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("$FreeBSD$");
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. We look at the address just before
306 * the saved instruction pointer as the saved EIP is after the
307 * call function, and if the function being called is marked as
308 * dead (such as panic() at the end of dblfault_handler()), then
309 * the instruction at the saved EIP will be part of a different
310 * function (syscall() in this example) rather than the one that
311 * actually made the call.
312 */
313 frame_type = NORMAL;
314 sym = db_search_symbol(rip - 1, DB_STGY_ANY, &offset);
315 db_symbol_values(sym, &name, NULL);
316 if (name != NULL) {
317 if (strcmp(name, "calltrap") == 0 ||
318 strcmp(name, "fork_trampoline") == 0)
319 frame_type = TRAP;
320 else if (strncmp(name, "Xatpic_intr", 11) == 0 ||
321 strncmp(name, "Xatpic_fastintr", 15) == 0 ||
322 strncmp(name, "Xapic_isr", 9) == 0)
323 frame_type = INTERRUPT;
324 else if (strcmp(name, "Xfast_syscall") == 0)
325 frame_type = SYSCALL;
326 }
327
328 /*
329 * Normal frames need no special processing.
330 */
331 if (frame_type == NORMAL) {
332 *ip = (db_addr_t) rip;
333 *fp = (struct amd64_frame *) rbp;
334 return;
335 }
336
337 db_print_stack_entry(name, 0, 0, 0, rip);
338
339 /*
340 * Point to base of trapframe which is just above the
341 * current frame.
342 */
343 tf = (struct trapframe *)((long)*fp + 16);
344
345 if (INKERNEL((long) tf)) {
346 rsp = get_rsp(tf);
347 rip = tf->tf_rip;
348 rbp = tf->tf_rbp;
349 switch (frame_type) {
350 case TRAP:
351 db_printf("--- trap %#lr", tf->tf_trapno);
352 break;
353 case SYSCALL:
354 db_printf("--- syscall");
355 decode_syscall(tf->tf_rax, td);
356 break;
357 case INTERRUPT:
358 db_printf("--- interrupt");
359 break;
360 default:
361 panic("The moon has moved again.");
362 }
363 db_printf(", rip = %#lr, rsp = %#lr, rbp = %#lr ---\n", rip,
364 rsp, rbp);
365 }
366
367 *ip = (db_addr_t) rip;
368 *fp = (struct amd64_frame *) rbp;
369 }
370
371 static int
372 db_backtrace(struct thread *td, struct trapframe *tf,
373 struct amd64_frame *frame, db_addr_t pc, int count)
374 {
375 struct amd64_frame *actframe;
376 #define MAXNARG 16
377 char *argnames[MAXNARG], **argnp = NULL;
378 const char *name;
379 long *argp;
380 db_expr_t offset;
381 c_db_sym_t sym;
382 int narg, quit;
383 boolean_t first;
384
385 if (count == -1)
386 count = 1024;
387
388 first = TRUE;
389 quit = 0;
390 db_setup_paging(db_simple_pager, &quit, db_lines_per_page);
391 while (count-- && !quit) {
392 sym = db_search_symbol(pc, DB_STGY_ANY, &offset);
393 db_symbol_values(sym, &name, NULL);
394
395 /*
396 * Attempt to determine a (possibly fake) frame that gives
397 * the caller's pc. It may differ from `frame' if the
398 * current function never sets up a standard frame or hasn't
399 * set one up yet or has just discarded one. The last two
400 * cases can be guessed fairly reliably for code generated
401 * by gcc. The first case is too much trouble to handle in
402 * general because the amount of junk on the stack depends
403 * on the pc (the special handling of "calltrap", etc. in
404 * db_nextframe() works because the `next' pc is special).
