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/9.1/sys/amd64/amd64/db_trace.c 205014 2010-03-11 14:49:06Z nwhitehorn $");
29
30 #include "opt_compat.h"
31
32 #include <sys/param.h>
33 #include <sys/systm.h>
34 #include <sys/kdb.h>
35 #include <sys/proc.h>
36 #include <sys/stack.h>
37 #include <sys/sysent.h>
38
39 #include <machine/cpu.h>
40 #include <machine/md_var.h>
41 #include <machine/pcb.h>
42 #include <machine/reg.h>
43 #include <machine/stack.h>
44
45 #include <vm/vm.h>
46 #include <vm/vm_param.h>
47 #include <vm/pmap.h>
48
49 #include <ddb/ddb.h>
50 #include <ddb/db_access.h>
51 #include <ddb/db_sym.h>
52 #include <ddb/db_variables.h>
53
54 static db_varfcn_t db_dr0;
55 static db_varfcn_t db_dr1;
56 static db_varfcn_t db_dr2;
57 static db_varfcn_t db_dr3;
58 static db_varfcn_t db_dr4;
59 static db_varfcn_t db_dr5;
60 static db_varfcn_t db_dr6;
61 static db_varfcn_t db_dr7;
62 static db_varfcn_t db_frame;
63 static db_varfcn_t db_rsp;
64 static db_varfcn_t db_ss;
65
66 /*
67 * Machine register set.
68 */
69 #define DB_OFFSET(x) (db_expr_t *)offsetof(struct trapframe, x)
70 struct db_variable db_regs[] = {
71 { "cs", DB_OFFSET(tf_cs), db_frame },
72 { "ds", DB_OFFSET(tf_ds), db_frame },
73 { "es", DB_OFFSET(tf_es), db_frame },
74 { "fs", DB_OFFSET(tf_fs), db_frame },
75 { "gs", DB_OFFSET(tf_gs), db_frame },
76 { "ss", NULL, db_ss },
77 { "rax", DB_OFFSET(tf_rax), db_frame },
78 { "rcx", DB_OFFSET(tf_rcx), db_frame },
79 { "rdx", DB_OFFSET(tf_rdx), db_frame },
80 { "rbx", DB_OFFSET(tf_rbx), db_frame },
81 { "rsp", NULL, db_rsp },
82 { "rbp", DB_OFFSET(tf_rbp), db_frame },
83 { "rsi", DB_OFFSET(tf_rsi), db_frame },
84 { "rdi", DB_OFFSET(tf_rdi), db_frame },
85 { "r8", DB_OFFSET(tf_r8), db_frame },
86 { "r9", DB_OFFSET(tf_r9), db_frame },
87 { "r10", DB_OFFSET(tf_r10), db_frame },
88 { "r11", DB_OFFSET(tf_r11), db_frame },
89 { "r12", DB_OFFSET(tf_r12), db_frame },
90 { "r13", DB_OFFSET(tf_r13), db_frame },
91 { "r14", DB_OFFSET(tf_r14), db_frame },
92 { "r15", DB_OFFSET(tf_r15), db_frame },
93 { "rip", DB_OFFSET(tf_rip), db_frame },
94 { "rflags", DB_OFFSET(tf_rflags), db_frame },
95 #define DB_N_SHOW_REGS 24 /* Don't show registers after here. */
96 { "dr0", NULL, db_dr0 },
97 { "dr1", NULL, db_dr1 },
98 { "dr2", NULL, db_dr2 },
99 { "dr3", NULL, db_dr3 },
100 { "dr4", NULL, db_dr4 },
101 { "dr5", NULL, db_dr5 },
102 { "dr6", NULL, db_dr6 },
103 { "dr7", NULL, db_dr7 },
104 };
105 struct db_variable *db_eregs = db_regs + DB_N_SHOW_REGS;
106
107 #define DB_DRX_FUNC(reg) \
108 static int \
109 db_ ## reg (vp, valuep, op) \
