From: David Gow Date: Sat, 17 Dec 2022 04:44:35 +0000 (+0800) Subject: rust: arch/um: Disable FP/SIMD instruction to match x86 X-Git-Tag: baikal/mips/sdk6.1~97 X-Git-Url: https://git.baikalelectronics.ru/sdk/?a=commitdiff_plain;h=2114052517401dfb079066cfc907cd971ca55c7b;p=kernel.git rust: arch/um: Disable FP/SIMD instruction to match x86 [ Upstream commit 493ed30c5a9a010ff9e9438f1405af0e6f14aa8a ] The kernel disables all SSE and similar FP/SIMD instructions on x86-based architectures (partly because we shouldn't be using floats in the kernel, and partly to avoid the need for stack alignment, see: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=53383 ) UML does not do the same thing, which isn't in itself a problem, but does add to the list of differences between UML and "normal" x86 builds. In addition, there was a crash bug with LLVM < 15 / rustc < 1.65 when building with SSE, so disabling it fixes rust builds with earlier compiler versions, see: https://github.com/Rust-for-Linux/linux/pull/881 Signed-off-by: David Gow Reviewed-by: Sergio González Collado Signed-off-by: Richard Weinberger Signed-off-by: Sasha Levin --- diff --git a/arch/x86/Makefile.um b/arch/x86/Makefile.um index b3c1ae084180d..d2e95d1d4db77 100644 --- a/arch/x86/Makefile.um +++ b/arch/x86/Makefile.um @@ -1,6 +1,12 @@ # SPDX-License-Identifier: GPL-2.0 core-y += arch/x86/crypto/ +# +# Disable SSE and other FP/SIMD instructions to match normal x86 +# +KBUILD_CFLAGS += -mno-sse -mno-mmx -mno-sse2 -mno-3dnow -mno-avx +KBUILD_RUSTFLAGS += -Ctarget-feature=-sse,-sse2,-sse3,-ssse3,-sse4.1,-sse4.2,-avx,-avx2 + ifeq ($(CONFIG_X86_32),y) START := 0x8048000