kbuild: improve linker compatibility with lib-ksyms.o build

lib-ksyms.o is created by linking an empty input file with a linker script containing the interesting bits. Currently the empty input file is an archive containing nothing, however this causes the gold linker to segfault. I have opened a bug against gold https://sourceware.org/bugzilla/show_bug.cgi?id=20767 However this can be worked around by assembling an empty file to link with instead. The resulting lib-ksyms.o is slightly larger (seemingly due to empty .text, .data, .bss setions added), but final linked output should not be changed.

Nicholas Piggin committed 9 years ago

Commit 9da2f581 parent 7e441fe1 file · +1 −1Browse files

Unified · Split

scripts/Makefile.build+1−1

@@ -424,7 +424,7 @@ quiet_cmd_export_list = EXPORTS $@ · 423 unmodified lines
424	424	cmd_export_list = $(OBJDUMP) -h $< \| \
425	425	sed -ne '/___ksymtab/{s/.+/$(ref_prefix)/;s/ ./)/;p}' >$(ksyms-lds);\
426	426	rm -f $(dummy-object);\
427		− $(AR) rcs$(KBUILD_ARFLAGS) $(dummy-object);\
	427	+ echo \| $(CC) $(a_flags) -c -o $(dummy-object) -x assembler -;\
428	428	$(LD) $(ld_flags) -r -o $@ -T $(ksyms-lds) $(dummy-object);\
429	429	rm $(dummy-object) $(ksyms-lds)
430	430