bfd/rs6000-core.c

   1 /* IBM RS/6000 "XCOFF" back-end for BFD.
   2    Copyright 1990, 91, 92, 93, 94, 95, 96, 97, 98, 2000
   3    Free Software Foundation, Inc.
   4    FIXME: Can someone provide a transliteration of this name into ASCII?
   5    Using the following chars caused a compiler warning on HIUX (so I replaced
   6    them with octal escapes), and isn't useful without an understanding of what
   7    character set it is.
   8    Written by Metin G. Ozisik, Mimi Ph\373\364ng-Th\345o V\365,
   9      and John Gilmore.
  10    Archive support from Damon A. Permezel.
  11    Contributed by IBM Corporation and Cygnus Support.
  12
  13 This file is part of BFD, the Binary File Descriptor library.
  14
  15 This program is free software; you can redistribute it and/or modify
  16 it under the terms of the GNU General Public License as published by
  17 the Free Software Foundation; either version 2 of the License, or
  18 (at your option) any later version.
  19
  20 This program is distributed in the hope that it will be useful,
  21 but WITHOUT ANY WARRANTY; without even the implied warranty of
  22 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  23 GNU General Public License for more details.
  24
  25 You should have received a copy of the GNU General Public License
  26 along with this program; if not, write to the Free Software
  27 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
  28
  29 /* This port currently only handles reading object files, except when
  30    compiled on an RS/6000 host.  -- no archive support, no core files.
  31    In all cases, it does not support writing.
  32
  33    FIXMEmgo comments are left from Metin Ozisik's original port.
  34
  35    This is in a separate file from coff-rs6000.c, because it includes
  36    system include files that conflict with coff/rs6000.h.
  37   */
  38
  39 /* Internalcoff.h and coffcode.h modify themselves based on this flag.  */
  40 #define RS6000COFF_C 1
  41
  42 /* The AIX 4.1 kernel is obviously compiled with -D_LONG_LONG, so
  43    we have to define _LONG_LONG for older versions of gcc to get the
  44    proper alignments in the user structure.  */
  45 #if defined(_AIX41) && !defined(_LONG_LONG)
  46 #define _LONG_LONG
  47 #endif
  48
  49 #include "bfd.h"
  50 #include "sysdep.h"
  51 #include "libbfd.h"
  52
  53 #ifdef AIX_CORE
  54
  55 /* AOUTHDR is defined by the above.  We need another defn of it, from the
  56    system include files.  Punt the old one and get us a new name for the
  57    typedef in the system include files.  */
  58 #ifdef AOUTHDR
  59 #undef AOUTHDR
  60 #endif
  61 #define AOUTHDR second_AOUTHDR
  62
  63 #undef  SCNHDR
  64
  65
  66 /* ------------------------------------------------------------------------ */
  67 /*      Support for core file stuff..                                       */
  68 /* ------------------------------------------------------------------------ */
  69
  70 #include <sys/user.h>
  71 #include <sys/ldr.h>
  72 #include <sys/core.h>
  73
  74
  75 /* Number of special purpose registers supported by gdb.  This value
  76    should match `tm.h' in gdb directory.  Clean this mess up and use
  77    the macros in sys/reg.h.  FIXMEmgo. */
  78
  79 #define NUM_OF_SPEC_REGS  7
  80
  81 #define core_hdr(bfd)           (((Rs6kCorData*)(bfd->tdata.any))->hdr)
  82
  83 /* AIX 4.1 Changed the names and locations of a few items in the core file,
  84    this seems to be the quickest/easiest way to deal with it.
  85
  86    Note however that encoding magic addresses (STACK_END_ADDR) is going
  87    to be _very_ fragile.  But I don't see any easy way to get that info
  88    right now.
