gdb/gdbserver/regcache.c - gdb

Functions defined

Source code

  1. /* Register support routines for the remote server for GDB.
  2.    Copyright (C) 2001-2015 Free Software Foundation, Inc.

  4.    This file is part of GDB.

  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.

  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.

  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/>.  */

  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

  26. struct regcache *
  27. ‌get_thread_regcache (struct thread_info *thread, int fetch)
  28. {
  29.   struct regcache *regcache;

  31.   regcache = (struct regcache *) inferior_regcache_data (thread);

  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);

  44.       gdb_assert (proc->tdesc != NULL);

  46.       regcache = new_register_cache (proc->tdesc);
  47.       set_inferior_regcache_data (thread, regcache);
  48.     }

  50.   if (fetch && regcache->registers_valid == 0)
  51.     {
  52.       struct thread_info *saved_thread = current_thread;

  54.       current_thread = thread;
  55.       /* Invalidate all registers, to prevent stale left-overs.  */
  56.       memset (regcache->register_status, REG_UNAVAILABLE,
  57.               regcache->tdesc->num_registers);
  58.       fetch_inferior_registers (regcache, -1);
  59.       current_thread = saved_thread;
  60.       regcache->registers_valid = 1;
  61.     }

  63.   return regcache;
  64. }

  66. /* See common/common-regcache.h.  */

  68. struct regcache *
  69. ‌get_thread_regcache_for_ptid (ptid_t ptid)
  70. {
  71.   return get_thread_regcache (find_thread_ptid (ptid), 1);
  72. }

  74. void
  75. ‌regcache_invalidate_thread (struct thread_info *thread)
  76. {
  77.   struct regcache *regcache;

  79.   regcache = (struct regcache *) inferior_regcache_data (thread);

  81.   if (regcache == NULL)
  82.     return;

  84.   if (regcache->registers_valid)
  85.     {
  86.       struct thread_info *saved_thread = current_thread;

  88.       current_thread = thread;
  89.       store_inferior_registers (regcache, -1);
  90.       current_thread = saved_thread;
  91.     }

  93.   regcache->registers_valid = 0;
  94. }

  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;

  103.   /* Only invalidate the regcaches of threads of this process.  */
  104.   if (ptid_get_pid (entry->id) == pid)
  105.     regcache_invalidate_thread (thread);

  107.   return 0;
  108. }

  110. void
  111. ‌regcache_invalidate (void)
  112. {
  113.   /* Only update the threads of the current process.  */
  114.   int pid = ptid_get_pid (current_thread->entry.id);

  116.   find_inferior (&all_threads, regcache_invalidate_one, &pid);
  117. }

  119. #endif

  121. struct regcache *
  122. ‌init_register_cache (struct regcache *regcache,
  123.                      const struct target_desc *tdesc,
  124.                      unsigned char *regbuf)
  125. {
  126.   if (regbuf == NULL)
  127.     {
  128. #ifndef IN_PROCESS_AGENT
  129.       /* Make sure to zero-initialize the register cache when it is
  130.          created, in case there are registers the target never
  131.          fetches.  This way they'll read as zero instead of
  132.          garbage.  */
  133.       regcache->tdesc = tdesc;
  134.       regcache->registers = xcalloc (1, tdesc->registers_size);
  135.       regcache->registers_owned = 1;
  136.       regcache->register_status = xcalloc (1, tdesc->num_registers);
  137.       gdb_assert (REG_UNAVAILABLE == 0);
  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.     }

  152.   regcache->registers_valid = 0;

  154.   return regcache;
  155. }

  157. #ifndef IN_PROCESS_AGENT

  159. struct regcache *
  160. ‌new_register_cache (const struct target_desc *tdesc)
  161. {
  162.   struct regcache *regcache;

  164.   gdb_assert (tdesc->registers_size != 0);

  166.   regcache = xmalloc (sizeof (*regcache));
  167.   return init_register_cache (regcache, tdesc, NULL);
  168. }

  170. void
  171. ‌free_register_cache (struct regcache *regcache)
  172. {
  173.   if (regcache)
  174.     {
  175.       if (regcache->registers_owned)
  176.         free (regcache->registers);
  177.       free (regcache->register_status);
  178.       free (regcache);
  179.     }
  180. }

