| 1 | /* Handle JIT code generation in the inferior for GDB, the GNU Debugger. |
| 2 | |
| 3 | Copyright (C) 2009-2020 Free Software Foundation, Inc. |
| 4 | |
| 5 | This file is part of GDB. |
| 6 | |
| 7 | This program is free software; you can redistribute it and/or modify |
| 8 | it under the terms of the GNU General Public License as published by |
| 9 | the Free Software Foundation; either version 3 of the License, or |
| 10 | (at your option) any later version. |
| 11 | |
| 12 | This program is distributed in the hope that it will be useful, |
| 13 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 15 | GNU General Public License for more details. |
| 16 | |
| 17 | You should have received a copy of the GNU General Public License |
| 18 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
| 19 | |
| 20 | #include "defs.h" |
| 21 | |
| 22 | #include "jit.h" |
| 23 | #include "jit-reader.h" |
| 24 | #include "block.h" |
| 25 | #include "breakpoint.h" |
| 26 | #include "command.h" |
| 27 | #include "dictionary.h" |
| 28 | #include "filenames.h" |
| 29 | #include "frame-unwind.h" |
| 30 | #include "gdbcmd.h" |
| 31 | #include "gdbcore.h" |
| 32 | #include "inferior.h" |
| 33 | #include "observable.h" |
| 34 | #include "objfiles.h" |
| 35 | #include "regcache.h" |
| 36 | #include "symfile.h" |
| 37 | #include "symtab.h" |
| 38 | #include "target.h" |
| 39 | #include "gdbsupport/gdb-dlfcn.h" |
| 40 | #include <sys/stat.h> |
| 41 | #include "gdb_bfd.h" |
| 42 | #include "readline/tilde.h" |
| 43 | #include "completer.h" |
| 44 | #include <forward_list> |
| 45 | |
| 46 | static std::string jit_reader_dir; |
| 47 | |
| 48 | static const struct objfile_data *jit_objfile_data; |
| 49 | |
| 50 | static const char *const jit_break_name = "__jit_debug_register_code"; |
| 51 | |
| 52 | static const char *const jit_descriptor_name = "__jit_debug_descriptor"; |
| 53 | |
| 54 | static void jit_inferior_init (struct gdbarch *gdbarch); |
| 55 | static void jit_inferior_exit_hook (struct inferior *inf); |
| 56 | |
| 57 | /* An unwinder is registered for every gdbarch. This key is used to |
| 58 | remember if the unwinder has been registered for a particular |
| 59 | gdbarch. */ |
| 60 | |
| 61 | static struct gdbarch_data *jit_gdbarch_data; |
| 62 | |
| 63 | /* Non-zero if we want to see trace of jit level stuff. */ |
| 64 | |
| 65 | static unsigned int jit_debug = 0; |
| 66 | |
| 67 | static void |
| 68 | show_jit_debug (struct ui_file *file, int from_tty, |
| 69 | struct cmd_list_element *c, const char *value) |
| 70 | { |
| 71 | fprintf_filtered (file, _("JIT debugging is %s.\n"), value); |
| 72 | } |
| 73 | |
| 74 | struct target_buffer |
| 75 | { |
| 76 | CORE_ADDR base; |
| 77 | ULONGEST size; |
| 78 | }; |
| 79 | |
| 80 | /* Opening the file is a no-op. */ |
| 81 | |
| 82 | static void * |
| 83 | mem_bfd_iovec_open (struct bfd *abfd, void *open_closure) |
| 84 | { |
| 85 | return open_closure; |
| 86 | } |
| 87 | |
| 88 | /* Closing the file is just freeing the base/size pair on our side. */ |
| 89 | |
| 90 | static int |
| 91 | mem_bfd_iovec_close (struct bfd *abfd, void *stream) |
| 92 | { |
| 93 | xfree (stream); |
| 94 | |
| 95 | /* Zero means success. */ |
| 96 | return 0; |
| 97 | } |
| 98 | |
| 99 | /* For reading the file, we just need to pass through to target_read_memory and |
| 100 | fix up the arguments and return values. */ |
| 101 | |
| 102 | static file_ptr |
| 103 | mem_bfd_iovec_pread (struct bfd *abfd, void *stream, void *buf, |
| 104 | file_ptr nbytes, file_ptr offset) |
| 105 | { |
| 106 | int err; |
| 107 | struct target_buffer *buffer = (struct target_buffer *) stream; |
| 108 | |
| 109 | /* If this read will read all of the file, limit it to just the rest. */ |
| 110 | if (offset + nbytes > buffer->size) |
| 111 | nbytes = buffer->size - offset; |
| 112 | |
| 113 | /* If there are no more bytes left, we've reached EOF. */ |
| 114 | if (nbytes == 0) |
| 115 | return 0; |
| 116 | |
| 117 | err = target_read_memory (buffer->base + offset, (gdb_byte *) buf, nbytes); |
| 118 | if (err) |
| 119 | return -1; |
| 120 | |
| 121 | return nbytes; |
| 122 | } |
| 123 | |
| 124 | /* For statting the file, we only support the st_size attribute. */ |
| 125 | |
| 126 | static int |
| 127 | mem_bfd_iovec_stat (struct bfd *abfd, void *stream, struct stat *sb) |
| 128 | { |
| 129 | struct target_buffer *buffer = (struct target_buffer*) stream; |
| 130 | |
| 131 | memset (sb, 0, sizeof (struct stat)); |
| 132 | sb->st_size = buffer->size; |
| 133 | return 0; |
| 134 | } |
| 135 | |
| 136 | /* Open a BFD from the target's memory. */ |
| 137 | |
| 138 | static gdb_bfd_ref_ptr |
| 139 | bfd_open_from_target_memory (CORE_ADDR addr, ULONGEST size, char *target) |
| 140 | { |
| 141 | struct target_buffer *buffer = XNEW (struct target_buffer); |
| 142 | |
| 143 | buffer->base = addr; |
| 144 | buffer->size = size; |
| 145 | return gdb_bfd_openr_iovec ("<in-memory>", target, |
| 146 | mem_bfd_iovec_open, |
| 147 | buffer, |
| 148 | mem_bfd_iovec_pread, |
| 149 | mem_bfd_iovec_close, |
| 150 | mem_bfd_iovec_stat); |
| 151 | } |
| 152 | |
| 153 | struct jit_reader |
| 154 | { |
| 155 | jit_reader (struct gdb_reader_funcs *f, gdb_dlhandle_up &&h) |
| 156 | : functions (f), handle (std::move (h)) |
| 157 | { |
| 158 | } |
| 159 | |
| 160 | ~jit_reader () |
| 161 | { |
| 162 | functions->destroy (functions); |
| 163 | } |
| 164 | |
| 165 | DISABLE_COPY_AND_ASSIGN (jit_reader); |
| 166 | |
| 167 | struct gdb_reader_funcs *functions; |
| 168 | gdb_dlhandle_up handle; |
| 169 | }; |
| 170 | |
| 171 | /* One reader that has been loaded successfully, and can potentially be used to |
| 172 | parse debug info. */ |
| 173 | |
| 174 | static struct jit_reader *loaded_jit_reader = NULL; |
| 175 | |
| 176 | typedef struct gdb_reader_funcs * (reader_init_fn_type) (void); |
| 177 | static const char *reader_init_fn_sym = "gdb_init_reader"; |
| 178 | |
| 179 | /* Try to load FILE_NAME as a JIT debug info reader. */ |
| 180 | |
| 181 | static struct jit_reader * |
| 182 | jit_reader_load (const char *file_name) |
| 183 | { |
| 184 | reader_init_fn_type *init_fn; |
| 185 | struct gdb_reader_funcs *funcs = NULL; |
| 186 | |
| 187 | if (jit_debug) |
| 188 | fprintf_unfiltered (gdb_stdlog, _("Opening shared object %s.\n"), |
| 189 | file_name); |
| 190 | gdb_dlhandle_up so = gdb_dlopen (file_name); |
| 191 | |
| 192 | init_fn = (reader_init_fn_type *) gdb_dlsym (so, reader_init_fn_sym); |
| 193 | if (!init_fn) |
| 194 | error (_("Could not locate initialization function: %s."), |
| 195 | reader_init_fn_sym); |
| 196 | |
