gdb/i386-darwin-nat.c

   1 /* Darwin support for GDB, the GNU debugger.
   2    Copyright 1997, 1998, 1999, 2000, 2001, 2002, 2008, 2009, 2010, 2011
   3    Free Software Foundation, Inc.
   4
   5    Contributed by Apple Computer, Inc.
   6
   7    This file is part of GDB.
   8
   9    This program is free software; you can redistribute it and/or modify
  10    it under the terms of the GNU General Public License as published by
  11    the Free Software Foundation; either version 3 of the License, or
  12    (at your option) any later version.
  13
  14    This program is distributed in the hope that it will be useful,
  15    but WITHOUT ANY WARRANTY; without even the implied warranty of
  16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17    GNU General Public License for more details.
  18
  19    You should have received a copy of the GNU General Public License
  20    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  21
  22 #include "defs.h"
  23 #include "frame.h"
  24 #include "inferior.h"
  25 #include "target.h"
  26 #include "symfile.h"
  27 #include "symtab.h"
  28 #include "objfiles.h"
  29 #include "gdbcmd.h"
  30 #include "regcache.h"
  31 #include "gdb_assert.h"
  32 #include "i386-tdep.h"
  33 #include "i387-tdep.h"
  34 #include "gdbarch.h"
  35 #include "arch-utils.h"
  36 #include "gdbcore.h"
  37
  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%ulx"),
  74                                  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%ulx"),
  94                                  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           i386_thread_state_t gp_regs;
 107           unsigned int gp_count = i386_THREAD_STATE_COUNT;
 108           kern_return_t ret;
 109           int i;
 110
 111           ret = thread_get_state
 112             (current_thread, i386_THREAD_STATE, (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%ulx"),
 118                                  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           i386_float_state_t fp_regs;
 133           unsigned int fp_count = i386_FLOAT_STATE_COUNT;
 134           kern_return_t ret;
 135
 136           ret = thread_get_state
 137             (current_thread, i386_FLOAT_STATE, (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%ulx"),
 143                                  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           i386_thread_state_t gp_regs;
 220           kern_return_t ret;
 221           unsigned int gp_count = i386_THREAD_STATE_COUNT;
 222           int i;
 223
 224           ret = thread_get_state
 225             (current_thread, i386_THREAD_STATE, (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, i386_THREAD_STATE,
 236                                   (thread_state_t) & gp_regs,
 237                                   i386_THREAD_STATE_COUNT);
 238           MACH_CHECK_ERROR (ret);
 239         }
 240
 241       if (regno == -1
 242           || (regno >= I386_ST0_REGNUM && regno < I386_SSE_NUM_REGS))
 243         {
 244           i386_float_state_t fp_regs;
 245           unsigned int fp_count = i386_FLOAT_STATE_COUNT;
 246           kern_return_t ret;
 247
 248           ret = thread_get_state
 249             (current_thread, i386_FLOAT_STATE, (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, i386_FLOAT_STATE,
 256                                   (thread_state_t) & fp_regs,
 257                                   i386_FLOAT_STATE_COUNT);
 258           MACH_CHECK_ERROR (ret);
 259         }
 260     }
 261 }
 262
 263
 264 /* Support for debug registers, boosted mostly from i386-linux-nat.c.  */
 265
 266 #ifndef DR_FIRSTADDR
