| 1 | /* Support for 32-bit i386 NLM (NetWare Loadable Module) |
| 2 | Copyright (C) 1993-2014 Free Software Foundation, Inc. |
| 3 | |
| 4 | This file is part of BFD, the Binary File Descriptor library. |
| 5 | |
| 6 | This program is free software; you can redistribute it and/or modify |
| 7 | it under the terms of the GNU General Public License as published by |
| 8 | the Free Software Foundation; either version 3 of the License, or |
| 9 | (at your option) any later version. |
| 10 | |
| 11 | This program is distributed in the hope that it will be useful, |
| 12 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 14 | GNU General Public License for more details. |
| 15 | |
| 16 | You should have received a copy of the GNU General Public License |
| 17 | along with this program; if not, write to the Free Software |
| 18 | Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, |
| 19 | MA 02110-1301, USA. */ |
| 20 | |
| 21 | #include "sysdep.h" |
| 22 | #include "bfd.h" |
| 23 | #include "libbfd.h" |
| 24 | |
| 25 | #define ARCH_SIZE 32 |
| 26 | |
| 27 | #include "nlm/i386-ext.h" |
| 28 | #define Nlm_External_Fixed_Header Nlm32_i386_External_Fixed_Header |
| 29 | |
| 30 | #include "libnlm.h" |
| 31 | |
| 32 | /* Adjust the reloc location by an absolute value. */ |
| 33 | |
| 34 | static reloc_howto_type nlm_i386_abs_howto = |
| 35 | HOWTO (0, /* Type. */ |
| 36 | 0, /* Rightshift. */ |
| 37 | 2, /* Size (0 = byte, 1 = short, 2 = long). */ |
| 38 | 32, /* Bitsize. */ |
| 39 | FALSE, /* PC relative. */ |
| 40 | 0, /* Bitpos. */ |
| 41 | complain_overflow_bitfield, /* Complain_on_overflow. */ |
| 42 | 0, /* Special_function. */ |
| 43 | "32", /* Name. */ |
| 44 | TRUE, /* Partial_inplace. */ |
| 45 | 0xffffffff, /* Source mask. */ |
| 46 | 0xffffffff, /* Dest mask. */ |
| 47 | FALSE); /* PR rel_offset. */ |
| 48 | |
| 49 | /* Adjust the reloc location by a PC relative displacement. */ |
| 50 | |
| 51 | static reloc_howto_type nlm_i386_pcrel_howto = |
| 52 | HOWTO (1, /* Type. */ |
| 53 | 0, /* Rightshift. */ |
| 54 | 2, /* Size (0 = byte, 1 = short, 2 = long). */ |
| 55 | 32, /* Bitsize. */ |
| 56 | TRUE, /* PC relative. */ |
| 57 | 0, /* Bitpos. */ |
| 58 | complain_overflow_signed, /* Complain_on_overflow. */ |
| 59 | 0, /* Special_function. */ |
| 60 | "DISP32", /* Name. */ |
| 61 | TRUE, /* Partial_inplace. */ |
| 62 | 0xffffffff, /* Source mask. */ |
| 63 | 0xffffffff, /* Dest mask. */ |
| 64 | TRUE); /* PR rel_offset. */ |
| 65 | |
| 66 | /* Read a NetWare i386 reloc. */ |
| 67 | |
| 68 | static bfd_boolean |
| 69 | nlm_i386_read_reloc (bfd *abfd, |
| 70 | nlmNAME (symbol_type) *sym, |
| 71 | asection **secp, |
| 72 | arelent *rel) |
| 73 | { |
| 74 | bfd_byte temp[4]; |
| 75 | bfd_vma val; |
| 76 | const char *name; |
| 77 | |
| 78 | if (bfd_bread (temp, (bfd_size_type) sizeof (temp), abfd) != sizeof (temp)) |
| 79 | return FALSE; |
| 80 | |
| 81 | val = bfd_get_32 (abfd, temp); |
| 82 | |
| 83 | /* The value is an offset into either the code or data segment. |
| 84 | This is the location which needs to be adjusted. |
| 85 | |
| 86 | If this is a relocation fixup rather than an imported symbol (the |
