bfd/ptrace-core.c

   1 /* BFD backend for core files which use the ptrace_user structure
   2    Copyright (C) 1993-2017 Free Software Foundation, Inc.
   3    The structure of this file is based on trad-core.c written by John Gilmore
   4    of Cygnus Support.
   5    Modified to work with the ptrace_user structure by Kevin A. Buettner.
   6    (Longterm it may be better to merge this file with trad-core.c)
   7
   8    This file is part of BFD, the Binary File Descriptor library.
   9
  10    This program is free software; you can redistribute it and/or modify
  11    it under the terms of the GNU General Public License as published by
  12    the Free Software Foundation; either version 3 of the License, or
  13    (at your option) any later version.
  14
  15    This program is distributed in the hope that it will be useful,
  16    but WITHOUT ANY WARRANTY; without even the implied warranty of
  17    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18    GNU General Public License for more details.
  19
  20    You should have received a copy of the GNU General Public License
  21    along with this program; if not, write to the Free Software
  22    Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
  23    MA 02110-1301, USA.  */
  24
  25 #ifdef PTRACE_CORE
  26
  27 #include "sysdep.h"
  28 #include "bfd.h"
  29 #include "libbfd.h"
  30
  31 #include <sys/param.h>
  32 #include <sys/dir.h>
  33 #include <signal.h>
  34 #include <sys/ptrace.h>
  35
  36 struct trad_core_struct
  37 {
  38   asection *data_section;
  39   asection *stack_section;
  40   asection *reg_section;
  41   struct ptrace_user u;
  42 };
  43
  44 #define core_upage(bfd)  (&((bfd)->tdata.trad_core_data->u))
  45 #define core_datasec(bfd)  ((bfd)->tdata.trad_core_data->data_section)
  46 #define core_stacksec(bfd) ((bfd)->tdata.trad_core_data->stack_section)
  47 #define core_regsec(bfd)   ((bfd)->tdata.trad_core_data->reg_section)
  48
  49 /* forward declarations */
  50
  51 const bfd_target *ptrace_unix_core_file_p (bfd *abfd);
  52 char * ptrace_unix_core_file_failing_command (bfd *abfd);
  53 int ptrace_unix_core_file_failing_signal (bfd *abfd);
  54 #define ptrace_unix_core_file_matches_executable_p generic_core_file_matches_executable_p
  55 #define ptrace_unix_core_file_pid _bfd_nocore_core_file_pid
  56 static void swap_abort (void);
  57
  58 const bfd_target *
  59 ptrace_unix_core_file_p (bfd *abfd)
  60 {
  61   int val;
  62   struct ptrace_user u;
  63   struct trad_core_struct *rawptr;
  64   bfd_size_type amt;
  65   flagword flags;
  66
  67   val = bfd_bread ((void *)&u, (bfd_size_type) sizeof u, abfd);
  68   if (val != sizeof u || u.pt_magic != _BCS_PTRACE_MAGIC
  69       || u.pt_rev != _BCS_PTRACE_REV)
  70     {
  71       /* Too small to be a core file */
  72       bfd_set_error (bfd_error_wrong_format);
  73       return 0;
  74     }
  75
  76   /* OK, we believe you.  You're a core file (sure, sure).  */
  77
  78   /* Allocate both the upage and the struct core_data at once, so
  79      a single free() will free them both.  */
  80   amt = sizeof (struct trad_core_struct);
  81   rawptr = (struct trad_core_struct *) bfd_zalloc (abfd, amt);
  82
  83   if (rawptr == NULL)
  84     return 0;
  85
  86   abfd->tdata.trad_core_data = rawptr;
  87
  88   rawptr->u = u; /*Copy the uarea into the tdata part of the bfd */
  89
  90   /* Create the sections.  */
  91
  92   flags = SEC_ALLOC + SEC_LOAD + SEC_HAS_CONTENTS;
  93   core_stacksec (abfd) = bfd_make_section_anyway_with_flags (abfd, ".stack",
  94                                                              flags);
  95   if (core_stacksec (abfd) == NULL)
  96     goto fail;
  97   core_datasec (abfd) = bfd_make_section_anyway_with_flags (abfd, ".data",
  98                                                             flags);
  99   if (core_datasec (abfd) == NULL)
 100     goto fail;
 101   core_regsec (abfd) = bfd_make_section_anyway_with_flags (abfd, ".reg",
 102                                                            SEC_HAS_CONTENTS);
 103   if (core_regsec (abfd) == NULL)
 104     goto fail;
 105
 106   /* FIXME:  Need to worry about shared memory, library data, and library
 107      text.  I don't think that any of these things are supported on the