110 struct db_variable *vp; \
111 db_expr_t * valuep; \
112 int op; \
113 { \
114 if (op == DB_VAR_GET) \
115 *valuep = r ## reg (); \
116 else \
117 load_ ## reg (*valuep); \
118 return (1); \
119 }
120
121 DB_DRX_FUNC(dr0)
122 DB_DRX_FUNC(dr1)
123 DB_DRX_FUNC(dr2)
124 DB_DRX_FUNC(dr3)
125 DB_DRX_FUNC(dr4)
126 DB_DRX_FUNC(dr5)
127 DB_DRX_FUNC(dr6)
128 DB_DRX_FUNC(dr7)
129
130 static __inline long
131 get_rsp(struct trapframe *tf)
132 {
133 return ((ISPL(tf->tf_cs)) ? tf->tf_rsp :
134 (db_expr_t)tf + offsetof(struct trapframe, tf_rsp));
135 }
136
137 static int
138 db_frame(struct db_variable *vp, db_expr_t *valuep, int op)
139 {
140 long *reg;
141
142 if (kdb_frame == NULL)
143 return (0);
144
145 reg = (long *)((uintptr_t)kdb_frame + (db_expr_t)vp->valuep);
146 if (op == DB_VAR_GET)
147 *valuep = *reg;
148 else
149 *reg = *valuep;
150 return (1);
151 }
152
153 static int
154 db_rsp(struct db_variable *vp, db_expr_t *valuep, int op)
155 {
156
157 if (kdb_frame == NULL)
158 return (0);
159
160 if (op == DB_VAR_GET)
161 *valuep = get_rsp(kdb_frame);
162 else if (ISPL(kdb_frame->tf_cs))
163 kdb_frame->tf_rsp = *valuep;
164 return (1);
165 }
166
167 static int
168 db_ss(struct db_variable *vp, db_expr_t *valuep, int op)
169 {
170
171 if (kdb_frame == NULL)
172 return (0);
173
174 if (op == DB_VAR_GET)
175 *valuep = (ISPL(kdb_frame->tf_cs)) ? kdb_frame->tf_ss : rss();
176 else if (ISPL(kdb_frame->tf_cs))
177 kdb_frame->tf_ss = *valuep;
178 return (1);
179 }
180
181 #define NORMAL 0
182 #define TRAP 1
183 #define INTERRUPT 2
184 #define SYSCALL 3
185 #define TRAP_INTERRUPT 5
186
187 static void db_nextframe(struct amd64_frame **, db_addr_t *, struct thread *);
188 static int db_numargs(struct amd64_frame *);
189 static void db_print_stack_entry(const char *, int, char **, long *, db_addr_t);
190 static void decode_syscall(int, struct thread *);
191
192 static const char * watchtype_str(int type);
193 int amd64_set_watch(int watchnum, unsigned long watchaddr, int size,
194 int access, struct dbreg *d);
195 int amd64_clr_watch(int watchnum, struct dbreg *d);
196
197 /*
198 * Figure out how many arguments were passed into the frame at "fp".
199 */
200 static int
201 db_numargs(fp)
202 struct amd64_frame *fp;
203 {
204 #if 1
205 return (0); /* regparm, needs dwarf2 info */
206 #else
207 long *argp;
208 int inst;
209 int args;
210
211 argp = (long *)db_get_value((long)&fp->f_retaddr, 8, FALSE);
212 /*
213 * XXX etext is wrong for LKMs. We should attempt to interpret
214 * the instruction at the return address in all cases. This
215 * may require better fault handling.