| 87 | sym argument is NULL) then the high bit is 0 if the location |
| 88 | needs to be adjusted by the address of the data segment, or 1 if |
| 89 | the location needs to be adjusted by the address of the code |
| 90 | segment. If this is an imported symbol, then the high bit is 0 |
| 91 | if the location is 0 if the location should be adjusted by the |
| 92 | offset to the symbol, or 1 if the location should adjusted by the |
| 93 | absolute value of the symbol. |
| 94 | |
| 95 | The second most significant bit is 0 if the value is an offset |
| 96 | into the data segment, or 1 if the value is an offset into the |
| 97 | code segment. |
| 98 | |
| 99 | All this translates fairly easily into a BFD reloc. */ |
| 100 | |
| 101 | if (sym == NULL) |
| 102 | { |
| 103 | if ((val & NLM_HIBIT) == 0) |
| 104 | name = NLM_INITIALIZED_DATA_NAME; |
| 105 | else |
| 106 | { |
| 107 | name = NLM_CODE_NAME; |
| 108 | val &=~ NLM_HIBIT; |
| 109 | } |
| 110 | rel->sym_ptr_ptr = bfd_get_section_by_name (abfd, name)->symbol_ptr_ptr; |
| 111 | rel->howto = &nlm_i386_abs_howto; |
| 112 | } |
| 113 | else |
| 114 | { |
| 115 | /* In this case we do not need to set the sym_ptr_ptr field. */ |
| 116 | rel->sym_ptr_ptr = NULL; |
| 117 | if ((val & NLM_HIBIT) == 0) |
| 118 | rel->howto = &nlm_i386_pcrel_howto; |
| 119 | else |
| 120 | { |
| 121 | rel->howto = &nlm_i386_abs_howto; |
| 122 | val &=~ NLM_HIBIT; |
| 123 | } |
| 124 | } |
| 125 | |
| 126 | if ((val & (NLM_HIBIT >> 1)) == 0) |
| 127 | *secp = bfd_get_section_by_name (abfd, NLM_INITIALIZED_DATA_NAME); |
| 128 | else |
| 129 | { |
| 130 | *secp = bfd_get_section_by_name (abfd, NLM_CODE_NAME); |
| 131 | val &=~ (NLM_HIBIT >> 1); |
| 132 | } |
| 133 | |
| 134 | rel->address = val; |
| 135 | rel->addend = 0; |
| 136 | |
| 137 | return TRUE; |
| 138 | } |
| 139 | |
| 140 | /* Write a NetWare i386 reloc. */ |
| 141 | |
| 142 | static bfd_boolean |
| 143 | nlm_i386_write_import (bfd * abfd, asection * sec, arelent * rel) |
| 144 | { |
| 145 | asymbol *sym; |
| 146 | bfd_vma val; |
| 147 | bfd_byte temp[4]; |
| 148 | |
| 149 | /* NetWare only supports two kinds of relocs. We should check |
| 150 | special_function here, as well, but at the moment coff-i386 |
| 151 | relocs uses a special_function which does not affect what we do |
| 152 | here. */ |
| 153 | if (rel->addend != 0 |
| 154 | || rel->howto == NULL |
| 155 | || rel->howto->rightshift != 0 |
| 156 | || rel->howto->size != 2 |
| 157 | || rel->howto->bitsize != 32 |
| 158 | || rel->howto->bitpos != 0 |
| 159 | || rel->howto->src_mask != 0xffffffff |
| 160 | || rel->howto->dst_mask != 0xffffffff) |
| 161 | { |
| 162 | bfd_set_error (bfd_error_invalid_operation); |
| 163 | return FALSE; |
| 164 | } |
| 165 | |
| 166 | sym = *rel->sym_ptr_ptr; |
| 167 | |
| 168 | /* The value we write out is the offset into the appropriate |
| 169 | segment. This offset is the section vma, adjusted by the vma of |
| 170 | the lowest section in that segment, plus the address of the |
| 171 | relocation. */ |
| 172 | val = bfd_get_section_vma (abfd, sec) + rel->address; |
| 173 | |
