Re: 2.6.7-mm6

[Andrew Morton <akpm@osdl.org>]

William Lee Irwin III <wli@holomorphy.com> wrote:
>
> Third, some naive check for undefined symbols failed to understand the
> relocation types indicating that a given operand refers to some hard
> register, which manifest as undefined symbols in ELF executables. A
> patch to refine its criteria, which I used to build with, follows. rmk
> and hpa have some other ideas on this undefined symbol issue I've not
> quite had the opportunity to get a clear statement of yet.

I converted that to a non-fatal warning due to the same problem on sparc64.

Here's the current patch against -linus.  I think I'll drop it.  Could you
please work with rmk to come up with a final version?


diff -puN Makefile~check-for-undefined-symbols Makefile
--- 25/Makefile~check-for-undefined-symbols	Tue Jul  6 14:41:49 2004
+++ 25-akpm/Makefile	Tue Jul  6 15:33:15 2004
@@ -586,6 +586,15 @@ define rule_verify_kallsyms
 		(echo Inconsistent kallsyms data, try setting CONFIG_KALLSYMS_EXTRA_PASS ; rm .tmp_kallsyms* ; false)
 endef
 
+# Warn if there are undefined symbols in the final linked image.  They can lead
+# to silent link failures.
+define rule_check_vmlinux
+	if $(NM) $@ | grep -q '^ *U '; then				\
+		echo 'ldchk: $@: final image has undefined symbols:';	\
+		$(NM) $@ | sed 's/^ *U \(.*\)/  \1/p;d';		\
+	fi;
+endef
+
 quiet_cmd_kallsyms = KSYM    $@
 cmd_kallsyms = $(NM) -n $< | $(KALLSYMS) $(foreach x,$(CONFIG_KALLSYMS_ALL),--all-symbols) > $@
 
@@ -612,6 +621,7 @@ define rule_vmlinux
 	$(rule_vmlinux__); \
 	$(call do_system_map, $@, System.map)
 	$(rule_verify_kallsyms)
+	$(rule_check_vmlinux)
 endef
 
 vmlinux: $(vmlinux-objs) $(kallsyms.o) arch/$(ARCH)/kernel/vmlinux.lds.s FORCE
_