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
  25 #include <stdlib.h>
  26 #include <string.h>
  27
  28 #ifndef IN_PROCESS_AGENT
  29
  30 struct regcache *
  31 get_thread_regcache (struct thread_info *thread, int fetch)
  32 {
  33   struct regcache *regcache;
  34
  35   regcache = (struct regcache *) inferior_regcache_data (thread);
  36
  37   /* Threads' regcaches are created lazily, because biarch targets add
  38      the main thread/lwp before seeing it stop for the first time, and
  39      it is only after the target sees the thread stop for the first
  40      time that the target has a chance of determining the process's
  41      architecture.  IOW, when we first add the process's main thread
  42      we don't know which architecture/tdesc its regcache should
  43      have.  */
  44   if (regcache == NULL)
  45     {
  46       struct process_info *proc = get_thread_process (thread);
  47
  48       if (proc->tdesc == NULL)
  49         fatal ("no target description");
  50
  51       regcache = new_register_cache (proc->tdesc);
  52       set_inferior_regcache_data (thread, regcache);
  53     }
  54
  55   if (fetch && regcache->registers_valid == 0)
  56     {
  57       struct thread_info *saved_inferior = current_inferior;
  58
  59       current_inferior = thread;
  60       fetch_inferior_registers (regcache, -1);
  61       current_inferior = saved_inferior;
  62       regcache->registers_valid = 1;
  63     }
  64
  65   return regcache;
  66 }
  67
  68 void
  69 regcache_invalidate_thread (struct thread_info *thread)
  70 {
  71   struct regcache *regcache;
  72
  73   regcache = (struct regcache *) inferior_regcache_data (thread);
  74
  75   if (regcache == NULL)
  76     return;
  77
  78   if (regcache->registers_valid)
  79     {
  80       struct thread_info *saved_inferior = current_inferior;
  81
  82       current_inferior = thread;
  83       store_inferior_registers (regcache, -1);
  84       current_inferior = saved_inferior;
  85     }
  86
  87   regcache->registers_valid = 0;
  88 }
  89
  90 static int
  91 regcache_invalidate_one (struct inferior_list_entry *entry,
  92                          void *pid_p)
  93 {
  94   struct thread_info *thread = (struct thread_info *) entry;
  95   int pid = *(int *) pid_p;
  96
  97   /* Only invalidate the regcaches of threads of this process.  */
  98   if (ptid_get_pid (entry->id) == pid)
  99     regcache_invalidate_thread (thread);
 100
 101   return 0;
 102 }
 103
 104 void
 105 regcache_invalidate (void)
 106 {
 107   /* Only update the threads of the current process.  */
 108   int pid = ptid_get_pid (current_inferior->entry.id);
 109
 110   find_inferior (&all_threads, regcache_invalidate_one, &pid);
 111 }
 112
 113 #endif
 114
 115 struct regcache *
 116 init_register_cache (struct regcache *regcache,
 117                      const struct target_desc *tdesc,
 118                      unsigned char *regbuf)
 119 {
 120   if (regbuf == NULL)
 121     {
 122 #ifndef IN_PROCESS_AGENT
 123       /* Make sure to zero-initialize the register cache when it is
 124          created, in case there are registers the target never
 125          fetches.  This way they'll read as zero instead of
 126          garbage.  */
 127       regcache->tdesc = tdesc;
 128       regcache->registers = xcalloc (1, tdesc->registers_size);
 129       regcache->registers_owned = 1;
 130       regcache->register_status = xcalloc (1, tdesc->num_registers);
 131       gdb_assert (REG_UNAVAILABLE == 0);
 132 #else
 133       fatal ("init_register_cache: can't allocate memory from the heap");
 134 #endif
 135     }
 136   else
 137     {
 138       regcache->tdesc = tdesc;
 139       regcache->registers = regbuf;
 140       regcache->registers_owned = 0;
 141 #ifndef IN_PROCESS_AGENT
 142       regcache->register_status = NULL;
 143 #endif
 144     }
 145
 146   regcache->registers_valid = 0;
 147
 148   return regcache;
 149 }
 150
 151 #ifndef IN_PROCESS_AGENT
 152
 153 struct regcache *
 154 new_register_cache (const struct target_desc *tdesc)
 155 {
 156   struct regcache *regcache;
 157
 158   gdb_assert (tdesc->registers_size != 0);
 159
 160   regcache = xmalloc (sizeof (*regcache));
 161   return init_register_cache (regcache, tdesc, NULL);
 162 }
 163
 164 void
 165 free_register_cache (struct regcache *regcache)