| 174 | /* The second most significant bit is 0 if the value is an offset |
| 175 | into the data segment, or 1 if the value is an offset into the |
| 176 | code segment. */ |
| 177 | if (bfd_get_section_flags (abfd, sec) & SEC_CODE) |
| 178 | { |
| 179 | val -= nlm_get_text_low (abfd); |
| 180 | val |= NLM_HIBIT >> 1; |
| 181 | } |
| 182 | else |
| 183 | val -= nlm_get_data_low (abfd); |
| 184 | |
| 185 | if (! bfd_is_und_section (bfd_get_section (sym))) |
| 186 | { |
| 187 | /* NetWare only supports absolute internal relocs. */ |
| 188 | if (rel->howto->pc_relative) |
| 189 | { |
| 190 | bfd_set_error (bfd_error_invalid_operation); |
| 191 | return FALSE; |
| 192 | } |
| 193 | |
| 194 | /* The high bit is 1 if the reloc is against the code section, 0 |
| 195 | if against the data section. */ |
| 196 | if (bfd_get_section_flags (abfd, bfd_get_section (sym)) & SEC_CODE) |
| 197 | val |= NLM_HIBIT; |
| 198 | } |
| 199 | else |
| 200 | { |
| 201 | /* The high bit is 1 if this is an absolute reloc, 0 if it is PC |
| 202 | relative. */ |
| 203 | if (! rel->howto->pc_relative) |
| 204 | val |= NLM_HIBIT; |
| 205 | else |
| 206 | { |
| 207 | /* PC relative relocs on NetWare must be pcrel_offset. */ |
| 208 | if (! rel->howto->pcrel_offset) |
| 209 | { |
| 210 | bfd_set_error (bfd_error_invalid_operation); |
| 211 | return FALSE; |
| 212 | } |
| 213 | } |
| 214 | } |
| 215 | |
| 216 | bfd_put_32 (abfd, val, temp); |
| 217 | if (bfd_bwrite (temp, (bfd_size_type) sizeof (temp), abfd) != sizeof (temp)) |
| 218 | return FALSE; |
| 219 | |
| 220 | return TRUE; |
| 221 | } |
| 222 | |
| 223 | /* I want to be able to use objcopy to turn an i386 a.out or COFF file |
| 224 | into a NetWare i386 module. That means that the relocs from the |
| 225 | source file have to be mapped into relocs that apply to the target |
| 226 | file. This function is called by nlm_set_section_contents to give |
| 227 | it a chance to rework the relocs. |
| 228 | |
| 229 | This is actually a fairly general concept. However, this is not a |
| 230 | general implementation. */ |
| 231 | |
| 232 | static bfd_boolean |
| 233 | nlm_i386_mangle_relocs (bfd *abfd, |
| 234 | asection *sec, |
| 235 | const void * data, |
| 236 | bfd_vma offset, |
| 237 | bfd_size_type count) |
| 238 | { |
| 239 | arelent **rel_ptr_ptr, **rel_end; |
| 240 | |
| 241 | rel_ptr_ptr = sec->orelocation; |
| 242 | rel_end = rel_ptr_ptr + sec->reloc_count; |
| 243 | for (; rel_ptr_ptr < rel_end; rel_ptr_ptr++) |
| 244 | { |
| 245 | arelent *rel; |
| 246 | asymbol *sym; |
| 247 | bfd_vma addend; |
| 248 | |
| 249 | rel = *rel_ptr_ptr; |
| 250 | sym = *rel->sym_ptr_ptr; |
| 251 | |
| 252 | /* Note that no serious harm will ensue if we fail to change a |
| 253 | reloc. We will wind up failing in nlm_i386_write_import. */ |
| 254 | |
| 255 | /* Make sure this reloc is within the data we have. We only 4 |
| 256 | byte relocs here, so we insist on having 4 bytes. */ |
| 257 | if (rel->address < offset |
| 258 | || rel->address + 4 > offset + count) |
| 259 | continue; |
| 260 | |
| 261 | /* NetWare doesn't support reloc addends, so we get rid of them |
