gdb/rs6000-nat.c

   1 /* IBM RS/6000 native-dependent code for GDB, the GNU debugger.
   2
   3    Copyright (C) 1986-2014 Free Software Foundation, Inc.
   4
   5    This file is part of GDB.
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  19
  20 #include "defs.h"
  21 #include "inferior.h"
  22 #include "target.h"
  23 #include "gdbcore.h"
  24 #include "symfile.h"
  25 #include "objfiles.h"
  26 #include "libbfd.h"             /* For bfd_default_set_arch_mach (FIXME) */
  27 #include "bfd.h"
  28 #include "exceptions.h"
  29 #include "gdb-stabs.h"
  30 #include "regcache.h"
  31 #include "arch-utils.h"
  32 #include "inf-child.h"
  33 #include "inf-ptrace.h"
  34 #include "ppc-tdep.h"
  35 #include "rs6000-tdep.h"
  36 #include "rs6000-aix-tdep.h"
  37 #include "exec.h"
  38 #include "observer.h"
  39 #include "xcoffread.h"
  40
  41 #include <sys/ptrace.h>
  42 #include <sys/reg.h>
  43
  44 #include <sys/dir.h>
  45 #include <sys/user.h>
  46 #include <signal.h>
  47 #include <sys/ioctl.h>
  48 #include <fcntl.h>
  49
  50 #include <a.out.h>
  51 #include <sys/file.h>
  52 #include <sys/stat.h>
  53 #include "gdb_bfd.h"
  54 #include <sys/core.h>
  55 #define __LDINFO_PTRACE32__     /* for __ld_info32 */
  56 #define __LDINFO_PTRACE64__     /* for __ld_info64 */
  57 #include <sys/ldr.h>
  58 #include <sys/systemcfg.h>
  59
  60 /* On AIX4.3+, sys/ldr.h provides different versions of struct ld_info for
  61    debugging 32-bit and 64-bit processes.  Define a typedef and macros for
  62    accessing fields in the appropriate structures.  */
  63
  64 /* In 32-bit compilation mode (which is the only mode from which ptrace()
  65    works on 4.3), __ld_info32 is #defined as equivalent to ld_info.  */
  66
  67 #if defined (__ld_info32) || defined (__ld_info64)
  68 # define ARCH3264
  69 #endif
  70
  71 /* Return whether the current architecture is 64-bit.  */
  72
  73 #ifndef ARCH3264
  74 # define ARCH64() 0
  75 #else
  76 # define ARCH64() (register_size (target_gdbarch (), 0) == 8)
  77 #endif
  78
  79 static target_xfer_partial_ftype rs6000_xfer_shared_libraries;
  80
  81 /* Given REGNO, a gdb register number, return the corresponding
  82    number suitable for use as a ptrace() parameter.  Return -1 if
  83    there's no suitable mapping.  Also, set the int pointed to by
  84    ISFLOAT to indicate whether REGNO is a floating point register.  */
  85
  86 static int
  87 regmap (struct gdbarch *gdbarch, int regno, int *isfloat)
  88 {
  89   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
  90
  91   *isfloat = 0;
  92   if (tdep->ppc_gp0_regnum <= regno
  93       && regno < tdep->ppc_gp0_regnum + ppc_num_gprs)
  94     return regno;
  95   else if (tdep->ppc_fp0_regnum >= 0
  96            && tdep->ppc_fp0_regnum <= regno
  97            && regno < tdep->ppc_fp0_regnum + ppc_num_fprs)
  98     {
  99       *isfloat = 1;
 100       return regno - tdep->ppc_fp0_regnum + FPR0;
 101     }
 102   else if (regno == gdbarch_pc_regnum (gdbarch))
 103     return IAR;
 104   else if (regno == tdep->ppc_ps_regnum)
 105     return MSR;
 106   else if (regno == tdep->ppc_cr_regnum)
 107     return CR;
 108   else if (regno == tdep->ppc_lr_regnum)
 109     return LR;
 110   else if (regno == tdep->ppc_ctr_regnum)
 111     return CTR;
 112   else if (regno == tdep->ppc_xer_regnum)
 113     return XER;
 114   else if (tdep->ppc_fpscr_regnum >= 0
 115            && regno == tdep->ppc_fpscr_regnum)
