C++-fy and prepare for sharing fork_inferior
[deliverable/binutils-gdb.git] / gdb / rs6000-nat.c
1 /* IBM RS/6000 native-dependent code for GDB, the GNU debugger.
2
3 Copyright (C) 1986-2017 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 "defs.h"
21 #include "inferior.h"
22 #include "target.h"
23 #include "gdbcore.h"
24 #include "symfile.h"
25 #include "objfiles.h"
26 #include "bfd.h"
27 #include "gdb-stabs.h"
28 #include "regcache.h"
29 #include "arch-utils.h"
30 #include "inf-child.h"
31 #include "inf-ptrace.h"
32 #include "ppc-tdep.h"
33 #include "rs6000-tdep.h"
34 #include "rs6000-aix-tdep.h"
35 #include "exec.h"
36 #include "observer.h"
37 #include "xcoffread.h"
38
39 #include <sys/ptrace.h>
40 #include <sys/reg.h>
41
42 #include <sys/dir.h>
43 #include <sys/user.h>
44 #include <signal.h>
45 #include <sys/ioctl.h>
46 #include <fcntl.h>
47
48 #include <a.out.h>
49 #include <sys/file.h>
50 #include <sys/stat.h>
51 #include "gdb_bfd.h"
52 #include <sys/core.h>
53 #define __LDINFO_PTRACE32__ /* for __ld_info32 */
54 #define __LDINFO_PTRACE64__ /* for __ld_info64 */
55 #include <sys/ldr.h>
56 #include <sys/systemcfg.h>
57
58 /* On AIX4.3+, sys/ldr.h provides different versions of struct ld_info for
59 debugging 32-bit and 64-bit processes. Define a typedef and macros for
60 accessing fields in the appropriate structures. */
61
62 /* In 32-bit compilation mode (which is the only mode from which ptrace()
63 works on 4.3), __ld_info32 is #defined as equivalent to ld_info. */
64
65 #if defined (__ld_info32) || defined (__ld_info64)
66 # define ARCH3264
67 #endif
68
69 /* Return whether the current architecture is 64-bit. */
70
71 #ifndef ARCH3264
72 # define ARCH64() 0
73 #else
74 # define ARCH64() (register_size (target_gdbarch (), 0) == 8)
75 #endif
76
77 static target_xfer_partial_ftype rs6000_xfer_shared_libraries;
78
79 /* Given REGNO, a gdb register number, return the corresponding
80 number suitable for use as a ptrace() parameter. Return -1 if
81 there's no suitable mapping. Also, set the int pointed to by
82 ISFLOAT to indicate whether REGNO is a floating point register. */
83
84 static int
85 regmap (struct gdbarch *gdbarch, int regno, int *isfloat)
86 {
87 struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
88
89 *isfloat = 0;
90 if (tdep->ppc_gp0_regnum <= regno
91 && regno < tdep->ppc_gp0_regnum + ppc_num_gprs)
92 return regno;
93 else if (tdep->ppc_fp0_regnum >= 0
94 && tdep->ppc_fp0_regnum <= regno
95 && regno < tdep->ppc_fp0_regnum + ppc_num_fprs)
96 {
97 *isfloat = 1;
98 return regno - tdep->ppc_fp0_regnum + FPR0;
99 }
100 else if (regno == gdbarch_pc_regnum (gdbarch))
101 return IAR;
102 else if (regno == tdep->ppc_ps_regnum)
103 return MSR;
104 else if (regno == tdep->ppc_cr_regnum)
105 return CR;
106 else if (regno == tdep->ppc_lr_regnum)
107 return LR;
108 else if (regno == tdep->ppc_ctr_regnum)
109 return CTR;
110 else if (regno == tdep->ppc_xer_regnum)
