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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 <errno.h>
21#include <inttypes.h>
22#include <stdbool.h>
23#include "util.h"
24#include "debug.h"
25#include "dwarf-aux.h"
26#include "string2.h"
27
28/**
29 * cu_find_realpath - Find the realpath of the target file
30 * @cu_die: A DIE(dwarf information entry) of CU(compilation Unit)
31 * @fname: The tail filename of the target file
32 *
33 * Find the real(long) path of @fname in @cu_die.
34 */
35const char *cu_find_realpath(Dwarf_Die *cu_die, const char *fname)
36{
37 Dwarf_Files *files;
38 size_t nfiles, i;
39 const char *src = NULL;
40 int ret;
41
42 if (!fname)
43 return NULL;
44
45 ret = dwarf_getsrcfiles(cu_die, &files, &nfiles);
46 if (ret != 0)
47 return NULL;
48
49 for (i = 0; i < nfiles; i++) {
50 src = dwarf_filesrc(files, i, NULL, NULL);
51 if (strtailcmp(src, fname) == 0)
52 break;
53 }
54 if (i == nfiles)
55 return NULL;
56 return src;
57}
58
59/**
60 * cu_get_comp_dir - Get the path of compilation directory
61 * @cu_die: a CU DIE
62 *
63 * Get the path of compilation directory of given @cu_die.
64 * Since this depends on DW_AT_comp_dir, older gcc will not
65 * embedded it. In that case, this returns NULL.
66 */
67const char *cu_get_comp_dir(Dwarf_Die *cu_die)
68{
69 Dwarf_Attribute attr;
70 if (dwarf_attr(cu_die, DW_AT_comp_dir, &attr) == NULL)
71 return NULL;
72 return dwarf_formstring(&attr);
73}
74
75/**
76 * cu_find_lineinfo - Get a line number and file name for given address
77 * @cu_die: a CU DIE
78 * @addr: An address
79 * @fname: a pointer which returns the file name string
80 * @lineno: a pointer which returns the line number
81 *
82 * Find a line number and file name for @addr in @cu_die.
83 */
84int cu_find_lineinfo(Dwarf_Die *cu_die, unsigned long addr,
85 const char **fname, int *lineno)
86{
87 Dwarf_Line *line;
88 Dwarf_Addr laddr;
89
90 line = dwarf_getsrc_die(cu_die, (Dwarf_Addr)addr);
91 if (line && dwarf_lineaddr(line, &laddr) == 0 &&
92 addr == (unsigned long)laddr && dwarf_lineno(line, lineno) == 0) {
93 *fname = dwarf_linesrc(line, NULL, NULL);
94 if (!*fname)
95 /* line number is useless without filename */
96 *lineno = 0;
97 }
98
99 return *lineno ?: -ENOENT;
100}
101
102static int __die_find_inline_cb(Dwarf_Die *die_mem, void *data);
103
104/**
105 * cu_walk_functions_at - Walk on function DIEs at given address
106 * @cu_die: A CU DIE
107 * @addr: An address
108 * @callback: A callback which called with found DIEs
109 * @data: A user data
110 *
111 * Walk on function DIEs at given @addr in @cu_die. Passed DIEs
112 * should be subprogram or inlined-subroutines.
113 */
114int cu_walk_functions_at(Dwarf_Die *cu_die, Dwarf_Addr addr,
115 int (*callback)(Dwarf_Die *, void *), void *data)
116{
117 Dwarf_Die die_mem;
118 Dwarf_Die *sc_die;
119 int ret = -ENOENT;
120
121 /* Inlined function could be recursive. Trace it until fail */
122 for (sc_die = die_find_realfunc(cu_die, addr, &die_mem);
123 sc_die != NULL;
124 sc_die = die_find_child(sc_die, __die_find_inline_cb, &addr,
125 &die_mem)) {
126 ret = callback(sc_die, data);
127 if (ret)
128 break;
129 }
130
131 return ret;
132
133}
134
135/**
136 * die_get_linkage_name - Get the linkage name of the object
137 * @dw_die: A DIE of the object
138 *
139 * Get the linkage name attiribute of given @dw_die.
140 * For C++ binary, the linkage name will be the mangled symbol.
141 */
142const char *die_get_linkage_name(Dwarf_Die *dw_die)
143{
144 Dwarf_Attribute attr;
145
146 if (dwarf_attr_integrate(dw_die, DW_AT_linkage_name, &attr) == NULL)
147 return NULL;
148 return dwarf_formstring(&attr);
149}
150
151/**
152 * die_compare_name - Compare diename and tname
153 * @dw_die: a DIE
154 * @tname: a string of target name
155 *
156 * Compare the name of @dw_die and @tname. Return false if @dw_die has no name.
157 */
158bool die_compare_name(Dwarf_Die *dw_die, const char *tname)
159{
160 const char *name;
161
162 name = dwarf_diename(dw_die);
163 return name ? (strcmp(tname, name) == 0) : false;
164}
165
166/**
167 * die_match_name - Match diename/linkage name and glob
168 * @dw_die: a DIE
169 * @glob: a string of target glob pattern
170 *
171 * Glob matching the name of @dw_die and @glob. Return false if matching fail.
172 * This also match linkage name.
173 */
174bool die_match_name(Dwarf_Die *dw_die, const char *glob)
175{
176 const char *name;
177
178 name = dwarf_diename(dw_die);
179 if (name && strglobmatch(name, glob))
180 return true;
181 /* fall back to check linkage name */
182 name = die_get_linkage_name(dw_die);
183 if (name && strglobmatch(name, glob))
184 return true;
185
186 return false;
187}
188
189/**
190 * die_get_call_lineno - Get callsite line number of inline-function instance
191 * @in_die: a DIE of an inlined function instance
192 *
193 * Get call-site line number of @in_die. This means from where the inline
194 * function is called.
195 */
196int die_get_call_lineno(Dwarf_Die *in_die)
197{
198 Dwarf_Attribute attr;
199 Dwarf_Word ret;
200
201 if (!dwarf_attr(in_die, DW_AT_call_line, &attr))
202 return -ENOENT;
203
204 dwarf_formudata(&attr, &ret);
205 return (int)ret;
206}
207
208/**
209 * die_get_type - Get type DIE
210 * @vr_die: a DIE of a variable
211 * @die_mem: where to store a type DIE
212 *
213 * Get a DIE of the type of given variable (@vr_die), and store
214 * it to die_mem. Return NULL if fails to get a type DIE.
215 */
216Dwarf_Die *die_get_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem)
217{
218 Dwarf_Attribute attr;
219
220 if (dwarf_attr_integrate(vr_die, DW_AT_type, &attr) &&
221 dwarf_formref_die(&attr, die_mem))
222 return die_mem;
223 else
224 return NULL;
225}
226
227/* Get a type die, but skip qualifiers */
228static Dwarf_Die *__die_get_real_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem)
229{
230 int tag;
231
232 do {
233 vr_die = die_get_type(vr_die, die_mem);
234 if (!vr_die)
235 break;
236 tag = dwarf_tag(vr_die);
237 } while (tag == DW_TAG_const_type ||
238 tag == DW_TAG_restrict_type ||
239 tag == DW_TAG_volatile_type ||
240 tag == DW_TAG_shared_type);
241
242 return vr_die;
243}
244
245/**
246 * die_get_real_type - Get a type die, but skip qualifiers and typedef
247 * @vr_die: a DIE of a variable
248 * @die_mem: where to store a type DIE
249 *
250 * Get a DIE of the type of given variable (@vr_die), and store
251 * it to die_mem. Return NULL if fails to get a type DIE.
252 * If the type is qualifiers (e.g. const) or typedef, this skips it
253 * and tries to find real type (structure or basic types, e.g. int).
254 */
255Dwarf_Die *die_get_real_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem)
256{
257 do {
258 vr_die = __die_get_real_type(vr_die, die_mem);
259 } while (vr_die && dwarf_tag(vr_die) == DW_TAG_typedef);
260
261 return vr_die;
262}
263
264/* Get attribute and translate it as a udata */
265static int die_get_attr_udata(Dwarf_Die *tp_die, unsigned int attr_name,
266 Dwarf_Word *result)
267{
268 Dwarf_Attribute attr;
269
270 if (dwarf_attr(tp_die, attr_name, &attr) == NULL ||
271 dwarf_formudata(&attr, result) != 0)
272 return -ENOENT;
273
274 return 0;
275}
276
277/* Get attribute and translate it as a sdata */
278static int die_get_attr_sdata(Dwarf_Die *tp_die, unsigned int attr_name,
279 Dwarf_Sword *result)
280{
281 Dwarf_Attribute attr;
282
283 if (dwarf_attr(tp_die, attr_name, &attr) == NULL ||
284 dwarf_formsdata(&attr, result) != 0)
285 return -ENOENT;
286
287 return 0;
288}
289
290/**
291 * die_is_signed_type - Check whether a type DIE is signed or not
292 * @tp_die: a DIE of a type
293 *
294 * Get the encoding of @tp_die and return true if the encoding
295 * is signed.
