Merge branch 'topic/objtool' into next

Merge the powerpc objtool support, which we were keeping in a topic
branch in case of any merge conflicts.

19 files changed, 271 insertions, 56 deletions

diff --git a/tools/objtool/arch/powerpc/Build b/tools/objtool/arch/powerpc/Build
new file mode 100644
index 000000000000..d24d5636a5b8
--- /dev/null
+++ b/tools/objtool/arch/powerpc/Build
@@ -0,0 +1,2 @@
+objtool-y += decode.o
+objtool-y += special.o
diff --git a/tools/objtool/arch/powerpc/decode.c b/tools/objtool/arch/powerpc/decode.c
new file mode 100644
index 000000000000..9c653805a08a
--- /dev/null
+++ b/tools/objtool/arch/powerpc/decode.c
@@ -0,0 +1,110 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <objtool/check.h>
+#include <objtool/elf.h>
+#include <objtool/arch.h>
+#include <objtool/warn.h>
+#include <objtool/builtin.h>
+#include <objtool/endianness.h>
+
+int arch_ftrace_match(char *name)
+{
+	return !strcmp(name, "_mcount");
+}
+
+unsigned long arch_dest_reloc_offset(int addend)
+{
+	return addend;
+}
+
+bool arch_callee_saved_reg(unsigned char reg)
+{
+	return false;
+}
+
+int arch_decode_hint_reg(u8 sp_reg, int *base)
+{
+	exit(-1);
+}
+
+const char *arch_nop_insn(int len)
+{
+	exit(-1);
+}
+
+const char *arch_ret_insn(int len)
+{
+	exit(-1);
+}
+
+int arch_decode_instruction(struct objtool_file *file, const struct section *sec,
+			    unsigned long offset, unsigned int maxlen,
+			    unsigned int *len, enum insn_type *type,
+			    unsigned long *immediate,
+			    struct list_head *ops_list)
+{
+	unsigned int opcode;
+	enum insn_type typ;
+	unsigned long imm;
+	u32 insn;
+
+	insn = bswap_if_needed(file->elf, *(u32 *)(sec->data->d_buf + offset));
+	opcode = insn >> 26;
+	typ = INSN_OTHER;
+	imm = 0;
+
+	switch (opcode) {
+	case 18: /* b[l][a] */
+		if ((insn & 3) == 1) /* bl */
+			typ = INSN_CALL;
+
+		imm = insn & 0x3fffffc;
+		if (imm & 0x2000000)
+			imm -= 0x4000000;
+		break;
+	}
+
+	if (opcode == 1)
+		*len = 8;
+	else
+		*len = 4;
+
+	*type = typ;
+	*immediate = imm;
+
+	return 0;
+}
+
+unsigned long arch_jump_destination(struct instruction *insn)
+{
+	return insn->offset + insn->immediate;
+}
+
+bool arch_pc_relative_reloc(struct reloc *reloc)
+{
+	/*
+	 * The powerpc build only allows certain relocation types, see
+	 * relocs_check.sh, and none of those accepted are PC relative.
+	 */
+	return false;
+}
+
+void arch_initial_func_cfi_state(struct cfi_init_state *state)
+{
+	int i;
+
+	for (i = 0; i < CFI_NUM_REGS; i++) {
+		state->regs[i].base = CFI_UNDEFINED;
+		state->regs[i].offset = 0;
+	}
+
+	/* initial CFA (call frame address) */
+	state->cfa.base = CFI_SP;
+	state->cfa.offset = 0;
+
+	/* initial LR (return address) */
