| 1 | /* Memory breakpoint operations for the remote server for GDB. |
| 2 | Copyright (C) 2002, 2003, 2005, 2007, 2008, 2009, 2010, 2011 |
| 3 | Free Software Foundation, Inc. |
| 4 | |
| 5 | Contributed by MontaVista Software. |
| 6 | |
| 7 | This file is part of GDB. |
| 8 | |
| 9 | This program is free software; you can redistribute it and/or modify |
| 10 | it under the terms of the GNU General Public License as published by |
| 11 | the Free Software Foundation; either version 3 of the License, or |
| 12 | (at your option) any later version. |
| 13 | |
| 14 | This program is distributed in the hope that it will be useful, |
| 15 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 16 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 17 | GNU General Public License for more details. |
| 18 | |
| 19 | You should have received a copy of the GNU General Public License |
| 20 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
| 21 | |
| 22 | #include "server.h" |
| 23 | |
| 24 | const unsigned char *breakpoint_data; |
| 25 | int breakpoint_len; |
| 26 | |
| 27 | #define MAX_BREAKPOINT_LEN 8 |
| 28 | |
| 29 | /* GDB will never try to install multiple breakpoints at the same |
| 30 | address. But, we need to keep track of internal breakpoints too, |
| 31 | and so we do need to be able to install multiple breakpoints at the |
| 32 | same address transparently. We keep track of two different, and |
| 33 | closely related structures. A raw breakpoint, which manages the |
| 34 | low level, close to the metal aspect of a breakpoint. It holds the |
| 35 | breakpoint address, and a buffer holding a copy of the instructions |
| 36 | that would be in memory had not been a breakpoint there (we call |
| 37 | that the shadow memory of the breakpoint). We occasionally need to |
| 38 | temporarilly uninsert a breakpoint without the client knowing about |
| 39 | it (e.g., to step over an internal breakpoint), so we keep an |
| 40 | `inserted' state associated with this low level breakpoint |
| 41 | structure. There can only be one such object for a given address. |
| 42 | Then, we have (a bit higher level) breakpoints. This structure |
| 43 | holds a callback to be called whenever a breakpoint is hit, a |
| 44 | high-level type, and a link to a low level raw breakpoint. There |
| 45 | can be many high-level breakpoints at the same address, and all of |
| 46 | them will point to the same raw breakpoint, which is reference |
| 47 | counted. */ |
| 48 | |
| 49 | /* The low level, physical, raw breakpoint. */ |
| 50 | struct raw_breakpoint |
| 51 | { |
| 52 | struct raw_breakpoint *next; |
| 53 | |
| 54 | /* A reference count. Each high level breakpoint referencing this |
| 55 | raw breakpoint accounts for one reference. */ |
| 56 | int refcount; |
| 57 | |
| 58 | /* The breakpoint's insertion address. There can only be one raw |
| 59 | breakpoint for a given PC. */ |
| 60 | CORE_ADDR pc; |
| 61 | |
| 62 | /* The breakpoint's shadow memory. */ |
| 63 | unsigned char old_data[MAX_BREAKPOINT_LEN]; |
| 64 | |
| 65 | /* Non-zero if this breakpoint is currently inserted in the |
| 66 | inferior. */ |
| 67 | int inserted; |
| 68 | |
| 69 | /* Non-zero if this breakpoint is currently disabled because we no |
| 70 | longer detect it as inserted. */ |
| 71 | int shlib_disabled; |
| 72 | }; |
| 73 | |
| 74 | /* The type of a breakpoint. */ |
| 75 | enum bkpt_type |
| 76 | { |
| 77 | /* A GDB breakpoint, requested with a Z0 packet. */ |
| 78 | gdb_breakpoint, |
| 79 | |
| 80 | /* A basic-software-single-step breakpoint. */ |
| 81 | reinsert_breakpoint, |
| 82 | |
| 83 | /* Any other breakpoint type that doesn't require specific |
| 84 | treatment goes here. E.g., an event breakpoint. */ |
| 85 | other_breakpoint, |
| 86 | }; |
| 87 | |
| 88 | /* A high level (in gdbserver's perspective) breakpoint. */ |
| 89 | struct breakpoint |
| 90 | { |
| 91 | struct breakpoint *next; |
| 92 | |
| 93 | /* The breakpoint's type. */ |
| 94 | enum bkpt_type type; |
| 95 | |
| 96 | /* Link to this breakpoint's raw breakpoint. This is always |
| 97 | non-NULL. */ |
| 98 | struct raw_breakpoint *raw; |
| 99 | |
| 100 | /* Function to call when we hit this breakpoint. If it returns 1, |
| 101 | the breakpoint shall be deleted; 0 or if this callback is NULL, |
| 102 | it will be left inserted. */ |
| 103 | int (*handler) (CORE_ADDR); |
| 104 | }; |
| 105 | |
| 106 | static struct raw_breakpoint * |
| 107 | find_raw_breakpoint_at (CORE_ADDR where) |
| 108 | { |
| 109 | struct process_info *proc = current_process (); |
| 110 | struct raw_breakpoint *bp; |
| 111 | |
| 112 | for (bp = proc->raw_breakpoints; bp != NULL; bp = bp->next) |
