gdb/gdbserver/linux-x86-low.c

   1 /* GNU/Linux/x86-64 specific low level interface, for the remote server
   2    for GDB.
   3    Copyright (C) 2002, 2004, 2005, 2006, 2007, 2008, 2009, 2010
   4    Free Software Foundation, Inc.
   5
   6    This file is part of GDB.
   7
   8    This program is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 3 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  20
  21 #include <stddef.h>
  22 #include <signal.h>
  23 #include "server.h"
  24 #include "linux-low.h"
  25 #include "i387-fp.h"
  26 #include "i386-low.h"
  27
  28 #include "gdb_proc_service.h"
  29
  30 /* Defined in auto-generated file reg-i386-linux.c.  */
  31 void init_registers_i386_linux (void);
  32 /* Defined in auto-generated file reg-x86-64-linux.c.  */
  33 void init_registers_x86_64_linux (void);
  34
  35 #include <sys/reg.h>
  36 #include <sys/procfs.h>
  37 #include <sys/ptrace.h>
  38
  39 #ifndef PTRACE_GET_THREAD_AREA
  40 #define PTRACE_GET_THREAD_AREA 25
  41 #endif
  42
  43 /* This definition comes from prctl.h, but some kernels may not have it.  */
  44 #ifndef PTRACE_ARCH_PRCTL
  45 #define PTRACE_ARCH_PRCTL      30
  46 #endif
  47
  48 /* The following definitions come from prctl.h, but may be absent
  49    for certain configurations.  */
  50 #ifndef ARCH_GET_FS
  51 #define ARCH_SET_GS 0x1001
  52 #define ARCH_SET_FS 0x1002
  53 #define ARCH_GET_FS 0x1003
  54 #define ARCH_GET_GS 0x1004
  55 #endif
  56
  57 /* Per-process arch-specific data we want to keep.  */
  58
  59 struct arch_process_info
  60 {
  61   struct i386_debug_reg_state debug_reg_state;
  62 };
  63
  64 /* Per-thread arch-specific data we want to keep.  */
  65
  66 struct arch_lwp_info
  67 {
  68   /* Non-zero if our copy differs from what's recorded in the thread.  */
  69   int debug_registers_changed;
  70 };
  71
  72 #ifdef __x86_64__
  73
  74 /* Mapping between the general-purpose registers in `struct user'
  75    format and GDB's register array layout.
  76    Note that the transfer layout uses 64-bit regs.  */
  77 static /*const*/ int i386_regmap[] =
  78 {
  79   RAX * 8, RCX * 8, RDX * 8, RBX * 8,
  80   RSP * 8, RBP * 8, RSI * 8, RDI * 8,
  81   RIP * 8, EFLAGS * 8, CS * 8, SS * 8,
  82   DS * 8, ES * 8, FS * 8, GS * 8
  83 };
  84
  85 #define I386_NUM_REGS (sizeof (i386_regmap) / sizeof (i386_regmap[0]))
  86
  87 /* So code below doesn't have to care, i386 or amd64.  */
  88 #define ORIG_EAX ORIG_RAX
  89
  90 static const int x86_64_regmap[] =
  91 {
  92   RAX * 8, RBX * 8, RCX * 8, RDX * 8,
  93   RSI * 8, RDI * 8, RBP * 8, RSP * 8,
  94   R8 * 8, R9 * 8, R10 * 8, R11 * 8,
  95   R12 * 8, R13 * 8, R14 * 8, R15 * 8,
  96   RIP * 8, EFLAGS * 8, CS * 8, SS * 8,
  97   DS * 8, ES * 8, FS * 8, GS * 8,
  98   -1, -1, -1, -1, -1, -1, -1, -1,
  99   -1, -1, -1, -1, -1, -1, -1, -1,
 100   -1, -1, -1, -1, -1, -1, -1, -1,
 101   -1, -1, -1, -1, -1, -1, -1, -1, -1,
 102   ORIG_RAX * 8
 103 };
 104
 105 #define X86_64_NUM_REGS (sizeof (x86_64_regmap) / sizeof (x86_64_regmap[0]))
 106
 107 #else /* ! __x86_64__ */
 108
 109 /* Mapping between the general-purpose registers in `struct user'
 110    format and GDB's register array layout.  */
 111 static /*const*/ int i386_regmap[] =
 112 {
 113   EAX * 4, ECX * 4, EDX * 4, EBX * 4,
