gdb/i386-darwin-nat.c

   1 /* Darwin support for GDB, the GNU debugger.
   2    Copyright 1997, 1998, 1999, 2000, 2001, 2002, 2008, 2009
   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 "amd64-nat.h"
  34 #include "i387-tdep.h"
  35 #include "gdbarch.h"
  36 #include "arch-utils.h"
  37 #include "gdbcore.h"
  38
  39 #include "darwin-nat.h"
  40 #include "i386-darwin-tdep.h"
  41
  42 /* Read register values from the inferior process.
  43    If REGNO is -1, do this for all registers.
  44    Otherwise, REGNO specifies which register (so we can save time).  */
  45 static void
  46 i386_darwin_fetch_inferior_registers (struct target_ops *ops,
  47                                       struct regcache *regcache, int regno)
  48 {
  49   thread_t current_thread = ptid_get_tid (inferior_ptid);
  50   int fetched = 0;
  51   struct gdbarch *gdbarch = get_regcache_arch (regcache);
  52
  53   if (gdbarch_ptr_bit (gdbarch) == 64)
  54     {
  55       if (regno == -1 || amd64_native_gregset_supplies_p (gdbarch, regno))
  56         {
  57           x86_thread_state_t gp_regs;
  58           unsigned int gp_count = x86_THREAD_STATE_COUNT;
  59           kern_return_t ret;
  60
  61           ret = thread_get_state
  62             (current_thread, x86_THREAD_STATE, (thread_state_t) & gp_regs,
  63              &gp_count);
  64           if (ret != KERN_SUCCESS)
  65             {
  66               printf_unfiltered (_("Error calling thread_get_state for GP registers for thread 0x%ulx"), current_thread);
  67               MACH_CHECK_ERROR (ret);
  68             }
  69           amd64_supply_native_gregset (regcache, &gp_regs.uts, -1);
  70           fetched++;
  71         }
  72
  73       if (regno == -1 || !amd64_native_gregset_supplies_p (gdbarch, regno))
  74         {
  75           x86_float_state_t fp_regs;
  76           unsigned int fp_count = x86_FLOAT_STATE_COUNT;
  77           kern_return_t ret;
  78
  79           ret = thread_get_state
  80             (current_thread, x86_FLOAT_STATE, (thread_state_t) & fp_regs,
  81              &fp_count);
  82           if (ret != KERN_SUCCESS)
  83             {
  84               printf_unfiltered (_("Error calling thread_get_state for float registers for thread 0x%ulx"), current_thread);
  85               MACH_CHECK_ERROR (ret);
  86             }
  87           i387_supply_fxsave (regcache, -1, &fp_regs.ufs.fs64);
  88           fetched++;
  89         }
  90     }
  91   else
  92     {
  93       if (regno == -1 || regno < I386_NUM_GREGS)
  94         {
  95           i386_thread_state_t gp_regs;
  96           unsigned int gp_count = i386_THREAD_STATE_COUNT;
  97           kern_return_t ret;
  98           int i;
  99
 100           ret = thread_get_state
 101             (current_thread, i386_THREAD_STATE, (thread_state_t) & gp_regs,
 102              &gp_count);
 103           if (ret != KERN_SUCCESS)
 104             {
 105               printf_unfiltered (_("Error calling thread_get_state for GP registers for thread 0x%ulx"), current_thread);
 106               MACH_CHECK_ERROR (ret);
 107             }
 108           for (i = 0; i < I386_NUM_GREGS; i++)
 109             regcache_raw_supply
 110               (regcache, i,
 111                (char *)&gp_regs + i386_darwin_thread_state_reg_offset[i]);
 112
 113           fetched++;
 114         }
 115
 116       if (regno == -1
 117           || (regno >= I386_ST0_REGNUM && regno < I386_SSE_NUM_REGS))
 118         {
 119           i386_float_state_t fp_regs;
 120           unsigned int fp_count = i386_FLOAT_STATE_COUNT;
 121           kern_return_t ret;
 122
 123           ret = thread_get_state
 124             (current_thread, i386_FLOAT_STATE, (thread_state_t) & fp_regs,
 125              &fp_count);
 126           if (ret != KERN_SUCCESS)
 127             {
 128               printf_unfiltered (_("Error calling thread_get_state for float registers for thread 0x%ulx"), current_thread);
 129               MACH_CHECK_ERROR (ret);
 130             }
 131           i387_supply_fxsave (regcache, -1, &fp_regs.__fpu_fcw);
 132           fetched++;
 133         }
 134     }
 135
 136   if (! fetched)
 137     {
 138       warning (_("unknown register %d"), regno);
 139       regcache_raw_supply (regcache, regno, NULL);
 140     }
 141 }
 142
 143 /* Store our register values back into the inferior.
