From patchwork Tue Dec 1 21:36:52 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sami Tolvanen X-Patchwork-Id: 11943893 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=-26.2 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT,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 2BE7FC71155 for ; Tue, 1 Dec 2020 21:38:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9F5F72085B for ; Tue, 1 Dec 2020 21:38:32 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="dodU69bM" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729590AbgLAVib (ORCPT ); Tue, 1 Dec 2020 16:38:31 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56336 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728461AbgLAVib (ORCPT ); Tue, 1 Dec 2020 16:38:31 -0500 Received: from mail-qt1-x849.google.com (mail-qt1-x849.google.com [IPv6:2607:f8b0:4864:20::849]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1243BC061A47 for ; Tue, 1 Dec 2020 13:37:13 -0800 (PST) Received: by mail-qt1-x849.google.com with SMTP id n95so2268775qte.16 for ; Tue, 01 Dec 2020 13:37:13 -0800 (PST) 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=VOfy7I+JfJNFr5nKa99p/PnWq1cmu5wGQSaePmGF9lo=; b=dodU69bM2w4739uzVye+y4jtglX3kpRzjscI0GbwcduOaRiiAF4qIiLCdF1q6oX3wk pUD5Ndeh73E2deG4Whw5KpplKyo+tERYmf13gaWfLYPGdA3PlmgrkbjNepiosHlzkLxk bNPX9Mln5u4xxSb2ddOYEHu9vBV5aswLRqXq1YvmJGNA+UFionr74fPHqks/AmBjSG5K wImLilm8AUw64QLRFpWry1xi+iqe+xBzAckeWyBEk70hGn1j6CtUCDU71oPM5PyxtS24 uxteYTrSE1Z32cdNjH3k9kEfWfQDveAyVC+dZStPY32Swa3uQRYzcILaUV3t8/keJNMz No+w== 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=VOfy7I+JfJNFr5nKa99p/PnWq1cmu5wGQSaePmGF9lo=; b=Q7e0ba/8Ddkinz6LsffJIEBy6iQKuDtEzzOgUCAMVVhU2umMpzS04uLKMRTntI9S5J KPKqFnoyX9sjlsRrT58N6QErdGPagabKPnHhH8ue7s6y3lTXyFUg5lzWtffNkW9jIsYi HAGTwgU3JxzTv8J8yXFvetsCL38lIsWnAzSxte4LRQajQhGXmq3GOe1A8N+8KIGAoX0q ZwJYlndif/qcx1A4zXryDV+3nKiKpOMTweDGuYBWDiQ+ohRj55HJDwEsCqoTBSrD3iaW x+YvNlqgao1VmsJUDf99p2dlFN8I9vfKk4RMj96tT+LtiZ4lmOxpaHNgzSPPE1JywJBt hyYw== X-Gm-Message-State: AOAM533Gr5tIPNNd4zt19DuizQ6gw4b5gHTj2JJwQxWl213K1yQSHzVM Db0AIj6m/l6L7GOCqI3zdCwJd0NUOtOWOiewcJ0= X-Google-Smtp-Source: ABdhPJx8i2LYOaIAUm1xZq5QecJCqb89qpX2sshqEwhakWHanNfyXjOyqmKUAn8b1Ee504d4LisYbH/jTs0JuebquqY= Sender: "samitolvanen via sendgmr" X-Received: from samitolvanen1.mtv.corp.google.com ([2620:15c:201:2:f693:9fff:fef4:1b6d]) (user=samitolvanen job=sendgmr) by 2002:a0c:bd10:: with SMTP id m16mr5440647qvg.15.1606858632172; Tue, 01 Dec 2020 13:37:12 -0800 (PST) Date: Tue, 1 Dec 2020 13:36:52 -0800 In-Reply-To: <20201201213707.541432-1-samitolvanen@google.com> Message-Id: <20201201213707.541432-2-samitolvanen@google.com> Mime-Version: 1.0 References: <20201201213707.541432-1-samitolvanen@google.com> X-Mailer: git-send-email 2.29.2.576.ga3fc446d84-goog Subject: [PATCH v8 01/16] tracing: move function tracer options to Kconfig From: Sami Tolvanen To: Masahiro Yamada , Steven Rostedt , Will Deacon Cc: Josh Poimboeuf , Peter Zijlstra , 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, Sami Tolvanen Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org Move function tracer options to Kconfig to make it easier to add new methods for generating __mcount_loc, and to make the options available also when building kernel modules. Note that FTRACE_MCOUNT_USE_* options are updated on rebuild and therefore, work even if the .config was generated in a different environment. Signed-off-by: Sami Tolvanen Acked-by: Steven Rostedt (VMware) --- Makefile | 20 ++++++++------------ kernel/trace/Kconfig | 16 ++++++++++++++++ scripts/Makefile.build | 6 ++---- 3 files changed, 26 insertions(+), 16 deletions(-) diff --git a/Makefile b/Makefile index 43ecedeb3f02..16b7f0890e75 100644 --- a/Makefile +++ b/Makefile @@ -849,12 +849,8 @@ KBUILD_CFLAGS += $(DEBUG_CFLAGS) export DEBUG_CFLAGS ifdef CONFIG_FUNCTION_TRACER -ifdef CONFIG_FTRACE_MCOUNT_RECORD - # gcc 5 supports generating the mcount tables directly - ifeq ($(call cc-option-yn,-mrecord-mcount),y) - CC_FLAGS_FTRACE += -mrecord-mcount - export CC_USING_RECORD_MCOUNT := 1 - endif +ifdef CONFIG_FTRACE_MCOUNT_USE_CC + CC_FLAGS_FTRACE += -mrecord-mcount ifdef CONFIG_HAVE_NOP_MCOUNT ifeq ($(call cc-option-yn, -mnop-mcount),y) CC_FLAGS_FTRACE += -mnop-mcount @@ -862,6 +858,12 @@ ifdef CONFIG_FTRACE_MCOUNT_RECORD endif endif endif +ifdef CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT + ifdef CONFIG_HAVE_C_RECORDMCOUNT + BUILD_C_RECORDMCOUNT := y + export BUILD_C_RECORDMCOUNT + endif +endif ifdef CONFIG_HAVE_FENTRY ifeq ($(call cc-option-yn, -mfentry),y) CC_FLAGS_FTRACE += -mfentry @@ -871,12 +873,6 @@ endif export CC_FLAGS_FTRACE KBUILD_CFLAGS += $(CC_FLAGS_FTRACE) $(CC_FLAGS_USING) KBUILD_AFLAGS += $(CC_FLAGS_USING) -ifdef CONFIG_DYNAMIC_FTRACE - ifdef CONFIG_HAVE_C_RECORDMCOUNT - BUILD_C_RECORDMCOUNT := y - export BUILD_C_RECORDMCOUNT - endif -endif endif # We trigger additional mismatches with less inlining diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index a4020c0b4508..927ad004888a 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -595,6 +595,22 @@ config FTRACE_MCOUNT_RECORD depends on DYNAMIC_FTRACE depends on HAVE_FTRACE_MCOUNT_RECORD +config FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY + bool + depends on FTRACE_MCOUNT_RECORD + +config FTRACE_MCOUNT_USE_CC + def_bool y + depends on $(cc-option,-mrecord-mcount) + depends on !FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY + depends on FTRACE_MCOUNT_RECORD + +config FTRACE_MCOUNT_USE_RECORDMCOUNT + def_bool y + depends on !FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY + depends on !FTRACE_MCOUNT_USE_CC + depends on FTRACE_MCOUNT_RECORD + config TRACING_MAP bool depends on ARCH_HAVE_NMI_SAFE_CMPXCHG diff --git a/scripts/Makefile.build b/scripts/Makefile.build index ae647379b579..2175ddb1ee0c 100644 --- a/scripts/Makefile.build +++ b/scripts/Makefile.build @@ -178,8 +178,7 @@ cmd_modversions_c = \ fi endif -ifdef CONFIG_FTRACE_MCOUNT_RECORD -ifndef CC_USING_RECORD_MCOUNT +ifdef CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT # compiler will not generate __mcount_loc use recordmcount or recordmcount.pl ifdef BUILD_C_RECORDMCOUNT ifeq ("$(origin RECORDMCOUNT_WARN)", "command line") @@ -206,8 +205,7 @@ recordmcount_source := $(srctree)/scripts/recordmcount.pl endif # BUILD_C_RECORDMCOUNT cmd_record_mcount = $(if $(findstring $(strip $(CC_FLAGS_FTRACE)),$(_c_flags)), \ $(sub_cmd_record_mcount)) -endif # CC_USING_RECORD_MCOUNT -endif # CONFIG_FTRACE_MCOUNT_RECORD +endif # CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT ifdef CONFIG_STACK_VALIDATION ifneq ($(SKIP_STACK_VALIDATION),1) From patchwork Tue Dec 1 21:36:53 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sami Tolvanen X-Patchwork-Id: 11943895 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=-31.2 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT,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 DAD01C71156 for ; Tue, 1 Dec 2020 21:38:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 83FD12087C for ; Tue, 1 Dec 2020 21:38:33 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="ld3ZUnH3" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728634AbgLAVic (ORCPT ); Tue, 1 Dec 2020 16:38:32 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56344 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729472AbgLAVib (ORCPT ); Tue, 1 Dec 2020 16:38:31 -0500 Received: from mail-yb1-xb4a.google.com (mail-yb1-xb4a.google.com [IPv6:2607:f8b0:4864:20::b4a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A4A3DC061A4B for ; Tue, 1 Dec 2020 13:37:15 -0800 (PST) Received: by mail-yb1-xb4a.google.com with SMTP id z29so3959327ybi.23 for ; Tue, 01 Dec 2020 13:37:15 -0800 (PST) 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=fygjglTRsKGmnadS+2qeS3fGBk6lf/IWx2oHvO7WNxI=; b=ld3ZUnH3OtCUhEynkUOEkRj5Y8DCnq4JLr8zgSNXp9Us0msShiJvRbOGSRCG3pfSoV Mxp2Qp/ocZDzWnzxhsdFIWtvjFNXXS5/rrKWXNRJ/AxULYdaP0q998bTbDlFcyB2nAle ZtzcETw1Te8SHGChUMsSRF2c6lZk74b5RlogLs64x6Blq9zd2VODbbxQ/OGylzBALucJ zQBhKlAcgP8eGfWtkepIF9obp4/L3e/4LwOH74wTMKzBSH5d5mfSytb4Bjh0idD3Kx6c o9o5IwHTt+8cQt7zyRp+Xglk8ZnIUi+TO6u852lX8WTOMgfHsOQG5S72tjfPloSbGtyu /KdA== 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=fygjglTRsKGmnadS+2qeS3fGBk6lf/IWx2oHvO7WNxI=; b=Y5FuiXqyVGPoPgl2HIM+PDHtIaBw6K1wkiwOuFwd18rYETBFMlYamqAAUwSuTIGPE3 rK5lRg+kLa0BXN1ZP08TkxryUfP3fMUNgRWLDBq+iwxdbJt+g9PO0Ppig7Kig2GUk84I /t6W4tbGY9/fh7adun350eTuPh03PkkqTbDWN7EV2OjjKkD40qkjxGVdyc7r9hVfag7r yFDm6ZxtSJ9N/yB4A3RUoqEX6mjb3sl0D872ur2UzM/ZONDWP1rmbI55a3w+cTnQ//Te 3PzvAdOg0a7j00fwRbpWrE1SYpqbmJbKscxyiaEL3C7u0T/F35muvSylOocLj2ebqu1g YHcQ== X-Gm-Message-State: AOAM5337Hj/LjNP9WQFmdvJkIWv1jN8DddqBQmtIVkWn6hOA10khA/Sz tU1ga387cq2l5UYC1e8GLMJ8j/882gmboKWHWPM= X-Google-Smtp-Source: ABdhPJzfUE3Px8AQFizwOVTAW068CHUEcQQsuwqRNDgzG+AIPviLQFJyvHJvyBp677JPugmd1GlJnmWIP3ofkFkUIXg= Sender: "samitolvanen via sendgmr" X-Received: from samitolvanen1.mtv.corp.google.com ([2620:15c:201:2:f693:9fff:fef4:1b6d]) (user=samitolvanen job=sendgmr) by 2002:a5b:f01:: with SMTP id x1mr6309054ybr.291.1606858634882; Tue, 01 Dec 2020 13:37:14 -0800 (PST) Date: Tue, 1 Dec 2020 13:36:53 -0800 In-Reply-To: <20201201213707.541432-1-samitolvanen@google.com> Message-Id: <20201201213707.541432-3-samitolvanen@google.com> Mime-Version: 1.0 References: <20201201213707.541432-1-samitolvanen@google.com> X-Mailer: git-send-email 2.29.2.576.ga3fc446d84-goog Subject: [PATCH v8 02/16] kbuild: add support for Clang LTO From: Sami Tolvanen To: Masahiro Yamada , Steven Rostedt , Will Deacon Cc: Josh Poimboeuf , Peter Zijlstra , 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, Sami Tolvanen Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org This change adds build system support for Clang's Link Time Optimization (LTO). With -flto, instead of ELF object files, Clang produces LLVM bitcode, which is compiled into native code at link time, allowing the final binary to be optimized globally. For more details, see: https://llvm.org/docs/LinkTimeOptimization.html The Kconfig option CONFIG_LTO_CLANG is implemented as a choice, which defaults to LTO being disabled. To use LTO, the architecture must select ARCH_SUPPORTS_LTO_CLANG and support: - compiling with Clang, - compiling inline assembly with Clang's integrated assembler, - and linking with LLD. While using full LTO results in the best runtime performance, the compilation is not scalable in time or memory. CONFIG_THINLTO enables ThinLTO, which allows parallel optimization and faster incremental builds. ThinLTO is used by default if the architecture also selects ARCH_SUPPORTS_THINLTO: https://clang.llvm.org/docs/ThinLTO.html To enable LTO, LLVM tools must be used to handle bitcode files. The easiest way is to pass the LLVM=1 option to make: $ make LLVM=1 defconfig $ scripts/config -e LTO_CLANG $ make LLVM=1 Alternatively, at least the following LLVM tools must be used: CC=clang LD=ld.lld AR=llvm-ar NM=llvm-nm To prepare for LTO support with other compilers, common parts are gated behind the CONFIG_LTO option, and LTO can be disabled for specific files by filtering out CC_FLAGS_LTO. Signed-off-by: Sami Tolvanen Reviewed-by: Kees Cook Reviewed-by: Nick Desaulniers --- Makefile | 19 ++++++- arch/Kconfig | 88 +++++++++++++++++++++++++++++++ include/asm-generic/vmlinux.lds.h | 11 ++-- scripts/Makefile.build | 9 +++- scripts/Makefile.modfinal | 9 +++- scripts/Makefile.modpost | 21 +++++++- scripts/link-vmlinux.sh | 32 ++++++++--- 7 files changed, 171 insertions(+), 18 deletions(-) diff --git a/Makefile b/Makefile index 16b7f0890e75..f5cac2428efc 100644 --- a/Makefile +++ b/Makefile @@ -891,6 +891,21 @@ KBUILD_CFLAGS += $(CC_FLAGS_SCS) export