216 */
217 if (argp < (long *)btext || argp >= (long *)etext) {
218 args = 5;
219 } else {
220 inst = db_get_value((long)argp, 4, FALSE);
221 if ((inst & 0xff) == 0x59) /* popl %ecx */
222 args = 1;
223 else if ((inst & 0xffff) == 0xc483) /* addl $Ibs, %esp */
224 args = ((inst >> 16) & 0xff) / 4;
225 else
226 args = 5;
227 }
228 return (args);
229 #endif
230 }
231
232 static void
233 db_print_stack_entry(name, narg, argnp, argp, callpc)
234 const char *name;
235 int narg;
236 char **argnp;
237 long *argp;
238 db_addr_t callpc;
239 {
240 db_printf("%s(", name);
241 #if 0
242 while (narg) {
243 if (argnp)
244 db_printf("%s=", *argnp++);
245 db_printf("%lr", (long)db_get_value((long)argp, 8, FALSE));
246 argp++;
247 if (--narg != 0)
248 db_printf(",");
249 }
250 #endif
251 db_printf(") at ");
252 db_printsym(callpc, DB_STGY_PROC);
253 db_printf("\n");
254 }
255
256 static void
257 decode_syscall(int number, struct thread *td)
258 {
259 struct proc *p;
260 c_db_sym_t sym;
261 db_expr_t diff;
262 sy_call_t *f;
263 const char *symname;
264
265 db_printf(" (%d", number);
266 p = (td != NULL) ? td->td_proc : NULL;
267 if (p != NULL && 0 <= number && number < p->p_sysent->sv_size) {
268 f = p->p_sysent->sv_table[number].sy_call;
269 sym = db_search_symbol((db_addr_t)f, DB_STGY_ANY, &diff);
270 if (sym != DB_SYM_NULL && diff == 0) {
271 db_symbol_values(sym, &symname, NULL);
272 db_printf(", %s, %s", p->p_sysent->sv_name, symname);
273 }
274 }
275 db_printf(")");
276 }
277
278 /*
279 * Figure out the next frame up in the call stack.
280 */
281 static void
282 db_nextframe(struct amd64_frame **fp, db_addr_t *ip, struct thread *td)
283 {
284 struct trapframe *tf;
285 int frame_type;
286 long rip, rsp, rbp;
287 db_expr_t offset;
288 c_db_sym_t sym;
289 const char *name;
290
291 rip = db_get_value((long) &(*fp)->f_retaddr, 8, FALSE);
292 rbp = db_get_value((long) &(*fp)->f_frame, 8, FALSE);
293
294 /*
295 * Figure out frame type. We look at the address just before
296 * the saved instruction pointer as the saved EIP is after the
297 * call function, and if the function being called is marked as
298 * dead (such as panic() at the end of dblfault_handler()), then
299 * the instruction at the saved EIP will be part of a different
300 * function (syscall() in this example) rather than the one that
301 * actually made the call.
302 */
303 frame_type = NORMAL;
304 sym = db_search_symbol(rip - 1, DB_STGY_ANY, &offset);
305 db_symbol_values(sym, &name, NULL);
306 if (name != NULL) {
307 if (strcmp(name, "calltrap") == 0 ||
308 strcmp(name, "fork_trampoline") == 0 ||
309 strcmp(name, "nmi_calltrap") == 0 ||
310 strcmp(name, "Xdblfault") == 0)
311 frame_type = TRAP;
312 else if (strncmp(name, "Xatpic_intr", 11) == 0 ||
313 strncmp(name, "Xapic_isr", 9) == 0 ||
314 strcmp(name, "Xtimerint") == 0 ||
315 strcmp(name, "Xipi_intr_bitmap_handler") == 0 ||
316 strcmp(name, "Xcpustop") == 0 ||
317 strcmp(name, "Xcpususpend") == 0 ||
318 strcmp(name, "Xrendezvous") == 0)
319 frame_type = INTERRUPT;
320 else if (strcmp(name, "Xfast_syscall") == 0)
321 frame_type = SYSCALL;
322 #ifdef COMPAT_FREEBSD32
323 else if (strcmp(name, "Xint0x80_syscall") == 0)
324 frame_type = SYSCALL;
325 #endif
326 /* XXX: These are interrupts with trap frames. */
327 else if (strcmp(name, "Xtimerint") == 0 ||
328 strcmp(name, "Xcpustop") == 0 ||
329 strcmp(name, "Xcpususpend") == 0 ||
330 strcmp(name, "Xrendezvous") == 0 ||
331 strcmp(name, "Xipi_intr_bitmap_handler") == 0)
332 frame_type = TRAP_INTERRUPT;
333 }
334
335 /*
336 * Normal frames need no special processing.
