From 61ce2b5a5324233febdd15ce815bab0f19f7aef1 Mon Sep 17 00:00:00 2001
From: Bill Wendling <morbo@google.com>
Date: Wed, 5 May 2021 22:37:46 -0700
Subject: [PATCH 1/5] create-diff-object: Add --arch option

We could be generating patches for architectures that are different from
the current one. Use "--arch" to specify the architecture.

Signed-off-by: Bill Wendling <morbo@google.com>
---
 kpatch-build/create-diff-object.c | 262 +++++++++++++++++-------------
 kpatch-build/kpatch-build         |  12 +-
 2 files changed, 161 insertions(+), 113 deletions(-)

diff --git a/kpatch-build/create-diff-object.c b/kpatch-build/create-diff-object.c
index 14eb1f587..82c5b6ddf 100644
--- a/kpatch-build/create-diff-object.c
+++ b/kpatch-build/create-diff-object.c
@@ -60,11 +60,15 @@
 	error(EXIT_STATUS_DIFF_FATAL, 0, "unreconcilable difference"); \
 })
 
-#ifdef __powerpc64__
-#define ABSOLUTE_RELA_TYPE R_PPC64_ADDR64
-#else
-#define ABSOLUTE_RELA_TYPE R_X86_64_64
-#endif
+#define ABSOLUTE_RELA_TYPE			\
+({						\
+	unsigned int __ret;			\
+	if (arch == X86_64)			\
+		__ret = R_X86_64_64;		\
+	else if (arch == PPC64)			\
+		__ret = R_PPC64_ADDR64;		\
+	__ret;					\
+})
 
 char *childobj;
 
@@ -76,6 +80,15 @@ enum subsection {
 
 enum loglevel loglevel = NORMAL;
 
+enum architecture {
+	X86_64 = 0x1 << 0,
+	PPC64  = 0x1 << 1,
+	DEFAULT_ARCH = X86_64,
+};
+
+/* Default to the x86 architecture. */
+enum architecture arch = DEFAULT_ARCH;
+
 bool KLP_ARCH;
 
 /*******************
@@ -83,6 +96,7 @@ bool KLP_ARCH;
  * ****************/
 struct special_section {
 	char *name;
+	enum architecture arch;
 	int (*group_size)(struct kpatch_elf *kelf, int offset);
 };
 
@@ -137,41 +151,37 @@ static int is_bundleable(struct symbol *sym)
 	return 0;
 }
 
-#ifdef __powerpc64__
 /* Symbol st_others value for powerpc */
 #define STO_PPC64_LOCAL_BIT     5
 #define STO_PPC64_LOCAL_MASK    (7 << STO_PPC64_LOCAL_BIT)
 #define PPC64_LOCAL_ENTRY_OFFSET(other)                                 \
 	        (((1 << (((other) & STO_PPC64_LOCAL_MASK) >> STO_PPC64_LOCAL_BIT)) >> 2) << 2)
 
-/*
- * On ppc64le, the function prologue generated by GCC 6+ has the sequence:
- *
- *	.globl my_func
- *	.type my_func, @function
- *	.quad .TOC.-my_func
- * my_func:
- *	.reloc ., R_PPC64_ENTRY ; optional
- *	ld r2,-8(r12)
- *	add r2,r2,r12
- *	.localentry my_func, .-my_func
- *
- * my_func is the global entry point, which, when called, sets up the TOC.
- * .localentry is the local entry point, for calls to the function from within
- * the object file.  The local entry point is 8 bytes after the global entry
- * point.
- */
-static int is_gcc6_localentry_bundled_sym(struct symbol *sym)
-{
-	return ((PPC64_LOCAL_ENTRY_OFFSET(sym->sym.st_other) != 0) &&
-		sym->sym.st_value == 8);
-}
-#else
 static int is_gcc6_localentry_bundled_sym(struct symbol *sym)
 {
+	if (arch == PPC64)
+		/*
+		 * On ppc64le, the function prologue generated by GCC 6+ has
+		 * the sequence:
+		 *
+		 *	.globl my_func
+		 *	.type my_func, @function
+		 *	.quad .TOC.-my_func
+		 * my_func:
+		 *	.reloc ., R_PPC64_ENTRY ; optional
+		 *	ld r2,-8(r12)
+		 *	add r2,r2,r12
+		 *	.localentry my_func, .-my_func
+		 *
+		 * my_func is the global entry point, which, when called, sets
+		 * up the TOC.  .localentry is the local entry point, for calls
+		 * to the function from within the object file.  The local
+		 * entry point is 8 bytes after the global entry point.
+		 */
+		return ((PPC64_LOCAL_ENTRY_OFFSET(sym->sym.st_other) != 0) &&
+			sym->sym.st_value == 8);
 	return 0;
 }
-#endif
 
 /*
  * On ppc64le, when a function references data, it does so indirectly, via the
@@ -577,7 +587,6 @@ static void kpatch_compare_correlated_section(struct section *sec)
 		log_debug("section %s has changed\n", sec->name);
 }
 
-#ifdef __x86_64__
 /*
  * Determine if a section has changed only due to a WARN* or might_sleep
  * macro call's embedding of the line number into an instruction operand.
@@ -609,7 +618,7 @@ static void kpatch_compare_correlated_section(struct section *sec)
  * 3) (optional) __warned.xxxxx static local rela
  * 4) warn_slowpath_* or __might_sleep or some other similar rela
  */
-static int kpatch_line_macro_change_only(struct section *sec)
+static int kpatch_line_macro_change_only_x86_64(struct section *sec)
 {
 	struct insn insn1, insn2;
 	unsigned long start1, start2, size, offset, length;
@@ -688,11 +697,11 @@ static int kpatch_line_macro_change_only(struct section *sec)
 
 	return 1;
 }
-#elif __powerpc64__
+
 #define PPC_INSTR_LEN 4
 #define PPC_RA_OFFSET 16
 