 144    If REGNO is -1, do this for all registers.
 145    Otherwise, REGNO specifies which register (so we can save time).  */
 146
 147 static void
 148 i386_darwin_store_inferior_registers (struct target_ops *ops,
 149                                       struct regcache *regcache, int regno)
 150 {
 151   thread_t current_thread = ptid_get_tid (inferior_ptid);
 152   struct gdbarch *gdbarch = get_regcache_arch (regcache);
 153
 154   if (gdbarch_ptr_bit (gdbarch) == 64)
 155     {
 156       if (regno == -1 || amd64_native_gregset_supplies_p (gdbarch, regno))
 157         {
 158           x86_thread_state_t gp_regs;
 159           kern_return_t ret;
 160           unsigned int gp_count = x86_THREAD_STATE_COUNT;
 161
 162           ret = thread_get_state
 163             (current_thread, x86_THREAD_STATE, (thread_state_t) &gp_regs,
 164              &gp_count);
 165           MACH_CHECK_ERROR (ret);
 166           gdb_assert (gp_regs.tsh.flavor == x86_THREAD_STATE64);
 167           gdb_assert (gp_regs.tsh.count == x86_THREAD_STATE64_COUNT);
 168
 169           amd64_collect_native_gregset (regcache, &gp_regs.uts, regno);
 170
 171           ret = thread_set_state (current_thread, x86_THREAD_STATE,
 172                                   (thread_state_t) &gp_regs,
 173                                   x86_THREAD_STATE_COUNT);
 174           MACH_CHECK_ERROR (ret);
 175         }
 176
 177       if (regno == -1 || !amd64_native_gregset_supplies_p (gdbarch, regno))
 178         {
 179           x86_float_state_t fp_regs;
 180           kern_return_t ret;
 181           unsigned int fp_count = x86_FLOAT_STATE_COUNT;
 182
 183           ret = thread_get_state
 184             (current_thread, x86_FLOAT_STATE, (thread_state_t) & fp_regs,
 185              &fp_count);
 186           MACH_CHECK_ERROR (ret);
 187           gdb_assert (fp_regs.fsh.flavor == x86_FLOAT_STATE64);
 188           gdb_assert (fp_regs.fsh.count == x86_FLOAT_STATE64_COUNT);
 189
 190           i387_collect_fxsave (regcache, regno, &fp_regs.ufs.fs64.__fpu_fcw);
 191
 192           ret = thread_set_state (current_thread, x86_FLOAT_STATE,
 193                                   (thread_state_t) & fp_regs,
 194                                   x86_FLOAT_STATE_COUNT);
 195           MACH_CHECK_ERROR (ret);
 196         }
 197     }
 198   else
 199     {
 200       if (regno == -1 || regno < I386_NUM_GREGS)
 201         {
 202           i386_thread_state_t gp_regs;
 203           kern_return_t ret;
 204           unsigned int gp_count = i386_THREAD_STATE_COUNT;
 205           int i;
 206
 207           ret = thread_get_state
 208             (current_thread, i386_THREAD_STATE, (thread_state_t) & gp_regs,
 209              &gp_count);
 210           MACH_CHECK_ERROR (ret);
 211
 212           for (i = 0; i < I386_NUM_GREGS; i++)
 213             if (regno == -1 || regno == i)
 214               regcache_raw_collect
 215                 (regcache, i,
 216                  (char *)&gp_regs + i386_darwin_thread_state_reg_offset[i]);
 217
 218           ret = thread_set_state (current_thread, i386_THREAD_STATE,
 219                                   (thread_state_t) & gp_regs,
 220                                   i386_THREAD_STATE_COUNT);
 221           MACH_CHECK_ERROR (ret);
 222         }
 223
 224       if (regno == -1
 225           || (regno >= I386_ST0_REGNUM && regno < I386_SSE_NUM_REGS))
 226         {
 227           i386_float_state_t fp_regs;
 228           unsigned int fp_count = i386_FLOAT_STATE_COUNT;