296 */
297bool die_is_signed_type(Dwarf_Die *tp_die)
298{
299 Dwarf_Word ret;
300
301 if (die_get_attr_udata(tp_die, DW_AT_encoding, &ret))
302 return false;
303
304 return (ret == DW_ATE_signed_char || ret == DW_ATE_signed ||
305 ret == DW_ATE_signed_fixed);
306}
307
308/**
309 * die_is_func_def - Ensure that this DIE is a subprogram and definition
310 * @dw_die: a DIE
311 *
312 * Ensure that this DIE is a subprogram and NOT a declaration. This
313 * returns true if @dw_die is a function definition.
314 **/
315bool die_is_func_def(Dwarf_Die *dw_die)
316{
317 Dwarf_Attribute attr;
318
319 return (dwarf_tag(dw_die) == DW_TAG_subprogram &&
320 dwarf_attr(dw_die, DW_AT_declaration, &attr) == NULL);
321}
322
323/**
324 * die_is_func_instance - Ensure that this DIE is an instance of a subprogram
325 * @dw_die: a DIE
326 *
327 * Ensure that this DIE is an instance (which has an entry address).
328 * This returns true if @dw_die is a function instance. If not, you need to
329 * call die_walk_instances() to find actual instances.
330 **/
331bool die_is_func_instance(Dwarf_Die *dw_die)
332{
333 Dwarf_Addr tmp;
334
335 /* Actually gcc optimizes non-inline as like as inlined */
336 return !dwarf_func_inline(dw_die) && dwarf_entrypc(dw_die, &tmp) == 0;
337}
338/**
339 * die_get_data_member_location - Get the data-member offset
340 * @mb_die: a DIE of a member of a data structure
341 * @offs: The offset of the member in the data structure
342 *
343 * Get the offset of @mb_die in the data structure including @mb_die, and
344 * stores result offset to @offs. If any error occurs this returns errno.
345 */
346int die_get_data_member_location(Dwarf_Die *mb_die, Dwarf_Word *offs)
347{
348 Dwarf_Attribute attr;
349 Dwarf_Op *expr;
350 size_t nexpr;
351 int ret;
352
353 if (dwarf_attr(mb_die, DW_AT_data_member_location, &attr) == NULL)
354 return -ENOENT;
355
356 if (dwarf_formudata(&attr, offs) != 0) {
357 /* DW_AT_data_member_location should be DW_OP_plus_uconst */
358 ret = dwarf_getlocation(&attr, &expr, &nexpr);
359 if (ret < 0 || nexpr == 0)
360 return -ENOENT;
361
362 if (expr[0].atom != DW_OP_plus_uconst || nexpr != 1) {
363 pr_debug("Unable to get offset:Unexpected OP %x (%zd)\n",
364 expr[0].atom, nexpr);
365 return -ENOTSUP;
366 }
367 *offs = (Dwarf_Word)expr[0].number;
368 }
369 return 0;
370}
371
372/* Get the call file index number in CU DIE */
373static int die_get_call_fileno(Dwarf_Die *in_die)
374{
375 Dwarf_Sword idx;
376
377 if (die_get_attr_sdata(in_die, DW_AT_call_file, &idx) == 0)
378 return (int)idx;
379 else
380 return -ENOENT;
381}
382
383/* Get the declared file index number in CU DIE */
384static int die_get_decl_fileno(Dwarf_Die *pdie)
385{
386 Dwarf_Sword idx;
387
388 if (die_get_attr_sdata(pdie, DW_AT_decl_file, &idx) == 0)
389 return (int)idx;
390 else
391 return -ENOENT;
392}
393
394/**
395 * die_get_call_file - Get callsite file name of inlined function instance
396 * @in_die: a DIE of an inlined function instance
397 *
398 * Get call-site file name of @in_die. This means from which file the inline
399 * function is called.
400 */
401const char *die_get_call_file(Dwarf_Die *in_die)
402{
403 Dwarf_Die cu_die;
404 Dwarf_Files *files;
405 int idx;
406
407 idx = die_get_call_fileno(in_die);
408 if (idx < 0 || !dwarf_diecu(in_die, &cu_die, NULL, NULL) ||
409 dwarf_getsrcfiles(&cu_die, &files, NULL) != 0)
410 return NULL;
411
412 return dwarf_filesrc(files, idx, NULL, NULL);
413}
414
415
416/**
417 * die_find_child - Generic DIE search function in DIE tree
418 * @rt_die: a root DIE
419 * @callback: a callback function
420 * @data: a user data passed to the callback function
421 * @die_mem: a buffer for result DIE
422 *
423 * Trace DIE tree from @rt_die and call @callback for each child DIE.
424 * If @callback returns DIE_FIND_CB_END, this stores the DIE into
425 * @die_mem and returns it. If @callback returns DIE_FIND_CB_CONTINUE,
426 * this continues to trace the tree. Optionally, @callback can return
427 * DIE_FIND_CB_CHILD and DIE_FIND_CB_SIBLING, those means trace only
428 * the children and trace only the siblings respectively.
429 * Returns NULL if @callback can't find any appropriate DIE.
430 */
431Dwarf_Die *die_find_child(Dwarf_Die *rt_die,
432 int (*callback)(Dwarf_Die *, void *),
433 void *data, Dwarf_Die *die_mem)
434{
435 Dwarf_Die child_die;
436 int ret;
437
438 ret = dwarf_child(rt_die, die_mem);
439 if (ret != 0)
440 return NULL;
441
442 do {
443 ret = callback(die_mem, data);
444 if (ret == DIE_FIND_CB_END)
445 return die_mem;
446
447 if ((ret & DIE_FIND_CB_CHILD) &&
448 die_find_child(die_mem, callback, data, &child_die)) {
449 memcpy(die_mem, &child_die, sizeof(Dwarf_Die));
450 return die_mem;
451 }
452 } while ((ret & DIE_FIND_CB_SIBLING) &&
453 dwarf_siblingof(die_mem, die_mem) == 0);
454
455 return NULL;
456}
457
458struct __addr_die_search_param {
459 Dwarf_Addr addr;
460 Dwarf_Die *die_mem;
461};
462
463static int __die_search_func_tail_cb(Dwarf_Die *fn_die, void *data)
464{
465 struct __addr_die_search_param *ad = data;
466 Dwarf_Addr addr = 0;
467
468 if (dwarf_tag(fn_die) == DW_TAG_subprogram &&
469 !dwarf_highpc(fn_die, &addr) &&
470 addr == ad->addr) {
471 memcpy(ad->die_mem, fn_die, sizeof(Dwarf_Die));
472 return DWARF_CB_ABORT;
473 }
474 return DWARF_CB_OK;
475}
476
477/**
478 * die_find_tailfunc - Search for a non-inlined function with tail call at
479 * given address
480 * @cu_die: a CU DIE which including @addr
481 * @addr: target address
482 * @die_mem: a buffer for result DIE
483 *
484 * Search for a non-inlined function DIE with tail call at @addr. Stores the
485 * DIE to @die_mem and returns it if found. Returns NULL if failed.
486 */
487Dwarf_Die *die_find_tailfunc(Dwarf_Die *cu_die, Dwarf_Addr addr,
488 Dwarf_Die *die_mem)
489{
490 struct __addr_die_search_param ad;
491 ad.addr = addr;
492 ad.die_mem = die_mem;
493 /* dwarf_getscopes can't find subprogram. */
494 if (!dwarf_getfuncs(cu_die, __die_search_func_tail_cb, &ad, 0))
495 return NULL;
496 else
497 return die_mem;
498}
499
500/* die_find callback for non-inlined function search */
501static int __die_search_func_cb(Dwarf_Die *fn_die, void *data)
502{
503 struct __addr_die_search_param *ad = data;
504
505 /*
506 * Since a declaration entry doesn't has given pc, this always returns
507 * function definition entry.
508 */
509 if (dwarf_tag(fn_die) == DW_TAG_subprogram &&
510 dwarf_haspc(fn_die, ad->addr)) {
511 memcpy(ad->die_mem, fn_die, sizeof(Dwarf_Die));
512 return DWARF_CB_ABORT;
513 }
514 return DWARF_CB_OK;
515}
516
517/**
518 * die_find_realfunc - Search a non-inlined function at given address
519 * @cu_die: a CU DIE which including @addr
520 * @addr: target address
521 * @die_mem: a buffer for result DIE
522 *
523 * Search a non-inlined function DIE which includes @addr. Stores the
524 * DIE to @die_mem and returns it if found. Returns NULL if failed.
525 */
526Dwarf_Die *die_find_realfunc(Dwarf_Die *cu_die, Dwarf_Addr addr,
527 Dwarf_Die *die_mem)
528{
529 struct __addr_die_search_param ad;
530 ad.addr = addr;
531 ad.die_mem = die_mem;
532 /* dwarf_getscopes can't find subprogram. */
533 if (!dwarf_getfuncs(cu_die, __die_search_func_cb, &ad, 0))
534 return NULL;
535 else
536 return die_mem;
537}
538
539/* die_find callback for inline function search */
540static int __die_find_inline_cb(Dwarf_Die *die_mem, void *data)
541{
542 Dwarf_Addr *addr = data;
543
544 if (dwarf_tag(die_mem) == DW_TAG_inlined_subroutine &&
545 dwarf_haspc(die_mem, *addr))
546 return DIE_FIND_CB_END;
547
548 return DIE_FIND_CB_CONTINUE;
549}
550
551/**
552 * die_find_top_inlinefunc - Search the top inlined function at given address
553 * @sp_die: a subprogram DIE which including @addr
554 * @addr: target address
555 * @die_mem: a buffer for result DIE
556 *
557 * Search an inlined function DIE which includes @addr. Stores the
558 * DIE to @die_mem and returns it if found. Returns NULL if failed.