-static int kpatch_line_macro_change_only(struct section *sec)
+static int kpatch_line_macro_change_only_ppc64le(struct section *sec)
 {
 	unsigned long start1, start2, size, offset;
 	unsigned int instr1, instr2;
@@ -754,12 +763,15 @@ static int kpatch_line_macro_change_only(struct section *sec)
 
 	return 1;
 }
-#else
+
 static int kpatch_line_macro_change_only(struct section *sec)
 {
+	if (arch == X86_64)
+		return kpatch_line_macro_change_only_x86_64(sec);
+	else if (arch == PPC64)
+		return kpatch_line_macro_change_only_ppc64le(sec);
 	return 0;
 }
-#endif
 
 /*
  * Child functions with "*.cold" names don't have _fentry_ calls, but "*.part",
@@ -1430,7 +1442,6 @@ static void kpatch_compare_correlated_elements(struct kpatch_elf *kelf)
 	kpatch_compare_symbols(&kelf->symbols);
 }
 
-#ifdef __x86_64__
 static void rela_insn(const struct section *sec, const struct rela *rela,
 		      struct insn *insn)
 {
@@ -1454,7 +1465,6 @@ static void rela_insn(const struct section *sec, const struct rela *rela,
 			return;
 	}
 }
-#endif
 
 static bool is_callback_section(struct section *sec) {
 
@@ -1525,22 +1535,23 @@ static void kpatch_replace_sections_syms(struct kpatch_elf *kelf)
 				continue;
 			}
 
-#ifdef __powerpc64__
-			add_off = 0;
-#else
-			if (rela->type == R_X86_64_PC32 ||
-			    rela->type == R_X86_64_PLT32) {
-				struct insn insn;
-				rela_insn(sec, rela, &insn);
-				add_off = (unsigned int)((long)insn.next_byte -
-					  (long)sec->base->data->d_buf -
-					  rela->offset);
-			} else if (rela->type == R_X86_64_64 ||
-				   rela->type == R_X86_64_32S)
+			if (arch == PPC64)
 				add_off = 0;
-			else
-				continue;
-#endif
+			else if (arch == X86_64) {
+				if (rela->type == R_X86_64_PC32 ||
+				    rela->type == R_X86_64_PLT32) {
+					struct insn insn;
+					rela_insn(sec, rela, &insn);
+					add_off = (unsigned int)((long)insn.next_byte -
+						  (long)sec->base->data->d_buf -
+						  rela->offset);
+				} else if (rela->type == R_X86_64_64 ||
+					   rela->type == R_X86_64_32S)
+					add_off = 0;
+				else
+					continue;
+			}
+
 
 			/*
 			 * Attempt to replace references to unbundled sections
@@ -2001,7 +2012,6 @@ static int jump_table_group_size(struct kpatch_elf *kelf, int offset)
 	return size;
 }
 
-#ifdef __x86_64__
 static int parainstructions_group_size(struct kpatch_elf *kelf, int offset)
 {
 	static int size = 0;
@@ -2051,8 +2061,7 @@ static int static_call_sites_group_size(struct kpatch_elf *kelf, int offset)
 
 	return size;
 }
-#endif
-#ifdef __powerpc64__
+
 static int fixup_entry_group_size(struct kpatch_elf *kelf, int offset)
 {
 	static int size = 0;
@@ -2077,7 +2086,6 @@ static int fixup_barrier_nospec_group_size(struct kpatch_elf *kelf, int offset)
 {
 	return 8;
 }
-#endif
 
 /*
  * The rela groups in the .fixup section vary in size.  The beginning of each
@@ -2132,60 +2140,69 @@ static int fixup_group_size(struct kpatch_elf *kelf, int offset)
 static struct special_section special_sections[] = {
 	{
 		.name		= "__bug_table",
+		.arch		= X86_64 | PPC64,
 		.group_size	= bug_table_group_size,
 	},
 	{
 		.name		= ".fixup",
+		.arch		= X86_64 | PPC64,
 		.group_size	= fixup_group_size,
 	},
 	{
 		.name		= "__ex_table", /* must come after .fixup */
+		.arch		= X86_64 | PPC64,
 		.group_size	= ex_table_group_size,
 	},
 	{
 		.name		= "__jump_table",
+		.arch		= X86_64 | PPC64,
 		.group_size	= jump_table_group_size,
 	},
-#ifdef __x86_64__
 	{
 		.name		= ".smp_locks",
+		.arch		= X86_64,
 		.group_size	= smp_locks_group_size,
 	},
 	{
 		.name		= ".parainstructions",
+		.arch		= X86_64,
 		.group_size	= parainstructions_group_size,
 	},
 	{
 		.name		= ".altinstructions",
+		.arch		= X86_64,
 		.group_size	= altinstructions_group_size,
 	},
 	{
 		.name		= ".static_call_sites",
+		.arch		= X86_64,
 		.group_size	= static_call_sites_group_size,
 	},
-#endif
-#ifdef __powerpc64__
 	{
 		.name		= "__ftr_fixup",
+		.arch		= PPC64,
 		.group_size	= fixup_entry_group_size,
 	},
 	{
 		.name		= "__mmu_ftr_fixup",
+		.arch		= PPC64,
 		.group_size	= fixup_entry_group_size,
 	},
 	{
 		.name		= "__fw_ftr_fixup",
+		.arch		= PPC64,
 		.group_size	= fixup_entry_group_size,
 	},
 	{
 		.name		= "__lwsync_fixup",
+		.arch		= PPC64,
 		.group_size	= fixup_lwsync_group_size,
 	},
 	{
 		.name		= "__barrier_nospec_fixup",
+		.arch		= PPC64,
 		.group_size	= fixup_barrier_nospec_group_size,
 	},
-#endif
 	{},
 };
 
