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=-15.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_ADSP_CUSTOM_MED,DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT 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 488E3C43463 for ; Fri, 18 Sep 2020 20:22:00 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 7983A20789 for ; Fri, 18 Sep 2020 20:21:59 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="FaTNTqoX"; dkim=fail reason="signature verification failed" (2048-bit key) header.d=google.com header.i=@google.com header.b="W2h/XnuG" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7983A20789 Authentication-Results: mail.kernel.org; dmarc=fail (p=reject dis=none) header.from=google.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:To:From:Subject:References:Mime-Version:Message-Id: In-Reply-To:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=wKPj7ucvnrgTckl/gP3TBR45ekSKEMokiH+0Lb6roVA=; b=FaTNTqoX9zeGRcRz+lhiP7vI8 F2GTuJvuJa3a071sYsCBHmqTG9XCXk8mGaq23e869u9hk755UtOjt97kW/1PNZ1MrSiqq0A51jNBl SsJgZFe6blDiDLin5TKSTLgRESA4OLetUS98QgW2rNnvM5iq0nAYyi1f7MgumVRtWgGhlF2KoY8hD JiGNZdYCi6g+6f5G8xNDaneTrfFVsQ+6EG9uAJ3qYiiA7zcnAmdgXC5KhmK39lGRGoQpfb49HMkwQ 0bWQ+RnYAIGwQj63reRHUvjy8B0smYtbnumJRNia1/T6sEKX6re4Zikgds1PY0OEULu4ZgffEMuPs PPbdBqCZQ==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kJMr2-0001N4-Id; Fri, 18 Sep 2020 20:19:36 +0000 Received: from mail-yb1-xb49.google.com ([2607:f8b0:4864:20::b49]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1kJMmm-0007iL-M8 for linux-arm-kernel@lists.infradead.org; Fri, 18 Sep 2020 20:15:19 +0000 Received: by mail-yb1-xb49.google.com with SMTP id v106so6678600ybi.6 for ; Fri, 18 Sep 2020 13:15:08 -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=D6tDM47xuke5ysE5WIIDa5rp1LAjlEXtWPHN9k1Y8+8=; b=W2h/XnuGzNlKV5NdC0adWKa37kl3xmgZiDqkHmcnEkH94kFjcNL9vASQEpry+o2tlh SfBC+DPIuAYiWU8pBcYhnBkk4MYMSQRxr8vnp5P4hse97LNHXff1HXT35d3k/6a2XuiT eFQ65bo3PHYA7ZULXIlrNE7ssaJVXvCHdWIs+w/N0bZjj4lG2tqKCTllU5W+bHP/uz3K qkChF8ODGR3zGLdbJMA86AqPoAhtjbqY74f8cX4z9omNFOlRGFgXhKC5HHQta0ZlGQBH vhvzn8bkpPjmmImHGKDSv1Gxy6AGXkufMcQ4EpIviMGuJbclkq23h5JjEGAU9g2QcPcL eVBQ== 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=D6tDM47xuke5ysE5WIIDa5rp1LAjlEXtWPHN9k1Y8+8=; b=JRd6RvBxMwIUcim5zo1r6sDDnulKFZX7FcD/D2pwOkGQGWyOO76EBDVCBi//CugkSd WPaTyU8DuQyWZBlW2APeiHJvIPiwFTYT9K8mms/sbNaKm9CEbE+T+US5HkVwid44w7mv PJ4GG91ywFbovIMSJpql4S6pNiv/fJAdbojuTCAuN0a1gGQU5dD5UMRzAKi7aUr3OKEW QJNrSiEUiJWBvlS9V45uhWauzvSVmDdE/p9k1DtCI+J7PfiYkrB3GC27Nq1wxBkzJ3Ic 4Yc3lv1EjZEMZ8XVYvka3F/Mv7tDAhFhbUjnoFAIsl3LNkJdUy9Lxn/lPSx8iOL3ZoiR PdIw== X-Gm-Message-State: AOAM5335zoGEgVHMjWyKDlbW56fb30F+USiYS57y7RU/PGs/DRxGP+Vz xDPXaN8bqCSfyKBQjgdnmGkEol410C0eZ+lLsGs= X-Google-Smtp-Source: ABdhPJwIKm2mW/7B7okzAhOoDkKFEdpCgso3ba9La2/d/DUtgiXB+PAEgrZZLuGQAGZ/+GH6mv8G2aj/fuFfm+e2Dis= X-Received: from samitolvanen1.mtv.corp.google.com ([2620:15c:201:2:f693:9fff:fef4:1b6d]) (user=samitolvanen job=sendgmr) by 2002:a25:bc46:: with SMTP id d6mr41185316ybk.511.1600460106948; Fri, 18 Sep 2020 13:15:06 -0700 (PDT) Date: Fri, 18 Sep 2020 13:14:18 -0700 In-Reply-To: <20200918201436.2932360-1-samitolvanen@google.com> Message-Id: <20200918201436.2932360-13-samitolvanen@google.com> Mime-Version: 1.0 References: <20200918201436.2932360-1-samitolvanen@google.com> X-Mailer: git-send-email 2.28.0.681.g6f77f65b4e-goog Subject: [PATCH v3 12/30] kbuild: lto: fix module versioning From: Sami Tolvanen