gdb/i386-darwin-nat.c

   1 /* Darwin support for GDB, the GNU debugger.
   2    Copyright 1997-2013 Free Software Foundation, Inc.
   3
   4    Contributed by Apple Computer, 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 "frame.h"
  23 #include "inferior.h"
  24 #include "target.h"
  25 #include "symfile.h"
  26 #include "symtab.h"
  27 #include "objfiles.h"
  28 #include "gdbcmd.h"
  29 #include "regcache.h"
  30 #include "gdb_assert.h"
  31 #include "i386-tdep.h"
  32 #include "i387-tdep.h"
  33 #include "gdbarch.h"
  34 #include "arch-utils.h"
  35 #include "gdbcore.h"
  36
  37 #include "i386-nat.h"
  38 #include "darwin-nat.h"
  39 #include "i386-darwin-tdep.h"
  40
  41 #ifdef BFD64
  42 #include "amd64-nat.h"
  43 #include "amd64-tdep.h"
  44 #include "amd64-darwin-tdep.h"
  45 #endif
  46
  47 /* Read register values from the inferior process.
  48    If REGNO is -1, do this for all registers.
  49    Otherwise, REGNO specifies which register (so we can save time).  */
  50 static void
  51 i386_darwin_fetch_inferior_registers (struct target_ops *ops,
  52                                       struct regcache *regcache, int regno)
  53 {
  54   thread_t current_thread = ptid_get_tid (inferior_ptid);
  55   int fetched = 0;
  56   struct gdbarch *gdbarch = get_regcache_arch (regcache);
  57
  58 #ifdef BFD64
  59   if (gdbarch_ptr_bit (gdbarch) == 64)
  60     {
  61       if (regno == -1 || amd64_native_gregset_supplies_p (gdbarch, regno))
  62         {
  63           x86_thread_state_t gp_regs;
  64           unsigned int gp_count = x86_THREAD_STATE_COUNT;
  65           kern_return_t ret;
  66
  67           ret = thread_get_state
  68             (current_thread, x86_THREAD_STATE, (thread_state_t) & gp_regs,
  69              &gp_count);
  70           if (ret != KERN_SUCCESS)
  71             {
  72               printf_unfiltered (_("Error calling thread_get_state for "
  73                                    "GP registers for thread 0x%lx\n"),
  74                                  (unsigned long) current_thread);
  75               MACH_CHECK_ERROR (ret);
  76             }
  77           amd64_supply_native_gregset (regcache, &gp_regs.uts, -1);
  78           fetched++;
  79         }
  80
  81       if (regno == -1 || !amd64_native_gregset_supplies_p (gdbarch, regno))
  82         {
  83           x86_float_state_t fp_regs;
  84           unsigned int fp_count = x86_FLOAT_STATE_COUNT;
  85           kern_return_t ret;
  86
  87           ret = thread_get_state
  88             (current_thread, x86_FLOAT_STATE, (thread_state_t) & fp_regs,
  89              &fp_count);
  90           if (ret != KERN_SUCCESS)
  91             {
  92               printf_unfiltered (_("Error calling thread_get_state for "
  93                                    "float registers for thread 0x%lx\n"),
  94                                  (unsigned long) current_thread);
  95               MACH_CHECK_ERROR (ret);
  96             }
  97           amd64_supply_fxsave (regcache, -1, &fp_regs.ufs.fs64.__fpu_fcw);
  98           fetched++;
  99         }
 100     }
 101   else
 102 #endif
 103     {
 104       if (regno == -1 || regno < I386_NUM_GREGS)
 105         {
 106           x86_thread_state32_t gp_regs;
 107           unsigned int gp_count = x86_THREAD_STATE32_COUNT;
 108           kern_return_t ret;
 109           int i;
 110