| 262 | here by simply adding them into the object data. We handle |
| 263 | the symbol value, if any, the same way. */ |
| 264 | addend = rel->addend + sym->value; |
| 265 | |
| 266 | /* The value of a symbol is the offset into the section. If the |
| 267 | symbol is in the .bss segment, we need to include the size of |
| 268 | the data segment in the offset as well. Fortunately, we know |
| 269 | that at this point the size of the data section is in the NLM |
| 270 | header. */ |
| 271 | if (((bfd_get_section_flags (abfd, bfd_get_section (sym)) |
| 272 | & SEC_LOAD) == 0) |
| 273 | && ((bfd_get_section_flags (abfd, bfd_get_section (sym)) |
| 274 | & SEC_ALLOC) != 0)) |
| 275 | addend += nlm_fixed_header (abfd)->dataImageSize; |
| 276 | |
| 277 | if (addend != 0 |
| 278 | && rel->howto != NULL |
| 279 | && rel->howto->rightshift == 0 |
| 280 | && rel->howto->size == 2 |
| 281 | && rel->howto->bitsize == 32 |
| 282 | && rel->howto->bitpos == 0 |
| 283 | && rel->howto->src_mask == 0xffffffff |
| 284 | && rel->howto->dst_mask == 0xffffffff) |
| 285 | { |
| 286 | bfd_vma val; |
| 287 | |
| 288 | val = bfd_get_32 (abfd, (bfd_byte *) data + rel->address - offset); |
| 289 | val += addend; |
| 290 | bfd_put_32 (abfd, val, (bfd_byte *) data + rel->address - offset); |
| 291 | rel->addend = 0; |
| 292 | } |
| 293 | |
| 294 | /* NetWare uses a reloc with pcrel_offset set. We adjust |
| 295 | pc_relative relocs accordingly. We are going to change the |
| 296 | howto field, so we can only do this if the current one is |
| 297 | compatible. We should check special_function here, but at |
| 298 | the moment coff-i386 uses a special_function which does not |
| 299 | affect what we are doing here. */ |
| 300 | if (rel->howto != NULL |
| 301 | && rel->howto->pc_relative |
| 302 | && ! rel->howto->pcrel_offset |
| 303 | && rel->howto->rightshift == 0 |
| 304 | && rel->howto->size == 2 |
| 305 | && rel->howto->bitsize == 32 |
| 306 | && rel->howto->bitpos == 0 |
| 307 | && rel->howto->src_mask == 0xffffffff |
| 308 | && rel->howto->dst_mask == 0xffffffff) |
| 309 | { |
| 310 | bfd_vma val; |
| 311 | |
| 312 | /* When pcrel_offset is not set, it means that the negative |
| 313 | of the address of the memory location is stored in the |
| 314 | memory location. We must add it back in. */ |
| 315 | val = bfd_get_32 (abfd, (bfd_byte *) data + rel->address - offset); |
| 316 | val += rel->address; |
| 317 | bfd_put_32 (abfd, val, (bfd_byte *) data + rel->address - offset); |
| 318 | |
| 319 | rel->howto = &nlm_i386_pcrel_howto; |
| 320 | } |
| 321 | } |
| 322 | |
| 323 | return TRUE; |
| 324 | } |
| 325 | |
| 326 | /* Read a NetWare i386 import record. */ |
| 327 | |
| 328 | static bfd_boolean |
| 329 | nlm_i386_read_import (bfd * abfd, nlmNAME (symbol_type) * sym) |
| 330 | { |
| 331 | struct nlm_relent *nlm_relocs; /* Relocation records for symbol. */ |
| 332 | bfd_size_type rcount; /* Number of relocs. */ |
| 333 | bfd_byte temp[NLM_TARGET_LONG_SIZE]; /* Temporary 32-bit value. */ |
| 334 | unsigned char symlength; /* Length of symbol name. */ |
| 335 | char *name; |
| 336 | |
| 337 | if (bfd_bread (& symlength, (bfd_size_type) sizeof (symlength), abfd) |
