gdb/gdbserver/regcache.c

   1 /* Register support routines for the remote server for GDB.
   2    Copyright (C) 2001-2018 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       if (regcache->register_status[i] == REG_VALID)
 211         {
 212           bin2hex (registers, buf, register_size (tdesc, i));
 213           buf += register_size (tdesc, i) * 2;
 214         }
 215       else
 216         {
 217           memset (buf, 'x', register_size (tdesc, i) * 2);
 218           buf += register_size (tdesc, i) * 2;
 219         }
 220       registers += register_size (tdesc, i);
 221     }
 222   *buf = '\0';
 223 }
 224
 225 void
 226 registers_from_string (struct regcache *regcache, char *buf)
 227 {
 228   int len = strlen (buf);
 229   unsigned char *registers = regcache->registers;
 230   const struct target_desc *tdesc = regcache->tdesc;
 231
 232   if (len != tdesc->registers_size * 2)
 233     {
 234       warning ("Wrong sized register packet (expected %d bytes, got %d)",
 235                2 * tdesc->registers_size, len);
 236       if (len > tdesc->registers_size * 2)
 237         len = tdesc->registers_size * 2;
 238     }
 239   hex2bin (buf, registers, len / 2);
 240 }
 241
 242 int
 243 find_regno (const struct target_desc *tdesc, const char *name)
 244 {
 245   for (int i = 0; i < tdesc->reg_defs.size (); ++i)
 246     {
 247       struct reg *reg = tdesc->reg_defs[i];
 248
 249       if (strcmp (name, reg->name) == 0)
 250         return i;
 251     }
 252   internal_error (__FILE__, __LINE__, "Unknown register %s requested",
 253                   name);
 254 }
 255
 256 #endif
 257
 258 struct reg *
 259 find_register_by_number (const struct target_desc *tdesc, int n)
 260 {
 261   return tdesc->reg_defs[n];
 262 }
 263
 264 #ifndef IN_PROCESS_AGENT
 265 static void
 266 free_register_cache_thread (struct thread_info *thread)
 267 {
 268   struct regcache *regcache = thread_regcache_data (thread);
 269
 270   if (regcache != NULL)
 271     {
 272       regcache_invalidate_thread (thread);
 273       free_register_cache (regcache);
 274       set_thread_regcache_data (thread, NULL);
 275     }
 276 }
 277
 278 void
 279 regcache_release (void)
 280 {
 281   /* Flush and release all pre-existing register caches.  */
 282   for_each_thread (free_register_cache_thread);
 283 }
 284 #endif
 285
 286 int
 287 register_cache_size (const struct target_desc *tdesc)
 288 {
 289   return tdesc->registers_size;
 290 }
 291
 292 int
 293 register_size (const struct target_desc *tdesc, int n)
 294 {
 295   return find_register_by_number (tdesc, n)->size / 8;
 296 }
 297
 298 /* See common/common-regcache.h.  */
 299
 300 int
 301 regcache_register_size (const struct regcache *regcache, int n)
 302 {
 303   return register_size (regcache->tdesc, n);
 304 }
 305
 306 static unsigned char *
 307 register_data (struct regcache *regcache, int n, int fetch)
 308 {
 309   return (regcache->registers
 310           + find_register_by_number (regcache->tdesc, n)->offset / 8);
 311 }
 312
 313 /* Supply register N, whose contents are stored in BUF, to REGCACHE.