| 197 | if (gdb_dlsym (so, "plugin_is_GPL_compatible") == NULL) |
| 198 | error (_("Reader not GPL compatible.")); |
| 199 | |
| 200 | funcs = init_fn (); |
| 201 | if (funcs->reader_version != GDB_READER_INTERFACE_VERSION) |
| 202 | error (_("Reader version does not match GDB version.")); |
| 203 | |
| 204 | return new jit_reader (funcs, std::move (so)); |
| 205 | } |
| 206 | |
| 207 | /* Provides the jit-reader-load command. */ |
| 208 | |
| 209 | static void |
| 210 | jit_reader_load_command (const char *args, int from_tty) |
| 211 | { |
| 212 | if (args == NULL) |
| 213 | error (_("No reader name provided.")); |
| 214 | gdb::unique_xmalloc_ptr<char> file (tilde_expand (args)); |
| 215 | |
| 216 | if (loaded_jit_reader != NULL) |
| 217 | error (_("JIT reader already loaded. Run jit-reader-unload first.")); |
| 218 | |
| 219 | if (!IS_ABSOLUTE_PATH (file.get ())) |
| 220 | file.reset (xstrprintf ("%s%s%s", jit_reader_dir.c_str (), SLASH_STRING, |
| 221 | file.get ())); |
| 222 | |
| 223 | loaded_jit_reader = jit_reader_load (file.get ()); |
| 224 | reinit_frame_cache (); |
| 225 | jit_inferior_created_hook (); |
| 226 | } |
| 227 | |
| 228 | /* Provides the jit-reader-unload command. */ |
| 229 | |
| 230 | static void |
| 231 | jit_reader_unload_command (const char *args, int from_tty) |
| 232 | { |
| 233 | if (!loaded_jit_reader) |
| 234 | error (_("No JIT reader loaded.")); |
| 235 | |
| 236 | reinit_frame_cache (); |
| 237 | jit_inferior_exit_hook (current_inferior ()); |
| 238 | |
| 239 | delete loaded_jit_reader; |
| 240 | loaded_jit_reader = NULL; |
| 241 | } |
| 242 | |
| 243 | /* Per-program space structure recording which objfile has the JIT |
| 244 | symbols. */ |
| 245 | |
| 246 | struct jit_program_space_data |
| 247 | { |
| 248 | /* The objfile. This is NULL if no objfile holds the JIT |
| 249 | symbols. */ |
| 250 | |
| 251 | struct objfile *objfile = nullptr; |
| 252 | |
| 253 | /* If this program space has __jit_debug_register_code, this is the |
| 254 | cached address from the minimal symbol. This is used to detect |
| 255 | relocations requiring the breakpoint to be re-created. */ |
| 256 | |
| 257 | CORE_ADDR cached_code_address = 0; |
| 258 | |
| 259 | /* This is the JIT event breakpoint, or NULL if it has not been |
| 260 | set. */ |
| 261 | |
| 262 | struct breakpoint *jit_breakpoint = nullptr; |
| 263 | }; |
| 264 | |
| 265 | static program_space_key<jit_program_space_data> jit_program_space_key; |
| 266 | |
| 267 | /* Per-objfile structure recording the addresses in the program space. |
| 268 | This object serves two purposes: for ordinary objfiles, it may |
| 269 | cache some symbols related to the JIT interface; and for |
| 270 | JIT-created objfiles, it holds some information about the |
| 271 | jit_code_entry. */ |
| 272 | |
| 273 | struct jit_objfile_data |
| 274 | { |
| 275 | /* Symbol for __jit_debug_register_code. */ |
| 276 | struct minimal_symbol *register_code; |
| 277 | |
| 278 | /* Symbol for __jit_debug_descriptor. */ |
| 279 | struct minimal_symbol *descriptor; |
| 280 | |
| 281 | /* Address of struct jit_code_entry in this objfile. This is only |
| 282 | non-zero for objfiles that represent code created by the JIT. */ |
| 283 | CORE_ADDR addr; |
| 284 | }; |
| 285 | |
| 286 | /* Fetch the jit_objfile_data associated with OBJF. If no data exists |
| 287 | yet, make a new structure and attach it. */ |
| 288 | |
| 289 | static struct jit_objfile_data * |
| 290 | get_jit_objfile_data (struct objfile *objf) |
| 291 | { |
| 292 | struct jit_objfile_data *objf_data; |
| 293 | |
| 294 | objf_data = (struct jit_objfile_data *) objfile_data (objf, jit_objfile_data); |
| 295 | if (objf_data == NULL) |
| 296 | { |
| 297 | objf_data = XCNEW (struct jit_objfile_data); |
| 298 | set_objfile_data (objf, jit_objfile_data, objf_data); |
| 299 | } |
| 300 | |
| 301 | return objf_data; |
| 302 | } |
| 303 | |
| 304 | /* Remember OBJFILE has been created for struct jit_code_entry located |
| 305 | at inferior address ENTRY. */ |
| 306 | |
| 307 | static void |
| 308 | add_objfile_entry (struct objfile *objfile, CORE_ADDR entry) |
| 309 | { |
| 310 | struct jit_objfile_data *objf_data; |
| 311 | |
| 312 | objf_data = get_jit_objfile_data (objfile); |
| 313 | objf_data->addr = entry; |
| 314 | } |
| 315 | |
| 316 | /* Return jit_program_space_data for current program space. Allocate |
| 317 | if not already present. */ |
| 318 | |
| 319 | static struct jit_program_space_data * |
| 320 | get_jit_program_space_data () |
| 321 | { |
| 322 | struct jit_program_space_data *ps_data; |
| 323 | |
| 324 | ps_data = jit_program_space_key.get (current_program_space); |
| 325 | if (ps_data == NULL) |
| 326 | ps_data = jit_program_space_key.emplace (current_program_space); |
| 327 | return ps_data; |
| 328 | } |
| 329 | |
| 330 | /* Helper function for reading the global JIT descriptor from remote |
| 331 | memory. Returns 1 if all went well, 0 otherwise. */ |
| 332 | |
| 333 | static int |
| 334 | jit_read_descriptor (struct gdbarch *gdbarch, |
| 335 | struct jit_descriptor *descriptor, |
| 336 | struct jit_program_space_data *ps_data) |
| 337 | { |
| 338 | int err; |
| 339 | struct type *ptr_type; |
| 340 | int ptr_size; |
| 341 | int desc_size; |
| 342 | gdb_byte *desc_buf; |
| 343 | enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); |
| 344 | struct jit_objfile_data *objf_data; |
| 345 | |
| 346 | if (ps_data->objfile == NULL) |
| 347 | return 0; |
| 348 | objf_data = get_jit_objfile_data (ps_data->objfile); |
| 349 | if (objf_data->descriptor == NULL) |
| 350 | return 0; |
| 351 | |
| 352 | if (jit_debug) |
| 353 | fprintf_unfiltered (gdb_stdlog, |
| 354 | "jit_read_descriptor, descriptor_addr = %s\n", |
| 355 | paddress (gdbarch, MSYMBOL_VALUE_ADDRESS (ps_data->objfile, |
| 356 | objf_data->descriptor))); |
| 357 | |
| 358 | /* Figure out how big the descriptor is on the remote and how to read it. */ |
| 359 | ptr_type = builtin_type (gdbarch)->builtin_data_ptr; |
| 360 | ptr_size = TYPE_LENGTH (ptr_type); |
| 361 | desc_size = 8 + 2 * ptr_size; /* Two 32-bit ints and two pointers. */ |
| 362 | desc_buf = (gdb_byte *) alloca (desc_size); |
| 363 | |
| 364 | /* Read the descriptor. */ |
| 365 | err = target_read_memory (MSYMBOL_VALUE_ADDRESS (ps_data->objfile, |
| 366 | objf_data->descriptor), |
| 367 | desc_buf, desc_size); |
| 368 | if (err) |
| 369 | { |
| 370 | printf_unfiltered (_("Unable to read JIT descriptor from " |
| 371 | "remote memory\n")); |
| 372 | return 0; |
| 373 | } |
| 374 | |
| 375 | /* Fix the endianness to match the host. */ |
| 376 | descriptor->version = extract_unsigned_integer (&desc_buf[0], 4, byte_order); |
