $(objtree)/$(obj)/test/rustc_sysroot; \
+ chmod u+x $(objtree)/$(obj)/test/rustc_sysroot; \
+ $(CARGO) -q new $(objtree)/$(obj)/test/dummy; \
+ RUSTC=$(objtree)/$(obj)/test/rustc_sysroot $(CARGO) $(cargo_quiet) \
+ test -Zbuild-std --target $(rustc_host_target) \
+ --manifest-path $(objtree)/$(obj)/test/dummy/Cargo.toml; \
+ rm $(objtree)/$(obj)/test/sysroot/lib/rustlib/$(rustc_host_target)/lib/*; \
+ cp $(objtree)/$(obj)/test/dummy/target/$(rustc_host_target)/debug/deps/* \
+ $(objtree)/$(obj)/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: $(src)/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: $(src)/kernel/lib.rs rusttest-prepare \
+ rusttestlib-build_error rusttestlib-macros FORCE
+ $(call if_changed,rustc_test)
+ $(call if_changed,rustc_test_library)
+
+filechk_rust_target = $(objtree)/scripts/generate_rust_target < $<
+
+$(obj)/target.json: $(objtree)/include/config/auto.conf FORCE
+ $(call filechk,rust_target)
+
+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) $(bindgen_target_extra)
+
+$(obj)/bindings_generated.rs: private bindgen_target_flags = \
+ $(shell grep -v '^\#\|^$$' $(srctree)/$(src)/bindgen_parameters)
+$(obj)/bindings_generated.rs: $(src)/kernel/bindings_helper.h \
+ $(src)/bindgen_parameters FORCE
+ $(call if_changed_dep,bindgen)
+
+# See `CFLAGS_REMOVE_helpers.o` above. In addition, Clang on C does not warn
+# with `-Wmissing-declarations` (unlike GCC), so it is not strictly needed here
+# given it is `libclang`; but for consistency, future Clang changes and/or
+# a potential future GCC backend for `bindgen`, we disable it too.
+$(obj)/bindings_helpers_generated.rs: private bindgen_target_flags = \
+ --blacklist-type '.*' --whitelist-var '' \
+ --whitelist-function 'rust_helper_.*'
+$(obj)/bindings_helpers_generated.rs: private bindgen_target_cflags = \
+ -I$(objtree)/$(obj) -Wno-missing-prototypes -Wno-missing-declarations
+$(obj)/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' $@
+$(obj)/bindings_helpers_generated.rs: $(src)/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);' > $@
+
+$(obj)/exports_core_generated.h: $(obj)/core.o FORCE
+ $(call if_changed,exports)
+
+$(obj)/exports_alloc_generated.h: $(obj)/alloc.o FORCE
+ $(call if_changed,exports)
+
+$(obj)/exports_kernel_generated.h: $(obj)/kernel.o FORCE
+ $(call if_changed,exports)
+
+quiet_cmd_rustc_procmacro = $(RUSTC_OR_CLIPPY_QUIET) P $@
+ cmd_rustc_procmacro = \
+ $(RUSTC_OR_CLIPPY) $(rust_common_flags) \
+ --emit=dep-info,link --extern proc_macro \
+ --crate-type proc-macro --out-dir $(objtree)/$(obj) \
+ --crate-name $(patsubst lib%.so,%,$(notdir $@)) $<; \
+ mv $(objtree)/$(obj)/$(patsubst lib%.so,%,$(notdir $@)).d $(depfile); \
+ sed -i '/^\#/d' $(depfile)
+
+# Procedural macros can only be used with the `rustc` that compiled it.
+# Therefore, to get `libmacros.so` automatically recompiled when the compiler
+# version changes, we add `core.o` as a dependency (even if it is not needed).