  89
  90    AIX 4.3 defines an entirely new structure (core_dumpx).  Yet the
  91    basic logic stays the same and we can still use our macro
  92    redefinition mechanism to effect the necessary changes.  */
  93
  94 #ifdef AIX_CORE_DUMPX_CORE
  95 #define CORE_DATA_SIZE_FIELD c_dataorg
  96 #define CORE_COMM_FIELD c_u.U_proc.pi_comm
  97 #define SAVE_FIELD c_flt.hctx.r32
  98 #define STACK_END_ADDR coredata.c_stackorg + coredata.c_size
  99 #define LOADER_OFFSET_FIELD c_loader
 100 #define LOADER_REGION_SIZE coredata.c_lsize
 101 #define CORE_DUMP core_dumpx
 102 #else
 103 #ifdef CORE_VERSION_1
 104 #define CORE_DATA_SIZE_FIELD c_u.U_dsize
 105 #define CORE_COMM_FIELD c_u.U_comm
 106 #define SAVE_FIELD c_mst
 107 #define STACK_END_ADDR 0x2ff23000
 108 #define LOADER_OFFSET_FIELD c_tab
 109 #define LOADER_REGION_SIZE 0x7ffffff
 110 #define CORE_DUMP core_dump
 111 #else
 112 #define CORE_DATA_SIZE_FIELD c_u.u_dsize
 113 #define CORE_COMM_FIELD c_u.u_comm
 114 #define SAVE_FIELD c_u.u_save
 115 #define STACK_END_ADDR 0x2ff80000
 116 #define LOADER_OFFSET_FIELD c_tab
 117 #define LOADER_REGION_SIZE 0x7ffffff
 118 #define CORE_DUMP core_dump
 119 #endif
 120 #endif
 121
 122 /* These are stored in the bfd's tdata */
 123 typedef struct {
 124   struct CORE_DUMP hdr;         /* core file header */
 125 } Rs6kCorData;
 126
 127 static asection *make_bfd_asection PARAMS ((bfd *, CONST char *, flagword,
 128                                             bfd_size_type, bfd_vma, file_ptr));
 129
 130 static asection *
 131 make_bfd_asection (abfd, name, flags, _raw_size, vma, filepos)
 132      bfd *abfd;
 133      CONST char *name;
 134      flagword flags;
 135      bfd_size_type _raw_size;
 136      bfd_vma vma;
 137      file_ptr filepos;
 138 {
 139   asection *asect;
 140
 141   asect = bfd_make_section_anyway (abfd, name);
 142   if (!asect)
 143     return NULL;
 144
 145   asect->flags = flags;
 146   asect->_raw_size = _raw_size;
 147   asect->vma = vma;
 148   asect->filepos = filepos;
 149   asect->alignment_power = 8;
 150
 151   return asect;
 152 }
 153
 154 /* Decide if a given bfd represents a `core' file or not. There really is no
 155    magic number or anything like, in rs6000coff. */
 156
 157 const bfd_target *
 158 rs6000coff_core_p (abfd)
 159      bfd *abfd;
 160 {
 161   struct CORE_DUMP coredata;
 162   struct stat statbuf;
 163   bfd_size_type nread;
 164   char *tmpptr;
 165
 166   if (bfd_seek (abfd, 0, SEEK_SET) != 0)
 167     return NULL;
 168
 169   nread = bfd_read (&coredata, 1, sizeof (struct CORE_DUMP), abfd);
 170   if (nread != sizeof (struct CORE_DUMP))
 171     {
 172       if (bfd_get_error () != bfd_error_system_call)
 173         bfd_set_error (bfd_error_wrong_format);
 174       return NULL;
 175     }
 176
 177   if (bfd_stat (abfd, &statbuf) < 0)
 178     {
 179       bfd_set_error (bfd_error_system_call);
 180       return NULL;
 181     }
 182
 183   /* If the core file ulimit is too small, the system will first
 184      omit the data segment, then omit the stack, then decline to
 185      dump core altogether (as far as I know UBLOCK_VALID and LE_VALID
 186      are always set) (this is based on experimentation on AIX 3.2).
 187      Now, the thing is that GDB users will be surprised
 188      if segments just silently don't appear (well, maybe they would
 189      think to check "info files", I don't know).
