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1/*
2 * dwarf-aux.c : libdw auxiliary interfaces
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
17 *
18 */
19
20#include <stdbool.h>
21#include "util.h"
22#include "debug.h"
23#include "dwarf-aux.h"
24
25/**
26 * cu_find_realpath - Find the realpath of the target file
27 * @cu_die: A DIE(dwarf information entry) of CU(compilation Unit)
28 * @fname: The tail filename of the target file
29 *
30 * Find the real(long) path of @fname in @cu_die.
31 */
32const char *cu_find_realpath(Dwarf_Die *cu_die, const char *fname)
33{
34 Dwarf_Files *files;
35 size_t nfiles, i;
36 const char *src = NULL;
37 int ret;
38
39 if (!fname)
40 return NULL;
41
42 ret = dwarf_getsrcfiles(cu_die, &files, &nfiles);
43 if (ret != 0)
44 return NULL;
45
46 for (i = 0; i < nfiles; i++) {
47 src = dwarf_filesrc(files, i, NULL, NULL);
48 if (strtailcmp(src, fname) == 0)
49 break;
50 }
51 if (i == nfiles)
52 return NULL;
53 return src;
54}
55
56/**
57 * cu_get_comp_dir - Get the path of compilation directory
58 * @cu_die: a CU DIE
59 *
60 * Get the path of compilation directory of given @cu_die.
61 * Since this depends on DW_AT_comp_dir, older gcc will not
62 * embedded it. In that case, this returns NULL.
63 */
64const char *cu_get_comp_dir(Dwarf_Die *cu_die)
65{
66 Dwarf_Attribute attr;
67 if (dwarf_attr(cu_die, DW_AT_comp_dir, &attr) == NULL)
68 return NULL;
69 return dwarf_formstring(&attr);
70}
71
72/**
73 * cu_find_lineinfo - Get a line number and file name for given address
74 * @cu_die: a CU DIE
75 * @addr: An address
76 * @fname: a pointer which returns the file name string
77 * @lineno: a pointer which returns the line number
78 *
79 * Find a line number and file name for @addr in @cu_die.
80 */
81int cu_find_lineinfo(Dwarf_Die *cu_die, unsigned long addr,
82 const char **fname, int *lineno)
83{
84 Dwarf_Line *line;
85 Dwarf_Addr laddr;
86
87 line = dwarf_getsrc_die(cu_die, (Dwarf_Addr)addr);
88 if (line && dwarf_lineaddr(line, &laddr) == 0 &&
89 addr == (unsigned long)laddr && dwarf_lineno(line, lineno) == 0) {
90 *fname = dwarf_linesrc(line, NULL, NULL);
91 if (!*fname)
92 /* line number is useless without filename */
93 *lineno = 0;
94 }
95
96 return *lineno ?: -ENOENT;
97}
98
99static int __die_find_inline_cb(Dwarf_Die *die_mem, void *data);
100
101/**
102 * cu_walk_functions_at - Walk on function DIEs at given address
103 * @cu_die: A CU DIE
104 * @addr: An address
105 * @callback: A callback which called with found DIEs
106 * @data: A user data
107 *
108 * Walk on function DIEs at given @addr in @cu_die. Passed DIEs
109 * should be subprogram or inlined-subroutines.
110 */
111int cu_walk_functions_at(Dwarf_Die *cu_die, Dwarf_Addr addr,
112 int (*callback)(Dwarf_Die *, void *), void *data)
113{
114 Dwarf_Die die_mem;
115 Dwarf_Die *sc_die;
116 int ret = -ENOENT;
117
118 /* Inlined function could be recursive. Trace it until fail */
119 for (sc_die = die_find_realfunc(cu_die, addr, &die_mem);
120 sc_die != NULL;
121 sc_die = die_find_child(sc_die, __die_find_inline_cb, &addr,
122 &die_mem)) {
123 ret = callback(sc_die, data);
124 if (ret)
125 break;
126 }
127
128 return ret;
129
130}
131
132/**
133 * die_compare_name - Compare diename and tname
134 * @dw_die: a DIE
135 * @tname: a string of target name
136 *
137 * Compare the name of @dw_die and @tname. Return false if @dw_die has no name.
138 */
139bool die_compare_name(Dwarf_Die *dw_die, const char *tname)
140{
141 const char *name;
142 name = dwarf_diename(dw_die);
143 return name ? (strcmp(tname, name) == 0) : false;
144}
145
146/**
147 * die_get_call_lineno - Get callsite line number of inline-function instance
148 * @in_die: a DIE of an inlined function instance
149 *
150 * Get call-site line number of @in_die. This means from where the inline
151 * function is called.
152 */
153int die_get_call_lineno(Dwarf_Die *in_die)
154{
155 Dwarf_Attribute attr;
156 Dwarf_Word ret;
157
158 if (!dwarf_attr(in_die, DW_AT_call_line, &attr))
159 return -ENOENT;
160
161 dwarf_formudata(&attr, &ret);
162 return (int)ret;
163}
164
165/**
166 * die_get_type - Get type DIE
167 * @vr_die: a DIE of a variable
168 * @die_mem: where to store a type DIE
169 *
170 * Get a DIE of the type of given variable (@vr_die), and store
171 * it to die_mem. Return NULL if fails to get a type DIE.
172 */
173Dwarf_Die *die_get_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem)
174{
175 Dwarf_Attribute attr;
176
177 if (dwarf_attr_integrate(vr_die, DW_AT_type, &attr) &&
178 dwarf_formref_die(&attr, die_mem))
179 return die_mem;
180 else
181 return NULL;
182}
183
184/* Get a type die, but skip qualifiers */
185static Dwarf_Die *__die_get_real_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem)
186{
187 int tag;
188
189 do {
190 vr_die = die_get_type(vr_die, die_mem);
191 if (!vr_die)
192 break;
193 tag = dwarf_tag(vr_die);
194 } while (tag == DW_TAG_const_type ||
195 tag == DW_TAG_restrict_type ||
196 tag == DW_TAG_volatile_type ||
197 tag == DW_TAG_shared_type);
198
199 return vr_die;
200}
201
202/**
203 * die_get_real_type - Get a type die, but skip qualifiers and typedef
204 * @vr_die: a DIE of a variable
205 * @die_mem: where to store a type DIE
206 *
207 * Get a DIE of the type of given variable (@vr_die), and store
208 * it to die_mem. Return NULL if fails to get a type DIE.
209 * If the type is qualifiers (e.g. const) or typedef, this skips it
210 * and tries to find real type (structure or basic types, e.g. int).
211 */
212Dwarf_Die *die_get_real_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem)
213{
214 do {
215 vr_die = __die_get_real_type(vr_die, die_mem);
216 } while (vr_die && dwarf_tag(vr_die) == DW_TAG_typedef);
217
218 return vr_die;
219}
220
221/* Get attribute and translate it as a udata */
222static int die_get_attr_udata(Dwarf_Die *tp_die, unsigned int attr_name,
223 Dwarf_Word *result)
224{
225 Dwarf_Attribute attr;
226
227 if (dwarf_attr(tp_die, attr_name, &attr) == NULL ||
228 dwarf_formudata(&attr, result) != 0)
229 return -ENOENT;
230
231 return 0;
232}
233
234/* Get attribute and translate it as a sdata */
235static int die_get_attr_sdata(Dwarf_Die *tp_die, unsigned int attr_name,
236 Dwarf_Sword *result)
237{
238 Dwarf_Attribute attr;
239
240 if (dwarf_attr(tp_die, attr_name, &attr) == NULL ||
241 dwarf_formsdata(&attr, result) != 0)
242 return -ENOENT;
243
244 return 0;
245}
246
247/**
248 * die_is_signed_type - Check whether a type DIE is signed or not
249 * @tp_die: a DIE of a type
250 *
251 * Get the encoding of @tp_die and return true if the encoding
252 * is signed.
