From patchwork Fri Sep 18 20:14:14 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sami Tolvanen X-Patchwork-Id: 11786149 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 9E2A8139A for ; Fri, 18 Sep 2020 20:17:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 73CE823600 for ; Fri, 18 Sep 2020 20:17:02 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="BHDVtSDH" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726465AbgIRUPD (ORCPT ); Fri, 18 Sep 2020 16:15:03 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52798 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726438AbgIRUPD (ORCPT ); Fri, 18 Sep 2020 16:15:03 -0400 Received: from mail-yb1-xb49.google.com (mail-yb1-xb49.google.com [IPv6:2607:f8b0:4864:20::b49]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1C681C0613E0 for ; Fri, 18 Sep 2020 13:14:58 -0700 (PDT) Received: by mail-yb1-xb49.google.com with SMTP id r9so6661898ybd.20 for ; Fri, 18 Sep 2020 13:14:58 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=sender:date:in-reply-to:message-id:mime-version:references:subject :from:to:cc; bh=0FkP4B0/Lnp0DM8m5kyaL0nHymB5hvp+911UgypF4fg=; b=BHDVtSDHetldKKo2hdUPaejxOUg5e/yc8Cf5jPF8KvuEYU3GPeekWljxiMYHIrEQq0 SlyjQ7nTB2hb4xCe7jrH9NeG7+TDkN36Iz/j80rDR1o/RiwSrjXAJOEYsiCKVTp1EsS6 kPHqV1oAHjGCvpXDEdRkyfZWKXgLztHP1xvR0z0sbav9R8NYsmyZq8qKO5Ia151oKysY OCZWaSCUeytDPg1IKXVAcTOAuX1oTxatIgD0DWK0uypAG8DRSWlWJ4vJsZUQFtoH7CT/ NjL3ZYY2wH7uPQXbbCEmQSU4LkhsBSSMBwvyPvVqydWk1LcDUSp0FxblKNC9q59gwKrA ljEA== 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=0FkP4B0/Lnp0DM8m5kyaL0nHymB5hvp+911UgypF4fg=; b=cxejWwjLqkifchrmtPipLJ+eZav8N6dQRW1FNqXT0V9hPtfOTT+lAQYoaaQ2qMVG6r 3nNbx5e+cyWWbLZomy+GO1oNauxZiN1EDhba7VflX1+htXTTT7LaLVw2Q184niA7zZFs Sc01bbrYYeS3GiTLvzY/dfjhWG4TgKSL47UChS3Kl6M6z7gPBhNCByjVwKtxH046K2bb 3p3OQnsxKZYzc/9PurCics0LB+m3pETMp112Sci9KDL+XoRsoIUtm5uULtkdON5FFKVT 01ZpfNCJFVF9Za4inMCnW52TmZVePOXy3/aq/+kAAvF1n3igROH8GjJeFhI2rwsfVcln G5gw== X-Gm-Message-State: AOAM5308qMpwPZh5E5V1bUHC6bWNB/xv7u5mf19i3h/HhLSslVFTKcDa 5wMH7iVkvCs2SdttLoa7ed39xm74QCFBlQiBOuo= X-Google-Smtp-Source: ABdhPJwQq1wvH1AAA6gtJNKkwcmiCxJWA5rmyg/i+mPJ3ehFUf0yVGK9jkmjYXbCBq8XTq/g+Yqu8LuBqPuiMAszYNA= 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:cf15:: with SMTP id f21mr5192645ybg.408.1600460097335; Fri, 18 Sep 2020 13:14:57 -0700 (PDT) Date: Fri, 18 Sep 2020 13:14:14 -0700 In-Reply-To: <20200918201436.2932360-1-samitolvanen@google.com> Message-Id: <20200918201436.2932360-9-samitolvanen@google.com> Mime-Version: 1.0 References: <20200918201436.2932360-1-samitolvanen@google.com> X-Mailer: git-send-email 2.28.0.681.g6f77f65b4e-goog Subject: [PATCH v3 08/30] kbuild: add support for objtool mcount From: Sami Tolvanen To: Masahiro Yamada , Will Deacon Cc: Peter Zijlstra , Steven Rostedt , 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, x86@kernel.org, Sami Tolvanen Precedence: bulk List-ID: X-Mailing-List: linux-kbuild@vger.kernel.org This change adds build support for using objtool to generate __mcount_loc sections. Signed-off-by: Sami Tolvanen Reviewed-by: Kees Cook --- Makefile | 38 ++++++++++++++++++++++++++++++-------- kernel/trace/Kconfig | 5 +++++ scripts/Makefile.build | 9 +++++---- 3 files changed, 