 114   UESP * 4, EBP * 4, ESI * 4, EDI * 4,
 115   EIP * 4, EFL * 4, CS * 4, SS * 4,
 116   DS * 4, ES * 4, FS * 4, GS * 4
 117 };
 118
 119 #define I386_NUM_REGS (sizeof (i386_regmap) / sizeof (i386_regmap[0]))
 120
 121 #endif
 122 \f
 123 /* Called by libthread_db.  */
 124
 125 ps_err_e
 126 ps_get_thread_area (const struct ps_prochandle *ph,
 127                     lwpid_t lwpid, int idx, void **base)
 128 {
 129 #ifdef __x86_64__
 130   int use_64bit = register_size (0) == 8;
 131
 132   if (use_64bit)
 133     {
 134       switch (idx)
 135         {
 136         case FS:
 137           if (ptrace (PTRACE_ARCH_PRCTL, lwpid, base, ARCH_GET_FS) == 0)
 138             return PS_OK;
 139           break;
 140         case GS:
 141           if (ptrace (PTRACE_ARCH_PRCTL, lwpid, base, ARCH_GET_GS) == 0)
 142             return PS_OK;
 143           break;
 144         default:
 145           return PS_BADADDR;
 146         }
 147       return PS_ERR;
 148     }
 149 #endif
 150
 151   {
 152     unsigned int desc[4];
 153
 154     if (ptrace (PTRACE_GET_THREAD_AREA, lwpid,
 155                 (void *) (intptr_t) idx, (unsigned long) &desc) < 0)
 156       return PS_ERR;
 157
 158     *(int *)base = desc[1];
 159     return PS_OK;
 160   }
 161 }
 162 \f
 163 static int
 164 i386_cannot_store_register (int regno)
 165 {
 166   return regno >= I386_NUM_REGS;
 167 }
 168
 169 static int
 170 i386_cannot_fetch_register (int regno)
 171 {
 172   return regno >= I386_NUM_REGS;
 173 }
 174
 175 static void
 176 x86_fill_gregset (void *buf)
 177 {
 178   int i;
 179
 180 #ifdef __x86_64__
 181   if (register_size (0) == 8)
 182     {
 183       for (i = 0; i < X86_64_NUM_REGS; i++)
 184         if (x86_64_regmap[i] != -1)
 185           collect_register (i, ((char *) buf) + x86_64_regmap[i]);
 186       return;
 187     }
 188 #endif
 189
 190   for (i = 0; i < I386_NUM_REGS; i++)
 191     collect_register (i, ((char *) buf) + i386_regmap[i]);
 192
 193   collect_register_by_name ("orig_eax", ((char *) buf) + ORIG_EAX * 4);
 194 }
 195
 196 static void
 197 x86_store_gregset (const void *buf)
 198 {
 199   int i;
 200
 201 #ifdef __x86_64__
 202   if (register_size (0) == 8)
 203     {
 204       for (i = 0; i < X86_64_NUM_REGS; i++)
 205         if (x86_64_regmap[i] != -1)
 206           supply_register (i, ((char *) buf) + x86_64_regmap[i]);
 207       return;
 208     }
 209 #endif
 210
 211   for (i = 0; i < I386_NUM_REGS; i++)
 212     supply_register (i, ((char *) buf) + i386_regmap[i]);
 213
 214   supply_register_by_name ("orig_eax", ((char *) buf) + ORIG_EAX * 4);
 215 }
 216
 217 static void
 218 x86_fill_fpregset (void *buf)
 219 {
 220 #ifdef __x86_64__
 221   i387_cache_to_fxsave (buf);
 222 #else
 223   i387_cache_to_fsave (buf);
 224 #endif
 225 }
 226
 227 static void
 228 x86_store_fpregset (const void *buf)
 229 {
 230 #ifdef __x86_64__
 231   i387_fxsave_to_cache (buf);
 232 #else
 233   i387_fsave_to_cache (buf);
 234 #endif
 235 }
 236
 237 #ifndef __x86_64__
 238
 239 static void
 240 x86_fill_fpxregset (void *buf)
 241 {
 242   i387_cache_to_fxsave (buf);
 243 }
 244
 245 static void
 246 x86_store_fpxregset (const void *buf)
 247 {
 248   i387_fxsave_to_cache (buf);
 249 }
 250
 251 #endif
 252
 253 /* ??? The non-biarch i386 case stores all the i387 regs twice.
