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linux/arch/x86/Makefile.um
David Gow 9a2123b397 arch: um: rust: Use the generated target.json again
The Rust compiler can take a target config from 'target.json', which is
generated by scripts/generate_rust_target.rs. It used to be that all
Linux architectures used this to generate a target.json, but now
architectures must opt-in to this, or they will default to the Rust
compiler's built-in target definition.

This is mostly okay for (64-bit) x86 and UML, except that it can
generate SSE instructions, which we can't use in the kernel. So
re-instate the custom target.json, which disables SSE (and generally
enables the 'soft-float' feature). This fixes the following compile
error:

error: <unknown>:0:0: in function _RNvMNtCs5QSdWC790r4_4core3f32f7next_up float (float): SSE register return with SSE disabled

Fixes: f82811e22b ("rust: Refactor the build target to allow the use of builtin targets")
Signed-off-by: David Gow <davidgow@google.com>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Tested-by: Miguel Ojeda <ojeda@kernel.org>
Reviewed-by: Miguel Ojeda <ojeda@kernel.org>
Link: https://patch.msgid.link/20240529093336.4075206-1-davidgow@google.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2024-07-03 12:22:11 +02:00

63 lines
1.6 KiB
Makefile

# SPDX-License-Identifier: GPL-2.0
core-y += arch/x86/crypto/
#
# Disable SSE and other FP/SIMD instructions to match normal x86
# This is required to work around issues in older LLVM versions, but breaks
# GCC versions < 11. See:
# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99652
#
ifeq ($(CONFIG_CC_IS_CLANG),y)
KBUILD_CFLAGS += -mno-sse -mno-mmx -mno-sse2 -mno-3dnow -mno-avx
KBUILD_RUSTFLAGS += --target=$(objtree)/scripts/target.json
KBUILD_RUSTFLAGS += -Ctarget-feature=-sse,-sse2,-sse3,-ssse3,-sse4.1,-sse4.2,-avx,-avx2
endif
ifeq ($(CONFIG_X86_32),y)
START := 0x8048000
KBUILD_LDFLAGS += -m elf_i386
ELF_ARCH := i386
ELF_FORMAT := elf32-i386
CHECKFLAGS += -D__i386__
KBUILD_CFLAGS += $(call cc-option,-m32)
KBUILD_AFLAGS += $(call cc-option,-m32)
LINK-y += $(call cc-option,-m32)
LDS_EXTRA := -Ui386
export LDS_EXTRA
# First of all, tune CFLAGS for the specific CPU. This actually sets cflags-y.
include $(srctree)/arch/x86/Makefile_32.cpu
# prevent gcc from keeping the stack 16 byte aligned. Taken from i386.
cflags-y += $(call cc-option,-mpreferred-stack-boundary=2)
# Prevent sprintf in nfsd from being converted to strcpy and resulting in
# an unresolved reference.
cflags-y += -ffreestanding
KBUILD_CFLAGS += $(cflags-y)
else
START := 0x60000000
KBUILD_CFLAGS += -fno-builtin -m64
CHECKFLAGS += -m64 -D__x86_64__
KBUILD_AFLAGS += -m64
KBUILD_LDFLAGS += -m elf_x86_64
KBUILD_CPPFLAGS += -m64
ELF_ARCH := i386:x86-64
ELF_FORMAT := elf64-x86-64
# Not on all 64-bit distros /lib is a symlink to /lib64. PLD is an example.
LINK-$(CONFIG_LD_SCRIPT_DYN_RPATH) += -Wl,-rpath,/lib64
LINK-y += -m64
endif