CC_FLAGS_SCS endif +ifdef CONFIG_LTO_CLANG +ifdef CONFIG_LTO_CLANG_THIN +CC_FLAGS_LTO += -flto=thin -fsplit-lto-unit +KBUILD_LDFLAGS += --thinlto-cache-dir=$(extmod-prefix).thinlto-cache +else +CC_FLAGS_LTO += -flto +endif +CC_FLAGS_LTO += -fvisibility=default +endif + +ifdef CONFIG_LTO +KBUILD_CFLAGS += $(CC_FLAGS_LTO) +export CC_FLAGS_LTO +endif + ifdef CONFIG_DEBUG_FORCE_FUNCTION_ALIGN_32B KBUILD_CFLAGS += -falign-functions=32 endif @@ -1471,7 +1486,7 @@ MRPROPER_FILES += include/config include/generated \ *.spec # Directories & files removed with 'make distclean' -DISTCLEAN_FILES += tags TAGS cscope* GPATH GTAGS GRTAGS GSYMS +DISTCLEAN_FILES += tags TAGS cscope* GPATH GTAGS GRTAGS GSYMS .thinlto-cache # clean - Delete most, but leave enough to build external modules # @@ -1717,7 +1732,7 @@ PHONY += compile_commands.json clean-dirs := $(KBUILD_EXTMOD) clean: rm-files := $(KBUILD_EXTMOD)/Module.symvers $(KBUILD_EXTMOD)/modules.nsdeps \ - $(KBUILD_EXTMOD)/compile_commands.json + $(KBUILD_EXTMOD)/compile_commands.json $(KBUILD_EXTMOD)/.thinlto-cache PHONY += help help: diff --git a/arch/Kconfig b/arch/Kconfig index 56b6ccc0e32d..30907b554451 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -598,6 +598,94 @@ config SHADOW_CALL_STACK reading and writing arbitrary memory may be able to locate them and hijack control flow by modifying the stacks. +config LTO + bool + help + Selected if the kernel will be built using the compiler's LTO feature. + +config LTO_CLANG + bool + select LTO + help + Selected if the kernel will be built using Clang's LTO feature. + +config ARCH_SUPPORTS_LTO_CLANG + bool + help + An architecture should select this option if it supports: + - compiling with Clang, + - compiling inline assembly with Clang's integrated assembler, + - and linking with LLD. + +config ARCH_SUPPORTS_LTO_CLANG_THIN + bool + help + An architecture should select this option if it can support Clang's + ThinLTO mode. + +config HAS_LTO_CLANG + def_bool y + # Clang >= 11: https://github.com/ClangBuiltLinux/linux/issues/510 + depends on CC_IS_CLANG && CLANG_VERSION >= 110000 && LD_IS_LLD + depends on $(success,$(NM) --help | head -n 1 | grep -qi llvm) + depends on $(success,$(AR) --help | head -n 1 | grep -qi llvm) + depends on ARCH_SUPPORTS_LTO_CLANG + depends on !FTRACE_MCOUNT_USE_RECORDMCOUNT + depends on !KASAN + depends on !GCOV_KERNEL + depends on !MODVERSIONS + help + The compiler and Kconfig options support building with Clang's + LTO. + +choice + prompt "Link Time Optimization (LTO)" + default LTO_NONE + help + This option enables Link Time Optimization (LTO), which allows the + compiler to optimize binaries globally. + + If unsure, select LTO_NONE. Note that LTO is very resource-intensive + so it's disabled by default. + +config LTO_NONE + bool "None" + help + Build the kernel normally, without Link Time Optimization (LTO). + +config LTO_CLANG_FULL + bool "Clang Full LTO (EXPERIMENTAL)" + depends on HAS_LTO_CLANG + select LTO_CLANG + help + This option enables Clang's full Link Time Optimization (LTO), which + allows the compiler to optimize the kernel globally. If you enable + this option, the compiler generates LLVM bitcode instead of ELF + object files, and the actual compilation from bitcode happens at + the LTO link step, which may take several minutes depending on the + kernel configuration. More information can be found from LLVM's + documentation: + + https://llvm.org/docs/LinkTimeOptimization.html + + During link time, this option can use a large amount of RAM, and + may take much longer than the ThinLTO option. + +config LTO_CLANG_THIN + bool "Clang ThinLTO (EXPERIMENTAL)" + depends on HAS_LTO_CLANG && ARCH_SUPPORTS_LTO_CLANG_THIN + select LTO_CLANG + help + This option enables Clang's ThinLTO, which allows for parallel + optimization and faster incremental compiles compared to the + CONFIG_LTO_CLANG_FULL option. More information can be found + from Clang's documentation: + + https://clang.llvm.org/docs/ThinLTO.html + + If unsure, say Y. +endchoice + config HAVE_ARCH_WITHIN_STACK_FRAMES bool help diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h index b2b3d81b1535..8988a2e445d8 100644 --- a/include/asm-generic/vmlinux.lds.h +++ b/include/asm-generic/vmlinux.lds.h @@ -90,15 +90,18 @@ * .data. We don't want to pull in .data..other sections, which Linux * has defined. Same for text and bss. * + * With LTO_CLANG, the linker also splits sections by default, so we need + * these macros to combine the sections during the final link. + * * RODATA_MAIN is not used because existing code already defines .rodata.x * sections to be brought in with rodata. */ -#ifdef CONFIG_LD_DEAD_CODE_DATA_ELIMINATION +#if defined(CONFIG_LD_DEAD_CODE_DATA_ELIMINATION) || defined(CONFIG_LTO_CLANG) #define TEXT_MAIN .text .text.[0-9a-zA-Z_]* -#define DATA_MAIN .data .data.[0-9a-zA-Z_]* .data..LPBX* +#define DATA_MAIN .data .data.[0-9a-zA-Z_]* .data..L* .data..compoundliteral* #define SDATA_MAIN .sdata .sdata.[0-9a-zA-Z_]* -#define RODATA_MAIN .rodata .rodata.[0-9a-zA-Z_]* -#define BSS_MAIN .bss .bss.[0-9a-zA-Z_]* +#define RODATA_MAIN .rodata .rodata.[0-9a-zA-Z_]* .rodata..L* +#define BSS_MAIN .bss .bss.[0-9a-zA-Z_]* .bss..compoundliteral* #define SBSS_MAIN .sbss .sbss.[0-9a-zA-Z_]* #else #define TEXT_MAIN .text diff --git a/scripts/Makefile.build b/scripts/Makefile.build index 2175ddb1ee0c..ed74b2f986f7 100644 --- a/scripts/Makefile.build +++ b/scripts/Makefile.build @@ -111,7 +111,7 @@ endif # --------------------------------------------------------------------------- quiet_cmd_cc_s_c = CC $(quiet_modtag) $@ - cmd_cc_s_c = $(CC) $(filter-out $(DEBUG_CFLAGS), $(c_flags)) -fverbose-asm -S -o $@ $< + cmd_cc_s_c = $(CC) $(filter-out $(DEBUG_CFLAGS) $(CC_FLAGS_LTO), $(c_flags)) -fverbose-asm -S -o $@ $< $(obj)/%.s: $(src)/%.c FORCE $(call if_changed_dep,cc_s_c) @@ -425,8 +425,15 @@ $(obj)/lib.a: $(lib-y) FORCE # Do not replace $(filter %.o,^) with $(real-prereqs). When a single object # module is turned into a multi object module, $^ will contain header file # dependencies recorded in the .*.cmd file. +ifdef CONFIG_LTO_CLANG +quiet_cmd_link_multi-m = AR [M] $@ +cmd_link_multi-m = \ + rm -f $@; \ + $(AR) cDPrsT $@ $(filter %.o,$^) +else quiet_cmd_link_multi-m = LD [M] $@ cmd_link_multi-m = $(LD) $(ld_flags) -r -o $@ $(filter %.o,$^) +endif $(multi-used-m): FORCE $(call if_changed,link_multi-m) diff --git a/scripts/Makefile.modfinal b/scripts/Makefile.modfinal index ae01baf96f4e..2cb9a1d88434 100644 --- a/scripts/Makefile.modfinal +++ b/scripts/Makefile.modfinal @@ -6,6 +6,7 @@ PHONY := __modfinal __modfinal: +include $(objtree)/include/config/auto.conf include $(srctree)/scripts/Kbuild.include # for c_flags @@ -29,6 +30,12 @@ quiet_cmd_cc_o_c = CC [M] $@ ARCH_POSTLINK := $(wildcard $(srctree)/arch/$(SRCARCH)/Makefile.postlink) +ifdef CONFIG_LTO_CLANG +# With CONFIG_LTO_CLANG, reuse the object file we compiled for modpost to +# avoid a second slow LTO link +prelink-ext := .lto +endif + quiet_cmd_ld_ko_o = LD [M] $@ cmd_ld_ko_o = \ $(LD) -r $(KBUILD_LDFLAGS) \ @@ -36,7 +43,7 @@ quiet_cmd_ld_ko_o = LD [M] $@ -T scripts/module.lds -o $@ $(filter %.o, $^); \ $(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) $@, true) -$(modules): %.ko: %.o %.mod.o scripts/module.lds FORCE +$(modules): %.ko: %$(prelink-ext).o %.mod.o scripts/module.lds FORCE +$(call if_changed,ld_ko_o) targets += $(modules) $(modules:.ko=.mod.o) diff --git a/scripts/Makefile.modpost b/scripts/Makefile.modpost index f54b6ac37ac2..9ff8bfdb574d 100644 --- a/scripts/Makefile.modpost +++ b/scripts/Makefile.modpost @@ -43,6 +43,9 @@ __modpost: include include/config/auto.conf include scripts/Kbuild.include +# for ld_flags +include scripts/Makefile.lib + MODPOST = scripts/mod/modpost \ $(if $(CONFIG_MODVERSIONS),-m) \ $(if $(CONFIG_MODULE_SRCVERSION_ALL),-a) \ @@ -102,12 +105,26 @@ $(input-symdump): @echo >&2 'WARNING: Symbol version dump "$@" is missing.' @echo >&2 ' Modules may not have dependencies or modversions.' +ifdef CONFIG_LTO_CLANG +# With CONFIG_LTO_CLANG, .o files might be LLVM bitcode, so we need to run +# LTO to compile them into native code before running modpost +prelink-ext := .lto + +quiet_cmd_cc_lto_link_modules = LTO [M] $@ +cmd_cc_lto_link_modules = $(LD) $(ld_flags) -r -o $@ --whole-archive $^ + +%.lto.o: %.o + $(call if_changed,cc_lto_link_modules) +endif + +modules := $(sort $(shell cat $(MODORDER))) + # Read out modules.order to pass in modpost. # Otherwise, allmodconfig would fail with "Argument list too long". quiet_cmd_modpost = MODPOST $@ - cmd_modpost = sed 's/ko$$/o/' $< | $(MODPOST) -T - + cmd_modpost = sed 's/\.ko$$/$(prelink-ext)\.o/' $< | $(MODPOST) -T - -$(output-symdump): $(MODORDER) $(input-symdump) FORCE +$(output-symdump): $(MODORDER) $(input-symdump) $(modules:.ko=$(prelink-ext).o) FORCE $(call if_changed,modpost) targets += $(output-symdump) diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh index 6eded325c837..596507573a48 100755 --- a/scripts/link-vmlinux.sh +++ b/scripts/link-vmlinux.sh @@ -56,6 +56,14 @@ modpost_link() ${KBUILD_VMLINUX_LIBS} \ --end-group" + if [ -n "${CONFIG_LTO_CLANG}" ]; then + # This might take a while, so indicate that we're doing + # an LTO link + info LTO ${1} + else + info LD ${1} + fi + ${LD} ${KBUILD_LDFLAGS} -r -o ${1} ${objects} } @@ -103,13 +111,22 @@ vmlinux_link() fi if [ "${SRCARCH}" != "um" ]; then - objects="--whole-archive \ - ${KBUILD_VMLINUX_OBJS} \ - --no-whole-archive \ - --start-group \ - ${KBUILD_VMLINUX_LIBS} \ - --end-group \ - ${@}" + if [ -n "${CONFIG_LTO_CLANG}" ]; then + # Use vmlinux.o instead of performing the slow LTO + # link again. + objects="--whole-archive \ + vmlinux.o \ + --no-whole-archive \ + ${@}" + else + objects="--whole-archive \ + ${KBUILD_VMLINUX_OBJS} \ + --no-whole-archive \ + --start-group \ + ${KBUILD_VMLINUX_LIBS} \ + --end-group \ + ${@}" + fi ${LD} ${KBUILD_LDFLAGS} ${LDFLAGS_vmlinux} \ ${strip_debug#-Wl,} \ @@ -274,7 +291,6 @@ fi; ${MAKE} -f "${srctree}/scripts/Makefile.build" obj=init need-builtin=1 #link vmlinux.o -info LD vmlinux.o modpost_link vmlinux.o objtool_link vmlinux.o From patchwork Tue Dec 1 21:36:54 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sami Tolvanen X-Patchwork-Id: 11943897 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=-26.2 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT,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 037C9C83013 for ; Tue, 1 Dec 2020 21:39:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8E9A32086A for ; Tue, 1 Dec 2020 21:39:02 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="bwNhyVWZ" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728211AbgLAVip (ORCPT ); Tue, 1 Dec 2020 16:38:45 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56370 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727686AbgLAVip (ORCPT ); Tue, 1 Dec 2020 16:38:45 -0500 Received: from mail-qv1-xf4a.google.com (mail-qv1-xf4a.google.com [IPv6:2607:f8b0:4864:20::f4a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3F449C061A4E for ; Tue, 1 Dec 2020 13:37:18 -0800 (PST) Received: by mail-qv1-xf4a.google.com with SMTP id s8so2183965qvr.20 for ; Tue, 01 Dec 2020 13:37:18 -0800 (PST) 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=CpR564RHFHlecC9BI5duKNRiR1OMzoa58D4GbdRgRFs=; b=bwNhyVWZHcRewPVZImRFuSBYqxqAvhv53nzPWJpCvu1j2Ifq/Ju8Unfqbw0XKl+NUR //XUIUuxACwARmVa7xqfgVLeMk6/Xw/Mn1NOey2j6WL6A1E/xUkIC/NL5P42D1qQ7P+E KnnhLk8BcdD3WAFCmYhIMhpJbRekLoOs3ECxDH38LPXgzEoEObVjS+xPBAzgUx9pRELG 2lCrVPMkGgraGqhxeH/UChRjDiDCLIejmiaep/hHlAZhnnPvxCc0brsWDSJLUZhau0CQ ++FjVnfoJVQsJ8sU6/T36c0ng9oPGvsA7lR8Y+mbBo3d6tjxrAO/xKCoCJs3O7XSE8df u28Q== 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=CpR564RHFHlecC9BI5duKNRiR1OMzoa58D4GbdRgRFs=; b=l9A1kF/rSm3s3VuRLtmwXhzw4bNW1XZxYU28GqRFuX23TUeopuSs6cSf4c1TRUrMI7 6301SPjRS3vHX5PrCP4NWnasJYmJtMr2Urmknawl0wkgrYwuS1X+Y39uChe8B/cwkLtG Y64DNzDCIKv+MXQM16hBGpd+oZoColLu7PujnWW83XY+7tnuNOmeyBWH3VjvLWrbDnDE QRwYxL11FQfvRjVlP4HgW7BKnSk0IkDAtu4Z8O+LzZnTZL2TT+d54h6UdzlyT+Mxa6wE iqCnd26oSdCqoI2pG+1ozcRitGKdatuRzXIixecz3u0RoRmF1LpR4XfDdhmDPo8JfYCU +pkg== X-Gm-Message-State: AOAM530MwQdKhRdCl+AiHZBCcCk7UOqxzdrHV1bXb1hK6ggY53ZNX9Mi E5dfx0VWBdcPba//kjwoaXsRgEoOMRh7FyAtwAw= X-Google-Smtp-Source: ABdhPJwpNYQYX/LIdE6XO55t39T0gcTh+jPomewCuzs7fJuBAQB6RoZTwyd4cfZvmBxECv2plo0Gj9TAMQiYfXrZCNQ= Sender: "samitolvanen via sendgmr" X-Received: from samitolvanen1.mtv.corp.google.com ([2620:15c:201:2:f693:9fff:fef4:1b6d]) (user=samitolvanen job=sendgmr) by 2002:a0c:fc52:: with SMTP id w18mr5436400qvp.48.1606858637452; Tue, 01 Dec 2020 13:37:17 -0800 (PST) Date: Tue, 1 Dec 2020 13:36:54 -0800 In-Reply-To: <20201201213707.541432-1-samitolvanen@google.com> Message-Id: <20201201213707.541432-4-samitolvanen@google.com> Mime-Version: 1.0 References: <20201201213707.541432-1-samitolvanen@google.com> X-Mailer: git-send-email 2.29.2.576.ga3fc446d84-goog Subject: [PATCH v8 03/16] kbuild: lto: fix module versioning From: Sami Tolvanen To: Masahiro Yamada , Steven Rostedt , Will Deacon Cc: Josh Poimboeuf , Peter Zijlstra , 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, Sami Tolvanen Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.