| 377 | descriptor->action_flag = |
| 378 | extract_unsigned_integer (&desc_buf[4], 4, byte_order); |
| 379 | descriptor->relevant_entry = extract_typed_address (&desc_buf[8], ptr_type); |
| 380 | descriptor->first_entry = |
| 381 | extract_typed_address (&desc_buf[8 + ptr_size], ptr_type); |
| 382 | |
| 383 | return 1; |
| 384 | } |
| 385 | |
| 386 | /* Helper function for reading a JITed code entry from remote memory. */ |
| 387 | |
| 388 | static void |
| 389 | jit_read_code_entry (struct gdbarch *gdbarch, |
| 390 | CORE_ADDR code_addr, struct jit_code_entry *code_entry) |
| 391 | { |
| 392 | int err, off; |
| 393 | struct type *ptr_type; |
| 394 | int ptr_size; |
| 395 | int entry_size; |
| 396 | int align_bytes; |
| 397 | gdb_byte *entry_buf; |
| 398 | enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); |
| 399 | |
| 400 | /* Figure out how big the entry is on the remote and how to read it. */ |
| 401 | ptr_type = builtin_type (gdbarch)->builtin_data_ptr; |
| 402 | ptr_size = TYPE_LENGTH (ptr_type); |
| 403 | |
| 404 | /* Figure out where the uint64_t value will be. */ |
| 405 | align_bytes = type_align (builtin_type (gdbarch)->builtin_uint64); |
| 406 | off = 3 * ptr_size; |
| 407 | off = (off + (align_bytes - 1)) & ~(align_bytes - 1); |
| 408 | |
| 409 | entry_size = off + 8; /* Three pointers and one 64-bit int. */ |
| 410 | entry_buf = (gdb_byte *) alloca (entry_size); |
| 411 | |
| 412 | /* Read the entry. */ |
| 413 | err = target_read_memory (code_addr, entry_buf, entry_size); |
| 414 | if (err) |
| 415 | error (_("Unable to read JIT code entry from remote memory!")); |
| 416 | |
| 417 | /* Fix the endianness to match the host. */ |
| 418 | ptr_type = builtin_type (gdbarch)->builtin_data_ptr; |
| 419 | code_entry->next_entry = extract_typed_address (&entry_buf[0], ptr_type); |
| 420 | code_entry->prev_entry = |
| 421 | extract_typed_address (&entry_buf[ptr_size], ptr_type); |
| 422 | code_entry->symfile_addr = |
| 423 | extract_typed_address (&entry_buf[2 * ptr_size], ptr_type); |
| 424 | code_entry->symfile_size = |
| 425 | extract_unsigned_integer (&entry_buf[off], 8, byte_order); |
| 426 | } |
| 427 | |
| 428 | /* Proxy object for building a block. */ |
| 429 | |
| 430 | struct gdb_block |
| 431 | { |
| 432 | gdb_block (gdb_block *parent, CORE_ADDR begin, CORE_ADDR end, |
| 433 | const char *name) |
| 434 | : parent (parent), |
| 435 | begin (begin), |
| 436 | end (end), |
| 437 | name (name != nullptr ? xstrdup (name) : nullptr) |
| 438 | {} |
| 439 | |
| 440 | /* The parent of this block. */ |
| 441 | struct gdb_block *parent; |
| 442 | |
| 443 | /* Points to the "real" block that is being built out of this |
| 444 | instance. This block will be added to a blockvector, which will |
| 445 | then be added to a symtab. */ |
| 446 | struct block *real_block = nullptr; |
| 447 | |
| 448 | /* The first and last code address corresponding to this block. */ |
| 449 | CORE_ADDR begin, end; |
| 450 | |
| 451 | /* The name of this block (if any). If this is non-NULL, the |
| 452 | FUNCTION symbol symbol is set to this value. */ |
| 453 | gdb::unique_xmalloc_ptr<char> name; |
| 454 | }; |
| 455 | |
| 456 | /* Proxy object for building a symtab. */ |
| 457 | |
| 458 | struct gdb_symtab |
| 459 | { |
| 460 | explicit gdb_symtab (const char *file_name) |
| 461 | : file_name (file_name != nullptr ? file_name : "") |
| 462 | {} |
| 463 | |
| 464 | /* The list of blocks in this symtab. These will eventually be |
| 465 | converted to real blocks. |
| 466 | |
| 467 | This is specifically a linked list, instead of, for example, a vector, |
| 468 | because the pointers are returned to the user's debug info reader. So |
| 469 | it's important that the objects don't change location during their |
| 470 | lifetime (which would happen with a vector of objects getting resized). */ |
| 471 | std::forward_list<gdb_block> blocks; |
| 472 | |
| 473 | /* The number of blocks inserted. */ |
| 474 | int nblocks = 0; |
| 475 | |
| 476 | /* A mapping between line numbers to PC. */ |
| 477 | gdb::unique_xmalloc_ptr<struct linetable> linetable; |
| 478 | |
| 479 | /* The source file for this symtab. */ |
| 480 | std::string file_name; |
| 481 | }; |
| 482 | |
| 483 | /* Proxy object for building an object. */ |
| 484 | |
| 485 | struct gdb_object |
| 486 | { |
| 487 | /* Symtabs of this object. |
| 488 | |
| 489 | This is specifically a linked list, instead of, for example, a vector, |
| 490 | because the pointers are returned to the user's debug info reader. So |
| 491 | it's important that the objects don't change location during their |
| 492 | lifetime (which would happen with a vector of objects getting resized). */ |
| 493 | std::forward_list<gdb_symtab> symtabs; |
| 494 | }; |
| 495 | |
| 496 | /* The type of the `private' data passed around by the callback |
| 497 | functions. */ |
| 498 | |
| 499 | typedef CORE_ADDR jit_dbg_reader_data; |
| 500 | |
| 501 | /* The reader calls into this function to read data off the targets |
| 502 | address space. */ |
| 503 | |
| 504 | static enum gdb_status |
| 505 | jit_target_read_impl (GDB_CORE_ADDR target_mem, void *gdb_buf, int len) |
| 506 | { |
| 507 | int result = target_read_memory ((CORE_ADDR) target_mem, |
| 508 | (gdb_byte *) gdb_buf, len); |
| 509 | if (result == 0) |
| 510 | return GDB_SUCCESS; |
| 511 | else |
| 512 | return GDB_FAIL; |
| 513 | } |
| 514 | |
| 515 | /* The reader calls into this function to create a new gdb_object |
| 516 | which it can then pass around to the other callbacks. Right now, |
| 517 | all that is required is allocating the memory. */ |
| 518 | |
| 519 | static struct gdb_object * |
| 520 | jit_object_open_impl (struct gdb_symbol_callbacks *cb) |
| 521 | { |
| 522 | /* CB is not required right now, but sometime in the future we might |
| 523 | need a handle to it, and we'd like to do that without breaking |
| 524 | the ABI. */ |
| 525 | return new gdb_object; |
| 526 | } |
| 527 | |
| 528 | /* Readers call into this function to open a new gdb_symtab, which, |
| 529 | again, is passed around to other callbacks. */ |
| 530 | |
| 531 | static struct gdb_symtab * |
| 532 | jit_symtab_open_impl (struct gdb_symbol_callbacks *cb, |
| 533 | struct gdb_object *object, |
| 534 | const char *file_name) |
| 535 | { |
| 536 | /* CB stays unused. See comment in jit_object_open_impl. */ |
| 537 | |
| 538 | object->symtabs.emplace_front (file_name); |
| 539 | return &object->symtabs.front (); |
| 540 | } |
| 541 | |
| 542 | /* Called by readers to open a new gdb_block. This function also |
