d7283a9703f90d215ec1aa4f8181a5e5df158a43
[deliverable/binutils-gdb.git] / gdb / gdbserver / spu-low.c
1 /* Low level interface to SPUs, for the remote server for GDB.
2 Copyright (C) 2006-2012 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 "server.h"
22
23 #include <sys/wait.h>
24 #include <stdio.h>
25 #include <sys/ptrace.h>
26 #include <fcntl.h>
27 #include <string.h>
28 #include <stdlib.h>
29 #include <unistd.h>
30 #include <errno.h>
31 #include <sys/syscall.h>
32
33 /* Some older glibc versions do not define this. */
34 #ifndef __WNOTHREAD
35 #define __WNOTHREAD 0x20000000 /* Don't wait on children of other
36 threads in this group */
37 #endif
38
39 #define PTRACE_TYPE_RET long
40 #define PTRACE_TYPE_ARG3 long
41
42 /* Number of registers. */
43 #define SPU_NUM_REGS 130
44 #define SPU_NUM_CORE_REGS 128
45
46 /* Special registers. */
47 #define SPU_ID_REGNUM 128
48 #define SPU_PC_REGNUM 129
49
50 /* PPU side system calls. */
51 #define INSTR_SC 0x44000002
52 #define NR_spu_run 0x0116
53
54 /* Get current thread ID (Linux task ID). */
55 #define current_ptid ((struct inferior_list_entry *)current_inferior)->id
56
57 /* These are used in remote-utils.c. */
58 int using_threads = 0;
59
60 /* Defined in auto-generated file reg-spu.c. */
61 void init_registers_spu (void);
62
63
64 /* Fetch PPU register REGNO. */
65 static CORE_ADDR
66 fetch_ppc_register (int regno)
67 {
68 PTRACE_TYPE_RET res;
69
70 int tid = ptid_get_lwp (current_ptid);
71
72 #ifndef __powerpc64__
73 /* If running as a 32-bit process on a 64-bit system, we attempt
74 to get the full 64-bit register content of the target process.
75 If the PPC special ptrace call fails, we're on a 32-bit system;
76 just fall through to the regular ptrace call in that case. */
77 {
78 char buf[8];
79
80 errno = 0;
81 ptrace (PPC_PTRACE_PEEKUSR_3264, tid,
82 (PTRACE_TYPE_ARG3) (regno * 8), buf);
83 if (errno == 0)
84 ptrace (PPC_PTRACE_PEEKUSR_3264, tid,
85 (PTRACE_TYPE_ARG3) (regno * 8 + 4), buf + 4);
86 if (errno == 0)
87 return (CORE_ADDR) *(unsigned long long *)buf;
88 }
89 #endif
90
91 errno = 0;
92 res = ptrace (PT_READ_U, tid,
93 (PTRACE_TYPE_ARG3) (regno * sizeof (PTRACE_TYPE_RET)), 0);
94 if (errno != 0)
95 {
96 char mess[128];
97 sprintf (mess, "reading PPC register #%d", regno);
98 perror_with_name (mess);
99 }
100
101 return (CORE_ADDR) (unsigned long) res;
102 }
103
104 /* Fetch WORD from PPU memory at (aligned) MEMADDR in thread TID. */
105 static int
106 fetch_ppc_memory_1 (int tid, CORE_ADDR memaddr, PTRACE_TYPE_RET *word)
107 {
108 errno = 0;
109
110 #ifndef __powerpc64__
111 if (memaddr >> 32)
112 {
113 unsigned long long addr_8 = (unsigned long long) memaddr;
114 ptrace (PPC_PTRACE_PEEKTEXT_3264, tid, (PTRACE_TYPE_ARG3) &addr_8, word);
115 }
116 else
117 #endif
118 *word = ptrace (PT_READ_I, tid, (PTRACE_TYPE_ARG3) (size_t) memaddr, 0);
119
120 return errno;
121 }
122
123 /* Store WORD into PPU memory at (aligned) MEMADDR in thread TID. */
124 static int
125 store_ppc_memory_1 (int tid, CORE_ADDR memaddr, PTRACE_TYPE_RET word)
126 {
127 errno = 0;
