gdb/i386-netbsd-tdep.c

   1 /* Target-dependent code for NetBSD/i386.
   2
   3    Copyright (C) 1988-2021 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 "netbsd-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 static 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 static 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    /* leal  0x10(%esp), %eax */
 110    { 0x8d, ULONGEST_MAX },
 111    { 0x44, ULONGEST_MAX },
 112    { 0x24, ULONGEST_MAX },
 113    { 0x10, ULONGEST_MAX },
 114
 115    /* pushl %eax */
 116    { 0x50, ULONGEST_MAX },
 117
 118    /* pushl %eax */
 119    { 0x50, ULONGEST_MAX },
 120
 121    /* movl  $0x127, %eax                # __sigreturn14 */
 122    { 0xb8, ULONGEST_MAX },
 123    { 0x27, ULONGEST_MAX },
 124    {0x01, ULONGEST_MAX },
 125    {0x00, ULONGEST_MAX },
 126    {0x00, ULONGEST_MAX },
 127
 128    /* int   $0x80 */
 129    { 0xcd, ULONGEST_MAX },
 130    { 0x80, ULONGEST_MAX},
 131
 132    /* movl  $0x1, %eax          # exit */
 133    { 0xb8, ULONGEST_MAX },
 134    { 0x01, ULONGEST_MAX },
 135    {0x00, ULONGEST_MAX },
 136    {0x00, ULONGEST_MAX },
 137    {0x00, ULONGEST_MAX },
 138
 139    /* int   $0x80 */
 140    { 0xcd, ULONGEST_MAX },
 141    { 0x80, ULONGEST_MAX},
 142
 143    { TRAMP_SENTINEL_INSN, ULONGEST_MAX }
 144   },
 145   i386nbsd_sigtramp_cache_init
 146 };
 147
 148 static const struct tramp_frame i386nbsd_sigtramp_sc2 =
 149 {
 150   SIGTRAMP_FRAME,
 151   1,
 152   {
 153    /* leal  0x0c(%esp), %eax */
 154    { 0x8d, ULONGEST_MAX },
 155    { 0x44, ULONGEST_MAX },
 156    { 0x24, ULONGEST_MAX },
 157    { 0x0c, ULONGEST_MAX },
 158    /* movl  %eax, 0x4(%esp) */
 159    { 0x89, ULONGEST_MAX },
 160    { 0x44, ULONGEST_MAX },
 161    { 0x24, ULONGEST_MAX },
 162    { 0x04, ULONGEST_MAX },
 163    /* movl  $0x127, %eax                # __sigreturn14 */
 164    { 0xb8, ULONGEST_MAX },
 165    { 0x27, ULONGEST_MAX },
 166    {0x01, ULONGEST_MAX },
 167    {0x00, ULONGEST_MAX },
 168    {0x00, ULONGEST_MAX },
 169    /* int   $0x80 */
 170    { 0xcd, ULONGEST_MAX },
 171    { 0x80, ULONGEST_MAX},
 172    /* movl  %eax, 0x4(%esp) */
 173    { 0x89, ULONGEST_MAX },
 174    { 0x44, ULONGEST_MAX },
 175    { 0x24, ULONGEST_MAX },
 176    { 0x04, ULONGEST_MAX },
 177    /* movl  $0x1, %eax */
 178    { 0xb8, ULONGEST_MAX },
 179    { 0x01, ULONGEST_MAX },
 180    {0x00, ULONGEST_MAX },
 181    {0x00, ULONGEST_MAX },
 182    {0x00, ULONGEST_MAX },
 183    /* int   $0x80 */
 184    { 0xcd, ULONGEST_MAX },
 185    { 0x80, ULONGEST_MAX},
 186    { TRAMP_SENTINEL_INSN, ULONGEST_MAX }
 187   },
 188   i386nbsd_sigtramp_cache_init
 189 };
 190
 191 static const struct tramp_frame i386nbsd_sigtramp_si2 =
 192 {
 193   SIGTRAMP_FRAME,
 194   1,
 195   {
 196    /* movl  8(%esp),%eax */
 197    { 0x8b, ULONGEST_MAX },
 198    { 0x44, ULONGEST_MAX },
 199    { 0x24, ULONGEST_MAX },
 200    { 0x08, ULONGEST_MAX },
 201    /* movl  %eax, 0x4(%esp) */
 202    { 0x89, ULONGEST_MAX },
 203    { 0x44, ULONGEST_MAX },
 204    { 0x24, ULONGEST_MAX },
 205    { 0x04, ULONGEST_MAX },
 206    /* movl  $0x134, %eax            # setcontext */
 207    { 0xb8, ULONGEST_MAX },
 208    { 0x34, ULONGEST_MAX },
 209    { 0x01, ULONGEST_MAX },
 210    { 0x00, ULONGEST_MAX },
 211    { 0x00, ULONGEST_MAX },
 212    /* int   $0x80 */
 213    { 0xcd, ULONGEST_MAX },
 214    { 0x80, ULONGEST_MAX },
 215    /* movl  %eax, 0x4(%esp) */
 216    { 0x89, ULONGEST_MAX },
 217    { 0x44, ULONGEST_MAX },
