xref: /titanic_41/usr/src/cmd/mdb/i86pc/modules/unix/unix.c (revision 95efa359b507db290a2484b8f615822b1e06096f)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 /*
22  * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  */
25 
26 #pragma ident	"%Z%%M%	%I%	%E% SMI"
27 
28 #include <mdb/mdb_modapi.h>
29 #include <mdb/mdb_ctf.h>
30 #include <sys/cpuvar.h>
31 #include <sys/systm.h>
32 #include <sys/traptrace.h>
33 #include <sys/x_call.h>
34 #include <sys/avintr.h>
35 #include <sys/systm.h>
36 #include <sys/trap.h>
37 #include <sys/mutex.h>
38 #include <sys/mutex_impl.h>
39 #include "i86mmu.h"
40 
41 #define	TT_HDLR_WIDTH	17
42 
43 static int
44 ttrace_ttr_size_check(void)
45 {
46 	mdb_ctf_id_t ttrtid;
47 	ssize_t ttr_size;
48 
49 	if (mdb_ctf_lookup_by_name("trap_trace_rec_t", &ttrtid) != 0 ||
50 	    mdb_ctf_type_resolve(ttrtid, &ttrtid) != 0) {
51 		mdb_warn("failed to determine size of trap_trace_rec_t; "
52 		    "non-TRAPTRACE kernel?\n");
53 		return (0);
54 	}
55 
56 	if ((ttr_size = mdb_ctf_type_size(ttrtid)) !=
57 	    sizeof (trap_trace_rec_t)) {
58 		/*
59 		 * On Intel machines, this will happen when TTR_STACK_DEPTH
60 		 * is changed.  This code could be smarter, and could
61 		 * dynamically adapt to different depths, but not until a
62 		 * need for such adaptation is demonstrated.
63 		 */
64 		mdb_warn("size of trap_trace_rec_t (%d bytes) doesn't "
65 		    "match expected %d\n", ttr_size, sizeof (trap_trace_rec_t));
66 		return (0);
67 	}
68 
69 	return (1);
70 }
71 
72 int
73 ttrace_walk_init(mdb_walk_state_t *wsp)
74 {
75 	trap_trace_ctl_t *ttcp;
76 	size_t ttc_size = sizeof (trap_trace_ctl_t) * NCPU;
77 	int i;
78 
79 	if (!ttrace_ttr_size_check())
80 		return (WALK_ERR);
81 
82 	ttcp = mdb_zalloc(ttc_size, UM_SLEEP);
83 
84 	if (wsp->walk_addr != NULL) {
85 		mdb_warn("ttrace only supports global walks\n");
86 		return (WALK_ERR);
87 	}
88 
89 	if (mdb_readsym(ttcp, ttc_size, "trap_trace_ctl") == -1) {
90 		mdb_warn("symbol 'trap_trace_ctl' not found; "
91 		    "non-TRAPTRACE kernel?\n");
92 		mdb_free(ttcp, ttc_size);
93 		return (WALK_ERR);
94 	}
95 
96 	/*
97 	 * We'll poach the ttc_current pointer (which isn't used for
98 	 * anything) to store a pointer to our current TRAPTRACE record.
99 	 * This allows us to only keep the array of trap_trace_ctl structures
100 	 * as our walker state (ttc_current may be the only kernel data
101 	 * structure member added exclusively to make writing the mdb walker
102 	 * a little easier).
103 	 */
104 	for (i = 0; i < NCPU; i++) {
105 		trap_trace_ctl_t *ttc = &ttcp[i];
106 
107 		if (ttc->ttc_first == NULL)
108 			continue;
109 
110 		/*
111 		 * Assign ttc_current to be the last completed record.
112 		 * Note that the error checking (i.e. in the ttc_next ==
113 		 * ttc_first case) is performed in the step function.
114 		 */
115 		ttc->ttc_current = ttc->ttc_next - sizeof (trap_trace_rec_t);
116 	}
117 
118 	wsp->walk_data = ttcp;
119 	return (WALK_NEXT);
120 }
121 
122 int
123 ttrace_walk_step(mdb_walk_state_t *wsp)
124 {
125 	trap_trace_ctl_t *ttcp = wsp->walk_data, *ttc, *latest_ttc;
126 	trap_trace_rec_t rec;
127 	int rval, i, recsize = sizeof (trap_trace_rec_t);
128 	hrtime_t latest = 0;
129 
130 	/*
131 	 * Loop through the CPUs, looking for the latest trap trace record
132 	 * (we want to walk through the trap trace records in reverse
133 	 * chronological order).
