1 // SPDX-License-Identifier: GPL-2.0-or-later
3  * elf.c - ELF access library
6  * Copyright (C) 2013-2015 Josh Poimboeuf <jpoimboe@redhat.com>
33 #define __elf_table(name)	(elf->name##_hash)
34 #define __elf_bits(name)	(elf->name##_bits)
42 	__node->next = __elf_table_entry(name, key);			\
52 		*head = node->next;  in __elf_hash_del()
56 	for (prev = NULL, cur = *head; cur; prev = cur, cur = cur->next) {  in __elf_hash_del()
58 			prev->next = cur->next;  in __elf_hash_del()
76 	     obj = elf_list_entry(obj->member.next, typeof(*(obj)), member))
83 				 MAP_PRIVATE|MAP_ANON, -1, 0);		\
84 	if (__elf_table(name) == (void *)-1L) {				\
93 	return s->offset;  in __sym_start()
98 	return s->offset + (s->len ? s->len - 1 : 0);  in __sym_last()
122 	if (sh->key < s->offset)  in symbol_hole_by_offset()
123 		return -1;  in symbol_hole_by_offset()
125 	if (sh->key >= s->offset + s->len) {  in symbol_hole_by_offset()
126 		sh->sym = s;  in symbol_hole_by_offset()
133 struct section *find_section_by_name(const struct elf *elf, const char *name)  in find_section_by_name()
135 	struct section *sec;  in find_section_by_name()
138 		if (!strcmp(sec->name, name))  in find_section_by_name()
145 static struct section *find_section_by_index(struct elf *elf,  in find_section_by_index()
148 	struct section *sec;  in find_section_by_index()
150 	elf_hash_for_each_possible(section, sec, hash, idx) {  in find_section_by_index()
151 		if (sec->idx == idx)  in find_section_by_index()
163 		if (sym->idx == idx)  in find_symbol_by_index()
170 struct symbol *find_symbol_by_offset(struct section *sec, unsigned long offset)  in find_symbol_by_offset()
172 	struct rb_root_cached *tree = (struct rb_root_cached *)&sec->symbol_tree;  in find_symbol_by_offset()
176 		if (sym->offset == offset && !is_sec_sym(sym))  in find_symbol_by_offset()
177 			return sym->alias;  in find_symbol_by_offset()
183 struct symbol *find_func_by_offset(struct section *sec, unsigned long offset)  in find_func_by_offset()
185 	struct rb_root_cached *tree = (struct rb_root_cached *)&sec->symbol_tree;  in find_func_by_offset()
189 		if (func->offset == offset && is_func_sym(func))  in find_func_by_offset()
190 			return func->alias;  in find_func_by_offset()
196 struct symbol *find_symbol_containing(const struct section *sec, unsigned long offset)  in find_symbol_containing()
198 	struct rb_root_cached *tree = (struct rb_root_cached *)&sec->symbol_tree;  in find_symbol_containing()
202 		if (tmp->len) {  in find_symbol_containing()
208 			if (sym->offset != tmp->offset || sym->len != tmp->len) {  in find_symbol_containing()
215 				if (tmp->len < sym->len)  in find_symbol_containing()
221 	return sym ? sym->alias : NULL;  in find_symbol_containing()
227 int find_symbol_hole_containing(const struct section *sec, unsigned long offset)  in find_symbol_hole_containing()
239 	n = rb_find(&hole, &sec->symbol_tree.rb_root, symbol_hole_by_offset);  in find_symbol_hole_containing()
246 	 * @offset >= sym->offset + sym->len, find symbol after it.  in find_symbol_hole_containing()
248 	 * If there is no symbol in the section, the first node will be NULL,  in find_symbol_hole_containing()
249 	 * in which case, -1 is returned to skip the whole section.  in find_symbol_hole_containing()
252 		n = rb_next(&hole.sym->node);  in find_symbol_hole_containing()
254 		n = rb_first_cached(&sec->symbol_tree);  in find_symbol_hole_containing()
257 		return -1; /* until end of address space */  in find_symbol_hole_containing()
261 	return s->offset - offset;  in find_symbol_hole_containing()
264 struct symbol *find_func_containing(struct section *sec, unsigned long offset)  in find_func_containing()
266 	struct rb_root_cached *tree = (struct rb_root_cached *)&sec->symbol_tree;  in find_func_containing()
271 			return func->alias;  in find_func_containing()
282 		if (!strcmp(sym->name, name))  in find_symbol_by_name()
297 		if (sym->bind == STB_LOCAL && sym->file == file &&  in find_local_symbol_by_file_and_name()
