bfd/rs6000-core.c

   1 /* IBM RS/6000 "XCOFF" back-end for BFD.
   2    Copyright (C) 1990, 1991 Free Software Foundation, Inc.
   3    FIXME: Can someone provide a transliteration of this name into ASCII?
   4    Using the following chars caused a compiler warning on HIUX (so I replaced
   5    them with octal escapes), and isn't useful without an understanding of what
   6    character set it is.
   7    Written by Metin G. Ozisik, Mimi Ph\373\364ng-Th\345o V\365,
   8      and John Gilmore.
   9    Archive support from Damon A. Permezel.
  10    Contributed by IBM Corporation and Cygnus Support.
  11
  12 This file is part of BFD, the Binary File Descriptor library.
  13
  14 This program is free software; you can redistribute it and/or modify
  15 it under the terms of the GNU General Public License as published by
  16 the Free Software Foundation; either version 2 of the License, or
  17 (at your option) any later version.
  18
  19 This program is distributed in the hope that it will be useful,
  20 but WITHOUT ANY WARRANTY; without even the implied warranty of
  21 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  22 GNU General Public License for more details.
  23
  24 You should have received a copy of the GNU General Public License
  25 along with this program; if not, write to the Free Software
  26 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */
  27
  28 /* This port currently only handles reading object files, except when
  29    compiled on an RS/6000 host.  -- no archive support, no core files.
  30    In all cases, it does not support writing.
  31
  32    FIXMEmgo comments are left from Metin Ozisik's original port.
  33
  34    This is in a separate file from coff-rs6000.c, because it includes
  35    system include files that conflict with coff/rs6000.h.
  36   */
  37
  38 /* Internalcoff.h and coffcode.h modify themselves based on this flag.  */
  39 #define RS6000COFF_C 1
  40
  41 #include "bfd.h"
  42 #include "sysdep.h"
  43 #include "libbfd.h"
  44
  45 #ifdef  COREFILES_PLEASE
  46
  47 /* AOUTHDR is defined by the above.  We need another defn of it, from the
  48    system include files.  Punt the old one and get us a new name for the
  49    typedef in the system include files.  */
  50 #ifdef AOUTHDR
  51 #undef AOUTHDR
  52 #endif
  53 #define AOUTHDR second_AOUTHDR
  54
  55 #undef  SCNHDR
  56
  57
  58 /* ------------------------------------------------------------------------ */
  59 /*      Support for core file stuff..                                       */
  60 /* ------------------------------------------------------------------------ */
  61
  62 #include <sys/user.h>
  63 #include <sys/ldr.h>
  64 #include <sys/core.h>
  65
  66
  67 /* Number of special purpose registers supported by gdb.  This value
  68    should match `tm.h' in gdb directory.  Clean this mess up and use
  69    the macros in sys/reg.h.  FIXMEmgo. */
  70
  71 #define NUM_OF_SPEC_REGS  7
  72 #define STACK_END_ADDR 0x2ff80000
  73
  74 #define core_hdr(bfd)           (((Rs6kCorData*)(bfd->tdata.any))->hdr)
  75 #define core_datasec(bfd)       (((Rs6kCorData*)(bfd->tdata.any))->data_section)
  76 #define core_stacksec(bfd)      (((Rs6kCorData*)(bfd->tdata.any))->stack_section)
  77 #define core_regsec(bfd)        (((Rs6kCorData*)(bfd->tdata.any))->reg_section)
  78 #define core_reg2sec(bfd)       (((Rs6kCorData*)(bfd->tdata.any))->reg2_section)
  79
  80 /* These are stored in the bfd's tdata */
  81 typedef struct {
  82   struct core *hdr;             /* core file header */
  83   asection *data_section,
  84            *stack_section,
  85            *reg_section,        /* section for GPRs and special registers. */
  86            *reg2_section;       /* section for FPRs. */
  87
  88   /* This tells us where everything is mapped (shared libraries and so on).
