gdb/gdbserver/regcache.c

   1 /* Register support routines for the remote server for GDB.
   2    Copyright (C) 2001-2016 Free Software Foundation, Inc.
   3
   4    This file is part of GDB.
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 3 of the License, or
   9    (at your option) any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  18
  19 #include "server.h"
  20 #include "regdef.h"
  21 #include "gdbthread.h"
  22 #include "tdesc.h"
  23 #include "rsp-low.h"
  24 #ifndef IN_PROCESS_AGENT
  25
  26 struct regcache *
  27 get_thread_regcache (struct thread_info *thread, int fetch)
  28 {
  29   struct regcache *regcache;
  30
  31   regcache = inferior_regcache_data (thread);
  32
  33   /* Threads' regcaches are created lazily, because biarch targets add
  34      the main thread/lwp before seeing it stop for the first time, and
  35      it is only after the target sees the thread stop for the first
  36      time that the target has a chance of determining the process's
  37      architecture.  IOW, when we first add the process's main thread
  38      we don't know which architecture/tdesc its regcache should
  39      have.  */
  40   if (regcache == NULL)
  41     {
  42       struct process_info *proc = get_thread_process (thread);
  43
  44       gdb_assert (proc->tdesc != NULL);
  45
  46       regcache = new_register_cache (proc->tdesc);
  47       set_inferior_regcache_data (thread, regcache);
  48     }
  49
  50   if (fetch && regcache->registers_valid == 0)
  51     {
  52       struct thread_info *saved_thread = current_thread;
  53
  54       current_thread = thread;
  55       /* Invalidate all registers, to prevent stale left-overs.  */
  56       memset (regcache->register_status, REG_UNAVAILABLE,
  57               regcache->tdesc->num_registers);
  58       fetch_inferior_registers (regcache, -1);
  59       current_thread = saved_thread;
  60       regcache->registers_valid = 1;
  61     }
  62
  63   return regcache;
  64 }
  65
  66 /* See common/common-regcache.h.  */
  67
  68 struct regcache *
  69 get_thread_regcache_for_ptid (ptid_t ptid)
  70 {
  71   return get_thread_regcache (find_thread_ptid (ptid), 1);
  72 }
  73
  74 void
  75 regcache_invalidate_thread (struct thread_info *thread)
  76 {
  77   struct regcache *regcache;
  78
  79   regcache = inferior_regcache_data (thread);
  80
  81   if (regcache == NULL)
  82     return;
  83
  84   if (regcache->registers_valid)
  85     {
  86       struct thread_info *saved_thread = current_thread;
  87
  88       current_thread = thread;
  89       store_inferior_registers (regcache, -1);
  90       current_thread = saved_thread;
  91     }
  92
  93   regcache->registers_valid = 0;
  94 }
  95
  96 static int
  97 regcache_invalidate_one (struct inferior_list_entry *entry,
  98                          void *pid_p)
  99 {
 100   struct thread_info *thread = (struct thread_info *) entry;
 101   int pid = *(int *) pid_p;
 102
 103   /* Only invalidate the regcaches of threads of this process.  */
 104   if (ptid_get_pid (entry->id) == pid)
 105     regcache_invalidate_thread (thread);
 106
 107   return 0;
 108 }
 109
 110 /* See regcache.h.  */
 111
 112 void
 113 regcache_invalidate_pid (int pid)
 114 {
 115   find_inferior (&all_threads, regcache_invalidate_one, &pid);