+	state->regs[CFI_RA].base = CFI_CFA;
+	state->regs[CFI_RA].offset = 0;
+}
diff --git a/tools/objtool/arch/powerpc/include/arch/cfi_regs.h b/tools/objtool/arch/powerpc/include/arch/cfi_regs.h
new file mode 100644
index 000000000000..59638ebeafc8
--- /dev/null
+++ b/tools/objtool/arch/powerpc/include/arch/cfi_regs.h
@@ -0,0 +1,11 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
+#ifndef _OBJTOOL_CFI_REGS_H
+#define _OBJTOOL_CFI_REGS_H
+
+#define CFI_BP 1
+#define CFI_SP CFI_BP
+#define CFI_RA 32
+#define CFI_NUM_REGS 33
+
+#endif
diff --git a/tools/objtool/arch/powerpc/include/arch/elf.h b/tools/objtool/arch/powerpc/include/arch/elf.h
new file mode 100644
index 000000000000..73f9ae172fe5
--- /dev/null
+++ b/tools/objtool/arch/powerpc/include/arch/elf.h
@@ -0,0 +1,10 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
+#ifndef _OBJTOOL_ARCH_ELF
+#define _OBJTOOL_ARCH_ELF
+
+#define R_NONE R_PPC_NONE
+#define R_ABS64 R_PPC64_ADDR64
+#define R_ABS32 R_PPC_ADDR32
+
+#endif /* _OBJTOOL_ARCH_ELF */
diff --git a/tools/objtool/arch/powerpc/include/arch/special.h b/tools/objtool/arch/powerpc/include/arch/special.h
new file mode 100644
index 000000000000..ffef9ada7133
--- /dev/null
+++ b/tools/objtool/arch/powerpc/include/arch/special.h
@@ -0,0 +1,21 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+#ifndef _PPC_ARCH_SPECIAL_H
+#define _PPC_ARCH_SPECIAL_H
+
+#define EX_ENTRY_SIZE 8
+#define EX_ORIG_OFFSET 0
+#define EX_NEW_OFFSET 4
+
+#define JUMP_ENTRY_SIZE 16
+#define JUMP_ORIG_OFFSET 0
+#define JUMP_NEW_OFFSET 4
+#define JUMP_KEY_OFFSET 8
+
+#define ALT_ENTRY_SIZE 12
+#define ALT_ORIG_OFFSET 0
+#define ALT_NEW_OFFSET 4
+#define ALT_FEATURE_OFFSET 8
+#define ALT_ORIG_LEN_OFFSET 10
+#define ALT_NEW_LEN_OFFSET 11
+
+#endif /* _PPC_ARCH_SPECIAL_H */
diff --git a/tools/objtool/arch/powerpc/special.c b/tools/objtool/arch/powerpc/special.c
new file mode 100644
index 000000000000..d33868147196
--- /dev/null
+++ b/tools/objtool/arch/powerpc/special.c
@@ -0,0 +1,19 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+#include <string.h>
+#include <stdlib.h>
+#include <objtool/special.h>
+#include <objtool/builtin.h>
+
+
+bool arch_support_alt_relocation(struct special_alt *special_alt,
+				 struct instruction *insn,
+				 struct reloc *reloc)
+{
+	exit(-1);
+}
+
+struct reloc *arch_find_switch_table(struct objtool_file *file,
+				    struct instruction *insn)
+{
+	exit(-1);
+}
diff --git a/tools/objtool/arch/x86/decode.c b/tools/objtool/arch/x86/decode.c
index 1c253b4b7ce0..af7ad09c926c 100644
--- a/tools/objtool/arch/x86/decode.c
+++ b/tools/objtool/arch/x86/decode.c
@@ -23,6 +23,11 @@
 #include <objtool/builtin.h>
 #include <arch/elf.h>
 
