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               VEC_length (tdesc_reg_p, regcache->tdesc->reg_defs));
  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 (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 (VEC_length (tdesc_reg_p, tdesc->reg_defs));
 149       memset ((void *) regcache->register_status, REG_UNAVAILABLE,
 150               VEC_length (tdesc_reg_p, tdesc->reg_defs));
 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             VEC_length (tdesc_reg_p, src->tdesc->reg_defs));
 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   reg *reg;
 222
 223   for (i = 0; VEC_iterate (tdesc_reg_p, tdesc->reg_defs, i, reg); i++)
 224     {
 225       if (regcache->register_status[i] == REG_VALID)
 226         {
 227           bin2hex (registers, buf, register_size (tdesc, i));
 228           buf += register_size (tdesc, i) * 2;
 229         }
 230       else
 231         {
 232           memset (buf, 'x', register_size (tdesc, i) * 2);
 233           buf += register_size (tdesc, i) * 2;
 234         }
 235       registers += register_size (tdesc, i);
 236     }
 237   *buf = '\0';
 238 }
 239
 240 void
 241 registers_from_string (struct regcache *regcache, char *buf)
 242 {
 243   int len = strlen (buf);
 244   unsigned char *registers = regcache->registers;
 245   const struct target_desc *tdesc = regcache->tdesc;
 246
 247   if (len != tdesc->registers_size * 2)
 248     {
 249       warning ("Wrong sized register packet (expected %d bytes, got %d)",
 250                2 * tdesc->registers_size, len);
 251       if (len > tdesc->registers_size * 2)
 252         len = tdesc->registers_size * 2;
 253     }
 254   hex2bin (buf, registers, len / 2);
 255 }
 256
 257 int
 258 find_regno (const struct target_desc *tdesc, const char *name)
 259 {
 260   int i;
 261   reg *reg;
 262
 263   for (i = 0; VEC_iterate (tdesc_reg_p, tdesc->reg_defs, i, reg); i++)
 264     if (strcmp (name, reg->name) == 0)
 265       return i;
 266   internal_error (__FILE__, __LINE__, "Unknown register %s requested",
 267                   name);
 268 }
 269
 270 #endif
 271
 272 struct reg *
 273 find_register_by_number (const struct target_desc *tdesc, int n)
 274 {
 275   return VEC_index (tdesc_reg_p, tdesc->reg_defs, n);
 276 }
 277
 278 #ifndef IN_PROCESS_AGENT
 279 static void
 280 free_register_cache_thread (struct thread_info *thread)
 281 {
 282   struct regcache *regcache = thread_regcache_data (thread);
 283
 284   if (regcache != NULL)
 285     {
 286       regcache_invalidate_thread (thread);
 287       free_register_cache (regcache);
 288       set_thread_regcache_data (thread, NULL);
 289     }
 290 }
 291
 292 static void
 293 free_register_cache_thread_one (struct inferior_list_entry *entry)
 294 {
 295   struct thread_info *thread = (struct thread_info *) entry;
 296
 297   free_register_cache_thread (thread);
 298 }
 299
 300 void
 301 regcache_release (void)
 302 {
 303   /* Flush and release all pre-existing register caches.  */
 304   for_each_inferior (&all_threads, free_register_cache_thread_one);
 305 }
 306 #endif
 307
 308 int
 309 register_cache_size (const struct target_desc *tdesc)
 310 {
 311   return tdesc->registers_size;
 312 }
 313
 314 int
 315 register_size (const struct target_desc *tdesc, int n)
 316 {
 317   return find_register_by_number (tdesc, n)->size / 8;
 318 }
 319
 320 /* See common/common-regcache.h.  */
 321
 322 int
 323 regcache_register_size (const struct regcache *regcache, int n)
 324 {
 325   return register_size (regcache->tdesc, n);
 326 }
 327
 328 static unsigned char *
 329 register_data (struct regcache *regcache, int n, int fetch)
 330 {
 331   return (regcache->registers
 332           + find_register_by_number (regcache->tdesc, n)->offset / 8);
 333 }
 334
 335 /* Supply register N, whose contents are stored in BUF, to REGCACHE.
