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 2009 Sun Microsystems, Inc. All rights reserved.
23 * Use is subject to license terms.
24 */
25
26 /*
27 * Copyright (c) 2012 by Delphix. All rights reserved.
28 * Copyright (c) 2012 Joyent, Inc. All rights reserved.
29 */
30
31 #include <mdb/mdb_modapi.h>
32 #include <mdb/mdb.h>
33 #include <mdb/mdb_io.h>
34 #include <mdb/mdb_module.h>
35 #include <mdb/mdb_string.h>
36 #include <mdb/mdb_whatis.h>
37 #include <mdb/mdb_whatis_impl.h>
38 #include <limits.h>
39
40 static int whatis_debug = 0;
41
42 /* for bsearch; r is an array of {base, size}, e points into w->w_addrs */
43 static int
find_range(const void * r,const void * e)44 find_range(const void *r, const void *e)
45 {
46 const uintptr_t *range = r;
47 uintptr_t el = *(const uintptr_t *)e;
48
49 if (el < range[0])
50 return (1);
51
52 if ((el - range[0]) >= range[1])
53 return (-1);
54
55 return (0);
56 }
57
58 /* for qsort; simple uintptr comparator */
59 static int
uintptr_cmp(const void * l,const void * r)60 uintptr_cmp(const void *l, const void *r)
61 {
62 uintptr_t lhs = *(const uintptr_t *)l;
63 uintptr_t rhs = *(const uintptr_t *)r;
64
65 if (lhs < rhs)
66 return (-1);
67 if (lhs > rhs)
68 return (1);
69 return (0);
70 }
71
72 static const uintptr_t *
mdb_whatis_search(mdb_whatis_t * w,uintptr_t base,size_t size)73 mdb_whatis_search(mdb_whatis_t *w, uintptr_t base, size_t size)
74 {
75 uintptr_t range[2];
76
77 range[0] = base;
78 range[1] = size;
79
80 return (bsearch(range, w->w_addrs, w->w_naddrs, sizeof (*w->w_addrs),
81 find_range));
82 }
83
84 /*
85 * Returns non-zero if and only if there is at least one address of interest
86 * in the range [base, base+size).
87 */
88 int
mdb_whatis_overlaps(mdb_whatis_t * w,uintptr_t base,size_t size)89 mdb_whatis_overlaps(mdb_whatis_t *w, uintptr_t base, size_t size)
90 {
91 const uintptr_t *f;
92 uint_t offset, cur;
93
94 if (whatis_debug && w->w_magic != WHATIS_MAGIC) {
95 mdb_warn(
96 "mdb_whatis_overlaps(): bogus mdb_whatis_t pointer\n");
97 return (0);
98 }
99
100 if (w->w_done || size == 0)
101 return (0);
102
103 if (base + size - 1 < base) {
104 mdb_warn("mdb_whatis_overlaps(): [%p, %p+%p) overflows\n",
105 base, base, size);
106 return (0);
107 }
108
109 f = mdb_whatis_search(w, base, size);
110 if (f == NULL)
111 return (0);
112
113 cur = offset = f - w->w_addrs;
114
115 /*
116 * We only return success if there's an address we'll actually
117 * match in the range. We can quickly check for the ALL flag
118 * or a non-found address at our match point.
119 */
120 if ((w->w_flags & WHATIS_ALL) || !w->w_addrfound[cur])
121 return (1);
122
123 /* Search backwards then forwards for a non-found address */
124 while (cur > 0) {
125 cur--;
126
127 if (w->w_addrs[cur] < base)
128 break;
129
130 if (!w->w_addrfound[cur])
131 return (1);
132 }
133
134 for (cur = offset + 1; cur < w->w_naddrs; cur++) {
135 if ((w->w_addrs[cur] - base) >= size)
136 break;
137
138 if (!w->w_addrfound[cur])
139 return (1);
140 }
141
142 return (0); /* everything has already been seen */
143 }
144
145 /*
146 * Iteratively search our list of addresses for matches in [base, base+size).
