gdb/i386-netbsd-tdep.c

   1 /* Target-dependent code for NetBSD/i386.
   2
   3    Copyright (C) 1988-2024 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 "arch-utils.h"
  21 #include "frame.h"
  22 #include "gdbcore.h"
  23 #include "regcache.h"
  24 #include "regset.h"
  25 #include "osabi.h"
  26 #include "symtab.h"
  27 #include "trad-frame.h"
  28 #include "tramp-frame.h"
  29
  30 #include "i386-tdep.h"
  31 #include "i387-tdep.h"
  32 #include "netbsd-tdep.h"
  33 #include "solib-svr4.h"
  34
  35 /* From <machine/reg.h>.  */
  36 static int i386nbsd_r_reg_offset[] =
  37 {
  38   0 * 4,                        /* %eax */
  39   1 * 4,                        /* %ecx */
  40   2 * 4,                        /* %edx */
  41   3 * 4,                        /* %ebx */
  42   4 * 4,                        /* %esp */
  43   5 * 4,                        /* %ebp */
  44   6 * 4,                        /* %esi */
  45   7 * 4,                        /* %edi */
  46   8 * 4,                        /* %eip */
  47   9 * 4,                        /* %eflags */
  48   10 * 4,                       /* %cs */
  49   11 * 4,                       /* %ss */
  50   12 * 4,                       /* %ds */
  51   13 * 4,                       /* %es */
  52   14 * 4,                       /* %fs */
  53   15 * 4                        /* %gs */
  54 };
  55
  56 /* From <machine/signal.h>.  */
  57 static int i386nbsd_sc_reg_offset[] =
  58 {
  59   10 * 4,                       /* %eax */
  60   9 * 4,                        /* %ecx */
  61   8 * 4,                        /* %edx */
  62   7 * 4,                        /* %ebx */
  63   14 * 4,                       /* %esp */
  64   6 * 4,                        /* %ebp */
  65   5 * 4,                        /* %esi */
  66   4 * 4,                        /* %edi */
  67   11 * 4,                       /* %eip */
  68   13 * 4,                       /* %eflags */
  69   12 * 4,                       /* %cs */
  70   15 * 4,                       /* %ss */
  71   3 * 4,                        /* %ds */
  72   2 * 4,                        /* %es */
  73   1 * 4,                        /* %fs */
  74   0 * 4                         /* %gs */
  75 };
  76
  77 /* From <machine/mcontext.h>.  */
  78 static int i386nbsd_mc_reg_offset[] =
  79 {
  80   11 * 4,                       /* %eax */
  81   10 * 4,                       /* %ecx */
  82   9 * 4,                        /* %edx */
  83   8 * 4,                        /* %ebx */
  84   7 * 4,                        /* %esp */
  85   6 * 4,                        /* %ebp */
  86   5 * 4,                        /* %esi */
  87   4 * 4,                        /* %edi */
  88   14 * 4,                       /* %eip */
  89   16 * 4,                       /* %eflags */
  90   15 * 4,                       /* %cs */
  91   18 * 4,                       /* %ss */
  92   3 * 4,                        /* %ds */
  93   2 * 4,                        /* %es */
  94   1 * 4,                        /* %fs */
  95   0 * 4                         /* %gs */
  96 };
  97
  98 static void i386nbsd_sigtramp_cache_init (const struct tramp_frame *,
  99                                           const frame_info_ptr &,
 100                                           struct trad_frame_cache *,
 101                                           CORE_ADDR);
 102
 103 static const struct tramp_frame i386nbsd_sigtramp_sc16 =
