From patchwork Tue Sep 29 21:46:31 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sami Tolvanen X-Patchwork-Id: 11807145 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id CA357139F for ; Tue, 29 Sep 2020 21:48:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A9B90208B8 for ; Tue, 29 Sep 2020 21:48:48 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="eAC3sd7F" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728180AbgI2Vss (ORCPT ); Tue, 29 Sep 2020 17:48:48 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48488 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729422AbgI2Vsj (ORCPT ); Tue, 29 Sep 2020 17:48:39 -0400 Received: from mail-yb1-xb49.google.com (mail-yb1-xb49.google.com [IPv6:2607:f8b0:4864:20::b49]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0B661C0613AF for ; Tue, 29 Sep 2020 14:47:41 -0700 (PDT) Received: by mail-yb1-xb49.google.com with SMTP id p187so6465160ybg.14 for ; Tue, 29 Sep 2020 14:47:41 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=sender:date:in-reply-to:message-id:mime-version:references:subject :from:to:cc; bh=Dx9e+jODClwF/iJJnqk8YtFURfMacOCvss9V22Z0Fc8=; b=eAC3sd7FrybIqBNLqwYFttqKxR61Obt0chM7GPqJ2OxngMW62bPdYhZA03LkxasyLY B3iIEkAaae/i6FcyaXra7MzsSeTktk9SwvMjM5fm2HSdLmalbA1n/A2LnoW2enoNz2xH Pa+KaLqo0+4ezjXKZ3nIXcw8vdNmqiqgTTdM1O4aI1LZoCE0afJrbw/Lg6fCj7Knl79R dCZ2OQwKJA3VuP7P5zfT+/aSxe8doPfdOU5zwJ44DkhelW0fuXKUxoxboiSN5Vgcgh8/ 1UpdKZV3POTPW1YqyNWdduZmHvQs7b6iJJF0ZHtHSgHddEocODQ/IaHpeomSTeSTfXWd 9F7Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=Dx9e+jODClwF/iJJnqk8YtFURfMacOCvss9V22Z0Fc8=; b=LRfGUM3RzilAVaB3YrL5PFzBRr+luEgCbAlf2RIyvomfSrpgxBC/vwYoAHotaJdrQo rkhiC5oyYmK9hYhrlOcZCtwDI6tdObTF45Tk8pZZRMGsekMcWITmtQf3+1Y+okCC0+5f Qw8caGWIyvTATivrYjaJQguljqclvSetRZYtNOK0LSUdJpu0YQozVUPzbrWC0js+gyyo rwETWWbbHC+KJ+Kg2q05HvsLWQZFCzLOlgqtt8GB+VwkgPPtoG51m+6BaDdb94cqvlB1 s5mtuaQaCWc+T6hxRomPGbgM7v5wxy4fVEv3DH3lAj3/FuHTHHvYMFPnnh/ebwg6rsgH Gu5Q== X-Gm-Message-State: AOAM533mL9lfB7bTMrOQxP256bOrNBaezN+oWSFFZA9YudsmCkCS79z7 J+fbvF/fafud+L+/pf09xICM3ye3LXJFRii4s9s= X-Google-Smtp-Source: ABdhPJyHM8XluAgvy34F/u1LNyOoQbT0Sdbx3DlubA3WLU9aFNNTvcz1CX/0eQ5kfYR71jHg9kQHDJLqsi2a5BN5I2k= Sender: "samitolvanen via sendgmr" X-Received: from samitolvanen1.mtv.corp.google.com ([2620:15c:201:2:f693:9fff:fef4:1b6d]) (user=samitolvanen job=sendgmr) by 2002:a25:bfcf:: with SMTP id q15mr8695443ybm.133.1601416060255; Tue, 29 Sep 2020 14:47:40 -0700 (PDT) Date: Tue, 29 Sep 2020 14:46:31 -0700 In-Reply-To: <20200929214631.3516445-1-samitolvanen@google.com> Message-Id: <20200929214631.3516445-30-samitolvanen@google.com> Mime-Version: 1.0 References: <20200929214631.3516445-1-samitolvanen@google.com> X-Mailer: git-send-email 2.28.0.709.gb0816b6eb0-goog Subject: [PATCH v4 29/29] x86, build: allow LTO_CLANG and THINLTO to be selected From: Sami Tolvanen To: Masahiro Yamada , Will Deacon , Steven Rostedt Cc: Peter Zijlstra , Greg Kroah-Hartman , "Paul E. McKenney" , Kees Cook , Nick Desaulniers , clang-built-linux@googlegroups.com, kernel-hardening@lists.openwall.com, linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kbuild@vger.kernel.org, linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, x86@kernel.org, Sami Tolvanen Precedence: bulk List-ID: X-Mailing-List: linux-kbuild@vger.kernel.org Pass code model and stack alignment to the linker as these are not stored in LLVM bitcode, and allow both CONFIG_LTO_CLANG and CONFIG_THINLTO to be selected. Signed-off-by: Sami Tolvanen Reviewed-by: Kees Cook --- arch/x86/Kconfig | 2 ++ arch/x86/Makefile | 5 +++++ 2 files changed, 7 insertions(+) diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 6de2e5c0bdba..0a49008c2363 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -92,6 +92,8 @@ config X86 select ARCH_SUPPORTS_ACPI select ARCH_SUPPORTS_ATOMIC_RMW select ARCH_SUPPORTS_NUMA_BALANCING if X86_64 + select ARCH_SUPPORTS_LTO_CLANG if X86_64 + select ARCH_SUPPORTS_THINLTO if X86_64 select ARCH_USE_BUILTIN_BSWAP select ARCH_USE_QUEUED_RWLOCKS select ARCH_USE_QUEUED_SPINLOCKS diff --git a/arch/x86/Makefile b/arch/x86/Makefile index 4346ffb2e39f..49e3b8674eb5 100644 --- a/arch/x86/Makefile +++ b/arch/x86/Makefile @@ -173,6 +173,11 @@ ifeq ($(ACCUMULATE_OUTGOING_ARGS), 1) KBUILD_CFLAGS += $(call cc-option,-maccumulate-outgoing-args,) endif +ifdef CONFIG_LTO_CLANG +KBUILD_LDFLAGS += -plugin-opt=-code-model=kernel \ + -plugin-opt=-stack-alignment=$(if $(CONFIG_X86_32),4,8) +endif + # Workaround for a gcc prelease that unfortunately was shipped in a suse release KBUILD_CFLAGS += -Wno-sign-compare #