+int arch_ftrace_match(char *name)
+{
+	return !strcmp(name, "__fentry__");
+}
+
 static int is_x86_64(const struct elf *elf)
 {
 	switch (elf->ehdr.e_machine) {
diff --git a/tools/objtool/arch/x86/include/arch/elf.h b/tools/objtool/arch/x86/include/arch/elf.h
index 69cc4264b28a..ac14987cf687 100644
--- a/tools/objtool/arch/x86/include/arch/elf.h
+++ b/tools/objtool/arch/x86/include/arch/elf.h
@@ -2,5 +2,7 @@
 #define _OBJTOOL_ARCH_ELF
 
 #define R_NONE R_X86_64_NONE
+#define R_ABS64 R_X86_64_64
+#define R_ABS32 R_X86_64_32
 
 #endif /* _OBJTOOL_ARCH_ELF */
diff --git a/tools/objtool/arch/x86/include/arch/endianness.h b/tools/objtool/arch/x86/include/arch/endianness.h
deleted file mode 100644
index 7c362527da20..000000000000
--- a/tools/objtool/arch/x86/include/arch/endianness.h
+++ /dev/null
@@ -1,9 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0-or-later */
-#ifndef _ARCH_ENDIANNESS_H
-#define _ARCH_ENDIANNESS_H
-
-#include <endian.h>
-
-#define __TARGET_BYTE_ORDER __LITTLE_ENDIAN
-
-#endif /* _ARCH_ENDIANNESS_H */
diff --git a/tools/objtool/builtin-check.c b/tools/objtool/builtin-check.c
index 24fbe803a0d3..9bd347d3c244 100644
--- a/tools/objtool/builtin-check.c
+++ b/tools/objtool/builtin-check.c
@@ -82,6 +82,7 @@ const struct option check_options[] = {
 	OPT_BOOLEAN(0, "dry-run", &opts.dryrun, "don't write modifications"),
 	OPT_BOOLEAN(0, "link", &opts.link, "object is a linked object"),
 	OPT_BOOLEAN(0, "module", &opts.module, "object is part of a kernel module"),
+	OPT_BOOLEAN(0, "mnop", &opts.mnop, "nop out mcount call sites"),
 	OPT_BOOLEAN(0, "no-unreachable", &opts.no_unreachable, "skip 'unreachable instruction' warnings"),
 	OPT_BOOLEAN(0, "sec-address", &opts.sec_address, "print section addresses in warnings"),
 	OPT_BOOLEAN(0, "stats", &opts.stats, "print statistics"),
@@ -150,6 +151,16 @@ static bool opts_valid(void)
 	return false;
 }
 
+static bool mnop_opts_valid(void)
+{
+	if (opts.mnop && !opts.mcount) {
+		ERROR("--mnop requires --mcount");
+		return false;
+	}
+
+	return true;
+}
+
 static bool link_opts_valid(struct objtool_file *file)
 {
 	if (opts.link)
@@ -198,6 +209,9 @@ int objtool_run(int argc, const char **argv)
 	if (!file)
 		return 1;
 
+	if (!mnop_opts_valid())
+		return 1;
+
 	if (!link_opts_valid(file))
 		return 1;
 
diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 43ec14c29a60..7580c66ca5c8 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -207,7 +207,7 @@ static bool __dead_end_function(struct objtool_file *file, struct symbol *func,
 		return false;
 
 	insn = find_insn(file, func->sec, func->offset);
-	if (!insn->func)
+	if (!insn || !insn->func)
 		return false;
 
 	func_for_each_insn(file, func, insn) {
@@ -852,9 +852,9 @@ static int create_ibt_endbr_seal_sections(struct objtool_file *file)
 
 static int create_mcount_loc_sections(struct objtool_file *file)
 {
-	struct section *sec;
-	unsigned long *loc;
+	int addrsize = elf_class_addrsize(file->elf);
 	struct instruction *insn;
+	struct section *sec;
 	int idx;
 
 	sec = find_section_by_name(file->elf, "__mcount_loc");
@@ -871,23 +871,25 @@ static int create_mcount_loc_sections(struct objtool_file *file)
 	list_for_each_entry(insn, &file->mcount_loc_list, call_node)
 		idx++;
 
-	sec = elf_create_section(file->elf, "__mcount_loc", 0, sizeof(unsigned long), idx);
+	sec = elf_create_section(file->elf, "__mcount_loc", 0, addrsize, idx);
 	if (!sec)
 		return -1;
 
+	sec->sh.sh_addralign = addrsize;
+
 	idx = 0;
 	list_for_each_entry(insn, &file->mcount_loc_list, call_node) {
+		void *loc;
 
-		loc = (unsigned long *)sec->data->d_buf + idx;
-		memset(loc, 0, sizeof(unsigned long));
+		loc = sec->data->d_buf + idx;
+		memset(loc, 0, addrsize);
 