 111           ret = thread_get_state
 112             (current_thread, x86_THREAD_STATE32, (thread_state_t) &gp_regs,
 113              &gp_count);
 114           if (ret != KERN_SUCCESS)
 115             {
 116               printf_unfiltered (_("Error calling thread_get_state for "
 117                                    "GP registers for thread 0x%lx\n"),
 118                                  (unsigned long) current_thread);
 119               MACH_CHECK_ERROR (ret);
 120             }
 121           for (i = 0; i < I386_NUM_GREGS; i++)
 122             regcache_raw_supply
 123               (regcache, i,
 124                (char *)&gp_regs + i386_darwin_thread_state_reg_offset[i]);
 125
 126           fetched++;
 127         }
 128
 129       if (regno == -1
 130           || (regno >= I386_ST0_REGNUM && regno < I386_SSE_NUM_REGS))
 131         {
 132           x86_float_state32_t fp_regs;
 133           unsigned int fp_count = x86_FLOAT_STATE32_COUNT;
 134           kern_return_t ret;
 135
 136           ret = thread_get_state
 137             (current_thread, x86_FLOAT_STATE32, (thread_state_t) &fp_regs,
 138              &fp_count);
 139           if (ret != KERN_SUCCESS)
 140             {
 141               printf_unfiltered (_("Error calling thread_get_state for "
 142                                    "float registers for thread 0x%lx\n"),
 143                                  (unsigned long) current_thread);
 144               MACH_CHECK_ERROR (ret);
 145             }
 146           i387_supply_fxsave (regcache, -1, &fp_regs.__fpu_fcw);
 147           fetched++;
 148         }
 149     }
 150
 151   if (! fetched)
 152     {
 153       warning (_("unknown register %d"), regno);
 154       regcache_raw_supply (regcache, regno, NULL);
 155     }
 156 }
 157
 158 /* Store our register values back into the inferior.
 159    If REGNO is -1, do this for all registers.
 160    Otherwise, REGNO specifies which register (so we can save time).  */
 161
 162 static void
 163 i386_darwin_store_inferior_registers (struct target_ops *ops,
 164                                       struct regcache *regcache, int regno)
 165 {
 166   thread_t current_thread = ptid_get_tid (inferior_ptid);
 167   struct gdbarch *gdbarch = get_regcache_arch (regcache);
 168
 169 #ifdef BFD64
 170   if (gdbarch_ptr_bit (gdbarch) == 64)
 171     {
 172       if (regno == -1 || amd64_native_gregset_supplies_p (gdbarch, regno))
 173         {
 174           x86_thread_state_t gp_regs;
 175           kern_return_t ret;
 176           unsigned int gp_count = x86_THREAD_STATE_COUNT;
 177
 178           ret = thread_get_state
 179             (current_thread, x86_THREAD_STATE, (thread_state_t) &gp_regs,
 180              &gp_count);
 181           MACH_CHECK_ERROR (ret);
 182           gdb_assert (gp_regs.tsh.flavor == x86_THREAD_STATE64);
 183           gdb_assert (gp_regs.tsh.count == x86_THREAD_STATE64_COUNT);
 184
 185           amd64_collect_native_gregset (regcache, &gp_regs.uts, regno);
 186
 187           ret = thread_set_state (current_thread, x86_THREAD_STATE,
 188                                   (thread_state_t) &gp_regs,
 189                                   x86_THREAD_STATE_COUNT);
 190           MACH_CHECK_ERROR (ret);
 191         }
 192
 193       if (regno == -1 || !amd64_native_gregset_supplies_p (gdbarch, regno))
 194         {
 195           x86_float_state_t fp_regs;
