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 = XCNEW (struct regcache);
 163
 164   gdb_assert (tdesc->registers_size != 0);
 165
 166   return init_register_cache (regcache, tdesc, NULL);
 167 }
 168
 169 void
 170 free_register_cache (struct regcache *regcache)
 171 {
 172   if (regcache)
 173     {
 174       if (regcache->registers_owned)
 175         free (regcache->registers);
 176       free (regcache->register_status);
 177       free (regcache);
 178     }
 179 }
 180
 181 #endif
 182
 183 void
 184 regcache_cpy (struct regcache *dst, struct regcache *src)
 185 {
 186   gdb_assert (src != NULL && dst != NULL);
 187   gdb_assert (src->tdesc == dst->tdesc);
 188   gdb_assert (src != dst);
 189
 190   memcpy (dst->registers, src->registers, src->tdesc->registers_size);
 191 #ifndef IN_PROCESS_AGENT
 192   if (dst->register_status != NULL && src->register_status != NULL)
 193     memcpy (dst->register_status, src->register_status,
 194             src->tdesc->num_registers);
 195 #endif
 196   dst->registers_valid = src->registers_valid;
 197 }
 198
 199
 200 #ifndef IN_PROCESS_AGENT
 201
 202 void
 203 registers_to_string (struct regcache *regcache, char *buf)
 204 {
 205   unsigned char *registers = regcache->registers;
 206   const struct target_desc *tdesc = regcache->tdesc;
 207   int i;
 208
 209   for (i = 0; i < tdesc->num_registers; i++)
 210     {
 211       if (regcache->register_status[i] == REG_VALID)
 212         {
 213           bin2hex (registers, buf, register_size (tdesc, i));
 214           buf += register_size (tdesc, i) * 2;
 215         }
 216       else
 217         {
 218           memset (buf, 'x', register_size (tdesc, i) * 2);
 219           buf += register_size (tdesc, i) * 2;
 220         }
 221       registers += register_size (tdesc, i);
 222     }
 223   *buf = '\0';
 224 }
 225
 226 void
 227 registers_from_string (struct regcache *regcache, char *buf)
 228 {
 229   int len = strlen (buf);
 230   unsigned char *registers = regcache->registers;
 231   const struct target_desc *tdesc = regcache->tdesc;
 232
 233   if (len != tdesc->registers_size * 2)
 234     {
 235       warning ("Wrong sized register packet (expected %d bytes, got %d)",
 236                2 * tdesc->registers_size, len);
 237       if (len > tdesc->registers_size * 2)
 238         len = tdesc->registers_size * 2;
 239     }
 240   hex2bin (buf, registers, len / 2);
 241 }
 242
 243 struct reg *
 244 find_register_by_name (const struct target_desc *tdesc, const char *name)
 245 {
 246   int i;
 247
 248   for (i = 0; i < tdesc->num_registers; i++)
 249     if (strcmp (name, tdesc->reg_defs[i].name) == 0)
 250       return &tdesc->reg_defs[i];
 251   internal_error (__FILE__, __LINE__, "Unknown register %s requested",
 252                   name);
 253 }
 254
 255 int
 256 find_regno (const struct target_desc *tdesc, const char *name)
 257 {
 258   int i;
 259
 260   for (i = 0; i < tdesc->num_registers; i++)
 261     if (strcmp (name, tdesc->reg_defs[i].name) == 0)
 262       return i;
 263   internal_error (__FILE__, __LINE__, "Unknown register %s requested",
 264                   name);
 265 }
 266
 267 struct reg *
 268 find_register_by_number (const struct target_desc *tdesc, int n)
 269 {
 270   return &tdesc->reg_defs[n];
 271 }
 272
 273 #endif
 274
 275 #ifndef IN_PROCESS_AGENT
 276 static void
 277 free_register_cache_thread (struct thread_info *thread)
 278 {
 279   struct regcache *regcache = inferior_regcache_data (thread);
 280
 281   if (regcache != NULL)
 282     {
 283       regcache_invalidate_thread (thread);
 284       free_register_cache (regcache);
 285       set_inferior_regcache_data (thread, NULL);
 286     }
 287 }
 288
 289 static void
 290 free_register_cache_thread_one (struct inferior_list_entry *entry)
 291 {
 292   struct thread_info *thread = (struct thread_info *) entry;
 293
 294   free_register_cache_thread (thread);
 295 }
 296
 297 void
 298 regcache_release (void)
 299 {
 300   /* Flush and release all pre-existing register caches.  */
 301   for_each_inferior (&all_threads, free_register_cache_thread_one);
 302 }
 303 #endif
 304
 305 int
 306 register_cache_size (const struct target_desc *tdesc)
 307 {
 308   return tdesc->registers_size;
 309 }
 310
 311 int
 312 register_size (const struct target_desc *tdesc, int n)
 313 {
 314   return tdesc->reg_defs[n].size / 8;
 315 }
 316
 317 static unsigned char *
 318 register_data (struct regcache *regcache, int n, int fetch)
 319 {
 320   return regcache->registers + regcache->tdesc->reg_defs[n].offset / 8;
 321 }
 322
 323 /* Supply register N, whose contents are stored in BUF, to REGCACHE.