@@ -2723,6 +2740,9 @@ static void kpatch_create_kpatch_arch_section(struct kpatch_elf *kelf, char *obj
 		ERROR("can't find .kpatch.strings symbol");
 
 	for (special = special_sections; special->name; special++) {
+		if ((special->arch & arch) == 0)
+			continue;
+
 		if (strcmp(special->name, ".parainstructions") &&
 		    strcmp(special->name, ".altinstructions"))
 			continue;
@@ -2764,6 +2784,9 @@ static void kpatch_process_special_sections(struct kpatch_elf *kelf,
 	int altinstr = 0;
 
 	for (special = special_sections; special->name; special++) {
+		if ((special->arch & arch) == 0)
+			continue;
+
 		sec = find_section_by_name(&kelf->sections, special->name);
 		if (!sec || !sec->rela)
 			continue;
@@ -3232,9 +3255,13 @@ static void kpatch_create_intermediate_sections(struct kpatch_elf *kelf,
 			continue;
 
 		special = false;
-		for (s = special_sections; s->name; s++)
+		for (s = special_sections; s->name; s++) {
+			if ((s->arch & arch) == 0)
+				continue;
+
 			if (!strcmp(sec->base->name, s->name))
 				special = true;
+		}
 
 		list_for_each_entry_safe(rela, safe, &sec->relas, list) {
 			if (!rela->need_dynrela)
@@ -3433,65 +3460,63 @@ static void kpatch_create_mcount_sections(struct kpatch_elf *kelf)
 			continue;
 		}
 
-#ifdef __x86_64__
-
-		rela = list_first_entry(&sym->sec->rela->relas, struct rela, list);
-
-		/*
-		 * For "call fentry", the relocation points to 1 byte past the
-		 * beginning of the instruction.
-		 */
-		insn_offset = rela->offset - 1;
 
-		if (rela->type == R_X86_64_NONE) {
-			void *newdata;
-			unsigned char *insn;
+		if (arch == X86_64) {
+			rela = list_first_entry(&sym->sec->rela->relas, struct rela, list);
 
 			/*
-			 * R_X86_64_NONE is only generated by older versions of
-			 * kernel/gcc which use the mcount script.  There's a
-			 * NOP instead of a call to fentry.
+			 * For "call fentry", the relocation points to 1 byte past the
+			 * beginning of the instruction.
 			 */
+			insn_offset = rela->offset - 1;
 
-			/* Make a writable copy of the text section data */
-			newdata = malloc(sym->sec->data->d_size);
-			memcpy(newdata, sym->sec->data->d_buf, sym->sec->data->d_size);
-			sym->sec->data->d_buf = newdata;
-			insn = newdata;
+			if (rela->type == R_X86_64_NONE) {
+				void *newdata;
+				unsigned char *insn;
 
-			/*
-			 * Replace the NOP with a call to fentry.  The fentry
-			 * rela symbol is already there, just need to change
-			 * the relocation type accordingly.
-			 */
-			insn = sym->sec->data->d_buf;
-			if (insn[0] != 0xf)
-				ERROR("%s: unexpected instruction at the start of the function", sym->name);
-			insn[0] = 0xe8;
-			insn[1] = 0;
-			insn[2] = 0;
-			insn[3] = 0;
-			insn[4] = 0;
-
-			rela->type = R_X86_64_PC32;
-		}
+				/*
+				 * R_X86_64_NONE is only generated by older versions of
+				 * kernel/gcc which use the mcount script.  There's a
+				 * NOP instead of a call to fentry.
+				 */
 
-#else /* __powerpc64__ */
-{
-		bool found = false;
+				/* Make a writable copy of the text section data */
+				newdata = malloc(sym->sec->data->d_size);
+				memcpy(newdata, sym->sec->data->d_buf, sym->sec->data->d_size);
+				sym->sec->data->d_buf = newdata;
+				insn = newdata;
 
-		list_for_each_entry(rela, &sym->sec->rela->relas, list)
-			if (!strcmp(rela->sym->name, "_mcount")) {
-				found = true;
-				break;
+				/*
+				 * Replace the NOP with a call to fentry.  The fentry
+				 * rela symbol is already there, just need to change
+				 * the relocation type accordingly.
+				 */
+				insn = sym->sec->data->d_buf;
+				if (insn[0] != 0xf)
+					ERROR("%s: unexpected instruction at the start of the function", sym->name);
+				insn[0] = 0xe8;
+				insn[1] = 0;
+				insn[2] = 0;
+				insn[3] = 0;
+				insn[4] = 0;
+
+				rela->type = R_X86_64_PC32;
 			}
+		} else if (arch == PPC64) {
+			bool found = false;
 
-		if (!found)
-			ERROR("%s: unexpected missing call to _mcount()", __func__);
+			list_for_each_entry(rela, &sym->sec->rela->relas, list)
+				if (!strcmp(rela->sym->name, "_mcount")) {
+					found = true;
+					break;
+				}
+
+			if (!found)
+				ERROR("%s: unexpected missing call to _mcount()", __func__);
+
+			insn_offset = rela->offset;
+		}
 