559 * Even if several inlined functions are expanded recursively, this
560 * doesn't trace it down, and returns the topmost one.
561 */
562Dwarf_Die *die_find_top_inlinefunc(Dwarf_Die *sp_die, Dwarf_Addr addr,
563 Dwarf_Die *die_mem)
564{
565 return die_find_child(sp_die, __die_find_inline_cb, &addr, die_mem);
566}
567
568/**
569 * die_find_inlinefunc - Search an inlined function at given address
570 * @sp_die: a subprogram DIE which including @addr
571 * @addr: target address
572 * @die_mem: a buffer for result DIE
573 *
574 * Search an inlined function DIE which includes @addr. Stores the
575 * DIE to @die_mem and returns it if found. Returns NULL if failed.
576 * If several inlined functions are expanded recursively, this trace
577 * it down and returns deepest one.
578 */
579Dwarf_Die *die_find_inlinefunc(Dwarf_Die *sp_die, Dwarf_Addr addr,
580 Dwarf_Die *die_mem)
581{
582 Dwarf_Die tmp_die;
583
584 sp_die = die_find_child(sp_die, __die_find_inline_cb, &addr, &tmp_die);
585 if (!sp_die)
586 return NULL;
587
588 /* Inlined function could be recursive. Trace it until fail */
589 while (sp_die) {
590 memcpy(die_mem, sp_die, sizeof(Dwarf_Die));
591 sp_die = die_find_child(sp_die, __die_find_inline_cb, &addr,
592 &tmp_die);
593 }
594
595 return die_mem;
596}
597
598struct __instance_walk_param {
599 void *addr;
600 int (*callback)(Dwarf_Die *, void *);
601 void *data;
602 int retval;
603};
604
605static int __die_walk_instances_cb(Dwarf_Die *inst, void *data)
606{
607 struct __instance_walk_param *iwp = data;
608 Dwarf_Attribute attr_mem;
609 Dwarf_Die origin_mem;
610 Dwarf_Attribute *attr;
611 Dwarf_Die *origin;
612 int tmp;
613
614 attr = dwarf_attr(inst, DW_AT_abstract_origin, &attr_mem);
615 if (attr == NULL)
616 return DIE_FIND_CB_CONTINUE;
617
618 origin = dwarf_formref_die(attr, &origin_mem);
619 if (origin == NULL || origin->addr != iwp->addr)
620 return DIE_FIND_CB_CONTINUE;
621
622 /* Ignore redundant instances */
623 if (dwarf_tag(inst) == DW_TAG_inlined_subroutine) {
624 dwarf_decl_line(origin, &tmp);
625 if (die_get_call_lineno(inst) == tmp) {
626 tmp = die_get_decl_fileno(origin);
627 if (die_get_call_fileno(inst) == tmp)
628 return DIE_FIND_CB_CONTINUE;
629 }
630 }
631
632 iwp->retval = iwp->callback(inst, iwp->data);
633
634 return (iwp->retval) ? DIE_FIND_CB_END : DIE_FIND_CB_CONTINUE;
635}
636
637/**
638 * die_walk_instances - Walk on instances of given DIE
639 * @or_die: an abstract original DIE
640 * @callback: a callback function which is called with instance DIE
641 * @data: user data
642 *
643 * Walk on the instances of give @in_die. @in_die must be an inlined function
644 * declartion. This returns the return value of @callback if it returns
645 * non-zero value, or -ENOENT if there is no instance.
646 */
647int die_walk_instances(Dwarf_Die *or_die, int (*callback)(Dwarf_Die *, void *),
648 void *data)
649{
650 Dwarf_Die cu_die;
651 Dwarf_Die die_mem;
652 struct __instance_walk_param iwp = {
653 .addr = or_die->addr,
654 .callback = callback,
655 .data = data,
656 .retval = -ENOENT,
657 };
658
659 if (dwarf_diecu(or_die, &cu_die, NULL, NULL) == NULL)
660 return -ENOENT;
661
662 die_find_child(&cu_die, __die_walk_instances_cb, &iwp, &die_mem);
663
664 return iwp.retval;
665}
666
667/* Line walker internal parameters */
668struct __line_walk_param {
669 bool recursive;
670 line_walk_callback_t callback;
671 void *data;
672 int retval;
673};
674
675static int __die_walk_funclines_cb(Dwarf_Die *in_die, void *data)
676{
677 struct __line_walk_param *lw = data;
678 Dwarf_Addr addr = 0;
679 const char *fname;
680 int lineno;
681
682 if (dwarf_tag(in_die) == DW_TAG_inlined_subroutine) {
683 fname = die_get_call_file(in_die);
684 lineno = die_get_call_lineno(in_die);
685 if (fname && lineno > 0 && dwarf_entrypc(in_die, &addr) == 0) {
686 lw->retval = lw->callback(fname, lineno, addr, lw->data);
687 if (lw->retval != 0)
688 return DIE_FIND_CB_END;
689 }
690 }
691 if (!lw->recursive)
692 /* Don't need to search recursively */
693 return DIE_FIND_CB_SIBLING;
694
695 if (addr) {
696 fname = dwarf_decl_file(in_die);
697 if (fname && dwarf_decl_line(in_die, &lineno) == 0) {
698 lw->retval = lw->callback(fname, lineno, addr, lw->data);
699 if (lw->retval != 0)
700 return DIE_FIND_CB_END;
701 }
702 }
703
704 /* Continue to search nested inlined function call-sites */
705 return DIE_FIND_CB_CONTINUE;
706}
707
708/* Walk on lines of blocks included in given DIE */
709static int __die_walk_funclines(Dwarf_Die *sp_die, bool recursive,
710 line_walk_callback_t callback, void *data)
711{
712 struct __line_walk_param lw = {
713 .recursive = recursive,
714 .callback = callback,
715 .data = data,
716 .retval = 0,
717 };
718 Dwarf_Die die_mem;
719 Dwarf_Addr addr;
720 const char *fname;
721 int lineno;
722
723 /* Handle function declaration line */
724 fname = dwarf_decl_file(sp_die);
725 if (fname && dwarf_decl_line(sp_die, &lineno) == 0 &&
726 dwarf_entrypc(sp_die, &addr) == 0) {
727 lw.retval = callback(fname, lineno, addr, data);
728 if (lw.retval != 0)
729 goto done;
730 }
731 die_find_child(sp_die, __die_walk_funclines_cb, &lw, &die_mem);
732done:
733 return lw.retval;
734}
735
736static int __die_walk_culines_cb(Dwarf_Die *sp_die, void *data)
737{
738 struct __line_walk_param *lw = data;
739
740 lw->retval = __die_walk_funclines(sp_die, true, lw->callback, lw->data);
741 if (lw->retval != 0)
742 return DWARF_CB_ABORT;
743
744 return DWARF_CB_OK;
745}
746
747/**
748 * die_walk_lines - Walk on lines inside given DIE
749 * @rt_die: a root DIE (CU, subprogram or inlined_subroutine)
750 * @callback: callback routine
751 * @data: user data
752 *
753 * Walk on all lines inside given @rt_die and call @callback on each line.
754 * If the @rt_die is a function, walk only on the lines inside the function,
755 * otherwise @rt_die must be a CU DIE.
756 * Note that this walks not only dwarf line list, but also function entries
757 * and inline call-site.
758 */
759int die_walk_lines(Dwarf_Die *rt_die, line_walk_callback_t callback, void *data)
760{
761 Dwarf_Lines *lines;
762 Dwarf_Line *line;
763 Dwarf_Addr addr;
764 const char *fname, *decf = NULL;
765 int lineno, ret = 0;
766 int decl = 0, inl;
767 Dwarf_Die die_mem, *cu_die;
768 size_t nlines, i;
769
770 /* Get the CU die */
771 if (dwarf_tag(rt_die) != DW_TAG_compile_unit) {
772 cu_die = dwarf_diecu(rt_die, &die_mem, NULL, NULL);
773 dwarf_decl_line(rt_die, &decl);
774 decf = dwarf_decl_file(rt_die);
775 } else
776 cu_die = rt_die;
777 if (!cu_die) {
778 pr_debug2("Failed to get CU from given DIE.\n");
779 return -EINVAL;
780 }
781
782 /* Get lines list in the CU */
783 if (dwarf_getsrclines(cu_die, &lines, &nlines) != 0) {
784 pr_debug2("Failed to get source lines on this CU.\n");
785 return -ENOENT;
786 }
787 pr_debug2("Get %zd lines from this CU\n", nlines);
788
789 /* Walk on the lines on lines list */
790 for (i = 0; i < nlines; i++) {
791 line = dwarf_onesrcline(lines, i);
792 if (line == NULL ||
793 dwarf_lineno(line, &lineno) != 0 ||
794 dwarf_lineaddr(line, &addr) != 0) {
795 pr_debug2("Failed to get line info. "
796 "Possible error in debuginfo.\n");
797 continue;
798 }
799 /* Filter lines based on address */
800 if (rt_die != cu_die) {
801 /*
802 * Address filtering
803 * The line is included in given function, and
804 * no inline block includes it.