128
129 #ifndef __powerpc64__
130 if (memaddr >> 32)
131 {
132 unsigned long long addr_8 = (unsigned long long) memaddr;
133 ptrace (PPC_PTRACE_POKEDATA_3264, tid, (PTRACE_TYPE_ARG3) &addr_8, word);
134 }
135 else
136 #endif
137 ptrace (PT_WRITE_D, tid, (PTRACE_TYPE_ARG3) (size_t) memaddr, word);
138
139 return errno;
140 }
141
142 /* Fetch LEN bytes of PPU memory at MEMADDR to MYADDR. */
143 static int
144 fetch_ppc_memory (CORE_ADDR memaddr, char *myaddr, int len)
145 {
146 int i, ret;
147
148 CORE_ADDR addr = memaddr & -(CORE_ADDR) sizeof (PTRACE_TYPE_RET);
149 int count = ((((memaddr + len) - addr) + sizeof (PTRACE_TYPE_RET) - 1)
150 / sizeof (PTRACE_TYPE_RET));
151 PTRACE_TYPE_RET *buffer;
152
153 int tid = ptid_get_lwp (current_ptid);
154
155 buffer = (PTRACE_TYPE_RET *) alloca (count * sizeof (PTRACE_TYPE_RET));
156 for (i = 0; i < count; i++, addr += sizeof (PTRACE_TYPE_RET))
157 if ((ret = fetch_ppc_memory_1 (tid, addr, &buffer[i])) != 0)
158 return ret;
159
160 memcpy (myaddr,
161 (char *) buffer + (memaddr & (sizeof (PTRACE_TYPE_RET) - 1)),
162 len);
163
164 return 0;
165 }
166
167 /* Store LEN bytes from MYADDR to PPU memory at MEMADDR. */
168 static int
169 store_ppc_memory (CORE_ADDR memaddr, char *myaddr, int len)
170 {
171 int i, ret;
172
173 CORE_ADDR addr = memaddr & -(CORE_ADDR) sizeof (PTRACE_TYPE_RET);
174 int count = ((((memaddr + len) - addr) + sizeof (PTRACE_TYPE_RET) - 1)
175 / sizeof (PTRACE_TYPE_RET));
176 PTRACE_TYPE_RET *buffer;
177
178 int tid = ptid_get_lwp (current_ptid);
179
180 buffer = (PTRACE_TYPE_RET *) alloca (count * sizeof (PTRACE_TYPE_RET));
181
182 if (addr != memaddr || len < (int) sizeof (PTRACE_TYPE_RET))
183 if ((ret = fetch_ppc_memory_1 (tid, addr, &buffer[0])) != 0)
184 return ret;
185
186 if (count > 1)
187 if ((ret = fetch_ppc_memory_1 (tid, addr + (count - 1)
188 * sizeof (PTRACE_TYPE_RET),
189 &buffer[count - 1])) != 0)
190 return ret;
191
192 memcpy ((char *) buffer + (memaddr & (sizeof (PTRACE_TYPE_RET) - 1)),
193 myaddr, len);
194
195 for (i = 0; i < count; i++, addr += sizeof (PTRACE_TYPE_RET))
196 if ((ret = store_ppc_memory_1 (tid, addr, buffer[i])) != 0)
197 return ret;
198
199 return 0;
200 }
201
202
203 /* If the PPU thread is currently stopped on a spu_run system call,
204 return to FD and ADDR the file handle and NPC parameter address
205 used with the system call. Return non-zero if successful. */
206 static int
207 parse_spufs_run (int *fd, CORE_ADDR *addr)
208 {
209 unsigned int insn;
210 CORE_ADDR pc = fetch_ppc_register (32); /* nip */
211
212 /* Fetch instruction preceding current NIP. */
213 if (fetch_ppc_memory (pc-4, (char *) &insn, 4) != 0)
214 return 0;
215 /* It should be a "sc" instruction. */
216 if (insn != INSTR_SC)
217 return 0;
218 /* System call number should be NR_spu_run. */
219 if (fetch_ppc_register (0) != NR_spu_run)
220 return 0;
221
222 /* Register 3 contains fd, register 4 the NPC param pointer. */
223 *fd = fetch_ppc_register (34); /* orig_gpr3 */
224 *addr = fetch_ppc_register (4);
225 return 1;
226 }
227
228
