| 1 | /* OS ABI variant handling for GDB. |
| 2 | Copyright 2001, 2002 Free Software Foundation, Inc. |
| 3 | |
| 4 | This file is part of GDB. |
| 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 2 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., 59 Temple Place - Suite 330, |
| 19 | Boston, MA 02111-1307, USA. */ |
| 20 | |
| 21 | #include "defs.h" |
| 22 | #include "gdb_string.h" |
| 23 | #include "osabi.h" |
| 24 | |
| 25 | #include "elf-bfd.h" |
| 26 | |
| 27 | |
| 28 | /* This table matches the indices assigned to enum gdb_osabi. Keep |
| 29 | them in sync. */ |
| 30 | static const char * const gdb_osabi_names[] = |
| 31 | { |
| 32 | "<unknown>", |
| 33 | |
| 34 | "SVR4", |
| 35 | "GNU/Hurd", |
| 36 | "Solaris", |
| 37 | "OSF/1", |
| 38 | "GNU/Linux", |
| 39 | "FreeBSD a.out", |
| 40 | "FreeBSD ELF", |
| 41 | "NetBSD a.out", |
| 42 | "NetBSD ELF", |
| 43 | "Windows CE", |
| 44 | "DJGPP", |
| 45 | "NetWare", |
| 46 | "Irix", |
| 47 | "LynxOS", |
| 48 | |
| 49 | "ARM EABI v1", |
| 50 | "ARM EABI v2", |
| 51 | "ARM APCS", |
| 52 | |
| 53 | "<invalid>" |
| 54 | }; |
| 55 | |
| 56 | const char * |
| 57 | gdbarch_osabi_name (enum gdb_osabi osabi) |
| 58 | { |
| 59 | if (osabi >= GDB_OSABI_UNKNOWN && osabi < GDB_OSABI_INVALID) |
| 60 | return gdb_osabi_names[osabi]; |
| 61 | |
| 62 | return gdb_osabi_names[GDB_OSABI_INVALID]; |
| 63 | } |
| 64 | |
| 65 | /* Handler for a given architecture/OS ABI pair. There should be only |
| 66 | one handler for a given OS ABI each architecture family. */ |
| 67 | struct gdb_osabi_handler |
| 68 | { |
| 69 | struct gdb_osabi_handler *next; |
| 70 | enum bfd_architecture arch; |
| 71 | enum gdb_osabi osabi; |
| 72 | void (*init_osabi)(struct gdbarch_info, struct gdbarch *); |
| 73 | }; |
| 74 | |
| 75 | static struct gdb_osabi_handler *gdb_osabi_handler_list; |
| 76 | |
| 77 | void |
| 78 | gdbarch_register_osabi (enum bfd_architecture arch, enum gdb_osabi osabi, |
| 79 | void (*init_osabi)(struct gdbarch_info, |
| 80 | struct gdbarch *)) |
| 81 | { |
| 82 | struct gdb_osabi_handler **handler_p; |
| 83 | |
| 84 | /* Registering an OS ABI handler for "unknown" is not allowed. */ |
| 85 | if (osabi == GDB_OSABI_UNKNOWN) |
| 86 | { |
| 87 | internal_error |
| 88 | (__FILE__, __LINE__, |
| 89 | "gdbarch_register_osabi: An attempt to register a handler for " |
| 90 | "OS ABI \"%s\" for architecture %s was made. The handler will " |
| 91 | "not be registered", |
| 92 | gdbarch_osabi_name (osabi), |
| 93 | bfd_printable_arch_mach (arch, 0)); |
| 94 | return; |
| 95 | } |
| 96 | |
| 97 | for (handler_p = &gdb_osabi_handler_list; *handler_p != NULL; |
| 98 | handler_p = &(*handler_p)->next) |
| 99 | { |
| 100 | if ((*handler_p)->arch == arch |
| 101 | && (*handler_p)->osabi == osabi) |
| 102 | { |
| 103 | internal_error |
| 104 | (__FILE__, __LINE__, |