 116 }
 117
 118 /* See regcache.h.  */
 119
 120 void
 121 regcache_invalidate (void)
 122 {
 123   /* Only update the threads of the current process.  */
 124   int pid = ptid_get_pid (current_thread->entry.id);
 125
 126   regcache_invalidate_pid (pid);
 127 }
 128
 129 #endif
 130
 131 struct regcache *
 132 init_register_cache (struct regcache *regcache,
 133                      const struct target_desc *tdesc,
 134                      unsigned char *regbuf)
 135 {
 136   if (regbuf == NULL)
 137     {
 138 #ifndef IN_PROCESS_AGENT
 139       /* Make sure to zero-initialize the register cache when it is
 140          created, in case there are registers the target never
 141          fetches.  This way they'll read as zero instead of
 142          garbage.  */
 143       regcache->tdesc = tdesc;
 144       regcache->registers
 145         = (unsigned char *) xcalloc (1, tdesc->registers_size);
 146       regcache->registers_owned = 1;
 147       regcache->register_status
 148         = (unsigned char *) xmalloc (tdesc->num_registers);
 149       memset ((void *) regcache->register_status, REG_UNAVAILABLE,
 150               tdesc->num_registers);
 151 #else
 152       gdb_assert_not_reached ("can't allocate memory from the heap");
 153 #endif
 154     }
 155   else
 156     {
 157       regcache->tdesc = tdesc;
 158       regcache->registers = regbuf;
 159       regcache->registers_owned = 0;
 160 #ifndef IN_PROCESS_AGENT
 161       regcache->register_status = NULL;
 162 #endif
 163     }
 164
 165   regcache->registers_valid = 0;
 166
 167   return regcache;
 168 }
 169
 170 #ifndef IN_PROCESS_AGENT
 171
 172 struct regcache *
 173 new_register_cache (const struct target_desc *tdesc)
 174 {
 175   struct regcache *regcache = XCNEW (struct regcache);
 176
 177   gdb_assert (tdesc->registers_size != 0);
 178
 179   return init_register_cache (regcache, tdesc, NULL);
 180 }
 181
 182 void
 183 free_register_cache (struct regcache *regcache)
 184 {
 185   if (regcache)
 186     {
 187       if (regcache->registers_owned)
 188         free (regcache->registers);
 189       free (regcache->register_status);
 190       free (regcache);
 191     }
 192 }
 193
 194 #endif
 195
 196 void
 197 regcache_cpy (struct regcache *dst, struct regcache *src)
 198 {
 199   gdb_assert (src != NULL && dst != NULL);
 200   gdb_assert (src->tdesc == dst->tdesc);
 201   gdb_assert (src != dst);
 202
 203   memcpy (dst->registers, src->registers, src->tdesc->registers_size);
 204 #ifndef IN_PROCESS_AGENT
 205   if (dst->register_status != NULL && src->register_status != NULL)
 206     memcpy (dst->register_status, src->register_status,
 207             src->tdesc->num_registers);
 208 #endif
 209   dst->registers_valid = src->registers_valid;
 210 }
 211
 212
 213 #ifndef IN_PROCESS_AGENT
 214
 215 void
 216 registers_to_string (struct regcache *regcache, char *buf)
 217 {
 218   unsigned char *registers = regcache->registers;
 219   const struct target_desc *tdesc = regcache->tdesc;
 220   int i;
 221
 222   for (i = 0; i < tdesc->num_registers; i++)
 223     {
 224       if (regcache->register_status[i] == REG_VALID)
 225         {
 226           bin2hex (registers, buf, register_size (tdesc, i));
 227           buf += register_size (tdesc, i) * 2;
