1/* SPDX-License-Identifier: GPL-2.0-or-later */
  2/*
  3 * Copyright (C) 2015 Josh Poimboeuf <jpoimboe@redhat.com>
  4 */
  5
  6#ifndef _OBJTOOL_ELF_H
  7#define _OBJTOOL_ELF_H
  8
  9#include <stdio.h>
 10#include <gelf.h>
 11#include <linux/list.h>
 12#include <linux/hashtable.h>
 13#include <linux/rbtree.h>
 14#include <linux/jhash.h>
 15
 16#ifdef LIBELF_USE_DEPRECATED
 17# define elf_getshdrnum    elf_getshnum
 18# define elf_getshdrstrndx elf_getshstrndx
 19#endif
 20
 21/*
 22 * Fallback for systems without this "read, mmaping if possible" cmd.
 23 */
 24#ifndef ELF_C_READ_MMAP
 25#define ELF_C_READ_MMAP ELF_C_READ
 26#endif
 27
 28struct section {
 29	struct list_head list;
 30	struct hlist_node hash;
 31	struct hlist_node name_hash;
 32	GElf_Shdr sh;
 33	struct rb_root symbol_tree;
 34	struct list_head symbol_list;
 35	struct list_head reloc_list;
 36	struct section *base, *reloc;
 37	struct symbol *sym;
 38	Elf_Data *data;
 39	char *name;
 40	int idx;
 41	unsigned int len;
 42	bool changed, text, rodata, noinstr;
 43};
 44
 45struct symbol {
 46	struct list_head list;
 47	struct rb_node node;
 48	struct hlist_node hash;
 49	struct hlist_node name_hash;
 50	GElf_Sym sym;
 51	struct section *sec;
 52	char *name;
 53	unsigned int idx;
 54	unsigned char bind, type;
 55	unsigned long offset;
 56	unsigned int len;
 57	struct symbol *pfunc, *cfunc, *alias;
 58	bool uaccess_safe;
 59};
 60
 61struct reloc {
 62	struct list_head list;
 63	struct hlist_node hash;
 64	union {
 65		GElf_Rela rela;
 66		GElf_Rel  rel;
 67	};
 68	struct section *sec;
 69	struct symbol *sym;
 70	unsigned long offset;
 71	unsigned int type;
 72	int addend;
 73	int idx;
 74	bool jump_table_start;
 75};
 76
 77#define ELF_HASH_BITS	20
 78
 79struct elf {
 80	Elf *elf;
 81	GElf_Ehdr ehdr;
 82	int fd;
 83	bool changed;
 84	char *name;
 85	struct list_head sections;
 86	DECLARE_HASHTABLE(symbol_hash, ELF_HASH_BITS);
 87	DECLARE_HASHTABLE(symbol_name_hash, ELF_HASH_BITS);
 88	DECLARE_HASHTABLE(section_hash, ELF_HASH_BITS);
 89	DECLARE_HASHTABLE(section_name_hash, ELF_HASH_BITS);
 90	DECLARE_HASHTABLE(reloc_hash, ELF_HASH_BITS);
 91};
 92
 93#define OFFSET_STRIDE_BITS	4
 94#define OFFSET_STRIDE		(1UL << OFFSET_STRIDE_BITS)
 95#define OFFSET_STRIDE_MASK	(~(OFFSET_STRIDE - 1))
 96
 97#define for_offset_range(_offset, _start, _end)			\
 98	for (_offset = ((_start) & OFFSET_STRIDE_MASK);		\
 99	     _offset >= ((_start) & OFFSET_STRIDE_MASK) &&	\
100	     _offset <= ((_end) & OFFSET_STRIDE_MASK);		\
101	     _offset += OFFSET_STRIDE)
102
103static inline u32 sec_offset_hash(struct section *sec, unsigned long offset)
104{
105	u32 ol, oh, idx = sec->idx;
106
107	offset &= OFFSET_STRIDE_MASK;
108
109	ol = offset;
110	oh = (offset >> 16) >> 16;
111
112	__jhash_mix(ol, oh, idx);
113
114	return ol;
115}
116
117static inline u32 reloc_hash(struct reloc *reloc)
118{
119	return sec_offset_hash(reloc->sec, reloc->offset);
120}
121
122struct elf *elf_open_read(const char *name, int flags);
123struct section *elf_create_section(struct elf *elf, const char *name, size_t entsize, int nr);
124struct section *elf_create_reloc_section(struct elf *elf, struct section *base, int reltype);
125void elf_add_reloc(struct elf *elf, struct reloc *reloc);
126int elf_write_insn(struct elf *elf, struct section *sec,
127		   unsigned long offset, unsigned int len,
128		   const char *insn);
129int elf_write_reloc(struct elf *elf, struct reloc *reloc);
130int elf_write(struct elf *elf);
131void elf_close(struct elf *elf);
132
133struct section *find_section_by_name(const struct elf *elf, const char *name);
134struct symbol *find_func_by_offset(struct section *sec, unsigned long offset);
135struct symbol *find_symbol_by_offset(struct section *sec, unsigned long offset);
136struct symbol *find_symbol_by_name(const struct elf *elf, const char *name);
137struct symbol *find_symbol_containing(const struct section *sec, unsigned long offset);
138struct reloc *find_reloc_by_dest(const struct elf *elf, struct section *sec, unsigned long offset);
139struct reloc *find_reloc_by_dest_range(const struct elf *elf, struct section *sec,
140				     unsigned long offset, unsigned int len);
141struct symbol *find_func_containing(struct section *sec, unsigned long offset);
142int elf_rebuild_reloc_section(struct elf *elf, struct section *sec);
143
144#define for_each_sec(file, sec)						\
145	list_for_each_entry(sec, &file->elf->sections, list)
146
147#endif /* _OBJTOOL_ELF_H */