229 /* Copy LEN bytes at OFFSET in spufs file ANNEX into/from READBUF or WRITEBUF,
230 using the /proc file system. */
231 static int
232 spu_proc_xfer_spu (const char *annex, unsigned char *readbuf,
233 const unsigned char *writebuf,
234 CORE_ADDR offset, int len)
235 {
236 char buf[128];
237 int fd = 0;
238 int ret = -1;
239
240 if (!annex)
241 return 0;
242
243 sprintf (buf, "/proc/%ld/fd/%s", ptid_get_lwp (current_ptid), annex);
244 fd = open (buf, writebuf? O_WRONLY : O_RDONLY);
245 if (fd <= 0)
246 return -1;
247
248 if (offset != 0
249 && lseek (fd, (off_t) offset, SEEK_SET) != (off_t) offset)
250 {
251 close (fd);
252 return 0;
253 }
254
255 if (writebuf)
256 ret = write (fd, writebuf, (size_t) len);
257 else if (readbuf)
258 ret = read (fd, readbuf, (size_t) len);
259
260 close (fd);
261 return ret;
262 }
263
264
265 /* Start an inferior process and returns its pid.
266 ALLARGS is a vector of program-name and args. */
267 static int
268 spu_create_inferior (char *program, char **allargs)
269 {
270 int pid;
271 ptid_t ptid;
272
273 pid = fork ();
274 if (pid < 0)
275 perror_with_name ("fork");
276
277 if (pid == 0)
278 {
279 ptrace (PTRACE_TRACEME, 0, 0, 0);
280
281 setpgid (0, 0);
282
283 execv (program, allargs);
284 if (errno == ENOENT)
285 execvp (program, allargs);
286
287 fprintf (stderr, "Cannot exec %s: %s.\n", program,
288 strerror (errno));
289 fflush (stderr);
290 _exit (0177);
291 }
292
293 add_process (pid, 0);
294
295 ptid = ptid_build (pid, pid, 0);
296 add_thread (ptid, NULL);
297 return pid;
298 }
299
300 /* Attach to an inferior process. */
301 int
302 spu_attach (unsigned long pid)
303 {
304 ptid_t ptid;
305
306 if (ptrace (PTRACE_ATTACH, pid, 0, 0) != 0)
307 {
308 fprintf (stderr, "Cannot attach to process %ld: %s (%d)\n", pid,
309 strerror (errno), errno);
310 fflush (stderr);
311 _exit (0177);
312 }
313
314 add_process (pid, 1);
315 ptid = ptid_build (pid, pid, 0);
316 add_thread (ptid, NULL);
317 return 0;
318 }
319
320 /* Kill the inferior process. */
321 static int
322 spu_kill (int pid)
323 {
324 int status, ret;
325 struct process_info *process = find_process_pid (pid);
326 if (process == NULL)
327 return -1;
328
329 ptrace (PTRACE_KILL, pid, 0, 0);
330
331 do {
332 ret = waitpid (pid, &status, 0);
333 if (WIFEXITED (status) || WIFSIGNALED (status))
334 break;
335 } while (ret != -1 || errno != ECHILD);
336
337 clear_inferiors ();
338 remove_process (process);
339 return 0;
340 }
341
342 /* Detach from inferior process. */
343 static int
344 spu_detach (int pid)
345 {
346 struct process_info *process = find_process_pid (pid);
347 if (process == NULL)
348 return -1;
349
350 ptrace (PTRACE_DETACH, pid, 0, 0);
351
352 clear_inferiors ();
353 remove_process (process);
354 return 0;
355 }
356
357 static void
358 spu_mourn (struct process_info *process)
359 {
360 remove_process (process);
361 }
362
363 static void
364 spu_join (int pid)
365 {
366 int status, ret;
367
368 do {
369 ret = waitpid (pid, &status, 0);
370 if (WIFEXITED (status) || WIFSIGNALED (status))
371 break;
372 } while (ret != -1 || errno != ECHILD);
