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 void
 111 regcache_invalidate (void)
 112 {
 113   /* Only update the threads of the current process.  */
 114   int pid = ptid_get_pid (current_thread->entry.id);
 115
 116   find_inferior (&all_threads, regcache_invalidate_one, &pid);
 117 }
 118
 119 #endif
 120
 121 struct regcache *
 122 init_register_cache (struct regcache *regcache,
 123                      const struct target_desc *tdesc,
 124                      unsigned char *regbuf)
 125 {
 126   if (regbuf == NULL)
 127     {
 128 #ifndef IN_PROCESS_AGENT
 129       /* Make sure to zero-initialize the register cache when it is
 130          created, in case there are registers the target never
 131          fetches.  This way they'll read as zero instead of
 132          garbage.  */
 133       regcache->tdesc = tdesc;
 134       regcache->registers
 135         = (unsigned char *) xcalloc (1, tdesc->registers_size);
 136       regcache->registers_owned = 1;
 137       regcache->register_status
 138         = (unsigned char *) xcalloc (1, tdesc->num_registers);
 139       gdb_assert (REG_UNAVAILABLE == 0);
 140 #else
 141       gdb_assert_not_reached ("can't allocate memory from the heap");
 142 #endif
 143     }
 144   else
 145     {
 146       regcache->tdesc = tdesc;
 147       regcache->registers = regbuf;
 148       regcache->registers_owned = 0;
 149 #ifndef IN_PROCESS_AGENT
 150       regcache->register_status = NULL;
 151 #endif
 152     }
 153
 154   regcache->registers_valid = 0;
 155
 156   return regcache;
 157 }
 158
 159 #ifndef IN_PROCESS_AGENT
 160
 161 struct regcache *
 162 new_register_cache (const struct target_desc *tdesc)
 163 {
 164   struct regcache *regcache = XCNEW (struct regcache);
 165
 166   gdb_assert (tdesc->registers_size != 0);
 167
 168   return init_register_cache (regcache, tdesc, NULL);
 169 }
 170
 171 void
 172 free_register_cache (struct regcache *regcache)
 173 {
 174   if (regcache)
 175     {
 176       if (regcache->registers_owned)
 177         free (regcache->registers);
 178       free (regcache->register_status);
 179       free (regcache);
 180     }
 181 }
 182
 183 #endif
 184
 185 void
 186 regcache_cpy (struct regcache *dst, struct regcache *src)
 187 {
 188   gdb_assert (src != NULL && dst != NULL);
 189   gdb_assert (src->tdesc == dst->tdesc);
 190   gdb_assert (src != dst);
 191
 192   memcpy (dst->registers, src->registers, src->tdesc->registers_size);
 193 #ifndef IN_PROCESS_AGENT
 194   if (dst->register_status != NULL && src->register_status != NULL)
 195     memcpy (dst->register_status, src->register_status,
 196             src->tdesc->num_registers);
 197 #endif
 198   dst->registers_valid = src->registers_valid;
 199 }
 200
 201
 202 #ifndef IN_PROCESS_AGENT
 203
 204 void
 205 registers_to_string (struct regcache *regcache, char *buf)
 206 {
 207   unsigned char *registers = regcache->registers;
 208   const struct target_desc *tdesc = regcache->tdesc;
 209   int i;
 210
 211   for (i = 0; i < tdesc->num_registers; i++)
 212     {
 213       if (regcache->register_status[i] == REG_VALID)
 214         {
 215           bin2hex (registers, buf, register_size (tdesc, i));
 216           buf += register_size (tdesc, i) * 2;
 217         }