+$(obj)/libmacros.so: $(src)/macros/lib.rs $(obj)/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) $(rustc_target_flags)) \
+ --emit=dep-info,obj,metadata --crate-type rlib \
+ --out-dir $(objtree)/$(obj) -L$(objtree)/$(obj) \
+ --crate-name $(patsubst %.o,%,$(notdir $@)) $<; \
+ mv $(objtree)/$(obj)/$(patsubst %.o,%,$(notdir $@)).d $(depfile); \
+ sed -i '/^\#/d' $(depfile) \
+ $(if $(rustc_objcopy),;$(OBJCOPY) $(rustc_objcopy) $@)
+
+rust-analyzer:
+ $(Q)$(srctree)/scripts/generate_rust_analyzer.py $(srctree) $(objtree) \
+ $(RUST_LIB_SRC) > $(objtree)/rust-project.json
+
+$(obj)/core.o: private skip_clippy = 1
+$(obj)/core.o: private skip_flags = -Dunreachable_pub
+$(obj)/core.o: private rustc_target_flags = $(core-cfgs)
+$(obj)/core.o: $(RUST_LIB_SRC)/core/src/lib.rs $(obj)/target.json FORCE
+ $(call if_changed_dep,rustc_library)
+
+$(obj)/compiler_builtins.o: private rustc_objcopy = -w -W '__*'
+$(obj)/compiler_builtins.o: $(src)/compiler_builtins.rs $(obj)/core.o FORCE
+ $(call if_changed_dep,rustc_library)
+
+$(obj)/alloc.o: private skip_clippy = 1
+$(obj)/alloc.o: private skip_flags = -Dunreachable_pub
+$(obj)/alloc.o: private rustc_target_flags = $(alloc-cfgs)
+$(obj)/alloc.o: $(src)/alloc/lib.rs $(obj)/compiler_builtins.o FORCE
+ $(call if_changed_dep,rustc_library)
+
+$(obj)/build_error.o: $(src)/build_error.rs $(obj)/compiler_builtins.o FORCE
+ $(call if_changed_dep,rustc_library)
+
+$(obj)/kernel.o: private rustc_target_flags = --extern alloc \
+ --extern build_error --extern macros
+$(obj)/kernel.o: $(src)/kernel/lib.rs $(obj)/alloc.o $(obj)/build_error.o \
+ $(obj)/libmacros.so $(obj)/bindings_generated.rs \
+ $(obj)/bindings_helpers_generated.rs FORCE
+ $(call if_changed_dep,rustc_library)
+
+endif # CONFIG_RUST
diff --git a/rust/bindgen_parameters b/rust/bindgen_parameters
new file mode 100644
index 000000000000..6c77865e8345
--- /dev/null
+++ b/rust/bindgen_parameters
@@ -0,0 +1,17 @@
+# SPDX-License-Identifier: GPL-2.0
+
+--opaque-type xregs_state
+--opaque-type desc_struct
+--opaque-type arch_lbr_state
+--opaque-type local_apic
+
+# `try` is a reserved keyword since Rust 2018; solved in `bindgen` v0.59.2,
+# commit 2aed6b021680 ("context: Escape the try keyword properly").
+--opaque-type kunit_try_catch
+
+# 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/.gitignore b/scripts/.gitignore
index eed308bef604..b7aec8eb1bd4 100644
--- a/scripts/.gitignore
+++ b/scripts/.gitignore
@@ -1,6 +1,7 @@
# SPDX-License-Identifier: GPL-2.0-only
/asn1_compiler
/bin2c
+/generate_rust_target
/insert-sys-cert
/kallsyms
/module.lds
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 $2)
diff --git a/scripts/Makefile b/scripts/Makefile
index ce5aa9030b74..a278345e7820 100644
--- a/scripts/Makefile
+++ b/scripts/Makefile
@@ -10,6 +10,9 @@ hostprogs-always-$(CONFIG_BUILDTIME_TABLE_SORT) += sorttable
hostprogs-always-$(CONFIG_ASN1) += asn1_compiler
hostprogs-always-$(CONFIG_MODULE_SIG_FORMAT) += sign-file
hostprogs-always-$(CONFIG_SYSTEM_EXTRA_CERTIFICATE) += insert-sys-cert
+hostprogs-always-$(CONFIG_RUST) += generate_rust_target
+
+generate_rust_target-rust := y
HOSTCFLAGS_sorttable.o = -I$(srctree)/tools/include
HOSTLDLIBS_sorttable = -lpthread
diff --git a/scripts/Makefile.build b/scripts/Makefile.build
index 33c1ed581522..533631753b16 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 +325,65 @@ quiet_cmd_cc_lst_c = MKLST $@
$(obj)/%.lst: $(src)/%.c FORCE
$(call if_changed_dep,cc_lst_c)
+# Compile Rust sources (.rs)
+# ---------------------------------------------------------------------------
+
+rust_allowed_features := allocator_api,bench_black_box,concat_idents,generic_associated_types
+
+rust_common_cmd = \
+ RUST_MODFILE=$(modfile) $(RUSTC_OR_CLIPPY) $(rust_flags) \
+ -Zallow-features=$(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.host b/scripts/Makefile.host