373 }
374
375 /* Return nonzero if the given thread is still alive. */
376 static int
377 spu_thread_alive (ptid_t ptid)
378 {
379 return ptid_equal (ptid, current_ptid);
380 }
381
382 /* Resume process. */
383 static void
384 spu_resume (struct thread_resume *resume_info, size_t n)
385 {
386 size_t i;
387
388 for (i = 0; i < n; i++)
389 if (ptid_equal (resume_info[i].thread, minus_one_ptid)
390 || ptid_equal (resume_info[i].thread, current_ptid))
391 break;
392
393 if (i == n)
394 return;
395
396 /* We don't support hardware single-stepping right now, assume
397 GDB knows to use software single-stepping. */
398 if (resume_info[i].kind == resume_step)
399 fprintf (stderr, "Hardware single-step not supported.\n");
400
401 regcache_invalidate ();
402
403 errno = 0;
404 ptrace (PTRACE_CONT, ptid_get_lwp (current_ptid), 0, resume_info[i].sig);
405 if (errno)
406 perror_with_name ("ptrace");
407 }
408
409 /* Wait for process, returns status. */
410 static ptid_t
411 spu_wait (ptid_t ptid, struct target_waitstatus *ourstatus, int options)
412 {
413 int pid = ptid_get_pid (ptid);
414 int w;
415 int ret;
416
417 while (1)
418 {
419 ret = waitpid (pid, &w, WNOHANG | __WALL | __WNOTHREAD);
420
421 if (ret == -1)
422 {
423 if (errno != ECHILD)
424 perror_with_name ("waitpid");
425 }
426 else if (ret > 0)
427 break;
428
429 usleep (1000);
430 }
431
432 /* On the first wait, continue running the inferior until we are
433 blocked inside an spu_run system call. */
434 if (!server_waiting)
435 {
436 int fd;
437 CORE_ADDR addr;
438
439 while (!parse_spufs_run (&fd, &addr))
440 {
441 ptrace (PT_SYSCALL, pid, (PTRACE_TYPE_ARG3) 0, 0);
442 waitpid (pid, NULL, __WALL | __WNOTHREAD);
443 }
444 }
445
446 if (WIFEXITED (w))
447 {
448 fprintf (stderr, "\nChild exited with retcode = %x \n", WEXITSTATUS (w));
449 ourstatus->kind = TARGET_WAITKIND_EXITED;
450 ourstatus->value.integer = WEXITSTATUS (w);
451 clear_inferiors ();
452 return pid_to_ptid (ret);
453 }
454 else if (!WIFSTOPPED (w))
455 {
456 fprintf (stderr, "\nChild terminated with signal = %x \n", WTERMSIG (w));
457 ourstatus->kind = TARGET_WAITKIND_SIGNALLED;
458 ourstatus->value.sig = gdb_signal_from_host (WTERMSIG (w));
459 clear_inferiors ();
460 return pid_to_ptid (ret);
461 }
462
463 /* After attach, we may have received a SIGSTOP. Do not return this
464 as signal to GDB, or else it will try to continue with SIGSTOP ... */
465 if (!server_waiting)
466 {
467 ourstatus->kind = TARGET_WAITKIND_STOPPED;
468 ourstatus->value.sig = GDB_SIGNAL_0;
469 return ptid_build (ret, ret, 0);
470 }
471
472 ourstatus->kind = TARGET_WAITKIND_STOPPED;
473 ourstatus->value.sig = gdb_signal_from_host (WSTOPSIG (w));
474 return ptid_build (ret, ret, 0);
475 }
476
477 /* Fetch inferior registers. */
478 static void
479 spu_fetch_registers (struct regcache *regcache, int regno)
480 {
481 int fd;
482 CORE_ADDR addr;
483
484 /* We must be stopped on a spu_run system call. */
485 if (!parse_spufs_run (&fd, &addr))
486 return;
487
488 /* The ID register holds the spufs file handle. */
