From: Philipp Rudo prudo@linux.ibm.com Subject: x86/purgatory: add missing FORCE to Makefile target
- Build the kernel without the fix - Add some flag to the purgatories KBUILD_CFLAGS,I used -fno-asynchronous-unwind-tables - Re-build the kernel
When you look at makes output you see that sha256.o is not re-build in the last step. Also readelf -S still shows the .eh_frame section for sha256.o.
With the fix sha256.o is rebuilt in the last step.
Without FORCE make does not detect changes only made to the command line options. So object files might not be re-built even when they should be. Fix this by adding FORCE where it is missing.
Link: http://lkml.kernel.org/r/20180704110044.29279-2-prudo@linux.ibm.com Fixes: df6f2801f511 ("kernel/kexec_file.c: move purgatories sha256 to common code") Signed-off-by: Philipp Rudo prudo@linux.ibm.com Acked-by: Dave Young dyoung@redhat.com Cc: Ingo Molnar mingo@redhat.com Cc: Thomas Gleixner tglx@linutronix.de Cc: stable@vger.kernel.org [4.17+] Signed-off-by: Andrew Morton akpm@linux-foundation.org ---
arch/x86/purgatory/Makefile | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff -puN arch/x86/purgatory/Makefile~x86-purgatory-add-missing-force-to-makefile-target arch/x86/purgatory/Makefile --- a/arch/x86/purgatory/Makefile~x86-purgatory-add-missing-force-to-makefile-target +++ a/arch/x86/purgatory/Makefile @@ -6,7 +6,7 @@ purgatory-y := purgatory.o stack.o setup targets += $(purgatory-y) PURGATORY_OBJS = $(addprefix $(obj)/,$(purgatory-y))
-$(obj)/sha256.o: $(srctree)/lib/sha256.c +$(obj)/sha256.o: $(srctree)/lib/sha256.c FORCE $(call if_changed_rule,cc_o_c)
LDFLAGS_purgatory.ro := -e purgatory_start -r --no-undefined -nostdlib -z nodefaultlib _