 228         }
 229       else
 230         {
 231           memset (buf, 'x', register_size (tdesc, i) * 2);
 232           buf += register_size (tdesc, i) * 2;
 233         }
 234       registers += register_size (tdesc, i);
 235     }
 236   *buf = '\0';
 237 }
 238
 239 void
 240 registers_from_string (struct regcache *regcache, char *buf)
 241 {
 242   int len = strlen (buf);
 243   unsigned char *registers = regcache->registers;
 244   const struct target_desc *tdesc = regcache->tdesc;
 245
 246   if (len != tdesc->registers_size * 2)
 247     {
 248       warning ("Wrong sized register packet (expected %d bytes, got %d)",
 249                2 * tdesc->registers_size, len);
 250       if (len > tdesc->registers_size * 2)
 251         len = tdesc->registers_size * 2;
 252     }
 253   hex2bin (buf, registers, len / 2);
 254 }
 255
 256 struct reg *
 257 find_register_by_name (const struct target_desc *tdesc, const char *name)
 258 {
 259   int i;
 260
 261   for (i = 0; i < tdesc->num_registers; i++)
 262     if (strcmp (name, tdesc->reg_defs[i].name) == 0)
 263       return &tdesc->reg_defs[i];
 264   internal_error (__FILE__, __LINE__, "Unknown register %s requested",
 265                   name);
 266 }
 267
 268 int
 269 find_regno (const struct target_desc *tdesc, const char *name)
 270 {
 271   int i;
 272
 273   for (i = 0; i < tdesc->num_registers; i++)
 274     if (strcmp (name, tdesc->reg_defs[i].name) == 0)
 275       return i;
 276   internal_error (__FILE__, __LINE__, "Unknown register %s requested",
 277                   name);
 278 }
 279
 280 struct reg *
 281 find_register_by_number (const struct target_desc *tdesc, int n)
 282 {
 283   return &tdesc->reg_defs[n];
 284 }
 285
 286 #endif
 287
 288 #ifndef IN_PROCESS_AGENT
 289 static void
 290 free_register_cache_thread (struct thread_info *thread)
 291 {
 292   struct regcache *regcache = inferior_regcache_data (thread);
 293
 294   if (regcache != NULL)
 295     {
 296       regcache_invalidate_thread (thread);
 297       free_register_cache (regcache);
 298       set_inferior_regcache_data (thread, NULL);
 299     }
 300 }
 301
 302 static void
 303 free_register_cache_thread_one (struct inferior_list_entry *entry)
 304 {
 305   struct thread_info *thread = (struct thread_info *) entry;
 306
 307   free_register_cache_thread (thread);
 308 }
 309
 310 void
 311 regcache_release (void)
 312 {
 313   /* Flush and release all pre-existing register caches.  */
 314   for_each_inferior (&all_threads, free_register_cache_thread_one);
 315 }
 316 #endif
 317
 318 int
 319 register_cache_size (const struct target_desc *tdesc)
 320 {
 321   return tdesc->registers_size;
 322 }
 323
 324 int
 325 register_size (const struct target_desc *tdesc, int n)
 326 {
 327   return tdesc->reg_defs[n].size / 8;
 328 }
 329
 330 /* See common/common-regcache.h.  */
 331
 332 int
 333 regcache_register_size (const struct regcache *regcache, int n)
 334 {
 335   return register_size (regcache->tdesc, n);
 336 }
 337
 338 static unsigned char *
 339 register_data (struct regcache *regcache, int n, int fetch)
 340 {
 341   return regcache->registers + regcache->tdesc->reg_defs[n].offset / 8;
 342 }
 343
 344 /* Supply register N, whose contents are stored in BUF, to REGCACHE.
