Merge tag 'objtool-core-2020-08-03' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull objtool updates from Ingo Molnar:

 - Add support for non-rela relocations, in preparation to merge
   'recordmcount' functionality into objtool

 - Fix assumption that broke under --ffunction-sections (LTO) builds

 - Misc cleanups

* tag 'objtool-core-2020-08-03' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  objtool: Add support for relocations without addends
  objtool: Rename rela to reloc
  objtool: Use sh_info to find the base for .rela sections
  objtool: Do not assume order of parent/child functions

tools/objtool/arch.h

@@ -82,7 +82,7 @@ bool arch_callee_saved_reg(unsigned char reg);
 
 unsigned long arch_jump_destination(struct instruction *insn);
 
-unsigned long arch_dest_rela_offset(int addend);
+unsigned long arch_dest_reloc_offset(int addend);
 
 const char *arch_nop_insn(int len);
 

tools/objtool/arch/x86/decode.c

@@ -67,7 +67,7 @@ bool arch_callee_saved_reg(unsigned char reg)
 	}
 }
 
-unsigned long arch_dest_rela_offset(int addend)
+unsigned long arch_dest_reloc_offset(int addend)
 {
 	return addend + 4;
 }

tools/objtool/check.h

@@ -37,7 +37,7 @@ struct instruction {
 	struct symbol *call_dest;
 	struct instruction *jump_dest;
 	struct instruction *first_jump_src;
-	struct rela *jump_table;
+	struct reloc *jump_table;
 	struct list_head alts;
 	struct symbol *func;
 	struct list_head stack_ops;

tools/objtool/elf.h

@@ -32,8 +32,8 @@ struct section {
 	GElf_Shdr sh;
 	struct rb_root symbol_tree;
 	struct list_head symbol_list;
-	struct list_head rela_list;
-	struct section *base, *rela;
+	struct list_head reloc_list;
+	struct section *base, *reloc;
 	struct symbol *sym;
 	Elf_Data *data;
 	char *name;
@@ -58,10 +58,13 @@ struct symbol {
 	bool uaccess_safe;
 };
 
-struct rela {
+struct reloc {
 	struct list_head list;
 	struct hlist_node hash;
-	GElf_Rela rela;
+	union {
+		GElf_Rela rela;
+		GElf_Rel  rel;
+	};
 	struct section *sec;
 	struct symbol *sym;
 	unsigned long offset;
@@ -84,7 +87,7 @@ struct elf {
 	DECLARE_HASHTABLE(symbol_name_hash, ELF_HASH_BITS);
 	DECLARE_HASHTABLE(section_hash, ELF_HASH_BITS);
 	DECLARE_HASHTABLE(section_name_hash, ELF_HASH_BITS);
-	DECLARE_HASHTABLE(rela_hash, ELF_HASH_BITS);
+	DECLARE_HASHTABLE(reloc_hash, ELF_HASH_BITS);
 };
 
 #define OFFSET_STRIDE_BITS	4
@@ -111,19 +114,19 @@ static inline u32 sec_offset_hash(struct section *sec, unsigned long offset)
 	return ol;
 }
 
-static inline u32 rela_hash(struct rela *rela)
+static inline u32 reloc_hash(struct reloc *reloc)
 {
-	return sec_offset_hash(rela->sec, rela->offset);
+	return sec_offset_hash(reloc->sec, reloc->offset);
 }
 
 struct elf *elf_open_read(const char *name, int flags);
 struct section *elf_create_section(struct elf *elf, const char *name, size_t entsize, int nr);
-struct section *elf_create_rela_section(struct elf *elf, struct section *base);
-void elf_add_rela(struct elf *elf, struct rela *rela);
+struct section *elf_create_reloc_section(struct elf *elf, struct section *base, int reltype);
+void elf_add_reloc(struct elf *elf, struct reloc *reloc);
 int elf_write_insn(struct elf *elf, struct section *sec,
 		   unsigned long offset, unsigned int len,
 		   const char *insn);
-int elf_write_rela(struct elf *elf, struct rela *rela);
+int elf_write_reloc(struct elf *elf, struct reloc *reloc);
 int elf_write(struct elf *elf);
 void elf_close(struct elf *elf);
 
