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
  11 #define R_NUM      R_AARCH64_NUM
  12
  13 #define ELF_START_ADDR 0x00400000
  14 #define ELF_PAGE_SIZE 0x1000
  15
  16 #define PCRELATIVE_DLLPLT 1
  17 #define RELOCATE_DLLPLT 1
  18
  19 #else /* !TARGET_DEFS_ONLY */
  20
  21 #include "tcc.h"
  22
  23 /* Returns 1 for a code relocation, 0 for a data relocation. For unknown
  24    relocations, returns -1. */
  25 int code_reloc (int reloc_type)
  26 {
  27     switch (reloc_type) {
  28         case R_AARCH64_ABS32:
  29         case R_AARCH64_ABS64:
  30         case R_AARCH64_PREL32:
  31         case R_AARCH64_MOVW_UABS_G0_NC:
  32         case R_AARCH64_MOVW_UABS_G1_NC:
  33         case R_AARCH64_MOVW_UABS_G2_NC:
  34         case R_AARCH64_MOVW_UABS_G3:
  35         case R_AARCH64_ADR_PREL_PG_HI21:
  36         case R_AARCH64_ADD_ABS_LO12_NC:
  37         case R_AARCH64_ADR_GOT_PAGE:
  38         case R_AARCH64_LD64_GOT_LO12_NC:
  39         case R_AARCH64_GLOB_DAT:
  40         case R_AARCH64_COPY:
  41             return 0;
  42
  43         case R_AARCH64_JUMP26:
  44         case R_AARCH64_CALL26:
  45         case R_AARCH64_JUMP_SLOT:
  46             return 1;
  47     }
  48
  49     tcc_error ("Unknown relocation type: %d", reloc_type);
  50     return -1;
  51 }
  52
  53 /* Returns an enumerator to describe wether 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_ABS32:
  60         case R_AARCH64_ABS64:
  61         case R_AARCH64_PREL32:
  62         case R_AARCH64_MOVW_UABS_G0_NC:
  63         case R_AARCH64_MOVW_UABS_G1_NC:
  64         case R_AARCH64_MOVW_UABS_G2_NC:
  65         case R_AARCH64_MOVW_UABS_G3:
  66         case R_AARCH64_ADR_PREL_PG_HI21:
  67         case R_AARCH64_ADD_ABS_LO12_NC:
  68         case R_AARCH64_GLOB_DAT:
  69         case R_AARCH64_JUMP_SLOT:
  70         case R_AARCH64_COPY:
  71             return NO_GOTPLT_ENTRY;
  72
  73         case R_AARCH64_JUMP26:
  74         case R_AARCH64_CALL26:
  75             return AUTO_GOTPLT_ENTRY;
  76
  77         case R_AARCH64_ADR_GOT_PAGE:
  78         case R_AARCH64_LD64_GOT_LO12_NC:
  79             return ALWAYS_GOTPLT_ENTRY;
  80     }
  81
  82     tcc_error ("Unknown relocation type: %d", reloc_type);
  83     return -1;
  84 }
  85
  86 ST_FUNC unsigned create_plt_entry(TCCState *s1, unsigned got_offset, struct sym_attr *attr)
  87 {
  88     Section *plt = s1->plt;
  89     uint8_t *p;
  90     unsigned plt_offset;
  91
  92     if (s1->output_type == TCC_OUTPUT_DLL)
  93         tcc_error("DLLs unimplemented!");
  94
  95     if (plt->data_offset == 0) {
  96         section_ptr_add(plt, 32);
  97     }
  98     plt_offset = plt->data_offset;
  99
 100     p = section_ptr_add(plt, 16);
 101     write32le(p, got_offset);
 102     write32le(p + 4, (uint64_t) got_offset >> 32);
 103     return plt_offset;
 104 }
 105
 106 /* relocate the PLT: compute addresses and offsets in the PLT now that final
 107    address for PLT and GOT are known (see fill_program_header) */
 108 ST_FUNC void relocate_plt(TCCState *s1)
 109 {
 110     uint8_t *p, *p_end;
 111
 112     if (!s1->plt)
 113       return;
 114
 115     p = s1->plt->data;
 116     p_end = p + s1->plt->data_offset;
 117
 118     if (p < p_end) {
 119         uint64_t plt = s1->plt->sh_addr;
 120         uint64_t got = s1->got->sh_addr;
 121         uint64_t off = (got >> 12) - (plt >> 12);
 122         if ((off + ((uint32_t)1 << 20)) >> 21)
 123             tcc_error("Failed relocating PLT (off=0x%lx, got=0x%lx, plt=0x%lx)", off, got, plt);
 124         write32le(p, 0xa9bf7bf0); // stp x16,x30,[sp,#-16]!
 125         write32le(p + 4, (0x90000010 | // adrp x16,...
 126                           (off & 0x1ffffc) << 3 | (off & 3) << 29));
 127         write32le(p + 8, (0xf9400211 | // ldr x17,[x16,#...]
 128                           (got & 0xff8) << 7));
 129         write32le(p + 12, (0x91000210 | // add x16,x16,#...
 130                            (got & 0xfff) << 10));
 131         write32le(p + 16, 0xd61f0220); // br x17
 132         write32le(p + 20, 0xd503201f); // nop
 133         write32le(p + 24, 0xd503201f); // nop
 134         write32le(p + 28, 0xd503201f); // nop
 135         p += 32;
 136         while (p < p_end) {
 137             uint64_t pc = plt + (p - s1->plt->data);
 138             uint64_t addr = got + read64le(p);
 139             uint64_t off = (addr >> 12) - (pc >> 12);
 140             if ((off + ((uint32_t)1 << 20)) >> 21)
 141                 tcc_error("Failed relocating PLT (off=0x%lx, addr=0x%lx, pc=0x%lx)", off, addr, pc);
 142             write32le(p, (0x90000010 | // adrp x16,...