111 return XER;
112 else if (tdep->ppc_fpscr_regnum >= 0
113 && regno == tdep->ppc_fpscr_regnum)
114 return FPSCR;
115 else if (tdep->ppc_mq_regnum >= 0 && regno == tdep->ppc_mq_regnum)
116 return MQ;
117 else
118 return -1;
119 }
120
121 /* Call ptrace(REQ, ID, ADDR, DATA, BUF). */
122
123 static int
124 rs6000_ptrace32 (int req, int id, int *addr, int data, int *buf)
125 {
126 #ifdef HAVE_PTRACE64
127 int ret = ptrace64 (req, id, (uintptr_t) addr, data, buf);
128 #else
129 int ret = ptrace (req, id, (int *)addr, data, buf);
130 #endif
131 #if 0
132 printf ("rs6000_ptrace32 (%d, %d, 0x%x, %08x, 0x%x) = 0x%x\n",
133 req, id, (unsigned int)addr, data, (unsigned int)buf, ret);
134 #endif
135 return ret;
136 }
137
138 /* Call ptracex(REQ, ID, ADDR, DATA, BUF). */
139
140 static int
141 rs6000_ptrace64 (int req, int id, long long addr, int data, void *buf)
142 {
143 #ifdef ARCH3264
144 # ifdef HAVE_PTRACE64
145 int ret = ptrace64 (req, id, addr, data, (PTRACE_TYPE_ARG5) buf);
146 # else
147 int ret = ptracex (req, id, addr, data, (PTRACE_TYPE_ARG5) buf);
148 # endif
149 #else
150 int ret = 0;
151 #endif
152 #if 0
153 printf ("rs6000_ptrace64 (%d, %d, %s, %08x, 0x%x) = 0x%x\n",
154 req, id, hex_string (addr), data, (unsigned int)buf, ret);
155 #endif
156 return ret;
157 }
158
159 /* Fetch register REGNO from the inferior. */
160
161 static void
162 fetch_register (struct regcache *regcache, int regno)
163 {
164 struct gdbarch *gdbarch = get_regcache_arch (regcache);
165 int addr[MAX_REGISTER_SIZE];
166 int nr, isfloat;
167 pid_t pid = ptid_get_pid (regcache_get_ptid (regcache));
168
169 /* Retrieved values may be -1, so infer errors from errno. */
170 errno = 0;
171
172 nr = regmap (gdbarch, regno, &isfloat);
173
174 /* Floating-point registers. */
175 if (isfloat)
176 rs6000_ptrace32 (PT_READ_FPR, pid, addr, nr, 0);
177
178 /* Bogus register number. */
179 else if (nr < 0)
180 {
181 if (regno >= gdbarch_num_regs (gdbarch))
182 fprintf_unfiltered (gdb_stderr,
183 "gdb error: register no %d not implemented.\n",
184 regno);
185 return;
186 }
187
188 /* Fixed-point registers. */
189 else
190 {
191 if (!ARCH64 ())
192 *addr = rs6000_ptrace32 (PT_READ_GPR, pid, (int *) nr, 0, 0);
193 else
194 {
195 /* PT_READ_GPR requires the buffer parameter to point to long long,
196 even if the register is really only 32 bits. */
197 long long buf;
198 rs6000_ptrace64 (PT_READ_GPR, pid, nr, 0, &buf);
199 if (register_size (gdbarch, regno) == 8)
200 memcpy (addr, &buf, 8);
201 else
202 *addr = buf;
203 }
204 }
205
206 if (!errno)
207 regcache_raw_supply (regcache, regno, (char *) addr);
208 else
209 {
210 #if 0
211 /* FIXME: this happens 3 times at the start of each 64-bit program. */
212 perror (_("ptrace read"));
213 #endif
214 errno = 0;
215 }
216 }
217
218 /* Store register REGNO back into the inferior. */
219
220 static void
221 store_register (struct regcache *regcache, int regno)
222 {