 190
 191      For the data segment, we have no choice but to keep going if it's
 192      not there, since the default behavior is not to dump it (regardless
 193      of the ulimit, it's based on SA_FULLDUMP).  But for the stack segment,
 194      if it's not there, we refuse to have anything to do with this core
 195      file.  The usefulness of a core dump without a stack segment is pretty
 196      limited anyway.  */
 197
 198   if (!(coredata.c_flag & UBLOCK_VALID)
 199       || !(coredata.c_flag & LE_VALID))
 200     {
 201       bfd_set_error (bfd_error_wrong_format);
 202       return NULL;
 203     }
 204
 205   if (!(coredata.c_flag & USTACK_VALID))
 206     {
 207       bfd_set_error (bfd_error_file_truncated);
 208       return NULL;
 209     }
 210
 211   /* Don't check the core file size for a full core, AIX 4.1 includes
 212      additional shared library sections in a full core.  */
 213   if (!(coredata.c_flag & (FULL_CORE | CORE_TRUNC))
 214       && ((bfd_vma)coredata.c_stack + coredata.c_size) != statbuf.st_size)
 215     {
 216       /* If the size is wrong, it means we're misinterpreting something.  */
 217       bfd_set_error (bfd_error_wrong_format);
 218       return NULL;
 219     }
 220
 221 #ifdef AIX_CORE_DUMPX_CORE
 222   /* For the core_dumpx format, make sure c_entries == 0  If it does
 223      not, the core file uses the old format */
 224   if (coredata.c_entries != 0)
 225     {
 226       bfd_set_error (bfd_error_wrong_format);
 227       return NULL;
 228     }
 229 #else
 230   /* Sanity check on the c_tab field.  */
 231   if ((u_long) coredata.c_tab < sizeof coredata ||
 232       (u_long) coredata.c_tab >= statbuf.st_size ||
 233       (long) coredata.c_tab >= (long)coredata.c_stack)
 234     {
 235       bfd_set_error (bfd_error_wrong_format);
 236       return NULL;
 237     }
 238 #endif
 239
 240   /* Issue warning if the core file was truncated during writing.  */
 241   if (coredata.c_flag & CORE_TRUNC)
 242     (*_bfd_error_handler) (_("%s: warning core file truncated"),
 243                            bfd_get_filename (abfd));
 244
 245   /* Allocate core file header.  */
 246   tmpptr = (char*) bfd_zalloc (abfd, sizeof (Rs6kCorData));
 247   if (!tmpptr)
 248     return NULL;
 249
 250   set_tdata (abfd, tmpptr);
 251
 252   /* Copy core file header.  */
 253   core_hdr (abfd) = coredata;
 254
 255   /* .stack section. */
 256   if (!make_bfd_asection (abfd, ".stack",
 257                           SEC_ALLOC | SEC_LOAD | SEC_HAS_CONTENTS,
 258                           (bfd_size_type) coredata.c_size,
 259                           (bfd_vma) (STACK_END_ADDR - coredata.c_size),
 260                           (file_ptr) coredata.c_stack))
 261     return NULL;
 262
 263   /* .reg section for GPRs and special registers. */
 264   if (!make_bfd_asection (abfd, ".reg",
 265                           SEC_HAS_CONTENTS,
 266                           (bfd_size_type) ((32 + NUM_OF_SPEC_REGS) * 4),
 267                           (bfd_vma) 0,
 268                           (file_ptr) ((char *) &coredata.SAVE_FIELD
 269                                       - (char *) &coredata)))
 270     return NULL;
 271
 272   /* .reg2 section for FPRs (floating point registers). */
 273   if (!make_bfd_asection (abfd, ".reg2",
 274                           SEC_HAS_CONTENTS,
 275                           (bfd_size_type) 8 * 32,       /* 32 FPRs. */
 276                           (bfd_vma) 0,
 277                           (file_ptr) ((char *) &coredata.SAVE_FIELD.fpr[0]
 278                                       - (char *) &coredata)))
 279     return NULL;
 280
 281   /* .ldinfo section.
 282      To actually find out how long this section is in this particular
 283      core dump would require going down the whole list of struct ld_info's.
 284      See if we can just fake it.  */
 285   if (!make_bfd_asection (abfd, ".ldinfo",
 286                           SEC_HAS_CONTENTS,
 287                           (bfd_size_type) LOADER_REGION_SIZE,
 288                           (bfd_vma) 0,
 289                           (file_ptr) coredata.LOADER_OFFSET_FIELD))
 290     return NULL;
 291
 292 #ifndef CORE_VERSION_1
 293   /* .data section if present.
 294      AIX 3 dumps the complete data section and sets FULL_CORE if the
 295      ulimit is large enough, otherwise the data section is omitted.