 267 #define DR_FIRSTADDR 0
 268 #endif
 269
 270 #ifndef DR_LASTADDR
 271 #define DR_LASTADDR 3
 272 #endif
 273
 274 #ifndef DR_STATUS
 275 #define DR_STATUS 6
 276 #endif
 277
 278 #ifndef DR_CONTROL
 279 #define DR_CONTROL 7
 280 #endif
 281
 282
 283 static void
 284 i386_darwin_dr_set (int regnum, uint32_t value)
 285 {
 286   int current_pid;
 287   thread_t current_thread;
 288   x86_debug_state_t dr_regs;
 289   kern_return_t ret;
 290   unsigned int dr_count = x86_DEBUG_STATE_COUNT;
 291
 292   gdb_assert (regnum >= 0 && regnum <= DR_CONTROL);
 293
 294   current_thread = ptid_get_tid (inferior_ptid);
 295
 296   dr_regs.dsh.flavor = x86_DEBUG_STATE32;
 297   dr_regs.dsh.count = x86_DEBUG_STATE32_COUNT;
 298   dr_count = x86_DEBUG_STATE_COUNT;
 299   ret = thread_get_state (current_thread, x86_DEBUG_STATE,
 300                           (thread_state_t) &dr_regs, &dr_count);
 301
 302   if (ret != KERN_SUCCESS)
 303     {
 304       printf_unfiltered (_("Error reading debug registers "
 305                            "thread 0x%x via thread_get_state\n"),
 306                          (int) current_thread);
 307       MACH_CHECK_ERROR (ret);
 308     }
 309
 310   switch (regnum)
 311     {
 312       case 0:
 313         dr_regs.uds.ds32.__dr0 = value;
 314         break;
 315       case 1:
 316         dr_regs.uds.ds32.__dr1 = value;
 317         break;
 318       case 2:
 319         dr_regs.uds.ds32.__dr2 = value;
 320         break;
 321       case 3:
 322         dr_regs.uds.ds32.__dr3 = value;
 323         break;
 324       case 4:
 325         dr_regs.uds.ds32.__dr4 = value;
 326         break;
 327       case 5:
 328         dr_regs.uds.ds32.__dr5 = value;
 329         break;
 330       case 6:
 331         dr_regs.uds.ds32.__dr6 = value;
 332         break;
 333       case 7:
 334         dr_regs.uds.ds32.__dr7 = value;
 335         break;
 336     }
 337
 338   ret = thread_set_state (current_thread, x86_DEBUG_STATE,
 339                           (thread_state_t) &dr_regs, dr_count);
 340
 341   if (ret != KERN_SUCCESS)
 342     {
 343       printf_unfiltered (_("Error writing debug registers "
 344                            "thread 0x%x via thread_get_state\n"),
 345                          (int) current_thread);
 346       MACH_CHECK_ERROR (ret);
 347     }
 348 }
 349
 350 static uint32_t
 351 i386_darwin_dr_get (int regnum)
 352 {
 353   thread_t current_thread;
 354   x86_debug_state_t dr_regs;
 355   kern_return_t ret;
 356   unsigned int dr_count = x86_DEBUG_STATE_COUNT;
 357
 358   gdb_assert (regnum >= 0 && regnum <= DR_CONTROL);
 359
 360   current_thread = ptid_get_tid (inferior_ptid);
 361
 362   dr_regs.dsh.flavor = x86_DEBUG_STATE32;
 363   dr_regs.dsh.count = x86_DEBUG_STATE32_COUNT;
 364   dr_count = x86_DEBUG_STATE_COUNT;
 365   ret = thread_get_state (current_thread, x86_DEBUG_STATE,
 366                           (thread_state_t) &dr_regs, &dr_count);
 367
 368   if (ret != KERN_SUCCESS)
 369     {
 370       printf_unfiltered (_("Error reading debug registers "
 371                            "thread 0x%x via thread_get_state\n"),
 372                          (int) current_thread);
 373       MACH_CHECK_ERROR (ret);
 374     }
 375
 376   switch (regnum)
 377     {
 378       case 0:
 379         return dr_regs.uds.ds32.__dr0;
 380       case 1:
 381         return dr_regs.uds.ds32.__dr1;
 382       case 2:
 383         return dr_regs.uds.ds32.__dr2;
 384       case 3:
 385         return dr_regs.uds.ds32.__dr3;
 386       case 4:
 387         return dr_regs.uds.ds32.__dr4;
 388       case 5:
 389         return dr_regs.uds.ds32.__dr5;
 390       case 6:
 391         return dr_regs.uds.ds32.__dr6;