| 113 | if (bp->pc == where) |
| 114 | return bp; |
| 115 | |
| 116 | return NULL; |
| 117 | } |
| 118 | |
| 119 | static struct raw_breakpoint * |
| 120 | set_raw_breakpoint_at (CORE_ADDR where) |
| 121 | { |
| 122 | struct process_info *proc = current_process (); |
| 123 | struct raw_breakpoint *bp; |
| 124 | int err; |
| 125 | |
| 126 | if (breakpoint_data == NULL) |
| 127 | error ("Target does not support breakpoints."); |
| 128 | |
| 129 | bp = find_raw_breakpoint_at (where); |
| 130 | if (bp != NULL) |
| 131 | { |
| 132 | bp->refcount++; |
| 133 | return bp; |
| 134 | } |
| 135 | |
| 136 | bp = xcalloc (1, sizeof (*bp)); |
| 137 | bp->pc = where; |
| 138 | bp->refcount = 1; |
| 139 | |
| 140 | /* Note that there can be fast tracepoint jumps installed in the |
| 141 | same memory range, so to get at the original memory, we need to |
| 142 | use read_inferior_memory, which masks those out. */ |
| 143 | err = read_inferior_memory (where, bp->old_data, breakpoint_len); |
| 144 | if (err != 0) |
| 145 | { |
| 146 | if (debug_threads) |
| 147 | fprintf (stderr, |
| 148 | "Failed to read shadow memory of" |
| 149 | " breakpoint at 0x%s (%s).\n", |
| 150 | paddress (where), strerror (err)); |
| 151 | free (bp); |
| 152 | return NULL; |
| 153 | } |
| 154 | |
| 155 | err = (*the_target->write_memory) (where, breakpoint_data, |
| 156 | breakpoint_len); |
| 157 | if (err != 0) |
| 158 | { |
| 159 | if (debug_threads) |
| 160 | fprintf (stderr, |
| 161 | "Failed to insert breakpoint at 0x%s (%s).\n", |
| 162 | paddress (where), strerror (err)); |
| 163 | free (bp); |
| 164 | return NULL; |
| 165 | } |
| 166 | |
| 167 | /* Link the breakpoint in. */ |
| 168 | bp->inserted = 1; |
| 169 | bp->next = proc->raw_breakpoints; |
| 170 | proc->raw_breakpoints = bp; |
| 171 | return bp; |
| 172 | } |
| 173 | |
| 174 | /* Notice that breakpoint traps are always installed on top of fast |
| 175 | tracepoint jumps. This is even if the fast tracepoint is installed |
| 176 | at a later time compared to when the breakpoint was installed. |
| 177 | This means that a stopping breakpoint or tracepoint has higher |
| 178 | "priority". In turn, this allows having fast and slow tracepoints |
| 179 | (and breakpoints) at the same address behave correctly. */ |
| 180 | |
| 181 | |
| 182 | /* A fast tracepoint jump. */ |
| 183 | |
| 184 | struct fast_tracepoint_jump |
| 185 | { |
| 186 | struct fast_tracepoint_jump *next; |
| 187 | |
| 188 | /* A reference count. GDB can install more than one fast tracepoint |
| 189 | at the same address (each with its own action list, for |
| 190 | example). */ |
| 191 | int refcount; |
| 192 | |
| 193 | /* The fast tracepoint's insertion address. There can only be one |
| 194 | of these for a given PC. */ |
| 195 | CORE_ADDR pc; |
| 196 | |
| 197 | /* Non-zero if this fast tracepoint jump is currently inserted in |
| 198 | the inferior. */ |
| 199 | int inserted; |
| 200 | |
| 201 | /* The length of the jump instruction. */ |
| 202 | int length; |
| 203 | |
| 204 | /* A poor-man's flexible array member, holding both the jump |
| 205 | instruction to insert, and a copy of the instruction that would |
| 206 | be in memory had not been a jump there (the shadow memory of the |
| 207 | tracepoint jump). */ |
| 208 | unsigned char insn_and_shadow[0]; |
| 209 | }; |
| 210 | |
| 211 | /* Fast tracepoint FP's jump instruction to insert. */ |
| 212 | #define fast_tracepoint_jump_insn(fp) \ |
| 213 | ((fp)->insn_and_shadow + 0) |
| 214 | |
| 215 | /* The shadow memory of fast tracepoint jump FP. */ |
| 216 | #define fast_tracepoint_jump_shadow(fp) \ |
| 217 | ((fp)->insn_and_shadow + (fp)->length) |
| 218 | |
| 219 | |
| 220 | /* Return the fast tracepoint jump set at WHERE. */ |
| 221 | |
| 222 | static struct fast_tracepoint_jump * |
| 223 | find_fast_tracepoint_jump_at (CORE_ADDR where) |
| 224 | { |
| 225 | struct process_info *proc = current_process (); |
| 226 | struct fast_tracepoint_jump *jp; |
| 227 | |
| 228 | for (jp = proc->fast_tracepoint_jumps; jp != NULL; jp = jp->next) |
| 229 | if (jp->pc == where) |
| 230 | return jp; |
| 231 | |
| 232 | return NULL; |
| 233 | } |
| 234 | |
| 235 | int |
| 236 | fast_tracepoint_jump_here (CORE_ADDR where) |
| 237 | { |
| 238 | struct fast_tracepoint_jump *jp = find_fast_tracepoint_jump_at (where); |
| 239 | |
| 240 | return (jp != NULL); |
| 241 | } |
| 242 | |
| 243 | int |
| 244 | delete_fast_tracepoint_jump (struct fast_tracepoint_jump *todel) |
| 245 | { |
| 246 | struct fast_tracepoint_jump *bp, **bp_link; |
| 247 | int ret; |
| 248 | struct process_info *proc = current_process (); |
| 249 | |