 108      system on which I am developing this for though.  */
 109
 110   core_datasec (abfd)->size =  u.pt_dsize;
 111   core_stacksec (abfd)->size = u.pt_ssize;
 112   core_regsec (abfd)->size = sizeof (u);
 113
 114   core_datasec (abfd)->vma = u.pt_o_data_start;
 115   core_stacksec (abfd)->vma = USRSTACK - u.pt_ssize;
 116   core_regsec (abfd)->vma = 0 - sizeof (u);     /* see trad-core.c */
 117
 118   core_datasec (abfd)->filepos = (int) u.pt_dataptr;
 119   core_stacksec (abfd)->filepos = (int) (u.pt_dataptr + u.pt_dsize);
 120   core_regsec (abfd)->filepos = 0; /* Register segment is ptrace_user */
 121
 122   /* Align to word at least */
 123   core_stacksec (abfd)->alignment_power = 2;
 124   core_datasec (abfd)->alignment_power = 2;
 125   core_regsec (abfd)->alignment_power = 2;
 126
 127   return abfd->xvec;
 128
 129  fail:
 130   bfd_release (abfd, abfd->tdata.any);
 131   abfd->tdata.any = NULL;
 132   bfd_section_list_clear (abfd);
 133   return NULL;
 134 }
 135
 136 char *
 137 ptrace_unix_core_file_failing_command (bfd *abfd)
 138 {
 139   char *com = abfd->tdata.trad_core_data->u.pt_comm;
 140
 141   if (*com)
 142     return com;
 143   else
 144     return 0;
 145 }
 146
 147 int
 148 ptrace_unix_core_file_failing_signal (bfd *abfd)
 149 {
 150   return abfd->tdata.trad_core_data->u.pt_sigframe.sig_num;
 151 }
 152 \f
 153 /* If somebody calls any byte-swapping routines, shoot them.  */
 154 static void
 155 swap_abort (void)
 156 {
 157   abort (); /* This way doesn't require any declaration for ANSI to fuck up */
 158 }
 159
 160 #define NO_GET ((bfd_vma (*) (const void *)) swap_abort)
 161 #define NO_PUT ((void (*) (bfd_vma, void *)) swap_abort)
 162 #define NO_GETS ((bfd_signed_vma (*) (const void *)) swap_abort)
 163 #define NO_GET64 ((bfd_uint64_t (*) (const void *)) swap_abort)
 164 #define NO_PUT64 ((void (*) (bfd_uint64_t, void *)) swap_abort)
 165 #define NO_GETS64 ((bfd_int64_t (*) (const void *)) swap_abort)
 166
 167 const bfd_target core_ptrace_vec =
 168   {
 169     "trad-core",
 170     bfd_target_unknown_flavour,
 171     BFD_ENDIAN_UNKNOWN,         /* target byte order */
 172     BFD_ENDIAN_UNKNOWN,         /* target headers byte order */
 173     (HAS_RELOC | EXEC_P |       /* object flags */
 174      HAS_LINENO | HAS_DEBUG |
 175      HAS_SYMS | HAS_LOCALS | WP_TEXT | D_PAGED),
 176     (SEC_HAS_CONTENTS | SEC_ALLOC | SEC_LOAD | SEC_RELOC), /* section flags */
 177     0,                                                     /* symbol prefix */
 178     ' ',                                                   /* ar_pad_char */
 179     16,                                                    /* ar_max_namelen */
 180     NO_GET64, NO_GETS64, NO_PUT64,      /* 64 bit data */
 181     NO_GET, NO_GETS, NO_PUT,            /* 32 bit data */
 182     NO_GET, NO_GETS, NO_PUT,            /* 16 bit data */
 183     NO_GET64, NO_GETS64, NO_PUT64,      /* 64 bit hdrs */
 184     NO_GET, NO_GETS, NO_PUT,            /* 32 bit hdrs */
 185     NO_GET, NO_GETS, NO_PUT,            /* 16 bit hdrs */
 186
 187     {                           /* bfd_check_format */
 188       _bfd_dummy_target,                /* unknown format */
 189       _bfd_dummy_target,                /* object file */
 190       _bfd_dummy_target,                /* archive */
 191       ptrace_unix_core_file_p           /* a core file */
 192     },
 193     {                           /* bfd_set_format */
 194       bfd_false, bfd_false,
 195       bfd_false, bfd_false
 196     },
 197     {                           /* bfd_write_contents */
 198       bfd_false, bfd_false,
 199       bfd_false, bfd_false
 200     },
 201
 202     BFD_JUMP_TABLE_GENERIC (_bfd_generic),
 203     BFD_JUMP_TABLE_COPY (_bfd_generic),
 204     BFD_JUMP_TABLE_CORE (ptrace_unix),
 205     BFD_JUMP_TABLE_ARCHIVE (_bfd_noarchive),
 206     BFD_JUMP_TABLE_SYMBOLS (_bfd_nosymbols),
 207     BFD_JUMP_TABLE_RELOCS (_bfd_norelocs),
 208     BFD_JUMP_TABLE_WRITE (_bfd_generic),
 209     BFD_JUMP_TABLE_LINK (_bfd_nolink),
 210     BFD_JUMP_TABLE_DYNAMIC (_bfd_nodynamic),
 211
 212     NULL,
 213
 214     NULL                        /* backend_data */
 215   };
 216
 217 #endif /* PTRACE_CORE */