index 278b4d6ac945..da133780b751 100644
--- a/scripts/Makefile.host
+++ b/scripts/Makefile.host
@@ -22,6 +22,8 @@ $(obj)/%.tab.c $(obj)/%.tab.h: $(src)/%.y FORCE
# to preprocess a data file.
#
# Both C and C++ are supported, but preferred language is C for such utilities.
+# Rust is also supported, but it may only be used in scenarios where a Rust
+# toolchain is required to be available (e.g. when `CONFIG_RUST` is enabled).
#
# Sample syntax (see Documentation/kbuild/makefiles.rst for reference)
# hostprogs := bin2hex
@@ -37,15 +39,20 @@ $(obj)/%.tab.c $(obj)/%.tab.h: $(src)/%.y FORCE
# qconf-objs := menu.o
# Will compile qconf as a C++ program, and menu as a C program.
# They are linked as C++ code to the executable qconf
+#
+# hostprogs := target
+# target-rust := y
+# Will compile `target` as a Rust program, using `target.rs` as the crate root.
+# The crate may consist of several source files.
# C code
# Executables compiled from a single .c file
host-csingle := $(foreach m,$(hostprogs), \
- $(if $($(m)-objs)$($(m)-cxxobjs),,$(m)))
+ $(if $($(m)-objs)$($(m)-cxxobjs)$($(m)-rust),,$(m)))
# C executables linked based on several .o files
host-cmulti := $(foreach m,$(hostprogs),\
- $(if $($(m)-cxxobjs),,$(if $($(m)-objs),$(m))))
+ $(if $($(m)-cxxobjs)$($(m)-rust),,$(if $($(m)-objs),$(m))))
# Object (.o) files compiled from .c files
host-cobjs := $(sort $(foreach m,$(hostprogs),$($(m)-objs)))
@@ -58,11 +65,17 @@ host-cxxmulti := $(foreach m,$(hostprogs),$(if $($(m)-cxxobjs),$(m)))
# C++ Object (.o) files compiled from .cc files
host-cxxobjs := $(sort $(foreach m,$(host-cxxmulti),$($(m)-cxxobjs)))
+# Rust code
+# Executables compiled from a single Rust crate (which may consist of
+# one or more .rs files)
+host-rust := $(foreach m,$(hostprogs),$(if $($(m)-rust),$(m)))
+
host-csingle := $(addprefix $(obj)/,$(host-csingle))
host-cmulti := $(addprefix $(obj)/,$(host-cmulti))
host-cobjs := $(addprefix $(obj)/,$(host-cobjs))
host-cxxmulti := $(addprefix $(obj)/,$(host-cxxmulti))
host-cxxobjs := $(addprefix $(obj)/,$(host-cxxobjs))
+host-rust := $(addprefix $(obj)/,$(host-rust))
#####
# Handle options to gcc. Support building with separate output directory
@@ -71,6 +84,8 @@ _hostc_flags = $(KBUILD_HOSTCFLAGS) $(HOST_EXTRACFLAGS) \
$(HOSTCFLAGS_$(target-stem).o)
_hostcxx_flags = $(KBUILD_HOSTCXXFLAGS) $(HOST_EXTRACXXFLAGS) \
$(HOSTCXXFLAGS_$(target-stem).o)
+_hostrust_flags = $(KBUILD_HOSTRUSTFLAGS) $(HOST_EXTRARUSTFLAGS) \
+ $(HOSTRUSTFLAGS_$(target-stem))
# $(objtree)/$(obj) for including generated headers from checkin source files
ifeq ($(KBUILD_EXTMOD),)
@@ -82,6 +97,7 @@ endif
hostc_flags = -Wp,-MMD,$(depfile) $(_hostc_flags)
hostcxx_flags = -Wp,-MMD,$(depfile) $(_hostcxx_flags)
+hostrust_flags = $(_hostrust_flags)
#####
# Compile programs on the host
@@ -128,5 +144,17 @@ quiet_cmd_host-cxxobjs = HOSTCXX $@
$(host-cxxobjs): $(obj)/%.o: $(src)/%.cc FORCE
$(call if_changed_dep,host-cxxobjs)
+# Create executable from a single Rust crate (which may consist of
+# one or more `.rs` files)
+# host-rust -> Executable
+quiet_cmd_host-rust = HOSTRUSTC $@
+ cmd_host-rust = \
+ $(HOSTRUSTC) $(hostrust_flags) --emit=dep-info,link \
+ --out-dir=$(obj)/ $<; \
+ mv $(obj)/$(target-stem).d $(depfile); \
+ sed -i '/^\#/d' $(depfile)
+$(host-rust): $(obj)/%: $(src)/%.rs FORCE
+ $(call if_changed_dep,host-rust)
