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_LDST64_ABS_LO12_NC:
  41         case R_AARCH64_LDST8_ABS_LO12_NC:
  42         case R_AARCH64_GLOB_DAT:
  43         case R_AARCH64_COPY:
  44             return 0;
  45
  46         case R_AARCH64_JUMP26:
  47         case R_AARCH64_CALL26:
  48         case R_AARCH64_JUMP_SLOT:
  49             return 1;
  50     }
  51     return -1;
  52 }
  53
  54 /* Returns an enumerator to describe whether and when the relocation needs a
  55    GOT and/or PLT entry to be created. See tcc.h for a description of the
  56    different values. */
  57 int gotplt_entry_type (int reloc_type)
  58 {
  59     switch (reloc_type) {
  60         case R_AARCH64_PREL32:
  61         case R_AARCH64_MOVW_UABS_G0_NC:
  62         case R_AARCH64_MOVW_UABS_G1_NC:
  63         case R_AARCH64_MOVW_UABS_G2_NC:
  64         case R_AARCH64_MOVW_UABS_G3:
  65         case R_AARCH64_ADR_PREL_PG_HI21:
  66         case R_AARCH64_ADD_ABS_LO12_NC:
  67         case R_AARCH64_LDST64_ABS_LO12_NC:
  68         case R_AARCH64_LDST8_ABS_LO12_NC:
  69         case R_AARCH64_GLOB_DAT:
  70         case R_AARCH64_JUMP_SLOT:
  71         case R_AARCH64_COPY:
  72             return NO_GOTPLT_ENTRY;
  73
  74         case R_AARCH64_ABS32:
  75         case R_AARCH64_ABS64:
  76         case R_AARCH64_JUMP26:
  77         case R_AARCH64_CALL26:
  78             return AUTO_GOTPLT_ENTRY;
  79
  80         case R_AARCH64_ADR_GOT_PAGE:
  81         case R_AARCH64_LD64_GOT_LO12_NC:
  82             return ALWAYS_GOTPLT_ENTRY;
  83     }
  84     return -1;
  85 }
  86
  87 ST_FUNC unsigned create_plt_entry(TCCState *s1, unsigned got_offset, struct sym_attr *attr)
  88 {
  89     Section *plt = s1->plt;
  90     uint8_t *p;
  91     unsigned plt_offset;
  92
  93     if (plt->data_offset == 0) {
  94         section_ptr_add(plt, 32);
  95     }
  96     plt_offset = plt->data_offset;
  97
  98     p = section_ptr_add(plt, 16);
  99     write32le(p, got_offset);
 100     write32le(p + 4, (uint64_t) got_offset >> 32);
 101     return plt_offset;
 102 }
 103
 104 /* relocate the PLT: compute addresses and offsets in the PLT now that final
 105    address for PLT and GOT are known (see fill_program_header) */
 106 ST_FUNC void relocate_plt(TCCState *s1)
 107 {
 108     uint8_t *p, *p_end;
 109
 110     if (!s1->plt)
 111       return;
 112
 113     p = s1->plt->data;
 114     p_end = p + s1->plt->data_offset;
 115
 116     if (p < p_end) {
 117         uint64_t plt = s1->plt->sh_addr;
 118         uint64_t got = s1->got->sh_addr + 16;
 119         uint64_t off = (got >> 12) - (plt >> 12);
 120         if ((off + ((uint32_t)1 << 20)) >> 21)
 121             tcc_error("Failed relocating PLT (off=0x%lx, got=0x%lx, plt=0x%lx)", (long)off, (long)got, (long)plt);
 122         write32le(p, 0xa9bf7bf0); // stp x16,x30,[sp,#-16]!
 123         write32le(p + 4, (0x90000010 | // adrp x16,...
 124                           (off & 0x1ffffc) << 3 | (off & 3) << 29));
 125         write32le(p + 8, (0xf9400211 | // ldr x17,[x16,#...]
 126                           (got & 0xff8) << 7));
 127         write32le(p + 12, (0x91000210 | // add x16,x16,#...
