linux/scripts/Makefile
David Gow ab0f4cedc3 arch: um: rust: Add i386 support for Rust
At present, Rust in the kernel only supports 64-bit x86, so UML has
followed suit. However, it's significantly easier to support 32-bit i386
on UML than on bare metal, as UML does not use the -mregparm option
(which alters the ABI), which is not yet supported by rustc[1].

Add support for CONFIG_RUST on um/i386, by adding a new target config to
generate_rust_target, and replacing various checks on CONFIG_X86_64 to
also support CONFIG_X86_32.

We still use generate_rust_target, rather than a built-in rustc target,
in order to match x86_64, provide a future place for -mregparm, and more
easily disable floating point instructions.

With these changes, the KUnit tests pass with:
kunit.py run --make_options LLVM=1 --kconfig_add CONFIG_RUST=y
--kconfig_add CONFIG_64BIT=n --kconfig_add CONFIG_FORTIFY_SOURCE=n

An earlier version of these changes was proposed on the Rust-for-Linux
github[2].

[1]: https://github.com/rust-lang/rust/issues/116972
[2]: https://github.com/Rust-for-Linux/linux/pull/966

Signed-off-by: David Gow <davidgow@google.com>
Link: https://patch.msgid.link/20240604224052.3138504-1-davidgow@google.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2024-07-03 12:22:22 +02:00

60 lines
2 KiB
Makefile

# SPDX-License-Identifier: GPL-2.0
###
# scripts contains sources for various helper programs used throughout
# the kernel for the build process.
hostprogs-always-$(CONFIG_KALLSYMS) += kallsyms
hostprogs-always-$(BUILD_C_RECORDMCOUNT) += recordmcount
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-$(CONFIG_RUST_KERNEL_DOCTESTS) += rustdoc_test_builder
hostprogs-always-$(CONFIG_RUST_KERNEL_DOCTESTS) += rustdoc_test_gen
ifneq ($(or $(CONFIG_X86_64),$(CONFIG_X86_32)),)
always-$(CONFIG_RUST) += target.json
filechk_rust_target = $< < include/config/auto.conf
$(obj)/target.json: scripts/generate_rust_target include/config/auto.conf FORCE
$(call filechk,rust_target)
endif
hostprogs += generate_rust_target
generate_rust_target-rust := y
rustdoc_test_builder-rust := y
rustdoc_test_gen-rust := y
HOSTCFLAGS_sorttable.o = -I$(srctree)/tools/include
HOSTLDLIBS_sorttable = -lpthread
HOSTCFLAGS_asn1_compiler.o = -I$(srctree)/include
HOSTCFLAGS_sign-file.o = $(shell $(HOSTPKG_CONFIG) --cflags libcrypto 2> /dev/null)
HOSTLDLIBS_sign-file = $(shell $(HOSTPKG_CONFIG) --libs libcrypto 2> /dev/null || echo -lcrypto)
ifdef CONFIG_UNWINDER_ORC
ifeq ($(ARCH),x86_64)
SRCARCH := x86
endif
ifeq ($(ARCH),loongarch)
SRCARCH := loongarch
endif
HOSTCFLAGS_sorttable.o += -I$(srctree)/tools/arch/$(SRCARCH)/include
HOSTCFLAGS_sorttable.o += -DUNWINDER_ORC_ENABLED
endif
ifdef CONFIG_BUILDTIME_MCOUNT_SORT
HOSTCFLAGS_sorttable.o += -DMCOUNT_SORT_ENABLED
endif
# The following programs are only built on demand
hostprogs += unifdef
# The module linker script is preprocessed on demand
targets += module.lds
subdir-$(CONFIG_GCC_PLUGINS) += gcc-plugins
subdir-$(CONFIG_MODVERSIONS) += genksyms
subdir-$(CONFIG_SECURITY_SELINUX) += selinux
# Let clean descend into subdirs
subdir- += basic dtc gdb kconfig mod