+
targets += $(host-csingle) $(host-cmulti) $(host-cobjs) \
- $(host-cxxmulti) $(host-cxxobjs)
+ $(host-cxxmulti) $(host-cxxobjs) $(host-rust)
diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
index 9f69ecdd7977..f3e623f242df 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
# ===========================================================================
@@ -128,6 +129,10 @@ _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)) \
@@ -202,6 +207,11 @@ 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) $(AFLAGS_KERNEL))
@@ -211,6 +221,8 @@ c_flags = -Wp,-MMD,$(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/generate_rust_target.rs b/scripts/generate_rust_target.rs
new file mode 100644
index 000000000000..c146a3407183
--- /dev/null
+++ b/scripts/generate_rust_target.rs
@@ -0,0 +1,227 @@
+// SPDX-License-Identifier: GPL-2.0
+
+//! The custom target specification file generator for `rustc`.
+//!
+//! To configure a target from scratch, a JSON-encoded file has to be passed
+//! to `rustc` (introduced in [RFC 131]). These options and the file itself are
+//! unstable. Eventually, `rustc` should provide a way to do this in a stable
+//! manner. For instance, via command-line arguments. Therefore, this file
+//! should avoid using keys which can be set via `-C` or `-Z` options.
+//!
+//! [RFC 131]: https://rust-lang.github.io/rfcs/0131-target-specification.html
+
+use std::{
+ collections::HashMap,
+ fmt::{Display, Formatter, Result},
+ io::BufRead,
+};
+
+enum Value {
+ Boolean(bool),
+ Number(i32),
+ String(String),
+ Object(Object),
+}
+
+type Object = Vec<(String, Value)>;
+
+/// Minimal "almost JSON" generator (e.g. no `null`s, no arrays, no escaping),
+/// enough for this purpose.
+impl Display for Value {
+ fn fmt(&self, formatter: &mut Formatter<'_>) -> Result {
+ match self {
+ Value::Boolean(boolean) => write!(formatter, "{}", boolean),
+ Value::Number(number) => write!(formatter, "{}", number),
+ Value::String(string) => write!(formatter, "\"{}\"", string),
+ Value::Object(object) => {
+ formatter.write_str("{")?;
+ if let [ref rest @ .., ref last] = object[..] {
+ for (key, value) in rest {
+ write!(formatter, "\"{}\": {},", key, value)?;
+ }
+ write!(formatter, "\"{}\": {}", last.0, last.1)?;
+ }
+ formatter.write_str("}")
+ }
+ }
+ }
+}
+
+struct TargetSpec(Object);
+
+impl TargetSpec {
+ fn new() -> TargetSpec {
+ TargetSpec(Vec::new())
+ }
+}
+
+trait Push<T> {
+ fn push(&mut self, key: &str, value: T);
+}
+
+impl Push<bool> for TargetSpec {
+ fn push(&mut self, key: &str, value: bool) {
+ self.0.push((key.to_string(), Value::Boolean(value)));
+ }
+}
+
+impl Push<i32> for TargetSpec {
+ fn push(&mut self, key: &str, value: i32) {
+ self.0.push((key.to_string(), Value::Number(value)));
+ }
+}
+
+impl Push<String> for TargetSpec {
+ fn push(&mut self, key: &str, value: String) {
+ self.0.push((key.to_string(), Value::String(value)));
+ }
+}
+
+impl Push<&str> for TargetSpec {
+ fn push(&mut self, key: &str, value: &str) {
+ self.push(key, value.to_string());
+ }
+}
+
+impl Push<Object> for TargetSpec {
+ fn push(&mut self, key: &str, value: Object) {
+ self.0.push((key.to_string(), Value::Object(value)));
+ }
+}
+
+impl Display for TargetSpec {
+ fn fmt(&self, formatter: &mut Formatter<'_>) -> Result {
+ // We add some newlines for clarity.
