1 /*
2 * Mach Operating System
3 * Copyright (c) 1991,1990 Carnegie Mellon University
4 * All Rights Reserved.
5 *
6 * Permission to use, copy, modify and distribute this software and its
7 * documentation is hereby granted, provided that both the copyright
8 * notice and this permission notice appear in all copies of the
9 * software, derivative works or modified versions, and any portions
10 * thereof, and that both notices appear in supporting documentation.
11 *
12 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS
13 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
14 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
15 *
16 * Carnegie Mellon requests users of this software to return to
17 *
18 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
19 * School of Computer Science
20 * Carnegie Mellon University
21 * Pittsburgh PA 15213-3890
22 *
23 * any improvements or extensions that they make and grant Carnegie the
24 * rights to redistribute these changes.
25 */
26
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD: releng/5.3/sys/amd64/amd64/db_trace.c 132482 2004-07-21 05:07:09Z marcel $");
29
30 #include <sys/param.h>
31 #include <sys/systm.h>
32 #include <sys/kdb.h>
33 #include <sys/proc.h>
34 #include <sys/sysent.h>
35
36 #include <machine/cpu.h>
37 #include <machine/md_var.h>
38 #include <machine/pcb.h>
39 #include <machine/reg.h>
40
41 #include <vm/vm.h>
42 #include <vm/vm_param.h>
43 #include <vm/pmap.h>
44
45 #include <ddb/ddb.h>
46 #include <ddb/db_access.h>
47 #include <ddb/db_sym.h>
48 #include <ddb/db_variables.h>
49
50 static db_varfcn_t db_dr0;
51 static db_varfcn_t db_dr1;
52 static db_varfcn_t db_dr2;
53 static db_varfcn_t db_dr3;
54 static db_varfcn_t db_dr4;
55 static db_varfcn_t db_dr5;
56 static db_varfcn_t db_dr6;
57 static db_varfcn_t db_dr7;
58 static db_varfcn_t db_frame;
59 static db_varfcn_t db_rsp;
60 static db_varfcn_t db_ss;
61
62 /*
63 * Machine register set.
64 */
65 #define DB_OFFSET(x) (db_expr_t *)offsetof(struct trapframe, x)
66 struct db_variable db_regs[] = {
67 { "cs", DB_OFFSET(tf_cs), db_frame },
68 #if 0
69 { "ds", DB_OFFSET(tf_ds), db_frame },
70 { "es", DB_OFFSET(tf_es), db_frame },
71 { "fs", DB_OFFSET(tf_fs), db_frame },
72 { "gs", DB_OFFSET(tf_gs), db_frame },
73 #endif
74 { "ss", NULL, db_ss },
75 { "rax", DB_OFFSET(tf_rax), db_frame },
76 { "rcx", DB_OFFSET(tf_rcx), db_frame },
77 { "rdx", DB_OFFSET(tf_rdx), db_frame },
78 { "rbx", DB_OFFSET(tf_rbx), db_frame },
79 { "rsp", NULL, db_rsp },
80 { "rbp", DB_OFFSET(tf_rbp), db_frame },
81 { "rsi", DB_OFFSET(tf_rsi), db_frame },
82 { "rdi", DB_OFFSET(tf_rdi), db_frame },
83 { "r8", DB_OFFSET(tf_r8), db_frame },
84 { "r9", DB_OFFSET(tf_r9), db_frame },
85 { "r10", DB_OFFSET(tf_r10), db_frame },
86 { "r11", DB_OFFSET(tf_r11), db_frame },
87 { "r12", DB_OFFSET(tf_r12), db_frame },
88 { "r13", DB_OFFSET(tf_r13), db_frame },
89 { "r14", DB_OFFSET(tf_r14), db_frame },
90 { "r15", DB_OFFSET(tf_r15), db_frame },
91 { "rip", DB_OFFSET(tf_rip), db_frame },
92 { "rflags", DB_OFFSET(tf_rflags), db_frame },
93 { "dr0", NULL, db_dr0 },
94 { "dr1", NULL, db_dr1 },
95 { "dr2", NULL, db_dr2 },
96 { "dr3", NULL, db_dr3 },
97 { "dr4", NULL, db_dr4 },