 128                            (got & 0xfff) << 10));
 129         write32le(p + 16, 0xd61f0220); // br x17
 130         write32le(p + 20, 0xd503201f); // nop
 131         write32le(p + 24, 0xd503201f); // nop
 132         write32le(p + 28, 0xd503201f); // nop
 133         p += 32;
 134         got = s1->got->sh_addr;
 135         while (p < p_end) {
 136             uint64_t pc = plt + (p - s1->plt->data);
 137             uint64_t addr = got + read64le(p);
 138             uint64_t off = (addr >> 12) - (pc >> 12);
 139             if ((off + ((uint32_t)1 << 20)) >> 21)
 140                 tcc_error("Failed relocating PLT (off=0x%lx, addr=0x%lx, pc=0x%lx)", (long)off, (long)addr, (long)pc);
 141             write32le(p, (0x90000010 | // adrp x16,...
 142                           (off & 0x1ffffc) << 3 | (off & 3) << 29));
 143             write32le(p + 4, (0xf9400211 | // ldr x17,[x16,#...]
 144                               (addr & 0xff8) << 7));
 145             write32le(p + 8, (0x91000210 | // add x16,x16,#...
 146                               (addr & 0xfff) << 10));
 147             write32le(p + 12, 0xd61f0220); // br x17
 148             p += 16;
 149         }
 150     }
 151
 152     if (s1->got->relocplt) {
 153         int mem = s1->output_type == TCC_OUTPUT_MEMORY;
 154         ElfW_Rel *rel;
 155
 156         p = s1->got->data;
 157         for_each_elem(s1->got->relocplt, 0, rel, ElfW_Rel) {
 158             int sym_index = ELFW(R_SYM)(rel->r_info);
 159             ElfW(Sym) *sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
 160             write64le(p + rel->r_offset, mem ? sym->st_value : s1->plt->sh_addr);
 161         }
 162     }
 163 }
 164
 165 void relocate(TCCState *s1, ElfW_Rel *rel, int type, unsigned char *ptr, addr_t addr, addr_t val)
 166 {
 167     int sym_index = ELFW(R_SYM)(rel->r_info), esym_index;
 168 #ifdef DEBUG_RELOC
 169     ElfW(Sym) *sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
 170 #endif
 171
 172     switch(type) {
 173         case R_AARCH64_ABS64:
 174             if (s1->output_type == TCC_OUTPUT_DLL) {
 175                 esym_index = get_sym_attr(s1, sym_index, 0)->dyn_index;
 176                 qrel->r_offset = rel->r_offset;
 177                 if (esym_index) {
 178                     qrel->r_info = ELFW(R_INFO)(esym_index, R_AARCH64_ABS64);
 179                     qrel->r_addend = rel->r_addend;
 180                     qrel++;
 181                     break;
 182                 } else {
 183                     qrel->r_info = ELFW(R_INFO)(0, R_AARCH64_RELATIVE);
 184                     qrel->r_addend = read64le(ptr) + val;
 185                     qrel++;
 186                 }
 187             }
 188             add64le(ptr, val);
 189             return;
 190         case R_AARCH64_ABS32:
 191             if (s1->output_type == TCC_OUTPUT_DLL) {
 192                 /* XXX: this logic may depend on TCC's codegen
 193                    now TCC uses R_AARCH64_RELATIVE even for a 64bit pointer */
 194                 qrel->r_offset = rel->r_offset;
 195                 qrel->r_info = ELFW(R_INFO)(0, R_AARCH64_RELATIVE);
 196                 /* Use sign extension! */
 197                 qrel->r_addend = (int)read32le(ptr) + val;
 198                 qrel++;
 199             }
 200             add32le(ptr, val);
 201             return;
 202         case R_AARCH64_PREL32:
 203             if (s1->output_type == TCC_OUTPUT_DLL) {
 204                 /* DLL relocation */
 205                 esym_index = get_sym_attr(s1, sym_index, 0)->dyn_index;
 206                 if (esym_index) {
 207                     qrel->r_offset = rel->r_offset;
 208                     qrel->r_info = ELFW(R_INFO)(esym_index, R_AARCH64_PREL32);
 209                     /* Use sign extension! */
 210                     qrel->r_addend = (int)read32le(ptr) + rel->r_addend;
 211                     qrel++;
 212                     break;
 213                 }
 214             }
 215             write32le(ptr, val - addr);
 216             return;
