From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-19.4 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_IN_DEF_DKIM_WL autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B974EC47259 for ; Wed, 6 May 2020 17:17:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9773E20936 for ; Wed, 6 May 2020 17:17:21 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="AoWlyDRv" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730006AbgEFRRV (ORCPT ); Wed, 6 May 2020 13:17:21 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48330 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729900AbgEFRRS (ORCPT ); Wed, 6 May 2020 13:17:18 -0400 Received: from mail-pl1-x641.google.com (mail-pl1-x641.google.com [IPv6:2607:f8b0:4864:20::641]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 88CA7C061A10 for ; Wed, 6 May 2020 10:17:18 -0700 (PDT) Received: by mail-pl1-x641.google.com with SMTP id f15so771962plr.3 for ; Wed, 06 May 2020 10:17:18 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=/k/x3jvD4hIY8pDNsyuRYJAWCjnjlkQj95o1100b+nU=; b=AoWlyDRvgvgfz7OXgRvmqbZq6U8eVGyvK/25YzVKraEel8OmtkOdz2BW5cyKKN+B9T lEgbKudq8lqfvZcc0Bi648R42oxIhUjrYoffQ8Pl1H0dbp92fpYcf/ynrRCKVnTxHnc2 jkJnZkh325ckYdhrmmHLfDG16i0rJSiyd+Zv3Qt4C+5MhFk8kmN7vsaFKHVJhFnVi28I BUftmHbmElrqRsxk91bDZkkdM2b6RMZpk2ctFThP4FhABx3J6RNF4W7EfO8FzFbMsf7v CCXjr9xbkvksrdNlppx8YSdgFiilZJpQOX2Atv6Tgjvh+0RwwMnHTy8wof2Roe99T5MU Cf8g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=/k/x3jvD4hIY8pDNsyuRYJAWCjnjlkQj95o1100b+nU=; b=LKoa0aHAj2W6PfDmkhhcIHmakKNhaxGjMxJyl9bx5N7idi8z+KgXb98skhKWV0NEOm /sMt6hR/biLKDorI9GlgxLFS0KYEDFdSN7qKFe2Fg1//R283ZNlnrOaJKNhK3uakUyd2 DuccwxOA8gmCrDIRnUd59v0TbLtAhDZOQJ71HsRiayljaszruRTNwWjLOTanllAFlJEf i/TkRM6vyuX3bjM2PmVRqblxYwXPXgO3UVbBaJyHY4u9AiZn/08elntFntV/6RBTS5fm Z+qBKHraIFi+5q4vcXJGa19h5sx5BA0voYg1aN/L9+JQM9iREEHYnitw3VvmEwT/CXiT 9xxg== X-Gm-Message-State: AGi0PuY5cpur0PpwymywS+ADSBXhRggS/wsxOZY/2pPjnPR8/XxU4u38 CiqChZ58QG/lG15XBTz5Ddxbnjdocf8xcHjTOLHYbQ== X-Google-Smtp-Source: APiQypLnpQ9fey9MWfkvN5jK3cTisnhcJeTBQn37c1umPrLJpul/zCxeo6IzqY/pYCZUn/CL8vsxMaNBNscsUYb0zG8= X-Received: by 2002:a17:902:ac87:: with SMTP id h7mr8736134plr.119.1588785437559; Wed, 06 May 2020 10:17:17 -0700 (PDT) MIME-Version: 1.0 References: <20200506055245.3013374-1-jiaxun.yang@flygoat.com> In-Reply-To: <20200506055245.3013374-1-jiaxun.yang@flygoat.com> From: Nick Desaulniers Date: Wed, 6 May 2020 10:17:06 -0700 Message-ID: Subject: Re: To: Jiaxun Yang Cc: linux-mips@vger.kernel.org, clang-built-linux , "Maciej W . Rozycki" , Fangrui Song , Kees Cook , Nathan Chancellor , Thomas Bogendoerfer , Paul Burton , Masahiro Yamada , Jouni Hogander , Kevin Darbyshire-Bryant , Borislav Petkov , Heiko Carstens , LKML Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, May 5, 2020 at 10:52 PM Jiaxun Yang wrote: > > Subject: [PATCH v6] MIPS: Truncate link address into 32bit for 32bit kernel > In-Reply-To: <20200413062651.3992652-1-jiaxun.yang@flygoat.com> > > LLD failed to link vmlinux with 64bit load address for 32bit ELF > while bfd will strip 64bit address into 32bit silently. > To fix LLD build, we