xref: /titanic_51/usr/src/cmd/dis/dis_main.c (revision 15d9d0b528387242011cdcc6190c9e598cfe3a07)
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 /*
23  * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 #pragma ident	"%Z%%M%	%I%	%E% SMI"
28 
29 #include <ctype.h>
30 #include <getopt.h>
31 #include <stdio.h>
32 #include <stdlib.h>
33 #include <string.h>
34 #include <sys/sysmacros.h>
35 #include <sys/elf_SPARC.h>
36 
37 #include <libdisasm.h>
38 
39 #include "dis_target.h"
40 #include "dis_util.h"
41 #include "dis_list.h"
42 
43 int g_demangle;		/* Demangle C++ names */
44 int g_quiet;		/* Quiet mode */
45 int g_numeric;		/* Numeric mode */
46 int g_flags;		/* libdisasm language flags */
47 int g_doall;		/* true if no functions or sections were given */
48 
49 dis_namelist_t *g_funclist;	/* list of functions to disassemble, if any */
50 dis_namelist_t *g_seclist;	/* list of sections to disassemble, if any */
51 
52 /*
53  * Section options for -d, -D, and -s
54  */
55 #define	DIS_DATA_RELATIVE	1
56 #define	DIS_DATA_ABSOLUTE	2
57 #define	DIS_TEXT		3
58 
59 /*
60  * libdisasm callback data.  Keeps track of current data (function or section)
61  * and offset within that data.
62  */
63 typedef struct dis_buffer {
64 	dis_tgt_t	*db_tgt;	/* current dis target */
65 	void		*db_data;	/* function or section data */
66 	uint64_t	db_addr;	/* address of function start */
67 	size_t		db_size;	/* size of data */
68 	uint64_t	db_nextaddr;	/* next address to be read */
69 } dis_buffer_t;
70 
71 #define	MINSYMWIDTH	22	/* Minimum width of symbol portion of line */
72 
73 /*
74  * Given a symbol+offset as returned by dis_tgt_lookup(), print an appropriately
75  * formatted symbol, based on the offset and current setttings.
76  */
77 void
78 getsymname(uint64_t addr, const char *symbol, off_t offset, char *buf,
79     size_t buflen)
80 {
81 	if (symbol == NULL || g_numeric) {
82 		if (g_flags & DIS_OCTAL)
83 			(void) snprintf(buf, buflen, "0%llo", addr);
84 		else
85 			(void) snprintf(buf, buflen, "0x%llx", addr);
86 	} else {
87 		if (g_demangle)
88 			symbol = dis_demangle(symbol);
89 
90 		if (offset == 0)
91 			(void) snprintf(buf, buflen, "%s", symbol);
92 		else if (g_flags & DIS_OCTAL)
93 			(void) snprintf(buf, buflen, "%s+0%o", symbol, offset);
94 		else
95 			(void) snprintf(buf, buflen, "%s+0x%x", symbol, offset);
96 	}
97 }
98 
99 /*
100  * The main disassembly routine.  Given a fixed-sized buffer and starting
101  * address, disassemble the data using the supplied target and libdisasm handle.
102  */
103 void
104 dis_data(dis_tgt_t *tgt, dis_handle_t *dhp, uint64_t addr, void *data,
105     size_t datalen)
106 {
107 	dis_buffer_t db = { 0 };
108 	char buf[BUFSIZE];
109 	char symbuf[BUFSIZE];
110 	const char *symbol;
111 	off_t symoffset;
112 	int i;
113 	int bytesperline;
114 	size_t symsize;
115 	int isfunc;
116 	size_t symwidth = 0;
117 
118 	db.db_tgt = tgt;
119 	db.db_data = data;
120 	db.db_addr = addr;
121 	db.db_size = datalen;
122 
123 	dis_set_data(dhp, &db);
124 
125 	if ((bytesperline = dis_max_instrlen(dhp)) > 6)
126 		bytesperline = 6;
127 
128 	while (addr < db.db_addr + db.db_size) {
129 
130 		if (dis_disassemble(dhp, addr, buf, BUFSIZE) != 0) {
131 			/*
132 			 * If we encounter an invalid opcode, we just
133 			 * print "*** invalid opcode ***" at that first bad
134 			 * instruction and continue with printing the rest
135 			 * of the instruction stream as hex data,
136 			 * We then find the next valid symbol in the section,
137 			 * and disassemble from there.
