gdb/elf-none-tdep.c

   1 /* Common code for targets with the none ABI (bare-metal), but where the
   2    BFD library is build with ELF support.
   3
   4    Copyright (C) 2020-2023 Free Software Foundation, Inc.
   5
   6    This file is part of GDB.
   7
   8    This program is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 3 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  20
  21 #include "defs.h"
  22 #include "elf-none-tdep.h"
  23 #include "regset.h"
  24 #include "elf-bfd.h"
  25 #include "inferior.h"
  26 #include "regcache.h"
  27 #include "gdbarch.h"
  28 #include "gcore.h"
  29 #include "gcore-elf.h"
  30
  31 /* Build the note section for a corefile, and return it in a malloc
  32    buffer.  Currently this just dumps all available registers for each
  33    thread.  */
  34
  35 static gdb::unique_xmalloc_ptr<char>
  36 elf_none_make_corefile_notes (struct gdbarch *gdbarch, bfd *obfd,
  37                               int *note_size)
  38 {
  39   gdb::unique_xmalloc_ptr<char> note_data;
  40
  41   /* Add note information about the executable and its arguments.  */
  42   std::string fname;
  43   std::string psargs;
  44   static const size_t fname_len = 16;
  45   static const size_t psargs_len = 80;
  46   if (get_exec_file (0))
  47     {
  48       const char *exe = get_exec_file (0);
  49       fname = lbasename (exe);
  50       psargs = std::string (exe);
  51
  52       const std::string &infargs = current_inferior ()->args ();
  53       if (!infargs.empty ())
  54         psargs += ' ' + infargs;
  55
  56       /* All existing targets that handle writing out prpsinfo expect the
  57          fname and psargs strings to be at least 16 and 80 characters long
  58          respectively, including a null terminator at the end.  Resize to
  59          the expected length minus one to ensure there is a null within the
  60          required length.  */
  61       fname.resize (fname_len - 1);
  62       psargs.resize (psargs_len - 1);
  63     }
  64
  65   /* Resize the buffers up to their required lengths.  This will fill any
  66      remaining space with the null character.  */
  67   fname.resize (fname_len);
  68   psargs.resize (psargs_len);
  69
  70   /* Now write out the prpsinfo structure.  */
  71   note_data.reset (elfcore_write_prpsinfo (obfd, note_data.release (),
  72                                            note_size, fname.c_str (),
  73                                            psargs.c_str ()));
  74   if (note_data == nullptr)
  75     return nullptr;
  76
  77   /* Thread register information.  */
  78   try
  79     {
  80       update_thread_list ();
  81     }
  82   catch (const gdb_exception_error &e)
  83     {
  84       exception_print (gdb_stderr, e);
  85     }
  86
  87   /* Like the Linux kernel, prefer dumping the signalled thread first.
  88      "First thread" is what tools use to infer the signalled thread.  */
  89   thread_info *signalled_thr = gcore_find_signalled_thread ();
  90
  91   /* All threads are reported as having been stopped by the same signal
  92      that stopped SIGNALLED_THR.  */
  93   gdb_signal stop_signal;
  94   if (signalled_thr != nullptr)
  95     stop_signal = signalled_thr->stop_signal ();
  96   else
  97     stop_signal = GDB_SIGNAL_0;
  98
  99   if (signalled_thr != nullptr)
 100     gcore_elf_build_thread_register_notes (gdbarch, signalled_thr,
 101                                            stop_signal, obfd, &note_data,
 102                                            note_size);
 103   for (thread_info *thr : current_inferior ()->non_exited_threads ())
 104     {
 105       if (thr == signalled_thr)
 106         continue;
 107
 108       gcore_elf_build_thread_register_notes (gdbarch, thr, stop_signal, obfd,
 109                                              &note_data, note_size);
 110     }
 111
 112
 113   /* Include the target description when possible.  Some architectures
 114      allow for per-thread gdbarch so we should really be emitting a tdesc
 115      per-thread, however, we don't currently support reading in a
 116      per-thread tdesc, so just emit the tdesc for the signalled thread.  */
 117   gdbarch = target_thread_architecture (signalled_thr->ptid);
 118   gcore_elf_make_tdesc_note (gdbarch, obfd, &note_data, note_size);
 119
 120   return note_data;
 121 }
 122
 123 /* See none-tdep.h.  */
 124
 125 void
 126 elf_none_init_abi (struct gdbarch *gdbarch)
 127 {
 128   /* Default core file support.  */
 129   set_gdbarch_make_corefile_notes (gdbarch, elf_none_make_corefile_notes);
 130 }