405 */
406 actframe = frame;
407 if (first) {
408 if (tf != NULL) {
409 int instr;
410
411 instr = db_get_value(pc, 4, FALSE);
412 if ((instr & 0xffffffff) == 0xe5894855) {
413 /* pushq %rbp; movq %rsp, %rbp */
414 actframe = (void *)(get_rsp(tf) - 8);
415 } else if ((instr & 0xffffff) == 0xe58948) {
416 /* movq %rsp, %rbp */
417 actframe = (void *)get_rsp(tf);
418 if (tf->tf_rbp == 0) {
419 /* Fake frame better. */
420 frame = actframe;
421 }
422 } else if ((instr & 0xff) == 0xc3) {
423 /* ret */
424 actframe = (void *)(get_rsp(tf) - 8);
425 } else if (offset == 0) {
426 /* Probably an assembler symbol. */
427 actframe = (void *)(get_rsp(tf) - 8);
428 }
429 } else if (strcmp(name, "fork_trampoline") == 0) {
430 /*
431 * Don't try to walk back on a stack for a
432 * process that hasn't actually been run yet.
433 */
434 db_print_stack_entry(name, 0, 0, 0, pc);
435 break;
436 }
437 first = FALSE;
438 }
439
440 argp = &actframe->f_arg0;
441 narg = MAXNARG;
442 if (sym != NULL && db_sym_numargs(sym, &narg, argnames)) {
443 argnp = argnames;
444 } else {
445 narg = db_numargs(frame);
446 }
447
448 db_print_stack_entry(name, narg, argnp, argp, pc);
449
450 if (actframe != frame) {
451 /* `frame' belongs to caller. */
452 pc = (db_addr_t)
453 db_get_value((long)&actframe->f_retaddr, 8, FALSE);
454 continue;
455 }
456
457 db_nextframe(&frame, &pc, td);
458
459 if (INKERNEL((long)pc) && !INKERNEL((long)frame)) {
460 sym = db_search_symbol(pc, DB_STGY_ANY, &offset);
461 db_symbol_values(sym, &name, NULL);
462 db_print_stack_entry(name, 0, 0, 0, pc);
463 break;
464 }
465 if (!INKERNEL((long) frame)) {
466 break;
467 }
468 }
469
470 return (0);
471 }
472
473 void
474 db_trace_self(void)
475 {
476 struct amd64_frame *frame;
477 db_addr_t callpc;
478 register_t rbp;
479
480 __asm __volatile("movq %%rbp,%0" : "=r" (rbp));
481 frame = (struct amd64_frame *)rbp;
482 callpc = (db_addr_t)db_get_value((long)&frame->f_retaddr, 8, FALSE);
483 frame = frame->f_frame;
484 db_backtrace(curthread, NULL, frame, callpc, -1);
485 }
486
487 int
488 db_trace_thread(struct thread *thr, int count)
489 {
490 struct pcb *ctx;
491
492 ctx = kdb_thr_ctx(thr);
493 return (db_backtrace(thr, NULL, (struct amd64_frame *)ctx->pcb_rbp,
494 ctx->pcb_rip, count));
495 }
496
497 int
498 amd64_set_watch(watchnum, watchaddr, size, access, d)
499 int watchnum;
500 unsigned int watchaddr;
501 int size;
502 int access;
503 struct dbreg * d;
504 {
505 int i;
506 unsigned int mask;
507
508 if (watchnum == -1) {
509 for (i = 0, mask = 0x3; i < 4; i++, mask <<= 2)
510 if ((d->dr[7] & mask) == 0)
511 break;
512 if (i < 4)
513 watchnum = i;
514 else
515 return (-1);
516 }
517
518 switch (access) {
519 case DBREG_DR7_EXEC:
520 size = 1; /* size must be 1 for an execution breakpoint */
521 /* fall through */
522 case DBREG_DR7_WRONLY:
523 case DBREG_DR7_RDWR:
524 break;
525 default : return (-1);
526 }
527
528 /*
529 * we can watch a 1, 2, or 4 byte sized location
530 */
531 switch (size) {
532 case 1 : mask = 0x00; break;