 104 {
 105   SIGTRAMP_FRAME,
 106   1,
 107   {
 108    /* leal  0x10(%esp), %eax */
 109    { 0x8d, ULONGEST_MAX },
 110    { 0x44, ULONGEST_MAX },
 111    { 0x24, ULONGEST_MAX },
 112    { 0x10, ULONGEST_MAX },
 113
 114    /* pushl %eax */
 115    { 0x50, ULONGEST_MAX },
 116
 117    /* pushl %eax */
 118    { 0x50, ULONGEST_MAX },
 119
 120    /* movl  $0x127, %eax                # __sigreturn14 */
 121    { 0xb8, ULONGEST_MAX },
 122    { 0x27, ULONGEST_MAX },
 123    {0x01, ULONGEST_MAX },
 124    {0x00, ULONGEST_MAX },
 125    {0x00, ULONGEST_MAX },
 126
 127    /* int   $0x80 */
 128    { 0xcd, ULONGEST_MAX },
 129    { 0x80, ULONGEST_MAX},
 130
 131    /* movl  $0x1, %eax          # exit */
 132    { 0xb8, ULONGEST_MAX },
 133    { 0x01, ULONGEST_MAX },
 134    {0x00, ULONGEST_MAX },
 135    {0x00, ULONGEST_MAX },
 136    {0x00, ULONGEST_MAX },
 137
 138    /* int   $0x80 */
 139    { 0xcd, ULONGEST_MAX },
 140    { 0x80, ULONGEST_MAX},
 141
 142    { TRAMP_SENTINEL_INSN, ULONGEST_MAX }
 143   },
 144   i386nbsd_sigtramp_cache_init
 145 };
 146
 147 static const struct tramp_frame i386nbsd_sigtramp_sc2 =
 148 {
 149   SIGTRAMP_FRAME,
 150   1,
 151   {
 152    /* leal  0x0c(%esp), %eax */
 153    { 0x8d, ULONGEST_MAX },
 154    { 0x44, ULONGEST_MAX },
 155    { 0x24, ULONGEST_MAX },
 156    { 0x0c, ULONGEST_MAX },
 157    /* movl  %eax, 0x4(%esp) */
 158    { 0x89, ULONGEST_MAX },
 159    { 0x44, ULONGEST_MAX },
 160    { 0x24, ULONGEST_MAX },
 161    { 0x04, ULONGEST_MAX },
 162    /* movl  $0x127, %eax                # __sigreturn14 */
 163    { 0xb8, ULONGEST_MAX },
 164    { 0x27, ULONGEST_MAX },
 165    {0x01, ULONGEST_MAX },
 166    {0x00, ULONGEST_MAX },
 167    {0x00, ULONGEST_MAX },
 168    /* int   $0x80 */
 169    { 0xcd, ULONGEST_MAX },
 170    { 0x80, ULONGEST_MAX},
 171    /* movl  %eax, 0x4(%esp) */
 172    { 0x89, ULONGEST_MAX },
 173    { 0x44, ULONGEST_MAX },
 174    { 0x24, ULONGEST_MAX },
 175    { 0x04, ULONGEST_MAX },
 176    /* movl  $0x1, %eax */
 177    { 0xb8, ULONGEST_MAX },
 178    { 0x01, ULONGEST_MAX },
 179    {0x00, ULONGEST_MAX },
 180    {0x00, ULONGEST_MAX },
 181    {0x00, ULONGEST_MAX },
 182    /* int   $0x80 */
 183    { 0xcd, ULONGEST_MAX },
 184    { 0x80, ULONGEST_MAX},
 185    { TRAMP_SENTINEL_INSN, ULONGEST_MAX }
 186   },
 187   i386nbsd_sigtramp_cache_init
 188 };
 189
 190 static const struct tramp_frame i386nbsd_sigtramp_si2 =
 191 {
 192   SIGTRAMP_FRAME,
 193   1,
 194   {
 195    /* movl  8(%esp),%eax */
 196    { 0x8b, ULONGEST_MAX },
 197    { 0x44, ULONGEST_MAX },
 198    { 0x24, ULONGEST_MAX },
 199    { 0x08, ULONGEST_MAX },
 200    /* movl  %eax, 0x4(%esp) */
 201    { 0x89, ULONGEST_MAX },
 202    { 0x44, ULONGEST_MAX },
 203    { 0x24, ULONGEST_MAX },
 204    { 0x04, ULONGEST_MAX },
 205    /* movl  $0x134, %eax            # setcontext */
 206    { 0xb8, ULONGEST_MAX },
 207    { 0x34, ULONGEST_MAX },
 208    { 0x01, ULONGEST_MAX },
 209    { 0x00, ULONGEST_MAX },
 210    { 0x00, ULONGEST_MAX },
 211    /* int   $0x80 */
 212    { 0xcd, ULONGEST_MAX },
 213    { 0x80, ULONGEST_MAX },
 214    /* movl  %eax, 0x4(%esp) */
 215    { 0x89, ULONGEST_MAX },
 216    { 0x44, ULONGEST_MAX },
 217    { 0x24, ULONGEST_MAX },
 218    { 0x04, ULONGEST_MAX },
 219    /* movl  $0x1, %eax */
 220    { 0xb8, ULONGEST_MAX },
 221    { 0x01, ULONGEST_MAX },
 222    { 0x00, ULONGEST_MAX },
