Re: [PATCH v2 2/8] kbuild: Support for Symbols.list creation

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



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@xxxxxxx>

---

   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



[Index of Archives]     [Linux&nblp;USB Development]     [Linux Media]     [Video for Linux]     [Linux Audio Users]     [Yosemite Secrets]     [Linux Kernel]     [Linux SCSI]

  Powered by Linux