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 = xcalloc (1, tdesc->registers_size);
 135       regcache->registers_owned = 1;
 136       regcache->register_status = xcalloc (1, tdesc->num_registers);
 137       gdb_assert (REG_UNAVAILABLE == 0);
 138 #else
 139       gdb_assert_not_reached ("can't allocate memory from the heap");
 140 #endif
 141     }
 142   else
 143     {
 144       regcache->tdesc = tdesc;
 145       regcache->registers = regbuf;
 146       regcache->registers_owned = 0;
 147 #ifndef IN_PROCESS_AGENT
 148       regcache->register_status = NULL;
 149 #endif
 150     }
 151
 152   regcache->registers_valid = 0;
 153
 154   return regcache;
 155 }
 156
 157 #ifndef IN_PROCESS_AGENT
 158
 159 struct regcache *
 160 new_register_cache (const struct target_desc *tdesc)
 161 {
 162   struct regcache *regcache;
 163
 164   gdb_assert (tdesc->registers_size != 0);
 165
 166   regcache = xmalloc (sizeof (*regcache));
 167   return init_register_cache (regcache, tdesc, NULL);
 168 }
 169
 170 void
 171 free_register_cache (struct regcache *regcache)
 172 {
 173   if (regcache)
 174     {
 175       if (regcache->registers_owned)
 176         free (regcache->registers);
 177       free (regcache->register_status);
 178       free (regcache);
 179     }
 180 }
 181
 182 #endif
 183
 184 void
 185 regcache_cpy (struct regcache *dst, struct regcache *src)
 186 {
 187   gdb_assert (src != NULL && dst != NULL);
 188   gdb_assert (src->tdesc == dst->tdesc);
 189   gdb_assert (src != dst);
 190
 191   memcpy (dst->registers, src->registers, src->tdesc->registers_size);
 192 #ifndef IN_PROCESS_AGENT
 193   if (dst->register_status != NULL && src->register_status != NULL)
 194     memcpy (dst->register_status, src->register_status,
 195             src->tdesc->num_registers);
 196 #endif
 197   dst->registers_valid = src->registers_valid;
 198 }
 199
 200
 201 #ifndef IN_PROCESS_AGENT
 202
 203 void
 204 registers_to_string (struct regcache *regcache, char *buf)
 205 {
 206   unsigned char *registers = regcache->registers;
 207   const struct target_desc *tdesc = regcache->tdesc;
 208   int i;
 209
 210   for (i = 0; i < tdesc->num_registers; i++)
 211     {
 212       if (regcache->register_status[i] == REG_VALID)
 213         {
 214           bin2hex (registers, buf, register_size (tdesc, i));
 215           buf += register_size (tdesc, i) * 2;
 216         }
 217       else
 218         {
 219           memset (buf, 'x', register_size (tdesc, i) * 2);
 220           buf += register_size (tdesc, i) * 2;
 221         }
 222       registers += register_size (tdesc, i);
 223     }
 224   *buf = '\0';
 225 }
 226
 227 void
 228 registers_from_string (struct regcache *regcache, char *buf)
 229 {
 230   int len = strlen (buf);
 231   unsigned char *registers = regcache->registers;
 232   const struct target_desc *tdesc = regcache->tdesc;
 233
 234   if (len != tdesc->registers_size * 2)
 235     {
 236       warning ("Wrong sized register packet (expected %d bytes, got %d)",
 237                2 * tdesc->registers_size, len);
 238       if (len > tdesc->registers_size * 2)
 239         len = tdesc->registers_size * 2;
 240     }
 241   hex2bin (buf, registers, len / 2);
 242 }
 243
 244 struct reg *
 245 find_register_by_name (const struct target_desc *tdesc, const char *name)
 246 {
 247   int i;
 248
 249   for (i = 0; i < tdesc->num_registers; i++)
 250     if (strcmp (name, tdesc->reg_defs[i].name) == 0)
 251       return &tdesc->reg_defs[i];
 252   internal_error (__FILE__, __LINE__, "Unknown register %s requested",
 253                   name);
 254 }
 255
 256 int
 257 find_regno (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 i;
 264   internal_error (__FILE__, __LINE__, "Unknown register %s requested",
 265                   name);
 266 }
 267
 268 struct reg *
 269 find_register_by_number (const struct target_desc *tdesc, int n)
 270 {
 271   return &tdesc->reg_defs[n];
 272 }
 273
 274 #endif
 275
 276 #ifndef IN_PROCESS_AGENT
 277 static void
 278 free_register_cache_thread (struct thread_info *thread)
 279 {
 280   struct regcache *regcache = inferior_regcache_data (thread);
 281
 282   if (regcache != NULL)
 283     {
 284       regcache_invalidate_thread (thread);
 285       free_register_cache (regcache);
 286       set_inferior_regcache_data (thread, NULL);
 287     }
 288 }
 289
 290 static void
 291 free_register_cache_thread_one (struct inferior_list_entry *entry)
 292 {
 293   struct thread_info *thread = (struct thread_info *) entry;
 294
 295   free_register_cache_thread (thread);
 296 }
 297
 298 void
 299 regcache_release (void)
 300 {
 301   /* Flush and release all pre-existing register caches.  */
 302   for_each_inferior (&all_threads, free_register_cache_thread_one);
 303 }
 304 #endif
 305
 306 int
 307 register_cache_size (const struct target_desc *tdesc)
 308 {
 309   return tdesc->registers_size;
 310 }
 311
 312 int
 313 register_size (const struct target_desc *tdesc, int n)
 314 {
 315   return tdesc->reg_defs[n].size / 8;
 316 }
 317
 318 static unsigned char *
 319 register_data (struct regcache *regcache, int n, int fetch)
 320 {
 321   return regcache->registers + regcache->tdesc->reg_defs[n].offset / 8;
 322 }
 323
 324 /* Supply register N, whose contents are stored in BUF, to REGCACHE.