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 | 23 ++++++++++++++++++++++- 6 files changed, 61 insertions(+), 6 deletions(-) diff --git a/.gitignore b/.gitignore index d01cda8e1177..44e34991875e 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 f5cac2428efc..222ae96d179d 100644 --- a/Makefile +++ b/Makefile @@ -1829,7 +1829,8 @@ 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 30907b554451..c3c13ec9a74c 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -633,7 +633,6 @@ config HAS_LTO_CLANG depends on !FTRACE_MCOUNT_USE_RECORDMCOUNT depends on !KASAN depends on !GCOV_KERNEL - depends on !MODVERSIONS help The compiler and Kconfig options support building with Clang's LTO. diff --git a/scripts/Makefile.build b/scripts/Makefile.build index ed74b2f986f7..eae2f5386a03 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 CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT # compiler will not generate __mcount_loc use recordmcount or recordmcount.pl @@ -390,6 +400,18 @@ $(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) # @@ -397,8 +419,11 @@ $(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 @@ -418,8 +443,11 @@ $(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 @@ -428,6 +456,7 @@ $(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 9ff8bfdb574d..066beffca09a 100644 --- a/scripts/Makefile.modpost +++ b/scripts/Makefile.modpost @@ -111,7 +111,11 @@ 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 596507573a48..78e55fe7210b 100755 --- a/scripts/link-vmlinux.sh +++ b/scripts/link-vmlinux.sh @@ -43,11 +43,26 @@ 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 o in ${KBUILD_VMLINUX_OBJS} ${KBUILD_VMLINUX_LIBS}; do + if [ -f ${o}.symversions ]; then + cat ${o}.symversions >> .tmp_symversions.lds + fi + done +} + # Link of vmlinux.o used for section mismatch analysis # ${1} output file modpost_link() { local objects + local lds="" objects="--whole-archive \ ${KBUILD_VMLINUX_OBJS} \ @@ -57,6 +72,11 @@ modpost_link() --end-group" if [ -n "${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 +84,7 @@ 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 +262,7 @@ 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 From patchwork Tue Dec 1 21:36:55 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sami Tolvanen X-Patchwork-Id: 11943901 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=-26.2 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT,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 EAA62C8301B for ; Tue, 1 Dec 2020 21:39:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A8B002085B for ; Tue, 1 Dec 2020 21:39:04 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="WQCyqpyw" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730188AbgLAViy (ORCPT ); Tue, 1 Dec 2020 16:38:54 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56342 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730057AbgLAViw (ORCPT ); Tue, 1 Dec 2020 16:38:52 -0500 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 B2638C061A55 for ; Tue, 1 Dec 2020 13:37:20 -0800 (PST) Received: by mail-yb1-xb49.google.com with SMTP id a13so4033114ybj.3 for ; Tue, 01 Dec 2020 13:37:20 -0800 (PST) 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=vhe2fhhubG0SMFTgpBNX4/KlbzQ2mtF+9llrSjbBo08=; b=WQCyqpywTb9sjhDQE0uOd7b+9m6ebi816QKf9yVHZCPLWaGBG+ipLHxcUm8kqWX+KJ kfKXPytExTkGVOe4NfXDntXrOaPJsp9DGA/e+Z5eC+AB1fjt5JjOY6moHYKtMdYABXlc pqwT9bceah0mNt1zUgNTQJmG7XZ4Nqu08tOaPOFkTunOluNW1v+MiVxaG85YN4/M5u+k HXPgLPzYDq4JSCLjbyTdrYr0q8bfH/+KpCl0SDkUgF3lejzLr/TISZQcZo011awEDOER hEKx1vs28+FQbBudhpM53qOZF9Lg00bdHxOHtQRU8na1jUSF06Ou0gmHopnqw5/ud94s 4QmQ== 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=vhe2fhhubG0SMFTgpBNX4/KlbzQ2mtF+9llrSjbBo08=; b=nJBKIkV3BPkdVYdijC6LQqPVOAo/+NhpQhukAEBdMp1+UA/Rk2aK6wsxb0ygJgogAx /PQDaX6VmzBXj7fpCBDh4tM05XQcnA78D/6ZraARaYKYlkI2VJ+MBywia8UTjmCsRzuH sEq10M6CX87NFFUsGUEj3k91XkIkz0YQakUR7oSOGG2gpBZOxrwU29KEjlsDcJioyIBr oIEfBFc3kpMbT3MNfKg1ps2n4q3GXBdCXi4ncAxzjsyOabM2wPOKdJOCOalbiZ3pFT+G ydynhD/ONloJRsDIvP0aei8ew9MAhriqOg6fMrlfHoA0tguf3M1pU9pIwwehRBpooR6q duhQ== X-Gm-Message-State: AOAM5320uAmYru3xPmXi0qP2xOOBMxYZ16UabXqOxJBH6H19qzgd3Acj dhtEOh401ZfCJw2lwQY2wOWBx+pSxMe3/fCQKxI= X-Google-Smtp-Source: ABdhPJzj8ZnKlwOa7MfJuQkhiVpth6ScVKMd4AIpnLjVPcTB19+WZbXrany4DQG3oU9eJ5gCXDSYO/sX5i8KB6YTJcA= Sender: "samitolvanen via sendgmr" X-Received: from samitolvanen1.mtv.corp.google.com ([2620:15c:201:2:f693:9fff:fef4:1b6d]) (user=samitolvanen job=sendgmr) by 2002:a25:468a:: with SMTP id t132mr5364497yba.312.1606858639932; Tue, 01 Dec 2020 13:37:19 -0800 (PST) Date: Tue, 1 Dec 2020 13:36:55 -0800 In-Reply-To: <20201201213707.541432-1-samitolvanen@google.com> Message-Id: <20201201213707.541432-5-samitolvanen@google.com> Mime-Version: 1.0 References: <20201201213707.541432-1-samitolvanen@google.com> X-Mailer: git-send-email 2.29.2.576.ga3fc446d84-goog Subject: [PATCH v8 04/16] kbuild: lto: limit inlining From: Sami Tolvanen To: Masahiro Yamada , Steven Rostedt , Will Deacon Cc: Josh Poimboeuf , Peter Zijlstra , 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, Sami Tolvanen Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org This change limits function inlining across translation unit boundaries in order to reduce the binary size with LTO. The -import-instr-limit flag defines a size limit, as the number of LLVM IR instructions, for importing functions from other TUs, defaulting to 100. Based on testing with arm64 defconfig, we found that a limit of 5 is a reasonable compromise between performance and binary size, reducing the size of a stripped vmlinux by 11%. Suggested-by: George Burgess IV Signed-off-by: Sami Tolvanen Reviewed-by: Kees Cook --- Makefile | 3 +++ 1 file changed, 3 insertions(+) diff --git a/Makefile b/Makefile index 222ae96d179d..ac836907d8b1 100644 --- a/Makefile +++ b/Makefile @@ -899,6 +899,9 @@ else CC_FLAGS_LTO += -flto endif CC_FLAGS_LTO += -fvisibility=default + +# Limit inlining across translation units to reduce binary size +KBUILD_LDFLAGS += -mllvm -import-instr-limit=5 endif ifdef CONFIG_LTO From patchwork Tue Dec 1 21:36:56 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sami Tolvanen X-Patchwork-Id: 11943899 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=-26.2 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT,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 D2C75C8301C for ; Tue, 1 Dec 2020 21:39:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6B25F20870 for ; Tue, 1 Dec 2020 21:39:04 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="YDu+NEbK" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729910AbgLAVix (ORCPT ); Tue, 1 Dec 2020 16:38:53 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56344 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730188AbgLAViw (ORCPT ); Tue, 1 Dec 2020 16:38:52 -0500 Received: from mail-qk1-x749.google.com (mail-qk1-x749.google.com [IPv6:2607:f8b0:4864:20::749]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4BA48C08C5F2 for ; Tue, 1 Dec 2020 13:37:23 -0800 (PST) Received: by mail-qk1-x749.google.com with SMTP id r124so2464086qkd.8 for ; Tue, 01 Dec 2020 13:37:23 -0800 (PST) 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=IWPxRCPjFejanLxpgRG3fapg45p9YOPZWT66lZNPqfI=; b=YDu+NEbK+WVQ3hPM5go5aRizvBPWGGUzdvz8JEp/EAM6XiJoc9pJY3o1c2yVOjp89i bM5tOhFBbqEU2HQ2OR1Oz9/GYaHkOiYtWb5Q/Up3jv4DGF65KdvTcqz6rms02w5eohLl bSgLnGHcyC3YR0xGck//SCcspRfKindzzlyNPE4Y9xXTCXxQ4vUqhJqdcirb9QLh5+ns ApAi4cfhdsSK/ZIzIp7xZ4Eh09o6zM62jKDTDmzug7/qSo6JjgobotZDPriqLtM88GHc /m6WRULzENBGmq+MzEixv/Y7a6Pjdo782dcWw/2FdAhHAKNAMhOCFWjGtsnxviZBNnlf h74g== 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=IWPxRCPjFejanLxpgRG3fapg45p9YOPZWT66lZNPqfI=; b=G78/vQ2+rLuGtX7PKmoN9TvGFe0JHsFzVAYXCaHn2jBvdD9IqnSy5LPcfdMQrwqhDN CNQ89Iq/eGi3JJwioIaHOaQpg74gFYw+RkglVoCrEmbmUPg3Ab9+/3T/lE1jb3777neZ wxOjvYYPMt8QADQhyuhDh9WKxlflWtZyqFyzWa+qNY6wEmKDmMVimYAysAZgcC8BmG6o 098qpPfyrRk9QM0smfGNjjkj5FBtHjvQyVfox+Ju8H25OuBvErlYqH2l5Zz5rIygfKpV X9MpYOQVfjpo1XWsPYSQmMYtcROyWimwXm1PvD0qMU4kilW8fJLPYV05AMbJMb1x/nR7 r9Mg== X-Gm-Message-State: AOAM533/wzidK4btk2TkiK0pQo9dJpAmZR8NZg4K6WPTSep1jcyJXHnE nz1J/RUFVhI3PSSHvj+dRLVWKronkOpxBIwEj44= X-Google-Smtp-Source: ABdhPJzl3kQyAlKR1pr/4OX/xbphbD6nNLxnI7REpTqaNoxBrsxlLak2ddu4/JEFd5wju+8eNvtcAAOR8w+vlfUWVUM= Sender: "samitolvanen via sendgmr" X-Received: from samitolvanen1.mtv.corp.google.com ([2620:15c:201:2:f693:9fff:fef4:1b6d]) (user=samitolvanen job=sendgmr) by 2002:a0c:b508:: with SMTP id d8mr5050639qve.8.1606858642454; Tue, 01 Dec 2020 13:37:22 -0800 (PST) Date: Tue, 1 Dec 2020 13:36:56 -0800 In-Reply-To: <20201201213707.541432-1-samitolvanen@google.com> Message-Id: <20201201213707.541432-6-samitolvanen@google.com> Mime-Version: 1.0 References: <20201201213707.541432-1-samitolvanen@google.com> X-Mailer: git-send-email 2.29.2.576.ga3fc446d84-goog Subject: [PATCH v8 05/16] kbuild: lto: merge module sections From: Sami Tolvanen To: Masahiro Yamada , Steven Rostedt , Will Deacon Cc: Josh Poimboeuf , Peter Zijlstra , 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, Sami Tolvanen Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org LLD always splits sections with LTO, which increases module sizes. This change adds linker script rules to merge the split sections in the final module. Suggested-by: Nick Desaulniers Signed-off-by: Sami Tolvanen Reviewed-by: Kees Cook --- scripts/module.lds.S | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+) diff --git a/scripts/module.lds.S b/scripts/module.lds.S index 69b9b71a6a47..18d5b8423635 100644 --- a/scripts/module.lds.S +++ b/scripts/module.lds.S @@ -23,6 +23,30 @@ SECTIONS { .init_array 0 : ALIGN(8) { *(SORT(.init_array.*)) *(.init_array) } __jump_table 0 : ALIGN(8) { KEEP(*(__jump_table)) } + + __patchable_function_entries : { *(__patchable_function_entries) } + + /* + * With CONFIG_LTO_CLANG, LLD always enables -fdata-sections and + * -ffunction-sections, which increases the size of the final module. + * Merge the split sections in the final binary. + */ + .bss : { + *(.bss .bss.[0-9a-zA-Z_]*) + *(.bss..L*) + } + + .data : { + *(.data .data.