arm64-link.c

   1 #ifdef TARGET_DEFS_ONLY
   2
   3 #define EM_TCC_TARGET EM_AARCH64
   4
   5 #define R_DATA_32  R_AARCH64_ABS32
   6 #define R_DATA_PTR R_AARCH64_ABS64
   7 #define R_JMP_SLOT R_AARCH64_JUMP_SLOT
   8 #define R_GLOB_DAT R_AARCH64_GLOB_DAT
   9 #define R_COPY     R_AARCH64_COPY
  10 #define R_RELATIVE R_AARCH64_RELATIVE
  11
  12 #define R_NUM      R_AARCH64_NUM
  13
  14 #define ELF_START_ADDR 0x00400000
  15 #define ELF_PAGE_SIZE 0x10000
  16
  17 #define PCRELATIVE_DLLPLT 1
  18 #define RELOCATE_DLLPLT 1
  19
  20 #else /* !TARGET_DEFS_ONLY */
  21
  22 #include "tcc.h"
  23
  24 #ifdef NEED_RELOC_TYPE
  25 /* Returns 1 for a code relocation, 0 for a data relocation. For unknown
  26    relocations, returns -1. */
  27 int code_reloc (int reloc_type)
  28 {
  29     switch (reloc_type) {
  30         case R_AARCH64_ABS32:
  31         case R_AARCH64_ABS64:
  32         case R_AARCH64_PREL32:
  33         case R_AARCH64_MOVW_UABS_G0_NC:
  34         case R_AARCH64_MOVW_UABS_G1_NC:
  35         case R_AARCH64_MOVW_UABS_G2_NC:
  36         case R_AARCH64_MOVW_UABS_G3:
  37         case R_AARCH64_ADR_PREL_PG_HI21:
  38         case R_AARCH64_ADD_ABS_LO12_NC:
  39         case R_AARCH64_ADR_GOT_PAGE:
  40         case R_AARCH64_LD64_GOT_LO12_NC:
  41         case R_AARCH64_LDST128_ABS_LO12_NC:
  42         case R_AARCH64_LDST64_ABS_LO12_NC:
  43         case R_AARCH64_LDST32_ABS_LO12_NC:
  44         case R_AARCH64_LDST16_ABS_LO12_NC:
  45         case R_AARCH64_LDST8_ABS_LO12_NC:
  46         case R_AARCH64_GLOB_DAT:
  47         case R_AARCH64_COPY:
  48             return 0;
  49
  50         case R_AARCH64_JUMP26:
  51         case R_AARCH64_CALL26:
  52         case R_AARCH64_JUMP_SLOT:
  53             return 1;
  54     }
  55     return -1;
  56 }
  57
  58 /* Returns an enumerator to describe whether and when the relocation needs a
  59    GOT and/or PLT entry to be created. See tcc.h for a description of the
  60    different values. */
  61 int gotplt_entry_type (int reloc_type)
  62 {
  63     switch (reloc_type) {
  64         case R_AARCH64_PREL32:
  65         case R_AARCH64_MOVW_UABS_G0_NC:
  66         case R_AARCH64_MOVW_UABS_G1_NC:
  67         case R_AARCH64_MOVW_UABS_G2_NC:
  68         case R_AARCH64_MOVW_UABS_G3:
  69         case R_AARCH64_ADR_PREL_PG_HI21:
  70         case R_AARCH64_ADD_ABS_LO12_NC:
  71         case R_AARCH64_LDST128_ABS_LO12_NC:
  72         case R_AARCH64_LDST64_ABS_LO12_NC:
  73         case R_AARCH64_LDST32_ABS_LO12_NC:
  74         case R_AARCH64_LDST16_ABS_LO12_NC:
  75         case R_AARCH64_LDST8_ABS_LO12_NC:
  76         case R_AARCH64_GLOB_DAT:
  77         case R_AARCH64_JUMP_SLOT:
  78         case R_AARCH64_COPY:
  79             return NO_GOTPLT_ENTRY;
  80
  81         case R_AARCH64_ABS32:
  82         case R_AARCH64_ABS64:
  83         case R_AARCH64_JUMP26:
  84         case R_AARCH64_CALL26:
  85             return AUTO_GOTPLT_ENTRY;
  86
  87         case R_AARCH64_ADR_GOT_PAGE:
  88         case R_AARCH64_LD64_GOT_LO12_NC:
  89             return ALWAYS_GOTPLT_ENTRY;
  90     }
  91     return -1;
  92 }
  93
  94 #ifdef NEED_BUILD_GOT
  95 ST_FUNC unsigned create_plt_entry(TCCState *s1, unsigned got_offset, struct sym_attr *attr)
  96 {
  97     Section *plt = s1->plt;
  98     uint8_t *p;
  99     unsigned plt_offset;
 100
 101     if (plt->data_offset == 0) {
 102         section_ptr_add(plt, 32);
 103     }
 104     plt_offset = plt->data_offset;
 105
 106     p = section_ptr_add(plt, 16);
 107     write32le(p, got_offset);
 108     write32le(p + 4, (uint64_t) got_offset >> 32);
 109     return plt_offset;
 110 }
 111
 112 /* relocate the PLT: compute addresses and offsets in the PLT now that final
 113    address for PLT and GOT are known (see fill_program_header) */
 114 ST_FUNC void relocate_plt(TCCState *s1)
 115 {
 116     uint8_t *p, *p_end;
 117
 118     if (!s1->plt)
 119       return;
 120
 121     p = s1->plt->data;
 122     p_end = p + s1->plt->data_offset;
 123
 124     if (p < p_end) {
 125         uint64_t plt = s1->plt->sh_addr;
 126         uint64_t got = s1->got->sh_addr + 16;
 127         uint64_t off = (got >> 12) - (plt >> 12);
 128         if ((off + ((uint32_t)1 << 20)) >> 21)
 129             tcc_error_noabort("Failed relocating PLT (off=0x%lx, got=0x%lx, plt=0x%lx)", (long)off, (long)got, (long)plt);
 130         write32le(p, 0xa9bf7bf0); // stp x16,x30,[sp,#-16]!
 131         write32le(p + 4, (0x90000010 | // adrp x16,...
 132                           (off & 0x1ffffc) << 3 | (off & 3) << 29));
 133         write32le(p + 8, (0xf9400211 | // ldr x17,[x16,#...]
 134                           (got & 0xff8) << 7));
 135         write32le(p + 12, (0x91000210 | // add x16,x16,#...
 136                            (got & 0xfff) << 10));
 137         write32le(p + 16, 0xd61f0220); // br x17
 138         write32le(p + 20, 0xd503201f); // nop
 139         write32le(p + 24, 0xd503201f); // nop
 140         write32le(p + 28, 0xd503201f); // nop
 141         p += 32;
 142         got = s1->got->sh_addr;
 143         while (p < p_end) {
 144             uint64_t pc = plt + (p - s1->plt->data);
 145             uint64_t addr = got + read64le(p);
 146             uint64_t off = (addr >> 12) - (pc >> 12);
 147             if ((off + ((uint32_t)1 << 20)) >> 21)
 148                 tcc_error_noabort("Failed relocating PLT (off=0x%lx, addr=0x%lx, pc=0x%lx)", (long)off, (long)addr, (long)pc);
 149             write32le(p, (0x90000010 | // adrp x16,...
 150                           (off & 0x1ffffc) << 3 | (off & 3) << 29));
 151             write32le(p + 4, (0xf9400211 | // ldr x17,[x16,#...]
 152                               (addr & 0xff8) << 7));
 153             write32le(p + 8, (0x91000210 | // add x16,x16,#...