98 { "dr5", NULL, db_dr5 },
99 { "dr6", NULL, db_dr6 },
100 { "dr7", NULL, db_dr7 },
101 };
102 struct db_variable *db_eregs = db_regs + sizeof(db_regs)/sizeof(db_regs[0]);
103
104 #define DB_DRX_FUNC(reg) \
105 static int \
106 db_ ## reg (vp, valuep, op) \
107 struct db_variable *vp; \
108 db_expr_t * valuep; \
109 int op; \
110 { \
111 if (op == DB_VAR_GET) \
112 *valuep = r ## reg (); \
113 else \
114 load_ ## reg (*valuep); \
115 return (1); \
116 }
117
118 DB_DRX_FUNC(dr0)
119 DB_DRX_FUNC(dr1)
120 DB_DRX_FUNC(dr2)
121 DB_DRX_FUNC(dr3)
122 DB_DRX_FUNC(dr4)
123 DB_DRX_FUNC(dr5)
124 DB_DRX_FUNC(dr6)
125 DB_DRX_FUNC(dr7)
126
127 static __inline long
128 get_rsp(struct trapframe *tf)
129 {
130 return ((ISPL(tf->tf_cs)) ? tf->tf_rsp :
131 (db_expr_t)tf + offsetof(struct trapframe, tf_rsp));
132 }
133
134 static int
135 db_frame(struct db_variable *vp, db_expr_t *valuep, int op)
136 {
137 long *reg;
138
139 if (kdb_frame == NULL)
140 return (0);
141
142 reg = (long *)((uintptr_t)kdb_frame + (db_expr_t)vp->valuep);
143 if (op == DB_VAR_GET)
144 *valuep = *reg;
145 else
146 *reg = *valuep;
147 return (1);
148 }
149
150 static int
151 db_rsp(struct db_variable *vp, db_expr_t *valuep, int op)
152 {
153
154 if (kdb_frame == NULL)
155 return (0);
156
157 if (op == DB_VAR_GET)
158 *valuep = get_rsp(kdb_frame);
159 else if (ISPL(kdb_frame->tf_cs))
160 kdb_frame->tf_rsp = *valuep;
161 return (1);
162 }
163
164 static int
165 db_ss(struct db_variable *vp, db_expr_t *valuep, int op)
166 {
167
168 if (kdb_frame == NULL)
169 return (0);
170
171 if (op == DB_VAR_GET)
172 *valuep = (ISPL(kdb_frame->tf_cs)) ? kdb_frame->tf_ss : rss();
173 else if (ISPL(kdb_frame->tf_cs))
174 kdb_frame->tf_ss = *valuep;
175 return (1);
176 }
177
178 /*
179 * Stack trace.
180 */
181 #define INKERNEL(va) (((vm_offset_t)(va)) >= USRSTACK)
182
183 struct amd64_frame {
184 struct amd64_frame *f_frame;
185 long f_retaddr;
186 long f_arg0;
187 };
188
189 #define NORMAL 0
190 #define TRAP 1
191 #define INTERRUPT 2
192 #define SYSCALL 3
193
194 static void db_nextframe(struct amd64_frame **, db_addr_t *, struct thread *);
195 static int db_numargs(struct amd64_frame *);
196 static void db_print_stack_entry(const char *, int, char **, long *, db_addr_t);
197 static void decode_syscall(int, struct thread *);
198
199 static char * watchtype_str(int type);
200 int amd64_set_watch(int watchnum, unsigned int watchaddr, int size, int access,
201 struct dbreg * d);
202 int amd64_clr_watch(int watchnum, struct dbreg * d);
203 int db_md_set_watchpoint(db_expr_t addr, db_expr_t size);
204 int db_md_clr_watchpoint(db_expr_t addr, db_expr_t size);
205 void db_md_list_watchpoints(void);
206
207 /*
208 * Figure out how many arguments were passed into the frame at "fp".
209 */
210 static int
211 db_numargs(fp)
212 struct amd64_frame *fp;
213 {
214 #if 1
215 return (0); /* regparm, needs dwarf2 info */
216 #else
217 long *argp;
218 int inst;
219 int args;
220
221 argp = (long *)db_get_value((long)&fp->f_retaddr, 8, FALSE);
222 /*
223 * XXX etext is wrong for LKMs. We should attempt to interpret
224 * the instruction at the return address in all cases. This
225 * may require better fault handling.
