gdb/gdbserver/regcache.c

   1 /* Register support routines for the remote server for GDB.
   2    Copyright (C) 2001-2017 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 = thread_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_thread_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->reg_defs.size ());
  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 = thread_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 (thread_info *thread, void *pid_p)
  98 {
  99   int pid = *(int *) pid_p;
 100
 101   /* Only invalidate the regcaches of threads of this process.  */
 102   if (thread->id.pid () == pid)
 103     regcache_invalidate_thread (thread);
 104
 105   return 0;
 106 }
 107
 108 /* See regcache.h.  */
 109
 110 void
 111 regcache_invalidate_pid (int pid)
 112 {
 113   find_inferior (&all_threads, regcache_invalidate_one, &pid);
 114 }
 115
 116 /* See regcache.h.  */
 117
 118 void
 119 regcache_invalidate (void)
 120 {
 121   /* Only update the threads of the current process.  */
 122   int pid = current_thread->id.pid ();
 123
 124   regcache_invalidate_pid (pid);
 125 }
 126
 127 #endif
 128
 129 struct regcache *
 130 init_register_cache (struct regcache *regcache,
 131                      const struct target_desc *tdesc,
 132                      unsigned char *regbuf)
 133 {
 134   if (regbuf == NULL)
 135     {
 136 #ifndef IN_PROCESS_AGENT
 137       /* Make sure to zero-initialize the register cache when it is
 138          created, in case there are registers the target never
 139          fetches.  This way they'll read as zero instead of
 140          garbage.  */
 141       regcache->tdesc = tdesc;
 142       regcache->registers
 143         = (unsigned char *) xcalloc (1, tdesc->registers_size);
 144       regcache->registers_owned = 1;
 145       regcache->register_status
 146         = (unsigned char *) xmalloc (tdesc->reg_defs.size ());
 147       memset ((void *) regcache->register_status, REG_UNAVAILABLE,
 148               tdesc->reg_defs.size ());
 149 #else
 150       gdb_assert_not_reached ("can't allocate memory from the heap");
 151 #endif
 152     }
 153   else
 154     {
 155       regcache->tdesc = tdesc;
 156       regcache->registers = regbuf;
 157       regcache->registers_owned = 0;
 158 #ifndef IN_PROCESS_AGENT
 159       regcache->register_status = NULL;
 160 #endif
 161     }
 162
 163   regcache->registers_valid = 0;
 164
 165   return regcache;
 166 }
 167
 168 #ifndef IN_PROCESS_AGENT
 169
 170 struct regcache *
 171 new_register_cache (const struct target_desc *tdesc)
 172 {
 173   struct regcache *regcache = XCNEW (struct regcache);
 174
 175   gdb_assert (tdesc->registers_size != 0);
 176
 177   return init_register_cache (regcache, tdesc, NULL);
 178 }
 179
 180 void
 181 free_register_cache (struct regcache *regcache)
 182 {
 183   if (regcache)
 184     {
 185       if (regcache->registers_owned)
 186         free (regcache->registers);
 187       free (regcache->register_status);
 188       free (regcache);
 189     }
 190 }
 191
 192 #endif
 193
 194 void
 195 regcache_cpy (struct regcache *dst, struct regcache *src)
 196 {
 197   gdb_assert (src != NULL && dst != NULL);
 198   gdb_assert (src->tdesc == dst->tdesc);
 199   gdb_assert (src != dst);
 200
 201   memcpy (dst->registers, src->registers, src->tdesc->registers_size);
 202 #ifndef IN_PROCESS_AGENT
 203   if (dst->register_status != NULL && src->register_status != NULL)
 204     memcpy (dst->register_status, src->register_status,
 205             src->tdesc->reg_defs.size ());
 206 #endif
 207   dst->registers_valid = src->registers_valid;
 208 }
 209
 210
 211 #ifndef IN_PROCESS_AGENT
 212
 213 void
 214 registers_to_string (struct regcache *regcache, char *buf)
 215 {
 216   unsigned char *registers = regcache->registers;
 217   const struct target_desc *tdesc = regcache->tdesc;
 218
 219   for (int i = 0; i < tdesc->reg_defs.size (); ++i)
 220     {
 221       struct reg *reg = tdesc->reg_defs[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 int
 256 find_regno (const struct target_desc *tdesc, const char *name)
 257 {
 258   for (int i = 0; i < tdesc->reg_defs.size (); ++i)
 259     {
 260       struct reg *reg = tdesc->reg_defs[i];
 261
 262       if (strcmp (name, reg->name) == 0)
 263         return i;
 264     }
 265   internal_error (__FILE__, __LINE__, "Unknown register %s requested",
 266                   name);
 267 }
 268
 269 #endif
 270
 271 struct reg *
 272 find_register_by_number (const struct target_desc *tdesc, int n)
 273 {
 274   return tdesc->reg_defs[n];
 275 }
 276
 277 #ifndef IN_PROCESS_AGENT
 278 static void
 279 free_register_cache_thread (struct thread_info *thread)
 280 {
 281   struct regcache *regcache = thread_regcache_data (thread);
 282
 283   if (regcache != NULL)
 284     {
 285       regcache_invalidate_thread (thread);
 286       free_register_cache (regcache);
 287       set_thread_regcache_data (thread, NULL);
 288     }
 289 }
 290
 291 void
 292 regcache_release (void)
 293 {
 294   /* Flush and release all pre-existing register caches.  */
 295   for_each_inferior (&all_threads, free_register_cache_thread);
 296 }
 297 #endif
 298
 299 int
 300 register_cache_size (const struct target_desc *tdesc)
 301 {
 302   return tdesc->registers_size;
 303 }
 304
 305 int
 306 register_size (const struct target_desc *tdesc, int n)
 307 {
 308   return find_register_by_number (tdesc, n)->size / 8;
 309 }
 310
 311 /* See common/common-regcache.h.  */
 312
 313 int
 314 regcache_register_size (const struct regcache *regcache, int n)
 315 {
 316   return register_size (regcache->tdesc, n);
 317 }
 318
 319 static unsigned char *
 320 register_data (struct regcache *regcache, int n, int fetch)
 321 {
 322   return (regcache->registers
 323           + find_register_by_number (regcache->tdesc, n)->offset / 8);
 324 }
 325
 326 /* Supply register N, whose contents are stored in BUF, to REGCACHE.
