gdb/hppa-bsd-tdep.c

   1 /* Target-dependent code for HP PA-RISC BSD's.
   2
   3    Copyright (C) 2004-2020 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 "objfiles.h"
  22 #include "target.h"
  23 #include "value.h"
  24
  25 #include "elf/common.h"
  26
  27 #include "hppa-tdep.h"
  28 #include "hppa-bsd-tdep.h"
  29 #include "dwarf2-frame.h"
  30 #include "solib-svr4.h"
  31
  32 static CORE_ADDR
  33 hppabsd_find_global_pointer (struct gdbarch *gdbarch, struct value *function)
  34 {
  35   enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
  36   CORE_ADDR faddr = value_as_address (function);
  37   struct obj_section *faddr_sec;
  38
  39   /* Is this a plabel? If so, dereference it to get the Global Pointer
  40      value.  */
  41   if (faddr & 2)
  42     {
  43       gdb_byte buf[4];
  44       if (target_read_memory ((faddr & ~3) + 4, buf, sizeof buf) == 0)
  45         return extract_unsigned_integer (buf, sizeof buf, byte_order);
  46     }
  47
  48   /* If the address is in the .plt section, then the real function
  49      hasn't yet been fixed up by the linker so we cannot determine the
  50      Global Pointer for that function.  */
  51   if (in_plt_section (faddr))
  52     return 0;
  53
  54   faddr_sec = find_pc_section (faddr);
  55   if (faddr_sec != NULL)
  56     {
  57       struct obj_section *sec;
  58
  59       ALL_OBJFILE_OSECTIONS (faddr_sec->objfile, sec)
  60         {
  61           if (strcmp (sec->the_bfd_section->name, ".dynamic") == 0)
  62             break;
  63         }
  64
  65       if (sec < faddr_sec->objfile->sections_end)
  66         {
  67           CORE_ADDR addr = obj_section_addr (sec);
  68           CORE_ADDR endaddr = obj_section_endaddr (sec);
  69
  70           while (addr < endaddr)
  71             {
  72               gdb_byte buf[4];
  73               LONGEST tag;
  74
  75               if (target_read_memory (addr, buf, sizeof buf) != 0)
  76                 break;
  77
  78               tag = extract_signed_integer (buf, sizeof buf, byte_order);
  79               if (tag == DT_PLTGOT)
  80                 {
  81                   CORE_ADDR pltgot;
  82
  83                   if (target_read_memory (addr + 4, buf, sizeof buf) != 0)
  84                     break;
  85
  86                   /* The NetBSD/OpenBSD ld.so doesn't relocate DT_PLTGOT, so
  87                      we have to do it ourselves.  */
  88                   pltgot = extract_unsigned_integer (buf, sizeof buf,
  89                                                      byte_order);
  90                   pltgot += sec->objfile->section_offsets[SECT_OFF_TEXT (sec->objfile)];
  91
  92                   return pltgot;
  93                 }
  94
  95               if (tag == DT_NULL)
  96                 break;
  97
  98               addr += 8;
  99             }
 100         }
 101     }
 102
 103   return 0;
 104 }
 105 \f
 106
 107 static void
 108 hppabsd_dwarf2_frame_init_reg (struct gdbarch *gdbarch, int regnum,
 109                                struct dwarf2_frame_state_reg *reg,
 110                                struct frame_info *this_frame)
 111 {
 112   if (regnum == HPPA_PCOQ_HEAD_REGNUM)
 113     reg->how = DWARF2_FRAME_REG_RA;
 114   else if (regnum == HPPA_SP_REGNUM)
 115     reg->how = DWARF2_FRAME_REG_CFA;
 116 }
 117
 118 void
 119 hppabsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 120 {
 121   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 122
 123   /* OpenBSD and NetBSD have a 64-bit 'long double'.  */
 124   set_gdbarch_long_double_bit (gdbarch, 64);
 125   set_gdbarch_long_double_format (gdbarch, floatformats_ieee_double);
 126
 127   /* OpenBSD and NetBSD use ELF.  */
 128   tdep->is_elf = 1;
 129   tdep->find_global_pointer = hppabsd_find_global_pointer;
 130   tdep->in_solib_call_trampoline = hppa_in_solib_call_trampoline;
 131   set_gdbarch_skip_trampoline_code (gdbarch, hppa_skip_trampoline_code);
 132
 133   /* OpenBSD and NetBSD use SVR4-style shared libraries.  */
 134   set_solib_svr4_fetch_link_map_offsets
 135     (gdbarch, svr4_ilp32_fetch_link_map_offsets);
 136
 137   /* Hook in the DWARF CFI frame unwinder.  */
 138   dwarf2_frame_set_init_reg (gdbarch, hppabsd_dwarf2_frame_init_reg);
 139   dwarf2_append_unwinders (gdbarch);
 140 }