138 			 */
139 			off_t next;
140 
141 			(void) snprintf(buf, sizeof (buf),
142 			    "*** invalid opcode ***");
143 
144 			if ((next = dis_tgt_next_symbol(tgt, addr)) == 0) {
145 				db.db_nextaddr = db.db_addr + db.db_size;
146 			} else {
147 				if (next > db.db_size)
148 					db.db_nextaddr = db.db_addr +
149 					    db.db_size;
150 				else
151 					db.db_nextaddr = addr + next;
152 			}
153 		}
154 
155 		/*
156 		 * Print out the line as:
157 		 *
158 		 * 	address:	bytes	text
159 		 *
160 		 * If there are more than 6 bytes in any given instruction,
161 		 * spread the bytes across two lines.  We try to get symbolic
162 		 * information for the address, but if that fails we print out
163 		 * the numeric address instead.
164 		 *
165 		 * We try to keep the address portion of the text aligned at
166 		 * MINSYMWIDTH characters.  If we are disassembling a function
167 		 * with a long name, this can be annoying.  So we pick a width
168 		 * based on the maximum width that the current symbol can be.
169 		 * This at least produces text aligned within each function.
170 		 */
171 		symbol = dis_tgt_lookup(tgt, addr, &symoffset, 1, &symsize,
172 		    &isfunc);
173 		/* Get the maximum length for this symbol */
174 		getsymname(addr, symbol, symsize, symbuf, sizeof (symbuf));
175 		symwidth = MAX(strlen(symbuf), MINSYMWIDTH);
176 
177 		getsymname(addr, symbol, symoffset, symbuf, sizeof (symbuf));
178 
179 		/*
180 		 * If we've crossed a new function boundary, print out the
181 		 * function name on a blank line.
182 		 */
183 		if (!g_quiet && symoffset == 0 && symbol != NULL && isfunc)
184 			(void) printf("%s()\n", symbol);
185 
186 		(void) printf("    %s:%*s ", symbuf,
187 		    symwidth - strlen(symbuf), "");
188 
189 		/* print bytes */
190 		for (i = 0; i < MIN(bytesperline, (db.db_nextaddr - addr));
191 		    i++) {
192 			int byte = *((uchar_t *)data + (addr - db.db_addr) + i);
193 			if (g_flags & DIS_OCTAL)
194 				(void) printf("%03o ", byte);
195 			else
196 				(void) printf("%02x ", byte);
197 		}
198 
199 		/* trailing spaces for missing bytes */
200 		for (; i < bytesperline; i++) {
201 			if (g_flags & DIS_OCTAL)
202 				(void) printf("    ");
203 			else
204 				(void) printf("   ");
205 		}
206 
207 		/* contents of disassembly */
208 		(void) printf(" %s", buf);
209 
210 		/* excess bytes that spill over onto subsequent lines */
211 		for (; i < db.db_nextaddr - addr; i++) {
212 			int byte = *((uchar_t *)data + (addr - db.db_addr) + i);
213 			if (i % bytesperline == 0)
214 				(void) printf("\n    %*s  ", symwidth, "");
215 			if (g_flags & DIS_OCTAL)
216 				(void) printf("%03o ", byte);
217 			else
218 				(void) printf("%02x ", byte);
219 		}
220 
221 		(void) printf("\n");
222 
223 		addr = db.db_nextaddr;
224 	}
225 }
226 
227 /*
228  * libdisasm wrapper around symbol lookup.  Invoke the target-specific lookup
229  * function, and convert the result using getsymname().
