gdb/i386-nbsd-tdep.c

   1 /* Target-dependent code for NetBSD/i386.
   2
   3    Copyright (C) 1988-2017 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 "i386-tdep.h"
  32 #include "i387-tdep.h"
  33 #include "nbsd-tdep.h"
  34 #include "solib-svr4.h"
  35
  36 /* From <machine/reg.h>.  */
  37 static int i386nbsd_r_reg_offset[] =
  38 {
  39   0 * 4,                        /* %eax */
  40   1 * 4,                        /* %ecx */
  41   2 * 4,                        /* %edx */
  42   3 * 4,                        /* %ebx */
  43   4 * 4,                        /* %esp */
  44   5 * 4,                        /* %ebp */
  45   6 * 4,                        /* %esi */
  46   7 * 4,                        /* %edi */
  47   8 * 4,                        /* %eip */
  48   9 * 4,                        /* %eflags */
  49   10 * 4,                       /* %cs */
  50   11 * 4,                       /* %ss */
  51   12 * 4,                       /* %ds */
  52   13 * 4,                       /* %es */
  53   14 * 4,                       /* %fs */
  54   15 * 4                        /* %gs */
  55 };
  56
  57 /* From <machine/signal.h>.  */
  58 int i386nbsd_sc_reg_offset[] =
  59 {
  60   10 * 4,                       /* %eax */
  61   9 * 4,                        /* %ecx */
  62   8 * 4,                        /* %edx */
  63   7 * 4,                        /* %ebx */
  64   14 * 4,                       /* %esp */
  65   6 * 4,                        /* %ebp */
  66   5 * 4,                        /* %esi */
  67   4 * 4,                        /* %edi */
  68   11 * 4,                       /* %eip */
  69   13 * 4,                       /* %eflags */
  70   12 * 4,                       /* %cs */
  71   15 * 4,                       /* %ss */
  72   3 * 4,                        /* %ds */
  73   2 * 4,                        /* %es */
  74   1 * 4,                        /* %fs */
  75   0 * 4                         /* %gs */
  76 };
  77
  78 /* From <machine/mcontext.h>.  */
  79 int i386nbsd_mc_reg_offset[] =
  80 {
  81   11 * 4,                       /* %eax */
  82   10 * 4,                       /* %ecx */
  83   9 * 4,                        /* %edx */
  84   8 * 4,                        /* %ebx */
  85   7 * 4,                        /* %esp */
  86   6 * 4,                        /* %ebp */
  87   5 * 4,                        /* %esi */
  88   4 * 4,                        /* %edi */
  89   14 * 4,                       /* %eip */
  90   16 * 4,                       /* %eflags */
  91   15 * 4,                       /* %cs */
  92   18 * 4,                       /* %ss */
  93   3 * 4,                        /* %ds */
  94   2 * 4,                        /* %es */
  95   1 * 4,                        /* %fs */
  96   0 * 4                         /* %gs */
  97 };
  98
  99 static void i386nbsd_sigtramp_cache_init (const struct tramp_frame *,
 100                                           struct frame_info *,
 101                                           struct trad_frame_cache *,
 102                                           CORE_ADDR);
 103
 104 static const struct tramp_frame i386nbsd_sigtramp_sc16 =
 105 {
 106   SIGTRAMP_FRAME,
 107   1,
 108   {
 109     { 0x8d, -1 }, { 0x44, -1 }, { 0x24, -1 }, { 0x10, -1 },
 110                         /* leal  0x10(%esp), %eax */
 111     { 0x50, -1 },       /* pushl %eax */
 112     { 0x50, -1 },       /* pushl %eax */
 113     { 0xb8, -1 }, { 0x27, -1 }, {0x01, -1 }, {0x00, -1 }, {0x00, -1 },
 114                         /* movl  $0x127, %eax           # __sigreturn14 */
 115     { 0xcd, -1 }, { 0x80, -1},
 116                         /* int   $0x80 */
 117     { 0xb8, -1 }, { 0x01, -1 }, {0x00, -1 }, {0x00, -1 }, {0x00, -1 },
 118                         /* movl  $0x1, %eax             # exit */
 119     { 0xcd, -1 }, { 0x80, -1},
 120                         /* int   $0x80 */
 121     { TRAMP_SENTINEL_INSN, -1 }
