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