40 insertions(+), 12 deletions(-) diff --git a/Makefile b/Makefile index 24fd733c142e..d2fb3cd0f506 100644 --- a/Makefile +++ b/Makefile @@ -858,17 +858,34 @@ ifdef CONFIG_HAVE_FENTRY ifeq ($(call cc-option-yn, -mfentry),y) CC_FLAGS_FTRACE += -mfentry CC_FLAGS_USING += -DCC_USING_FENTRY + export CC_USING_FENTRY := 1 endif 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 + ifndef CC_USING_RECORD_MCOUNT + ifndef CC_USING_PATCHABLE_FUNCTION_ENTRY + # use objtool or recordmcount to generate mcount tables + ifdef CONFIG_HAVE_OBJTOOL_MCOUNT + ifdef CC_USING_FENTRY + USE_OBJTOOL_MCOUNT := y + CC_FLAGS_USING += -DCC_USING_NOP_MCOUNT + export USE_OBJTOOL_MCOUNT + endif + endif + ifndef USE_OBJTOOL_MCOUNT + USE_RECORDMCOUNT := y + export USE_RECORDMCOUNT + ifdef CONFIG_HAVE_C_RECORDMCOUNT + BUILD_C_RECORDMCOUNT := y + export BUILD_C_RECORDMCOUNT + endif + endif + endif + endif endif +KBUILD_CFLAGS += $(CC_FLAGS_FTRACE) $(CC_FLAGS_USING) +KBUILD_AFLAGS += $(CC_FLAGS_USING) endif # We trigger additional mismatches with less inlining @@ -1213,11 +1230,16 @@ uapi-asm-generic: PHONY += prepare-objtool prepare-resolve_btfids prepare-objtool: $(objtool_target) ifeq ($(SKIP_STACK_VALIDATION),1) +objtool-lib-prompt := "please install libelf-dev, libelf-devel or elfutils-libelf-devel" +ifdef USE_OBJTOOL_MCOUNT + @echo "error: Cannot generate __mcount_loc for CONFIG_DYNAMIC_FTRACE=y, $(objtool-lib-prompt)" >&2 + @false +endif ifdef CONFIG_UNWINDER_ORC - @echo "error: Cannot generate ORC metadata for CONFIG_UNWINDER_ORC=y, please install libelf-dev, libelf-devel or elfutils-libelf-devel" >&2 + @echo "error: Cannot generate ORC metadata for CONFIG_UNWINDER_ORC=y, $(objtool-lib-prompt)" >&2 @false else - @echo "warning: Cannot use CONFIG_STACK_VALIDATION=y, please install libelf-dev, libelf-devel or elfutils-libelf-devel" >&2 + @echo "warning: Cannot use CONFIG_STACK_VALIDATION=y, $(objtool-lib-prompt)" >&2 endif endif diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index a4020c0b4508..b510af5b216c 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -56,6 +56,11 @@ config HAVE_C_RECORDMCOUNT help C version of recordmcount available? +config HAVE_OBJTOOL_MCOUNT + bool + help + Arch supports objtool --mcount + config TRACER_MAX_TRACE bool diff --git a/scripts/Makefile.build b/scripts/Makefile.build index a467b9323442..6ecf30c70ced 100644 --- a/scripts/Makefile.build +++ b/scripts/Makefile.build @@ -178,8 +178,7 @@ cmd_modversions_c = \ fi endif -ifdef CONFIG_FTRACE_MCOUNT_RECORD -ifndef CC_USING_RECORD_MCOUNT +ifdef USE_RECORDMCOUNT # compiler will not generate __mcount_loc use recordmcount or recordmcount.pl ifdef BUILD_C_RECORDMCOUNT ifeq ("$(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)), \ $(sub_cmd_record_mcount)) -endif # CC_USING_RECORD_MCOUNT -endif # CONFIG_FTRACE_MCOUNT_RECORD +endif # USE_RECORDMCOUNT ifdef CONFIG_STACK_VALIDATION ifneq ($(SKIP_STACK_VALIDATION),1) @@ -230,6 +228,9 @@ endif ifdef CONFIG_X86_SMAP objtool_args += --uaccess endif +ifdef USE_OBJTOOL_MCOUNT + objtool_args += --mcount +endif # 'OBJECT_FILES_NON_STANDARD := y': skip objtool checking for a directory # 'OBJECT_FILES_NON_STANDARD_foo.o := 'y': skip objtool checking for a file