 166 {
 167   if (regcache)
 168     {
 169       if (regcache->registers_owned)
 170         free (regcache->registers);
 171       free (regcache->register_status);
 172       free (regcache);
 173     }
 174 }
 175
 176 #endif
 177
 178 void
 179 regcache_cpy (struct regcache *dst, struct regcache *src)
 180 {
 181   gdb_assert (src != NULL && dst != NULL);
 182   gdb_assert (src->tdesc == dst->tdesc);
 183   gdb_assert (src != dst);
 184
 185   memcpy (dst->registers, src->registers, src->tdesc->registers_size);
 186 #ifndef IN_PROCESS_AGENT
 187   if (dst->register_status != NULL && src->register_status != NULL)
 188     memcpy (dst->register_status, src->register_status,
 189             src->tdesc->num_registers);
 190 #endif
 191   dst->registers_valid = src->registers_valid;
 192 }
 193
 194
 195 #ifndef IN_PROCESS_AGENT
 196
 197 void
 198 registers_to_string (struct regcache *regcache, char *buf)
 199 {
 200   unsigned char *registers = regcache->registers;
 201   const struct target_desc *tdesc = regcache->tdesc;
 202   int i;
 203
 204   for (i = 0; i < tdesc->num_registers; i++)
 205     {
 206       if (regcache->register_status[i] == REG_VALID)
 207         {
 208           bin2hex (registers, buf, register_size (tdesc, i));
 209           buf += register_size (tdesc, i) * 2;
 210         }
 211       else
 212         {
 213           memset (buf, 'x', register_size (tdesc, i) * 2);
 214           buf += register_size (tdesc, i) * 2;
 215         }
 216       registers += register_size (tdesc, i);
 217     }
 218   *buf = '\0';
 219 }
 220
 221 void
 222 registers_from_string (struct regcache *regcache, char *buf)
 223 {
 224   int len = strlen (buf);
 225   unsigned char *registers = regcache->registers;
 226   const struct target_desc *tdesc = regcache->tdesc;
 227
 228   if (len != tdesc->registers_size * 2)
 229     {
 230       warning ("Wrong sized register packet (expected %d bytes, got %d)",
 231                2 * tdesc->registers_size, len);
 232       if (len > tdesc->registers_size * 2)
 233         len = tdesc->registers_size * 2;
 234     }
 235   hex2bin (buf, registers, len / 2);
 236 }
 237
 238 struct reg *
 239 find_register_by_name (const struct target_desc *tdesc, const char *name)
 240 {
 241   int i;
 242
 243   for (i = 0; i < tdesc->num_registers; i++)
 244     if (strcmp (name, tdesc->reg_defs[i].name) == 0)
 245       return &tdesc->reg_defs[i];
 246   fatal ("Unknown register %s requested", name);
 247   return 0;
 248 }
 249
 250 int
 251 find_regno (const struct target_desc *tdesc, const char *name)
 252 {
 253   int i;
 254
 255   for (i = 0; i < tdesc->num_registers; i++)
 256     if (strcmp (name, tdesc->reg_defs[i].name) == 0)
 257       return i;
 258   fatal ("Unknown register %s requested", name);
 259   return -1;
 260 }
 261
 262 struct reg *
 263 find_register_by_number (const struct target_desc *tdesc, int n)
 264 {
 265   return &tdesc->reg_defs[n];
 266 }
 267
 268 #endif
 269
 270 #ifndef IN_PROCESS_AGENT
 271 static void
 272 free_register_cache_thread (struct thread_info *thread)
 273 {
 274   struct regcache *regcache
 275     = (struct regcache *) inferior_regcache_data (thread);
 276
 277   if (regcache != NULL)
 278     {
 279       regcache_invalidate_thread (thread);
 280       free_register_cache (regcache);
 281       set_inferior_regcache_data (thread, NULL);
 282     }
 283 }
 284
 285 static void
 286 free_register_cache_thread_one (struct inferior_list_entry *entry)
 287 {
 288   struct thread_info *thread = (struct thread_info *) entry;
 289
 290   free_register_cache_thread (thread);
 291 }
 292
 293 void
 294 regcache_release (void)
 295 {
 296   /* Flush and release all pre-existing register caches.  */
 297   for_each_inferior (&all_threads, free_register_cache_thread_one);
 298 }
 299 #endif
 300
 301 int
 302 register_cache_size (const struct target_desc *tdesc)
 303 {
 304   return tdesc->registers_size;
 305 }
 306
 307 int
 308 register_size (const struct target_desc *tdesc, int n)
 309 {
 310   return tdesc->reg_defs[n].size / 8;
 311 }
 312
 313 static unsigned char *
 314 register_data (struct regcache *regcache, int n, int fetch)
 315 {
 316   return regcache->registers + regcache->tdesc->reg_defs[n].offset / 8;
 317 }
 318
 319 /* Supply register N, whose contents are stored in BUF, to REGCACHE.
