gdb/rs6000-nat.c

   1 /* IBM RS/6000 native-dependent code for GDB, the GNU debugger.
   2
   3    Copyright (C) 1986-2015 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 "gdb-stabs.h"
  29 #include "regcache.h"
  30 #include "arch-utils.h"
  31 #include "inf-child.h"
  32 #include "inf-ptrace.h"
  33 #include "ppc-tdep.h"
  34 #include "rs6000-tdep.h"
  35 #include "rs6000-aix-tdep.h"
  36 #include "exec.h"
  37 #include "observer.h"
  38 #include "xcoffread.h"
  39
  40 #include <sys/ptrace.h>
  41 #include <sys/reg.h>
  42
  43 #include <sys/dir.h>
  44 #include <sys/user.h>
  45 #include <signal.h>
  46 #include <sys/ioctl.h>
  47 #include <fcntl.h>
  48
  49 #include <a.out.h>
  50 #include <sys/file.h>
  51 #include <sys/stat.h>
  52 #include "gdb_bfd.h"
  53 #include <sys/core.h>
  54 #define __LDINFO_PTRACE32__     /* for __ld_info32 */
  55 #define __LDINFO_PTRACE64__     /* for __ld_info64 */
  56 #include <sys/ldr.h>
  57 #include <sys/systemcfg.h>
  58
  59 /* On AIX4.3+, sys/ldr.h provides different versions of struct ld_info for
  60    debugging 32-bit and 64-bit processes.  Define a typedef and macros for
  61    accessing fields in the appropriate structures.  */
  62
  63 /* In 32-bit compilation mode (which is the only mode from which ptrace()
  64    works on 4.3), __ld_info32 is #defined as equivalent to ld_info.  */
  65
  66 #if defined (__ld_info32) || defined (__ld_info64)
  67 # define ARCH3264
  68 #endif
  69
  70 /* Return whether the current architecture is 64-bit.  */
  71
  72 #ifndef ARCH3264
  73 # define ARCH64() 0
  74 #else
  75 # define ARCH64() (register_size (target_gdbarch (), 0) == 8)
  76 #endif
  77
  78 static target_xfer_partial_ftype rs6000_xfer_shared_libraries;
  79
  80 /* Given REGNO, a gdb register number, return the corresponding
  81    number suitable for use as a ptrace() parameter.  Return -1 if
  82    there's no suitable mapping.  Also, set the int pointed to by
  83    ISFLOAT to indicate whether REGNO is a floating point register.  */
  84
  85 static int
  86 regmap (struct gdbarch *gdbarch, int regno, int *isfloat)
  87 {
  88   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
  89
  90   *isfloat = 0;
  91   if (tdep->ppc_gp0_regnum <= regno
  92       && regno < tdep->ppc_gp0_regnum + ppc_num_gprs)
  93     return regno;
  94   else if (tdep->ppc_fp0_regnum >= 0
  95            && tdep->ppc_fp0_regnum <= regno
  96            && regno < tdep->ppc_fp0_regnum + ppc_num_fprs)
  97     {
  98       *isfloat = 1;
  99       return regno - tdep->ppc_fp0_regnum + FPR0;
 100     }
 101   else if (regno == gdbarch_pc_regnum (gdbarch))
 102     return IAR;
 103   else if (regno == tdep->ppc_ps_regnum)
 104     return MSR;
 105   else if (regno == tdep->ppc_cr_regnum)
 106     return CR;
 107   else if (regno == tdep->ppc_lr_regnum)
 108     return LR;
 109   else if (regno == tdep->ppc_ctr_regnum)
 110     return CTR;
 111   else if (regno == tdep->ppc_xer_regnum)
 112     return XER;
 113   else if (tdep->ppc_fpscr_regnum >= 0
 114            && regno == tdep->ppc_fpscr_regnum)
 115     return FPSCR;
 116   else if (tdep->ppc_mq_regnum >= 0 && regno == tdep->ppc_mq_regnum)
 117     return MQ;
 118   else
 119     return -1;
 120 }
 121
 122 /* Call ptrace(REQ, ID, ADDR, DATA, BUF).  */
 123
 124 static int
