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 #ifndef IN_PROCESS_AGENT
 121   if (regbuf == NULL)
 122     {
 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     }
 133   else
 134 #else
 135   if (regbuf == NULL)
 136     fatal ("init_register_cache: can't allocate memory from the heap");
 137   else
 138 #endif
 139     {
 140       regcache->tdesc = tdesc;
 141       regcache->registers = regbuf;
 142       regcache->registers_owned = 0;
 143 #ifndef IN_PROCESS_AGENT
 144       regcache->register_status = NULL;
 145 #endif
 146     }
 147
 148   regcache->registers_valid = 0;
 149
 150   return regcache;
 151 }
 152
 153 #ifndef IN_PROCESS_AGENT
 154
 155 struct regcache *
 156 new_register_cache (const struct target_desc *tdesc)
 157 {
 158   struct regcache *regcache;
 159
 160   gdb_assert (tdesc->registers_size != 0);
 161
 162   regcache = xmalloc (sizeof (*regcache));
 163   return init_register_cache (regcache, tdesc, NULL);
 164 }
 165
 166 void
 167 free_register_cache (struct regcache *regcache)
 168 {
 169   if (regcache)
 170     {
 171       if (regcache->registers_owned)
 172         free (regcache->registers);
 173       free (regcache->register_status);
 174       free (regcache);
 175     }
 176 }
 177
 178 #endif
 179
 180 void
 181 regcache_cpy (struct regcache *dst, struct regcache *src)
 182 {
 183   gdb_assert (src != NULL && dst != NULL);
 184   gdb_assert (src->tdesc == dst->tdesc);
 185   gdb_assert (src != dst);
 186
 187   memcpy (dst->registers, src->registers, src->tdesc->registers_size);
 188 #ifndef IN_PROCESS_AGENT
 189   if (dst->register_status != NULL && src->register_status != NULL)
 190     memcpy (dst->register_status, src->register_status,
 191             src->tdesc->num_registers);
 192 #endif
 193   dst->registers_valid = src->registers_valid;
 194 }
 195
 196
 197 #ifndef IN_PROCESS_AGENT
 198
 199 void
 200 registers_to_string (struct regcache *regcache, char *buf)
 201 {
 202   unsigned char *registers = regcache->registers;
 203   const struct target_desc *tdesc = regcache->tdesc;
 204   int i;
 205
 206   for (i = 0; i < tdesc->num_registers; i++)
 207     {
 208       if (regcache->register_status[i] == REG_VALID)
 209         {
 210           bin2hex (registers, buf, register_size (tdesc, i));
 211           buf += register_size (tdesc, i) * 2;
 212         }
 213       else
 214         {
 215           memset (buf, 'x', register_size (tdesc, i) * 2);
 216           buf += register_size (tdesc, i) * 2;
 217         }
 218       registers += register_size (tdesc, i);
 219     }
 220   *buf = '\0';
 221 }
 222
 223 void
 224 registers_from_string (struct regcache *regcache, char *buf)
 225 {
 226   int len = strlen (buf);
 227   unsigned char *registers = regcache->registers;
 228   const struct target_desc *tdesc = regcache->tdesc;
 229
 230   if (len != tdesc->registers_size * 2)
 231     {
 232       warning ("Wrong sized register packet (expected %d bytes, got %d)",
 233                2 * tdesc->registers_size, len);
 234       if (len > tdesc->registers_size * 2)
 235         len = tdesc->registers_size * 2;
 236     }
 237   hex2bin (buf, registers, len / 2);
 238 }
 239
 240 struct reg *
 241 find_register_by_name (const struct target_desc *tdesc, const char *name)
 242 {
 243   int i;
 244
 245   for (i = 0; i < tdesc->num_registers; i++)
 246     if (strcmp (name, tdesc->reg_defs[i].name) == 0)
 247       return &tdesc->reg_defs[i];
 248   fatal ("Unknown register %s requested", name);
 249   return 0;
 250 }
 251
 252 int
 253 find_regno (const struct target_desc *tdesc, const char *name)
 254 {
 255   int i;
 256
 257   for (i = 0; i < tdesc->num_registers; i++)
 258     if (strcmp (name, tdesc->reg_defs[i].name) == 0)
 259       return i;
 260   fatal ("Unknown register %s requested", name);
 261   return -1;
 262 }
 263
 264 struct reg *
 265 find_register_by_number (const struct target_desc *tdesc, int n)
 266 {
 267   return &tdesc->reg_defs[n];
 268 }
 269
 270 #endif
 271
 272 #ifndef IN_PROCESS_AGENT
 273 static void
 274 free_register_cache_thread (struct thread_info *thread)
 275 {
 276   struct regcache *regcache
 277     = (struct regcache *) inferior_regcache_data (thread);
 278
 279   if (regcache != NULL)
 280     {
 281       regcache_invalidate_thread (thread);
 282       free_register_cache (regcache);
 283       set_inferior_regcache_data (thread, NULL);
 284     }
 285 }
 286
 287 static void
 288 free_register_cache_thread_one (struct inferior_list_entry *entry)
 289 {
 290   struct thread_info *thread = (struct thread_info *) entry;
 291
 292   free_register_cache_thread (thread);
 293 }
 294
 295 void
 296 regcache_release (void)
 297 {
 298   /* Flush and release all pre-existing register caches.  */
 299   for_each_inferior (&all_threads, free_register_cache_thread_one);
 300 }
 301 #endif
 302
 303 int
 304 register_cache_size (const struct target_desc *tdesc)
 305 {
 306   return tdesc->registers_size;
 307 }
 308
 309 int
 310 register_size (const struct target_desc *tdesc, int n)
 311 {
 312   return tdesc->reg_defs[n].size / 8;
 313 }
 314
 315 static unsigned char *
 316 register_data (struct regcache *regcache, int n, int fetch)
 317 {
 318   return regcache->registers + regcache->tdesc->reg_defs[n].offset / 8;
 319 }
 320
 321 /* Supply register N, whose contents are stored in BUF, to REGCACHE.