 196           kern_return_t ret;
 197           unsigned int fp_count = x86_FLOAT_STATE_COUNT;
 198
 199           ret = thread_get_state
 200             (current_thread, x86_FLOAT_STATE, (thread_state_t) & fp_regs,
 201              &fp_count);
 202           MACH_CHECK_ERROR (ret);
 203           gdb_assert (fp_regs.fsh.flavor == x86_FLOAT_STATE64);
 204           gdb_assert (fp_regs.fsh.count == x86_FLOAT_STATE64_COUNT);
 205
 206           amd64_collect_fxsave (regcache, regno, &fp_regs.ufs.fs64.__fpu_fcw);
 207
 208           ret = thread_set_state (current_thread, x86_FLOAT_STATE,
 209                                   (thread_state_t) & fp_regs,
 210                                   x86_FLOAT_STATE_COUNT);
 211           MACH_CHECK_ERROR (ret);
 212         }
 213     }
 214   else
 215 #endif
 216     {
 217       if (regno == -1 || regno < I386_NUM_GREGS)
 218         {
 219           x86_thread_state32_t gp_regs;
 220           kern_return_t ret;
 221           unsigned int gp_count = x86_THREAD_STATE32_COUNT;
 222           int i;
 223
 224           ret = thread_get_state
 225             (current_thread, x86_THREAD_STATE32, (thread_state_t) &gp_regs,
 226              &gp_count);
 227           MACH_CHECK_ERROR (ret);
 228
 229           for (i = 0; i < I386_NUM_GREGS; i++)
 230             if (regno == -1 || regno == i)
 231               regcache_raw_collect
 232                 (regcache, i,
 233                  (char *)&gp_regs + i386_darwin_thread_state_reg_offset[i]);
 234
 235           ret = thread_set_state (current_thread, x86_THREAD_STATE32,
 236                                   (thread_state_t) &gp_regs,
 237                                   x86_THREAD_STATE32_COUNT);
 238           MACH_CHECK_ERROR (ret);
 239         }
 240
 241       if (regno == -1
 242           || (regno >= I386_ST0_REGNUM && regno < I386_SSE_NUM_REGS))
 243         {
 244           x86_float_state32_t fp_regs;
 245           unsigned int fp_count = x86_FLOAT_STATE32_COUNT;
 246           kern_return_t ret;
 247
 248           ret = thread_get_state
 249             (current_thread, x86_FLOAT_STATE32, (thread_state_t) & fp_regs,
 250              &fp_count);
 251           MACH_CHECK_ERROR (ret);
 252
 253           i387_collect_fxsave (regcache, regno, &fp_regs.__fpu_fcw);
 254
 255           ret = thread_set_state (current_thread, x86_FLOAT_STATE32,
 256                                   (thread_state_t) &fp_regs,
 257                                   x86_FLOAT_STATE32_COUNT);
 258           MACH_CHECK_ERROR (ret);
 259         }
 260     }
 261 }
 262
 263 #ifdef HW_WATCHPOINT_NOT_YET_ENABLED
 264 /* Support for debug registers, boosted mostly from i386-linux-nat.c.  */
 265
 266 static void
 267 i386_darwin_dr_set (int regnum, uint32_t value)
 268 {
 269   int current_pid;
 270   thread_t current_thread;
 271   x86_debug_state_t dr_regs;
 272   kern_return_t ret;
 273   unsigned int dr_count = x86_DEBUG_STATE_COUNT;
 274
 275   gdb_assert (regnum >= 0 && regnum <= DR_CONTROL);
 276
 277   current_thread = ptid_get_tid (inferior_ptid);
 278
 279   dr_regs.dsh.flavor = x86_DEBUG_STATE32;
 280   dr_regs.dsh.count = x86_DEBUG_STATE32_COUNT;
 281   dr_count = x86_DEBUG_STATE_COUNT;
 282   ret = thread_get_state (current_thread, x86_DEBUG_STATE,
 283                           (thread_state_t) &dr_regs, &dr_count);
 284