 125 rs6000_ptrace32 (int req, int id, int *addr, int data, int *buf)
 126 {
 127 #ifdef HAVE_PTRACE64
 128   int ret = ptrace64 (req, id, (uintptr_t) addr, data, buf);
 129 #else
 130   int ret = ptrace (req, id, (int *)addr, data, buf);
 131 #endif
 132 #if 0
 133   printf ("rs6000_ptrace32 (%d, %d, 0x%x, %08x, 0x%x) = 0x%x\n",
 134           req, id, (unsigned int)addr, data, (unsigned int)buf, ret);
 135 #endif
 136   return ret;
 137 }
 138
 139 /* Call ptracex(REQ, ID, ADDR, DATA, BUF).  */
 140
 141 static int
 142 rs6000_ptrace64 (int req, int id, long long addr, int data, void *buf)
 143 {
 144 #ifdef ARCH3264
 145 #  ifdef HAVE_PTRACE64
 146   int ret = ptrace64 (req, id, addr, data, buf);
 147 #  else
 148   int ret = ptracex (req, id, addr, data, buf);
 149 #  endif
 150 #else
 151   int ret = 0;
 152 #endif
 153 #if 0
 154   printf ("rs6000_ptrace64 (%d, %d, %s, %08x, 0x%x) = 0x%x\n",
 155           req, id, hex_string (addr), data, (unsigned int)buf, ret);
 156 #endif
 157   return ret;
 158 }
 159
 160 /* Fetch register REGNO from the inferior.  */
 161
 162 static void
 163 fetch_register (struct regcache *regcache, int regno)
 164 {
 165   struct gdbarch *gdbarch = get_regcache_arch (regcache);
 166   int addr[MAX_REGISTER_SIZE];
 167   int nr, isfloat;
 168
 169   /* Retrieved values may be -1, so infer errors from errno.  */
 170   errno = 0;
 171
 172   nr = regmap (gdbarch, regno, &isfloat);
 173
 174   /* Floating-point registers.  */
 175   if (isfloat)
 176     rs6000_ptrace32 (PT_READ_FPR, ptid_get_pid (inferior_ptid), addr, nr, 0);
 177
 178   /* Bogus register number.  */
 179   else if (nr < 0)
 180     {
 181       if (regno >= gdbarch_num_regs (gdbarch))
 182         fprintf_unfiltered (gdb_stderr,
 183                             "gdb error: register no %d not implemented.\n",
 184                             regno);
 185       return;
 186     }
 187
 188   /* Fixed-point registers.  */
 189   else
 190     {
 191       if (!ARCH64 ())
 192         *addr = rs6000_ptrace32 (PT_READ_GPR, ptid_get_pid (inferior_ptid),
 193                                  (int *) nr, 0, 0);
 194       else
 195         {
 196           /* PT_READ_GPR requires the buffer parameter to point to long long,
 197              even if the register is really only 32 bits.  */
 198           long long buf;
 199           rs6000_ptrace64 (PT_READ_GPR, ptid_get_pid (inferior_ptid),
 200                            nr, 0, &buf);
 201           if (register_size (gdbarch, regno) == 8)
 202             memcpy (addr, &buf, 8);
 203           else
 204             *addr = buf;
 205         }
 206     }
 207
 208   if (!errno)
 209     regcache_raw_supply (regcache, regno, (char *) addr);
 210   else
 211     {
 212 #if 0
 213       /* FIXME: this happens 3 times at the start of each 64-bit program.  */
 214       perror (_("ptrace read"));
 215 #endif
 216       errno = 0;
 217     }
 218 }
 219
 220 /* Store register REGNO back into the inferior.  */
 221
 222 static void
 223 store_register (struct regcache *regcache, int regno)
 224 {
 225   struct gdbarch *gdbarch = get_regcache_arch (regcache);
 226   int addr[MAX_REGISTER_SIZE];
 227   int nr, isfloat;
 228
 229   /* Fetch the register's value from the register cache.  */
 230   regcache_raw_collect (regcache, regno, addr);
 231
 232   /* -1 can be a successful return value, so infer errors from errno.  */