134 	 */
135 	for (i = 0; i < NCPU; i++) {
136 		ttc = &ttcp[i];
137 
138 		if (ttc->ttc_current == NULL)
139 			continue;
140 
141 		if (ttc->ttc_current < ttc->ttc_first)
142 			ttc->ttc_current = ttc->ttc_limit - recsize;
143 
144 		if (mdb_vread(&rec, sizeof (rec), ttc->ttc_current) == -1) {
145 			mdb_warn("couldn't read rec at %p", ttc->ttc_current);
146 			return (WALK_ERR);
147 		}
148 
149 		if (rec.ttr_stamp > latest) {
150 			latest = rec.ttr_stamp;
151 			latest_ttc = ttc;
152 		}
153 	}
154 
155 	if (latest == 0)
156 		return (WALK_DONE);
157 
158 	ttc = latest_ttc;
159 
160 	if (mdb_vread(&rec, sizeof (rec), ttc->ttc_current) == -1) {
161 		mdb_warn("couldn't read rec at %p", ttc->ttc_current);
162 		return (WALK_ERR);
163 	}
164 
165 	rval = wsp->walk_callback(ttc->ttc_current, &rec, wsp->walk_cbdata);
166 
167 	if (ttc->ttc_current == ttc->ttc_next)
168 		ttc->ttc_current = NULL;
169 	else
170 		ttc->ttc_current -= sizeof (trap_trace_rec_t);
171 
172 	return (rval);
173 }
174 
175 void
176 ttrace_walk_fini(mdb_walk_state_t *wsp)
177 {
178 	mdb_free(wsp->walk_data, sizeof (trap_trace_ctl_t) * NCPU);
179 }
180 
181 static int
182 ttrace_syscall(trap_trace_rec_t *rec)
183 {
184 	GElf_Sym sym;
185 	int sysnum = rec->ttr_sysnum;
186 	uintptr_t addr;
187 	struct sysent sys;
188 
189 	mdb_printf("%-3x", sysnum);
190 
191 	if (rec->ttr_sysnum > NSYSCALL) {
192 		mdb_printf(" %-*d", TT_HDLR_WIDTH, rec->ttr_sysnum);
193 		return (0);
194 	}
195 
196 	if (mdb_lookup_by_name("sysent", &sym) == -1) {
197 		mdb_warn("\ncouldn't find 'sysent'");
198 		return (-1);
199 	}
200 
201 	addr = (uintptr_t)sym.st_value + sysnum * sizeof (struct sysent);
202 
203 	if (addr >= (uintptr_t)sym.st_value + sym.st_size) {
204 		mdb_warn("\nsysnum %d out-of-range\n", sysnum);
205 		return (-1);
206 	}
207 
208 	if (mdb_vread(&sys, sizeof (sys), addr) == -1) {
209 		mdb_warn("\nfailed to read sysent at %p", addr);
210 		return (-1);
211 	}
212 
213 	mdb_printf(" %-*a", TT_HDLR_WIDTH, sys.sy_callc);
214 
215 	return (0);
216 }
217 
218 static int
219 ttrace_interrupt(trap_trace_rec_t *rec)
220 {
221 	GElf_Sym sym;
222 	uintptr_t addr;
223 	struct av_head hd;
224 	struct autovec av;
225 
226 	switch (rec->ttr_regs.r_trapno) {
227 	case T_SOFTINT:
228 		mdb_printf("%-3s %-*s", "-", TT_HDLR_WIDTH, "(fakesoftint)");
229 		return (0);
230 	default:
231 		break;
232 	}
233 
234 	mdb_printf("%-3x ", rec->ttr_vector);
235 
236 	if (mdb_lookup_by_name("autovect", &sym) == -1) {
237 		mdb_warn("\ncouldn't find 'autovect'");
238 		return (-1);
239 	}
240 
241 	addr = (uintptr_t)sym.st_value +
242 	    rec->ttr_vector * sizeof (struct av_head);
243 
244 	if (addr >= (uintptr_t)sym.st_value + sym.st_size) {
245 		mdb_warn("\nav_head for vec %x is corrupt\n", rec->ttr_vector);
246 		return (-1);
