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 #include <string.h>
  25
  26 #ifndef IN_PROCESS_AGENT
  27
  28 struct regcache *
  29 get_thread_regcache (struct thread_info *thread, int fetch)
  30 {
  31   struct regcache *regcache;
  32
  33   regcache = (struct regcache *) inferior_regcache_data (thread);
  34
  35   /* Threads' regcaches are created lazily, because biarch targets add
  36      the main thread/lwp before seeing it stop for the first time, and
  37      it is only after the target sees the thread stop for the first
  38      time that the target has a chance of determining the process's
  39      architecture.  IOW, when we first add the process's main thread
  40      we don't know which architecture/tdesc its regcache should
  41      have.  */
  42   if (regcache == NULL)
  43     {
  44       struct process_info *proc = get_thread_process (thread);
  45
  46       if (proc->tdesc == NULL)
  47         fatal ("no target description");
  48
  49       regcache = new_register_cache (proc->tdesc);
  50       set_inferior_regcache_data (thread, regcache);
  51     }
  52
  53   if (fetch && regcache->registers_valid == 0)
  54     {
  55       struct thread_info *saved_inferior = current_inferior;
  56
  57       current_inferior = thread;
  58       fetch_inferior_registers (regcache, -1);
  59       current_inferior = saved_inferior;
  60       regcache->registers_valid = 1;
  61     }
  62
  63   return regcache;
  64 }
  65
  66 void
  67 regcache_invalidate_thread (struct thread_info *thread)
  68 {
  69   struct regcache *regcache;
  70
  71   regcache = (struct regcache *) inferior_regcache_data (thread);
  72
  73   if (regcache == NULL)
  74     return;
  75
  76   if (regcache->registers_valid)
  77     {
  78       struct thread_info *saved_inferior = current_inferior;
  79
  80       current_inferior = thread;
  81       store_inferior_registers (regcache, -1);
  82       current_inferior = saved_inferior;
  83     }
  84
  85   regcache->registers_valid = 0;
  86 }
  87
  88 static int
  89 regcache_invalidate_one (struct inferior_list_entry *entry,
  90                          void *pid_p)
  91 {
  92   struct thread_info *thread = (struct thread_info *) entry;
  93   int pid = *(int *) pid_p;
  94
  95   /* Only invalidate the regcaches of threads of this process.  */
  96   if (ptid_get_pid (entry->id) == pid)
  97     regcache_invalidate_thread (thread);
  98
  99   return 0;
 100 }
 101
 102 void
 103 regcache_invalidate (void)
 104 {
 105   /* Only update the threads of the current process.  */
 106   int pid = ptid_get_pid (current_inferior->entry.id);
 107
 108   find_inferior (&all_threads, regcache_invalidate_one, &pid);
 109 }
 110
 111 #endif
 112
 113 struct regcache *
 114 init_register_cache (struct regcache *regcache,
 115                      const struct target_desc *tdesc,
 116                      unsigned char *regbuf)
 117 {
 118   if (regbuf == NULL)
 119     {
 120 #ifndef IN_PROCESS_AGENT
 121       /* Make sure to zero-initialize the register cache when it is
 122          created, in case there are registers the target never
 123          fetches.  This way they'll read as zero instead of
 124          garbage.  */
 125       regcache->tdesc = tdesc;
 126       regcache->registers = xcalloc (1, tdesc->registers_size);
 127       regcache->registers_owned = 1;
 128       regcache->register_status = xcalloc (1, tdesc->num_registers);
 129       gdb_assert (REG_UNAVAILABLE == 0);
 130 #else
 131       fatal ("init_register_cache: can't allocate memory from the heap");
 132 #endif
 133     }
 134   else
 135     {
 136       regcache->tdesc = tdesc;
 137       regcache->registers = regbuf;
 138       regcache->registers_owned = 0;
 139 #ifndef IN_PROCESS_AGENT
 140       regcache->register_status = NULL;
 141 #endif
 142     }
 143
 144   regcache->registers_valid = 0;
 145
 146   return regcache;
 147 }
 148
 149 #ifndef IN_PROCESS_AGENT
 150
 151 struct regcache *
 152 new_register_cache (const struct target_desc *tdesc)
 153 {
 154   struct regcache *regcache;
 155
 156   gdb_assert (tdesc->registers_size != 0);
 157
 158   regcache = xmalloc (sizeof (*regcache));
 159   return init_register_cache (regcache, tdesc, NULL);
 160 }
 161
 162 void
 163 free_register_cache (struct regcache *regcache)
 164 {
