bfd/ptrace-core.c

   1 /* BFD backend for core files which use the ptrace_user structure
   2    Copyright (C) 1993-2025 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 bfd_cleanup 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 bfd_cleanup
  59 ptrace_unix_core_file_p (bfd *abfd)
  60 {
  61   int val;
  62   struct ptrace_user u;
  63   struct trad_core_struct *rawptr;
  64   flagword flags;
  65
  66   val = bfd_read (&u, sizeof u, abfd);
  67   if (val != sizeof u || u.pt_magic != _BCS_PTRACE_MAGIC
  68       || u.pt_rev != _BCS_PTRACE_REV)
  69     {
  70       /* Too small to be a core file */
  71       bfd_set_error (bfd_error_wrong_format);
  72       return 0;
  73     }
  74
  75   /* OK, we believe you.  You're a core file (sure, sure).  */
  76
  77   /* Allocate both the upage and the struct core_data at once, so
  78      a single free() will free them both.  */
  79   rawptr = bfd_alloc (abfd, sizeof (*rawptr) + 1);
  80
  81   if (rawptr == NULL)
  82     return 0;
  83
  84   abfd->tdata.trad_core_data = rawptr;
  85
  86   rawptr->u = u; /*Copy the uarea into the tdata part of the bfd */
  87
  88   /* Ensure core_file_failing_command string is terminated.  This is
  89      just to stop buffer overflows on fuzzed files.  */
  90   ((char *) rawptr)[sizeof (*rawptr)] = 0;
  91
  92   /* Create the sections.  */
  93
  94   flags = SEC_ALLOC + SEC_LOAD + SEC_HAS_CONTENTS;
  95   core_stacksec (abfd) = bfd_make_section_anyway_with_flags (abfd, ".stack",
  96                                                              flags);
  97   if (core_stacksec (abfd) == NULL)
  98     goto fail;
  99   core_datasec (abfd) = bfd_make_section_anyway_with_flags (abfd, ".data",
 100                                                             flags);
 101   if (core_datasec (abfd) == NULL)
 102     goto fail;
 103   core_regsec (abfd) = bfd_make_section_anyway_with_flags (abfd, ".reg",
 104                                                            SEC_HAS_CONTENTS);
 105   if (core_regsec (abfd) == NULL)
 106     goto fail;
 107
 108   /* FIXME:  Need to worry about shared memory, library data, and library
 109      text.  I don't think that any of these things are supported on the
 110      system on which I am developing this for though.  */
 111
 112   core_datasec (abfd)->size =  u.pt_dsize;
 113   core_stacksec (abfd)->size = u.pt_ssize;
 114   core_regsec (abfd)->size = sizeof (u);
 115
 116   core_datasec (abfd)->vma = u.pt_o_data_start;
 117   core_stacksec (abfd)->vma = USRSTACK - u.pt_ssize;
 118   core_regsec (abfd)->vma = 0 - sizeof (u);     /* see trad-core.c */
 119
 120   core_datasec (abfd)->filepos = (int) u.pt_dataptr;
 121   core_stacksec (abfd)->filepos = (int) (u.pt_dataptr + u.pt_dsize);
 122   core_regsec (abfd)->filepos = 0; /* Register segment is ptrace_user */
 123
 124   /* Align to word at least */
 125   core_stacksec (abfd)->alignment_power = 2;
 126   core_datasec (abfd)->alignment_power = 2;
 127   core_regsec (abfd)->alignment_power = 2;
 128
 129   return _bfd_no_cleanup;
 130
 131  fail:
 132   bfd_release (abfd, abfd->tdata.any);
 133   abfd->tdata.any = NULL;
 134   bfd_section_list_clear (abfd);
 135   return NULL;
 136 }
 137
 138 char *
 139 ptrace_unix_core_file_failing_command (bfd *abfd)
 140 {
 141   char *com = abfd->tdata.trad_core_data->u.pt_comm;