805 */
806 if (!dwarf_haspc(rt_die, addr))
807 continue;
808 if (die_find_inlinefunc(rt_die, addr, &die_mem)) {
809 dwarf_decl_line(&die_mem, &inl);
810 if (inl != decl ||
811 decf != dwarf_decl_file(&die_mem))
812 continue;
813 }
814 }
815 /* Get source line */
816 fname = dwarf_linesrc(line, NULL, NULL);
817
818 ret = callback(fname, lineno, addr, data);
819 if (ret != 0)
820 return ret;
821 }
822
823 /*
824 * Dwarf lines doesn't include function declarations and inlined
825 * subroutines. We have to check functions list or given function.
826 */
827 if (rt_die != cu_die)
828 /*
829 * Don't need walk functions recursively, because nested
830 * inlined functions don't have lines of the specified DIE.
831 */
832 ret = __die_walk_funclines(rt_die, false, callback, data);
833 else {
834 struct __line_walk_param param = {
835 .callback = callback,
836 .data = data,
837 .retval = 0,
838 };
839 dwarf_getfuncs(cu_die, __die_walk_culines_cb, ¶m, 0);
840 ret = param.retval;
841 }
842
843 return ret;
844}
845
846struct __find_variable_param {
847 const char *name;
848 Dwarf_Addr addr;
849};
850
851static int __die_find_variable_cb(Dwarf_Die *die_mem, void *data)
852{
853 struct __find_variable_param *fvp = data;
854 Dwarf_Attribute attr;
855 int tag;
856
857 tag = dwarf_tag(die_mem);
858 if ((tag == DW_TAG_formal_parameter ||
859 tag == DW_TAG_variable) &&
860 die_compare_name(die_mem, fvp->name) &&
861 /* Does the DIE have location information or external instance? */
862 (dwarf_attr(die_mem, DW_AT_external, &attr) ||
863 dwarf_attr(die_mem, DW_AT_location, &attr)))
864 return DIE_FIND_CB_END;
865 if (dwarf_haspc(die_mem, fvp->addr))
866 return DIE_FIND_CB_CONTINUE;
867 else
868 return DIE_FIND_CB_SIBLING;
869}
870
871/**
872 * die_find_variable_at - Find a given name variable at given address
873 * @sp_die: a function DIE
874 * @name: variable name
875 * @addr: address
876 * @die_mem: a buffer for result DIE
877 *
878 * Find a variable DIE called @name at @addr in @sp_die.
879 */
880Dwarf_Die *die_find_variable_at(Dwarf_Die *sp_die, const char *name,
881 Dwarf_Addr addr, Dwarf_Die *die_mem)
882{
883 struct __find_variable_param fvp = { .name = name, .addr = addr};
884
885 return die_find_child(sp_die, __die_find_variable_cb, (void *)&fvp,
886 die_mem);
887}
888
889static int __die_find_member_cb(Dwarf_Die *die_mem, void *data)
890{
891 const char *name = data;
892
893 if (dwarf_tag(die_mem) == DW_TAG_member) {
894 if (die_compare_name(die_mem, name))
895 return DIE_FIND_CB_END;
896 else if (!dwarf_diename(die_mem)) { /* Unnamed structure */
897 Dwarf_Die type_die, tmp_die;
898 if (die_get_type(die_mem, &type_die) &&
899 die_find_member(&type_die, name, &tmp_die))
900 return DIE_FIND_CB_END;
901 }
902 }
903 return DIE_FIND_CB_SIBLING;
904}
905
906/**
907 * die_find_member - Find a given name member in a data structure
908 * @st_die: a data structure type DIE
909 * @name: member name
910 * @die_mem: a buffer for result DIE
911 *
912 * Find a member DIE called @name in @st_die.
913 */
914Dwarf_Die *die_find_member(Dwarf_Die *st_die, const char *name,
915 Dwarf_Die *die_mem)
916{
917 return die_find_child(st_die, __die_find_member_cb, (void *)name,
918 die_mem);
919}
920
921/**
922 * die_get_typename - Get the name of given variable DIE
923 * @vr_die: a variable DIE
924 * @buf: a strbuf for result type name
925 *
926 * Get the name of @vr_die and stores it to @buf. Return 0 if succeeded.
927 * and Return -ENOENT if failed to find type name.
928 * Note that the result will stores typedef name if possible, and stores
929 * "*(function_type)" if the type is a function pointer.
930 */
931int die_get_typename(Dwarf_Die *vr_die, struct strbuf *buf)
932{
933 Dwarf_Die type;
934 int tag, ret;
935 const char *tmp = "";
936
937 if (__die_get_real_type(vr_die, &type) == NULL)
938 return -ENOENT;
939
940 tag = dwarf_tag(&type);
941 if (tag == DW_TAG_array_type || tag == DW_TAG_pointer_type)
942 tmp = "*";
943 else if (tag == DW_TAG_subroutine_type) {
944 /* Function pointer */
945 return strbuf_add(buf, "(function_type)", 15);
946 } else {
947 if (!dwarf_diename(&type))
948 return -ENOENT;
949 if (tag == DW_TAG_union_type)
950 tmp = "union ";
951 else if (tag == DW_TAG_structure_type)
952 tmp = "struct ";
953 else if (tag == DW_TAG_enumeration_type)
954 tmp = "enum ";
955 /* Write a base name */
956 return strbuf_addf(buf, "%s%s", tmp, dwarf_diename(&type));
957 }
958 ret = die_get_typename(&type, buf);
959 return ret ? ret : strbuf_addstr(buf, tmp);
960}
961
962/**
963 * die_get_varname - Get the name and type of given variable DIE
964 * @vr_die: a variable DIE
965 * @buf: a strbuf for type and variable name
966 *
967 * Get the name and type of @vr_die and stores it in @buf as "type\tname".
968 */
969int die_get_varname(Dwarf_Die *vr_die, struct strbuf *buf)
970{
971 int ret;
972
973 ret = die_get_typename(vr_die, buf);
974 if (ret < 0) {
975 pr_debug("Failed to get type, make it unknown.\n");
976 ret = strbuf_add(buf, " (unknown_type)", 14);
977 }
978
979 return ret < 0 ? ret : strbuf_addf(buf, "\t%s", dwarf_diename(vr_die));
980}
981
982#ifdef HAVE_DWARF_GETLOCATIONS_SUPPORT
983/**
984 * die_get_var_innermost_scope - Get innermost scope range of given variable DIE
985 * @sp_die: a subprogram DIE
986 * @vr_die: a variable DIE
987 * @buf: a strbuf for variable byte offset range
988 *
989 * Get the innermost scope range of @vr_die and stores it in @buf as
990 * "@<function_name+[NN-NN,NN-NN]>".
991 */
992static int die_get_var_innermost_scope(Dwarf_Die *sp_die, Dwarf_Die *vr_die,
993 struct strbuf *buf)
994{
995 Dwarf_Die *scopes;
996 int count;
997 size_t offset = 0;
998 Dwarf_Addr base;
999 Dwarf_Addr start, end;
1000 Dwarf_Addr entry;
1001 int ret;
1002 bool first = true;
1003 const char *name;
1004
1005 ret = dwarf_entrypc(sp_die, &entry);
1006 if (ret)
1007 return ret;
1008
1009 name = dwarf_diename(sp_die);
1010 if (!name)
1011 return -ENOENT;
1012
1013 count = dwarf_getscopes_die(vr_die, &scopes);
1014
1015 /* (*SCOPES)[1] is the DIE for the scope containing that scope */
1016 if (count <= 1) {
1017 ret = -EINVAL;
1018 goto out;
1019 }
1020
1021 while ((offset = dwarf_ranges(&scopes[1], offset, &base,
1022 &start, &end)) > 0) {
1023 start -= entry;
1024 end -= entry;
1025
1026 if (first) {
1027 ret = strbuf_addf(buf, "@<%s+[%" PRIu64 "-%" PRIu64,
1028 name, start, end);
1029 first = false;
1030 } else {
1031 ret = strbuf_addf(buf, ",%" PRIu64 "-%" PRIu64,
1032 start, end);
1033 }
1034 if (ret < 0)
1035 goto out;
1036 }
1037
1038 if (!first)
1039 ret = strbuf_add(buf, "]>", 2);
1040
1041out:
1042 free(scopes);
1043 return ret;
1044}
1045
1046/**
1047 * die_get_var_range - Get byte offset range of given variable DIE
1048 * @sp_die: a subprogram DIE
1049 * @vr_die: a variable DIE
1050 * @buf: a strbuf for type and variable name and byte offset range
1051 *
1052 * Get the byte offset range of @vr_die and stores it in @buf as
1053 * "@<function_name+[NN-NN,NN-NN]>".
