elf.h
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/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
* Copyright (C) 2015 Josh Poimboeuf <jpoimboe@redhat.com>
*/
#ifndef _OBJTOOL_ELF_H
#define _OBJTOOL_ELF_H
#include <stdio.h>
#include <gelf.h>
#include <linux/list.h>
#include <linux/hashtable.h>
#include <linux/rbtree.h>
#include <linux/jhash.h>
#ifdef LIBELF_USE_DEPRECATED
# define elf_getshdrnum elf_getshnum
# define elf_getshdrstrndx elf_getshstrndx
#endif
/*
* Fallback for systems without this "read, mmaping if possible" cmd.
*/
#ifndef ELF_C_READ_MMAP
#define ELF_C_READ_MMAP ELF_C_READ
#endif
struct section {
struct list_head list;
struct hlist_node hash;
struct hlist_node name_hash;
GElf_Shdr sh;
struct rb_root symbol_tree;
struct list_head symbol_list;
struct list_head reloc_list;
struct section *base, *reloc;
struct symbol *sym;
Elf_Data *data;
char *name;
int idx;
unsigned int len;
bool changed, text, rodata, noinstr;
};
struct symbol {
struct list_head list;
struct rb_node node;
struct hlist_node hash;
struct hlist_node name_hash;
GElf_Sym sym;
struct section *sec;
char *name;
unsigned int idx;
unsigned char bind, type;
unsigned long offset;
unsigned int len;
struct symbol *pfunc, *cfunc, *alias;
bool uaccess_safe;
bool static_call_tramp;
};
struct reloc {
struct list_head list;
struct hlist_node hash;
union {
GElf_Rela rela;
GElf_Rel rel;
};
struct section *sec;
struct symbol *sym;
unsigned long offset;
unsigned int type;
int addend;
int idx;
bool jump_table_start;
};
#define ELF_HASH_BITS 20
struct elf {
Elf *elf;
GElf_Ehdr ehdr;
int fd;
bool changed;
char *name;
struct list_head sections;
DECLARE_HASHTABLE(symbol_hash, ELF_HASH_BITS);
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(reloc_hash, ELF_HASH_BITS);
};
#define OFFSET_STRIDE_BITS 4
#define OFFSET_STRIDE (1UL << OFFSET_STRIDE_BITS)
#define OFFSET_STRIDE_MASK (~(OFFSET_STRIDE - 1))
#define for_offset_range(_offset, _start, _end) \
for (_offset = ((_start) & OFFSET_STRIDE_MASK); \
_offset >= ((_start) & OFFSET_STRIDE_MASK) && \
_offset <= ((_end) & OFFSET_STRIDE_MASK); \
_offset += OFFSET_STRIDE)
static inline u32 sec_offset_hash(struct section *sec, unsigned long offset)
{
u32 ol, oh, idx = sec->idx;
offset &= OFFSET_STRIDE_MASK;
ol = offset;
oh = (offset >> 16) >> 16;
__jhash_mix(ol, oh, idx);
return ol;
}
static inline u32 reloc_hash(struct reloc *reloc)
{
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, unsigned int sh_flags, size_t entsize, int nr);
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_reloc(struct elf *elf, struct reloc *reloc);
int elf_write(struct elf *elf);
void elf_close(struct elf *elf);
struct section *find_section_by_name(const struct elf *elf, const char *name);
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 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_reloc_section(struct elf *elf, struct section *sec);
#define for_each_sec(file, sec) \
list_for_each_entry(sec, &file->elf->sections, list)
#endif /* _OBJTOOL_ELF_H */