298 		    !strcmp(sym->name, name)) {  in find_local_symbol_by_file_and_name()
311 		if (!strcmp(sym->name, name) && !is_local_sym(sym))  in find_global_symbol_by_name()
318 struct reloc *find_reloc_by_dest_range(const struct elf *elf, struct section *sec,  in find_reloc_by_dest_range()
322 	struct section *rsec;  in find_reloc_by_dest_range()
325 	rsec = sec->rsec;  in find_reloc_by_dest_range()
332 			if (reloc->sec != rsec)  in find_reloc_by_dest_range()
348 struct reloc *find_reloc_by_dest(const struct elf *elf, struct section *sec, unsigned long offset)  in find_reloc_by_dest()
353 static bool is_dwarf_section(struct section *sec)  in is_dwarf_section()
355 	return !strncmp(sec->name, ".debug_", 7);  in is_dwarf_section()
361 	struct section *sec;  in read_sections()
365 	if (elf_getshdrnum(elf->elf, &sections_nr)) {  in read_sections()
367 		return -1;  in read_sections()
370 	if (elf_getshdrstrndx(elf->elf, &shstrndx)) {  in read_sections()
372 		return -1;  in read_sections()
375 	if (!elf_alloc_hash(section, sections_nr) ||  in read_sections()
377 		return -1;  in read_sections()
379 	elf->section_data = calloc(sections_nr, sizeof(*sec));  in read_sections()
380 	if (!elf->section_data) {  in read_sections()
382 		return -1;  in read_sections()
385 		sec = &elf->section_data[i];  in read_sections()
387 		INIT_LIST_HEAD(&sec->symbol_list);  in read_sections()
389 		s = elf_getscn(elf->elf, i);  in read_sections()
392 			return -1;  in read_sections()
395 		sec->idx = elf_ndxscn(s);  in read_sections()
397 		if (!gelf_getshdr(s, &sec->sh)) {  in read_sections()
399 			return -1;  in read_sections()
402 		sec->name = elf_strptr(elf->elf, shstrndx, sec->sh.sh_name);  in read_sections()
403 		if (!sec->name) {  in read_sections()
405 			return -1;  in read_sections()
409 			sec->data = elf_getdata(s, NULL);  in read_sections()
410 			if (!sec->data) {  in read_sections()
412 				return -1;  in read_sections()
414 			if (sec->data->d_off != 0 ||  in read_sections()
415 			    sec->data->d_size != sec_size(sec)) {  in read_sections()
416 				ERROR("unexpected data attributes for %s", sec->name);  in read_sections()
417 				return -1;  in read_sections()
421 		list_add_tail(&sec->list, &elf->sections);  in read_sections()
422 		elf_hash_add(section, &sec->hash, sec->idx);  in read_sections()
423 		elf_hash_add(section_name, &sec->name_hash, str_hash(sec->name));  in read_sections()
426 			elf->num_relocs += sec_num_entries(sec);  in read_sections()
431 		printf("section_bits: %d\n", elf->section_bits);  in read_sections()
435 	if (elf_nextscn(elf->elf, s)) {  in read_sections()
436 		ERROR("section entry mismatch");  in read_sections()
437 		return -1;  in read_sections()
448 		return sym->name;  in demangle_name()
451 		return sym->name;  in demangle_name()
453 	if (!strstarts(sym->name, "__UNIQUE_ID_") && !strchr(sym->name, '.'))  in demangle_name()
454 		return sym->name;  in demangle_name()
456 	str = strdup(sym->name);  in demangle_name()
462 	for (int i = strlen(str) - 1; i >= 0; i--) {  in demangle_name()
480 	INIT_LIST_HEAD(&sym->pv_target);  in elf_add_symbol()
481 	sym->alias = sym;  in elf_add_symbol()
483 	sym->type = GELF_ST_TYPE(sym->sym.st_info);  in elf_add_symbol()
484 	sym->bind = GELF_ST_BIND(sym->sym.st_info);  in elf_add_symbol()
487 		elf->num_files++;  in elf_add_symbol()
489 	sym->offset = sym->sym.st_value;  in elf_add_symbol()
490 	sym->len = sym->sym.st_size;  in elf_add_symbol()
492 	__sym_for_each(iter, &sym->sec->symbol_tree, sym->offset, sym->offset) {  in elf_add_symbol()
493 		if (!is_undef_sym(iter) && iter->offset == sym->offset &&  in elf_add_symbol()
494 		    iter->type == sym->type && iter->len == sym->len)  in elf_add_symbol()
495 			iter->alias = sym;  in elf_add_symbol()
498 	__sym_insert(sym, &sym->sec->symbol_tree);  in elf_add_symbol()
499 	pnode = rb_prev(&sym->node);  in elf_add_symbol()
501 		entry = &rb_entry(pnode, struct symbol, node)->list;  in elf_add_symbol()