 223    { 0x00, ULONGEST_MAX },
 224    { 0x00, ULONGEST_MAX },
 225    /* int   $0x80 */
 226    { 0xcd, ULONGEST_MAX },
 227    { 0x80, ULONGEST_MAX },
 228    { TRAMP_SENTINEL_INSN, ULONGEST_MAX }
 229   },
 230   i386nbsd_sigtramp_cache_init
 231 };
 232
 233 static const struct tramp_frame i386nbsd_sigtramp_si31 =
 234 {
 235   SIGTRAMP_FRAME,
 236   1,
 237   {
 238    /* leal  0x8c(%esp), %eax */
 239    { 0x8d, ULONGEST_MAX },
 240    { 0x84, ULONGEST_MAX },
 241    { 0x24, ULONGEST_MAX },
 242    { 0x8c, ULONGEST_MAX },
 243    { 0x00, ULONGEST_MAX },
 244    { 0x00, ULONGEST_MAX },
 245    { 0x00, ULONGEST_MAX },
 246    /* movl  %eax, 0x4(%esp) */
 247    { 0x89, ULONGEST_MAX },
 248    { 0x44, ULONGEST_MAX },
 249    { 0x24, ULONGEST_MAX },
 250    { 0x04, ULONGEST_MAX },
 251    /* movl  $0x134, %eax            # setcontext */
 252    { 0xb8, ULONGEST_MAX },
 253    { 0x34, ULONGEST_MAX },
 254    { 0x01, ULONGEST_MAX },
 255    { 0x00, ULONGEST_MAX },
 256    { 0x00, ULONGEST_MAX },
 257    /* int   $0x80 */
 258    { 0xcd, ULONGEST_MAX },
 259    { 0x80, ULONGEST_MAX},
 260    /* movl  %eax, 0x4(%esp) */
 261    { 0x89, ULONGEST_MAX },
 262    { 0x44, ULONGEST_MAX },
 263    { 0x24, ULONGEST_MAX },
 264    { 0x04, ULONGEST_MAX },
 265    /* movl  $0x1, %eax */
 266    { 0xb8, ULONGEST_MAX },
 267    { 0x01, ULONGEST_MAX },
 268    {0x00, ULONGEST_MAX },
 269    {0x00, ULONGEST_MAX },
 270    {0x00, ULONGEST_MAX },
 271    /* int   $0x80 */
 272    { 0xcd, ULONGEST_MAX },
 273    { 0x80, ULONGEST_MAX},
 274    { TRAMP_SENTINEL_INSN, ULONGEST_MAX }
 275   },
 276   i386nbsd_sigtramp_cache_init
 277 };
 278
 279 static const struct tramp_frame i386nbsd_sigtramp_si4 =
 280 {
 281   SIGTRAMP_FRAME,
 282   1,
 283   {
 284    /* leal  0x8c(%esp), %eax */
 285    { 0x8d, ULONGEST_MAX },
 286    { 0x84, ULONGEST_MAX },
 287    { 0x24, ULONGEST_MAX },
 288    { 0x8c, ULONGEST_MAX },
 289    { 0x00, ULONGEST_MAX },
 290    { 0x00, ULONGEST_MAX },
 291    { 0x00, ULONGEST_MAX },
 292    /* movl  %eax, 0x4(%esp) */
 293    { 0x89, ULONGEST_MAX },
 294    { 0x44, ULONGEST_MAX },
 295    { 0x24, ULONGEST_MAX },
 296    { 0x04, ULONGEST_MAX },
 297    /* movl  $0x134, %eax            # setcontext */
 298    { 0xb8, ULONGEST_MAX },
 299    { 0x34, ULONGEST_MAX },
 300    { 0x01, ULONGEST_MAX },
 301    { 0x00, ULONGEST_MAX },
 302    { 0x00, ULONGEST_MAX },
 303    /* int   $0x80 */
 304    { 0xcd, ULONGEST_MAX },
 305    { 0x80, ULONGEST_MAX},
 306    /* movl   $0xffffffff,0x4(%esp) */
 307    { 0xc7, ULONGEST_MAX },
 308    { 0x44, ULONGEST_MAX },
 309    { 0x24, ULONGEST_MAX },
 310    { 0x04, ULONGEST_MAX },
 311    { 0xff, ULONGEST_MAX },
 312    { 0xff, ULONGEST_MAX },
 313    { 0xff, ULONGEST_MAX },
 314    { 0xff, ULONGEST_MAX },
 315    /* movl  $0x1, %eax */
 316    { 0xb8, ULONGEST_MAX },
 317    { 0x01, ULONGEST_MAX },
 318    {0x00, ULONGEST_MAX },
 319    {0x00, ULONGEST_MAX },
 320    {0x00, ULONGEST_MAX },
 321    /* int   $0x80 */
 322    { 0xcd, ULONGEST_MAX },
 323    { 0x80, ULONGEST_MAX},
 324    { TRAMP_SENTINEL_INSN, ULONGEST_MAX }
 325   },
 326   i386nbsd_sigtramp_cache_init
 327 };
 328
 329 static void
 330 i386nbsd_sigtramp_cache_init (const struct tramp_frame *self,
 331                               const frame_info_ptr &this_frame,
 332                               struct trad_frame_cache *this_cache,
 333                               CORE_ADDR func)