247 	}
248 
249 	if (mdb_vread(&hd, sizeof (hd), addr) == -1) {
250 		mdb_warn("\ncouldn't read av_head for vec %x", rec->ttr_vector);
251 		return (-1);
252 	}
253 
254 	if (hd.avh_link == NULL) {
255 		if (rec->ttr_ipl == XC_CPUPOKE_PIL)
256 			mdb_printf("%-*s", TT_HDLR_WIDTH, "(cpupoke)");
257 		else
258 			mdb_printf("%-*s", TT_HDLR_WIDTH, "(spurious)");
259 	} else {
260 		if (mdb_vread(&av, sizeof (av), (uintptr_t)hd.avh_link) == -1) {
261 			mdb_warn("couldn't read autovec at %p",
262 			    (uintptr_t)hd.avh_link);
263 		}
264 
265 		mdb_printf("%-*a", TT_HDLR_WIDTH, av.av_vector);
266 	}
267 
268 	return (0);
269 }
270 
271 static struct {
272 	int tt_trapno;
273 	char *tt_name;
274 } ttrace_traps[] = {
275 	{ T_ZERODIV,	"divide-error" },
276 	{ T_SGLSTP,	"debug-exception" },
277 	{ T_NMIFLT,	"nmi-interrupt" },
278 	{ T_BPTFLT,	"breakpoint" },
279 	{ T_OVFLW,	"into-overflow" },
280 	{ T_BOUNDFLT,	"bound-exceeded" },
281 	{ T_ILLINST,	"invalid-opcode" },
282 	{ T_NOEXTFLT,	"device-not-avail" },
283 	{ T_DBLFLT,	"double-fault" },
284 	{ T_EXTOVRFLT,	"segment-overrun" },
285 	{ T_TSSFLT,	"invalid-tss" },
286 	{ T_SEGFLT,	"segment-not-pres" },
287 	{ T_STKFLT,	"stack-fault" },
288 	{ T_GPFLT,	"general-protectn" },
289 	{ T_PGFLT,	"page-fault" },
290 	{ T_EXTERRFLT,	"error-fault" },
291 	{ T_ALIGNMENT,	"alignment-check" },
292 	{ T_MCE,	"machine-check" },
293 	{ T_SIMDFPE,	"sse-exception" },
294 
295 	{ T_DBGENTR,	"debug-enter" },
296 	{ T_FASTTRAP,	"fasttrap-0xd2" },
297 	{ T_SYSCALLINT,	"syscall-0x91" },
298 	{ T_DTRACE_RET,	"dtrace-ret" },
299 	{ T_SOFTINT,	"softint" },
300 	{ T_INTERRUPT,	"interrupt" },
301 	{ T_FAULT,	"fault" },
302 	{ T_AST,	"ast" },
303 	{ T_SYSCALL,	"syscall" },
304 
305 	{ 0,		NULL }
306 };
307 
308 static int
309 ttrace_trap(trap_trace_rec_t *rec)
310 {
311 	int i;
312 
313 	if (rec->ttr_regs.r_trapno == T_AST)
314 		mdb_printf("%-3s ", "-");
315 	else
316 		mdb_printf("%-3x ", rec->ttr_regs.r_trapno);
317 
318 	for (i = 0; ttrace_traps[i].tt_name != NULL; i++) {
319 		if (rec->ttr_regs.r_trapno == ttrace_traps[i].tt_trapno)
320 			break;
321 	}
322 
323 	if (ttrace_traps[i].tt_name == NULL)
324 		mdb_printf("%-*s", TT_HDLR_WIDTH, "(unknown)");
325 	else
326 		mdb_printf("%-*s", TT_HDLR_WIDTH, ttrace_traps[i].tt_name);
327 
328 	return (0);
329 }
330 
331 static struct {
332 	int	tt_type;
333 	char	*tt_name;
334 } ttrace_xcalls[] = {
335 	{ TT_XC_SVC_BEGIN,	"<svc-begin>" },
336 	{ TT_XC_SVC_END,	"<svc-end>" },
337 	{ TT_XC_START,		"<start>" },
338 	{ TT_XC_WAIT,		"<wait>" },
339 	{ TT_XC_ACK,		"<ack>" },
340 	{ TT_XC_CAPTURE,	"<capture>" },
341 	{ TT_XC_RELEASE,	"<release>" },
342 	{ TT_XC_POKE_CPU,	"<poke-cpu>" },
343 	{ TT_XC_CBE_FIRE,	"<cbe-fire>" },
344 	{ TT_XC_CBE_XCALL,	"<cbe-xcall>" },
345 	{ 0,			NULL }
346 };
347 
348 static int