 254    Once in i387_.*fsave.* and once in i387_.*fxsave.*.
 255    This is, presumably, to handle the case where PTRACE_[GS]ETFPXREGS
 256    doesn't work.  IWBN to avoid the duplication in the case where it
 257    does work.  Maybe the arch_setup routine could check whether it works
 258    and update target_regsets accordingly, maybe by moving target_regsets
 259    to linux_target_ops and set the right one there, rather than having to
 260    modify the target_regsets global.  */
 261
 262 struct regset_info target_regsets[] =
 263 {
 264 #ifdef HAVE_PTRACE_GETREGS
 265   { PTRACE_GETREGS, PTRACE_SETREGS, sizeof (elf_gregset_t),
 266     GENERAL_REGS,
 267     x86_fill_gregset, x86_store_gregset },
 268 # ifndef __x86_64__
 269 #  ifdef HAVE_PTRACE_GETFPXREGS
 270   { PTRACE_GETFPXREGS, PTRACE_SETFPXREGS, sizeof (elf_fpxregset_t),
 271     EXTENDED_REGS,
 272     x86_fill_fpxregset, x86_store_fpxregset },
 273 #  endif
 274 # endif
 275   { PTRACE_GETFPREGS, PTRACE_SETFPREGS, sizeof (elf_fpregset_t),
 276     FP_REGS,
 277     x86_fill_fpregset, x86_store_fpregset },
 278 #endif /* HAVE_PTRACE_GETREGS */
 279   { 0, 0, -1, -1, NULL, NULL }
 280 };
 281
 282 static CORE_ADDR
 283 x86_get_pc (void)
 284 {
 285   int use_64bit = register_size (0) == 8;
 286
 287   if (use_64bit)
 288     {
 289       unsigned long pc;
 290       collect_register_by_name ("rip", &pc);
 291       return (CORE_ADDR) pc;
 292     }
 293   else
 294     {
 295       unsigned int pc;
 296       collect_register_by_name ("eip", &pc);
 297       return (CORE_ADDR) pc;
 298     }
 299 }
 300
 301 static void
 302 x86_set_pc (CORE_ADDR pc)
 303 {
 304   int use_64bit = register_size (0) == 8;
 305
 306   if (use_64bit)
 307     {
 308       unsigned long newpc = pc;
 309       supply_register_by_name ("rip", &newpc);
 310     }
 311   else
 312     {
 313       unsigned int newpc = pc;
 314       supply_register_by_name ("eip", &newpc);
 315     }
 316 }
 317 \f
 318 static const unsigned char x86_breakpoint[] = { 0xCC };
 319 #define x86_breakpoint_len 1
 320
 321 static int
 322 x86_breakpoint_at (CORE_ADDR pc)
 323 {
 324   unsigned char c;
 325
 326   read_inferior_memory (pc, &c, 1);
 327   if (c == 0xCC)
 328     return 1;
 329
 330   return 0;
 331 }
 332 \f
 333 /* Support for debug registers.  */
 334
 335 static unsigned long
 336 x86_linux_dr_get (ptid_t ptid, int regnum)
 337 {
 338   int tid;
 339   unsigned long value;
 340
 341   tid = ptid_get_lwp (ptid);
 342
 343   errno = 0;
 344   value = ptrace (PTRACE_PEEKUSER, tid,
 345                   offsetof (struct user, u_debugreg[regnum]), 0);
 346   if (errno != 0)
 347     error ("Couldn't read debug register");
 348
 349   return value;
 350 }
 351
 352 static void
 353 x86_linux_dr_set (ptid_t ptid, int regnum, unsigned long value)
 354 {
 355   int tid;
 356
 357   tid = ptid_get_lwp (ptid);
 358
 359   errno = 0;
 360   ptrace (PTRACE_POKEUSER, tid,
 361           offsetof (struct user, u_debugreg[regnum]), value);
 362   if (errno != 0)
 363     error ("Couldn't write debug register");
 364 }
 365
 366 /* Update the inferior's debug register REGNUM from STATE.  */
 367
 368 void
 369 i386_dr_low_set_addr (const struct i386_debug_reg_state *state, int regnum)
 370 {
 371   struct inferior_list_entry *lp;
 372   CORE_ADDR addr;
 373   /* Only need to update the threads of this process.  */
 374   int pid = pid_of (get_thread_lwp (current_inferior));
 375
 376   if (! (regnum >= 0 && regnum <= DR_LASTADDR - DR_FIRSTADDR))
 377     fatal ("Invalid debug register %d", regnum);
 378
 379   addr = state->dr_mirror[regnum];