 324    If BUF is NULL, the register's value is recorded as
 325    unavailable.  */
 326
 327 void
 328 supply_register (struct regcache *regcache, int n, const void *buf)
 329 {
 330   if (buf)
 331     {
 332       memcpy (register_data (regcache, n, 0), buf,
 333               register_size (regcache->tdesc, n));
 334 #ifndef IN_PROCESS_AGENT
 335       if (regcache->register_status != NULL)
 336         regcache->register_status[n] = REG_VALID;
 337 #endif
 338     }
 339   else
 340     {
 341       memset (register_data (regcache, n, 0), 0,
 342               register_size (regcache->tdesc, n));
 343 #ifndef IN_PROCESS_AGENT
 344       if (regcache->register_status != NULL)
 345         regcache->register_status[n] = REG_UNAVAILABLE;
 346 #endif
 347     }
 348 }
 349
 350 /* Supply register N with value zero to REGCACHE.  */
 351
 352 void
 353 supply_register_zeroed (struct regcache *regcache, int n)
 354 {
 355   memset (register_data (regcache, n, 0), 0,
 356           register_size (regcache->tdesc, n));
 357 #ifndef IN_PROCESS_AGENT
 358   if (regcache->register_status != NULL)
 359     regcache->register_status[n] = REG_VALID;
 360 #endif
 361 }
 362
 363 /* Supply the whole register set whose contents are stored in BUF, to
 364    REGCACHE.  If BUF is NULL, all the registers' values are recorded
 365    as unavailable.  */
 366
 367 void
 368 supply_regblock (struct regcache *regcache, const void *buf)
 369 {
 370   if (buf)
 371     {
 372       const struct target_desc *tdesc = regcache->tdesc;
 373
 374       memcpy (regcache->registers, buf, tdesc->registers_size);
 375 #ifndef IN_PROCESS_AGENT
 376       {
 377         int i;
 378
 379         for (i = 0; i < tdesc->num_registers; i++)
 380           regcache->register_status[i] = REG_VALID;
 381       }
 382 #endif
 383     }
 384   else
 385     {
 386       const struct target_desc *tdesc = regcache->tdesc;
 387
 388       memset (regcache->registers, 0, tdesc->registers_size);
 389 #ifndef IN_PROCESS_AGENT
 390       {
 391         int i;
 392
 393         for (i = 0; i < tdesc->num_registers; i++)
 394           regcache->register_status[i] = REG_UNAVAILABLE;
 395       }
 396 #endif
 397     }
 398 }
 399
 400 #ifndef IN_PROCESS_AGENT
 401
 402 void
 403 supply_register_by_name (struct regcache *regcache,
 404                          const char *name, const void *buf)
 405 {
 406   supply_register (regcache, find_regno (regcache->tdesc, name), buf);
 407 }
 408
 409 #endif
 410
 411 void
 412 collect_register (struct regcache *regcache, int n, void *buf)
 413 {
 414   memcpy (buf, register_data (regcache, n, 1),
 415           register_size (regcache->tdesc, n));
 416 }
 417
 418 #ifndef IN_PROCESS_AGENT
 419
 420 void
 421 collect_register_as_string (struct regcache *regcache, int n, char *buf)
 422 {
 423   bin2hex (register_data (regcache, n, 1), buf,
 424            register_size (regcache->tdesc, n));
 425 }
 426
 427 void
 428 collect_register_by_name (struct regcache *regcache,
 429                           const char *name, void *buf)
 430 {
 431   collect_register (regcache, find_regno (regcache->tdesc, name), buf);
 432 }
 433
 434 /* Special handling for register PC.  */
 435
 436 CORE_ADDR
 437 regcache_read_pc (struct regcache *regcache)
 438 {
 439   CORE_ADDR pc_val;
 440
 441   if (the_target->read_pc)
 442     pc_val = the_target->read_pc (regcache);
 443   else
 444     internal_error (__FILE__, __LINE__,
 445                     "regcache_read_pc: Unable to find PC");
 446
 447   return pc_val;
 448 }
 449
 450 void
 451 regcache_write_pc (struct regcache *regcache, CORE_ADDR pc)
 452 {
 453   if (the_target->write_pc)
 454     the_target->write_pc (regcache, pc);
 455   else
 456     internal_error (__FILE__, __LINE__,
 457                     "regcache_write_pc: Unable to update PC");
 458 }
 459
 460 #endif