s390/build: use size command to perform empty .bss check

Currently empty .bss checks performed do not pay attention to "common
objects" in object files which end up in .bss section eventually.

The "size" tool is a part of binutils and since version 2.18 provides
"--common" command line option, which allows to account "common objects"
sizes in .bss section size. Utilize "size --common" to perform accurate
check that .bss section is unused. Besides that the size tool handles
object files without .bss section gracefully and doesn't require
additional objdump run.

The linux kernel requires binutils 2.20 since 4.13.

Kbuild exports OBJSIZE to reference the right size tool.

Link: http://lkml.kernel.org/r/patch-2.thread-2257a1.git-2257a1c53d4a.your-ad-here.call-01565088755-ext-5120@work.hours
Reported-and-tested-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
This commit is contained in:
Vasily Gorbik 2019-01-21 13:54:53 +01:00
parent 7bac98707f
commit 739bacbf7a
1 changed files with 1 additions and 2 deletions

View File

@ -11,8 +11,7 @@ chkbss: $(addprefix $(obj)/, $(chkbss-files))
quiet_cmd_chkbss = CHKBSS $<
cmd_chkbss = \
if $(OBJDUMP) -h $< | grep -q "\.bss" && \
! $(OBJDUMP) -j .bss -w -h $< | awk 'END { if ($$3) exit 1 }'; then \
if ! $(OBJSIZE) --common $< | $(AWK) 'END { if ($$3) exit 1 }'; then \
echo "error: $< .bss section is not empty" >&2; exit 1; \
fi; \
touch $@;