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 /* 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_AARCH64_ABS32:
  30         case R_AARCH64_ABS64:
  31         case R_AARCH64_PREL32:
  32         case R_AARCH64_MOVW_UABS_G0_NC:
  33         case R_AARCH64_MOVW_UABS_G1_NC:
  34         case R_AARCH64_MOVW_UABS_G2_NC:
  35         case R_AARCH64_MOVW_UABS_G3:
  36         case R_AARCH64_ADR_PREL_PG_HI21:
  37         case R_AARCH64_ADD_ABS_LO12_NC:
  38         case R_AARCH64_ADR_GOT_PAGE:
  39         case R_AARCH64_LD64_GOT_LO12_NC:
  40         case R_AARCH64_LDST128_ABS_LO12_NC:
  41         case R_AARCH64_LDST64_ABS_LO12_NC:
  42         case R_AARCH64_LDST32_ABS_LO12_NC:
  43         case R_AARCH64_LDST16_ABS_LO12_NC:
  44         case R_AARCH64_LDST8_ABS_LO12_NC:
  45         case R_AARCH64_GLOB_DAT:
  46         case R_AARCH64_COPY:
  47             return 0;
  48
  49         case R_AARCH64_JUMP26:
  50         case R_AARCH64_CALL26:
  51         case R_AARCH64_JUMP_SLOT:
  52             return 1;
  53     }
  54     return -1;
  55 }
  56
  57 /* Returns an enumerator to describe whether and when the relocation needs a
  58    GOT and/or PLT entry to be created. See tcc.h for a description of the
  59    different values. */
  60 int gotplt_entry_type (int reloc_type)
  61 {
  62     switch (reloc_type) {
  63         case R_AARCH64_PREL32:
  64         case R_AARCH64_MOVW_UABS_G0_NC:
  65         case R_AARCH64_MOVW_UABS_G1_NC:
  66         case R_AARCH64_MOVW_UABS_G2_NC:
  67         case R_AARCH64_MOVW_UABS_G3:
  68         case R_AARCH64_ADR_PREL_PG_HI21:
  69         case R_AARCH64_ADD_ABS_LO12_NC:
  70         case R_AARCH64_LDST128_ABS_LO12_NC:
  71         case R_AARCH64_LDST64_ABS_LO12_NC:
  72         case R_AARCH64_LDST32_ABS_LO12_NC:
  73         case R_AARCH64_LDST16_ABS_LO12_NC:
  74         case R_AARCH64_LDST8_ABS_LO12_NC:
  75         case R_AARCH64_GLOB_DAT:
  76         case R_AARCH64_JUMP_SLOT:
  77         case R_AARCH64_COPY:
  78             return NO_GOTPLT_ENTRY;
  79
  80         case R_AARCH64_ABS32:
  81         case R_AARCH64_ABS64:
  82         case R_AARCH64_JUMP26:
  83         case R_AARCH64_CALL26:
  84             return AUTO_GOTPLT_ENTRY;
  85
  86         case R_AARCH64_ADR_GOT_PAGE:
  87         case R_AARCH64_LD64_GOT_LO12_NC:
  88             return ALWAYS_GOTPLT_ENTRY;
  89     }
  90     return -1;
  91 }
  92
  93 ST_FUNC unsigned create_plt_entry(TCCState *s1, unsigned got_offset, struct sym_attr *attr)
  94 {
  95     Section *plt = s1->plt;
  96     uint8_t *p;
  97     unsigned plt_offset;
  98
  99     if (plt->data_offset == 0) {
 100         section_ptr_add(plt, 32);
 101     }
 102     plt_offset = plt->data_offset;
 103
 104     p = section_ptr_add(plt, 16);
 105     write32le(p, got_offset);
 106     write32le(p + 4, (uint64_t) got_offset >> 32);
 107     return plt_offset;
 108 }
 109
 110 /* relocate the PLT: compute addresses and offsets in the PLT now that final
 111    address for PLT and GOT are known (see fill_program_header) */
 112 ST_FUNC void relocate_plt(TCCState *s1)
 113 {
 114     uint8_t *p, *p_end;
 115
 116     if (!s1->plt)
 117       return;
 118
 119     p = s1->plt->data;
 120     p_end = p + s1->plt->data_offset;
 121
 122     if (p < p_end) {
 123         uint64_t plt = s1->plt->sh_addr;
 124         uint64_t got = s1->got->sh_addr + 16;
 125         uint64_t off = (got >> 12) - (plt >> 12);
 126         if ((off + ((uint32_t)1 << 20)) >> 21)
 127             tcc_error("Failed relocating PLT (off=0x%lx, got=0x%lx, plt=0x%lx)", (long)off, (long)got, (long)plt);
 128         write32le(p, 0xa9bf7bf0); // stp x16,x30,[sp,#-16]!
 129         write32le(p + 4, (0x90000010 | // adrp x16,...