147 */
148 int
mdb_whatis_match(mdb_whatis_t * w,uintptr_t base,size_t size,uintptr_t * out)149 mdb_whatis_match(mdb_whatis_t *w, uintptr_t base, size_t size, uintptr_t *out)
150 {
151 size_t offset;
152
153 if (whatis_debug) {
154 if (w->w_magic != WHATIS_MAGIC) {
155 mdb_warn(
156 "mdb_whatis_match(): bogus mdb_whatis_t pointer\n");
157 goto done;
158 }
159 }
160
161 if (w->w_done || size == 0)
162 goto done;
163
164 if (base + size - 1 < base) {
165 mdb_warn("mdb_whatis_match(): [%p, %p+%x) overflows\n",
166 base, base, size);
167 return (0);
168 }
169
170 if ((offset = w->w_match_next) != 0 &&
171 (base != w->w_match_base || size != w->w_match_size)) {
172 mdb_warn("mdb_whatis_match(): new range [%p, %p+%p) "
173 "while still searching [%p, %p+%p)\n",
174 base, base, size,
175 w->w_match_base, w->w_match_base, w->w_match_size);
176 offset = 0;
177 }
178
179 if (offset == 0) {
180 const uintptr_t *f = mdb_whatis_search(w, base, size);
181
182 if (f == NULL)
183 goto done;
184
185 offset = (f - w->w_addrs);
186
187 /* Walk backwards until we reach the first match */
188 while (offset > 0 && w->w_addrs[offset - 1] >= base)
189 offset--;
190
191 w->w_match_base = base;
192 w->w_match_size = size;
193 }
194
195 for (; offset < w->w_naddrs && ((w->w_addrs[offset] - base) < size);
196 offset++) {
197
198 *out = w->w_addrs[offset];
199 w->w_match_next = offset + 1;
200
201 if (w->w_addrfound[offset]) {
202 /* if we're not seeing everything, skip it */
203 if (!(w->w_flags & WHATIS_ALL))
204 continue;
205
206 return (1);
207 }
208
209 /* We haven't seen this address yet. */
210 w->w_found++;
211 w->w_addrfound[offset] = 1;
212
213 /* If we've found them all, we're done */
214 if (w->w_found == w->w_naddrs && !(w->w_flags & WHATIS_ALL))
215 w->w_done = 1;
216
217 return (1);
218 }
219
220 done:
221 w->w_match_next = 0;
222 w->w_match_base = 0;
223 w->w_match_size = 0;
224 return (0);
225 }
226
227 /*
228 * Report a pointer (addr) in an object beginning at (base) in standard
229 * whatis-style. (format, ...) are mdb_printf() arguments, to be printed
230 * after the address information. The caller is responsible for printing
231 * a newline (either in format or after the call returns)
232 */
233 /*ARGSUSED*/
234 void
mdb_whatis_report_object(mdb_whatis_t * w,uintptr_t addr,uintptr_t base,const char * format,...)235 mdb_whatis_report_object(mdb_whatis_t *w,
236 uintptr_t addr, uintptr_t base, const char *format, ...)
237 {
238 va_list alist;
239
240 if (whatis_debug) {
241 if (mdb_whatis_search(w, addr, 1) == NULL)
242 mdb_warn("mdb_whatis_report_object(): addr "
243 "%p is not a pointer of interest.\n", addr);
244 }
245
246 if (addr < base)
247 mdb_warn("whatis: addr (%p) is less than base (%p)\n",
248 addr, base);
249
250 if (addr == base)
251 mdb_printf("%p is ", addr);
252 else
253 mdb_printf("%p is %p+%p, ", addr, base, addr - base);
254
255 if (format == NULL)
256 return;
257
258 va_start(alist, format);
259 mdb_iob_vprintf(mdb.m_out, format, alist);
260 va_end(alist);
261 }
262
263 /*
264 * Report an address (addr), with symbolic information if available, in
265 * standard whatis-style. (format, ...) are mdb_printf() arguments, to be
266 * printed after the address information. The caller is responsible for
267 * printing a newline (either in format or after the call returns)
268 */
269 /*ARGSUSED*/
270 void
mdb_whatis_report_address(mdb_whatis_t * w,uintptr_t addr,const char * format,...)271 mdb_whatis_report_address(mdb_whatis_t *w, uintptr_t addr,
272 const char *format, ...)
