gdb/i386nbsd-tdep.c

   1 /* Target-dependent code for NetBSD/i386.
   2
   3    Copyright (C) 1988, 1989, 1991, 1992, 1994, 1996, 2000, 2001, 2002, 2003,
   4    2004, 2007, 2008, 2009, 2010 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 "arch-utils.h"
  23 #include "frame.h"
  24 #include "gdbcore.h"
  25 #include "regcache.h"
  26 #include "regset.h"
  27 #include "osabi.h"
  28 #include "symtab.h"
  29 #include "trad-frame.h"
  30 #include "tramp-frame.h"
  31
  32 #include "gdb_assert.h"
  33 #include "gdb_string.h"
  34
  35 #include "i386-tdep.h"
  36 #include "i387-tdep.h"
  37 #include "nbsd-tdep.h"
  38 #include "solib-svr4.h"
  39
  40 /* From <machine/reg.h>.  */
  41 static int i386nbsd_r_reg_offset[] =
  42 {
  43   0 * 4,                        /* %eax */
  44   1 * 4,                        /* %ecx */
  45   2 * 4,                        /* %edx */
  46   3 * 4,                        /* %ebx */
  47   4 * 4,                        /* %esp */
  48   5 * 4,                        /* %ebp */
  49   6 * 4,                        /* %esi */
  50   7 * 4,                        /* %edi */
  51   8 * 4,                        /* %eip */
  52   9 * 4,                        /* %eflags */
  53   10 * 4,                       /* %cs */
  54   11 * 4,                       /* %ss */
  55   12 * 4,                       /* %ds */
  56   13 * 4,                       /* %es */
  57   14 * 4,                       /* %fs */
  58   15 * 4                        /* %gs */
  59 };
  60
  61 /* From <machine/signal.h>.  */
  62 int i386nbsd_sc_reg_offset[] =
  63 {
  64   10 * 4,                       /* %eax */
  65   9 * 4,                        /* %ecx */
  66   8 * 4,                        /* %edx */
  67   7 * 4,                        /* %ebx */
  68   14 * 4,                       /* %esp */
  69   6 * 4,                        /* %ebp */
  70   5 * 4,                        /* %esi */
  71   4 * 4,                        /* %edi */
  72   11 * 4,                       /* %eip */
  73   13 * 4,                       /* %eflags */
  74   12 * 4,                       /* %cs */
  75   15 * 4,                       /* %ss */
  76   3 * 4,                        /* %ds */
  77   2 * 4,                        /* %es */
  78   1 * 4,                        /* %fs */
  79   0 * 4                         /* %gs */
  80 };
  81
  82 /* From <machine/mcontext.h>.  */
  83 int i386nbsd_mc_reg_offset[] =
  84 {
  85   11 * 4,                       /* %eax */
  86   10 * 4,                       /* %ecx */
  87   9 * 4,                        /* %edx */
  88   8 * 4,                        /* %ebx */
  89   7 * 4,                        /* %esp */
  90   6 * 4,                        /* %ebp */
  91   5 * 4,                        /* %esi */
  92   4 * 4,                        /* %edi */
  93   14 * 4,                       /* %eip */
  94   16 * 4,                       /* %eflags */
  95   15 * 4,                       /* %cs */
  96   18 * 4,                       /* %ss */
  97   3 * 4,                        /* %ds */
  98   2 * 4,                        /* %es */
