| 1 | /* Functions that provide the mechanism to parse a syscall XML file |
| 2 | and get its values. |
| 3 | |
| 4 | Copyright (C) 2009-2021 Free Software Foundation, Inc. |
| 5 | |
| 6 | This file is part of GDB. |
| 7 | |
| 8 | This program is free software; you can redistribute it and/or modify |
| 9 | it under the terms of the GNU General Public License as published by |
| 10 | the Free Software Foundation; either version 3 of the License, or |
| 11 | (at your option) any later version. |
| 12 | |
| 13 | This program is distributed in the hope that it will be useful, |
| 14 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 16 | GNU General Public License for more details. |
| 17 | |
| 18 | You should have received a copy of the GNU General Public License |
| 19 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
| 20 | |
| 21 | #include "defs.h" |
| 22 | #include "gdbtypes.h" |
| 23 | #include "xml-support.h" |
| 24 | #include "xml-syscall.h" |
| 25 | #include "gdbarch.h" |
| 26 | |
| 27 | /* For the struct syscall definition. */ |
| 28 | #include "target.h" |
| 29 | |
| 30 | #include "filenames.h" |
| 31 | |
| 32 | #ifndef HAVE_LIBEXPAT |
| 33 | |
| 34 | /* Dummy functions to indicate that there's no support for fetching |
| 35 | syscalls information. */ |
| 36 | |
| 37 | static void |
| 38 | syscall_warn_user (void) |
| 39 | { |
| 40 | static int have_warned = 0; |
| 41 | if (!have_warned) |
| 42 | { |
| 43 | have_warned = 1; |
| 44 | warning (_("Can not parse XML syscalls information; XML support was " |
| 45 | "disabled at compile time.")); |
| 46 | } |
| 47 | } |
| 48 | |
| 49 | void |
| 50 | set_xml_syscall_file_name (struct gdbarch *gdbarch, const char *name) |
| 51 | { |
| 52 | return; |
| 53 | } |
| 54 | |
| 55 | void |
| 56 | get_syscall_by_number (struct gdbarch *gdbarch, |
| 57 | int syscall_number, struct syscall *s) |
| 58 | { |
| 59 | syscall_warn_user (); |
| 60 | s->number = syscall_number; |
| 61 | s->name = NULL; |
| 62 | } |
| 63 | |
| 64 | bool |
| 65 | get_syscalls_by_name (struct gdbarch *gdbarch, const char *syscall_name, |
| 66 | std::vector<int> *syscall_numbers) |
| 67 | { |
| 68 | syscall_warn_user (); |
| 69 | return false; |
| 70 | } |
| 71 | |
| 72 | const char ** |
| 73 | get_syscall_names (struct gdbarch *gdbarch) |
| 74 | { |
| 75 | syscall_warn_user (); |
| 76 | return NULL; |
| 77 | } |
| 78 | |
| 79 | bool |
| 80 | get_syscalls_by_group (struct gdbarch *gdbarch, const char *group, |
| 81 | std::vector<int> *syscall_numbers) |
| 82 | { |
| 83 | syscall_warn_user (); |
| 84 | return false; |
| 85 | } |
| 86 | |
| 87 | const char ** |
| 88 | get_syscall_group_names (struct gdbarch *gdbarch) |
| 89 | { |
| 90 | syscall_warn_user (); |
| 91 | return NULL; |
| 92 | } |
| 93 | |
| 94 | #else /* ! HAVE_LIBEXPAT */ |
| 95 | |
| 96 | /* Structure which describes a syscall. */ |
| 97 | struct syscall_desc |
| 98 | { |
| 99 | syscall_desc (int number_, std::string name_, std::string alias_) |
| 100 | : number (number_), name (name_), alias (alias_) |
| 101 | {} |
| 102 | |
| 103 | /* The syscall number. */ |
| 104 | |
| 105 | int number; |
| 106 | |
| 107 | /* The syscall name. */ |