-		insn_offset = rela->offset;
-}
-#endif
 		/*
 		 * 'rela' points to the mcount/fentry call.
 		 *
@@ -3606,11 +3631,13 @@ static void kpatch_build_strings_section_data(struct kpatch_elf *kelf)
  */
 static void kpatch_no_sibling_calls_ppc64le(struct kpatch_elf *kelf)
 {
-#ifdef __powerpc64__
 	struct symbol *sym;
 	unsigned int insn;
 	unsigned int offset;
 
+	if (arch != PPC64)
+		return;
+
 	list_for_each_entry(sym, &kelf->symbols, list) {
 		if (sym->type != STT_FUNC || sym->status != CHANGED)
 			continue;
@@ -3643,17 +3670,18 @@ static void kpatch_no_sibling_calls_ppc64le(struct kpatch_elf *kelf)
 			      sym->name, sym->sym.st_value + offset, sym->name);
 		}
 	}
-#endif
 }
 
 struct arguments {
 	char *args[7];
+	enum architecture arch;
 	bool debug, klp_arch;
 };
 
 static char args_doc[] = "original.o patched.o parent-name parent-symtab Module.symvers patch-module-name output.o";
 
 static struct argp_option options[] = {
+	{"arch",	777, "ARCH", 0, "Architecture: x86_64, powerpc [default: x86_64]"},
 	{"debug",	'd', NULL, 0, "Show debug output" },
 	{"klp-arch",	'a', NULL, 0, "Kernel supports .klp.arch section" },
 	{ NULL }
@@ -3673,6 +3701,14 @@ static error_t parse_opt (int key, char *arg, struct argp_state *state)
 		case 'a':
 			arguments->klp_arch = 1;
 			break;
+		case 777: /* --arch */
+			if (!strcmp(arg, "x86_64"))
+				arguments->arch = X86_64;
+			else if (!strcmp(arg, "powerpc"))
+				arguments->arch = PPC64;
+			else
+				argp_failure (state, 1, 0, "invalid value for --arch: %s", arg);
+			break;
 		case ARGP_KEY_ARG:
 			if (state->arg_num >= 7)
 				/* Too many arguments. */
@@ -3710,6 +3746,8 @@ int main(int argc, char *argv[])
 		loglevel = DEBUG;
 	if (arguments.klp_arch)
 		KLP_ARCH = true;
+	if (arguments.arch != DEFAULT_ARCH)
+		arch = arguments.arch;
 
 	elf_version(EV_CURRENT);
 
diff --git a/kpatch-build/kpatch-build b/kpatch-build/kpatch-build
index 617f85780..4825fecc8 100755
--- a/kpatch-build/kpatch-build
+++ b/kpatch-build/kpatch-build
@@ -1057,7 +1057,17 @@ for i in $FILES; do
 
 		# create-diff-object orig.o patched.o parent-name parent-symtab
 		#		     Module.symvers patch-mod-name output.o
-		"$TOOLSDIR"/create-diff-object $CDO_FLAGS "orig/$i" "patched/$i" "$KOBJFILE_NAME" \
+		arch=$(readelf --file-header "orig/$i" | grep "Machine:" | sed -e 's,.*Machine:\s*,,')
+		case "${arch}" in
+			PowerPC*)
+				ARCH_FLAG="--arch powerpc"
+				;;
+			*)
+				ARCH_FLAG="--arch x86_64"
+				;;
+		esac
+		"$TOOLSDIR"/create-diff-object ${ARCH_FLAG} $CDO_FLAGS \
+			"orig/$i" "patched/$i" "$KOBJFILE_NAME" \
 			"$SYMTAB" "$SYMVERS_FILE" "${MODNAME//-/_}" \
 			"output/$i" 2>&1 | logger 1
 		check_pipe_status create-diff-object

From e0902068e4f37c7915c536642036cedb8654e275 Mon Sep 17 00:00:00 2001
From: Bill Wendling <morbo@google.com>
Date: Wed, 5 May 2021 22:49:42 -0700
Subject: [PATCH 2/5] Properly quote the ARCH_FLAG variable

---
 kpatch-build/kpatch-build | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kpatch-build/kpatch-build b/kpatch-build/kpatch-build
index 4825fecc8..e5a891292 100755
--- a/kpatch-build/kpatch-build
+++ b/kpatch-build/kpatch-build
@@ -1066,7 +1066,7 @@ for i in $FILES; do
 				ARCH_FLAG="--arch x86_64"
 				;;
 		esac
-		"$TOOLSDIR"/create-diff-object ${ARCH_FLAG} $CDO_FLAGS \
+		"$TOOLSDIR"/create-diff-object "$ARCH_FLAG" $CDO_FLAGS \
 			"orig/$i" "patched/$i" "$KOBJFILE_NAME" \
 			"$SYMTAB" "$SYMVERS_FILE" "${MODNAME//-/_}" \
 			"output/$i" 2>&1 | logger 1

From a01387cac973cdc34ffab63b69ee68efbced73a0 Mon Sep 17 00:00:00 2001
From: Bill Wendling <morbo@google.com>
Date: Mon, 7 Jun 2021 11:11:23 -0700
Subject: [PATCH 3/5] kpatch-build: add "--arch" flag to other create-*
 binaries