 392       case 7:
 393         return dr_regs.uds.ds32.__dr7;
 394       default:
 395         return -1;
 396     }
 397 }
 398
 399 void
 400 i386_darwin_dr_set_control (unsigned long control)
 401 {
 402   i386_darwin_dr_set (DR_CONTROL, control);
 403 }
 404
 405 void
 406 i386_darwin_dr_set_addr (int regnum, CORE_ADDR addr)
 407 {
 408   gdb_assert (regnum >= 0 && regnum <= DR_LASTADDR - DR_FIRSTADDR);
 409
 410   i386_darwin_dr_set (DR_FIRSTADDR + regnum, addr);
 411 }
 412
 413 void
 414 i386_darwin_dr_reset_addr (int regnum)
 415 {
 416   gdb_assert (regnum >= 0 && regnum <= DR_LASTADDR - DR_FIRSTADDR);
 417
 418   i386_darwin_dr_set (DR_FIRSTADDR + regnum, 0L);
 419 }
 420
 421 unsigned long
 422 i386_darwin_dr_get_status (void)
 423 {
 424   return i386_darwin_dr_get (DR_STATUS);
 425 }
 426
 427 void
 428 darwin_check_osabi (darwin_inferior *inf, thread_t thread)
 429 {
 430   if (gdbarch_osabi (target_gdbarch) == GDB_OSABI_UNKNOWN)
 431     {
 432       /* Attaching to a process.  Let's figure out what kind it is.  */
 433       x86_thread_state_t gp_regs;
 434       struct gdbarch_info info;
 435       unsigned int gp_count = x86_THREAD_STATE_COUNT;
 436       kern_return_t ret;
 437
 438       ret = thread_get_state (thread, x86_THREAD_STATE,
 439                               (thread_state_t) &gp_regs, &gp_count);
 440       if (ret != KERN_SUCCESS)
 441         {
 442           MACH_CHECK_ERROR (ret);
 443           return;
 444         }
 445
 446       gdbarch_info_init (&info);
 447       gdbarch_info_fill (&info);
 448       info.byte_order = gdbarch_byte_order (target_gdbarch);
 449       info.osabi = GDB_OSABI_DARWIN;
 450       if (gp_regs.tsh.flavor == x86_THREAD_STATE64)
 451         info.bfd_arch_info = bfd_lookup_arch (bfd_arch_i386,
 452                                               bfd_mach_x86_64);
 453       else
 454         info.bfd_arch_info = bfd_lookup_arch (bfd_arch_i386,
 455                                               bfd_mach_i386_i386);
 456       gdbarch_update_p (info);
 457     }
 458 }
 459
 460 #define X86_EFLAGS_T 0x100UL
 461
 462 /* Returning from a signal trampoline is done by calling a
 463    special system call (sigreturn).  This system call
 464    restores the registers that were saved when the signal was
 465    raised, including %eflags/%rflags.  That means that single-stepping
 466    won't work.  Instead, we'll have to modify the signal context
 467    that's about to be restored, and set the trace flag there.  */
 468
 469 static int
 470 i386_darwin_sstep_at_sigreturn (x86_thread_state_t *regs)
 471 {
 472   enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch);
 473   static const gdb_byte darwin_syscall[] = { 0xcd, 0x80 }; /* int 0x80 */
 474   gdb_byte buf[sizeof (darwin_syscall)];
 475
 476   /* Check if PC is at a sigreturn system call.  */
 477   if (target_read_memory (regs->uts.ts32.__eip, buf, sizeof (buf)) == 0
 478       && memcmp (buf, darwin_syscall, sizeof (darwin_syscall)) == 0
 479       && regs->uts.ts32.__eax == 0xb8 /* SYS_sigreturn */)
 480     {
 481       ULONGEST uctx_addr;
 482       ULONGEST mctx_addr;
 483       ULONGEST flags_addr;
 484       unsigned int eflags;
 485
 486       uctx_addr = read_memory_unsigned_integer
 487                     (regs->uts.ts32.__esp + 4, 4, byte_order);
 488       mctx_addr = read_memory_unsigned_integer
 489                     (uctx_addr + 28, 4, byte_order);
 490
 491       flags_addr = mctx_addr + 12 + 9 * 4;
 492       read_memory (flags_addr, (gdb_byte *) &eflags, 4);
 493       eflags |= X86_EFLAGS_T;
 494       write_memory (flags_addr, (gdb_byte *) &eflags, 4);
