Re: [PATCH v2 5/8] modpost: Integrate klp-convert

Joao Moreira
2019-04-04T13:56:07Z

On 4/4/19 8:31 AM, Miroslav Benes wrote:
> On Fri, 22 Mar 2019, Joe Lawrence wrote:
>
>> On Fri, Mar 01, 2019 at 11:13:10AM -0300, Joao Moreira wrote:
>>> From: Josh Poimboeuf <jpoimboe@redhat.com>
>>>
>>> Create cmd_klp_convert and hook it into scripts/Makefile.modpost.
>>> cmd_klp_convert invokes klp-convert with the right arguments for the
>>> conversion of unresolved symbols inside a livepatch.
>>>
>>> [khlebnikov:
>>> * save cmd_ld_ko_o into .module.cmd, if_changed_rule doesn't do that
>>> * fix bashisms for debian where /bin/sh is a symlink to /bin/dash
>>> * rename rule_link_module to rule_ld_ko_o, otherwise arg-check inside
>>> if_changed_rule compares cmd_link_module and cmd_ld_ko_o
>>> * check modinfo -F livepatch only if CONFIG_LIVEPATCH is true
>>> ]
>>>
>>> [mbenes:
>>> * remove modinfo call. LIVEPATCH_ in Makefiled
>>> ]
>>>
>>> [jmoreira:
>>> * split up: move the .livepatch file-based scheme for identifying
>>> livepatches to a previous patch, as it was required for correctly
>>> building Symbols.list there.
>>> ]
>>>
>>> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
>>> Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
>>> Signed-off-by: Miroslav Benes <mbenes@suse.cz>
>>> Signed-off-by: Joao Moreira <jmoreira@suse.de>
>>> ---
>>> scripts/Kbuild.include | 4 +++-
>>> scripts/Makefile.modpost | 16 +++++++++++++++-
>>> scripts/mod/modpost.c | 6 +++++-
>>> scripts/mod/modpost.h | 1 +
>>> 4 files changed, 24 insertions(+), 3 deletions(-)
>>>
>>>
>>> [ ... snip ... ]
>>>
>>> diff --git a/scripts/Makefile.modpost b/scripts/Makefile.modpost
>>> index 7d4af0d0accb..da779a185218 100644
>>> --- a/scripts/Makefile.modpost
>>> +++ b/scripts/Makefile.modpost
>>> @@ -125,8 +125,22 @@ quiet_cmd_ld_ko_o = LD [M] $@
>>> -o $@ $(filter-out FORCE,$^) ; \
>>> $(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) $@, true)
>>>
>>> +SLIST = $(objtree)/Symbols.list
>>> +KLP_CONVERT = scripts/livepatch/klp-convert
>>> +quiet_cmd_klp_convert = KLP $@
>>> + cmd_klp_convert = mv $@ $(@:.ko=.klp.o); \
>>> + $(KLP_CONVERT) $(SLIST) $(@:.ko=.klp.o) $@
>>> +
>>> +define rule_ld_ko_o
>>> + $(call cmd,ld_ko_o) $(cmd_ld_ko_o) ; \
>> ^
>> Should there be a ';' semicolon here (and maybe a line-break) between
>> $(call cmd,ld_ko_o) and $(cmd_ld_ko_o)?
>
> Probably yes.
>
> Originally there was
> $(call echo-cmd,ld_ko_o) $(cmd_ld_ko_o) ;
>
> but "echo-" disappeared somewhere. Joao?

Hi,

I just verified my sources and the echo-cmd got lost in between the v2
rebases. I believe it must have happened while I was manually fixing a
conflict, or something. Sorry.

Here is a piece of the original snippet, as it was supposed to be:

define rule_ld_ko_o

$(call echo-cmd,ld_ko_o) $(cmd_ld_ko_o) ;
\
$(call save-cmd,ld_ko_o) ;
\
$(if $(CONFIG_LIVEPATCH), \

Joe, do you mind fixing it for v3?

Thanks for spotting it.

>
> So maybe even
> $(call cmd,ld_ko_o)
> could be enough, because cmd contains echo-cmd, but I'm not good at
> reading scripts/Kbuild.include.
>
>> I didn't see this in my x86_64 VM, but on a ppc64le box, I kept getting
>> really strange build errors that I traced to this line. Without a
>> semicolon, the build was trying to run a make command with a linker
>> command smashed onto the end of it:
>>
>> make -f ./arch/powerpc/Makefile.postlink crypto/xts.ko ld -r -EL -m elf64lppc -T ./scripts/module-common.lds -T ./arch/powerpc/kernel/module.lds --save-restore-funcs --build-id -o crypto/xts.ko crypto/xts.o crypto/xts.mod.o
>
> Miroslav
>