1 /* Darwin support for GDB, the GNU debugger.
2 Copyright (C) 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
i386_darwin_fetch_inferior_registers(struct target_ops * ops,struct regcache * regcache,int regno)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
i386_darwin_store_inferior_registers(struct target_ops * ops,struct regcache * regcache,int regno)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
i386_darwin_dr_set(int regnum,uint32_t value)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
i386_darwin_dr_get(int regnum)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
i386_darwin_dr_set_control(unsigned long control)383 i386_darwin_dr_set_control (unsigned long control)
384 {
385 i386_darwin_dr_set (DR_CONTROL, control);
386 }
387
388 void
i386_darwin_dr_set_addr(int regnum,CORE_ADDR addr)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
i386_darwin_dr_get_addr(int regnum)397 i386_darwin_dr_get_addr (int regnum)
398 {
399 return i386_darwin_dr_get (regnum);
400 }
401
402 unsigned long
i386_darwin_dr_get_status(void)403 i386_darwin_dr_get_status (void)
404 {
405 return i386_darwin_dr_get (DR_STATUS);
406 }
407
408 unsigned long
i386_darwin_dr_get_control(void)409 i386_darwin_dr_get_control (void)
410 {
411 return i386_darwin_dr_get (DR_CONTROL);
412 }
413 #endif
414
415 void
darwin_check_osabi(darwin_inferior * inf,thread_t thread)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
i386_darwin_sstep_at_sigreturn(x86_thread_state_t * regs)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
amd64_darwin_sstep_at_sigreturn(x86_thread_state_t * regs)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
darwin_set_sstep(thread_t thread,int enable)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) ®s, &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 (®s))
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) ®s, 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 (®s))
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) ®s, 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
darwin_complete_target(struct target_ops * target)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 }
589