From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50514 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2406359AbgFXUdJ (ORCPT ); Wed, 24 Jun 2020 16:33:09 -0400 Received: from mail-qt1-x84a.google.com (mail-qt1-x84a.google.com [IPv6:2607:f8b0:4864:20::84a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8CA32C061796 for ; Wed, 24 Jun 2020 13:33:07 -0700 (PDT) Received: by mail-qt1-x84a.google.com with SMTP id c22so2436042qtp.9 for ; Wed, 24 Jun 2020 13:33:07 -0700 (PDT) Date: Wed, 24 Jun 2020 13:31:43 -0700 In-Reply-To: <20200624203200.78870-1-samitolvanen@google.com> Message-Id: <20200624203200.78870-6-samitolvanen@google.com> Mime-Version: 1.0 References: <20200624203200.78870-1-samitolvanen@google.com> Subject: [PATCH 05/22] kbuild: lto: postpone objtool From: Sami Tolvanen Content-Type: text/plain; charset="UTF-8" Sender: linux-kbuild-owner@vger.kernel.org List-ID: To: Masahiro Yamada , Will Deacon Cc: 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 With LTO, LLVM bitcode won't be compiled into native code until modpost_link, or modfinal for modules. This change postpones calls to objtool until after these steps. Signed-off-by: Sami Tolvanen --- include/linux/compiler.h | 2 +- lib/Kconfig.debug | 2 +- scripts/Makefile.build | 2 ++ scripts/Makefile.modfinal | 15 +++++++++++++++ 4 files changed, 19 insertions(+), 2 deletions(-) diff --git a/include/linux/compiler.h b/include/linux/compiler.h index 30827f82ad62..12b115152532 100644 --- a/include/linux/compiler.h +++ b/include/linux/compiler.h @@ -120,7 +120,7 @@ void ftrace_likely_update(struct ftrace_likely_data *f, int val, /* Annotate a C jump table to allow objtool to follow the code flow */ #define __annotate_jump_table __section(.rodata..c_jump_table) -#ifdef CONFIG_DEBUG_ENTRY +#if defined(CONFIG_DEBUG_ENTRY) || defined(CONFIG_LTO_CLANG) /* Begin/end of an instrumentation safe region */ #define instrumentation_begin() ({ \ asm volatile("%c0:\n\t" \ diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 9ad9210d70a1..9fdba71c135a 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -399,7 +399,7 @@ config STACK_VALIDATION config VMLINUX_VALIDATION bool - depends on STACK_VALIDATION && DEBUG_ENTRY && !PARAVIRT + depends on STACK_VALIDATION && (DEBUG_ENTRY || LTO_CLANG) && !PARAVIRT default y config DEBUG_FORCE_WEAK_PER_CPU diff --git a/scripts/Makefile.build b/scripts/Makefile.build index 64e99f4baa5b..82977350f5a6 100644 --- a/scripts/Makefile.build +++ b/scripts/Makefile.build @@ -226,6 +226,7 @@ endif # CC_USING_PATCHABLE_FUNCTION_ENTRY endif # CONFIG_FTRACE_MCOUNT_RECORD ifdef CONFIG_STACK_VALIDATION +ifndef CONFIG_LTO_CLANG ifneq ($(SKIP_STACK_VALIDATION),1) __objtool_obj := $(objtree)/tools/objtool/objtool @@ -258,6 +259,7 @@ objtool_obj = $(if $(patsubst y%,, \ $(__objtool_obj)) endif # SKIP_STACK_VALIDATION +endif # CONFIG_LTO_CLANG endif # CONFIG_STACK_VALIDATION # Rebuild all objects when objtool changes, or is enabled/disabled. diff --git a/scripts/Makefile.modfinal b/scripts/Makefile.modfinal index d168f0cfe67c..9f1df2f1fab5 100644 --- a/scripts/Makefile.modfinal +++ b/scripts/Makefile.modfinal @@ -48,6 +48,21 @@ endif # CC_USING_PATCHABLE_FUNCTION_ENTRY endif # CC_USING_RECORD_MCOUNT endif # CONFIG_FTRACE_MCOUNT_RECORD +ifdef CONFIG_STACK_VALIDATION +ifneq ($(SKIP_STACK_VALIDATION),1) +cmd_ld_ko_o += \ + $(objtree)/tools/objtool/objtool \ + $(if $(CONFIG_UNWINDER_ORC),orc generate,check) \ + --module \ + $(if $(CONFIG_FRAME_POINTER),,--no-fp) \ + $(if $(CONFIG_GCOV_KERNEL),--no-unreachable,) \ + $(if $(CONFIG_RETPOLINE),--retpoline,) \ + $(if $(CONFIG_X86_SMAP),--uaccess,) \ + $(@:.ko=$(prelink-ext).o); + +endif # SKIP_STACK_VALIDATION +endif # CONFIG_STACK_VALIDATION + endif # CONFIG_LTO_CLANG quiet_cmd_ld_ko_o = LD [M] $@ -- 2.27.0.212.ge8ba1cc988-goog