  99   1 * 4,                        /* %fs */
 100   0 * 4                         /* %gs */
 101 };
 102
 103 static void i386nbsd_sigtramp_cache_init (const struct tramp_frame *,
 104                                           struct frame_info *,
 105                                           struct trad_frame_cache *,
 106                                           CORE_ADDR);
 107
 108 static const struct tramp_frame i386nbsd_sigtramp_sc16 =
 109 {
 110   SIGTRAMP_FRAME,
 111   1,
 112   {
 113     { 0x8d, -1 }, { 0x44, -1 }, { 0x24, -1 }, { 0x10, -1 },
 114                         /* leal  0x10(%esp), %eax */
 115     { 0x50, -1 },       /* pushl %eax */
 116     { 0x50, -1 },       /* pushl %eax */
 117     { 0xb8, -1 }, { 0x27, -1 }, {0x01, -1 }, {0x00, -1 }, {0x00, -1 },
 118                         /* movl  $0x127, %eax           # __sigreturn14 */
 119     { 0xcd, -1 }, { 0x80, -1},
 120                         /* int   $0x80 */
 121     { 0xb8, -1 }, { 0x01, -1 }, {0x00, -1 }, {0x00, -1 }, {0x00, -1 },
 122                         /* movl  $0x1, %eax             # exit */
 123     { 0xcd, -1 }, { 0x80, -1},
 124                         /* int   $0x80 */
 125     { TRAMP_SENTINEL_INSN, -1 }
 126   },
 127   i386nbsd_sigtramp_cache_init
 128 };
 129
 130 static const struct tramp_frame i386nbsd_sigtramp_sc2 =
 131 {
 132   SIGTRAMP_FRAME,
 133   1,
 134   {
 135     { 0x8d, -1 }, { 0x44, -1 }, { 0x24, -1 }, { 0x0c, -1 },
 136                         /* leal  0x0c(%esp), %eax */
 137     { 0x89, -1 }, { 0x44, -1 }, { 0x24, -1 }, { 0x04, -1 },
 138                         /* movl  %eax, 0x4(%esp) */
 139     { 0xb8, -1 }, { 0x27, -1 }, {0x01, -1 }, {0x00, -1 }, {0x00, -1 },
 140                         /* movl  $0x127, %eax           # __sigreturn14 */
 141     { 0xcd, -1 }, { 0x80, -1},
 142                         /* int   $0x80 */
 143     { 0x89, -1 }, { 0x44, -1 }, { 0x24, -1 }, { 0x04, -1 },
 144                         /* movl  %eax, 0x4(%esp) */
 145     { 0xb8, -1 }, { 0x01, -1 }, {0x00, -1 }, {0x00, -1 }, {0x00, -1 },
 146                         /* movl  $0x1, %eax */
 147     { 0xcd, -1 }, { 0x80, -1},
 148                         /* int   $0x80 */
 149     { TRAMP_SENTINEL_INSN, -1 }
 150   },
 151   i386nbsd_sigtramp_cache_init
 152 };
 153
 154 static const struct tramp_frame i386nbsd_sigtramp_si2 =
 155 {
 156   SIGTRAMP_FRAME,
 157   1,
 158   {
 159     { 0x8b, -1 }, { 0x44, -1 }, { 0x24, -1 }, { 0x08, -1 },
 160                         /* movl  8(%esp),%eax */
 161     { 0x89, -1 }, { 0x44, -1 }, { 0x24, -1 }, { 0x04, -1 },
 162                         /* movl  %eax, 0x4(%esp) */
 163     { 0xb8, -1 }, { 0x34, -1 }, { 0x01, -1 }, { 0x00, -1 }, { 0x00, -1 },
 164                         /* movl  $0x134, %eax            # setcontext */
 165     { 0xcd, -1 }, { 0x80, -1 },
 166                         /* int   $0x80 */
 167     { 0x89, -1 }, { 0x44, -1 }, { 0x24, -1 }, { 0x04, -1 },
 168                         /* movl  %eax, 0x4(%esp) */
 169     { 0xb8, -1 }, { 0x01, -1 }, { 0x00, -1 }, { 0x00, -1 }, { 0x00, -1 },
