gdb/rs6000-aix-nat.c

   1 /* IBM RS/6000 native-dependent code for GDB, the GNU debugger.
   2
   3    Copyright (C) 1986-2021 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 "bfd.h"
  27 #include "gdb-stabs.h"
  28 #include "regcache.h"
  29 #include "arch-utils.h"
  30 #include "inf-child.h"
  31 #include "inf-ptrace.h"
  32 #include "ppc-tdep.h"
  33 #include "rs6000-aix-tdep.h"
  34 #include "exec.h"
  35 #include "observable.h"
  36 #include "xcoffread.h"
  37
  38 #include <sys/ptrace.h>
  39 #include <sys/reg.h>
  40
  41 #include <sys/dir.h>
  42 #include <sys/user.h>
  43 #include <signal.h>
  44 #include <sys/ioctl.h>
  45 #include <fcntl.h>
  46
  47 #include <a.out.h>
  48 #include <sys/file.h>
  49 #include <sys/stat.h>
  50 #include "gdb_bfd.h"
  51 #include <sys/core.h>
  52 #define __LDINFO_PTRACE32__     /* for __ld_info32 */
  53 #define __LDINFO_PTRACE64__     /* for __ld_info64 */
  54 #include <sys/ldr.h>
  55 #include <sys/systemcfg.h>
  56
  57 /* On AIX4.3+, sys/ldr.h provides different versions of struct ld_info for
  58    debugging 32-bit and 64-bit processes.  Define a typedef and macros for
  59    accessing fields in the appropriate structures.  */
  60
  61 /* In 32-bit compilation mode (which is the only mode from which ptrace()
  62    works on 4.3), __ld_info32 is #defined as equivalent to ld_info.  */
  63
  64 #if defined (__ld_info32) || defined (__ld_info64)
  65 # define ARCH3264
  66 #endif
  67
  68 /* Return whether the current architecture is 64-bit.  */
  69
  70 #ifndef ARCH3264
  71 # define ARCH64() 0
  72 #else
  73 # define ARCH64() (register_size (target_gdbarch (), 0) == 8)
  74 #endif
  75
  76 class rs6000_nat_target final : public inf_ptrace_target
  77 {
  78 public:
  79   void fetch_registers (struct regcache *, int) override;
  80   void store_registers (struct regcache *, int) override;
  81
  82   enum target_xfer_status xfer_partial (enum target_object object,
  83                                         const char *annex,
  84                                         gdb_byte *readbuf,
  85                                         const gdb_byte *writebuf,
  86                                         ULONGEST offset, ULONGEST len,
  87                                         ULONGEST *xfered_len) override;
  88
  89   void create_inferior (const char *, const std::string &,
  90                         char **, int) override;
  91
  92   ptid_t wait (ptid_t, struct target_waitstatus *, target_wait_flags) override;
  93
  94 private:
  95   enum target_xfer_status
  96     xfer_shared_libraries (enum target_object object,
  97                            const char *annex, gdb_byte *readbuf,
  98                            const gdb_byte *writebuf,
  99                            ULONGEST offset, ULONGEST len,
 100                            ULONGEST *xfered_len);
 101 };
 102
 103 static rs6000_nat_target the_rs6000_nat_target;
 104
 105 /* Given REGNO, a gdb register number, return the corresponding
 106    number suitable for use as a ptrace() parameter.  Return -1 if
 107    there's no suitable mapping.  Also, set the int pointed to by
 108    ISFLOAT to indicate whether REGNO is a floating point register.  */
 109
 110 static int
 111 regmap (struct gdbarch *gdbarch, int regno, int *isfloat)
 112 {
 113   ppc_gdbarch_tdep *tdep = (ppc_gdbarch_tdep *) gdbarch_tdep (gdbarch);
 114
 115   *isfloat = 0;
 116   if (tdep->ppc_gp0_regnum <= regno
 117       && regno < tdep->ppc_gp0_regnum + ppc_num_gprs)
 118     return regno;
 119   else if (tdep->ppc_fp0_regnum >= 0
 120            && tdep->ppc_fp0_regnum <= regno
 121            && regno < tdep->ppc_fp0_regnum + ppc_num_fprs)
