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