| 108 | |
| 109 | std::string name; |
| 110 | |
| 111 | /* An optional alias. */ |
| 112 | |
| 113 | std::string alias; |
| 114 | }; |
| 115 | |
| 116 | typedef std::unique_ptr<syscall_desc> syscall_desc_up; |
| 117 | |
| 118 | /* Structure of a syscall group. */ |
| 119 | struct syscall_group_desc |
| 120 | { |
| 121 | syscall_group_desc (const std::string &name_) |
| 122 | : name (name_) |
| 123 | {} |
| 124 | |
| 125 | /* The group name. */ |
| 126 | |
| 127 | std::string name; |
| 128 | |
| 129 | /* The syscalls that are part of the group. This is a non-owning |
| 130 | reference. */ |
| 131 | |
| 132 | std::vector<syscall_desc *> syscalls; |
| 133 | }; |
| 134 | |
| 135 | typedef std::unique_ptr<syscall_group_desc> syscall_group_desc_up; |
| 136 | |
| 137 | /* Structure that represents syscalls information. */ |
| 138 | struct syscalls_info |
| 139 | { |
| 140 | /* The syscalls. */ |
| 141 | |
| 142 | std::vector<syscall_desc_up> syscalls; |
| 143 | |
| 144 | /* The syscall groups. */ |
| 145 | |
| 146 | std::vector<syscall_group_desc_up> groups; |
| 147 | |
| 148 | /* Variable that will hold the last known data-directory. This is |
| 149 | useful to know whether we should re-read the XML info for the |
| 150 | target. */ |
| 151 | |
| 152 | std::string my_gdb_datadir; |
| 153 | }; |
| 154 | |
| 155 | typedef std::unique_ptr<syscalls_info> syscalls_info_up; |
| 156 | |
| 157 | /* Callback data for syscall information parsing. */ |
| 158 | struct syscall_parsing_data |
| 159 | { |
| 160 | /* The syscalls_info we are building. */ |
| 161 | |
| 162 | struct syscalls_info *syscalls_info; |
| 163 | }; |
| 164 | |
| 165 | /* Create a new syscall group. Return pointer to the |
| 166 | syscall_group_desc structure that represents the new group. */ |
| 167 | |
| 168 | static struct syscall_group_desc * |
| 169 | syscall_group_create_syscall_group_desc (struct syscalls_info *syscalls_info, |
| 170 | const char *group) |
| 171 | { |
| 172 | syscall_group_desc *groupdesc = new syscall_group_desc (group); |
| 173 | |
| 174 | syscalls_info->groups.emplace_back (groupdesc); |
| 175 | |
| 176 | return groupdesc; |
| 177 | } |
| 178 | |
| 179 | /* Add a syscall to the group. If group doesn't exist, create it. */ |
| 180 | |
| 181 | static void |
| 182 | syscall_group_add_syscall (struct syscalls_info *syscalls_info, |
| 183 | struct syscall_desc *syscall, |
| 184 | const char *group) |
| 185 | { |
| 186 | /* Search for an existing group. */ |
| 187 | std::vector<syscall_group_desc_up>::iterator it |
| 188 | = syscalls_info->groups.begin (); |
| 189 | |
| 190 | for (; it != syscalls_info->groups.end (); it++) |
| 191 | { |
| 192 | if ((*it)->name == group) |
| 193 | break; |
| 194 | } |
| 195 | |
| 196 | syscall_group_desc *groupdesc; |
| 197 | |
| 198 | if (it != syscalls_info->groups.end ()) |
| 199 | groupdesc = it->get (); |
| 200 | else |
| 201 | { |
| 202 | /* No group was found with this name. We must create a new |
| 203 | one. */ |
| 204 | groupdesc = syscall_group_create_syscall_group_desc (syscalls_info, |
| 205 | group); |
| 206 | } |
| 207 | |
| 208 | groupdesc->syscalls.push_back (syscall); |
| 209 | } |
| 210 | |
| 211 | static void |