| 105 | "gdbarch_register_osabi: A handler for OS ABI \"%s\" " |
| 106 | "has already been registered for architecture %s", |
| 107 | gdbarch_osabi_name (osabi), |
| 108 | bfd_printable_arch_mach (arch, 0)); |
| 109 | /* If user wants to continue, override previous definition. */ |
| 110 | (*handler_p)->init_osabi = init_osabi; |
| 111 | return; |
| 112 | } |
| 113 | } |
| 114 | |
| 115 | (*handler_p) |
| 116 | = (struct gdb_osabi_handler *) xmalloc (sizeof (struct gdb_osabi_handler)); |
| 117 | (*handler_p)->next = NULL; |
| 118 | (*handler_p)->arch = arch; |
| 119 | (*handler_p)->osabi = osabi; |
| 120 | (*handler_p)->init_osabi = init_osabi; |
| 121 | } |
| 122 | \f |
| 123 | |
| 124 | /* Sniffer to find the OS ABI for a given file's architecture and flavour. |
| 125 | It is legal to have multiple sniffers for each arch/flavour pair, to |
| 126 | disambiguate one OS's a.out from another, for example. The first sniffer |
| 127 | to return something other than GDB_OSABI_UNKNOWN wins, so a sniffer should |
| 128 | be careful to claim a file only if it knows for sure what it is. */ |
| 129 | struct gdb_osabi_sniffer |
| 130 | { |
| 131 | struct gdb_osabi_sniffer *next; |
| 132 | enum bfd_architecture arch; /* bfd_arch_unknown == wildcard */ |
| 133 | enum bfd_flavour flavour; |
| 134 | enum gdb_osabi (*sniffer)(bfd *); |
| 135 | }; |
| 136 | |
| 137 | static struct gdb_osabi_sniffer *gdb_osabi_sniffer_list; |
| 138 | |
| 139 | void |
| 140 | gdbarch_register_osabi_sniffer (enum bfd_architecture arch, |
| 141 | enum bfd_flavour flavour, |
| 142 | enum gdb_osabi (*sniffer_fn)(bfd *)) |
| 143 | { |
| 144 | struct gdb_osabi_sniffer *sniffer; |
| 145 | |
| 146 | sniffer = |
| 147 | (struct gdb_osabi_sniffer *) xmalloc (sizeof (struct gdb_osabi_sniffer)); |
| 148 | sniffer->arch = arch; |
| 149 | sniffer->flavour = flavour; |
| 150 | sniffer->sniffer = sniffer_fn; |
| 151 | |
| 152 | sniffer->next = gdb_osabi_sniffer_list; |
| 153 | gdb_osabi_sniffer_list = sniffer; |
| 154 | } |
| 155 | \f |
| 156 | |
| 157 | enum gdb_osabi |
| 158 | gdbarch_lookup_osabi (bfd *abfd) |
| 159 | { |
| 160 | struct gdb_osabi_sniffer *sniffer; |
| 161 | enum gdb_osabi osabi, match; |
| 162 | int match_specific; |
| 163 | |
| 164 | match = GDB_OSABI_UNKNOWN; |
| 165 | match_specific = 0; |
| 166 | |
| 167 | for (sniffer = gdb_osabi_sniffer_list; sniffer != NULL; |
| 168 | sniffer = sniffer->next) |
| 169 | { |
| 170 | if ((sniffer->arch == bfd_arch_unknown /* wildcard */ |
| 171 | || sniffer->arch == bfd_get_arch (abfd)) |
| 172 | && sniffer->flavour == bfd_get_flavour (abfd)) |
| 173 | { |
| 174 | osabi = (*sniffer->sniffer) (abfd); |
| 175 | if (osabi < GDB_OSABI_UNKNOWN || osabi >= GDB_OSABI_INVALID) |
| 176 | { |
| 177 | internal_error |
| 178 | (__FILE__, __LINE__, |
| 179 | "gdbarch_lookup_osabi: invalid OS ABI (%d) from sniffer " |
