gdb/amd64fbsd-tdep.c

   1 /* Target-dependent code for FreeBSD/amd64.
   2
   3    Copyright (C) 2003-2015 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 "arch-utils.h"
  22 #include "frame.h"
  23 #include "gdbcore.h"
  24 #include "regcache.h"
  25 #include "osabi.h"
  26
  27 #include "amd64-tdep.h"
  28 #include "bsd-uthread.h"
  29 #include "fbsd-tdep.h"
  30 #include "solib-svr4.h"
  31
  32 /* Support for signal handlers.  */
  33
  34 /* Assuming THIS_FRAME is for a BSD sigtramp routine, return the
  35    address of the associated sigcontext structure.  */
  36
  37 static CORE_ADDR
  38 amd64fbsd_sigcontext_addr (struct frame_info *this_frame)
  39 {
  40   struct gdbarch *gdbarch = get_frame_arch (this_frame);
  41   enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
  42   CORE_ADDR sp;
  43   gdb_byte buf[8];
  44
  45   /* The `struct sigcontext' (which really is an `ucontext_t' on
  46      FreeBSD/amd64) lives at a fixed offset in the signal frame.  See
  47      <machine/sigframe.h>.  */
  48   get_frame_register (this_frame, AMD64_RSP_REGNUM, buf);
  49   sp = extract_unsigned_integer (buf, 8, byte_order);
  50   return sp + 16;
  51 }
  52 \f
  53 /* FreeBSD 5.1-RELEASE or later.  */
  54
  55 /* Mapping between the general-purpose registers in `struct reg'
  56    format and GDB's register cache layout.
  57
  58    Note that some registers are 32-bit, but since we're little-endian
  59    we get away with that.  */
  60
  61 /* From <machine/reg.h>.  */
  62 static int amd64fbsd_r_reg_offset[] =
  63 {
  64   14 * 8,                       /* %rax */
  65   11 * 8,                       /* %rbx */
  66   13 * 8,                       /* %rcx */
  67   12 * 8,                       /* %rdx */
  68   9 * 8,                        /* %rsi */
  69   8 * 8,                        /* %rdi */
  70   10 * 8,                       /* %rbp */
  71   20 * 8,                       /* %rsp */
  72   7 * 8,                        /* %r8 ...  */
  73   6 * 8,
  74   5 * 8,
  75   4 * 8,
  76   3 * 8,
  77   2 * 8,
  78   1 * 8,
  79   0 * 8,                        /* ... %r15 */
  80   17 * 8,                       /* %rip */
  81   19 * 8,                       /* %eflags */
  82   18 * 8,                       /* %cs */
  83   21 * 8,                       /* %ss */
  84   -1,                           /* %ds */
  85   -1,                           /* %es */
  86   -1,                           /* %fs */
  87   -1                            /* %gs */
  88 };
  89
  90 /* Location of the signal trampoline.  */
  91 CORE_ADDR amd64fbsd_sigtramp_start_addr = 0x7fffffffffc0ULL;
  92 CORE_ADDR amd64fbsd_sigtramp_end_addr = 0x7fffffffffe0ULL;
  93
  94 /* From <machine/signal.h>.  */
  95 int amd64fbsd_sc_reg_offset[] =
  96 {
  97   24 + 6 * 8,                   /* %rax */
  98   24 + 7 * 8,                   /* %rbx */
  99   24 + 3 * 8,                   /* %rcx */
 100   24 + 2 * 8,                   /* %rdx */
 101   24 + 1 * 8,                   /* %rsi */
 102   24 + 0 * 8,                   /* %rdi */
 103   24 + 8 * 8,                   /* %rbp */
 104   24 + 22 * 8,                  /* %rsp */
 105   24 + 4 * 8,                   /* %r8 ...  */
 106   24 + 5 * 8,
 107   24 + 9 * 8,
 108   24 + 10 * 8,
 109   24 + 11 * 8,
 110   24 + 12 * 8,
 111   24 + 13 * 8,
 112   24 + 14 * 8,                  /* ... %r15 */
 113   24 + 19 * 8,                  /* %rip */
 114   24 + 21 * 8,                  /* %eflags */
 115   24 + 20 * 8,                  /* %cs */
 116   24 + 23 * 8,                  /* %ss */
 117   -1,                           /* %ds */
 118   -1,                           /* %es */