| 212 | syscall_create_syscall_desc (struct syscalls_info *syscalls_info, |
| 213 | const char *name, int number, const char *alias, |
| 214 | char *groups) |
| 215 | { |
| 216 | syscall_desc *sysdesc = new syscall_desc (number, name, |
| 217 | alias != NULL ? alias : ""); |
| 218 | |
| 219 | syscalls_info->syscalls.emplace_back (sysdesc); |
| 220 | |
| 221 | /* Add syscall to its groups. */ |
| 222 | if (groups != NULL) |
| 223 | { |
| 224 | char *saveptr; |
| 225 | for (char *group = strtok_r (groups, ",", &saveptr); |
| 226 | group != NULL; |
| 227 | group = strtok_r (NULL, ",", &saveptr)) |
| 228 | syscall_group_add_syscall (syscalls_info, sysdesc, group); |
| 229 | } |
| 230 | } |
| 231 | |
| 232 | /* Handle the start of a <syscall> element. */ |
| 233 | static void |
| 234 | syscall_start_syscall (struct gdb_xml_parser *parser, |
| 235 | const struct gdb_xml_element *element, |
| 236 | void *user_data, |
| 237 | std::vector<gdb_xml_value> &attributes) |
| 238 | { |
| 239 | struct syscall_parsing_data *data = (struct syscall_parsing_data *) user_data; |
| 240 | /* syscall info. */ |
| 241 | char *name = NULL; |
| 242 | int number = 0; |
| 243 | char *alias = NULL; |
| 244 | char *groups = NULL; |
| 245 | |
| 246 | for (const gdb_xml_value &attr : attributes) |
| 247 | { |
| 248 | if (strcmp (attr.name, "name") == 0) |
| 249 | name = (char *) attr.value.get (); |
| 250 | else if (strcmp (attr.name, "number") == 0) |
| 251 | number = * (ULONGEST *) attr.value.get (); |
| 252 | else if (strcmp (attr.name, "alias") == 0) |
| 253 | alias = (char *) attr.value.get (); |
| 254 | else if (strcmp (attr.name, "groups") == 0) |
| 255 | groups = (char *) attr.value.get (); |
| 256 | else |
| 257 | internal_error (__FILE__, __LINE__, |
| 258 | _("Unknown attribute name '%s'."), attr.name); |
| 259 | } |
| 260 | |
| 261 | gdb_assert (name); |
| 262 | syscall_create_syscall_desc (data->syscalls_info, name, number, alias, |
| 263 | groups); |
| 264 | } |
| 265 | |
| 266 | |
| 267 | /* The elements and attributes of an XML syscall document. */ |
| 268 | static const struct gdb_xml_attribute syscall_attr[] = { |
| 269 | { "number", GDB_XML_AF_NONE, gdb_xml_parse_attr_ulongest, NULL }, |
| 270 | { "name", GDB_XML_AF_NONE, NULL, NULL }, |
| 271 | { "alias", GDB_XML_AF_OPTIONAL, NULL, NULL }, |
| 272 | { "groups", GDB_XML_AF_OPTIONAL, NULL, NULL }, |
| 273 | { NULL, GDB_XML_AF_NONE, NULL, NULL } |
| 274 | }; |
| 275 | |
| 276 | static const struct gdb_xml_element syscalls_info_children[] = { |
| 277 | { "syscall", syscall_attr, NULL, |
| 278 | GDB_XML_EF_OPTIONAL | GDB_XML_EF_REPEATABLE, |
| 279 | syscall_start_syscall, NULL }, |
| 280 | { NULL, NULL, NULL, GDB_XML_EF_NONE, NULL, NULL } |
| 281 | }; |
| 282 | |
| 283 | static const struct gdb_xml_element syselements[] = { |
| 284 | { "syscalls_info", NULL, syscalls_info_children, |
| 285 | GDB_XML_EF_NONE, NULL, NULL }, |
| 286 | { NULL, NULL, NULL, GDB_XML_EF_NONE, NULL, NULL } |
| 287 | }; |
| 288 | |
| 289 | static struct syscalls_info * |
| 290 | syscall_parse_xml (const char *document, xml_fetch_another fetcher) |
| 291 | { |
| 292 | struct syscall_parsing_data data; |