 116     return FPSCR;
 117   else if (tdep->ppc_mq_regnum >= 0 && regno == tdep->ppc_mq_regnum)
 118     return MQ;
 119   else
 120     return -1;
 121 }
 122
 123 /* Call ptrace(REQ, ID, ADDR, DATA, BUF).  */
 124
 125 static int
 126 rs6000_ptrace32 (int req, int id, int *addr, int data, int *buf)
 127 {
 128 #ifdef HAVE_PTRACE64
 129   int ret = ptrace64 (req, id, (uintptr_t) addr, data, buf);
 130 #else
 131   int ret = ptrace (req, id, (int *)addr, data, buf);
 132 #endif
 133 #if 0
 134   printf ("rs6000_ptrace32 (%d, %d, 0x%x, %08x, 0x%x) = 0x%x\n",
 135           req, id, (unsigned int)addr, data, (unsigned int)buf, ret);
 136 #endif
 137   return ret;
 138 }
 139
 140 /* Call ptracex(REQ, ID, ADDR, DATA, BUF).  */
 141
 142 static int
 143 rs6000_ptrace64 (int req, int id, long long addr, int data, void *buf)
 144 {
 145 #ifdef ARCH3264
 146 #  ifdef HAVE_PTRACE64
 147   int ret = ptrace64 (req, id, addr, data, buf);
 148 #  else
 149   int ret = ptracex (req, id, addr, data, buf);
 150 #  endif
 151 #else
 152   int ret = 0;
 153 #endif
 154 #if 0
 155   printf ("rs6000_ptrace64 (%d, %d, %s, %08x, 0x%x) = 0x%x\n",
 156           req, id, hex_string (addr), data, (unsigned int)buf, ret);
 157 #endif
 158   return ret;
 159 }
 160
 161 /* Fetch register REGNO from the inferior.  */
 162
 163 static void
 164 fetch_register (struct regcache *regcache, int regno)
 165 {
 166   struct gdbarch *gdbarch = get_regcache_arch (regcache);
 167   int addr[MAX_REGISTER_SIZE];
 168   int nr, isfloat;
 169
 170   /* Retrieved values may be -1, so infer errors from errno.  */
 171   errno = 0;
 172
 173   nr = regmap (gdbarch, regno, &isfloat);
 174
 175   /* Floating-point registers.  */
 176   if (isfloat)
 177     rs6000_ptrace32 (PT_READ_FPR, ptid_get_pid (inferior_ptid), addr, nr, 0);
 178
 179   /* Bogus register number.  */
 180   else if (nr < 0)
 181     {
 182       if (regno >= gdbarch_num_regs (gdbarch))
 183         fprintf_unfiltered (gdb_stderr,
 184                             "gdb error: register no %d not implemented.\n",
 185                             regno);
 186       return;
 187     }
 188
 189   /* Fixed-point registers.  */
 190   else
 191     {
 192       if (!ARCH64 ())
 193         *addr = rs6000_ptrace32 (PT_READ_GPR, ptid_get_pid (inferior_ptid),
 194                                  (int *) nr, 0, 0);
 195       else
 196         {
 197           /* PT_READ_GPR requires the buffer parameter to point to long long,
 198              even if the register is really only 32 bits.  */
 199           long long buf;
 200           rs6000_ptrace64 (PT_READ_GPR, ptid_get_pid (inferior_ptid),
 201                            nr, 0, &buf);
 202           if (register_size (gdbarch, regno) == 8)
 203             memcpy (addr, &buf, 8);
 204           else
 205             *addr = buf;
 206         }
 207     }
 208
 209   if (!errno)
 210     regcache_raw_supply (regcache, regno, (char *) addr);
 211   else
 212     {
 213 #if 0
 214       /* FIXME: this happens 3 times at the start of each 64-bit program.  */
 215       perror (_("ptrace read"));
 216 #endif
 217       errno = 0;
 218     }
 219 }
 220
 221 /* Store register REGNO back into the inferior.  */
 222
 223 static void
 224 store_register (struct regcache *regcache, int regno)
 225 {
 226   struct gdbarch *gdbarch = get_regcache_arch (regcache);
 227   int addr[MAX_REGISTER_SIZE];
 228   int nr, isfloat;
 229
 230   /* Fetch the register's value from the register cache.  */