503 		entry = &sym->sec->symbol_list;  in elf_add_symbol()
504 	list_add(&sym->list, entry);  in elf_add_symbol()
506 	list_add_tail(&sym->global_list, &elf->symbols);  in elf_add_symbol()
507 	elf_hash_add(symbol, &sym->hash, sym->idx);  in elf_add_symbol()
508 	elf_hash_add(symbol_name, &sym->name_hash, str_hash(sym->name));  in elf_add_symbol()
511 	    (strstarts(sym->name, "__pfx_") ||  in elf_add_symbol()
512 	     strstarts(sym->name, "__cfi_") ||  in elf_add_symbol()
513 	     strstarts(sym->name, "__pi___pfx_") ||  in elf_add_symbol()
514 	     strstarts(sym->name, "__pi___cfi_")))  in elf_add_symbol()
515 		sym->prefix = 1;  in elf_add_symbol()
517 	if (strstarts(sym->name, ".klp.sym"))  in elf_add_symbol()
518 		sym->klp = 1;  in elf_add_symbol()
520 	if (!sym->klp && !is_sec_sym(sym) && strstr(sym->name, ".cold")) {  in elf_add_symbol()
521 		sym->cold = 1;  in elf_add_symbol()
527 		sym->type = STT_FUNC;  in elf_add_symbol()
530 	sym->pfunc = sym->cfunc = sym;  in elf_add_symbol()
532 	sym->demangled_name = demangle_name(sym);  in elf_add_symbol()
533 	if (!sym->demangled_name)  in elf_add_symbol()
534 		return -1;  in elf_add_symbol()
541 	struct section *symtab, *symtab_shndx, *sec;  in read_symbols()
552 			shndx_data = symtab_shndx->data;  in read_symbols()
567 		return -1;  in read_symbols()
569 	elf->symbol_data = calloc(symbols_nr, sizeof(*sym));  in read_symbols()
570 	if (!elf->symbol_data) {  in read_symbols()
572 		return -1;  in read_symbols()
575 	INIT_LIST_HEAD(&elf->symbols);  in read_symbols()
578 		sym = &elf->symbol_data[i];  in read_symbols()
580 		sym->idx = i;  in read_symbols()
582 		if (!gelf_getsymshndx(symtab->data, shndx_data, i, &sym->sym,  in read_symbols()
585 			return -1;  in read_symbols()
588 		sym->name = elf_strptr(elf->elf, symtab->sh.sh_link,  in read_symbols()
589 				       sym->sym.st_name);  in read_symbols()
590 		if (!sym->name) {  in read_symbols()
592 			return -1;  in read_symbols()
595 		if ((sym->sym.st_shndx > SHN_UNDEF &&  in read_symbols()
596 		     sym->sym.st_shndx < SHN_LORESERVE) ||  in read_symbols()
597 		    (shndx_data && sym->sym.st_shndx == SHN_XINDEX)) {  in read_symbols()
598 			if (sym->sym.st_shndx != SHN_XINDEX)  in read_symbols()
599 				shndx = sym->sym.st_shndx;  in read_symbols()
601 			sym->sec = find_section_by_index(elf, shndx);  in read_symbols()
602 			if (!sym->sec) {  in read_symbols()
603 				ERROR("couldn't find section for symbol %s", sym->name);  in read_symbols()
604 				return -1;  in read_symbols()
606 			if (GELF_ST_TYPE(sym->sym.st_info) == STT_SECTION) {  in read_symbols()
607 				sym->name = sym->sec->name;  in read_symbols()
608 				sym->sec->sym = sym;  in read_symbols()
611 			sym->sec = find_section_by_index(elf, 0);  in read_symbols()
614 			return -1;  in read_symbols()
616 		if (sym->type == STT_FILE)  in read_symbols()
618 		else if (sym->bind == STB_LOCAL)  in read_symbols()
619 			sym->file = file;  in read_symbols()
624 		printf("symbol_bits: %d\n", elf->symbol_bits);  in read_symbols()
628 	list_for_each_entry(sec, &elf->sections, list) {  in read_symbols()
633 			if (!sym->cold)  in read_symbols()
636 			coldstr = strstr(sym->name, ".cold");  in read_symbols()
638 				ERROR("%s(): cold subfunction without \".cold\"?", sym->name);  in read_symbols()
639 				return -1;  in read_symbols()
642 			pnamelen = coldstr - sym->name;  in read_symbols()
643 			pname = strndup(sym->name, pnamelen);  in read_symbols()
645 				ERROR("%s(): failed to allocate memory", sym->name);  in read_symbols()
646 				return -1;  in read_symbols()
649 			pfunc = find_local_symbol_by_file_and_name(elf, sym->file, pname);  in read_symbols()
655 				ERROR("%s(): can't find parent function", sym->name);  in read_symbols()
656 				return -1;  in read_symbols()
659 			sym->pfunc = pfunc->alias;  in read_symbols()
660 			pfunc->cfunc = sym;  in read_symbols()
661 			pfunc->alias->cfunc = sym;  in read_symbols()
664 			 * Unfortunately, -fnoreorder-functions puts the child  in read_symbols()
