Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754020AbbHLEnV (ORCPT ); Wed, 12 Aug 2015 00:43:21 -0400 Received: from mx1.redhat.com ([209.132.183.28]:56503 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751766AbbHLEnU (ORCPT ); Wed, 12 Aug 2015 00:43:20 -0400 Date: Tue, 11 Aug 2015 23:43:17 -0500 From: Josh Poimboeuf To: Chris J Arges Cc: Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , Michal Marek , Peter Zijlstra , Andy Lutomirski , Borislav Petkov , Linus Torvalds , Andi Kleen , Pedro Alves , Namhyung Kim , Bernd Petrovitsch , x86@kernel.org, live-patching@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v8 00/21] Compile-time stack validation Message-ID: <20150812044317.GB25439@treble.redhat.com> References: <55CA699B.4070809@canonical.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <55CA699B.4070809@canonical.com> User-Agent: Mutt/1.5.23.1-rc1 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4672 Lines: 126 On Tue, Aug 11, 2015 at 04:31:07PM -0500, Chris J Arges wrote: > Josh, > > I've applied and tried to build your patchset against the latest > mainline kernel with the following config: > http://paste.ubuntu.com/12058017/ > > I can build if I disable CONFIG_STACK_VALIDATION, then re-enable it > after all objects are already built, so this seems like it should be > resolvable in Makefiles. Any suggestions for debugging this? > > Building from clean I get the following: > ~/linux$ make > HOSTCC scripts/basic/fixdep > HOSTCC scripts/basic/bin2c > GEN arch/x86/lib/inat-tables.c > HOSTCC arch/x86/tools/relocs_32.o > HOSTCC arch/x86/tools/relocs_64.o > HOSTCC arch/x86/tools/relocs_common.o > HOSTLD arch/x86/tools/relocs > CHK include/config/kernel.release > CHK include/generated/uapi/linux/version.h > CHK include/generated/utsrelease.h > CC arch/x86/purgatory/purgatory.o > AS arch/x86/purgatory/stack.o > AS arch/x86/purgatory/setup-x86_64.o > CC arch/x86/purgatory/sha256.o > AS arch/x86/purgatory/entry64.o > CC arch/x86/purgatory/string.o > LD arch/x86/purgatory/purgatory.ro > BIN2C arch/x86/purgatory/kexec-purgatory.c > CC kernel/bounds.s > CHK include/generated/bounds.h > CHK include/generated/timeconst.h > CC arch/x86/kernel/asm-offsets.s > CHK include/generated/asm-offsets.h > CALL scripts/checksyscalls.sh > HOSTCC scripts/genksyms/genksyms.o > HOSTCC scripts/genksyms/parse.tab.o > HOSTCC scripts/genksyms/lex.lex.o > HOSTLD scripts/genksyms/genksyms > CC scripts/mod/empty.o > scripts/mod/empty.o > open: No such file or directory > error reading elf file scripts/mod/empty.o > scripts/Makefile.build:284: recipe for target 'scripts/mod/empty.o' failed > make[2]: *** [scripts/mod/empty.o] Error 1 > scripts/Makefile.build:429: recipe for target 'scripts/mod' failed > make[1]: *** [scripts/mod] Error 2 > Makefile:545: recipe for target 'scripts' failed > make: *** [scripts] Error 2 Thanks for trying it out. I couldn't figure out how to recreate this exact error, but I played around with "make mrproper" and saw some probably related errors. Does this fix it? ---8<--- Subject: [PATCH] stackvalidate: fix circular build dependencies After "make mrproper" with CONFIG_STACK_VALIDATION enabled, I get the following errors: make[2]: *** No rule to make target 'arch/x86/purgatory/purgatory.o', needed by 'arch/x86/purgatory/purgatory.ro'. Stop. make[3]: *** No rule to make target 'scripts/mod/empty.o', needed by 'scripts/mod/elfconfig.h'. Stop. These are caused by circular dependencies. The %.o pattern rules in scripts/Makefile.build have the stackvalidate binary listed as a dependency. But stackvalidate gets built *after* archprepare and scripts/mod, both of which build objects using the %.o pattern rules. The STACKVALIDATE and STACKVALIDATE_foo.o variables are already used to determine whether to validate a given object. Also use them to determine whether to create the pattern rule dependency. Signed-off-by: Josh Poimboeuf --- scripts/Makefile.build | 7 +++++-- scripts/mod/Makefile | 2 ++ 2 files changed, 7 insertions(+), 2 deletions(-) diff --git a/scripts/Makefile.build b/scripts/Makefile.build index a1270d3..ec96c51 100644 --- a/scripts/Makefile.build +++ b/scripts/Makefile.build @@ -243,7 +243,7 @@ endif ifdef CONFIG_STACK_VALIDATION -stackvalidate = $(objtree)/scripts/stackvalidate/stackvalidate +__stackvalidate = $(objtree)/scripts/stackvalidate/stackvalidate ifndef CONFIG_FRAME_POINTER nofp = --no-frame-pointer @@ -251,9 +251,12 @@ endif # Set STACKVALIDATE_foo.o=n to skip stack validation for a file. # Set STACKVALIDATE=n to skip stack validation for a directory. +stackvalidate = $(if $(patsubst n%,, \ + $(STACKVALIDATE_$(basetarget).o)$(STACKVALIDATE)y), \ + $(__stackvalidate)) cmd_stackvalidate = $(if $(patsubst n%,, \ $(STACKVALIDATE_$(basetarget).o)$(STACKVALIDATE)y), \ - $(stackvalidate) $(nofp) "$(@)";) + $(__stackvalidate) $(nofp) "$(@)";) endif # CONFIG_STACK_VALIDATION diff --git a/scripts/mod/Makefile b/scripts/mod/Makefile index c11212f..374c413 100644 --- a/scripts/mod/Makefile +++ b/scripts/mod/Makefile @@ -1,3 +1,5 @@ +STACKVALIDATE := n + hostprogs-y := modpost mk_elfconfig always := $(hostprogs-y) empty.o -- 2.4.3 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/