 345    If BUF is NULL, the register's value is recorded as
 346    unavailable.  */
 347
 348 void
 349 supply_register (struct regcache *regcache, int n, const void *buf)
 350 {
 351   if (buf)
 352     {
 353       memcpy (register_data (regcache, n, 0), buf,
 354               register_size (regcache->tdesc, n));
 355 #ifndef IN_PROCESS_AGENT
 356       if (regcache->register_status != NULL)
 357         regcache->register_status[n] = REG_VALID;
 358 #endif
 359     }
 360   else
 361     {
 362       memset (register_data (regcache, n, 0), 0,
 363               register_size (regcache->tdesc, n));
 364 #ifndef IN_PROCESS_AGENT
 365       if (regcache->register_status != NULL)
 366         regcache->register_status[n] = REG_UNAVAILABLE;
 367 #endif
 368     }
 369 }
 370
 371 /* Supply register N with value zero to REGCACHE.  */
 372
 373 void
 374 supply_register_zeroed (struct regcache *regcache, int n)
 375 {
 376   memset (register_data (regcache, n, 0), 0,
 377           register_size (regcache->tdesc, n));
 378 #ifndef IN_PROCESS_AGENT
 379   if (regcache->register_status != NULL)
 380     regcache->register_status[n] = REG_VALID;
 381 #endif
 382 }
 383
 384 /* Supply the whole register set whose contents are stored in BUF, to
 385    REGCACHE.  If BUF is NULL, all the registers' values are recorded
 386    as unavailable.  */
 387
 388 void
 389 supply_regblock (struct regcache *regcache, const void *buf)
 390 {
 391   if (buf)
 392     {
 393       const struct target_desc *tdesc = regcache->tdesc;
 394
 395       memcpy (regcache->registers, buf, tdesc->registers_size);
 396 #ifndef IN_PROCESS_AGENT
 397       {
 398         int i;
 399
 400         for (i = 0; i < tdesc->num_registers; i++)
 401           regcache->register_status[i] = REG_VALID;
 402       }
 403 #endif
 404     }
 405   else
 406     {
 407       const struct target_desc *tdesc = regcache->tdesc;
 408
 409       memset (regcache->registers, 0, tdesc->registers_size);
 410 #ifndef IN_PROCESS_AGENT
 411       {
 412         int i;
 413
 414         for (i = 0; i < tdesc->num_registers; i++)
 415           regcache->register_status[i] = REG_UNAVAILABLE;
 416       }
 417 #endif
 418     }
 419 }
 420
 421 #ifndef IN_PROCESS_AGENT
 422
 423 void
 424 supply_register_by_name (struct regcache *regcache,
 425                          const char *name, const void *buf)
 426 {
 427   supply_register (regcache, find_regno (regcache->tdesc, name), buf);
 428 }
 429
 430 #endif
 431
 432 void
 433 collect_register (struct regcache *regcache, int n, void *buf)
 434 {
 435   memcpy (buf, register_data (regcache, n, 1),
 436           register_size (regcache->tdesc, n));
 437 }
 438
 439 enum register_status
 440 regcache_raw_read_unsigned (struct regcache *regcache, int regnum,
 441                             ULONGEST *val)
 442 {
 443   int size;
 444
 445   gdb_assert (regcache != NULL);
 446   gdb_assert (regnum >= 0 && regnum < regcache->tdesc->num_registers);
 447
 448   size = register_size (regcache->tdesc, regnum);
 449
 450   if (size > (int) sizeof (ULONGEST))
 451     error (_("That operation is not available on integers of more than"
 452             "%d bytes."),
 453           (int) sizeof (ULONGEST));
 454
 455   collect_register (regcache, regnum, val);
 456
 457   return REG_VALID;
 458 }
 459
 460 #ifndef IN_PROCESS_AGENT
 461
 462 void
 463 collect_register_as_string (struct regcache *regcache, int n, char *buf)
 464 {
 465   bin2hex (register_data (regcache, n, 1), buf,
 466            register_size (regcache->tdesc, n));
 467 }
 468
 469 void
 470 collect_register_by_name (struct regcache *regcache,
 471                           const char *name, void *buf)
 472 {
 473   collect_register (regcache, find_regno (regcache->tdesc, name), buf);
 474 }
 475
 476 /* Special handling for register PC.  */
 477
 478 CORE_ADDR
 479 regcache_read_pc (struct regcache *regcache)
 480 {
 481   CORE_ADDR pc_val;
 482
 483   if (the_target->read_pc)
 484     pc_val = the_target->read_pc (regcache);
 485   else
 486     internal_error (__FILE__, __LINE__,
 487                     "regcache_read_pc: Unable to find PC");
 488
 489   return pc_val;
 490 }
 491
 492 void
 493 regcache_write_pc (struct regcache *regcache, CORE_ADDR pc)
 494 {
 495   if (the_target->write_pc)
 496     the_target->write_pc (regcache, pc);
 497   else
 498     internal_error (__FILE__, __LINE__,
 499                     "regcache_write_pc: Unable to update PC");
 500 }
 501
 502 #endif