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      1 /* BFD back end for traditional Unix core files (U-area and raw sections)
      2    Copyright (C) 1988-2014 Free Software Foundation, Inc.
      3    Written by John Gilmore of Cygnus Support.
      4 
      5    This file is part of BFD, the Binary File Descriptor library.
      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, write to the Free Software
     19    Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
     20    MA 02110-1301, USA.  */
     21 
     22 #include "sysdep.h"
     23 #include "bfd.h"
     24 #include "libbfd.h"
     25 #include "libaout.h"           /* BFD a.out internal data structures */
     26 
     27 #include <sys/param.h>
     28 #ifdef HAVE_DIRENT_H
     29 # include <dirent.h>
     30 #else
     31 # ifdef HAVE_SYS_NDIR_H
     32 #  include <sys/ndir.h>
     33 # endif
     34 # ifdef HAVE_SYS_DIR_H
     35 #  include <sys/dir.h>
     36 # endif
     37 # ifdef HAVE_NDIR_H
     38 #  include <ndir.h>
     39 # endif
     40 #endif
     41 #include <signal.h>
     42 
     43 #include <sys/user.h>		/* After a.out.h  */
     44 
     45 #ifdef TRAD_HEADER
     46 #include TRAD_HEADER
     47 #endif
     48 
     49 #ifndef NBPG
     50 # define NBPG getpagesize()
     51 #endif
     52 
     53 struct trad_core_struct
     54 {
     55   asection *data_section;
     56   asection *stack_section;
     57   asection *reg_section;
     58   struct user u;
     59 };
     60 
     61 #define core_upage(bfd)  (&((bfd)->tdata.trad_core_data->u))
     62 #define core_datasec(bfd)  ((bfd)->tdata.trad_core_data->data_section)
     63 #define core_stacksec(bfd) ((bfd)->tdata.trad_core_data->stack_section)
     64 #define core_regsec(bfd)   ((bfd)->tdata.trad_core_data->reg_section)
     65 
     66 /* forward declarations */
     67 
     68 #define trad_unix_core_file_matches_executable_p generic_core_file_matches_executable_p
     69 #define trad_unix_core_file_pid _bfd_nocore_core_file_pid
     70 
     71 
     72 /* Handle 4.2-style (and perhaps also sysV-style) core dump file.  */
     73 
     74 static const bfd_target *
     75 trad_unix_core_file_p (bfd *abfd)
     76 {
     77   int val;
     78   struct user u;
     79   struct trad_core_struct *rawptr;
     80   bfd_size_type amt;
     81   flagword flags;
     82 
     83 #ifdef TRAD_CORE_USER_OFFSET
     84   /* If defined, this macro is the file position of the user struct.  */
     85   if (bfd_seek (abfd, (file_ptr) TRAD_CORE_USER_OFFSET, SEEK_SET) != 0)
     86     return 0;
     87 #endif
     88 
     89   val = bfd_bread ((void *) &u, (bfd_size_type) sizeof u, abfd);
     90   if (val != sizeof u)
     91     {
     92       /* Too small to be a core file */
     93       bfd_set_error (bfd_error_wrong_format);
     94       return 0;
     95     }
     96 
     97   /* Sanity check perhaps??? */
     98   if (u.u_dsize > 0x1000000)	/* Remember, it's in pages...  */
     99     {
    100       bfd_set_error (bfd_error_wrong_format);
    101       return 0;
    102     }
    103   if (u.u_ssize > 0x1000000)
    104     {
    105       bfd_set_error (bfd_error_wrong_format);
    106       return 0;
    107     }
    108 
    109   /* Check that the size claimed is no greater than the file size.  */
    110   {
    111     struct stat statbuf;
    112 
    113     if (bfd_stat (abfd, &statbuf) < 0)
    114       return 0;
    115 
