gdb/gdbserver/regcache.c

   1 /* Register support routines for the remote server for GDB.
   2    Copyright (C) 2001-2017 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 = thread_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_thread_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->reg_defs.size ());
  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 = thread_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 /* See regcache.h.  */
 111
 112 void
 113 regcache_invalidate_pid (int pid)
 114 {
 115   find_inferior (&all_threads, regcache_invalidate_one, &pid);
 116 }
 117
 118 /* See regcache.h.  */
 119
 120 void
 121 regcache_invalidate (void)
 122 {
 123   /* Only update the threads of the current process.  */
 124   int pid = ptid_get_pid (current_thread->entry.id);
 125
 126   regcache_invalidate_pid (pid);
 127 }
 128
 129 #endif
 130
 131 struct regcache *
 132 init_register_cache (struct regcache *regcache,
 133                      const struct target_desc *tdesc,
 134                      unsigned char *regbuf)
 135 {
 136   if (regbuf == NULL)
 137     {
 138 #ifndef IN_PROCESS_AGENT
 139       /* Make sure to zero-initialize the register cache when it is
 140          created, in case there are registers the target never
 141          fetches.  This way they'll read as zero instead of
 142          garbage.  */
 143       regcache->tdesc = tdesc;
 144       regcache->registers
 145         = (unsigned char *) xcalloc (1, tdesc->registers_size);
 146       regcache->registers_owned = 1;
 147       regcache->register_status
 148         = (unsigned char *) xmalloc (tdesc->reg_defs.size ());
 149       memset ((void *) regcache->register_status, REG_UNAVAILABLE,
 150               tdesc->reg_defs.size ());
 151 #else
 152       gdb_assert_not_reached ("can't allocate memory from the heap");
 153 #endif
 154     }
 155   else
 156     {
 157       regcache->tdesc = tdesc;
 158       regcache->registers = regbuf;
 159       regcache->registers_owned = 0;
 160 #ifndef IN_PROCESS_AGENT
 161       regcache->register_status = NULL;
 162 #endif
 163     }
 164
 165   regcache->registers_valid = 0;
 166
 167   return regcache;
 168 }
 169
 170 #ifndef IN_PROCESS_AGENT
 171
 172 struct regcache *
 173 new_register_cache (const struct target_desc *tdesc)
 174 {
 175   struct regcache *regcache = XCNEW (struct regcache);
 176
 177   gdb_assert (tdesc->registers_size != 0);
 178
 179   return init_register_cache (regcache, tdesc, NULL);
 180 }
 181
 182 void
 183 free_register_cache (struct regcache *regcache)
 184 {
 185   if (regcache)
 186     {
 187       if (regcache->registers_owned)
 188         free (regcache->registers);
 189       free (regcache->register_status);
 190       free (regcache);
 191     }
 192 }
 193
 194 #endif
 195
 196 void
 197 regcache_cpy (struct regcache *dst, struct regcache *src)
 198 {
 199   gdb_assert (src != NULL && dst != NULL);
 200   gdb_assert (src->tdesc == dst->tdesc);
 201   gdb_assert (src != dst);
 202
 203   memcpy (dst->registers, src->registers, src->tdesc->registers_size);
 204 #ifndef IN_PROCESS_AGENT
 205   if (dst->register_status != NULL && src->register_status != NULL)
 206     memcpy (dst->register_status, src->register_status,
 207             src->tdesc->reg_defs.size ());
 208 #endif
 209   dst->registers_valid = src->registers_valid;
 210 }
 211
 212
 213 #ifndef IN_PROCESS_AGENT
 214
 215 void