| 250 | bp = proc->fast_tracepoint_jumps; |
| 251 | bp_link = &proc->fast_tracepoint_jumps; |
| 252 | |
| 253 | while (bp) |
| 254 | { |
| 255 | if (bp == todel) |
| 256 | { |
| 257 | if (--bp->refcount == 0) |
| 258 | { |
| 259 | struct fast_tracepoint_jump *prev_bp_link = *bp_link; |
| 260 | |
| 261 | /* Unlink it. */ |
| 262 | *bp_link = bp->next; |
| 263 | |
| 264 | /* Since there can be breakpoints inserted in the same |
| 265 | address range, we use `write_inferior_memory', which |
| 266 | takes care of layering breakpoints on top of fast |
| 267 | tracepoints, and on top of the buffer we pass it. |
| 268 | This works because we've already unlinked the fast |
| 269 | tracepoint jump above. Also note that we need to |
| 270 | pass the current shadow contents, because |
| 271 | write_inferior_memory updates any shadow memory with |
| 272 | what we pass here, and we want that to be a nop. */ |
| 273 | ret = write_inferior_memory (bp->pc, |
| 274 | fast_tracepoint_jump_shadow (bp), |
| 275 | bp->length); |
| 276 | if (ret != 0) |
| 277 | { |
| 278 | /* Something went wrong, relink the jump. */ |
| 279 | *bp_link = prev_bp_link; |
| 280 | |
| 281 | if (debug_threads) |
| 282 | fprintf (stderr, |
| 283 | "Failed to uninsert fast tracepoint jump " |
| 284 | "at 0x%s (%s) while deleting it.\n", |
| 285 | paddress (bp->pc), strerror (ret)); |
| 286 | return ret; |
| 287 | } |
| 288 | |
| 289 | free (bp); |
| 290 | } |
| 291 | |
| 292 | return 0; |
| 293 | } |
| 294 | else |
| 295 | { |
| 296 | bp_link = &bp->next; |
| 297 | bp = *bp_link; |
| 298 | } |
| 299 | } |
| 300 | |
| 301 | warning ("Could not find fast tracepoint jump in list."); |
| 302 | return ENOENT; |
| 303 | } |
| 304 | |
| 305 | void |
| 306 | inc_ref_fast_tracepoint_jump (struct fast_tracepoint_jump *jp) |
| 307 | { |
| 308 | jp->refcount++; |
| 309 | } |
| 310 | |
| 311 | struct fast_tracepoint_jump * |
| 312 | set_fast_tracepoint_jump (CORE_ADDR where, |
| 313 | unsigned char *insn, ULONGEST length) |
| 314 | { |
| 315 | struct process_info *proc = current_process (); |
| 316 | struct fast_tracepoint_jump *jp; |
| 317 | int err; |
| 318 | |
| 319 | /* We refcount fast tracepoint jumps. Check if we already know |
| 320 | about a jump at this address. */ |
| 321 | jp = find_fast_tracepoint_jump_at (where); |
| 322 | if (jp != NULL) |
| 323 | { |
| 324 | jp->refcount++; |
| 325 | return jp; |
| 326 | } |
| 327 | |
| 328 | /* We don't, so create a new object. Double the length, because the |
| 329 | flexible array member holds both the jump insn, and the |
| 330 | shadow. */ |
| 331 | jp = xcalloc (1, sizeof (*jp) + (length * 2)); |
| 332 | jp->pc = where; |
| 333 | jp->length = length; |
| 334 | memcpy (fast_tracepoint_jump_insn (jp), insn, length); |
| 335 | jp->refcount = 1; |
| 336 | |
| 337 | /* Note that there can be trap breakpoints inserted in the same |
| 338 | address range. To access the original memory contents, we use |
| 339 | `read_inferior_memory', which masks out breakpoints. */ |
| 340 | err = read_inferior_memory (where, |
| 341 | fast_tracepoint_jump_shadow (jp), jp->length); |
| 342 | if (err != 0) |
| 343 | { |
| 344 | if (debug_threads) |
| 345 | fprintf (stderr, |
| 346 | "Failed to read shadow memory of" |
| 347 | " fast tracepoint at 0x%s (%s).\n", |
| 348 | paddress (where), strerror (err)); |
| 349 | free (jp); |
| 350 | return NULL; |
| 351 | } |
| 352 | |
| 353 | /* Link the jump in. */ |
| 354 | jp->inserted = 1; |
| 355 | jp->next = proc->fast_tracepoint_jumps; |
| 356 | proc->fast_tracepoint_jumps = jp; |
| 357 | |
| 358 | /* Since there can be trap breakpoints inserted in the same address |
| 359 | range, we use use `write_inferior_memory', which takes care of |
| 360 | layering breakpoints on top of fast tracepoints, on top of the |
| 361 | buffer we pass it. This works because we've already linked in |
| 362 | the fast tracepoint jump above. Also note that we need to pass |
| 363 | the current shadow contents, because write_inferior_memory |
| 364 | updates any shadow memory with what we pass here, and we want |
| 365 | that to be a nop. */ |
| 366 | err = write_inferior_memory (where, fast_tracepoint_jump_shadow (jp), |
| 367 | length); |
| 368 | if (err != 0) |
| 369 | { |
| 370 | if (debug_threads) |
| 371 | fprintf (stderr, |
| 372 | "Failed to insert fast tracepoint jump at 0x%s (%s).\n", |
| 373 | paddress (where), strerror (err)); |
| 374 | |
| 375 | /* Unlink it. */ |
| 376 | proc->fast_tracepoint_jumps = jp->next; |
| 377 | free (jp); |
| 378 | |
| 379 | return NULL; |
| 380 | } |
| 381 | |
| 382 | return jp; |
| 383 | } |
| 384 | |
| 385 | void |