1054 */
1055int die_get_var_range(Dwarf_Die *sp_die, Dwarf_Die *vr_die, struct strbuf *buf)
1056{
1057 int ret = 0;
1058 Dwarf_Addr base;
1059 Dwarf_Addr start, end;
1060 Dwarf_Addr entry;
1061 Dwarf_Op *op;
1062 size_t nops;
1063 size_t offset = 0;
1064 Dwarf_Attribute attr;
1065 bool first = true;
1066 const char *name;
1067
1068 ret = dwarf_entrypc(sp_die, &entry);
1069 if (ret)
1070 return ret;
1071
1072 name = dwarf_diename(sp_die);
1073 if (!name)
1074 return -ENOENT;
1075
1076 if (dwarf_attr(vr_die, DW_AT_location, &attr) == NULL)
1077 return -EINVAL;
1078
1079 while ((offset = dwarf_getlocations(&attr, offset, &base,
1080 &start, &end, &op, &nops)) > 0) {
1081 if (start == 0) {
1082 /* Single Location Descriptions */
1083 ret = die_get_var_innermost_scope(sp_die, vr_die, buf);
1084 goto out;
1085 }
1086
1087 /* Location Lists */
1088 start -= entry;
1089 end -= entry;
1090 if (first) {
1091 ret = strbuf_addf(buf, "@<%s+[%" PRIu64 "-%" PRIu64,
1092 name, start, end);
1093 first = false;
1094 } else {
1095 ret = strbuf_addf(buf, ",%" PRIu64 "-%" PRIu64,
1096 start, end);
1097 }
1098 if (ret < 0)
1099 goto out;
1100 }
1101
1102 if (!first)
1103 ret = strbuf_add(buf, "]>", 2);
1104out:
1105 return ret;
1106}
1107#else
1108int die_get_var_range(Dwarf_Die *sp_die __maybe_unused,
1109 Dwarf_Die *vr_die __maybe_unused,
1110 struct strbuf *buf __maybe_unused)
1111{
1112 return -ENOTSUP;
1113}
1114#endif
1115
1116/*
1117 * die_has_loclist - Check if DW_AT_location of @vr_die is a location list
1118 * @vr_die: a variable DIE
1119 */
1120static bool die_has_loclist(Dwarf_Die *vr_die)
1121{
1122 Dwarf_Attribute loc;
1123 int tag = dwarf_tag(vr_die);
1124
1125 if (tag != DW_TAG_formal_parameter &&
1126 tag != DW_TAG_variable)
1127 return false;
1128
1129 return (dwarf_attr_integrate(vr_die, DW_AT_location, &loc) &&
1130 dwarf_whatform(&loc) == DW_FORM_sec_offset);
1131}
1132
1133/*
1134 * die_is_optimized_target - Check if target program is compiled with
1135 * optimization
1136 * @cu_die: a CU DIE
1137 *
1138 * For any object in given CU whose DW_AT_location is a location list,
1139 * target program is compiled with optimization. This is applicable to
1140 * clang as well.
1141 */
1142bool die_is_optimized_target(Dwarf_Die *cu_die)
1143{
1144 Dwarf_Die tmp_die;
1145
1146 if (die_has_loclist(cu_die))
1147 return true;
1148
1149 if (!dwarf_child(cu_die, &tmp_die) &&
1150 die_is_optimized_target(&tmp_die))
1151 return true;
1152
1153 if (!dwarf_siblingof(cu_die, &tmp_die) &&
1154 die_is_optimized_target(&tmp_die))
1155 return true;
1156
1157 return false;
1158}
1159
1160/*
1161 * die_search_idx - Search index of given line address
1162 * @lines: Line records of single CU
1163 * @nr_lines: Number of @lines
1164 * @addr: address we are looking for
1165 * @idx: index to be set by this function (return value)
1166 *
1167 * Search for @addr by looping over every lines of CU. If address
1168 * matches, set index of that line in @idx. Note that single source
1169 * line can have multiple line records. i.e. single source line can
1170 * have multiple index.
1171 */
1172static bool die_search_idx(Dwarf_Lines *lines, unsigned long nr_lines,
1173 Dwarf_Addr addr, unsigned long *idx)
1174{
1175 unsigned long i;
1176 Dwarf_Addr tmp;
1177
1178 for (i = 0; i < nr_lines; i++) {
1179 if (dwarf_lineaddr(dwarf_onesrcline(lines, i), &tmp))
1180 return false;
1181
1182 if (tmp == addr) {
1183 *idx = i;
1184 return true;
1185 }
1186 }
1187 return false;
1188}
1189
1190/*
1191 * die_get_postprologue_addr - Search next address after function prologue
1192 * @entrypc_idx: entrypc index
1193 * @lines: Line records of single CU
1194 * @nr_lines: Number of @lines
1195 * @hignpc: high PC address of function
1196 * @postprologue_addr: Next address after function prologue (return value)
1197 *
1198 * Look for prologue-end marker. If there is no explicit marker, return
1199 * address of next line record or next source line.
1200 */
1201static bool die_get_postprologue_addr(unsigned long entrypc_idx,
1202 Dwarf_Lines *lines,
1203 unsigned long nr_lines,
1204 Dwarf_Addr highpc,
1205 Dwarf_Addr *postprologue_addr)
1206{
1207 unsigned long i;
1208 int entrypc_lno, lno;
1209 Dwarf_Line *line;
1210 Dwarf_Addr addr;
1211 bool p_end;
1212
1213 /* entrypc_lno is actual source line number */
1214 line = dwarf_onesrcline(lines, entrypc_idx);
1215 if (dwarf_lineno(line, &entrypc_lno))
1216 return false;
1217
1218 for (i = entrypc_idx; i < nr_lines; i++) {
1219 line = dwarf_onesrcline(lines, i);
1220
1221 if (dwarf_lineaddr(line, &addr) ||
1222 dwarf_lineno(line, &lno) ||
1223 dwarf_lineprologueend(line, &p_end))
1224 return false;
1225
1226 /* highpc is exclusive. [entrypc,highpc) */
1227 if (addr >= highpc)
1228 break;
1229
1230 /* clang supports prologue-end marker */
1231 if (p_end)
1232 break;
1233
1234 /* Actual next line in source */
1235 if (lno != entrypc_lno)
1236 break;
1237
1238 /*
1239 * Single source line can have multiple line records.
1240 * For Example,
1241 * void foo() { printf("hello\n"); }
1242 * contains two line records. One points to declaration and
1243 * other points to printf() line. Variable 'lno' won't get
1244 * incremented in this case but 'i' will.
1245 */
1246 if (i != entrypc_idx)
1247 break;
1248 }
1249
1250 dwarf_lineaddr(line, postprologue_addr);
1251 if (*postprologue_addr >= highpc)
1252 dwarf_lineaddr(dwarf_onesrcline(lines, i - 1),
1253 postprologue_addr);
1254
1255 return true;
1256}
1257
1258/*
1259 * die_skip_prologue - Use next address after prologue as probe location
1260 * @sp_die: a subprogram DIE
1261 * @cu_die: a CU DIE
1262 * @entrypc: entrypc of the function
1263 *
1264 * Function prologue prepares stack and registers before executing function
1265 * logic. When target program is compiled without optimization, function
1266 * parameter information is only valid after prologue. When we probe entrypc
1267 * of the function, and try to record function parameter, it contains
1268 * garbage value.
1269 */
1270void die_skip_prologue(Dwarf_Die *sp_die, Dwarf_Die *cu_die,
1271 Dwarf_Addr *entrypc)
1272{
1273 size_t nr_lines = 0;
1274 unsigned long entrypc_idx = 0;
1275 Dwarf_Lines *lines = NULL;
1276 Dwarf_Addr postprologue_addr;
1277 Dwarf_Addr highpc;
1278
1279 if (dwarf_highpc(sp_die, &highpc))
1280 return;
1281
1282 if (dwarf_getsrclines(cu_die, &lines, &nr_lines))
1283 return;
1284
1285 if (!die_search_idx(lines, nr_lines, *entrypc, &entrypc_idx))
1286 return;
1287
1288 if (!die_get_postprologue_addr(entrypc_idx, lines, nr_lines,
1289 highpc, &postprologue_addr))
1290 return;
1291
1292 *entrypc = postprologue_addr;
1293}
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_get_linkage_name - Get the linkage name of the object
134 * @dw_die: A DIE of the object
135 *
136 * Get the linkage name attiribute of given @dw_die.
137 * For C++ binary, the linkage name will be the mangled symbol.
138 */
139const char *die_get_linkage_name(Dwarf_Die *dw_die)
140{
141 Dwarf_Attribute attr;
142
143 if (dwarf_attr_integrate(dw_die, DW_AT_linkage_name, &attr) == NULL)
144 return NULL;
145 return dwarf_formstring(&attr);
146}
147
148/**
149 * die_compare_name - Compare diename and tname
150 * @dw_die: a DIE
151 * @tname: a string of target name
152 *
153 * Compare the name of @dw_die and @tname. Return false if @dw_die has no name.
154 */
155bool die_compare_name(Dwarf_Die *dw_die, const char *tname)
156{
157 const char *name;
158
159 name = dwarf_diename(dw_die);
160 return name ? (strcmp(tname, name) == 0) : false;
161}
162
163/**
164 * die_match_name - Match diename/linkage name and glob
165 * @dw_die: a DIE
166 * @glob: a string of target glob pattern
167 *
168 * Glob matching the name of @dw_die and @glob. Return false if matching fail.
169 * This also match linkage name.
170 */
171bool die_match_name(Dwarf_Die *dw_die, const char *glob)
172{
173 const char *name;
174
175 name = dwarf_diename(dw_die);
176 if (name && strglobmatch(name, glob))
177 return true;
178 /* fall back to check linkage name */
179 name = die_get_linkage_name(dw_die);
180 if (name && strglobmatch(name, glob))
181 return true;
182
183 return false;
184}
185
186/**
187 * die_get_call_lineno - Get callsite line number of inline-function instance
188 * @in_die: a DIE of an inlined function instance
189 *
190 * Get call-site line number of @in_die. This means from where the inline
191 * function is called.