 380
 381   for (lp = all_lwps.head; lp; lp = lp->next)
 382     {
 383       struct lwp_info *lwp = (struct lwp_info *) lp;
 384
 385       /* The actual update is done later, we just mark that the register
 386          needs updating.  */
 387       if (pid_of (lwp) == pid)
 388         lwp->arch_private->debug_registers_changed = 1;
 389     }
 390 }
 391
 392 /* Update the inferior's DR7 debug control register from STATE.  */
 393
 394 void
 395 i386_dr_low_set_control (const struct i386_debug_reg_state *state)
 396 {
 397   struct inferior_list_entry *lp;
 398   /* Only need to update the threads of this process.  */
 399   int pid = pid_of (get_thread_lwp (current_inferior));
 400
 401   for (lp = all_lwps.head; lp; lp = lp->next)
 402     {
 403       struct lwp_info *lwp = (struct lwp_info *) lp;
 404
 405       /* The actual update is done later, we just mark that the register
 406          needs updating.  */
 407       if (pid_of (lwp) == pid)
 408         lwp->arch_private->debug_registers_changed = 1;
 409     }
 410 }
 411
 412 /* Get the value of the DR6 debug status register from the inferior
 413    and record it in STATE.  */
 414
 415 void
 416 i386_dr_low_get_status (struct i386_debug_reg_state *state)
 417 {
 418   struct lwp_info *lwp = get_thread_lwp (current_inferior);
 419   ptid_t ptid = ptid_of (lwp);
 420
 421   state->dr_status_mirror = x86_linux_dr_get (ptid, DR_STATUS);
 422 }
 423 \f
 424 /* Watchpoint support.  */
 425
 426 static int
 427 x86_insert_point (char type, CORE_ADDR addr, int len)
 428 {
 429   struct process_info *proc = current_process ();
 430   switch (type)
 431     {
 432     case '2':
 433     case '3':
 434     case '4':
 435       return i386_low_insert_watchpoint (&proc->private->arch_private->debug_reg_state,
 436                                          type, addr, len);
 437     default:
 438       /* Unsupported.  */
 439       return 1;
 440     }
 441 }
 442
 443 static int
 444 x86_remove_point (char type, CORE_ADDR addr, int len)
 445 {
 446   struct process_info *proc = current_process ();
 447   switch (type)
 448     {
 449     case '2':
 450     case '3':
 451     case '4':
 452       return i386_low_remove_watchpoint (&proc->private->arch_private->debug_reg_state,
 453                                          type, addr, len);
 454     default:
 455       /* Unsupported.  */
 456       return 1;
 457     }
 458 }
 459
 460 static int
 461 x86_stopped_by_watchpoint (void)
 462 {
 463   struct process_info *proc = current_process ();
 464   return i386_low_stopped_by_watchpoint (&proc->private->arch_private->debug_reg_state);
 465 }
 466
 467 static CORE_ADDR
 468 x86_stopped_data_address (void)
 469 {
 470   struct process_info *proc = current_process ();
 471   CORE_ADDR addr;
 472   if (i386_low_stopped_data_address (&proc->private->arch_private->debug_reg_state,
 473                                      &addr))
 474     return addr;
 475   return 0;
 476 }
 477 \f
 478 /* Called when a new process is created.  */
 479
 480 static struct arch_process_info *
 481 x86_linux_new_process (void)
 482 {
 483   struct arch_process_info *info = xcalloc (1, sizeof (*info));
 484
 485   i386_low_init_dregs (&info->debug_reg_state);
 486
 487   return info;
 488 }
 489
 490 /* Called when a new thread is detected.  */
 491
 492 static struct arch_lwp_info *
 493 x86_linux_new_thread (void)
 494 {
 495   struct arch_lwp_info *info = xcalloc (1, sizeof (*info));
 496
 497   info->debug_registers_changed = 1;
 498
 499   return info;
 500 }
 501
 502 /* Called when resuming a thread.