| 338 | != sizeof (symlength)) |
| 339 | return FALSE; |
| 340 | sym -> symbol.the_bfd = abfd; |
| 341 | name = bfd_alloc (abfd, (bfd_size_type) symlength + 1); |
| 342 | if (name == NULL) |
| 343 | return FALSE; |
| 344 | if (bfd_bread (name, (bfd_size_type) symlength, abfd) != symlength) |
| 345 | return FALSE; |
| 346 | name[symlength] = '\0'; |
| 347 | sym -> symbol.name = name; |
| 348 | sym -> symbol.flags = 0; |
| 349 | sym -> symbol.value = 0; |
| 350 | sym -> symbol.section = bfd_und_section_ptr; |
| 351 | if (bfd_bread (temp, (bfd_size_type) sizeof (temp), abfd) != sizeof (temp)) |
| 352 | return FALSE; |
| 353 | rcount = H_GET_32 (abfd, temp); |
| 354 | nlm_relocs = bfd_alloc (abfd, rcount * sizeof (struct nlm_relent)); |
| 355 | if (!nlm_relocs) |
| 356 | return FALSE; |
| 357 | sym -> relocs = nlm_relocs; |
| 358 | sym -> rcnt = 0; |
| 359 | while (sym -> rcnt < rcount) |
| 360 | { |
| 361 | asection *section; |
| 362 | |
| 363 | if (! nlm_i386_read_reloc (abfd, sym, §ion, &nlm_relocs -> reloc)) |
| 364 | return FALSE; |
| 365 | nlm_relocs -> section = section; |
| 366 | nlm_relocs++; |
| 367 | sym -> rcnt++; |
| 368 | } |
| 369 | return TRUE; |
| 370 | } |
| 371 | |
| 372 | /* Write out an external reference. */ |
| 373 | |
| 374 | static bfd_boolean |
| 375 | nlm_i386_write_external (bfd *abfd, |
| 376 | bfd_size_type count, |
| 377 | asymbol *sym, |
| 378 | struct reloc_and_sec *relocs) |
| 379 | { |
| 380 | unsigned int i; |
| 381 | bfd_byte len; |
| 382 | unsigned char temp[NLM_TARGET_LONG_SIZE]; |
| 383 | |
| 384 | len = strlen (sym->name); |
| 385 | if ((bfd_bwrite (&len, (bfd_size_type) sizeof (bfd_byte), abfd) |
| 386 | != sizeof (bfd_byte)) |
| 387 | || bfd_bwrite (sym->name, (bfd_size_type) len, abfd) != len) |
| 388 | return FALSE; |
| 389 | |
| 390 | bfd_put_32 (abfd, count, temp); |
| 391 | if (bfd_bwrite (temp, (bfd_size_type) sizeof (temp), abfd) != sizeof (temp)) |
| 392 | return FALSE; |
| 393 | |
| 394 | for (i = 0; i < count; i++) |
| 395 | if (! nlm_i386_write_import (abfd, relocs[i].sec, relocs[i].rel)) |
| 396 | return FALSE; |
| 397 | |
| 398 | return TRUE; |
| 399 | } |
| 400 | |
| 401 | #include "nlmswap.h" |
| 402 | |
| 403 | static const struct nlm_backend_data nlm32_i386_backend = |
| 404 | { |
| 405 | "NetWare Loadable Module\032", |
| 406 | sizeof (Nlm32_i386_External_Fixed_Header), |
| 407 | 0, /* Optional_prefix_size. */ |
| 408 | bfd_arch_i386, |
| 409 | 0, |
| 410 | FALSE, |
| 411 | 0, /* Backend_object_p. */ |
| 412 | 0, /* Write_prefix_func. */ |
| 413 | nlm_i386_read_reloc, |
| 414 | nlm_i386_mangle_relocs, |
| 415 | nlm_i386_read_import, |
| 416 | nlm_i386_write_import, |
| 417 | 0, /* Set_public_section. */ |
| 418 | 0, /* Set_public_offset. */ |
| 419 | nlm_swap_fixed_header_in, |
| 420 | nlm_swap_fixed_header_out, |
| 421 | nlm_i386_write_external, |
| 422 | 0, /* Write_export. */ |
| 423 | }; |
| 424 | |
| 425 | #define TARGET_LITTLE_NAME "nlm32-i386" |
| 426 | #define TARGET_LITTLE_SYM nlmNAME (i386_vec) |
| 427 | #define TARGET_BACKEND_DATA & nlm32_i386_backend |
| 428 | |
| 429 | #include "nlm-target.h" |