liblttng-ust/lttng-ust-elf.h

   1 /*
   2  * SPDX-License-Identifier: LGPL-2.1-or-later
   3  *
   4  * Copyright (C) 2015 Antoine Busque <abusque@efficios.com>
   5  */
   6
   7 #ifndef _LIB_LTTNG_UST_ELF_H
   8 #define _LIB_LTTNG_UST_ELF_H
   9
  10 #include <elf.h>
  11 #include <lttng/ust-endian.h>
  12
  13 /*
  14  * Determine native endianness in order to convert when reading an ELF
  15  * file if there is a mismatch.
  16  */
  17 #if BYTE_ORDER == LITTLE_ENDIAN
  18 #define NATIVE_ELF_ENDIANNESS ELFDATA2LSB
  19 #else
  20 #define NATIVE_ELF_ENDIANNESS ELFDATA2MSB
  21 #endif
  22
  23 /*
  24  * The size in bytes of the debug link CRC as contained in an ELF
  25  * section.
  26  */
  27 #define ELF_CRC_SIZE            4
  28 /*
  29  * ELF notes are aligned on 4 bytes. ref: ELF specification version
  30  * 1.1 p. 2-5.
  31  */
  32 #define ELF_NOTE_ENTRY_ALIGN    4
  33 /*
  34  * Within an ELF note, the `desc` field is also aligned on 4
  35  * bytes. ref: ELF specification version 1.1 p. 2-5.
  36  */
  37 #define ELF_NOTE_DESC_ALIGN     4
  38
  39 #define bswap(x)                                \
  40         do {                                    \
  41                 switch (sizeof(x)) {            \
  42                 case 8:                         \
  43                         x = bswap_64(x);        \
  44                         break;                  \
  45                 case 4:                         \
  46                         x = bswap_32(x);        \
  47                         break;                  \
  48                 case 2:                         \
  49                         x = bswap_16(x);        \
  50                         break;                  \
  51                 case 1:                         \
  52                         break;                  \
  53                 default:                        \
  54                         abort();                \
  55                 }                               \
  56         } while (0)
  57
  58 #define bswap_phdr(phdr)                \
  59         do {                            \
  60                 bswap((phdr).p_type);   \
  61                 bswap((phdr).p_offset); \
  62                 bswap((phdr).p_filesz); \
  63                 bswap((phdr).p_memsz);  \
  64                 bswap((phdr).p_align);  \
  65                 bswap((phdr).p_vaddr);  \
  66         } while (0)
  67
  68 #define bswap_shdr(shdr)                    \
  69         do {                                \
  70                 bswap((shdr).sh_name);      \
  71                 bswap((shdr).sh_type);      \
  72                 bswap((shdr).sh_flags);     \
  73                 bswap((shdr).sh_addr);      \
  74                 bswap((shdr).sh_offset);    \
  75                 bswap((shdr).sh_size);      \
  76                 bswap((shdr).sh_link);      \
  77                 bswap((shdr).sh_info);      \
  78                 bswap((shdr).sh_addralign); \
  79                 bswap((shdr).sh_entsize);   \
  80         } while (0)
  81
  82 #define bswap_ehdr(ehdr)                                \
  83         do {                                            \
  84                 bswap((ehdr).e_type);                   \
  85                 bswap((ehdr).e_machine);                \
  86                 bswap((ehdr).e_version);                \
  87                 bswap((ehdr).e_entry);                  \
  88                 bswap((ehdr).e_phoff);                  \
  89                 bswap((ehdr).e_shoff);                  \
  90                 bswap((ehdr).e_flags);                  \
  91                 bswap((ehdr).e_ehsize);                 \
  92                 bswap((ehdr).e_phentsize);              \
  93                 bswap((ehdr).e_phnum);                  \
  94                 bswap((ehdr).e_shentsize);              \
  95                 bswap((ehdr).e_shnum);                  \
  96                 bswap((ehdr).e_shstrndx);               \
  97         } while (0)
  98
  99 #define copy_phdr(src_phdr, dst_phdr)                           \
 100         do {                                                    \
 101                 (dst_phdr).p_type = (src_phdr).p_type;          \
 102                 (dst_phdr).p_offset = (src_phdr).p_offset;      \
 103                 (dst_phdr).p_filesz = (src_phdr).p_filesz;      \
 104                 (dst_phdr).p_memsz = (src_phdr).p_memsz;        \
 105                 (dst_phdr).p_align = (src_phdr).p_align;        \
 106                 (dst_phdr).p_vaddr = (src_phdr).p_vaddr;        \
 107         } while (0)
 108
 109 #define copy_shdr(src_shdr, dst_shdr)                                   \
 110         do {                                                            \
 111                 (dst_shdr).sh_name = (src_shdr).sh_name;                \
 112                 (dst_shdr).sh_type = (src_shdr).sh_type;                \
 113                 (dst_shdr).sh_flags = (src_shdr).sh_flags;              \
 114                 (dst_shdr).sh_addr = (src_shdr).sh_addr;                \
 115                 (dst_shdr).sh_offset = (src_shdr).sh_offset;            \
 116                 (dst_shdr).sh_size = (src_shdr).sh_size;                \
 117                 (dst_shdr).sh_link = (src_shdr).sh_link;                \
 118                 (dst_shdr).sh_info = (src_shdr).sh_info;                \
 119                 (dst_shdr).sh_addralign = (src_shdr).sh_addralign;      \
 120                 (dst_shdr).sh_entsize = (src_shdr).sh_entsize;          \
 121         } while (0)
 122
 123 #define copy_ehdr(src_ehdr, dst_ehdr)                                   \
 124         do {                                                            \
 125                 (dst_ehdr).e_type = (src_ehdr).e_type;                  \
 126                 (dst_ehdr).e_machine = (src_ehdr).e_machine;            \
 127                 (dst_ehdr).e_version = (src_ehdr).e_version;            \
 128                 (dst_ehdr).e_entry = (src_ehdr).e_entry;                \
 129                 (dst_ehdr).e_phoff = (src_ehdr).e_phoff;                \
 130                 (dst_ehdr).e_shoff = (src_ehdr).e_shoff;                \
 131                 (dst_ehdr).e_flags = (src_ehdr).e_flags;                \
 132                 (dst_ehdr).e_ehsize = (src_ehdr).e_ehsize;              \
 133                 (dst_ehdr).e_phentsize = (src_ehdr).e_phentsize;        \
 134                 (dst_ehdr).e_phnum = (src_ehdr).e_phnum;                \
 135                 (dst_ehdr).e_shentsize = (src_ehdr).e_shentsize;        \
 136                 (dst_ehdr).e_shnum = (src_ehdr).e_shnum;                \
 137                 (dst_ehdr).e_shstrndx = (src_ehdr).e_shstrndx;          \
 138         } while (0)
 139
 140 static inline
 141 int is_elf_32_bit(struct lttng_ust_elf *elf)
 142 {
 143         return elf->bitness == ELFCLASS32;
 144 }
 145
 146 static inline
 147 int is_elf_native_endian(struct lttng_ust_elf *elf)
 148 {
 149         return elf->endianness == NATIVE_ELF_ENDIANNESS;
 150 }
 151
 152 #endif