230  */
231 int
232 do_lookup(void *data, uint64_t addr, char *buf, size_t buflen, uint64_t *start,
233     size_t *symlen)
234 {
235 	dis_buffer_t *db = data;
236 	const char *symbol;
237 	off_t offset;
238 	size_t size;
239 
240 	/*
241 	 * If NULL symbol is returned, getsymname takes care of
242 	 * printing appropriate address in buf instead of symbol.
243 	 */
244 	symbol = dis_tgt_lookup(db->db_tgt, addr, &offset, 0, &size, NULL);
245 
246 	if (buf != NULL)
247 		getsymname(addr, symbol, offset, buf, buflen);
248 
249 	if (start != NULL)
250 		*start = addr - offset;
251 	if (symlen != NULL)
252 		*symlen = size;
253 
254 	if (symbol == NULL)
255 		return (-1);
256 
257 	return (0);
258 }
259 
260 /*
261  * libdisasm wrapper around target reading.  libdisasm will always read data
262  * in order, so update our current offset within the buffer appropriately.
263  * We only support reading from within the current object; libdisasm should
264  * never ask us to do otherwise.
265  */
266 int
267 do_read(void *data, uint64_t addr, void *buf, size_t len)
268 {
269 	dis_buffer_t *db = data;
270 	size_t offset;
271 
272 	if (addr < db->db_addr || addr >= db->db_addr + db->db_size)
273 		return (-1);
274 
275 	offset = addr - db->db_addr;
276 	len = MIN(len, db->db_size - offset);
277 
278 	(void) memcpy(buf, (char *)db->db_data + offset, len);
279 
280 	db->db_nextaddr = addr + len;
281 
282 	return (len);
283 }
284 
285 /*
286  * Routine to dump raw data in a human-readable format.  Used by the -d and -D
287  * options.  We model our output after the xxd(1) program, which gives nicely
288  * formatted output, along with an ASCII translation of the result.
289  */
290 void
291 dump_data(uint64_t addr, void *data, size_t datalen)
292 {
293 	uintptr_t curaddr = addr & (~0xf);
294 	uint8_t *bytes = data;
295 	int i;
296 	int width;
297 
298 	/*
299 	 * Determine if the address given to us fits in 32-bit range, in which
300 	 * case use a 4-byte width.
301 	 */
302 	if (((addr + datalen) & 0xffffffff00000000ULL) == 0ULL)
303 		width = 8;
304 	else
305 		width = 16;
306 
307 	while (curaddr < addr + datalen) {
308 		/*
309 		 * Display leading address
310 		 */
311 		(void) printf("%0*x: ", width, curaddr);
312 
313 		/*
314 		 * Print out data in two-byte chunks.  If the current address
315 		 * is before the starting address or after the end of the
316 		 * section, print spaces.
317 		 */
318 		for (i = 0; i < 16; i++) {
319 			if (curaddr + i < addr ||curaddr + i >= addr + datalen)
320 				(void) printf("  ");
321 			else
322 				(void) printf("%02x",
323 				    bytes[curaddr + i - addr]);
324 
325 			if (i & 1)
326 				(void) printf(" ");
327 		}
328 
329 		(void) printf(" ");
330 
331 		/*
332 		 * Print out the ASCII representation
333 		 */
334 		for (i = 0; i < 16; i++) {
335 			if (curaddr + i < addr ||
336 			    curaddr + i >= addr + datalen) {
337 				(void) printf(" ");
338 			} else {
339 				uint8_t byte = bytes[curaddr + i - addr];
340 				if (isprint(byte))
341 					(void) printf("%c", byte);
342 				else
343 					(void) printf(".");
344 			}
345 		}
346 
347 		(void) printf("\n");
348 
349 		curaddr += 16;
350 	}
351 }
352 
353 /*
354  * Disassemble a section implicitly specified as part of a file.  This function
355  * is called for all sections when no other flags are specified.  We ignore any
356  * data sections, and print out only those sections containing text.