 285   if (ret != KERN_SUCCESS)
 286     {
 287       printf_unfiltered (_("Error reading debug registers "
 288                            "thread 0x%x via thread_get_state\n"),
 289                          (int) current_thread);
 290       MACH_CHECK_ERROR (ret);
 291     }
 292
 293   switch (regnum)
 294     {
 295       case 0:
 296         dr_regs.uds.ds32.__dr0 = value;
 297         break;
 298       case 1:
 299         dr_regs.uds.ds32.__dr1 = value;
 300         break;
 301       case 2:
 302         dr_regs.uds.ds32.__dr2 = value;
 303         break;
 304       case 3:
 305         dr_regs.uds.ds32.__dr3 = value;
 306         break;
 307       case 4:
 308         dr_regs.uds.ds32.__dr4 = value;
 309         break;
 310       case 5:
 311         dr_regs.uds.ds32.__dr5 = value;
 312         break;
 313       case 6:
 314         dr_regs.uds.ds32.__dr6 = value;
 315         break;
 316       case 7:
 317         dr_regs.uds.ds32.__dr7 = value;
 318         break;
 319     }
 320
 321   ret = thread_set_state (current_thread, x86_DEBUG_STATE,
 322                           (thread_state_t) &dr_regs, dr_count);
 323
 324   if (ret != KERN_SUCCESS)
 325     {
 326       printf_unfiltered (_("Error writing debug registers "
 327                            "thread 0x%x via thread_get_state\n"),
 328                          (int) current_thread);
 329       MACH_CHECK_ERROR (ret);
 330     }
 331 }
 332
 333 static uint32_t
 334 i386_darwin_dr_get (int regnum)
 335 {
 336   thread_t current_thread;
 337   x86_debug_state_t dr_regs;
 338   kern_return_t ret;
 339   unsigned int dr_count = x86_DEBUG_STATE_COUNT;
 340
 341   gdb_assert (regnum >= 0 && regnum <= DR_CONTROL);
 342
 343   current_thread = ptid_get_tid (inferior_ptid);
 344
 345   dr_regs.dsh.flavor = x86_DEBUG_STATE32;
 346   dr_regs.dsh.count = x86_DEBUG_STATE32_COUNT;
 347   dr_count = x86_DEBUG_STATE_COUNT;
 348   ret = thread_get_state (current_thread, x86_DEBUG_STATE,
 349                           (thread_state_t) &dr_regs, &dr_count);
 350
 351   if (ret != KERN_SUCCESS)
 352     {
 353       printf_unfiltered (_("Error reading debug registers "
 354                            "thread 0x%x via thread_get_state\n"),
 355                          (int) current_thread);
 356       MACH_CHECK_ERROR (ret);
 357     }
 358
 359   switch (regnum)
 360     {
 361       case 0:
 362         return dr_regs.uds.ds32.__dr0;
 363       case 1:
 364         return dr_regs.uds.ds32.__dr1;
 365       case 2:
 366         return dr_regs.uds.ds32.__dr2;
 367       case 3:
 368         return dr_regs.uds.ds32.__dr3;
 369       case 4:
 370         return dr_regs.uds.ds32.__dr4;
 371       case 5:
 372         return dr_regs.uds.ds32.__dr5;
 373       case 6:
 374         return dr_regs.uds.ds32.__dr6;
 375       case 7:
 376         return dr_regs.uds.ds32.__dr7;
 377       default:
 378         return -1;
 379     }
 380 }
 381
 382 void
 383 i386_darwin_dr_set_control (unsigned long control)
 384 {
 385   i386_darwin_dr_set (DR_CONTROL, control);
 386 }
 387
 388 void
 389 i386_darwin_dr_set_addr (int regnum, CORE_ADDR addr)
 390 {
 391   gdb_assert (regnum >= 0 && regnum <= DR_LASTADDR - DR_FIRSTADDR);
 392
 393   i386_darwin_dr_set (DR_FIRSTADDR + regnum, addr);
 394 }
 395
 396 CORE_ADDR
 397 i386_darwin_dr_get_addr (int regnum)
 398 {
 399   return i386_darwin_dr_get (regnum);
 400 }