 314    If BUF is NULL, the register's value is recorded as
 315    unavailable.  */
 316
 317 void
 318 supply_register (struct regcache *regcache, int n, const void *buf)
 319 {
 320   if (buf)
 321     {
 322       memcpy (register_data (regcache, n, 0), buf,
 323               register_size (regcache->tdesc, n));
 324 #ifndef IN_PROCESS_AGENT
 325       if (regcache->register_status != NULL)
 326         regcache->register_status[n] = REG_VALID;
 327 #endif
 328     }
 329   else
 330     {
 331       memset (register_data (regcache, n, 0), 0,
 332               register_size (regcache->tdesc, n));
 333 #ifndef IN_PROCESS_AGENT
 334       if (regcache->register_status != NULL)
 335         regcache->register_status[n] = REG_UNAVAILABLE;
 336 #endif
 337     }
 338 }
 339
 340 /* Supply register N with value zero to REGCACHE.  */
 341
 342 void
 343 supply_register_zeroed (struct regcache *regcache, int n)
 344 {
 345   memset (register_data (regcache, n, 0), 0,
 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
 353 /* Supply the whole register set whose contents are stored in BUF, to
 354    REGCACHE.  If BUF is NULL, all the registers' values are recorded
 355    as unavailable.  */
 356
 357 void
 358 supply_regblock (struct regcache *regcache, const void *buf)
 359 {
 360   if (buf)
 361     {
 362       const struct target_desc *tdesc = regcache->tdesc;
 363
 364       memcpy (regcache->registers, buf, tdesc->registers_size);
 365 #ifndef IN_PROCESS_AGENT
 366       {
 367         int i;
 368
 369         for (i = 0; i < tdesc->reg_defs.size (); i++)
 370           regcache->register_status[i] = REG_VALID;
 371       }
 372 #endif
 373     }
 374   else
 375     {
 376       const struct target_desc *tdesc = regcache->tdesc;
 377
 378       memset (regcache->registers, 0, tdesc->registers_size);
 379 #ifndef IN_PROCESS_AGENT
 380       {
 381         int i;
 382
 383         for (i = 0; i < tdesc->reg_defs.size (); i++)
 384           regcache->register_status[i] = REG_UNAVAILABLE;
 385       }
 386 #endif
 387     }
 388 }
 389
 390 #ifndef IN_PROCESS_AGENT
 391
 392 void
 393 supply_register_by_name (struct regcache *regcache,
 394                          const char *name, const void *buf)
 395 {
 396   supply_register (regcache, find_regno (regcache->tdesc, name), buf);
 397 }
 398
 399 #endif
 400
 401 void
 402 collect_register (struct regcache *regcache, int n, void *buf)
 403 {
 404   memcpy (buf, register_data (regcache, n, 1),
 405           register_size (regcache->tdesc, n));
 406 }
 407
 408 enum register_status
 409 regcache_raw_read_unsigned (struct regcache *regcache, int regnum,
 410                             ULONGEST *val)
 411 {
 412   int size;
 413
 414   gdb_assert (regcache != NULL);
 415   gdb_assert (regnum >= 0
 416               && regnum < regcache->tdesc->reg_defs.size ());
 417
 418   size = register_size (regcache->tdesc, regnum);
 419
 420   if (size > (int) sizeof (ULONGEST))
 421     error (_("That operation is not available on integers of more than"
 422             "%d bytes."),
 423           (int) sizeof (ULONGEST));
 424
 425   *val = 0;
 426   collect_register (regcache, regnum, val);
 427
 428   return REG_VALID;
 429 }
 430
 431 #ifndef IN_PROCESS_AGENT
 432
 433 void
 434 collect_register_as_string (struct regcache *regcache, int n, char *buf)
 435 {
 436   bin2hex (register_data (regcache, n, 1), buf,
 437            register_size (regcache->tdesc, n));
 438 }
 439
 440 void
 441 collect_register_by_name (struct regcache *regcache,
 442                           const char *name, void *buf)
 443 {
 444   collect_register (regcache, find_regno (regcache->tdesc, name), buf);
 445 }
 446
 447 /* Special handling for register PC.  */
 448
 449 CORE_ADDR
 450 regcache_read_pc (struct regcache *regcache)
 451 {
 452   CORE_ADDR pc_val;
 453
 454   if (the_target->read_pc)
 455     pc_val = the_target->read_pc (regcache);
 456   else
 457     internal_error (__FILE__, __LINE__,
 458                     "regcache_read_pc: Unable to find PC");
 459
 460   return pc_val;
 461 }
 462
 463 void
 464 regcache_write_pc (struct regcache *regcache, CORE_ADDR pc)
 465 {
 466   if (the_target->write_pc)
 467     the_target->write_pc (regcache, pc);
 468   else
 469     internal_error (__FILE__, __LINE__,
 470                     "regcache_write_pc: Unable to update PC");
 471 }
 472
 473 #endif