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1 /* SPU native-dependent code for GDB, the GNU debugger.
2 Copyright (C) 2006-2017 Free Software Foundation, Inc.
3
4 Contributed by Ulrich Weigand <uweigand@de.ibm.com>.
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 "gdbcore.h"
23 #include "target.h"
24 #include "inferior.h"
25 #include "inf-child.h"
26 #include "inf-ptrace.h"
27 #include "regcache.h"
28 #include "symfile.h"
29 #include "gdb_wait.h"
30 #include "gdbthread.h"
31 #include "gdb_bfd.h"
32
33 #include "nat/gdb_ptrace.h"
34 #include <asm/ptrace.h>
35 #include <sys/types.h>
36
37 #include "spu-tdep.h"
38
39 /* PPU side system calls. */
40 #define INSTR_SC 0x44000002
41 #define NR_spu_run 0x0116
42
43
44 /* Fetch PPU register REGNO. */
45 static ULONGEST
46 fetch_ppc_register (int regno)
47 {
48 PTRACE_TYPE_RET res;
49
50 int tid = ptid_get_lwp (inferior_ptid);
51 if (tid == 0)
52 tid = ptid_get_pid (inferior_ptid);
53
54 #ifndef __powerpc64__
55 /* If running as a 32-bit process on a 64-bit system, we attempt
56 to get the full 64-bit register content of the target process.
57 If the PPC special ptrace call fails, we're on a 32-bit system;
58 just fall through to the regular ptrace call in that case. */
59 {
60 gdb_byte buf[8];
61
62 errno = 0;
63 ptrace (PPC_PTRACE_PEEKUSR_3264, tid,
64 (PTRACE_TYPE_ARG3) (regno * 8), buf);
65 if (errno == 0)
66 ptrace (PPC_PTRACE_PEEKUSR_3264, tid,
67 (PTRACE_TYPE_ARG3) (regno * 8 + 4), buf + 4);
68 if (errno == 0)
69 return (ULONGEST) *(uint64_t *)buf;
70 }
71 #endif
72
73 errno = 0;
74 res = ptrace (PT_READ_U, tid,
75 (PTRACE_TYPE_ARG3) (regno * sizeof (PTRACE_TYPE_RET)), 0);
76 if (errno != 0)
77 {
78 char mess[128];
79 xsnprintf (mess, sizeof mess, "reading PPC register #%d", regno);
80 perror_with_name (_(mess));
81 }
82
83 return (ULONGEST) (unsigned long) res;
84 }
85
86 /* Fetch WORD from PPU memory at (aligned) MEMADDR in thread TID. */
87 static int
88 fetch_ppc_memory_1 (int tid, ULONGEST memaddr, PTRACE_TYPE_RET *word)
89 {
90 errno = 0;
91
92 #ifndef __powerpc64__
93 if (memaddr >> 32)
94 {
95 uint64_t addr_8 = (uint64_t) memaddr;
96 ptrace (PPC_PTRACE_PEEKTEXT_3264, tid, (PTRACE_TYPE_ARG3) &addr_8, word);
97 }
98 else
99 #endif
100 *word = ptrace (PT_READ_I, tid, (PTRACE_TYPE_ARG3) (size_t) memaddr, 0);
101
102 return errno;
103 }
104
105 /* Store WORD into PPU memory at (aligned) MEMADDR in thread TID. */
106 static int
107 store_ppc_memory_1 (int tid, ULONGEST memaddr, PTRACE_TYPE_RET word)
108 {
109 errno = 0;
110
111 #ifndef __powerpc64__
112 if (memaddr >> 32)
113 {
114 uint64_t addr_8 = (uint64_t) memaddr;
115 ptrace (PPC_PTRACE_POKEDATA_3264, tid, (PTRACE_TYPE_ARG3) &addr_8, word);
116 }
117 else
118 #endif
119 ptrace (PT_WRITE_D, tid, (PTRACE_TYPE_ARG3) (size_t) memaddr, word);
120
121 return errno;
122 }
123
124 /* Fetch LEN bytes of PPU memory at MEMADDR to MYADDR. */
125 static int
126 fetch_ppc_memory (ULONGEST memaddr, gdb_byte *myaddr, int len)