226 */
227 if (argp < (long *)btext || argp >= (long *)etext) {
228 args = 5;
229 } else {
230 inst = db_get_value((long)argp, 4, FALSE);
231 if ((inst & 0xff) == 0x59) /* popl %ecx */
232 args = 1;
233 else if ((inst & 0xffff) == 0xc483) /* addl $Ibs, %esp */
234 args = ((inst >> 16) & 0xff) / 4;
235 else
236 args = 5;
237 }
238 return (args);
239 #endif
240 }
241
242 static void
243 db_print_stack_entry(name, narg, argnp, argp, callpc)
244 const char *name;
245 int narg;
246 char **argnp;
247 long *argp;
248 db_addr_t callpc;
249 {
250 db_printf("%s(", name);
251 #if 0
252 while (narg) {
253 if (argnp)
254 db_printf("%s=", *argnp++);
255 db_printf("%lr", (long)db_get_value((long)argp, 8, FALSE));
256 argp++;
257 if (--narg != 0)
258 db_printf(",");
259 }
260 #endif
261 db_printf(") at ");
262 db_printsym(callpc, DB_STGY_PROC);
263 db_printf("\n");
264 }
265
266 static void
267 decode_syscall(int number, struct thread *td)
268 {
269 struct proc *p;
270 c_db_sym_t sym;
271 db_expr_t diff;
272 sy_call_t *f;
273 const char *symname;
274
275 db_printf(" (%d", number);
276 p = (td != NULL) ? td->td_proc : NULL;
277 if (p != NULL && 0 <= number && number < p->p_sysent->sv_size) {
278 f = p->p_sysent->sv_table[number].sy_call;
279 sym = db_search_symbol((db_addr_t)f, DB_STGY_ANY, &diff);
280 if (sym != DB_SYM_NULL && diff == 0) {
281 db_symbol_values(sym, &symname, NULL);
282 db_printf(", %s, %s", p->p_sysent->sv_name, symname);
283 }
284 }
285 db_printf(")");
286 }
287
288 /*
289 * Figure out the next frame up in the call stack.
290 */
291 static void
292 db_nextframe(struct amd64_frame **fp, db_addr_t *ip, struct thread *td)
293 {
294 struct trapframe *tf;
295 int frame_type;
296 long rip, rsp, rbp;
297 db_expr_t offset;
298 c_db_sym_t sym;
299 const char *name;
300
301 rip = db_get_value((long) &(*fp)->f_retaddr, 8, FALSE);
302 rbp = db_get_value((long) &(*fp)->f_frame, 8, FALSE);
303
304 /*
305 * Figure out frame type.
306 */
307 frame_type = NORMAL;
308 sym = db_search_symbol(rip, DB_STGY_ANY, &offset);
309 db_symbol_values(sym, &name, NULL);
310 if (name != NULL) {
311 if (strcmp(name, "calltrap") == 0 ||
312 strcmp(name, "fork_trampoline") == 0)
313 frame_type = TRAP;
314 else if (strncmp(name, "Xatpic_intr", 11) == 0 ||
315 strncmp(name, "Xatpic_fastintr", 15) == 0 ||
316 strncmp(name, "Xapic_isr", 9) == 0)
317 frame_type = INTERRUPT;
318 else if (strcmp(name, "Xfast_syscall") == 0)
319 frame_type = SYSCALL;
320 }
321
322 /*
323 * Normal frames need no special processing.
324 */
325 if (frame_type == NORMAL) {
326 *ip = (db_addr_t) rip;
327 *fp = (struct amd64_frame *) rbp;
328 return;
329 }
330
331 db_print_stack_entry(name, 0, 0, 0, rip);
332
333 /*
334 * Point to base of trapframe which is just above the
335 * current frame.
336 */
337 tf = (struct trapframe *)((long)*fp + 16);
338
339 if (INKERNEL((long) tf)) {
340 rsp = get_rsp(tf);
341 rip = tf->tf_rip;
342 rbp = tf->tf_rbp;
343 switch (frame_type) {
344 case TRAP:
345 db_printf("--- trap %#lr", tf->tf_trapno);
346 break;
347 case SYSCALL:
348 db_printf("--- syscall");
349 decode_syscall(tf->tf_rax, td);
350 break;
351 case INTERRUPT:
352 db_printf("--- interrupt");
353 break;
354 default:
355 panic("The moon has moved again.");
356 }
357 db_printf(", rip = %#lr, rsp = %#lr, rbp = %#lr ---\n", rip,
358 rsp, rbp);
359 }
360
361 *ip = (db_addr_t) rip;
362 *fp = (struct amd64_frame *) rbp;
363 }
364
365 static int
366 db_backtrace(struct thread *td, struct trapframe *tf,
367 struct amd64_frame *frame, db_addr_t pc, int count)
368 {
369 struct amd64_frame *actframe;
370 #define MAXNARG 16
371 char *argnames[MAXNARG], **argnp = NULL;
372 const char *name;
373 long *argp;
374 db_expr_t offset;
375 c_db_sym_t sym;
376 int narg;
377 boolean_t first;
378
379 if (count == -1)
380 count = 1024;
381
382 first = TRUE;
383 while (count--) {
384 sym = db_search_symbol(pc, DB_STGY_ANY, &offset);
385 db_symbol_values(sym, &name, NULL);
386
387 /*
388 * Attempt to determine a (possibly fake) frame that gives
389 * the caller's pc. It may differ from `frame' if the
390 * current function never sets up a standard frame or hasn't
391 * set one up yet or has just discarded one. The last two
392 * cases can be guessed fairly reliably for code generated
393 * by gcc. The first case is too much trouble to handle in
394 * general because the amount of junk on the stack depends
395 * on the pc (the special handling of "calltrap", etc. in
396 * db_nextframe() works because the `next' pc is special).