[0-9a-zA-Z_]*) + *(.data..L*) + } + + .rodata : { + *(.rodata .rodata.[0-9a-zA-Z_]*) + *(.rodata..L*) + } + + .text : { *(.text .text.[0-9a-zA-Z_]*) } } /* bring in arch-specific sections */ From patchwork Tue Dec 1 21:36:57 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sami Tolvanen X-Patchwork-Id: 11943915 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=-26.2 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT,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 C25E6C64E7B for ; Tue, 1 Dec 2020 21:39:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6162E2086A for ; Tue, 1 Dec 2020 21:39:38 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="cTOyof8D" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389518AbgLAVjP (ORCPT ); Tue, 1 Dec 2020 16:39:15 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56466 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388640AbgLAVjM (ORCPT ); Tue, 1 Dec 2020 16:39:12 -0500 Received: from mail-qt1-x849.google.com (mail-qt1-x849.google.com [IPv6:2607:f8b0:4864:20::849]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9D170C08E862 for ; Tue, 1 Dec 2020 13:37:25 -0800 (PST) Received: by mail-qt1-x849.google.com with SMTP id z8so2273792qti.17 for ; Tue, 01 Dec 2020 13:37:25 -0800 (PST) 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=Ioq5snZDZDriQbZnteUYOvtfB50kdQ3NzmE0Bt/uZj4=; b=cTOyof8D27Eb15ctHFkguMw8fQJTDxevhAv86xzy/JyHIKohwC9kcPozSDGX4ZvhjH hv1rR4G53Z3ln+Cmqb9RjUK77Rma8WI1knxtAcMzXLo7jpqZX03s3IjAuAKcPGe698IA tqCRwqNReUE6+2DHbVXsqGEAH3DKihfcNiemIM2g7zH4vjz4yRgdtjEGOxPucEoKGI7o TP0NKml15Zj0kVGxkNppCMBBYfw5RCgEPqWu/IFdSOVZwRHRqv5Cob9LcnhewWjKXfLJ uxIRAby/D2ArEQUd3zLg1F9Be0crsc+S/9EwAcR/g6vVudxNV4zhBdGhHukse6etLm6r ljAg== 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=Ioq5snZDZDriQbZnteUYOvtfB50kdQ3NzmE0Bt/uZj4=; b=YL6AaadIaN6T4OwELEdA3e0wy4IryJ+dXJOG6NEJJc9RF/Rperf3xxbpsisDtSfxIJ UGJpgEOxvYA8mTio2izwvO5KUfg8b9j6Z8PZcEHXttTUoJIPVCoX29+7CygVU/FlaVic s7QoMYKC+MHfaGt/6E2Bu6ndS6Uf/RP9ox8gkmya3Nro6sewj0++2Xi8k6OHLTtiEGT0 JiLJ/OA4xdiDE8+BonbkDr7MzXtdS2xv93eGvaghEOSt9rFAiFPsI8T/iDqOrUHBm9dZ oHo7Z5K6Q7YJeRTIBzNQj0QLmU4NQxA4JHGctvXk+JHEFtcaWx+2IULt+DIalhXm+7nB PELA== X-Gm-Message-State: AOAM533BjErwL/EbBUiUEtb4mAPenA0s89D6eNR3eW9pPGHsBNyUV2YP ky9W+VzxF+RWTnf2vGlkfkjyM78Pcb2yCLjAplo= X-Google-Smtp-Source: ABdhPJys1KC5O8D1Yq/SB6UjKKBqwmwFlcdQVBXthpLtwbdm6607CxLE6p9eN4XkDXwUu6B0iPn5A0SVU7zu7mNfSPU= Sender: "samitolvanen via sendgmr" X-Received: from samitolvanen1.mtv.corp.google.com ([2620:15c:201:2:f693:9fff:fef4:1b6d]) (user=samitolvanen job=sendgmr) by 2002:ad4:4051:: with SMTP id r17mr5301753qvp.39.1606858644813; Tue, 01 Dec 2020 13:37:24 -0800 (PST) Date: Tue, 1 Dec 2020 13:36:57 -0800 In-Reply-To: <20201201213707.541432-1-samitolvanen@google.com> Message-Id: <20201201213707.541432-7-samitolvanen@google.com> Mime-Version: 1.0 References: <20201201213707.541432-1-samitolvanen@google.com> X-Mailer: git-send-email 2.29.2.576.ga3fc446d84-goog Subject: [PATCH v8 06/16] kbuild: lto: remove duplicate dependencies from .mod files From: Sami Tolvanen To: Masahiro Yamada , Steven Rostedt , Will Deacon Cc: Josh Poimboeuf , Peter Zijlstra , 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, Sami Tolvanen Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org With LTO, llvm-nm prints out symbols for each archive member separately, which results in a lot of duplicate dependencies in the .mod file when CONFIG_TRIM_UNUSED_SYMS is enabled. When a module consists of several compilation units, the output can exceed the default xargs command size limit and split the dependency list to multiple lines, which results in used symbols getting trimmed. This change removes duplicate dependencies, which will reduce the probability of this happening and makes .mod files smaller and easier to read. Signed-off-by: Sami Tolvanen Reviewed-by: Kees Cook --- scripts/Makefile.build | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/scripts/Makefile.build b/scripts/Makefile.build index eae2f5386a03..f80ada58271d 100644 --- a/scripts/Makefile.build +++ b/scripts/Makefile.build @@ -281,7 +281,7 @@ endef # List module undefined symbols (or empty line if not enabled) ifdef CONFIG_TRIM_UNUSED_KSYMS -cmd_undef_syms = $(NM) $< | sed -n 's/^ *U //p' | xargs echo +cmd_undef_syms = $(NM) $< | sed -n 's/^ *U //p' | sort -u | xargs echo else cmd_undef_syms = echo endif From patchwork Tue Dec 1 21:36:58 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sami Tolvanen X-Patchwork-Id: 11943903 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=-26.2 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT,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 16CACC71155 for ; Tue, 1 Dec 2020 21:39:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9CE502085B for ; Tue, 1 Dec 2020 21:39:35 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="mOfnYdsl" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730351AbgLAVjH (ORCPT ); Tue, 1 Dec 2020 16:39:07 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56372 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730057AbgLAVjG (ORCPT ); Tue, 1 Dec 2020 16:39:06 -0500 Received: from mail-pj1-x1049.google.com (mail-pj1-x1049.google.com [IPv6:2607:f8b0:4864:20::1049]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 20C4DC094240 for ; Tue, 1 Dec 2020 13:37:28 -0800 (PST) Received: by mail-pj1-x1049.google.com with SMTP id p20so2032687pjz.0 for ; Tue, 01 Dec 2020 13:37:28 -0800 (PST) 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=DEh4YQa+R45/8JIheIwP7TMswwLQCrcoONiWpbyz8co=; b=mOfnYdslAVcd7xutJY5iEUKK7XbAN+Puk7RudDJj7Ssj3KWYsxONW5H09eqNi1FwdB dCuFFAHtUyQcGjTiFUY0appl3Z6ucroSNL6A8xXblmYWsgVzF7Bml8+Ux1F3S5Tb0aqq viscgH8O/t1E7J0iilnPqJKCzWP2UkVWn0u6gndoeh4YLEfCpZxUeZs7L0nmuf9GLWf1 qiejfaSl5vZDT9vau+qUVmhFrrEoEbo48FYbwVmKg24gLlEoj/AJJvi3RFVm/joWkYit uTS8mWiqXU1qEPX63UDkKsKviYWlQnIoi7GuTUy/+P/A6kLQywZ/HXvDLO7uBb/5bcPU lTag== 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=DEh4YQa+R45/8JIheIwP7TMswwLQCrcoONiWpbyz8co=; b=rN9+CSQFDr7ghghwTTtwQcA3hMVBtUSF+/A4aEI+2svXBTjI15XaohV3KNi5uXdbJX Vy88Olx+Xp17VRVrlkrK7EtO03rYra7wGqi8lpcXzFOgcyLXoXQhTZ2kLJ1EvdXsExjH GBQ2qphMW+G1HcfLu8lqtfyWQR5IiSrqBeIU1aWmnptDX17tRYReCcfu3A8rZ+FHvX6z eW1W4/VsANans75knuJZwD9XCrQs6xYHL6HIKAjW7RYP7jkcfsstHHEFJtztbXJ7cpHQ sX74Zk7wIBGBJEQZ3wZg+2bhYMt2jIXMP9c0vg1LA+jXZMuCZmzYiUz0ygUUuX7lGlOP n4xg== X-Gm-Message-State: AOAM533btFmlTRH+B5p9wsOUFpI9FZIu/D8BI+i8X0uDjlo0ZeVZG1kB or2RBOFV8ubxdTe4BkAfScccNTdFo6OWlvolyfY= X-Google-Smtp-Source: ABdhPJzff702JmC+Tq5OOVFcd0YmjbkQ4KOjYdzJnVO630bJQnTo+JI0+yXZItMQN2WYkRqSIUzjFyUXV/Mw1Klj3t4= Sender: "samitolvanen via sendgmr" X-Received: from samitolvanen1.mtv.corp.google.com ([2620:15c:201:2:f693:9fff:fef4:1b6d]) (user=samitolvanen job=sendgmr) by 2002:a62:e901:0:b029:197:ca81:4bb9 with SMTP id j1-20020a62e9010000b0290197ca814bb9mr4566889pfh.26.1606858647381; Tue, 01 Dec 2020 13:37:27 -0800 (PST) Date: Tue, 1 Dec 2020 13:36:58 -0800 In-Reply-To: <20201201213707.541432-1-samitolvanen@google.com> Message-Id: <20201201213707.541432-8-samitolvanen@google.com> Mime-Version: 1.0 References: <20201201213707.541432-1-samitolvanen@google.com> X-Mailer: git-send-email 2.29.2.576.ga3fc446d84-goog Subject: [PATCH v8 07/16] init: lto: ensure initcall ordering From: Sami Tolvanen To: Masahiro Yamada , Steven Rostedt , Will Deacon Cc: Josh Poimboeuf , Peter Zijlstra , 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, Sami Tolvanen Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org With LTO, the compiler doesn't necessarily obey the link order for initcalls, and initcall variables need globally unique names to avoid collisions at link time. This change exports __KBUILD_MODNAME and adds the initcall_id() macro, which uses it together with __COUNTER__ and __LINE__ to help ensure these variables have unique names, and moves each variable to its own section when LTO is enabled, so the correct order can be specified using a linker script. The generate_initcall_ordering.pl script uses nm to find initcalls from the object files passed to the linker, and generates a linker script that specifies the same order for initcalls that we would have without LTO. With LTO enabled, the script is called in link-vmlinux.sh through jobserver-exec to limit the number of jobs spawned. Signed-off-by: Sami Tolvanen Reviewed-by: Kees Cook --- include/linux/init.h | 52 +++++- scripts/Makefile.lib | 6 +- scripts/generate_initcall_order.pl | 270 +++++++++++++++++++++++++++++ scripts/link-vmlinux.sh | 15 ++ 4 files changed, 334 insertions(+), 9 deletions(-) create mode 100755 scripts/generate_initcall_order.pl diff --git a/include/linux/init.h b/include/linux/init.h index 7b53cb3092ee..d466bea7ecba 100644 --- a/include/linux/init.h +++ b/include/linux/init.h @@ -184,19 +184,57 @@ extern bool initcall_debug; * as KEEP() in the linker script. */ +/* Format: ____ */ +#define __initcall_id(fn) \ + __PASTE(__KBUILD_MODNAME, \ + __PASTE(__, \ + __PASTE(__COUNTER__, \ + __PASTE(_, \ + __PASTE(__LINE__, \ + __PASTE(_, fn)))))) + +/* Format: ____ */ +#define __initcall_name(prefix, __iid, id) \ + __PASTE(__, \ + __PASTE(prefix, \ + __PASTE(__, \ + __PASTE(__iid, id)))) + +#ifdef CONFIG_LTO_CLANG +/* + * With LTO, the compiler doesn't necessarily obey link order for + * initcalls. In order to preserve the correct order, we add each + * variable into its own section and generate a linker script (in + * scripts/link-vmlinux.sh) to specify the order of the sections. + */ +#define __initcall_section(__sec, __iid) \ + #__sec ".init.." #__iid +#else +#define __initcall_section(__sec, __iid) \ + #__sec ".init" +#endif + #ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS -#define ___define_initcall(fn, id, __sec) \ +#define ____define_initcall(fn, __name, __sec) \ __ADDRESSABLE(fn) \ - asm(".section \"" #__sec ".init\", \"a\" \n" \ - "__initcall_" #fn #id ": \n" \ + asm(".section \"" __sec "\", \"a\" \n" \ + __stringify(__name) ": \n" \ ".long " #fn " - . \n" \ ".previous \n"); #else -#define ___define_initcall(fn, id, __sec) \ - static initcall_t __initcall_##fn##id __used \ - __attribute__((__section__(#__sec ".init"))) = fn; +#define ____define_initcall(fn, __name, __sec) \ + static initcall_t __name __used \ + __attribute__((__section__(__sec))) = fn; #endif +#define __unique_initcall(fn, id, __sec, __iid) \ + ____define_initcall(fn, \ + __initcall_name(initcall, __iid, id), \ + __initcall_section(__sec, __iid)) + +#define ___define_initcall(fn, id, __sec) \ + __unique_initcall(fn, id, __sec, __initcall_id(fn)) + #define __define_initcall(fn, id) ___define_initcall(fn, id, .initcall##id) /* @@ -236,7 +274,7 @@ extern bool initcall_debug; #define __exitcall(fn) \ static exitcall_t __exitcall_##fn __exit_call = fn -#define console_initcall(fn) ___define_initcall(fn,, .con_initcall) +#define console_initcall(fn) ___define_initcall(fn, con, .con_initcall) struct obs_kernel_param { const char *str; diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib index 94133708889d..53aa3e18ce8a 100644 --- a/scripts/Makefile.lib +++ b/scripts/Makefile.lib @@ -117,9 +117,11 @@ target-stem = $(basename $(patsubst $(obj)/%,%,$@)) # These flags are needed for modversions and compiling, so we define them here # $(modname_flags) defines KBUILD_MODNAME as the name of the module it will # end up in (or would, if it gets compiled in) -name-fix = $(call stringify,$(subst $(comma),_,$(subst -,_,$1))) +name-fix-token = $(subst $(comma),_,$(subst -,_,$1)) +name-fix = $(call stringify,$(call name-fix-token,$1)) basename_flags = -DKBUILD_BASENAME=$(call name-fix,$(basetarget)) -modname_flags = -DKBUILD_MODNAME=$(call name-fix,$(modname)) +modname_flags = -DKBUILD_MODNAME=$(call name-fix,$(modname)) \ + -D__KBUILD_MODNAME=kmod_$(call name-fix-token,$(modname)) modfile_flags = -DKBUILD_MODFILE=$(call stringify,$(modfile)) _c_flags = $(filter-out $(CFLAGS_REMOVE_$(target-stem).o), \ diff --git a/scripts/generate_initcall_order.pl b/scripts/generate_initcall_order.pl new file mode 100755 index 000000000000..1a88d3f1b913 --- /dev/null +++ b/scripts/generate_initcall_order.pl @@ -0,0 +1,270 @@ +#!