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=-9.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_PASS,USER_AGENT_GIT autolearn=ham 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 49151C04E53 for ; Wed, 15 May 2019 12:00:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0D35220657 for ; Wed, 15 May 2019 12:00:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1557921636; bh=mIA+ijLf2ja/Iq0cq7ACxz8V/vsqmwrX8eLerHHUmQs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=Cdwu0OBYmN9DkOvJ0I7pebzenFEPwOV9T0m6W0j7IlKv4iI4rX0Sh9bP+CO2NIKMZ 9HA1WlDVsajsH24I1k9GhnEFL7Abh8KAc3/n54r3IIan6G2a4UD+GMee3SAbAMqmkJ +M1wInzlVCK3Lq4jUcG1KNZwtGX/137aLtXNF7nU= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730193AbfEOMAe (ORCPT ); Wed, 15 May 2019 08:00:34 -0400 Received: from mail.kernel.org ([198.145.29.99]:50892 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726975AbfEOLOm (ORCPT ); Wed, 15 May 2019 07:14:42 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 968E520843; Wed, 15 May 2019 11:14:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1557918882; bh=mIA+ijLf2ja/Iq0cq7ACxz8V/vsqmwrX8eLerHHUmQs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=jnCHTuuvURrSMhtvaIr3oREV+SEeMOGt9oAqqbOSogp221VE6JCd9QTB6fuBKXQCJ X+n9sNDNB9TE4LXJBM5ogQ77IknBCOFIqyaK6I5+jnGB/BP6T7X1rCZ0gw5gSlPhi3 3GLYDije/kz/38WwEVBlQQ80QErMsr59bmr20x5I= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Alistair Strachan , Thomas Gleixner , Andy Lutomirski , "H. Peter Anvin" , kernel-team@android.com, joel@joelfernandes.org, Andi Kleen , Nathan Chancellor , Sasha Levin Subject: [PATCH 4.9 36/51] x86: vdso: Use $LD instead of $CC to link Date: Wed, 15 May 2019 12:56:11 +0200 Message-Id: <20190515090627.121123141@linuxfoundation.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190515090616.669619870@linuxfoundation.org> References: <20190515090616.669619870@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org commit 379d98ddf41344273d9718556f761420f4dc80b3 upstream. The vdso{32,64}.so can fail to link with CC=clang when clang tries to find a suitable GCC toolchain to link these libraries with. /usr/bin/ld: arch/x86/entry/vdso/vclock_gettime.o: access beyond end of merged section (782) This happens because the host environment leaked into the cross compiler environment due to the way clang searches for suitable GCC toolchains. Clang is a retargetable compiler, and each invocation of it must provide --target= --gcc-toolchain= to allow it to find the correct binutils for cross compilation. These flags had been added to KBUILD_CFLAGS, but the vdso code uses CC and not KBUILD_CFLAGS (for various reasons) which breaks clang's ability to find the correct linker when cross compiling. Most of the time this goes unnoticed because the host linker is new enough to work anyway, or is incompatible and skipped, but this cannot be reliably assumed. This change alters the vdso makefile to just use LD directly, which bypasses clang and thus the searching problem. The makefile will just use ${CROSS_COMPILE}ld instead, which is always what we want. This matches the method used to link vmlinux. This drops references to DISABLE_LTO; this option doesn't seem to be set anywhere, and not knowing what its possible values are, it's not clear how to convert it from CC to LD flag. Signed-off-by: Alistair Strachan Signed-off-by: Thomas Gleixner Acked-by: Andy Lutomirski Cc: "H. Peter Anvin" Cc: Greg Kroah-Hartman Cc: kernel-team@android.com Cc: joel@joelfernandes.org Cc: Andi Kleen Link: https://lkml.kernel.org/r/20180803173931.117515-1-astrachan@google.com Signed-off-by: Nathan Chancellor Signed-off-by: Sasha Levin --- arch/x86/entry/vdso/Makefile | 22 +++++++++------------- 1 file changed, 9 insertions(+), 13 deletions(-) diff --git a/arch/x86/entry/vdso/Makefile b/arch/x86/entry/vdso/Makefile index d5409660f5de6..2ae92c6b1de6d 100644 --- a/arch/x86/entry/vdso/Makefile +++ b/arch/x86/entry/vdso/Makefile @@ -47,10 +47,8 @@ targets += $(vdso_img_sodbg) export CPPFLAGS_vdso.lds += -P -C -VDSO_LDFLAGS_vdso.lds = -m64 -Wl,-soname=linux-vdso.so.1 \ - -Wl,--no-undefined \ - -Wl,-z,max-page-size=4096 -Wl,-z,common-page-size=4096 \ - $(DISABLE_LTO) +VDSO_LDFLAGS_vdso.lds = -m elf_x86_64 -soname linux-vdso.so.1 --no-undefined \ + -z max-page-size=4096 -z common-page-size=4096 $(obj)/vdso64.so.dbg: $(src)/vdso.lds $(vobjs) FORCE $(call if_changed,vdso) @@ -96,10 +94,8 @@ CFLAGS_REMOVE_vvar.o = -pg # CPPFLAGS_vdsox32.lds = $(CPPFLAGS_vdso.lds) -VDSO_LDFLAGS_vdsox32.lds = -Wl,-m,elf32_x86_64 \ - -Wl,-soname=linux-vdso.so.1 \ - -Wl,-z,max-page-size=4096 \ - -Wl,-z,common-page-size=4096 +VDSO_LDFLAGS_vdsox32.lds = -m elf32_x86_64 -soname linux-vdso.so.1 \ + -z max-page-size=4096 -z common-page-size=4096 # 64-bit objects to re-brand as x32 vobjs64-for-x32 := $(filter-out $(vobjs-nox32),$(vobjs-y)) @@ -127,7 +123,7 @@ $(obj)/vdsox32.so.dbg: $(src)/vdsox32.lds $(vobjx32s) FORCE $(call if_changed,vdso) CPPFLAGS_vdso32.lds = $(CPPFLAGS_vdso.lds) -VDSO_LDFLAGS_vdso32.lds = -m32 -Wl,-m,elf_i386 -Wl,-soname=linux-gate.so.1 +VDSO_LDFLAGS_vdso32.lds = -m elf_i386 -soname linux-gate.so.1 # This makes sure the $(obj) subdirectory exists even though vdso32/ # is not a kbuild sub-make subdirectory. @@ -165,13 +161,13 @@ $(obj)/vdso32.so.dbg: FORCE \ # The DSO images are built using a special linker script. # quiet_cmd_vdso = VDSO $@ - cmd_vdso = $(CC) -nostdlib -o $@ \ + cmd_vdso = $(LD) -nostdlib -o $@ \ $(VDSO_LDFLAGS) $(VDSO_LDFLAGS_$(filter %.lds,$(^F))) \ - -Wl,-T,$(filter %.lds,$^) $(filter %.o,$^) && \ + -T $(filter %.lds,$^) $(filter %.o,$^) && \ sh $(srctree)/$(src)/checkundef.sh '$(NM)' '$@' -VDSO_LDFLAGS = -fPIC -shared $(call cc-ldoption, -Wl$(comma)--hash-style=both) \ - $(call cc-ldoption, -Wl$(comma)--build-id) -Wl,-Bsymbolic $(LTO_CFLAGS) +VDSO_LDFLAGS = -shared $(call ld-option, --hash-style=both) \ + $(call ld-option, --build-id) -Bsymbolic GCOV_PROFILE := n # -- 2.20.1