349 ttrace_xcall(trap_trace_rec_t *rec)
350 {
351 	struct _xc_entry *xce = &(rec->ttr_info.xc_entry);
352 	int i;
353 
354 	for (i = 0; ttrace_xcalls[i].tt_name != NULL; i++)
355 		if (ttrace_xcalls[i].tt_type == xce->xce_marker)
356 			break;
357 
358 	switch (xce->xce_marker) {
359 	case TT_XC_SVC_BEGIN:
360 	case TT_XC_SVC_END:
361 		mdb_printf("%3s ", "-");
362 		break;
363 	default:
364 		mdb_printf("%3x ", (int)xce->xce_arg);
365 		break;
366 	}
367 
368 	if (ttrace_xcalls[i].tt_name == NULL)
369 		mdb_printf("%-*s", TT_HDLR_WIDTH, "(unknown)");
370 	else
371 		mdb_printf("%-*s", TT_HDLR_WIDTH, ttrace_xcalls[i].tt_name);
372 	return (0);
373 }
374 
375 static char *
376 xc_pri_to_str(int pri)
377 {
378 	switch (pri) {
379 	case X_CALL_LOPRI:
380 		return (" low");
381 	case X_CALL_MEDPRI:
382 		return (" med");
383 	case X_CALL_HIPRI:
384 		return ("high");
385 	default:
386 		return ("bad?");
387 	}
388 }
389 
390 static char *
391 xc_state_to_str(uint8_t state)
392 {
393 	switch (state) {
394 	case XC_DONE:
395 		return ("done");
396 	case XC_HOLD:
397 		return ("hold");
398 	case XC_SYNC_OP:
399 		return ("sync");
400 	case XC_CALL_OP:
401 		return ("call");
402 	case XC_WAIT:
403 		return ("wait");
404 	default:
405 		return ("bad?");
406 	}
407 }
408 
409 static void
410 ttrace_intr_detail(trap_trace_rec_t *rec)
411 {
412 	mdb_printf("\tirq %x ipl %d oldpri %d basepri %d\n", rec->ttr_vector,
413 	    rec->ttr_ipl, rec->ttr_pri, rec->ttr_spl);
414 }
415 
416 static void
417 ttrace_xcall_detail(trap_trace_rec_t *rec)
418 {
419 	struct _xc_entry *xce = &(rec->ttr_info.xc_entry);
420 
421 	if ((uint_t)xce->xce_pri < X_CALL_LEVELS)
422 		mdb_printf("\t%s pri [%s] ", xc_pri_to_str(xce->xce_pri),
423 		    xc_state_to_str(xce->xce_state));
424 	else
425 		mdb_printf("\t");
426 
427 	switch (xce->xce_marker) {
428 	case TT_XC_SVC_BEGIN:
429 		if (xce->xce_pri != X_CALL_MEDPRI && xce->xce_func != NULL)
430 			mdb_printf("call %a() ..", xce->xce_func);
431 		break;
432 	case TT_XC_SVC_END:
433 		if (xce->xce_arg == DDI_INTR_UNCLAIMED)
434 			mdb_printf("[spurious]");
435 		else if (xce->xce_pri != X_CALL_MEDPRI &&
436 		    xce->xce_func != NULL)
437 			mdb_printf(".. called %a() returned %d",
438 			    xce->xce_func, xce->xce_retval);
439 		break;
440 	case TT_XC_START:
441 	case TT_XC_CAPTURE:
442 		mdb_printf("--> cpu%d", (int)xce->xce_arg);
443 		break;
444 	case TT_XC_RELEASE:
445 	case TT_XC_WAIT:
446 	case TT_XC_ACK:
447 		mdb_printf("<-- cpu%d", (int)xce->xce_arg);
448 		break;
449 	case TT_XC_POKE_CPU:
450 	case TT_XC_CBE_FIRE:
451 	case TT_XC_CBE_XCALL:
452 		mdb_printf("--> cpu%d", (int)xce->xce_arg);
453 		break;
454 	default:
455 		mdb_printf("tag %d? arg 0x%lx",
456 		    xce->xce_marker, xce->xce_arg);
457 		break;
458 	}
459 	mdb_printf("\n\n");
