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,URIBL_BLOCKED,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 05E34C10F11 for ; Wed, 24 Apr 2019 17:18:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BD09A21908 for ; Wed, 24 Apr 2019 17:18:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1556126333; bh=YQOdLFHXVpWPlJJ98yXTD12UNE/hUOMPXd0bX1kjtEI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=JEYDFFQmt1dasdJ9W0v7uOJREc4ZXe+Un7tMAi/4qPt3e46oadZ7v2Tm/tD4HWQbS AQdHFs8Q6Y3672sqUQjFjqJ+gJ8GqXjVygpcsc6Xw3a0MOCECO7CcvnjrZyrAmxC1v RZW/nkzTSHucEvNNTUMX2K46mXrpGoAlRkjf+pIc= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388910AbfDXRSw (ORCPT ); Wed, 24 Apr 2019 13:18:52 -0400 Received: from mail.kernel.org ([198.145.29.99]:43842 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388208AbfDXRSo (ORCPT ); Wed, 24 Apr 2019 13:18:44 -0400 Received: from localhost (62-193-50-229.as16211.net [62.193.50.229]) (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 5F6E621908; Wed, 24 Apr 2019 17:18:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1556126323; bh=YQOdLFHXVpWPlJJ98yXTD12UNE/hUOMPXd0bX1kjtEI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=q8FmDZHmqzxK4KuKckNu4VzFLwq80cO/4wml8Ss+BrZ2MVkQOZ1arZk5nF/qX/YBc ILXPkGgGbuNtm24xAGRLV6yZRkXtfE005WC7HJmUGqgLLXISUi52y1pIobZvunQyW7 WdhrzZRH9MvooxrIpQ+gWulGOj7owFfFMsfYTbhI= 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 4.4 072/168] x86: vdso: Use $LD instead of $CC to link Date: Wed, 24 Apr 2019 19:08:36 +0200 Message-Id: <20190424170927.981145923@linuxfoundation.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190424170923.452349382@linuxfoundation.org> References: <20190424170923.452349382@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 265c0ed68118..84c4a7105c2a 100644 --- a/arch/x86/entry/vdso/Makefile +++ b/arch/x86/entry/vdso/Makefile @@ -41,10 +41,8 @@ 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) @@ -90,10 +88,8 @@ 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)) @@ -121,7 +117,7 @@ $(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. @@ -157,13 +153,13 @@ $(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 # -- 2.19.1