397 */
398 actframe = frame;
399 if (first) {
400 if (tf != NULL) {
401 int instr;
402
403 instr = db_get_value(pc, 4, FALSE);
404 if ((instr & 0xffffffff) == 0xe5894855) {
405 /* pushq %rbp; movq %rsp, %rbp */
406 actframe = (void *)(get_rsp(tf) - 8);
407 } else if ((instr & 0xffffff) == 0xe58948) {
408 /* movq %rsp, %rbp */
409 actframe = (void *)get_rsp(tf);
410 if (tf->tf_rbp == 0) {
411 /* Fake frame better. */
412 frame = actframe;
413 }
414 } else if ((instr & 0xff) == 0xc3) {
415 /* ret */
416 actframe = (void *)(get_rsp(tf) - 8);
417 } else if (offset == 0) {
418 /* Probably an assembler symbol. */
419 actframe = (void *)(get_rsp(tf) - 8);
420 }
421 } else if (strcmp(name, "fork_trampoline") == 0) {
422 /*
423 * Don't try to walk back on a stack for a
424 * process that hasn't actually been run yet.
425 */
426 db_print_stack_entry(name, 0, 0, 0, pc);
427 break;
428 }
429 first = FALSE;
430 }
431
432 argp = &actframe->f_arg0;
433 narg = MAXNARG;
434 if (sym != NULL && db_sym_numargs(sym, &narg, argnames)) {
435 argnp = argnames;
436 } else {
437 narg = db_numargs(frame);
438 }
439
440 db_print_stack_entry(name, narg, argnp, argp, pc);
441
442 if (actframe != frame) {
443 /* `frame' belongs to caller. */
444 pc = (db_addr_t)
445 db_get_value((long)&actframe->f_retaddr, 8, FALSE);
446 continue;
447 }
448
449 db_nextframe(&frame, &pc, td);
450
451 if (INKERNEL((long)pc) && !INKERNEL((long)frame)) {
452 sym = db_search_symbol(pc, DB_STGY_ANY, &offset);
453 db_symbol_values(sym, &name, NULL);
454 db_print_stack_entry(name, 0, 0, 0, pc);
455 break;
456 }
457 if (!INKERNEL((long) frame)) {
458 break;
459 }
460 }
461
462 return (0);
463 }
464
465 void
466 db_trace_self(void)
467 {
468 struct amd64_frame *frame;
469 db_addr_t callpc;
470 register_t rbp;
471
472 __asm __volatile("movq %%rbp,%0" : "=r" (rbp));
473 frame = (struct amd64_frame *)rbp;
474 callpc = (db_addr_t)db_get_value((long)&frame->f_retaddr, 8, FALSE);
475 frame = frame->f_frame;
476 db_backtrace(curthread, NULL, frame, callpc, -1);
477 }
478
479 int
480 db_trace_thread(struct thread *thr, int count)
481 {
482 struct pcb *ctx;
483
484 ctx = kdb_thr_ctx(thr);
485 return (db_backtrace(thr, NULL, (struct amd64_frame *)ctx->pcb_rbp,
486 ctx->pcb_rip, count));
487 }
488
489 int
490 amd64_set_watch(watchnum, watchaddr, size, access, d)
491 int watchnum;
492 unsigned int watchaddr;
493 int size;
494 int access;
495 struct dbreg * d;
496 {
497 int i;
498 unsigned int mask;
499
500 if (watchnum == -1) {
501 for (i = 0, mask = 0x3; i < 4; i++, mask <<= 2)
502 if ((d->dr[7] & mask) == 0)
503 break;
504 if (i < 4)
505 watchnum = i;
506 else
507 return (-1);
508 }
509
510 switch (access) {
511 case DBREG_DR7_EXEC:
512 size = 1; /* size must be 1 for an execution breakpoint */
513 /* fall through */
514 case DBREG_DR7_WRONLY:
515 case DBREG_DR7_RDWR:
516 break;
517 default : return (-1);
518 }
519
520 /*
521 * we can watch a 1, 2, or 4 byte sized location
522 */
523 switch (size) {
524 case 1 : mask = 0x00; break;