 122     {
 123       *isfloat = 1;
 124       return regno - tdep->ppc_fp0_regnum + FPR0;
 125     }
 126   else if (regno == gdbarch_pc_regnum (gdbarch))
 127     return IAR;
 128   else if (regno == tdep->ppc_ps_regnum)
 129     return MSR;
 130   else if (regno == tdep->ppc_cr_regnum)
 131     return CR;
 132   else if (regno == tdep->ppc_lr_regnum)
 133     return LR;
 134   else if (regno == tdep->ppc_ctr_regnum)
 135     return CTR;
 136   else if (regno == tdep->ppc_xer_regnum)
 137     return XER;
 138   else if (tdep->ppc_fpscr_regnum >= 0
 139            && regno == tdep->ppc_fpscr_regnum)
 140     return FPSCR;
 141   else if (tdep->ppc_mq_regnum >= 0 && regno == tdep->ppc_mq_regnum)
 142     return MQ;
 143   else
 144     return -1;
 145 }
 146
 147 /* Call ptrace(REQ, ID, ADDR, DATA, BUF).  */
 148
 149 static int
 150 rs6000_ptrace32 (int req, int id, int *addr, int data, int *buf)
 151 {
 152 #ifdef HAVE_PTRACE64
 153   int ret = ptrace64 (req, id, (uintptr_t) addr, data, buf);
 154 #else
 155   int ret = ptrace (req, id, (int *)addr, data, buf);
 156 #endif
 157 #if 0
 158   printf ("rs6000_ptrace32 (%d, %d, 0x%x, %08x, 0x%x) = 0x%x\n",
 159           req, id, (unsigned int)addr, data, (unsigned int)buf, ret);
 160 #endif
 161   return ret;
 162 }
 163
 164 /* Call ptracex(REQ, ID, ADDR, DATA, BUF).  */
 165
 166 static int
 167 rs6000_ptrace64 (int req, int id, long long addr, int data, void *buf)
 168 {
 169 #ifdef ARCH3264
 170 #  ifdef HAVE_PTRACE64
 171   int ret = ptrace64 (req, id, addr, data, (PTRACE_TYPE_ARG5) buf);
 172 #  else
 173   int ret = ptracex (req, id, addr, data, (PTRACE_TYPE_ARG5) buf);
 174 #  endif
 175 #else
 176   int ret = 0;
 177 #endif
 178 #if 0
 179   printf ("rs6000_ptrace64 (%d, %d, %s, %08x, 0x%x) = 0x%x\n",
 180           req, id, hex_string (addr), data, (unsigned int)buf, ret);
 181 #endif
 182   return ret;
 183 }
 184
 185 /* Fetch register REGNO from the inferior.  */
 186
 187 static void
 188 fetch_register (struct regcache *regcache, int regno)
 189 {
 190   struct gdbarch *gdbarch = regcache->arch ();
 191   int addr[PPC_MAX_REGISTER_SIZE];
 192   int nr, isfloat;
 193   pid_t pid = regcache->ptid ().pid ();
 194
 195   /* Retrieved values may be -1, so infer errors from errno.  */
 196   errno = 0;
 197
 198   nr = regmap (gdbarch, regno, &isfloat);
 199
 200   /* Floating-point registers.  */
 201   if (isfloat)
 202     rs6000_ptrace32 (PT_READ_FPR, pid, addr, nr, 0);
 203
 204   /* Bogus register number.  */
 205   else if (nr < 0)
 206     {
 207       if (regno >= gdbarch_num_regs (gdbarch))
 208         fprintf_unfiltered (gdb_stderr,
 209                             "gdb error: register no %d not implemented.\n",
 210                             regno);
 211       return;
 212     }
 213
 214   /* Fixed-point registers.  */
 215   else
 216     {
 217       if (!ARCH64 ())
 218         *addr = rs6000_ptrace32 (PT_READ_GPR, pid, (int *) nr, 0, 0);
 219       else
 220         {
 221           /* PT_READ_GPR requires the buffer parameter to point to long long,
 222              even if the register is really only 32 bits.  */
 223           long long buf;
 224           rs6000_ptrace64 (PT_READ_GPR, pid, nr, 0, &buf);
 225           if (register_size (gdbarch, regno) == 8)
 226             memcpy (addr, &buf, 8);
 227           else
 228             *addr = buf;
 229         }
 230     }
 231
 232   if (!errno)
 233     regcache->raw_supply (regno, (char *) addr);
 234   else
 235     {
 236 #if 0
 237       /* FIXME: this happens 3 times at the start of each 64-bit program.  */
 238       perror (_("ptrace read"));