127 {
128 int i, ret;
129
130 ULONGEST addr = memaddr & -(ULONGEST) sizeof (PTRACE_TYPE_RET);
131 int count = ((((memaddr + len) - addr) + sizeof (PTRACE_TYPE_RET) - 1)
132 / sizeof (PTRACE_TYPE_RET));
133 PTRACE_TYPE_RET *buffer;
134
135 int tid = ptid_get_lwp (inferior_ptid);
136 if (tid == 0)
137 tid = ptid_get_pid (inferior_ptid);
138
139 buffer = (PTRACE_TYPE_RET *) alloca (count * sizeof (PTRACE_TYPE_RET));
140 for (i = 0; i < count; i++, addr += sizeof (PTRACE_TYPE_RET))
141 {
142 ret = fetch_ppc_memory_1 (tid, addr, &buffer[i]);
143 if (ret)
144 return ret;
145 }
146
147 memcpy (myaddr,
148 (char *) buffer + (memaddr & (sizeof (PTRACE_TYPE_RET) - 1)),
149 len);
150
151 return 0;
152 }
153
154 /* Store LEN bytes from MYADDR to PPU memory at MEMADDR. */
155 static int
156 store_ppc_memory (ULONGEST memaddr, const gdb_byte *myaddr, int len)
157 {
158 int i, ret;
159
160 ULONGEST addr = memaddr & -(ULONGEST) sizeof (PTRACE_TYPE_RET);
161 int count = ((((memaddr + len) - addr) + sizeof (PTRACE_TYPE_RET) - 1)
162 / sizeof (PTRACE_TYPE_RET));
163 PTRACE_TYPE_RET *buffer;
164
165 int tid = ptid_get_lwp (inferior_ptid);
166 if (tid == 0)
167 tid = ptid_get_pid (inferior_ptid);
168
169 buffer = (PTRACE_TYPE_RET *) alloca (count * sizeof (PTRACE_TYPE_RET));
170
171 if (addr != memaddr || len < (int) sizeof (PTRACE_TYPE_RET))
172 {
173 ret = fetch_ppc_memory_1 (tid, addr, &buffer[0]);
174 if (ret)
175 return ret;
176 }
177
178 if (count > 1)
179 {
180 ret = fetch_ppc_memory_1 (tid, addr + (count - 1)
181 * sizeof (PTRACE_TYPE_RET),
182 &buffer[count - 1]);
183 if (ret)
184 return ret;
185 }
186
187 memcpy ((char *) buffer + (memaddr & (sizeof (PTRACE_TYPE_RET) - 1)),
188 myaddr, len);
189
190 for (i = 0; i < count; i++, addr += sizeof (PTRACE_TYPE_RET))
191 {
192 ret = store_ppc_memory_1 (tid, addr, buffer[i]);
193 if (ret)
194 return ret;
195 }
196
197 return 0;
198 }
199
200
201 /* If the PPU thread is currently stopped on a spu_run system call,
202 return to FD and ADDR the file handle and NPC parameter address
203 used with the system call. Return non-zero if successful. */
204 static int
205 parse_spufs_run (int *fd, ULONGEST *addr)
206 {
207 enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch ());
208 gdb_byte buf[4];
209 ULONGEST pc = fetch_ppc_register (32); /* nip */
210
211 /* Fetch instruction preceding current NIP. */
212 if (fetch_ppc_memory (pc-4, buf, 4) != 0)
213 return 0;
214 /* It should be a "sc" instruction. */
215 if (extract_unsigned_integer (buf, 4, byte_order) != INSTR_SC)
216 return 0;
217 /* System call number should be NR_spu_run. */
218 if (fetch_ppc_register (0) != NR_spu_run)
219 return 0;
220
221 /* Register 3 contains fd, register 4 the NPC param pointer. */
222 *fd = fetch_ppc_register (34); /* orig_gpr3 */
223 *addr = fetch_ppc_register (4);
224 return 1;
225 }
226
227
228 /* Implement the to_xfer_partial target_ops method for TARGET_OBJECT_SPU.