 325    If BUF is NULL, the register's value is recorded as
 326    unavailable.  */
 327
 328 void
 329 supply_register (struct regcache *regcache, int n, const void *buf)
 330 {
 331   if (buf)
 332     {
 333       memcpy (register_data (regcache, n, 0), buf,
 334               register_size (regcache->tdesc, n));
 335 #ifndef IN_PROCESS_AGENT
 336       if (regcache->register_status != NULL)
 337         regcache->register_status[n] = REG_VALID;
 338 #endif
 339     }
 340   else
 341     {
 342       memset (register_data (regcache, n, 0), 0,
 343               register_size (regcache->tdesc, n));
 344 #ifndef IN_PROCESS_AGENT
 345       if (regcache->register_status != NULL)
 346         regcache->register_status[n] = REG_UNAVAILABLE;
 347 #endif
 348     }
 349 }
 350
 351 /* Supply register N with value zero to REGCACHE.  */
 352
 353 void
 354 supply_register_zeroed (struct regcache *regcache, int n)
 355 {
 356   memset (register_data (regcache, n, 0), 0,
 357           register_size (regcache->tdesc, n));
 358 #ifndef IN_PROCESS_AGENT
 359   if (regcache->register_status != NULL)
 360     regcache->register_status[n] = REG_VALID;
 361 #endif
 362 }
 363
 364 /* Supply the whole register set whose contents are stored in BUF, to
 365    REGCACHE.  If BUF is NULL, all the registers' values are recorded
 366    as unavailable.  */
 367
 368 void
 369 supply_regblock (struct regcache *regcache, const void *buf)
 370 {
 371   if (buf)
 372     {
 373       const struct target_desc *tdesc = regcache->tdesc;
 374
 375       memcpy (regcache->registers, buf, tdesc->registers_size);
 376 #ifndef IN_PROCESS_AGENT
 377       {
 378         int i;
 379
 380         for (i = 0; i < tdesc->num_registers; i++)
 381           regcache->register_status[i] = REG_VALID;
 382       }
 383 #endif
 384     }
 385   else
 386     {
 387       const struct target_desc *tdesc = regcache->tdesc;
 388
 389       memset (regcache->registers, 0, tdesc->registers_size);
 390 #ifndef IN_PROCESS_AGENT
 391       {
 392         int i;
 393
 394         for (i = 0; i < tdesc->num_registers; i++)
 395           regcache->register_status[i] = REG_UNAVAILABLE;
 396       }
 397 #endif
 398     }
 399 }
 400
 401 #ifndef IN_PROCESS_AGENT
 402
 403 void
 404 supply_register_by_name (struct regcache *regcache,
 405                          const char *name, const void *buf)
 406 {
 407   supply_register (regcache, find_regno (regcache->tdesc, name), buf);
 408 }
 409
 410 #endif
 411
 412 void
 413 collect_register (struct regcache *regcache, int n, void *buf)
 414 {
 415   memcpy (buf, register_data (regcache, n, 1),
 416           register_size (regcache->tdesc, n));
 417 }
 418
 419 #ifndef IN_PROCESS_AGENT
 420
 421 void
 422 collect_register_as_string (struct regcache *regcache, int n, char *buf)
 423 {
 424   bin2hex (register_data (regcache, n, 1), buf,
 425            register_size (regcache->tdesc, n));
 426 }
 427
 428 void
 429 collect_register_by_name (struct regcache *regcache,
 430                           const char *name, void *buf)
 431 {
 432   collect_register (regcache, find_regno (regcache->tdesc, name), buf);
 433 }
 434
 435 /* Special handling for register PC.  */
 436
 437 CORE_ADDR
 438 regcache_read_pc (struct regcache *regcache)
 439 {
 440   CORE_ADDR pc_val;
 441
 442   if (the_target->read_pc)
 443     pc_val = the_target->read_pc (regcache);
 444   else
 445     internal_error (__FILE__, __LINE__,
 446                     "regcache_read_pc: Unable to find PC");
 447
 448   return pc_val;
 449 }
 450
 451 void
 452 regcache_write_pc (struct regcache *regcache, CORE_ADDR pc)
 453 {
 454   if (the_target->write_pc)
 455     the_target->write_pc (regcache, pc);
 456   else
 457     internal_error (__FILE__, __LINE__,
 458                     "regcache_write_pc: Unable to update PC");
 459 }
 460
 461 #endif