460 }
461 
462 static struct {
463 	uchar_t t_marker;
464 	char *t_name;
465 	int (*t_hdlr)(trap_trace_rec_t *);
466 } ttrace_hdlr[] = {
467 	{ TT_SYSCALL, "sysc", ttrace_syscall },
468 	{ TT_SYSENTER, "syse", ttrace_syscall },
469 	{ TT_SYSC, "asys", ttrace_syscall },
470 	{ TT_SYSC64, "sc64", ttrace_syscall },
471 	{ TT_INTERRUPT, "intr", ttrace_interrupt },
472 	{ TT_TRAP, "trap", ttrace_trap },
473 	{ TT_EVENT, "evnt", ttrace_trap },
474 	{ TT_XCALL, "xcal", ttrace_xcall },
475 	{ 0, NULL, NULL }
476 };
477 
478 typedef struct ttrace_dcmd {
479 	processorid_t ttd_cpu;
480 	uint_t ttd_extended;
481 	trap_trace_ctl_t ttd_ttc[NCPU];
482 } ttrace_dcmd_t;
483 
484 #if defined(__amd64)
485 
486 #define	DUMP(reg) #reg, regs->r_##reg
487 #define	THREEREGS	"         %3s: %16lx %3s: %16lx %3s: %16lx\n"
488 
489 static void
490 ttrace_dumpregs(trap_trace_rec_t *rec)
491 {
492 	struct regs *regs = &rec->ttr_regs;
493 
494 	mdb_printf(THREEREGS, DUMP(rdi), DUMP(rsi), DUMP(rdx));
495 	mdb_printf(THREEREGS, DUMP(rcx), DUMP(r8), DUMP(r9));
496 	mdb_printf(THREEREGS, DUMP(rax), DUMP(rbx), DUMP(rbp));
497 	mdb_printf(THREEREGS, DUMP(r10), DUMP(r11), DUMP(r12));
498 	mdb_printf(THREEREGS, DUMP(r13), DUMP(r14), DUMP(r15));
499 	mdb_printf(THREEREGS, DUMP(ds), DUMP(es), DUMP(fs));
500 	mdb_printf(THREEREGS, DUMP(gs), "trp", regs->r_trapno, DUMP(err));
501 	mdb_printf(THREEREGS, DUMP(rip), DUMP(cs), DUMP(rfl));
502 	mdb_printf(THREEREGS, DUMP(rsp), DUMP(ss), "cr2", rec->ttr_cr2);
503 	mdb_printf("\n");
504 }
505 
506 #else
507 
508 #define	DUMP(reg) #reg, regs->r_##reg
509 #define	FOURREGS	"         %3s: %08x %3s: %08x %3s: %08x %3s: %08x\n"
510 
511 static void
512 ttrace_dumpregs(trap_trace_rec_t *rec)
513 {
514 	struct regs *regs = &rec->ttr_regs;
515 
516 	mdb_printf(FOURREGS, DUMP(gs), DUMP(fs), DUMP(es), DUMP(ds));
517 	mdb_printf(FOURREGS, DUMP(edi), DUMP(esi), DUMP(ebp), DUMP(esp));
518 	mdb_printf(FOURREGS, DUMP(ebx), DUMP(edx), DUMP(ecx), DUMP(eax));
519 	mdb_printf(FOURREGS, "trp", regs->r_trapno, DUMP(err),
520 	    DUMP(pc), DUMP(cs));
521 	mdb_printf(FOURREGS, DUMP(efl), "usp", regs->r_uesp, DUMP(ss),
522 	    "cr2", rec->ttr_cr2);
523 	mdb_printf("\n");
524 }
525 
526 #endif	/* __amd64 */
527 
528 int
529 ttrace_walk(uintptr_t addr, trap_trace_rec_t *rec, ttrace_dcmd_t *dcmd)
530 {
531 	struct regs *regs = &rec->ttr_regs;
532 	processorid_t cpu = -1, i;
533 
534 	for (i = 0; i < NCPU; i++) {
535 		if (addr >= dcmd->ttd_ttc[i].ttc_first &&
536 		    addr < dcmd->ttd_ttc[i].ttc_limit) {
537 			cpu = i;
538 			break;
539 		}
540 	}
541 
542 	if (cpu == -1) {
543 		mdb_warn("couldn't find %p in any trap trace ctl\n", addr);
544 		return (WALK_ERR);
545 	}
546 
547 	if (dcmd->ttd_cpu != -1 && cpu != dcmd->ttd_cpu)
548 		return (WALK_NEXT);
549 
