gdb/i386nbsd-tdep.c

   1 /* Target-dependent code for NetBSD/i386.
   2
   3    Copyright (C) 1988-2014 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 "regset.h"
  26 #include "osabi.h"
  27 #include "symtab.h"
  28 #include "trad-frame.h"
  29 #include "tramp-frame.h"
  30
  31 #include "gdb_assert.h"
  32 #include <string.h>
  33
  34 #include "i386-tdep.h"
  35 #include "i387-tdep.h"
  36 #include "nbsd-tdep.h"
  37 #include "solib-svr4.h"
  38
  39 /* From <machine/reg.h>.  */
  40 static int i386nbsd_r_reg_offset[] =
  41 {
  42   0 * 4,                        /* %eax */
  43   1 * 4,                        /* %ecx */
  44   2 * 4,                        /* %edx */
  45   3 * 4,                        /* %ebx */
  46   4 * 4,                        /* %esp */
  47   5 * 4,                        /* %ebp */
  48   6 * 4,                        /* %esi */
  49   7 * 4,                        /* %edi */
  50   8 * 4,                        /* %eip */
  51   9 * 4,                        /* %eflags */
  52   10 * 4,                       /* %cs */
  53   11 * 4,                       /* %ss */
  54   12 * 4,                       /* %ds */
  55   13 * 4,                       /* %es */
  56   14 * 4,                       /* %fs */
  57   15 * 4                        /* %gs */
  58 };
  59
  60 /* From <machine/signal.h>.  */
  61 int i386nbsd_sc_reg_offset[] =
  62 {
  63   10 * 4,                       /* %eax */
  64   9 * 4,                        /* %ecx */
  65   8 * 4,                        /* %edx */
  66   7 * 4,                        /* %ebx */
  67   14 * 4,                       /* %esp */
  68   6 * 4,                        /* %ebp */
  69   5 * 4,                        /* %esi */
  70   4 * 4,                        /* %edi */
  71   11 * 4,                       /* %eip */
  72   13 * 4,                       /* %eflags */
  73   12 * 4,                       /* %cs */
  74   15 * 4,                       /* %ss */
  75   3 * 4,                        /* %ds */
  76   2 * 4,                        /* %es */
  77   1 * 4,                        /* %fs */
  78   0 * 4                         /* %gs */
  79 };
  80
  81 /* From <machine/mcontext.h>.  */
  82 int i386nbsd_mc_reg_offset[] =
  83 {
  84   11 * 4,                       /* %eax */
  85   10 * 4,                       /* %ecx */
  86   9 * 4,                        /* %edx */
  87   8 * 4,                        /* %ebx */
  88   7 * 4,                        /* %esp */
  89   6 * 4,                        /* %ebp */
  90   5 * 4,                        /* %esi */
  91   4 * 4,                        /* %edi */
  92   14 * 4,                       /* %eip */
  93   16 * 4,                       /* %eflags */
  94   15 * 4,                       /* %cs */
  95   18 * 4,                       /* %ss */
  96   3 * 4,                        /* %ds */
  97   2 * 4,                        /* %es */
  98   1 * 4,                        /* %fs */
  99   0 * 4                         /* %gs */
 100 };
 101
 102 static void i386nbsd_sigtramp_cache_init (const struct tramp_frame *,
 103                                           struct frame_info *,
 104                                           struct trad_frame_cache *,
 105                                           CORE_ADDR);
 106
 107 static const struct tramp_frame i386nbsd_sigtramp_sc16 =
 108 {
 109   SIGTRAMP_FRAME,
 110   1,
 111   {
 112     { 0x8d, -1 }, { 0x44, -1 }, { 0x24, -1 }, { 0x10, -1 },
 113                         /* leal  0x10(%esp), %eax */
 114     { 0x50, -1 },       /* pushl %eax */
 115     { 0x50, -1 },       /* pushl %eax */
 116     { 0xb8, -1 }, { 0x27, -1 }, {0x01, -1 }, {0x00, -1 }, {0x00, -1 },
 117                         /* movl  $0x127, %eax           # __sigreturn14 */
 118     { 0xcd, -1 }, { 0x80, -1},
 119                         /* int   $0x80 */
 120     { 0xb8, -1 }, { 0x01, -1 }, {0x00, -1 }, {0x00, -1 }, {0x00, -1 },
 121                         /* movl  $0x1, %eax             # exit */
 122     { 0xcd, -1 }, { 0x80, -1},