---
 kpatch-build/create-diff-object.c   | 112 ++++++++++++++--------------
 kpatch-build/create-klp-module.c    |  17 +++++
 kpatch-build/create-kpatch-module.c |  17 +++++
 kpatch-build/kpatch-elf.c           |  32 ++++----
 kpatch-build/kpatch-elf.h           |   8 ++
 test/unit/Makefile.include          |   5 +-
 6 files changed, 117 insertions(+), 74 deletions(-)

diff --git a/kpatch-build/create-diff-object.c b/kpatch-build/create-diff-object.c
index 82c5b6ddf..34d611a86 100644
--- a/kpatch-build/create-diff-object.c
+++ b/kpatch-build/create-diff-object.c
@@ -60,13 +60,14 @@
 	error(EXIT_STATUS_DIFF_FATAL, 0, "unreconcilable difference"); \
 })
 
-#define ABSOLUTE_RELA_TYPE			\
+#define ABSOLUTE_RELA_TYPE \
 ({						\
-	unsigned int __ret;			\
-	if (arch == X86_64)			\
-		__ret = R_X86_64_64;		\
-	else if (arch == PPC64)			\
-		__ret = R_PPC64_ADDR64;		\
+	typeof(R_X86_64_64) __ret = 0;		\
+	switch (current_arch) {			\
+	case ARM64:  __ret = R_AARCH64_ABS64;	\
+	case PPC64:  __ret = R_PPC64_ADDR64;	\
+	case X86_64: __ret = R_X86_64_64;	\
+	}					\
 	__ret;					\
 })
 
@@ -80,17 +81,10 @@ enum subsection {
 
 enum loglevel loglevel = NORMAL;
 
-enum architecture {
-	X86_64 = 0x1 << 0,
-	PPC64  = 0x1 << 1,
-	DEFAULT_ARCH = X86_64,
-};
-
-/* Default to the x86 architecture. */
-enum architecture arch = DEFAULT_ARCH;
-
 bool KLP_ARCH;
 
+enum architecture current_arch;
+
 /*******************
  * Data structures
  * ****************/
@@ -157,30 +151,29 @@ static int is_bundleable(struct symbol *sym)
 #define PPC64_LOCAL_ENTRY_OFFSET(other)                                 \
 	        (((1 << (((other) & STO_PPC64_LOCAL_MASK) >> STO_PPC64_LOCAL_BIT)) >> 2) << 2)
 
+/*
+ * On ppc64le, the function prologue generated by GCC 6+ has the sequence:
+ *
+ *	.globl my_func
+ *	.type my_func, @function
+ *	.quad .TOC.-my_func
+ * my_func:
+ *	.reloc ., R_PPC64_ENTRY ; optional
+ *	ld r2,-8(r12)
+ *	add r2,r2,r12
+ *	.localentry my_func, .-my_func
+ *
+ * my_func is the global entry point, which, when called, sets up the TOC.
+ * .localentry is the local entry point, for calls to the function from within
+ * the object file.  The local entry point is 8 bytes after the global entry
+ * point.
+ */
 static int is_gcc6_localentry_bundled_sym(struct symbol *sym)
 {
-	if (arch == PPC64)
-		/*
-		 * On ppc64le, the function prologue generated by GCC 6+ has
-		 * the sequence:
-		 *
-		 *	.globl my_func
-		 *	.type my_func, @function
-		 *	.quad .TOC.-my_func
-		 * my_func:
-		 *	.reloc ., R_PPC64_ENTRY ; optional
-		 *	ld r2,-8(r12)
-		 *	add r2,r2,r12
-		 *	.localentry my_func, .-my_func
-		 *
-		 * my_func is the global entry point, which, when called, sets
-		 * up the TOC.  .localentry is the local entry point, for calls
-		 * to the function from within the object file.  The local
-		 * entry point is 8 bytes after the global entry point.
-		 */
-		return ((PPC64_LOCAL_ENTRY_OFFSET(sym->sym.st_other) != 0) &&
-			sym->sym.st_value == 8);
-	return 0;
+	if (current_arch != PPC64)
+		return 0;
+	return ((PPC64_LOCAL_ENTRY_OFFSET(sym->sym.st_other) != 0) &&
+		sym->sym.st_value == 8);
 }
 
 /*
@@ -701,7 +694,7 @@ static int kpatch_line_macro_change_only_x86_64(struct section *sec)
 #define PPC_INSTR_LEN 4
 #define PPC_RA_OFFSET 16
 
-static int kpatch_line_macro_change_only_ppc64le(struct section *sec)
+static int kpatch_line_macro_change_only_ppc64(struct section *sec)
 {
 	unsigned long start1, start2, size, offset;
 	unsigned int instr1, instr2;
@@ -764,12 +757,19 @@ static int kpatch_line_macro_change_only_ppc64le(struct section *sec)
 	return 1;
 }
 
+static int kpatch_line_macro_change_only_arm64(struct section *sec)
+{
+	/* TODO */
+	return 0;
+}
+
 static int kpatch_line_macro_change_only(struct section *sec)
 {
-	if (arch == X86_64)
-		return kpatch_line_macro_change_only_x86_64(sec);
-	else if (arch == PPC64)
-		return kpatch_line_macro_change_only_ppc64le(sec);
+	switch (current_arch) {
+	case ARM64:  return kpatch_line_macro_change_only_arm64(sec);
+	case PPC64:  return kpatch_line_macro_change_only_ppc64(sec);
+	case X86_64: return kpatch_line_macro_change_only_x86_64(sec);
+	}
 	return 0;
 }
 