To: Masahiro Yamada , Will Deacon X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200918_161512_809092_558243A3 X-CRM114-Status: GOOD ( 17.42 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-arch@vger.kernel.org, x86@kernel.org, Kees Cook , "Paul E. McKenney" , kernel-hardening@lists.openwall.com, Peter Zijlstra , Greg Kroah-Hartman , linux-kbuild@vger.kernel.org, Nick Desaulniers , linux-kernel@vger.kernel.org, Steven Rostedt , clang-built-linux@googlegroups.com, Sami Tolvanen , linux-pci@vger.kernel.org, linux-arm-kernel@lists.infradead.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org With CONFIG_MODVERSIONS, version information is linked into each compilation unit that exports symbols. With LTO, we cannot use this method as all C code is compiled into LLVM bitcode instead. This change collects symbol versions into .symversions files and merges them in link-vmlinux.sh where they are all linked into vmlinux.o at the same time. Signed-off-by: Sami Tolvanen Reviewed-by: Kees Cook --- .gitignore | 1 + Makefile | 3 ++- arch/Kconfig | 1 - scripts/Makefile.build | 33 +++++++++++++++++++++++++++++++-- scripts/Makefile.modpost | 6 +++++- scripts/link-vmlinux.sh | 25 ++++++++++++++++++++++++- 6 files changed, 63 insertions(+), 6 deletions(-) diff --git a/.gitignore b/.gitignore index 162bd2b67bdf..06e76dc39ffe 100644 --- a/.gitignore +++ b/.gitignore @@ -41,6 +41,7 @@ *.so.dbg *.su *.symtypes +*.symversions *.tab.[ch] *.tar *.xz diff --git a/Makefile b/Makefile index be923c18421a..629d4b18e413 100644 --- a/Makefile +++ b/Makefile @@ -1845,7 +1845,8 @@ clean: $(clean-dirs) -o -name '.tmp_*.o.*' \ -o -name '*.c.[012]*.*' \ -o -name '*.ll' \ - -o -name '*.gcno' \) -type f -print | xargs rm -f + -o -name '*.gcno' \ + -o -name '*.*.symversions' \) -type f -print | xargs rm -f # Generate tags for editors # --------------------------------------------------------------------------- diff --git a/arch/Kconfig b/arch/Kconfig index 0742ec643d79..520e900efc75 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -603,7 +603,6 @@ config LTO_CLANG depends on !FTRACE_MCOUNT_RECORD depends on !KASAN depends on !GCOV_KERNEL - depends on !MODVERSIONS select LTO help This option enables Clang's Link Time Optimization (LTO), which diff --git a/scripts/Makefile.build b/scripts/Makefile.build index cab9d1024c23..44b6d964bcad 100644 --- a/scripts/Makefile.build +++ b/scripts/Makefile.build @@ -166,6 +166,15 @@ ifdef CONFIG_MODVERSIONS # the actual value of the checksum generated by genksyms # o remove .tmp_.o to .o +ifdef CONFIG_LTO_CLANG +# Generate .o.symversions files for each .o with exported symbols, and link these +# to the kernel and/or modules at the end. +cmd_modversions_c = \ + if $(NM) $@ 2>/dev/null | grep -q __ksymtab; then \ + $(call cmd_gensymtypes_c,$(KBUILD_SYMTYPES),$(@:.o=.symtypes)) \ + > $@.symversions; \ + fi; +else cmd_modversions_c = \ if $(OBJDUMP) -h $@ | grep -q __ksymtab; then \ $(call cmd_gensymtypes_c,$(KBUILD_SYMTYPES),$(@:.o=.symtypes)) \ @@ -177,6 +186,7 @@ cmd_modversions_c = \ rm -f $(@D)/.tmp_$(@F:.o=.ver); \ fi endif +endif ifdef USE_RECORDMCOUNT # compiler will not generate __mcount_loc use recordmcount or recordmcount.pl @@ -393,6 +403,18 @@ $(obj)/%.asn1.c $(obj)/%.asn1.h: $(src)/%.asn1 $(objtree)/scripts/asn1_compiler $(subdir-builtin): $(obj)/%/built-in.a: $(obj)/% ; $(subdir-modorder): $(obj)/%/modules.order: $(obj)/% ; +# combine symversions for later