| 386 | uninsert_fast_tracepoint_jumps_at (CORE_ADDR pc) |
| 387 | { |
| 388 | struct fast_tracepoint_jump *jp; |
| 389 | int err; |
| 390 | |
| 391 | jp = find_fast_tracepoint_jump_at (pc); |
| 392 | if (jp == NULL) |
| 393 | { |
| 394 | /* This can happen when we remove all breakpoints while handling |
| 395 | a step-over. */ |
| 396 | if (debug_threads) |
| 397 | fprintf (stderr, |
| 398 | "Could not find fast tracepoint jump at 0x%s " |
| 399 | "in list (uninserting).\n", |
| 400 | paddress (pc)); |
| 401 | return; |
| 402 | } |
| 403 | |
| 404 | if (jp->inserted) |
| 405 | { |
| 406 | jp->inserted = 0; |
| 407 | |
| 408 | /* Since there can be trap breakpoints inserted in the same |
| 409 | address range, we use use `write_inferior_memory', which |
| 410 | takes care of layering breakpoints on top of fast |
| 411 | tracepoints, and on top of the buffer we pass it. This works |
| 412 | because we've already marked the fast tracepoint fast |
| 413 | tracepoint jump uninserted above. Also note that we need to |
| 414 | pass the current shadow contents, because |
| 415 | write_inferior_memory updates any shadow memory with what we |
| 416 | pass here, and we want that to be a nop. */ |
| 417 | err = write_inferior_memory (jp->pc, |
| 418 | fast_tracepoint_jump_shadow (jp), |
| 419 | jp->length); |
| 420 | if (err != 0) |
| 421 | { |
| 422 | jp->inserted = 1; |
| 423 | |
| 424 | if (debug_threads) |
| 425 | fprintf (stderr, |
| 426 | "Failed to uninsert fast tracepoint jump at 0x%s (%s).\n", |
| 427 | paddress (pc), strerror (err)); |
| 428 | } |
| 429 | } |
| 430 | } |
| 431 | |
| 432 | void |
| 433 | reinsert_fast_tracepoint_jumps_at (CORE_ADDR where) |
| 434 | { |
| 435 | struct fast_tracepoint_jump *jp; |
| 436 | int err; |
| 437 | |
| 438 | jp = find_fast_tracepoint_jump_at (where); |
| 439 | if (jp == NULL) |
| 440 | { |
| 441 | /* This can happen when we remove breakpoints when a tracepoint |
| 442 | hit causes a tracing stop, while handling a step-over. */ |
| 443 | if (debug_threads) |
| 444 | fprintf (stderr, |
| 445 | "Could not find fast tracepoint jump at 0x%s " |
| 446 | "in list (reinserting).\n", |
| 447 | paddress (where)); |
| 448 | return; |
| 449 | } |
| 450 | |
| 451 | if (jp->inserted) |
| 452 | error ("Jump already inserted at reinsert time."); |
| 453 | |
| 454 | jp->inserted = 1; |
| 455 | |
| 456 | /* Since there can be trap breakpoints inserted in the same address |
| 457 | range, we use `write_inferior_memory', which takes care of |
| 458 | layering breakpoints on top of fast tracepoints, and on top of |
| 459 | the buffer we pass it. This works because we've already marked |
| 460 | the fast tracepoint jump inserted above. Also note that we need |
| 461 | to pass the current shadow contents, because |
| 462 | write_inferior_memory updates any shadow memory with what we pass |
| 463 | here, and we want that to be a nop. */ |
| 464 | err = write_inferior_memory (where, |
| 465 | fast_tracepoint_jump_shadow (jp), jp->length); |
| 466 | if (err != 0) |
| 467 | { |
| 468 | jp->inserted = 0; |
| 469 | |
| 470 | if (debug_threads) |
| 471 | fprintf (stderr, |
| 472 | "Failed to reinsert fast tracepoint jump at 0x%s (%s).\n", |
| 473 | paddress (where), strerror (err)); |
| 474 | } |
| 475 | } |
| 476 | |
| 477 | struct breakpoint * |
| 478 | set_breakpoint_at (CORE_ADDR where, int (*handler) (CORE_ADDR)) |
| 479 | { |
| 480 | struct process_info *proc = current_process (); |
| 481 | struct breakpoint *bp; |
| 482 | struct raw_breakpoint *raw; |
| 483 | |
| 484 | raw = set_raw_breakpoint_at (where); |
| 485 | |
| 486 | if (raw == NULL) |
| 487 | { |
| 488 | /* warn? */ |
| 489 | return NULL; |
| 490 | } |
| 491 | |
| 492 | bp = xcalloc (1, sizeof (struct breakpoint)); |
| 493 | bp->type = other_breakpoint; |
| 494 | |
| 495 | bp->raw = raw; |
| 496 | bp->handler = handler; |
| 497 | |
| 498 | bp->next = proc->breakpoints; |
| 499 | proc->breakpoints = bp; |
| 500 | |
| 501 | return bp; |
| 502 | } |
| 503 | |
| 504 | static int |
| 505 | delete_raw_breakpoint (struct process_info *proc, struct raw_breakpoint *todel) |
| 506 | { |
| 507 | struct raw_breakpoint *bp, **bp_link; |
| 508 | int ret; |
| 509 | |
| 510 | bp = proc->raw_breakpoints; |
| 511 | bp_link = &proc->raw_breakpoints; |
| 512 | |
| 513 | while (bp) |
| 514 | { |
| 515 | if (bp == todel) |
| 516 | { |
| 517 | if (bp->inserted) |
| 518 | { |
| 519 | struct raw_breakpoint *prev_bp_link = *bp_link; |
| 520 | |
| 521 | *bp_link = bp->next; |
| 522 | |
| 523 | /* Since there can be trap breakpoints inserted in the |
| 524 | same address range, we use `write_inferior_memory', |