 217         case R_AARCH64_MOVW_UABS_G0_NC:
 218             write32le(ptr, ((read32le(ptr) & 0xffe0001f) |
 219                             (val & 0xffff) << 5));
 220             return;
 221         case R_AARCH64_MOVW_UABS_G1_NC:
 222             write32le(ptr, ((read32le(ptr) & 0xffe0001f) |
 223                             (val >> 16 & 0xffff) << 5));
 224             return;
 225         case R_AARCH64_MOVW_UABS_G2_NC:
 226             write32le(ptr, ((read32le(ptr) & 0xffe0001f) |
 227                             (val >> 32 & 0xffff) << 5));
 228             return;
 229         case R_AARCH64_MOVW_UABS_G3:
 230             write32le(ptr, ((read32le(ptr) & 0xffe0001f) |
 231                             (val >> 48 & 0xffff) << 5));
 232             return;
 233         case R_AARCH64_ADR_PREL_PG_HI21: {
 234             uint64_t off = (val >> 12) - (addr >> 12);
 235             if ((off + ((uint64_t)1 << 20)) >> 21)
 236                 tcc_error("R_AARCH64_ADR_PREL_PG_HI21 relocation failed");
 237             write32le(ptr, ((read32le(ptr) & 0x9f00001f) |
 238                             (off & 0x1ffffc) << 3 | (off & 3) << 29));
 239             return;
 240         }
 241         case R_AARCH64_ADD_ABS_LO12_NC:
 242         case R_AARCH64_LDST8_ABS_LO12_NC:
 243             write32le(ptr, ((read32le(ptr) & 0xffc003ff) |
 244                             (val & 0xfff) << 10));
 245             return;
 246         case R_AARCH64_LDST64_ABS_LO12_NC:
 247             write32le(ptr, ((read32le(ptr) & 0xffc003ff) |
 248                             (val & 0xff8) << 7));
 249             return;
 250         case R_AARCH64_JUMP26:
 251         case R_AARCH64_CALL26:
 252 #ifdef DEBUG_RELOC
 253             printf ("reloc %d @ 0x%lx: val=0x%lx name=%s\n", type, addr, val,
 254                     (char *) symtab_section->link->data + sym->st_name);
 255 #endif
 256             if (((val - addr) + ((uint64_t)1 << 27)) & ~(uint64_t)0xffffffc)
 257                 tcc_error("R_AARCH64_(JUMP|CALL)26 relocation failed"
 258                           " (val=%lx, addr=%lx)", (long)val, (long)addr);
 259             write32le(ptr, (0x14000000 |
 260                             (uint32_t)(type == R_AARCH64_CALL26) << 31 |
 261                             ((val - addr) >> 2 & 0x3ffffff)));
 262             return;
 263         case R_AARCH64_ADR_GOT_PAGE: {
 264             uint64_t off =
 265                 (((s1->got->sh_addr +
 266                    get_sym_attr(s1, sym_index, 0)->got_offset) >> 12) - (addr >> 12));
 267             if ((off + ((uint64_t)1 << 20)) >> 21)
 268                 tcc_error("R_AARCH64_ADR_GOT_PAGE relocation failed");
 269             write32le(ptr, ((read32le(ptr) & 0x9f00001f) |
 270                             (off & 0x1ffffc) << 3 | (off & 3) << 29));
 271             return;
 272         }
 273         case R_AARCH64_LD64_GOT_LO12_NC:
 274             write32le(ptr,
 275                       ((read32le(ptr) & 0xfff803ff) |
 276                        ((s1->got->sh_addr +
 277                          get_sym_attr(s1, sym_index, 0)->got_offset) & 0xff8) << 7));
 278             return;
 279         case R_AARCH64_COPY:
 280             return;
 281         case R_AARCH64_GLOB_DAT:
 282         case R_AARCH64_JUMP_SLOT:
 283             /* They don't need addend */
 284 #ifdef DEBUG_RELOC
 285             printf ("reloc %d @ 0x%lx: val=0x%lx name=%s\n", type, addr,
 286                     val - rel->r_addend,
 287                     (char *) symtab_section->link->data + sym->st_name);
 288 #endif
 289             write64le(ptr, val - rel->r_addend);
 290             return;
 291         case R_AARCH64_RELATIVE:
 292 #ifdef TCC_TARGET_PE
 293             add32le(ptr, val - s1->pe_imagebase);
 294 #endif
 295             /* do nothing */
 296             return;
 297         default:
 298             fprintf(stderr, "FIXME: handle reloc type %x at %x [%p] to %x\n",
 299                     type, (unsigned)addr, ptr, (unsigned)val);
 300             return;
 301     }
 302 }
 303
 304 #endif /* !TARGET_DEFS_ONLY */