From patchwork Thu Sep 3 20:30:53 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sami Tolvanen X-Patchwork-Id: 11754783 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 82684746 for ; Thu, 3 Sep 2020 20:34:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 658A320684 for ; Thu, 3 Sep 2020 20:34:02 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=google.com header.i=@google.com header.b="VrQ+aR64" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729631AbgICUd6 (ORCPT ); Thu, 3 Sep 2020 16:33:58 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35442 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729625AbgICUdP (ORCPT ); Thu, 3 Sep 2020 16:33:15 -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 DA1D2C061A1E for ; Thu, 3 Sep 2020 13:31:54 -0700 (PDT) Received: by mail-yb1-xb49.google.com with SMTP id v77so4097242ybi.2 for ; Thu, 03 Sep 2020 13:31:54 -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=3m31rwYywYePbNZAmvKakEWxPdLPkgQobcut8O2cWG8=; b=VrQ+aR64rJWvhe7qjvWHs3a3oZWcccWruofQtzpu1HjveXL8xoPtaOlTNWbvDUD61B CoQzytJVd31K/jZ98Hg6Rczs0j7T787BLqQ5rqWRSzjudgYpVfrS9u0CsEHLtYnV1HXj NBkXfjSc2/VDWHrHbvNxyyimbc/ENPMtS0Y4BlD1srNMrvDB6zxF7/e4JTm8bBAhExmj LBbYZBX5JZqg1Vi4vTQXgFJ8/sXigHGqY1/Ls2EwD9Mkv+uzMqNXG3LvVwSRu3v/TI6m 0G3wr9PaIys5H7yv+q5Zpneul8N+hYLXyyZ0Ns0Se+O9j2y9H4vAevWAkkxVlU5oauch vreg== 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=3m31rwYywYePbNZAmvKakEWxPdLPkgQobcut8O2cWG8=; b=OeMYeZgiFLYHfi/qotz37+yW2jfllpbLKrr540UMa/mARp7OSkkJgB2UUkb0qWDbvK 9KU2ws4UZpWSOu6XnbIs29uzJppcaKc8lkDyZoXG7xrRbGFP9yNu4WOYIRQsZ/BO0qDi kwF3n3G4sjY/kZTr0ieMnVjR0fk8tvkRRBlYLye4Vcjt3ACuawFdVuZj8akuXM2Sy+zZ tKBsdfppi7m5qsfcNFkEHhPGtcwNwACfE3cDenMGNhDB6BBmHrMwv1I3n1XWKZbSfYD8 AHZ14X2Lbz1HH3SVUR3+GLtW17wNY8xr1pCrZTy08HsgpI2ifnJxpWIEXgeEuzwl6+mV TKMA== X-Gm-Message-State: AOAM532v0msjYvgjXK8F4d9ocJMSloagIOd3AqN7F6jPzSqif9XAHPHA WEwDZeRUoJcrkaKcGy6Hovc1RSJ4Mpc+yYGpUnI= X-Google-Smtp-Source: ABdhPJzAEZ6HmlaoXFTkGyE0iiWNV3l9gW+re2enIfjvIje5wJCTs+Cu5Q/oOeRF8HT4Mmvs4O3RMcG4QddEnv8aRg0= X-Received: from samitolvanen1.mtv.corp.google.com ([2620:15c:201:2:f693:9fff:fef4:1b6d]) (user=samitolvanen job=sendgmr) by 2002:a25:2006:: with SMTP id g6mr5905482ybg.143.1599165114037; Thu, 03 Sep 2020 13:31:54 -0700 (PDT) Date: Thu, 3 Sep 2020 13:30:53 -0700 In-Reply-To: <20200903203053.3411268-1-samitolvanen@google.com> Message-Id: <20200903203053.3411268-29-samitolvanen@google.com> Mime-Version: 1.0 References: <20200624203200.78870-1-samitolvanen@google.com> <20200903203053.3411268-1-samitolvanen@google.com> X-Mailer: git-send-email 2.28.0.526.ge36021eeef-goog Subject: [PATCH v2 28/28] x86, build: allow LTO_CLANG and THINLTO to be selected From: Sami Tolvanen To: Masahiro Yamada , Will Deacon Cc: Peter Zijlstra , Steven Rostedt , 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 Sender: linux-kbuild-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kbuild@vger.kernel.org Allow CONFIG_LTO_CLANG and CONFIG_THINLTO to be enabled. 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 #