668 			 * Note that pfunc->len now no longer matches  in read_symbols()
669 			 * pfunc->sym.st_size.  in read_symbols()
671 			if (sym->sec == pfunc->sec &&  in read_symbols()
672 			    sym->offset >= pfunc->offset &&  in read_symbols()
673 			    sym->offset + sym->len == pfunc->offset + pfunc->len) {  in read_symbols()
674 				pfunc->len -= sym->len;  in read_symbols()
684 	struct section *symtab, *sec;  in mark_group_syms()
690 		return -1;  in mark_group_syms()
694 		if (sec->sh.sh_type == SHT_GROUP &&  in mark_group_syms()
695 		    sec->sh.sh_link == symtab->idx) {  in mark_group_syms()
696 			sym = find_symbol_by_index(elf, sec->sh.sh_info);  in mark_group_syms()
699 				      sec->name);  in mark_group_syms()
700 				return -1;  in mark_group_syms()
703 			sym->group_sec = sec;  in mark_group_syms()
717 	for (reloc = sym->relocs; reloc; reloc = sym_next_reloc(reloc))  in elf_update_sym_relocs()
718 		set_reloc_sym(elf, reloc, reloc->sym->idx);  in elf_update_sym_relocs()
731 static int elf_update_symbol(struct elf *elf, struct section *symtab,  in elf_update_symbol()
732 			     struct section *symtab_shndx, struct symbol *sym)  in elf_update_symbol()
736 	Elf64_Xword entsize = symtab->sh.sh_entsize;  in elf_update_symbol()
737 	int max_idx, idx = sym->idx;  in elf_update_symbol()
739 	bool is_special_shndx = sym->sym.st_shndx >= SHN_LORESERVE &&  in elf_update_symbol()
740 				sym->sym.st_shndx != SHN_XINDEX;  in elf_update_symbol()
742 	shndx = is_special_shndx ? sym->sym.st_shndx : sym->sec->idx;  in elf_update_symbol()
744 	s = elf_getscn(elf->elf, symtab->idx);  in elf_update_symbol()
747 		return -1;  in elf_update_symbol()
751 		t = elf_getscn(elf->elf, symtab_shndx->idx);  in elf_update_symbol()
754 			return -1;  in elf_update_symbol()
764 		/* end-of-list */  in elf_update_symbol()
767 			 * Over-allocate to avoid O(n^2) symbol creation  in elf_update_symbol()
771 			int num = max(1U, sym->idx/3);  in elf_update_symbol()
777 				return -1;  in elf_update_symbol()
788 				return -1;  in elf_update_symbol()
791 			symtab_data->d_buf = buf;  in elf_update_symbol()
792 			symtab_data->d_size = num * entsize;  in elf_update_symbol()
793 			symtab_data->d_align = 1;  in elf_update_symbol()
794 			symtab_data->d_type = ELF_T_SYM;  in elf_update_symbol()
797 			symtab->truncate = true;  in elf_update_symbol()
803 					return -1;  in elf_update_symbol()
806 				shndx_data->d_buf = buf;  in elf_update_symbol()
807 				shndx_data->d_size = num * sizeof(Elf32_Word);  in elf_update_symbol()
808 				shndx_data->d_align = sizeof(Elf32_Word);  in elf_update_symbol()
809 				shndx_data->d_type = ELF_T_WORD;  in elf_update_symbol()
812 				symtab_shndx->truncate = true;  in elf_update_symbol()
819 		if (!symtab_data->d_size) {  in elf_update_symbol()
821 			return -1;  in elf_update_symbol()
825 		max_idx = symtab_data->d_size / entsize;  in elf_update_symbol()
830 		idx -= max_idx;  in elf_update_symbol()
833 	/* something went side-ways */  in elf_update_symbol()
836 		return -1;  in elf_update_symbol()
839 	/* setup extended section index magic and write the symbol */  in elf_update_symbol()
841 		sym->sym.st_shndx = shndx;  in elf_update_symbol()
845 		sym->sym.st_shndx = SHN_XINDEX;  in elf_update_symbol()
848 			return -1;  in elf_update_symbol()
852 	if (!gelf_update_symshndx(symtab_data, shndx_data, idx, &sym->sym, shndx)) {  in elf_update_symbol()
854 		return -1;  in elf_update_symbol()
861 				 struct section *sec, unsigned int bind,  in elf_create_symbol()
865 	struct section *symtab, *symtab_shndx;  in elf_create_symbol()
875 	sym->name = strdup(name);  in elf_create_symbol()
876 	if (!sym->name) {  in elf_create_symbol()
882 		sym->sym.st_name = elf_add_string(elf, NULL, sym->name);  in elf_create_symbol()
883 		if (sym->sym.st_name == -1)  in elf_create_symbol()
888 		sym->sec = sec;  in elf_create_symbol()
890 		sym->sec = find_section_by_index(elf, 0);  in elf_create_symbol()