192 */
193int die_get_call_lineno(Dwarf_Die *in_die)
194{
195 Dwarf_Attribute attr;
196 Dwarf_Word ret;
197
198 if (!dwarf_attr(in_die, DW_AT_call_line, &attr))
199 return -ENOENT;
200
201 dwarf_formudata(&attr, &ret);
202 return (int)ret;
203}
204
205/**
206 * die_get_type - Get type DIE
207 * @vr_die: a DIE of a variable
208 * @die_mem: where to store a type DIE
209 *
210 * Get a DIE of the type of given variable (@vr_die), and store
211 * it to die_mem. Return NULL if fails to get a type DIE.
212 */
213Dwarf_Die *die_get_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem)
214{
215 Dwarf_Attribute attr;
216
217 if (dwarf_attr_integrate(vr_die, DW_AT_type, &attr) &&
218 dwarf_formref_die(&attr, die_mem))
219 return die_mem;
220 else
221 return NULL;
222}
223
224/* Get a type die, but skip qualifiers */
225static Dwarf_Die *__die_get_real_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem)
226{
227 int tag;
228
229 do {
230 vr_die = die_get_type(vr_die, die_mem);
231 if (!vr_die)
232 break;
233 tag = dwarf_tag(vr_die);
234 } while (tag == DW_TAG_const_type ||
235 tag == DW_TAG_restrict_type ||
236 tag == DW_TAG_volatile_type ||
237 tag == DW_TAG_shared_type);
238
239 return vr_die;
240}
241
242/**
243 * die_get_real_type - Get a type die, but skip qualifiers and typedef
244 * @vr_die: a DIE of a variable
245 * @die_mem: where to store a type DIE
246 *
247 * Get a DIE of the type of given variable (@vr_die), and store
248 * it to die_mem. Return NULL if fails to get a type DIE.
249 * If the type is qualifiers (e.g. const) or typedef, this skips it
250 * and tries to find real type (structure or basic types, e.g. int).
251 */
252Dwarf_Die *die_get_real_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem)
253{
254 do {
255 vr_die = __die_get_real_type(vr_die, die_mem);
256 } while (vr_die && dwarf_tag(vr_die) == DW_TAG_typedef);
257
258 return vr_die;
259}
260
261/* Get attribute and translate it as a udata */
262static int die_get_attr_udata(Dwarf_Die *tp_die, unsigned int attr_name,
263 Dwarf_Word *result)
264{
265 Dwarf_Attribute attr;
266
267 if (dwarf_attr(tp_die, attr_name, &attr) == NULL ||
268 dwarf_formudata(&attr, result) != 0)
269 return -ENOENT;
270
271 return 0;
272}
273
274/* Get attribute and translate it as a sdata */
275static int die_get_attr_sdata(Dwarf_Die *tp_die, unsigned int attr_name,
276 Dwarf_Sword *result)
277{
278 Dwarf_Attribute attr;
279
280 if (dwarf_attr(tp_die, attr_name, &attr) == NULL ||
281 dwarf_formsdata(&attr, result) != 0)
282 return -ENOENT;
283
284 return 0;
285}
286
287/**
288 * die_is_signed_type - Check whether a type DIE is signed or not
289 * @tp_die: a DIE of a type
290 *
291 * Get the encoding of @tp_die and return true if the encoding
292 * is signed.
293 */
294bool die_is_signed_type(Dwarf_Die *tp_die)
295{
296 Dwarf_Word ret;
297
298 if (die_get_attr_udata(tp_die, DW_AT_encoding, &ret))
299 return false;
300
301 return (ret == DW_ATE_signed_char || ret == DW_ATE_signed ||
302 ret == DW_ATE_signed_fixed);
303}
304
305/**
306 * die_is_func_def - Ensure that this DIE is a subprogram and definition
307 * @dw_die: a DIE
308 *
309 * Ensure that this DIE is a subprogram and NOT a declaration. This
310 * returns true if @dw_die is a function definition.
311 **/
312bool die_is_func_def(Dwarf_Die *dw_die)
313{
314 Dwarf_Attribute attr;
315
316 return (dwarf_tag(dw_die) == DW_TAG_subprogram &&
317 dwarf_attr(dw_die, DW_AT_declaration, &attr) == NULL);
318}
319
320/**
321 * die_is_func_instance - Ensure that this DIE is an instance of a subprogram
322 * @dw_die: a DIE
323 *
324 * Ensure that this DIE is an instance (which has an entry address).
325 * This returns true if @dw_die is a function instance. If not, you need to
326 * call die_walk_instances() to find actual instances.
327 **/
328bool die_is_func_instance(Dwarf_Die *dw_die)
329{
330 Dwarf_Addr tmp;
331
332 /* Actually gcc optimizes non-inline as like as inlined */
333 return !dwarf_func_inline(dw_die) && dwarf_entrypc(dw_die, &tmp) == 0;
334}
335/**
336 * die_get_data_member_location - Get the data-member offset
337 * @mb_die: a DIE of a member of a data structure
338 * @offs: The offset of the member in the data structure
339 *
340 * Get the offset of @mb_die in the data structure including @mb_die, and
341 * stores result offset to @offs. If any error occurs this returns errno.
342 */
343int die_get_data_member_location(Dwarf_Die *mb_die, Dwarf_Word *offs)
344{
345 Dwarf_Attribute attr;
346 Dwarf_Op *expr;
347 size_t nexpr;
348 int ret;
349
350 if (dwarf_attr(mb_die, DW_AT_data_member_location, &attr) == NULL)
351 return -ENOENT;
352
353 if (dwarf_formudata(&attr, offs) != 0) {
354 /* DW_AT_data_member_location should be DW_OP_plus_uconst */
355 ret = dwarf_getlocation(&attr, &expr, &nexpr);
356 if (ret < 0 || nexpr == 0)
357 return -ENOENT;
358
359 if (expr[0].atom != DW_OP_plus_uconst || nexpr != 1) {
360 pr_debug("Unable to get offset:Unexpected OP %x (%zd)\n",
361 expr[0].atom, nexpr);
362 return -ENOTSUP;
363 }
364 *offs = (Dwarf_Word)expr[0].number;
365 }
366 return 0;
367}
368
369/* Get the call file index number in CU DIE */
370static int die_get_call_fileno(Dwarf_Die *in_die)
371{
372 Dwarf_Sword idx;
373
374 if (die_get_attr_sdata(in_die, DW_AT_call_file, &idx) == 0)
375 return (int)idx;
376 else
377 return -ENOENT;
378}
379
380/* Get the declared file index number in CU DIE */
381static int die_get_decl_fileno(Dwarf_Die *pdie)
382{
383 Dwarf_Sword idx;
384
385 if (die_get_attr_sdata(pdie, DW_AT_decl_file, &idx) == 0)
386 return (int)idx;
387 else
388 return -ENOENT;
389}
390
391/**
392 * die_get_call_file - Get callsite file name of inlined function instance
393 * @in_die: a DIE of an inlined function instance
394 *
395 * Get call-site file name of @in_die. This means from which file the inline
396 * function is called.
397 */
398const char *die_get_call_file(Dwarf_Die *in_die)
399{
400 Dwarf_Die cu_die;
401 Dwarf_Files *files;
402 int idx;
403
404 idx = die_get_call_fileno(in_die);
405 if (idx < 0 || !dwarf_diecu(in_die, &cu_die, NULL, NULL) ||
406 dwarf_getsrcfiles(&cu_die, &files, NULL) != 0)
407 return NULL;
408
409 return dwarf_filesrc(files, idx, NULL, NULL);
410}
411
412
413/**
414 * die_find_child - Generic DIE search function in DIE tree
415 * @rt_die: a root DIE
416 * @callback: a callback function
417 * @data: a user data passed to the callback function
418 * @die_mem: a buffer for result DIE
419 *
420 * Trace DIE tree from @rt_die and call @callback for each child DIE.
421 * If @callback returns DIE_FIND_CB_END, this stores the DIE into
422 * @die_mem and returns it. If @callback returns DIE_FIND_CB_CONTINUE,
423 * this continues to trace the tree. Optionally, @callback can return
424 * DIE_FIND_CB_CHILD and DIE_FIND_CB_SIBLING, those means trace only
425 * the children and trace only the siblings respectively.
426 * Returns NULL if @callback can't find any appropriate DIE.