253 */
254bool die_is_signed_type(Dwarf_Die *tp_die)
255{
256 Dwarf_Word ret;
257
258 if (die_get_attr_udata(tp_die, DW_AT_encoding, &ret))
259 return false;
260
261 return (ret == DW_ATE_signed_char || ret == DW_ATE_signed ||
262 ret == DW_ATE_signed_fixed);
263}
264
265/**
266 * die_is_func_def - Ensure that this DIE is a subprogram and definition
267 * @dw_die: a DIE
268 *
269 * Ensure that this DIE is a subprogram and NOT a declaration. This
270 * returns true if @dw_die is a function definition.
271 **/
272bool die_is_func_def(Dwarf_Die *dw_die)
273{
274 Dwarf_Attribute attr;
275
276 return (dwarf_tag(dw_die) == DW_TAG_subprogram &&
277 dwarf_attr(dw_die, DW_AT_declaration, &attr) == NULL);
278}
279
280/**
281 * die_get_data_member_location - Get the data-member offset
282 * @mb_die: a DIE of a member of a data structure
283 * @offs: The offset of the member in the data structure
284 *
285 * Get the offset of @mb_die in the data structure including @mb_die, and
286 * stores result offset to @offs. If any error occurs this returns errno.
287 */
288int die_get_data_member_location(Dwarf_Die *mb_die, Dwarf_Word *offs)
289{
290 Dwarf_Attribute attr;
291 Dwarf_Op *expr;
292 size_t nexpr;
293 int ret;
294
295 if (dwarf_attr(mb_die, DW_AT_data_member_location, &attr) == NULL)
296 return -ENOENT;
297
298 if (dwarf_formudata(&attr, offs) != 0) {
299 /* DW_AT_data_member_location should be DW_OP_plus_uconst */
300 ret = dwarf_getlocation(&attr, &expr, &nexpr);
301 if (ret < 0 || nexpr == 0)
302 return -ENOENT;
303
304 if (expr[0].atom != DW_OP_plus_uconst || nexpr != 1) {
305 pr_debug("Unable to get offset:Unexpected OP %x (%zd)\n",
306 expr[0].atom, nexpr);
307 return -ENOTSUP;
308 }
309 *offs = (Dwarf_Word)expr[0].number;
310 }
311 return 0;
312}
313
314/* Get the call file index number in CU DIE */
315static int die_get_call_fileno(Dwarf_Die *in_die)
316{
317 Dwarf_Sword idx;
318
319 if (die_get_attr_sdata(in_die, DW_AT_call_file, &idx) == 0)
320 return (int)idx;
321 else
322 return -ENOENT;
323}
324
325/* Get the declared file index number in CU DIE */
326static int die_get_decl_fileno(Dwarf_Die *pdie)
327{
328 Dwarf_Sword idx;
329
330 if (die_get_attr_sdata(pdie, DW_AT_decl_file, &idx) == 0)
331 return (int)idx;
332 else
333 return -ENOENT;
334}
335
336/**
337 * die_get_call_file - Get callsite file name of inlined function instance
338 * @in_die: a DIE of an inlined function instance
339 *
340 * Get call-site file name of @in_die. This means from which file the inline
341 * function is called.
342 */
343const char *die_get_call_file(Dwarf_Die *in_die)
344{
345 Dwarf_Die cu_die;
346 Dwarf_Files *files;
347 int idx;
348
349 idx = die_get_call_fileno(in_die);
350 if (idx < 0 || !dwarf_diecu(in_die, &cu_die, NULL, NULL) ||
351 dwarf_getsrcfiles(&cu_die, &files, NULL) != 0)
352 return NULL;
353
354 return dwarf_filesrc(files, idx, NULL, NULL);
355}
356
357
358/**
359 * die_find_child - Generic DIE search function in DIE tree
360 * @rt_die: a root DIE
361 * @callback: a callback function
362 * @data: a user data passed to the callback function
363 * @die_mem: a buffer for result DIE
364 *
365 * Trace DIE tree from @rt_die and call @callback for each child DIE.
366 * If @callback returns DIE_FIND_CB_END, this stores the DIE into
367 * @die_mem and returns it. If @callback returns DIE_FIND_CB_CONTINUE,
368 * this continues to trace the tree. Optionally, @callback can return
369 * DIE_FIND_CB_CHILD and DIE_FIND_CB_SIBLING, those means trace only
370 * the children and trace only the siblings respectively.
371 * Returns NULL if @callback can't find any appropriate DIE.
372 */
373Dwarf_Die *die_find_child(Dwarf_Die *rt_die,
374 int (*callback)(Dwarf_Die *, void *),
375 void *data, Dwarf_Die *die_mem)
376{
377 Dwarf_Die child_die;
378 int ret;
379
380 ret = dwarf_child(rt_die, die_mem);
381 if (ret != 0)
382 return NULL;
383
384 do {
385 ret = callback(die_mem, data);
386 if (ret == DIE_FIND_CB_END)
387 return die_mem;
388
389 if ((ret & DIE_FIND_CB_CHILD) &&
390 die_find_child(die_mem, callback, data, &child_die)) {
391 memcpy(die_mem, &child_die, sizeof(Dwarf_Die));
392 return die_mem;
393 }
394 } while ((ret & DIE_FIND_CB_SIBLING) &&
395 dwarf_siblingof(die_mem, die_mem) == 0);
396
397 return NULL;
398}
399
400struct __addr_die_search_param {
401 Dwarf_Addr addr;
402 Dwarf_Die *die_mem;
403};
404
405/* die_find callback for non-inlined function search */
406static int __die_search_func_cb(Dwarf_Die *fn_die, void *data)
407{
408 struct __addr_die_search_param *ad = data;
409
410 /*
411 * Since a declaration entry doesn't has given pc, this always returns
412 * function definition entry.
413 */
414 if (dwarf_tag(fn_die) == DW_TAG_subprogram &&
415 dwarf_haspc(fn_die, ad->addr)) {
416 memcpy(ad->die_mem, fn_die, sizeof(Dwarf_Die));
417 return DWARF_CB_ABORT;
418 }
419 return DWARF_CB_OK;
420}
421
422/**
423 * die_find_realfunc - Search a non-inlined function at given address
424 * @cu_die: a CU DIE which including @addr
425 * @addr: target address
426 * @die_mem: a buffer for result DIE
427 *
428 * Search a non-inlined function DIE which includes @addr. Stores the
429 * DIE to @die_mem and returns it if found. Returns NULL if failed.
430 */
431Dwarf_Die *die_find_realfunc(Dwarf_Die *cu_die, Dwarf_Addr addr,
432 Dwarf_Die *die_mem)
433{
434 struct __addr_die_search_param ad;
435 ad.addr = addr;
436 ad.die_mem = die_mem;
437 /* dwarf_getscopes can't find subprogram. */
438 if (!dwarf_getfuncs(cu_die, __die_search_func_cb, &ad, 0))
439 return NULL;
440 else
441 return die_mem;
442}
443
444/* die_find callback for inline function search */
445static int __die_find_inline_cb(Dwarf_Die *die_mem, void *data)
446{
447 Dwarf_Addr *addr = data;
448
449 if (dwarf_tag(die_mem) == DW_TAG_inlined_subroutine &&
450 dwarf_haspc(die_mem, *addr))
451 return DIE_FIND_CB_END;
452
453 return DIE_FIND_CB_CONTINUE;
454}
455
456/**
457 * die_find_top_inlinefunc - Search the top inlined function at given address
458 * @sp_die: a subprogram DIE which including @addr
459 * @addr: target address
460 * @die_mem: a buffer for result DIE
461 *
462 * Search an inlined function DIE which includes @addr. Stores the
463 * DIE to @die_mem and returns it if found. Returns NULL if failed.