 218    { 0x24, ULONGEST_MAX },
 219    { 0x04, ULONGEST_MAX },
 220    /* movl  $0x1, %eax */
 221    { 0xb8, ULONGEST_MAX },
 222    { 0x01, ULONGEST_MAX },
 223    { 0x00, ULONGEST_MAX },
 224    { 0x00, ULONGEST_MAX },
 225    { 0x00, ULONGEST_MAX },
 226    /* int   $0x80 */
 227    { 0xcd, ULONGEST_MAX },
 228    { 0x80, ULONGEST_MAX },
 229    { TRAMP_SENTINEL_INSN, ULONGEST_MAX }
 230   },
 231   i386nbsd_sigtramp_cache_init
 232 };
 233
 234 static const struct tramp_frame i386nbsd_sigtramp_si31 =
 235 {
 236   SIGTRAMP_FRAME,
 237   1,
 238   {
 239    /* leal  0x8c(%esp), %eax */
 240    { 0x8d, ULONGEST_MAX },
 241    { 0x84, ULONGEST_MAX },
 242    { 0x24, ULONGEST_MAX },
 243    { 0x8c, ULONGEST_MAX },
 244    { 0x00, ULONGEST_MAX },
 245    { 0x00, ULONGEST_MAX },
 246    { 0x00, ULONGEST_MAX },
 247    /* movl  %eax, 0x4(%esp) */
 248    { 0x89, ULONGEST_MAX },
 249    { 0x44, ULONGEST_MAX },
 250    { 0x24, ULONGEST_MAX },
 251    { 0x04, ULONGEST_MAX },
 252    /* movl  $0x134, %eax            # setcontext */
 253    { 0xb8, ULONGEST_MAX },
 254    { 0x34, ULONGEST_MAX },
 255    { 0x01, ULONGEST_MAX },
 256    { 0x00, ULONGEST_MAX },
 257    { 0x00, ULONGEST_MAX },
 258    /* int   $0x80 */
 259    { 0xcd, ULONGEST_MAX },
 260    { 0x80, ULONGEST_MAX},
 261    /* movl  %eax, 0x4(%esp) */
 262    { 0x89, ULONGEST_MAX },
 263    { 0x44, ULONGEST_MAX },
 264    { 0x24, ULONGEST_MAX },
 265    { 0x04, ULONGEST_MAX },
 266    /* movl  $0x1, %eax */
 267    { 0xb8, ULONGEST_MAX },
 268    { 0x01, ULONGEST_MAX },
 269    {0x00, ULONGEST_MAX },
 270    {0x00, ULONGEST_MAX },
 271    {0x00, ULONGEST_MAX },
 272    /* int   $0x80 */
 273    { 0xcd, ULONGEST_MAX },
 274    { 0x80, ULONGEST_MAX},
 275    { TRAMP_SENTINEL_INSN, ULONGEST_MAX }
 276   },
 277   i386nbsd_sigtramp_cache_init
 278 };
 279
 280 static const struct tramp_frame i386nbsd_sigtramp_si4 =
 281 {
 282   SIGTRAMP_FRAME,
 283   1,
 284   {
 285    /* leal  0x8c(%esp), %eax */
 286    { 0x8d, ULONGEST_MAX },
 287    { 0x84, ULONGEST_MAX },
 288    { 0x24, ULONGEST_MAX },
 289    { 0x8c, ULONGEST_MAX },
 290    { 0x00, ULONGEST_MAX },
 291    { 0x00, ULONGEST_MAX },
 292    { 0x00, ULONGEST_MAX },
 293    /* movl  %eax, 0x4(%esp) */
 294    { 0x89, ULONGEST_MAX },
 295    { 0x44, ULONGEST_MAX },
 296    { 0x24, ULONGEST_MAX },
 297    { 0x04, ULONGEST_MAX },
 298    /* movl  $0x134, %eax            # setcontext */
 299    { 0xb8, ULONGEST_MAX },
 300    { 0x34, ULONGEST_MAX },
 301    { 0x01, ULONGEST_MAX },
 302    { 0x00, ULONGEST_MAX },
 303    { 0x00, ULONGEST_MAX },
 304    /* int   $0x80 */
 305    { 0xcd, ULONGEST_MAX },
 306    { 0x80, ULONGEST_MAX},
 307    /* movl   $0xffffffff,0x4(%esp) */
 308    { 0xc7, ULONGEST_MAX },
 309    { 0x44, ULONGEST_MAX },
 310    { 0x24, ULONGEST_MAX },
 311    { 0x04, ULONGEST_MAX },
 312    { 0xff, ULONGEST_MAX },
 313    { 0xff, ULONGEST_MAX },
 314    { 0xff, ULONGEST_MAX },
 315    { 0xff, ULONGEST_MAX },
 316    /* movl  $0x1, %eax */
 317    { 0xb8, ULONGEST_MAX },
 318    { 0x01, ULONGEST_MAX },
 319    {0x00, ULONGEST_MAX },
 320    {0x00, ULONGEST_MAX },
 321    {0x00, ULONGEST_MAX },
 322    /* int   $0x80 */
 323    { 0xcd, ULONGEST_MAX },
 324    { 0x80, ULONGEST_MAX},
 325    { TRAMP_SENTINEL_INSN, ULONGEST_MAX }
 326   },
 327   i386nbsd_sigtramp_cache_init
 328 };
 329
 330 static void
 331 i386nbsd_sigtramp_cache_init (const struct tramp_frame *self,
 332                               struct frame_info *this_frame,