891 		if (!sym->sec) {  in elf_create_symbol()
892 			ERROR("no NULL section");  in elf_create_symbol()
897 	sym->sym.st_info  = GELF_ST_INFO(bind, type);  in elf_create_symbol()
898 	sym->sym.st_value = offset;  in elf_create_symbol()
899 	sym->sym.st_size  = size;  in elf_create_symbol()
918 	first_non_local = symtab->sh.sh_info;  in elf_create_symbol()
922 		elf_hash_del(symbol, &old->hash, old->idx);  in elf_create_symbol()
923 		elf_hash_add(symbol, &old->hash, new_idx);  in elf_create_symbol()
924 		old->idx = new_idx;  in elf_create_symbol()
934 		if (old->group_sec) {  in elf_create_symbol()
935 			old->group_sec->sh.sh_info = new_idx;  in elf_create_symbol()
936 			mark_sec_changed(elf, old->group_sec, true);  in elf_create_symbol()
945 	symtab->sh.sh_info += 1;  in elf_create_symbol()
948 	sym->idx = new_idx;  in elf_create_symbol()
949 	if (sym->idx && elf_update_symbol(elf, symtab, symtab_shndx, sym))  in elf_create_symbol()
952 	symtab->sh.sh_size += symtab->sh.sh_entsize;  in elf_create_symbol()
956 		symtab_shndx->sh.sh_size += sizeof(Elf32_Word);  in elf_create_symbol()
966 struct symbol *elf_create_section_symbol(struct elf *elf, struct section *sec)  in elf_create_section_symbol()
970 	sym = elf_create_symbol(elf, sec->name, sec, STB_LOCAL, STT_SECTION, 0, 0);  in elf_create_section_symbol()
974 	sec->sym = sym;  in elf_create_section_symbol()
979 struct reloc *elf_init_reloc(struct elf *elf, struct section *rsec,  in elf_init_reloc()
987 		      __func__, reloc_idx, rsec->name, sec_num_entries(rsec));  in elf_init_reloc()
991 	reloc = &rsec->relocs[reloc_idx];  in elf_init_reloc()
995 		      __func__, rsec->name, reloc_idx);  in elf_init_reloc()
999 	reloc->sec = rsec;  in elf_init_reloc()
1000 	reloc->sym = sym;  in elf_init_reloc()
1003 	set_reloc_sym(elf, reloc, sym->idx);  in elf_init_reloc()
1007 	elf_hash_add(reloc, &reloc->hash, reloc_hash(reloc));  in elf_init_reloc()
1008 	set_sym_next_reloc(reloc, sym->relocs);  in elf_init_reloc()
1009 	sym->relocs = reloc;  in elf_init_reloc()
1014 struct reloc *elf_init_reloc_text_sym(struct elf *elf, struct section *sec,  in elf_init_reloc_text_sym()
1017 				      struct section *insn_sec,  in elf_init_reloc_text_sym()
1020 	struct symbol *sym = insn_sec->sym;  in elf_init_reloc_text_sym()
1024 		ERROR("bad call to %s() for data symbol %s", __func__, sym->name);  in elf_init_reloc_text_sym()
1030 		 * Due to how weak functions work, we must use section based  in elf_init_reloc_text_sym()
1032 		 * weak and non-weak function annotations being overlaid on the  in elf_init_reloc_text_sym()
1033 		 * non-weak function after linking.  in elf_init_reloc_text_sym()
1040 	return elf_init_reloc(elf, sec->rsec, reloc_idx, offset, sym, addend,  in elf_init_reloc_text_sym()
1044 struct reloc *elf_init_reloc_data_sym(struct elf *elf, struct section *sec,  in elf_init_reloc_data_sym()
1051 		ERROR("bad call to %s() for text symbol %s", __func__, sym->name);  in elf_init_reloc_data_sym()
1055 	return elf_init_reloc(elf, sec->rsec, reloc_idx, offset, sym, addend,  in elf_init_reloc_data_sym()
1062 	struct section *rsec;  in read_relocs()
1068 	if (!elf_alloc_hash(reloc, elf->num_relocs))  in read_relocs()
1069 		return -1;  in read_relocs()
1071 	list_for_each_entry(rsec, &elf->sections, list) {  in read_relocs()
1075 		rsec->base = find_section_by_index(elf, rsec->sh.sh_info);  in read_relocs()
1076 		if (!rsec->base) {  in read_relocs()
1077 			ERROR("can't find base section for reloc section %s", rsec->name);  in read_relocs()
1078 			return -1;  in read_relocs()
1081 		rsec->base->rsec = rsec;  in read_relocs()
1084 		rsec->nr_alloc_relocs = 0;  in read_relocs()
1086 		rsec->relocs = calloc(sec_num_entries(rsec), sizeof(*reloc));  in read_relocs()
1087 		if (!rsec->relocs) {  in read_relocs()
1089 			return -1;  in read_relocs()
1094 			reloc = &rsec->relocs[i];  in read_relocs()
1096 			reloc->sec = rsec;  in read_relocs()
1098 			reloc->sym = sym = find_symbol_by_index(elf, symndx);  in read_relocs()