 165   if (regcache)
 166     {
 167       if (regcache->registers_owned)
 168         free (regcache->registers);
 169       free (regcache->register_status);
 170       free (regcache);
 171     }
 172 }
 173
 174 #endif
 175
 176 void
 177 regcache_cpy (struct regcache *dst, struct regcache *src)
 178 {
 179   gdb_assert (src != NULL && dst != NULL);
 180   gdb_assert (src->tdesc == dst->tdesc);
 181   gdb_assert (src != dst);
 182
 183   memcpy (dst->registers, src->registers, src->tdesc->registers_size);
 184 #ifndef IN_PROCESS_AGENT
 185   if (dst->register_status != NULL && src->register_status != NULL)
 186     memcpy (dst->register_status, src->register_status,
 187             src->tdesc->num_registers);
 188 #endif
 189   dst->registers_valid = src->registers_valid;
 190 }
 191
 192
 193 #ifndef IN_PROCESS_AGENT
 194
 195 void
 196 registers_to_string (struct regcache *regcache, char *buf)
 197 {
 198   unsigned char *registers = regcache->registers;
 199   const struct target_desc *tdesc = regcache->tdesc;
 200   int i;
 201
 202   for (i = 0; i < tdesc->num_registers; i++)
 203     {
 204       if (regcache->register_status[i] == REG_VALID)
 205         {
 206           bin2hex (registers, buf, register_size (tdesc, i));
 207           buf += register_size (tdesc, i) * 2;
 208         }
 209       else
 210         {
 211           memset (buf, 'x', register_size (tdesc, i) * 2);
 212           buf += register_size (tdesc, i) * 2;
 213         }
 214       registers += register_size (tdesc, i);
 215     }
 216   *buf = '\0';
 217 }
 218
 219 void
 220 registers_from_string (struct regcache *regcache, char *buf)
 221 {
 222   int len = strlen (buf);
 223   unsigned char *registers = regcache->registers;
 224   const struct target_desc *tdesc = regcache->tdesc;
 225
 226   if (len != tdesc->registers_size * 2)
 227     {
 228       warning ("Wrong sized register packet (expected %d bytes, got %d)",
 229                2 * tdesc->registers_size, len);
 230       if (len > tdesc->registers_size * 2)
 231         len = tdesc->registers_size * 2;
 232     }
 233   hex2bin (buf, registers, len / 2);
 234 }
 235
 236 struct reg *
 237 find_register_by_name (const struct target_desc *tdesc, const char *name)
 238 {
 239   int i;
 240
 241   for (i = 0; i < tdesc->num_registers; i++)
 242     if (strcmp (name, tdesc->reg_defs[i].name) == 0)
 243       return &tdesc->reg_defs[i];
 244   fatal ("Unknown register %s requested", name);
 245   return 0;
 246 }
 247
 248 int
 249 find_regno (const struct target_desc *tdesc, const char *name)
 250 {
 251   int i;
 252
 253   for (i = 0; i < tdesc->num_registers; i++)
 254     if (strcmp (name, tdesc->reg_defs[i].name) == 0)
 255       return i;
 256   fatal ("Unknown register %s requested", name);
 257   return -1;
 258 }
 259
 260 struct reg *
 261 find_register_by_number (const struct target_desc *tdesc, int n)
 262 {
 263   return &tdesc->reg_defs[n];
 264 }
 265
 266 #endif
 267
 268 #ifndef IN_PROCESS_AGENT
 269 static void
 270 free_register_cache_thread (struct thread_info *thread)
 271 {
 272   struct regcache *regcache
 273     = (struct regcache *) inferior_regcache_data (thread);
 274
 275   if (regcache != NULL)
 276     {
 277       regcache_invalidate_thread (thread);
 278       free_register_cache (regcache);
 279       set_inferior_regcache_data (thread, NULL);
 280     }
 281 }
 282
 283 static void
 284 free_register_cache_thread_one (struct inferior_list_entry *entry)
 285 {
 286   struct thread_info *thread = (struct thread_info *) entry;
 287
 288   free_register_cache_thread (thread);
 289 }
 290
 291 void
 292 regcache_release (void)
 293 {
 294   /* Flush and release all pre-existing register caches.  */
 295   for_each_inferior (&all_threads, free_register_cache_thread_one);
 296 }
 297 #endif
 298
 299 int
 300 register_cache_size (const struct target_desc *tdesc)
 301 {
 302   return tdesc->registers_size;
 303 }
 304
 305 int
 306 register_size (const struct target_desc *tdesc, int n)
 307 {
 308   return tdesc->reg_defs[n].size / 8;
 309 }
 310
 311 static unsigned char *
 312 register_data (struct regcache *regcache, int n, int fetch)
 313 {
 314   return regcache->registers + regcache->tdesc->reg_defs[n].offset / 8;
 315 }
 316
 317 /* Supply register N, whose contents are stored in BUF, to REGCACHE.