229 Copy LEN bytes at OFFSET in spufs file ANNEX into/from READBUF or WRITEBUF,
230 using the /proc file system. */
231
232 static enum target_xfer_status
233 spu_proc_xfer_spu (const char *annex, gdb_byte *readbuf,
234 const gdb_byte *writebuf,
235 ULONGEST offset, ULONGEST len, ULONGEST *xfered_len)
236 {
237 char buf[128];
238 int fd = 0;
239 int ret = -1;
240 int pid = ptid_get_pid (inferior_ptid);
241
242 if (!annex)
243 return TARGET_XFER_EOF;
244
245 xsnprintf (buf, sizeof buf, "/proc/%d/fd/%s", pid, annex);
246 fd = open (buf, writebuf? O_WRONLY : O_RDONLY);
247 if (fd <= 0)
248 return TARGET_XFER_E_IO;
249
250 if (offset != 0
251 && lseek (fd, (off_t) offset, SEEK_SET) != (off_t) offset)
252 {
253 close (fd);
254 return TARGET_XFER_EOF;
255 }
256
257 if (writebuf)
258 ret = write (fd, writebuf, (size_t) len);
259 else if (readbuf)
260 ret = read (fd, readbuf, (size_t) len);
261
262 close (fd);
263 if (ret < 0)
264 return TARGET_XFER_E_IO;
265 else if (ret == 0)
266 return TARGET_XFER_EOF;
267 else
268 {
269 *xfered_len = (ULONGEST) ret;
270 return TARGET_XFER_OK;
271 }
272 }
273
274
275 /* Inferior memory should contain an SPE executable image at location ADDR.
276 Allocate a BFD representing that executable. Return NULL on error. */
277
278 static void *
279 spu_bfd_iovec_open (struct bfd *nbfd, void *open_closure)
280 {
281 return open_closure;
282 }
283
284 static int
285 spu_bfd_iovec_close (struct bfd *nbfd, void *stream)
286 {
287 xfree (stream);
288
289 /* Zero means success. */
290 return 0;
291 }
292
293 static file_ptr
294 spu_bfd_iovec_pread (struct bfd *abfd, void *stream, void *buf,
295 file_ptr nbytes, file_ptr offset)
296 {
297 ULONGEST addr = *(ULONGEST *)stream;
298
299 if (fetch_ppc_memory (addr + offset, (gdb_byte *)buf, nbytes) != 0)
300 {
301 bfd_set_error (bfd_error_invalid_operation);
302 return -1;
303 }
304
305 return nbytes;
306 }
307
308 static int
309 spu_bfd_iovec_stat (struct bfd *abfd, void *stream, struct stat *sb)
310 {
311 /* We don't have an easy way of finding the size of embedded spu
312 images. We could parse the in-memory ELF header and section
313 table to find the extent of the last section but that seems
314 pointless when the size is needed only for checks of other
315 parsed values in dbxread.c. */
316 memset (sb, 0, sizeof (struct stat));
317 sb->st_size = INT_MAX;
318 return 0;
319 }
320
321 static gdb_bfd_ref_ptr
322 spu_bfd_open (ULONGEST addr)
323 {
324 asection *spu_name;
325
326 ULONGEST *open_closure = XNEW (ULONGEST);
327 *open_closure = addr;
328
329 gdb_bfd_ref_ptr nbfd (gdb_bfd_openr_iovec ("<in-memory>", "elf32-spu",
330 spu_bfd_iovec_open, open_closure,
331 spu_bfd_iovec_pread,
332 spu_bfd_iovec_close,
333 spu_bfd_iovec_stat));
334 if (nbfd == NULL)
335 return NULL;
336
337 if (!bfd_check_format (nbfd.get (), bfd_object))
338 return NULL;
339
340 /* Retrieve SPU name note and update BFD name. */
341 spu_name = bfd_get_section_by_name (nbfd.get (), ".note.spu_name");
342 if (spu_name)
343 {
344 int sect_size = bfd_section_size (nbfd.get (), spu_name);
345 if (sect_size > 20)
346 {