 231   regcache_raw_collect (regcache, regno, addr);
 232
 233   /* -1 can be a successful return value, so infer errors from errno.  */
 234   errno = 0;
 235
 236   nr = regmap (gdbarch, regno, &isfloat);
 237
 238   /* Floating-point registers.  */
 239   if (isfloat)
 240     rs6000_ptrace32 (PT_WRITE_FPR, ptid_get_pid (inferior_ptid), addr, nr, 0);
 241
 242   /* Bogus register number.  */
 243   else if (nr < 0)
 244     {
 245       if (regno >= gdbarch_num_regs (gdbarch))
 246         fprintf_unfiltered (gdb_stderr,
 247                             "gdb error: register no %d not implemented.\n",
 248                             regno);
 249     }
 250
 251   /* Fixed-point registers.  */
 252   else
 253     {
 254       /* The PT_WRITE_GPR operation is rather odd.  For 32-bit inferiors,
 255          the register's value is passed by value, but for 64-bit inferiors,
 256          the address of a buffer containing the value is passed.  */
 257       if (!ARCH64 ())
 258         rs6000_ptrace32 (PT_WRITE_GPR, ptid_get_pid (inferior_ptid),
 259                          (int *) nr, *addr, 0);
 260       else
 261         {
 262           /* PT_WRITE_GPR requires the buffer parameter to point to an 8-byte
 263              area, even if the register is really only 32 bits.  */
 264           long long buf;
 265           if (register_size (gdbarch, regno) == 8)
 266             memcpy (&buf, addr, 8);
 267           else
 268             buf = *addr;
 269           rs6000_ptrace64 (PT_WRITE_GPR, ptid_get_pid (inferior_ptid),
 270                            nr, 0, &buf);
 271         }
 272     }
 273
 274   if (errno)
 275     {
 276       perror (_("ptrace write"));
 277       errno = 0;
 278     }
 279 }
 280
 281 /* Read from the inferior all registers if REGNO == -1 and just register
 282    REGNO otherwise.  */
 283
 284 static void
 285 rs6000_fetch_inferior_registers (struct target_ops *ops,
 286                                  struct regcache *regcache, int regno)
 287 {
 288   struct gdbarch *gdbarch = get_regcache_arch (regcache);
 289   if (regno != -1)
 290     fetch_register (regcache, regno);
 291
 292   else
 293     {
 294       struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 295
 296       /* Read 32 general purpose registers.  */
 297       for (regno = tdep->ppc_gp0_regnum;
 298            regno < tdep->ppc_gp0_regnum + ppc_num_gprs;
 299            regno++)
 300         {
 301           fetch_register (regcache, regno);
 302         }
 303
 304       /* Read general purpose floating point registers.  */
 305       if (tdep->ppc_fp0_regnum >= 0)
 306         for (regno = 0; regno < ppc_num_fprs; regno++)
 307           fetch_register (regcache, tdep->ppc_fp0_regnum + regno);
 308
 309       /* Read special registers.  */
 310       fetch_register (regcache, gdbarch_pc_regnum (gdbarch));
 311       fetch_register (regcache, tdep->ppc_ps_regnum);
 312       fetch_register (regcache, tdep->ppc_cr_regnum);
 313       fetch_register (regcache, tdep->ppc_lr_regnum);
 314       fetch_register (regcache, tdep->ppc_ctr_regnum);
 315       fetch_register (regcache, tdep->ppc_xer_regnum);
 316       if (tdep->ppc_fpscr_regnum >= 0)
 317         fetch_register (regcache, tdep->ppc_fpscr_regnum);
 318       if (tdep->ppc_mq_regnum >= 0)
 319         fetch_register (regcache, tdep->ppc_mq_regnum);
 320     }
 321 }
 322
 323 /* Store our register values back into the inferior.