 170                         /* movl  $0x1, %eax */
 171     { 0xcd, -1 }, { 0x80, -1 },
 172                         /* int   $0x80 */
 173     { TRAMP_SENTINEL_INSN, -1 }
 174   },
 175   i386nbsd_sigtramp_cache_init
 176 };
 177
 178 static const struct tramp_frame i386nbsd_sigtramp_si31 =
 179 {
 180   SIGTRAMP_FRAME,
 181   1,
 182   {
 183     { 0x8d, -1 }, { 0x84, -1 }, { 0x24, -1 },
 184         { 0x8c, -1 }, { 0x00, -1 }, { 0x00, -1 }, { 0x00, -1 },
 185                         /* leal  0x8c(%esp), %eax */
 186     { 0x89, -1 }, { 0x44, -1 }, { 0x24, -1 }, { 0x04, -1 },
 187                         /* movl  %eax, 0x4(%esp) */
 188     { 0xb8, -1 }, { 0x34, -1 }, { 0x01, -1 }, { 0x00, -1 }, { 0x00, -1 },
 189                         /* movl  $0x134, %eax            # setcontext */
 190     { 0xcd, -1 }, { 0x80, -1},
 191                         /* int   $0x80 */
 192     { 0x89, -1 }, { 0x44, -1 }, { 0x24, -1 }, { 0x04, -1 },
 193                         /* movl  %eax, 0x4(%esp) */
 194     { 0xb8, -1 }, { 0x01, -1 }, {0x00, -1 }, {0x00, -1 }, {0x00, -1 },
 195                         /* movl  $0x1, %eax */
 196     { 0xcd, -1 }, { 0x80, -1},
 197                         /* int   $0x80 */
 198     { TRAMP_SENTINEL_INSN, -1 }
 199   },
 200   i386nbsd_sigtramp_cache_init
 201 };
 202
 203 static const struct tramp_frame i386nbsd_sigtramp_si4 =
 204 {
 205   SIGTRAMP_FRAME,
 206   1,
 207   {
 208     { 0x8d, -1 }, { 0x84, -1 }, { 0x24, -1 },
 209         { 0x8c, -1 }, { 0x00, -1 }, { 0x00, -1 }, { 0x00, -1 },
 210                         /* leal  0x8c(%esp), %eax */
 211     { 0x89, -1 }, { 0x44, -1 }, { 0x24, -1 }, { 0x04, -1 },
 212                         /* movl  %eax, 0x4(%esp) */
 213     { 0xb8, -1 }, { 0x34, -1 }, { 0x01, -1 }, { 0x00, -1 }, { 0x00, -1 },
 214                         /* movl  $0x134, %eax            # setcontext */
 215     { 0xcd, -1 }, { 0x80, -1},
 216                         /* int   $0x80 */
 217     { 0xc7, -1 }, { 0x44, -1 }, { 0x24, -1 }, { 0x04, -1 },
 218         { 0xff, -1 }, { 0xff, -1 }, { 0xff, -1 }, { 0xff, -1 },
 219                         /* movl   $0xffffffff,0x4(%esp) */
 220     { 0xb8, -1 }, { 0x01, -1 }, {0x00, -1 }, {0x00, -1 }, {0x00, -1 },
 221                         /* movl  $0x1, %eax */
 222     { 0xcd, -1 }, { 0x80, -1},
 223                         /* int   $0x80 */
 224     { TRAMP_SENTINEL_INSN, -1 }
 225   },
 226   i386nbsd_sigtramp_cache_init
 227 };
 228
 229 static void
 230 i386nbsd_sigtramp_cache_init (const struct tramp_frame *self,
 231                               struct frame_info *this_frame,
 232                               struct trad_frame_cache *this_cache,
 233                               CORE_ADDR func)
 234 {
 235   struct gdbarch *gdbarch = get_frame_arch (this_frame);
 236   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 237   enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
 238   CORE_ADDR sp = get_frame_register_unsigned (this_frame, I386_ESP_REGNUM);
 239   CORE_ADDR base;
 240   int *reg_offset;
 241   int num_regs;
 242   int i;
 243