| 525 | which takes care of layering breakpoints on top of |
| 526 | fast tracepoints, and on top of the buffer we pass |
| 527 | it. This works because we've already unlinked the |
| 528 | fast tracepoint jump above. Also note that we need |
| 529 | to pass the current shadow contents, because |
| 530 | write_inferior_memory updates any shadow memory with |
| 531 | what we pass here, and we want that to be a nop. */ |
| 532 | ret = write_inferior_memory (bp->pc, bp->old_data, |
| 533 | breakpoint_len); |
| 534 | if (ret != 0) |
| 535 | { |
| 536 | /* Something went wrong, relink the breakpoint. */ |
| 537 | *bp_link = prev_bp_link; |
| 538 | |
| 539 | if (debug_threads) |
| 540 | fprintf (stderr, |
| 541 | "Failed to uninsert raw breakpoint " |
| 542 | "at 0x%s (%s) while deleting it.\n", |
| 543 | paddress (bp->pc), strerror (ret)); |
| 544 | return ret; |
| 545 | } |
| 546 | |
| 547 | } |
| 548 | else |
| 549 | *bp_link = bp->next; |
| 550 | |
| 551 | free (bp); |
| 552 | return 0; |
| 553 | } |
| 554 | else |
| 555 | { |
| 556 | bp_link = &bp->next; |
| 557 | bp = *bp_link; |
| 558 | } |
| 559 | } |
| 560 | |
| 561 | warning ("Could not find raw breakpoint in list."); |
| 562 | return ENOENT; |
| 563 | } |
| 564 | |
| 565 | static int |
| 566 | release_breakpoint (struct process_info *proc, struct breakpoint *bp) |
| 567 | { |
| 568 | int newrefcount; |
| 569 | int ret; |
| 570 | |
| 571 | newrefcount = bp->raw->refcount - 1; |
| 572 | if (newrefcount == 0) |
| 573 | { |
| 574 | ret = delete_raw_breakpoint (proc, bp->raw); |
| 575 | if (ret != 0) |
| 576 | return ret; |
| 577 | } |
| 578 | else |
| 579 | bp->raw->refcount = newrefcount; |
| 580 | |
| 581 | free (bp); |
| 582 | |
| 583 | return 0; |
| 584 | } |
| 585 | |
| 586 | static int |
| 587 | delete_breakpoint_1 (struct process_info *proc, struct breakpoint *todel) |
| 588 | { |
| 589 | struct breakpoint *bp, **bp_link; |
| 590 | int err; |
| 591 | |
| 592 | bp = proc->breakpoints; |
| 593 | bp_link = &proc->breakpoints; |
| 594 | |
| 595 | while (bp) |
| 596 | { |
| 597 | if (bp == todel) |
| 598 | { |
| 599 | *bp_link = bp->next; |
| 600 | |
| 601 | err = release_breakpoint (proc, bp); |
| 602 | if (err != 0) |
| 603 | return err; |
| 604 | |
| 605 | bp = *bp_link; |
| 606 | return 0; |
| 607 | } |
| 608 | else |
| 609 | { |
| 610 | bp_link = &bp->next; |
| 611 | bp = *bp_link; |
| 612 | } |
| 613 | } |
| 614 | |
| 615 | warning ("Could not find breakpoint in list."); |
| 616 | return ENOENT; |
| 617 | } |
| 618 | |
| 619 | int |
| 620 | delete_breakpoint (struct breakpoint *todel) |
| 621 | { |
| 622 | struct process_info *proc = current_process (); |
| 623 | return delete_breakpoint_1 (proc, todel); |
| 624 | } |
| 625 | |
| 626 | static struct breakpoint * |
| 627 | find_gdb_breakpoint_at (CORE_ADDR where) |
| 628 | { |
| 629 | struct process_info *proc = current_process (); |
| 630 | struct breakpoint *bp; |
| 631 | |
| 632 | for (bp = proc->breakpoints; bp != NULL; bp = bp->next) |
| 633 | if (bp->type == gdb_breakpoint && bp->raw->pc == where) |
| 634 | return bp; |
| 635 | |
| 636 | return NULL; |
| 637 | } |
| 638 | |
| 639 | int |
| 640 | set_gdb_breakpoint_at (CORE_ADDR where) |
| 641 | { |
| 642 | struct breakpoint *bp; |
| 643 | |
| 644 | if (breakpoint_data == NULL) |
| 645 | return 1; |
| 646 | |
| 647 | /* If we see GDB inserting a second breakpoint at the same address, |
| 648 | then the first breakpoint must have disappeared due to a shared |
| 649 | library unload. On targets where the shared libraries are |
| 650 | handled by userspace, like SVR4, for example, GDBserver can't |
| 651 | tell if a library was loaded or unloaded. Since we refcount |
| 652 | breakpoints, if we didn't do this, we'd just increase the |
| 653 | refcount of the previous breakpoint at this address, but the trap |
| 654 | was not planted in the inferior anymore, thus the breakpoint |
| 655 | would never be hit. */ |
| 656 | bp = find_gdb_breakpoint_at (where); |
| 657 | if (bp != NULL) |
| 658 | { |
| 659 | delete_gdb_breakpoint_at (where); |
| 660 | |
| 661 | /* Might as well validate all other breakpoints. */ |
| 662 | validate_breakpoints (); |
| 663 | } |
| 664 | |
| 665 | bp = set_breakpoint_at (where, NULL); |
| 666 | if (bp == NULL) |
| 667 | return -1; |
| 668 | |
| 669 | bp->type = gdb_breakpoint; |
| 670 | return 0; |
| 671 | } |
| 672 | |
| 673 | int |
| 674 | delete_gdb_breakpoint_at (CORE_ADDR addr) |
| 675 | { |
| 676 | struct breakpoint *bp; |
| 677 | int err; |
| 678 | |
| 679 | if (breakpoint_data == NULL) |
| 680 | return 1; |
| 681 | |
| 682 | bp = find_gdb_breakpoint_at (addr); |
| 683 | if (bp == NULL) |
| 684 | return -1; |