 233   errno = 0;
 234
 235   nr = regmap (gdbarch, regno, &isfloat);
 236
 237   /* Floating-point registers.  */
 238   if (isfloat)
 239     rs6000_ptrace32 (PT_WRITE_FPR, ptid_get_pid (inferior_ptid), addr, nr, 0);
 240
 241   /* Bogus register number.  */
 242   else if (nr < 0)
 243     {
 244       if (regno >= gdbarch_num_regs (gdbarch))
 245         fprintf_unfiltered (gdb_stderr,
 246                             "gdb error: register no %d not implemented.\n",
 247                             regno);
 248     }
 249
 250   /* Fixed-point registers.  */
 251   else
 252     {
 253       /* The PT_WRITE_GPR operation is rather odd.  For 32-bit inferiors,
 254          the register's value is passed by value, but for 64-bit inferiors,
 255          the address of a buffer containing the value is passed.  */
 256       if (!ARCH64 ())
 257         rs6000_ptrace32 (PT_WRITE_GPR, ptid_get_pid (inferior_ptid),
 258                          (int *) nr, *addr, 0);
 259       else
 260         {
 261           /* PT_WRITE_GPR requires the buffer parameter to point to an 8-byte
 262              area, even if the register is really only 32 bits.  */
 263           long long buf;
 264           if (register_size (gdbarch, regno) == 8)
 265             memcpy (&buf, addr, 8);
 266           else
 267             buf = *addr;
 268           rs6000_ptrace64 (PT_WRITE_GPR, ptid_get_pid (inferior_ptid),
 269                            nr, 0, &buf);
 270         }
 271     }
 272
 273   if (errno)
 274     {
 275       perror (_("ptrace write"));
 276       errno = 0;
 277     }
 278 }
 279
 280 /* Read from the inferior all registers if REGNO == -1 and just register
 281    REGNO otherwise.  */
 282
 283 static void
 284 rs6000_fetch_inferior_registers (struct target_ops *ops,
 285                                  struct regcache *regcache, int regno)
 286 {
 287   struct gdbarch *gdbarch = get_regcache_arch (regcache);
 288   if (regno != -1)
 289     fetch_register (regcache, regno);
 290
 291   else
 292     {
 293       struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 294
 295       /* Read 32 general purpose registers.  */
 296       for (regno = tdep->ppc_gp0_regnum;
 297            regno < tdep->ppc_gp0_regnum + ppc_num_gprs;
 298            regno++)
 299         {
 300           fetch_register (regcache, regno);
 301         }
 302
 303       /* Read general purpose floating point registers.  */
 304       if (tdep->ppc_fp0_regnum >= 0)
 305         for (regno = 0; regno < ppc_num_fprs; regno++)
 306           fetch_register (regcache, tdep->ppc_fp0_regnum + regno);
 307
 308       /* Read special registers.  */
 309       fetch_register (regcache, gdbarch_pc_regnum (gdbarch));
 310       fetch_register (regcache, tdep->ppc_ps_regnum);
 311       fetch_register (regcache, tdep->ppc_cr_regnum);
 312       fetch_register (regcache, tdep->ppc_lr_regnum);
 313       fetch_register (regcache, tdep->ppc_ctr_regnum);
 314       fetch_register (regcache, tdep->ppc_xer_regnum);
 315       if (tdep->ppc_fpscr_regnum >= 0)
 316         fetch_register (regcache, tdep->ppc_fpscr_regnum);
 317       if (tdep->ppc_mq_regnum >= 0)
 318         fetch_register (regcache, tdep->ppc_mq_regnum);
 319     }
 320 }
 321
 322 /* Store our register values back into the inferior.