 119   -1,                           /* %fs */
 120   -1                            /* %gs */
 121 };
 122
 123 /* From /usr/src/lib/libc/amd64/gen/_setjmp.S.  */
 124 static int amd64fbsd_jmp_buf_reg_offset[] =
 125 {
 126   -1,                           /* %rax */
 127   1 * 8,                        /* %rbx */
 128   -1,                           /* %rcx */
 129   -1,                           /* %rdx */
 130   -1,                           /* %rsi */
 131   -1,                           /* %rdi */
 132   3 * 8,                        /* %rbp */
 133   2 * 8,                        /* %rsp */
 134   -1,                           /* %r8 ...  */
 135   -1,
 136   -1,
 137   -1,                           /* ... %r11 */
 138   4 * 8,                        /* %r12 ...  */
 139   5 * 8,
 140   6 * 8,
 141   7 * 8,                        /* ... %r15 */
 142   0 * 8                         /* %rip */
 143 };
 144
 145 static void
 146 amd64fbsd_supply_uthread (struct regcache *regcache,
 147                           int regnum, CORE_ADDR addr)
 148 {
 149   gdb_byte buf[8];
 150   int i;
 151
 152   gdb_assert (regnum >= -1);
 153
 154   for (i = 0; i < ARRAY_SIZE (amd64fbsd_jmp_buf_reg_offset); i++)
 155     {
 156       if (amd64fbsd_jmp_buf_reg_offset[i] != -1
 157           && (regnum == -1 || regnum == i))
 158         {
 159           read_memory (addr + amd64fbsd_jmp_buf_reg_offset[i], buf, 8);
 160           regcache_raw_supply (regcache, i, buf);
 161         }
 162     }
 163 }
 164
 165 static void
 166 amd64fbsd_collect_uthread (const struct regcache *regcache,
 167                            int regnum, CORE_ADDR addr)
 168 {
 169   gdb_byte buf[8];
 170   int i;
 171
 172   gdb_assert (regnum >= -1);
 173
 174   for (i = 0; i < ARRAY_SIZE (amd64fbsd_jmp_buf_reg_offset); i++)
 175     {
 176       if (amd64fbsd_jmp_buf_reg_offset[i] != -1
 177           && (regnum == -1 || regnum == i))
 178         {
 179           regcache_raw_collect (regcache, i, buf);
 180           write_memory (addr + amd64fbsd_jmp_buf_reg_offset[i], buf, 8);
 181         }
 182     }
 183 }
 184
 185 static void
 186 amd64fbsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 187 {
 188   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 189
 190   /* Generic FreeBSD support. */
 191   fbsd_init_abi (info, gdbarch);
 192
 193   /* Obviously FreeBSD is BSD-based.  */
 194   i386bsd_init_abi (info, gdbarch);
 195
 196   tdep->gregset_reg_offset = amd64fbsd_r_reg_offset;
 197   tdep->gregset_num_regs = ARRAY_SIZE (amd64fbsd_r_reg_offset);
 198   tdep->sizeof_gregset = 22 * 8;
 199
 200   amd64_init_abi (info, gdbarch);
 201
 202   tdep->sigtramp_start = amd64fbsd_sigtramp_start_addr;
 203   tdep->sigtramp_end = amd64fbsd_sigtramp_end_addr;
 204   tdep->sigcontext_addr = amd64fbsd_sigcontext_addr;
 205   tdep->sc_reg_offset = amd64fbsd_sc_reg_offset;
 206   tdep->sc_num_regs = ARRAY_SIZE (amd64fbsd_sc_reg_offset);
 207
 208   /* FreeBSD provides a user-level threads implementation.  */
 209   bsd_uthread_set_supply_uthread (gdbarch, amd64fbsd_supply_uthread);
 210   bsd_uthread_set_collect_uthread (gdbarch, amd64fbsd_collect_uthread);
 211
 212   /* FreeBSD uses SVR4-style shared libraries.  */
 213   set_solib_svr4_fetch_link_map_offsets
 214     (gdbarch, svr4_lp64_fetch_link_map_offsets);
 215 }
 216 \f
 217
 218 /* Provide a prototype to silence -Wmissing-prototypes.  */
 219 void _initialize_amd64fbsd_tdep (void);
 220
 221 void
 222 _initialize_amd64fbsd_tdep (void)
 223 {
 224   gdbarch_register_osabi (bfd_arch_i386, bfd_mach_x86_64,
 225                           GDB_OSABI_FREEBSD_ELF, amd64fbsd_init_abi);
 226 }