  182. #endif

  184. void
  185. ‌regcache_cpy (struct regcache *dst, struct regcache *src)
  186. {
  187.   gdb_assert (src != NULL && dst != NULL);
  188.   gdb_assert (src->tdesc == dst->tdesc);
  189.   gdb_assert (src != dst);

  191.   memcpy (dst->registers, src->registers, src->tdesc->registers_size);
  192. #ifndef IN_PROCESS_AGENT
  193.   if (dst->register_status != NULL && src->register_status != NULL)
  194.     memcpy (dst->register_status, src->register_status,
  195.             src->tdesc->num_registers);
  196. #endif
  197.   dst->registers_valid = src->registers_valid;
  198. }


  201. #ifndef IN_PROCESS_AGENT

  203. void
  204. ‌registers_to_string (struct regcache *regcache, char *buf)
  205. {
  206.   unsigned char *registers = regcache->registers;
  207.   const struct target_desc *tdesc = regcache->tdesc;
  208.   int i;

  210.   for (i = 0; i < tdesc->num_registers; 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. }

  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;

  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. }

  244. struct reg *
  245. ‌find_register_by_name (const struct target_desc *tdesc, const char *name)
  246. {
  247.   int i;

  249.   for (i = 0; i < tdesc->num_registers; i++)
  250.     if (strcmp (name, tdesc->reg_defs[i].name) == 0)
  251.       return &tdesc->reg_defs[i];
  252.   internal_error (__FILE__, __LINE__, "Unknown register %s requested",
  253.                   name);
  254. }

  256. int
  257. ‌find_regno (const struct target_desc *tdesc, const char *name)
  258. {
  259.   int i;

  261.   for (i = 0; i < tdesc->num_registers; i++)
  262.     if (strcmp (name, tdesc->reg_defs[i].name) == 0)
  263.       return i;
  264.   internal_error (__FILE__, __LINE__, "Unknown register %s requested",
  265.                   name);
  266. }

  268. struct reg *
  269. ‌find_register_by_number (const struct target_desc *tdesc, int n)
  270. {
  271.   return &tdesc->reg_defs[n];
  272. }

  274. #endif

  276. #ifndef IN_PROCESS_AGENT
  277. static void
  278. ‌free_register_cache_thread (struct thread_info *thread)
  279. {
  280.   struct regcache *regcache
  281.     = (struct regcache *) inferior_regcache_data (thread);

  283.   if (regcache != NULL)
  284.     {
  285.       regcache_invalidate_thread (thread);
  286.       free_register_cache (regcache);
  287.       set_inferior_regcache_data (thread, NULL);
  288.     }
  289. }

  291. static void
  292. ‌free_register_cache_thread_one (struct inferior_list_entry *entry)
  293. {
  294.   struct thread_info *thread = (struct thread_info *) entry;

  296.   free_register_cache_thread (thread);
  297. }

  299. void
  300. ‌regcache_release (void)
  301. {
  302.   /* Flush and release all pre-existing register caches.  */
  303.   for_each_inferior (&all_threads, free_register_cache_thread_one);
  304. }
  305. #endif

  307. int
  308. ‌register_cache_size (const struct target_desc *tdesc)
  309. {
  310.   return tdesc->registers_size;
  311. }

  313. int
  314. ‌register_size (const struct target_desc *tdesc, int n)
  315. {
  316.   return tdesc->reg_defs[n].size / 8;
  317. }

  319. static unsigned char *
  320. ‌register_data (struct regcache *regcache, int n, int fetch)
  321. {
  322.   return regcache->registers + regcache->tdesc->reg_defs[n].offset / 8;
  323. }

  325. /* Supply register N, whose contents are stored in BUF, to REGCACHE.
  326.    If BUF is NULL, the register's value is recorded as
  327.    unavailable.  */