 336    If BUF is NULL, the register's value is recorded as
 337    unavailable.  */
 338
 339 void
 340 supply_register (struct regcache *regcache, int n, const void *buf)
 341 {
 342   if (buf)
 343     {
 344       memcpy (register_data (regcache, n, 0), buf,
 345               register_size (regcache->tdesc, n));
 346 #ifndef IN_PROCESS_AGENT
 347       if (regcache->register_status != NULL)
 348         regcache->register_status[n] = REG_VALID;
 349 #endif
 350     }
 351   else
 352     {
 353       memset (register_data (regcache, n, 0), 0,
 354               register_size (regcache->tdesc, n));
 355 #ifndef IN_PROCESS_AGENT
 356       if (regcache->register_status != NULL)
 357         regcache->register_status[n] = REG_UNAVAILABLE;
 358 #endif
 359     }
 360 }
 361
 362 /* Supply register N with value zero to REGCACHE.  */
 363
 364 void
 365 supply_register_zeroed (struct regcache *regcache, int n)
 366 {
 367   memset (register_data (regcache, n, 0), 0,
 368           register_size (regcache->tdesc, n));
 369 #ifndef IN_PROCESS_AGENT
 370   if (regcache->register_status != NULL)
 371     regcache->register_status[n] = REG_VALID;
 372 #endif
 373 }
 374
 375 /* Supply the whole register set whose contents are stored in BUF, to
 376    REGCACHE.  If BUF is NULL, all the registers' values are recorded
 377    as unavailable.  */
 378
 379 void
 380 supply_regblock (struct regcache *regcache, const void *buf)
 381 {
 382   if (buf)
 383     {
 384       const struct target_desc *tdesc = regcache->tdesc;
 385
 386       memcpy (regcache->registers, buf, tdesc->registers_size);
 387 #ifndef IN_PROCESS_AGENT
 388       {
 389         int i;
 390
 391         for (i = 0; i < VEC_length (tdesc_reg_p, tdesc->reg_defs); i++)
 392           regcache->register_status[i] = REG_VALID;
 393       }
 394 #endif
 395     }
 396   else
 397     {
 398       const struct target_desc *tdesc = regcache->tdesc;
 399
 400       memset (regcache->registers, 0, tdesc->registers_size);
 401 #ifndef IN_PROCESS_AGENT
 402       {
 403         int i;
 404
 405         for (i = 0; i < VEC_length (tdesc_reg_p, tdesc->reg_defs); i++)
 406           regcache->register_status[i] = REG_UNAVAILABLE;
 407       }
 408 #endif
 409     }
 410 }
 411
 412 #ifndef IN_PROCESS_AGENT
 413
 414 void
 415 supply_register_by_name (struct regcache *regcache,
 416                          const char *name, const void *buf)
 417 {
 418   supply_register (regcache, find_regno (regcache->tdesc, name), buf);
 419 }
 420
 421 #endif
 422
 423 void
 424 collect_register (struct regcache *regcache, int n, void *buf)
 425 {
 426   memcpy (buf, register_data (regcache, n, 1),
 427           register_size (regcache->tdesc, n));
 428 }
 429
 430 enum register_status
 431 regcache_raw_read_unsigned (struct regcache *regcache, int regnum,
 432                             ULONGEST *val)
 433 {
 434   int size;
 435
 436   gdb_assert (regcache != NULL);
 437   gdb_assert (regnum >= 0
 438               && regnum < VEC_length (tdesc_reg_p, regcache->tdesc->reg_defs));
 439
 440   size = register_size (regcache->tdesc, regnum);
 441
 442   if (size > (int) sizeof (ULONGEST))
 443     error (_("That operation is not available on integers of more than"
 444             "%d bytes."),
 445           (int) sizeof (ULONGEST));
 446
 447   *val = 0;
 448   collect_register (regcache, regnum, val);
 449
 450   return REG_VALID;
 451 }
 452
 453 #ifndef IN_PROCESS_AGENT
 454
 455 void
 456 collect_register_as_string (struct regcache *regcache, int n, char *buf)
 457 {
 458   bin2hex (register_data (regcache, n, 1), buf,
 459            register_size (regcache->tdesc, n));
 460 }
 461
 462 void
 463 collect_register_by_name (struct regcache *regcache,
 464                           const char *name, void *buf)
 465 {
 466   collect_register (regcache, find_regno (regcache->tdesc, name), buf);
 467 }
 468
 469 /* Special handling for register PC.  */
 470
 471 CORE_ADDR
 472 regcache_read_pc (struct regcache *regcache)
 473 {
 474   CORE_ADDR pc_val;
 475
 476   if (the_target->read_pc)
 477     pc_val = the_target->read_pc (regcache);
 478   else
 479     internal_error (__FILE__, __LINE__,
 480                     "regcache_read_pc: Unable to find PC");
 481
 482   return pc_val;
 483 }
 484
 485 void
 486 regcache_write_pc (struct regcache *regcache, CORE_ADDR pc)
 487 {
 488   if (the_target->write_pc)
 489     the_target->write_pc (regcache, pc);
 490   else
 491     internal_error (__FILE__, __LINE__,
 492                     "regcache_write_pc: Unable to update PC");
 493 }
 494
 495 #endif