-		if (elf_add_reloc_to_insn(file->elf, sec,
-					  idx * sizeof(unsigned long),
-					  R_X86_64_64,
+		if (elf_add_reloc_to_insn(file->elf, sec, idx,
+					  addrsize == sizeof(u64) ? R_ABS64 : R_ABS32,
 					  insn->sec, insn->offset))
 			return -1;
 
-		idx++;
+		idx += addrsize;
 	}
 
 	return 0;
@@ -1254,17 +1256,18 @@ static void annotate_call_site(struct objtool_file *file,
 	if (opts.mcount && sym->fentry) {
 		if (sibling)
 			WARN_FUNC("Tail call to __fentry__ !?!?", insn->sec, insn->offset);
+		if (opts.mnop) {
+			if (reloc) {
+				reloc->type = R_NONE;
+				elf_write_reloc(file->elf, reloc);
+			}
 
-		if (reloc) {
-			reloc->type = R_NONE;
-			elf_write_reloc(file->elf, reloc);
-		}
-
-		elf_write_insn(file->elf, insn->sec,
-			       insn->offset, insn->len,
-			       arch_nop_insn(insn->len));
+			elf_write_insn(file->elf, insn->sec,
+				       insn->offset, insn->len,
+				       arch_nop_insn(insn->len));
 
-		insn->type = INSN_NOP;
+			insn->type = INSN_NOP;
+		}
 
 		list_add_tail(&insn->call_node, &file->mcount_loc_list);
 		return;
@@ -2100,7 +2103,7 @@ static int read_unwind_hints(struct objtool_file *file)
 			return -1;
 		}
 
-		cfi.cfa.offset = bswap_if_needed(hint->sp_offset);
+		cfi.cfa.offset = bswap_if_needed(file->elf, hint->sp_offset);
 		cfi.type = hint->type;
 		cfi.end = hint->end;
 
@@ -2313,7 +2316,7 @@ static int classify_symbols(struct objtool_file *file)
 			if (arch_is_rethunk(func))
 				func->return_thunk = true;
 
-			if (!strcmp(func->name, "__fentry__"))
+			if (arch_ftrace_match(func->name))
 				func->fentry = true;
 
 			if (is_profiling_func(func->name))
@@ -2389,9 +2392,11 @@ static int decode_sections(struct objtool_file *file)
 	 * Must be before add_jump_destinations(), which depends on 'func'
 	 * being set for alternatives, to enable proper sibling call detection.
 	 */
-	ret = add_special_section_alts(file);
-	if (ret)
-		return ret;
+	if (opts.stackval || opts.orc || opts.uaccess || opts.noinstr) {
+		ret = add_special_section_alts(file);
+		if (ret)
+			return ret;
+	}
 
 	ret = add_jump_destinations(file);
 	if (ret)
diff --git a/tools/objtool/elf.c b/tools/objtool/elf.c
index 7e24b09b1163..33739865735b 100644
--- a/tools/objtool/elf.c
+++ b/tools/objtool/elf.c
@@ -1129,6 +1129,7 @@ static struct section *elf_create_rela_reloc_section(struct elf *elf, struct sec
 {
 	char *relocname;
 	struct section *sec;
+	int addrsize = elf_class_addrsize(elf);
 
 	relocname = malloc(strlen(base->name) + strlen(".rela") + 1);
 	if (!relocname) {
@@ -1138,7 +1139,10 @@ static struct section *elf_create_rela_reloc_section(struct elf *elf, struct sec
 	strcpy(relocname, ".rela");
 	strcat(relocname, base->name);
 
-	sec = elf_create_section(elf, relocname, 0, sizeof(GElf_Rela), 0);
+	if (addrsize == sizeof(u32))
+		sec = elf_create_section(elf, relocname, 0, sizeof(Elf32_Rela), 0);
+	else
+		sec = elf_create_section(elf, relocname, 0, sizeof(GElf_Rela), 0);
 	free(relocname);
 	if (!sec)
 		return NULL;
@@ -1147,7 +1151,7 @@ static struct section *elf_create_rela_reloc_section(struct elf *elf, struct sec
 	sec->base = base;
 
 	sec->sh.sh_type = SHT_RELA;
-	sec->sh.sh_addralign = 8;
+	sec->sh.sh_addralign = addrsize;
 	sec->sh.sh_link = find_section_by_name(elf, ".symtab")->idx;
 	sec->sh.sh_info = base->idx;
 	sec->sh.sh_flags = SHF_INFO_LINK;
diff --git a/tools/objtool/include/objtool/arch.h b/tools/objtool/include/objtool/arch.h
index beb2f3aa94ff..4ecb480131c7 100644
--- a/tools/objtool/include/objtool/arch.h
+++ b/tools/objtool/include/objtool/arch.h
@@ -69,6 +69,8 @@ struct stack_op {
 
 struct instruction;
 