 323    If REGNO is -1, do this for all registers.
 324    Otherwise, REGNO specifies which register (so we can save time).  */
 325
 326 static void
 327 rs6000_store_inferior_registers (struct target_ops *ops,
 328                                  struct regcache *regcache, int regno)
 329 {
 330   struct gdbarch *gdbarch = get_regcache_arch (regcache);
 331   if (regno != -1)
 332     store_register (regcache, regno);
 333
 334   else
 335     {
 336       struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 337
 338       /* Write general purpose registers first.  */
 339       for (regno = tdep->ppc_gp0_regnum;
 340            regno < tdep->ppc_gp0_regnum + ppc_num_gprs;
 341            regno++)
 342         {
 343           store_register (regcache, regno);
 344         }
 345
 346       /* Write floating point registers.  */
 347       if (tdep->ppc_fp0_regnum >= 0)
 348         for (regno = 0; regno < ppc_num_fprs; regno++)
 349           store_register (regcache, tdep->ppc_fp0_regnum + regno);
 350
 351       /* Write special registers.  */
 352       store_register (regcache, gdbarch_pc_regnum (gdbarch));
 353       store_register (regcache, tdep->ppc_ps_regnum);
 354       store_register (regcache, tdep->ppc_cr_regnum);
 355       store_register (regcache, tdep->ppc_lr_regnum);
 356       store_register (regcache, tdep->ppc_ctr_regnum);
 357       store_register (regcache, tdep->ppc_xer_regnum);
 358       if (tdep->ppc_fpscr_regnum >= 0)
 359         store_register (regcache, tdep->ppc_fpscr_regnum);
 360       if (tdep->ppc_mq_regnum >= 0)
 361         store_register (regcache, tdep->ppc_mq_regnum);
 362     }
 363 }
 364
 365 /* Implement the to_xfer_partial target_ops method.  */
 366
 367 static enum target_xfer_status
 368 rs6000_xfer_partial (struct target_ops *ops, enum target_object object,
 369                      const char *annex, gdb_byte *readbuf,
 370                      const gdb_byte *writebuf,
 371                      ULONGEST offset, ULONGEST len, ULONGEST *xfered_len)
 372 {
 373   pid_t pid = ptid_get_pid (inferior_ptid);
 374   int arch64 = ARCH64 ();
 375
 376   switch (object)
 377     {
 378     case TARGET_OBJECT_LIBRARIES_AIX:
 379       return rs6000_xfer_shared_libraries (ops, object, annex,
 380                                            readbuf, writebuf,
 381                                            offset, len, xfered_len);
 382     case TARGET_OBJECT_MEMORY:
 383       {
 384         union
 385         {
 386           PTRACE_TYPE_RET word;
 387           gdb_byte byte[sizeof (PTRACE_TYPE_RET)];
 388         } buffer;
 389         ULONGEST rounded_offset;
 390         LONGEST partial_len;
 391
 392         /* Round the start offset down to the next long word
 393            boundary.  */
 394         rounded_offset = offset & -(ULONGEST) sizeof (PTRACE_TYPE_RET);
 395
 396         /* Since ptrace will transfer a single word starting at that
 397            rounded_offset the partial_len needs to be adjusted down to
 398            that (remember this function only does a single transfer).
 399            Should the required length be even less, adjust it down
 400            again.  */
 401         partial_len = (rounded_offset + sizeof (PTRACE_TYPE_RET)) - offset;
 402         if (partial_len > len)
 403           partial_len = len;
 404
 405         if (writebuf)
 406           {
 407             /* If OFFSET:PARTIAL_LEN is smaller than
 408                ROUNDED_OFFSET:WORDSIZE then a read/modify write will
 409                be needed.  Read in the entire word.  */
 410             if (rounded_offset < offset
 411                 || (offset + partial_len
 412                     < rounded_offset + sizeof (PTRACE_TYPE_RET)))
 413               {
 414                 /* Need part of initial word -- fetch it.  */
 415                 if (arch64)
 416                   buffer.word = rs6000_ptrace64 (PT_READ_I, pid,
 417                                                  rounded_offset, 0, NULL);
 418                 else
 419                   buffer.word = rs6000_ptrace32 (PT_READ_I, pid,
 420                                                  (int *) (uintptr_t)
 421                                                  rounded_offset,
 422                                                  0, NULL);
 423               }
 424
 425             /* Copy data to be written over corresponding part of
 426                buffer.  */
 427             memcpy (buffer.byte + (offset - rounded_offset),