 318    If BUF is NULL, the register's value is recorded as
 319    unavailable.  */
 320
 321 void
 322 supply_register (struct regcache *regcache, int n, const void *buf)
 323 {
 324   if (buf)
 325     {
 326       memcpy (register_data (regcache, n, 0), buf,
 327               register_size (regcache->tdesc, n));
 328 #ifndef IN_PROCESS_AGENT
 329       if (regcache->register_status != NULL)
 330         regcache->register_status[n] = REG_VALID;
 331 #endif
 332     }
 333   else
 334     {
 335       memset (register_data (regcache, n, 0), 0,
 336               register_size (regcache->tdesc, n));
 337 #ifndef IN_PROCESS_AGENT
 338       if (regcache->register_status != NULL)
 339         regcache->register_status[n] = REG_UNAVAILABLE;
 340 #endif
 341     }
 342 }
 343
 344 /* Supply register N with value zero to REGCACHE.  */
 345
 346 void
 347 supply_register_zeroed (struct regcache *regcache, int n)
 348 {
 349   memset (register_data (regcache, n, 0), 0,
 350           register_size (regcache->tdesc, n));
 351 #ifndef IN_PROCESS_AGENT
 352   if (regcache->register_status != NULL)
 353     regcache->register_status[n] = REG_VALID;
 354 #endif
 355 }
 356
 357 /* Supply the whole register set whose contents are stored in BUF, to
 358    REGCACHE.  If BUF is NULL, all the registers' values are recorded
 359    as unavailable.  */
 360
 361 void
 362 supply_regblock (struct regcache *regcache, const void *buf)
 363 {
 364   if (buf)
 365     {
 366       const struct target_desc *tdesc = regcache->tdesc;
 367
 368       memcpy (regcache->registers, buf, tdesc->registers_size);
 369 #ifndef IN_PROCESS_AGENT
 370       {
 371         int i;
 372
 373         for (i = 0; i < tdesc->num_registers; i++)
 374           regcache->register_status[i] = REG_VALID;
 375       }
 376 #endif
 377     }
 378   else
 379     {
 380       const struct target_desc *tdesc = regcache->tdesc;
 381
 382       memset (regcache->registers, 0, tdesc->registers_size);
 383 #ifndef IN_PROCESS_AGENT
 384       {
 385         int i;
 386
 387         for (i = 0; i < tdesc->num_registers; i++)
 388           regcache->register_status[i] = REG_UNAVAILABLE;
 389       }
 390 #endif
 391     }
 392 }
 393
 394 #ifndef IN_PROCESS_AGENT
 395
 396 void
 397 supply_register_by_name (struct regcache *regcache,
 398                          const char *name, const void *buf)
 399 {
 400   supply_register (regcache, find_regno (regcache->tdesc, name), buf);
 401 }
 402
 403 #endif
 404
 405 void
 406 collect_register (struct regcache *regcache, int n, void *buf)
 407 {
 408   memcpy (buf, register_data (regcache, n, 1),
 409           register_size (regcache->tdesc, n));
 410 }
 411
 412 #ifndef IN_PROCESS_AGENT
 413
 414 void
 415 collect_register_as_string (struct regcache *regcache, int n, char *buf)
 416 {
 417   bin2hex (register_data (regcache, n, 1), buf,
 418            register_size (regcache->tdesc, n));
 419 }
 420
 421 void
 422 collect_register_by_name (struct regcache *regcache,
 423                           const char *name, void *buf)
 424 {
 425   collect_register (regcache, find_regno (regcache->tdesc, name), buf);
 426 }
 427
 428 /* Special handling for register PC.  */
 429
 430 CORE_ADDR
 431 regcache_read_pc (struct regcache *regcache)
 432 {
 433   CORE_ADDR pc_val;
 434
 435   if (the_target->read_pc)
 436     pc_val = the_target->read_pc (regcache);
 437   else
 438     internal_error (__FILE__, __LINE__,
 439                     "regcache_read_pc: Unable to find PC");
 440
 441   return pc_val;
 442 }
 443
 444 void
 445 regcache_write_pc (struct regcache *regcache, CORE_ADDR pc)
 446 {
 447   if (the_target->write_pc)
 448     the_target->write_pc (regcache, pc);
 449   else
 450     internal_error (__FILE__, __LINE__,
 451                     "regcache_write_pc: Unable to update PC");
 452 }
 453
 454 #endif