processing +quiet_cmd_update_lto_symversions = SYMVER $@ +ifeq ($(CONFIG_LTO_CLANG) $(CONFIG_MODVERSIONS),y y) + cmd_update_lto_symversions = \ + rm -f $@.symversions \ + $(foreach n, $(filter-out FORCE,$^), \ + $(if $(wildcard $(n).symversions), \ + ; cat $(n).symversions >> $@.symversions)) +else + cmd_update_lto_symversions = echo >/dev/null +endif + # # Rule to compile a set of .o files into one .a file (without symbol table) # @@ -400,8 +422,11 @@ $(subdir-modorder): $(obj)/%/modules.order: $(obj)/% ; quiet_cmd_ar_builtin = AR $@ cmd_ar_builtin = rm -f $@; $(AR) cDPrST $@ $(real-prereqs) +quiet_cmd_ar_and_symver = AR $@ + cmd_ar_and_symver = $(cmd_update_lto_symversions); $(cmd_ar_builtin) + $(obj)/built-in.a: $(real-obj-y) FORCE - $(call if_changed,ar_builtin) + $(call if_changed,ar_and_symver) # # Rule to create modules.order file @@ -421,8 +446,11 @@ $(obj)/modules.order: $(obj-m) FORCE # # Rule to compile a set of .o files into one .a file (with symbol table) # +quiet_cmd_ar_lib = AR $@ + cmd_ar_lib = $(cmd_update_lto_symversions); $(cmd_ar) + $(obj)/lib.a: $(lib-y) FORCE - $(call if_changed,ar) + $(call if_changed,ar_lib) # NOTE: # Do not replace $(filter %.o,^) with $(real-prereqs). When a single object @@ -431,6 +459,7 @@ $(obj)/lib.a: $(lib-y) FORCE ifdef CONFIG_LTO_CLANG quiet_cmd_link_multi-m = AR [M] $@ cmd_link_multi-m = \ + $(cmd_update_lto_symversions); \ rm -f $@; \ $(AR) cDPrsT $@ $(filter %.o,$^) else diff --git a/scripts/Makefile.modpost b/scripts/Makefile.modpost index 66e0c256403c..753725b88683 100644 --- a/scripts/Makefile.modpost +++ b/scripts/Makefile.modpost @@ -108,7 +108,11 @@ ifdef CONFIG_LTO_CLANG prelink-ext = .lto quiet_cmd_cc_lto_link_modules = LTO [M] $@ -cmd_cc_lto_link_modules = $(LD) $(ld_flags) -r -o $@ --whole-archive $^ +cmd_cc_lto_link_modules = \ + $(LD) $(ld_flags) -r -o $@ \ + $(shell [ -s $(@:.lto.o=.o.symversions) ] && \ + echo -T $(@:.lto.o=.o.symversions)) \ + --whole-archive $^ %.lto.o: %.o $(call if_changed,cc_lto_link_modules) diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh index ebb9f912aab6..3e99a19b9195 100755 --- a/scripts/link-vmlinux.sh +++ b/scripts/link-vmlinux.sh @@ -43,11 +43,28 @@ info() fi } +# If CONFIG_LTO_CLANG is selected, collect generated symbol versions into +# .tmp_symversions.lds +gen_symversions() +{ + info GEN .tmp_symversions.lds + rm -f .tmp_symversions.lds + + for a in ${KBUILD_VMLINUX_OBJS} ${KBUILD_VMLINUX_LIBS}; do + for o in $(${AR} t $a 2>/dev/null); do + if [ -f ${o}.symversions ]; then + cat ${o}.symversions >> .tmp_symversions.lds + fi + done + done +} + # Link of vmlinux.o used for section mismatch analysis # ${1} output file modpost_link() { local objects + local lds="" objects="--whole-archive \ ${KBUILD_VMLINUX_OBJS} \ @@ -57,6 +74,11 @@ modpost_link() --end-group" if [ -n "${CONFIG_LTO_CLANG}" ]; then + if [ -n "${CONFIG_MODVERSIONS}" ]; then + gen_symversions + lds="${lds} -T .tmp_symversions.lds" + fi + # This might take a while, so indicate that we're doing # an LTO link info LTO ${1} @@ -64,7 +86,7 @@ modpost_link() info LD ${1} fi - ${LD} ${KBUILD_LDFLAGS} -r -o ${1} ${objects} + ${LD} ${KBUILD_LDFLAGS} -r -o ${1} ${lds} ${objects} } objtool_link() @@ -242,6 +264,7 @@ cleanup() { rm -f .btf.* rm -f .tmp_System.map + rm -f .tmp_symversions.lds rm -f .tmp_vmlinux* rm -f System.map rm -f vmlinux -- 2.28.0.681.g6f77f65b4e-goog _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel