x86_64-link.c

   1 #ifdef TARGET_DEFS_ONLY
   2
   3 #define EM_TCC_TARGET EM_X86_64
   4
   5 /* relocation type for 32 bit data relocation */
   6 #define R_DATA_32   R_X86_64_32
   7 #define R_DATA_PTR  R_X86_64_64
   8 #define R_JMP_SLOT  R_X86_64_JUMP_SLOT
   9 #define R_GLOB_DAT  R_X86_64_GLOB_DAT
  10 #define R_COPY      R_X86_64_COPY
  11
  12 #define R_NUM       R_X86_64_NUM
  13
  14 #define ELF_START_ADDR 0x400000
  15 #define ELF_PAGE_SIZE  0x200000
  16
  17 #define HAVE_SECTION_RELOC
  18 #define PCRELATIVE_DLLPLT 1
  19
  20 #else /* !TARGET_DEFS_ONLY */
  21
  22 #include "tcc.h"
  23
  24 /* Returns 1 for a code relocation, 0 for a data relocation. For unknown
  25    relocations, returns -1. */
  26 int code_reloc (int reloc_type)
  27 {
  28     switch (reloc_type) {
  29         case R_X86_64_32:
  30         case R_X86_64_32S:
  31         case R_X86_64_64:
  32         case R_X86_64_GOTPCREL:
  33         case R_X86_64_GOTPCRELX:
  34         case R_X86_64_REX_GOTPCRELX:
  35         case R_X86_64_GOTTPOFF:
  36         case R_X86_64_GOT32:
  37         case R_X86_64_GLOB_DAT:
  38         case R_X86_64_COPY:
  39             return 0;
  40
  41         case R_X86_64_PC32:
  42         case R_X86_64_PLT32:
  43         case R_X86_64_JUMP_SLOT:
  44             return 1;
  45     }
  46
  47     tcc_error ("Unknown relocation type: %d", reloc_type);
  48     return -1;
  49 }
  50
  51 /* Returns an enumerator to describe wether and when the relocation needs a
  52    GOT and/or PLT entry to be created. See tcc.h for a description of the
  53    different values. */
  54 int gotplt_entry_type (int reloc_type)
  55 {
  56     switch (reloc_type) {
  57         case R_X86_64_GLOB_DAT:
  58         case R_X86_64_JUMP_SLOT:
  59         case R_X86_64_COPY:
  60             return NO_GOTPLT_ENTRY;
  61
  62         case R_X86_64_32:
  63         case R_X86_64_32S:
  64         case R_X86_64_64:
  65         case R_X86_64_PC32:
  66             return AUTO_GOTPLT_ENTRY;
  67
  68         case R_X86_64_GOTTPOFF:
  69             return BUILD_GOT_ONLY;
  70
  71         case R_X86_64_GOT32:
  72         case R_X86_64_GOTPCREL:
  73         case R_X86_64_GOTPCRELX:
  74         case R_X86_64_REX_GOTPCRELX:
  75         case R_X86_64_PLT32:
  76             return ALWAYS_GOTPLT_ENTRY;
  77     }
  78
  79     tcc_error ("Unknown relocation type: %d", reloc_type);
  80     return -1;
  81 }
  82
  83 static ElfW_Rel *qrel; /* ptr to next reloc entry reused */
  84
  85 void relocate_init(Section *sr)
  86 {
  87     qrel = (ElfW_Rel *) sr->data;
  88 }
  89
  90 void relocate(TCCState *s1, ElfW_Rel *rel, int type, char *ptr, addr_t addr, addr_t val)
  91 {
  92     int sym_index, esym_index;
  93
  94     sym_index = ELFW(R_SYM)(rel->r_info);
  95
  96     switch (type) {
  97         case R_X86_64_64:
  98             if (s1->output_type == TCC_OUTPUT_DLL) {
  99                 esym_index = s1->symtab_to_dynsym[sym_index];
 100                 qrel->r_offset = rel->r_offset;
 101                 if (esym_index) {
 102                     qrel->r_info = ELFW(R_INFO)(esym_index, R_X86_64_64);
 103                     qrel->r_addend = rel->r_addend;
 104                     qrel++;
 105                     break;
 106                 } else {
 107                     qrel->r_info = ELFW(R_INFO)(0, R_X86_64_RELATIVE);
 108                     qrel->r_addend = read64le(ptr) + val;
 109                     qrel++;
 110                 }
 111             }
 112             add64le(ptr, val);
 113             break;
 114         case R_X86_64_32:
 115         case R_X86_64_32S:
 116             if (s1->output_type == TCC_OUTPUT_DLL) {
 117                 /* XXX: this logic may depend on TCC's codegen
 118                    now TCC uses R_X86_64_32 even for a 64bit pointer */
 119                 qrel->r_info = ELFW(R_INFO)(0, R_X86_64_RELATIVE);
 120                 /* Use sign extension! */
 121                 qrel->r_addend = (int)read32le(ptr) + val;
 122                 qrel++;
 123             }
 124             add32le(ptr, val);
 125             break;
 126
 127         case R_X86_64_PC32:
 128             if (s1->output_type == TCC_OUTPUT_DLL) {
 129                 /* DLL relocation */
 130                 esym_index = s1->symtab_to_dynsym[sym_index];
 131                 if (esym_index) {
 132                     qrel->r_offset = rel->r_offset;
 133                     qrel->r_info = ELFW(R_INFO)(esym_index, R_X86_64_PC32);
 134                     /* Use sign extension! */
 135                     qrel->r_addend = (int)read32le(ptr) + rel->r_addend;
 136                     qrel++;
 137                     break;
 138                 }
 139             }
 140             goto plt32pc32;
 141
 142         case R_X86_64_PLT32:
 143             /* fallthrough: val already holds the PLT slot address */
 144
 145         plt32pc32:
 146         {
 147             long long diff;
 148             diff = (long long)val - addr;
 149             if (diff < -2147483648LL || diff > 2147483647LL) {
 150                 tcc_error("internal error: relocation failed");
 151             }
 152             add32le(ptr, diff);
 153         }
 154             break;
 155         case R_X86_64_GLOB_DAT:
 156         case R_X86_64_JUMP_SLOT:
 157             /* They don't need addend */
 158             write64le(ptr, val - rel->r_addend);
 159             break;
 160         case R_X86_64_GOTPCREL:
 161         case R_X86_64_GOTPCRELX:
 162         case R_X86_64_REX_GOTPCRELX:
 163             add32le(ptr, s1->got->sh_addr - addr +
 164                          s1->sym_attrs[sym_index].got_offset - 4);
 165             break;
 166         case R_X86_64_GOTTPOFF:
 167             add32le(ptr, val - s1->got->sh_addr);
 168             break;
 169         case R_X86_64_GOT32:
 170             /* we load the got offset */
 171             add32le(ptr, s1->sym_attrs[sym_index].got_offset);
 172             break;
 173     }
 174 }
 175
 176 #endif /* !TARGET_DEFS_ONLY */