    116     if ((ufile_ptr) NBPG * (UPAGES + u.u_dsize
    117 #ifdef TRAD_CORE_DSIZE_INCLUDES_TSIZE
    118 			    - u.u_tsize
    119 #endif
    120 			    + u.u_ssize)
    121 	> (ufile_ptr) statbuf.st_size)
    122       {
    123 	bfd_set_error (bfd_error_wrong_format);
    124 	return 0;
    125       }
    126 #ifndef TRAD_CORE_ALLOW_ANY_EXTRA_SIZE
    127     if (((ufile_ptr) NBPG * (UPAGES + u.u_dsize + u.u_ssize)
    128 #ifdef TRAD_CORE_EXTRA_SIZE_ALLOWED
    129 	/* Some systems write the file too big.  */
    130 	 + TRAD_CORE_EXTRA_SIZE_ALLOWED
    131 #endif
    132 	 )
    133 	< (ufile_ptr) statbuf.st_size)
    134       {
    135 	/* The file is too big.  Maybe it's not a core file
    136 	   or we otherwise have bad values for u_dsize and u_ssize).  */
    137 	bfd_set_error (bfd_error_wrong_format);
    138 	return 0;
    139       }
    140 #endif
    141   }
    142 
    143   /* OK, we believe you.  You're a core file (sure, sure).  */
    144 
    145   /* Allocate both the upage and the struct core_data at once, so
    146      a single free() will free them both.  */
    147   amt = sizeof (struct trad_core_struct);
    148   rawptr = (struct trad_core_struct *) bfd_zmalloc (amt);
    149   if (rawptr == NULL)
    150     return 0;
    151 
    152   abfd->tdata.trad_core_data = rawptr;
    153 
    154   rawptr->u = u; /*Copy the uarea into the tdata part of the bfd */
    155 
    156   /* Create the sections.  */
    157 
    158   flags = SEC_ALLOC + SEC_LOAD + SEC_HAS_CONTENTS;
    159   core_stacksec(abfd) = bfd_make_section_anyway_with_flags (abfd, ".stack",
    160 							    flags);
    161   if (core_stacksec (abfd) == NULL)
    162     goto fail;
    163   core_datasec (abfd) = bfd_make_section_anyway_with_flags (abfd, ".data",
    164 							    flags);
    165   if (core_datasec (abfd) == NULL)
    166     goto fail;
    167   core_regsec (abfd) = bfd_make_section_anyway_with_flags (abfd, ".reg",
    168 							   SEC_HAS_CONTENTS);
    169   if (core_regsec (abfd) == NULL)
    170     goto fail;
    171 
    172   core_datasec (abfd)->size =  NBPG * u.u_dsize
    173 #ifdef TRAD_CORE_DSIZE_INCLUDES_TSIZE
    174     - NBPG * u.u_tsize
    175 #endif
    176       ;
    177   core_stacksec (abfd)->size = NBPG * u.u_ssize;
    178   core_regsec (abfd)->size = NBPG * UPAGES; /* Larger than sizeof struct u */
    179 
    180   /* What a hack... we'd like to steal it from the exec file,
    181      since the upage does not seem to provide it.  FIXME.  */
    182 #ifdef HOST_DATA_START_ADDR
    183   core_datasec (abfd)->vma = HOST_DATA_START_ADDR;
    184 #else
    185   core_datasec (abfd)->vma = HOST_TEXT_START_ADDR + (NBPG * u.u_tsize);
    186 #endif
    187 
    188 #ifdef HOST_STACK_START_ADDR
    189   core_stacksec (abfd)->vma = HOST_STACK_START_ADDR;
    190 #else
    191   core_stacksec (abfd)->vma = HOST_STACK_END_ADDR - (NBPG * u.u_ssize);
    192 #endif
    193 
    194   /* This is tricky.  As the "register section", we give them the entire
    195      upage and stack.  u.u_ar0 points to where "register 0" is stored.
    196      There are two tricks with this, though.  One is that the rest of the
    197      registers might be at positive or negative (or both) displacements
    198      from *u_ar0.  The other is that u_ar0 is sometimes an absolute address
    199      in kernel memory, and on other systems it is an offset from the beginning
    200      of the `struct user'.