@@ -132,11 +135,11 @@ struct symbol *find_func_by_offset(struct section *sec, unsigned long offset);
 struct symbol *find_symbol_by_offset(struct section *sec, unsigned long offset);
 struct symbol *find_symbol_by_name(const struct elf *elf, const char *name);
 struct symbol *find_symbol_containing(const struct section *sec, unsigned long offset);
-struct rela *find_rela_by_dest(const struct elf *elf, struct section *sec, unsigned long offset);
-struct rela *find_rela_by_dest_range(const struct elf *elf, struct section *sec,
+struct reloc *find_reloc_by_dest(const struct elf *elf, struct section *sec, unsigned long offset);
+struct reloc *find_reloc_by_dest_range(const struct elf *elf, struct section *sec,
 				     unsigned long offset, unsigned int len);
 struct symbol *find_func_containing(struct section *sec, unsigned long offset);
-int elf_rebuild_rela_section(struct elf *elf, struct section *sec);
+int elf_rebuild_reloc_section(struct elf *elf, struct section *sec);
 
 #define for_each_sec(file, sec)						\
 	list_for_each_entry(sec, &file->elf->sections, list)

tools/objtool/orc_gen.c

@@ -80,56 +80,56 @@ int create_orc(struct objtool_file *file)
 	return 0;
 }
 
-static int create_orc_entry(struct elf *elf, struct section *u_sec, struct section *ip_relasec,
+static int create_orc_entry(struct elf *elf, struct section *u_sec, struct section *ip_relocsec,
 				unsigned int idx, struct section *insn_sec,
 				unsigned long insn_off, struct orc_entry *o)
 {
 	struct orc_entry *orc;
-	struct rela *rela;
+	struct reloc *reloc;
 
 	/* populate ORC data */
 	orc = (struct orc_entry *)u_sec->data->d_buf + idx;
 	memcpy(orc, o, sizeof(*orc));
 
-	/* populate rela for ip */
-	rela = malloc(sizeof(*rela));
-	if (!rela) {
+	/* populate reloc for ip */
+	reloc = malloc(sizeof(*reloc));
+	if (!reloc) {
 		perror("malloc");
 		return -1;
 	}
-	memset(rela, 0, sizeof(*rela));
+	memset(reloc, 0, sizeof(*reloc));
 
 	if (insn_sec->sym) {
-		rela->sym = insn_sec->sym;
-		rela->addend = insn_off;
+		reloc->sym = insn_sec->sym;
+		reloc->addend = insn_off;
 	} else {
 		/*
 		 * The Clang assembler doesn't produce section symbols, so we
 		 * have to reference the function symbol instead:
 		 */
-		rela->sym = find_symbol_containing(insn_sec, insn_off);
-		if (!rela->sym) {
+		reloc->sym = find_symbol_containing(insn_sec, insn_off);
+		if (!reloc->sym) {
 			/*
 			 * Hack alert.  This happens when we need to reference
 			 * the NOP pad insn immediately after the function.
 			 */
-			rela->sym = find_symbol_containing(insn_sec,
+			reloc->sym = find_symbol_containing(insn_sec,
 							   insn_off - 1);
 		}
-		if (!rela->sym) {
+		if (!reloc->sym) {
 			WARN("missing symbol for insn at offset 0x%lx\n",
 			     insn_off);
 			return -1;
 		}
 
-		rela->addend = insn_off - rela->sym->offset;
+		reloc->addend = insn_off - reloc->sym->offset;
 	}
 
-	rela->type = R_X86_64_PC32;
-	rela->offset = idx * sizeof(int);
-	rela->sec = ip_relasec;
+	reloc->type = R_X86_64_PC32;
+	reloc->offset = idx * sizeof(int);
+	reloc->sec = ip_relocsec;
 
-	elf_add_rela(elf, rela);
+	elf_add_reloc(elf, reloc);
 
 	return 0;
 }
@@ -137,7 +137,7 @@ static int create_orc_entry(struct elf *elf, struct section *u_sec, struct secti
 int create_orc_sections(struct objtool_file *file)
 {
 	struct instruction *insn, *prev_insn;
-	struct section *sec, *u_sec, *ip_relasec;
+	struct section *sec, *u_sec, *ip_relocsec;
 	unsigned int idx;
 
 	struct orc_entry empty = {
@@ -181,8 +181,8 @@ int create_orc_sections(struct objtool_file *file)
 	if (!sec)
 		return -1;
 