464 * Even if several inlined functions are expanded recursively, this
465 * doesn't trace it down, and returns the topmost one.
466 */
467Dwarf_Die *die_find_top_inlinefunc(Dwarf_Die *sp_die, Dwarf_Addr addr,
468 Dwarf_Die *die_mem)
469{
470 return die_find_child(sp_die, __die_find_inline_cb, &addr, die_mem);
471}
472
473/**
474 * die_find_inlinefunc - Search an inlined function at given address
475 * @sp_die: a subprogram DIE which including @addr
476 * @addr: target address
477 * @die_mem: a buffer for result DIE
478 *
479 * Search an inlined function DIE which includes @addr. Stores the
480 * DIE to @die_mem and returns it if found. Returns NULL if failed.
481 * If several inlined functions are expanded recursively, this trace
482 * it down and returns deepest one.
483 */
484Dwarf_Die *die_find_inlinefunc(Dwarf_Die *sp_die, Dwarf_Addr addr,
485 Dwarf_Die *die_mem)
486{
487 Dwarf_Die tmp_die;
488
489 sp_die = die_find_child(sp_die, __die_find_inline_cb, &addr, &tmp_die);
490 if (!sp_die)
491 return NULL;
492
493 /* Inlined function could be recursive. Trace it until fail */
494 while (sp_die) {
495 memcpy(die_mem, sp_die, sizeof(Dwarf_Die));
496 sp_die = die_find_child(sp_die, __die_find_inline_cb, &addr,
497 &tmp_die);
498 }
499
500 return die_mem;
501}
502
503struct __instance_walk_param {
504 void *addr;
505 int (*callback)(Dwarf_Die *, void *);
506 void *data;
507 int retval;
508};
509
510static int __die_walk_instances_cb(Dwarf_Die *inst, void *data)
511{
512 struct __instance_walk_param *iwp = data;
513 Dwarf_Attribute attr_mem;
514 Dwarf_Die origin_mem;
515 Dwarf_Attribute *attr;
516 Dwarf_Die *origin;
517 int tmp;
518
519 attr = dwarf_attr(inst, DW_AT_abstract_origin, &attr_mem);
520 if (attr == NULL)
521 return DIE_FIND_CB_CONTINUE;
522
523 origin = dwarf_formref_die(attr, &origin_mem);
524 if (origin == NULL || origin->addr != iwp->addr)
525 return DIE_FIND_CB_CONTINUE;
526
527 /* Ignore redundant instances */
528 if (dwarf_tag(inst) == DW_TAG_inlined_subroutine) {
529 dwarf_decl_line(origin, &tmp);
530 if (die_get_call_lineno(inst) == tmp) {
531 tmp = die_get_decl_fileno(origin);
532 if (die_get_call_fileno(inst) == tmp)
533 return DIE_FIND_CB_CONTINUE;
534 }
535 }
536
537 iwp->retval = iwp->callback(inst, iwp->data);
538
539 return (iwp->retval) ? DIE_FIND_CB_END : DIE_FIND_CB_CONTINUE;
540}
541
542/**
543 * die_walk_instances - Walk on instances of given DIE
544 * @or_die: an abstract original DIE
545 * @callback: a callback function which is called with instance DIE
546 * @data: user data
547 *
548 * Walk on the instances of give @in_die. @in_die must be an inlined function
549 * declartion. This returns the return value of @callback if it returns
550 * non-zero value, or -ENOENT if there is no instance.
551 */
552int die_walk_instances(Dwarf_Die *or_die, int (*callback)(Dwarf_Die *, void *),
553 void *data)
554{
555 Dwarf_Die cu_die;
556 Dwarf_Die die_mem;
557 struct __instance_walk_param iwp = {
558 .addr = or_die->addr,
559 .callback = callback,
560 .data = data,
561 .retval = -ENOENT,
562 };
563
564 if (dwarf_diecu(or_die, &cu_die, NULL, NULL) == NULL)
565 return -ENOENT;
566
567 die_find_child(&cu_die, __die_walk_instances_cb, &iwp, &die_mem);
568
569 return iwp.retval;
570}
571
572/* Line walker internal parameters */
573struct __line_walk_param {
574 bool recursive;
575 line_walk_callback_t callback;
576 void *data;
577 int retval;
578};
579
580static int __die_walk_funclines_cb(Dwarf_Die *in_die, void *data)
581{
582 struct __line_walk_param *lw = data;
583 Dwarf_Addr addr = 0;
584 const char *fname;
585 int lineno;
586
587 if (dwarf_tag(in_die) == DW_TAG_inlined_subroutine) {
588 fname = die_get_call_file(in_die);
589 lineno = die_get_call_lineno(in_die);
590 if (fname && lineno > 0 && dwarf_entrypc(in_die, &addr) == 0) {
591 lw->retval = lw->callback(fname, lineno, addr, lw->data);
592 if (lw->retval != 0)
593 return DIE_FIND_CB_END;
594 }
595 }
596 if (!lw->recursive)
597 /* Don't need to search recursively */
598 return DIE_FIND_CB_SIBLING;
599
600 if (addr) {
601 fname = dwarf_decl_file(in_die);
602 if (fname && dwarf_decl_line(in_die, &lineno) == 0) {
603 lw->retval = lw->callback(fname, lineno, addr, lw->data);
604 if (lw->retval != 0)
605 return DIE_FIND_CB_END;
606 }
607 }
608
609 /* Continue to search nested inlined function call-sites */
610 return DIE_FIND_CB_CONTINUE;
611}
612
613/* Walk on lines of blocks included in given DIE */
614static int __die_walk_funclines(Dwarf_Die *sp_die, bool recursive,
615 line_walk_callback_t callback, void *data)
616{
617 struct __line_walk_param lw = {
618 .recursive = recursive,
619 .callback = callback,
620 .data = data,
621 .retval = 0,
622 };
623 Dwarf_Die die_mem;
624 Dwarf_Addr addr;
625 const char *fname;
626 int lineno;
627
628 /* Handle function declaration line */
629 fname = dwarf_decl_file(sp_die);
630 if (fname && dwarf_decl_line(sp_die, &lineno) == 0 &&
631 dwarf_entrypc(sp_die, &addr) == 0) {
632 lw.retval = callback(fname, lineno, addr, data);
633 if (lw.retval != 0)
634 goto done;
635 }
636 die_find_child(sp_die, __die_walk_funclines_cb, &lw, &die_mem);
637done:
638 return lw.retval;
639}
640
641static int __die_walk_culines_cb(Dwarf_Die *sp_die, void *data)
642{
643 struct __line_walk_param *lw = data;
644
645 lw->retval = __die_walk_funclines(sp_die, true, lw->callback, lw->data);
646 if (lw->retval != 0)
647 return DWARF_CB_ABORT;
648
649 return DWARF_CB_OK;
650}
651
652/**
653 * die_walk_lines - Walk on lines inside given DIE
654 * @rt_die: a root DIE (CU, subprogram or inlined_subroutine)
655 * @callback: callback routine
656 * @data: user data
657 *
658 * Walk on all lines inside given @rt_die and call @callback on each line.