 122   },
 123   i386nbsd_sigtramp_cache_init
 124 };
 125
 126 static const struct tramp_frame i386nbsd_sigtramp_sc2 =
 127 {
 128   SIGTRAMP_FRAME,
 129   1,
 130   {
 131     { 0x8d, -1 }, { 0x44, -1 }, { 0x24, -1 }, { 0x0c, -1 },
 132                         /* leal  0x0c(%esp), %eax */
 133     { 0x89, -1 }, { 0x44, -1 }, { 0x24, -1 }, { 0x04, -1 },
 134                         /* movl  %eax, 0x4(%esp) */
 135     { 0xb8, -1 }, { 0x27, -1 }, {0x01, -1 }, {0x00, -1 }, {0x00, -1 },
 136                         /* movl  $0x127, %eax           # __sigreturn14 */
 137     { 0xcd, -1 }, { 0x80, -1},
 138                         /* int   $0x80 */
 139     { 0x89, -1 }, { 0x44, -1 }, { 0x24, -1 }, { 0x04, -1 },
 140                         /* movl  %eax, 0x4(%esp) */
 141     { 0xb8, -1 }, { 0x01, -1 }, {0x00, -1 }, {0x00, -1 }, {0x00, -1 },
 142                         /* movl  $0x1, %eax */
 143     { 0xcd, -1 }, { 0x80, -1},
 144                         /* int   $0x80 */
 145     { TRAMP_SENTINEL_INSN, -1 }
 146   },
 147   i386nbsd_sigtramp_cache_init
 148 };
 149
 150 static const struct tramp_frame i386nbsd_sigtramp_si2 =
 151 {
 152   SIGTRAMP_FRAME,
 153   1,
 154   {
 155     { 0x8b, -1 }, { 0x44, -1 }, { 0x24, -1 }, { 0x08, -1 },
 156                         /* movl  8(%esp),%eax */
 157     { 0x89, -1 }, { 0x44, -1 }, { 0x24, -1 }, { 0x04, -1 },
 158                         /* movl  %eax, 0x4(%esp) */
 159     { 0xb8, -1 }, { 0x34, -1 }, { 0x01, -1 }, { 0x00, -1 }, { 0x00, -1 },
 160                         /* movl  $0x134, %eax            # setcontext */
 161     { 0xcd, -1 }, { 0x80, -1 },
 162                         /* int   $0x80 */
 163     { 0x89, -1 }, { 0x44, -1 }, { 0x24, -1 }, { 0x04, -1 },
 164                         /* movl  %eax, 0x4(%esp) */
 165     { 0xb8, -1 }, { 0x01, -1 }, { 0x00, -1 }, { 0x00, -1 }, { 0x00, -1 },
 166                         /* movl  $0x1, %eax */
 167     { 0xcd, -1 }, { 0x80, -1 },
 168                         /* int   $0x80 */
 169     { TRAMP_SENTINEL_INSN, -1 }
 170   },
 171   i386nbsd_sigtramp_cache_init
 172 };
 173
 174 static const struct tramp_frame i386nbsd_sigtramp_si31 =
 175 {
 176   SIGTRAMP_FRAME,
 177   1,
 178   {
 179     { 0x8d, -1 }, { 0x84, -1 }, { 0x24, -1 },
 180         { 0x8c, -1 }, { 0x00, -1 }, { 0x00, -1 }, { 0x00, -1 },
 181                         /* leal  0x8c(%esp), %eax */
 182     { 0x89, -1 }, { 0x44, -1 }, { 0x24, -1 }, { 0x04, -1 },
 183                         /* movl  %eax, 0x4(%esp) */
 184     { 0xb8, -1 }, { 0x34, -1 }, { 0x01, -1 }, { 0x00, -1 }, { 0x00, -1 },
 185                         /* movl  $0x134, %eax            # setcontext */
 186     { 0xcd, -1 }, { 0x80, -1},
 187                         /* int   $0x80 */
 188     { 0x89, -1 }, { 0x44, -1 }, { 0x24, -1 }, { 0x04, -1 },
 189                         /* movl  %eax, 0x4(%esp) */
 190     { 0xb8, -1 }, { 0x01, -1 }, {0x00, -1 }, {0x00, -1 }, {0x00, -1 },
 191                         /* movl  $0x1, %eax */
 192     { 0xcd, -1 }, { 0x80, -1},
 193                         /* int   $0x80 */
 194     { TRAMP_SENTINEL_INSN, -1 }
 195   },
 196   i386nbsd_sigtramp_cache_init
 197 };
 198
 199 static const struct tramp_frame i386nbsd_sigtramp_si4 =
 200 {
 201   SIGTRAMP_FRAME,
 202   1,
 203   {
 204     { 0x8d, -1 }, { 0x84, -1 }, { 0x24, -1 },
 205         { 0x8c, -1 }, { 0x00, -1 }, { 0x00, -1 }, { 0x00, -1 },
 206                         /* leal  0x8c(%esp), %eax */
 207     { 0x89, -1 }, { 0x44, -1 }, { 0x24, -1 }, { 0x04, -1 },
 208                         /* movl  %eax, 0x4(%esp) */
 209     { 0xb8, -1 }, { 0x34, -1 }, { 0x01, -1 }, { 0x00, -1 }, { 0x00, -1 },
 210                         /* movl  $0x134, %eax            # setcontext */
 211     { 0xcd, -1 }, { 0x80, -1},
 212                         /* int   $0x80 */
 213     { 0xc7, -1 }, { 0x44, -1 }, { 0x24, -1 }, { 0x04, -1 },
 214         { 0xff, -1 }, { 0xff, -1 }, { 0xff, -1 }, { 0xff, -1 },