223 struct gdbarch *gdbarch = get_regcache_arch (regcache);
224 int addr[MAX_REGISTER_SIZE];
225 int nr, isfloat;
226 pid_t pid = ptid_get_pid (regcache_get_ptid (regcache));
227
228 /* Fetch the register's value from the register cache. */
229 regcache_raw_collect (regcache, regno, addr);
230
231 /* -1 can be a successful return value, so infer errors from errno. */
232 errno = 0;
233
234 nr = regmap (gdbarch, regno, &isfloat);
235
236 /* Floating-point registers. */
237 if (isfloat)
238 rs6000_ptrace32 (PT_WRITE_FPR, pid, addr, nr, 0);
239
240 /* Bogus register number. */
241 else if (nr < 0)
242 {
243 if (regno >= gdbarch_num_regs (gdbarch))
244 fprintf_unfiltered (gdb_stderr,
245 "gdb error: register no %d not implemented.\n",
246 regno);
247 }
248
249 /* Fixed-point registers. */
250 else
251 {
252 /* The PT_WRITE_GPR operation is rather odd. For 32-bit inferiors,
253 the register's value is passed by value, but for 64-bit inferiors,
254 the address of a buffer containing the value is passed. */
255 if (!ARCH64 ())
256 rs6000_ptrace32 (PT_WRITE_GPR, pid, (int *) nr, *addr, 0);
257 else
258 {
259 /* PT_WRITE_GPR requires the buffer parameter to point to an 8-byte
260 area, even if the register is really only 32 bits. */
261 long long buf;
262 if (register_size (gdbarch, regno) == 8)
263 memcpy (&buf, addr, 8);
264 else
265 buf = *addr;
266 rs6000_ptrace64 (PT_WRITE_GPR, pid, nr, 0, &buf);
267 }
268 }
269
270 if (errno)
271 {
272 perror (_("ptrace write"));
273 errno = 0;
274 }
275 }
276
277 /* Read from the inferior all registers if REGNO == -1 and just register
278 REGNO otherwise. */
279
280 static void
281 rs6000_fetch_inferior_registers (struct target_ops *ops,
282 struct regcache *regcache, int regno)
283 {
284 struct gdbarch *gdbarch = get_regcache_arch (regcache);
285 if (regno != -1)
286 fetch_register (regcache, regno);
287
288 else
289 {
290 struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
291
292 /* Read 32 general purpose registers. */
293 for (regno = tdep->ppc_gp0_regnum;
294 regno < tdep->ppc_gp0_regnum + ppc_num_gprs;
295 regno++)
296 {
297 fetch_register (regcache, regno);
298 }
299
300 /* Read general purpose floating point registers. */
301 if (tdep->ppc_fp0_regnum >= 0)
302 for (regno = 0; regno < ppc_num_fprs; regno++)
303 fetch_register (regcache, tdep->ppc_fp0_regnum + regno);
304
305 /* Read special registers. */
306 fetch_register (regcache, gdbarch_pc_regnum (gdbarch));
307 fetch_register (regcache, tdep->ppc_ps_regnum);
308 fetch_register (regcache, tdep->ppc_cr_regnum);
309 fetch_register (regcache, tdep->ppc_lr_regnum);
310 fetch_register (regcache, tdep->ppc_ctr_regnum);
311 fetch_register (regcache, tdep->ppc_xer_regnum);
312 if (tdep->ppc_fpscr_regnum >= 0)
313 fetch_register (regcache, tdep->ppc_fpscr_regnum);
314 if (tdep->ppc_mq_regnum >= 0)
315 fetch_register (regcache, tdep->ppc_mq_regnum);
316 }
317 }
318
319 /* Store our register values back into the inferior.
