[RFC v5 08/57] objtool: Make ORC support optional

[Julien Thierry]

Currently, only x86 supports ORC. To simplify the addition of other
supported architectures to objtool 'check' command, make the 'orc'
objtool command optional to implement for a given architecture.

Signed-off-by: Julien Thierry <jthierry@xxxxxxxxxx>
---
 tools/objtool/Build     |  2 +-
 tools/objtool/Makefile  | 10 +++++++++-
 tools/objtool/check.c   |  4 ++++
 tools/objtool/objtool.c |  2 ++
 tools/objtool/orc.h     | 33 +++++++++++++++++++++++++++++++--
 5 files changed, 47 insertions(+), 4 deletions(-)

diff --git a/tools/objtool/Build b/tools/objtool/Build
index d069d26d97fa..6e7163f9522a 100644
--- a/tools/objtool/Build
+++ b/tools/objtool/Build
@@ -1,6 +1,6 @@
 objtool-y += arch/$(SRCARCH)/
 objtool-y += builtin-check.o
-objtool-y += builtin-orc.o
+objtool-$(OBJTOOL_ORC) += builtin-orc.o
 objtool-y += check.o
 objtool-y += elf.o
 objtool-y += special.o
diff --git a/tools/objtool/Makefile b/tools/objtool/Makefile
index d2a19b0bc05a..24d653e0b6ec 100644
--- a/tools/objtool/Makefile
+++ b/tools/objtool/Makefile
@@ -6,6 +6,10 @@ ifeq ($(ARCH),x86_64)
 ARCH := x86
 endif
 
+ifeq ($(ARCH),x86)
+OBJTOOL_ORC := y
+endif
+
 # always use the host compiler
 HOSTAR	?= ar
 HOSTCC	?= gcc
@@ -42,8 +46,12 @@ LDFLAGS  += $(LIBELF_LIBS) $(LIBSUBCMD) $(KBUILD_HOSTLDFLAGS)
 elfshdr := $(shell echo '$(pound)include <libelf.h>' | $(CC) $(CFLAGS) -x c -E - | grep elf_getshdr)
 CFLAGS += $(if $(elfshdr),,-DLIBELF_USE_DEPRECATED)
 
+ifeq ($(OBJTOOL_ORC),y)
+CFLAGS	+= -DOBJTOOL_ORC
+endif
+
 AWK = awk
-export srctree OUTPUT CFLAGS SRCARCH AWK
+export srctree OUTPUT CFLAGS SRCARCH AWK OBJTOOL_ORC
 include $(srctree)/tools/build/Makefile.include
 
 $(OBJTOOL_IN): fixdep FORCE
diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 2c5ccf61510a..8f2ff030936d 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -1317,6 +1317,7 @@ static bool has_valid_stack_frame(struct insn_state *state)
 	return false;
 }
 
+#ifdef OBJTOOL_ORC
 static int update_insn_state_regs(struct instruction *insn, struct insn_state *state)
 {
 	struct cfi_reg *cfa = &state->cfa;
@@ -1340,6 +1341,7 @@ static int update_insn_state_regs(struct instruction *insn, struct insn_state *s
 
 	return 0;
 }
+#endif
 
 static void save_reg(struct insn_state *state, unsigned char reg, int base,
 		     int offset)
@@ -1425,8 +1427,10 @@ static int update_insn_state(struct instruction *insn, struct insn_state *state)
 		return 0;
 	}
 
+#ifdef OBJTOOL_ORC
 	if (state->type == ORC_TYPE_REGS || state->type == ORC_TYPE_REGS_IRET)
 		return update_insn_state_regs(insn, state);
+#endif
 
 	switch (op->dest.type) {
 
diff --git a/tools/objtool/objtool.c b/tools/objtool/objtool.c
index 0b3528f05053..8db7139b72cd 100644
--- a/tools/objtool/objtool.c
+++ b/tools/objtool/objtool.c
@@ -34,7 +34,9 @@ static const char objtool_usage_string[] =
 
 static struct cmd_struct objtool_cmds[] = {
 	{"check",	cmd_check,	"Perform stack metadata validation on an object file" },
+#ifdef OBJTOOL_ORC
 	{"orc",		cmd_orc,	"Generate in-place ORC unwind tables for an object file" },
+#endif
 };
 
 bool help;
diff --git a/tools/objtool/orc.h b/tools/objtool/orc.h
index ffda072cf4ad..f5303b8264e3 100644
--- a/tools/objtool/orc.h
+++ b/tools/objtool/orc.h
@@ -6,14 +6,43 @@
 #ifndef _ORC_H
 #define _ORC_H
 
-#include <asm/orc_types.h>
-
 struct objtool_file;
 
+#ifdef OBJTOOL_ORC
+
+#include <asm/orc_types.h>
+
 int arch_orc_init(struct objtool_file *file);
 int arch_orc_create_sections(struct objtool_file *file);
 int arch_orc_read_unwind_hints(struct objtool_file *file);
 
 int orc_dump(const char *objname);
 
+#else
+
+struct orc_entry {
+};
+
+static inline int arch_orc_init(struct objtool_file *file)
+{
+	return 0;
+}
+
+static inline int arch_orc_create_sections(struct objtool_file *file)
+{
+	return 0;
+}
+
+static inline int arch_orc_read_unwind_hints(struct objtool_file *file)
+{
+	return 0;
+}
+
+static inline int orc_dump(const char *objname)
+{
+	return 0;
+}
+
+#endif /* OBJTOOL_ORC */
+
 #endif /* _ORC_H */
-- 
2.21.0