+ formatter.write_str("{\n")?;
+ if let [ref rest @ .., ref last] = self.0[..] {
+ for (key, value) in rest {
+ write!(formatter, " \"{}\": {},\n", key, value)?;
+ }
+ write!(formatter, " \"{}\": {}\n", last.0, last.1)?;
+ }
+ formatter.write_str("}")
+ }
+}
+
+struct KernelConfig(HashMap<String, String>);
+
+impl KernelConfig {
+ /// Parses `include/config/auto.conf` from `stdin`.
+ fn from_stdin() -> KernelConfig {
+ let mut result = HashMap::new();
+
+ let stdin = std::io::stdin();
+ let mut handle = stdin.lock();
+ let mut line = String::new();
+
+ loop {
+ line.clear();
+
+ if handle.read_line(&mut line).unwrap() == 0 {
+ break;
+ }
+
+ if line.starts_with('#') {
+ continue;
+ }
+
+ let (key, value) = line.split_once('=').expect("Missing `=` in line.");
+ result.insert(key.to_string(), value.trim_end_matches('\n').to_string());
+ }
+
+ KernelConfig(result)
+ }
+
+ /// Does the option exist in the configuration (any value)?
+ ///
+ /// The argument must be passed without the `CONFIG_` prefix.
+ /// This avoids repetition and it also avoids `fixdep` making us
+ /// depend on it.
+ fn has(&self, option: &str) -> bool {
+ let option = "CONFIG_".to_owned() + option;
+ self.0.contains_key(&option)
+ }
+}
+
+fn main() {
+ let cfg = KernelConfig::from_stdin();
+ let mut ts = TargetSpec::new();
+
+ // `llvm-target`s are taken from `scripts/Makefile.clang`.
+ if cfg.has("ARM") {
+ ts.push("arch", "arm");
+ ts.push(
+ "data-layout",
+ "e-m:e-p:32:32-Fi8-i64:64-v128:64:128-a:0:32-n32-S64",
+ );
+ ts.push("features", "+strict-align,+v6");
+ ts.push("llvm-target", "arm-linux-gnueabi");
+ ts.push("max-atomic-width", 64);
+ ts.push("target-mcount", "\\u0001__gnu_mcount_nc");
+ ts.push("target-pointer-width", "32");
+ } else if cfg.has("ARM64") {
+ ts.push("arch", "aarch64");
+ ts.push(
+ "data-layout",
+ "e-m:e-i8:8:32-i16:16:32-i64:64-i128:128-n32:64-S128",
+ );
+ ts.push("disable-redzone", true);
+ ts.push("features", "+strict-align,-neon,-fp-armv8");
+ ts.push("llvm-target", "aarch64-linux-gnu");
+ ts.push("max-atomic-width", 128);
+ ts.push("target-pointer-width", "64");
+ } else if cfg.has("PPC") {
+ ts.push("arch", "powerpc64");
+ ts.push("code-model", "large");
+ ts.push("data-layout", "e-m:e-i64:64-n32:64");
+ ts.push("features", "-altivec,-vsx,-hard-float");
+ ts.push("llvm-target", "powerpc64le-linux-gnu");
+ ts.push("max-atomic-width", 64);
+ ts.push("target-mcount", "_mcount");
+ ts.push("target-pointer-width", "64");
+ } else if cfg.has("RISCV") {
+ if cfg.has("64BIT") {
+ ts.push("arch", "riscv64");
+ ts.push("data-layout", "e-m:e-p:64:64-i64:64-i128:128-n64-S128");
+ ts.push("llvm-target", "riscv64-linux-gnu");
+ ts.push("target-pointer-width", "64");
+ } else {
+ ts.push("arch", "riscv32");
+ ts.push("data-layout", "e-m:e-p:32:32-i64:64-n32-S128");
+ ts.push("llvm-target", "riscv32-linux-gnu");
+ ts.push("target-pointer-width", "32");
+ }
+ ts.push("code-model", "medium");
+ ts.push("disable-redzone", true);
+ let mut features = "+m,+a".to_string();