273 {
274 GElf_Sym sym;
275 va_list alist;
276
277 if (whatis_debug) {
278 if (mdb_whatis_search(w, addr, 1) == NULL)
279 mdb_warn("mdb_whatis_report_adddress(): addr "
280 "%p is not a pointer of interest.\n", addr);
281 }
282
283 mdb_printf("%p is ", addr);
284
285 if (mdb_lookup_by_addr(addr, MDB_SYM_FUZZY, NULL, 0, &sym) != -1 &&
286 (addr - (uintptr_t)sym.st_value) < sym.st_size) {
287 mdb_printf("%a, ", addr);
288 }
289
290 va_start(alist, format);
291 mdb_iob_vprintf(mdb.m_out, format, alist);
292 va_end(alist);
293 }
294
295 uint_t
mdb_whatis_flags(mdb_whatis_t * w)296 mdb_whatis_flags(mdb_whatis_t *w)
297 {
298 /* Mask out the internal-only flags */
299 return (w->w_flags & WHATIS_PUBLIC);
300 }
301
302 uint_t
mdb_whatis_done(mdb_whatis_t * w)303 mdb_whatis_done(mdb_whatis_t *w)
304 {
305 return (w->w_done);
306 }
307
308 /*
309 * Whatis callback list management
310 */
311 typedef struct whatis_callback {
312 uint64_t wcb_index;
313 mdb_module_t *wcb_module;
314 const char *wcb_modname;
315 char *wcb_name;
316 mdb_whatis_cb_f *wcb_func;
317 void *wcb_arg;
318 uint_t wcb_prio;
319 uint_t wcb_flags;
320 } whatis_callback_t;
321
322 static whatis_callback_t builtin_whatis[] = {
323 { 0, NULL, "mdb", "mappings", whatis_run_mappings, NULL,
324 WHATIS_PRIO_MIN, WHATIS_REG_NO_ID }
325 };
326 #define NBUILTINS (sizeof (builtin_whatis) / sizeof (*builtin_whatis))
327
328 static whatis_callback_t *whatis_cb_start[NBUILTINS];
329 static whatis_callback_t **whatis_cb = NULL; /* callback array */
330 static size_t whatis_cb_count; /* count of callbacks */
331 static size_t whatis_cb_size; /* size of whatis_cb array */
332 static uint64_t whatis_cb_index; /* global count */
333
334 #define WHATIS_CB_SIZE_MIN 8 /* initial allocation size */
335
336 static int
whatis_cbcmp(const void * lhs,const void * rhs)337 whatis_cbcmp(const void *lhs, const void *rhs)
338 {
339 whatis_callback_t *l = *(whatis_callback_t * const *)lhs;
340 whatis_callback_t *r = *(whatis_callback_t * const *)rhs;
341 int ret;
342
343 /* First, handle NULLs; we want them at the end */
344 if (l == NULL && r == NULL)
345 return (0);
346 if (l == NULL)
347 return (1);
348 if (r == NULL)
349 return (-1);
350
351 /* Next, compare priorities */
352 if (l->wcb_prio < r->wcb_prio)
353 return (-1);
354 if (l->wcb_prio > r->wcb_prio)