| 543 | inserts the new gdb_block in the correct place in the corresponding |
| 544 | gdb_symtab. */ |
| 545 | |
| 546 | static struct gdb_block * |
| 547 | jit_block_open_impl (struct gdb_symbol_callbacks *cb, |
| 548 | struct gdb_symtab *symtab, struct gdb_block *parent, |
| 549 | GDB_CORE_ADDR begin, GDB_CORE_ADDR end, const char *name) |
| 550 | { |
| 551 | /* Place the block at the beginning of the list, it will be sorted when the |
| 552 | symtab is finalized. */ |
| 553 | symtab->blocks.emplace_front (parent, begin, end, name); |
| 554 | symtab->nblocks++; |
| 555 | |
| 556 | return &symtab->blocks.front (); |
| 557 | } |
| 558 | |
| 559 | /* Readers call this to add a line mapping (from PC to line number) to |
| 560 | a gdb_symtab. */ |
| 561 | |
| 562 | static void |
| 563 | jit_symtab_line_mapping_add_impl (struct gdb_symbol_callbacks *cb, |
| 564 | struct gdb_symtab *stab, int nlines, |
| 565 | struct gdb_line_mapping *map) |
| 566 | { |
| 567 | int i; |
| 568 | int alloc_len; |
| 569 | |
| 570 | if (nlines < 1) |
| 571 | return; |
| 572 | |
| 573 | alloc_len = sizeof (struct linetable) |
| 574 | + (nlines - 1) * sizeof (struct linetable_entry); |
| 575 | stab->linetable.reset (XNEWVAR (struct linetable, alloc_len)); |
| 576 | stab->linetable->nitems = nlines; |
| 577 | for (i = 0; i < nlines; i++) |
| 578 | { |
| 579 | stab->linetable->item[i].pc = (CORE_ADDR) map[i].pc; |
| 580 | stab->linetable->item[i].line = map[i].line; |
| 581 | } |
| 582 | } |
| 583 | |
| 584 | /* Called by readers to close a gdb_symtab. Does not need to do |
| 585 | anything as of now. */ |
| 586 | |
| 587 | static void |
| 588 | jit_symtab_close_impl (struct gdb_symbol_callbacks *cb, |
| 589 | struct gdb_symtab *stab) |
| 590 | { |
| 591 | /* Right now nothing needs to be done here. We may need to do some |
| 592 | cleanup here in the future (again, without breaking the plugin |
| 593 | ABI). */ |
| 594 | } |
| 595 | |
| 596 | /* Transform STAB to a proper symtab, and add it it OBJFILE. */ |
| 597 | |
| 598 | static void |
| 599 | finalize_symtab (struct gdb_symtab *stab, struct objfile *objfile) |
| 600 | { |
| 601 | struct compunit_symtab *cust; |
| 602 | size_t blockvector_size; |
| 603 | CORE_ADDR begin, end; |
| 604 | struct blockvector *bv; |
| 605 | |
| 606 | int actual_nblocks = FIRST_LOCAL_BLOCK + stab->nblocks; |
| 607 | |
| 608 | /* Sort the blocks in the order they should appear in the blockvector. */ |
| 609 | stab->blocks.sort([] (const gdb_block &a, const gdb_block &b) |
| 610 | { |
| 611 | if (a.begin != b.begin) |
| 612 | return a.begin < b.begin; |
| 613 | |
| 614 | return a.end > b.end; |
| 615 | }); |
| 616 | |
| 617 | cust = allocate_compunit_symtab (objfile, stab->file_name.c_str ()); |
| 618 | allocate_symtab (cust, stab->file_name.c_str ()); |
| 619 | add_compunit_symtab_to_objfile (cust); |
| 620 | |
| 621 | /* JIT compilers compile in memory. */ |
| 622 | COMPUNIT_DIRNAME (cust) = NULL; |
| 623 | |
| 624 | /* Copy over the linetable entry if one was provided. */ |
| 625 | if (stab->linetable) |
| 626 | { |
| 627 | size_t size = ((stab->linetable->nitems - 1) |
| 628 | * sizeof (struct linetable_entry) |
| 629 | + sizeof (struct linetable)); |
| 630 | SYMTAB_LINETABLE (COMPUNIT_FILETABS (cust)) |
| 631 | = (struct linetable *) obstack_alloc (&objfile->objfile_obstack, size); |
| 632 | memcpy (SYMTAB_LINETABLE (COMPUNIT_FILETABS (cust)), |
| 633 | stab->linetable.get (), size); |
| 634 | } |
| 635 | |
| 636 | blockvector_size = (sizeof (struct blockvector) |
| 637 | + (actual_nblocks - 1) * sizeof (struct block *)); |
| 638 | bv = (struct blockvector *) obstack_alloc (&objfile->objfile_obstack, |
| 639 | blockvector_size); |
| 640 | COMPUNIT_BLOCKVECTOR (cust) = bv; |
| 641 | |
| 642 | /* At the end of this function, (begin, end) will contain the PC range this |
| 643 | entire blockvector spans. */ |
| 644 | BLOCKVECTOR_MAP (bv) = NULL; |
| 645 | begin = stab->blocks.front ().begin; |
| 646 | end = stab->blocks.front ().end; |
| 647 | BLOCKVECTOR_NBLOCKS (bv) = actual_nblocks; |
| 648 | |
| 649 | /* First run over all the gdb_block objects, creating a real block |
| 650 | object for each. Simultaneously, keep setting the real_block |
| 651 | fields. */ |
| 652 | int block_idx = FIRST_LOCAL_BLOCK; |
| 653 | for (gdb_block &gdb_block_iter : stab->blocks) |
| 654 | { |
| 655 | struct block *new_block = allocate_block (&objfile->objfile_obstack); |
| 656 | struct symbol *block_name = allocate_symbol (objfile); |
| 657 | struct type *block_type = arch_type (get_objfile_arch (objfile), |
| 658 | TYPE_CODE_VOID, |
| 659 | TARGET_CHAR_BIT, |
| 660 | "void"); |
| 661 | |
| 662 | BLOCK_MULTIDICT (new_block) |
| 663 | = mdict_create_linear (&objfile->objfile_obstack, NULL); |
| 664 | /* The address range. */ |
| 665 | BLOCK_START (new_block) = (CORE_ADDR) gdb_block_iter.begin; |
| 666 | BLOCK_END (new_block) = (CORE_ADDR) gdb_block_iter.end; |
| 667 | |
| 668 | /* The name. */ |
| 669 | SYMBOL_DOMAIN (block_name) = VAR_DOMAIN; |
| 670 | SYMBOL_ACLASS_INDEX (block_name) = LOC_BLOCK; |
| 671 | symbol_set_symtab (block_name, COMPUNIT_FILETABS (cust)); |
| 672 | SYMBOL_TYPE (block_name) = lookup_function_type (block_type); |
| 673 | SYMBOL_BLOCK_VALUE (block_name) = new_block; |
| 674 | |
| 675 | block_name->m_name = obstack_strdup (&objfile->objfile_obstack, |
| 676 | gdb_block_iter.name.get ()); |
| 677 | |
| 678 | BLOCK_FUNCTION (new_block) = block_name; |
| 679 | |
| 680 | BLOCKVECTOR_BLOCK (bv, block_idx) = new_block; |
| 681 | if (begin > BLOCK_START (new_block)) |
| 682 | begin = BLOCK_START (new_block); |
| 683 | if (end < BLOCK_END (new_block)) |
| 684 | end = BLOCK_END (new_block); |
| 685 | |
| 686 | gdb_block_iter.real_block = new_block; |
| 687 | |
| 688 | block_idx++; |
| 689 | } |
| 690 | |
| 691 | /* Now add the special blocks. */ |
| 692 | struct block *block_iter = NULL; |
| 693 | for (enum block_enum i : { GLOBAL_BLOCK, STATIC_BLOCK }) |
| 694 | { |
| 695 | struct block *new_block; |
| 696 | |
| 697 | new_block = (i == GLOBAL_BLOCK |
| 698 | ? allocate_global_block (&objfile->objfile_obstack) |
| 699 | : allocate_block (&objfile->objfile_obstack)); |
| 700 | BLOCK_MULTIDICT (new_block) |
| 701 | = mdict_create_linear (&objfile->objfile_obstack, NULL); |
| 702 | BLOCK_SUPERBLOCK (new_block) = block_iter; |
| 703 | block_iter = new_block; |
| 704 | |
| 705 | BLOCK_START (new_block) = (CORE_ADDR) begin; |
| 706 | BLOCK_END (new_block) = (CORE_ADDR) end; |
| 707 | |
| 708 | BLOCKVECTOR_BLOCK (bv, i) = new_block; |
| 709 | |
| 710 | if (i == GLOBAL_BLOCK) |
| 711 | set_block_compunit_symtab (new_block, cust); |
| 712 | } |
| 713 | |