 123                         /* int   $0x80 */
 124     { TRAMP_SENTINEL_INSN, -1 }
 125   },
 126   i386nbsd_sigtramp_cache_init
 127 };
 128
 129 static const struct tramp_frame i386nbsd_sigtramp_sc2 =
 130 {
 131   SIGTRAMP_FRAME,
 132   1,
 133   {
 134     { 0x8d, -1 }, { 0x44, -1 }, { 0x24, -1 }, { 0x0c, -1 },
 135                         /* leal  0x0c(%esp), %eax */
 136     { 0x89, -1 }, { 0x44, -1 }, { 0x24, -1 }, { 0x04, -1 },
 137                         /* movl  %eax, 0x4(%esp) */
 138     { 0xb8, -1 }, { 0x27, -1 }, {0x01, -1 }, {0x00, -1 }, {0x00, -1 },
 139                         /* movl  $0x127, %eax           # __sigreturn14 */
 140     { 0xcd, -1 }, { 0x80, -1},
 141                         /* int   $0x80 */
 142     { 0x89, -1 }, { 0x44, -1 }, { 0x24, -1 }, { 0x04, -1 },
 143                         /* movl  %eax, 0x4(%esp) */
 144     { 0xb8, -1 }, { 0x01, -1 }, {0x00, -1 }, {0x00, -1 }, {0x00, -1 },
 145                         /* movl  $0x1, %eax */
 146     { 0xcd, -1 }, { 0x80, -1},
 147                         /* int   $0x80 */
 148     { TRAMP_SENTINEL_INSN, -1 }
 149   },
 150   i386nbsd_sigtramp_cache_init
 151 };
 152
 153 static const struct tramp_frame i386nbsd_sigtramp_si2 =
 154 {
 155   SIGTRAMP_FRAME,
 156   1,
 157   {
 158     { 0x8b, -1 }, { 0x44, -1 }, { 0x24, -1 }, { 0x08, -1 },
 159                         /* movl  8(%esp),%eax */
 160     { 0x89, -1 }, { 0x44, -1 }, { 0x24, -1 }, { 0x04, -1 },
 161                         /* movl  %eax, 0x4(%esp) */
 162     { 0xb8, -1 }, { 0x34, -1 }, { 0x01, -1 }, { 0x00, -1 }, { 0x00, -1 },
 163                         /* movl  $0x134, %eax            # setcontext */
 164     { 0xcd, -1 }, { 0x80, -1 },
 165                         /* int   $0x80 */
 166     { 0x89, -1 }, { 0x44, -1 }, { 0x24, -1 }, { 0x04, -1 },
 167                         /* movl  %eax, 0x4(%esp) */
 168     { 0xb8, -1 }, { 0x01, -1 }, { 0x00, -1 }, { 0x00, -1 }, { 0x00, -1 },
 169                         /* movl  $0x1, %eax */
 170     { 0xcd, -1 }, { 0x80, -1 },
 171                         /* int   $0x80 */
 172     { TRAMP_SENTINEL_INSN, -1 }
 173   },
 174   i386nbsd_sigtramp_cache_init
 175 };
 176
 177 static const struct tramp_frame i386nbsd_sigtramp_si31 =
 178 {
 179   SIGTRAMP_FRAME,
 180   1,
 181   {
 182     { 0x8d, -1 }, { 0x84, -1 }, { 0x24, -1 },
 183         { 0x8c, -1 }, { 0x00, -1 }, { 0x00, -1 }, { 0x00, -1 },
 184                         /* leal  0x8c(%esp), %eax */
 185     { 0x89, -1 }, { 0x44, -1 }, { 0x24, -1 }, { 0x04, -1 },
 186                         /* movl  %eax, 0x4(%esp) */
 187     { 0xb8, -1 }, { 0x34, -1 }, { 0x01, -1 }, { 0x00, -1 }, { 0x00, -1 },
 188                         /* movl  $0x134, %eax            # setcontext */
 189     { 0xcd, -1 }, { 0x80, -1},
 190                         /* int   $0x80 */
 191     { 0x89, -1 }, { 0x44, -1 }, { 0x24, -1 }, { 0x04, -1 },
 192                         /* movl  %eax, 0x4(%esp) */
 193     { 0xb8, -1 }, { 0x01, -1 }, {0x00, -1 }, {0x00, -1 }, {0x00, -1 },
 194                         /* movl  $0x1, %eax */
 195     { 0xcd, -1 }, { 0x80, -1},
 196                         /* int   $0x80 */
 197     { TRAMP_SENTINEL_INSN, -1 }
 198   },
 199   i386nbsd_sigtramp_cache_init
 200 };
 201
 202 static const struct tramp_frame i386nbsd_sigtramp_si4 =
 203 {
 204   SIGTRAMP_FRAME,
 205   1,
 206   {
 207     { 0x8d, -1 }, { 0x84, -1 }, { 0x24, -1 },
 208         { 0x8c, -1 }, { 0x00, -1 }, { 0x00, -1 }, { 0x00, -1 },
 209                         /* leal  0x8c(%esp), %eax */
 210     { 0x89, -1 }, { 0x44, -1 }, { 0x24, -1 }, { 0x04, -1 },
 211                         /* movl  %eax, 0x4(%esp) */
 212     { 0xb8, -1 }, { 0x34, -1 }, { 0x01, -1 }, { 0x00, -1 }, { 0x00, -1 },
 213                         /* movl  $0x134, %eax            # setcontext */
 214     { 0xcd, -1 }, { 0x80, -1},
 215                         /* int   $0x80 */
 216     { 0xc7, -1 }, { 0x44, -1 }, { 0x24, -1 }, { 0x04, -1 },
 217         { 0xff, -1 }, { 0xff, -1 }, { 0xff, -1 }, { 0xff, -1 },
 218                         /* movl   $0xffffffff,0x4(%esp) */