550 	mdb_printf("%3d %15llx ", cpu, rec->ttr_stamp);
551 
552 	for (i = 0; ttrace_hdlr[i].t_hdlr != NULL; i++) {
553 		if (rec->ttr_marker != ttrace_hdlr[i].t_marker)
554 			continue;
555 		mdb_printf("%4s ", ttrace_hdlr[i].t_name);
556 		if (ttrace_hdlr[i].t_hdlr(rec) == -1)
557 			return (WALK_ERR);
558 	}
559 
560 	mdb_printf(" %a\n", regs->r_pc);
561 
562 	if (dcmd->ttd_extended == FALSE)
563 		return (WALK_NEXT);
564 
565 	if (rec->ttr_marker == TT_XCALL)
566 		ttrace_xcall_detail(rec);
567 	else if (rec->ttr_marker == TT_INTERRUPT)
568 		ttrace_intr_detail(rec);
569 	else
570 		ttrace_dumpregs(rec);
571 
572 	if (rec->ttr_sdepth > 0) {
573 		for (i = 0; i < rec->ttr_sdepth; i++) {
574 			if (i >= TTR_STACK_DEPTH) {
575 				mdb_printf("%17s*** invalid ttr_sdepth (is %d, "
576 				    "should be <= %d)\n", " ", rec->ttr_sdepth,
577 				    TTR_STACK_DEPTH);
578 				break;
579 			}
580 
581 			mdb_printf("%17s %a()\n", " ", rec->ttr_stack[i]);
582 		}
583 		mdb_printf("\n");
584 	}
585 
586 	return (WALK_NEXT);
587 }
588 
589 int
590 ttrace(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
591 {
592 	ttrace_dcmd_t dcmd;
593 	trap_trace_ctl_t *ttc = dcmd.ttd_ttc;
594 	trap_trace_rec_t rec;
595 	size_t ttc_size = sizeof (trap_trace_ctl_t) * NCPU;
596 
597 	if (!ttrace_ttr_size_check())
598 		return (WALK_ERR);
599 
600 	bzero(&dcmd, sizeof (dcmd));
601 	dcmd.ttd_cpu = -1;
602 	dcmd.ttd_extended = FALSE;
603 
604 	if (mdb_readsym(ttc, ttc_size, "trap_trace_ctl") == -1) {
605 		mdb_warn("symbol 'trap_trace_ctl' not found; "
606 		    "non-TRAPTRACE kernel?\n");
607 		return (DCMD_ERR);
608 	}
609 
610 	if (mdb_getopts(argc, argv,
611 	    'x', MDB_OPT_SETBITS, TRUE, &dcmd.ttd_extended, NULL) != argc)
612 		return (DCMD_USAGE);
613 
614 	if (DCMD_HDRSPEC(flags)) {
615 		mdb_printf("%3s %15s %4s %2s %-*s%s\n", "CPU",
616 		    "TIMESTAMP", "TYPE", "Vec", TT_HDLR_WIDTH, "HANDLER",
617 		    " EIP");
618 	}
619 
620 	if (flags & DCMD_ADDRSPEC) {
621 		if (addr >= NCPU) {
622 			if (mdb_vread(&rec, sizeof (rec), addr) == -1) {
623 				mdb_warn("couldn't read trap trace record "
624 				    "at %p", addr);
625 				return (DCMD_ERR);
626 			}
627 
628 			if (ttrace_walk(addr, &rec, &dcmd) == WALK_ERR)
629 				return (DCMD_ERR);
630 
631 			return (DCMD_OK);
632 		}
633 		dcmd.ttd_cpu = addr;
634 	}
635 
636 	if (mdb_walk("ttrace", (mdb_walk_cb_t)ttrace_walk, &dcmd) == -1) {
637 		mdb_warn("couldn't walk 'ttrace'");
638 		return (DCMD_ERR);
639 	}
640 
641 	return (DCMD_OK);
642 }
643 
644 /*ARGSUSED*/
645 int
646 mutex_owner_init(mdb_walk_state_t *wsp)
647 {
648 	return (WALK_NEXT);
649 }
650 
651 int
652 mutex_owner_step(mdb_walk_state_t *wsp)
653 {
654 	uintptr_t addr = wsp->walk_addr;
655 	mutex_impl_t mtx;
656 	uintptr_t owner;
657 	kthread_t thr;
658 
659 	if (mdb_vread(&mtx, sizeof (mtx), addr) == -1)