+ if cfg.has("RISCV_ISA_C") {
+ features += ",+c";
+ }
+ ts.push("features", features);
+ } else if cfg.has("X86_64") {
+ ts.push("arch", "x86_64");
+ ts.push(
+ "data-layout",
+ "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128",
+ );
+ ts.push("llvm-target", "x86_64-linux-gnu");
+ ts.push("target-pointer-width", "64");
+ } else {
+ panic!("Unsupported architecture");
+ }
+
+ ts.push("emit-debug-gdb-scripts", false);
+ ts.push("frame-pointer", "may-omit");
+ ts.push(
+ "stack-probes",
+ vec![("kind".to_string(), Value::String("none".to_string()))],
+ );
+
+ // Everything else is LE, whether `CPU_LITTLE_ENDIAN` is declared or not
+ // (e.g. x86). It is also `rustc`'s default.
+ if cfg.has("CPU_BIG_ENDIAN") {
+ ts.push("target-endian", "big");
+ }
+
+ println!("{}", ts);
+}
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 c4340c90e172..b7c9f1dd5e42 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",
@@ -745,6 +755,65 @@ 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.
@@ -1132,6 +1201,12 @@ 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..53fe64856015 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 1.60.0
+ ;;
+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
--
2.36.1
> +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.
I'm super not into having the rust optimization level differ from the
C optimization level. This is just someone having too much fun
wrapping every compiler flag in a kbuild option. Either folks wan't
smaller size or more optimizations. Allowing for RUST_OPT_LEVEL_S and
CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE or RUST_OPT_LEVEL_3 and
CONFIG_CC_OPTIMIZE_FOR_SIZE is just wacky nonsense that's going to
make randconfig bug reports more confusing to tease out.
--
Thanks,
~Nick Desaulniers
On Mon, May 23, 2022 at 8:45 PM Nick Desaulniers
<[email protected]> wrote:
>
> I'm super not into having the rust optimization level differ from the
> C optimization level. This is just someone having too much fun
> wrapping every compiler flag in a kbuild option. Either folks wan't
I mean, `Makefile`s are not my favorite pastime... :)
> smaller size or more optimizations. Allowing for RUST_OPT_LEVEL_S and
> CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE or RUST_OPT_LEVEL_3 and
> CONFIG_CC_OPTIMIZE_FOR_SIZE is just wacky nonsense that's going to
> make randconfig bug reports more confusing to tease out.
I think what is important is to decide whether extra levels, for C and
Rust, should be kept compile-able/maintained or not (I also replied in
the `-O1` for C thread [1]).
Note that the Rust side can be compiled as `-O0` or `-O1` at the
moment, which is something we do not have for the C side; thus having
only the C == Rust option means we will not have a configuration with
those anymore.
For me it is less complex to not have them, and I have not heard more
opinions on this, either for or against (apart from that thread
suggesting `-O1` for the C side), so if nobody else chimes in, I will
remove them.
