From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 3BD2C290A for ; Fri, 28 Apr 2023 11:28:26 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B0856C4339B; Fri, 28 Apr 2023 11:28:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1682681306; bh=TGacCA78SpAnhDpnDr4rgr74iXcfKsborm+MBtYH6hU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Q0tBWhUBPcupmPb2d7KzeaoUcheYPIAcMW9eiFVJAbh+vy18KVUwaiMYaFyISPXAf U7YG16zd1zD8NyNgeYuXAN1HGoCxLXaazKj7USlg1lG7QPki5aTGabt/qWUUgrElWk kBb5Lm4HlIJOxyqq9XDLuBVfGtsqDWvlrMKK9MDM= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, David Gow , =?UTF-8?q?Sergio=20Gonz=C3=A1lez=20Collado?= , Richard Weinberger Subject: [PATCH 6.2 01/15] rust: arch/um: Disable FP/SIMD instruction to match x86 Date: Fri, 28 Apr 2023 13:27:45 +0200 Message-Id: <20230428112040.188522448@linuxfoundation.org> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20230428112040.137898986@linuxfoundation.org> References: <20230428112040.137898986@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: David Gow commit 8849818679478933dd1d9718741f4daa3f4e8b86 upstream. 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: Greg Kroah-Hartman --- arch/x86/Makefile.um | 6 ++++++ 1 file changed, 6 insertions(+) --- 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