1099 			if (!reloc->sym) {  in read_relocs()
1100 				ERROR("can't find reloc entry symbol %d for %s", symndx, rsec->name);  in read_relocs()
1101 				return -1;  in read_relocs()
1104 			elf_hash_add(reloc, &reloc->hash, reloc_hash(reloc));  in read_relocs()
1105 			set_sym_next_reloc(reloc, sym->relocs);  in read_relocs()
1106 			sym->relocs = reloc;  in read_relocs()
1115 		printf("num_relocs: %lu\n", elf->num_relocs);  in read_relocs()
1116 		printf("reloc_bits: %d\n", elf->reloc_bits);  in read_relocs()
1136 	INIT_LIST_HEAD(&elf->sections);  in elf_open_read()
1138 	elf->fd = open(name, flags);  in elf_open_read()
1139 	if (elf->fd == -1) {  in elf_open_read()
1145 	elf->name = strdup(name);  in elf_open_read()
1146 	if (!elf->name) {  in elf_open_read()
1158 	elf->elf = elf_begin(elf->fd, cmd, NULL);  in elf_open_read()
1159 	if (!elf->elf) {  in elf_open_read()
1164 	if (!gelf_getehdr(elf->elf, &elf->ehdr)) {  in elf_open_read()
1190 	struct section *null, *symtab, *strtab, *shstrtab;  in elf_create_file()
1203 	INIT_LIST_HEAD(&elf->sections);  in elf_create_file()
1213 	elf->fd = mkstemp(tmp_name);  in elf_create_file()
1214 	if (elf->fd == -1) {  in elf_create_file()
1219 	elf->tmp_name = tmp_name;  in elf_create_file()
1221 	elf->name = strdup(name);  in elf_create_file()
1222 	if (!elf->name) {  in elf_create_file()
1227 	elf->elf = elf_begin(elf->fd, ELF_C_WRITE, NULL);  in elf_create_file()
1228 	if (!elf->elf) {  in elf_create_file()
1233 	if (!gelf_newehdr(elf->elf, ELFCLASS64)) {  in elf_create_file()
1238 	memcpy(&elf->ehdr, ehdr, sizeof(elf->ehdr));  in elf_create_file()
1240 	if (!gelf_update_ehdr(elf->elf, &elf->ehdr)) {  in elf_create_file()
1245 	INIT_LIST_HEAD(&elf->symbols);  in elf_create_file()
1247 	if (!elf_alloc_hash(section,		1000) ||  in elf_create_file()
1261 	null->name	= "";  in elf_create_file()
1262 	shstrtab->name	= ".shstrtab";  in elf_create_file()
1263 	strtab->name	= ".strtab";  in elf_create_file()
1265 	null->sh.sh_name	= elf_add_string(elf, shstrtab, null->name);  in elf_create_file()
1266 	shstrtab->sh.sh_name	= elf_add_string(elf, shstrtab, shstrtab->name);  in elf_create_file()
1267 	strtab->sh.sh_name	= elf_add_string(elf, shstrtab, strtab->name);  in elf_create_file()
1269 	if (null->sh.sh_name == -1 || shstrtab->sh.sh_name == -1 || strtab->sh.sh_name == -1)  in elf_create_file()
1272 	elf_hash_add(section_name, &null->name_hash,		str_hash(null->name));  in elf_create_file()
1273 	elf_hash_add(section_name, &strtab->name_hash,		str_hash(strtab->name));  in elf_create_file()
1274 	elf_hash_add(section_name, &shstrtab->name_hash,	str_hash(shstrtab->name));  in elf_create_file()
1276 	if (elf_add_string(elf, strtab, "") == -1)  in elf_create_file()
1283 	symtab->sh.sh_link = strtab->idx;  in elf_create_file()
1284 	symtab->sh.sh_info = 1;  in elf_create_file()
1286 	elf->ehdr.e_shstrndx = shstrtab->idx;  in elf_create_file()
1287 	if (!gelf_update_ehdr(elf->elf, &elf->ehdr)) {  in elf_create_file()
1298 	sym->name = "";  in elf_create_file()
1299 	sym->sec = null;  in elf_create_file()
1305 unsigned int elf_add_string(struct elf *elf, struct section *strtab, const char *str)  in elf_add_string()
1312 		ERROR("can't find .strtab section");  in elf_add_string()
1313 		return -1;  in elf_add_string()
1316 	if (!strtab->sh.sh_addralign) {  in elf_add_string()
1317 		ERROR("'%s': invalid sh_addralign", strtab->name);  in elf_add_string()
1318 		return -1;  in elf_add_string()
1321 	offset = ALIGN(strtab->sh.sh_size, strtab->sh.sh_addralign);  in elf_add_string()
1324 		return -1;  in elf_add_string()
1329 void *elf_add_data(struct elf *elf, struct section *sec, const void *data, size_t size)  in elf_add_data()
1334 	if (!sec->sh.sh_addralign) {  in elf_add_data()
1335 		ERROR("'%s': invalid sh_addralign", sec->name);  in elf_add_data()
1339 	s = elf_getscn(elf->elf, sec->idx);  in elf_add_data()
1345 	sec->data = elf_newdata(s);  in elf_add_data()
1346 	if (!sec->data) {  in elf_add_data()