 229           kern_return_t ret;
 230
 231           ret = thread_get_state
 232             (current_thread, i386_FLOAT_STATE, (thread_state_t) & fp_regs,
 233              &fp_count);
 234           MACH_CHECK_ERROR (ret);
 235
 236           i387_collect_fxsave (regcache, regno, &fp_regs.__fpu_fcw);
 237
 238           ret = thread_set_state (current_thread, i386_FLOAT_STATE,
 239                                   (thread_state_t) & fp_regs,
 240                                   i386_FLOAT_STATE_COUNT);
 241           MACH_CHECK_ERROR (ret);
 242         }
 243     }
 244 }
 245
 246
 247 /* Support for debug registers, boosted mostly from i386-linux-nat.c.  */
 248
 249 #ifndef DR_FIRSTADDR
 250 #define DR_FIRSTADDR 0
 251 #endif
 252
 253 #ifndef DR_LASTADDR
 254 #define DR_LASTADDR 3
 255 #endif
 256
 257 #ifndef DR_STATUS
 258 #define DR_STATUS 6
 259 #endif
 260
 261 #ifndef DR_CONTROL
 262 #define DR_CONTROL 7
 263 #endif
 264
 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 thread 0x%x via thread_get_state\n"), (int) current_thread);
 288       MACH_CHECK_ERROR (ret);
 289     }
 290
 291   switch (regnum)
 292     {
 293       case 0:
 294         dr_regs.uds.ds32.__dr0 = value;
 295         break;
 296       case 1:
 297         dr_regs.uds.ds32.__dr1 = value;
 298         break;
 299       case 2:
 300         dr_regs.uds.ds32.__dr2 = value;
 301         break;
 302       case 3:
 303         dr_regs.uds.ds32.__dr3 = value;
 304         break;
 305       case 4:
 306         dr_regs.uds.ds32.__dr4 = value;
 307         break;
 308       case 5:
 309         dr_regs.uds.ds32.__dr5 = value;
 310         break;
 311       case 6:
 312         dr_regs.uds.ds32.__dr6 = value;
 313         break;
 314       case 7:
 315         dr_regs.uds.ds32.__dr7 = value;
 316         break;
 317     }
 318
 319   ret = thread_set_state (current_thread, x86_DEBUG_STATE,
 320                           (thread_state_t) &dr_regs, dr_count);
 321
 322   if (ret != KERN_SUCCESS)
 323     {
 324       printf_unfiltered (_("Error writing debug registers thread 0x%x via thread_get_state\n"), (int) current_thread);
 325       MACH_CHECK_ERROR (ret);
 326     }
 327 }
 328
 329 static uint32_t
 330 i386_darwin_dr_get (int regnum)
 331 {
 332   thread_t current_thread;
 333   x86_debug_state_t dr_regs;
 334   kern_return_t ret;
 335   unsigned int dr_count = x86_DEBUG_STATE_COUNT;
 336
 337   gdb_assert (regnum >= 0 && regnum <= DR_CONTROL);
 338
 339   current_thread = ptid_get_tid (inferior_ptid);
 340
 341   dr_regs.dsh.flavor = x86_DEBUG_STATE32;
 342   dr_regs.dsh.count = x86_DEBUG_STATE32_COUNT;
 343   dr_count = x86_DEBUG_STATE_COUNT;
 344   ret = thread_get_state (current_thread, x86_DEBUG_STATE,
 345                           (thread_state_t) &dr_regs, &dr_count);
 346
 347   if (ret != KERN_SUCCESS)
 348     {
 349       printf_unfiltered (_("Error reading debug registers thread 0x%x via thread_get_state\n"), (int) current_thread);
 350       MACH_CHECK_ERROR (ret);
 351     }
 352
 353   switch (regnum)
 354     {
 355       case 0:
 356         return dr_regs.uds.ds32.__dr0;
 357       case 1:
 358         return dr_regs.uds.ds32.__dr1;
 359       case 2:
 360         return dr_regs.uds.ds32.__dr2;
 361       case 3:
 362         return dr_regs.uds.ds32.__dr3;
 363       case 4:
 364         return dr_regs.uds.ds32.__dr4;
 365       case 5:
 366         return dr_regs.uds.ds32.__dr5;
 367       case 6:
 368         return dr_regs.uds.ds32.__dr6;