659 * If the @rt_die is a function, walk only on the lines inside the function,
660 * otherwise @rt_die must be a CU DIE.
661 * Note that this walks not only dwarf line list, but also function entries
662 * and inline call-site.
663 */
664int die_walk_lines(Dwarf_Die *rt_die, line_walk_callback_t callback, void *data)
665{
666 Dwarf_Lines *lines;
667 Dwarf_Line *line;
668 Dwarf_Addr addr;
669 const char *fname;
670 int lineno, ret = 0;
671 Dwarf_Die die_mem, *cu_die;
672 size_t nlines, i;
673
674 /* Get the CU die */
675 if (dwarf_tag(rt_die) != DW_TAG_compile_unit)
676 cu_die = dwarf_diecu(rt_die, &die_mem, NULL, NULL);
677 else
678 cu_die = rt_die;
679 if (!cu_die) {
680 pr_debug2("Failed to get CU from given DIE.\n");
681 return -EINVAL;
682 }
683
684 /* Get lines list in the CU */
685 if (dwarf_getsrclines(cu_die, &lines, &nlines) != 0) {
686 pr_debug2("Failed to get source lines on this CU.\n");
687 return -ENOENT;
688 }
689 pr_debug2("Get %zd lines from this CU\n", nlines);
690
691 /* Walk on the lines on lines list */
692 for (i = 0; i < nlines; i++) {
693 line = dwarf_onesrcline(lines, i);
694 if (line == NULL ||
695 dwarf_lineno(line, &lineno) != 0 ||
696 dwarf_lineaddr(line, &addr) != 0) {
697 pr_debug2("Failed to get line info. "
698 "Possible error in debuginfo.\n");
699 continue;
700 }
701 /* Filter lines based on address */
702 if (rt_die != cu_die)
703 /*
704 * Address filtering
705 * The line is included in given function, and
706 * no inline block includes it.
707 */
708 if (!dwarf_haspc(rt_die, addr) ||
709 die_find_inlinefunc(rt_die, addr, &die_mem))
710 continue;
711 /* Get source line */
712 fname = dwarf_linesrc(line, NULL, NULL);
713
714 ret = callback(fname, lineno, addr, data);
715 if (ret != 0)
716 return ret;
717 }
718
719 /*
720 * Dwarf lines doesn't include function declarations and inlined
721 * subroutines. We have to check functions list or given function.
722 */
723 if (rt_die != cu_die)
724 /*
725 * Don't need walk functions recursively, because nested
726 * inlined functions don't have lines of the specified DIE.
727 */
728 ret = __die_walk_funclines(rt_die, false, callback, data);
729 else {
730 struct __line_walk_param param = {
731 .callback = callback,
732 .data = data,
733 .retval = 0,
734 };
735 dwarf_getfuncs(cu_die, __die_walk_culines_cb, ¶m, 0);
736 ret = param.retval;
737 }
738
739 return ret;
740}
741
742struct __find_variable_param {
743 const char *name;
744 Dwarf_Addr addr;
745};
746
747static int __die_find_variable_cb(Dwarf_Die *die_mem, void *data)
748{
749 struct __find_variable_param *fvp = data;
750 Dwarf_Attribute attr;
751 int tag;
752
753 tag = dwarf_tag(die_mem);
754 if ((tag == DW_TAG_formal_parameter ||
755 tag == DW_TAG_variable) &&
756 die_compare_name(die_mem, fvp->name) &&
757 /* Does the DIE have location information or external instance? */
758 (dwarf_attr(die_mem, DW_AT_external, &attr) ||
759 dwarf_attr(die_mem, DW_AT_location, &attr)))
760 return DIE_FIND_CB_END;
761 if (dwarf_haspc(die_mem, fvp->addr))
762 return DIE_FIND_CB_CONTINUE;
763 else
764 return DIE_FIND_CB_SIBLING;
765}
766
767/**
768 * die_find_variable_at - Find a given name variable at given address
769 * @sp_die: a function DIE
770 * @name: variable name
771 * @addr: address
772 * @die_mem: a buffer for result DIE
773 *
774 * Find a variable DIE called @name at @addr in @sp_die.
775 */
776Dwarf_Die *die_find_variable_at(Dwarf_Die *sp_die, const char *name,
777 Dwarf_Addr addr, Dwarf_Die *die_mem)
778{
779 struct __find_variable_param fvp = { .name = name, .addr = addr};
780
781 return die_find_child(sp_die, __die_find_variable_cb, (void *)&fvp,
782 die_mem);
783}
784
785static int __die_find_member_cb(Dwarf_Die *die_mem, void *data)
786{
787 const char *name = data;
788
789 if ((dwarf_tag(die_mem) == DW_TAG_member) &&
790 die_compare_name(die_mem, name))
791 return DIE_FIND_CB_END;
792
793 return DIE_FIND_CB_SIBLING;
794}
795
796/**
797 * die_find_member - Find a given name member in a data structure
798 * @st_die: a data structure type DIE
799 * @name: member name
800 * @die_mem: a buffer for result DIE
801 *
802 * Find a member DIE called @name in @st_die.
803 */
804Dwarf_Die *die_find_member(Dwarf_Die *st_die, const char *name,
805 Dwarf_Die *die_mem)
806{
807 return die_find_child(st_die, __die_find_member_cb, (void *)name,
808 die_mem);
809}
810
811/**
812 * die_get_typename - Get the name of given variable DIE
813 * @vr_die: a variable DIE
814 * @buf: a buffer for result type name
815 * @len: a max-length of @buf
816 *
817 * Get the name of @vr_die and stores it to @buf. Return the actual length
818 * of type name if succeeded. Return -E2BIG if @len is not enough long, and
819 * Return -ENOENT if failed to find type name.
820 * Note that the result will stores typedef name if possible, and stores
821 * "*(function_type)" if the type is a function pointer.
822 */
823int die_get_typename(Dwarf_Die *vr_die, char *buf, int len)
824{
825 Dwarf_Die type;
826 int tag, ret, ret2;
827 const char *tmp = "";
828
829 if (__die_get_real_type(vr_die, &type) == NULL)
830 return -ENOENT;
831
832 tag = dwarf_tag(&type);
833 if (tag == DW_TAG_array_type || tag == DW_TAG_pointer_type)
834 tmp = "*";
835 else if (tag == DW_TAG_subroutine_type) {
836 /* Function pointer */
837 ret = snprintf(buf, len, "(function_type)");
838 return (ret >= len) ? -E2BIG : ret;
839 } else {
840 if (!dwarf_diename(&type))
841 return -ENOENT;
842 if (tag == DW_TAG_union_type)
843 tmp = "union ";
844 else if (tag == DW_TAG_structure_type)
845 tmp = "struct ";
846 else if (tag == DW_TAG_enumeration_type)
847 tmp = "enum ";
848 /* Write a base name */
849 ret = snprintf(buf, len, "%s%s", tmp, dwarf_diename(&type));
850 return (ret >= len) ? -E2BIG : ret;
851 }
852 ret = die_get_typename(&type, buf, len);
853 if (ret > 0) {
854 ret2 = snprintf(buf + ret, len - ret, "%s", tmp);
855 ret = (ret2 >= len - ret) ? -E2BIG : ret2 + ret;
856 }
857 return ret;
858}
859
860/**
861 * die_get_varname - Get the name and type of given variable DIE
862 * @vr_die: a variable DIE
863 * @buf: a buffer for type and variable name
864 * @len: the max-length of @buf
865 *
866 * Get the name and type of @vr_die and stores it in @buf as "type\tname".