 244   if (self == &i386nbsd_sigtramp_sc16 || self == &i386nbsd_sigtramp_sc2)
 245     {
 246       reg_offset = i386nbsd_sc_reg_offset;
 247       num_regs = ARRAY_SIZE (i386nbsd_sc_reg_offset);
 248
 249       /* Read in the sigcontext address */
 250       base = read_memory_unsigned_integer (sp + 8, 4, byte_order);
 251     }
 252   else
 253     {
 254       reg_offset = i386nbsd_mc_reg_offset;
 255       num_regs = ARRAY_SIZE (i386nbsd_mc_reg_offset);
 256
 257       /* Read in the ucontext address */
 258       base = read_memory_unsigned_integer (sp + 8, 4, byte_order);
 259       /* offsetof(ucontext_t, uc_mcontext) == 36 */
 260       base += 36;
 261     }
 262
 263   for (i = 0; i < num_regs; i++)
 264     if (reg_offset[i] != -1)
 265       trad_frame_set_reg_addr (this_cache, i, base + reg_offset[i]);
 266
 267   /* Construct the frame ID using the function start.  */
 268   trad_frame_set_id (this_cache, frame_id_build (sp, func));
 269 }
 270 \f
 271
 272 static void
 273 i386nbsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 274 {
 275   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 276
 277   /* Obviously NetBSD is BSD-based.  */
 278   i386bsd_init_abi (info, gdbarch);
 279
 280   /* NetBSD has a different `struct reg'.  */
 281   tdep->gregset_reg_offset = i386nbsd_r_reg_offset;
 282   tdep->gregset_num_regs = ARRAY_SIZE (i386nbsd_r_reg_offset);
 283   tdep->sizeof_gregset = 16 * 4;
 284
 285   /* NetBSD uses -freg-struct-return by default.  */
 286   tdep->struct_return = reg_struct_return;
 287
 288   /* NetBSD uses tramp_frame sniffers for signal trampolines. */
 289   tdep->sigcontext_addr= 0;
 290   tdep->sigtramp_start = 0;
 291   tdep->sigtramp_end = 0;
 292   tdep->sigtramp_p = 0;
 293   tdep->sc_reg_offset = 0;
 294   tdep->sc_num_regs = 0;
 295
 296   tramp_frame_prepend_unwinder (gdbarch, &i386nbsd_sigtramp_sc16);
 297   tramp_frame_prepend_unwinder (gdbarch, &i386nbsd_sigtramp_sc2);
 298   tramp_frame_prepend_unwinder (gdbarch, &i386nbsd_sigtramp_si2);
 299   tramp_frame_prepend_unwinder (gdbarch, &i386nbsd_sigtramp_si31);
 300   tramp_frame_prepend_unwinder (gdbarch, &i386nbsd_sigtramp_si4);
 301 }
 302
 303 /* NetBSD ELF.  */
 304
 305 static void
 306 i386nbsdelf_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 307 {
 308   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 309
 310   /* It's still NetBSD.  */
 311   i386nbsd_init_abi (info, gdbarch);
 312
 313   /* But ELF-based.  */
 314   i386_elf_init_abi (info, gdbarch);
 315
 316   /* NetBSD ELF uses SVR4-style shared libraries.  */
 317   set_solib_svr4_fetch_link_map_offsets
 318     (gdbarch, svr4_ilp32_fetch_link_map_offsets);
 319
 320   /* NetBSD ELF uses -fpcc-struct-return by default.  */
 321   tdep->struct_return = pcc_struct_return;
 322 }
 323
 324 /* Provide a prototype to silence -Wmissing-prototypes.  */
 325 extern initialize_file_ftype _initialize_i386nbsd_tdep;
 326
 327 void
 328 _initialize_i386nbsd_tdep (void)
 329 {
 330   gdbarch_register_osabi (bfd_arch_i386, 0, GDB_OSABI_NETBSD_ELF,
 331                           i386nbsdelf_init_abi);
 332 }