 327    If BUF is NULL, the register's value is recorded as
 328    unavailable.  */
 329
 330 void
 331 supply_register (struct regcache *regcache, int n, const void *buf)
 332 {
 333   if (buf)
 334     {
 335       memcpy (register_data (regcache, n, 0), buf,
 336               register_size (regcache->tdesc, n));
 337 #ifndef IN_PROCESS_AGENT
 338       if (regcache->register_status != NULL)
 339         regcache->register_status[n] = REG_VALID;
 340 #endif
 341     }
 342   else
 343     {
 344       memset (register_data (regcache, n, 0), 0,
 345               register_size (regcache->tdesc, n));
 346 #ifndef IN_PROCESS_AGENT
 347       if (regcache->register_status != NULL)
 348         regcache->register_status[n] = REG_UNAVAILABLE;
 349 #endif
 350     }
 351 }
 352
 353 /* Supply register N with value zero to REGCACHE.  */
 354
 355 void
 356 supply_register_zeroed (struct regcache *regcache, int n)
 357 {
 358   memset (register_data (regcache, n, 0), 0,
 359           register_size (regcache->tdesc, n));
 360 #ifndef IN_PROCESS_AGENT
 361   if (regcache->register_status != NULL)
 362     regcache->register_status[n] = REG_VALID;
 363 #endif
 364 }
 365
 366 /* Supply the whole register set whose contents are stored in BUF, to
 367    REGCACHE.  If BUF is NULL, all the registers' values are recorded
 368    as unavailable.  */
 369
 370 void
 371 supply_regblock (struct regcache *regcache, const void *buf)
 372 {
 373   if (buf)
 374     {
 375       const struct target_desc *tdesc = regcache->tdesc;
 376
 377       memcpy (regcache->registers, buf, tdesc->registers_size);
 378 #ifndef IN_PROCESS_AGENT
 379       {
 380         int i;
 381
 382         for (i = 0; i < tdesc->reg_defs.size (); i++)
 383           regcache->register_status[i] = REG_VALID;
 384       }
 385 #endif
 386     }
 387   else
 388     {
 389       const struct target_desc *tdesc = regcache->tdesc;
 390
 391       memset (regcache->registers, 0, tdesc->registers_size);
 392 #ifndef IN_PROCESS_AGENT
 393       {
 394         int i;
 395
 396         for (i = 0; i < tdesc->reg_defs.size (); i++)
 397           regcache->register_status[i] = REG_UNAVAILABLE;
 398       }
 399 #endif
 400     }
 401 }
 402
 403 #ifndef IN_PROCESS_AGENT
 404
 405 void
 406 supply_register_by_name (struct regcache *regcache,
 407                          const char *name, const void *buf)
 408 {
 409   supply_register (regcache, find_regno (regcache->tdesc, name), buf);
 410 }
 411
 412 #endif
 413
 414 void
 415 collect_register (struct regcache *regcache, int n, void *buf)
 416 {
 417   memcpy (buf, register_data (regcache, n, 1),
 418           register_size (regcache->tdesc, n));
 419 }
 420
 421 enum register_status
 422 regcache_raw_read_unsigned (struct regcache *regcache, int regnum,
 423                             ULONGEST *val)
 424 {
 425   int size;
 426
 427   gdb_assert (regcache != NULL);
 428   gdb_assert (regnum >= 0
 429               && regnum < regcache->tdesc->reg_defs.size ());
 430
 431   size = register_size (regcache->tdesc, regnum);
 432
 433   if (size > (int) sizeof (ULONGEST))
 434     error (_("That operation is not available on integers of more than"
 435             "%d bytes."),
 436           (int) sizeof (ULONGEST));
 437
 438   *val = 0;
 439   collect_register (regcache, regnum, val);
 440
 441   return REG_VALID;
 442 }
 443
 444 #ifndef IN_PROCESS_AGENT
 445
 446 void
 447 collect_register_as_string (struct regcache *regcache, int n, char *buf)
 448 {
 449   bin2hex (register_data (regcache, n, 1), buf,
 450            register_size (regcache->tdesc, n));
 451 }
 452
 453 void
 454 collect_register_by_name (struct regcache *regcache,
 455                           const char *name, void *buf)
 456 {
 457   collect_register (regcache, find_regno (regcache->tdesc, name), buf);
 458 }
 459
 460 /* Special handling for register PC.  */
 461
 462 CORE_ADDR
 463 regcache_read_pc (struct regcache *regcache)
 464 {
 465   CORE_ADDR pc_val;
 466
 467   if (the_target->read_pc)
 468     pc_val = the_target->read_pc (regcache);
 469   else
 470     internal_error (__FILE__, __LINE__,
 471                     "regcache_read_pc: Unable to find PC");
 472
 473   return pc_val;
 474 }
 475
 476 void
 477 regcache_write_pc (struct regcache *regcache, CORE_ADDR pc)
 478 {
 479   if (the_target->write_pc)
 480     the_target->write_pc (regcache, pc);
 481   else
 482     internal_error (__FILE__, __LINE__,
 483                     "regcache_write_pc: Unable to update PC");
 484 }
 485
 486 #endif