| 714 | /* Fill up the superblock fields for the real blocks, using the |
| 715 | real_block fields populated earlier. */ |
| 716 | for (gdb_block &gdb_block_iter : stab->blocks) |
| 717 | { |
| 718 | if (gdb_block_iter.parent != NULL) |
| 719 | { |
| 720 | /* If the plugin specifically mentioned a parent block, we |
| 721 | use that. */ |
| 722 | BLOCK_SUPERBLOCK (gdb_block_iter.real_block) = |
| 723 | gdb_block_iter.parent->real_block; |
| 724 | } |
| 725 | else |
| 726 | { |
| 727 | /* And if not, we set a default parent block. */ |
| 728 | BLOCK_SUPERBLOCK (gdb_block_iter.real_block) = |
| 729 | BLOCKVECTOR_BLOCK (bv, STATIC_BLOCK); |
| 730 | } |
| 731 | } |
| 732 | } |
| 733 | |
| 734 | /* Called when closing a gdb_objfile. Converts OBJ to a proper |
| 735 | objfile. */ |
| 736 | |
| 737 | static void |
| 738 | jit_object_close_impl (struct gdb_symbol_callbacks *cb, |
| 739 | struct gdb_object *obj) |
| 740 | { |
| 741 | struct objfile *objfile; |
| 742 | jit_dbg_reader_data *priv_data; |
| 743 | |
| 744 | priv_data = (jit_dbg_reader_data *) cb->priv_data; |
| 745 | |
| 746 | objfile = objfile::make (nullptr, "<< JIT compiled code >>", |
| 747 | OBJF_NOT_FILENAME); |
| 748 | objfile->per_bfd->gdbarch = target_gdbarch (); |
| 749 | |
| 750 | for (gdb_symtab &symtab : obj->symtabs) |
| 751 | finalize_symtab (&symtab, objfile); |
| 752 | |
| 753 | add_objfile_entry (objfile, *priv_data); |
| 754 | |
| 755 | delete obj; |
| 756 | } |
| 757 | |
| 758 | /* Try to read CODE_ENTRY using the loaded jit reader (if any). |
| 759 | ENTRY_ADDR is the address of the struct jit_code_entry in the |
| 760 | inferior address space. */ |
| 761 | |
| 762 | static int |
| 763 | jit_reader_try_read_symtab (struct jit_code_entry *code_entry, |
| 764 | CORE_ADDR entry_addr) |
| 765 | { |
| 766 | int status; |
| 767 | jit_dbg_reader_data priv_data; |
| 768 | struct gdb_reader_funcs *funcs; |
| 769 | struct gdb_symbol_callbacks callbacks = |
| 770 | { |
| 771 | jit_object_open_impl, |
| 772 | jit_symtab_open_impl, |
| 773 | jit_block_open_impl, |
| 774 | jit_symtab_close_impl, |
| 775 | jit_object_close_impl, |
| 776 | |
| 777 | jit_symtab_line_mapping_add_impl, |
| 778 | jit_target_read_impl, |
| 779 | |
| 780 | &priv_data |
| 781 | }; |
| 782 | |
| 783 | priv_data = entry_addr; |
| 784 | |
| 785 | if (!loaded_jit_reader) |
| 786 | return 0; |
| 787 | |
| 788 | gdb::byte_vector gdb_mem (code_entry->symfile_size); |
| 789 | |
| 790 | status = 1; |
| 791 | try |
| 792 | { |
| 793 | if (target_read_memory (code_entry->symfile_addr, gdb_mem.data (), |
| 794 | code_entry->symfile_size)) |
| 795 | status = 0; |
| 796 | } |
| 797 | catch (const gdb_exception &e) |
| 798 | { |
| 799 | status = 0; |
| 800 | } |
| 801 | |
| 802 | if (status) |
| 803 | { |
| 804 | funcs = loaded_jit_reader->functions; |
| 805 | if (funcs->read (funcs, &callbacks, gdb_mem.data (), |
| 806 | code_entry->symfile_size) |
| 807 | != GDB_SUCCESS) |
| 808 | status = 0; |
| 809 | } |
| 810 | |
| 811 | if (jit_debug && status == 0) |
| 812 | fprintf_unfiltered (gdb_stdlog, |
| 813 | "Could not read symtab using the loaded JIT reader.\n"); |
| 814 | return status; |
| 815 | } |
| 816 | |
| 817 | /* Try to read CODE_ENTRY using BFD. ENTRY_ADDR is the address of the |
| 818 | struct jit_code_entry in the inferior address space. */ |
| 819 | |
| 820 | static void |
| 821 | jit_bfd_try_read_symtab (struct jit_code_entry *code_entry, |
| 822 | CORE_ADDR entry_addr, |
| 823 | struct gdbarch *gdbarch) |
| 824 | { |
| 825 | struct bfd_section *sec; |
| 826 | struct objfile *objfile; |
| 827 | const struct bfd_arch_info *b; |
| 828 | |
| 829 | if (jit_debug) |
| 830 | fprintf_unfiltered (gdb_stdlog, |
| 831 | "jit_bfd_try_read_symtab, symfile_addr = %s, " |
| 832 | "symfile_size = %s\n", |
| 833 | paddress (gdbarch, code_entry->symfile_addr), |
| 834 | pulongest (code_entry->symfile_size)); |
| 835 | |
| 836 | gdb_bfd_ref_ptr nbfd (bfd_open_from_target_memory (code_entry->symfile_addr, |
| 837 | code_entry->symfile_size, |
| 838 | gnutarget)); |
| 839 | if (nbfd == NULL) |
| 840 | { |
| 841 | puts_unfiltered (_("Error opening JITed symbol file, ignoring it.\n")); |
| 842 | return; |
| 843 | } |
| 844 | |
| 845 | /* Check the format. NOTE: This initializes important data that GDB uses! |
| 846 | We would segfault later without this line. */ |
| 847 | if (!bfd_check_format (nbfd.get (), bfd_object)) |
| 848 | { |
| 849 | printf_unfiltered (_("\ |
| 850 | JITed symbol file is not an object file, ignoring it.\n")); |
| 851 | return; |
| 852 | } |
| 853 | |
| 854 | /* Check bfd arch. */ |
| 855 | b = gdbarch_bfd_arch_info (gdbarch); |
| 856 | if (b->compatible (b, bfd_get_arch_info (nbfd.get ())) != b) |
| 857 | warning (_("JITed object file architecture %s is not compatible " |
| 858 | "with target architecture %s."), |
| 859 | bfd_get_arch_info (nbfd.get ())->printable_name, |
| 860 | b->printable_name); |
| 861 | |
| 862 | /* Read the section address information out of the symbol file. Since the |
| 863 | file is generated by the JIT at runtime, it should all of the absolute |
| 864 | addresses that we care about. */ |
| 865 | section_addr_info sai; |
| 866 | for (sec = nbfd->sections; sec != NULL; sec = sec->next) |
| 867 | if ((bfd_section_flags (sec) & (SEC_ALLOC|SEC_LOAD)) != 0) |
| 868 | { |
| 869 | /* We assume that these virtual addresses are absolute, and do not |
| 870 | treat them as offsets. */ |
| 871 | sai.emplace_back (bfd_section_vma (sec), |
| 872 | bfd_section_name (sec), |
| 873 | sec->index); |
| 874 | } |
| 875 | |
| 876 | /* This call does not take ownership of SAI. */ |
| 877 | objfile = symbol_file_add_from_bfd (nbfd.get (), |
| 878 | bfd_get_filename (nbfd.get ()), 0, |
| 879 | &sai, |
| 880 | OBJF_SHARED | OBJF_NOT_FILENAME, NULL); |
| 881 | |
| 882 | add_objfile_entry (objfile, entry_addr); |
| 883 | } |
| 884 | |
| 885 | /* This function registers code associated with a JIT code entry. It uses the |
| 886 | pointer and size pair in the entry to read the symbol file from the remote |
| 887 | and then calls symbol_file_add_from_local_memory to add it as though it were |
| 888 | a symbol file added by the user. */ |
| 889 | |
| 890 | static void |
| 891 | jit_register_code (struct gdbarch *gdbarch, |
| 892 | CORE_ADDR entry_addr, struct jit_code_entry *code_entry) |
| 893 | { |
| 894 | int success; |
| 895 | |
| 896 | if (jit_debug) |
| 897 | fprintf_unfiltered (gdb_stdlog, |
| 898 | "jit_register_code, symfile_addr = %s, " |
| 899 | "symfile_size = %s\n", |
| 900 | paddress (gdbarch, code_entry->symfile_addr), |
| 901 | pulongest (code_entry->symfile_size)); |