| 180 | "for architecture %s flavour %d", |
| 181 | (int) osabi, |
| 182 | bfd_printable_arch_mach (bfd_get_arch (abfd), 0), |
| 183 | (int) bfd_get_flavour (abfd)); |
| 184 | } |
| 185 | else if (osabi != GDB_OSABI_UNKNOWN) |
| 186 | { |
| 187 | /* A specific sniffer always overrides a generic sniffer. |
| 188 | Croak on multiple match if the two matches are of the |
| 189 | same class. If the user wishes to continue, we'll use |
| 190 | the first match. */ |
| 191 | if (match != GDB_OSABI_UNKNOWN) |
| 192 | { |
| 193 | if ((match_specific && sniffer->arch != bfd_arch_unknown) |
| 194 | || (!match_specific && sniffer->arch == bfd_arch_unknown)) |
| 195 | { |
| 196 | internal_error |
| 197 | (__FILE__, __LINE__, |
| 198 | "gdbarch_lookup_osabi: multiple %sspecific OS ABI " |
| 199 | "match for architecture %s flavour %d: first " |
| 200 | "match \"%s\", second match \"%s\"", |
| 201 | match_specific ? "" : "non-", |
| 202 | bfd_printable_arch_mach (bfd_get_arch (abfd), 0), |
| 203 | (int) bfd_get_flavour (abfd), |
| 204 | gdbarch_osabi_name (match), |
| 205 | gdbarch_osabi_name (osabi)); |
| 206 | } |
| 207 | else if (sniffer->arch != bfd_arch_unknown) |
| 208 | { |
| 209 | match = osabi; |
| 210 | match_specific = 1; |
| 211 | } |
| 212 | } |
| 213 | else |
| 214 | { |
| 215 | match = osabi; |
| 216 | if (sniffer->arch != bfd_arch_unknown) |
| 217 | match_specific = 1; |
| 218 | } |
| 219 | } |
| 220 | } |
| 221 | } |
| 222 | |
| 223 | return match; |
| 224 | } |
| 225 | |
| 226 | void |
| 227 | gdbarch_init_osabi (struct gdbarch_info info, struct gdbarch *gdbarch, |
| 228 | enum gdb_osabi osabi) |
| 229 | { |
| 230 | struct gdb_osabi_handler *handler; |
| 231 | bfd *abfd = info.abfd; |
| 232 | const struct bfd_arch_info *arch_info = gdbarch_bfd_arch_info (gdbarch); |
| 233 | |
| 234 | if (osabi == GDB_OSABI_UNKNOWN) |
| 235 | { |
| 236 | /* Don't complain about an unknown OSABI. Assume the user knows |
| 237 | what they are doing. */ |
| 238 | return; |
| 239 | } |
| 240 | |
| 241 | for (handler = gdb_osabi_handler_list; handler != NULL; |
| 242 | handler = handler->next) |
| 243 | { |
| 244 | if (handler->arch == bfd_get_arch (abfd) |
| 245 | && handler->osabi == osabi) |
| 246 | { |
| 247 | (*handler->init_osabi) (info, gdbarch); |
| 248 | return; |
| 249 | } |
| 250 | } |
| 251 | |
| 252 | /* We assume that if GDB_MULTI_ARCH is less than GDB_MULTI_ARCH_TM |
| 253 | that an ABI variant can be supported by overriding definitions in |
| 254 | the tm-file. */ |
| 255 | if (GDB_MULTI_ARCH > GDB_MULTI_ARCH_PARTIAL) |
| 256 | fprintf_filtered |
| 257 | (gdb_stderr, |
| 258 | "A handler for the OS ABI \"%s\" is not built into this " |
| 259 | "configuration of GDB. " |
| 260 | "Attempting to continue with the default %s settings", |
| 261 | gdbarch_osabi_name (osabi), |