489 if (regno == -1 || regno == SPU_ID_REGNUM)
490 supply_register (regcache, SPU_ID_REGNUM, (char *)&fd);
491
492 /* The NPC register is found at ADDR. */
493 if (regno == -1 || regno == SPU_PC_REGNUM)
494 {
495 char buf[4];
496 if (fetch_ppc_memory (addr, buf, 4) == 0)
497 supply_register (regcache, SPU_PC_REGNUM, buf);
498 }
499
500 /* The GPRs are found in the "regs" spufs file. */
501 if (regno == -1 || (regno >= 0 && regno < SPU_NUM_CORE_REGS))
502 {
503 unsigned char buf[16*SPU_NUM_CORE_REGS];
504 char annex[32];
505 int i;
506
507 sprintf (annex, "%d/regs", fd);
508 if (spu_proc_xfer_spu (annex, buf, NULL, 0, sizeof buf) == sizeof buf)
509 for (i = 0; i < SPU_NUM_CORE_REGS; i++)
510 supply_register (regcache, i, buf + i*16);
511 }
512 }
513
514 /* Store inferior registers. */
515 static void
516 spu_store_registers (struct regcache *regcache, int regno)
517 {
518 int fd;
519 CORE_ADDR addr;
520
521 /* ??? Some callers use 0 to mean all registers. */
522 if (regno == 0)
523 regno = -1;
524
525 /* We must be stopped on a spu_run system call. */
526 if (!parse_spufs_run (&fd, &addr))
527 return;
528
529 /* The NPC register is found at ADDR. */
530 if (regno == -1 || regno == SPU_PC_REGNUM)
531 {
532 char buf[4];
533 collect_register (regcache, SPU_PC_REGNUM, buf);
534 store_ppc_memory (addr, buf, 4);
535 }
536
537 /* The GPRs are found in the "regs" spufs file. */
538 if (regno == -1 || (regno >= 0 && regno < SPU_NUM_CORE_REGS))
539 {
540 unsigned char buf[16*SPU_NUM_CORE_REGS];
541 char annex[32];
542 int i;
543
544 for (i = 0; i < SPU_NUM_CORE_REGS; i++)
545 collect_register (regcache, i, buf + i*16);
546
547 sprintf (annex, "%d/regs", fd);
548 spu_proc_xfer_spu (annex, NULL, buf, 0, sizeof buf);
549 }
550 }
551
552 /* Copy LEN bytes from inferior's memory starting at MEMADDR
553 to debugger memory starting at MYADDR. */
554 static int
555 spu_read_memory (CORE_ADDR memaddr, unsigned char *myaddr, int len)
556 {
557 int fd, ret;
558 CORE_ADDR addr;
559 char annex[32], lslr_annex[32], buf[32];
560 CORE_ADDR lslr;
561
562 /* We must be stopped on a spu_run system call. */
563 if (!parse_spufs_run (&fd, &addr))
564 return 0;
565
566 /* Use the "mem" spufs file to access SPU local store. */
567 sprintf (annex, "%d/mem", fd);
568 ret = spu_proc_xfer_spu (annex, myaddr, NULL, memaddr, len);
569 if (ret > 0)
570 return ret == len ? 0 : EIO;
571
572 /* SPU local store access wraps the address around at the
573 local store limit. We emulate this here. To avoid needing
574 an extra access to retrieve the LSLR, we only do that after
575 trying the original address first, and getting end-of-file. */
576 sprintf (lslr_annex, "%d/lslr", fd);
577 memset (buf, 0, sizeof buf);
578 if (spu_proc_xfer_spu (lslr_annex, (unsigned char *)buf, NULL,
579 0, sizeof buf) <= 0)
580 return ret;
581
582 lslr = strtoul (buf, NULL, 16);
583 ret = spu_proc_xfer_spu (annex, myaddr, NULL, memaddr & lslr, len);
584
585 return ret == len ? 0 : EIO;
586 }
587
588 /* Copy LEN bytes of data from debugger memory at MYADDR
589 to inferior's memory at MEMADDR.