347 char *buf = (char *)alloca (sect_size - 20 + 1);
348 bfd_get_section_contents (nbfd.get (), spu_name, buf, 20,
349 sect_size - 20);
350 buf[sect_size - 20] = '\0';
351
352 xfree ((char *)nbfd->filename);
353 nbfd->filename = xstrdup (buf);
354 }
355 }
356
357 return nbfd;
358 }
359
360 /* INFERIOR_FD is a file handle passed by the inferior to the
361 spu_run system call. Assuming the SPE context was allocated
362 by the libspe library, try to retrieve the main SPE executable
363 file from its copy within the target process. */
364 static void
365 spu_symbol_file_add_from_memory (int inferior_fd)
366 {
367 ULONGEST addr;
368
369 gdb_byte id[128];
370 char annex[32];
371 ULONGEST len;
372 enum target_xfer_status status;
373
374 /* Read object ID. */
375 xsnprintf (annex, sizeof annex, "%d/object-id", inferior_fd);
376 status = spu_proc_xfer_spu (annex, id, NULL, 0, sizeof id, &len);
377 if (status != TARGET_XFER_OK || len >= sizeof id)
378 return;
379 id[len] = 0;
380 addr = strtoulst ((const char *) id, NULL, 16);
381 if (!addr)
382 return;
383
384 /* Open BFD representing SPE executable and read its symbols. */
385 gdb_bfd_ref_ptr nbfd (spu_bfd_open (addr));
386 if (nbfd != NULL)
387 {
388 symbol_file_add_from_bfd (nbfd.get (), bfd_get_filename (nbfd),
389 SYMFILE_VERBOSE | SYMFILE_MAINLINE,
390 NULL, 0, NULL);
391 }
392 }
393
394
395 /* Override the post_startup_inferior routine to continue running
396 the inferior until the first spu_run system call. */
397 static void
398 spu_child_post_startup_inferior (struct target_ops *self, ptid_t ptid)
399 {
400 int fd;
401 ULONGEST addr;
402
403 int tid = ptid_get_lwp (ptid);
404 if (tid == 0)
405 tid = ptid_get_pid (ptid);
406
407 while (!parse_spufs_run (&fd, &addr))
408 {
409 ptrace (PT_SYSCALL, tid, (PTRACE_TYPE_ARG3) 0, 0);
410 waitpid (tid, NULL, __WALL | __WNOTHREAD);
411 }
412 }
413
414 /* Override the post_attach routine to try load the SPE executable
415 file image from its copy inside the target process. */
416 static void
417 spu_child_post_attach (struct target_ops *self, int pid)
418 {
419 int fd;
420 ULONGEST addr;
421
422 /* Like child_post_startup_inferior, if we happened to attach to
423 the inferior while it wasn't currently in spu_run, continue
424 running it until we get back there. */
425 while (!parse_spufs_run (&fd, &addr))
426 {
427 ptrace (PT_SYSCALL, pid, (PTRACE_TYPE_ARG3) 0, 0);
428 waitpid (pid, NULL, __WALL | __WNOTHREAD);
429 }
430
431 /* If the user has not provided an executable file, try to extract
432 the image from inside the target process. */
433 if (!get_exec_file (0))
434 spu_symbol_file_add_from_memory (fd);
435 }
436
437 /* Wait for child PTID to do something. Return id of the child,
438 minus_one_ptid in case of error; store status into *OURSTATUS. */
439 static ptid_t
440 spu_child_wait (struct target_ops *ops,
441 ptid_t ptid, struct target_waitstatus *ourstatus, int options)
442 {
443 int save_errno;
444 int status;
445 pid_t pid;
446
447 do
448 {
449 set_sigint_trap (); /* Causes SIGINT to be passed on to the
450 attached process. */
451
452 pid = waitpid (ptid_get_pid (ptid), &status, 0);
