From 2e51f26245701cb28f154552836b7807159088a8 Mon Sep 17 00:00:00 2001
From: Jan Beulich
Date: Mon, 16 May 2016 15:31:07 -0500
Subject: [PATCH] objtool: Allow building with older libelf
The switch to elf_getshdr{num,strndx} post-dates the oldest tool chain
the kernel is supposed to be able to build with, so try to cope with
such an environment.
Signed-off-by: Jan Beulich
Signed-off-by: Josh Poimboeuf
Cc: # for v4.6
Cc: Alexander Shishkin
Cc: Arnaldo Carvalho de Melo
Cc: Jan Beulich
Cc: Jiri Olsa
Cc: Linus Torvalds
Cc: Peter Zijlstra
Cc: Stephane Eranian
Cc: Thomas Gleixner
Cc: Vince Weaver
Link: http://lkml.kernel.org/r/732dae6872b7ff187d94f22bb699a12849d3fe04.1463430618.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar
---
tools/objtool/Makefile | 4 ++++
tools/objtool/elf.h | 5 +++++
2 files changed, 9 insertions(+)
diff --git a/tools/objtool/Makefile b/tools/objtool/Makefile
index 6765c7e949f35c..f094f3c4ed8400 100644
--- a/tools/objtool/Makefile
+++ b/tools/objtool/Makefile
@@ -30,6 +30,10 @@ INCLUDES := -I$(srctree)/tools/include
CFLAGS += -Wall -Werror $(EXTRA_WARNINGS) -fomit-frame-pointer -O2 -g $(INCLUDES)
LDFLAGS += -lelf $(LIBSUBCMD)
+# Allow old libelf to be used:
+elfshdr := $(shell echo '\#include ' | $(CC) $(CFLAGS) -x c -E - | grep elf_getshdr)
+CFLAGS += $(if $(elfshdr),,-DLIBELF_USE_DEPRECATED)
+
AWK = awk
export srctree OUTPUT CFLAGS ARCH AWK
include $(srctree)/tools/build/Makefile.include
diff --git a/tools/objtool/elf.h b/tools/objtool/elf.h
index 7f3e00a2f9078d..aa1ff6596684f9 100644
--- a/tools/objtool/elf.h
+++ b/tools/objtool/elf.h
@@ -23,6 +23,11 @@
#include
#include
+#ifdef LIBELF_USE_DEPRECATED
+# define elf_getshdrnum elf_getshnum
+# define elf_getshdrstrndx elf_getshstrndx
+#endif
+
struct section {
struct list_head list;
GElf_Shdr sh;