  89      GDB needs it.  */
  90   asection *ldinfo_section;
  91 #define core_ldinfosec(bfd) (((Rs6kCorData *)(bfd->tdata.any))->ldinfo_section)
  92 } Rs6kCorData;
  93
  94
  95 /* Decide if a given bfd represents a `core' file or not. There really is no
  96    magic number or anything like, in rs6000coff. */
  97
  98 bfd_target *
  99 rs6000coff_core_p (abfd)
 100      bfd *abfd;
 101 {
 102   int fd;
 103   struct core_dump coredata;
 104   struct stat statbuf;
 105   char *tmpptr;
 106
 107   /* Use bfd_xxx routines, rather than O/S primitives to read coredata. FIXMEmgo */
 108   fd = open (abfd->filename, O_RDONLY);
 109   if (fd < 0)
 110     {
 111       bfd_error = system_call_error;
 112       return NULL;
 113     }
 114
 115   if (fstat (fd, &statbuf) < 0)
 116     {
 117       bfd_error = system_call_error;
 118       close (fd);
 119       return NULL;
 120     }
 121   if (read (fd, &coredata, sizeof (struct core_dump))
 122       != sizeof (struct core_dump))
 123     {
 124       bfd_error = wrong_format;
 125       close (fd);
 126       return NULL;
 127     }
 128
 129   if (close (fd) < 0)
 130     {
 131       bfd_error = system_call_error;
 132       return NULL;
 133     }
 134
 135   /* If the core file ulimit is too small, the system will first
 136      omit the data segment, then omit the stack, then decline to
 137      dump core altogether (as far as I know UBLOCK_VALID and LE_VALID
 138      are always set) (this is based on experimentation on AIX 3.2).
 139      Now, the thing is that GDB users will be surprised
 140      if segments just silently don't appear (well, maybe they would
 141      think to check "info files", I don't know), but we have no way of
 142      returning warnings (as opposed to errors).
 143
 144      For the data segment, we have no choice but to keep going if it's
 145      not there, since the default behavior is not to dump it (regardless
 146      of the ulimit, it's based on SA_FULLDUMP).  But for the stack segment,
 147      if it's not there, we refuse to have anything to do with this core
 148      file.  The usefulness of a core dump without a stack segment is pretty
 149      limited anyway.  */
 150
 151   if (!(coredata.c_flag & UBLOCK_VALID)
 152       || !(coredata.c_flag & LE_VALID))
 153     {
 154       bfd_error = wrong_format;
 155       return NULL;
 156     }
 157
 158   if ((coredata.c_flag & CORE_TRUNC)
 159       || !(coredata.c_flag & USTACK_VALID))
 160     {
 161       bfd_error = file_truncated;
 162       return NULL;
 163     }
 164
 165   if (((bfd_vma)coredata.c_stack + coredata.c_size
 166        + ((coredata.c_flag & FULL_CORE) ? coredata.c_u.u_dsize : 0))
 167       != statbuf.st_size)
 168     {
 169       /* If the size is wrong, it means we're misinterpreting something.  */
 170       bfd_error = wrong_format;
 171       return NULL;
 172     }
 173
 174   /* Sanity check on the c_tab field.  */
 175   if ((u_long) coredata.c_tab < sizeof coredata ||
 176       (u_long) coredata.c_tab >= statbuf.st_size ||
 177       (long) coredata.c_tab >= (long)coredata.c_stack)
 178     {
 179       bfd_error = wrong_format;
 180       return NULL;
 181     }
 182
 183   /* maybe you should alloc space for the whole core chunk over here!! FIXMEmgo */
 184   tmpptr = (char*)bfd_zalloc (abfd, sizeof (Rs6kCorData));
 185   if (!tmpptr)
 186     {
 187       bfd_error = no_memory;
 188       return NULL;
 189     }
 190
 191   set_tdata (abfd, tmpptr);
 192
 193   /* .stack section. */
 194   if ((core_stacksec (abfd) = (asection*) bfd_zalloc (abfd, sizeof (asection)))
 195        == NULL)  {
 196     bfd_error = no_memory;
 197     /* bfd_release (abfd, ???? ) */
 198     return NULL;
 199   }