 428                     writebuf, partial_len);
 429
 430             errno = 0;
 431             if (arch64)
 432               rs6000_ptrace64 (PT_WRITE_D, pid,
 433                                rounded_offset, buffer.word, NULL);
 434             else
 435               rs6000_ptrace32 (PT_WRITE_D, pid,
 436                                (int *) (uintptr_t) rounded_offset,
 437                                buffer.word, NULL);
 438             if (errno)
 439               return TARGET_XFER_EOF;
 440           }
 441
 442         if (readbuf)
 443           {
 444             errno = 0;
 445             if (arch64)
 446               buffer.word = rs6000_ptrace64 (PT_READ_I, pid,
 447                                              rounded_offset, 0, NULL);
 448             else
 449               buffer.word = rs6000_ptrace32 (PT_READ_I, pid,
 450                                              (int *)(uintptr_t)rounded_offset,
 451                                              0, NULL);
 452             if (errno)
 453               return TARGET_XFER_EOF;
 454
 455             /* Copy appropriate bytes out of the buffer.  */
 456             memcpy (readbuf, buffer.byte + (offset - rounded_offset),
 457                     partial_len);
 458           }
 459
 460         *xfered_len = (ULONGEST) partial_len;
 461         return TARGET_XFER_OK;
 462       }
 463
 464     default:
 465       return TARGET_XFER_E_IO;
 466     }
 467 }
 468
 469 /* Wait for the child specified by PTID to do something.  Return the
 470    process ID of the child, or MINUS_ONE_PTID in case of error; store
 471    the status in *OURSTATUS.  */
 472
 473 static ptid_t
 474 rs6000_wait (struct target_ops *ops,
 475              ptid_t ptid, struct target_waitstatus *ourstatus, int options)
 476 {
 477   pid_t pid;
 478   int status, save_errno;
 479
 480   do
 481     {
 482       set_sigint_trap ();
 483
 484       do
 485         {
 486           pid = waitpid (ptid_get_pid (ptid), &status, 0);
 487           save_errno = errno;
 488         }
 489       while (pid == -1 && errno == EINTR);
 490
 491       clear_sigint_trap ();
 492
 493       if (pid == -1)
 494         {
 495           fprintf_unfiltered (gdb_stderr,
 496                               _("Child process unexpectedly missing: %s.\n"),
 497                               safe_strerror (save_errno));
 498
 499           /* Claim it exited with unknown signal.  */
 500           ourstatus->kind = TARGET_WAITKIND_SIGNALLED;
 501           ourstatus->value.sig = GDB_SIGNAL_UNKNOWN;
 502           return inferior_ptid;
 503         }
 504
 505       /* Ignore terminated detached child processes.  */
 506       if (!WIFSTOPPED (status) && pid != ptid_get_pid (inferior_ptid))
 507         pid = -1;
 508     }
 509   while (pid == -1);
 510
 511   /* AIX has a couple of strange returns from wait().  */
 512
 513   /* stop after load" status.  */
 514   if (status == 0x57c)
 515     ourstatus->kind = TARGET_WAITKIND_LOADED;
 516   /* signal 0.  I have no idea why wait(2) returns with this status word.  */
 517   else if (status == 0x7f)
 518     ourstatus->kind = TARGET_WAITKIND_SPURIOUS;
 519   /* A normal waitstatus.  Let the usual macros deal with it.  */
 520   else
 521     store_waitstatus (ourstatus, status);
 522
 523   return pid_to_ptid (pid);
 524 }
 525 \f
 526
 527 /* Set the current architecture from the host running GDB.  Called when
 528    starting a child process.  */
 529
 530 static void (*super_create_inferior) (struct target_ops *,char *exec_file,
 531                                       char *allargs, char **env, int from_tty);
 532 static void
 533 rs6000_create_inferior (struct target_ops * ops, char *exec_file,
 534                         char *allargs, char **env, int from_tty)
 535 {
 536   enum bfd_architecture arch;
 537   unsigned long mach;
 538   bfd abfd;
 539   struct gdbarch_info info;
 540
 541   super_create_inferior (ops, exec_file, allargs, env, from_tty);
 542
 543   if (__power_rs ())
 544     {
 545       arch = bfd_arch_rs6000;
 546       mach = bfd_mach_rs6k;
 547     }
 548   else
 549     {
 550       arch = bfd_arch_powerpc;
 551       mach = bfd_mach_ppc;
 552     }
 553
 554   /* FIXME: schauer/2002-02-25:
 555      We don't know if we are executing a 32 or 64 bit executable,
 556      and have no way to pass the proper word size to rs6000_gdbarch_init.
 557      So we have to avoid switching to a new architecture, if the architecture
 558      matches already.