453 if (pid == -1 && errno == ECHILD)
454 /* Try again with __WCLONE to check cloned processes. */
455 pid = waitpid (ptid_get_pid (ptid), &status, __WCLONE);
456
457 save_errno = errno;
458
459 /* Make sure we don't report an event for the exit of the
460 original program, if we've detached from it. */
461 if (pid != -1 && !WIFSTOPPED (status)
462 && pid != ptid_get_pid (inferior_ptid))
463 {
464 pid = -1;
465 save_errno = EINTR;
466 }
467
468 clear_sigint_trap ();
469 }
470 while (pid == -1 && save_errno == EINTR);
471
472 if (pid == -1)
473 {
474 warning (_("Child process unexpectedly missing: %s"),
475 safe_strerror (save_errno));
476
477 /* Claim it exited with unknown signal. */
478 ourstatus->kind = TARGET_WAITKIND_SIGNALLED;
479 ourstatus->value.sig = GDB_SIGNAL_UNKNOWN;
480 return inferior_ptid;
481 }
482
483 store_waitstatus (ourstatus, status);
484 return pid_to_ptid (pid);
485 }
486
487 /* Override the fetch_inferior_register routine. */
488 static void
489 spu_fetch_inferior_registers (struct target_ops *ops,
490 struct regcache *regcache, int regno)
491 {
492 int fd;
493 ULONGEST addr;
494
495 /* Since we use functions that rely on inferior_ptid, we need to set and
496 restore it. */
497 scoped_restore save_ptid
498 = make_scoped_restore (&inferior_ptid, regcache_get_ptid (regcache));
499
500 /* We must be stopped on a spu_run system call. */
501 if (!parse_spufs_run (&fd, &addr))
502 return;
503
504 /* The ID register holds the spufs file handle. */
505 if (regno == -1 || regno == SPU_ID_REGNUM)
506 {
507 struct gdbarch *gdbarch = regcache->arch ();
508 enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
509 gdb_byte buf[4];
510 store_unsigned_integer (buf, 4, byte_order, fd);
511 regcache_raw_supply (regcache, SPU_ID_REGNUM, buf);
512 }
513
514 /* The NPC register is found at ADDR. */
515 if (regno == -1 || regno == SPU_PC_REGNUM)
516 {
517 gdb_byte buf[4];
518 if (fetch_ppc_memory (addr, buf, 4) == 0)
519 regcache_raw_supply (regcache, SPU_PC_REGNUM, buf);
520 }
521
522 /* The GPRs are found in the "regs" spufs file. */
523 if (regno == -1 || (regno >= 0 && regno < SPU_NUM_GPRS))
524 {
525 gdb_byte buf[16 * SPU_NUM_GPRS];
526 char annex[32];
527 int i;
528 ULONGEST len;
529
530 xsnprintf (annex, sizeof annex, "%d/regs", fd);
531 if ((spu_proc_xfer_spu (annex, buf, NULL, 0, sizeof buf, &len)
532 == TARGET_XFER_OK)
533 && len == sizeof buf)
534 for (i = 0; i < SPU_NUM_GPRS; i++)
535 regcache_raw_supply (regcache, i, buf + i*16);
536 }
537 }
538
539 /* Override the store_inferior_register routine. */
540 static void
541 spu_store_inferior_registers (struct target_ops *ops,
542 struct regcache *regcache, int regno)
543 {
544 int fd;
545 ULONGEST addr;
546
547 /* Since we use functions that rely on inferior_ptid, we need to set and
548 restore it. */
549 scoped_restore save_ptid
550 = make_scoped_restore (&inferior_ptid, regcache_get_ptid (regcache));
551
552 /* We must be stopped on a spu_run system call. */
553 if (!parse_spufs_run (&fd, &addr))
554 return;
555
556 /* The NPC register is found at ADDR. */