| 685 | |
| 686 | err = delete_breakpoint (bp); |
| 687 | if (err) |
| 688 | return -1; |
| 689 | |
| 690 | return 0; |
| 691 | } |
| 692 | |
| 693 | int |
| 694 | gdb_breakpoint_here (CORE_ADDR where) |
| 695 | { |
| 696 | struct breakpoint *bp = find_gdb_breakpoint_at (where); |
| 697 | |
| 698 | return (bp != NULL); |
| 699 | } |
| 700 | |
| 701 | void |
| 702 | set_reinsert_breakpoint (CORE_ADDR stop_at) |
| 703 | { |
| 704 | struct breakpoint *bp; |
| 705 | |
| 706 | bp = set_breakpoint_at (stop_at, NULL); |
| 707 | bp->type = reinsert_breakpoint; |
| 708 | } |
| 709 | |
| 710 | void |
| 711 | delete_reinsert_breakpoints (void) |
| 712 | { |
| 713 | struct process_info *proc = current_process (); |
| 714 | struct breakpoint *bp, **bp_link; |
| 715 | |
| 716 | bp = proc->breakpoints; |
| 717 | bp_link = &proc->breakpoints; |
| 718 | |
| 719 | while (bp) |
| 720 | { |
| 721 | if (bp->type == reinsert_breakpoint) |
| 722 | { |
| 723 | *bp_link = bp->next; |
| 724 | release_breakpoint (proc, bp); |
| 725 | bp = *bp_link; |
| 726 | } |
| 727 | else |
| 728 | { |
| 729 | bp_link = &bp->next; |
| 730 | bp = *bp_link; |
| 731 | } |
| 732 | } |
| 733 | } |
| 734 | |
| 735 | static void |
| 736 | uninsert_raw_breakpoint (struct raw_breakpoint *bp) |
| 737 | { |
| 738 | if (bp->inserted) |
| 739 | { |
| 740 | int err; |
| 741 | |
| 742 | bp->inserted = 0; |
| 743 | /* Since there can be fast tracepoint jumps inserted in the same |
| 744 | address range, we use `write_inferior_memory', which takes |
| 745 | care of layering breakpoints on top of fast tracepoints, and |
| 746 | on top of the buffer we pass it. This works because we've |
| 747 | already unlinked the fast tracepoint jump above. Also note |
| 748 | that we need to pass the current shadow contents, because |
| 749 | write_inferior_memory updates any shadow memory with what we |
| 750 | pass here, and we want that to be a nop. */ |
| 751 | err = write_inferior_memory (bp->pc, bp->old_data, |
| 752 | breakpoint_len); |
| 753 | if (err != 0) |
| 754 | { |
| 755 | bp->inserted = 1; |
| 756 | |
| 757 | if (debug_threads) |
| 758 | fprintf (stderr, |
| 759 | "Failed to uninsert raw breakpoint at 0x%s (%s).\n", |
| 760 | paddress (bp->pc), strerror (err)); |
| 761 | } |
| 762 | } |
| 763 | } |
| 764 | |
| 765 | void |
| 766 | uninsert_breakpoints_at (CORE_ADDR pc) |
| 767 | { |
| 768 | struct raw_breakpoint *bp; |
| 769 | |
| 770 | bp = find_raw_breakpoint_at (pc); |
| 771 | if (bp == NULL) |
| 772 | { |
| 773 | /* This can happen when we remove all breakpoints while handling |
| 774 | a step-over. */ |
| 775 | if (debug_threads) |
| 776 | fprintf (stderr, |
| 777 | "Could not find breakpoint at 0x%s " |
| 778 | "in list (uninserting).\n", |
| 779 | paddress (pc)); |
| 780 | return; |
| 781 | } |
| 782 | |
| 783 | if (bp->inserted) |
| 784 | uninsert_raw_breakpoint (bp); |
| 785 | } |
| 786 | |
| 787 | void |
| 788 | uninsert_all_breakpoints (void) |
| 789 | { |
| 790 | struct process_info *proc = current_process (); |
| 791 | struct raw_breakpoint *bp; |
| 792 | |
| 793 | for (bp = proc->raw_breakpoints; bp != NULL; bp = bp->next) |
| 794 | if (bp->inserted) |
| 795 | uninsert_raw_breakpoint (bp); |
| 796 | } |
| 797 | |
| 798 | static void |
| 799 | reinsert_raw_breakpoint (struct raw_breakpoint *bp) |
| 800 | { |
| 801 | int err; |
| 802 | |
| 803 | if (bp->inserted) |
| 804 | error ("Breakpoint already inserted at reinsert time."); |
| 805 | |
| 806 | err = (*the_target->write_memory) (bp->pc, breakpoint_data, |
| 807 | breakpoint_len); |
| 808 | if (err == 0) |
| 809 | bp->inserted = 1; |
| 810 | else if (debug_threads) |
| 811 | fprintf (stderr, |
| 812 | "Failed to reinsert breakpoint at 0x%s (%s).\n", |
| 813 | paddress (bp->pc), strerror (err)); |
| 814 | } |
| 815 | |
| 816 | void |
| 817 | reinsert_breakpoints_at (CORE_ADDR pc) |
| 818 | { |
| 819 | struct raw_breakpoint *bp; |
| 820 | |
| 821 | bp = find_raw_breakpoint_at (pc); |
| 822 | if (bp == NULL) |
| 823 | { |
| 824 | /* This can happen when we remove all breakpoints while handling |
| 825 | a step-over. */ |
| 826 | if (debug_threads) |
| 827 | fprintf (stderr, |
| 828 | "Could not find raw breakpoint at 0x%s " |
| 829 | "in list (reinserting).\n", |
| 830 | paddress (pc)); |
| 831 | return; |
| 832 | } |
| 833 | |
| 834 | reinsert_raw_breakpoint (bp); |
| 835 | } |
| 836 | |
| 837 | void |
| 838 | reinsert_all_breakpoints (void) |
| 839 | { |
| 840 | struct process_info *proc = current_process (); |
| 841 | struct raw_breakpoint *bp; |
| 842 | |
| 843 | for (bp = proc->raw_breakpoints; bp != NULL; bp = bp->next) |
| 844 | if (!bp->inserted) |