 334 {
 335   struct gdbarch *gdbarch = get_frame_arch (this_frame);
 336   enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
 337   CORE_ADDR sp = get_frame_register_unsigned (this_frame, I386_ESP_REGNUM);
 338   CORE_ADDR base;
 339   int *reg_offset;
 340   int num_regs;
 341   int i;
 342
 343   if (self == &i386nbsd_sigtramp_sc16 || self == &i386nbsd_sigtramp_sc2)
 344     {
 345       reg_offset = i386nbsd_sc_reg_offset;
 346       num_regs = ARRAY_SIZE (i386nbsd_sc_reg_offset);
 347
 348       /* Read in the sigcontext address.  */
 349       base = read_memory_unsigned_integer (sp + 8, 4, byte_order);
 350     }
 351   else
 352     {
 353       reg_offset = i386nbsd_mc_reg_offset;
 354       num_regs = ARRAY_SIZE (i386nbsd_mc_reg_offset);
 355
 356       /* Read in the ucontext address.  */
 357       base = read_memory_unsigned_integer (sp + 8, 4, byte_order);
 358       /* offsetof(ucontext_t, uc_mcontext) == 36 */
 359       base += 36;
 360     }
 361
 362   for (i = 0; i < num_regs; i++)
 363     if (reg_offset[i] != -1)
 364       trad_frame_set_reg_addr (this_cache, i, base + reg_offset[i]);
 365
 366   /* Construct the frame ID using the function start.  */
 367   trad_frame_set_id (this_cache, frame_id_build (sp, func));
 368 }
 369 \f
 370
 371 static void
 372 i386nbsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 373 {
 374   i386_gdbarch_tdep *tdep = gdbarch_tdep<i386_gdbarch_tdep> (gdbarch);
 375
 376   /* Obviously NetBSD is BSD-based.  */
 377   i386bsd_init_abi (info, gdbarch);
 378
 379   nbsd_init_abi (info, gdbarch);
 380
 381   /* NetBSD has a different `struct reg'.  */
 382   tdep->gregset_reg_offset = i386nbsd_r_reg_offset;
 383   tdep->gregset_num_regs = ARRAY_SIZE (i386nbsd_r_reg_offset);
 384   tdep->sizeof_gregset = 16 * 4;
 385
 386   /* NetBSD uses -freg-struct-return by default.  */
 387   tdep->struct_return = reg_struct_return;
 388
 389   /* NetBSD uses tramp_frame sniffers for signal trampolines.  */
 390   tdep->sigcontext_addr= 0;
 391   tdep->sigtramp_start = 0;
 392   tdep->sigtramp_end = 0;
 393   tdep->sigtramp_p = 0;
 394   tdep->sc_reg_offset = 0;
 395   tdep->sc_num_regs = 0;
 396
 397   tramp_frame_prepend_unwinder (gdbarch, &i386nbsd_sigtramp_sc16);
 398   tramp_frame_prepend_unwinder (gdbarch, &i386nbsd_sigtramp_sc2);
 399   tramp_frame_prepend_unwinder (gdbarch, &i386nbsd_sigtramp_si2);
 400   tramp_frame_prepend_unwinder (gdbarch, &i386nbsd_sigtramp_si31);
 401   tramp_frame_prepend_unwinder (gdbarch, &i386nbsd_sigtramp_si4);
 402 }
 403
 404 /* NetBSD ELF.  */
 405
 406 static void
 407 i386nbsdelf_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 408 {
 409   i386_gdbarch_tdep *tdep = gdbarch_tdep<i386_gdbarch_tdep> (gdbarch);
 410
 411   /* It's still NetBSD.  */
 412   i386nbsd_init_abi (info, gdbarch);
 413
 414   /* But ELF-based.  */
 415   i386_elf_init_abi (info, gdbarch);
 416
 417   /* NetBSD ELF uses SVR4-style shared libraries.  */
 418   set_solib_svr4_fetch_link_map_offsets
 419     (gdbarch, svr4_ilp32_fetch_link_map_offsets);
 420
 421   /* NetBSD ELF uses -fpcc-struct-return by default.  */
 422   tdep->struct_return = pcc_struct_return;
 423 }
 424
 425 void _initialize_i386nbsd_tdep ();
 426 void
 427 _initialize_i386nbsd_tdep ()
 428 {
 429   gdbarch_register_osabi (bfd_arch_i386, 0, GDB_OSABI_NETBSD,
 430                           i386nbsdelf_init_abi);
 431 }