| 262 | bfd_printable_arch_mach (arch_info->arch, arch_info->mach)); |
| 263 | } |
| 264 | \f |
| 265 | |
| 266 | /* Generic sniffer for ELF flavoured files. */ |
| 267 | |
| 268 | void |
| 269 | generic_elf_osabi_sniff_abi_tag_sections (bfd *abfd, asection *sect, void *obj) |
| 270 | { |
| 271 | enum gdb_osabi *os_ident_ptr = obj; |
| 272 | const char *name; |
| 273 | unsigned int sectsize; |
| 274 | |
| 275 | name = bfd_get_section_name (abfd, sect); |
| 276 | sectsize = bfd_section_size (abfd, sect); |
| 277 | |
| 278 | /* .note.ABI-tag notes, used by GNU/Linux and FreeBSD. */ |
| 279 | if (strcmp (name, ".note.ABI-tag") == 0 && sectsize > 0) |
| 280 | { |
| 281 | unsigned int name_length, data_length, note_type; |
| 282 | char *note; |
| 283 | |
| 284 | /* If the section is larger than this, it's probably not what we are |
| 285 | looking for. */ |
| 286 | if (sectsize > 128) |
| 287 | sectsize = 128; |
| 288 | |
| 289 | note = alloca (sectsize); |
| 290 | |
| 291 | bfd_get_section_contents (abfd, sect, note, |
| 292 | (file_ptr) 0, (bfd_size_type) sectsize); |
| 293 | |
| 294 | name_length = bfd_h_get_32 (abfd, note); |
| 295 | data_length = bfd_h_get_32 (abfd, note + 4); |
| 296 | note_type = bfd_h_get_32 (abfd, note + 8); |
| 297 | |
| 298 | if (name_length == 4 && data_length == 16 && note_type == NT_GNU_ABI_TAG |
| 299 | && strcmp (note + 12, "GNU") == 0) |
| 300 | { |
| 301 | int os_number = bfd_h_get_32 (abfd, note + 16); |
| 302 | |
| 303 | switch (os_number) |
| 304 | { |
| 305 | case GNU_ABI_TAG_LINUX: |
| 306 | *os_ident_ptr = GDB_OSABI_LINUX; |
| 307 | break; |
| 308 | |
| 309 | case GNU_ABI_TAG_HURD: |
| 310 | *os_ident_ptr = GDB_OSABI_HURD; |
| 311 | break; |
| 312 | |
| 313 | case GNU_ABI_TAG_SOLARIS: |
| 314 | *os_ident_ptr = GDB_OSABI_SOLARIS; |
| 315 | break; |
| 316 | |
| 317 | default: |
| 318 | internal_error |
| 319 | (__FILE__, __LINE__, |
| 320 | "generic_elf_osabi_sniff_abi_tag_sections: unknown OS number %d", |
| 321 | os_number); |
| 322 | } |
| 323 | return; |
| 324 | } |
| 325 | else if (name_length == 8 && data_length == 4 |
| 326 | && note_type == NT_FREEBSD_ABI_TAG |
| 327 | && strcmp (note + 12, "FreeBSD") == 0) |
| 328 | { |
| 329 | /* XXX Should we check the version here? Probably not |
| 330 | necessary yet. */ |
| 331 | *os_ident_ptr = GDB_OSABI_FREEBSD_ELF; |
| 332 | } |
| 333 | return; |
| 334 | } |
| 335 | |
| 336 | /* .note.netbsd.ident notes, used by NetBSD. */ |
| 337 | if (strcmp (name, ".note.netbsd.ident") == 0 && sectsize > 0) |
| 338 | { |
| 339 | unsigned int name_length, data_length, note_type; |
| 340 | char *note; |
| 341 | |
| 342 | /* If the section is larger than this, it's probably not what we are |
| 343 | looking for. */ |
| 344 | if (sectsize > 128) |
| 345 | sectsize = 128; |
| 346 | |
| 347 | note = alloca (sectsize); |
| 348 | |