427 */
428Dwarf_Die *die_find_child(Dwarf_Die *rt_die,
429 int (*callback)(Dwarf_Die *, void *),
430 void *data, Dwarf_Die *die_mem)
431{
432 Dwarf_Die child_die;
433 int ret;
434
435 ret = dwarf_child(rt_die, die_mem);
436 if (ret != 0)
437 return NULL;
438
439 do {
440 ret = callback(die_mem, data);
441 if (ret == DIE_FIND_CB_END)
442 return die_mem;
443
444 if ((ret & DIE_FIND_CB_CHILD) &&
445 die_find_child(die_mem, callback, data, &child_die)) {
446 memcpy(die_mem, &child_die, sizeof(Dwarf_Die));
447 return die_mem;
448 }
449 } while ((ret & DIE_FIND_CB_SIBLING) &&
450 dwarf_siblingof(die_mem, die_mem) == 0);
451
452 return NULL;
453}
454
455struct __addr_die_search_param {
456 Dwarf_Addr addr;
457 Dwarf_Die *die_mem;
458};
459
460static int __die_search_func_tail_cb(Dwarf_Die *fn_die, void *data)
461{
462 struct __addr_die_search_param *ad = data;
463 Dwarf_Addr addr = 0;
464
465 if (dwarf_tag(fn_die) == DW_TAG_subprogram &&
466 !dwarf_highpc(fn_die, &addr) &&
467 addr == ad->addr) {
468 memcpy(ad->die_mem, fn_die, sizeof(Dwarf_Die));
469 return DWARF_CB_ABORT;
470 }
471 return DWARF_CB_OK;
472}
473
474/**
475 * die_find_tailfunc - Search for a non-inlined function with tail call at
476 * given address
477 * @cu_die: a CU DIE which including @addr
478 * @addr: target address
479 * @die_mem: a buffer for result DIE
480 *
481 * Search for a non-inlined function DIE with tail call at @addr. Stores the
482 * DIE to @die_mem and returns it if found. Returns NULL if failed.
483 */
484Dwarf_Die *die_find_tailfunc(Dwarf_Die *cu_die, Dwarf_Addr addr,
485 Dwarf_Die *die_mem)
486{
487 struct __addr_die_search_param ad;
488 ad.addr = addr;
489 ad.die_mem = die_mem;
490 /* dwarf_getscopes can't find subprogram. */
491 if (!dwarf_getfuncs(cu_die, __die_search_func_tail_cb, &ad, 0))
492 return NULL;
493 else
494 return die_mem;
495}
496
497/* die_find callback for non-inlined function search */
498static int __die_search_func_cb(Dwarf_Die *fn_die, void *data)
499{
500 struct __addr_die_search_param *ad = data;
501
502 /*
503 * Since a declaration entry doesn't has given pc, this always returns
504 * function definition entry.
505 */
506 if (dwarf_tag(fn_die) == DW_TAG_subprogram &&
507 dwarf_haspc(fn_die, ad->addr)) {
508 memcpy(ad->die_mem, fn_die, sizeof(Dwarf_Die));
509 return DWARF_CB_ABORT;
510 }
511 return DWARF_CB_OK;
512}
513
514/**
515 * die_find_realfunc - Search a non-inlined function at given address
516 * @cu_die: a CU DIE which including @addr
517 * @addr: target address
518 * @die_mem: a buffer for result DIE
519 *
520 * Search a non-inlined function DIE which includes @addr. Stores the
521 * DIE to @die_mem and returns it if found. Returns NULL if failed.
522 */
523Dwarf_Die *die_find_realfunc(Dwarf_Die *cu_die, Dwarf_Addr addr,
524 Dwarf_Die *die_mem)
525{
526 struct __addr_die_search_param ad;
527 ad.addr = addr;
528 ad.die_mem = die_mem;
529 /* dwarf_getscopes can't find subprogram. */
530 if (!dwarf_getfuncs(cu_die, __die_search_func_cb, &ad, 0))
531 return NULL;
532 else
533 return die_mem;
534}
535
536/* die_find callback for inline function search */
537static int __die_find_inline_cb(Dwarf_Die *die_mem, void *data)
538{
539 Dwarf_Addr *addr = data;
540
541 if (dwarf_tag(die_mem) == DW_TAG_inlined_subroutine &&
542 dwarf_haspc(die_mem, *addr))
543 return DIE_FIND_CB_END;
544
545 return DIE_FIND_CB_CONTINUE;
546}
547
548/**
549 * die_find_top_inlinefunc - Search the top inlined function at given address
550 * @sp_die: a subprogram DIE which including @addr
551 * @addr: target address
552 * @die_mem: a buffer for result DIE
553 *
554 * Search an inlined function DIE which includes @addr. Stores the
555 * DIE to @die_mem and returns it if found. Returns NULL if failed.
556 * Even if several inlined functions are expanded recursively, this
557 * doesn't trace it down, and returns the topmost one.
558 */
559Dwarf_Die *die_find_top_inlinefunc(Dwarf_Die *sp_die, Dwarf_Addr addr,
560 Dwarf_Die *die_mem)
561{
562 return die_find_child(sp_die, __die_find_inline_cb, &addr, die_mem);
563}
564
565/**
566 * die_find_inlinefunc - Search an inlined function at given address
567 * @sp_die: a subprogram DIE which including @addr
568 * @addr: target address
569 * @die_mem: a buffer for result DIE
570 *
571 * Search an inlined function DIE which includes @addr. Stores the
572 * DIE to @die_mem and returns it if found. Returns NULL if failed.
573 * If several inlined functions are expanded recursively, this trace
574 * it down and returns deepest one.
575 */
576Dwarf_Die *die_find_inlinefunc(Dwarf_Die *sp_die, Dwarf_Addr addr,
577 Dwarf_Die *die_mem)
578{
579 Dwarf_Die tmp_die;
580
581 sp_die = die_find_child(sp_die, __die_find_inline_cb, &addr, &tmp_die);
582 if (!sp_die)
583 return NULL;
584
585 /* Inlined function could be recursive. Trace it until fail */
586 while (sp_die) {
587 memcpy(die_mem, sp_die, sizeof(Dwarf_Die));
588 sp_die = die_find_child(sp_die, __die_find_inline_cb, &addr,
589 &tmp_die);
590 }
591
592 return die_mem;
593}
594
595struct __instance_walk_param {
596 void *addr;
597 int (*callback)(Dwarf_Die *, void *);
598 void *data;
599 int retval;
600};
601
602static int __die_walk_instances_cb(Dwarf_Die *inst, void *data)
603{
604 struct __instance_walk_param *iwp = data;
605 Dwarf_Attribute attr_mem;
606 Dwarf_Die origin_mem;
607 Dwarf_Attribute *attr;
608 Dwarf_Die *origin;
609 int tmp;
610
611 attr = dwarf_attr(inst, DW_AT_abstract_origin, &attr_mem);
612 if (attr == NULL)
613 return DIE_FIND_CB_CONTINUE;
614
615 origin = dwarf_formref_die(attr, &origin_mem);
616 if (origin == NULL || origin->addr != iwp->addr)
617 return DIE_FIND_CB_CONTINUE;
618
619 /* Ignore redundant instances */
620 if (dwarf_tag(inst) == DW_TAG_inlined_subroutine) {
621 dwarf_decl_line(origin, &tmp);
622 if (die_get_call_lineno(inst) == tmp) {
623 tmp = die_get_decl_fileno(origin);
624 if (die_get_call_fileno(inst) == tmp)
625 return DIE_FIND_CB_CONTINUE;
626 }
627 }
628
629 iwp->retval = iwp->callback(inst, iwp->data);
630
631 return (iwp->retval) ? DIE_FIND_CB_END : DIE_FIND_CB_CONTINUE;
632}
633
634/**
635 * die_walk_instances - Walk on instances of given DIE
636 * @or_die: an abstract original DIE
637 * @callback: a callback function which is called with instance DIE
638 * @data: user data
639 *
640 * Walk on the instances of give @in_die. @in_die must be an inlined function
641 * declartion. This returns the return value of @callback if it returns
642 * non-zero value, or -ENOENT if there is no instance.
643 */
644int die_walk_instances(Dwarf_Die *or_die, int (*callback)(Dwarf_Die *, void *),
645 void *data)
646{
647 Dwarf_Die cu_die;
648 Dwarf_Die die_mem;
649 struct __instance_walk_param iwp = {
650 .addr = or_die->addr,
651 .callback = callback,
652 .data = data,
653 .retval = -ENOENT,
654 };
655
656 if (dwarf_diecu(or_die, &cu_die, NULL, NULL) == NULL)
657 return -ENOENT;
658
659 die_find_child(&cu_die, __die_walk_instances_cb, &iwp, &die_mem);
660
661 return iwp.retval;
662}
663
664/* Line walker internal parameters */
665struct __line_walk_param {
666 bool recursive;
667 line_walk_callback_t callback;
668 void *data;
669 int retval;
670};
671
672static int __die_walk_funclines_cb(Dwarf_Die *in_die, void *data)
673{
674 struct __line_walk_param *lw = data;
675 Dwarf_Addr addr = 0;
676 const char *fname;
677 int lineno;
678
679 if (dwarf_tag(in_die) == DW_TAG_inlined_subroutine) {
680 fname = die_get_call_file(in_die);
681 lineno = die_get_call_lineno(in_die);
682 if (fname && lineno > 0 && dwarf_entrypc(in_die, &addr) == 0) {
683 lw->retval = lw->callback(fname, lineno, addr, lw->data);
684 if (lw->retval != 0)
685 return DIE_FIND_CB_END;
686 }
687 }
688 if (!lw->recursive)
689 /* Don't need to search recursively */
690 return DIE_FIND_CB_SIBLING;
691
692 if (addr) {
693 fname = dwarf_decl_file(in_die);
694 if (fname && dwarf_decl_line(in_die, &lineno) == 0) {
695 lw->retval = lw->callback(fname, lineno, addr, lw->data);
696 if (lw->retval != 0)
697 return DIE_FIND_CB_END;
698 }
699 }
700
701 /* Continue to search nested inlined function call-sites */
702 return DIE_FIND_CB_CONTINUE;
703}
704
705/* Walk on lines of blocks included in given DIE */
706static int __die_walk_funclines(Dwarf_Die *sp_die, bool recursive,
707 line_walk_callback_t callback, void *data)
708{
709 struct __line_walk_param lw = {
710 .recursive = recursive,
711 .callback = callback,
712 .data = data,
713 .retval = 0,
714 };
715 Dwarf_Die die_mem;
716 Dwarf_Addr addr;
717 const char *fname;
718 int lineno;
719
720 /* Handle function declaration line */
721 fname = dwarf_decl_file(sp_die);
722 if (fname && dwarf_decl_line(sp_die, &lineno) == 0 &&
723 dwarf_entrypc(sp_die, &addr) == 0) {
724 lw.retval = callback(fname, lineno, addr, data);
725 if (lw.retval != 0)
726 goto done;
727 }
728 die_find_child(sp_die, __die_walk_funclines_cb, &lw, &die_mem);
729done:
730 return lw.retval;
731}
732
733static int __die_walk_culines_cb(Dwarf_Die *sp_die, void *data)
734{
735 struct __line_walk_param *lw = data;
736
737 lw->retval = __die_walk_funclines(sp_die, true, lw->callback, lw->data);
738 if (lw->retval != 0)
739 return DWARF_CB_ABORT;
740
741 return DWARF_CB_OK;
742}
743
744/**
745 * die_walk_lines - Walk on lines inside given DIE
746 * @rt_die: a root DIE (CU, subprogram or inlined_subroutine)
747 * @callback: callback routine
748 * @data: user data
749 *
750 * Walk on all lines inside given @rt_die and call @callback on each line.