 154                               (addr & 0xfff) << 10));
 155             write32le(p + 12, 0xd61f0220); // br x17
 156             p += 16;
 157         }
 158     }
 159
 160     if (s1->plt->reloc) {
 161         ElfW_Rel *rel;
 162         p = s1->got->data;
 163         for_each_elem(s1->plt->reloc, 0, rel, ElfW_Rel) {
 164             write64le(p + rel->r_offset, s1->plt->sh_addr);
 165         }
 166     }
 167 }
 168 #endif
 169 #endif
 170
 171 void relocate(TCCState *s1, ElfW_Rel *rel, int type, unsigned char *ptr, addr_t addr, addr_t val)
 172 {
 173     int sym_index = ELFW(R_SYM)(rel->r_info), esym_index;
 174 #ifdef DEBUG_RELOC
 175     ElfW(Sym) *sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
 176 #endif
 177
 178     switch(type) {
 179         case R_AARCH64_ABS64:
 180             if ((s1->output_type & TCC_OUTPUT_DYN)) {
 181                 esym_index = get_sym_attr(s1, sym_index, 0)->dyn_index;
 182                 qrel->r_offset = rel->r_offset;
 183                 if (esym_index) {
 184                     qrel->r_info = ELFW(R_INFO)(esym_index, R_AARCH64_ABS64);
 185                     qrel->r_addend = rel->r_addend;
 186                     qrel++;
 187                     break;
 188                 } else {
 189                     qrel->r_info = ELFW(R_INFO)(0, R_AARCH64_RELATIVE);
 190                     qrel->r_addend = read64le(ptr) + val;
 191                     qrel++;
 192                 }
 193             }
 194             add64le(ptr, val);
 195             return;
 196         case R_AARCH64_ABS32:
 197             if (s1->output_type & TCC_OUTPUT_DYN) {
 198                 /* XXX: this logic may depend on TCC's codegen
 199                    now TCC uses R_AARCH64_RELATIVE even for a 64bit pointer */
 200                 qrel->r_offset = rel->r_offset;
 201                 qrel->r_info = ELFW(R_INFO)(0, R_AARCH64_RELATIVE);
 202                 /* Use sign extension! */
 203                 qrel->r_addend = (int)read32le(ptr) + val;
 204                 qrel++;
 205             }
 206             add32le(ptr, val);
 207             return;
 208         case R_AARCH64_PREL32:
 209             if (s1->output_type == TCC_OUTPUT_DLL) {
 210                 /* DLL relocation */
 211                 esym_index = get_sym_attr(s1, sym_index, 0)->dyn_index;
 212                 if (esym_index) {
 213                     qrel->r_offset = rel->r_offset;
 214                     qrel->r_info = ELFW(R_INFO)(esym_index, R_AARCH64_PREL32);
 215                     /* Use sign extension! */
 216                     qrel->r_addend = (int)read32le(ptr) + rel->r_addend;
 217                     qrel++;
 218                     break;
 219                 }
 220             }
 221             write32le(ptr, val - addr);
 222             return;
 223         case R_AARCH64_MOVW_UABS_G0_NC:
 224             write32le(ptr, ((read32le(ptr) & 0xffe0001f) |
 225                             (val & 0xffff) << 5));
 226             return;
 227         case R_AARCH64_MOVW_UABS_G1_NC:
 228             write32le(ptr, ((read32le(ptr) & 0xffe0001f) |
 229                             (val >> 16 & 0xffff) << 5));
 230             return;
 231         case R_AARCH64_MOVW_UABS_G2_NC:
 232             write32le(ptr, ((read32le(ptr) & 0xffe0001f) |
 233                             (val >> 32 & 0xffff) << 5));
 234             return;
 235         case R_AARCH64_MOVW_UABS_G3:
 236             write32le(ptr, ((read32le(ptr) & 0xffe0001f) |
 237                             (val >> 48 & 0xffff) << 5));
 238             return;
 239         case R_AARCH64_ADR_PREL_PG_HI21: {
 240             uint64_t off = (val >> 12) - (addr >> 12);
 241             if ((off + ((uint64_t)1 << 20)) >> 21)