 143                           (off & 0x1ffffc) << 3 | (off & 3) << 29));
 144             write32le(p + 4, (0xf9400211 | // ldr x17,[x16,#...]
 145                               (addr & 0xff8) << 7));
 146             write32le(p + 8, (0x91000210 | // add x16,x16,#...
 147                               (addr & 0xfff) << 10));
 148             write32le(p + 12, 0xd61f0220); // br x17
 149             p += 16;
 150         }
 151     }
 152 }
 153
 154 void relocate_init(Section *sr) {}
 155
 156 void relocate(TCCState *s1, ElfW_Rel *rel, int type, char *ptr, addr_t addr, addr_t val)
 157 {
 158     int sym_index = ELFW(R_SYM)(rel->r_info);
 159 #ifdef DEBUG_RELOC
 160     ElfW(Sym) *sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
 161 #endif
 162
 163     switch(type) {
 164         case R_AARCH64_ABS64:
 165             write64le(ptr, val);
 166             return;
 167         case R_AARCH64_ABS32:
 168             write32le(ptr, val);
 169             return;
 170         case R_AARCH64_PREL32:
 171             write32le(ptr, val - addr);
 172             return;
 173         case R_AARCH64_MOVW_UABS_G0_NC:
 174             write32le(ptr, ((read32le(ptr) & 0xffe0001f) |
 175                             (val & 0xffff) << 5));
 176             return;
 177         case R_AARCH64_MOVW_UABS_G1_NC:
 178             write32le(ptr, ((read32le(ptr) & 0xffe0001f) |
 179                             (val >> 16 & 0xffff) << 5));
 180             return;
 181         case R_AARCH64_MOVW_UABS_G2_NC:
 182             write32le(ptr, ((read32le(ptr) & 0xffe0001f) |
 183                             (val >> 32 & 0xffff) << 5));
 184             return;
 185         case R_AARCH64_MOVW_UABS_G3:
 186             write32le(ptr, ((read32le(ptr) & 0xffe0001f) |
 187                             (val >> 48 & 0xffff) << 5));
 188             return;
 189         case R_AARCH64_ADR_PREL_PG_HI21: {
 190             uint64_t off = (val >> 12) - (addr >> 12);
 191             if ((off + ((uint64_t)1 << 20)) >> 21)
 192                 tcc_error("R_AARCH64_ADR_PREL_PG_HI21 relocation failed");
 193             write32le(ptr, ((read32le(ptr) & 0x9f00001f) |
 194                             (off & 0x1ffffc) << 3 | (off & 3) << 29));
 195             return;
 196         }
 197         case R_AARCH64_ADD_ABS_LO12_NC:
 198             write32le(ptr, ((read32le(ptr) & 0xffc003ff) |
 199                             (val & 0xfff) << 10));
 200             return;
 201         case R_AARCH64_JUMP26:
 202         case R_AARCH64_CALL26:
 203 #ifdef DEBUG_RELOC
 204             printf ("reloc %d @ 0x%lx: val=0x%lx name=%s\n", type, addr, val,
 205                     (char *) symtab_section->link->data + sym->st_name);
 206 #endif
 207             if (((val - addr) + ((uint64_t)1 << 27)) & ~(uint64_t)0xffffffc)
 208                 tcc_error("R_AARCH64_(JUMP|CALL)26 relocation failed"
 209                           " (val=%lx, addr=%lx)", val, addr);
 210             write32le(ptr, (0x14000000 |
 211                             (uint32_t)(type == R_AARCH64_CALL26) << 31 |
 212                             ((val - addr) >> 2 & 0x3ffffff)));
 213             return;
 214         case R_AARCH64_ADR_GOT_PAGE: {
 215             uint64_t off =
 216                 (((s1->got->sh_addr +
 217                    s1->sym_attrs[sym_index].got_offset) >> 12) - (addr >> 12));
 218             if ((off + ((uint64_t)1 << 20)) >> 21)
 219                 tcc_error("R_AARCH64_ADR_GOT_PAGE relocation failed");
 220             write32le(ptr, ((read32le(ptr) & 0x9f00001f) |
 221                             (off & 0x1ffffc) << 3 | (off & 3) << 29));
 222             return;
 223         }
 224         case R_AARCH64_LD64_GOT_LO12_NC:
 225             write32le(ptr,
 226                       ((read32le(ptr) & 0xfff803ff) |
 227                        ((s1->got->sh_addr +
 228                          s1->sym_attrs[sym_index].got_offset) & 0xff8) << 7));
 229             return;
 230         case R_AARCH64_COPY:
 231             return;
 232         case R_AARCH64_GLOB_DAT:
 233         case R_AARCH64_JUMP_SLOT:
 234             /* They don't need addend */
 235 #ifdef DEBUG_RELOC
 236             printf ("reloc %d @ 0x%lx: val=0x%lx name=%s\n", type, addr,
 237                     val - rel->r_addend,
 238                     (char *) symtab_section->link->data + sym->st_name);
 239 #endif
 240             write64le(ptr, val - rel->r_addend);
 241             return;
 242         default:
 243             fprintf(stderr, "FIXME: handle reloc type %x at %x [%p] to %x\n",
 244                     type, (unsigned)addr, ptr, (unsigned)val);
 245             return;
 246     }
 247 }
 248
 249 #endif /* !TARGET_DEFS_ONLY */