867 */
868int die_get_varname(Dwarf_Die *vr_die, char *buf, int len)
869{
870 int ret, ret2;
871
872 ret = die_get_typename(vr_die, buf, len);
873 if (ret < 0) {
874 pr_debug("Failed to get type, make it unknown.\n");
875 ret = snprintf(buf, len, "(unknown_type)");
876 }
877 if (ret > 0) {
878 ret2 = snprintf(buf + ret, len - ret, "\t%s",
879 dwarf_diename(vr_die));
880 ret = (ret2 >= len - ret) ? -E2BIG : ret2 + ret;
881 }
882 return ret;
883}
884
1/*
2 * dwarf-aux.c : libdw auxiliary interfaces
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
17 *
18 */
19
20#include <stdbool.h>
21#include "util.h"
22#include "debug.h"
23#include "dwarf-aux.h"
24
25/**
26 * cu_find_realpath - Find the realpath of the target file
27 * @cu_die: A DIE(dwarf information entry) of CU(compilation Unit)
28 * @fname: The tail filename of the target file
29 *
30 * Find the real(long) path of @fname in @cu_die.
31 */
32const char *cu_find_realpath(Dwarf_Die *cu_die, const char *fname)
33{
34 Dwarf_Files *files;
35 size_t nfiles, i;
36 const char *src = NULL;
37 int ret;
38
39 if (!fname)
40 return NULL;
41
42 ret = dwarf_getsrcfiles(cu_die, &files, &nfiles);
43 if (ret != 0)
44 return NULL;
45
46 for (i = 0; i < nfiles; i++) {
47 src = dwarf_filesrc(files, i, NULL, NULL);
48 if (strtailcmp(src, fname) == 0)
49 break;
50 }
51 if (i == nfiles)
52 return NULL;
53 return src;
54}
55
56/**
57 * cu_get_comp_dir - Get the path of compilation directory
58 * @cu_die: a CU DIE
59 *
60 * Get the path of compilation directory of given @cu_die.
61 * Since this depends on DW_AT_comp_dir, older gcc will not
62 * embedded it. In that case, this returns NULL.
63 */
64const char *cu_get_comp_dir(Dwarf_Die *cu_die)
65{
66 Dwarf_Attribute attr;
67 if (dwarf_attr(cu_die, DW_AT_comp_dir, &attr) == NULL)
68 return NULL;
69 return dwarf_formstring(&attr);
70}
71
72/**
73 * cu_find_lineinfo - Get a line number and file name for given address
74 * @cu_die: a CU DIE
75 * @addr: An address
76 * @fname: a pointer which returns the file name string
77 * @lineno: a pointer which returns the line number
78 *
79 * Find a line number and file name for @addr in @cu_die.
80 */
81int cu_find_lineinfo(Dwarf_Die *cu_die, unsigned long addr,
82 const char **fname, int *lineno)
83{
84 Dwarf_Line *line;
85 Dwarf_Addr laddr;
86
87 line = dwarf_getsrc_die(cu_die, (Dwarf_Addr)addr);
88 if (line && dwarf_lineaddr(line, &laddr) == 0 &&
89 addr == (unsigned long)laddr && dwarf_lineno(line, lineno) == 0) {
90 *fname = dwarf_linesrc(line, NULL, NULL);
91 if (!*fname)
92 /* line number is useless without filename */
93 *lineno = 0;
94 }
95
96 return *lineno ?: -ENOENT;
97}
98
99static int __die_find_inline_cb(Dwarf_Die *die_mem, void *data);
100
101/**
102 * cu_walk_functions_at - Walk on function DIEs at given address
103 * @cu_die: A CU DIE
104 * @addr: An address
105 * @callback: A callback which called with found DIEs
106 * @data: A user data
107 *
108 * Walk on function DIEs at given @addr in @cu_die. Passed DIEs
109 * should be subprogram or inlined-subroutines.
110 */
111int cu_walk_functions_at(Dwarf_Die *cu_die, Dwarf_Addr addr,
112 int (*callback)(Dwarf_Die *, void *), void *data)
113{
114 Dwarf_Die die_mem;
115 Dwarf_Die *sc_die;
116 int ret = -ENOENT;
117
118 /* Inlined function could be recursive. Trace it until fail */
119 for (sc_die = die_find_realfunc(cu_die, addr, &die_mem);
120 sc_die != NULL;
121 sc_die = die_find_child(sc_die, __die_find_inline_cb, &addr,
122 &die_mem)) {
123 ret = callback(sc_die, data);
124 if (ret)
125 break;
126 }
127
128 return ret;
129
130}
131
132/**
133 * die_compare_name - Compare diename and tname
134 * @dw_die: a DIE
135 * @tname: a string of target name
136 *
137 * Compare the name of @dw_die and @tname. Return false if @dw_die has no name.
138 */
139bool die_compare_name(Dwarf_Die *dw_die, const char *tname)
140{
141 const char *name;
142 name = dwarf_diename(dw_die);
143 return name ? (strcmp(tname, name) == 0) : false;
144}
145
146/**
147 * die_get_call_lineno - Get callsite line number of inline-function instance
148 * @in_die: a DIE of an inlined function instance
149 *
150 * Get call-site line number of @in_die. This means from where the inline
151 * function is called.
152 */
153int die_get_call_lineno(Dwarf_Die *in_die)
154{
155 Dwarf_Attribute attr;
156 Dwarf_Word ret;
157
158 if (!dwarf_attr(in_die, DW_AT_call_line, &attr))
159 return -ENOENT;
160
161 dwarf_formudata(&attr, &ret);
162 return (int)ret;
163}
164
165/**
166 * die_get_type - Get type DIE
167 * @vr_die: a DIE of a variable
168 * @die_mem: where to store a type DIE
169 *
170 * Get a DIE of the type of given variable (@vr_die), and store
171 * it to die_mem. Return NULL if fails to get a type DIE.
172 */
173Dwarf_Die *die_get_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem)
174{
175 Dwarf_Attribute attr;
176
177 if (dwarf_attr_integrate(vr_die, DW_AT_type, &attr) &&
178 dwarf_formref_die(&attr, die_mem))
179 return die_mem;
180 else
181 return NULL;
182}
183
184/* Get a type die, but skip qualifiers */
185static Dwarf_Die *__die_get_real_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem)
186{
187 int tag;
188
189 do {
190 vr_die = die_get_type(vr_die, die_mem);
191 if (!vr_die)
192 break;
193 tag = dwarf_tag(vr_die);
194 } while (tag == DW_TAG_const_type ||
195 tag == DW_TAG_restrict_type ||
196 tag == DW_TAG_volatile_type ||
197 tag == DW_TAG_shared_type);
198
199 return vr_die;
200}
201
202/**
203 * die_get_real_type - Get a type die, but skip qualifiers and typedef
204 * @vr_die: a DIE of a variable
205 * @die_mem: where to store a type DIE
206 *
207 * Get a DIE of the type of given variable (@vr_die), and store
208 * it to die_mem. Return NULL if fails to get a type DIE.
209 * If the type is qualifiers (e.g. const) or typedef, this skips it
210 * and tries to find real type (structure or basic types, e.g. int).