  329. void
  330. ‌supply_register (struct regcache *regcache, int n, const void *buf)
  331. {
  332.   if (buf)
  333.     {
  334.       memcpy (register_data (regcache, n, 0), buf,
  335.               register_size (regcache->tdesc, n));
  336. #ifndef IN_PROCESS_AGENT
  337.       if (regcache->register_status != NULL)
  338.         regcache->register_status[n] = REG_VALID;
  339. #endif
  340.     }
  341.   else
  342.     {
  343.       memset (register_data (regcache, n, 0), 0,
  344.               register_size (regcache->tdesc, n));
  345. #ifndef IN_PROCESS_AGENT
  346.       if (regcache->register_status != NULL)
  347.         regcache->register_status[n] = REG_UNAVAILABLE;
  348. #endif
  349.     }
  350. }

  352. /* Supply register N with value zero to REGCACHE.  */

  354. void
  355. ‌supply_register_zeroed (struct regcache *regcache, int n)
  356. {
  357.   memset (register_data (regcache, n, 0), 0,
  358.           register_size (regcache->tdesc, n));
  359. #ifndef IN_PROCESS_AGENT
  360.   if (regcache->register_status != NULL)
  361.     regcache->register_status[n] = REG_VALID;
  362. #endif
  363. }

  365. /* Supply the whole register set whose contents are stored in BUF, to
  366.    REGCACHE.  If BUF is NULL, all the registers' values are recorded
  367.    as unavailable.  */

  369. void
  370. ‌supply_regblock (struct regcache *regcache, const void *buf)
  371. {
  372.   if (buf)
  373.     {
  374.       const struct target_desc *tdesc = regcache->tdesc;

  376.       memcpy (regcache->registers, buf, tdesc->registers_size);
  377. #ifndef IN_PROCESS_AGENT
  378.       {
  379.         int i;

  381.         for (i = 0; i < tdesc->num_registers; i++)
  382.           regcache->register_status[i] = REG_VALID;
  383.       }
  384. #endif
  385.     }
  386.   else
  387.     {
  388.       const struct target_desc *tdesc = regcache->tdesc;

  390.       memset (regcache->registers, 0, tdesc->registers_size);
  391. #ifndef IN_PROCESS_AGENT
  392.       {
  393.         int i;

  395.         for (i = 0; i < tdesc->num_registers; i++)
  396.           regcache->register_status[i] = REG_UNAVAILABLE;
  397.       }
  398. #endif
  399.     }
  400. }

  402. #ifndef IN_PROCESS_AGENT

  404. void
  405. ‌supply_register_by_name (struct regcache *regcache,
  406.                          const char *name, const void *buf)
  407. {
  408.   supply_register (regcache, find_regno (regcache->tdesc, name), buf);
  409. }

  411. #endif

  413. void
  414. ‌collect_register (struct regcache *regcache, int n, void *buf)
  415. {
  416.   memcpy (buf, register_data (regcache, n, 1),
  417.           register_size (regcache->tdesc, n));
  418. }

  420. #ifndef IN_PROCESS_AGENT

  422. void
  423. ‌collect_register_as_string (struct regcache *regcache, int n, char *buf)
  424. {
  425.   bin2hex (register_data (regcache, n, 1), buf,
  426.            register_size (regcache->tdesc, n));
  427. }

  429. void
  430. ‌collect_register_by_name (struct regcache *regcache,
  431.                           const char *name, void *buf)
  432. {
  433.   collect_register (regcache, find_regno (regcache->tdesc, name), buf);
  434. }

  436. /* Special handling for register PC.  */

  438. CORE_ADDR
  439. ‌regcache_read_pc (struct regcache *regcache)
  440. {
  441.   CORE_ADDR pc_val;

  443.   if (the_target->read_pc)
  444.     pc_val = the_target->read_pc (regcache);
  445.   else
  446.     internal_error (__FILE__, __LINE__,
  447.                     "regcache_read_pc: Unable to find PC");

  449.   return pc_val;
  450. }

  452. void
  453. ‌regcache_write_pc (struct regcache *regcache, CORE_ADDR pc)
  454. {
  455.   if (the_target->write_pc)
  456.     the_target->write_pc (regcache, pc);
  457.   else
  458.     internal_error (__FILE__, __LINE__,
  459.                     "regcache_write_pc: Unable to update PC");
  460. }

  462. #endif