 503    If the debug regs have changed, update the thread's copies.  */
 504
 505 static void
 506 x86_linux_prepare_to_resume (struct lwp_info *lwp)
 507 {
 508   if (lwp->arch_private->debug_registers_changed)
 509     {
 510       int i;
 511       ptid_t ptid = ptid_of (lwp);
 512       int pid = ptid_get_pid (ptid);
 513       struct process_info *proc = find_process_pid (pid);
 514       struct i386_debug_reg_state *state = &proc->private->arch_private->debug_reg_state;
 515
 516       for (i = DR_FIRSTADDR; i <= DR_LASTADDR; i++)
 517         x86_linux_dr_set (ptid, i, state->dr_mirror[i]);
 518
 519       x86_linux_dr_set (ptid, DR_CONTROL, state->dr_control_mirror);
 520
 521       lwp->arch_private->debug_registers_changed = 0;
 522     }
 523 }
 524 \f
 525 /* When GDBSERVER is built as a 64-bit application on linux, the
 526    PTRACE_GETSIGINFO data is always presented in 64-bit layout.  Since
 527    debugging a 32-bit inferior with a 64-bit GDBSERVER should look the same
 528    as debugging it with a 32-bit GDBSERVER, we do the 32-bit <-> 64-bit
 529    conversion in-place ourselves.  */
 530
 531 /* These types below (compat_*) define a siginfo type that is layout
 532    compatible with the siginfo type exported by the 32-bit userspace
 533    support.  */
 534
 535 #ifdef __x86_64__
 536
 537 typedef int compat_int_t;
 538 typedef unsigned int compat_uptr_t;
 539
 540 typedef int compat_time_t;
 541 typedef int compat_timer_t;
 542 typedef int compat_clock_t;
 543
 544 struct compat_timeval
 545 {
 546   compat_time_t tv_sec;
 547   int tv_usec;
 548 };
 549
 550 typedef union compat_sigval
 551 {
 552   compat_int_t sival_int;
 553   compat_uptr_t sival_ptr;
 554 } compat_sigval_t;
 555
 556 typedef struct compat_siginfo
 557 {
 558   int si_signo;
 559   int si_errno;
 560   int si_code;
 561
 562   union
 563   {
 564     int _pad[((128 / sizeof (int)) - 3)];
 565
 566     /* kill() */
 567     struct
 568     {
 569       unsigned int _pid;
 570       unsigned int _uid;
 571     } _kill;
 572
 573     /* POSIX.1b timers */
 574     struct
 575     {
 576       compat_timer_t _tid;
 577       int _overrun;
 578       compat_sigval_t _sigval;
 579     } _timer;
 580
 581     /* POSIX.1b signals */
 582     struct
 583     {
 584       unsigned int _pid;
 585       unsigned int _uid;
 586       compat_sigval_t _sigval;
 587     } _rt;
 588
 589     /* SIGCHLD */
 590     struct
 591     {
 592       unsigned int _pid;
 593       unsigned int _uid;
 594       int _status;
 595       compat_clock_t _utime;
 596       compat_clock_t _stime;
 597     } _sigchld;
 598
 599     /* SIGILL, SIGFPE, SIGSEGV, SIGBUS */
 600     struct
 601     {
 602       unsigned int _addr;
 603     } _sigfault;
 604
 605     /* SIGPOLL */
 606     struct
 607     {
 608       int _band;
 609       int _fd;
 610     } _sigpoll;
 611   } _sifields;
 612 } compat_siginfo_t;
 613
 614 #define cpt_si_pid _sifields._kill._pid
 615 #define cpt_si_uid _sifields._kill._uid
 616 #define cpt_si_timerid _sifields._timer._tid
 617 #define cpt_si_overrun _sifields._timer._overrun
 618 #define cpt_si_status _sifields._sigchld._status
 619 #define cpt_si_utime _sifields._sigchld._utime
 620 #define cpt_si_stime _sifields._sigchld._stime
 621 #define cpt_si_ptr _sifields._rt._sigval.sival_ptr
 622 #define cpt_si_addr _sifields._sigfault._addr
 623 #define cpt_si_band _sifields._sigpoll._band
 624 #define cpt_si_fd _sifields._sigpoll._fd
 625
 626 /* glibc at least up to 2.3.2 doesn't have si_timerid, si_overrun.
