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: 11943927 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 5B6B0C64E7A 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 EEE5C2087C 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 S1729611AbgLAVib (ORCPT ); Tue, 1 Dec 2020 16:38:31 -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 S1728676AbgLAVib (ORCPT ); Tue, 1 Dec 2020 16:38:31 -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 88BC8C061A48 for ; Tue, 1 Dec 2020 13:37:13 -0800 (PST) Received: by mail-qk1-x749.google.com with SMTP id d206so2446328qkc.23 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=R+w3NhLut/GMH4EXKf9tAunDJIgGOYLzdRTqhwommPgSqsj+r9+eJXvlj68UMvUD1l Ay9eUNvxRuaD+nGdj7ws1bqsNkT8KIIEvi3EACoZpaDXayDN+xdzeXJt0RJblq25wZUk 93zX6esbQzr47hraw+xq32r0Ef5ZjvALQVmCKCURKykgNUv44rfsICbyNbvHbqp3HXXz EW/RZK1HWTKu9GYUC7r8F1zKLFXI14G9+DhoM+2HwxGIfM79PP1r+9p0lm+X9qICuYRE F+Uaawv/zF+Di6I+tFGpYejIh1ZCQcqIDSOv8qYjLCki5uM8xFQybwD1M3U05NiCVbzI jyzw== X-Gm-Message-State: AOAM533DzMbMNX4m0ZeeLGI40sQZd6U4eHngmaJ7NExO/6nnmXr2isND Fj9+8zitc8kIGqHwgxBbLsFx9jyHdOfmFpX5/UQ= 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-kbuild@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; 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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-kbuild@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; 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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-kbuild@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: 11943933 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 6BEF7C83016 for ; 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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-kbuild@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: 11943935 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 2B172C83017 for ; Tue, 1 Dec 2020 21:39:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BF32C20C56 for ; Tue, 1 Dec 2020 21:39:36 +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 S2388655AbgLAVjM (ORCPT ); Tue, 1 Dec 2020 16:39:12 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56462 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389078AbgLAVjM (ORCPT ); Tue, 1 Dec 2020 16:39:12 -0500 Received: from mail-qk1-x74a.google.com (mail-qk1-x74a.google.com [IPv6:2607:f8b0:4864:20::74a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4BACBC08E85E for ; Tue, 1 Dec 2020 13:37:23 -0800 (PST) Received: by mail-qk1-x74a.google.com with SMTP id x196so2461905qkb.12 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=D41GDUbAaHCiQSCWQuxjSSU+gSrbpQ39KUiCivklZ67fVTcEMod8HyuCzomY091G51 quQLe9boyn7XeyCUV2sP1xpl5SI6VS+b9aEneJHnkMA/K5iX4WqyeUH0+AxlWwfUCTaF tQZ5+6TZhmbxlOJm14/3LiW9cv+vDyjR/C5LEsP1EbzObZEAxl8EGM8EDE+dblaOGk8o nkrIJyPtJogoLo9Ho966wKWU2ohADTQ5eZebavDNylBJYicpm7ZEFVpDoC466l/gIGQm PJJ7bh3WrnuXCf8BGNhzhEGjX2MksawEh4n+wensPzUDeLoQ12HK8WDNbZpQtAQDPhWE 0ezA== X-Gm-Message-State: AOAM531fJatOuHdfLse2MLe2QAEnEAmxGGJrHfOa8wVNQOjYavnkKPyN sK3WyPpXkgUmfB40vGZQ4qlODQmbQirtzrPvyEE= 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-kbuild@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: 11943937 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 7E70DC8301F for ; Tue, 1 Dec 2020 21:39:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2317A2086A