gdb/gdbserver/regcache.c

   1 /* Register support routines for the remote server for GDB.
   2    Copyright (C) 2001-2015 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 *) xcalloc (1, tdesc->num_registers);
 149       gdb_assert (REG_UNAVAILABLE == 0);
 150 #else
 151       gdb_assert_not_reached ("can't allocate memory from the heap");
 152 #endif
 153     }
 154   else
 155     {
 156       regcache->tdesc = tdesc;
 157       regcache->registers = regbuf;
 158       regcache->registers_owned = 0;
 159 #ifndef IN_PROCESS_AGENT
 160       regcache->register_status = NULL;
 161 #endif
 162     }
 163
 164   regcache->registers_valid = 0;
 165
 166   return regcache;
 167 }
 168
 169 #ifndef IN_PROCESS_AGENT
 170
 171 struct regcache *
 172 new_register_cache (const struct target_desc *tdesc)
 173 {
 174   struct regcache *regcache = XCNEW (struct regcache);
 175
 176   gdb_assert (tdesc->registers_size != 0);
 177
 178   return init_register_cache (regcache, tdesc, NULL);
 179 }
 180
 181 void
 182 free_register_cache (struct regcache *regcache)
 183 {
 184   if (regcache)
 185     {
 186       if (regcache->registers_owned)
 187         free (regcache->registers);
 188       free (regcache->register_status);
 189       free (regcache);
 190     }
 191 }
 192
 193 #endif
 194
 195 void
 196 regcache_cpy (struct regcache *dst, struct regcache *src)
 197 {
 198   gdb_assert (src != NULL && dst != NULL);
 199   gdb_assert (src->tdesc == dst->tdesc);
 200   gdb_assert (src != dst);
 201
 202   memcpy (dst->registers, src->registers, src->tdesc->registers_size);
 203 #ifndef IN_PROCESS_AGENT
 204   if (dst->register_status != NULL && src->register_status != NULL)
 205     memcpy (dst->register_status, src->register_status,
 206             src->tdesc->num_registers);
 207 #endif
 208   dst->registers_valid = src->registers_valid;
 209 }
 210
 211
 212 #ifndef IN_PROCESS_AGENT
 213
 214 void
 215 registers_to_string (struct regcache *regcache, char *buf)
 216 {
 217   unsigned char *registers = regcache->registers;
 218   const struct target_desc *tdesc = regcache->tdesc;
 219   int i;
 220
 221   for (i = 0; i < tdesc->num_registers; i++)
 222     {
 223       if (regcache->register_status[i] == REG_VALID)
 224         {
 225           bin2hex (registers, buf, register_size (tdesc, i));
 226           buf += register_size (tdesc, i) * 2;
 227         }
 228       else
 229         {
 230           memset (buf, 'x', register_size (tdesc, i) * 2);
 231           buf += register_size (tdesc, i) * 2;
 232         }
 233       registers += register_size (tdesc, i);
 234     }
 235   *buf = '\0';
 236 }
 237
 238 void
 239 registers_from_string (struct regcache *regcache, char *buf)
 240 {
 241   int len = strlen (buf);
 242   unsigned char *registers = regcache->registers;
 243   const struct target_desc *tdesc = regcache->tdesc;
 244
 245   if (len != tdesc->registers_size * 2)
 246     {
 247       warning ("Wrong sized register packet (expected %d bytes, got %d)",
 248                2 * tdesc->registers_size, len);
 249       if (len > tdesc->registers_size * 2)
 250         len = tdesc->registers_size * 2;
 251     }
 252   hex2bin (buf, registers, len / 2);
 253 }
 254
 255 struct reg *
 256 find_register_by_name (const struct target_desc *tdesc, const char *name)
 257 {
 258   int i;
 259
 260   for (i = 0; i < tdesc->num_registers; i++)
 261     if (strcmp (name, tdesc->reg_defs[i].name) == 0)
 262       return &tdesc->reg_defs[i];
 263   internal_error (__FILE__, __LINE__, "Unknown register %s requested",
 264                   name);
 265 }
 266
 267 int
 268 find_regno (const struct target_desc *tdesc, const char *name)
 269 {
 270   int i;
 271
 272   for (i = 0; i < tdesc->num_registers; i++)
 273     if (strcmp (name, tdesc->reg_defs[i].name) == 0)
 274       return i;
 275   internal_error (__FILE__, __LINE__, "Unknown register %s requested",
 276                   name);
 277 }
 278
 279 struct reg *
 280 find_register_by_number (const struct target_desc *tdesc, int n)
 281 {
 282   return &tdesc->reg_defs[n];
 283 }
 284
 285 #endif
 286
 287 #ifndef IN_PROCESS_AGENT
 288 static void
 289 free_register_cache_thread (struct thread_info *thread)
 290 {
 291   struct regcache *regcache = inferior_regcache_data (thread);
 292
 293   if (regcache != NULL)
 294     {
 295       regcache_invalidate_thread (thread);
 296       free_register_cache (regcache);
 297       set_inferior_regcache_data (thread, NULL);
 298     }
 299 }
 300
 301 static void
 302 free_register_cache_thread_one (struct inferior_list_entry *entry)
 303 {
 304   struct thread_info *thread = (struct thread_info *) entry;
 305
 306   free_register_cache_thread (thread);
 307 }
 308
 309 void
 310 regcache_release (void)
 311 {
 312   /* Flush and release all pre-existing register caches.  */
 313   for_each_inferior (&all_threads, free_register_cache_thread_one);
 314 }
 315 #endif
 316
 317 int
 318 register_cache_size (const struct target_desc *tdesc)
 319 {
 320   return tdesc->registers_size;
 321 }
 322
 323 int
 324 register_size (const struct target_desc *tdesc, int n)
 325 {
 326   return tdesc->reg_defs[n].size / 8;
 327 }
 328
 329 /* See common/common-regcache.h.  */
 330
 331 int
 332 regcache_register_size (const struct regcache *regcache, int n)
 333 {
 334   return register_size (regcache->tdesc, n);
 335 }
 336
 337 static unsigned char *
 338 register_data (struct regcache *regcache, int n, int fetch)
 339 {
 340   return regcache->registers + regcache->tdesc->reg_defs[n].offset / 8;
 341 }
 342
 343 /* Supply register N, whose contents are stored in BUF, to REGCACHE.