 200   core_stacksec (abfd)->name = ".stack";
 201   core_stacksec (abfd)->flags = SEC_ALLOC + SEC_LOAD;
 202   core_stacksec (abfd)->_raw_size = coredata.c_size;
 203   core_stacksec (abfd)->vma = STACK_END_ADDR - coredata.c_size;
 204   core_stacksec (abfd)->filepos = (int)coredata.c_stack;        /*???? */
 205
 206   /* .reg section for GPRs and special registers. */
 207   if ((core_regsec (abfd) = (asection*) bfd_zalloc (abfd, sizeof (asection)))
 208        == NULL)  {
 209     bfd_error = no_memory;
 210     /* bfd_release (abfd, ???? ) */
 211     return NULL;
 212   }
 213   core_regsec (abfd)->name = ".reg";
 214   core_regsec (abfd)->flags = SEC_ALLOC;
 215   core_regsec (abfd)->_raw_size = (32 + NUM_OF_SPEC_REGS) * 4;
 216   core_regsec (abfd)->vma = 0;                  /* not used?? */
 217   core_regsec (abfd)->filepos =
 218         (char*)&coredata.c_u.u_save - (char*)&coredata;
 219
 220   /* .reg2 section for FPRs (floating point registers). */
 221   if ((core_reg2sec (abfd) = (asection*) bfd_zalloc (abfd, sizeof (asection)))
 222        == NULL)  {
 223     bfd_error = no_memory;
 224     /* bfd_release (abfd, ???? ) */
 225     return NULL;
 226   }
 227   core_reg2sec (abfd)->name = ".reg2";
 228   core_reg2sec (abfd)->flags = SEC_ALLOC;
 229   core_reg2sec (abfd)->_raw_size = 8 * 32;                      /* 32 FPRs. */
 230   core_reg2sec (abfd)->vma = 0;                 /* not used?? */
 231   core_reg2sec (abfd)->filepos =
 232         (char*)&coredata.c_u.u_save.fpr[0] - (char*)&coredata;
 233
 234   if ((core_ldinfosec (abfd) = (asection*) bfd_zalloc (abfd, sizeof (asection)))
 235        == NULL)  {
 236     bfd_error = no_memory;
 237     /* bfd_release (abfd, ???? ) */
 238     return NULL;
 239   }
 240   core_ldinfosec (abfd)->name = ".ldinfo";
 241   core_ldinfosec (abfd)->flags = SEC_ALLOC + SEC_LOAD;
 242   /* To actually find out how long this section is in this particular
 243      core dump would require going down the whole list of struct ld_info's.
 244      See if we can just fake it.  */
 245   core_ldinfosec (abfd)->_raw_size = 0x7fffffff;
 246   /* Not relevant for ldinfo section.  */
 247   core_ldinfosec (abfd)->vma = 0;
 248   core_ldinfosec (abfd)->filepos = coredata.c_tab;
 249
 250   /* set up section chain here. */
 251   abfd->section_count = 4;
 252   abfd->sections = core_stacksec (abfd);
 253   core_stacksec (abfd)->next = core_regsec(abfd);
 254   core_regsec (abfd)->next = core_reg2sec (abfd);
 255   core_reg2sec (abfd)->next = core_ldinfosec (abfd);
 256   core_ldinfosec (abfd)->next = NULL;
 257
 258   if (coredata.c_flag & FULL_CORE)
 259     {
 260       asection *sec = (asection *) bfd_zalloc (abfd, sizeof (asection));
 261       if (sec == NULL)
 262         {
 263           bfd_error = no_memory;
 264           return NULL;
 265         }
 266       sec->name = ".data";
 267       sec->flags = SEC_ALLOC | SEC_LOAD | SEC_HAS_CONTENTS;
 268       sec->_raw_size = coredata.c_u.u_dsize;
 269       sec->vma = CDATA_ADDR (coredata.c_u.u_dsize);
 270       sec->filepos = (int)coredata.c_stack + coredata.c_size;
 271
 272       sec->next = abfd->sections;
 273       abfd->sections = sec;
 274       ++abfd->section_count;
 275     }
 276
 277   return abfd->xvec;                            /* this is garbage for now. */
 278 }
 279
 280
 281
 282 /* return `true' if given core is from the given executable.. */
 283 boolean
 284 rs6000coff_core_file_matches_executable_p (core_bfd, exec_bfd)
 285      bfd *core_bfd;
 286      bfd *exec_bfd;
 287 {
 288   FILE *fd;
 289   struct core_dump coredata;
 290   struct ld_info ldinfo;
 291   char pathname [1024];
 292   char *str1, *str2;
 293
 294   /* Use bfd_xxx routines, rather than O/S primitives, do error checking!!