355 return (1);
356
357 /* then module name */
358 if ((ret = strcmp(l->wcb_modname, r->wcb_modname)) != 0)
359 return (ret);
360
361 /* and finally insertion order */
362 if (l->wcb_index < r->wcb_index)
363 return (-1);
364 if (l->wcb_index > r->wcb_index)
365 return (1);
366
367 mdb_warn("whatis_cbcmp(): can't happen: duplicate indices\n");
368 return (0);
369 }
370
371 static void
whatis_init(void)372 whatis_init(void)
373 {
374 int idx;
375
376 for (idx = 0; idx < NBUILTINS; idx++) {
377 whatis_cb_start[idx] = &builtin_whatis[idx];
378 whatis_cb_start[idx]->wcb_index = idx;
379 }
380 whatis_cb_index = idx;
381
382 whatis_cb = whatis_cb_start;
383 whatis_cb_count = whatis_cb_size = NBUILTINS;
384
385 qsort(whatis_cb, whatis_cb_count, sizeof (*whatis_cb), whatis_cbcmp);
386 }
387
388 void
mdb_whatis_register(const char * name,mdb_whatis_cb_f * func,void * arg,uint_t prio,uint_t flags)389 mdb_whatis_register(const char *name, mdb_whatis_cb_f *func, void *arg,
390 uint_t prio, uint_t flags)
391 {
392 whatis_callback_t *wcp;
393
394 if (mdb.m_lmod == NULL) {
395 mdb_warn("mdb_whatis_register(): can only be called during "
396 "module load\n");
397 return;
398 }
399
400 if (strbadid(name)) {
401 mdb_warn("mdb_whatis_register(): whatis name '%s' contains "
402 "illegal characters\n");
403 return;
404 }
405
406 if ((flags & ~(WHATIS_REG_NO_ID|WHATIS_REG_ID_ONLY)) != 0) {
407 mdb_warn("mdb_whatis_register(): flags (%x) contain unknown "
408 "flags\n", flags);
409 return;
410 }
411 if ((flags & WHATIS_REG_NO_ID) && (flags & WHATIS_REG_ID_ONLY)) {
412 mdb_warn("mdb_whatis_register(): flags (%x) contains both "
413 "NO_ID and ID_ONLY.\n", flags);
414 return;
415 }
416
417 if (prio > WHATIS_PRIO_MIN)
418 prio = WHATIS_PRIO_MIN;
419
420 if (whatis_cb == NULL)
421 whatis_init();
422
423 wcp = mdb_zalloc(sizeof (*wcp), UM_SLEEP);
424
425 wcp->wcb_index = whatis_cb_index++;
426 wcp->wcb_prio = prio;
427 wcp->wcb_module = mdb.m_lmod;
428 wcp->wcb_modname = mdb.m_lmod->mod_name;
429 wcp->wcb_name = strdup(name);
430 wcp->wcb_func = func;
431 wcp->wcb_arg = arg;
432 wcp->wcb_flags = flags;
433
434 /*
435 * See if we need to grow the array; note that at initialization
436 * time, whatis_cb_count is greater than whatis_cb_size; this clues
437 * us in to the fact that the array doesn't need to be freed.