| 902 | |
| 903 | success = jit_reader_try_read_symtab (code_entry, entry_addr); |
| 904 | |
| 905 | if (!success) |
| 906 | jit_bfd_try_read_symtab (code_entry, entry_addr, gdbarch); |
| 907 | } |
| 908 | |
| 909 | /* Look up the objfile with this code entry address. */ |
| 910 | |
| 911 | static struct objfile * |
| 912 | jit_find_objf_with_entry_addr (CORE_ADDR entry_addr) |
| 913 | { |
| 914 | for (objfile *objf : current_program_space->objfiles ()) |
| 915 | { |
| 916 | struct jit_objfile_data *objf_data; |
| 917 | |
| 918 | objf_data |
| 919 | = (struct jit_objfile_data *) objfile_data (objf, jit_objfile_data); |
| 920 | if (objf_data != NULL && objf_data->addr == entry_addr) |
| 921 | return objf; |
| 922 | } |
| 923 | return NULL; |
| 924 | } |
| 925 | |
| 926 | /* This is called when a breakpoint is deleted. It updates the |
| 927 | inferior's cache, if needed. */ |
| 928 | |
| 929 | static void |
| 930 | jit_breakpoint_deleted (struct breakpoint *b) |
| 931 | { |
| 932 | struct bp_location *iter; |
| 933 | |
| 934 | if (b->type != bp_jit_event) |
| 935 | return; |
| 936 | |
| 937 | for (iter = b->loc; iter != NULL; iter = iter->next) |
| 938 | { |
| 939 | struct jit_program_space_data *ps_data; |
| 940 | |
| 941 | ps_data = jit_program_space_key.get (iter->pspace); |
| 942 | if (ps_data != NULL && ps_data->jit_breakpoint == iter->owner) |
| 943 | { |
| 944 | ps_data->cached_code_address = 0; |
| 945 | ps_data->jit_breakpoint = NULL; |
| 946 | } |
| 947 | } |
| 948 | } |
| 949 | |
| 950 | /* (Re-)Initialize the jit breakpoint if necessary. |
| 951 | Return 0 if the jit breakpoint has been successfully initialized. */ |
| 952 | |
| 953 | static int |
| 954 | jit_breakpoint_re_set_internal (struct gdbarch *gdbarch, |
| 955 | struct jit_program_space_data *ps_data) |
| 956 | { |
| 957 | struct bound_minimal_symbol reg_symbol; |
| 958 | struct bound_minimal_symbol desc_symbol; |
| 959 | struct jit_objfile_data *objf_data; |
| 960 | CORE_ADDR addr; |
| 961 | |
| 962 | if (ps_data->objfile == NULL) |
| 963 | { |
| 964 | /* Lookup the registration symbol. If it is missing, then we |
| 965 | assume we are not attached to a JIT. */ |
| 966 | reg_symbol = lookup_bound_minimal_symbol (jit_break_name); |
| 967 | if (reg_symbol.minsym == NULL |
| 968 | || BMSYMBOL_VALUE_ADDRESS (reg_symbol) == 0) |
| 969 | return 1; |
| 970 | |
| 971 | desc_symbol = lookup_minimal_symbol (jit_descriptor_name, NULL, |
| 972 | reg_symbol.objfile); |
| 973 | if (desc_symbol.minsym == NULL |
| 974 | || BMSYMBOL_VALUE_ADDRESS (desc_symbol) == 0) |
| 975 | return 1; |
| 976 | |
| 977 | objf_data = get_jit_objfile_data (reg_symbol.objfile); |
| 978 | objf_data->register_code = reg_symbol.minsym; |
| 979 | objf_data->descriptor = desc_symbol.minsym; |
| 980 | |
| 981 | ps_data->objfile = reg_symbol.objfile; |
| 982 | } |
| 983 | else |
| 984 | objf_data = get_jit_objfile_data (ps_data->objfile); |
| 985 | |
| 986 | addr = MSYMBOL_VALUE_ADDRESS (ps_data->objfile, objf_data->register_code); |
| 987 | |
| 988 | if (jit_debug) |
| 989 | fprintf_unfiltered (gdb_stdlog, |
| 990 | "jit_breakpoint_re_set_internal, " |
| 991 | "breakpoint_addr = %s\n", |
| 992 | paddress (gdbarch, addr)); |
| 993 | |
| 994 | if (ps_data->cached_code_address == addr) |
| 995 | return 0; |
| 996 | |
| 997 | /* Delete the old breakpoint. */ |
| 998 | if (ps_data->jit_breakpoint != NULL) |
| 999 | delete_breakpoint (ps_data->jit_breakpoint); |
| 1000 | |
| 1001 | /* Put a breakpoint in the registration symbol. */ |
| 1002 | ps_data->cached_code_address = addr; |
| 1003 | ps_data->jit_breakpoint = create_jit_event_breakpoint (gdbarch, addr); |
| 1004 | |
| 1005 | return 0; |
| 1006 | } |
| 1007 | |
| 1008 | /* The private data passed around in the frame unwind callback |
| 1009 | functions. */ |
| 1010 | |
| 1011 | struct jit_unwind_private |
| 1012 | { |
| 1013 | /* Cached register values. See jit_frame_sniffer to see how this |
| 1014 | works. */ |
| 1015 | detached_regcache *regcache; |
| 1016 | |
| 1017 | /* The frame being unwound. */ |
| 1018 | struct frame_info *this_frame; |
| 1019 | }; |
| 1020 | |
| 1021 | /* Sets the value of a particular register in this frame. */ |
| 1022 | |
| 1023 | static void |
| 1024 | jit_unwind_reg_set_impl (struct gdb_unwind_callbacks *cb, int dwarf_regnum, |
| 1025 | struct gdb_reg_value *value) |
| 1026 | { |
| 1027 | struct jit_unwind_private *priv; |
| 1028 | int gdb_reg; |
| 1029 | |
| 1030 | priv = (struct jit_unwind_private *) cb->priv_data; |
| 1031 | |
| 1032 | gdb_reg = gdbarch_dwarf2_reg_to_regnum (get_frame_arch (priv->this_frame), |
| 1033 | dwarf_regnum); |
| 1034 | if (gdb_reg == -1) |
| 1035 | { |
| 1036 | if (jit_debug) |
| 1037 | fprintf_unfiltered (gdb_stdlog, |
| 1038 | _("Could not recognize DWARF regnum %d"), |
| 1039 | dwarf_regnum); |
| 1040 | value->free (value); |
| 1041 | return; |
| 1042 | } |
| 1043 | |
| 1044 | priv->regcache->raw_supply (gdb_reg, value->value); |
| 1045 | value->free (value); |
| 1046 | } |
| 1047 | |
| 1048 | static void |
| 1049 | reg_value_free_impl (struct gdb_reg_value *value) |
| 1050 | { |
| 1051 | xfree (value); |
| 1052 | } |
| 1053 | |
| 1054 | /* Get the value of register REGNUM in the previous frame. */ |
| 1055 | |
| 1056 | static struct gdb_reg_value * |
| 1057 | jit_unwind_reg_get_impl (struct gdb_unwind_callbacks *cb, int regnum) |
| 1058 | { |
| 1059 | struct jit_unwind_private *priv; |
| 1060 | struct gdb_reg_value *value; |
| 1061 | int gdb_reg, size; |
| 1062 | struct gdbarch *frame_arch; |
| 1063 | |
| 1064 | priv = (struct jit_unwind_private *) cb->priv_data; |
| 1065 | frame_arch = get_frame_arch (priv->this_frame); |
| 1066 | |
| 1067 | gdb_reg = gdbarch_dwarf2_reg_to_regnum (frame_arch, regnum); |
| 1068 | size = register_size (frame_arch, gdb_reg); |
| 1069 | value = ((struct gdb_reg_value *) |
| 1070 | xmalloc (sizeof (struct gdb_reg_value) + size - 1)); |
| 1071 | value->defined = deprecated_frame_register_read (priv->this_frame, gdb_reg, |
| 1072 | value->value); |
| 1073 | value->size = size; |
| 1074 | value->free = reg_value_free_impl; |
| 1075 | return value; |
| 1076 | } |
| 1077 | |
| 1078 | /* gdb_reg_value has a free function, which must be called on each |
| 1079 | saved register value. */ |
| 1080 | |
| 1081 | static void |
| 1082 | jit_dealloc_cache (struct frame_info *this_frame, void *cache) |
| 1083 | { |
| 1084 | struct jit_unwind_private *priv_data = (struct jit_unwind_private *) cache; |
| 1085 | |
| 1086 | gdb_assert (priv_data->regcache != NULL); |
| 1087 | delete priv_data->regcache; |
| 1088 | xfree (priv_data); |
| 1089 | } |