660 		return (WALK_ERR);
661 
662 	if (!MUTEX_TYPE_ADAPTIVE(&mtx))
663 		return (WALK_DONE);
664 
665 	if ((owner = (uintptr_t)MUTEX_OWNER(&mtx)) == NULL)
666 		return (WALK_DONE);
667 
668 	if (mdb_vread(&thr, sizeof (thr), owner) != -1)
669 		(void) wsp->walk_callback(owner, &thr, wsp->walk_cbdata);
670 
671 	return (WALK_DONE);
672 }
673 
674 static void
675 gate_desc_dump(gate_desc_t *gate, const char *label, int header)
676 {
677 	const char *lastnm;
678 	uint_t lastval;
679 	char type[4];
680 
681 	switch (gate->sgd_type) {
682 	case SDT_SYSIGT:
683 		strcpy(type, "int");
684 		break;
685 	case SDT_SYSTGT:
686 		strcpy(type, "trp");
687 		break;
688 	case SDT_SYSTASKGT:
689 		strcpy(type, "tsk");
690 		break;
691 	default:
692 		(void) mdb_snprintf(type, sizeof (type), "%3x", gate->sgd_type);
693 	}
694 
695 #if defined(__amd64)
696 	lastnm = "IST";
697 	lastval = gate->sgd_ist;
698 #else
699 	lastnm = "STK";
700 	lastval = gate->sgd_stkcpy;
701 #endif
702 
703 	if (header) {
704 		mdb_printf("%*s%<u>%-30s%</u> %<u>%-4s%</u> %<u>%3s%</u> "
705 		    "%<u>%1s%</u> %<u>%3s%</u> %<u>%3s%</u>\n", strlen(label),
706 		    "", "HANDLER", "SEL", "DPL", "P", "TYP", lastnm);
707 	}
708 
709 	mdb_printf("%s", label);
710 
711 	if (gate->sgd_type == SDT_SYSTASKGT)
712 		mdb_printf("%-30s ", "-");
713 	else
714 		mdb_printf("%-30a ", GATESEG_GETOFFSET(gate));
715 
716 	mdb_printf("%4x  %d  %c %3s %2x\n", gate->sgd_selector,
717 	    gate->sgd_dpl, (gate->sgd_p ? '+' : ' '), type, lastval);
718 }
719 
720 /*ARGSUSED*/
721 static int
722 gate_desc(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
723 {
724 	gate_desc_t gate;
725 
726 	if (argc != 0 || !(flags & DCMD_ADDRSPEC))
727 		return (DCMD_USAGE);
728 
729 	if (mdb_vread(&gate, sizeof (gate_desc_t), addr) !=
730 	    sizeof (gate_desc_t)) {
731 		mdb_warn("failed to read gate descriptor at %p\n", addr);
732 		return (DCMD_ERR);
733 	}
734 
735 	gate_desc_dump(&gate, "", DCMD_HDRSPEC(flags));
736 
737 	return (DCMD_OK);
738 }
739 
740 /*ARGSUSED*/
741 static int
742 idt(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
743 {
744 	int i;
745 
746 	if (!(flags & DCMD_ADDRSPEC)) {
747 		GElf_Sym idt0_va;
748 		gate_desc_t *idt0;
749 
750 		if (mdb_lookup_by_name("idt0", &idt0_va) < 0) {
751 			mdb_warn("failed to find VA of idt0");
752 			return (DCMD_ERR);
753 		}
754 
755 		addr = idt0_va.st_value;
756 		if (mdb_vread(&idt0, sizeof (idt0), addr) != sizeof (idt0)) {
757 			mdb_warn("failed to read idt0 at %p\n", addr);
758 			return (DCMD_ERR);
759 		}
760 
761 		addr = (uintptr_t)idt0;
762 	}
763 
764 	for (i = 0; i < NIDT; i++, addr += sizeof (gate_desc_t)) {
765 		gate_desc_t gate;
766 		char label[6];
767 
768 		if (mdb_vread(&gate, sizeof (gate_desc_t), addr) !=
769 		    sizeof (gate_desc_t)) {