| 845 | reinsert_raw_breakpoint (bp); |
| 846 | } |
| 847 | |
| 848 | void |
| 849 | check_breakpoints (CORE_ADDR stop_pc) |
| 850 | { |
| 851 | struct process_info *proc = current_process (); |
| 852 | struct breakpoint *bp, **bp_link; |
| 853 | |
| 854 | bp = proc->breakpoints; |
| 855 | bp_link = &proc->breakpoints; |
| 856 | |
| 857 | while (bp) |
| 858 | { |
| 859 | if (bp->raw->pc == stop_pc) |
| 860 | { |
| 861 | if (!bp->raw->inserted) |
| 862 | { |
| 863 | warning ("Hit a removed breakpoint?"); |
| 864 | return; |
| 865 | } |
| 866 | |
| 867 | if (bp->handler != NULL && (*bp->handler) (stop_pc)) |
| 868 | { |
| 869 | *bp_link = bp->next; |
| 870 | |
| 871 | release_breakpoint (proc, bp); |
| 872 | |
| 873 | bp = *bp_link; |
| 874 | continue; |
| 875 | } |
| 876 | } |
| 877 | |
| 878 | bp_link = &bp->next; |
| 879 | bp = *bp_link; |
| 880 | } |
| 881 | } |
| 882 | |
| 883 | void |
| 884 | set_breakpoint_data (const unsigned char *bp_data, int bp_len) |
| 885 | { |
| 886 | breakpoint_data = bp_data; |
| 887 | breakpoint_len = bp_len; |
| 888 | } |
| 889 | |
| 890 | int |
| 891 | breakpoint_here (CORE_ADDR addr) |
| 892 | { |
| 893 | return (find_raw_breakpoint_at (addr) != NULL); |
| 894 | } |
| 895 | |
| 896 | int |
| 897 | breakpoint_inserted_here (CORE_ADDR addr) |
| 898 | { |
| 899 | struct raw_breakpoint *bp; |
| 900 | |
| 901 | bp = find_raw_breakpoint_at (addr); |
| 902 | |
| 903 | return (bp != NULL && bp->inserted); |
| 904 | } |
| 905 | |
| 906 | static int |
| 907 | validate_inserted_breakpoint (struct raw_breakpoint *bp) |
| 908 | { |
| 909 | unsigned char *buf; |
| 910 | int err; |
| 911 | |
| 912 | gdb_assert (bp->inserted); |
| 913 | |
| 914 | buf = alloca (breakpoint_len); |
| 915 | err = (*the_target->read_memory) (bp->pc, buf, breakpoint_len); |
| 916 | if (err || memcmp (buf, breakpoint_data, breakpoint_len) != 0) |
| 917 | { |
| 918 | /* Tag it as gone. */ |
| 919 | bp->inserted = 0; |
| 920 | bp->shlib_disabled = 1; |
| 921 | return 0; |
| 922 | } |
| 923 | |
| 924 | return 1; |
| 925 | } |
| 926 | |
| 927 | static void |
| 928 | delete_disabled_breakpoints (void) |
| 929 | { |
| 930 | struct process_info *proc = current_process (); |
| 931 | struct breakpoint *bp, *next; |
| 932 | |
| 933 | for (bp = proc->breakpoints; bp != NULL; bp = next) |
| 934 | { |
| 935 | next = bp->next; |
| 936 | if (bp->raw->shlib_disabled) |
| 937 | delete_breakpoint_1 (proc, bp); |
| 938 | } |
| 939 | } |
| 940 | |
| 941 | /* Check if breakpoints we inserted still appear to be inserted. They |
| 942 | may disappear due to a shared library unload, and worse, a new |
| 943 | shared library may be reloaded at the same address as the |
| 944 | previously unloaded one. If that happens, we should make sure that |
| 945 | the shadow memory of the old breakpoints isn't used when reading or |
| 946 | writing memory. */ |
| 947 | |
| 948 | void |
| 949 | validate_breakpoints (void) |
| 950 | { |
| 951 | struct process_info *proc = current_process (); |
| 952 | struct breakpoint *bp; |
| 953 | |
| 954 | for (bp = proc->breakpoints; bp != NULL; bp = bp->next) |
| 955 | { |
| 956 | if (bp->raw->inserted) |
| 957 | validate_inserted_breakpoint (bp->raw); |
| 958 | } |
| 959 | |
| 960 | delete_disabled_breakpoints (); |
| 961 | } |
| 962 | |
| 963 | void |
| 964 | check_mem_read (CORE_ADDR mem_addr, unsigned char *buf, int mem_len) |
| 965 | { |
| 966 | struct process_info *proc = current_process (); |
| 967 | struct raw_breakpoint *bp = proc->raw_breakpoints; |
| 968 | struct fast_tracepoint_jump *jp = proc->fast_tracepoint_jumps; |
| 969 | CORE_ADDR mem_end = mem_addr + mem_len; |
| 970 | int disabled_one = 0; |
| 971 | |
| 972 | for (; jp != NULL; jp = jp->next) |
| 973 | { |
| 974 | CORE_ADDR bp_end = jp->pc + jp->length; |
| 975 | CORE_ADDR start, end; |
| 976 | int copy_offset, copy_len, buf_offset; |
| 977 | |
| 978 | if (mem_addr >= bp_end) |
| 979 | continue; |
| 980 | if (jp->pc >= mem_end) |
| 981 | continue; |
| 982 | |
| 983 | start = jp->pc; |
| 984 | if (mem_addr > start) |
| 985 | start = mem_addr; |
| 986 | |
| 987 | end = bp_end; |
| 988 | if (end > mem_end) |
| 989 | end = mem_end; |
| 990 | |
| 991 | copy_len = end - start; |
| 992 | copy_offset = start - jp->pc; |
| 993 | buf_offset = start - mem_addr; |
| 994 | |
| 995 | if (jp->inserted) |
| 996 | memcpy (buf + buf_offset, |
| 997 | fast_tracepoint_jump_shadow (jp) + copy_offset, |
| 998 | copy_len); |
| 999 | } |
| 1000 | |
| 1001 | for (; bp != NULL; bp = bp->next) |
| 1002 | { |
| 1003 | CORE_ADDR bp_end = bp->pc + breakpoint_len; |
| 1004 | CORE_ADDR start, end; |
| 1005 | int copy_offset, copy_len, buf_offset; |