 216 registers_to_string (struct regcache *regcache, char *buf)
 217 {
 218   unsigned char *registers = regcache->registers;
 219   const struct target_desc *tdesc = regcache->tdesc;
 220
 221   for (int i = 0; i < tdesc->reg_defs.size (); ++i)
 222     {
 223       struct reg *reg = tdesc->reg_defs[i];
 224
 225       if (regcache->register_status[i] == REG_VALID)
 226         {
 227           bin2hex (registers, buf, register_size (tdesc, i));
 228           buf += register_size (tdesc, i) * 2;
 229         }
 230       else
 231         {
 232           memset (buf, 'x', register_size (tdesc, i) * 2);
 233           buf += register_size (tdesc, i) * 2;
 234         }
 235       registers += register_size (tdesc, i);
 236     }
 237   *buf = '\0';
 238 }
 239
 240 void
 241 registers_from_string (struct regcache *regcache, char *buf)
 242 {
 243   int len = strlen (buf);
 244   unsigned char *registers = regcache->registers;
 245   const struct target_desc *tdesc = regcache->tdesc;
 246
 247   if (len != tdesc->registers_size * 2)
 248     {
 249       warning ("Wrong sized register packet (expected %d bytes, got %d)",
 250                2 * tdesc->registers_size, len);
 251       if (len > tdesc->registers_size * 2)
 252         len = tdesc->registers_size * 2;
 253     }
 254   hex2bin (buf, registers, len / 2);
 255 }
 256
 257 int
 258 find_regno (const struct target_desc *tdesc, const char *name)
 259 {
 260   for (int i = 0; i < tdesc->reg_defs.size (); ++i)
 261     {
 262       struct reg *reg = tdesc->reg_defs[i];
 263
 264       if (strcmp (name, reg->name) == 0)
 265         return i;
 266     }
 267   internal_error (__FILE__, __LINE__, "Unknown register %s requested",
 268                   name);
 269 }
 270
 271 #endif
 272
 273 struct reg *
 274 find_register_by_number (const struct target_desc *tdesc, int n)
 275 {
 276   return tdesc->reg_defs[n];
 277 }
 278
 279 #ifndef IN_PROCESS_AGENT
 280 static void
 281 free_register_cache_thread (struct thread_info *thread)
 282 {
 283   struct regcache *regcache = thread_regcache_data (thread);
 284
 285   if (regcache != NULL)
 286     {
 287       regcache_invalidate_thread (thread);
 288       free_register_cache (regcache);
 289       set_thread_regcache_data (thread, NULL);
 290     }
 291 }
 292
 293 static void
 294 free_register_cache_thread_one (struct inferior_list_entry *entry)
 295 {
 296   struct thread_info *thread = (struct thread_info *) entry;
 297
 298   free_register_cache_thread (thread);
 299 }
 300
 301 void
 302 regcache_release (void)
 303 {
 304   /* Flush and release all pre-existing register caches.  */
 305   for_each_inferior (&all_threads, free_register_cache_thread_one);
 306 }
 307 #endif
 308
 309 int
 310 register_cache_size (const struct target_desc *tdesc)
 311 {
 312   return tdesc->registers_size;
 313 }
 314
 315 int
 316 register_size (const struct target_desc *tdesc, int n)
 317 {
 318   return find_register_by_number (tdesc, n)->size / 8;
 319 }
 320
 321 /* See common/common-regcache.h.  */
 322
 323 int
 324 regcache_register_size (const struct regcache *regcache, int n)
 325 {
 326   return register_size (regcache->tdesc, n);
 327 }
 328
 329 static unsigned char *
 330 register_data (struct regcache *regcache, int n, int fetch)
 331 {
 332   return (regcache->registers
 333           + find_register_by_number (regcache->tdesc, n)->offset / 8);
 334 }
 335
 336 /* Supply register N, whose contents are stored in BUF, to REGCACHE.