320 If REGNO is -1, do this for all registers.
321 Otherwise, REGNO specifies which register (so we can save time). */
322
323 static void
324 rs6000_store_inferior_registers (struct target_ops *ops,
325 struct regcache *regcache, int regno)
326 {
327 struct gdbarch *gdbarch = get_regcache_arch (regcache);
328 if (regno != -1)
329 store_register (regcache, regno);
330
331 else
332 {
333 struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
334
335 /* Write general purpose registers first. */
336 for (regno = tdep->ppc_gp0_regnum;
337 regno < tdep->ppc_gp0_regnum + ppc_num_gprs;
338 regno++)
339 {
340 store_register (regcache, regno);
341 }
342
343 /* Write floating point registers. */
344 if (tdep->ppc_fp0_regnum >= 0)
345 for (regno = 0; regno < ppc_num_fprs; regno++)
346 store_register (regcache, tdep->ppc_fp0_regnum + regno);
347
348 /* Write special registers. */
349 store_register (regcache, gdbarch_pc_regnum (gdbarch));
350 store_register (regcache, tdep->ppc_ps_regnum);
351 store_register (regcache, tdep->ppc_cr_regnum);
352 store_register (regcache, tdep->ppc_lr_regnum);
353 store_register (regcache, tdep->ppc_ctr_regnum);
354 store_register (regcache, tdep->ppc_xer_regnum);
355 if (tdep->ppc_fpscr_regnum >= 0)
356 store_register (regcache, tdep->ppc_fpscr_regnum);
357 if (tdep->ppc_mq_regnum >= 0)
358 store_register (regcache, tdep->ppc_mq_regnum);
359 }
360 }
361
362 /* Implement the to_xfer_partial target_ops method. */
363
364 static enum target_xfer_status
365 rs6000_xfer_partial (struct target_ops *ops, enum target_object object,
366 const char *annex, gdb_byte *readbuf,
367 const gdb_byte *writebuf,
368 ULONGEST offset, ULONGEST len, ULONGEST *xfered_len)
369 {
370 pid_t pid = ptid_get_pid (inferior_ptid);
371 int arch64 = ARCH64 ();
372
373 switch (object)
374 {
375 case TARGET_OBJECT_LIBRARIES_AIX:
376 return rs6000_xfer_shared_libraries (ops, object, annex,
377 readbuf, writebuf,
378 offset, len, xfered_len);
379 case TARGET_OBJECT_MEMORY:
380 {
381 union
382 {
383 PTRACE_TYPE_RET word;
384 gdb_byte byte[sizeof (PTRACE_TYPE_RET)];
385 } buffer;
386 ULONGEST rounded_offset;
387 LONGEST partial_len;
388
389 /* Round the start offset down to the next long word
390 boundary. */
391 rounded_offset = offset & -(ULONGEST) sizeof (PTRACE_TYPE_RET);
392
393 /* Since ptrace will transfer a single word starting at that
394 rounded_offset the partial_len needs to be adjusted down to
395 that (remember this function only does a single transfer).
396 Should the required length be even less, adjust it down
397 again. */
398 partial_len = (rounded_offset + sizeof (PTRACE_TYPE_RET)) - offset;
399 if (partial_len > len)
400 partial_len = len;
401
402 if (writebuf)
403 {
404 /* If OFFSET:PARTIAL_LEN is smaller than
405 ROUNDED_OFFSET:WORDSIZE then a read/modify write will
406 be needed. Read in the entire word. */
407 if (rounded_offset < offset
408 || (offset + partial_len
409 < rounded_offset + sizeof (PTRACE_TYPE_RET)))
410 {
411 /* Need part of initial word -- fetch it. */
412 if (arch64)
413 buffer.word = rs6000_ptrace64 (PT_READ_I, pid,
414 rounded_offset, 0, NULL);
415 else
416 buffer.word = rs6000_ptrace32 (PT_READ_I, pid,
417 (int *) (uintptr_t)
418 rounded_offset,
419 0, NULL);
420 }
421
422 /* Copy data to be written over corresponding part of
423 buffer. */
424 memcpy (buffer.byte + (offset - rounded_offset),
425 writebuf, partial_len);
426
427 errno = 0;