for ; Tue, 1 Dec 2020 21:39:39 +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 S2389618AbgLAVjT (ORCPT ); Tue, 1 Dec 2020 16:39:19 -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 S2388640AbgLAVjR (ORCPT ); Tue, 1 Dec 2020 16:39:17 -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 9E61FC08E864 for ; Tue, 1 Dec 2020 13:37:25 -0800 (PST) Received: by mail-qt1-x849.google.com with SMTP id o1so2289606qtp.7 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=GCNcmQt/S9WdBaxThbzzRpdt6Gf/Q1AWBduG2bJrB8f5ClptYcU/s2pExE7hXKO5en TL8lvvUG6uE00b/J8JUTPMKHJ7rRotrfxaM4bbQ5+H0dNj21hF4bZIhVDUbxMtpgeuo2 zUxX3MYGn1iXedDqm09HOw0do3IJ5pJC+idc70g4q7nHfH+cpRZdTtyp0dTe6HAQZcOO JowCYX2HE+Fr3hgH20ST+89+x9h9CzeVa5KCWRD2TXg6PX0WnxhvPyFar25vfBkP5X65 BOa46Bxv1F2cfWNpzjI1lmLBbV9ptxKU8qMZ6ANx5GXWNWLzGdm4jObSst8kKjLfDo73 3n5A== X-Gm-Message-State: AOAM5303m2uQwOJj+kR9INB3G+C8Kz7zl/W1bRhjyqJRGz4KQIxNqzfx 2sYBukZXfW/gj/W2pv3eYZDz/GevkGWpYHde44g= 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-kbuild@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: 11943943 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 C6BA4C83020 for ; Tue, 1 Dec 2020 21:39:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5D5A120870 for ; Tue, 1 Dec 2020 21:39:39 +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 S2388137AbgLAVjU (ORCPT ); Tue, 1 Dec 2020 16:39:20 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56484 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389578AbgLAVjR (ORCPT ); Tue, 1 Dec 2020 16:39:17 -0500 Received: from mail-pg1-x549.google.com (mail-pg1-x549.google.com [IPv6:2607:f8b0:4864:20::549]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1B454C08ED7E for ; Tue, 1 Dec 2020 13:37:28 -0800 (PST) Received: by mail-pg1-x549.google.com with SMTP id l7so1772973pgq.16 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=DxiafjU+26ycwRczkDZO0YTvuNUIJiShEDzEndKDB/AEHzi/DSBwnDfnQndzBRCPP/ zRpCSHfk0c1vYXRuYrp2NNln2M9baR6eVR1FP+Txo4aGZ6i0APm+k//i2hMcQBvpxFsv UHZrOW830BJ+54doy2JHTYkiyijP3NIPEKkP85thPJnSQfjWGH8ozBjNNQJwZDT6gR5/ 78jM4PWD+suHPnrGg2kbiRLXnK3M+Mq28m95w+QCuY98+wgir9w6t0Agwui8mG0PD6kz ANDFzXciGwxF7S0Svx1l+aYytw3dIC2epBcloUtTY+NKb9HiJMQJ/L9Fk5Y87IunzeN1 x6Ng== X-Gm-Message-State: AOAM532Rjq4WIctT1ZuaEVGddtWnC71YjezlKNFZKqDEh9Skz4CdqZCY 32ZMpeKJLYsU+AtDfqECO4cWW7jT12GT/jL/Evc= 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-kbuild@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: 11943947 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 02155C8302B for ; 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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-kbuild@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: 11943951 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 6F292C8301C 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 2362620870 for ; 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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-kbuild@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: 11943939 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 3F8BCC8301A 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 D534B221FF for ; Tue, 1 Dec 2020 21:39:37 +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 S2389541AbgLAVjO (ORCPT ); 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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-kbuild@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: 