438 */
439 if (whatis_cb_count == whatis_cb_size) {
440 size_t nsize = MAX(2 * whatis_cb_size, WHATIS_CB_SIZE_MIN);
441
442 size_t obytes = sizeof (*whatis_cb) * whatis_cb_size;
443 size_t nbytes = sizeof (*whatis_cb) * nsize;
444
445 whatis_callback_t **narray = mdb_zalloc(nbytes, UM_SLEEP);
446
447 bcopy(whatis_cb, narray, obytes);
448
449 if (whatis_cb != whatis_cb_start)
450 mdb_free(whatis_cb, obytes);
451 whatis_cb = narray;
452 whatis_cb_size = nsize;
453 }
454
455 /* add it into the table and re-sort */
456 whatis_cb[whatis_cb_count++] = wcp;
457 qsort(whatis_cb, whatis_cb_count, sizeof (*whatis_cb), whatis_cbcmp);
458 }
459
460 void
mdb_whatis_unregister_module(mdb_module_t * mod)461 mdb_whatis_unregister_module(mdb_module_t *mod)
462 {
463 int found = 0;
464 int idx;
465
466 if (mod == NULL)
467 return;
468
469 for (idx = 0; idx < whatis_cb_count; idx++) {
470 whatis_callback_t *cur = whatis_cb[idx];
471
472 if (cur->wcb_module == mod) {
473 found++;
474 whatis_cb[idx] = NULL;
475
476 strfree(cur->wcb_name);
477 mdb_free(cur, sizeof (*cur));
478 }
479 }
480 /* If any were removed, compact the array */
481 if (found != 0) {
482 qsort(whatis_cb, whatis_cb_count, sizeof (*whatis_cb),
483 whatis_cbcmp);
484 whatis_cb_count -= found;
485 }
486 }
487
488 int
cmd_whatis(uintptr_t addr,uint_t flags,int argc,const mdb_arg_t * argv)489 cmd_whatis(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
490 {
491 mdb_whatis_t w;
492 size_t idx;
493 int ret;
494 int keep = 0;
495 int list = 0;
496
497 if (flags & DCMD_PIPE_OUT) {
498 mdb_warn("whatis: cannot be output into a pipe\n");
499 return (DCMD_ERR);
500 }
501
502 if (mdb.m_lmod != NULL) {
503 mdb_warn("whatis: cannot be called during module load\n");
504 return (DCMD_ERR);
505 }
506
507 if (whatis_cb == NULL)
508 whatis_init();
509
510 bzero(&w, sizeof (w));
511 w.w_magic = WHATIS_MAGIC;
512
513 whatis_debug = 0;
514
515 if (mdb_getopts(argc, argv,
516 'D', MDB_OPT_SETBITS, TRUE, &whatis_debug, /* hidden */
517 'b', MDB_OPT_SETBITS, WHATIS_BUFCTL, &w.w_flags, /* hidden */
518 'l', MDB_OPT_SETBITS, TRUE, &list, /* hidden */
519 'a', MDB_OPT_SETBITS, WHATIS_ALL, &w.w_flags,
520 'i', MDB_OPT_SETBITS, WHATIS_IDSPACE, &w.w_flags,
521 'k', MDB_OPT_SETBITS, TRUE, &keep,
522 'q', MDB_OPT_SETBITS, WHATIS_QUIET, &w.w_flags,
523 'v', MDB_OPT_SETBITS, WHATIS_VERBOSE, &w.w_flags,
524 NULL) != argc)
525 return (DCMD_USAGE);
526
527 if (list) {
528 mdb_printf("%<u>%-16s %-12s %4s %?s %?s %8s%</u>",
529 "NAME", "MODULE", "PRIO", "FUNC", "ARG", "FLAGS");
530
531 for (idx = 0; idx < whatis_cb_count; idx++) {
532 whatis_callback_t *cur = whatis_cb[idx];
533
534 const char *curfl =
535 (cur->wcb_flags & WHATIS_REG_NO_ID) ? "NO_ID" :
536 (cur->wcb_flags & WHATIS_REG_ID_ONLY) ? "ID_ONLY" :
537 "none";
538
539 mdb_printf("%-16s %-12s %4d %-?p %-?p %8s\n",
540 cur->wcb_name, cur->wcb_modname, cur->wcb_prio,
541 cur->wcb_func, cur->wcb_arg, curfl);
542 }
543 return (DCMD_OK);
544 }
545
546 if (!(flags & DCMD_ADDRSPEC))
547 return (DCMD_USAGE);
548
549 w.w_addrs = &addr;
550 w.w_naddrs = 1;