@@ -1535,9 +1535,9 @@ static void kpatch_replace_sections_syms(struct kpatch_elf *kelf)
 				continue;
 			}
 
-			if (arch == PPC64)
+			if (current_arch == PPC64) {
 				add_off = 0;
-			else if (arch == X86_64) {
+			} else if (current_arch == X86_64) {
 				if (rela->type == R_X86_64_PC32 ||
 				    rela->type == R_X86_64_PLT32) {
 					struct insn insn;
@@ -1552,7 +1552,6 @@ static void kpatch_replace_sections_syms(struct kpatch_elf *kelf)
 					continue;
 			}
 
-
 			/*
 			 * Attempt to replace references to unbundled sections
 			 * with their symbols.
@@ -3460,8 +3459,7 @@ static void kpatch_create_mcount_sections(struct kpatch_elf *kelf)
 			continue;
 		}
 
-
-		if (arch == X86_64) {
+		if (current_arch == X86_64) {
 			rela = list_first_entry(&sym->sec->rela->relas, struct rela, list);
 
 			/*
@@ -3502,7 +3500,7 @@ static void kpatch_create_mcount_sections(struct kpatch_elf *kelf)
 
 				rela->type = R_X86_64_PC32;
 			}
-		} else if (arch == PPC64) {
+		} else if (current_arch == PPC64) {
 			bool found = false;
 
 			list_for_each_entry(rela, &sym->sec->rela->relas, list)
@@ -3635,7 +3633,7 @@ static void kpatch_no_sibling_calls_ppc64le(struct kpatch_elf *kelf)
 	unsigned int insn;
 	unsigned int offset;
 
-	if (arch != PPC64)
+	if (current_arch != PPC64)
 		return;
 
 	list_for_each_entry(sym, &kelf->symbols, list) {
@@ -3681,9 +3679,9 @@ struct arguments {
 static char args_doc[] = "original.o patched.o parent-name parent-symtab Module.symvers patch-module-name output.o";
 
 static struct argp_option options[] = {
-	{"arch",	777, "ARCH", 0, "Architecture: x86_64, powerpc [default: x86_64]"},
-	{"debug",	'd', NULL, 0, "Show debug output" },
-	{"klp-arch",	'a', NULL, 0, "Kernel supports .klp.arch section" },
+	{"arch",	777, "ARCH", 0, "Architecture [x86_64, ppc64, arm64]" },
+	{"debug",	'd', NULL,   0, "Show debug output" },
+	{"klp-arch",	'a', NULL,   0, "Kernel supports .klp.arch section" },
 	{ NULL }
 };
 
@@ -3704,10 +3702,13 @@ static error_t parse_opt (int key, char *arg, struct argp_state *state)
 		case 777: /* --arch */
 			if (!strcmp(arg, "x86_64"))
 				arguments->arch = X86_64;
-			else if (!strcmp(arg, "powerpc"))
+			else if (!strcmp(arg, "ppc64"))
 				arguments->arch = PPC64;
+			else if (!strcmp(arg, "arm64"))
+				arguments->arch = ARM64;
 			else
-				argp_failure (state, 1, 0, "invalid value for --arch: %s", arg);
+				/* Unsupported architecture */
+				argp_failure (state, 1, 0, "unsupported architecture: %s", arg);
 			break;
 		case ARGP_KEY_ARG:
 			if (state->arg_num >= 7)
@@ -3746,8 +3747,7 @@ int main(int argc, char *argv[])
 		loglevel = DEBUG;
 	if (arguments.klp_arch)
 		KLP_ARCH = true;
-	if (arguments.arch != DEFAULT_ARCH)
-		arch = arguments.arch;
+	current_arch = arguments.arch;
 
 	elf_version(EV_CURRENT);
 
diff --git a/kpatch-build/create-klp-module.c b/kpatch-build/create-klp-module.c
index d1b03fe7e..58ba0e16e 100644
--- a/kpatch-build/create-klp-module.c
+++ b/kpatch-build/create-klp-module.c
@@ -30,6 +30,9 @@
 char *childobj;
 enum loglevel loglevel = NORMAL;
 
+/* For kpatch-elf.c */
+enum architecture current_arch;
+
 /*
  * Add a symbol from .kpatch.symbols to the symbol table
  *
@@ -379,6 +382,7 @@ static void remove_intermediate_sections(struct kpatch_elf *kelf)
 
 struct arguments {
 	char *args[2];
+	enum architecture arch;
 	int debug;
 	int no_klp_arch;
 };
@@ -386,6 +390,7 @@ struct arguments {
 static char args_doc[] = "input.ko output.ko";
 
 static struct argp_option options[] = {
+	{"arch", 777, "ARCH", 0, "Architecture of objects [x86_64, ppc64, arm64]" },
 	{"debug", 'd', 0, 0, "Show debug output" },
 	{"no-klp-arch-sections", 'n', 0, 0, "Do not output .klp.arch.* sections" },
 	{ 0 }
@@ -405,6 +410,17 @@ static error_t parse_opt (int key, char *arg, struct argp_state *state)
 		case 'n':
 			arguments->no_klp_arch = 1;
 			break;
+		case 777:
+			if (!strcmp(arg, "x86_64"))
+				arguments->arch = X86_64;
+			else if (!strcmp(arg, "ppc64"))
+				arguments->arch = PPC64;
+			else if (!strcmp(arg, "arm64"))
+				arguments->arch = ARM64;
+			else
+				/* Unsupported architecture */
+				argp_usage (state);
+			break;
 		case ARGP_KEY_ARG:
 			if (state->arg_num >= 2)
 				/* Too many arguments. */
@@ -437,6 +453,7 @@ int main(int argc, char *argv[])
 	argp_parse (&argp, argc, argv, 0, 0, &arguments);
 	if (arguments.debug)
 		loglevel = DEBUG;
+	current_arch = arguments.arch;
 
 	elf_version(EV_CURRENT);
 
diff --git a/kpatch-build/create-kpatch-module.c b/kpatch-build/create-kpatch-module.c
index 2884f93d9..bbbeaaee5 100644
--- a/kpatch-build/create-kpatch-module.c
+++ b/kpatch-build/create-kpatch-module.c
@@ -31,6 +31,9 @@
 char *childobj;
 enum loglevel loglevel = NORMAL;
 