11943945 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 9A23DC83018 for ; 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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-kbuild@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: 11943941 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 D140DC83027 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 744EB2087C 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="N2hjZ+w1" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389600AbgLAVj0 (ORCPT ); Tue, 1 Dec 2020 16:39:26 -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 S2389777AbgLAVjX (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 0FA86C094258 for ; Tue, 1 Dec 2020 13:37:41 -0800 (PST) Received: by mail-yb1-xb4a.google.com with SMTP id n62so3988307ybf.19 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=q6H2+JnDx5K+99JAYJsqe8sqOuzS1eq803S/EB12cYXOn10koieyqg6fHDhms/8yy/ X05Co5WzBVec6VtBIkGSY6yHVmjj9goPGlaNZjGYaWKTxpey5M85nICYLzWzGCpRADGp P6VCVV0Bv1n12qEd2zw2HN6wVhLsox8khARo4G9V2MSo4drH+sJFll0xg++ssFTp31Gk GaAGWybxwnjLytewRxOIDNewJY1cZWuZ9BaVDjkTGQ1k4kcdKIZSxFrlWjbAZ+9TZxgc 1iQnihGIH7pYf5wvbLrePkZdlmVN9/nHpQyQhn1TZHkEYEypdN4VNwjFnnc1hZeRIfCE LhVA== X-Gm-Message-State: AOAM533QDTi6CPw5zSTVNwg6ToJqPEmTiVBUl/oeMgmhzTEjaLyzo232 Awn6B0edvVmAPT43nVOceajvI1qmWaAj5NOLZMs= 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-kbuild@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: 11943949 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 41492C8302A 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 D2A71208DB 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="vXHUajvU" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389934AbgLAVj2 (ORCPT ); Tue, 1 Dec 2020 16:39:28 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56462 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389855AbgLAVj1 (ORCPT ); Tue, 1 Dec 2020 16:39:27 -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 32D38C09425C for ; Tue, 1 Dec 2020 13:37:43 -0800 (PST) Received: by mail-qv1-xf4a.google.com with SMTP id b15so2199127qvm.10 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=ctyDnAfTMQsE9Z/HZ6p+k7xq5QEl4IR9MCwsUHbChiU9cnm3qxxQem+JL6aQdNJpu+ ZNIQyXDG7hEm9vr0ffhViGDGFduiAhlIgbTxKX4zdstXacG+2igRVDF99gJS9YsGaqk+ Ni2KIdOX+mqb3lVDHMKiO1l3SD9qfz3ibMjazZZg8FlvvFconKOsDktqauyo93djExfR Dx8ZiW3K9wkbh+yeJuCmKYMgL8sSgLGyQ+cA5RwNuOIn9x+0FA8uthgbgD7yO9QrUtcG T6RPfSbdb7c7kS6vEYGElqj1Vk15jXPT45QsVkm4nnNzpO80vOLRYyasDjvmn3GW23vA N9Ow== X-Gm-Message-State: AOAM532Boo5d8z5VTExFBibN3Lu+Gnmpri2MuUGtOww2TEmeAB4pK6B1 AF+T/fNxPPcX3o5RNo5eUpkV+PNF6Ueoe13ToOQ= 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-kbuild@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: 11943955 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 E8E16C8302F 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 918562085B for ; Tue, 1 Dec 2020 21:39:47 +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 S2390251AbgLAVjm (ORCPT ); Tue, 1 Dec 2020 16:39:42 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56464 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390273AbgLAVjk (ORCPT ); Tue, 1 Dec 2020 16:39:40 -0500 Received: from mail-qk1-x74a.google.com (mail-qk1-x74a.google.com [IPv6:2607:f8b0:4864:20::74a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 99FBAC094263 for ; Tue, 1 Dec 2020 13:37:45 -0800 (PST) Received: by mail-qk1-x74a.google.com with SMTP id s29so2477672qkm.3 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=sz0Wbc3DmAVflz32MY0tudFP8kC+9vW86SexPOgdu+M1xq1XZXj5tl/p48sfObjOus WSTVM26QNMDUeelc4FdZRjfS+VmKU1281BKFOT5/VPePlH7zMBK8/kS4wiD8xN2pVWht oET2MfjfYz9EgcviDl0ZO1Jl6tARyazMbnumEZLSqHyBARUenw4FHymWDFXgfMOOKXtx tCbM92rhyz5zpZhT9PdC35cZ76LlrOBEgy86gm8i3JilED3hXn2wjjHqF/BcVeQG1IFT MF1fgJ0aDIvn3jDxOYlgXieN++DBQX1nVU98fmtvTdgSQNtQEupHttvIFEDV1Pq/dqi8 RDmQ== X-Gm-Message-State: AOAM531oV4W4LQoETFWXHWxhEWlyP6vCopIiOWeibRYfV2ZGw3gfZ6kR wwi6cTdaWfRBayotlFyJ7pqailBZykmYXF/kRBY= 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-kbuild@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: 11943953 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 B0850C83030 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 48FC62086A for ; Tue, 1 Dec 2020 21:39:47 +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 S2390313AbgLAVjl (ORCPT ); Tue, 1 Dec 2020 16:39:41 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56484 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390251AbgLAVjk (ORCPT ); Tue, 1 Dec 2020 16:39:40 -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 10479C094264 for ; Tue, 1 Dec 2020 13:37:48 -0800 (PST) Received: by mail-yb1-xb4a.google.com with SMTP id j138so3968028ybg.20 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=o1oic6Cyk/dLuvjZqHu/mNhWNsqDhhHya/Vpsa0TAWnUw6vr1w1KILKO1MnnA09RzI HDsQ5JBgrwjE2HJhgJNSn29bZIQ3vKoH9x9fX3U8y0JYY1UQJ+vybZjg3Wi8R3VKOFa1 UuvdtkPMElF82ak/vZGA+mkpobekiGMHKmgrVMCBqoevQJSLyyfBDQvBWQMGx+99Kq3g 5kxte9ar+8t1dAUGE9Jqti3LjDZMPpSOyPTEeOcQjPgszjT+Ew1hIheuwLUM4Dr+s9PI EeNqAfhwek52xajJkByfX+5MblM6/dfMna4b1PY+cOEPxExu/3KBiDKG4SUP5mYVCTMc H+9Q== X-Gm-Message-State: AOAM531zJzh6DGt8LH+g9IMwIOwh4VkBzRLwQ6Eme0l3AxA6s1iosFma Uz5clllAdgoq1TzmFwfYsfQVQfezA5TuZJqV8ew= 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-kbuild@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: 11943957 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 CE827C8300F for ; Tue, 1 Dec 2020 21:40:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 69EA52085B for ; Tue, 1 Dec 2020 21:40:23 +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 S2390458AbgLAVjx (ORCPT ); Tue, 1 Dec 2020 16:39:53 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56462 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390476AbgLAVjt (ORCPT ); Tue, 1 Dec 2020 16:39:49 -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 7C3E5C09426B for ; Tue, 1 Dec 2020 13:37:50 -0800 (PST) Received: by mail-qk1-x749.google.com with SMTP id t141so2444179qke.22 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=JO/653soL3CIl9WI/7TfUywdIMqMWuR9b4/Gpw/3JyG1+zrh8D/v9il2oeDn4XEDyg /ePr0j7ZQ3RMmR5zUIhmXUWUVJWfpG9gEUKN33nLeEiQ3JLhg6IXLuvukbZUcGjnOvP2 IbovE/cUxbl9kwH07NrUqS/CGRhNQEh1EXDi2xvNCg35UW+hCCQ4w2ERlIpWQ+QNVRgU w0Mkjkk6uaJ0uIgaHWR1GPxq8rlLz0EP36qUEWpwuHMNz7yu/rqv1PKcnAN6AlqlV6FI 2xsXAEoKf9d2ETCHZUvBlcGgSGBOp5nKTXQ0JcW2rnqbR6s1cnOrD6siSRoDlrvl1RIv Fqag== X-Gm-Message-State: AOAM532R0i3kRBSpZv2gb0mVNUBuGtMiFtTnPt9K2UjGjkJYXF32TO5a dGhceH8ZAwXN12JxAKjnvjys5HytKRtmde993us= 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-kbuild@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