| 349 | bfd_get_section_contents (abfd, sect, note, |
| 350 | (file_ptr) 0, (bfd_size_type) sectsize); |
| 351 | |
| 352 | name_length = bfd_h_get_32 (abfd, note); |
| 353 | data_length = bfd_h_get_32 (abfd, note + 4); |
| 354 | note_type = bfd_h_get_32 (abfd, note + 8); |
| 355 | |
| 356 | if (name_length == 7 && data_length == 4 && note_type == NT_NETBSD_IDENT |
| 357 | && strcmp (note + 12, "NetBSD") == 0) |
| 358 | { |
| 359 | /* XXX Should we check the version here? Probably not |
| 360 | necessary yet. */ |
| 361 | *os_ident_ptr = GDB_OSABI_NETBSD_ELF; |
| 362 | } |
| 363 | return; |
| 364 | } |
| 365 | } |
| 366 | |
| 367 | static enum gdb_osabi |
| 368 | generic_elf_osabi_sniffer (bfd *abfd) |
| 369 | { |
| 370 | unsigned int elfosabi; |
| 371 | enum gdb_osabi osabi = GDB_OSABI_UNKNOWN; |
| 372 | |
| 373 | elfosabi = elf_elfheader (abfd)->e_ident[EI_OSABI]; |
| 374 | |
| 375 | switch (elfosabi) |
| 376 | { |
| 377 | case ELFOSABI_NONE: |
| 378 | /* When elfosabi is ELFOSABI_NONE (0), then the ELF structures in the |
| 379 | file are conforming to the base specification for that machine |
| 380 | (there are no OS-specific extensions). In order to determine the |
| 381 | real OS in use we must look for OS notes that have been added. */ |
| 382 | bfd_map_over_sections (abfd, |
| 383 | generic_elf_osabi_sniff_abi_tag_sections, |
| 384 | &osabi); |
| 385 | break; |
| 386 | |
| 387 | case ELFOSABI_FREEBSD: |
| 388 | osabi = GDB_OSABI_FREEBSD_ELF; |
| 389 | break; |
| 390 | |
| 391 | case ELFOSABI_NETBSD: |
| 392 | osabi = GDB_OSABI_NETBSD_ELF; |
| 393 | break; |
| 394 | |
| 395 | case ELFOSABI_LINUX: |
| 396 | osabi = GDB_OSABI_LINUX; |
| 397 | break; |
| 398 | |
| 399 | case ELFOSABI_HURD: |
| 400 | osabi = GDB_OSABI_HURD; |
| 401 | break; |
| 402 | |
| 403 | case ELFOSABI_SOLARIS: |
| 404 | osabi = GDB_OSABI_SOLARIS; |
| 405 | break; |
| 406 | } |
| 407 | |
| 408 | if (osabi == GDB_OSABI_UNKNOWN) |
| 409 | { |
| 410 | /* The FreeBSD folks have been naughty; they stored the string |
| 411 | "FreeBSD" in the padding of the e_ident field of the ELF |
| 412 | header to "brand" their ELF binaries in FreeBSD 3.x. */ |
| 413 | if (strcmp (&elf_elfheader (abfd)->e_ident[8], "FreeBSD") == 0) |
| 414 | osabi = GDB_OSABI_FREEBSD_ELF; |
| 415 | } |
| 416 | |
| 417 | return osabi; |
| 418 | } |
| 419 | \f |
| 420 | |
| 421 | void |
| 422 | _initialize_gdb_osabi (void) |
| 423 | { |
| 424 | if (strcmp (gdb_osabi_names[GDB_OSABI_INVALID], "<invalid>") != 0) |
| 425 | internal_error |
| 426 | (__FILE__, __LINE__, |
| 427 | "_initialize_gdb_osabi: gdb_osabi_names[] is inconsistent"); |
| 428 | |
| 429 | /* Register a generic sniffer for ELF flavoured files. */ |
| 430 | gdbarch_register_osabi_sniffer (bfd_arch_unknown, |
| 431 | bfd_target_elf_flavour, |
| 432 | generic_elf_osabi_sniffer); |
| 433 | } |