| 1006 | |
| 1007 | if (mem_addr >= bp_end) |
| 1008 | continue; |
| 1009 | if (bp->pc >= mem_end) |
| 1010 | continue; |
| 1011 | |
| 1012 | start = bp->pc; |
| 1013 | if (mem_addr > start) |
| 1014 | start = mem_addr; |
| 1015 | |
| 1016 | end = bp_end; |
| 1017 | if (end > mem_end) |
| 1018 | end = mem_end; |
| 1019 | |
| 1020 | copy_len = end - start; |
| 1021 | copy_offset = start - bp->pc; |
| 1022 | buf_offset = start - mem_addr; |
| 1023 | |
| 1024 | if (bp->inserted) |
| 1025 | { |
| 1026 | if (validate_inserted_breakpoint (bp)) |
| 1027 | memcpy (buf + buf_offset, bp->old_data + copy_offset, copy_len); |
| 1028 | else |
| 1029 | disabled_one = 1; |
| 1030 | } |
| 1031 | } |
| 1032 | |
| 1033 | if (disabled_one) |
| 1034 | delete_disabled_breakpoints (); |
| 1035 | } |
| 1036 | |
| 1037 | void |
| 1038 | check_mem_write (CORE_ADDR mem_addr, unsigned char *buf, |
| 1039 | const unsigned char *myaddr, int mem_len) |
| 1040 | { |
| 1041 | struct process_info *proc = current_process (); |
| 1042 | struct raw_breakpoint *bp = proc->raw_breakpoints; |
| 1043 | struct fast_tracepoint_jump *jp = proc->fast_tracepoint_jumps; |
| 1044 | CORE_ADDR mem_end = mem_addr + mem_len; |
| 1045 | int disabled_one = 0; |
| 1046 | |
| 1047 | /* First fast tracepoint jumps, then breakpoint traps on top. */ |
| 1048 | |
| 1049 | for (; jp != NULL; jp = jp->next) |
| 1050 | { |
| 1051 | CORE_ADDR jp_end = jp->pc + jp->length; |
| 1052 | CORE_ADDR start, end; |
| 1053 | int copy_offset, copy_len, buf_offset; |
| 1054 | |
| 1055 | if (mem_addr >= jp_end) |
| 1056 | continue; |
| 1057 | if (jp->pc >= mem_end) |
| 1058 | continue; |
| 1059 | |
| 1060 | start = jp->pc; |
| 1061 | if (mem_addr > start) |
| 1062 | start = mem_addr; |
| 1063 | |
| 1064 | end = jp_end; |
| 1065 | if (end > mem_end) |
| 1066 | end = mem_end; |
| 1067 | |
| 1068 | copy_len = end - start; |
| 1069 | copy_offset = start - jp->pc; |
| 1070 | buf_offset = start - mem_addr; |
| 1071 | |
| 1072 | memcpy (fast_tracepoint_jump_shadow (jp) + copy_offset, |
| 1073 | myaddr + buf_offset, copy_len); |
| 1074 | if (jp->inserted) |
| 1075 | memcpy (buf + buf_offset, |
| 1076 | fast_tracepoint_jump_insn (jp) + copy_offset, copy_len); |
| 1077 | } |
| 1078 | |
| 1079 | for (; bp != NULL; bp = bp->next) |
| 1080 | { |
| 1081 | CORE_ADDR bp_end = bp->pc + breakpoint_len; |
| 1082 | CORE_ADDR start, end; |
| 1083 | int copy_offset, copy_len, buf_offset; |
| 1084 | |
| 1085 | if (mem_addr >= bp_end) |
| 1086 | continue; |
| 1087 | if (bp->pc >= mem_end) |
| 1088 | continue; |
| 1089 | |
| 1090 | start = bp->pc; |
| 1091 | if (mem_addr > start) |
| 1092 | start = mem_addr; |
| 1093 | |
| 1094 | end = bp_end; |
| 1095 | if (end > mem_end) |
| 1096 | end = mem_end; |
| 1097 | |
| 1098 | copy_len = end - start; |
| 1099 | copy_offset = start - bp->pc; |
| 1100 | buf_offset = start - mem_addr; |
| 1101 | |
| 1102 | memcpy (bp->old_data + copy_offset, myaddr + buf_offset, copy_len); |
| 1103 | if (bp->inserted) |
| 1104 | { |
| 1105 | if (validate_inserted_breakpoint (bp)) |
| 1106 | memcpy (buf + buf_offset, breakpoint_data + copy_offset, copy_len); |
| 1107 | else |
| 1108 | disabled_one = 1; |
| 1109 | } |
| 1110 | } |
| 1111 | |
| 1112 | if (disabled_one) |
| 1113 | delete_disabled_breakpoints (); |
| 1114 | } |
| 1115 | |
| 1116 | /* Delete all breakpoints, and un-insert them from the inferior. */ |
| 1117 | |
| 1118 | void |
| 1119 | delete_all_breakpoints (void) |
| 1120 | { |
| 1121 | struct process_info *proc = current_process (); |
| 1122 | |
| 1123 | while (proc->breakpoints) |
| 1124 | delete_breakpoint_1 (proc, proc->breakpoints); |
| 1125 | } |
| 1126 | |
| 1127 | /* Clear the "inserted" flag in all breakpoints. */ |
| 1128 | |
| 1129 | void |
| 1130 | mark_breakpoints_out (struct process_info *proc) |
| 1131 | { |
| 1132 | struct raw_breakpoint *raw_bp; |
| 1133 | |
| 1134 | for (raw_bp = proc->raw_breakpoints; raw_bp != NULL; raw_bp = raw_bp->next) |
| 1135 | raw_bp->inserted = 0; |
| 1136 | } |
| 1137 | |
| 1138 | /* Release all breakpoints, but do not try to un-insert them from the |
| 1139 | inferior. */ |
| 1140 | |
| 1141 | void |
| 1142 | free_all_breakpoints (struct process_info *proc) |
| 1143 | { |
| 1144 | mark_breakpoints_out (proc); |
| 1145 | |
| 1146 | /* Note: use PROC explicitly instead of deferring to |
| 1147 | delete_all_breakpoints --- CURRENT_INFERIOR may already have been |
| 1148 | released when we get here. There should be no call to |
| 1149 | current_process from here on. */ |
| 1150 | while (proc->breakpoints) |
| 1151 | delete_breakpoint_1 (proc, proc->breakpoints); |
| 1152 | } |