-	ip_relasec = elf_create_rela_section(file->elf, sec);
-	if (!ip_relasec)
+	ip_relocsec = elf_create_reloc_section(file->elf, sec, SHT_RELA);
+	if (!ip_relocsec)
 		return -1;
 
 	/* create .orc_unwind section */
@@ -200,7 +200,7 @@ int create_orc_sections(struct objtool_file *file)
 			if (!prev_insn || memcmp(&insn->orc, &prev_insn->orc,
 						 sizeof(struct orc_entry))) {
 
-				if (create_orc_entry(file->elf, u_sec, ip_relasec, idx,
+				if (create_orc_entry(file->elf, u_sec, ip_relocsec, idx,
 						     insn->sec, insn->offset,
 						     &insn->orc))
 					return -1;
@@ -212,7 +212,7 @@ int create_orc_sections(struct objtool_file *file)
 
 		/* section terminator */
 		if (prev_insn) {
-			if (create_orc_entry(file->elf, u_sec, ip_relasec, idx,
+			if (create_orc_entry(file->elf, u_sec, ip_relocsec, idx,
 					     prev_insn->sec,
 					     prev_insn->offset + prev_insn->len,
 					     &empty))
@@ -222,7 +222,7 @@ int create_orc_sections(struct objtool_file *file)
 		}
 	}
 
-	if (elf_rebuild_rela_section(file->elf, ip_relasec))
+	if (elf_rebuild_reloc_section(file->elf, ip_relocsec))
 		return -1;
 
 	return 0;

tools/objtool/special.c

@@ -72,7 +72,7 @@ static int get_alt_entry(struct elf *elf, struct special_entry *entry,
 			 struct section *sec, int idx,
 			 struct special_alt *alt)
 {
-	struct rela *orig_rela, *new_rela;
+	struct reloc *orig_reloc, *new_reloc;
 	unsigned long offset;
 
 	offset = idx * entry->size;
@@ -118,30 +118,30 @@ static int get_alt_entry(struct elf *elf, struct special_entry *entry,
 		}
 	}
 
-	orig_rela = find_rela_by_dest(elf, sec, offset + entry->orig);
-	if (!orig_rela) {
-		WARN_FUNC("can't find orig rela", sec, offset + entry->orig);
+	orig_reloc = find_reloc_by_dest(elf, sec, offset + entry->orig);
+	if (!orig_reloc) {
+		WARN_FUNC("can't find orig reloc", sec, offset + entry->orig);
 		return -1;
 	}
-	if (orig_rela->sym->type != STT_SECTION) {
-		WARN_FUNC("don't know how to handle non-section rela symbol %s",
-			   sec, offset + entry->orig, orig_rela->sym->name);
+	if (orig_reloc->sym->type != STT_SECTION) {
+		WARN_FUNC("don't know how to handle non-section reloc symbol %s",
+			   sec, offset + entry->orig, orig_reloc->sym->name);
 		return -1;
 	}
 
-	alt->orig_sec = orig_rela->sym->sec;
-	alt->orig_off = orig_rela->addend;
+	alt->orig_sec = orig_reloc->sym->sec;
+	alt->orig_off = orig_reloc->addend;
 
 	if (!entry->group || alt->new_len) {
-		new_rela = find_rela_by_dest(elf, sec, offset + entry->new);
-		if (!new_rela) {
-			WARN_FUNC("can't find new rela",
+		new_reloc = find_reloc_by_dest(elf, sec, offset + entry->new);
+		if (!new_reloc) {
+			WARN_FUNC("can't find new reloc",
 				  sec, offset + entry->new);
 			return -1;
 		}
 
-		alt->new_sec = new_rela->sym->sec;
-		alt->new_off = (unsigned int)new_rela->addend;
+		alt->new_sec = new_reloc->sym->sec;
+		alt->new_off = (unsigned int)new_reloc->addend;
 
 		/* _ASM_EXTABLE_EX hack */
 		if (alt->new_off >= 0x7ffffff0)