    201 
    202      As a practical matter, we don't know where the registers actually are,
    203      so we have to pass the whole area to GDB.  We encode the value of u_ar0
    204      by setting the .regs section up so that its virtual memory address
    205      0 is at the place pointed to by u_ar0 (by setting the vma of the start
    206      of the section to -u_ar0).  GDB uses this info to locate the regs,
    207      using minor trickery to get around the offset-or-absolute-addr problem.  */
    208   core_regsec (abfd)->vma = - (bfd_vma) (unsigned long) u.u_ar0;
    209 
    210   core_datasec (abfd)->filepos = NBPG * UPAGES;
    211   core_stacksec (abfd)->filepos = (NBPG * UPAGES) + NBPG * u.u_dsize
    212 #ifdef TRAD_CORE_DSIZE_INCLUDES_TSIZE
    213     - NBPG * u.u_tsize
    214 #endif
    215       ;
    216   core_regsec (abfd)->filepos = 0; /* Register segment is the upage */
    217 
    218   /* Align to word at least */
    219   core_stacksec (abfd)->alignment_power = 2;
    220   core_datasec (abfd)->alignment_power = 2;
    221   core_regsec (abfd)->alignment_power = 2;
    222 
    223   return abfd->xvec;
    224 
    225  fail:
    226   bfd_release (abfd, abfd->tdata.any);
    227   abfd->tdata.any = NULL;
    228   bfd_section_list_clear (abfd);
    229   return NULL;
    230 }
    231 
    232 static char *
    233 trad_unix_core_file_failing_command (bfd *abfd)
    234 {
    235 #ifndef NO_CORE_COMMAND
    236   char *com = abfd->tdata.trad_core_data->u.u_comm;
    237   if (*com)
    238     return com;
    239   else
    240 #endif
    241     return 0;
    242 }
    243 
    244 static int
    245 trad_unix_core_file_failing_signal (bfd *ignore_abfd ATTRIBUTE_UNUSED)
    246 {
    247 #ifdef TRAD_UNIX_CORE_FILE_FAILING_SIGNAL
    248   return TRAD_UNIX_CORE_FILE_FAILING_SIGNAL(ignore_abfd);
    249 #else
    250   return -1;		/* FIXME, where is it? */
    251 #endif
    252 }
    253 
    254 /* If somebody calls any byte-swapping routines, shoot them.  */
    256 static void
    257 swap_abort (void)
    258 {
    259   abort (); /* This way doesn't require any declaration for ANSI to fuck up */
    260 }
    261 
    262 #define	NO_GET ((bfd_vma (*) (const void *)) swap_abort)
    263 #define	NO_PUT ((void (*) (bfd_vma, void *)) swap_abort)
    264 #define	NO_GETS ((bfd_signed_vma (*) (const void *)) swap_abort)
    265 #define	NO_GET64 ((bfd_uint64_t (*) (const void *)) swap_abort)
    266 #define	NO_PUT64 ((void (*) (bfd_uint64_t, void *)) swap_abort)
    267 #define	NO_GETS64 ((bfd_int64_t (*) (const void *)) swap_abort)
    268 
    269 const bfd_target core_trad_vec =
    270   {
    271     "trad-core",
    272     bfd_target_unknown_flavour,
    273     BFD_ENDIAN_UNKNOWN,		/* target byte order */
    274     BFD_ENDIAN_UNKNOWN,		/* target headers byte order */
    275     (HAS_RELOC | EXEC_P |	/* object flags */
    276      HAS_LINENO | HAS_DEBUG |
    277      HAS_SYMS | HAS_LOCALS | WP_TEXT | D_PAGED),
    278     (SEC_HAS_CONTENTS | SEC_ALLOC | SEC_LOAD | SEC_RELOC), /* section flags */
    279     0,				/* symbol prefix */
    280     ' ',			/* ar_pad_char */
    281     16,				/* ar_max_namelen */
    282     0,				/* match priority.  */
    283     NO_GET64, NO_GETS64, NO_PUT64,	/* 64 bit data */
    284     NO_GET, NO_GETS, NO_PUT,		/* 32 bit data */
    285     NO_GET, NO_GETS, NO_PUT,		/* 16 bit data */
    286     NO_GET64, NO_GETS64, NO_PUT64,	/* 64 bit hdrs */
    287     NO_GET, NO_GETS, NO_PUT,		/* 32 bit hdrs */
    288     NO_GET, NO_GETS, NO_PUT,		/* 16 bit hdrs */
    289 
    290     {				/* bfd_check_format */
    291       _bfd_dummy_target,		/* unknown format */
    292       _bfd_dummy_target,		/* object file */
    293       _bfd_dummy_target,		/* archive */
    294       trad_unix_core_file_p		/* a core file */
    295     },
    296     {				/* bfd_set_format */
    297       bfd_false, bfd_false,
    298       bfd_false, bfd_false
    299     },
    300     {				/* bfd_write_contents */
    301       bfd_false, bfd_false,
    302       bfd_false, bfd_false
    303     },
    304 
    305     BFD_JUMP_TABLE_GENERIC (_bfd_generic),
    306     BFD_JUMP_TABLE_COPY (_bfd_generic),
    307     BFD_JUMP_TABLE_CORE (trad_unix),
    308     BFD_JUMP_TABLE_ARCHIVE (_bfd_noarchive),
    309     BFD_JUMP_TABLE_SYMBOLS (_bfd_nosymbols),
    310     BFD_JUMP_TABLE_RELOCS (_bfd_norelocs),
    311     BFD_JUMP_TABLE_WRITE (_bfd_generic),
    312     BFD_JUMP_TABLE_LINK (_bfd_nolink),
    313     BFD_JUMP_TABLE_DYNAMIC (_bfd_nodynamic),
    314 
    315     NULL,
    316 
    317     NULL			/* backend_data */
    318   };
    319