+/* For kpatch-elf.c */
+enum architecture current_arch = X86_64;
+
 /*
  * Create .kpatch.dynrelas from .kpatch.relocations and .kpatch.symbols sections
  *
@@ -153,12 +156,14 @@ static void remove_intermediate_sections(struct kpatch_elf *kelf)
 
 struct arguments {
 	char *args[2];
+	enum architecture arch;
 	int debug;
 };
 
 static char args_doc[] = "input.o output.o";
 
 static struct argp_option options[] = {
+	{"arch",	777, "ARCH", 0, "Architecture of objects [x86_64, ppc64, arm64]" },
 	{"debug", 'd', 0, 0, "Show debug output" },
 	{ 0 }
 };
@@ -174,6 +179,17 @@ static error_t parse_opt (int key, char *arg, struct argp_state *state)
 		case 'd':
 			arguments->debug = 1;
 			break;
+		case 777:
+			if (!strcmp(arg, "x86_64"))
+				arguments->arch = X86_64;
+			else if (!strcmp(arg, "ppc64"))
+				arguments->arch = PPC64;
+			else if (!strcmp(arg, "arm64"))
+				arguments->arch = ARM64;
+			else
+				/* Unsupported architecture */
+				argp_usage (state);
+			break;
 		case ARGP_KEY_ARG:
 			if (state->arg_num >= 2)
 				/* Too many arguments. */
@@ -205,6 +221,7 @@ int main(int argc, char *argv[])
 	argp_parse (&argp, argc, argv, 0, 0, &arguments);
 	if (arguments.debug)
 		loglevel = DEBUG;
+	current_arch = arguments.arch;
 
 	elf_version(EV_CURRENT);
 
diff --git a/kpatch-build/kpatch-elf.c b/kpatch-build/kpatch-elf.c
index 7e272e2c8..a72467091 100644
--- a/kpatch-build/kpatch-elf.c
+++ b/kpatch-build/kpatch-elf.c
@@ -325,24 +325,24 @@ static void kpatch_find_func_profiling_calls(struct kpatch_elf *kelf)
 	list_for_each_entry(sym, &kelf->symbols, list) {
 		if (sym->type != STT_FUNC || !sym->sec || !sym->sec->rela)
 			continue;
-#ifdef __powerpc64__
-		list_for_each_entry(rela, &sym->sec->rela->relas, list) {
-			if (!strcmp(rela->sym->name, "_mcount")) {
-				sym->has_func_profiling = 1;
-				break;
+		if (current_arch == PPC64) {
+			list_for_each_entry(rela, &sym->sec->rela->relas, list) {
+				if (!strcmp(rela->sym->name, "_mcount")) {
+					sym->has_func_profiling = 1;
+					break;
+				}
 			}
+		} else {
+			rela = list_first_entry(&sym->sec->rela->relas, struct rela,
+						list);
+			if ((rela->type != R_X86_64_NONE &&
+			     rela->type != R_X86_64_PC32 &&
+			     rela->type != R_X86_64_PLT32) ||
+			    strcmp(rela->sym->name, "__fentry__"))
+				continue;
+
+			sym->has_func_profiling = 1;
 		}
-#else
-		rela = list_first_entry(&sym->sec->rela->relas, struct rela,
-					list);
-		if ((rela->type != R_X86_64_NONE &&
-		     rela->type != R_X86_64_PC32 &&
-		     rela->type != R_X86_64_PLT32) ||
-		    strcmp(rela->sym->name, "__fentry__"))
-			continue;
-
-		sym->has_func_profiling = 1;
-#endif
 	}
 }
 
diff --git a/kpatch-build/kpatch-elf.h b/kpatch-build/kpatch-elf.h
index 36f500aab..4a717679f 100644
--- a/kpatch-build/kpatch-elf.h
+++ b/kpatch-build/kpatch-elf.h
@@ -110,6 +110,14 @@ struct kpatch_elf {
 	int fd;
 };
 
+enum architecture {
+	ARM64,
+	PPC64,
+	X86_64,
+};
+
+extern enum architecture current_arch;
+
 /*******************
  * Helper functions
  ******************/
diff --git a/test/unit/Makefile.include b/test/unit/Makefile.include
index 21e6be8d4..21bda7383 100644
--- a/test/unit/Makefile.include
+++ b/test/unit/Makefile.include
@@ -8,6 +8,7 @@ EXT_SYMTAB      ?= symtab
 EXT_SYMVERS     ?= symvers
 EXT_ENV         ?= env
 TNAME            = $(@:.$(EXT_OUTPUT)=)
+ARCH		 = --arch=x86_64
 
 ifndef VERBOSE
 MUTE_PASS := >/dev/null
@@ -57,7 +58,7 @@ clean:
 	@echo "BUILD $(TNAME)"
 	$(call check_all,$(TNAME).$(EXT_ORIG))
 	$(call check_all,$(TNAME).$(EXT_PATCHED))
-	$(CDO_ENV) $(shell cat $(TNAME).$(EXT_ENV) 2>/dev/null) $(CDO) $(TNAME).$(EXT_ORIG) $(TNAME).$(EXT_PATCHED) \
+	$(CDO_ENV) $(shell cat $(TNAME).$(EXT_ENV) 2>/dev/null) $(CDO) $(ARCH) $(TNAME).$(EXT_ORIG) $(TNAME).$(EXT_PATCHED) \
 		vmlinux $(TNAME).$(EXT_SYMTAB) $(SYMVERS_FILE) \
 		test_$(TNAME) $@ $(MUTE_PASS)
 