 333                               struct trad_frame_cache *this_cache,
 334                               CORE_ADDR func)
 335 {
 336   struct gdbarch *gdbarch = get_frame_arch (this_frame);
 337   enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
 338   CORE_ADDR sp = get_frame_register_unsigned (this_frame, I386_ESP_REGNUM);
 339   CORE_ADDR base;
 340   int *reg_offset;
 341   int num_regs;
 342   int i;
 343
 344   if (self == &i386nbsd_sigtramp_sc16 || self == &i386nbsd_sigtramp_sc2)
 345     {
 346       reg_offset = i386nbsd_sc_reg_offset;
 347       num_regs = ARRAY_SIZE (i386nbsd_sc_reg_offset);
 348
 349       /* Read in the sigcontext address.  */
 350       base = read_memory_unsigned_integer (sp + 8, 4, byte_order);
 351     }
 352   else
 353     {
 354       reg_offset = i386nbsd_mc_reg_offset;
 355       num_regs = ARRAY_SIZE (i386nbsd_mc_reg_offset);
 356
 357       /* Read in the ucontext address.  */
 358       base = read_memory_unsigned_integer (sp + 8, 4, byte_order);
 359       /* offsetof(ucontext_t, uc_mcontext) == 36 */
 360       base += 36;
 361     }
 362
 363   for (i = 0; i < num_regs; i++)
 364     if (reg_offset[i] != -1)
 365       trad_frame_set_reg_addr (this_cache, i, base + reg_offset[i]);
 366
 367   /* Construct the frame ID using the function start.  */
 368   trad_frame_set_id (this_cache, frame_id_build (sp, func));
 369 }
 370 \f
 371
 372 static void
 373 i386nbsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 374 {
 375   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 376
 377   /* Obviously NetBSD is BSD-based.  */
 378   i386bsd_init_abi (info, gdbarch);
 379
 380   nbsd_init_abi (info, gdbarch);
 381
 382   /* NetBSD has a different `struct reg'.  */
 383   tdep->gregset_reg_offset = i386nbsd_r_reg_offset;
 384   tdep->gregset_num_regs = ARRAY_SIZE (i386nbsd_r_reg_offset);
 385   tdep->sizeof_gregset = 16 * 4;
 386
 387   /* NetBSD uses -freg-struct-return by default.  */
 388   tdep->struct_return = reg_struct_return;
 389
 390   /* NetBSD uses tramp_frame sniffers for signal trampolines.  */
 391   tdep->sigcontext_addr= 0;
 392   tdep->sigtramp_start = 0;
 393   tdep->sigtramp_end = 0;
 394   tdep->sigtramp_p = 0;
 395   tdep->sc_reg_offset = 0;
 396   tdep->sc_num_regs = 0;
 397
 398   tramp_frame_prepend_unwinder (gdbarch, &i386nbsd_sigtramp_sc16);
 399   tramp_frame_prepend_unwinder (gdbarch, &i386nbsd_sigtramp_sc2);
 400   tramp_frame_prepend_unwinder (gdbarch, &i386nbsd_sigtramp_si2);
 401   tramp_frame_prepend_unwinder (gdbarch, &i386nbsd_sigtramp_si31);
 402   tramp_frame_prepend_unwinder (gdbarch, &i386nbsd_sigtramp_si4);
 403 }
 404
 405 /* NetBSD ELF.  */
 406
 407 static void
 408 i386nbsdelf_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 409 {
 410   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 411
 412   /* It's still NetBSD.  */
 413   i386nbsd_init_abi (info, gdbarch);
 414
 415   /* But ELF-based.  */
 416   i386_elf_init_abi (info, gdbarch);
 417
 418   /* NetBSD ELF uses SVR4-style shared libraries.  */
 419   set_solib_svr4_fetch_link_map_offsets
 420     (gdbarch, svr4_ilp32_fetch_link_map_offsets);
 421
 422   /* NetBSD ELF uses -fpcc-struct-return by default.  */
 423   tdep->struct_return = pcc_struct_return;
 424 }
 425
 426 void _initialize_i386nbsd_tdep ();
 427 void
 428 _initialize_i386nbsd_tdep ()
 429 {
 430   gdbarch_register_osabi (bfd_arch_i386, 0, GDB_OSABI_NETBSD,
 431                           i386nbsdelf_init_abi);
 432 }