337 */
338 if (frame_type == NORMAL) {
339 *ip = (db_addr_t) rip;
340 *fp = (struct amd64_frame *) rbp;
341 return;
342 }
343
344 db_print_stack_entry(name, 0, 0, 0, rip);
345
346 /*
347 * Point to base of trapframe which is just above the
348 * current frame.
349 */
350 tf = (struct trapframe *)((long)*fp + 16);
351
352 if (INKERNEL((long) tf)) {
353 rsp = get_rsp(tf);
354 rip = tf->tf_rip;
355 rbp = tf->tf_rbp;
356 switch (frame_type) {
357 case TRAP:
358 db_printf("--- trap %#r", tf->tf_trapno);
359 break;
360 case SYSCALL:
361 db_printf("--- syscall");
362 decode_syscall(tf->tf_rax, td);
363 break;
364 case TRAP_INTERRUPT:
365 case INTERRUPT:
366 db_printf("--- interrupt");
367 break;
368 default:
369 panic("The moon has moved again.");
370 }
371 db_printf(", rip = %#lr, rsp = %#lr, rbp = %#lr ---\n", rip,
372 rsp, rbp);
373 }
374
375 *ip = (db_addr_t) rip;
376 *fp = (struct amd64_frame *) rbp;
377 }
378
379 static int
380 db_backtrace(struct thread *td, struct trapframe *tf,
381 struct amd64_frame *frame, db_addr_t pc, int count)
382 {
383 struct amd64_frame *actframe;
384 #define MAXNARG 16
385 char *argnames[MAXNARG], **argnp = NULL;
386 const char *name;
387 long *argp;
388 db_expr_t offset;
389 c_db_sym_t sym;
390 int narg;
391 boolean_t first;
392
393 if (count == -1)
394 count = 1024;
395
396 first = TRUE;
397 while (count-- && !db_pager_quit) {
398 sym = db_search_symbol(pc, DB_STGY_ANY, &offset);
399 db_symbol_values(sym, &name, NULL);
400
401 /*
402 * Attempt to determine a (possibly fake) frame that gives
403 * the caller's pc. It may differ from `frame' if the
404 * current function never sets up a standard frame or hasn't
405 * set one up yet or has just discarded one. The last two
406 * cases can be guessed fairly reliably for code generated
407 * by gcc. The first case is too much trouble to handle in
408 * general because the amount of junk on the stack depends
409 * on the pc (the special handling of "calltrap", etc. in
410 * db_nextframe() works because the `next' pc is special).
411 */
412 actframe = frame;
413 if (first) {
414 if (tf != NULL) {
415 int instr;
416
417 instr = db_get_value(pc, 4, FALSE);
418 if ((instr & 0xffffffff) == 0xe5894855) {
419 /* pushq %rbp; movq %rsp, %rbp */
420 actframe = (void *)(get_rsp(tf) - 8);
421 } else if ((instr & 0xffffff) == 0xe58948) {
422 /* movq %rsp, %rbp */
423 actframe = (void *)get_rsp(tf);
424 if (tf->tf_rbp == 0) {
425 /* Fake frame better. */
426 frame = actframe;
427 }
428 } else if ((instr & 0xff) == 0xc3) {
429 /* ret */
430 actframe = (void *)(get_rsp(tf) - 8);
431 } else if (offset == 0) {
432 /* Probably an assembler symbol. */
433 actframe = (void *)(get_rsp(tf) - 8);
434 }
435 } else if (strcmp(name, "fork_trampoline") == 0) {
436 /*
437 * Don't try to walk back on a stack for a
438 * process that hasn't actually been run yet.