 369       case 7:
 370         return dr_regs.uds.ds32.__dr7;
 371       default:
 372         return -1;
 373     }
 374 }
 375
 376 void
 377 i386_darwin_dr_set_control (unsigned long control)
 378 {
 379   i386_darwin_dr_set (DR_CONTROL, control);
 380 }
 381
 382 void
 383 i386_darwin_dr_set_addr (int regnum, CORE_ADDR addr)
 384 {
 385   gdb_assert (regnum >= 0 && regnum <= DR_LASTADDR - DR_FIRSTADDR);
 386
 387   i386_darwin_dr_set (DR_FIRSTADDR + regnum, addr);
 388 }
 389
 390 void
 391 i386_darwin_dr_reset_addr (int regnum)
 392 {
 393   gdb_assert (regnum >= 0 && regnum <= DR_LASTADDR - DR_FIRSTADDR);
 394
 395   i386_darwin_dr_set (DR_FIRSTADDR + regnum, 0L);
 396 }
 397
 398 unsigned long
 399 i386_darwin_dr_get_status (void)
 400 {
 401   return i386_darwin_dr_get (DR_STATUS);
 402 }
 403
 404 void
 405 darwin_check_osabi (darwin_inferior *inf, thread_t thread)
 406 {
 407   if (gdbarch_osabi (target_gdbarch) == GDB_OSABI_UNKNOWN)
 408     {
 409       /* Attaching to a process.  Let's figure out what kind it is.  */
 410       x86_thread_state_t gp_regs;
 411       struct gdbarch_info info;
 412       unsigned int gp_count = x86_THREAD_STATE_COUNT;
 413       kern_return_t ret;
 414
 415       ret = thread_get_state (thread, x86_THREAD_STATE,
 416                               (thread_state_t) &gp_regs, &gp_count);
 417       if (ret != KERN_SUCCESS)
 418         {
 419           MACH_CHECK_ERROR (ret);
 420           return;
 421         }
 422
 423       gdbarch_info_init (&info);
 424       gdbarch_info_fill (&info);
 425       info.byte_order = gdbarch_byte_order (target_gdbarch);
 426       info.osabi = GDB_OSABI_DARWIN;
 427       if (gp_regs.tsh.flavor == x86_THREAD_STATE64)
 428         info.bfd_arch_info = bfd_lookup_arch (bfd_arch_i386,
 429                                               bfd_mach_x86_64);
 430       else
 431         info.bfd_arch_info = bfd_lookup_arch (bfd_arch_i386,
 432                                               bfd_mach_i386_i386);
 433       gdbarch_update_p (info);
 434     }
 435 }
 436
 437 #define X86_EFLAGS_T 0x100UL
 438
 439 /* Returning from a signal trampoline is done by calling a
 440    special system call (sigreturn).  This system call
 441    restores the registers that were saved when the signal was
 442    raised, including %eflags/%rflags.  That means that single-stepping
 443    won't work.  Instead, we'll have to modify the signal context
 444    that's about to be restored, and set the trace flag there.  */
 445
 446 static int
 447 i386_darwin_sstep_at_sigreturn (x86_thread_state_t *regs)
 448 {
 449   enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch);
 450   static const gdb_byte darwin_syscall[] = { 0xcd, 0x80 }; /* int 0x80 */
 451   gdb_byte buf[sizeof (darwin_syscall)];
 452
 453   /* Check if PC is at a sigreturn system call.  */
 454   if (target_read_memory (regs->uts.ts32.__eip, buf, sizeof (buf)) == 0
 455       && memcmp (buf, darwin_syscall, sizeof (darwin_syscall)) == 0
 456       && regs->uts.ts32.__eax == 0xb8 /* SYS_sigreturn */)
 457     {
 458       ULONGEST uctx_addr;
 459       ULONGEST mctx_addr;
 460       ULONGEST flags_addr;
 461       unsigned int eflags;
 462
 463       uctx_addr = read_memory_unsigned_integer
 464                     (regs->uts.ts32.__esp + 4, 4, byte_order);
 465       mctx_addr = read_memory_unsigned_integer
 466                     (uctx_addr + 28, 4, byte_order);
 467
 468       flags_addr = mctx_addr + 12 + 9 * 4;