 627    In their place is si_timer1,si_timer2.  */
 628 #ifndef si_timerid
 629 #define si_timerid si_timer1
 630 #endif
 631 #ifndef si_overrun
 632 #define si_overrun si_timer2
 633 #endif
 634
 635 static void
 636 compat_siginfo_from_siginfo (compat_siginfo_t *to, siginfo_t *from)
 637 {
 638   memset (to, 0, sizeof (*to));
 639
 640   to->si_signo = from->si_signo;
 641   to->si_errno = from->si_errno;
 642   to->si_code = from->si_code;
 643
 644   if (to->si_code < 0)
 645     {
 646       to->cpt_si_ptr = (intptr_t) from->si_ptr;
 647     }
 648   else if (to->si_code == SI_USER)
 649     {
 650       to->cpt_si_pid = from->si_pid;
 651       to->cpt_si_uid = from->si_uid;
 652     }
 653   else if (to->si_code == SI_TIMER)
 654     {
 655       to->cpt_si_timerid = from->si_timerid;
 656       to->cpt_si_overrun = from->si_overrun;
 657       to->cpt_si_ptr = (intptr_t) from->si_ptr;
 658     }
 659   else
 660     {
 661       switch (to->si_signo)
 662         {
 663         case SIGCHLD:
 664           to->cpt_si_pid = from->si_pid;
 665           to->cpt_si_uid = from->si_uid;
 666           to->cpt_si_status = from->si_status;
 667           to->cpt_si_utime = from->si_utime;
 668           to->cpt_si_stime = from->si_stime;
 669           break;
 670         case SIGILL:
 671         case SIGFPE:
 672         case SIGSEGV:
 673         case SIGBUS:
 674           to->cpt_si_addr = (intptr_t) from->si_addr;
 675           break;
 676         case SIGPOLL:
 677           to->cpt_si_band = from->si_band;
 678           to->cpt_si_fd = from->si_fd;
 679           break;
 680         default:
 681           to->cpt_si_pid = from->si_pid;
 682           to->cpt_si_uid = from->si_uid;
 683           to->cpt_si_ptr = (intptr_t) from->si_ptr;
 684           break;
 685         }
 686     }
 687 }
 688
 689 static void
 690 siginfo_from_compat_siginfo (siginfo_t *to, compat_siginfo_t *from)
 691 {
 692   memset (to, 0, sizeof (*to));
 693
 694   to->si_signo = from->si_signo;
 695   to->si_errno = from->si_errno;
 696   to->si_code = from->si_code;
 697
 698   if (to->si_code < 0)
 699     {
 700       to->si_ptr = (void *) (intptr_t) from->cpt_si_ptr;
 701     }
 702   else if (to->si_code == SI_USER)
 703     {
 704       to->si_pid = from->cpt_si_pid;
 705       to->si_uid = from->cpt_si_uid;
 706     }
 707   else if (to->si_code == SI_TIMER)
 708     {
 709       to->si_timerid = from->cpt_si_timerid;
 710       to->si_overrun = from->cpt_si_overrun;
 711       to->si_ptr = (void *) (intptr_t) from->cpt_si_ptr;
 712     }
 713   else
 714     {
 715       switch (to->si_signo)
 716         {
 717         case SIGCHLD:
 718           to->si_pid = from->cpt_si_pid;
 719           to->si_uid = from->cpt_si_uid;
 720           to->si_status = from->cpt_si_status;
 721           to->si_utime = from->cpt_si_utime;
 722           to->si_stime = from->cpt_si_stime;
 723           break;
 724         case SIGILL:
 725         case SIGFPE:
 726         case SIGSEGV:
 727         case SIGBUS:
 728           to->si_addr = (void *) (intptr_t) from->cpt_si_addr;
 729           break;
 730         case SIGPOLL:
 731           to->si_band = from->cpt_si_band;
 732           to->si_fd = from->cpt_si_fd;
 733           break;
 734         default:
 735           to->si_pid = from->cpt_si_pid;
 736           to->si_uid = from->cpt_si_uid;
 737           to->si_ptr = (void* ) (intptr_t) from->cpt_si_ptr;
 738           break;
