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