 324    If REGNO is -1, do this for all registers.
 325    Otherwise, REGNO specifies which register (so we can save time).  */
 326
 327 static void
 328 rs6000_store_inferior_registers (struct target_ops *ops,
 329                                  struct regcache *regcache, int regno)
 330 {
 331   struct gdbarch *gdbarch = get_regcache_arch (regcache);
 332   if (regno != -1)
 333     store_register (regcache, regno);
 334
 335   else
 336     {
 337       struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 338
 339       /* Write general purpose registers first.  */
 340       for (regno = tdep->ppc_gp0_regnum;
 341            regno < tdep->ppc_gp0_regnum + ppc_num_gprs;
 342            regno++)
 343         {
 344           store_register (regcache, regno);
 345         }
 346
 347       /* Write floating point registers.  */
 348       if (tdep->ppc_fp0_regnum >= 0)
 349         for (regno = 0; regno < ppc_num_fprs; regno++)
 350           store_register (regcache, tdep->ppc_fp0_regnum + regno);
 351
 352       /* Write special registers.  */
 353       store_register (regcache, gdbarch_pc_regnum (gdbarch));
 354       store_register (regcache, tdep->ppc_ps_regnum);
 355       store_register (regcache, tdep->ppc_cr_regnum);
 356       store_register (regcache, tdep->ppc_lr_regnum);
 357       store_register (regcache, tdep->ppc_ctr_regnum);
 358       store_register (regcache, tdep->ppc_xer_regnum);
 359       if (tdep->ppc_fpscr_regnum >= 0)
 360         store_register (regcache, tdep->ppc_fpscr_regnum);
 361       if (tdep->ppc_mq_regnum >= 0)
 362         store_register (regcache, tdep->ppc_mq_regnum);
 363     }
 364 }
 365
 366 /* Implement the to_xfer_partial target_ops method.  */
 367
 368 static enum target_xfer_status
 369 rs6000_xfer_partial (struct target_ops *ops, enum target_object object,
 370                      const char *annex, gdb_byte *readbuf,
 371                      const gdb_byte *writebuf,
 372                      ULONGEST offset, ULONGEST len, ULONGEST *xfered_len)
 373 {
 374   pid_t pid = ptid_get_pid (inferior_ptid);
 375   int arch64 = ARCH64 ();
 376
 377   switch (object)
 378     {
 379     case TARGET_OBJECT_LIBRARIES_AIX:
 380       return rs6000_xfer_shared_libraries (ops, object, annex,
 381                                            readbuf, writebuf,
 382                                            offset, len, xfered_len);
 383     case TARGET_OBJECT_MEMORY:
 384       {
 385         union
 386         {
 387           PTRACE_TYPE_RET word;
 388           gdb_byte byte[sizeof (PTRACE_TYPE_RET)];
 389         } buffer;
 390         ULONGEST rounded_offset;
 391         LONGEST partial_len;
 392
 393         /* Round the start offset down to the next long word
 394            boundary.  */
 395         rounded_offset = offset & -(ULONGEST) sizeof (PTRACE_TYPE_RET);
 396
 397         /* Since ptrace will transfer a single word starting at that
 398            rounded_offset the partial_len needs to be adjusted down to
 399            that (remember this function only does a single transfer).
 400            Should the required length be even less, adjust it down
 401            again.  */
 402         partial_len = (rounded_offset + sizeof (PTRACE_TYPE_RET)) - offset;
 403         if (partial_len > len)
 404           partial_len = len;
 405
 406         if (writebuf)
 407           {
 408             /* If OFFSET:PARTIAL_LEN is smaller than
 409                ROUNDED_OFFSET:WORDSIZE then a read/modify write will
 410                be needed.  Read in the entire word.  */
 411             if (rounded_offset < offset
 412                 || (offset + partial_len
 413                     < rounded_offset + sizeof (PTRACE_TYPE_RET)))
 414               {
 415                 /* Need part of initial word -- fetch it.  */
 416                 if (arch64)
 417                   buffer.word = rs6000_ptrace64 (PT_READ_I, pid,
 418                                                  rounded_offset, 0, NULL);
 419                 else
 420                   buffer.word = rs6000_ptrace32 (PT_READ_I, pid,
 421                                                  (int *) (uintptr_t)
 422                                                  rounded_offset,
 423                                                  0, NULL);
 424               }
 425
 426             /* Copy data to be written over corresponding part of
 427                buffer.  */
 428             memcpy (buffer.byte + (offset - rounded_offset),