 559      Blindly calling rs6000_gdbarch_init used to work in older versions of
 560      GDB, as rs6000_gdbarch_init incorrectly used the previous tdep to
 561      determine the wordsize.  */
 562   if (exec_bfd)
 563     {
 564       const struct bfd_arch_info *exec_bfd_arch_info;
 565
 566       exec_bfd_arch_info = bfd_get_arch_info (exec_bfd);
 567       if (arch == exec_bfd_arch_info->arch)
 568         return;
 569     }
 570
 571   bfd_default_set_arch_mach (&abfd, arch, mach);
 572
 573   gdbarch_info_init (&info);
 574   info.bfd_arch_info = bfd_get_arch_info (&abfd);
 575   info.abfd = exec_bfd;
 576
 577   if (!gdbarch_update_p (info))
 578     internal_error (__FILE__, __LINE__,
 579                     _("rs6000_create_inferior: failed "
 580                       "to select architecture"));
 581 }
 582 \f
 583
 584 /* Shared Object support.  */
 585
 586 /* Return the LdInfo data for the given process.  Raises an error
 587    if the data could not be obtained.
 588
 589    The returned value must be deallocated after use.  */
 590
 591 static gdb_byte *
 592 rs6000_ptrace_ldinfo (ptid_t ptid)
 593 {
 594   const int pid = ptid_get_pid (ptid);
 595   int ldi_size = 1024;
 596   gdb_byte *ldi = xmalloc (ldi_size);
 597   int rc = -1;
 598
 599   while (1)
 600     {
 601       if (ARCH64 ())
 602         rc = rs6000_ptrace64 (PT_LDINFO, pid, (unsigned long) ldi, ldi_size,
 603                               NULL);
 604       else
 605         rc = rs6000_ptrace32 (PT_LDINFO, pid, (int *) ldi, ldi_size, NULL);
 606
 607       if (rc != -1)
 608         break; /* Success, we got the entire ld_info data.  */
 609
 610       if (errno != ENOMEM)
 611         perror_with_name (_("ptrace ldinfo"));
 612
 613       /* ldi is not big enough.  Double it and try again.  */
 614       ldi_size *= 2;
 615       ldi = xrealloc (ldi, ldi_size);
 616     }
 617
 618   return ldi;
 619 }
 620
 621 /* Implement the to_xfer_partial target_ops method for
 622    TARGET_OBJECT_LIBRARIES_AIX objects.  */
 623
 624 static enum target_xfer_status
 625 rs6000_xfer_shared_libraries
 626   (struct target_ops *ops, enum target_object object,
 627    const char *annex, gdb_byte *readbuf, const gdb_byte *writebuf,
 628    ULONGEST offset, ULONGEST len, ULONGEST *xfered_len)
 629 {
 630   gdb_byte *ldi_buf;
 631   ULONGEST result;
 632   struct cleanup *cleanup;
 633
 634   /* This function assumes that it is being run with a live process.
 635      Core files are handled via gdbarch.  */
 636   gdb_assert (target_has_execution);
 637
 638   if (writebuf)
 639     return TARGET_XFER_E_IO;
 640
 641   ldi_buf = rs6000_ptrace_ldinfo (inferior_ptid);
 642   gdb_assert (ldi_buf != NULL);
 643   cleanup = make_cleanup (xfree, ldi_buf);
 644   result = rs6000_aix_ld_info_to_xml (target_gdbarch (), ldi_buf,
 645                                       readbuf, offset, len, 1);
 646   xfree (ldi_buf);
 647
 648   do_cleanups (cleanup);
 649
 650   if (result == 0)
 651     return TARGET_XFER_EOF;
 652   else
 653     {
 654       *xfered_len = result;
 655       return TARGET_XFER_OK;
 656     }
 657 }
 658
 659 void _initialize_rs6000_nat (void);
 660
 661 void
 662 _initialize_rs6000_nat (void)
 663 {
 664   struct target_ops *t;
 665
 666   t = inf_ptrace_target ();
 667   t->to_fetch_registers = rs6000_fetch_inferior_registers;
 668   t->to_store_registers = rs6000_store_inferior_registers;
 669   t->to_xfer_partial = rs6000_xfer_partial;
 670
 671   super_create_inferior = t->to_create_inferior;
 672   t->to_create_inferior = rs6000_create_inferior;
 673
 674   t->to_wait = rs6000_wait;
 675
 676   add_target (t);
 677 }