551
552 /* If our input is a pipe, try to slurp it all up. */
553 if (!keep && (flags & DCMD_PIPE)) {
554 mdb_pipe_t p;
555 mdb_get_pipe(&p);
556
557 if (p.pipe_len != 0) {
558 w.w_addrs = p.pipe_data;
559 w.w_naddrs = p.pipe_len;
560
561 /* sort the address list */
562 qsort(w.w_addrs, w.w_naddrs, sizeof (*w.w_addrs),
563 uintptr_cmp);
564 }
565 }
566 w.w_addrfound = mdb_zalloc(w.w_naddrs * sizeof (*w.w_addrfound),
567 UM_SLEEP | UM_GC);
568
569 if (whatis_debug) {
570 mdb_printf("Searching for:\n");
571 for (idx = 0; idx < w.w_naddrs; idx++)
572 mdb_printf(" %p", w.w_addrs[idx]);
573 }
574
575 ret = 0;
576
577 /* call in to the registered handlers */
578 for (idx = 0; idx < whatis_cb_count; idx++) {
579 whatis_callback_t *cur = whatis_cb[idx];
580
581 /* Honor the ident flags */
582 if (w.w_flags & WHATIS_IDSPACE) {
583 if (cur->wcb_flags & WHATIS_REG_NO_ID)
584 continue;
585 } else {
586 if (cur->wcb_flags & WHATIS_REG_ID_ONLY)
587 continue;
588 }
589
590 if (w.w_flags & WHATIS_VERBOSE)
591 mdb_printf("Searching %s`%s...\n",
592 cur->wcb_modname, cur->wcb_name);
593
594 if (cur->wcb_func(&w, cur->wcb_arg) != 0)
595 ret = 1;
596
597 /* reset the match state for the next callback */
598 w.w_match_next = 0;
599 w.w_match_base = 0;
600 w.w_match_size = 0;
601
602 if (w.w_done)
603 break;
604 }
605
606 /* Report any unexplained pointers */
607 for (idx = 0; idx < w.w_naddrs; idx++) {
608 uintptr_t addr = w.w_addrs[idx];
609
610 if (w.w_addrfound[idx])
611 continue;
612
613 mdb_whatis_report_object(&w, addr, addr, "unknown\n");
614 }
615
616 return ((ret != 0) ? DCMD_ERR : DCMD_OK);
617 }
618
619 void
whatis_help(void)620 whatis_help(void)
621 {
622 int idx;
623
624 mdb_printf("%s\n",
625 "Given a virtual address (with -i, an identifier), report where it came\n"
626 "from.\n"
627 "\n"
628 "When fed from a pipeline, ::whatis will not maintain the order the input\n"
629 "comes in; addresses will be reported as it finds them. (-k prevents this;\n"
630 "the output will be in the same order as the input)\n");
631 (void) mdb_dec_indent(2);
632 mdb_printf("%<b>OPTIONS%</b>\n");
633 (void) mdb_inc_indent(2);
634 mdb_printf("%s",
635 " -a Report all information about each address/identifier. The default\n"
636 " behavior is to report only the first (most specific) source for each\n"
637 " address/identifier.\n"
638 " -i addr is an identifier, not a virtual address.\n"
639 " -k Do not re-order the input. (may be slower)\n"
640 " -q Quiet; don't print multi-line reports. (stack traces, etc.)\n"
641 " -v Verbose output; display information about the progress of the search\n");
642
643 if (mdb.m_lmod != NULL)
644 return;
645
646 (void) mdb_dec_indent(2);
647 mdb_printf("\n%<b>SOURCES%</b>\n\n");
648 (void) mdb_inc_indent(2);
649 mdb_printf("The following information sources will be used:\n\n");
650
651 (void) mdb_inc_indent(2);
652 for (idx = 0; idx < whatis_cb_count; idx++) {
653 whatis_callback_t *cur = whatis_cb[idx];
654
655 mdb_printf("%s`%s\n", cur->wcb_modname, cur->wcb_name);
656 }
657 (void) mdb_dec_indent(2);
658 }
659