 296      AIX 4 sets FULL_CORE even if the core file is truncated, we have
 297      to examine coredata.c_datasize below to find out the actual size of
 298      the .data section.  */
 299   if (coredata.c_flag & FULL_CORE)
 300     {
 301       if (!make_bfd_asection (abfd, ".data",
 302                               SEC_ALLOC | SEC_LOAD | SEC_HAS_CONTENTS,
 303                               (bfd_size_type) coredata.CORE_DATA_SIZE_FIELD,
 304                               (bfd_vma)
 305                                 CDATA_ADDR (coredata.CORE_DATA_SIZE_FIELD),
 306                               (file_ptr) coredata.c_stack + coredata.c_size))
 307         return NULL;
 308     }
 309 #endif
 310
 311 #ifdef CORE_VERSION_1
 312   /* AIX 4 adds data sections from loaded objects to the core file,
 313      which can be found by examining ldinfo, and anonymously mmapped
 314      regions.  */
 315   {
 316     struct ld_info ldinfo;
 317     bfd_size_type ldinfo_size;
 318     file_ptr ldinfo_offset = (file_ptr) coredata.LOADER_OFFSET_FIELD;
 319
 320     /* .data section from executable.  */
 321     if (coredata.c_datasize)
 322       {
 323         if (!make_bfd_asection (abfd, ".data",
 324                                 SEC_ALLOC | SEC_LOAD | SEC_HAS_CONTENTS,
 325                                 (bfd_size_type) coredata.c_datasize,
 326                                 (bfd_vma)
 327                                   CDATA_ADDR (coredata.CORE_DATA_SIZE_FIELD),
 328                                 (file_ptr) coredata.c_data))
 329           return NULL;
 330       }
 331
 332     /* .data sections from loaded objects.  */
 333     ldinfo_size = (char *) &ldinfo.ldinfo_filename[0]
 334                   - (char *) &ldinfo.ldinfo_next;
 335     while (1)
 336       {
 337         if (bfd_seek (abfd, ldinfo_offset, SEEK_SET) != 0)
 338           return NULL;
 339         if (bfd_read (&ldinfo, ldinfo_size, 1, abfd) != ldinfo_size)
 340           return NULL;
 341         if (ldinfo.ldinfo_core)
 342           {
 343             if (!make_bfd_asection (abfd, ".data",
 344                                     SEC_ALLOC | SEC_LOAD | SEC_HAS_CONTENTS,
 345                                     (bfd_size_type) ldinfo.ldinfo_datasize,
 346                                     (bfd_vma) ldinfo.ldinfo_dataorg,
 347                                     (file_ptr) ldinfo.ldinfo_core))
 348               return NULL;
 349           }
 350         if (ldinfo.ldinfo_next == 0)
 351           break;
 352         ldinfo_offset += ldinfo.ldinfo_next;
 353       }
 354
 355     /* .vmdata sections from anonymously mmapped regions.  */
 356     if (coredata.c_vmregions)
 357       {
 358         int i;
 359
 360         if (bfd_seek (abfd, (file_ptr) coredata.c_vmm, SEEK_SET) != 0)
 361           return NULL;
 362
 363         for (i = 0; i < coredata.c_vmregions; i++)
 364           {
 365             struct vm_info vminfo;
 366
 367             if (bfd_read (&vminfo, sizeof (vminfo), 1, abfd) != sizeof (vminfo))
 368               return NULL;
 369             if (vminfo.vminfo_offset)
 370               {
 371                 if (!make_bfd_asection (abfd, ".vmdata",
 372                                         SEC_ALLOC | SEC_LOAD | SEC_HAS_CONTENTS,
 373                                         (bfd_size_type) vminfo.vminfo_size,
 374                                         (bfd_vma) vminfo.vminfo_addr,
 375                                         (file_ptr) vminfo.vminfo_offset))
 376                   return NULL;
 377               }
 378           }
 379       }
 380   }
 381 #endif
 382
 383   return abfd->xvec;                            /* this is garbage for now. */
 384 }
 385
 386
 387
 388 /* return `true' if given core is from the given executable.. */
 389 boolean
 390 rs6000coff_core_file_matches_executable_p (core_bfd, exec_bfd)
 391      bfd *core_bfd;
 392      bfd *exec_bfd;
 393 {
 394   struct CORE_DUMP coredata;
 395   struct ld_info ldinfo;
 396   bfd_size_type size;
 397   char *path, *s;
 398   size_t alloc;
 399   const char *str1, *str2;
 400   boolean ret;
 401
 402   if (bfd_seek (core_bfd, 0, SEEK_SET) != 0
 403       || bfd_read (&coredata, sizeof coredata, 1, core_bfd) != sizeof coredata)
