+ x86-purgatory-add-missing-force-to-makefile-target.patch added to -mm tree

+ x86-purgatory-add-missing-force-to-makefile-target.patch added to -mm tree

[akpm]

The patch titled
     Subject: x86/purgatory: add missing FORCE to Makefile target
has been added to the -mm tree.  Its filename is
     x86-purgatory-add-missing-force-to-makefile-target.patch

This patch should soon appear at
    http://ozlabs.org/~akpm/mmots/broken-out/x86-purgatory-add-missing-force-to-makefile-target.patch
and later at
    http://ozlabs.org/~akpm/mmotm/broken-out/x86-purgatory-add-missing-force-to-makefile-target.patch

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------------------------------------------------------
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
_

Patches currently in -mm which might be from prudo@linux.ibm.com are

x86-purgatory-add-missing-force-to-makefile-target.patch