tools/objtool/elf.h

   1 /*
   2  * Copyright (C) 2015 Josh Poimboeuf <jpoimboe@redhat.com>
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public License
   6  * as published by the Free Software Foundation; either version 2
   7  * of the License, or (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, see <http://www.gnu.org/licenses/>.
  16  */
  17
  18 #ifndef _OBJTOOL_ELF_H
  19 #define _OBJTOOL_ELF_H
  20
  21 #include <stdio.h>
  22 #include <gelf.h>
  23 #include <linux/list.h>
  24 #include <linux/hashtable.h>
  25
  26 #ifdef LIBELF_USE_DEPRECATED
  27 # define elf_getshdrnum    elf_getshnum
  28 # define elf_getshdrstrndx elf_getshstrndx
  29 #endif
  30
  31 /*
  32  * Fallback for systems without this "read, mmaping if possible" cmd.
  33  */
  34 #ifndef ELF_C_READ_MMAP
  35 #define ELF_C_READ_MMAP ELF_C_READ
  36 #endif
  37
  38 struct section {
  39         struct list_head list;
  40         GElf_Shdr sh;
  41         struct list_head symbol_list;
  42         DECLARE_HASHTABLE(symbol_hash, 8);
  43         struct list_head rela_list;
  44         DECLARE_HASHTABLE(rela_hash, 16);
  45         struct section *base, *rela;
  46         struct symbol *sym;
  47         Elf_Data *data;
  48         char *name;
  49         int idx;
  50         unsigned int len;
  51         bool changed, text;
  52 };
  53
  54 struct symbol {
  55         struct list_head list;
  56         struct hlist_node hash;
  57         GElf_Sym sym;
  58         struct section *sec;
  59         char *name;
  60         unsigned int idx;
  61         unsigned char bind, type;
  62         unsigned long offset;
  63         unsigned int len;
  64 };
  65
  66 struct rela {
  67         struct list_head list;
  68         struct hlist_node hash;
  69         GElf_Rela rela;
  70         struct symbol *sym;
  71         unsigned int type;
  72         unsigned long offset;
  73         int addend;
  74 };
  75
  76 struct elf {
  77         Elf *elf;
  78         GElf_Ehdr ehdr;
  79         int fd;
  80         char *name;
  81         struct list_head sections;
  82         DECLARE_HASHTABLE(rela_hash, 16);
  83 };
  84
  85
  86 struct elf *elf_open(const char *name, int flags);
  87 struct section *find_section_by_name(struct elf *elf, const char *name);
  88 struct symbol *find_symbol_by_offset(struct section *sec, unsigned long offset);
  89 struct symbol *find_symbol_containing(struct section *sec, unsigned long offset);
  90 struct rela *find_rela_by_dest(struct section *sec, unsigned long offset);
  91 struct rela *find_rela_by_dest_range(struct section *sec, unsigned long offset,
  92                                      unsigned int len);
  93 struct symbol *find_containing_func(struct section *sec, unsigned long offset);
  94 struct section *elf_create_section(struct elf *elf, const char *name, size_t
  95                                    entsize, int nr);
  96 struct section *elf_create_rela_section(struct elf *elf, struct section *base);
  97 int elf_rebuild_rela_section(struct section *sec);
  98 int elf_write(struct elf *elf);
  99 void elf_close(struct elf *elf);
 100
 101 #define for_each_sec(file, sec)                                         \
 102         list_for_each_entry(sec, &file->elf->sections, list)
 103
 104 #endif /* _OBJTOOL_ELF_H */