 215                         /* movl   $0xffffffff,0x4(%esp) */
 216     { 0xb8, -1 }, { 0x01, -1 }, {0x00, -1 }, {0x00, -1 }, {0x00, -1 },
 217                         /* movl  $0x1, %eax */
 218     { 0xcd, -1 }, { 0x80, -1},
 219                         /* int   $0x80 */
 220     { TRAMP_SENTINEL_INSN, -1 }
 221   },
 222   i386nbsd_sigtramp_cache_init
 223 };
 224
 225 static void
 226 i386nbsd_sigtramp_cache_init (const struct tramp_frame *self,
 227                               struct frame_info *this_frame,
 228                               struct trad_frame_cache *this_cache,
 229                               CORE_ADDR func)
 230 {
 231   struct gdbarch *gdbarch = get_frame_arch (this_frame);
 232   enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
 233   CORE_ADDR sp = get_frame_register_unsigned (this_frame, I386_ESP_REGNUM);
 234   CORE_ADDR base;
 235   int *reg_offset;
 236   int num_regs;
 237   int i;
 238
 239   if (self == &i386nbsd_sigtramp_sc16 || self == &i386nbsd_sigtramp_sc2)
 240     {
 241       reg_offset = i386nbsd_sc_reg_offset;
 242       num_regs = ARRAY_SIZE (i386nbsd_sc_reg_offset);
 243
 244       /* Read in the sigcontext address.  */
 245       base = read_memory_unsigned_integer (sp + 8, 4, byte_order);
 246     }
 247   else
 248     {
 249       reg_offset = i386nbsd_mc_reg_offset;
 250       num_regs = ARRAY_SIZE (i386nbsd_mc_reg_offset);
 251
 252       /* Read in the ucontext address.  */
 253       base = read_memory_unsigned_integer (sp + 8, 4, byte_order);
 254       /* offsetof(ucontext_t, uc_mcontext) == 36 */
 255       base += 36;
 256     }
 257
 258   for (i = 0; i < num_regs; i++)
 259     if (reg_offset[i] != -1)
 260       trad_frame_set_reg_addr (this_cache, i, base + reg_offset[i]);
 261
 262   /* Construct the frame ID using the function start.  */
 263   trad_frame_set_id (this_cache, frame_id_build (sp, func));
 264 }
 265 \f
 266
 267 static void
 268 i386nbsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 269 {
 270   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 271
 272   /* Obviously NetBSD is BSD-based.  */
 273   i386bsd_init_abi (info, gdbarch);
 274
 275   /* NetBSD has a different `struct reg'.  */
 276   tdep->gregset_reg_offset = i386nbsd_r_reg_offset;
 277   tdep->gregset_num_regs = ARRAY_SIZE (i386nbsd_r_reg_offset);
 278   tdep->sizeof_gregset = 16 * 4;
 279
 280   /* NetBSD uses -freg-struct-return by default.  */
 281   tdep->struct_return = reg_struct_return;
 282
 283   /* NetBSD uses tramp_frame sniffers for signal trampolines.  */
 284   tdep->sigcontext_addr= 0;
 285   tdep->sigtramp_start = 0;
 286   tdep->sigtramp_end = 0;
 287   tdep->sigtramp_p = 0;
 288   tdep->sc_reg_offset = 0;
 289   tdep->sc_num_regs = 0;
 290
 291   tramp_frame_prepend_unwinder (gdbarch, &i386nbsd_sigtramp_sc16);
 292   tramp_frame_prepend_unwinder (gdbarch, &i386nbsd_sigtramp_sc2);
 293   tramp_frame_prepend_unwinder (gdbarch, &i386nbsd_sigtramp_si2);
 294   tramp_frame_prepend_unwinder (gdbarch, &i386nbsd_sigtramp_si31);
 295   tramp_frame_prepend_unwinder (gdbarch, &i386nbsd_sigtramp_si4);
 296 }
 297
 298 /* NetBSD ELF.  */
 299
 300 static void
 301 i386nbsdelf_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 302 {
 303   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 304
 305   /* It's still NetBSD.  */
 306   i386nbsd_init_abi (info, gdbarch);
 307
 308   /* But ELF-based.  */
 309   i386_elf_init_abi (info, gdbarch);
 310
 311   /* NetBSD ELF uses SVR4-style shared libraries.  */
 312   set_solib_svr4_fetch_link_map_offsets
 313     (gdbarch, svr4_ilp32_fetch_link_map_offsets);
 314
 315   /* NetBSD ELF uses -fpcc-struct-return by default.  */
 316   tdep->struct_return = pcc_struct_return;
 317 }
 318
 319 void
 320 _initialize_i386nbsd_tdep (void)
 321 {
 322   gdbarch_register_osabi (bfd_arch_i386, 0, GDB_OSABI_NETBSD,
 323                           i386nbsdelf_init_abi);
 324 }