First, $(shell ...) getting executed before the containing command gets
invoked doesn't have the intended effect when the inner command wants
variables of the outer command expanded. This needs to be done by the
shell executing the entire command.

Second, pattern rules for intermediate files with their targets not
mentioned explicitly result in them getting deleted. Since the .*.o.d
files get generated on the first make run and included for the second,
the second run sees them mentioned explicitly and re-builds them (and
the final *.init.o files), which is particularly annoying if the second
build is actually an install (as root) while normal builds get run as
ordinary user: Some of the output files will suddenly be root owned,
possibly causing permission issues on a later rebuild.

Signed-off-by: Jan Beulich <jbeulich@xxxxxxxxxx>

--- a/xen/Rules.mk
+++ b/xen/Rules.mk
@@ -157,13 +157,13 @@ _clean_%/: FORCE
 SPECIAL_DATA_SECTIONS := rodata $(foreach n,1 2 4 8,rodata.str1.$(n)) \
 			 $(foreach r,rel rel.ro,data.$(r) data.$(r).local)
 
-%.init.o: %.o Makefile
+$(filter %.init.o,$(obj-y) $(obj-bin-y)): %.init.o: %.o Makefile
 	$(OBJDUMP) -h $< | sed -n '/[0-9]/{s,00*,0,g;p}' | while read idx name sz rest; do \
 		case "$$name" in \
 		.text|.text.*|.data|.data.*|.bss) \
 			test $$sz != 0 || continue; \
 			echo "Error: size of $<:$$name is 0x$$sz" >&2; \
-			exit $(shell expr $$idx + 1);; \
+			exit $$(expr $$idx + 1);; \
 		esac; \
 	done
 	$(OBJCOPY) $(foreach s,$(SPECIAL_DATA_SECTIONS),--rename-section .$(s)=.init.$(s)) $< $@