 295                                                                 FIXMEmgo */
 296   /* Actually should be able to use bfd_get_section_contents now that
 297      we have a .ldinfo section.  */
 298   fd = fopen (core_bfd->filename, FOPEN_RB);
 299
 300   fread (&coredata, sizeof (struct core_dump), 1, fd);
 301   fseek (fd, (long)coredata.c_tab, 0);
 302   fread (&ldinfo, (char*)&ldinfo.ldinfo_filename[0] - (char*)&ldinfo.ldinfo_next,
 303          1, fd);
 304   fscanf (fd, "%s", pathname);
 305
 306   str1 = strrchr (pathname, '/');
 307   str2 = strrchr (exec_bfd->filename, '/');
 308
 309   /* step over character '/' */
 310   str1 = str1 ? str1+1 : &pathname[0];
 311   str2 = str2 ? str2+1 : exec_bfd->filename;
 312
 313   fclose (fd);
 314   return strcmp (str1, str2) == 0;
 315 }
 316
 317
 318 boolean
 319 rs6000coff_get_section_contents (abfd, section, location, offset, count)
 320      bfd *abfd;
 321      sec_ptr section;
 322      PTR location;
 323      file_ptr offset;
 324      int count;
 325 {
 326     if (count == 0)
 327         return true;
 328
 329     /* Reading a core file's sections will be slightly different. For the
 330        rest of them we can use bfd_generic_get_section_contents () I suppose. */
 331     /* Make sure this routine works for any bfd and any section. FIXMEmgo. */
 332
 333     if (abfd->format == bfd_core && strcmp (section->name, ".reg") == 0) {
 334
 335       struct mstsave mstatus;
 336       int    regoffset = (char*)&mstatus.gpr[0] - (char*)&mstatus;
 337
 338       /* Assert that the only way this code will be executed is reading the
 339          whole section. */
 340       if (offset || count != (sizeof(mstatus.gpr) + (4 * NUM_OF_SPEC_REGS)))
 341         fprintf (stderr, "ERROR! in rs6000coff_get_section_contents()\n");
 342
 343       /* for `.reg' section, `filepos' is a pointer to the `mstsave' structure
 344          in the core file. */
 345
 346       /* read GPR's into the location. */
 347       if ( bfd_seek(abfd, section->filepos + regoffset, SEEK_SET) == -1
 348         || bfd_read(location, sizeof (mstatus.gpr), 1, abfd) != sizeof (mstatus.gpr))
 349         return (false); /* on error */
 350
 351       /* increment location to the beginning of special registers in the section,
 352          reset register offset value to the beginning of first special register
 353          in mstsave structure, and read special registers. */
 354
 355       location = (PTR) ((char*)location + sizeof (mstatus.gpr));
 356       regoffset = (char*)&mstatus.iar - (char*)&mstatus;
 357
 358       if ( bfd_seek(abfd, section->filepos + regoffset, SEEK_SET) == -1
 359         || bfd_read(location, 4 * NUM_OF_SPEC_REGS, 1, abfd) !=
 360                                                         4 * NUM_OF_SPEC_REGS)
 361         return (false); /* on error */
 362
 363       /* increment location address, and read the special registers.. */
 364       /* FIXMEmgo */
 365       return (true);
 366     }
 367
 368     /* else, use default bfd section content transfer. */
 369     else
 370       return bfd_generic_get_section_contents
 371                         (abfd, section, location, offset, count);
 372 }
 373
 374 #endif /* COREFILES_PLEASE */