 242                 tcc_error_noabort("R_AARCH64_ADR_PREL_PG_HI21 relocation failed");
 243             write32le(ptr, ((read32le(ptr) & 0x9f00001f) |
 244                             (off & 0x1ffffc) << 3 | (off & 3) << 29));
 245             return;
 246         }
 247         case R_AARCH64_ADD_ABS_LO12_NC:
 248         case R_AARCH64_LDST8_ABS_LO12_NC:
 249             write32le(ptr, ((read32le(ptr) & 0xffc003ff) |
 250                             (val & 0xfff) << 10));
 251             return;
 252         case R_AARCH64_LDST16_ABS_LO12_NC:
 253             write32le(ptr, ((read32le(ptr) & 0xffc003ff) |
 254                             (val & 0xffe) << 9));
 255             return;
 256         case R_AARCH64_LDST32_ABS_LO12_NC:
 257             write32le(ptr, ((read32le(ptr) & 0xffc003ff) |
 258                             (val & 0xffc) << 8));
 259             return;
 260         case R_AARCH64_LDST64_ABS_LO12_NC:
 261             write32le(ptr, ((read32le(ptr) & 0xffc003ff) |
 262                             (val & 0xff8) << 7));
 263             return;
 264         case R_AARCH64_LDST128_ABS_LO12_NC:
 265             write32le(ptr, ((read32le(ptr) & 0xffc003ff) |
 266                             (val & 0xff0) << 6));
 267             return;
 268         case R_AARCH64_JUMP26:
 269         case R_AARCH64_CALL26:
 270 #ifdef DEBUG_RELOC
 271             printf ("reloc %d @ 0x%lx: val=0x%lx name=%s\n", type, addr, val,
 272                     (char *) symtab_section->link->data + sym->st_name);
 273 #endif
 274             if (((val - addr) + ((uint64_t)1 << 27)) & ~(uint64_t)0xffffffc)
 275                 tcc_error_noabort("R_AARCH64_(JUMP|CALL)26 relocation failed"
 276                           " (val=%lx, addr=%lx)", (long)val, (long)addr);
 277             write32le(ptr, (0x14000000 |
 278                             (uint32_t)(type == R_AARCH64_CALL26) << 31 |
 279                             ((val - addr) >> 2 & 0x3ffffff)));
 280             return;
 281         case R_AARCH64_ADR_GOT_PAGE: {
 282             uint64_t off =
 283                 (((s1->got->sh_addr +
 284                    get_sym_attr(s1, sym_index, 0)->got_offset) >> 12) - (addr >> 12));
 285             if ((off + ((uint64_t)1 << 20)) >> 21)
 286                 tcc_error_noabort("R_AARCH64_ADR_GOT_PAGE relocation failed");
 287             write32le(ptr, ((read32le(ptr) & 0x9f00001f) |
 288                             (off & 0x1ffffc) << 3 | (off & 3) << 29));
 289             return;
 290         }
 291         case R_AARCH64_LD64_GOT_LO12_NC:
 292             write32le(ptr,
 293                       ((read32le(ptr) & 0xfff803ff) |
 294                        ((s1->got->sh_addr +
 295                          get_sym_attr(s1, sym_index, 0)->got_offset) & 0xff8) << 7));
 296             return;
 297         case R_AARCH64_COPY:
 298             return;
 299         case R_AARCH64_GLOB_DAT:
 300         case R_AARCH64_JUMP_SLOT:
 301             /* They don't need addend */
 302 #ifdef DEBUG_RELOC
 303             printf ("reloc %d @ 0x%lx: val=0x%lx name=%s\n", type, addr,
 304                     val - rel->r_addend,
 305                     (char *) symtab_section->link->data + sym->st_name);
 306 #endif
 307             write64le(ptr, val - rel->r_addend);
 308             return;
 309         case R_AARCH64_RELATIVE:
 310 #ifdef TCC_TARGET_PE
 311             add32le(ptr, val - s1->pe_imagebase);
 312 #endif
 313             /* do nothing */
 314             return;
 315         default:
 316             fprintf(stderr, "FIXME: handle reloc type %x at %x [%p] to %x\n",
 317                     type, (unsigned)addr, ptr, (unsigned)val);
 318             return;
 319     }
 320 }
 321
 322 #endif /* !TARGET_DEFS_ONLY */