357  */
358 void
359 dis_text_section(dis_tgt_t *tgt, dis_scn_t *scn, void *data)
360 {
361 	dis_handle_t *dhp = data;
362 
363 	/* ignore data sections */
364 	if (!dis_section_istext(scn))
365 		return;
366 
367 	if (!g_quiet)
368 		(void) printf("\nsection %s\n", dis_section_name(scn));
369 
370 	dis_data(tgt, dhp, dis_section_addr(scn), dis_section_data(scn),
371 	    dis_section_size(scn));
372 }
373 
374 /*
375  * Structure passed to dis_named_{section,function} which keeps track of both
376  * the target and the libdisasm handle.
377  */
378 typedef struct callback_arg {
379 	dis_tgt_t	*ca_tgt;
380 	dis_handle_t	*ca_handle;
381 } callback_arg_t;
382 
383 /*
384  * Disassemble a section explicitly named with -s, -d, or -D.  The 'type'
385  * argument contains the type of argument given.  Pass the data onto the
386  * appropriate helper routine.
387  */
388 void
389 dis_named_section(dis_scn_t *scn, int type, void *data)
390 {
391 	callback_arg_t *ca = data;
392 
393 	if (!g_quiet)
394 		(void) printf("\nsection %s\n", dis_section_name(scn));
395 
396 	switch (type) {
397 	case DIS_DATA_RELATIVE:
398 		dump_data(0, dis_section_data(scn), dis_section_size(scn));
399 		break;
400 	case DIS_DATA_ABSOLUTE:
401 		dump_data(dis_section_addr(scn), dis_section_data(scn),
402 		    dis_section_size(scn));
403 		break;
404 	case DIS_TEXT:
405 		dis_data(ca->ca_tgt, ca->ca_handle, dis_section_addr(scn),
406 		    dis_section_data(scn), dis_section_size(scn));
407 		break;
408 	}
409 }
410 
411 /*
412  * Disassemble a function explicitly specified with '-F'.  The 'type' argument
413  * is unused.
414  */
415 /* ARGSUSED */
416 void
417 dis_named_function(dis_func_t *func, int type, void *data)
418 {
419 	callback_arg_t *ca = data;
420 
421 	dis_data(ca->ca_tgt, ca->ca_handle, dis_function_addr(func),
422 	    dis_function_data(func), dis_function_size(func));
423 }
424 
425 /*
426  * Disassemble a complete file.  First, we determine the type of the file based
427  * on the ELF machine type, and instantiate a version of the disassembler
428  * appropriate for the file.  We then resolve any named sections or functions
429  * against the file, and iterate over the results (or all sections if no flags
430  * were specified).
431  */
432 void
433 dis_file(const char *filename)
434 {
435 	dis_tgt_t *tgt, *current;
436 	dis_scnlist_t *sections;
437 	dis_funclist_t *functions;
438 	dis_handle_t *dhp;
439 	GElf_Ehdr ehdr;
440 
441 	/*
442 	 * First, initialize the target
443 	 */
444 	if ((tgt = dis_tgt_create(filename)) == NULL)
445 		return;
446 
447 	if (!g_quiet)
448 		(void) printf("disassembly for %s\n\n",  filename);
449 
450 	/*
451 	 * A given file may contain multiple targets (if it is an archive, for
452 	 * example).  We iterate over all possible targets if this is the case.
453 	 */
454 	for (current = tgt; current != NULL; current = dis_tgt_next(current)) {
455 		dis_tgt_ehdr(current, &ehdr);
456 
457 		/*
458 		 * Eventually, this should probably live within libdisasm, and
459 		 * we should be able to disassemble targets from different
460 		 * architectures.  For now, we only support objects as the
461 		 * native machine type.