 401
 402 unsigned long
 403 i386_darwin_dr_get_status (void)
 404 {
 405   return i386_darwin_dr_get (DR_STATUS);
 406 }
 407
 408 unsigned long
 409 i386_darwin_dr_get_control (void)
 410 {
 411   return i386_darwin_dr_get (DR_CONTROL);
 412 }
 413 #endif
 414
 415 void
 416 darwin_check_osabi (darwin_inferior *inf, thread_t thread)
 417 {
 418   if (gdbarch_osabi (target_gdbarch ()) == GDB_OSABI_UNKNOWN)
 419     {
 420       /* Attaching to a process.  Let's figure out what kind it is.  */
 421       x86_thread_state_t gp_regs;
 422       struct gdbarch_info info;
 423       unsigned int gp_count = x86_THREAD_STATE_COUNT;
 424       kern_return_t ret;
 425
 426       ret = thread_get_state (thread, x86_THREAD_STATE,
 427                               (thread_state_t) &gp_regs, &gp_count);
 428       if (ret != KERN_SUCCESS)
 429         {
 430           MACH_CHECK_ERROR (ret);
 431           return;
 432         }
 433
 434       gdbarch_info_init (&info);
 435       gdbarch_info_fill (&info);
 436       info.byte_order = gdbarch_byte_order (target_gdbarch ());
 437       info.osabi = GDB_OSABI_DARWIN;
 438       if (gp_regs.tsh.flavor == x86_THREAD_STATE64)
 439         info.bfd_arch_info = bfd_lookup_arch (bfd_arch_i386,
 440                                               bfd_mach_x86_64);
 441       else
 442         info.bfd_arch_info = bfd_lookup_arch (bfd_arch_i386,
 443                                               bfd_mach_i386_i386);
 444       gdbarch_update_p (info);
 445     }
 446 }
 447
 448 #define X86_EFLAGS_T 0x100UL
 449
 450 /* Returning from a signal trampoline is done by calling a
 451    special system call (sigreturn).  This system call
 452    restores the registers that were saved when the signal was
 453    raised, including %eflags/%rflags.  That means that single-stepping
 454    won't work.  Instead, we'll have to modify the signal context
 455    that's about to be restored, and set the trace flag there.  */
 456
 457 static int
 458 i386_darwin_sstep_at_sigreturn (x86_thread_state_t *regs)
 459 {
 460   enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch ());
 461   static const gdb_byte darwin_syscall[] = { 0xcd, 0x80 }; /* int 0x80 */
 462   gdb_byte buf[sizeof (darwin_syscall)];
 463
 464   /* Check if PC is at a sigreturn system call.  */
 465   if (target_read_memory (regs->uts.ts32.__eip, buf, sizeof (buf)) == 0
 466       && memcmp (buf, darwin_syscall, sizeof (darwin_syscall)) == 0
 467       && regs->uts.ts32.__eax == 0xb8 /* SYS_sigreturn */)
 468     {
 469       ULONGEST uctx_addr;
 470       ULONGEST mctx_addr;
 471       ULONGEST flags_addr;
 472       unsigned int eflags;
 473
 474       uctx_addr = read_memory_unsigned_integer
 475                     (regs->uts.ts32.__esp + 4, 4, byte_order);
 476       mctx_addr = read_memory_unsigned_integer
 477                     (uctx_addr + 28, 4, byte_order);
 478
 479       flags_addr = mctx_addr + 12 + 9 * 4;
 480       read_memory (flags_addr, (gdb_byte *) &eflags, 4);
 481       eflags |= X86_EFLAGS_T;
 482       write_memory (flags_addr, (gdb_byte *) &eflags, 4);
 483
 484       return 1;
 485     }
 486   return 0;
 487 }
 488
 489 #ifdef BFD64
 490 static int
 491 amd64_darwin_sstep_at_sigreturn (x86_thread_state_t *regs)
 492 {
 493   enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch ());
 494   static const gdb_byte darwin_syscall[] = { 0x0f, 0x05 }; /* syscall */