 218       else
 219         {
 220           memset (buf, 'x', register_size (tdesc, i) * 2);
 221           buf += register_size (tdesc, i) * 2;
 222         }
 223       registers += register_size (tdesc, i);
 224     }
 225   *buf = '\0';
 226 }
 227
 228 void
 229 registers_from_string (struct regcache *regcache, char *buf)
 230 {
 231   int len = strlen (buf);
 232   unsigned char *registers = regcache->registers;
 233   const struct target_desc *tdesc = regcache->tdesc;
 234
 235   if (len != tdesc->registers_size * 2)
 236     {
 237       warning ("Wrong sized register packet (expected %d bytes, got %d)",
 238                2 * tdesc->registers_size, len);
 239       if (len > tdesc->registers_size * 2)
 240         len = tdesc->registers_size * 2;
 241     }
 242   hex2bin (buf, registers, len / 2);
 243 }
 244
 245 struct reg *
 246 find_register_by_name (const struct target_desc *tdesc, const char *name)
 247 {
 248   int i;
 249
 250   for (i = 0; i < tdesc->num_registers; i++)
 251     if (strcmp (name, tdesc->reg_defs[i].name) == 0)
 252       return &tdesc->reg_defs[i];
 253   internal_error (__FILE__, __LINE__, "Unknown register %s requested",
 254                   name);
 255 }
 256
 257 int
 258 find_regno (const struct target_desc *tdesc, const char *name)
 259 {
 260   int i;
 261
 262   for (i = 0; i < tdesc->num_registers; i++)
 263     if (strcmp (name, tdesc->reg_defs[i].name) == 0)
 264       return i;
 265   internal_error (__FILE__, __LINE__, "Unknown register %s requested",
 266                   name);
 267 }
 268
 269 struct reg *
 270 find_register_by_number (const struct target_desc *tdesc, int n)
 271 {
 272   return &tdesc->reg_defs[n];
 273 }
 274
 275 #endif
 276
 277 #ifndef IN_PROCESS_AGENT
 278 static void
 279 free_register_cache_thread (struct thread_info *thread)
 280 {
 281   struct regcache *regcache = inferior_regcache_data (thread);
 282
 283   if (regcache != NULL)
 284     {
 285       regcache_invalidate_thread (thread);
 286       free_register_cache (regcache);
 287       set_inferior_regcache_data (thread, NULL);
 288     }
 289 }
 290
 291 static void
 292 free_register_cache_thread_one (struct inferior_list_entry *entry)
 293 {
 294   struct thread_info *thread = (struct thread_info *) entry;
 295
 296   free_register_cache_thread (thread);
 297 }
 298
 299 void
 300 regcache_release (void)
 301 {
 302   /* Flush and release all pre-existing register caches.  */
 303   for_each_inferior (&all_threads, free_register_cache_thread_one);
 304 }
 305 #endif
 306
 307 int
 308 register_cache_size (const struct target_desc *tdesc)
 309 {
 310   return tdesc->registers_size;
 311 }
 312
 313 int
 314 register_size (const struct target_desc *tdesc, int n)
 315 {
 316   return tdesc->reg_defs[n].size / 8;
 317 }
 318
 319 /* See common/common-regcache.h.  */
 320
 321 int
 322 regcache_register_size (const struct regcache *regcache, int n)
 323 {
 324   return register_size (regcache->tdesc, n);
 325 }
 326
 327 static unsigned char *
 328 register_data (struct regcache *regcache, int n, int fetch)
 329 {
 330   return regcache->registers + regcache->tdesc->reg_defs[n].offset / 8;
 331 }
 332
 333 /* Supply register N, whose contents are stored in BUF, to REGCACHE.
