gdb/gdbserver/regcache.c

   1 /* Register support routines for the remote server for GDB.
   2    Copyright (C) 2001-2014 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 = (struct 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_inferior = current_inferior;
  53
  54       current_inferior = thread;
  55       fetch_inferior_registers (regcache, -1);
  56       current_inferior = saved_inferior;
  57       regcache->registers_valid = 1;
  58     }
  59
  60   return regcache;
  61 }
  62
  63 /* See common/common-regcache.h.  */
  64
  65 struct regcache *
  66 get_thread_regcache_for_ptid (ptid_t ptid)
  67 {
  68   return get_thread_regcache (find_thread_ptid (ptid), 1);
  69 }
  70
  71 void
  72 regcache_invalidate_thread (struct thread_info *thread)
  73 {
  74   struct regcache *regcache;
  75
  76   regcache = (struct regcache *) inferior_regcache_data (thread);
  77
  78   if (regcache == NULL)
  79     return;
  80
  81   if (regcache->registers_valid)
  82     {
  83       struct thread_info *saved_inferior = current_inferior;
  84
  85       current_inferior = thread;
  86       store_inferior_registers (regcache, -1);
  87       current_inferior = saved_inferior;
  88     }
  89
  90   regcache->registers_valid = 0;
  91 }
  92
  93 static int
  94 regcache_invalidate_one (struct inferior_list_entry *entry,
  95                          void *pid_p)
  96 {
  97   struct thread_info *thread = (struct thread_info *) entry;
  98   int pid = *(int *) pid_p;
  99
 100   /* Only invalidate the regcaches of threads of this process.  */
 101   if (ptid_get_pid (entry->id) == pid)
 102     regcache_invalidate_thread (thread);
 103
 104   return 0;
 105 }
 106
 107 void
 108 regcache_invalidate (void)
 109 {
 110   /* Only update the threads of the current process.  */
 111   int pid = ptid_get_pid (current_inferior->entry.id);
 112
 113   find_inferior (&all_threads, regcache_invalidate_one, &pid);
 114 }
 115
 116 #endif
 117
 118 struct regcache *
 119 init_register_cache (struct regcache *regcache,
 120                      const struct target_desc *tdesc,
 121                      unsigned char *regbuf)
 122 {
 123   if (regbuf == NULL)
 124     {
 125 #ifndef IN_PROCESS_AGENT
 126       /* Make sure to zero-initialize the register cache when it is
 127          created, in case there are registers the target never
 128          fetches.  This way they'll read as zero instead of
 129          garbage.  */
 130       regcache->tdesc = tdesc;
 131       regcache->registers = xcalloc (1, tdesc->registers_size);
 132       regcache->registers_owned = 1;
 133       regcache->register_status = xcalloc (1, tdesc->num_registers);
 134       gdb_assert (REG_UNAVAILABLE == 0);
 135 #else
 136       gdb_assert_not_reached ("can't allocate memory from the heap");
 137 #endif
 138     }
 139   else
 140     {
 141       regcache->tdesc = tdesc;
 142       regcache->registers = regbuf;
 143       regcache->registers_owned = 0;
 144 #ifndef IN_PROCESS_AGENT
 145       regcache->register_status = NULL;
 146 #endif
 147     }
 148
 149   regcache->registers_valid = 0;
 150
 151   return regcache;
 152 }
 153
 154 #ifndef IN_PROCESS_AGENT
 155
 156 struct regcache *
 157 new_register_cache (const struct target_desc *tdesc)
 158 {
 159   struct regcache *regcache;
 160
 161   gdb_assert (tdesc->registers_size != 0);
 162
 163   regcache = xmalloc (sizeof (*regcache));
 164   return init_register_cache (regcache, tdesc, NULL);
 165 }
 166
 167 void
 168 free_register_cache (struct regcache *regcache)
 169 {
 170   if (regcache)
 171     {
 172       if (regcache->registers_owned)
 173         free (regcache->registers);
 174       free (regcache->register_status);
 175       free (regcache);
 176     }
 177 }
 178
 179 #endif
 180
 181 void
 182 regcache_cpy (struct regcache *dst, struct regcache *src)
 183 {
 184   gdb_assert (src != NULL && dst != NULL);
 185   gdb_assert (src->tdesc == dst->tdesc);
 186   gdb_assert (src != dst);