 469       read_memory (flags_addr, (gdb_byte *) &eflags, 4);
 470       eflags |= X86_EFLAGS_T;
 471       write_memory (flags_addr, (gdb_byte *) &eflags, 4);
 472
 473       return 1;
 474     }
 475   return 0;
 476 }
 477
 478 static int
 479 amd64_darwin_sstep_at_sigreturn (x86_thread_state_t *regs)
 480 {
 481   enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch);
 482   static const gdb_byte darwin_syscall[] = { 0x0f, 0x05 }; /* syscall */
 483   gdb_byte buf[sizeof (darwin_syscall)];
 484
 485   /* Check if PC is at a sigreturn system call.  */
 486   if (target_read_memory (regs->uts.ts64.__rip, buf, sizeof (buf)) == 0
 487       && memcmp (buf, darwin_syscall, sizeof (darwin_syscall)) == 0
 488       && (regs->uts.ts64.__rax & 0xffffffff) == 0x20000b8 /* SYS_sigreturn */)
 489     {
 490       ULONGEST mctx_addr;
 491       ULONGEST flags_addr;
 492       unsigned int rflags;
 493
 494       mctx_addr = read_memory_unsigned_integer
 495                     (regs->uts.ts64.__rdi + 48, 8, byte_order);
 496       flags_addr = mctx_addr + 16 + 17 * 8;
 497
 498       /* AMD64 is little endian.  */
 499       read_memory (flags_addr, (gdb_byte *) &rflags, 4);
 500       rflags |= X86_EFLAGS_T;
 501       write_memory (flags_addr, (gdb_byte *) &rflags, 4);
 502
 503       return 1;
 504     }
 505   return 0;
 506 }
 507
 508 void
 509 darwin_set_sstep (thread_t thread, int enable)
 510 {
 511   x86_thread_state_t regs;
 512   unsigned int count = x86_THREAD_STATE_COUNT;
 513   kern_return_t kret;
 514
 515   kret = thread_get_state (thread, x86_THREAD_STATE,
 516                            (thread_state_t) &regs, &count);
 517   if (kret != KERN_SUCCESS)
 518     {
 519       printf_unfiltered (_("darwin_set_sstep: error %x, thread=%x\n"),
 520                          kret, thread);
 521       return;
 522     }
 523
 524   switch (regs.tsh.flavor)
 525     {
 526     case x86_THREAD_STATE32:
 527       {
 528         __uint32_t bit = enable ? X86_EFLAGS_T : 0;
 529
 530         if (enable && i386_darwin_sstep_at_sigreturn (&regs))
 531           return;
 532         if ((regs.uts.ts32.__eflags & X86_EFLAGS_T) == bit)
 533           return;
 534         regs.uts.ts32.__eflags = (regs.uts.ts32.__eflags & ~X86_EFLAGS_T) | bit;
 535         kret = thread_set_state (thread, x86_THREAD_STATE,
 536                                  (thread_state_t) &regs, count);
 537         MACH_CHECK_ERROR (kret);
 538       }
 539       break;
 540     case x86_THREAD_STATE64:
 541       {
 542         __uint64_t bit = enable ? X86_EFLAGS_T : 0;
 543
 544         if (enable && amd64_darwin_sstep_at_sigreturn (&regs))
 545           return;
 546         if ((regs.uts.ts64.__rflags & X86_EFLAGS_T) == bit)
 547           return;
 548         regs.uts.ts64.__rflags = (regs.uts.ts64.__rflags & ~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     default:
 555       error (_("darwin_set_sstep: unknown flavour: %d\n"), regs.tsh.flavor);
 556     }
 557 }
 558
 559 void
 560 darwin_complete_target (struct target_ops *target)
 561 {
 562   amd64_native_gregset64_reg_offset = amd64_darwin_thread_state_reg_offset;
 563   amd64_native_gregset64_num_regs = amd64_darwin_thread_state_num_regs;
 564   amd64_native_gregset32_reg_offset = i386_darwin_thread_state_reg_offset;
 565   amd64_native_gregset32_num_regs = i386_darwin_thread_state_num_regs;
 566
 567   target->to_fetch_registers = i386_darwin_fetch_inferior_registers;
 568   target->to_store_registers = i386_darwin_store_inferior_registers;
 569 }