| 293 | syscalls_info_up sysinfo (new syscalls_info ()); |
| 294 | |
| 295 | data.syscalls_info = sysinfo.get (); |
| 296 | |
| 297 | if (gdb_xml_parse_quick (_("syscalls info"), NULL, |
| 298 | syselements, document, &data) == 0) |
| 299 | { |
| 300 | /* Parsed successfully. */ |
| 301 | return sysinfo.release (); |
| 302 | } |
| 303 | else |
| 304 | { |
| 305 | warning (_("Could not load XML syscalls info; ignoring")); |
| 306 | return NULL; |
| 307 | } |
| 308 | } |
| 309 | |
| 310 | /* Function responsible for initializing the information |
| 311 | about the syscalls. It reads the XML file and fills the |
| 312 | struct syscalls_info with the values. |
| 313 | |
| 314 | Returns the struct syscalls_info if the file is valid, NULL otherwise. */ |
| 315 | static struct syscalls_info * |
| 316 | xml_init_syscalls_info (const char *filename) |
| 317 | { |
| 318 | gdb::optional<gdb::char_vector> full_file |
| 319 | = xml_fetch_content_from_file (filename, |
| 320 | const_cast<char *>(gdb_datadir.c_str ())); |
| 321 | if (!full_file) |
| 322 | return NULL; |
| 323 | |
| 324 | const std::string dirname = ldirname (filename); |
| 325 | auto fetch_another = [&dirname] (const char *name) |
| 326 | { |
| 327 | return xml_fetch_content_from_file (name, dirname.c_str ()); |
| 328 | }; |
| 329 | |
| 330 | return syscall_parse_xml (full_file->data (), fetch_another); |
| 331 | } |
| 332 | |
| 333 | /* Initializes the syscalls_info structure according to the |
| 334 | architecture. */ |
| 335 | static void |
| 336 | init_syscalls_info (struct gdbarch *gdbarch) |
| 337 | { |
| 338 | struct syscalls_info *syscalls_info = gdbarch_syscalls_info (gdbarch); |
| 339 | const char *xml_syscall_file = gdbarch_xml_syscall_file (gdbarch); |
| 340 | |
| 341 | /* Should we re-read the XML info for this target? */ |
| 342 | if (syscalls_info != NULL && !syscalls_info->my_gdb_datadir.empty () |
| 343 | && filename_cmp (syscalls_info->my_gdb_datadir.c_str (), |
| 344 | gdb_datadir.c_str ()) != 0) |
| 345 | { |
| 346 | /* The data-directory changed from the last time we used it. |
| 347 | It means that we have to re-read the XML info. */ |
| 348 | delete syscalls_info; |
| 349 | syscalls_info = NULL; |
| 350 | set_gdbarch_syscalls_info (gdbarch, NULL); |
| 351 | } |
| 352 | |
| 353 | /* Did we succeed at initializing this? */ |
| 354 | if (syscalls_info != NULL) |
| 355 | return; |
| 356 | |
| 357 | syscalls_info = xml_init_syscalls_info (xml_syscall_file); |
| 358 | |
| 359 | /* If there was some error reading the XML file, we initialize |
| 360 | gdbarch->syscalls_info anyway, in order to store information |
| 361 | about our attempt. */ |
| 362 | if (syscalls_info == NULL) |
| 363 | syscalls_info = new struct syscalls_info (); |
| 364 | |
| 365 | if (syscalls_info->syscalls.empty ()) |
| 366 | { |
| 367 | if (xml_syscall_file != NULL) |
| 368 | warning (_("Could not load the syscall XML file `%s/%s'."), |
| 369 | gdb_datadir.c_str (), xml_syscall_file); |
| 370 | else |
| 371 | warning (_("There is no XML file to open.")); |
| 372 | |
| 373 | warning (_("GDB will not be able to display " |
| 374 | "syscall names nor to verify if\n" |