 187
 188   memcpy (dst->registers, src->registers, src->tdesc->registers_size);
 189 #ifndef IN_PROCESS_AGENT
 190   if (dst->register_status != NULL && src->register_status != NULL)
 191     memcpy (dst->register_status, src->register_status,
 192             src->tdesc->num_registers);
 193 #endif
 194   dst->registers_valid = src->registers_valid;
 195 }
 196
 197
 198 #ifndef IN_PROCESS_AGENT
 199
 200 void
 201 registers_to_string (struct regcache *regcache, char *buf)
 202 {
 203   unsigned char *registers = regcache->registers;
 204   const struct target_desc *tdesc = regcache->tdesc;
 205   int i;
 206
 207   for (i = 0; i < tdesc->num_registers; i++)
 208     {
 209       if (regcache->register_status[i] == REG_VALID)
 210         {
 211           bin2hex (registers, buf, register_size (tdesc, i));
 212           buf += register_size (tdesc, i) * 2;
 213         }
 214       else
 215         {
 216           memset (buf, 'x', register_size (tdesc, i) * 2);
 217           buf += register_size (tdesc, i) * 2;
 218         }
 219       registers += register_size (tdesc, i);
 220     }
 221   *buf = '\0';
 222 }
 223
 224 void
 225 registers_from_string (struct regcache *regcache, char *buf)
 226 {
 227   int len = strlen (buf);
 228   unsigned char *registers = regcache->registers;
 229   const struct target_desc *tdesc = regcache->tdesc;
 230
 231   if (len != tdesc->registers_size * 2)
 232     {
 233       warning ("Wrong sized register packet (expected %d bytes, got %d)",
 234                2 * tdesc->registers_size, len);
 235       if (len > tdesc->registers_size * 2)
 236         len = tdesc->registers_size * 2;
 237     }
 238   hex2bin (buf, registers, len / 2);
 239 }
 240
 241 struct reg *
 242 find_register_by_name (const struct target_desc *tdesc, const char *name)
 243 {
 244   int i;
 245
 246   for (i = 0; i < tdesc->num_registers; i++)
 247     if (strcmp (name, tdesc->reg_defs[i].name) == 0)
 248       return &tdesc->reg_defs[i];
 249   internal_error (__FILE__, __LINE__, "Unknown register %s requested",
 250                   name);
 251 }
 252
 253 int
 254 find_regno (const struct target_desc *tdesc, const char *name)
 255 {
 256   int i;
 257
 258   for (i = 0; i < tdesc->num_registers; i++)
 259     if (strcmp (name, tdesc->reg_defs[i].name) == 0)
 260       return i;
 261   internal_error (__FILE__, __LINE__, "Unknown register %s requested",
 262                   name);
 263 }
 264
 265 struct reg *
 266 find_register_by_number (const struct target_desc *tdesc, int n)
 267 {
 268   return &tdesc->reg_defs[n];
 269 }
 270
 271 #endif
 272
 273 #ifndef IN_PROCESS_AGENT
 274 static void
 275 free_register_cache_thread (struct thread_info *thread)
 276 {
 277   struct regcache *regcache
 278     = (struct regcache *) inferior_regcache_data (thread);
 279
 280   if (regcache != NULL)
 281     {
 282       regcache_invalidate_thread (thread);
 283       free_register_cache (regcache);
 284       set_inferior_regcache_data (thread, NULL);
 285     }
 286 }
 287
 288 static void
 289 free_register_cache_thread_one (struct inferior_list_entry *entry)
 290 {
 291   struct thread_info *thread = (struct thread_info *) entry;
 292
 293   free_register_cache_thread (thread);
 294 }
 295
 296 void
 297 regcache_release (void)
 298 {
 299   /* Flush and release all pre-existing register caches.  */
 300   for_each_inferior (&all_threads, free_register_cache_thread_one);
 301 }
 302 #endif
 303
 304 int
 305 register_cache_size (const struct target_desc *tdesc)
 306 {
 307   return tdesc->registers_size;
 308 }
 309
 310 int
 311 register_size (const struct target_desc *tdesc, int n)
 312 {
 313   return tdesc->reg_defs[n].size / 8;
 314 }
 315
 316 static unsigned char *
 317 register_data (struct regcache *regcache, int n, int fetch)
 318 {
 319   return regcache->registers + regcache->tdesc->reg_defs[n].offset / 8;
 320 }
 321
 322 /* Supply register N, whose contents are stored in BUF, to REGCACHE.