533 case 2 : mask = 0x01 << 2; break;
534 case 4 : mask = 0x03 << 2; break;
535 default : return (-1);
536 }
537
538 mask |= access;
539
540 /* clear the bits we are about to affect */
541 d->dr[7] &= ~((0x3 << (watchnum*2)) | (0x0f << (watchnum*4+16)));
542
543 /* set drN register to the address, N=watchnum */
544 DBREG_DRX(d,watchnum) = watchaddr;
545
546 /* enable the watchpoint */
547 d->dr[7] |= (0x2 << (watchnum*2)) | (mask << (watchnum*4+16));
548
549 return (watchnum);
550 }
551
552
553 int
554 amd64_clr_watch(watchnum, d)
555 int watchnum;
556 struct dbreg * d;
557 {
558
559 if (watchnum < 0 || watchnum >= 4)
560 return (-1);
561
562 d->dr[7] = d->dr[7] & ~((0x3 << (watchnum*2)) | (0x0f << (watchnum*4+16)));
563 DBREG_DRX(d,watchnum) = 0;
564
565 return (0);
566 }
567
568
569 int
570 db_md_set_watchpoint(addr, size)
571 db_expr_t addr;
572 db_expr_t size;
573 {
574 int avail, wsize;
575 int i;
576 struct dbreg d;
577
578 fill_dbregs(NULL, &d);
579
580 avail = 0;
581 for(i=0; i<4; i++) {
582 if ((d.dr[7] & (3 << (i*2))) == 0)
583 avail++;
584 }
585
586 if (avail*4 < size)
587 return (-1);
588
589 for (i=0; i<4 && (size != 0); i++) {
590 if ((d.dr[7] & (3<<(i*2))) == 0) {
591 if (size > 4)
592 wsize = 4;
593 else
594 wsize = size;
595 if (wsize == 3)
596 wsize++;
597 amd64_set_watch(i, addr, wsize,
598 DBREG_DR7_WRONLY, &d);
599 addr += wsize;
600 size -= wsize;
601 }
602 }
603
604 set_dbregs(NULL, &d);
605
606 return(0);
607 }
608
609
610 int
611 db_md_clr_watchpoint(addr, size)
612 db_expr_t addr;
613 db_expr_t size;
614 {
615 int i;
616 struct dbreg d;
617
618 fill_dbregs(NULL, &d);
619
620 for(i=0; i<4; i++) {
621 if (d.dr[7] & (3 << (i*2))) {
622 if ((DBREG_DRX((&d), i) >= addr) &&
623 (DBREG_DRX((&d), i) < addr+size))
624 amd64_clr_watch(i, &d);
625
626 }
627 }
628
629 set_dbregs(NULL, &d);
630
631 return(0);
632 }
633
634
635 static
636 char *
637 watchtype_str(type)
638 int type;
639 {
640 switch (type) {
641 case DBREG_DR7_EXEC : return "execute"; break;
642 case DBREG_DR7_RDWR : return "read/write"; break;
643 case DBREG_DR7_WRONLY : return "write"; break;
644 default : return "invalid"; break;
645 }
646 }
647
648
649 void
650 db_md_list_watchpoints()
651 {
652 int i;
653 struct dbreg d;
654
655 fill_dbregs(NULL, &d);
656
657 db_printf("\nhardware watchpoints:\n");
658 db_printf(" watch status type len address\n");
659 db_printf(" ----- -------- ---------- --- ----------\n");
660 for (i=0; i<4; i++) {
661 if (d.dr[7] & (0x03 << (i*2))) {
662 unsigned type, len;
663 type = (d.dr[7] >> (16+(i*4))) & 3;
664 len = (d.dr[7] >> (16+(i*4)+2)) & 3;
665 db_printf(" %-5d %-8s %10s %3d 0x%016lx\n",
666 i, "enabled", watchtype_str(type),
667 len + 1, DBREG_DRX((&d), i));
668 }
669 else {
670 db_printf(" %-5d disabled\n", i);
671 }
672 }
673
674 db_printf("\ndebug register values:\n");
675 for (i=0; i<8; i++) {
676 db_printf(" dr%d 0x%016lx\n", i, DBREG_DRX((&d), i));
677 }
678 db_printf("\n");
679 }
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