From: Joe Lawrence <joe.lawrence@redhat.com>
To: Joao Moreira <jmoreira@suse.de>, Miroslav Benes <mbenes@suse.cz>
Cc: live-patching@vger.kernel.org, pmladek@suse.cz, jikos@suse.cz,
nstange@suse.de, jpoimboe@redhat.com, khlebnikov@yandex-team.ru,
jeyu@kernel.org, matz@suse.de, linux-kernel@vger.kernel.org,
yamada.masahiro@socionext.com, linux-kbuild@vger.kernel.org,
michal.lkml@markovi.net
Subject: Re: [PATCH v2 2/8] kbuild: Support for Symbols.list creation
Date: Tue, 26 Mar 2019 12:15:28 -0400 [thread overview]
Message-ID: <ae018181-fd8a-03b2-69bf-e9302172bfeb@redhat.com> (raw)
In-Reply-To: <5f615af5-ced7-2361-5b71-71fece8b43c5@suse.de>
On 3/26/19 10:40 AM, Joao Moreira wrote:
>
>
> On 3/20/19 4:08 PM, Miroslav Benes wrote:
>>>> diff --git a/scripts/Makefile.build b/scripts/Makefile.build
>>>> index fd03d60f6c5a..1e28ad21314c 100644
>>>> --- a/scripts/Makefile.build
>>>> +++ b/scripts/Makefile.build
>>>> @@ -247,6 +247,11 @@ cmd_gen_ksymdeps = \
>>>> $(CONFIG_SHELL) $(srctree)/scripts/gen_ksymdeps.sh $@ >> $(dot-target).cmd
>>>> endif
>>>>
>>>> +ifdef CONFIG_LIVEPATCH
>>>> +cmd_livepatch = $(if $(LIVEPATCH_$(basetarget).o), \
>>>> + $(shell touch $(MODVERDIR)/$(basetarget).livepatch))
>>>> +endif
>>>> +
>>>> define rule_cc_o_c
>>>> $(call cmd,checksrc)
>>>> $(call cmd_and_fixdep,cc_o_c)
>>>> @@ -283,6 +288,7 @@ $(single-used-m): $(obj)/%.o: $(src)/%.c $(recordmcount_source) $(objtool_dep) F
>>>> $(call if_changed_rule,cc_o_c)
>>>> @{ echo $(@:.o=.ko); echo $@; \
>>>> $(cmd_undef_syms); } > $(MODVERDIR)/$(@F:.o=.mod)
>>>> + $(call cmd_livepatch)
>>>>
>>>> quiet_cmd_cc_lst_c = MKLST $@
>>>> cmd_cc_lst_c = $(CC) $(c_flags) -g -c -o $*.o $< && \
>>>
>>> Since cmd_livepatch is only called for single-used-m, does this mean
>>> that we can only klp-convert single object file livepatch modules?
>>>
>>> I stumbled upon this when trying to create a self-test module that
>>> incorporated two object files. I tried adding a $(call cmd_livepatch)
>>> in the recipe for $(obj)/%.o, but that didn't help. My kbuild foo
>>> wasn't good enough to figure this one out.
>>
>> I looked at my original code and it is a bit different there. I placed it
>> under rule_cc_o_c right after objtool command. If I remember correctly
>> this is the correct recipe for .c->.o. Unfortunately I forgot the details
>> and there is of course nothing about it in my notes.
>>
>> Does it help?
>>
>> Joao, is there a reason you moved it elsewhere?
>
> Hi,
>
> Unfortunately I can't remember why the chunk was moved to where it is in
> this version of the patch, sorry. Yet, I did try to move this into the
> rule cc_o_c and it seemed to work with not damage.
>
> Joe, would you kindly verify and squash properly the patch below, which
> places cmd_livepatch in rule_cc_o_c?
>
> Thank you.
>
> Subject: [PATCH] Move cmd_klp_convert to the right place
>
>
>
> Signed-off-by: Joao Moreira <jmoreira@suse.de>
>
> ---
>
> scripts/Makefile.build | 2 +-
>
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
>
>
> diff --git a/scripts/Makefile.build b/scripts/Makefile.build
> index 1e28ad21314c..5f66106a47d6 100644
> --- a/scripts/Makefile.build
> +++ b/scripts/Makefile.build
> @@ -260,6 +260,7 @@ define rule_cc_o_c
> $(call cmd,objtool)
> $(call cmd,modversions_c)
> $(call cmd,record_mcount)
> + $(call cmd,livepatch)
> endef
>
> define rule_as_o_S
> @@ -288,7 +289,6 @@ $(single-used-m): $(obj)/%.o: $(src)/%.c
> $(recordmcount_source) $(objtool_dep) F
> $(call if_changed_rule,cc_o_c)
> @{ echo $(@:.o=.ko); echo $@; \
> $(cmd_undef_syms); } > $(MODVERDIR)/$(@F:.o=.mod)
> - $(call cmd_livepatch)
>
> quiet_cmd_cc_lst_c = MKLST $@
> cmd_cc_lst_c = $(CC) $(c_flags) -g -c -o $*.o $< && \
Hi Joao,
This change seems to work okay for (again) single object modules, but
I'm having issues with multi-object modules.