| 375 | "any provided syscall numbers are valid.")); |
| 376 | } |
| 377 | |
| 378 | /* Saving the data-directory used to read this XML info. */ |
| 379 | syscalls_info->my_gdb_datadir.assign (gdb_datadir); |
| 380 | |
| 381 | set_gdbarch_syscalls_info (gdbarch, syscalls_info); |
| 382 | } |
| 383 | |
| 384 | /* Search for a syscall group by its name. Return syscall_group_desc |
| 385 | structure for the group if found or NULL otherwise. */ |
| 386 | |
| 387 | static struct syscall_group_desc * |
| 388 | syscall_group_get_group_by_name (const struct syscalls_info *syscalls_info, |
| 389 | const char *group) |
| 390 | { |
| 391 | if (syscalls_info == NULL) |
| 392 | return NULL; |
| 393 | |
| 394 | if (group == NULL) |
| 395 | return NULL; |
| 396 | |
| 397 | /* Search for existing group. */ |
| 398 | for (const syscall_group_desc_up &groupdesc : syscalls_info->groups) |
| 399 | { |
| 400 | if (groupdesc->name == group) |
| 401 | return groupdesc.get (); |
| 402 | } |
| 403 | |
| 404 | return NULL; |
| 405 | } |
| 406 | |
| 407 | static bool |
| 408 | xml_get_syscalls_by_name (struct gdbarch *gdbarch, const char *syscall_name, |
| 409 | std::vector<int> *syscall_numbers) |
| 410 | { |
| 411 | struct syscalls_info *syscalls_info = gdbarch_syscalls_info (gdbarch); |
| 412 | |
| 413 | bool found = false; |
| 414 | if (syscalls_info != NULL && syscall_name != NULL && syscall_numbers != NULL) |
| 415 | for (const syscall_desc_up &sysdesc : syscalls_info->syscalls) |
| 416 | if (sysdesc->name == syscall_name || sysdesc->alias == syscall_name) |
| 417 | { |
| 418 | syscall_numbers->push_back (sysdesc->number); |
| 419 | found = true; |
| 420 | } |
| 421 | |
| 422 | return found; |
| 423 | } |
| 424 | |
| 425 | static const char * |
| 426 | xml_get_syscall_name (struct gdbarch *gdbarch, |
| 427 | int syscall_number) |
| 428 | { |
| 429 | struct syscalls_info *syscalls_info = gdbarch_syscalls_info (gdbarch); |
| 430 | |
| 431 | if (syscalls_info == NULL |
| 432 | || syscall_number < 0) |
| 433 | return NULL; |
| 434 | |
| 435 | for (const syscall_desc_up &sysdesc : syscalls_info->syscalls) |
| 436 | if (sysdesc->number == syscall_number) |
| 437 | return sysdesc->name.c_str (); |
| 438 | |
| 439 | return NULL; |
| 440 | } |
| 441 | |
| 442 | static const char ** |
| 443 | xml_list_of_syscalls (struct gdbarch *gdbarch) |
| 444 | { |
| 445 | struct syscalls_info *syscalls_info = gdbarch_syscalls_info (gdbarch); |
| 446 | |
| 447 | if (syscalls_info == NULL) |
| 448 | return NULL; |
| 449 | |
| 450 | int nsyscalls = syscalls_info->syscalls.size (); |
| 451 | const char **names = XNEWVEC (const char *, nsyscalls + 1); |
| 452 | |
| 453 | int i; |
| 454 | for (i = 0; i < syscalls_info->syscalls.size (); i++) |
| 455 | names[i] = syscalls_info->syscalls[i]->name.c_str (); |
| 456 | |
| 457 | names[i] = NULL; |
| 458 | |
| 459 | return names; |
| 460 | } |
| 461 | |
| 462 | /* Iterate over the syscall_group_desc element to return a list of |
| 463 | syscalls that are part of the given group. If the syscall group |
| 464 | doesn't exist, return false. */ |
| 465 | |
| 466 | static bool |
| 467 | xml_list_syscalls_by_group (struct gdbarch *gdbarch, const char *group, |