439 */
440 db_print_stack_entry(name, 0, 0, 0, pc);
441 break;
442 }
443 first = FALSE;
444 }
445
446 argp = &actframe->f_arg0;
447 narg = MAXNARG;
448 if (sym != NULL && db_sym_numargs(sym, &narg, argnames)) {
449 argnp = argnames;
450 } else {
451 narg = db_numargs(frame);
452 }
453
454 db_print_stack_entry(name, narg, argnp, argp, pc);
455
456 if (actframe != frame) {
457 /* `frame' belongs to caller. */
458 pc = (db_addr_t)
459 db_get_value((long)&actframe->f_retaddr, 8, FALSE);
460 continue;
461 }
462
463 db_nextframe(&frame, &pc, td);
464
465 if (INKERNEL((long)pc) && !INKERNEL((long)frame)) {
466 sym = db_search_symbol(pc, DB_STGY_ANY, &offset);
467 db_symbol_values(sym, &name, NULL);
468 db_print_stack_entry(name, 0, 0, 0, pc);
469 break;
470 }
471 if (!INKERNEL((long) frame)) {
472 break;
473 }
474 }
475
476 return (0);
477 }
478
479 void
480 db_trace_self(void)
481 {
482 struct amd64_frame *frame;
483 db_addr_t callpc;
484 register_t rbp;
485
486 __asm __volatile("movq %%rbp,%0" : "=r" (rbp));
487 frame = (struct amd64_frame *)rbp;
488 callpc = (db_addr_t)db_get_value((long)&frame->f_retaddr, 8, FALSE);
489 frame = frame->f_frame;
490 db_backtrace(curthread, NULL, frame, callpc, -1);
491 }
492
493 int
494 db_trace_thread(struct thread *thr, int count)
495 {
496 struct pcb *ctx;
497
498 ctx = kdb_thr_ctx(thr);
499 return (db_backtrace(thr, NULL, (struct amd64_frame *)ctx->pcb_rbp,
500 ctx->pcb_rip, count));
501 }
502
503 int
504 amd64_set_watch(watchnum, watchaddr, size, access, d)
505 int watchnum;
506 unsigned long watchaddr;
507 int size;
508 int access;
509 struct dbreg *d;
510 {
511 int i, len;
512
513 if (watchnum == -1) {
514 for (i = 0; i < 4; i++)
515 if (!DBREG_DR7_ENABLED(d->dr[7], i))
516 break;
517 if (i < 4)
518 watchnum = i;
519 else
520 return (-1);
521 }
522
523 switch (access) {
524 case DBREG_DR7_EXEC:
525 size = 1; /* size must be 1 for an execution breakpoint */
526 /* fall through */
527 case DBREG_DR7_WRONLY:
528 case DBREG_DR7_RDWR:
529 break;
530 default:
531 return (-1);
532 }
533
534 /*
535 * we can watch a 1, 2, 4, or 8 byte sized location
536 */
537 switch (size) {
538 case 1:
539 len = DBREG_DR7_LEN_1;
540 break;
541 case 2:
542 len = DBREG_DR7_LEN_2;
543 break;
544 case 4:
545 len = DBREG_DR7_LEN_4;
546 break;
547 case 8:
548 len = DBREG_DR7_LEN_8;
549 break;
550 default:
551 return (-1);
552 }
553
554 /* clear the bits we are about to affect */
555 d->dr[7] &= ~DBREG_DR7_MASK(watchnum);
556
557 /* set drN register to the address, N=watchnum */
558 DBREG_DRX(d, watchnum) = watchaddr;
559
560 /* enable the watchpoint */
561 d->dr[7] |= DBREG_DR7_SET(watchnum, len, access,
562 DBREG_DR7_GLOBAL_ENABLE);
563