 344    If BUF is NULL, the register's value is recorded as
 345    unavailable.  */
 346
 347 void
 348 supply_register (struct regcache *regcache, int n, const void *buf)
 349 {
 350   if (buf)
 351     {
 352       memcpy (register_data (regcache, n, 0), buf,
 353               register_size (regcache->tdesc, n));
 354 #ifndef IN_PROCESS_AGENT
 355       if (regcache->register_status != NULL)
 356         regcache->register_status[n] = REG_VALID;
 357 #endif
 358     }
 359   else
 360     {
 361       memset (register_data (regcache, n, 0), 0,
 362               register_size (regcache->tdesc, n));
 363 #ifndef IN_PROCESS_AGENT
 364       if (regcache->register_status != NULL)
 365         regcache->register_status[n] = REG_UNAVAILABLE;
 366 #endif
 367     }
 368 }
 369
 370 /* Supply register N with value zero to REGCACHE.  */
 371
 372 void
 373 supply_register_zeroed (struct regcache *regcache, int n)
 374 {
 375   memset (register_data (regcache, n, 0), 0,
 376           register_size (regcache->tdesc, n));
 377 #ifndef IN_PROCESS_AGENT
 378   if (regcache->register_status != NULL)
 379     regcache->register_status[n] = REG_VALID;
 380 #endif
 381 }
 382
 383 /* Supply the whole register set whose contents are stored in BUF, to
 384    REGCACHE.  If BUF is NULL, all the registers' values are recorded
 385    as unavailable.  */
 386
 387 void
 388 supply_regblock (struct regcache *regcache, const void *buf)
 389 {
 390   if (buf)
 391     {
 392       const struct target_desc *tdesc = regcache->tdesc;
 393
 394       memcpy (regcache->registers, buf, tdesc->registers_size);
 395 #ifndef IN_PROCESS_AGENT
 396       {
 397         int i;
 398
 399         for (i = 0; i < tdesc->num_registers; i++)
 400           regcache->register_status[i] = REG_VALID;
 401       }
 402 #endif
 403     }
 404   else
 405     {
 406       const struct target_desc *tdesc = regcache->tdesc;
 407
 408       memset (regcache->registers, 0, tdesc->registers_size);
 409 #ifndef IN_PROCESS_AGENT
 410       {
 411         int i;
 412
 413         for (i = 0; i < tdesc->num_registers; i++)
 414           regcache->register_status[i] = REG_UNAVAILABLE;
 415       }
 416 #endif
 417     }
 418 }
 419
 420 #ifndef IN_PROCESS_AGENT
 421
 422 void
 423 supply_register_by_name (struct regcache *regcache,
 424                          const char *name, const void *buf)
 425 {
 426   supply_register (regcache, find_regno (regcache->tdesc, name), buf);
 427 }
 428
 429 #endif
 430
 431 void
 432 collect_register (struct regcache *regcache, int n, void *buf)
 433 {
 434   memcpy (buf, register_data (regcache, n, 1),
 435           register_size (regcache->tdesc, n));
 436 }
 437
 438 #ifndef IN_PROCESS_AGENT
 439
 440 void
 441 collect_register_as_string (struct regcache *regcache, int n, char *buf)
 442 {
 443   bin2hex (register_data (regcache, n, 1), buf,
 444            register_size (regcache->tdesc, n));
 445 }
 446
 447 void
 448 collect_register_by_name (struct regcache *regcache,
 449                           const char *name, void *buf)
 450 {
 451   collect_register (regcache, find_regno (regcache->tdesc, name), buf);
 452 }
 453
 454 /* Special handling for register PC.  */
 455
 456 CORE_ADDR
 457 regcache_read_pc (struct regcache *regcache)
 458 {
 459   CORE_ADDR pc_val;
 460
 461   if (the_target->read_pc)
 462     pc_val = the_target->read_pc (regcache);
 463   else
 464     internal_error (__FILE__, __LINE__,
 465                     "regcache_read_pc: Unable to find PC");
 466
 467   return pc_val;
 468 }
 469
 470 void
 471 regcache_write_pc (struct regcache *regcache, CORE_ADDR pc)
 472 {
 473   if (the_target->write_pc)
 474     the_target->write_pc (regcache, pc);
 475   else
 476     internal_error (__FILE__, __LINE__,
 477                     "regcache_write_pc: Unable to update PC");
 478 }
 479
 480 #endif