462 		 */
463 		switch (ehdr.e_machine) {
464 #ifdef __sparc
465 		case EM_SPARC:
466 			if (ehdr.e_ident[EI_CLASS] != ELFCLASS32 ||
467 			    ehdr.e_ident[EI_DATA] != ELFDATA2MSB) {
468 				warn("invalid E_IDENT field for SPARC object");
469 				return;
470 			}
471 			g_flags |= DIS_SPARC_V8;
472 			break;
473 
474 		case EM_SPARC32PLUS:
475 			if (ehdr.e_ident[EI_CLASS] != ELFCLASS32 ||
476 			    ehdr.e_ident[EI_DATA] != ELFDATA2MSB) {
477 				warn("invalid E_IDENT field for SPARC object");
478 				return;
479 			}
480 
481 			switch (ehdr.e_flags & EF_SPARC_32PLUS_MASK) {
482 			case (EF_SPARC_32PLUS | EF_SPARC_SUN_US1 |
483 			    EF_SPARC_SUN_US3):
484 			case (EF_SPARC_32PLUS | EF_SPARC_SUN_US1):
485 				g_flags |= DIS_SPARC_V9 | DIS_SPARC_V9_SGI;
486 			default:
487 				g_flags |= DIS_SPARC_V9;
488 			}
489 			break;
490 
491 		case EM_SPARCV9:
492 			if (ehdr.e_ident[EI_CLASS] != ELFCLASS64 ||
493 			    ehdr.e_ident[EI_DATA] != ELFDATA2MSB) {
494 				warn("invalid E_IDENT field for SPARC object");
495 				return;
496 			}
497 
498 			g_flags |= DIS_SPARC_V9 | DIS_SPARC_V9_SGI;
499 			break;
500 #endif /* __sparc */
501 
502 #if defined(__i386) || defined(__amd64)
503 		case EM_386:
504 			g_flags |= DIS_X86_SIZE32;
505 			break;
506 
507 		case EM_AMD64:
508 			g_flags |= DIS_X86_SIZE64;
509 			break;
510 #endif /* __i386 || __amd64 */
511 
512 		default:
513 			die("%s: unsupported ELF machine 0x%x", filename,
514 			    ehdr.e_machine);
515 		}
516 
517 		/*
518 		 * If ET_REL (.o), printing immediate symbols is likely to
519 		 * result in garbage, as symbol lookups on unrelocated
520 		 * immediates find false and useless matches.
521 		 */
522 
523 		if (ehdr.e_type == ET_REL)
524 			g_flags |= DIS_NOIMMSYM;
525 
526 		if (!g_quiet && dis_tgt_member(current) != NULL)
527 			(void) printf("\narchive member %s\n",
528 			    dis_tgt_member(current));
529 
530 		/*
531 		 * Instantiate a libdisasm handle based on the file type.
532 		 */
533 		if ((dhp = dis_handle_create(g_flags, current, do_lookup,
534 		    do_read)) == NULL)
535 			die("%s: failed to initialize disassembler: %s",
536 			    filename, dis_strerror(dis_errno()));
537 
538 		if (g_doall) {
539 			/*
540 			 * With no arguments, iterate over all sections and
541 			 * disassemble only those that contain text.
542 			 */
543 			dis_tgt_section_iter(current, dis_text_section, dhp);
544 		} else {
545 			callback_arg_t ca;
546 
547 			ca.ca_tgt = current;
548 			ca.ca_handle = dhp;
549 
550 			/*
551 			 * If sections or functions were explicitly specified,
552 			 * resolve those names against the object, and iterate
553 			 * over just the resulting data.