| 468 | std::vector<int> *syscalls) |
| 469 | { |
| 470 | struct syscalls_info *syscalls_info = gdbarch_syscalls_info (gdbarch); |
| 471 | struct syscall_group_desc *groupdesc; |
| 472 | |
| 473 | if (syscalls_info == NULL || syscalls == NULL) |
| 474 | return false; |
| 475 | |
| 476 | groupdesc = syscall_group_get_group_by_name (syscalls_info, group); |
| 477 | if (groupdesc == NULL) |
| 478 | return false; |
| 479 | |
| 480 | for (const syscall_desc *sysdesc : groupdesc->syscalls) |
| 481 | syscalls->push_back (sysdesc->number); |
| 482 | |
| 483 | return true; |
| 484 | } |
| 485 | |
| 486 | /* Return a NULL terminated list of syscall groups or an empty list, if |
| 487 | no syscall group is available. Return NULL, if there is no syscall |
| 488 | information available. */ |
| 489 | |
| 490 | static const char ** |
| 491 | xml_list_of_groups (struct gdbarch *gdbarch) |
| 492 | { |
| 493 | struct syscalls_info *syscalls_info = gdbarch_syscalls_info (gdbarch); |
| 494 | const char **names = NULL; |
| 495 | int ngroups; |
| 496 | int i; |
| 497 | |
| 498 | if (syscalls_info == NULL) |
| 499 | return NULL; |
| 500 | |
| 501 | ngroups = syscalls_info->groups.size (); |
| 502 | names = (const char**) xmalloc ((ngroups + 1) * sizeof (char *)); |
| 503 | |
| 504 | for (i = 0; i < syscalls_info->groups.size (); i++) |
| 505 | names[i] = syscalls_info->groups[i]->name.c_str (); |
| 506 | |
| 507 | names[i] = NULL; |
| 508 | |
| 509 | return names; |
| 510 | } |
| 511 | |
| 512 | void |
| 513 | set_xml_syscall_file_name (struct gdbarch *gdbarch, const char *name) |
| 514 | { |
| 515 | set_gdbarch_xml_syscall_file (gdbarch, name); |
| 516 | } |
| 517 | |
| 518 | void |
| 519 | get_syscall_by_number (struct gdbarch *gdbarch, |
| 520 | int syscall_number, struct syscall *s) |
| 521 | { |
| 522 | init_syscalls_info (gdbarch); |
| 523 | |
| 524 | s->number = syscall_number; |
| 525 | s->name = xml_get_syscall_name (gdbarch, syscall_number); |
| 526 | } |
| 527 | |
| 528 | bool |
| 529 | get_syscalls_by_name (struct gdbarch *gdbarch, const char *syscall_name, |
| 530 | std::vector<int> *syscall_numbers) |
| 531 | { |
| 532 | init_syscalls_info (gdbarch); |
| 533 | |
| 534 | return xml_get_syscalls_by_name (gdbarch, syscall_name, syscall_numbers); |
| 535 | } |
| 536 | |
| 537 | const char ** |
| 538 | get_syscall_names (struct gdbarch *gdbarch) |
| 539 | { |
| 540 | init_syscalls_info (gdbarch); |
| 541 | |
| 542 | return xml_list_of_syscalls (gdbarch); |
| 543 | } |
| 544 | |
| 545 | /* See comment in xml-syscall.h. */ |
| 546 | |
| 547 | bool |
| 548 | get_syscalls_by_group (struct gdbarch *gdbarch, const char *group, |
| 549 | std::vector<int> *syscall_numbers) |
| 550 | { |
| 551 | init_syscalls_info (gdbarch); |
| 552 | |
| 553 | return xml_list_syscalls_by_group (gdbarch, group, syscall_numbers); |
| 554 | } |
| 555 | |
| 556 | /* See comment in xml-syscall.h. */ |
| 557 | |
| 558 | const char ** |
| 559 | get_syscall_group_names (struct gdbarch *gdbarch) |
| 560 | { |
| 561 | init_syscalls_info (gdbarch); |
| 562 | |
| 563 | return xml_list_of_groups (gdbarch); |
| 564 | } |
| 565 | |
| 566 | #endif /* ! HAVE_LIBEXPAT */ |