[1] https://lore.kernel.org/lkml/CANiq72kySVvOQ7eqwe0Jzz3V0JTtrcqODHR9Ty4-sfDMdzP6XQ@mail.gmail.com/
Cheers,
Miguel
On Sun, May 22, 2022 at 7:04 PM Miguel Ojeda <[email protected]> wrote:
>
> --- a/Makefile
> +++ b/Makefile
> @@ -120,6 +120,15 @@ 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
Is there a reason to not just turn clippy on always? Might be nicer to
start off with good practices by default. :^)
> @@ -1494,7 +1588,8 @@ MRPROPER_FILES += include/config include/generated \
> certs/signing_key.pem \
> certs/x509.genkey \
> vmlinux-gdb.py \
> - *.spec
> + *.spec \
> + rust/target.json rust/libmacros.so
>
> # clean - Delete most, but leave enough to build external modules
> #
> @@ -1519,6 +1614,9 @@ $(mrproper-dirs):
>
> mrproper: clean $(mrproper-dirs)
> $(call cmd,rmfiles)
> + @find . $(RCS_FIND_IGNORE) \
> + \( -name '*.rmeta' \) \
> + -type f -print | xargs rm -f
Are there *.rmeta directories that we _don't_ want to remove via `make
mrproper`? I'm curious why *.rmeta isn't just part of MRPROPER_FILES?
>
> # distclean
> #
> @@ -1606,6 +1704,23 @@ 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'
I don't think we need to repeat dir/* here again for rust. The
existing targets listed above (outside this hunk) make sense in both
contexts.
Does rustc really use .i as a conventional suffix for macro expanded
sources? (The C compiler might use the -x flag to override the guess
it would make based on the file extension; I'm curious if rustc can
ingest .i files or will it warn?)
> diff --git a/init/Kconfig b/init/Kconfig
> index ddcbefe535e9..3457cf596588 100644
> --- a/init/Kconfig
> +++ b/init/Kconfig
> +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)
Are these two kconfigs used anywhere?
> 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)
Not that it's important to do so, but a couple hunks s/compiler/C
compiler/. Those _could_ probably get submitted ahead of this, but not
important to do so.
> 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
> +
How does enabling or disabling debug info work for rustc? I may have
missed it, but I was surprised to see no additional flags getting
passed to rustc based on CONFIG_DEBUG info.
> diff --git a/scripts/generate_rust_target.rs b/scripts/generate_rust_target.rs
> new file mode 100644
> index 000000000000..c146a3407183
> --- /dev/null
> +++ b/scripts/generate_rust_target.rs
Ah, that explains the host rust build infra. Bravo! Hard coding the
target files was my major concern last I looked at the series. I'm
very happy to see it be generated properly from .config!
I haven't actually reviewed this yet, but it makes me significantly
more confident in the series to see this approach added. Good job
whoever wrote this.
> 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:]]*$'
Does `$(READELF) -p .comment foo.o` print anything about which
compiler was used? That seems less brittle IMO.
---
Modulo the RUST_OPT_LEVEL_SIMILAR_AS_CHOSEN_FOR_C which I'm not a fan
of, this is looking good to me. Masahiro, what are your thoughts on
the build system support?
--
Thanks,
~Nick Desaulniers
On Thu, May 26, 2022 at 12:25 AM Nick Desaulniers
<[email protected]> wrote:
>
> Is there a reason to not just turn clippy on always? Might be nicer to
> start off with good practices by default. :^)
The idea crossed my mind too [1], but sadly Clippy disables some
optimizations and in general is not intended to be used for normal
compilation [2].
[1] https://github.com/rust-lang/rust-clippy/issues/8035
[2] https://github.com/rust-lang/rust-clippy/pull/8037
> Are there *.rmeta directories that we _don't_ want to remove via `make
> mrproper`? I'm curious why *.rmeta isn't just part of MRPROPER_FILES?
Putting them in `MRPROPER_FILES` would mean only those in a given
directory are removed (e.g. the root one), but the idea here is to
find them anywhere in the tree, since in the future we may have
library crates in different parts of the tree.
However, I am not sure I understand your first question in relation
with the second one -- if we put them in `MRPROPER_FILES`, that would
remove less, not more.
> I don't think we need to repeat dir/* here again for rust. The
> existing targets listed above (outside this hunk) make sense in both
> contexts.
The idea here is to document the differences (e.g. `RUSTFMT`) and that
we may have other targets in the future that do not apply to C (e.g.
MIR dump, if that happens to be useful).