+int arch_ftrace_match(char *name);
+
 void arch_initial_func_cfi_state(struct cfi_init_state *state);
 
 int arch_decode_instruction(struct objtool_file *file, const struct section *sec,
@@ -93,4 +95,6 @@ bool arch_is_rethunk(struct symbol *sym);
 
 int arch_rewrite_retpolines(struct objtool_file *file);
 
+bool arch_pc_relative_reloc(struct reloc *reloc);
+
 #endif /* _ARCH_H */
diff --git a/tools/objtool/include/objtool/builtin.h b/tools/objtool/include/objtool/builtin.h
index 42a52f1a0add..0785707c5a92 100644
--- a/tools/objtool/include/objtool/builtin.h
+++ b/tools/objtool/include/objtool/builtin.h
@@ -31,6 +31,7 @@ struct opts {
 	bool backup;
 	bool dryrun;
 	bool link;
+	bool mnop;
 	bool module;
 	bool no_unreachable;
 	bool sec_address;
diff --git a/tools/objtool/include/objtool/elf.h b/tools/objtool/include/objtool/elf.h
index 16f4067b82ae..78b3aa2e546d 100644
--- a/tools/objtool/include/objtool/elf.h
+++ b/tools/objtool/include/objtool/elf.h
@@ -142,6 +142,14 @@ static inline bool has_multiple_files(struct elf *elf)
 	return elf->num_files > 1;
 }
 
+static inline int elf_class_addrsize(struct elf *elf)
+{
+	if (elf->ehdr.e_ident[EI_CLASS] == ELFCLASS32)
+		return sizeof(u32);
+	else
+		return sizeof(u64);
+}
+
 struct elf *elf_open_read(const char *name, int flags);
 struct section *elf_create_section(struct elf *elf, const char *name, unsigned int sh_flags, size_t entsize, int nr);
 
diff --git a/tools/objtool/include/objtool/endianness.h b/tools/objtool/include/objtool/endianness.h
index 10241341eff3..4d2aa9b0fe2f 100644
--- a/tools/objtool/include/objtool/endianness.h
+++ b/tools/objtool/include/objtool/endianness.h
@@ -2,33 +2,33 @@
 #ifndef _OBJTOOL_ENDIANNESS_H
 #define _OBJTOOL_ENDIANNESS_H
 
-#include <arch/endianness.h>
 #include <linux/kernel.h>
 #include <endian.h>
-
-#ifndef __TARGET_BYTE_ORDER
-#error undefined arch __TARGET_BYTE_ORDER
-#endif
-
-#if __BYTE_ORDER != __TARGET_BYTE_ORDER
-#define __NEED_BSWAP 1
-#else
-#define __NEED_BSWAP 0
-#endif
+#include <objtool/elf.h>
 