@@ -65,7 +66,7 @@ clean:
 	@echo "BUILD $(TNAME)-FAIL"
 	$(call check_all,$(TNAME).$(EXT_ORIG))
 	$(call check_all,$(TNAME).$(EXT_FAIL))
-	! $(CDO_ENV) $(shell cat $(TNAME).$(EXT_ENV) 2>/dev/null) $(CDO) $(TNAME).$(EXT_ORIG) $(TNAME).$(EXT_FAIL) \
+	! $(CDO_ENV) $(shell cat $(TNAME).$(EXT_ENV) 2>/dev/null) $(CDO) $(ARCH) $(TNAME).$(EXT_ORIG) $(TNAME).$(EXT_FAIL) \
 		vmlinux $(TNAME).$(EXT_SYMTAB) $(SYMVERS_FILE) \
 		test_$(TNAME) $@ $(MUTE_FAIL)
 # Expecting to fail, thus create output file manually so we won't rerun the

From a17bc0f95eb5957492175af4052730cef0be8786 Mon Sep 17 00:00:00 2001
From: Bill Wendling <morbo@google.com>
Date: Mon, 7 Jun 2021 11:17:09 -0700
Subject: [PATCH 4/5] kpatch-build: make architecture masks so we can easily
 check them

---
 kpatch-build/create-diff-object.c | 6 +++---
 kpatch-build/kpatch-elf.h         | 6 +++---
 2 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/kpatch-build/create-diff-object.c b/kpatch-build/create-diff-object.c
index 34d611a86..d53401951 100644
--- a/kpatch-build/create-diff-object.c
+++ b/kpatch-build/create-diff-object.c
@@ -2739,7 +2739,7 @@ static void kpatch_create_kpatch_arch_section(struct kpatch_elf *kelf, char *obj
 		ERROR("can't find .kpatch.strings symbol");
 
 	for (special = special_sections; special->name; special++) {
-		if ((special->arch & arch) == 0)
+		if ((special->arch & current_arch) == 0)
 			continue;
 
 		if (strcmp(special->name, ".parainstructions") &&
@@ -2783,7 +2783,7 @@ static void kpatch_process_special_sections(struct kpatch_elf *kelf,
 	int altinstr = 0;
 
 	for (special = special_sections; special->name; special++) {
-		if ((special->arch & arch) == 0)
+		if ((special->arch & current_arch) == 0)
 			continue;
 
 		sec = find_section_by_name(&kelf->sections, special->name);
@@ -3255,7 +3255,7 @@ static void kpatch_create_intermediate_sections(struct kpatch_elf *kelf,
 
 		special = false;
 		for (s = special_sections; s->name; s++) {
-			if ((s->arch & arch) == 0)
+			if ((s->arch & current_arch) == 0)
 				continue;
 
 			if (!strcmp(sec->base->name, s->name))
diff --git a/kpatch-build/kpatch-elf.h b/kpatch-build/kpatch-elf.h
index 4a717679f..d69ade9d8 100644
--- a/kpatch-build/kpatch-elf.h
+++ b/kpatch-build/kpatch-elf.h
@@ -111,9 +111,9 @@ struct kpatch_elf {
 };
 
 enum architecture {
-	ARM64,
-	PPC64,
-	X86_64,
+	ARM64  = 0x1 << 0,
+	PPC64  = 0x1 << 1,
+	X86_64 = 0x1 << 2,
 };
 
 extern enum architecture current_arch;

From 0c814c3e3d21cd43dbd409859e9c0a14ecda449f Mon Sep 17 00:00:00 2001
From: Bill Wendling <morbo@google.com>
Date: Mon, 7 Jun 2021 11:22:03 -0700
Subject: [PATCH 5/5] kpatch-build: initialize variable to prevent spurious
 warning

---
 kpatch-build/create-diff-object.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/kpatch-build/create-diff-object.c b/kpatch-build/create-diff-object.c
index d53401951..4ab566fc0 100644
--- a/kpatch-build/create-diff-object.c
+++ b/kpatch-build/create-diff-object.c
@@ -1500,7 +1500,7 @@ static void kpatch_replace_sections_syms(struct kpatch_elf *kelf)
 	struct section *sec;
 	struct rela *rela;
 	struct symbol *sym;
-	unsigned int add_off;
+	unsigned int add_off = 0;
 
 	log_debug("\n");
 
@@ -3500,7 +3500,7 @@ static void kpatch_create_mcount_sections(struct kpatch_elf *kelf)
 
 				rela->type = R_X86_64_PC32;
 			}
-		} else if (current_arch == PPC64) {
+		} else { /* current_arch == PPC64 */
 			bool found = false;
 
 			list_for_each_entry(rela, &sym->sec->rela->relas, list)