should truncate load address provided by platform > into 32bit for 32bit kernel. > > Signed-off-by: Jiaxun Yang > Link: https://github.com/ClangBuiltLinux/linux/issues/786 > Link: https://sourceware.org/bugzilla/show_bug.cgi?id=25784 > Reviewed-by: Fangrui Song > Reviewed-by: Kees Cook > Tested-by: Nathan Chancellor > Cc: Maciej W. Rozycki Cool, this revision looks a bit simpler. Thanks for chasing this. Tested-by: Nick Desaulniers > --- > V2: Take MaskRay's shell magic. > > V3: After spent an hour on dealing with special character issue in > Makefile, I gave up to do shell hacks and write a util in C instead. > Thanks Maciej for pointing out Makefile variable problem. > > v4: Finally we managed to find a Makefile method to do it properly > thanks to Kees. As it's too far from the initial version, I removed > Review & Test tag from Nick and Fangrui and Cc instead. > > v5: Care vmlinuz as well. > > v6: Rename to LIKER_LOAD_ADDRESS > --- > arch/mips/Makefile | 13 ++++++++++++- > arch/mips/boot/compressed/Makefile | 2 +- > arch/mips/kernel/vmlinux.lds.S | 2 +- > 3 files changed, 14 insertions(+), 3 deletions(-) > > diff --git a/arch/mips/Makefile b/arch/mips/Makefile > index e1c44aed8156..68c0f22fefc0 100644 > --- a/arch/mips/Makefile > +++ b/arch/mips/Makefile > @@ -288,12 +288,23 @@ ifdef CONFIG_64BIT > endif > endif > > +# When linking a 32-bit executable the LLVM linker cannot cope with a > +# 32-bit load address that has been sign-extended to 64 bits. Simply > +# remove the upper 32 bits then, as it is safe to do so with other > +# linkers. > +ifdef CONFIG_64BIT > + load-ld = $(load-y) > +else > + load-ld = $(subst 0xffffffff,0x,$(load-y)) > +endif > + > KBUILD_AFLAGS += $(cflags-y) > KBUILD_CFLAGS += $(cflags-y) > -KBUILD_CPPFLAGS += -DVMLINUX_LOAD_ADDRESS=$(load-y) > +KBUILD_CPPFLAGS += -DVMLINUX_LOAD_ADDRESS=$(load-y) -DLINKER_LOAD_ADDRESS=$(load-ld) > KBUILD_CPPFLAGS += -DDATAOFFSET=$(if $(dataoffset-y),$(dataoffset-y),0) > > bootvars-y = VMLINUX_LOAD_ADDRESS=$(load-y) \ > + LINKER_LOAD_ADDRESS=$(load-ld) \ > VMLINUX_ENTRY_ADDRESS=$(entry-y) \ > PLATFORM="$(platform-y)" \ > ITS_INPUTS="$(its-y)" > diff --git a/arch/mips/boot/compressed/Makefile b/arch/mips/boot/compressed/Makefile > index 0df0ee8a298d..3d391256ab7e 100644 > --- a/arch/mips/boot/compressed/Makefile > +++ b/arch/mips/boot/compressed/Makefile > @@ -90,7 +90,7 @@ ifneq ($(zload-y),) > VMLINUZ_LOAD_ADDRESS := $(zload-y) > else > VMLINUZ_LOAD_ADDRESS = $(shell $(obj)/calc_vmlinuz_load_addr \ > - $(obj)/vmlinux.bin $(VMLINUX_LOAD_ADDRESS)) > + $(obj)/vmlinux.bin $(LINKER_LOAD_ADDRESS)) > endif > UIMAGE_LOADADDR = $(VMLINUZ_LOAD_ADDRESS) > > diff --git a/arch/mips/kernel/vmlinux.lds.S b/arch/mips/kernel/vmlinux.lds.S > index a5f00ec73ea6..5226cd8e4bee 100644 > --- a/arch/mips/kernel/vmlinux.lds.S > +++ b/arch/mips/kernel/vmlinux.lds.S > @@ -55,7 +55,7 @@ SECTIONS > /* . = 0xa800000000300000; */ > . = 0xffffffff80300000; > #endif > - . = VMLINUX_LOAD_ADDRESS; > + . = LINKER_LOAD_ADDRESS; > /* read-only */ > _text = .; /* Text and read-only data */ > .text : { > > -- -- Thanks, ~Nick Desaulniers