But maybe I can fit that in the normal place and make it still look
good... I will give it a try.
> Does rustc really use .i as a conventional suffix for macro expanded
> sources? (The C compiler might use the -x flag to override the guess
It is not a conventional suffix at all as far as I am aware.
Maybe we should use a different one to aid editors and users anyway,
e.g. `.rsi`, similar to `.mi` for Objective-C `.m` files.
> it would make based on the file extension; I'm curious if rustc can
> ingest .i files or will it warn?)
The macro expanded output is not intended to be used as a compilable
input, but as a debugging aid only. I can note this there.
Having said that, `rustc` accepts the "preprocessed" output in the
sense that it will just treat them as normal source files (no flag
needed, and e.g. both `.i` and `.rsi` work); however, it may give new
diagnostics or may require extra flags to enable some compiler
features.
From a quick test, I managed to compile a "preprocessed" Rust kernel
module with only command-line changes. But if we really wanted to
support this, we would need to ask upstream Rust to actually support
it.
> Are these two kconfigs used anywhere?
Not for the moment, but it could still be useful when getting
`.config` reports (and we could add it to `LINUX_COMPILER` etc. in the
future).
> How does enabling or disabling debug info work for rustc? I may have
> missed it, but I was surprised to see no additional flags getting
> passed to rustc based on CONFIG_DEBUG info.
`-Cdebuginfo=` is the one; by default there is no debug info and that
option enables it (i.e. it is not just the level but the enablement
too).
(Note that in userspace, when compiling a common program, you will get
some debug info coming from the standard library and other
dependencies).
> Ah, that explains the host rust build infra. Bravo! Hard coding the
> target files was my major concern last I looked at the series. I'm
> very happy to see it be generated properly from .config!
>
> I haven't actually reviewed this yet, but it makes me significantly
> more confident in the series to see this approach added. Good job
> whoever wrote this.
Thanks! I thought Rust would be a nice option for writing hostprogs,
though of course for the moment only programs that can assume Rust is
there may use it.
Note that non-x86 specific options need to be handled properly still
(e.g. move things between the arch Makefiles and the hostprog as
needed).
I would still want to see compilers come to some kind of common format
for this as we discussed other times, but... :)
> Does `$(READELF) -p .comment foo.o` print anything about which
> compiler was used? That seems less brittle IMO.
Currently, `rustc` does not add a `.comment` section; but we could
ask, I sent [3].
If debug info is enabled, another way is using the `DW_AT_language`
attribute, like `pahole` will be doing for a new option we need [4].
However, we would still need a way for the other case.
In any case, I am not sure something like `.comment` is less or more
brittle -- compilers could in theory change it (e.g. not emitting it),
while adding a symbol is something we control. So different kinds of
brittleness.
[3] https://github.com/rust-lang/rust/pull/97550
[4] https://git.kernel.org/pub/scm/devel/pahole/pahole.git/commit/?id=8ee363790b7437283c53090a85a9fec2f0b0fbc4
Cheers,
Miguel
On Mon, May 23, 2022 at 11:04 AM Miguel Ojeda <[email protected]> wrote:
>
> 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 specification
> generation script, the version detection script and a few
> other bits.
>
> 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]>
> Co-developed-by: David Gow <[email protected]>
> Signed-off-by: David Gow <[email protected]>
> Signed-off-by: Miguel Ojeda <[email protected]>
> ---
> +# Rust targets
> +# ---------------------------------------------------------------------------
> +
> +# "Is Rust available?" target
> +PHONY += rustavailable
> +rustavailable:
> + $(Q)$(CONFIG_SHELL) $(srctree)/scripts/rust-is-available.sh -v && echo >&2 "Rust is available!"
> +
Is it intentional to print the successful message to stderr?
--
Best Regards
Masahiro Yamada
Hi Masahiro,
On Sat, Jul 16, 2022 at 10:23 AM Masahiro Yamada <[email protected]> wrote:
>
> Is it intentional to print the successful message to stderr?
I think it makes sense to change it to `stdout`, given the message is
the main point of running `rustavailable` for normal users, and those
that just want the status code may ignore it.
Thanks for taking a look again!
Cheers,
Miguel