564 return (watchnum);
565 }
566
567
568 int
569 amd64_clr_watch(watchnum, d)
570 int watchnum;
571 struct dbreg *d;
572 {
573
574 if (watchnum < 0 || watchnum >= 4)
575 return (-1);
576
577 d->dr[7] &= ~DBREG_DR7_MASK(watchnum);
578 DBREG_DRX(d, watchnum) = 0;
579
580 return (0);
581 }
582
583
584 int
585 db_md_set_watchpoint(addr, size)
586 db_expr_t addr;
587 db_expr_t size;
588 {
589 struct dbreg d;
590 int avail, i, wsize;
591
592 fill_dbregs(NULL, &d);
593
594 avail = 0;
595 for(i = 0; i < 4; i++) {
596 if (!DBREG_DR7_ENABLED(d.dr[7], i))
597 avail++;
598 }
599
600 if (avail * 8 < size)
601 return (-1);
602
603 for (i = 0; i < 4 && (size > 0); i++) {
604 if (!DBREG_DR7_ENABLED(d.dr[7], i)) {
605 if (size >= 8 || (avail == 1 && size > 4))
606 wsize = 8;
607 else if (size > 2)
608 wsize = 4;
609 else
610 wsize = size;
611 amd64_set_watch(i, addr, wsize,
612 DBREG_DR7_WRONLY, &d);
613 addr += wsize;
614 size -= wsize;
615 avail--;
616 }
617 }
618
619 set_dbregs(NULL, &d);
620
621 return(0);
622 }
623
624
625 int
626 db_md_clr_watchpoint(addr, size)
627 db_expr_t addr;
628 db_expr_t size;
629 {
630 struct dbreg d;
631 int i;
632
633 fill_dbregs(NULL, &d);
634
635 for(i = 0; i < 4; i++) {
636 if (DBREG_DR7_ENABLED(d.dr[7], i)) {
637 if ((DBREG_DRX((&d), i) >= addr) &&
638 (DBREG_DRX((&d), i) < addr+size))
639 amd64_clr_watch(i, &d);
640
641 }
642 }
643
644 set_dbregs(NULL, &d);
645
646 return(0);
647 }
648
649
650 static const char *
651 watchtype_str(type)
652 int type;
653 {
654 switch (type) {
655 case DBREG_DR7_EXEC : return "execute"; break;
656 case DBREG_DR7_RDWR : return "read/write"; break;
657 case DBREG_DR7_WRONLY : return "write"; break;
658 default : return "invalid"; break;
659 }
660 }
661
662
663 void
664 db_md_list_watchpoints()
665 {
666 struct dbreg d;
667 int i, len, type;
668
669 fill_dbregs(NULL, &d);
670
671 db_printf("\nhardware watchpoints:\n");
672 db_printf(" watch status type len address\n");
673 db_printf(" ----- -------- ---------- --- ------------------\n");
674 for (i = 0; i < 4; i++) {
675 if (DBREG_DR7_ENABLED(d.dr[7], i)) {
676 type = DBREG_DR7_ACCESS(d.dr[7], i);
677 len = DBREG_DR7_LEN(d.dr[7], i);
678 if (len == DBREG_DR7_LEN_8)
679 len = 8;
680 else
681 len++;
682 db_printf(" %-5d %-8s %10s %3d ",
683 i, "enabled", watchtype_str(type), len);
684 db_printsym((db_addr_t)DBREG_DRX((&d), i), DB_STGY_ANY);
685 db_printf("\n");
686 } else {
687 db_printf(" %-5d disabled\n", i);
688 }
689 }
690
691 db_printf("\ndebug register values:\n");
692 for (i = 0; i < 8; i++) {
693 db_printf(" dr%d 0x%016lx\n", i, DBREG_DRX((&d), i));
694 }
695 db_printf("\n");
696 }
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