Here are my sources:
% head -n100 *
==> Makefile <==
KDIR := /lib/modules/$(shell uname -r)/build
PWD := $(shell pwd)
LIVEPATCH_test_mod_a.o := y
LIVEPATCH_test_mod_b.o := y
obj-m += test_mod.o
test_mod-y := \
test_mod_a.o \
test_mod_b.o
default:
$(MAKE) -C $(KDIR) M=$(PWD)
clean:
@rm -rf .tmp_versions/
@rm -f .*.cmd *.o *.mod.* *.ko modules.order Module.symvers
==> test_mod_a.c <==
#include <linux/module.h>
__used static void function(void) { }
MODULE_LICENSE("GPL");
==> test_mod_b.c <==
__used static void function(void) { }
But when I build, I don't see klp-convert invoked for any of the object
files:
% make
make -C /lib/modules/5.0.0+/build M=/home/cloud-user/klp-convert-modtest
make[1]: Entering directory '/home/cloud-user/disk/linux'
CC [M] /home/cloud-user/klp-convert-modtest/test_mod_a.o
CC [M] /home/cloud-user/klp-convert-modtest/test_mod_b.o
LD [M] /home/cloud-user/klp-convert-modtest/test_mod.o
Building modules, stage 2.
MODPOST 1 modules
CC /home/cloud-user/klp-convert-modtest/test_mod.mod.o
LD [M] /home/cloud-user/klp-convert-modtest/test_mod.ko
make[1]: Leaving directory '/home/cloud-user/disk/linux'
However, if I modify the Makefile to build test_mod_a.o into its own
module, I see "KLP
/home/cloud-user/klp-convert-modtest/test_mod_a.ko" in the build output.
-- Joe
next prev parent reply other threads:[~2019-03-26 16:15 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20190301141313.15057-1-jmoreira@suse.de>
2019-03-18 19:18 ` [PATCH v2 0/8] klp-convert Joe Lawrence
2019-03-26 20:18 ` Joao Moreira
2019-03-26 21:03 ` Joe Lawrence
2019-04-04 11:49 ` Miroslav Benes
2019-04-04 13:19 ` Joe Lawrence
[not found] ` <20190301141313.15057-3-jmoreira@suse.de>
2019-03-18 19:19 ` [PATCH v2 2/8] kbuild: Support for Symbols.list creation Joe Lawrence
2019-03-20 19:08 ` Miroslav Benes
2019-03-26 14:40 ` Joao Moreira
2019-03-26 16:15 ` Joe Lawrence [this message]
2019-03-26 18:13 ` Joao Moreira
2019-03-26 20:53 ` Joe Lawrence
2019-03-28 20:17 ` Joe Lawrence
2019-04-01 19:35 ` Joe Lawrence
2019-04-03 12:48 ` Miroslav Benes
2019-04-03 19:10 ` Joe Lawrence
2019-04-04 9:14 ` Miroslav Benes
2019-04-04 10:59 ` Miroslav Benes
[not found] ` <20190301141313.15057-4-jmoreira@suse.de>
2019-03-18 19:20 ` [PATCH v2 3/8] livepatch: Add klp-convert tool Joe Lawrence
2019-03-20 19:36 ` Miroslav Benes
2019-03-26 20:13 ` Joao Moreira
[not found] ` <20190301141313.15057-7-jmoreira@suse.de>
2019-03-18 19:20 ` [PATCH v2 6/8] modpost: Add modinfo flag to livepatch modules Joe Lawrence
[not found] ` <20190301141313.15057-8-jmoreira@suse.de>
2019-03-18 19:21 ` [PATCH v2 7/8] livepatch: Add sample livepatch module Joe Lawrence
[not found] ` <20190301141313.15057-9-jmoreira@suse.de>
2019-03-18 19:21 ` [PATCH v2 8/8] documentation: Update on livepatch elf format Joe Lawrence
2019-03-20 19:58 ` Miroslav Benes
[not found] ` <20190301141313.15057-6-jmoreira@suse.de>
2019-03-18 19:20 ` [PATCH v2 5/8] modpost: Integrate klp-convert Joe Lawrence
2019-03-22 14:54 ` Joe Lawrence
2019-03-22 16:37 ` Joao Moreira
2019-03-22 18:29 ` Joe Lawrence
2019-04-04 11:31 ` Miroslav Benes
2019-04-04 13:55 ` Joao Moreira
[not found] <20190130165446.19479-1-jmoreira@suse.de>
[not found] ` <20190130165446.19479-3-jmoreira@suse.de>
2019-02-20 14:09 ` [PATCH v2 2/8] kbuild: Support for Symbols.list creation Miroslav Benes
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