/usr/bin/env perl +# SPDX-License-Identifier: GPL-2.0 +# +# Generates a linker script that specifies the correct initcall order. +# +# Copyright (C) 2019 Google LLC + +use strict; +use warnings; +use IO::Handle; +use IO::Select; +use POSIX ":sys_wait_h"; + +my $nm = $ENV{'NM'} || die "$0: ERROR: NM not set?"; +my $objtree = $ENV{'objtree'} || '.'; + +## currently active child processes +my $jobs = {}; # child process pid -> file handle +## results from child processes +my $results = {}; # object index -> [ { level, secname }, ... ] + +## reads _NPROCESSORS_ONLN to determine the maximum number of processes to +## start +sub get_online_processors { + open(my $fh, "getconf _NPROCESSORS_ONLN 2>/dev/null |") + or die "$0: ERROR: failed to execute getconf: $!"; + my $procs = <$fh>; + close($fh); + + if (!($procs =~ /^\d+$/)) { + return 1; + } + + return int($procs); +} + +## writes results to the parent process +## format: +sub write_results { + my ($index, $initcalls) = @_; + + # sort by the counter value to ensure the order of initcalls within + # each object file is correct + foreach my $counter (sort { $a <=> $b } keys(%{$initcalls})) { + my $level = $initcalls->{$counter}->{'level'}; + + # section name for the initcall function + my $secname = $initcalls->{$counter}->{'module'} . '__' . + $counter . '_' . + $initcalls->{$counter}->{'line'} . '_' . + $initcalls->{$counter}->{'function'}; + + print "$index $level $secname\n"; + } +} + +## reads a result line from a child process and adds it to the $results array +sub read_results{ + my ($fh) = @_; + + # each child prints out a full line w/ autoflush and exits after the + # last line, so even if buffered I/O blocks here, it shouldn't block + # very long + my $data = <$fh>; + + if (!defined($data)) { + return 0; + } + + chomp($data); + + my ($index, $level, $secname) = $data =~ + /^(\d+)\ ([^\ ]+)\ (.*)$/; + + if (!defined($index) || + !defined($level) || + !defined($secname)) { + die "$0: ERROR: child process returned invalid data: $data\n"; + } + + $index = int($index); + + if (!exists($results->{$index})) { + $results->{$index} = []; + } + + push (@{$results->{$index}}, { + 'level' => $level, + 'secname' => $secname + }); + + return 1; +} + +## finds initcalls from an object file or all object files in an archive, and +## writes results back to the parent process +sub find_initcalls { + my ($index, $file) = @_; + + die "$0: ERROR: file $file doesn't exist?" if (! -f $file); + + open(my $fh, "\"$nm\" --defined-only \"$file\" 2>/dev/null |") + or die "$0: ERROR: failed to execute \"$nm\": $!"; + + my $initcalls = {}; + + while (<$fh>) { + chomp; + + # check for the start of a new object file (if processing an + # archive) + my ($path)= $_ =~ /^(.+)\:$/; + + if (defined($path)) { + write_results($index, $initcalls); + $initcalls = {}; + next; + } + + # look for an initcall + my ($module, $counter, $line, $symbol) = $_ =~ + /[a-z]\s+__initcall__(\S*)__(\d+)_(\d+)_(.*)$/; + + if (!defined($module)) { + $module = '' + } + + if (!defined($counter) || + !defined($line) || + !defined($symbol)) { + next; + } + + # parse initcall level + my ($function, $level) = $symbol =~ + /^(.*)((early|rootfs|con|[0-9])s?)$/; + + die "$0: ERROR: invalid initcall name $symbol in $file($path)" + if (!defined($function) || !defined($level)); + + $initcalls->{$counter} = { + 'module' => $module, + 'line' => $line, + 'function' => $function, + 'level' => $level, + }; + } + + close($fh); + write_results($index, $initcalls); +} + +## waits for any child process to complete, reads the results, and adds them to +## the $results array for later processing +sub wait_for_results { + my ($select) = @_; + + my $pid = 0; + do { + # unblock children that may have a full write buffer + foreach my $fh ($select->can_read(0)) { + read_results($fh); + } + + # check for children that have exited, read the remaining data + # from them, and clean up + $pid = waitpid(-1, WNOHANG); + if ($pid > 0) { + if (!exists($jobs->{$pid})) { + next; + } + + my $fh = $jobs->{$pid}; + $select->remove($fh); + + while (read_results($fh)) { + # until eof + } + + close($fh); + delete($jobs->{$pid}); + } + } while ($pid > 0); +} + +## forks a child to process each file passed in the command line and collects +## the results +sub process_files { + my $index = 0; + my $njobs = $ENV{'PARALLELISM'} || get_online_processors(); + my $select = IO::Select->new(); + + while (my $file = shift(@ARGV)) { + # fork a child process and read it's stdout + my $pid = open(my $fh, '-|'); + + if (!defined($pid)) { + die "$0: ERROR: failed to fork: $!"; + } elsif ($pid) { + # save the child process pid and the file handle + $select->add($fh); + $jobs->{$pid} = $fh; + } else { + # in the child process + STDOUT->autoflush(1); + find_initcalls($index, "$objtree/$file"); + exit; + } + + $index++; + + # limit the number of children to $njobs + if (scalar(keys(%{$jobs})) >= $njobs) { + wait_for_results($select); + } + } + + # wait for the remaining children to complete + while (scalar(keys(%{$jobs})) > 0) { + wait_for_results($select); + } +} + +sub generate_initcall_lds() { + process_files(); + + my $sections = {}; # level -> [ secname, ...] + + # sort results to retain link order and split to sections per + # initcall level + foreach my $index (sort { $a <=> $b } keys(%{$results})) { + foreach my $result (@{$results->{$index}}) { + my $level = $result->{'level'}; + + if (!exists($sections->{$level})) { + $sections->{$level} = []; + } + + push(@{$sections->{$level}}, $result->{'secname'}); + } + } + + die "$0: ERROR: no initcalls?" if (!keys(%{$sections})); + + # print out a linker script that defines the order of initcalls for + # each level + print "SECTIONS {\n"; + + foreach my $level (sort(keys(%{$sections}))) { + my $section; + + if ($level eq 'con') { + $section = '.con_initcall.init'; + } else { + $section = ".initcall${level}.init"; + } + + print "\t${section} : {\n"; + + foreach my $secname (@{$sections->{$level}}) { + print "\t\t*(${section}..${secname}) ;\n"; + } + + print "\t}\n"; + } + + print "}\n"; +} + +generate_initcall_lds(); diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh index 78e55fe7210b..c5919d5a0b4f 100755 --- a/scripts/link-vmlinux.sh +++ b/scripts/link-vmlinux.sh @@ -43,6 +43,17 @@ info() fi } +# Generate a linker script to ensure correct ordering of initcalls. +gen_initcalls() +{ + info GEN .tmp_initcalls.lds + + ${PYTHON} ${srctree}/scripts/jobserver-exec \ + ${PERL} ${srctree}/scripts/generate_initcall_order.pl \ + ${KBUILD_VMLINUX_OBJS} ${KBUILD_VMLINUX_LIBS} \ + > .tmp_initcalls.lds +} + # If CONFIG_LTO_CLANG is selected, collect generated symbol versions into # .tmp_symversions.lds gen_symversions() @@ -72,6 +83,9 @@ modpost_link() --end-group" if [ -n "${CONFIG_LTO_CLANG}" ]; then + gen_initcalls + lds="-T .tmp_initcalls.lds" + if [ -n "${CONFIG_MODVERSIONS}" ]; then gen_symversions lds="${lds} -T .tmp_symversions.lds" @@ -262,6 +276,7 @@ cleanup() { rm -f .btf.* rm -f .tmp_System.map + rm -f .tmp_initcalls.lds rm -f .tmp_symversions.lds rm -f .tmp_vmlinux* rm -f System.map From patchwork Tue Dec 1 21:36:59 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sami Tolvanen X-Patchwork-Id: 11943911 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=-26.2 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT,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 46C3DC8302C for ; Tue, 1 Dec 2020 21:39:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D7F042086A for ; Tue, 1 Dec 2020 21:39:45 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="ZHmcfGNp" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390171AbgLAVjg (ORCPT ); Tue, 1 Dec 2020 16:39:36 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56508 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389969AbgLAVjb (ORCPT ); Tue, 1 Dec 2020 16:39:31 -0500 Received: from mail-yb1-xb4a.google.com (mail-yb1-xb4a.google.com [IPv6:2607:f8b0:4864:20::b4a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C960EC094243 for ; Tue, 1 Dec 2020 13:37:30 -0800 (PST) Received: by mail-yb1-xb4a.google.com with SMTP id v12so4058693ybi.6 for ; Tue, 01 Dec 2020 13:37:30 -0800 (PST) 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=9TLfWaf58UYL7wICLMCVVnhaOCpYf+H5DpQSRdiy6Cc=; b=ZHmcfGNpa7ZNviH3Lhbi7/0SDEQ3Jls1Fd4loR1GsDVBD7tyPoyw8FMMexSiO0w9DW 9RjrozMTcLSgrBxEv1Vz8SoUuZs1OCJb++caQa3OdSsaiYW67cFBU7PQ9LNeGNpQOT/K 9NZ2TIpPQb7/71Uv+3b78ioZtiLnITOk2KjhIvpWKQSdMkCVpud7TsnvOO4ORqlpu2u5 nOj1pZxLhS/1QmdqjetYddIidvonWTCSBDRIzR5umGDHjrntwGXK/yd6oSDTP2uLIXdB crW36MjeZXAzVs/1lqNDI0q9ni6fGs696oymio04cAycbm2CdWTbsus3NowlMPBHIFwm bePw== 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=9TLfWaf58UYL7wICLMCVVnhaOCpYf+H5DpQSRdiy6Cc=; b=Vom2i0DNPa6+MPRiIwuO3EAnKEQcoQAoPuBOb6evEnaBuMeUy8CjVnsCniJhtyUyKD LqSQbwocnKQeuewjFnqCTUukNl9gr3mmFs9SbxF3ZClSx/HJ2RmVFFoxNLHuMGWOq2K7 fSOuo8xRVRePBXlmkm81xhywj7GdClD7H2VrQlbq/k0ysx4qfktFlw6L39rixieaQyo6 yASox+2B6eIadDle4w3+uBH+LCIiWIBFEKRGqGzMtodqQvVaAdpBx8GCd9oXW+/tEZlI OzBHQO66rOiZ1tppKgYkaMdkrp/EA36ZlHDoLwNl94ENn+XBWjmJbf6Xg/f4a00GvTid 269g== X-Gm-Message-State: AOAM532L2QTYMqF5LyQP62Fdmd22zTRg84IPf6GoGGyRmSXyMttmiScL b0BCZjLvqdwol9uSJqNNBAJN0MsuL9IUzku2nGo= X-Google-Smtp-Source: ABdhPJznzlwtgR/lC41/SY0FFtURTSnCC2xOHrCPe7akB5kk2L1nv9Me4GAJGApMzwCD081JTdMBkBEIq4IXR3L5M2Q= Sender: "samitolvanen via sendgmr" X-Received: from samitolvanen1.mtv.corp.google.com ([2620:15c:201:2:f693:9fff:fef4:1b6d]) (user=samitolvanen job=sendgmr) by 2002:a25:cf0a:: with SMTP id f10mr7383764ybg.353.1606858650073; Tue, 01 Dec 2020 13:37:30 -0800 (PST) Date: Tue, 1 Dec 2020 13:36:59 -0800 In-Reply-To: <20201201213707.541432-1-samitolvanen@google.com> Message-Id: <20201201213707.541432-9-samitolvanen@google.com> Mime-Version: 1.0 References: <20201201213707.541432-1-samitolvanen@google.com> X-Mailer: git-send-email 2.29.2.576.ga3fc446d84-goog Subject: [PATCH v8 08/16] init: lto: fix PREL32 relocations From: Sami Tolvanen To: Masahiro Yamada , Steven Rostedt , Will Deacon Cc: Josh Poimboeuf , Peter Zijlstra , 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, Sami Tolvanen Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org With LTO, the compiler can rename static functions to avoid global naming collisions. As initcall functions are typically static, renaming can break references to them in inline assembly. This change adds a global stub with a stable name for each initcall to fix the issue when PREL32 relocations are used. Signed-off-by: Sami Tolvanen Reviewed-by: Kees Cook --- include/linux/init.h | 31 +++++++++++++++++++++++++++---- 1 file changed, 27 insertions(+), 4 deletions(-) diff --git a/include/linux/init.h b/include/linux/init.h index d466bea7ecba..27b9478dcdef 100644 --- a/include/linux/init.h +++ b/include/linux/init.h @@ -209,26 +209,49 @@ extern bool initcall_debug; */ #define __initcall_section(__sec, __iid) \ #__sec ".init.." #__iid + +/* + * With LTO, the compiler can rename static functions to avoid + * global naming collisions. We use a global stub function for + * initcalls to create a stable symbol name whose address can be + * taken in inline assembly when PREL32 relocations are used. + */ +#define __initcall_stub(fn, __iid, id) \ + __initcall_name(initstub, __iid, id) + +#define __define_initcall_stub(__stub, fn) \ + int __init __stub(void); \ + int __init __stub(void) \ + { \ + return fn(); \ + } \ + __ADDRESSABLE(__stub) #else #define __initcall_section(__sec, __iid) \ #__sec ".init" + +#define __initcall_stub(fn, __iid, id) fn + +#define __define_initcall_stub(__stub, fn) \ + __ADDRESSABLE(fn) #endif #ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS -#define ____define_initcall(fn, __name, __sec) \ - __ADDRESSABLE(fn) \ +#define ____define_initcall(fn, __stub, __name, __sec) \ + __define_initcall_stub(__stub, fn) \ asm(".section \"" __sec "\", \"a\" \n" \ __stringify(__name) ": \n" \ - ".long " #fn " - . \n" \ + ".long " __stringify(__stub) " - . \n" \ ".previous \n"); #else -#define ____define_initcall(fn, __name, __sec) \ +#define ____define_initcall(fn, __unused, __name, __sec) \ static initcall_t __name __used \ __attribute__((__section__(__sec))) = fn; #endif #define __unique_initcall(fn, id, __sec, __iid) \ ____define_initcall(fn, \ + __initcall_stub(fn, __iid, id), \ __initcall_name(initcall, __iid, id), \ __initcall_section(__sec, __iid)) From patchwork Tue Dec 1 21:37:00 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sami Tolvanen X-Patchwork-Id: 11943905 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=-26.2 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT,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 961F1C71156 for ; Tue, 1 Dec 2020 21:39:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E9E8820C56 for ; Tue, 1 Dec 2020 21:39:35 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="gzp1vYR/" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729493AbgLAVjI (ORCPT ); Tue, 1 Dec 2020 16:39:08 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56336 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730057AbgLAVjH (ORCPT ); Tue, 1 Dec 2020 16:39:07 -0500 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 66C24C09424D for ; Tue, 1 Dec 2020 13:37:33 -0800 (PST) Received: by mail-yb1-xb49.google.com with SMTP id v12so4058792ybi.6 for ; Tue, 01 Dec 2020 13:37:33 -0800 (PST) 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=B5HJdqCXUeL43UIVLVZJnxtwrYZ/thw26FrV4EWKXXk=; b=gzp1vYR/oXkNJrTfyPC+gU9AshMDJf17d4hXlEixyq63WSCsKKx3kDXJjLE3705Nyq Fo5ieQYTx2JVLwmaGskMvm1+jyZULJ03SfEv9yykRb2g73uRagV1yTPJy+ahrYRV99Qs VfiuyAzo5OTZaK2vNHAaDjnnZkvg7bkbVueCSfy5zymqb9Zl9C2ZImkyynaqirPNK6ba e2o6MqYUTsj7xpc/+jQAgUOMDI+fKOFd22bNsjjuBqWiITez5IABxAqzwCC3dIQDnjj5 6X3ijsy0/J/N0HG3BH/CFt5ycSFf4nlbPH4Q6tCHT2m9Fj3AbeddPFsPWCTDAPwl02q1 wRIQ== 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=B5HJdqCXUeL43UIVLVZJnxtwrYZ/thw26FrV4EWKXXk=; b=psqkNJ0oakuYjXWWwSzzWSeUW/4m3Dz2RkOxn9Km77ktynrQEo2uNWiS56HRYizFsZ Khcpu6mVdzulf/GnjhctYYfS40PEinID0e0z6coxSiVGuHjAeGTKhcIzujQn/40kPgE4 YSt4KPZUBUpBh0q2kjR0qn8fNn0MqtLaUiRLO1fdOrd0z2+oHNZ31lzPfyVaTQ0NIpq6 1pgvV0lBYt3w9NIvP2lLXTr+558b0jyCls61tGRid1hUvehuaBNVTCPT1LRAkoZQHPMF F5SY+bgKF7RV0+5P6XsHYoykJdihG4NY1/gksdU0USJvidQq8J3r9clNR+vt8YLsQ82U cK5Q== X-Gm-Message-State: AOAM531pkPIcB6Bfzz7irCG3HiOAwzlTXnVN+UOYCFj7RA4Vc3QEGusw sqUxsoWP3/Zd1rgYL2y32eIWHE2siOWesZ9O4WI= X-Google-Smtp-Source: ABdhPJyOyTY3dsog0bEyrf8FQNmA+LgDAtxW1LSmGP4jpoGSceI7DnRj4mOHZ3s0UwiUKjNjBIGpuS4DR9GRfrOYGf0= Sender: "samitolvanen via sendgmr" X-Received: from samitolvanen1.mtv.corp.google.com ([2620:15c:201:2:f693:9fff:fef4:1b6d]) (user=samitolvanen job=sendgmr) by 2002:a25:4189:: with SMTP id o131mr7599389yba.95.1606858652596; Tue, 01 Dec 2020 13:37:32 -0800 (PST) Date: Tue, 1 Dec 2020 13:37:00 -0800 In-Reply-To: <20201201213707.541432-1-samitolvanen@google.com> Message-Id: <20201201213707.541432-10-samitolvanen@google.com> Mime-Version: 1.0 References: <20201201213707.541432-1-samitolvanen@google.com> X-Mailer: git-send-email 2.29.2.576.ga3fc446d84-goog Subject: [PATCH v8 09/16] PCI: Fix PREL32 relocations for LTO From: Sami Tolvanen To: Masahiro Yamada , Steven Rostedt , Will Deacon Cc: Josh Poimboeuf , Peter Zijlstra , 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, Sami Tolvanen Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org With Clang's Link Time Optimization (LTO), the compiler can rename static functions to avoid global naming collisions. As PCI fixup functions are typically static, renaming can break references to them in inline assembly. This change adds a global stub to DECLARE_PCI_FIXUP_SECTION to fix the issue when PREL32 relocations are used. Signed-off-by: Sami Tolvanen Acked-by: Bjorn Helgaas Reviewed-by: Kees Cook --- include/linux/pci.h | 19 ++++++++++++++----- 1 file changed, 14 insertions(+), 5 deletions(-) diff --git a/include/linux/pci.h b/include/linux/pci.h index 22207a79762c..5b8505a5ca5f 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -1912,19 +1912,28 @@ enum pci_fixup_pass { }; #ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS -#define __DECLARE_PCI_FIXUP_SECTION(sec, name, vendor, device, class, \ - class_shift, hook) \ - __ADDRESSABLE(hook) \ +#define ___DECLARE_PCI_FIXUP_SECTION(sec, name, vendor, device, class, \ + class_shift, hook, stub) \ + void stub(struct pci_dev *dev); \ + void stub(struct pci_dev *dev) \ + { \ + hook(dev); \ + } \ asm(".section " #sec ", \"a\" \n" \ ".balign 16 \n" \ ".short " #vendor ", " #device " \n" \ ".long " #class ", " #class_shift " \n" \ - ".long " #hook " - . \n" \ + ".long " #stub " - . \n" \ ".previous \n"); + +#define __DECLARE_PCI_FIXUP_SECTION(sec, name, vendor, device, class, \ + class_shift, hook, stub) \ + ___DECLARE_PCI_FIXUP_SECTION(sec, name, vendor, device, class, \ + class_shift, hook, stub) #define DECLARE_PCI_FIXUP_SECTION(sec, name, vendor, device, class, \ class_shift, hook) \ __DECLARE_PCI_FIXUP_SECTION(sec, name, vendor, device, class, \ - class_shift, hook) + class_shift, hook, __UNIQUE_ID(hook)) #else /* Anonymous variables would be nice... */ #define DECLARE_PCI_FIXUP_SECTION(section, name, vendor, device, class, \ From patchwork Tue Dec 1 21:37:01 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sami Tolvanen X-Patchwork-Id: 11943923 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=-26.2 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT,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 81B77C83023 for ; Tue, 1 Dec 2020 21:39:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 278EA2086A for ; Tue, 1 Dec 2020 21:39:40 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="uSKl5Hyg" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389591AbgLAVjV (ORCPT ); Tue, 1 Dec 2020 16:39:21 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56346 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389643AbgLAVjU (ORCPT ); Tue, 1 Dec 2020 16:39:20 -0500 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 ECC44C094253 for ; Tue, 1 Dec 2020 13:37:35 -0800 (PST) Received: by mail-yb1-xb49.google.com with SMTP id j138so3967512ybg.20 for ; Tue, 01 Dec 2020 13:37:35 -0800 (PST) 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=baTa63xSC0ZZvL8LmEJ0rysXSGBclqJkA0eq2XdQYu4=; b=uSKl5HygxSFku3YpTdgH92zmKIE08ozZOIdku0rdE1QVetGDukAW5zNct8DUP027uw URWQdtClz2Lqmykr7qURlRRoi54XeEUu1RNFyDxIDeMUvpG0iHYLlEVkKi2WrwC16Mag xqCGvMXwV9ADAX0kd9iwYYuz8KAJgAR0vAiOyZY3HFSRXyr3ecyoAG3asfhKd5xnA56j C0uauidumM11pi4Ni2mqK2sj3jEgFKCHCeIHT8eOoI3Oj7Se9gobAyg97sPy9VAmfmeW k2WyX9FDP9jnedQUelDpCgdiXGQAEN9BsBj4WsylG4Z2JMb6iSYkZx7yItSsSxiRphQJ 57Wg== 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=baTa63xSC0ZZvL8LmEJ0rysXSGBclqJkA0eq2XdQYu4=; b=kh1hlWNGFAlOxiQmSbJDvy4ygNIAKOmtBp6HTYm3keE8NNHmFjM7pGCkyG1iNPM3mS VXznBlKIOxsjPuDNMMkxK1KB2XySqrVOYZEsZlamnL298WuX5r2O8g3/0JAR0qtQJmUK 86uC2eIIeEm/3Nh137x1T5k6djR6ipeJwy4adBXNfvnjDm4Hw2diagKiBf7i3elp2Vx3 naeb+iovouVny0Udyc167TmZ9ALdwPVqPkQjBa3MxWxMZDNQxVBCEAZokcwz5XGMeeDO TOae1P1JPtWuBFJgEiR2gKqKdn7j4TdDBXuY5h4nXO0V25kdE+fLtSYqSropr965pgg6 eI4w== X-Gm-Message-State: AOAM5316ShfxSXm+tWQp8jE7cEOjLEgmLLAnA3k7762+BPfxgqf8Dxtr /VWWQPzG9zCheskgrNNPtCqrKF8r/ZJ/aTCWx7g= X-Google-Smtp-Source: ABdhPJx9UrJOBuVJFMgVMAJwkGX1h9O45KDxr7BrRQG9YqDPMiMlGPu3qHVL93NOaWHRQVSxnOLCqPD+XrASLbiYizk= Sender: "samitolvanen via sendgmr" X-Received: from samitolvanen1.mtv.corp.google.com ([2620:15c:201:2:f693:9fff:fef4:1b6d]) (user=samitolvanen job=sendgmr) by 2002:a25:8401:: with SMTP id u1mr9324352ybk.96.1606858655207; Tue, 01 Dec 2020 13:37:35 -0800 (PST) Date: Tue, 1 Dec 2020 13:37:01 -0800 In-Reply-To: <20201201213707.541432-1-samitolvanen@google.com> Message-Id: <20201201213707.541432-11-samitolvanen@google.com> Mime-Version: 1.0 References: <20201201213707.541432-1-samitolvanen@google.com> X-Mailer: git-send-email 2.29.2.576.ga3fc446d84-goog Subject: [PATCH v8 10/16] modpost: lto: strip .lto from module names From: Sami Tolvanen To: Masahiro Yamada , Steven Rostedt , Will Deacon Cc: Josh Poimboeuf , Peter Zijlstra , 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, Sami Tolvanen Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org With LTO, everything is compiled into LLVM bitcode, so we have to link each module into native code before modpost. Kbuild uses the .lto.o suffix for these files, which also ends up in module information. This change strips the unnecessary .lto suffix from the module name. Suggested-by: Bill Wendling Signed-off-by: Sami Tolvanen Reviewed-by: Kees Cook --- scripts/mod/modpost.c | 16 +++++++--------- scripts/mod/modpost.h | 9 +++++++++ scripts/mod/sumversion.c | 6 +++++- 3 files changed, 21 insertions(+), 10 deletions(-) diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c index f882ce0d9327..ebb15cc3f262 100644 --- a/scripts/mod/modpost.c +++ b/scripts/mod/modpost.c @@ -17,7 +17,6 @@ #include #include #include -#include #include #include "modpost.h" #include "../../include/linux/license.h" @@ -80,14 +79,6 @@ modpost_log(enum loglevel loglevel, const char *fmt, ...) exit(1); } -static inline bool strends(const char *str, const char *postfix) -{ - if (strlen(str) < strlen(postfix)) - return false; - - return strcmp(str + strlen(str) - strlen(postfix), postfix) == 0; -} - void *do_nofail(void *ptr, const char *expr) { if (!ptr) @@ -1984,6 +1975,10 @@ static char *remove_dot(char *s) size_t m = strspn(s + n + 1, "0123456789"); if (m && (s[n + m] == '.' || s[n + m] == 0)) s[n] = 0; + + /* strip trailing .lto */ + if (strends(s, ".lto")) + s[strlen(s) - 4] = '\0'; } return s; } @@ -2007,6 +2002,9 @@ static void read_symbols(const char *modname) /* strip trailing .o */ tmp = NOFAIL(strdup(modname)); tmp[strlen(tmp) - 2] = '\0'; + /* strip trailing .lto */ + if (strends(tmp, ".lto")) + tmp[strlen(tmp) - 4] = '\0'; mod = new_module(tmp); free(tmp); } diff --git a/scripts/mod/modpost.h b/scripts/mod/modpost.h index 3aa052722233..fab30d201f9e 100644 --- a/scripts/mod/modpost.h +++ b/scripts/mod/modpost.h @@ -2,6 +2,7 @@ #include #include #include +#include #include #include #include @@ -180,6 +181,14 @@ static inline unsigned int get_secindex(const struct elf_info *info, return info->symtab_shndx_start[sym - info->symtab_start]; } +static inline bool strends(const char *str, const char *postfix) +{ + if (strlen(str) < strlen(postfix)) + return false; + + return strcmp(str + strlen(str) - strlen(postfix), postfix) == 0; +} + /* file2alias.c */ extern unsigned int cross_build; void handle_moddevtable(struct module *mod, struct elf_info *info, diff --git a/scripts/mod/sumversion.c b/scripts/mod/sumversion.c index d587f40f1117..760e6baa7eda 100644 --- a/scripts/mod/sumversion.c +++ b/scripts/mod/sumversion.c @@ -391,10 +391,14 @@ void get_src_version(const char *modname, char sum[], unsigned sumlen) struct md4_ctx md; char *fname; char filelist[PATH_MAX + 1]; + int postfix_len = 1; + + if (strends(modname, ".lto.o")) + postfix_len = 5; /* objects for a module are listed in the first line of *.mod file. */ snprintf(filelist, sizeof(filelist), "%.