 130                           (off & 0x1ffffc) << 3 | (off & 3) << 29));
 131         write32le(p + 8, (0xf9400211 | // ldr x17,[x16,#...]
 132                           (got & 0xff8) << 7));
 133         write32le(p + 12, (0x91000210 | // add x16,x16,#...
 134                            (got & 0xfff) << 10));
 135         write32le(p + 16, 0xd61f0220); // br x17
 136         write32le(p + 20, 0xd503201f); // nop
 137         write32le(p + 24, 0xd503201f); // nop
 138         write32le(p + 28, 0xd503201f); // nop
 139         p += 32;
 140         got = s1->got->sh_addr;
 141         while (p < p_end) {
 142             uint64_t pc = plt + (p - s1->plt->data);
 143             uint64_t addr = got + read64le(p);
 144             uint64_t off = (addr >> 12) - (pc >> 12);
 145             if ((off + ((uint32_t)1 << 20)) >> 21)
 146                 tcc_error("Failed relocating PLT (off=0x%lx, addr=0x%lx, pc=0x%lx)", (long)off, (long)addr, (long)pc);
 147             write32le(p, (0x90000010 | // adrp x16,...
 148                           (off & 0x1ffffc) << 3 | (off & 3) << 29));
 149             write32le(p + 4, (0xf9400211 | // ldr x17,[x16,#...]
 150                               (addr & 0xff8) << 7));
 151             write32le(p + 8, (0x91000210 | // add x16,x16,#...
 152                               (addr & 0xfff) << 10));
 153             write32le(p + 12, 0xd61f0220); // br x17
 154             p += 16;
 155         }
 156     }
 157
 158     if (s1->plt->reloc) {
 159         ElfW_Rel *rel;
 160         p = s1->got->data;
 161         for_each_elem(s1->plt->reloc, 0, rel, ElfW_Rel) {
 162             write64le(p + rel->r_offset, s1->plt->sh_addr);
 163         }
 164     }
 165 }
 166
 167 void relocate(TCCState *s1, ElfW_Rel *rel, int type, unsigned char *ptr, addr_t addr, addr_t val)
 168 {
 169     int sym_index = ELFW(R_SYM)(rel->r_info), esym_index;
 170 #ifdef DEBUG_RELOC
 171     ElfW(Sym) *sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
 172 #endif
 173
 174     switch(type) {
 175         case R_AARCH64_ABS64:
 176             if (s1->output_type == TCC_OUTPUT_DLL) {
 177                 esym_index = get_sym_attr(s1, sym_index, 0)->dyn_index;
 178                 qrel->r_offset = rel->r_offset;
 179                 if (esym_index) {
 180                     qrel->r_info = ELFW(R_INFO)(esym_index, R_AARCH64_ABS64);
 181                     qrel->r_addend = rel->r_addend;
 182                     qrel++;
 183                     break;
 184                 } else {
 185                     qrel->r_info = ELFW(R_INFO)(0, R_AARCH64_RELATIVE);
 186                     qrel->r_addend = read64le(ptr) + val;
 187                     qrel++;
 188                 }
 189             }
 190             add64le(ptr, val);
 191             return;
 192         case R_AARCH64_ABS32:
 193             if (s1->output_type == TCC_OUTPUT_DLL) {
 194                 /* XXX: this logic may depend on TCC's codegen
 195                    now TCC uses R_AARCH64_RELATIVE even for a 64bit pointer */
 196                 qrel->r_offset = rel->r_offset;
 197                 qrel->r_info = ELFW(R_INFO)(0, R_AARCH64_RELATIVE);
 198                 /* Use sign extension! */
 199                 qrel->r_addend = (int)read32le(ptr) + val;
 200                 qrel++;
 201             }
 202             add32le(ptr, val);
 203             return;
 204         case R_AARCH64_PREL32:
 205             if (s1->output_type == TCC_OUTPUT_DLL) {
 206                 /* DLL relocation */
 207                 esym_index = get_sym_attr(s1, sym_index, 0)->dyn_index;
 208                 if (esym_index) {
 209                     qrel->r_offset = rel->r_offset;
 210                     qrel->r_info = ELFW(R_INFO)(esym_index, R_AARCH64_PREL32);
 211                     /* Use sign extension! */
 212                     qrel->r_addend = (int)read32le(ptr) + rel->r_addend;
 213                     qrel++;
 214                     break;
 215                 }
 216             }
 217             write32le(ptr, val - addr);
 218             return;
 219         case R_AARCH64_MOVW_UABS_G0_NC:
 220             write32le(ptr, ((read32le(ptr) & 0xffe0001f) |
 221                             (val & 0xffff) << 5));
 222             return;
 223         case R_AARCH64_MOVW_UABS_G1_NC:
 224             write32le(ptr, ((read32le(ptr) & 0xffe0001f) |