 219     { 0xb8, -1 }, { 0x01, -1 }, {0x00, -1 }, {0x00, -1 }, {0x00, -1 },
 220                         /* movl  $0x1, %eax */
 221     { 0xcd, -1 }, { 0x80, -1},
 222                         /* int   $0x80 */
 223     { TRAMP_SENTINEL_INSN, -1 }
 224   },
 225   i386nbsd_sigtramp_cache_init
 226 };
 227
 228 static void
 229 i386nbsd_sigtramp_cache_init (const struct tramp_frame *self,
 230                               struct frame_info *this_frame,
 231                               struct trad_frame_cache *this_cache,
 232                               CORE_ADDR func)
 233 {
 234   struct gdbarch *gdbarch = get_frame_arch (this_frame);
 235   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 236   enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
 237   CORE_ADDR sp = get_frame_register_unsigned (this_frame, I386_ESP_REGNUM);
 238   CORE_ADDR base;
 239   int *reg_offset;
 240   int num_regs;
 241   int i;
 242
 243   if (self == &i386nbsd_sigtramp_sc16 || self == &i386nbsd_sigtramp_sc2)
 244     {
 245       reg_offset = i386nbsd_sc_reg_offset;
 246       num_regs = ARRAY_SIZE (i386nbsd_sc_reg_offset);
 247
 248       /* Read in the sigcontext address.  */
 249       base = read_memory_unsigned_integer (sp + 8, 4, byte_order);
 250     }
 251   else
 252     {
 253       reg_offset = i386nbsd_mc_reg_offset;
 254       num_regs = ARRAY_SIZE (i386nbsd_mc_reg_offset);
 255
 256       /* Read in the ucontext address.  */
 257       base = read_memory_unsigned_integer (sp + 8, 4, byte_order);
 258       /* offsetof(ucontext_t, uc_mcontext) == 36 */
 259       base += 36;
 260     }
 261
 262   for (i = 0; i < num_regs; i++)
 263     if (reg_offset[i] != -1)
 264       trad_frame_set_reg_addr (this_cache, i, base + reg_offset[i]);
 265
 266   /* Construct the frame ID using the function start.  */
 267   trad_frame_set_id (this_cache, frame_id_build (sp, func));
 268 }
 269 \f
 270
 271 static void
 272 i386nbsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 273 {
 274   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 275
 276   /* Obviously NetBSD is BSD-based.  */
 277   i386bsd_init_abi (info, gdbarch);
 278
 279   /* NetBSD has a different `struct reg'.  */
 280   tdep->gregset_reg_offset = i386nbsd_r_reg_offset;
 281   tdep->gregset_num_regs = ARRAY_SIZE (i386nbsd_r_reg_offset);
 282   tdep->sizeof_gregset = 16 * 4;
 283
 284   /* NetBSD uses -freg-struct-return by default.  */
 285   tdep->struct_return = reg_struct_return;
 286
 287   /* NetBSD uses tramp_frame sniffers for signal trampolines.  */
 288   tdep->sigcontext_addr= 0;
 289   tdep->sigtramp_start = 0;
 290   tdep->sigtramp_end = 0;
 291   tdep->sigtramp_p = 0;
 292   tdep->sc_reg_offset = 0;
 293   tdep->sc_num_regs = 0;
 294
 295   tramp_frame_prepend_unwinder (gdbarch, &i386nbsd_sigtramp_sc16);
 296   tramp_frame_prepend_unwinder (gdbarch, &i386nbsd_sigtramp_sc2);
 297   tramp_frame_prepend_unwinder (gdbarch, &i386nbsd_sigtramp_si2);
 298   tramp_frame_prepend_unwinder (gdbarch, &i386nbsd_sigtramp_si31);
 299   tramp_frame_prepend_unwinder (gdbarch, &i386nbsd_sigtramp_si4);
 300 }
 301
 302 /* NetBSD ELF.  */
 303
 304 static void
 305 i386nbsdelf_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 306 {
 307   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 308
 309   /* It's still NetBSD.  */
 310   i386nbsd_init_abi (info, gdbarch);
 311
 312   /* But ELF-based.  */
 313   i386_elf_init_abi (info, gdbarch);
 314
 315   /* NetBSD ELF uses SVR4-style shared libraries.  */
 316   set_solib_svr4_fetch_link_map_offsets
 317     (gdbarch, svr4_ilp32_fetch_link_map_offsets);
 318
 319   /* NetBSD ELF uses -fpcc-struct-return by default.  */
 320   tdep->struct_return = pcc_struct_return;
 321 }
 322
 323 /* Provide a prototype to silence -Wmissing-prototypes.  */
 324 extern initialize_file_ftype _initialize_i386nbsd_tdep;
 325
 326 void
 327 _initialize_i386nbsd_tdep (void)
 328 {
 329   gdbarch_register_osabi (bfd_arch_i386, 0, GDB_OSABI_NETBSD_ELF,
 330                           i386nbsdelf_init_abi);
 331 }