211 */
212Dwarf_Die *die_get_real_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem)
213{
214 do {
215 vr_die = __die_get_real_type(vr_die, die_mem);
216 } while (vr_die && dwarf_tag(vr_die) == DW_TAG_typedef);
217
218 return vr_die;
219}
220
221/* Get attribute and translate it as a udata */
222static int die_get_attr_udata(Dwarf_Die *tp_die, unsigned int attr_name,
223 Dwarf_Word *result)
224{
225 Dwarf_Attribute attr;
226
227 if (dwarf_attr(tp_die, attr_name, &attr) == NULL ||
228 dwarf_formudata(&attr, result) != 0)
229 return -ENOENT;
230
231 return 0;
232}
233
234/* Get attribute and translate it as a sdata */
235static int die_get_attr_sdata(Dwarf_Die *tp_die, unsigned int attr_name,
236 Dwarf_Sword *result)
237{
238 Dwarf_Attribute attr;
239
240 if (dwarf_attr(tp_die, attr_name, &attr) == NULL ||
241 dwarf_formsdata(&attr, result) != 0)
242 return -ENOENT;
243
244 return 0;
245}
246
247/**
248 * die_is_signed_type - Check whether a type DIE is signed or not
249 * @tp_die: a DIE of a type
250 *
251 * Get the encoding of @tp_die and return true if the encoding
252 * is signed.
253 */
254bool die_is_signed_type(Dwarf_Die *tp_die)
255{
256 Dwarf_Word ret;
257
258 if (die_get_attr_udata(tp_die, DW_AT_encoding, &ret))
259 return false;
260
261 return (ret == DW_ATE_signed_char || ret == DW_ATE_signed ||
262 ret == DW_ATE_signed_fixed);
263}
264
265/**
266 * die_get_data_member_location - Get the data-member offset
267 * @mb_die: a DIE of a member of a data structure
268 * @offs: The offset of the member in the data structure
269 *
270 * Get the offset of @mb_die in the data structure including @mb_die, and
271 * stores result offset to @offs. If any error occurs this returns errno.
272 */
273int die_get_data_member_location(Dwarf_Die *mb_die, Dwarf_Word *offs)
274{
275 Dwarf_Attribute attr;
276 Dwarf_Op *expr;
277 size_t nexpr;
278 int ret;
279
280 if (dwarf_attr(mb_die, DW_AT_data_member_location, &attr) == NULL)
281 return -ENOENT;
282
283 if (dwarf_formudata(&attr, offs) != 0) {
284 /* DW_AT_data_member_location should be DW_OP_plus_uconst */
285 ret = dwarf_getlocation(&attr, &expr, &nexpr);
286 if (ret < 0 || nexpr == 0)
287 return -ENOENT;
288
289 if (expr[0].atom != DW_OP_plus_uconst || nexpr != 1) {
290 pr_debug("Unable to get offset:Unexpected OP %x (%zd)\n",
291 expr[0].atom, nexpr);
292 return -ENOTSUP;
293 }
294 *offs = (Dwarf_Word)expr[0].number;
295 }
296 return 0;
297}
298
299/* Get the call file index number in CU DIE */
300static int die_get_call_fileno(Dwarf_Die *in_die)
301{
302 Dwarf_Sword idx;
303
304 if (die_get_attr_sdata(in_die, DW_AT_call_file, &idx) == 0)
305 return (int)idx;
306 else
307 return -ENOENT;
308}
309
310/* Get the declared file index number in CU DIE */
311static int die_get_decl_fileno(Dwarf_Die *pdie)
312{
313 Dwarf_Sword idx;
314
315 if (die_get_attr_sdata(pdie, DW_AT_decl_file, &idx) == 0)
316 return (int)idx;
317 else
318 return -ENOENT;
319}
320
321/**
322 * die_get_call_file - Get callsite file name of inlined function instance
323 * @in_die: a DIE of an inlined function instance
324 *
325 * Get call-site file name of @in_die. This means from which file the inline
326 * function is called.
327 */
328const char *die_get_call_file(Dwarf_Die *in_die)
329{
330 Dwarf_Die cu_die;
331 Dwarf_Files *files;
332 int idx;
333
334 idx = die_get_call_fileno(in_die);
335 if (idx < 0 || !dwarf_diecu(in_die, &cu_die, NULL, NULL) ||
336 dwarf_getsrcfiles(&cu_die, &files, NULL) != 0)
337 return NULL;
338
339 return dwarf_filesrc(files, idx, NULL, NULL);
340}
341
342
343/**
344 * die_find_child - Generic DIE search function in DIE tree
345 * @rt_die: a root DIE
346 * @callback: a callback function
347 * @data: a user data passed to the callback function
348 * @die_mem: a buffer for result DIE
349 *
350 * Trace DIE tree from @rt_die and call @callback for each child DIE.
351 * If @callback returns DIE_FIND_CB_END, this stores the DIE into
352 * @die_mem and returns it. If @callback returns DIE_FIND_CB_CONTINUE,
353 * this continues to trace the tree. Optionally, @callback can return
354 * DIE_FIND_CB_CHILD and DIE_FIND_CB_SIBLING, those means trace only
355 * the children and trace only the siblings respectively.
356 * Returns NULL if @callback can't find any appropriate DIE.
357 */
358Dwarf_Die *die_find_child(Dwarf_Die *rt_die,
359 int (*callback)(Dwarf_Die *, void *),
360 void *data, Dwarf_Die *die_mem)
361{
362 Dwarf_Die child_die;
363 int ret;
364
365 ret = dwarf_child(rt_die, die_mem);
366 if (ret != 0)
367 return NULL;
368
369 do {
370 ret = callback(die_mem, data);
371 if (ret == DIE_FIND_CB_END)
372 return die_mem;
373
374 if ((ret & DIE_FIND_CB_CHILD) &&
375 die_find_child(die_mem, callback, data, &child_die)) {
376 memcpy(die_mem, &child_die, sizeof(Dwarf_Die));
377 return die_mem;
378 }
379 } while ((ret & DIE_FIND_CB_SIBLING) &&
380 dwarf_siblingof(die_mem, die_mem) == 0);
381
382 return NULL;
383}
384
385struct __addr_die_search_param {
386 Dwarf_Addr addr;
387 Dwarf_Die *die_mem;
388};
389
390/* die_find callback for non-inlined function search */
391static int __die_search_func_cb(Dwarf_Die *fn_die, void *data)
392{
393 struct __addr_die_search_param *ad = data;
394
395 if (dwarf_tag(fn_die) == DW_TAG_subprogram &&
396 dwarf_haspc(fn_die, ad->addr)) {
397 memcpy(ad->die_mem, fn_die, sizeof(Dwarf_Die));
398 return DWARF_CB_ABORT;
399 }
400 return DWARF_CB_OK;
401}
402
403/**
404 * die_find_realfunc - Search a non-inlined function at given address
405 * @cu_die: a CU DIE which including @addr
406 * @addr: target address
407 * @die_mem: a buffer for result DIE
408 *
409 * Search a non-inlined function DIE which includes @addr. Stores the
410 * DIE to @die_mem and returns it if found. Returns NULl if failed.