 225                             (val >> 16 & 0xffff) << 5));
 226             return;
 227         case R_AARCH64_MOVW_UABS_G2_NC:
 228             write32le(ptr, ((read32le(ptr) & 0xffe0001f) |
 229                             (val >> 32 & 0xffff) << 5));
 230             return;
 231         case R_AARCH64_MOVW_UABS_G3:
 232             write32le(ptr, ((read32le(ptr) & 0xffe0001f) |
 233                             (val >> 48 & 0xffff) << 5));
 234             return;
 235         case R_AARCH64_ADR_PREL_PG_HI21: {
 236             uint64_t off = (val >> 12) - (addr >> 12);
 237             if ((off + ((uint64_t)1 << 20)) >> 21)
 238                 tcc_error("R_AARCH64_ADR_PREL_PG_HI21 relocation failed");
 239             write32le(ptr, ((read32le(ptr) & 0x9f00001f) |
 240                             (off & 0x1ffffc) << 3 | (off & 3) << 29));
 241             return;
 242         }
 243         case R_AARCH64_ADD_ABS_LO12_NC:
 244         case R_AARCH64_LDST8_ABS_LO12_NC:
 245             write32le(ptr, ((read32le(ptr) & 0xffc003ff) |
 246                             (val & 0xfff) << 10));
 247             return;
 248         case R_AARCH64_LDST16_ABS_LO12_NC:
 249             write32le(ptr, ((read32le(ptr) & 0xffc003ff) |
 250                             (val & 0xffe) << 9));
 251             return;
 252         case R_AARCH64_LDST32_ABS_LO12_NC:
 253             write32le(ptr, ((read32le(ptr) & 0xffc003ff) |
 254                             (val & 0xffc) << 8));
 255             return;
 256         case R_AARCH64_LDST64_ABS_LO12_NC:
 257             write32le(ptr, ((read32le(ptr) & 0xffc003ff) |
 258                             (val & 0xff8) << 7));
 259             return;
 260         case R_AARCH64_LDST128_ABS_LO12_NC:
 261             write32le(ptr, ((read32le(ptr) & 0xffc003ff) |
 262                             (val & 0xff0) << 6));
 263             return;
 264         case R_AARCH64_JUMP26:
 265         case R_AARCH64_CALL26:
 266 #ifdef DEBUG_RELOC
 267             printf ("reloc %d @ 0x%lx: val=0x%lx name=%s\n", type, addr, val,
 268                     (char *) symtab_section->link->data + sym->st_name);
 269 #endif
 270             if (((val - addr) + ((uint64_t)1 << 27)) & ~(uint64_t)0xffffffc)
 271                 tcc_error("R_AARCH64_(JUMP|CALL)26 relocation failed"
 272                           " (val=%lx, addr=%lx)", (long)val, (long)addr);
 273             write32le(ptr, (0x14000000 |
 274                             (uint32_t)(type == R_AARCH64_CALL26) << 31 |
 275                             ((val - addr) >> 2 & 0x3ffffff)));
 276             return;
 277         case R_AARCH64_ADR_GOT_PAGE: {
 278             uint64_t off =
 279                 (((s1->got->sh_addr +
 280                    get_sym_attr(s1, sym_index, 0)->got_offset) >> 12) - (addr >> 12));
 281             if ((off + ((uint64_t)1 << 20)) >> 21)
 282                 tcc_error("R_AARCH64_ADR_GOT_PAGE relocation failed");
 283             write32le(ptr, ((read32le(ptr) & 0x9f00001f) |
 284                             (off & 0x1ffffc) << 3 | (off & 3) << 29));
 285             return;
 286         }
 287         case R_AARCH64_LD64_GOT_LO12_NC:
 288             write32le(ptr,
 289                       ((read32le(ptr) & 0xfff803ff) |
 290                        ((s1->got->sh_addr +
 291                          get_sym_attr(s1, sym_index, 0)->got_offset) & 0xff8) << 7));
 292             return;
 293         case R_AARCH64_COPY:
 294             return;
 295         case R_AARCH64_GLOB_DAT:
 296         case R_AARCH64_JUMP_SLOT:
 297             /* They don't need addend */
 298 #ifdef DEBUG_RELOC
 299             printf ("reloc %d @ 0x%lx: val=0x%lx name=%s\n", type, addr,
 300                     val - rel->r_addend,
 301                     (char *) symtab_section->link->data + sym->st_name);
 302 #endif
 303             write64le(ptr, val - rel->r_addend);
 304             return;
 305         case R_AARCH64_RELATIVE:
 306 #ifdef TCC_TARGET_PE
 307             add32le(ptr, val - s1->pe_imagebase);
 308 #endif
 309             /* do nothing */
 310             return;
 311         default:
 312             fprintf(stderr, "FIXME: handle reloc type %x at %x [%p] to %x\n",
 313                     type, (unsigned)addr, ptr, (unsigned)val);
 314             return;
 315     }
 316 }
 317
 318 #endif /* !TARGET_DEFS_ONLY */