 429                     writebuf, partial_len);
 430
 431             errno = 0;
 432             if (arch64)
 433               rs6000_ptrace64 (PT_WRITE_D, pid,
 434                                rounded_offset, buffer.word, NULL);
 435             else
 436               rs6000_ptrace32 (PT_WRITE_D, pid,
 437                                (int *) (uintptr_t) rounded_offset,
 438                                buffer.word, NULL);
 439             if (errno)
 440               return TARGET_XFER_EOF;
 441           }
 442
 443         if (readbuf)
 444           {
 445             errno = 0;
 446             if (arch64)
 447               buffer.word = rs6000_ptrace64 (PT_READ_I, pid,
 448                                              rounded_offset, 0, NULL);
 449             else
 450               buffer.word = rs6000_ptrace32 (PT_READ_I, pid,
 451                                              (int *)(uintptr_t)rounded_offset,
 452                                              0, NULL);
 453             if (errno)
 454               return TARGET_XFER_EOF;
 455
 456             /* Copy appropriate bytes out of the buffer.  */
 457             memcpy (readbuf, buffer.byte + (offset - rounded_offset),
 458                     partial_len);
 459           }
 460
 461         *xfered_len = (ULONGEST) partial_len;
 462         return TARGET_XFER_OK;
 463       }
 464
 465     default:
 466       return TARGET_XFER_E_IO;
 467     }
 468 }
 469
 470 /* Wait for the child specified by PTID to do something.  Return the
 471    process ID of the child, or MINUS_ONE_PTID in case of error; store
 472    the status in *OURSTATUS.  */
 473
 474 static ptid_t
 475 rs6000_wait (struct target_ops *ops,
 476              ptid_t ptid, struct target_waitstatus *ourstatus, int options)
 477 {
 478   pid_t pid;
 479   int status, save_errno;
 480
 481   do
 482     {
 483       set_sigint_trap ();
 484
 485       do
 486         {
 487           pid = waitpid (ptid_get_pid (ptid), &status, 0);
 488           save_errno = errno;
 489         }
 490       while (pid == -1 && errno == EINTR);
 491
 492       clear_sigint_trap ();
 493
 494       if (pid == -1)
 495         {
 496           fprintf_unfiltered (gdb_stderr,
 497                               _("Child process unexpectedly missing: %s.\n"),
 498                               safe_strerror (save_errno));
 499
 500           /* Claim it exited with unknown signal.  */
 501           ourstatus->kind = TARGET_WAITKIND_SIGNALLED;
 502           ourstatus->value.sig = GDB_SIGNAL_UNKNOWN;
 503           return inferior_ptid;
 504         }
 505
 506       /* Ignore terminated detached child processes.  */
 507       if (!WIFSTOPPED (status) && pid != ptid_get_pid (inferior_ptid))
 508         pid = -1;
 509     }
 510   while (pid == -1);
 511
 512   /* AIX has a couple of strange returns from wait().  */
 513
 514   /* stop after load" status.  */
 515   if (status == 0x57c)
 516     ourstatus->kind = TARGET_WAITKIND_LOADED;
 517   /* signal 0.  I have no idea why wait(2) returns with this status word.  */
 518   else if (status == 0x7f)
 519     ourstatus->kind = TARGET_WAITKIND_SPURIOUS;
 520   /* A normal waitstatus.  Let the usual macros deal with it.  */
 521   else
 522     store_waitstatus (ourstatus, status);
 523
 524   return pid_to_ptid (pid);
 525 }
 526 \f
 527
 528 /* Set the current architecture from the host running GDB.  Called when
 529    starting a child process.  */
 530
 531 static void (*super_create_inferior) (struct target_ops *,char *exec_file,
 532                                       char *allargs, char **env, int from_tty);
 533 static void
 534 rs6000_create_inferior (struct target_ops * ops, char *exec_file,
 535                         char *allargs, char **env, int from_tty)
 536 {
 537   enum bfd_architecture arch;
 538   unsigned long mach;
 539   bfd abfd;
 540   struct gdbarch_info info;
 541
 542   super_create_inferior (ops, exec_file, allargs, env, from_tty);
 543
 544   if (__power_rs ())
 545     {
 546       arch = bfd_arch_rs6000;
 547       mach = bfd_mach_rs6k;
 548     }
 549   else
 550     {
 551       arch = bfd_arch_powerpc;
 552       mach = bfd_mach_ppc;
 553     }
 554
 555   /* FIXME: schauer/2002-02-25:
 556      We don't know if we are executing a 32 or 64 bit executable,
 557      and have no way to pass the proper word size to rs6000_gdbarch_init.
 558      So we have to avoid switching to a new architecture, if the architecture
 559      matches already.
