Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757054AbcJQD50 (ORCPT ); Sun, 16 Oct 2016 23:57:26 -0400 Received: from mail-pf0-f195.google.com ([209.85.192.195]:34936 "EHLO mail-pf0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754005AbcJQD5U (ORCPT ); Sun, 16 Oct 2016 23:57:20 -0400 Date: Mon, 17 Oct 2016 14:57:09 +1100 From: Nicholas Piggin To: Omar Sandoval Cc: Michal Marek , Linus Torvalds , adobriyan@gmail.com, sfr@canb.auug.org.au, viro@zeniv.linux.org.uk, linux-kbuild@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [GIT PULL] kbuild changes for v4.9-rc1 Message-ID: <20161017145709.2882f33f@roar.ozlabs.ibm.com> In-Reply-To: <20161016002205.GA9686@vader> References: <20161014201246.GA28782@sepie.suse.cz> <20161016002205.GA9686@vader> Organization: IBM X-Mailer: Claws Mail 3.14.0 (GTK+ 2.24.31; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6827 Lines: 170 On Sat, 15 Oct 2016 17:22:05 -0700 Omar Sandoval wrote: > On Fri, Oct 14, 2016 at 10:12:46PM +0200, Michal Marek wrote: > > Hi Linus, > > > > please pull these kbuild changes for v4.9-rc1: > > > > - EXPORT_SYMBOL for asm source by Al Viro. This does bring a regression, > > because genksyms no longer generates checksums for these symbols > > (CONFIG_MODVERSIONS). Nick Piggin is working on a patch to fix this. > > Plus, we are talking about functions like strcpy(), which rarely > > change prototypes. > > So this has broken all module loading for me. I get the following dmesg > spew: > > ... > [ 4.586914] scsi_mod: no symbol version for memset > [ 4.587920] scsi_mod: Unknown symbol memset (err -22) > [ 4.588443] scsi_mod: no symbol version for ___preempt_schedule > [ 4.589026] scsi_mod: Unknown symbol ___preempt_schedule (err -22) > ... > > Reverting 784d5699eddc ("x86: move exports to actual definitions") fixes > it for me. This is with GCC 6.2.1, binutils 2.27, attached config. > Thanks for the report. Could you try this patch and see if it helps? Allow architectures to create asm/asm-prototypes.h file that provides C prototypes for exported asm functions, which enables proper CRC versions to be generated for them. It's done by creating a trivial C program that includes that file and the EXPORT_SYMBOL()s from the .S file, and preprocesses that then sends the result to genksyms. Signed-off-by: Nicholas Piggin --- scripts/Makefile.build | 71 +++++++++++++++++++++++++++++++++++++++++++++----- 1 file changed, 65 insertions(+), 6 deletions(-) diff --git a/scripts/Makefile.build b/scripts/Makefile.build index de46ab0..edcf876 100644 --- a/scripts/Makefile.build +++ b/scripts/Makefile.build @@ -159,7 +159,8 @@ cmd_cpp_i_c = $(CPP) $(c_flags) -o $@ $< $(obj)/%.i: $(src)/%.c FORCE $(call if_changed_dep,cpp_i_c) -cmd_gensymtypes = \ +# These mirror gensymtypes_S and co below, keep them in synch. +cmd_gensymtypes_c = \ $(CPP) -D__GENKSYMS__ $(c_flags) $< | \ $(GENKSYMS) $(if $(1), -T $(2)) \ $(patsubst y,-s _,$(CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX)) \ @@ -169,7 +170,7 @@ cmd_gensymtypes = \ quiet_cmd_cc_symtypes_c = SYM $(quiet_modtag) $@ cmd_cc_symtypes_c = \ set -e; \ - $(call cmd_gensymtypes,true,$@) >/dev/null; \ + $(call cmd_gensymtypes_c,true,$@) >/dev/null; \ test -s $@ || rm -f $@ $(obj)/%.symtypes : $(src)/%.c FORCE @@ -198,9 +199,10 @@ else # the actual value of the checksum generated by genksyms cmd_cc_o_c = $(CC) $(c_flags) -c -o $(@D)/.tmp_$(@F) $< -cmd_modversions = \ + +cmd_modversions_c = \ if $(OBJDUMP) -h $(@D)/.tmp_$(@F) | grep -q __ksymtab; then \ - $(call cmd_gensymtypes,$(KBUILD_SYMTYPES),$(@:.o=.symtypes)) \ + $(call cmd_gensymtypes_c,$(KBUILD_SYMTYPES),$(@:.o=.symtypes)) \ > $(@D)/.tmp_$(@F:.o=.ver); \ \ $(LD) $(LDFLAGS) -r -o $@ $(@D)/.tmp_$(@F) \ @@ -268,13 +270,14 @@ endif # CONFIG_STACK_VALIDATION define rule_cc_o_c $(call echo-cmd,checksrc) $(cmd_checksrc) \ $(call cmd_and_fixdep,cc_o_c) \ - $(cmd_modversions) \ + $(cmd_modversions_c) \ $(cmd_objtool) \ $(call echo-cmd,record_mcount) $(cmd_record_mcount) endef define rule_as_o_S $(call cmd_and_fixdep,as_o_S) \ + $(cmd_modversions_S) \ $(cmd_objtool) endef @@ -314,6 +317,32 @@ modkern_aflags := $(KBUILD_AFLAGS_KERNEL) $(AFLAGS_KERNEL) $(real-objs-m) : modkern_aflags := $(KBUILD_AFLAGS_MODULE) $(AFLAGS_MODULE) $(real-objs-m:.o=.s): modkern_aflags := $(KBUILD_AFLAGS_MODULE) $(AFLAGS_MODULE) +# .S file exports must have their C prototypes defined in asm/asm-prototypes.h +# or a file that it includes, in order to get versioned symbols. We build a +# dummy C file that includes asm-prototypes and the EXPORT_SYMBOL lines from +# the .S file (with trailing ';'), and run genksyms on that, to extract vers. +# +# These mirror gensymtypes_c and co above, keep them in synch. +cmd_gensymtypes_S = \ + (echo "\#include " ; \ + echo "\#include " ; \ + grep EXPORT_SYMBOL $< | sed 's/$$/;/' ) | \ + $(CPP) -D__GENKSYMS__ $(c_flags) -xc - | \ + $(GENKSYMS) $(if $(1), -T $(2)) \ + $(patsubst y,-s _,$(CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX)) \ + $(if $(KBUILD_PRESERVE),-p) \ + -r $(firstword $(wildcard $(2:.symtypes=.symref) /dev/null)) + +quiet_cmd_cc_symtypes_S = SYM $(quiet_modtag) $@ +cmd_cc_symtypes_S = \ + set -e; \ + $(call cmd_gensymtypes_S,true,$@) >/dev/null; \ + test -s $@ || rm -f $@ + +$(obj)/%.symtypes : $(src)/%.S FORCE + $(call cmd,cc_symtypes_S) + + quiet_cmd_cpp_s_S = CPP $(quiet_modtag) $@ cmd_cpp_s_S = $(CPP) $(a_flags) -o $@ $< @@ -321,7 +350,37 @@ $(obj)/%.s: $(src)/%.S FORCE $(call if_changed_dep,cpp_s_S) quiet_cmd_as_o_S = AS $(quiet_modtag) $@ -cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $< + +ifndef CONFIG_MODVERSIONS +cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $< + +else + +ASM_PROTOTYPES := $(wildcard $(srctree)/arch/$(SRCARCH)/include/asm/asm-prototypes.h) + +ifeq ($(ASM_PROTOTYPES),) +cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $< + +else + +# versioning matches the C process described above, with difference that +# we parse asm-prototypes.h C header to get function definitions. + +cmd_as_o_S = $(CC) $(a_flags) -c -o $(@D)/.tmp_$(@F) $< + +cmd_modversions_S = \ + if $(OBJDUMP) -h $(@D)/.tmp_$(@F) | grep -q __ksymtab; then \ + $(call cmd_gensymtypes_S,$(KBUILD_SYMTYPES),$(@:.o=.symtypes)) \ + > $(@D)/.tmp_$(@F:.o=.ver); \ + \ + $(LD) $(LDFLAGS) -r -o $@ $(@D)/.tmp_$(@F) \ + -T $(@D)/.tmp_$(@F:.o=.ver); \ + rm -f $(@D)/.tmp_$(@F) $(@D)/.tmp_$(@F:.o=.ver); \ + else \ + mv -f $(@D)/.tmp_$(@F) $@; \ + fi; +endif +endif $(obj)/%.o: $(src)/%.S $(objtool_obj) FORCE $(call if_changed_rule,as_o_S) -- 2.9.3