 337    If BUF is NULL, the register's value is recorded as
 338    unavailable.  */
 339
 340 void
 341 supply_register (struct regcache *regcache, int n, const void *buf)
 342 {
 343   if (buf)
 344     {
 345       memcpy (register_data (regcache, n, 0), buf,
 346               register_size (regcache->tdesc, n));
 347 #ifndef IN_PROCESS_AGENT
 348       if (regcache->register_status != NULL)
 349         regcache->register_status[n] = REG_VALID;
 350 #endif
 351     }
 352   else
 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_UNAVAILABLE;
 359 #endif
 360     }
 361 }
 362
 363 /* Supply register N with value zero to REGCACHE.  */
 364
 365 void
 366 supply_register_zeroed (struct regcache *regcache, int n)
 367 {
 368   memset (register_data (regcache, n, 0), 0,
 369           register_size (regcache->tdesc, n));
 370 #ifndef IN_PROCESS_AGENT
 371   if (regcache->register_status != NULL)
 372     regcache->register_status[n] = REG_VALID;
 373 #endif
 374 }
 375
 376 /* Supply the whole register set whose contents are stored in BUF, to
 377    REGCACHE.  If BUF is NULL, all the registers' values are recorded
 378    as unavailable.  */
 379
 380 void
 381 supply_regblock (struct regcache *regcache, const void *buf)
 382 {
 383   if (buf)
 384     {
 385       const struct target_desc *tdesc = regcache->tdesc;
 386
 387       memcpy (regcache->registers, buf, tdesc->registers_size);
 388 #ifndef IN_PROCESS_AGENT
 389       {
 390         int i;
 391
 392         for (i = 0; i < tdesc->reg_defs.size (); i++)
 393           regcache->register_status[i] = REG_VALID;
 394       }
 395 #endif
 396     }
 397   else
 398     {
 399       const struct target_desc *tdesc = regcache->tdesc;
 400
 401       memset (regcache->registers, 0, tdesc->registers_size);
 402 #ifndef IN_PROCESS_AGENT
 403       {
 404         int i;
 405
 406         for (i = 0; i < tdesc->reg_defs.size (); i++)
 407           regcache->register_status[i] = REG_UNAVAILABLE;
 408       }
 409 #endif
 410     }
 411 }
 412
 413 #ifndef IN_PROCESS_AGENT
 414
 415 void
 416 supply_register_by_name (struct regcache *regcache,
 417                          const char *name, const void *buf)
 418 {
 419   supply_register (regcache, find_regno (regcache->tdesc, name), buf);
 420 }
 421
 422 #endif
 423
 424 void
 425 collect_register (struct regcache *regcache, int n, void *buf)
 426 {
 427   memcpy (buf, register_data (regcache, n, 1),
 428           register_size (regcache->tdesc, n));
 429 }
 430
 431 enum register_status
 432 regcache_raw_read_unsigned (struct regcache *regcache, int regnum,
 433                             ULONGEST *val)
 434 {
 435   int size;
 436
 437   gdb_assert (regcache != NULL);
 438   gdb_assert (regnum >= 0
 439               && regnum < regcache->tdesc->reg_defs.size ());
 440
 441   size = register_size (regcache->tdesc, regnum);
 442
 443   if (size > (int) sizeof (ULONGEST))
 444     error (_("That operation is not available on integers of more than"
 445             "%d bytes."),
 446           (int) sizeof (ULONGEST));
 447
 448   *val = 0;
 449   collect_register (regcache, regnum, val);
 450
 451   return REG_VALID;
 452 }
 453
 454 #ifndef IN_PROCESS_AGENT
 455
 456 void
 457 collect_register_as_string (struct regcache *regcache, int n, char *buf)
 458 {
 459   bin2hex (register_data (regcache, n, 1), buf,
 460            register_size (regcache->tdesc, n));
 461 }
 462
 463 void
 464 collect_register_by_name (struct regcache *regcache,
 465                           const char *name, void *buf)
 466 {
 467   collect_register (regcache, find_regno (regcache->tdesc, name), buf);
 468 }
 469
 470 /* Special handling for register PC.  */
 471
 472 CORE_ADDR
 473 regcache_read_pc (struct regcache *regcache)
 474 {
 475   CORE_ADDR pc_val;
 476
 477   if (the_target->read_pc)
 478     pc_val = the_target->read_pc (regcache);
 479   else
 480     internal_error (__FILE__, __LINE__,
 481                     "regcache_read_pc: Unable to find PC");
 482
 483   return pc_val;
 484 }
 485
 486 void
 487 regcache_write_pc (struct regcache *regcache, CORE_ADDR pc)
 488 {
 489   if (the_target->write_pc)
 490     the_target->write_pc (regcache, pc);
 491   else
 492     internal_error (__FILE__, __LINE__,
 493                     "regcache_write_pc: Unable to update PC");
 494 }
 495
 496 #endif