 334    If BUF is NULL, the register's value is recorded as
 335    unavailable.  */
 336
 337 void
 338 supply_register (struct regcache *regcache, int n, const void *buf)
 339 {
 340   if (buf)
 341     {
 342       memcpy (register_data (regcache, n, 0), buf,
 343               register_size (regcache->tdesc, n));
 344 #ifndef IN_PROCESS_AGENT
 345       if (regcache->register_status != NULL)
 346         regcache->register_status[n] = REG_VALID;
 347 #endif
 348     }
 349   else
 350     {
 351       memset (register_data (regcache, n, 0), 0,
 352               register_size (regcache->tdesc, n));
 353 #ifndef IN_PROCESS_AGENT
 354       if (regcache->register_status != NULL)
 355         regcache->register_status[n] = REG_UNAVAILABLE;
 356 #endif
 357     }
 358 }
 359
 360 /* Supply register N with value zero to REGCACHE.  */
 361
 362 void
 363 supply_register_zeroed (struct regcache *regcache, int n)
 364 {
 365   memset (register_data (regcache, n, 0), 0,
 366           register_size (regcache->tdesc, n));
 367 #ifndef IN_PROCESS_AGENT
 368   if (regcache->register_status != NULL)
 369     regcache->register_status[n] = REG_VALID;
 370 #endif
 371 }
 372
 373 /* Supply the whole register set whose contents are stored in BUF, to
 374    REGCACHE.  If BUF is NULL, all the registers' values are recorded
 375    as unavailable.  */
 376
 377 void
 378 supply_regblock (struct regcache *regcache, const void *buf)
 379 {
 380   if (buf)
 381     {
 382       const struct target_desc *tdesc = regcache->tdesc;
 383
 384       memcpy (regcache->registers, buf, tdesc->registers_size);
 385 #ifndef IN_PROCESS_AGENT
 386       {
 387         int i;
 388
 389         for (i = 0; i < tdesc->num_registers; i++)
 390           regcache->register_status[i] = REG_VALID;
 391       }
 392 #endif
 393     }
 394   else
 395     {
 396       const struct target_desc *tdesc = regcache->tdesc;
 397
 398       memset (regcache->registers, 0, tdesc->registers_size);
 399 #ifndef IN_PROCESS_AGENT
 400       {
 401         int i;
 402
 403         for (i = 0; i < tdesc->num_registers; i++)
 404           regcache->register_status[i] = REG_UNAVAILABLE;
 405       }
 406 #endif
 407     }
 408 }
 409
 410 #ifndef IN_PROCESS_AGENT
 411
 412 void
 413 supply_register_by_name (struct regcache *regcache,
 414                          const char *name, const void *buf)
 415 {
 416   supply_register (regcache, find_regno (regcache->tdesc, name), buf);
 417 }
 418
 419 #endif
 420
 421 void
 422 collect_register (struct regcache *regcache, int n, void *buf)
 423 {
 424   memcpy (buf, register_data (regcache, n, 1),
 425           register_size (regcache->tdesc, n));
 426 }
 427
 428 #ifndef IN_PROCESS_AGENT
 429
 430 void
 431 collect_register_as_string (struct regcache *regcache, int n, char *buf)
 432 {
 433   bin2hex (register_data (regcache, n, 1), buf,
 434            register_size (regcache->tdesc, n));
 435 }
 436
 437 void
 438 collect_register_by_name (struct regcache *regcache,
 439                           const char *name, void *buf)
 440 {
 441   collect_register (regcache, find_regno (regcache->tdesc, name), buf);
 442 }
 443
 444 /* Special handling for register PC.  */
 445
 446 CORE_ADDR
 447 regcache_read_pc (struct regcache *regcache)
 448 {
 449   CORE_ADDR pc_val;
 450
 451   if (the_target->read_pc)
 452     pc_val = the_target->read_pc (regcache);
 453   else
 454     internal_error (__FILE__, __LINE__,
 455                     "regcache_read_pc: Unable to find PC");
 456
 457   return pc_val;
 458 }
 459
 460 void
 461 regcache_write_pc (struct regcache *regcache, CORE_ADDR pc)
 462 {
 463   if (the_target->write_pc)
 464     the_target->write_pc (regcache, pc);
 465   else
 466     internal_error (__FILE__, __LINE__,
 467                     "regcache_write_pc: Unable to update PC");
 468 }
 469
 470 #endif