 739         }
 740     }
 741 }
 742
 743 #endif /* __x86_64__ */
 744
 745 /* Convert a native/host siginfo object, into/from the siginfo in the
 746    layout of the inferiors' architecture.  Returns true if any
 747    conversion was done; false otherwise.  If DIRECTION is 1, then copy
 748    from INF to NATIVE.  If DIRECTION is 0, copy from NATIVE to
 749    INF.  */
 750
 751 static int
 752 x86_siginfo_fixup (struct siginfo *native, void *inf, int direction)
 753 {
 754 #ifdef __x86_64__
 755   /* Is the inferior 32-bit?  If so, then fixup the siginfo object.  */
 756   if (register_size (0) == 4)
 757     {
 758       if (sizeof (struct siginfo) != sizeof (compat_siginfo_t))
 759         fatal ("unexpected difference in siginfo");
 760
 761       if (direction == 0)
 762         compat_siginfo_from_siginfo ((struct compat_siginfo *) inf, native);
 763       else
 764         siginfo_from_compat_siginfo (native, (struct compat_siginfo *) inf);
 765
 766       return 1;
 767     }
 768 #endif
 769
 770   return 0;
 771 }
 772 \f
 773 /* Initialize gdbserver for the architecture of the inferior.  */
 774
 775 static void
 776 x86_arch_setup (void)
 777 {
 778 #ifdef __x86_64__
 779   int pid = pid_of (get_thread_lwp (current_inferior));
 780   char *file = linux_child_pid_to_exec_file (pid);
 781   int use_64bit = elf_64_file_p (file);
 782
 783   free (file);
 784
 785   if (use_64bit < 0)
 786     {
 787       /* This can only happen if /proc/<pid>/exe is unreadable,
 788          but "that can't happen" if we've gotten this far.
 789          Fall through and assume this is a 32-bit program.  */
 790     }
 791   else if (use_64bit)
 792     {
 793       init_registers_x86_64_linux ();
 794
 795       /* Amd64 doesn't have HAVE_LINUX_USRREGS.  */
 796       the_low_target.num_regs = -1;
 797       the_low_target.regmap = NULL;
 798       the_low_target.cannot_fetch_register = NULL;
 799       the_low_target.cannot_store_register = NULL;
 800
 801       /* Amd64 has 16 xmm regs.  */
 802       num_xmm_registers = 16;
 803
 804       return;
 805     }
 806 #endif
 807
 808   /* Ok we have a 32-bit inferior.  */
 809
 810   init_registers_i386_linux ();
 811
 812   the_low_target.num_regs = I386_NUM_REGS;
 813   the_low_target.regmap = i386_regmap;
 814   the_low_target.cannot_fetch_register = i386_cannot_fetch_register;
 815   the_low_target.cannot_store_register = i386_cannot_store_register;
 816
 817   /* I386 has 8 xmm regs.  */
 818   num_xmm_registers = 8;
 819 }
 820
 821 /* This is initialized assuming an amd64 target.
 822    x86_arch_setup will correct it for i386 or amd64 targets.  */
 823
 824 struct linux_target_ops the_low_target =
 825 {
 826   x86_arch_setup,
 827   -1,
 828   NULL,
 829   NULL,
 830   NULL,
 831   x86_get_pc,
 832   x86_set_pc,
 833   x86_breakpoint,
 834   x86_breakpoint_len,
 835   NULL,
 836   1,
 837   x86_breakpoint_at,
 838   x86_insert_point,
 839   x86_remove_point,
 840   x86_stopped_by_watchpoint,
 841   x86_stopped_data_address,
 842   /* collect_ptrace_register/supply_ptrace_register are not needed in the
 843      native i386 case (no registers smaller than an xfer unit), and are not
 844      used in the biarch case (HAVE_LINUX_USRREGS is not defined).  */
 845   NULL,
 846   NULL,
 847   /* need to fix up i386 siginfo if host is amd64 */
 848   x86_siginfo_fixup,
 849   x86_linux_new_process,
 850   x86_linux_new_thread,
 851   x86_linux_prepare_to_resume
 852 };