 /*
- * Does a byte swap if target endianness doesn't match the host, i.e. cross
+ * Does a byte swap if target file endianness doesn't match the host, i.e. cross
  * compilation for little endian on big endian and vice versa.
  * To be used for multi-byte values conversion, which are read from / about
  * to be written to a target native endianness ELF file.
  */
-#define bswap_if_needed(val)						\
+static inline bool need_bswap(struct elf *elf)
+{
+	return (__BYTE_ORDER == __LITTLE_ENDIAN) ^
+	       (elf->ehdr.e_ident[EI_DATA] == ELFDATA2LSB);
+}
+
+#define bswap_if_needed(elf, val)					\
 ({									\
 	__typeof__(val) __ret;						\
+	bool __need_bswap = need_bswap(elf);				\
 	switch (sizeof(val)) {						\
-	case 8: __ret = __NEED_BSWAP ? bswap_64(val) : (val); break;	\
-	case 4: __ret = __NEED_BSWAP ? bswap_32(val) : (val); break;	\
-	case 2: __ret = __NEED_BSWAP ? bswap_16(val) : (val); break;	\
+	case 8:								\
+		__ret = __need_bswap ? bswap_64(val) : (val); break;	\
+	case 4:								\
+		__ret = __need_bswap ? bswap_32(val) : (val); break;	\
+	case 2:								\
+		__ret = __need_bswap ? bswap_16(val) : (val); break;	\
 	default:							\
 		BUILD_BUG(); break;					\
 	}								\
diff --git a/tools/objtool/orc_dump.c b/tools/objtool/orc_dump.c
index f5a8508c42d6..4f1211fec82c 100644
--- a/tools/objtool/orc_dump.c
+++ b/tools/objtool/orc_dump.c
@@ -76,6 +76,7 @@ int orc_dump(const char *_objname)
 	GElf_Rela rela;
 	GElf_Sym sym;
 	Elf_Data *data, *symtab = NULL, *rela_orc_ip = NULL;
+	struct elf dummy_elf = {};
 
 
 	objname = _objname;
@@ -94,6 +95,12 @@ int orc_dump(const char *_objname)
 		return -1;
 	}
 
+	if (!elf64_getehdr(elf)) {
+		WARN_ELF("elf64_getehdr");
+		return -1;
+	}
+	memcpy(&dummy_elf.ehdr, elf64_getehdr(elf), sizeof(dummy_elf.ehdr));
+
 	if (elf_getshdrnum(elf, &nr_sections)) {
 		WARN_ELF("elf_getshdrnum");
 		return -1;
@@ -198,11 +205,11 @@ int orc_dump(const char *_objname)
 
 		printf(" sp:");
 
-		print_reg(orc[i].sp_reg, bswap_if_needed(orc[i].sp_offset));
+		print_reg(orc[i].sp_reg, bswap_if_needed(&dummy_elf, orc[i].sp_offset));
 
 		printf(" bp:");
 
-		print_reg(orc[i].bp_reg, bswap_if_needed(orc[i].bp_offset));
+		print_reg(orc[i].bp_reg, bswap_if_needed(&dummy_elf, orc[i].bp_offset));
 
 		printf(" type:%s end:%d\n",
 		       orc_type_name(orc[i].type), orc[i].end);
diff --git a/tools/objtool/orc_gen.c b/tools/objtool/orc_gen.c
index dd3c64af9db2..1f22b7ebae58 100644
--- a/tools/objtool/orc_gen.c
+++ b/tools/objtool/orc_gen.c
@@ -97,8 +97,8 @@ static int write_orc_entry(struct elf *elf, struct section *orc_sec,
 	/* populate ORC data */
 	orc = (struct orc_entry *)orc_sec->data->d_buf + idx;
 	memcpy(orc, o, sizeof(*orc));
-	orc->sp_offset = bswap_if_needed(orc->sp_offset);
-	orc->bp_offset = bswap_if_needed(orc->bp_offset);
+	orc->sp_offset = bswap_if_needed(elf, orc->sp_offset);
+	orc->bp_offset = bswap_if_needed(elf, orc->bp_offset);
 
 	/* populate reloc for ip */
 	if (elf_add_reloc_to_insn(elf, ip_sec, idx * sizeof(int), R_X86_64_PC32,
diff --git a/tools/objtool/special.c b/tools/objtool/special.c
index e2223dd91c37..9c8d827f69af 100644
--- a/tools/objtool/special.c
+++ b/tools/objtool/special.c
@@ -87,7 +87,8 @@ static int get_alt_entry(struct elf *elf, struct special_entry *entry,
 	if (entry->feature) {
 		unsigned short feature;
 
-		feature = bswap_if_needed(*(unsigned short *)(sec->data->d_buf +
+		feature = bswap_if_needed(elf,
+					  *(unsigned short *)(sec->data->d_buf +
 							      offset +
 							      entry->feature));
 		arch_handle_alternative(feature, alt);