525 case 2 : mask = 0x01 << 2; break;
526 case 4 : mask = 0x03 << 2; break;
527 default : return (-1);
528 }
529
530 mask |= access;
531
532 /* clear the bits we are about to affect */
533 d->dr[7] &= ~((0x3 << (watchnum*2)) | (0x0f << (watchnum*4+16)));
534
535 /* set drN register to the address, N=watchnum */
536 DBREG_DRX(d,watchnum) = watchaddr;
537
538 /* enable the watchpoint */
539 d->dr[7] |= (0x2 << (watchnum*2)) | (mask << (watchnum*4+16));
540
541 return (watchnum);
542 }
543
544
545 int
546 amd64_clr_watch(watchnum, d)
547 int watchnum;
548 struct dbreg * d;
549 {
550
551 if (watchnum < 0 || watchnum >= 4)
552 return (-1);
553
554 d->dr[7] = d->dr[7] & ~((0x3 << (watchnum*2)) | (0x0f << (watchnum*4+16)));
555 DBREG_DRX(d,watchnum) = 0;
556
557 return (0);
558 }
559
560
561 int
562 db_md_set_watchpoint(addr, size)
563 db_expr_t addr;
564 db_expr_t size;
565 {
566 int avail, wsize;
567 int i;
568 struct dbreg d;
569
570 fill_dbregs(NULL, &d);
571
572 avail = 0;
573 for(i=0; i<4; i++) {
574 if ((d.dr[7] & (3 << (i*2))) == 0)
575 avail++;
576 }
577
578 if (avail*4 < size)
579 return (-1);
580
581 for (i=0; i<4 && (size != 0); i++) {
582 if ((d.dr[7] & (3<<(i*2))) == 0) {
583 if (size > 4)
584 wsize = 4;
585 else
586 wsize = size;
587 if (wsize == 3)
588 wsize++;
589 amd64_set_watch(i, addr, wsize,
590 DBREG_DR7_WRONLY, &d);
591 addr += wsize;
592 size -= wsize;
593 }
594 }
595
596 set_dbregs(NULL, &d);
597
598 return(0);
599 }
600
601
602 int
603 db_md_clr_watchpoint(addr, size)
604 db_expr_t addr;
605 db_expr_t size;
606 {
607 int i;
608 struct dbreg d;
609
610 fill_dbregs(NULL, &d);
611
612 for(i=0; i<4; i++) {
613 if (d.dr[7] & (3 << (i*2))) {
614 if ((DBREG_DRX((&d), i) >= addr) &&
615 (DBREG_DRX((&d), i) < addr+size))
616 amd64_clr_watch(i, &d);
617
618 }
619 }
620
621 set_dbregs(NULL, &d);
622
623 return(0);
624 }
625
626
627 static
628 char *
629 watchtype_str(type)
630 int type;
631 {
632 switch (type) {
633 case DBREG_DR7_EXEC : return "execute"; break;
634 case DBREG_DR7_RDWR : return "read/write"; break;
635 case DBREG_DR7_WRONLY : return "write"; break;
636 default : return "invalid"; break;
637 }
638 }
639
640
641 void
642 db_md_list_watchpoints()
643 {
644 int i;
645 struct dbreg d;
646
647 fill_dbregs(NULL, &d);
648
649 db_printf("\nhardware watchpoints:\n");
650 db_printf(" watch status type len address\n");
651 db_printf(" ----- -------- ---------- --- ----------\n");
652 for (i=0; i<4; i++) {
653 if (d.dr[7] & (0x03 << (i*2))) {
654 unsigned type, len;
655 type = (d.dr[7] >> (16+(i*4))) & 3;
656 len = (d.dr[7] >> (16+(i*4)+2)) & 3;
657 db_printf(" %-5d %-8s %10s %3d 0x%016lx\n",
658 i, "enabled", watchtype_str(type),
659 len + 1, DBREG_DRX((&d), i));
660 }
661 else {
662 db_printf(" %-5d disabled\n", i);
663 }
664 }
665
666 db_printf("\ndebug register values:\n");
667 for (i=0; i<8; i++) {
668 db_printf(" dr%d 0x%016lx\n", i, DBREG_DRX((&d), i));
669 }
670 db_printf("\n");
671 }
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