 560      Blindly calling rs6000_gdbarch_init used to work in older versions of
 561      GDB, as rs6000_gdbarch_init incorrectly used the previous tdep to
 562      determine the wordsize.  */
 563   if (exec_bfd)
 564     {
 565       const struct bfd_arch_info *exec_bfd_arch_info;
 566
 567       exec_bfd_arch_info = bfd_get_arch_info (exec_bfd);
 568       if (arch == exec_bfd_arch_info->arch)
 569         return;
 570     }
 571
 572   bfd_default_set_arch_mach (&abfd, arch, mach);
 573
 574   gdbarch_info_init (&info);
 575   info.bfd_arch_info = bfd_get_arch_info (&abfd);
 576   info.abfd = exec_bfd;
 577
 578   if (!gdbarch_update_p (info))
 579     internal_error (__FILE__, __LINE__,
 580                     _("rs6000_create_inferior: failed "
 581                       "to select architecture"));
 582 }
 583 \f
 584
 585 /* Shared Object support.  */
 586
 587 /* Return the LdInfo data for the given process.  Raises an error
 588    if the data could not be obtained.
 589
 590    The returned value must be deallocated after use.  */
 591
 592 static gdb_byte *
 593 rs6000_ptrace_ldinfo (ptid_t ptid)
 594 {
 595   const int pid = ptid_get_pid (ptid);
 596   int ldi_size = 1024;
 597   gdb_byte *ldi = xmalloc (ldi_size);
 598   int rc = -1;
 599
 600   while (1)
 601     {
 602       if (ARCH64 ())
 603         rc = rs6000_ptrace64 (PT_LDINFO, pid, (unsigned long) ldi, ldi_size,
 604                               NULL);
 605       else
 606         rc = rs6000_ptrace32 (PT_LDINFO, pid, (int *) ldi, ldi_size, NULL);
 607
 608       if (rc != -1)
 609         break; /* Success, we got the entire ld_info data.  */
 610
 611       if (errno != ENOMEM)
 612         perror_with_name (_("ptrace ldinfo"));
 613
 614       /* ldi is not big enough.  Double it and try again.  */
 615       ldi_size *= 2;
 616       ldi = xrealloc (ldi, ldi_size);
 617     }
 618
 619   return ldi;
 620 }
 621
 622 /* Implement the to_xfer_partial target_ops method for
 623    TARGET_OBJECT_LIBRARIES_AIX objects.  */
 624
 625 static enum target_xfer_status
 626 rs6000_xfer_shared_libraries
 627   (struct target_ops *ops, enum target_object object,
 628    const char *annex, gdb_byte *readbuf, const gdb_byte *writebuf,
 629    ULONGEST offset, ULONGEST len, ULONGEST *xfered_len)
 630 {
 631   gdb_byte *ldi_buf;
 632   ULONGEST result;
 633   struct cleanup *cleanup;
 634
 635   /* This function assumes that it is being run with a live process.
 636      Core files are handled via gdbarch.  */
 637   gdb_assert (target_has_execution);
 638
 639   if (writebuf)
 640     return TARGET_XFER_E_IO;
 641
 642   ldi_buf = rs6000_ptrace_ldinfo (inferior_ptid);
 643   gdb_assert (ldi_buf != NULL);
 644   cleanup = make_cleanup (xfree, ldi_buf);
 645   result = rs6000_aix_ld_info_to_xml (target_gdbarch (), ldi_buf,
 646                                       readbuf, offset, len, 1);
 647   xfree (ldi_buf);
 648
 649   do_cleanups (cleanup);
 650
 651   if (result == 0)
 652     return TARGET_XFER_EOF;
 653   else
 654     {
 655       *xfered_len = result;
 656       return TARGET_XFER_OK;
 657     }
 658 }
 659
 660 void _initialize_rs6000_nat (void);
 661
 662 void
 663 _initialize_rs6000_nat (void)
 664 {
 665   struct target_ops *t;
 666
 667   t = inf_ptrace_target ();
 668   t->to_fetch_registers = rs6000_fetch_inferior_registers;
 669   t->to_store_registers = rs6000_store_inferior_registers;
 670   t->to_xfer_partial = rs6000_xfer_partial;
 671
 672   super_create_inferior = t->to_create_inferior;
 673   t->to_create_inferior = rs6000_create_inferior;
 674
 675   t->to_wait = rs6000_wait;
 676
 677   add_target (t);
 678 }