*smod", - (int)strlen(modname) - 1, modname); + (int)strlen(modname) - postfix_len, modname); buf = read_text_file(filelist); From patchwork Tue Dec 1 21:37:02 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sami Tolvanen X-Patchwork-Id: 11943907 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=-26.2 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT,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 A3E15C83026 for ; Tue, 1 Dec 2020 21:39:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3B92C2086A for ; Tue, 1 Dec 2020 21:39:41 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="oZ+MM9v/" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389783AbgLAVjX (ORCPT ); Tue, 1 Dec 2020 16:39:23 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56338 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389763AbgLAVjX (ORCPT ); Tue, 1 Dec 2020 16:39:23 -0500 Received: from mail-yb1-xb4a.google.com (mail-yb1-xb4a.google.com [IPv6:2607:f8b0:4864:20::b4a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8CD6EC094256 for ; Tue, 1 Dec 2020 13:37:38 -0800 (PST) Received: by mail-yb1-xb4a.google.com with SMTP id m186so4009851ybm.22 for ; Tue, 01 Dec 2020 13:37:38 -0800 (PST) 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=sUICI29mkgxH8XDf6qhMCrhn46+Hzc1owynREvsajYA=; b=oZ+MM9v/NqF/Ggik7eWdIKvvWz1hAClVJ55m2ya/8pnBTT4o/65pegfy91/nHJxuWW ng2vF4fEe4Kj1Wfo4enCljLrXc2mZuGKhe/N5E7LtdgFcAC58htdoc+UkHFNsGz4aAO6 TYAhpoNLG2sGulec3iEXV0wmrbA+e+YsFU8sNFgOxk4nqaFp778EB7curP1ohGdIJjsj jH7zCxSQUvDQVtB7+IQqbxbFDnA6gYb/Jb2c4ZAC83nAvZnZSoqo2Wh/6Eso5Pv41c0O eamKVAZq1cPjmGaxAjBPryDgnplTnhHhjw0xN8W2cnY2EG+4MSMt3K5GchHtvIv5V7pm oWsg== 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=sUICI29mkgxH8XDf6qhMCrhn46+Hzc1owynREvsajYA=; b=YwuFHtjFmwMf56ZHf5lb7F3F3wlwbKDyTJdE82UKpu8uJH+4KAsFZJyf/BalynYtaX s4iGNNc4aWR6qo9VDQcRbih4I3AiNr7/8KhU0YBYy88qa/7aO9aEgPj1gHJwb644DHMx R154eSQCCNUc83jCWyJ+sAg0F+/RchT8z7/L7KyGzVx9ay2reu8Xr0smSQfzDSs37S67 ucWGxioz1xT5Uj5/R5WhOgcqDIsz2sSUachywpqWExCuVyHbf9cjdiKf8O6dewZLKBIE k3Z2DxQerTt7Vst5yandPfvPIDT5eDxlOLZmG7zApbMwQJrF0jiRBsAPEcHYluog1J7O feWA== X-Gm-Message-State: AOAM533qmJMEeYriZvDfU9SKOGJtV16m9H+xkmjfrXOfBPHqK7KKekDm IQif95GOYQZ99ziymL1WkFzVbulVerLwDQV8ed8= X-Google-Smtp-Source: ABdhPJz1Mu2iPraONhTPw2Ye1e/CkH6U6l9Tg0xaIlFIbJtK0qFhhhtu0340/zvjR8Y2IkVG3dJHFOz9M5J3EVMgNhI= Sender: "samitolvanen via sendgmr" X-Received: from samitolvanen1.mtv.corp.google.com ([2620:15c:201:2:f693:9fff:fef4:1b6d]) (user=samitolvanen job=sendgmr) by 2002:a25:38c1:: with SMTP id f184mr5273120yba.41.1606858657749; Tue, 01 Dec 2020 13:37:37 -0800 (PST) Date: Tue, 1 Dec 2020 13:37:02 -0800 In-Reply-To: <20201201213707.541432-1-samitolvanen@google.com> Message-Id: <20201201213707.541432-12-samitolvanen@google.com> Mime-Version: 1.0 References: <20201201213707.541432-1-samitolvanen@google.com> X-Mailer: git-send-email 2.29.2.576.ga3fc446d84-goog Subject: [PATCH v8 11/16] scripts/mod: disable LTO for empty.c From: Sami Tolvanen To: Masahiro Yamada , Steven Rostedt , Will Deacon Cc: Josh Poimboeuf , Peter Zijlstra , 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, Sami Tolvanen Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org With CONFIG_LTO_CLANG, clang generates LLVM IR instead of ELF object files. As empty.o is used for probing target properties, disable LTO for it to produce an object file instead. Signed-off-by: Sami Tolvanen Reviewed-by: Kees Cook --- scripts/mod/Makefile | 1 + 1 file changed, 1 insertion(+) diff --git a/scripts/mod/Makefile b/scripts/mod/Makefile index 78071681d924..c9e38ad937fd 100644 --- a/scripts/mod/Makefile +++ b/scripts/mod/Makefile @@ -1,5 +1,6 @@ # SPDX-License-Identifier: GPL-2.0 OBJECT_FILES_NON_STANDARD := y +CFLAGS_REMOVE_empty.o += $(CC_FLAGS_LTO) hostprogs-always-y += modpost mk_elfconfig always-y += empty.o From patchwork Tue Dec 1 21:37:03 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sami Tolvanen X-Patchwork-Id: 11943909 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=-26.2 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT,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 7B51CC83028 for ; Tue, 1 Dec 2020 21:39:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 158A92087C for ; Tue, 1 Dec 2020 21:39:42 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="N2hjZ+w1" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389895AbgLAVj2 (ORCPT ); Tue, 1 Dec 2020 16:39:28 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56458 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389847AbgLAVj1 (ORCPT ); Tue, 1 Dec 2020 16:39:27 -0500 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 10CF8C09425B for ; Tue, 1 Dec 2020 13:37:41 -0800 (PST) Received: by mail-yb1-xb49.google.com with SMTP id e142so4033219ybf.16 for ; Tue, 01 Dec 2020 13:37:41 -0800 (PST) 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=2x/zjVn7tqzzMwlgW94lOF/53GHge2qEfxVssZKSVKU=; b=N2hjZ+w1m+tzNKULGFriHMyI0W/WLxUEDGY1DnBMXxPtD5xhjPfovZ1l0CpNo2iRQO +tTomPyUoponyE1362CelbbrDZwWrvZ66ad2D/JxuGm1GX6gaUseX8hQbfi3OUGkhp0H 9SmgV/+6Q7Bt3K0LuNqv/RrzRFY59diqYwZBhEZG9fnh7VFPaEUCT6hXis0JB7dm8/Jq tWSPkyod8RuoKjamef9WjpoKLdp1BdmoMZ4kk/XBfD1LF2w8eoyA6CMmckQwNxU7jj5H YD9zFativ+Sd8bT4A5VYcPCPPXLEbmnubfljTsMu/1a5ZsRn5Qy9mkUKuq9Y0tLJtllx jchQ== 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=2x/zjVn7tqzzMwlgW94lOF/53GHge2qEfxVssZKSVKU=; b=sT45soYepgnGh/Clgt+xnINFWtvHe33viGgS5TD84Pf+kQl9dcJSWfVFvC+59USfYY Ilb22RDjawQS4Rm3+c7M7JbXVvhEOT1Ga7ucUe/E0Ohb1VQPsz+WEO5bowfrKuQShBuV /4W9DsEt1VGzwpTWbUzaAQOmTWzBRIixcDW3yk8jlbiRZUeKo2kTEx95L41c1fhW/B68 ClO+N/A2jvEaGh8DBkdRknA/H1AajElT8mERC1kFFLV5BpV5mJnklxdA5Fp46Pm4zoAm V6AxbXsRHNPiQyJ93kpaqqwlK8MIKcCfiFXOl9rzCyVrs92Zv4PxIv0Kp+054wQO3Gfz xK6Q== X-Gm-Message-State: AOAM531Fun30Jh7eKbpin/aFsvsNhY43lSAaT7WiRe6mlL2oyrcBAwT7 kHPvB2aTcXUjBTxe28Cyfj+9PNyaRbNlSX5dq1c= X-Google-Smtp-Source: ABdhPJxHcUCj2mucLF7aE1IOS9CUSMZkQ+YtaXx/Kwh7BPBYbWWQuO91AIxxkwqaFlZSB+yJbXqZO28tnCnqith2Mko= Sender: "samitolvanen via sendgmr" X-Received: from samitolvanen1.mtv.corp.google.com ([2620:15c:201:2:f693:9fff:fef4:1b6d]) (user=samitolvanen job=sendgmr) by 2002:a25:c106:: with SMTP id r6mr7621086ybf.519.1606858660290; Tue, 01 Dec 2020 13:37:40 -0800 (PST) Date: Tue, 1 Dec 2020 13:37:03 -0800 In-Reply-To: <20201201213707.541432-1-samitolvanen@google.com> Message-Id: <20201201213707.541432-13-samitolvanen@google.com> Mime-Version: 1.0 References: <20201201213707.541432-1-samitolvanen@google.com> X-Mailer: git-send-email 2.29.2.576.ga3fc446d84-goog Subject: [PATCH v8 12/16] efi/libstub: disable LTO From: Sami Tolvanen To: Masahiro Yamada , Steven Rostedt , Will Deacon Cc: Josh Poimboeuf , Peter Zijlstra , 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, Sami Tolvanen Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org With CONFIG_LTO_CLANG, we produce LLVM bitcode instead of ELF object files. Since LTO is not really needed here and the Makefile assumes we produce an object file, disable LTO for libstub. Signed-off-by: Sami Tolvanen Reviewed-by: Kees Cook --- drivers/firmware/efi/libstub/Makefile | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/firmware/efi/libstub/Makefile b/drivers/firmware/efi/libstub/Makefile index 8a94388e38b3..c23466e05e60 100644 --- a/drivers/firmware/efi/libstub/Makefile +++ b/drivers/firmware/efi/libstub/Makefile @@ -38,6 +38,8 @@ KBUILD_CFLAGS := $(cflags-y) -Os -DDISABLE_BRANCH_PROFILING \ # remove SCS flags from all objects in this directory KBUILD_CFLAGS := $(filter-out $(CC_FLAGS_SCS), $(KBUILD_CFLAGS)) +# disable LTO +KBUILD_CFLAGS := $(filter-out $(CC_FLAGS_LTO), $(KBUILD_CFLAGS)) GCOV_PROFILE := n # Sanitizer runtimes are unavailable and cannot be linked here. From patchwork Tue Dec 1 21:37:04 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sami Tolvanen X-Patchwork-Id: 11943913 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=-26.2 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT,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 5C497C83029 for ; Tue, 1 Dec 2020 21:39:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1A35E20C56 for ; Tue, 1 Dec 2020 21:39:43 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="vXHUajvU" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390003AbgLAVjb (ORCPT ); Tue, 1 Dec 2020 16:39:31 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56342 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389969AbgLAVj3 (ORCPT ); Tue, 1 Dec 2020 16:39:29 -0500 Received: from mail-qv1-xf49.google.com (mail-qv1-xf49.google.com [IPv6:2607:f8b0:4864:20::f49]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3846CC09425F for ; Tue, 1 Dec 2020 13:37:43 -0800 (PST) Received: by mail-qv1-xf49.google.com with SMTP id d30so2216799qvf.3 for ; Tue, 01 Dec 2020 13:37:43 -0800 (PST) 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=aPTc8wYkBIIZS9XLhaJqPHrVGew/rHRzWtLqs6SwnEk=; b=vXHUajvUgn40LQCYOvZPKvqCWjM82atINdDHUGd5EhIZaxvZWNECR6Puf1wV/Xm1fz RZFUluVJoen54/2OkeSIKDLooJAqo6nO6jmid/KnIY+pQsB0jUK1FLQCjzUfvDCGjqfW 5DsweDMH7mPM+webX4KoPPbT06j0wd8ib/BAqCtFcLiXN9fRxFfzVzezsrV61oCpnhyb 7uduG6UItD7EnvVpEffELx2wbLPqlD3Oqd6UlZIDNGhgDg+wEFbzFvokQCivtnRsGs7N 92Et/EOjPux1Tii1bL3i8/gTtmbaMJpflMTGhVRAPssOG6ib3nwdVtng5zkY0hoNy4H7 BGdg== 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=aPTc8wYkBIIZS9XLhaJqPHrVGew/rHRzWtLqs6SwnEk=; b=UaSj3NOpCHbgEQYQ31ojhhrCfiJE9PsDf3Q3V5OP767GHn9XDTBOu9tHWVMMf199wU TmVxoofDjNJDv8LQt5V2wJBNYhU+wjpbDmqA8yV5GP3QBd/eYaMarzciTBhRmm3CpeK4 4C8n9DP78NFHOi/8GphR9W+oCkkWgeQtSYvTAFx2AQrQprHPUye0SYKRCyaMeGMrfs/Z Y109pfDBMj3ZbkmTzhfNjy2fRVVmR8UYU925V2GM5P8tL8EBMmc/Y7HUutWiG/axHC4q o18x/tkE41pAZccp9hWnJxANYgRIHDXqIPG+efOvqL8PVzXu6RVR8Tw/09yl5EVFAgGy IAng== X-Gm-Message-State: AOAM530Sb3ilRZ/QWw+mwjgtvRs7tgHdYQBFlqTIvgjA7CTOeDGVCAy1 prXMql8JkwKCYE1KHOLfy3HlzbBObA1UVfmwWUU= X-Google-Smtp-Source: ABdhPJx2UMQKvzPc9YbjuAcaOdZsXhK7RlcIM2M9pkfdRpnDBi+U9k28DqELenlSlo2tvxUYIND8c9jWK0Acmjv4ppQ= Sender: "samitolvanen via sendgmr" X-Received: from samitolvanen1.mtv.corp.google.com ([2620:15c:201:2:f693:9fff:fef4:1b6d]) (user=samitolvanen job=sendgmr) by 2002:ad4:5685:: with SMTP id bc5mr5091015qvb.48.1606858662372; Tue, 01 Dec 2020 13:37:42 -0800 (PST) Date: Tue, 1 Dec 2020 13:37:04 -0800 In-Reply-To: <20201201213707.541432-1-samitolvanen@google.com> Message-Id: <20201201213707.541432-14-samitolvanen@google.com> Mime-Version: 1.0 References: <20201201213707.541432-1-samitolvanen@google.com> X-Mailer: git-send-email 2.29.2.576.ga3fc446d84-goog Subject: [PATCH v8 13/16] drivers/misc/lkdtm: disable LTO for rodata.o From: Sami Tolvanen To: Masahiro Yamada , Steven Rostedt , Will Deacon Cc: Josh Poimboeuf , Peter Zijlstra , 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, Sami Tolvanen Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org Disable LTO for rodata.o to allow objcopy to be used to manipulate sections. Signed-off-by: Sami Tolvanen Acked-by: Kees Cook --- drivers/misc/lkdtm/Makefile | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/misc/lkdtm/Makefile b/drivers/misc/lkdtm/Makefile index c70b3822013f..dd4c936d4d73 100644 --- a/drivers/misc/lkdtm/Makefile +++ b/drivers/misc/lkdtm/Makefile @@ -13,6 +13,7 @@ lkdtm-$(CONFIG_LKDTM) += cfi.o KASAN_SANITIZE_stackleak.o := n KCOV_INSTRUMENT_rodata.o := n +CFLAGS_REMOVE_rodata.o += $(CC_FLAGS_LTO) OBJCOPYFLAGS := OBJCOPYFLAGS_rodata_objcopy.o := \ From patchwork Tue Dec 1 21:37:05 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sami Tolvanen X-Patchwork-Id: 11943917 