 239 #endif
 240       errno = 0;
 241     }
 242 }
 243
 244 /* Store register REGNO back into the inferior.  */
 245
 246 static void
 247 store_register (struct regcache *regcache, int regno)
 248 {
 249   struct gdbarch *gdbarch = regcache->arch ();
 250   int addr[PPC_MAX_REGISTER_SIZE];
 251   int nr, isfloat;
 252   pid_t pid = regcache->ptid ().pid ();
 253
 254   /* Fetch the register's value from the register cache.  */
 255   regcache->raw_collect (regno, addr);
 256
 257   /* -1 can be a successful return value, so infer errors from errno.  */
 258   errno = 0;
 259
 260   nr = regmap (gdbarch, regno, &isfloat);
 261
 262   /* Floating-point registers.  */
 263   if (isfloat)
 264     rs6000_ptrace32 (PT_WRITE_FPR, pid, addr, nr, 0);
 265
 266   /* Bogus register number.  */
 267   else if (nr < 0)
 268     {
 269       if (regno >= gdbarch_num_regs (gdbarch))
 270         fprintf_unfiltered (gdb_stderr,
 271                             "gdb error: register no %d not implemented.\n",
 272                             regno);
 273     }
 274
 275   /* Fixed-point registers.  */
 276   else
 277     {
 278       /* The PT_WRITE_GPR operation is rather odd.  For 32-bit inferiors,
 279          the register's value is passed by value, but for 64-bit inferiors,
 280          the address of a buffer containing the value is passed.  */
 281       if (!ARCH64 ())
 282         rs6000_ptrace32 (PT_WRITE_GPR, pid, (int *) nr, *addr, 0);
 283       else
 284         {
 285           /* PT_WRITE_GPR requires the buffer parameter to point to an 8-byte
 286              area, even if the register is really only 32 bits.  */
 287           long long buf;
 288           if (register_size (gdbarch, regno) == 8)
 289             memcpy (&buf, addr, 8);
 290           else
 291             buf = *addr;
 292           rs6000_ptrace64 (PT_WRITE_GPR, pid, nr, 0, &buf);
 293         }
 294     }
 295
 296   if (errno)
 297     {
 298       perror (_("ptrace write"));
 299       errno = 0;
 300     }
 301 }
 302
 303 /* Read from the inferior all registers if REGNO == -1 and just register
 304    REGNO otherwise.  */
 305
 306 void
 307 rs6000_nat_target::fetch_registers (struct regcache *regcache, int regno)
 308 {
 309   struct gdbarch *gdbarch = regcache->arch ();
 310   if (regno != -1)
 311     fetch_register (regcache, regno);
 312
 313   else
 314     {
 315       ppc_gdbarch_tdep *tdep = (ppc_gdbarch_tdep *) gdbarch_tdep (gdbarch);
 316
 317       /* Read 32 general purpose registers.  */
 318       for (regno = tdep->ppc_gp0_regnum;
 319            regno < tdep->ppc_gp0_regnum + ppc_num_gprs;
 320            regno++)
 321         {
 322           fetch_register (regcache, regno);
 323         }
 324
 325       /* Read general purpose floating point registers.  */
 326       if (tdep->ppc_fp0_regnum >= 0)
 327         for (regno = 0; regno < ppc_num_fprs; regno++)
 328           fetch_register (regcache, tdep->ppc_fp0_regnum + regno);
 329
 330       /* Read special registers.  */
 331       fetch_register (regcache, gdbarch_pc_regnum (gdbarch));
 332       fetch_register (regcache, tdep->ppc_ps_regnum);
 333       fetch_register (regcache, tdep->ppc_cr_regnum);
 334       fetch_register (regcache, tdep->ppc_lr_regnum);
 335       fetch_register (regcache, tdep->ppc_ctr_regnum);
 336       fetch_register (regcache, tdep->ppc_xer_regnum);
 337       if (tdep->ppc_fpscr_regnum >= 0)
 338         fetch_register (regcache, tdep->ppc_fpscr_regnum);
 339       if (tdep->ppc_mq_regnum >= 0)
 340         fetch_register (regcache, tdep->ppc_mq_regnum);
 341     }
 342 }
 343
 344 /* Store our register values back into the inferior.