 323    If BUF is NULL, the register's value is recorded as
 324    unavailable.  */
 325
 326 void
 327 supply_register (struct regcache *regcache, int n, const void *buf)
 328 {
 329   if (buf)
 330     {
 331       memcpy (register_data (regcache, n, 0), buf,
 332               register_size (regcache->tdesc, n));
 333 #ifndef IN_PROCESS_AGENT
 334       if (regcache->register_status != NULL)
 335         regcache->register_status[n] = REG_VALID;
 336 #endif
 337     }
 338   else
 339     {
 340       memset (register_data (regcache, n, 0), 0,
 341               register_size (regcache->tdesc, n));
 342 #ifndef IN_PROCESS_AGENT
 343       if (regcache->register_status != NULL)
 344         regcache->register_status[n] = REG_UNAVAILABLE;
 345 #endif
 346     }
 347 }
 348
 349 /* Supply register N with value zero to REGCACHE.  */
 350
 351 void
 352 supply_register_zeroed (struct regcache *regcache, int n)
 353 {
 354   memset (register_data (regcache, n, 0), 0,
 355           register_size (regcache->tdesc, n));
 356 #ifndef IN_PROCESS_AGENT
 357   if (regcache->register_status != NULL)
 358     regcache->register_status[n] = REG_VALID;
 359 #endif
 360 }
 361
 362 /* Supply the whole register set whose contents are stored in BUF, to
 363    REGCACHE.  If BUF is NULL, all the registers' values are recorded
 364    as unavailable.  */
 365
 366 void
 367 supply_regblock (struct regcache *regcache, const void *buf)
 368 {
 369   if (buf)
 370     {
 371       const struct target_desc *tdesc = regcache->tdesc;
 372
 373       memcpy (regcache->registers, buf, tdesc->registers_size);
 374 #ifndef IN_PROCESS_AGENT
 375       {
 376         int i;
 377
 378         for (i = 0; i < tdesc->num_registers; i++)
 379           regcache->register_status[i] = REG_VALID;
 380       }
 381 #endif
 382     }
 383   else
 384     {
 385       const struct target_desc *tdesc = regcache->tdesc;
 386
 387       memset (regcache->registers, 0, tdesc->registers_size);
 388 #ifndef IN_PROCESS_AGENT
 389       {
 390         int i;
 391
 392         for (i = 0; i < tdesc->num_registers; i++)
 393           regcache->register_status[i] = REG_UNAVAILABLE;
 394       }
 395 #endif
 396     }
 397 }
 398
 399 #ifndef IN_PROCESS_AGENT
 400
 401 void
 402 supply_register_by_name (struct regcache *regcache,
 403                          const char *name, const void *buf)
 404 {
 405   supply_register (regcache, find_regno (regcache->tdesc, name), buf);
 406 }
 407
 408 #endif
 409
 410 void
 411 collect_register (struct regcache *regcache, int n, void *buf)
 412 {
 413   memcpy (buf, register_data (regcache, n, 1),
 414           register_size (regcache->tdesc, n));
 415 }
 416
 417 #ifndef IN_PROCESS_AGENT
 418
 419 void
 420 collect_register_as_string (struct regcache *regcache, int n, char *buf)
 421 {
 422   bin2hex (register_data (regcache, n, 1), buf,
 423            register_size (regcache->tdesc, n));
 424 }
 425
 426 void
 427 collect_register_by_name (struct regcache *regcache,
 428                           const char *name, void *buf)
 429 {
 430   collect_register (regcache, find_regno (regcache->tdesc, name), buf);
 431 }
 432
 433 /* Special handling for register PC.  */
 434
 435 CORE_ADDR
 436 regcache_read_pc (struct regcache *regcache)
 437 {
 438   CORE_ADDR pc_val;
 439
 440   if (the_target->read_pc)
 441     pc_val = the_target->read_pc (regcache);
 442   else
 443     internal_error (__FILE__, __LINE__,
 444                     "regcache_read_pc: Unable to find PC");
 445
 446   return pc_val;
 447 }
 448
 449 void
 450 regcache_write_pc (struct regcache *regcache, CORE_ADDR pc)
 451 {
 452   if (the_target->write_pc)
 453     the_target->write_pc (regcache, pc);
 454   else
 455     internal_error (__FILE__, __LINE__,
 456                     "regcache_write_pc: Unable to update PC");
 457 }
 458
 459 #endif