 495   gdb_byte buf[sizeof (darwin_syscall)];
 496
 497   /* Check if PC is at a sigreturn system call.  */
 498   if (target_read_memory (regs->uts.ts64.__rip, buf, sizeof (buf)) == 0
 499       && memcmp (buf, darwin_syscall, sizeof (darwin_syscall)) == 0
 500       && (regs->uts.ts64.__rax & 0xffffffff) == 0x20000b8 /* SYS_sigreturn */)
 501     {
 502       ULONGEST mctx_addr;
 503       ULONGEST flags_addr;
 504       unsigned int rflags;
 505
 506       mctx_addr = read_memory_unsigned_integer
 507                     (regs->uts.ts64.__rdi + 48, 8, byte_order);
 508       flags_addr = mctx_addr + 16 + 17 * 8;
 509
 510       /* AMD64 is little endian.  */
 511       read_memory (flags_addr, (gdb_byte *) &rflags, 4);
 512       rflags |= X86_EFLAGS_T;
 513       write_memory (flags_addr, (gdb_byte *) &rflags, 4);
 514
 515       return 1;
 516     }
 517   return 0;
 518 }
 519 #endif
 520
 521 void
 522 darwin_set_sstep (thread_t thread, int enable)
 523 {
 524   x86_thread_state_t regs;
 525   unsigned int count = x86_THREAD_STATE_COUNT;
 526   kern_return_t kret;
 527
 528   kret = thread_get_state (thread, x86_THREAD_STATE,
 529                            (thread_state_t) &regs, &count);
 530   if (kret != KERN_SUCCESS)
 531     {
 532       printf_unfiltered (_("darwin_set_sstep: error %x, thread=%x\n"),
 533                          kret, thread);
 534       return;
 535     }
 536
 537   switch (regs.tsh.flavor)
 538     {
 539     case x86_THREAD_STATE32:
 540       {
 541         __uint32_t bit = enable ? X86_EFLAGS_T : 0;
 542
 543         if (enable && i386_darwin_sstep_at_sigreturn (&regs))
 544           return;
 545         if ((regs.uts.ts32.__eflags & X86_EFLAGS_T) == bit)
 546           return;
 547         regs.uts.ts32.__eflags
 548           = (regs.uts.ts32.__eflags & ~X86_EFLAGS_T) | bit;
 549         kret = thread_set_state (thread, x86_THREAD_STATE,
 550                                  (thread_state_t) &regs, count);
 551         MACH_CHECK_ERROR (kret);
 552       }
 553       break;
 554 #ifdef BFD64
 555     case x86_THREAD_STATE64:
 556       {
 557         __uint64_t bit = enable ? X86_EFLAGS_T : 0;
 558
 559         if (enable && amd64_darwin_sstep_at_sigreturn (&regs))
 560           return;
 561         if ((regs.uts.ts64.__rflags & X86_EFLAGS_T) == bit)
 562           return;
 563         regs.uts.ts64.__rflags
 564           = (regs.uts.ts64.__rflags & ~X86_EFLAGS_T) | bit;
 565         kret = thread_set_state (thread, x86_THREAD_STATE,
 566                                  (thread_state_t) &regs, count);
 567         MACH_CHECK_ERROR (kret);
 568       }
 569       break;
 570 #endif
 571     default:
 572       error (_("darwin_set_sstep: unknown flavour: %d"), regs.tsh.flavor);
 573     }
 574 }
 575
 576 void
 577 darwin_complete_target (struct target_ops *target)
 578 {
 579 #ifdef BFD64
 580   amd64_native_gregset64_reg_offset = amd64_darwin_thread_state_reg_offset;
 581   amd64_native_gregset64_num_regs = amd64_darwin_thread_state_num_regs;
 582   amd64_native_gregset32_reg_offset = i386_darwin_thread_state_reg_offset;
 583   amd64_native_gregset32_num_regs = i386_darwin_thread_state_num_regs;
 584 #endif
 585
 586   target->to_fetch_registers = i386_darwin_fetch_inferior_registers;
 587   target->to_store_registers = i386_darwin_store_inferior_registers;
 588 }