 345    If REGNO is -1, do this for all registers.
 346    Otherwise, REGNO specifies which register (so we can save time).  */
 347
 348 void
 349 rs6000_nat_target::store_registers (struct regcache *regcache, int regno)
 350 {
 351   struct gdbarch *gdbarch = regcache->arch ();
 352   if (regno != -1)
 353     store_register (regcache, regno);
 354
 355   else
 356     {
 357       ppc_gdbarch_tdep *tdep = (ppc_gdbarch_tdep *) gdbarch_tdep (gdbarch);
 358
 359       /* Write general purpose registers first.  */
 360       for (regno = tdep->ppc_gp0_regnum;
 361            regno < tdep->ppc_gp0_regnum + ppc_num_gprs;
 362            regno++)
 363         {
 364           store_register (regcache, regno);
 365         }
 366
 367       /* Write floating point registers.  */
 368       if (tdep->ppc_fp0_regnum >= 0)
 369         for (regno = 0; regno < ppc_num_fprs; regno++)
 370           store_register (regcache, tdep->ppc_fp0_regnum + regno);
 371
 372       /* Write special registers.  */
 373       store_register (regcache, gdbarch_pc_regnum (gdbarch));
 374       store_register (regcache, tdep->ppc_ps_regnum);
 375       store_register (regcache, tdep->ppc_cr_regnum);
 376       store_register (regcache, tdep->ppc_lr_regnum);
 377       store_register (regcache, tdep->ppc_ctr_regnum);
 378       store_register (regcache, tdep->ppc_xer_regnum);
 379       if (tdep->ppc_fpscr_regnum >= 0)
 380         store_register (regcache, tdep->ppc_fpscr_regnum);
 381       if (tdep->ppc_mq_regnum >= 0)
 382         store_register (regcache, tdep->ppc_mq_regnum);
 383     }
 384 }
 385
 386 /* Implement the to_xfer_partial target_ops method.  */
 387
 388 enum target_xfer_status
 389 rs6000_nat_target::xfer_partial (enum target_object object,
 390                                  const char *annex, gdb_byte *readbuf,
 391                                  const gdb_byte *writebuf,
 392                                  ULONGEST offset, ULONGEST len,
 393                                  ULONGEST *xfered_len)
 394 {
 395   pid_t pid = inferior_ptid.pid ();
 396   int arch64 = ARCH64 ();
 397
 398   switch (object)
 399     {
 400     case TARGET_OBJECT_LIBRARIES_AIX:
 401       return xfer_shared_libraries (object, annex,
 402                                     readbuf, writebuf,
 403                                     offset, len, xfered_len);
 404     case TARGET_OBJECT_MEMORY:
 405       {
 406         union
 407         {
 408           PTRACE_TYPE_RET word;
 409           gdb_byte byte[sizeof (PTRACE_TYPE_RET)];
 410         } buffer;
 411         ULONGEST rounded_offset;
 412         LONGEST partial_len;
 413
 414         /* Round the start offset down to the next long word
 415            boundary.  */
 416         rounded_offset = offset & -(ULONGEST) sizeof (PTRACE_TYPE_RET);
 417
 418         /* Since ptrace will transfer a single word starting at that
 419            rounded_offset the partial_len needs to be adjusted down to
 420            that (remember this function only does a single transfer).