411 */
412Dwarf_Die *die_find_realfunc(Dwarf_Die *cu_die, Dwarf_Addr addr,
413 Dwarf_Die *die_mem)
414{
415 struct __addr_die_search_param ad;
416 ad.addr = addr;
417 ad.die_mem = die_mem;
418 /* dwarf_getscopes can't find subprogram. */
419 if (!dwarf_getfuncs(cu_die, __die_search_func_cb, &ad, 0))
420 return NULL;
421 else
422 return die_mem;
423}
424
425/* die_find callback for inline function search */
426static int __die_find_inline_cb(Dwarf_Die *die_mem, void *data)
427{
428 Dwarf_Addr *addr = data;
429
430 if (dwarf_tag(die_mem) == DW_TAG_inlined_subroutine &&
431 dwarf_haspc(die_mem, *addr))
432 return DIE_FIND_CB_END;
433
434 return DIE_FIND_CB_CONTINUE;
435}
436
437/**
438 * die_find_inlinefunc - Search an inlined function at given address
439 * @cu_die: a CU DIE which including @addr
440 * @addr: target address
441 * @die_mem: a buffer for result DIE
442 *
443 * Search an inlined function DIE which includes @addr. Stores the
444 * DIE to @die_mem and returns it if found. Returns NULl if failed.
445 * If several inlined functions are expanded recursively, this trace
446 * it and returns deepest one.
447 */
448Dwarf_Die *die_find_inlinefunc(Dwarf_Die *sp_die, Dwarf_Addr addr,
449 Dwarf_Die *die_mem)
450{
451 Dwarf_Die tmp_die;
452
453 sp_die = die_find_child(sp_die, __die_find_inline_cb, &addr, &tmp_die);
454 if (!sp_die)
455 return NULL;
456
457 /* Inlined function could be recursive. Trace it until fail */
458 while (sp_die) {
459 memcpy(die_mem, sp_die, sizeof(Dwarf_Die));
460 sp_die = die_find_child(sp_die, __die_find_inline_cb, &addr,
461 &tmp_die);
462 }
463
464 return die_mem;
465}
466
467struct __instance_walk_param {
468 void *addr;
469 int (*callback)(Dwarf_Die *, void *);
470 void *data;
471 int retval;
472};
473
474static int __die_walk_instances_cb(Dwarf_Die *inst, void *data)
475{
476 struct __instance_walk_param *iwp = data;
477 Dwarf_Attribute attr_mem;
478 Dwarf_Die origin_mem;
479 Dwarf_Attribute *attr;
480 Dwarf_Die *origin;
481 int tmp;
482
483 attr = dwarf_attr(inst, DW_AT_abstract_origin, &attr_mem);
484 if (attr == NULL)
485 return DIE_FIND_CB_CONTINUE;
486
487 origin = dwarf_formref_die(attr, &origin_mem);
488 if (origin == NULL || origin->addr != iwp->addr)
489 return DIE_FIND_CB_CONTINUE;
490
491 /* Ignore redundant instances */
492 if (dwarf_tag(inst) == DW_TAG_inlined_subroutine) {
493 dwarf_decl_line(origin, &tmp);
494 if (die_get_call_lineno(inst) == tmp) {
495 tmp = die_get_decl_fileno(origin);
496 if (die_get_call_fileno(inst) == tmp)
497 return DIE_FIND_CB_CONTINUE;
498 }
499 }
500
501 iwp->retval = iwp->callback(inst, iwp->data);
502
503 return (iwp->retval) ? DIE_FIND_CB_END : DIE_FIND_CB_CONTINUE;
504}
505
506/**
507 * die_walk_instances - Walk on instances of given DIE
508 * @or_die: an abstract original DIE
509 * @callback: a callback function which is called with instance DIE
510 * @data: user data
511 *
512 * Walk on the instances of give @in_die. @in_die must be an inlined function
513 * declartion. This returns the return value of @callback if it returns
514 * non-zero value, or -ENOENT if there is no instance.
515 */
516int die_walk_instances(Dwarf_Die *or_die, int (*callback)(Dwarf_Die *, void *),
517 void *data)
518{
519 Dwarf_Die cu_die;
520 Dwarf_Die die_mem;
521 struct __instance_walk_param iwp = {
522 .addr = or_die->addr,
523 .callback = callback,
524 .data = data,
525 .retval = -ENOENT,
526 };
527
528 if (dwarf_diecu(or_die, &cu_die, NULL, NULL) == NULL)
529 return -ENOENT;
530
531 die_find_child(&cu_die, __die_walk_instances_cb, &iwp, &die_mem);
532
533 return iwp.retval;
534}
535
536/* Line walker internal parameters */
537struct __line_walk_param {
538 bool recursive;
539 line_walk_callback_t callback;
540 void *data;
541 int retval;
542};
543
544static int __die_walk_funclines_cb(Dwarf_Die *in_die, void *data)
545{
546 struct __line_walk_param *lw = data;
547 Dwarf_Addr addr = 0;
548 const char *fname;
549 int lineno;
550
551 if (dwarf_tag(in_die) == DW_TAG_inlined_subroutine) {
552 fname = die_get_call_file(in_die);
553 lineno = die_get_call_lineno(in_die);
554 if (fname && lineno > 0 && dwarf_entrypc(in_die, &addr) == 0) {
555 lw->retval = lw->callback(fname, lineno, addr, lw->data);
556 if (lw->retval != 0)
557 return DIE_FIND_CB_END;
558 }
559 }
560 if (!lw->recursive)
561 /* Don't need to search recursively */
562 return DIE_FIND_CB_SIBLING;
563
564 if (addr) {
565 fname = dwarf_decl_file(in_die);
566 if (fname && dwarf_decl_line(in_die, &lineno) == 0) {
567 lw->retval = lw->callback(fname, lineno, addr, lw->data);
568 if (lw->retval != 0)
569 return DIE_FIND_CB_END;
570 }
571 }
572
573 /* Continue to search nested inlined function call-sites */
574 return DIE_FIND_CB_CONTINUE;
575}
576
577/* Walk on lines of blocks included in given DIE */
578static int __die_walk_funclines(Dwarf_Die *sp_die, bool recursive,
579 line_walk_callback_t callback, void *data)
580{
581 struct __line_walk_param lw = {
582 .recursive = recursive,
583 .callback = callback,
584 .data = data,
585 .retval = 0,
586 };
587 Dwarf_Die die_mem;
588 Dwarf_Addr addr;
589 const char *fname;
590 int lineno;
591
592 /* Handle function declaration line */
593 fname = dwarf_decl_file(sp_die);
594 if (fname && dwarf_decl_line(sp_die, &lineno) == 0 &&
595 dwarf_entrypc(sp_die, &addr) == 0) {
596 lw.retval = callback(fname, lineno, addr, data);
597 if (lw.retval != 0)
598 goto done;
599 }
600 die_find_child(sp_die, __die_walk_funclines_cb, &lw, &die_mem);
601done:
602 return lw.retval;
603}
604
605static int __die_walk_culines_cb(Dwarf_Die *sp_die, void *data)
606{
607 struct __line_walk_param *lw = data;
608
609 lw->retval = __die_walk_funclines(sp_die, true, lw->callback, lw->data);
610 if (lw->retval != 0)
611 return DWARF_CB_ABORT;
612
613 return DWARF_CB_OK;
614}
615
616/**
617 * die_walk_lines - Walk on lines inside given DIE
618 * @rt_die: a root DIE (CU, subprogram or inlined_subroutine)
619 * @callback: callback routine
620 * @data: user data
621 *
622 * Walk on all lines inside given @rt_die and call @callback on each line.
623 * If the @rt_die is a function, walk only on the lines inside the function,
624 * otherwise @rt_die must be a CU DIE.
625 * Note that this walks not only dwarf line list, but also function entries
626 * and inline call-site.