1351 	sec->data->d_buf = calloc(1, size);  in elf_add_data()
1352 	if (!sec->data->d_buf) {  in elf_add_data()
1358 		memcpy(sec->data->d_buf, data, size);  in elf_add_data()
1360 	sec->data->d_size = size;  in elf_add_data()
1361 	sec->data->d_align = sec->sh.sh_addralign;  in elf_add_data()
1363 	offset = ALIGN(sec->sh.sh_size, sec->sh.sh_addralign);  in elf_add_data()
1364 	sec->sh.sh_size = offset + size;  in elf_add_data()
1368 	return sec->data->d_buf;  in elf_add_data()
1371 struct section *elf_create_section(struct elf *elf, const char *name,  in elf_create_section()
1376 	struct section *sec, *shstrtab;  in elf_create_section()
1380 		ERROR("section '%s' already exists", name);  in elf_create_section()
1390 	INIT_LIST_HEAD(&sec->symbol_list);  in elf_create_section()
1392 	/* don't actually create the section, just the data structures */  in elf_create_section()
1396 	s = elf_newscn(elf->elf);  in elf_create_section()
1402 	sec->idx = elf_ndxscn(s);  in elf_create_section()
1405 		sec->data = elf_newdata(s);  in elf_create_section()
1406 		if (!sec->data) {  in elf_create_section()
1411 		sec->data->d_size = size;  in elf_create_section()
1412 		sec->data->d_align = 1;  in elf_create_section()
1414 		sec->data->d_buf = calloc(1, size);  in elf_create_section()
1415 		if (!sec->data->d_buf) {  in elf_create_section()
1421 	if (!gelf_getshdr(s, &sec->sh)) {  in elf_create_section()
1426 	sec->sh.sh_size = size;  in elf_create_section()
1427 	sec->sh.sh_entsize = entsize;  in elf_create_section()
1428 	sec->sh.sh_type = type;  in elf_create_section()
1429 	sec->sh.sh_addralign = align;  in elf_create_section()
1430 	sec->sh.sh_flags = flags;  in elf_create_section()
1433 		sec->name = strdup(name);  in elf_create_section()
1434 		if (!sec->name) {  in elf_create_section()
1439 		/* Add section name to .shstrtab (or .strtab for Clang) */  in elf_create_section()
1448 		sec->sh.sh_name = elf_add_string(elf, shstrtab, sec->name);  in elf_create_section()
1449 		if (sec->sh.sh_name == -1)  in elf_create_section()
1452 		elf_hash_add(section_name, &sec->name_hash, str_hash(sec->name));  in elf_create_section()
1456 	list_add_tail(&sec->list, &elf->sections);  in elf_create_section()
1457 	elf_hash_add(section, &sec->hash, sec->idx);  in elf_create_section()
1464 static int elf_alloc_reloc(struct elf *elf, struct section *rsec)  in elf_alloc_reloc()
1472 	if (!rsec->data) {  in elf_alloc_reloc()
1473 		rsec->data = elf_newdata(elf_getscn(elf->elf, rsec->idx));  in elf_alloc_reloc()
1474 		if (!rsec->data) {  in elf_alloc_reloc()
1476 			return -1;  in elf_alloc_reloc()
1479 		rsec->data->d_align = 1;  in elf_alloc_reloc()
1480 		rsec->data->d_type = ELF_T_RELA;  in elf_alloc_reloc()
1481 		rsec->data->d_buf = NULL;  in elf_alloc_reloc()
1484 	rsec->data->d_size = nr_relocs_new * elf_rela_size(elf);  in elf_alloc_reloc()
1485 	rsec->sh.sh_size   = rsec->data->d_size;  in elf_alloc_reloc()
1488 	if (nr_alloc <= rsec->nr_alloc_relocs)  in elf_alloc_reloc()
1491 	if (rsec->data->d_buf && !rsec->nr_alloc_relocs) {  in elf_alloc_reloc()
1492 		void *orig_buf = rsec->data->d_buf;  in elf_alloc_reloc()
1498 		rsec->data->d_buf = malloc(nr_alloc * elf_rela_size(elf));  in elf_alloc_reloc()
1499 		if (!rsec->data->d_buf) {  in elf_alloc_reloc()
1501 			return -1;  in elf_alloc_reloc()
1503 		memcpy(rsec->data->d_buf, orig_buf,  in elf_alloc_reloc()
1506 		rsec->data->d_buf = realloc(rsec->data->d_buf,  in elf_alloc_reloc()
1508 		if (!rsec->data->d_buf) {  in elf_alloc_reloc()
1510 			return -1;  in elf_alloc_reloc()
1514 	rsec->nr_alloc_relocs = nr_alloc;  in elf_alloc_reloc()
1516 	old_relocs = rsec->relocs;  in elf_alloc_reloc()
1520 		return -1;  in elf_alloc_reloc()
1535 		reloc = sym->relocs;  in elf_alloc_reloc()
1540 			sym->relocs = &new_relocs[reloc - old_relocs];  in elf_alloc_reloc()
1549 				set_sym_next_reloc(reloc, &new_relocs[next_reloc - old_relocs]);  in elf_alloc_reloc()
1562 		elf_hash_del(reloc, &old->hash, key);  in elf_alloc_reloc()