 404     return false;
 405
 406   if (bfd_seek (core_bfd, (long) coredata.LOADER_OFFSET_FIELD, SEEK_SET) != 0)
 407     return false;
 408
 409   size = (char *) &ldinfo.ldinfo_filename[0] - (char *) &ldinfo.ldinfo_next;
 410   if (bfd_read (&ldinfo, size, 1, core_bfd) != size)
 411     return false;
 412
 413   alloc = 100;
 414   path = bfd_malloc (alloc);
 415   if (path == NULL)
 416     return false;
 417   s = path;
 418
 419   while (1)
 420     {
 421       if (bfd_read (s, 1, 1, core_bfd) != 1)
 422         {
 423           free (path);
 424           return false;
 425         }
 426       if (*s == '\0')
 427         break;
 428       ++s;
 429       if (s == path + alloc)
 430         {
 431           char *n;
 432
 433           alloc *= 2;
 434           n = bfd_realloc (path, alloc);
 435           if (n == NULL)
 436             {
 437               free (path);
 438               return false;
 439             }
 440           s = n + (path - s);
 441           path = n;
 442         }
 443     }
 444
 445   str1 = strrchr (path, '/');
 446   str2 = strrchr (exec_bfd->filename, '/');
 447
 448   /* step over character '/' */
 449   str1 = str1 != NULL ? str1 + 1 : path;
 450   str2 = str2 != NULL ? str2 + 1 : exec_bfd->filename;
 451
 452   if (strcmp (str1, str2) == 0)
 453     ret = true;
 454   else
 455     ret = false;
 456
 457   free (path);
 458
 459   return ret;
 460 }
 461
 462 char *
 463 rs6000coff_core_file_failing_command (abfd)
 464      bfd *abfd;
 465 {
 466   char *com = core_hdr (abfd).CORE_COMM_FIELD;
 467   if (*com)
 468     return com;
 469   else
 470     return 0;
 471 }
 472
 473 int
 474 rs6000coff_core_file_failing_signal (abfd)
 475      bfd *abfd;
 476 {
 477   return core_hdr (abfd).c_signo;
 478 }
 479
 480
 481 boolean
 482 rs6000coff_get_section_contents (abfd, section, location, offset, count)
 483      bfd *abfd;
 484      sec_ptr section;
 485      PTR location;
 486      file_ptr offset;
 487      bfd_size_type count;
 488 {
 489     if (count == 0)
 490         return true;
 491
 492     /* Reading a core file's sections will be slightly different. For the
 493        rest of them we can use bfd_generic_get_section_contents () I suppose. */
 494     /* Make sure this routine works for any bfd and any section. FIXMEmgo. */
 495
 496     if (abfd->format == bfd_core && strcmp (section->name, ".reg") == 0) {
 497
 498       struct mstsave mstatus;
 499       int    regoffset = (char*)&mstatus.gpr[0] - (char*)&mstatus;
 500
 501       /* Assert that the only way this code will be executed is reading the
 502          whole section. */
 503       if (offset || count != (sizeof(mstatus.gpr) + (4 * NUM_OF_SPEC_REGS)))
 504         (*_bfd_error_handler)
 505           (_("ERROR! in rs6000coff_get_section_contents()\n"));
 506
 507       /* for `.reg' section, `filepos' is a pointer to the `mstsave' structure
 508          in the core file. */
 509
 510       /* read GPR's into the location. */
 511       if ( bfd_seek(abfd, section->filepos + regoffset, SEEK_SET) == -1
 512         || bfd_read(location, sizeof (mstatus.gpr), 1, abfd) != sizeof (mstatus.gpr))
 513         return (false); /* on error */
 514
 515       /* increment location to the beginning of special registers in the section,
 516          reset register offset value to the beginning of first special register
 517          in mstsave structure, and read special registers. */
 518
 519       location = (PTR) ((char*)location + sizeof (mstatus.gpr));
 520       regoffset = (char*)&mstatus.iar - (char*)&mstatus;
 521
 522       if ( bfd_seek(abfd, section->filepos + regoffset, SEEK_SET) == -1
 523         || bfd_read(location, 4 * NUM_OF_SPEC_REGS, 1, abfd) !=
 524                                                         4 * NUM_OF_SPEC_REGS)
 525         return (false); /* on error */
 526
 527       /* increment location address, and read the special registers.. */
 528       /* FIXMEmgo */
 529       return (true);
 530     }
 531
 532     /* else, use default bfd section content transfer. */
 533     else
 534       return _bfd_generic_get_section_contents
 535                         (abfd, section, location, offset, count);
 536 }
 537
 538 #endif /* AIX_CORE */