627 */
628int die_walk_lines(Dwarf_Die *rt_die, line_walk_callback_t callback, void *data)
629{
630 Dwarf_Lines *lines;
631 Dwarf_Line *line;
632 Dwarf_Addr addr;
633 const char *fname;
634 int lineno, ret = 0;
635 Dwarf_Die die_mem, *cu_die;
636 size_t nlines, i;
637
638 /* Get the CU die */
639 if (dwarf_tag(rt_die) != DW_TAG_compile_unit)
640 cu_die = dwarf_diecu(rt_die, &die_mem, NULL, NULL);
641 else
642 cu_die = rt_die;
643 if (!cu_die) {
644 pr_debug2("Failed to get CU from given DIE.\n");
645 return -EINVAL;
646 }
647
648 /* Get lines list in the CU */
649 if (dwarf_getsrclines(cu_die, &lines, &nlines) != 0) {
650 pr_debug2("Failed to get source lines on this CU.\n");
651 return -ENOENT;
652 }
653 pr_debug2("Get %zd lines from this CU\n", nlines);
654
655 /* Walk on the lines on lines list */
656 for (i = 0; i < nlines; i++) {
657 line = dwarf_onesrcline(lines, i);
658 if (line == NULL ||
659 dwarf_lineno(line, &lineno) != 0 ||
660 dwarf_lineaddr(line, &addr) != 0) {
661 pr_debug2("Failed to get line info. "
662 "Possible error in debuginfo.\n");
663 continue;
664 }
665 /* Filter lines based on address */
666 if (rt_die != cu_die)
667 /*
668 * Address filtering
669 * The line is included in given function, and
670 * no inline block includes it.
671 */
672 if (!dwarf_haspc(rt_die, addr) ||
673 die_find_inlinefunc(rt_die, addr, &die_mem))
674 continue;
675 /* Get source line */
676 fname = dwarf_linesrc(line, NULL, NULL);
677
678 ret = callback(fname, lineno, addr, data);
679 if (ret != 0)
680 return ret;
681 }
682
683 /*
684 * Dwarf lines doesn't include function declarations and inlined
685 * subroutines. We have to check functions list or given function.
686 */
687 if (rt_die != cu_die)
688 /*
689 * Don't need walk functions recursively, because nested
690 * inlined functions don't have lines of the specified DIE.
691 */
692 ret = __die_walk_funclines(rt_die, false, callback, data);
693 else {
694 struct __line_walk_param param = {
695 .callback = callback,
696 .data = data,
697 .retval = 0,
698 };
699 dwarf_getfuncs(cu_die, __die_walk_culines_cb, ¶m, 0);
700 ret = param.retval;
701 }
702
703 return ret;
704}
705
706struct __find_variable_param {
707 const char *name;
708 Dwarf_Addr addr;
709};
710
711static int __die_find_variable_cb(Dwarf_Die *die_mem, void *data)
712{
713 struct __find_variable_param *fvp = data;
714 int tag;
715
716 tag = dwarf_tag(die_mem);
717 if ((tag == DW_TAG_formal_parameter ||
718 tag == DW_TAG_variable) &&
719 die_compare_name(die_mem, fvp->name))
720 return DIE_FIND_CB_END;
721
722 if (dwarf_haspc(die_mem, fvp->addr))
723 return DIE_FIND_CB_CONTINUE;
724 else
725 return DIE_FIND_CB_SIBLING;
726}
727
728/**
729 * die_find_variable_at - Find a given name variable at given address
730 * @sp_die: a function DIE
731 * @name: variable name
732 * @addr: address
733 * @die_mem: a buffer for result DIE
734 *
735 * Find a variable DIE called @name at @addr in @sp_die.
736 */
737Dwarf_Die *die_find_variable_at(Dwarf_Die *sp_die, const char *name,
738 Dwarf_Addr addr, Dwarf_Die *die_mem)
739{
740 struct __find_variable_param fvp = { .name = name, .addr = addr};
741
742 return die_find_child(sp_die, __die_find_variable_cb, (void *)&fvp,
743 die_mem);
744}
745
746static int __die_find_member_cb(Dwarf_Die *die_mem, void *data)
747{
748 const char *name = data;
749
750 if ((dwarf_tag(die_mem) == DW_TAG_member) &&
751 die_compare_name(die_mem, name))
752 return DIE_FIND_CB_END;
753
754 return DIE_FIND_CB_SIBLING;
755}
756
757/**
758 * die_find_member - Find a given name member in a data structure
759 * @st_die: a data structure type DIE
760 * @name: member name
761 * @die_mem: a buffer for result DIE
762 *
763 * Find a member DIE called @name in @st_die.
764 */
765Dwarf_Die *die_find_member(Dwarf_Die *st_die, const char *name,
766 Dwarf_Die *die_mem)
767{
768 return die_find_child(st_die, __die_find_member_cb, (void *)name,
769 die_mem);
770}
771
772/**
773 * die_get_typename - Get the name of given variable DIE
774 * @vr_die: a variable DIE
775 * @buf: a buffer for result type name
776 * @len: a max-length of @buf
777 *
778 * Get the name of @vr_die and stores it to @buf. Return the actual length
779 * of type name if succeeded. Return -E2BIG if @len is not enough long, and
780 * Return -ENOENT if failed to find type name.
781 * Note that the result will stores typedef name if possible, and stores
782 * "*(function_type)" if the type is a function pointer.
783 */
784int die_get_typename(Dwarf_Die *vr_die, char *buf, int len)
785{
786 Dwarf_Die type;
787 int tag, ret, ret2;
788 const char *tmp = "";
789
790 if (__die_get_real_type(vr_die, &type) == NULL)
791 return -ENOENT;
792
793 tag = dwarf_tag(&type);
794 if (tag == DW_TAG_array_type || tag == DW_TAG_pointer_type)
795 tmp = "*";
796 else if (tag == DW_TAG_subroutine_type) {
797 /* Function pointer */
798 ret = snprintf(buf, len, "(function_type)");
799 return (ret >= len) ? -E2BIG : ret;
800 } else {
801 if (!dwarf_diename(&type))
802 return -ENOENT;
803 if (tag == DW_TAG_union_type)
804 tmp = "union ";
805 else if (tag == DW_TAG_structure_type)
806 tmp = "struct ";
807 /* Write a base name */
808 ret = snprintf(buf, len, "%s%s", tmp, dwarf_diename(&type));
809 return (ret >= len) ? -E2BIG : ret;
810 }
811 ret = die_get_typename(&type, buf, len);
812 if (ret > 0) {
813 ret2 = snprintf(buf + ret, len - ret, "%s", tmp);
814 ret = (ret2 >= len - ret) ? -E2BIG : ret2 + ret;
815 }
816 return ret;
817}
818
819/**
820 * die_get_varname - Get the name and type of given variable DIE
821 * @vr_die: a variable DIE
822 * @buf: a buffer for type and variable name
823 * @len: the max-length of @buf
824 *
825 * Get the name and type of @vr_die and stores it in @buf as "type\tname".
826 */
827int die_get_varname(Dwarf_Die *vr_die, char *buf, int len)
828{
829 int ret, ret2;
830
831 ret = die_get_typename(vr_die, buf, len);
832 if (ret < 0) {
833 pr_debug("Failed to get type, make it unknown.\n");
834 ret = snprintf(buf, len, "(unknown_type)");
835 }
836 if (ret > 0) {
837 ret2 = snprintf(buf + ret, len - ret, "\t%s",
838 dwarf_diename(vr_die));
839 ret = (ret2 >= len - ret) ? -E2BIG : ret2 + ret;
840 }
841 return ret;
842}
843