 421            Should the required length be even less, adjust it down
 422            again.  */
 423         partial_len = (rounded_offset + sizeof (PTRACE_TYPE_RET)) - offset;
 424         if (partial_len > len)
 425           partial_len = len;
 426
 427         if (writebuf)
 428           {
 429             /* If OFFSET:PARTIAL_LEN is smaller than
 430                ROUNDED_OFFSET:WORDSIZE then a read/modify write will
 431                be needed.  Read in the entire word.  */
 432             if (rounded_offset < offset
 433                 || (offset + partial_len
 434                     < rounded_offset + sizeof (PTRACE_TYPE_RET)))
 435               {
 436                 /* Need part of initial word -- fetch it.  */
 437                 if (arch64)
 438                   buffer.word = rs6000_ptrace64 (PT_READ_I, pid,
 439                                                  rounded_offset, 0, NULL);
 440                 else
 441                   buffer.word = rs6000_ptrace32 (PT_READ_I, pid,
 442                                                  (int *) (uintptr_t)
 443                                                  rounded_offset,
 444                                                  0, NULL);
 445               }
 446
 447             /* Copy data to be written over corresponding part of
 448                buffer.  */
 449             memcpy (buffer.byte + (offset - rounded_offset),
 450                     writebuf, partial_len);
 451
 452             errno = 0;
 453             if (arch64)
 454               rs6000_ptrace64 (PT_WRITE_D, pid,
 455                                rounded_offset, buffer.word, NULL);
 456             else
 457               rs6000_ptrace32 (PT_WRITE_D, pid,
 458                                (int *) (uintptr_t) rounded_offset,
 459                                buffer.word, NULL);
 460             if (errno)
 461               return TARGET_XFER_EOF;
 462           }
 463
 464         if (readbuf)
 465           {
 466             errno = 0;
 467             if (arch64)
 468               buffer.word = rs6000_ptrace64 (PT_READ_I, pid,
 469                                              rounded_offset, 0, NULL);
 470             else
 471               buffer.word = rs6000_ptrace32 (PT_READ_I, pid,
 472                                              (int *)(uintptr_t)rounded_offset,
 473                                              0, NULL);
 474             if (errno)
 475               return TARGET_XFER_EOF;
 476
 477             /* Copy appropriate bytes out of the buffer.  */
 478             memcpy (readbuf, buffer.byte + (offset - rounded_offset),
 479                     partial_len);
 480           }
 481
 482         *xfered_len = (ULONGEST) partial_len;
 483         return TARGET_XFER_OK;
 484       }
 485
 486     default:
 487       return TARGET_XFER_E_IO;
 488     }
 489 }
 490
 491 /* Wait for the child specified by PTID to do something.  Return the
 492    process ID of the child, or MINUS_ONE_PTID in case of error; store
 493    the status in *OURSTATUS.  */
 494
 495 ptid_t
 496 rs6000_nat_target::wait (ptid_t ptid, struct target_waitstatus *ourstatus,
 497                          target_wait_flags options)
 498 {
 499   pid_t pid;
 500   int status, save_errno;
 501
 502   do
 503     {
 504       set_sigint_trap ();
 505
 506       do
 507         {
 508           pid = waitpid (ptid.pid (), &status, 0);
 509           save_errno = errno;
 510         }
 511       while (pid == -1 && errno == EINTR);
 512
 513       clear_sigint_trap ();
 514
 515       if (pid == -1)
 516         {
 517           fprintf_unfiltered (gdb_stderr,
 518                               _("Child process unexpectedly missing: %s.\n"),
 519                               safe_strerror (save_errno));
 520
 521           /* Claim it exited with unknown signal.  */
 522           ourstatus->set_signalled (GDB_SIGNAL_UNKNOWN);
 523           return inferior_ptid;
 524         }
 525
 526       /* Ignore terminated detached child processes.  */
 527       if (!WIFSTOPPED (status) && pid != inferior_ptid.pid ())
 528         pid = -1;
 529     }
 530   while (pid == -1);
 531
 532   /* AIX has a couple of strange returns from wait().  */
 533
 534   /* stop after load" status.  */
 535   if (status == 0x57c)
 536     ourstatus->set_loaded ();
 537   /* signal 0.  I have no idea why wait(2) returns with this status word.  */
 538   else if (status == 0x7f)
 539     ourstatus->set_spurious ();
 540   /* A normal waitstatus.  Let the usual macros deal with it.  */
 541   else
 542     store_waitstatus (ourstatus, status);
 543
 544   return ptid_t (pid);
 545 }
 546 \f
 547
 548 /* Set the current architecture from the host running GDB.  Called when
 549    starting a child process.  */
 550
 551 void
 552 rs6000_nat_target::create_inferior (const char *exec_file,
 553                                     const std::string &allargs,
 554                                     char **env, int from_tty)
 555 {
 556   enum bfd_architecture arch;
 557   unsigned long mach;
 558   bfd abfd;
 559
 560   inf_ptrace_target::create_inferior (exec_file, allargs, env, from_tty);
 561
 562   if (__power_rs ())
 563     {
 564       arch = bfd_arch_rs6000;
 565       mach = bfd_mach_rs6k;
 566     }
 567   else
 568     {
 569       arch = bfd_arch_powerpc;
 570       mach = bfd_mach_ppc;
 571     }
 572
 573   /* FIXME: schauer/2002-02-25:
 574      We don't know if we are executing a 32 or 64 bit executable,
 575      and have no way to pass the proper word size to rs6000_gdbarch_init.