554 			 */
555 			sections = dis_namelist_resolve_sections(g_seclist,
556 			    current);
557 			functions = dis_namelist_resolve_functions(g_funclist,
558 			    current);
559 
560 			dis_scnlist_iter(sections, dis_named_section, &ca);
561 			dis_funclist_iter(functions, dis_named_function, &ca);
562 
563 			dis_scnlist_destroy(sections);
564 			dis_funclist_destroy(functions);
565 		}
566 
567 		dis_handle_destroy(dhp);
568 	}
569 
570 	dis_tgt_destroy(tgt);
571 }
572 
573 void
574 usage(void)
575 {
576 	(void) fprintf(stderr, "usage: dis [-CVoqn] [-d sec] \n");
577 	(void) fprintf(stderr, "\t[-D sec] [-F function] [-t sec] file ..\n");
578 	exit(2);
579 }
580 
581 typedef struct lib_node {
582 	char *path;
583 	struct lib_node *next;
584 } lib_node_t;
585 
586 int
587 main(int argc, char **argv)
588 {
589 	int optchar;
590 	int i;
591 	lib_node_t *libs = NULL;
592 
593 	g_funclist = dis_namelist_create();
594 	g_seclist = dis_namelist_create();
595 
596 	while ((optchar = getopt(argc, argv, "Cd:D:F:l:Lot:Vqn")) != -1) {
597 		switch (optchar) {
598 		case 'C':
599 			g_demangle = 1;
600 			break;
601 		case 'd':
602 			dis_namelist_add(g_seclist, optarg, DIS_DATA_RELATIVE);
603 			break;
604 		case 'D':
605 			dis_namelist_add(g_seclist, optarg, DIS_DATA_ABSOLUTE);
606 			break;
607 		case 'F':
608 			dis_namelist_add(g_funclist, optarg, 0);
609 			break;
610 		case 'l': {
611 			/*
612 			 * The '-l foo' option historically would attempt to
613 			 * disassemble '$LIBDIR/libfoo.a'.  The $LIBDIR
614 			 * environment variable has never been supported or
615 			 * documented for our linker.  However, until this
616 			 * option is formally EOLed, we have to support it.
617 			 */
618 			char *dir;
619 			lib_node_t *node;
620 			size_t len;
621 
622 			if ((dir = getenv("LIBDIR")) == NULL ||
623 			    dir[0] == '\0')
624 				dir = "/usr/lib";
625 			node = safe_malloc(sizeof (lib_node_t));
626 			len = strlen(optarg) + strlen(dir) + sizeof ("/lib.a");
627 			node->path = safe_malloc(len);
628 
629 			(void) snprintf(node->path, len, "%s/lib%s.a", dir,
630 			    optarg);
631 			node->next = libs;
632 			libs = node;
633 			break;
634 		}
635 		case 'L':
636 			/*
637 			 * The '-L' option historically would attempt to read
638 			 * the .debug section of the target to determine source
639 			 * line information in order to annotate the output.
640 			 * No compiler has emitted these sections in many years,
641 			 * and the option has never done what it purported to
642 			 * do.  We silently consume the option for
643 			 * compatibility.
644 			 */
645 			break;
646 		case 'n':
647 			g_numeric = 1;
648 			break;
649 		case 'o':
650 			g_flags |= DIS_OCTAL;
651 			break;
652 		case 'q':
653 			g_quiet = 1;
654 			break;
655 		case 't':
656 			dis_namelist_add(g_seclist, optarg, DIS_TEXT);
657 			break;
658 		case 'V':
659 			(void) printf("Solaris disassembler version 1.0\n");
660 			return (0);
661 		default:
662 			usage();
663 			break;
664 		}
665 	}
666 
667 	argc -= optind;
668 	argv += optind;
669 
670 	if (argc == 0 && libs == NULL) {
671 		warn("no objects specified");
672 		usage();
673 	}
674 
675 	if (dis_namelist_empty(g_funclist) && dis_namelist_empty(g_seclist))
676 		g_doall = 1;
677 
678 	/*
679 	 * See comment for 'l' option, above.
680 	 */
681 	while (libs != NULL) {
682 		lib_node_t *node = libs->next;
683 
684 		dis_file(libs->path);
685 		free(libs->path);
686 		free(libs);
687 		libs = node;
688 	}
689 
690 	for (i = 0; i < argc; i++)
691 		dis_file(argv[i]);
692 
693 	dis_namelist_destroy(g_funclist);
694 	dis_namelist_destroy(g_seclist);
695 
696 	return (g_error);
697 }
698