 322    If BUF is NULL, the register's value is recorded as
 323    unavailable.  */
 324
 325 void
 326 supply_register (struct regcache *regcache, int n, const void *buf)
 327 {
 328   if (buf)
 329     {
 330       memcpy (register_data (regcache, n, 0), buf,
 331               register_size (regcache->tdesc, n));
 332 #ifndef IN_PROCESS_AGENT
 333       if (regcache->register_status != NULL)
 334         regcache->register_status[n] = REG_VALID;
 335 #endif
 336     }
 337   else
 338     {
 339       memset (register_data (regcache, n, 0), 0,
 340               register_size (regcache->tdesc, n));
 341 #ifndef IN_PROCESS_AGENT
 342       if (regcache->register_status != NULL)
 343         regcache->register_status[n] = REG_UNAVAILABLE;
 344 #endif
 345     }
 346 }
 347
 348 /* Supply register N with value zero to REGCACHE.  */
 349
 350 void
 351 supply_register_zeroed (struct regcache *regcache, int n)
 352 {
 353   memset (register_data (regcache, n, 0), 0,
 354           register_size (regcache->tdesc, n));
 355 #ifndef IN_PROCESS_AGENT
 356   if (regcache->register_status != NULL)
 357     regcache->register_status[n] = REG_VALID;
 358 #endif
 359 }
 360
 361 /* Supply the whole register set whose contents are stored in BUF, to
 362    REGCACHE.  If BUF is NULL, all the registers' values are recorded
 363    as unavailable.  */
 364
 365 void
 366 supply_regblock (struct regcache *regcache, const void *buf)
 367 {
 368   if (buf)
 369     {
 370       const struct target_desc *tdesc = regcache->tdesc;
 371
 372       memcpy (regcache->registers, buf, tdesc->registers_size);
 373 #ifndef IN_PROCESS_AGENT
 374       {
 375         int i;
 376
 377         for (i = 0; i < tdesc->num_registers; i++)
 378           regcache->register_status[i] = REG_VALID;
 379       }
 380 #endif
 381     }
 382   else
 383     {
 384       const struct target_desc *tdesc = regcache->tdesc;
 385
 386       memset (regcache->registers, 0, tdesc->registers_size);
 387 #ifndef IN_PROCESS_AGENT
 388       {
 389         int i;
 390
 391         for (i = 0; i < tdesc->num_registers; i++)
 392           regcache->register_status[i] = REG_UNAVAILABLE;
 393       }
 394 #endif
 395     }
 396 }
 397
 398 #ifndef IN_PROCESS_AGENT
 399
 400 void
 401 supply_register_by_name (struct regcache *regcache,
 402                          const char *name, const void *buf)
 403 {
 404   supply_register (regcache, find_regno (regcache->tdesc, name), buf);
 405 }
 406
 407 #endif
 408
 409 void
 410 collect_register (struct regcache *regcache, int n, void *buf)
 411 {
 412   memcpy (buf, register_data (regcache, n, 1),
 413           register_size (regcache->tdesc, n));
 414 }
 415
 416 #ifndef IN_PROCESS_AGENT
 417
 418 void
 419 collect_register_as_string (struct regcache *regcache, int n, char *buf)
 420 {
 421   bin2hex (register_data (regcache, n, 1), buf,
 422            register_size (regcache->tdesc, n));
 423 }
 424
 425 void
 426 collect_register_by_name (struct regcache *regcache,
 427                           const char *name, void *buf)
 428 {
 429   collect_register (regcache, find_regno (regcache->tdesc, name), buf);
 430 }
 431
 432 /* Special handling for register PC.  */
 433
 434 CORE_ADDR
 435 regcache_read_pc (struct regcache *regcache)
 436 {
 437   CORE_ADDR pc_val;
 438
 439   if (the_target->read_pc)
 440     pc_val = the_target->read_pc (regcache);
 441   else
 442     internal_error (__FILE__, __LINE__,
 443                     "regcache_read_pc: Unable to find PC");
 444
 445   return pc_val;
 446 }
 447
 448 void
 449 regcache_write_pc (struct regcache *regcache, CORE_ADDR pc)
 450 {
 451   if (the_target->write_pc)
 452     the_target->write_pc (regcache, pc);
 453   else
 454     internal_error (__FILE__, __LINE__,
 455                     "regcache_write_pc: Unable to update PC");
 456 }
 457
 458 #endif