Commit 741f98fe authored by Sam Ravnborg's avatar Sam Ravnborg
Browse files

kbuild: do section mismatch check on full vmlinux 



Previously we did do the check on the .o files used to link
vmlinux but that failed to find questionable references across
the .o files.
Create a dedicated vmlinux.o file used only for section mismatch checks
that uses the defualt linker script so section does not get renamed.

The vmlinux.o may later be used as part of the the final link of vmlinux
but for now it is used fo section mismatch only.
For a defconfig build this is instant but for an allyesconfig this
add two minutes to a full build (that anyways takes ~2 hours).

Signed-off-by: default avatarSam Ravnborg <sam@ravnborg.org>
parent 1e29a706

Makefile

+19 −3
Original line number Diff line number Diff line
@@ -612,7 +612,7 @@ quiet_cmd_vmlinux__ ?= LD $@ 
      cmd_vmlinux__ ?= $(LD) $(LDFLAGS) $(LDFLAGS_vmlinux) -o $@ \

      -T $(vmlinux-lds) $(vmlinux-init)                          \

      --start-group $(vmlinux-main) --end-group                  \

      $(filter-out $(vmlinux-lds) $(vmlinux-init) $(vmlinux-main) FORCE ,$^)

      $(filter-out $(vmlinux-lds) $(vmlinux-init) $(vmlinux-main) vmlinux.o FORCE ,$^)



# Generate new vmlinux version

quiet_cmd_vmlinux_version = GEN     .version
@@ -736,15 +736,31 @@ debug_kallsyms: .tmp_map$(last_kallsyms) 


endif # ifdef CONFIG_KALLSYMS



# Do modpost on a prelinked vmlinux. The finally linked vmlinux has

# relevant sections renamed as per the linker script.

quiet_cmd_vmlinux-modpost = LD      $@

      cmd_vmlinux-modpost = $(LD) $(LDFLAGS) -r -o $@                          \

	 $(vmlinux-init) --start-group $(vmlinux-main) --end-group             \

	 $(filter-out $(vmlinux-init) $(vmlinux-main) $(vmlinux-lds) FORCE ,$^)

define rule_vmlinux-modpost

	:

	+$(call cmd,vmlinux-modpost)

	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost $@

	$(Q)echo 'cmd_$@ := $(cmd_vmlinux-modpost)' > $(dot-target).cmd

endef



# vmlinux image - including updated kernel symbols

vmlinux: $(vmlinux-lds) $(vmlinux-init) $(vmlinux-main) $(kallsyms.o) FORCE

vmlinux: $(vmlinux-lds) $(vmlinux-init) $(vmlinux-main) $(kallsyms.o) vmlinux.o FORCE

ifdef CONFIG_HEADERS_CHECK

	$(Q)$(MAKE) -f $(srctree)/Makefile headers_check

endif

	$(call vmlinux-modpost)

	$(call if_changed_rule,vmlinux__)

	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost $@

	$(Q)rm -f .old_version



vmlinux.o: $(vmlinux-lds) $(vmlinux-init) $(vmlinux-main) $(kallsyms.o) FORCE

	$(call if_changed_rule,vmlinux-modpost)



# The actual objects are generated when descending, 

# make sure no implicit rule kicks in

$(sort $(vmlinux-init) $(vmlinux-main)) $(vmlinux-lds): $(vmlinux-dirs) ;

scripts/Makefile.modpost

+2 −2
Original line number Diff line number Diff line
@@ -70,10 +70,10 @@ __modpost: $(modules:.ko=.o) FORCE 
	$(call cmd,modpost) $(wildcard vmlinux) $(filter-out FORCE,$^)



quiet_cmd_kernel-mod = MODPOST $@

      cmd_kernel-mod = $(cmd_modpost) $(KBUILD_VMLINUX_OBJS)

      cmd_kernel-mod = $(cmd_modpost) $@



PHONY += vmlinux

vmlinux: FORCE

vmlinux.o: FORCE

	$(call cmd,kernel-mod)



# Declare generated files as targets for modpost

scripts/mod/modpost.c

+2 −1
Original line number Diff line number Diff line
@@ -75,7 +75,8 @@ static int is_vmlinux(const char *modname) 
	else

		myname = modname;



	return strcmp(myname, "vmlinux") == 0;

	return (strcmp(myname, "vmlinux") == 0) ||

	       (strcmp(myname, "vmlinux.o") == 0);

}



void *do_nofail(void *ptr, const char *expr)

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