 576      So we have to avoid switching to a new architecture, if the architecture
 577      matches already.
 578      Blindly calling rs6000_gdbarch_init used to work in older versions of
 579      GDB, as rs6000_gdbarch_init incorrectly used the previous tdep to
 580      determine the wordsize.  */
 581   if (current_program_space->exec_bfd ())
 582     {
 583       const struct bfd_arch_info *exec_bfd_arch_info;
 584
 585       exec_bfd_arch_info
 586         = bfd_get_arch_info (current_program_space->exec_bfd ());
 587       if (arch == exec_bfd_arch_info->arch)
 588         return;
 589     }
 590
 591   bfd_default_set_arch_mach (&abfd, arch, mach);
 592
 593   gdbarch_info info;
 594   info.bfd_arch_info = bfd_get_arch_info (&abfd);
 595   info.abfd = current_program_space->exec_bfd ();
 596
 597   if (!gdbarch_update_p (info))
 598     internal_error (__FILE__, __LINE__,
 599                     _("rs6000_create_inferior: failed "
 600                       "to select architecture"));
 601 }
 602 \f
 603
 604 /* Shared Object support.  */
 605
 606 /* Return the LdInfo data for the given process.  Raises an error
 607    if the data could not be obtained.  */
 608
 609 static gdb::byte_vector
 610 rs6000_ptrace_ldinfo (ptid_t ptid)
 611 {
 612   const int pid = ptid.pid ();
 613   gdb::byte_vector ldi (1024);
 614   int rc = -1;
 615
 616   while (1)
 617     {
 618       if (ARCH64 ())
 619         rc = rs6000_ptrace64 (PT_LDINFO, pid, (unsigned long) ldi.data (),
 620                               ldi.size (), NULL);
 621       else
 622         rc = rs6000_ptrace32 (PT_LDINFO, pid, (int *) ldi.data (),
 623                               ldi.size (), NULL);
 624
 625       if (rc != -1)
 626         break; /* Success, we got the entire ld_info data.  */
 627
 628       if (errno != ENOMEM)
 629         perror_with_name (_("ptrace ldinfo"));
 630
 631       /* ldi is not big enough.  Double it and try again.  */
 632       ldi.resize (ldi.size () * 2);
 633     }
 634
 635   return ldi;
 636 }
 637
 638 /* Implement the to_xfer_partial target_ops method for
 639    TARGET_OBJECT_LIBRARIES_AIX objects.  */
 640
 641 enum target_xfer_status
 642 rs6000_nat_target::xfer_shared_libraries
 643   (enum target_object object,
 644    const char *annex, gdb_byte *readbuf, const gdb_byte *writebuf,
 645    ULONGEST offset, ULONGEST len, ULONGEST *xfered_len)
 646 {
 647   ULONGEST result;
 648
 649   /* This function assumes that it is being run with a live process.
 650      Core files are handled via gdbarch.  */
 651   gdb_assert (target_has_execution ());
 652
 653   if (writebuf)
 654     return TARGET_XFER_E_IO;
 655
 656   gdb::byte_vector ldi_buf = rs6000_ptrace_ldinfo (inferior_ptid);
 657   result = rs6000_aix_ld_info_to_xml (target_gdbarch (), ldi_buf.data (),
 658                                       readbuf, offset, len, 1);
 659
 660   if (result == 0)
 661     return TARGET_XFER_EOF;
 662   else
 663     {
 664       *xfered_len = result;
 665       return TARGET_XFER_OK;
 666     }
 667 }
 668
 669 void _initialize_rs6000_nat ();
 670 void
 671 _initialize_rs6000_nat ()
 672 {
 673   add_inf_child_target (&the_rs6000_nat_target);
 674 }