590 On failure (cannot write the inferior)
591 returns the value of errno. */
592 static int
593 spu_write_memory (CORE_ADDR memaddr, const unsigned char *myaddr, int len)
594 {
595 int fd, ret;
596 CORE_ADDR addr;
597 char annex[32], lslr_annex[32], buf[32];
598 CORE_ADDR lslr;
599
600 /* We must be stopped on a spu_run system call. */
601 if (!parse_spufs_run (&fd, &addr))
602 return 0;
603
604 /* Use the "mem" spufs file to access SPU local store. */
605 sprintf (annex, "%d/mem", fd);
606 ret = spu_proc_xfer_spu (annex, NULL, myaddr, memaddr, len);
607 if (ret > 0)
608 return ret == len ? 0 : EIO;
609
610 /* SPU local store access wraps the address around at the
611 local store limit. We emulate this here. To avoid needing
612 an extra access to retrieve the LSLR, we only do that after
613 trying the original address first, and getting end-of-file. */
614 sprintf (lslr_annex, "%d/lslr", fd);
615 memset (buf, 0, sizeof buf);
616 if (spu_proc_xfer_spu (lslr_annex, (unsigned char *)buf, NULL,
617 0, sizeof buf) <= 0)
618 return ret;
619
620 lslr = strtoul (buf, NULL, 16);
621 ret = spu_proc_xfer_spu (annex, NULL, myaddr, memaddr & lslr, len);
622
623 return ret == len ? 0 : EIO;
624 }
625
626 /* Look up special symbols -- unneded here. */
627 static void
628 spu_look_up_symbols (void)
629 {
630 }
631
632 /* Send signal to inferior. */
633 static void
634 spu_request_interrupt (void)
635 {
636 syscall (SYS_tkill, ptid_get_lwp (current_ptid), SIGINT);
637 }
638
639 static struct target_ops spu_target_ops = {
640 spu_create_inferior,
641 spu_attach,
642 spu_kill,
643 spu_detach,
644 spu_mourn,
645 spu_join,
646 spu_thread_alive,
647 spu_resume,
648 spu_wait,
649 spu_fetch_registers,
650 spu_store_registers,
651 NULL, /* prepare_to_access_memory */
652 NULL, /* done_accessing_memory */
653 spu_read_memory,
654 spu_write_memory,
655 spu_look_up_symbols,
656 spu_request_interrupt,
657 NULL,
658 NULL,
659 NULL,
660 NULL,
661 NULL,
662 NULL,
663 NULL,
664 spu_proc_xfer_spu,
665 hostio_last_error_from_errno,
666 };
667
668 void
669 initialize_low (void)
670 {
671 static const unsigned char breakpoint[] = { 0x00, 0x00, 0x3f, 0xff };
672
673 set_target_ops (&spu_target_ops);
674 set_breakpoint_data (breakpoint, sizeof breakpoint);
675 init_registers_spu ();
676 }
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