770 			mdb_warn("failed to read gate descriptor at %p\n",
771 			    addr);
772 			return (DCMD_ERR);
773 		}
774 
775 		(void) mdb_snprintf(label, sizeof (label), "%3d: ", i);
776 		gate_desc_dump(&gate, label, i == 0);
777 	}
778 
779 	return (DCMD_OK);
780 }
781 
782 static void
783 htables_help(void)
784 {
785 	mdb_printf(
786 	    "Given a (hat_t *), generates the list of all (htable_t *)s\n"
787 	    "that correspond to that address space\n");
788 }
789 
790 static void
791 report_maps_help(void)
792 {
793 	mdb_printf(
794 	    "Given a PFN, report HAT structures that map the page, or use\n"
795 	    "the page as a pagetable.\n"
796 	    "\n"
797 	    "-m Interpret the PFN as an MFN (machine frame number)\n");
798 }
799 
800 static void
801 ptable_help(void)
802 {
803 	mdb_printf(
804 	    "Given a PFN holding a page table, print its contents, and\n"
805 	    "the address of the corresponding htable structure.\n"
806 	    "\n"
807 	    "-m Interpret the PFN as an MFN (machine frame number)\n");
808 }
809 
810 static const mdb_dcmd_t dcmds[] = {
811 	{ "gate_desc", ":", "dump a gate descriptor", gate_desc },
812 	{ "idt", ":[-v]", "dump an IDT", idt },
813 	{ "ttrace", "[-x]", "dump trap trace buffers", ttrace },
814 	{ "vatopfn", ":[-a as]", "translate address to physical page",
815 	    va2pfn_dcmd },
816 	{ "report_maps", ":[-m]",
817 	    "Given PFN, report mappings / page table usage",
818 	    report_maps_dcmd, report_maps_help },
819 	{ "htables", "", "Given hat_t *, lists all its htable_t * values",
820 	    htables_dcmd, htables_help },
821 	{ "ptable", ":[-m]", "Given PFN, dump contents of a page table",
822 	    ptable_dcmd, ptable_help },
823 	{ "pte", ":[-p XXXXX] [-l N]", "print human readable page table entry",
824 	    pte_dcmd },
825 	{ "page_num2pp", ":", "page frame number to page structure",
826 	    page_num2pp },
827 	{ "pfntomfn", ":", "convert physical page to hypervisor machine page",
828 	    pfntomfn_dcmd },
829 	{ "mfntopfn", ":", "convert hypervisor machine page to physical page",
830 	    mfntopfn_dcmd },
831 	{ "memseg_list", ":", "show memseg list", memseg_list },
832 	{ NULL }
833 };
834 
835 static const mdb_walker_t walkers[] = {
836 	{ "ttrace", "walks trap trace buffers in reverse chronological order",
837 		ttrace_walk_init, ttrace_walk_step, ttrace_walk_fini },
838 	{ "mutex_owner", "walks the owner of a mutex",
839 		mutex_owner_init, mutex_owner_step },
840 	{ "memseg", "walk the memseg structures",
841 		memseg_walk_init, memseg_walk_step, memseg_walk_fini },
842 	{ NULL }
843 };
844 
845 static const mdb_modinfo_t modinfo = { MDB_API_VERSION, dcmds, walkers };
846 
847 const mdb_modinfo_t *
848 _mdb_init(void)
849 {
850 	return (&modinfo);
851 }
852 
853 void
854 _mdb_fini(void)
855 {
856 	free_mmu();
857 }
858