428 if (arch64)
429 rs6000_ptrace64 (PT_WRITE_D, pid,
430 rounded_offset, buffer.word, NULL);
431 else
432 rs6000_ptrace32 (PT_WRITE_D, pid,
433 (int *) (uintptr_t) rounded_offset,
434 buffer.word, NULL);
435 if (errno)
436 return TARGET_XFER_EOF;
437 }
438
439 if (readbuf)
440 {
441 errno = 0;
442 if (arch64)
443 buffer.word = rs6000_ptrace64 (PT_READ_I, pid,
444 rounded_offset, 0, NULL);
445 else
446 buffer.word = rs6000_ptrace32 (PT_READ_I, pid,
447 (int *)(uintptr_t)rounded_offset,
448 0, NULL);
449 if (errno)
450 return TARGET_XFER_EOF;
451
452 /* Copy appropriate bytes out of the buffer. */
453 memcpy (readbuf, buffer.byte + (offset - rounded_offset),
454 partial_len);
455 }
456
457 *xfered_len = (ULONGEST) partial_len;
458 return TARGET_XFER_OK;
459 }
460
461 default:
462 return TARGET_XFER_E_IO;
463 }
464 }
465
466 /* Wait for the child specified by PTID to do something. Return the
467 process ID of the child, or MINUS_ONE_PTID in case of error; store
468 the status in *OURSTATUS. */
469
470 static ptid_t
471 rs6000_wait (struct target_ops *ops,
472 ptid_t ptid, struct target_waitstatus *ourstatus, int options)
473 {
474 pid_t pid;
475 int status, save_errno;
476
477 do
478 {
479 set_sigint_trap ();
480
481 do
482 {
483 pid = waitpid (ptid_get_pid (ptid), &status, 0);
484 save_errno = errno;
485 }
486 while (pid == -1 && errno == EINTR);
487
488 clear_sigint_trap ();
489
490 if (pid == -1)
491 {
492 fprintf_unfiltered (gdb_stderr,
493 _("Child process unexpectedly missing: %s.\n"),
494 safe_strerror (save_errno));
495
496 /* Claim it exited with unknown signal. */
497 ourstatus->kind = TARGET_WAITKIND_SIGNALLED;
498 ourstatus->value.sig = GDB_SIGNAL_UNKNOWN;
499 return inferior_ptid;
500 }
501
502 /* Ignore terminated detached child processes. */
503 if (!WIFSTOPPED (status) && pid != ptid_get_pid (inferior_ptid))
504 pid = -1;
505 }
506 while (pid == -1);
507
508 /* AIX has a couple of strange returns from wait(). */
509
510 /* stop after load" status. */
511 if (status == 0x57c)
512 ourstatus->kind = TARGET_WAITKIND_LOADED;
513 /* signal 0. I have no idea why wait(2) returns with this status word. */
514 else if (status == 0x7f)
515 ourstatus->kind = TARGET_WAITKIND_SPURIOUS;
516 /* A normal waitstatus. Let the usual macros deal with it. */
517 else
518 store_waitstatus (ourstatus, status);
519
520 return pid_to_ptid (pid);
521 }
522 \f
523
524 /* Set the current architecture from the host running GDB. Called when
525 starting a child process. */
526
527 static void (*super_create_inferior) (struct target_ops *,
528 const char *exec_file,
529 const std::string &allargs,
530 char **env, int from_tty);
531 static void
532 rs6000_create_inferior (struct target_ops * ops, const char *exec_file,
533 const std::string &allargs, char **env, int from_tty)
534 {
535 enum bfd_architecture arch;
536 unsigned long mach;
537 bfd abfd;
538 struct gdbarch_info info;
539
540 super_create_inferior (ops, exec_file, allargs, env, from_tty);
541
542 if (__power_rs ())
543 {
544 arch = bfd_arch_rs6000;
545 mach = bfd_mach_rs6k;
546 }
547 else
548 {
549 arch = bfd_arch_powerpc;
550 mach = bfd_mach_ppc;
551 }
552
553 /* FIXME: schauer/2002-02-25:
554 We don't know if we are executing a 32 or 64 bit executable,
555 and have no way to pass the proper word size to rs6000_gdbarch_init.
556 So we have to avoid switching to a new architecture, if the architecture
557 matches already.