 320    If BUF is NULL, the register's value is recorded as
 321    unavailable.  */
 322
 323 void
 324 supply_register (struct regcache *regcache, int n, const void *buf)
 325 {
 326   if (buf)
 327     {
 328       memcpy (register_data (regcache, n, 0), buf,
 329               register_size (regcache->tdesc, n));
 330 #ifndef IN_PROCESS_AGENT
 331       if (regcache->register_status != NULL)
 332         regcache->register_status[n] = REG_VALID;
 333 #endif
 334     }
 335   else
 336     {
 337       memset (register_data (regcache, n, 0), 0,
 338               register_size (regcache->tdesc, n));
 339 #ifndef IN_PROCESS_AGENT
 340       if (regcache->register_status != NULL)
 341         regcache->register_status[n] = REG_UNAVAILABLE;
 342 #endif
 343     }
 344 }
 345
 346 /* Supply register N with value zero to REGCACHE.  */
 347
 348 void
 349 supply_register_zeroed (struct regcache *regcache, int n)
 350 {
 351   memset (register_data (regcache, n, 0), 0,
 352           register_size (regcache->tdesc, n));
 353 #ifndef IN_PROCESS_AGENT
 354   if (regcache->register_status != NULL)
 355     regcache->register_status[n] = REG_VALID;
 356 #endif
 357 }
 358
 359 /* Supply the whole register set whose contents are stored in BUF, to
 360    REGCACHE.  If BUF is NULL, all the registers' values are recorded
 361    as unavailable.  */
 362
 363 void
 364 supply_regblock (struct regcache *regcache, const void *buf)
 365 {
 366   if (buf)
 367     {
 368       const struct target_desc *tdesc = regcache->tdesc;
 369
 370       memcpy (regcache->registers, buf, tdesc->registers_size);
 371 #ifndef IN_PROCESS_AGENT
 372       {
 373         int i;
 374
 375         for (i = 0; i < tdesc->num_registers; i++)
 376           regcache->register_status[i] = REG_VALID;
 377       }
 378 #endif
 379     }
 380   else
 381     {
 382       const struct target_desc *tdesc = regcache->tdesc;
 383
 384       memset (regcache->registers, 0, tdesc->registers_size);
 385 #ifndef IN_PROCESS_AGENT
 386       {
 387         int i;
 388
 389         for (i = 0; i < tdesc->num_registers; i++)
 390           regcache->register_status[i] = REG_UNAVAILABLE;
 391       }
 392 #endif
 393     }
 394 }
 395
 396 #ifndef IN_PROCESS_AGENT
 397
 398 void
 399 supply_register_by_name (struct regcache *regcache,
 400                          const char *name, const void *buf)
 401 {
 402   supply_register (regcache, find_regno (regcache->tdesc, name), buf);
 403 }
 404
 405 #endif
 406
 407 void
 408 collect_register (struct regcache *regcache, int n, void *buf)
 409 {
 410   memcpy (buf, register_data (regcache, n, 1),
 411           register_size (regcache->tdesc, n));
 412 }
 413
 414 #ifndef IN_PROCESS_AGENT
 415
 416 void
 417 collect_register_as_string (struct regcache *regcache, int n, char *buf)
 418 {
 419   bin2hex (register_data (regcache, n, 1), buf,
 420            register_size (regcache->tdesc, n));
 421 }
 422
 423 void
 424 collect_register_by_name (struct regcache *regcache,
 425                           const char *name, void *buf)
 426 {
 427   collect_register (regcache, find_regno (regcache->tdesc, name), buf);
 428 }
 429
 430 /* Special handling for register PC.  */
 431
 432 CORE_ADDR
 433 regcache_read_pc (struct regcache *regcache)
 434 {
 435   CORE_ADDR pc_val;
 436
 437   if (the_target->read_pc)
 438     pc_val = the_target->read_pc (regcache);
 439   else
 440     internal_error (__FILE__, __LINE__,
 441                     "regcache_read_pc: Unable to find PC");
 442
 443   return pc_val;
 444 }
 445
 446 void
 447 regcache_write_pc (struct regcache *regcache, CORE_ADDR pc)
 448 {
 449   if (the_target->write_pc)
 450     the_target->write_pc (regcache, pc);
 451   else
 452     internal_error (__FILE__, __LINE__,
 453                     "regcache_write_pc: Unable to update PC");
 454 }
 455
 456 #endif