 495
 496       return 1;
 497     }
 498   return 0;
 499 }
 500
 501 #ifdef BFD64
 502 static int
 503 amd64_darwin_sstep_at_sigreturn (x86_thread_state_t *regs)
 504 {
 505   enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch);
 506   static const gdb_byte darwin_syscall[] = { 0x0f, 0x05 }; /* syscall */
 507   gdb_byte buf[sizeof (darwin_syscall)];
 508
 509   /* Check if PC is at a sigreturn system call.  */
 510   if (target_read_memory (regs->uts.ts64.__rip, buf, sizeof (buf)) == 0
 511       && memcmp (buf, darwin_syscall, sizeof (darwin_syscall)) == 0
 512       && (regs->uts.ts64.__rax & 0xffffffff) == 0x20000b8 /* SYS_sigreturn */)
 513     {
 514       ULONGEST mctx_addr;
 515       ULONGEST flags_addr;
 516       unsigned int rflags;
 517
 518       mctx_addr = read_memory_unsigned_integer
 519                     (regs->uts.ts64.__rdi + 48, 8, byte_order);
 520       flags_addr = mctx_addr + 16 + 17 * 8;
 521
 522       /* AMD64 is little endian.  */
 523       read_memory (flags_addr, (gdb_byte *) &rflags, 4);
 524       rflags |= X86_EFLAGS_T;
 525       write_memory (flags_addr, (gdb_byte *) &rflags, 4);
 526
 527       return 1;
 528     }
 529   return 0;
 530 }
 531 #endif
 532
 533 void
 534 darwin_set_sstep (thread_t thread, int enable)
 535 {
 536   x86_thread_state_t regs;
 537   unsigned int count = x86_THREAD_STATE_COUNT;
 538   kern_return_t kret;
 539
 540   kret = thread_get_state (thread, x86_THREAD_STATE,
 541                            (thread_state_t) &regs, &count);
 542   if (kret != KERN_SUCCESS)
 543     {
 544       printf_unfiltered (_("darwin_set_sstep: error %x, thread=%x\n"),
 545                          kret, thread);
 546       return;
 547     }
 548
 549   switch (regs.tsh.flavor)
 550     {
 551     case x86_THREAD_STATE32:
 552       {
 553         __uint32_t bit = enable ? X86_EFLAGS_T : 0;
 554
 555         if (enable && i386_darwin_sstep_at_sigreturn (&regs))
 556           return;
 557         if ((regs.uts.ts32.__eflags & X86_EFLAGS_T) == bit)
 558           return;
 559         regs.uts.ts32.__eflags
 560           = (regs.uts.ts32.__eflags & ~X86_EFLAGS_T) | bit;
 561         kret = thread_set_state (thread, x86_THREAD_STATE,
 562                                  (thread_state_t) &regs, count);
 563         MACH_CHECK_ERROR (kret);
 564       }
 565       break;
 566 #ifdef BFD64
 567     case x86_THREAD_STATE64:
 568       {
 569         __uint64_t bit = enable ? X86_EFLAGS_T : 0;
 570
 571         if (enable && amd64_darwin_sstep_at_sigreturn (&regs))
 572           return;
 573         if ((regs.uts.ts64.__rflags & X86_EFLAGS_T) == bit)
 574           return;
 575         regs.uts.ts64.__rflags
 576           = (regs.uts.ts64.__rflags & ~X86_EFLAGS_T) | bit;
 577         kret = thread_set_state (thread, x86_THREAD_STATE,
 578                                  (thread_state_t) &regs, count);
 579         MACH_CHECK_ERROR (kret);
 580       }
 581       break;
 582 #endif
 583     default:
 584       error (_("darwin_set_sstep: unknown flavour: %d"), regs.tsh.flavor);
 585     }
 586 }
 587
 588 void
 589 darwin_complete_target (struct target_ops *target)
 590 {
 591 #ifdef BFD64
 592   amd64_native_gregset64_reg_offset = amd64_darwin_thread_state_reg_offset;
 593   amd64_native_gregset64_num_regs = amd64_darwin_thread_state_num_regs;
 594   amd64_native_gregset32_reg_offset = i386_darwin_thread_state_reg_offset;
 595   amd64_native_gregset32_num_regs = i386_darwin_thread_state_num_regs;
 596 #endif
 597
 598   target->to_fetch_registers = i386_darwin_fetch_inferior_registers;
 599   target->to_store_registers = i386_darwin_store_inferior_registers;
 600 }