x86_64-link.c

   1 #include "tcc.h"
   2 #define HAVE_SECTION_RELOC
   3
   4 static ElfW_Rel *qrel; /* ptr to next reloc entry reused */
   5
   6 void relocate_init(Section *sr)
   7 {
   8     qrel = (ElfW_Rel *) sr->data;
   9 }
  10
  11 void relocate(TCCState *s1, ElfW_Rel *rel, int type, char *ptr, addr_t addr, addr_t val)
  12 {
  13     int sym_index, esym_index;
  14
  15     sym_index = ELFW(R_SYM)(rel->r_info);
  16
  17     switch (type) {
  18         case R_X86_64_64:
  19             if (s1->output_type == TCC_OUTPUT_DLL) {
  20                 esym_index = s1->symtab_to_dynsym[sym_index];
  21                 qrel->r_offset = rel->r_offset;
  22                 if (esym_index) {
  23                     qrel->r_info = ELFW(R_INFO)(esym_index, R_X86_64_64);
  24                     qrel->r_addend = rel->r_addend;
  25                     qrel++;
  26                     break;
  27                 } else {
  28                     qrel->r_info = ELFW(R_INFO)(0, R_X86_64_RELATIVE);
  29                     qrel->r_addend = read64le(ptr) + val;
  30                     qrel++;
  31                 }
  32             }
  33             add64le(ptr, val);
  34             break;
  35         case R_X86_64_32:
  36         case R_X86_64_32S:
  37             if (s1->output_type == TCC_OUTPUT_DLL) {
  38                 /* XXX: this logic may depend on TCC's codegen
  39                    now TCC uses R_X86_64_32 even for a 64bit pointer */
  40                 qrel->r_info = ELFW(R_INFO)(0, R_X86_64_RELATIVE);
  41                 /* Use sign extension! */
  42                 qrel->r_addend = (int)read32le(ptr) + val;
  43                 qrel++;
  44             }
  45             add32le(ptr, val);
  46             break;
  47
  48         case R_X86_64_PC32:
  49             if (s1->output_type == TCC_OUTPUT_DLL) {
  50                 /* DLL relocation */
  51                 esym_index = s1->symtab_to_dynsym[sym_index];
  52                 if (esym_index) {
  53                     qrel->r_offset = rel->r_offset;
  54                     qrel->r_info = ELFW(R_INFO)(esym_index, R_X86_64_PC32);
  55                     /* Use sign extension! */
  56                     qrel->r_addend = (int)read32le(ptr) + rel->r_addend;
  57                     qrel++;
  58                     break;
  59                 }
  60             }
  61             goto plt32pc32;
  62
  63         case R_X86_64_PLT32:
  64             /* We've put the PLT slot offset into r_addend when generating
  65                it, and that's what we must use as relocation value (adjusted
  66                by section offset of course).  */
  67             val = s1->plt->sh_addr + rel->r_addend;
  68             /* fallthrough.  */
  69
  70         plt32pc32:
  71         {
  72             long long diff;
  73             diff = (long long)val - addr;
  74             if (diff < -2147483648LL || diff > 2147483647LL) {
  75                 tcc_error("internal error: relocation failed");
  76             }
  77             add32le(ptr, diff);
  78         }
  79             break;
  80         case R_X86_64_GLOB_DAT:
  81         case R_X86_64_JUMP_SLOT:
  82             /* They don't need addend */
  83             write64le(ptr, val - rel->r_addend);
  84             break;
  85         case R_X86_64_GOTPCREL:
  86         case R_X86_64_GOTPCRELX:
  87         case R_X86_64_REX_GOTPCRELX:
  88             add32le(ptr, s1->got->sh_addr - addr +
  89                          s1->sym_attrs[sym_index].got_offset - 4);
  90             break;
  91         case R_X86_64_GOTTPOFF:
  92             add32le(ptr, val - s1->got->sh_addr);
  93             break;
  94         case R_X86_64_GOT32:
  95             /* we load the got offset */
  96             add32le(ptr, s1->sym_attrs[sym_index].got_offset);
  97             break;
  98     }
  99 }