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 /* See regcache.h.  */
  97
  98 void
  99 regcache_invalidate_pid (int pid)
 100 {
 101   /* Only invalidate the regcaches of threads of this process.  */
 102   for_each_thread (pid, regcache_invalidate_thread);
 103 }
 104
 105 /* See regcache.h.  */
 106
 107 void
 108 regcache_invalidate (void)
 109 {
 110   /* Only update the threads of the current process.  */
 111   int pid = current_thread->id.pid ();
 112
 113   regcache_invalidate_pid (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
 132         = (unsigned char *) xcalloc (1, tdesc->registers_size);
 133       regcache->registers_owned = 1;
 134       regcache->register_status
 135         = (unsigned char *) xmalloc (tdesc->reg_defs.size ());
 136       memset ((void *) regcache->register_status, REG_UNAVAILABLE,
 137               tdesc->reg_defs.size ());
 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->reg_defs.size ());
 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
 208   for (int i = 0; i < tdesc->reg_defs.size (); ++i)
 209     {
 210       struct reg *reg = tdesc->reg_defs[i];
 211
 212       if (regcache->register_status[i] == REG_VALID)
 213         {
 214           bin2hex (registers, buf, register_size (tdesc, i));
 215           buf += register_size (tdesc, i) * 2;
 216         }
 217       else
 218         {
 219           memset (buf, 'x', register_size (tdesc, i) * 2);
 220           buf += register_size (tdesc, i) * 2;
 221         }
 222       registers += register_size (tdesc, i);
 223     }
 224   *buf = '\0';
 225 }
 226
 227 void
 228 registers_from_string (struct regcache *regcache, char *buf)
 229 {
 230   int len = strlen (buf);
 231   unsigned char *registers = regcache->registers;
 232   const struct target_desc *tdesc = regcache->tdesc;
 233
 234   if (len != tdesc->registers_size * 2)
 235     {
 236       warning ("Wrong sized register packet (expected %d bytes, got %d)",
 237                2 * tdesc->registers_size, len);
 238       if (len > tdesc->registers_size * 2)
 239         len = tdesc->registers_size * 2;
 240     }
 241   hex2bin (buf, registers, len / 2);
 242 }
 243
 244 int
 245 find_regno (const struct target_desc *tdesc, const char *name)
 246 {
 247   for (int i = 0; i < tdesc->reg_defs.size (); ++i)
 248     {
 249       struct reg *reg = tdesc->reg_defs[i];
 250
 251       if (strcmp (name, reg->name) == 0)
 252         return i;
 253     }
 254   internal_error (__FILE__, __LINE__, "Unknown register %s requested",
 255                   name);
 256 }
 257
 258 #endif
 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 #ifndef IN_PROCESS_AGENT
 267 static void
 268 free_register_cache_thread (struct thread_info *thread)
 269 {
 270   struct regcache *regcache = thread_regcache_data (thread);
 271
 272   if (regcache != NULL)
 273     {
 274       regcache_invalidate_thread (thread);
 275       free_register_cache (regcache);
 276       set_thread_regcache_data (thread, NULL);
 277     }
 278 }
 279
 280 void
 281 regcache_release (void)
 282 {
 283   /* Flush and release all pre-existing register caches.  */
 284   for_each_thread (free_register_cache_thread);
 285 }
 286 #endif
 287
 288 int
 289 register_cache_size (const struct target_desc *tdesc)
 290 {
 291   return tdesc->registers_size;
 292 }
 293
 294 int
 295 register_size (const struct target_desc *tdesc, int n)
 296 {
 297   return find_register_by_number (tdesc, n)->size / 8;
 298 }
 299
 300 /* See common/common-regcache.h.  */
 301
 302 int
 303 regcache_register_size (const struct regcache *regcache, int n)
 304 {
 305   return register_size (regcache->tdesc, n);
 306 }
 307
 308 static unsigned char *
 309 register_data (struct regcache *regcache, int n, int fetch)
 310 {
 311   return (regcache->registers
 312           + find_register_by_number (regcache->tdesc, n)->offset / 8);
 313 }
 314
 315 /* Supply register N, whose contents are stored in BUF, to REGCACHE.