1563 		elf_hash_add(reloc, &new->hash, key);  in elf_alloc_reloc()
1568 	rsec->relocs = new_relocs;  in elf_alloc_reloc()
1572 struct section *elf_create_rela_section(struct elf *elf, struct section *sec,  in elf_create_rela_section()
1575 	struct section *rsec;  in elf_create_rela_section()
1578 	rsec_name = malloc(strlen(sec->name) + strlen(".rela") + 1);  in elf_create_rela_section()
1584 	strcat(rsec_name, sec->name);  in elf_create_rela_section()
1594 		rsec->data->d_type = ELF_T_RELA;  in elf_create_rela_section()
1596 		rsec->nr_alloc_relocs = nr_relocs;  in elf_create_rela_section()
1597 		rsec->relocs = calloc(nr_relocs, sizeof(struct reloc));  in elf_create_rela_section()
1598 		if (!rsec->relocs) {  in elf_create_rela_section()
1604 	rsec->sh.sh_link = find_section_by_name(elf, ".symtab")->idx;  in elf_create_rela_section()
1605 	rsec->sh.sh_info = sec->idx;  in elf_create_rela_section()
1607 	sec->rsec = rsec;  in elf_create_rela_section()
1608 	rsec->base = sec;  in elf_create_rela_section()
1613 struct reloc *elf_create_reloc(struct elf *elf, struct section *sec,  in elf_create_reloc()
1618 	struct section *rsec = sec->rsec;  in elf_create_reloc()
1636 	return elf_init_reloc(elf, rsec, sec_num_entries(rsec) - 1, offset, sym,  in elf_create_reloc()
1640 struct section *elf_create_section_pair(struct elf *elf, const char *name,  in elf_create_section_pair()
1644 	struct section *sec;  in elf_create_section_pair()
1657 int elf_write_insn(struct elf *elf, struct section *sec,  in elf_write_insn()
1661 	Elf_Data *data = sec->data;  in elf_write_insn()
1663 	if (data->d_type != ELF_T_BYTE || data->d_off) {  in elf_write_insn()
1664 		ERROR("write to unexpected data for section: %s", sec->name);  in elf_write_insn()
1665 		return -1;  in elf_write_insn()
1668 	memcpy(data->d_buf + offset, insn, len);  in elf_write_insn()
1679  *   A) adhere to the section header and truncate the data, or
1680  *   B) ignore the section header and write out all the data you've got?
1682  * Yes, libelf sucks and we need to manually truncate if we over-allocate data.
1684 static int elf_truncate_section(struct elf *elf, struct section *sec)  in elf_truncate_section()
1691 	s = elf_getscn(elf->elf, sec->idx);  in elf_truncate_section()
1694 		return -1;  in elf_truncate_section()
1698 		/* get next data descriptor for the relevant section */  in elf_truncate_section()
1702 				ERROR("end of section data but non-zero size left\n");  in elf_truncate_section()
1703 				return -1;  in elf_truncate_section()
1711 			return -1;  in elf_truncate_section()
1714 		if (!data->d_size) {  in elf_truncate_section()
1716 			return -1;  in elf_truncate_section()
1719 		if (data->d_size > size) {  in elf_truncate_section()
1721 			data->d_size = size;  in elf_truncate_section()
1724 		size -= data->d_size;  in elf_truncate_section()
1730 	struct section *sec;  in elf_write()
1733 	/* Update changed relocation sections and section headers: */  in elf_write()
1734 	list_for_each_entry(sec, &elf->sections, list) {  in elf_write()
1735 		if (sec->truncate && elf_truncate_section(elf, sec))  in elf_write()
1736 			return -1;  in elf_write()
1739 			s = elf_getscn(elf->elf, sec->idx);  in elf_write()
1742 				return -1;  in elf_write()
1745 			/* Note this also flags the section dirty */  in elf_write()
1746 			if (!gelf_update_shdr(s, &sec->sh)) {  in elf_write()
1748 				return -1;  in elf_write()
1755 	/* Make sure the new section header entries get updated properly. */  in elf_write()
1756 	elf_flagelf(elf->elf, ELF_C_SET, ELF_F_DIRTY);  in elf_write()
1759 	if (elf_update(elf->elf, ELF_C_WRITE) < 0) {  in elf_write()
1761 		return -1;  in elf_write()
1764 	elf->changed = false;  in elf_write()
1771 	if (elf->elf)  in elf_close()
1772 		elf_end(elf->elf);  in elf_close()
1774 	if (elf->fd > 0)  in elf_close()
1775 		close(elf->fd);  in elf_close()
1777 	if (elf->tmp_name && rename(elf->tmp_name, elf->name))  in elf_close()
1778 		return -1;  in elf_close()