| 1090 | |
| 1091 | /* The frame sniffer for the pseudo unwinder. |
| 1092 | |
| 1093 | While this is nominally a frame sniffer, in the case where the JIT |
| 1094 | reader actually recognizes the frame, it does a lot more work -- it |
| 1095 | unwinds the frame and saves the corresponding register values in |
| 1096 | the cache. jit_frame_prev_register simply returns the saved |
| 1097 | register values. */ |
| 1098 | |
| 1099 | static int |
| 1100 | jit_frame_sniffer (const struct frame_unwind *self, |
| 1101 | struct frame_info *this_frame, void **cache) |
| 1102 | { |
| 1103 | struct jit_unwind_private *priv_data; |
| 1104 | struct gdb_unwind_callbacks callbacks; |
| 1105 | struct gdb_reader_funcs *funcs; |
| 1106 | |
| 1107 | callbacks.reg_get = jit_unwind_reg_get_impl; |
| 1108 | callbacks.reg_set = jit_unwind_reg_set_impl; |
| 1109 | callbacks.target_read = jit_target_read_impl; |
| 1110 | |
| 1111 | if (loaded_jit_reader == NULL) |
| 1112 | return 0; |
| 1113 | |
| 1114 | funcs = loaded_jit_reader->functions; |
| 1115 | |
| 1116 | gdb_assert (!*cache); |
| 1117 | |
| 1118 | *cache = XCNEW (struct jit_unwind_private); |
| 1119 | priv_data = (struct jit_unwind_private *) *cache; |
| 1120 | /* Take a snapshot of current regcache. */ |
| 1121 | priv_data->regcache = new detached_regcache (get_frame_arch (this_frame), |
| 1122 | true); |
| 1123 | priv_data->this_frame = this_frame; |
| 1124 | |
| 1125 | callbacks.priv_data = priv_data; |
| 1126 | |
| 1127 | /* Try to coax the provided unwinder to unwind the stack */ |
| 1128 | if (funcs->unwind (funcs, &callbacks) == GDB_SUCCESS) |
| 1129 | { |
| 1130 | if (jit_debug) |
| 1131 | fprintf_unfiltered (gdb_stdlog, _("Successfully unwound frame using " |
| 1132 | "JIT reader.\n")); |
| 1133 | return 1; |
| 1134 | } |
| 1135 | if (jit_debug) |
| 1136 | fprintf_unfiltered (gdb_stdlog, _("Could not unwind frame using " |
| 1137 | "JIT reader.\n")); |
| 1138 | |
| 1139 | jit_dealloc_cache (this_frame, *cache); |
| 1140 | *cache = NULL; |
| 1141 | |
| 1142 | return 0; |
| 1143 | } |
| 1144 | |
| 1145 | |
| 1146 | /* The frame_id function for the pseudo unwinder. Relays the call to |
| 1147 | the loaded plugin. */ |
| 1148 | |
| 1149 | static void |
| 1150 | jit_frame_this_id (struct frame_info *this_frame, void **cache, |
| 1151 | struct frame_id *this_id) |
| 1152 | { |
| 1153 | struct jit_unwind_private priv; |
| 1154 | struct gdb_frame_id frame_id; |
| 1155 | struct gdb_reader_funcs *funcs; |
| 1156 | struct gdb_unwind_callbacks callbacks; |
| 1157 | |
| 1158 | priv.regcache = NULL; |
| 1159 | priv.this_frame = this_frame; |
| 1160 | |
| 1161 | /* We don't expect the frame_id function to set any registers, so we |
| 1162 | set reg_set to NULL. */ |
| 1163 | callbacks.reg_get = jit_unwind_reg_get_impl; |
| 1164 | callbacks.reg_set = NULL; |
| 1165 | callbacks.target_read = jit_target_read_impl; |
| 1166 | callbacks.priv_data = &priv; |
| 1167 | |
| 1168 | gdb_assert (loaded_jit_reader); |
| 1169 | funcs = loaded_jit_reader->functions; |
| 1170 | |
| 1171 | frame_id = funcs->get_frame_id (funcs, &callbacks); |
| 1172 | *this_id = frame_id_build (frame_id.stack_address, frame_id.code_address); |
| 1173 | } |
| 1174 | |
| 1175 | /* Pseudo unwinder function. Reads the previously fetched value for |
| 1176 | the register from the cache. */ |
| 1177 | |
| 1178 | static struct value * |
| 1179 | jit_frame_prev_register (struct frame_info *this_frame, void **cache, int reg) |
| 1180 | { |
| 1181 | struct jit_unwind_private *priv = (struct jit_unwind_private *) *cache; |
| 1182 | struct gdbarch *gdbarch; |
| 1183 | |
| 1184 | if (priv == NULL) |
| 1185 | return frame_unwind_got_optimized (this_frame, reg); |
| 1186 | |
| 1187 | gdbarch = priv->regcache->arch (); |
| 1188 | gdb_byte *buf = (gdb_byte *) alloca (register_size (gdbarch, reg)); |
| 1189 | enum register_status status = priv->regcache->cooked_read (reg, buf); |
| 1190 | |
| 1191 | if (status == REG_VALID) |
| 1192 | return frame_unwind_got_bytes (this_frame, reg, buf); |
| 1193 | else |
| 1194 | return frame_unwind_got_optimized (this_frame, reg); |
| 1195 | } |
| 1196 | |
| 1197 | /* Relay everything back to the unwinder registered by the JIT debug |
| 1198 | info reader.*/ |
| 1199 | |
| 1200 | static const struct frame_unwind jit_frame_unwind = |
| 1201 | { |
| 1202 | NORMAL_FRAME, |
| 1203 | default_frame_unwind_stop_reason, |
| 1204 | jit_frame_this_id, |
| 1205 | jit_frame_prev_register, |
| 1206 | NULL, |
| 1207 | jit_frame_sniffer, |
| 1208 | jit_dealloc_cache |
| 1209 | }; |
| 1210 | |
| 1211 | |
| 1212 | /* This is the information that is stored at jit_gdbarch_data for each |
| 1213 | architecture. */ |
| 1214 | |
| 1215 | struct jit_gdbarch_data_type |
| 1216 | { |
| 1217 | /* Has the (pseudo) unwinder been prepended? */ |
| 1218 | int unwinder_registered; |
| 1219 | }; |
| 1220 | |
| 1221 | /* Check GDBARCH and prepend the pseudo JIT unwinder if needed. */ |
| 1222 | |
| 1223 | static void |
| 1224 | jit_prepend_unwinder (struct gdbarch *gdbarch) |
| 1225 | { |
| 1226 | struct jit_gdbarch_data_type *data; |
| 1227 | |
| 1228 | data |
| 1229 | = (struct jit_gdbarch_data_type *) gdbarch_data (gdbarch, jit_gdbarch_data); |
| 1230 | if (!data->unwinder_registered) |
| 1231 | { |
| 1232 | frame_unwind_prepend_unwinder (gdbarch, &jit_frame_unwind); |
| 1233 | data->unwinder_registered = 1; |
| 1234 | } |
| 1235 | } |
| 1236 | |
| 1237 | /* Register any already created translations. */ |
| 1238 | |
| 1239 | static void |
| 1240 | jit_inferior_init (struct gdbarch *gdbarch) |
| 1241 | { |
| 1242 | struct jit_descriptor descriptor; |
| 1243 | struct jit_code_entry cur_entry; |
| 1244 | struct jit_program_space_data *ps_data; |
| 1245 | CORE_ADDR cur_entry_addr; |
| 1246 | |
| 1247 | if (jit_debug) |
| 1248 | fprintf_unfiltered (gdb_stdlog, "jit_inferior_init\n"); |
| 1249 | |
| 1250 | jit_prepend_unwinder (gdbarch); |
| 1251 | |
| 1252 | ps_data = get_jit_program_space_data (); |
| 1253 | if (jit_breakpoint_re_set_internal (gdbarch, ps_data) != 0) |
| 1254 | return; |
| 1255 | |
| 1256 | /* Read the descriptor so we can check the version number and load |
| 1257 | any already JITed functions. */ |
| 1258 | if (!jit_read_descriptor (gdbarch, &descriptor, ps_data)) |
| 1259 | return; |
| 1260 | |
| 1261 | /* Check that the version number agrees with that we support. */ |
| 1262 | if (descriptor.version != 1) |
| 1263 | { |
| 1264 | printf_unfiltered (_("Unsupported JIT protocol version %ld " |
| 1265 | "in descriptor (expected 1)\n"), |
| 1266 | (long) descriptor.version); |
| 1267 | return; |
| 1268 | } |