 142
 143   if (*com)
 144     return com;
 145   else
 146     return 0;
 147 }
 148
 149 int
 150 ptrace_unix_core_file_failing_signal (bfd *abfd)
 151 {
 152   return abfd->tdata.trad_core_data->u.pt_sigframe.sig_num;
 153 }
 154 \f
 155 /* If somebody calls any byte-swapping routines, shoot them.  */
 156 static void
 157 swap_abort (void)
 158 {
 159   abort (); /* This way doesn't require any declaration for ANSI to fuck up */
 160 }
 161
 162 #define NO_GET ((bfd_vma (*) (const void *)) swap_abort)
 163 #define NO_PUT ((void (*) (bfd_vma, void *)) swap_abort)
 164 #define NO_GETS ((bfd_signed_vma (*) (const void *)) swap_abort)
 165 #define NO_GET64 ((uint64_t (*) (const void *)) swap_abort)
 166 #define NO_PUT64 ((void (*) (uint64_t, void *)) swap_abort)
 167 #define NO_GETS64 ((int64_t (*) (const void *)) swap_abort)
 168
 169 const bfd_target core_ptrace_vec =
 170   {
 171     "trad-core",
 172     bfd_target_unknown_flavour,
 173     BFD_ENDIAN_UNKNOWN,         /* target byte order */
 174     BFD_ENDIAN_UNKNOWN,         /* target headers byte order */
 175     (HAS_RELOC | EXEC_P |       /* object flags */
 176      HAS_LINENO | HAS_DEBUG |
 177      HAS_SYMS | HAS_LOCALS | WP_TEXT | D_PAGED),
 178     (SEC_HAS_CONTENTS | SEC_ALLOC | SEC_LOAD | SEC_RELOC), /* section flags */
 179     0,                                                     /* symbol prefix */
 180     ' ',                                                   /* ar_pad_char */
 181     16,                                                    /* ar_max_namelen */
 182     TARGET_KEEP_UNUSED_SECTION_SYMBOLS, /* keep unused section symbols.  */
 183     NO_GET64, NO_GETS64, NO_PUT64,      /* 64 bit data */
 184     NO_GET, NO_GETS, NO_PUT,            /* 32 bit data */
 185     NO_GET, NO_GETS, NO_PUT,            /* 16 bit data */
 186     NO_GET64, NO_GETS64, NO_PUT64,      /* 64 bit hdrs */
 187     NO_GET, NO_GETS, NO_PUT,            /* 32 bit hdrs */
 188     NO_GET, NO_GETS, NO_PUT,            /* 16 bit hdrs */
 189
 190     {                           /* bfd_check_format */
 191       _bfd_dummy_target,                /* unknown format */
 192       _bfd_dummy_target,                /* object file */
 193       _bfd_dummy_target,                /* archive */
 194       ptrace_unix_core_file_p           /* a core file */
 195     },
 196     {                           /* bfd_set_format */
 197       _bfd_bool_bfd_false_error,
 198       _bfd_bool_bfd_false_error,
 199       _bfd_bool_bfd_false_error,
 200       _bfd_bool_bfd_false_error,
 201     },
 202     {                           /* bfd_write_contents */
 203       _bfd_bool_bfd_false_error,
 204       _bfd_bool_bfd_false_error,
 205       _bfd_bool_bfd_false_error,
 206       _bfd_bool_bfd_false_error,
 207     },
 208
 209     BFD_JUMP_TABLE_GENERIC (_bfd_generic),
 210     BFD_JUMP_TABLE_COPY (_bfd_generic),
 211     BFD_JUMP_TABLE_CORE (ptrace_unix),
 212     BFD_JUMP_TABLE_ARCHIVE (_bfd_noarchive),
 213     BFD_JUMP_TABLE_SYMBOLS (_bfd_nosymbols),
 214     BFD_JUMP_TABLE_RELOCS (_bfd_norelocs),
 215     BFD_JUMP_TABLE_WRITE (_bfd_generic),
 216     BFD_JUMP_TABLE_LINK (_bfd_nolink),
 217     BFD_JUMP_TABLE_DYNAMIC (_bfd_nodynamic),
 218
 219     NULL,
 220
 221     NULL                        /* backend_data */
 222   };
 223
 224 #endif /* PTRACE_CORE */