gdb/linux-tdep.c

   1 /* Target-dependent code for GNU/Linux, architecture independent.
   2
   3    Copyright (C) 2009 Free Software Foundation, Inc.
   4
   5    This file is part of GDB.
   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, see <http://www.gnu.org/licenses/>.  */
  19
  20 #include "defs.h"
  21 #include "gdbcore.h"
  22 #include "gdbtypes.h"
  23 #include "linux-tdep.h"
  24 #include "observer.h"
  25
  26 #include "elf-bfd.h"
  27
  28 /* This function is suitable for architectures that don't
  29    extend/override the standard siginfo structure.  */
  30
  31 struct type *
  32 linux_get_siginfo_type (struct gdbarch *gdbarch)
  33 {
  34   struct type *int_type, *uint_type, *long_type, *void_ptr_type;
  35   struct type *uid_type, *pid_type;
  36   struct type *sigval_type, *clock_type;
  37   struct type *siginfo_type, *sifields_type;
  38   struct type *type;
  39
  40   int_type = arch_integer_type (gdbarch, gdbarch_int_bit (gdbarch),
  41                                 0, "int");
  42   uint_type = arch_integer_type (gdbarch, gdbarch_int_bit (gdbarch),
  43                                  1, "unsigned int");
  44   long_type = arch_integer_type (gdbarch, gdbarch_long_bit (gdbarch),
  45                                  0, "long");
  46   void_ptr_type = lookup_pointer_type (builtin_type (gdbarch)->builtin_void);
  47
  48   /* sival_t */
  49   sigval_type = arch_composite_type (gdbarch, NULL, TYPE_CODE_UNION);
  50   TYPE_NAME (sigval_type) = xstrdup ("sigval_t");
  51   append_composite_type_field (sigval_type, "sival_int", int_type);
  52   append_composite_type_field (sigval_type, "sival_ptr", void_ptr_type);
  53
  54   /* __pid_t */
  55   pid_type = arch_type (gdbarch, TYPE_CODE_TYPEDEF, TYPE_LENGTH (int_type),
  56                         xstrdup ("__pid_t"));
  57   TYPE_TARGET_TYPE (pid_type) = int_type;
  58   TYPE_TARGET_STUB (pid_type) = 1;
  59
  60   /* __uid_t */
  61   uid_type = arch_type (gdbarch, TYPE_CODE_TYPEDEF, TYPE_LENGTH (uint_type),
  62                         xstrdup ("__uid_t"));
  63   TYPE_TARGET_TYPE (uid_type) = uint_type;
  64   TYPE_TARGET_STUB (uid_type) = 1;
  65
  66   /* __clock_t */
  67   clock_type = arch_type (gdbarch, TYPE_CODE_TYPEDEF, TYPE_LENGTH (long_type),
  68                           xstrdup ("__clock_t"));
  69   TYPE_TARGET_TYPE (clock_type) = long_type;
  70   TYPE_TARGET_STUB (clock_type) = 1;
  71
  72   /* _sifields */
  73   sifields_type = arch_composite_type (gdbarch, NULL, TYPE_CODE_UNION);
  74
  75   {
  76     const int si_max_size = 128;
  77     int si_pad_size;
  78     int size_of_int = gdbarch_int_bit (gdbarch) / HOST_CHAR_BIT;
  79
  80     /* _pad */
  81     if (gdbarch_ptr_bit (gdbarch) == 64)
  82       si_pad_size = (si_max_size / size_of_int) - 4;
  83     else
  84       si_pad_size = (si_max_size / size_of_int) - 3;
  85     append_composite_type_field (sifields_type, "_pad",
  86                                  init_vector_type (int_type, si_pad_size));
  87   }
  88
  89   /* _kill */
  90   type = arch_composite_type (gdbarch, NULL, TYPE_CODE_STRUCT);
  91   append_composite_type_field (type, "si_pid", pid_type);
  92   append_composite_type_field (type, "si_uid", uid_type);
  93   append_composite_type_field (sifields_type, "_kill", type);
  94
  95   /* _timer */
  96   type = arch_composite_type (gdbarch, NULL, TYPE_CODE_STRUCT);
  97   append_composite_type_field (type, "si_tid", int_type);
  98   append_composite_type_field (type, "si_overrun", int_type);
  99   append_composite_type_field (type, "si_sigval", sigval_type);
 100   append_composite_type_field (sifields_type, "_timer", type);
 101
 102   /* _rt */
 103   type = arch_composite_type (gdbarch, NULL, TYPE_CODE_STRUCT);
 104   append_composite_type_field (type, "si_pid", pid_type);
 105   append_composite_type_field (type, "si_uid", uid_type);
 106   append_composite_type_field (type, "si_sigval", sigval_type);
 107   append_composite_type_field (sifields_type, "_rt", type);
 108
 109   /* _sigchld */
 110   type = arch_composite_type (gdbarch, NULL, TYPE_CODE_STRUCT);
 111   append_composite_type_field (type, "si_pid", pid_type);
 112   append_composite_type_field (type, "si_uid", uid_type);
 113   append_composite_type_field (type, "si_status", int_type);
 114   append_composite_type_field (type, "si_utime", clock_type);
 115   append_composite_type_field (type, "si_stime", clock_type);
 116   append_composite_type_field (sifields_type, "_sigchld", type);
 117
 118   /* _sigfault */
 119   type = arch_composite_type (gdbarch, NULL, TYPE_CODE_STRUCT);
 120   append_composite_type_field (type, "si_addr", void_ptr_type);
 121   append_composite_type_field (sifields_type, "_sigfault", type);
 122
 123   /* _sigpoll */
 124   type = arch_composite_type (gdbarch, NULL, TYPE_CODE_STRUCT);
 125   append_composite_type_field (type, "si_band", long_type);
 126   append_composite_type_field (type, "si_fd", int_type);
 127   append_composite_type_field (sifields_type, "_sigpoll", type);
 128
 129   /* struct siginfo */
 130   siginfo_type = arch_composite_type (gdbarch, NULL, TYPE_CODE_STRUCT);
 131   TYPE_NAME (siginfo_type) = xstrdup ("siginfo");
 132   append_composite_type_field (siginfo_type, "si_signo", int_type);
 133   append_composite_type_field (siginfo_type, "si_errno", int_type);
 134   append_composite_type_field (siginfo_type, "si_code", int_type);
 135   append_composite_type_field_aligned (siginfo_type,
 136                                        "_sifields", sifields_type,
 137                                        TYPE_LENGTH (long_type));
 138
 139   return siginfo_type;
 140 }
 141
 142 /* Observer for the executable_changed event, to check whether the new
 143    exec binary is a PIE (Position Independent Executable) specimen, which
 144    is currently unsupported.  */
 145
 146 static void
 147 check_is_pie_binary (void)
 148 {
 149   Elf_Internal_Ehdr *elf_hdr;
 150
 151   if (!exec_bfd)
 152     return;
 153   else if (bfd_get_flavour (exec_bfd) != bfd_target_elf_flavour)
 154     return;
 155
 156   if (elf_tdata (exec_bfd)->elf_header->e_type == ET_DYN)
 157     warning (_("\
 158 The current binary is a PIE (Position Independent Executable), which\n\
 159 GDB does NOT currently support.  Most debugger features will fail if used\n\
 160 in this session.\n"));
 161 }
 162
 163 void
 164 _initialize_linux_tdep (void)
 165 {
 166   observer_attach_executable_changed (check_is_pie_binary);
 167 }