| 1269 | |
| 1270 | /* If we've attached to a running program, we need to check the descriptor |
| 1271 | to register any functions that were already generated. */ |
| 1272 | for (cur_entry_addr = descriptor.first_entry; |
| 1273 | cur_entry_addr != 0; |
| 1274 | cur_entry_addr = cur_entry.next_entry) |
| 1275 | { |
| 1276 | jit_read_code_entry (gdbarch, cur_entry_addr, &cur_entry); |
| 1277 | |
| 1278 | /* This hook may be called many times during setup, so make sure we don't |
| 1279 | add the same symbol file twice. */ |
| 1280 | if (jit_find_objf_with_entry_addr (cur_entry_addr) != NULL) |
| 1281 | continue; |
| 1282 | |
| 1283 | jit_register_code (gdbarch, cur_entry_addr, &cur_entry); |
| 1284 | } |
| 1285 | } |
| 1286 | |
| 1287 | /* inferior_created observer. */ |
| 1288 | |
| 1289 | static void |
| 1290 | jit_inferior_created (struct target_ops *ops, int from_tty) |
| 1291 | { |
| 1292 | jit_inferior_created_hook (); |
| 1293 | } |
| 1294 | |
| 1295 | /* Exported routine to call when an inferior has been created. */ |
| 1296 | |
| 1297 | void |
| 1298 | jit_inferior_created_hook (void) |
| 1299 | { |
| 1300 | jit_inferior_init (target_gdbarch ()); |
| 1301 | } |
| 1302 | |
| 1303 | /* Exported routine to call to re-set the jit breakpoints, |
| 1304 | e.g. when a program is rerun. */ |
| 1305 | |
| 1306 | void |
| 1307 | jit_breakpoint_re_set (void) |
| 1308 | { |
| 1309 | jit_breakpoint_re_set_internal (target_gdbarch (), |
| 1310 | get_jit_program_space_data ()); |
| 1311 | } |
| 1312 | |
| 1313 | /* This function cleans up any code entries left over when the |
| 1314 | inferior exits. We get left over code when the inferior exits |
| 1315 | without unregistering its code, for example when it crashes. */ |
| 1316 | |
| 1317 | static void |
| 1318 | jit_inferior_exit_hook (struct inferior *inf) |
| 1319 | { |
| 1320 | for (objfile *objf : current_program_space->objfiles_safe ()) |
| 1321 | { |
| 1322 | struct jit_objfile_data *objf_data |
| 1323 | = (struct jit_objfile_data *) objfile_data (objf, jit_objfile_data); |
| 1324 | |
| 1325 | if (objf_data != NULL && objf_data->addr != 0) |
| 1326 | objf->unlink (); |
| 1327 | } |
| 1328 | } |
| 1329 | |
| 1330 | void |
| 1331 | jit_event_handler (struct gdbarch *gdbarch) |
| 1332 | { |
| 1333 | struct jit_descriptor descriptor; |
| 1334 | struct jit_code_entry code_entry; |
| 1335 | CORE_ADDR entry_addr; |
| 1336 | struct objfile *objf; |
| 1337 | |
| 1338 | /* Read the descriptor from remote memory. */ |
| 1339 | if (!jit_read_descriptor (gdbarch, &descriptor, |
| 1340 | get_jit_program_space_data ())) |
| 1341 | return; |
| 1342 | entry_addr = descriptor.relevant_entry; |
| 1343 | |
| 1344 | /* Do the corresponding action. */ |
| 1345 | switch (descriptor.action_flag) |
| 1346 | { |
| 1347 | case JIT_NOACTION: |
| 1348 | break; |
| 1349 | case JIT_REGISTER: |
| 1350 | jit_read_code_entry (gdbarch, entry_addr, &code_entry); |
| 1351 | jit_register_code (gdbarch, entry_addr, &code_entry); |
| 1352 | break; |
| 1353 | case JIT_UNREGISTER: |
| 1354 | objf = jit_find_objf_with_entry_addr (entry_addr); |
| 1355 | if (objf == NULL) |
| 1356 | printf_unfiltered (_("Unable to find JITed code " |
| 1357 | "entry at address: %s\n"), |
| 1358 | paddress (gdbarch, entry_addr)); |
| 1359 | else |
| 1360 | objf->unlink (); |
| 1361 | |
| 1362 | break; |
| 1363 | default: |
| 1364 | error (_("Unknown action_flag value in JIT descriptor!")); |
| 1365 | break; |
| 1366 | } |
| 1367 | } |
| 1368 | |
| 1369 | /* Called to free the data allocated to the jit_program_space_data slot. */ |
| 1370 | |
| 1371 | static void |
| 1372 | free_objfile_data (struct objfile *objfile, void *data) |
| 1373 | { |
| 1374 | struct jit_objfile_data *objf_data = (struct jit_objfile_data *) data; |
| 1375 | |
| 1376 | if (objf_data->register_code != NULL) |
| 1377 | { |
| 1378 | struct jit_program_space_data *ps_data; |
| 1379 | |
| 1380 | ps_data = jit_program_space_key.get (objfile->pspace); |
| 1381 | if (ps_data != NULL && ps_data->objfile == objfile) |
| 1382 | { |
| 1383 | ps_data->objfile = NULL; |
| 1384 | if (ps_data->jit_breakpoint != NULL) |
| 1385 | delete_breakpoint (ps_data->jit_breakpoint); |
| 1386 | ps_data->cached_code_address = 0; |
| 1387 | } |
| 1388 | } |
| 1389 | |
| 1390 | xfree (data); |
| 1391 | } |
| 1392 | |
| 1393 | /* Initialize the jit_gdbarch_data slot with an instance of struct |
| 1394 | jit_gdbarch_data_type */ |
| 1395 | |
| 1396 | static void * |
| 1397 | jit_gdbarch_data_init (struct obstack *obstack) |
| 1398 | { |
| 1399 | struct jit_gdbarch_data_type *data = |
| 1400 | XOBNEW (obstack, struct jit_gdbarch_data_type); |
| 1401 | |
| 1402 | data->unwinder_registered = 0; |
| 1403 | |
| 1404 | return data; |
| 1405 | } |
| 1406 | |
| 1407 | void |
| 1408 | _initialize_jit (void) |
| 1409 | { |
| 1410 | jit_reader_dir = relocate_gdb_directory (JIT_READER_DIR, |
| 1411 | JIT_READER_DIR_RELOCATABLE); |
| 1412 | add_setshow_zuinteger_cmd ("jit", class_maintenance, &jit_debug, |
| 1413 | _("Set JIT debugging."), |
| 1414 | _("Show JIT debugging."), |
| 1415 | _("When non-zero, JIT debugging is enabled."), |
| 1416 | NULL, |
| 1417 | show_jit_debug, |
| 1418 | &setdebuglist, &showdebuglist); |
| 1419 | |
| 1420 | gdb::observers::inferior_created.attach (jit_inferior_created); |
| 1421 | gdb::observers::inferior_exit.attach (jit_inferior_exit_hook); |
| 1422 | gdb::observers::breakpoint_deleted.attach (jit_breakpoint_deleted); |
| 1423 | |
| 1424 | jit_objfile_data = |
| 1425 | register_objfile_data_with_cleanup (NULL, free_objfile_data); |
| 1426 | jit_gdbarch_data = gdbarch_data_register_pre_init (jit_gdbarch_data_init); |
| 1427 | if (is_dl_available ()) |
| 1428 | { |
| 1429 | struct cmd_list_element *c; |
| 1430 | |
| 1431 | c = add_com ("jit-reader-load", no_class, jit_reader_load_command, _("\ |
| 1432 | Load FILE as debug info reader and unwinder for JIT compiled code.\n\ |
| 1433 | Usage: jit-reader-load FILE\n\ |
| 1434 | Try to load file FILE as a debug info reader (and unwinder) for\n\ |
| 1435 | JIT compiled code. The file is loaded from " JIT_READER_DIR ",\n\ |
| 1436 | relocated relative to the GDB executable if required.")); |
| 1437 | set_cmd_completer (c, filename_completer); |
| 1438 | |
| 1439 | c = add_com ("jit-reader-unload", no_class, |
| 1440 | jit_reader_unload_command, _("\ |
| 1441 | Unload the currently loaded JIT debug info reader.\n\ |
| 1442 | Usage: jit-reader-unload\n\n\ |
| 1443 | Do \"help jit-reader-load\" for info on loading debug info readers.")); |
| 1444 | set_cmd_completer (c, noop_completer); |
| 1445 | } |
| 1446 | } |