558 Blindly calling rs6000_gdbarch_init used to work in older versions of
559 GDB, as rs6000_gdbarch_init incorrectly used the previous tdep to
560 determine the wordsize. */
561 if (exec_bfd)
562 {
563 const struct bfd_arch_info *exec_bfd_arch_info;
564
565 exec_bfd_arch_info = bfd_get_arch_info (exec_bfd);
566 if (arch == exec_bfd_arch_info->arch)
567 return;
568 }
569
570 bfd_default_set_arch_mach (&abfd, arch, mach);
571
572 gdbarch_info_init (&info);
573 info.bfd_arch_info = bfd_get_arch_info (&abfd);
574 info.abfd = exec_bfd;
575
576 if (!gdbarch_update_p (info))
577 internal_error (__FILE__, __LINE__,
578 _("rs6000_create_inferior: failed "
579 "to select architecture"));
580 }
581 \f
582
583 /* Shared Object support. */
584
585 /* Return the LdInfo data for the given process. Raises an error
586 if the data could not be obtained.
587
588 The returned value must be deallocated after use. */
589
590 static gdb_byte *
591 rs6000_ptrace_ldinfo (ptid_t ptid)
592 {
593 const int pid = ptid_get_pid (ptid);
594 int ldi_size = 1024;
595 void *ldi = xmalloc (ldi_size);
596 int rc = -1;
597
598 while (1)
599 {
600 if (ARCH64 ())
601 rc = rs6000_ptrace64 (PT_LDINFO, pid, (unsigned long) ldi, ldi_size,
602 NULL);
603 else
604 rc = rs6000_ptrace32 (PT_LDINFO, pid, (int *) ldi, ldi_size, NULL);
605
606 if (rc != -1)
607 break; /* Success, we got the entire ld_info data. */
608
609 if (errno != ENOMEM)
610 perror_with_name (_("ptrace ldinfo"));
611
612 /* ldi is not big enough. Double it and try again. */
613 ldi_size *= 2;
614 ldi = xrealloc (ldi, ldi_size);
615 }
616
617 return (gdb_byte *) ldi;
618 }
619
620 /* Implement the to_xfer_partial target_ops method for
621 TARGET_OBJECT_LIBRARIES_AIX objects. */
622
623 static enum target_xfer_status
624 rs6000_xfer_shared_libraries
625 (struct target_ops *ops, enum target_object object,
626 const char *annex, gdb_byte *readbuf, const gdb_byte *writebuf,
627 ULONGEST offset, ULONGEST len, ULONGEST *xfered_len)
628 {
629 gdb_byte *ldi_buf;
630 ULONGEST result;
631 struct cleanup *cleanup;
632
633 /* This function assumes that it is being run with a live process.
634 Core files are handled via gdbarch. */
635 gdb_assert (target_has_execution);
636
637 if (writebuf)
638 return TARGET_XFER_E_IO;
639
640 ldi_buf = rs6000_ptrace_ldinfo (inferior_ptid);
641 gdb_assert (ldi_buf != NULL);
642 cleanup = make_cleanup (xfree, ldi_buf);
643 result = rs6000_aix_ld_info_to_xml (target_gdbarch (), ldi_buf,
644 readbuf, offset, len, 1);
645 xfree (ldi_buf);
646
647 do_cleanups (cleanup);
648
649 if (result == 0)
650 return TARGET_XFER_EOF;
651 else
652 {
653 *xfered_len = result;
654 return TARGET_XFER_OK;
655 }
656 }
657
658 void _initialize_rs6000_nat (void);
659
660 void
661 _initialize_rs6000_nat (void)
662 {
663 struct target_ops *t;
664
665 t = inf_ptrace_target ();
666 t->to_fetch_registers = rs6000_fetch_inferior_registers;
667 t->to_store_registers = rs6000_store_inferior_registers;
668 t->to_xfer_partial = rs6000_xfer_partial;
669
670 super_create_inferior = t->to_create_inferior;
671 t->to_create_inferior = rs6000_create_inferior;
672
673 t->to_wait = rs6000_wait;
674
675 add_target (t);
676 }
This page took 0.046247 seconds and 5 git commands to generate.