 316    If BUF is NULL, the register's value is recorded as
 317    unavailable.  */
 318
 319 void
 320 supply_register (struct regcache *regcache, int n, const void *buf)
 321 {
 322   if (buf)
 323     {
 324       memcpy (register_data (regcache, n, 0), buf,
 325               register_size (regcache->tdesc, n));
 326 #ifndef IN_PROCESS_AGENT
 327       if (regcache->register_status != NULL)
 328         regcache->register_status[n] = REG_VALID;
 329 #endif
 330     }
 331   else
 332     {
 333       memset (register_data (regcache, n, 0), 0,
 334               register_size (regcache->tdesc, n));
 335 #ifndef IN_PROCESS_AGENT
 336       if (regcache->register_status != NULL)
 337         regcache->register_status[n] = REG_UNAVAILABLE;
 338 #endif
 339     }
 340 }
 341
 342 /* Supply register N with value zero to REGCACHE.  */
 343
 344 void
 345 supply_register_zeroed (struct regcache *regcache, int n)
 346 {
 347   memset (register_data (regcache, n, 0), 0,
 348           register_size (regcache->tdesc, n));
 349 #ifndef IN_PROCESS_AGENT
 350   if (regcache->register_status != NULL)
 351     regcache->register_status[n] = REG_VALID;
 352 #endif
 353 }
 354
 355 /* Supply the whole register set whose contents are stored in BUF, to
 356    REGCACHE.  If BUF is NULL, all the registers' values are recorded
 357    as unavailable.  */
 358
 359 void
 360 supply_regblock (struct regcache *regcache, const void *buf)
 361 {
 362   if (buf)
 363     {
 364       const struct target_desc *tdesc = regcache->tdesc;
 365
 366       memcpy (regcache->registers, buf, tdesc->registers_size);
 367 #ifndef IN_PROCESS_AGENT
 368       {
 369         int i;
 370
 371         for (i = 0; i < tdesc->reg_defs.size (); i++)
 372           regcache->register_status[i] = REG_VALID;
 373       }
 374 #endif
 375     }
 376   else
 377     {
 378       const struct target_desc *tdesc = regcache->tdesc;
 379
 380       memset (regcache->registers, 0, tdesc->registers_size);
 381 #ifndef IN_PROCESS_AGENT
 382       {
 383         int i;
 384
 385         for (i = 0; i < tdesc->reg_defs.size (); i++)
 386           regcache->register_status[i] = REG_UNAVAILABLE;
 387       }
 388 #endif
 389     }
 390 }
 391
 392 #ifndef IN_PROCESS_AGENT
 393
 394 void
 395 supply_register_by_name (struct regcache *regcache,
 396                          const char *name, const void *buf)
 397 {
 398   supply_register (regcache, find_regno (regcache->tdesc, name), buf);
 399 }
 400
 401 #endif
 402
 403 void
 404 collect_register (struct regcache *regcache, int n, void *buf)
 405 {
 406   memcpy (buf, register_data (regcache, n, 1),
 407           register_size (regcache->tdesc, n));
 408 }
 409
 410 enum register_status
 411 regcache_raw_read_unsigned (struct regcache *regcache, int regnum,
 412                             ULONGEST *val)
 413 {
 414   int size;
 415
 416   gdb_assert (regcache != NULL);
 417   gdb_assert (regnum >= 0
 418               && regnum < regcache->tdesc->reg_defs.size ());
 419
 420   size = register_size (regcache->tdesc, regnum);
 421
 422   if (size > (int) sizeof (ULONGEST))
 423     error (_("That operation is not available on integers of more than"
 424             "%d bytes."),
 425           (int) sizeof (ULONGEST));
 426
 427   *val = 0;
 428   collect_register (regcache, regnum, val);
 429
 430   return REG_VALID;
 431 }
 432
 433 #ifndef IN_PROCESS_AGENT
 434
 435 void
 436 collect_register_as_string (struct regcache *regcache, int n, char *buf)
 437 {
 438   bin2hex (register_data (regcache, n, 1), buf,
 439            register_size (regcache->tdesc, n));
 440 }
 441
 442 void
 443 collect_register_by_name (struct regcache *regcache,
 444                           const char *name, void *buf)
 445 {
 446   collect_register (regcache, find_regno (regcache->tdesc, name), buf);
 447 }
 448
 449 /* Special handling for register PC.  */
 450
 451 CORE_ADDR
 452 regcache_read_pc (struct regcache *regcache)
 453 {
 454   CORE_ADDR pc_val;
 455
 456   if (the_target->read_pc)
 457     pc_val = the_target->read_pc (regcache);
 458   else
 459     internal_error (__FILE__, __LINE__,
 460                     "regcache_read_pc: Unable to find PC");
 461
 462   return pc_val;
 463 }
 464
 465 void
 466 regcache_write_pc (struct regcache *regcache, CORE_ADDR pc)
 467 {
 468   if (the_target->write_pc)
 469     the_target->write_pc (regcache, pc);
 470   else
 471     internal_error (__FILE__, __LINE__,
 472                     "regcache_write_pc: Unable to update PC");
 473 }
 474
 475 #endif