gdb/hppa-bsd-tdep.c

   1 /* Target-dependent code for HP PA-RISC BSD's.
   2
   3    Copyright (C) 2004-2023 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       for (struct obj_section *sec : faddr_sec->objfile->sections ())
  58         {
  59           if (strcmp (sec->the_bfd_section->name, ".dynamic") == 0)
  60             {
  61               CORE_ADDR addr = sec->addr ();
  62               CORE_ADDR endaddr = sec->endaddr ();
  63
  64               while (addr < endaddr)
  65                 {
  66                   gdb_byte buf[4];
  67                   LONGEST tag;
  68
  69                   if (target_read_memory (addr, buf, sizeof buf) != 0)
  70                     break;
  71
  72                   tag = extract_signed_integer (buf, byte_order);
  73                   if (tag == DT_PLTGOT)
  74                     {
  75                       CORE_ADDR pltgot;
  76
  77                       if (target_read_memory (addr + 4, buf, sizeof buf) != 0)
  78                         break;
  79
  80                       /* The NetBSD/OpenBSD ld.so doesn't relocate
  81                          DT_PLTGOT, so we have to do it ourselves.  */
  82                       pltgot = extract_unsigned_integer (buf, sizeof buf,
  83                                                          byte_order);
  84                       pltgot += sec->objfile->text_section_offset ();
  85
  86                       return pltgot;
  87                     }
  88
  89                   if (tag == DT_NULL)
  90                     break;
  91
  92                   addr += 8;
  93                 }
  94
  95               break;
  96             }
  97         }
  98     }
  99
 100   return 0;
 101 }
 102 \f
 103
 104 static void
 105 hppabsd_dwarf2_frame_init_reg (struct gdbarch *gdbarch, int regnum,
 106                                struct dwarf2_frame_state_reg *reg,
 107                                frame_info_ptr this_frame)
 108 {
 109   if (regnum == HPPA_PCOQ_HEAD_REGNUM)
 110     reg->how = DWARF2_FRAME_REG_RA;
 111   else if (regnum == HPPA_SP_REGNUM)
 112     reg->how = DWARF2_FRAME_REG_CFA;
 113 }
 114
 115 void
 116 hppabsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 117 {
 118   hppa_gdbarch_tdep *tdep = gdbarch_tdep<hppa_gdbarch_tdep> (gdbarch);
 119
 120   /* OpenBSD and NetBSD have a 64-bit 'long double'.  */
 121   set_gdbarch_long_double_bit (gdbarch, 64);
 122   set_gdbarch_long_double_format (gdbarch, floatformats_ieee_double);
 123
 124   /* OpenBSD and NetBSD use ELF.  */
 125   tdep->is_elf = 1;
 126   tdep->find_global_pointer = hppabsd_find_global_pointer;
 127   tdep->in_solib_call_trampoline = hppa_in_solib_call_trampoline;
 128   set_gdbarch_skip_trampoline_code (gdbarch, hppa_skip_trampoline_code);
 129
 130   /* OpenBSD and NetBSD use SVR4-style shared libraries.  */
 131   set_solib_svr4_fetch_link_map_offsets
 132     (gdbarch, svr4_ilp32_fetch_link_map_offsets);
 133
 134   /* Hook in the DWARF CFI frame unwinder.  */
 135   dwarf2_frame_set_init_reg (gdbarch, hppabsd_dwarf2_frame_init_reg);
 136   dwarf2_append_unwinders (gdbarch);
 137 }