557 if (regno == -1 || regno == SPU_PC_REGNUM)
558 {
559 gdb_byte buf[4];
560 regcache_raw_collect (regcache, SPU_PC_REGNUM, buf);
561 store_ppc_memory (addr, buf, 4);
562 }
563
564 /* The GPRs are found in the "regs" spufs file. */
565 if (regno == -1 || (regno >= 0 && regno < SPU_NUM_GPRS))
566 {
567 gdb_byte buf[16 * SPU_NUM_GPRS];
568 char annex[32];
569 int i;
570 ULONGEST len;
571
572 for (i = 0; i < SPU_NUM_GPRS; i++)
573 regcache_raw_collect (regcache, i, buf + i*16);
574
575 xsnprintf (annex, sizeof annex, "%d/regs", fd);
576 spu_proc_xfer_spu (annex, NULL, buf, 0, sizeof buf, &len);
577 }
578 }
579
580 /* Override the to_xfer_partial routine. */
581 static enum target_xfer_status
582 spu_xfer_partial (struct target_ops *ops,
583 enum target_object object, const char *annex,
584 gdb_byte *readbuf, const gdb_byte *writebuf,
585 ULONGEST offset, ULONGEST len, ULONGEST *xfered_len)
586 {
587 if (object == TARGET_OBJECT_SPU)
588 return spu_proc_xfer_spu (annex, readbuf, writebuf, offset, len,
589 xfered_len);
590
591 if (object == TARGET_OBJECT_MEMORY)
592 {
593 int fd;
594 ULONGEST addr;
595 char mem_annex[32], lslr_annex[32];
596 gdb_byte buf[32];
597 ULONGEST lslr;
598 enum target_xfer_status ret;
599
600 /* We must be stopped on a spu_run system call. */
601 if (!parse_spufs_run (&fd, &addr))
602 return TARGET_XFER_EOF;
603
604 /* Use the "mem" spufs file to access SPU local store. */
605 xsnprintf (mem_annex, sizeof mem_annex, "%d/mem", fd);
606 ret = spu_proc_xfer_spu (mem_annex, readbuf, writebuf, offset, len,
607 xfered_len);
608 if (ret == TARGET_XFER_OK)
609 return ret;
610
611 /* SPU local store access wraps the address around at the
612 local store limit. We emulate this here. To avoid needing
613 an extra access to retrieve the LSLR, we only do that after
614 trying the original address first, and getting end-of-file. */
615 xsnprintf (lslr_annex, sizeof lslr_annex, "%d/lslr", fd);
616 memset (buf, 0, sizeof buf);
617 if (spu_proc_xfer_spu (lslr_annex, buf, NULL, 0, sizeof buf, xfered_len)
618 != TARGET_XFER_OK)
619 return ret;
620
621 lslr = strtoulst ((const char *) buf, NULL, 16);
622 return spu_proc_xfer_spu (mem_annex, readbuf, writebuf,
623 offset & lslr, len, xfered_len);
624 }
625
626 return TARGET_XFER_E_IO;
627 }
628
629 /* Override the to_can_use_hw_breakpoint routine. */
630 static int
631 spu_can_use_hw_breakpoint (struct target_ops *self,
632 enum bptype type, int cnt, int othertype)
633 {
634 return 0;
635 }
636
637 /* Initialize SPU native target. */
638 void
639 _initialize_spu_nat (void)
640 {
641 /* Generic ptrace methods. */
642 struct target_ops *t;
643 t = inf_ptrace_target ();
644
645 /* Add SPU methods. */
646 t->to_post_attach = spu_child_post_attach;
647 t->to_post_startup_inferior = spu_child_post_startup_inferior;
648 t->to_wait = spu_child_wait;
649 t->to_fetch_registers = spu_fetch_inferior_registers;
650 t->to_store_registers = spu_store_inferior_registers;
651 t->to_xfer_partial = spu_xfer_partial;
652 t->to_can_use_hw_breakpoint = spu_can_use_hw_breakpoint;
653
654 /* Register SPU target. */
655 add_target (t);
656 }