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=-26.2 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT,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 4B339C8301A for ; Tue, 1 Dec 2020 21:39:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E32882086A for ; Tue, 1 Dec 2020 21:39:48 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="ty5f8H7k" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389306AbgLAVjp (ORCPT ); Tue, 1 Dec 2020 16:39:45 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56482 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390156AbgLAVje (ORCPT ); Tue, 1 Dec 2020 16:39:34 -0500 Received: from mail-qv1-xf49.google.com (mail-qv1-xf49.google.com [IPv6:2607:f8b0:4864:20::f49]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 98E22C094262 for ; Tue, 1 Dec 2020 13:37:45 -0800 (PST) Received: by mail-qv1-xf49.google.com with SMTP id i2so2210963qvb.2 for ; Tue, 01 Dec 2020 13:37:45 -0800 (PST) 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=D9wH7plBpsyKB7z0MJo6lESfcO9at50jK7OVp+0NdAo=; b=ty5f8H7kzpU+lvDsHXGI++1V0wurJB7DQJHEXEwufmtrCxIRoiPJOPP1X/3lLsz1Jb yjTR/AGDyQQn3kRjvvw2d88GiqDY8VcvMWomB5DuCrtNFFxHuktvMeKvMrFz+Xfk1Q77 MRmeM7k7VctuQepKTW4pproEuOE+zIwcrFORj2gPW2IlyOU7IhN8JpWoK+mpfeUx5C/d ojaTkHbYjh10G7mgJCJekN588v9SPU5sVPQSTu4fzbRdcVzLgMGzXyAyI0u1gJhvAtr+ L9s0tFmZLbeuu51bgQUHw9Ysitz1s+n7ja3zUrLOpDRRdxizWkaeqCKUaIf410z146BI /CXw== 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=D9wH7plBpsyKB7z0MJo6lESfcO9at50jK7OVp+0NdAo=; b=FVsR3I3nynFmXkIiN6pgK6zHF27pZBpwUwH+fXNgs0op0phuqhJAObiKcUtNclm7Nh Ng3t2LXCp9IZ2zyOBvNe3YwrINoxDJDHQG0PilLDu2PHUF+9D26qnYQYuCmGXDqM9G2k VfCdNW+QVRuYM66H5v7dtlU4/YlJV1BB7Wj5qb1Tc27j0TmOWgBG9yl7iFzuDMqRWSBe rry5SbEnBFRcCDVk8+MekhNn5ntviEC9/tdlMmuOttGJBsuGkT6hjzvijOLfqCLOa4Fv CDu0RZF85xAcflS2YLAh83rW5ltHMTrHDeJ4IQRuUMVSGetoAbWd5vXGjbN4bKXP0HQu OvaA== X-Gm-Message-State: AOAM531k1M72IpsAjfocHxKB2y6o8Rl7ONlO+j6aKT5XYei0gW0I8yzT X2Y+gmJBJl1YxmAPlOSfzsh2mw8ugkPskEQEyO0= X-Google-Smtp-Source: ABdhPJz0uxxT0ZlEK90fhImd7lL6Fuzds0C69/eAFTomtuQ0mN0EZEi1KhWi4R7wk6mCpdkDbecP4SoP9hzTb5uJL7A= Sender: "samitolvanen via sendgmr" X-Received: from samitolvanen1.mtv.corp.google.com ([2620:15c:201:2:f693:9fff:fef4:1b6d]) (user=samitolvanen job=sendgmr) by 2002:ad4:4d84:: with SMTP id cv4mr5421264qvb.14.1606858664762; Tue, 01 Dec 2020 13:37:44 -0800 (PST) Date: Tue, 1 Dec 2020 13:37:05 -0800 In-Reply-To: <20201201213707.541432-1-samitolvanen@google.com> Message-Id: <20201201213707.541432-15-samitolvanen@google.com> Mime-Version: 1.0 References: <20201201213707.541432-1-samitolvanen@google.com> X-Mailer: git-send-email 2.29.2.576.ga3fc446d84-goog Subject: [PATCH v8 14/16] arm64: vdso: disable LTO From: Sami Tolvanen To: Masahiro Yamada , Steven Rostedt , Will Deacon Cc: Josh Poimboeuf , Peter Zijlstra , 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, Sami Tolvanen Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org Disable LTO for the vDSO by filtering out CC_FLAGS_LTO, as there's no point in using link-time optimization for the small amount of C code. Signed-off-by: Sami Tolvanen Reviewed-by: Kees Cook Acked-by: Will Deacon --- arch/arm64/kernel/vdso/Makefile | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/arch/arm64/kernel/vdso/Makefile b/arch/arm64/kernel/vdso/Makefile index d65f52264aba..50fe49fb4d95 100644 --- a/arch/arm64/kernel/vdso/Makefile +++ b/arch/arm64/kernel/vdso/Makefile @@ -30,7 +30,8 @@ ldflags-y := -shared -nostdlib -soname=linux-vdso.so.1 --hash-style=sysv \ ccflags-y := -fno-common -fno-builtin -fno-stack-protector -ffixed-x18 ccflags-y += -DDISABLE_BRANCH_PROFILING -CFLAGS_REMOVE_vgettimeofday.o = $(CC_FLAGS_FTRACE) -Os $(CC_FLAGS_SCS) $(GCC_PLUGINS_CFLAGS) +CFLAGS_REMOVE_vgettimeofday.o = $(CC_FLAGS_FTRACE) -Os $(CC_FLAGS_SCS) $(GCC_PLUGINS_CFLAGS) \ + $(CC_FLAGS_LTO) KASAN_SANITIZE := n UBSAN_SANITIZE := n OBJECT_FILES_NON_STANDARD := y From patchwork Tue Dec 1 21:37:06 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sami Tolvanen X-Patchwork-Id: 11943921 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=-26.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT,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 B3958C83034 for ; Tue, 1 Dec 2020 21:39:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6A87E2086A for ; Tue, 1 Dec 2020 21:39:48 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="lDxihdeJ" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390338AbgLAVjn (ORCPT ); Tue, 1 Dec 2020 16:39:43 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56346 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390015AbgLAVjg (ORCPT ); Tue, 1 Dec 2020 16:39:36 -0500 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 109B7C094265 for ; Tue, 1 Dec 2020 13:37:48 -0800 (PST) Received: by mail-yb1-xb49.google.com with SMTP id r4so4041905ybs.1 for ; Tue, 01 Dec 2020 13:37:48 -0800 (PST) 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=IAko/M6Zt1aSlSrXq3lDXb64GB1qle9I29x8xbslmiM=; b=lDxihdeJWmA2e6zRs4TGwE13O3VOmpH1sdyN7CY6HZcKARE8DZM0oCaAv6PGzLBfOm /ZsEq2PPIQPCS7MFloSyMFj7kgAkVbls55naobKLn/H//1ss0itsdOqec9UmTUefWOkZ OevqTXLVnJWnu1+9lA+fUkD3ZpM/Bc/Cp+H1CtYxrDQiJ2zLyi7mQrSw2Tg1RcvR5Pvc MD3SFVwZjAlr2nZrrAuw1JZnaw4C+tIlbEJxCUwAQygLAddc8jWwS1H6U4ZPPTd1zOuh GskRIIGrCvhTFuMt7A9YPnLuQPcn84b4pMM7zxhzZZSJJBkFobXmIeaBIWWVW35FDAmE F+jQ== 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=IAko/M6Zt1aSlSrXq3lDXb64GB1qle9I29x8xbslmiM=; b=narelk/azl97tz1beqz8chNouKCDkpHFXt8lxUBmP4iGYfn0ZdUl+V7WgDfXFm/PCJ l79PamRy7mtkmxDzaJ8V2bY5rx2olNwTmyZkce7OdxlzFKii/sGD5dn4ViH5RXTLX5Wx jR4TqtTAbu5r29QFoxZjuEmDbpWGx7I03ETw1tx4i+o93M2K1eVy/hpRtSkBBfcpK4rK 89UKK8Pr+c2v/y8Np0NNLCPBo8hFZxT/95/nLR2J3St3b+AT3ZwIhs9A4xxx54qQh4yi +2LyfSdt7Xy1vkjYJhUQZsxTDleGNqek8pgqGrNyCXsIQosbniX7VIpsDgWPnl508Obo 4vjg== X-Gm-Message-State: AOAM532QlPhDrfhLhVohBnSZGhRWzwQO3GJv/ECu7asqzC+jgi7ZRBIU sMagLkiFhPxYd1Mz20KXoDCWgYhxHli9qyPm8kA= X-Google-Smtp-Source: ABdhPJyD/SxDjfpLtYpnbWVyCumboZuxaJdYA+0/Z6lOz73HHAOHqcYxLyKCh9v/FKkBiugIvNe82fBMfluge4BLrG0= Sender: "samitolvanen via sendgmr" X-Received: from samitolvanen1.mtv.corp.google.com ([2620:15c:201:2:f693:9fff:fef4:1b6d]) (user=samitolvanen job=sendgmr) by 2002:a5b:846:: with SMTP id v6mr6465998ybq.436.1606858667278; Tue, 01 Dec 2020 13:37:47 -0800 (PST) Date: Tue, 1 Dec 2020 13:37:06 -0800 In-Reply-To: <20201201213707.541432-1-samitolvanen@google.com> Message-Id: <20201201213707.541432-16-samitolvanen@google.com> Mime-Version: 1.0 References: <20201201213707.541432-1-samitolvanen@google.com> X-Mailer: git-send-email 2.29.2.576.ga3fc446d84-goog Subject: [PATCH v8 15/16] arm64: disable recordmcount with DYNAMIC_FTRACE_WITH_REGS From: Sami Tolvanen To: Masahiro Yamada , Steven Rostedt , Will Deacon Cc: Josh Poimboeuf , Peter Zijlstra , 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, Sami Tolvanen Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org DYNAMIC_FTRACE_WITH_REGS uses -fpatchable-function-entry, which makes running recordmcount unnecessary as there are no mcount calls in object files, and __mcount_loc doesn't need to be generated. While there's normally no harm in running recordmcount even when it's not strictly needed, this won't work with LTO as we have LLVM bitcode instead of ELF objects. This change selects FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY, which disables recordmcount when patchable function entries are used instead. Signed-off-by: Sami Tolvanen Acked-by: Will Deacon --- arch/arm64/Kconfig | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 1515f6f153a0..c7f07978f5b6 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -158,6 +158,8 @@ config ARM64 select HAVE_DYNAMIC_FTRACE select HAVE_DYNAMIC_FTRACE_WITH_REGS \ if $(cc-option,-fpatchable-function-entry=2) + select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY \ + if DYNAMIC_FTRACE_WITH_REGS select HAVE_EFFICIENT_UNALIGNED_ACCESS select HAVE_FAST_GUP select HAVE_FTRACE_MCOUNT_RECORD From patchwork Tue Dec 1 21:37:07 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sami Tolvanen X-Patchwork-Id: 11943919 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=-26.2 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT,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 01D8FC8301F for ; Tue, 1 Dec 2020 21:39:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B5E732087C for ; Tue, 1 Dec 2020 21:39:46 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="PhIES9mZ" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390311AbgLAVjk (ORCPT ); Tue, 1 Dec 2020 16:39:40 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56348 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390273AbgLAVjj (ORCPT ); Tue, 1 Dec 2020 16:39:39 -0500 Received: from mail-qk1-x749.google.com (mail-qk1-x749.google.com [IPv6:2607:f8b0:4864:20::749]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7B9AAC094269 for ; Tue, 1 Dec 2020 13:37:50 -0800 (PST) Received: by mail-qk1-x749.google.com with SMTP id l7so2452499qkl.16 for ; Tue, 01 Dec 2020 13:37:50 -0800 (PST) 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=e77AaMfAoOs/rzHffqgIcODt2AF3tTsGcr7ctg09Fiw=; b=PhIES9mZeaV2CcOOl8w4l+2ikBXS+wckgodD2kCIALpUfGhJq/JokBFVnpLyEDHks9 s8KS77HbtwZgIGJAF1Tgq1CMBOT+U0TGPDCswFllP9/Wb/lsfsDB5gnxFlvnlGfpeufY Hy8In8h71u/8sWWwnYUrcWgb/UQdJioTucpyV/6eOUpCpsAT76h4F1u2jVLu4RS0k6r7 PUe2D5YpmZV4+lsiyaOpuXMkzEX6Xy4dTdjoE4jUNMaeybvIa8H1LPOZHv/Qe2/UnLMt PTMAailmADrwZlpd1jeXUYN/0RA5Dv57F0Y3YPHXVxD2ACvJtXUB7QfmCy0vCpyChfJ+ bQ1g== 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=e77AaMfAoOs/rzHffqgIcODt2AF3tTsGcr7ctg09Fiw=; b=Mt67d1RvRrZK6V4k3aa2Itsz+/aschEdmrswKXkx1cL6100S8lwKaQgfc7kzATIbJi AMMgz2dMotXU8cQY0EZrTJnpuOmJjWVcznXMC+CWgqAUODi2IvAlDgFvOvXD9ahmTVdm BsJglFx2BCTcv3Kja2fvr+D6LLYVM16DZsx99mZOOATw0neZx7q1fK4nzkFu+GMDImBX /JEeVYTCXQ5xD0WL6VD8ZFAIZ5VT//xQXun9Nx510ceV4staAWSlokrtkdPZokmjMsO4 A6mAM/CHoeqxJyyEs9bTWIZ0sh5gbZUMZ1MQrMHd5EXL5TV8ogWLfOd0wiZAvNK9qJKa LApQ== X-Gm-Message-State: AOAM531WaZWKnih5hc8U2WsCxurgSlQA6pCMpCUtvD7VSJl4gAXD4Ayl exm3F32Mslc3PRVIBiEUSN1IFM0A1BBVSH6/oXw= X-Google-Smtp-Source: ABdhPJweI4qeGM+e2zDq2SHC9xWM5C+tGpvQFN+igQT76ck/RAf7jjMcn/GQMDX+kf4UQlLCPrmaZJR673f61g+6O7E= Sender: "samitolvanen via sendgmr" X-Received: from samitolvanen1.mtv.corp.google.com ([2620:15c:201:2:f693:9fff:fef4:1b6d]) (user=samitolvanen job=sendgmr) by 2002:a0c:a9d0:: with SMTP id c16mr5348289qvb.5.1606858669593; Tue, 01 Dec 2020 13:37:49 -0800 (PST) Date: Tue, 1 Dec 2020 13:37:07 -0800 In-Reply-To: <20201201213707.541432-1-samitolvanen@google.com> Message-Id: <20201201213707.541432-17-samitolvanen@google.com> Mime-Version: 1.0 References: <20201201213707.541432-1-samitolvanen@google.com> X-Mailer: git-send-email 2.29.2.576.ga3fc446d84-goog Subject: [PATCH v8 16/16] arm64: allow LTO to be selected From: Sami Tolvanen To: Masahiro Yamada , Steven Rostedt , Will Deacon Cc: Josh Poimboeuf , Peter Zijlstra , 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, Sami Tolvanen Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org Allow CONFIG_LTO_CLANG to be enabled. Signed-off-by: Sami Tolvanen Reviewed-by: Kees Cook Acked-by: Will Deacon --- arch/arm64/Kconfig | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index c7f07978f5b6..9d29c48ecd4f 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -73,6 +73,8 @@ config ARM64 select ARCH_USE_SYM_ANNOTATIONS select ARCH_SUPPORTS_MEMORY_FAILURE select ARCH_SUPPORTS_SHADOW_CALL_STACK if CC_HAVE_SHADOW_CALL_STACK + select ARCH_SUPPORTS_LTO_CLANG + select ARCH_SUPPORTS_LTO_CLANG_THIN select ARCH_SUPPORTS_ATOMIC_RMW select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 && (GCC_VERSION >= 50000 || CC_IS_CLANG) select ARCH_SUPPORTS_NUMA_BALANCING