751 * If the @rt_die is a function, walk only on the lines inside the function,
752 * otherwise @rt_die must be a CU DIE.
753 * Note that this walks not only dwarf line list, but also function entries
754 * and inline call-site.
755 */
756int die_walk_lines(Dwarf_Die *rt_die, line_walk_callback_t callback, void *data)
757{
758 Dwarf_Lines *lines;
759 Dwarf_Line *line;
760 Dwarf_Addr addr;
761 const char *fname, *decf = NULL;
762 int lineno, ret = 0;
763 int decl = 0, inl;
764 Dwarf_Die die_mem, *cu_die;
765 size_t nlines, i;
766
767 /* Get the CU die */
768 if (dwarf_tag(rt_die) != DW_TAG_compile_unit) {
769 cu_die = dwarf_diecu(rt_die, &die_mem, NULL, NULL);
770 dwarf_decl_line(rt_die, &decl);
771 decf = dwarf_decl_file(rt_die);
772 } else
773 cu_die = rt_die;
774 if (!cu_die) {
775 pr_debug2("Failed to get CU from given DIE.\n");
776 return -EINVAL;
777 }
778
779 /* Get lines list in the CU */
780 if (dwarf_getsrclines(cu_die, &lines, &nlines) != 0) {
781 pr_debug2("Failed to get source lines on this CU.\n");
782 return -ENOENT;
783 }
784 pr_debug2("Get %zd lines from this CU\n", nlines);
785
786 /* Walk on the lines on lines list */
787 for (i = 0; i < nlines; i++) {
788 line = dwarf_onesrcline(lines, i);
789 if (line == NULL ||
790 dwarf_lineno(line, &lineno) != 0 ||
791 dwarf_lineaddr(line, &addr) != 0) {
792 pr_debug2("Failed to get line info. "
793 "Possible error in debuginfo.\n");
794 continue;
795 }
796 /* Filter lines based on address */
797 if (rt_die != cu_die) {
798 /*
799 * Address filtering
800 * The line is included in given function, and
801 * no inline block includes it.
802 */
803 if (!dwarf_haspc(rt_die, addr))
804 continue;
805 if (die_find_inlinefunc(rt_die, addr, &die_mem)) {
806 dwarf_decl_line(&die_mem, &inl);
807 if (inl != decl ||
808 decf != dwarf_decl_file(&die_mem))
809 continue;
810 }
811 }
812 /* Get source line */
813 fname = dwarf_linesrc(line, NULL, NULL);
814
815 ret = callback(fname, lineno, addr, data);
816 if (ret != 0)
817 return ret;
818 }
819
820 /*
821 * Dwarf lines doesn't include function declarations and inlined
822 * subroutines. We have to check functions list or given function.
823 */
824 if (rt_die != cu_die)
825 /*
826 * Don't need walk functions recursively, because nested
827 * inlined functions don't have lines of the specified DIE.
828 */
829 ret = __die_walk_funclines(rt_die, false, callback, data);
830 else {
831 struct __line_walk_param param = {
832 .callback = callback,
833 .data = data,
834 .retval = 0,
835 };
836 dwarf_getfuncs(cu_die, __die_walk_culines_cb, ¶m, 0);
837 ret = param.retval;
838 }
839
840 return ret;
841}
842
843struct __find_variable_param {
844 const char *name;
845 Dwarf_Addr addr;
846};
847
848static int __die_find_variable_cb(Dwarf_Die *die_mem, void *data)
849{
850 struct __find_variable_param *fvp = data;
851 Dwarf_Attribute attr;
852 int tag;
853
854 tag = dwarf_tag(die_mem);
855 if ((tag == DW_TAG_formal_parameter ||
856 tag == DW_TAG_variable) &&
857 die_compare_name(die_mem, fvp->name) &&
858 /* Does the DIE have location information or external instance? */
859 (dwarf_attr(die_mem, DW_AT_external, &attr) ||
860 dwarf_attr(die_mem, DW_AT_location, &attr)))
861 return DIE_FIND_CB_END;
862 if (dwarf_haspc(die_mem, fvp->addr))
863 return DIE_FIND_CB_CONTINUE;
864 else
865 return DIE_FIND_CB_SIBLING;
866}
867
868/**
869 * die_find_variable_at - Find a given name variable at given address
870 * @sp_die: a function DIE
871 * @name: variable name
872 * @addr: address
873 * @die_mem: a buffer for result DIE
874 *
875 * Find a variable DIE called @name at @addr in @sp_die.
876 */
877Dwarf_Die *die_find_variable_at(Dwarf_Die *sp_die, const char *name,
878 Dwarf_Addr addr, Dwarf_Die *die_mem)
879{
880 struct __find_variable_param fvp = { .name = name, .addr = addr};
881
882 return die_find_child(sp_die, __die_find_variable_cb, (void *)&fvp,
883 die_mem);
884}
885
886static int __die_find_member_cb(Dwarf_Die *die_mem, void *data)
887{
888 const char *name = data;
889
890 if (dwarf_tag(die_mem) == DW_TAG_member) {
891 if (die_compare_name(die_mem, name))
892 return DIE_FIND_CB_END;
893 else if (!dwarf_diename(die_mem)) { /* Unnamed structure */
894 Dwarf_Die type_die, tmp_die;
895 if (die_get_type(die_mem, &type_die) &&
896 die_find_member(&type_die, name, &tmp_die))
897 return DIE_FIND_CB_END;
898 }
899 }
900 return DIE_FIND_CB_SIBLING;
901}
902
903/**
904 * die_find_member - Find a given name member in a data structure
905 * @st_die: a data structure type DIE
906 * @name: member name
907 * @die_mem: a buffer for result DIE
908 *
909 * Find a member DIE called @name in @st_die.
910 */
911Dwarf_Die *die_find_member(Dwarf_Die *st_die, const char *name,
912 Dwarf_Die *die_mem)
913{
914 return die_find_child(st_die, __die_find_member_cb, (void *)name,
915 die_mem);
916}
917
918/**
919 * die_get_typename - Get the name of given variable DIE
920 * @vr_die: a variable DIE
921 * @buf: a strbuf for result type name
922 *
923 * Get the name of @vr_die and stores it to @buf. Return 0 if succeeded.
924 * and Return -ENOENT if failed to find type name.
925 * Note that the result will stores typedef name if possible, and stores
926 * "*(function_type)" if the type is a function pointer.
927 */
928int die_get_typename(Dwarf_Die *vr_die, struct strbuf *buf)
929{
930 Dwarf_Die type;
931 int tag, ret;
932 const char *tmp = "";
933
934 if (__die_get_real_type(vr_die, &type) == NULL)
935 return -ENOENT;
936
937 tag = dwarf_tag(&type);
938 if (tag == DW_TAG_array_type || tag == DW_TAG_pointer_type)
939 tmp = "*";
940 else if (tag == DW_TAG_subroutine_type) {
941 /* Function pointer */
942 return strbuf_add(buf, "(function_type)", 15);
943 } else {
944 if (!dwarf_diename(&type))
945 return -ENOENT;
946 if (tag == DW_TAG_union_type)
947 tmp = "union ";
948 else if (tag == DW_TAG_structure_type)
949 tmp = "struct ";
950 else if (tag == DW_TAG_enumeration_type)
951 tmp = "enum ";
952 /* Write a base name */
953 return strbuf_addf(buf, "%s%s", tmp, dwarf_diename(&type));
954 }
955 ret = die_get_typename(&type, buf);
956 return ret ? ret : strbuf_addstr(buf, tmp);
957}
958
959/**
960 * die_get_varname - Get the name and type of given variable DIE
961 * @vr_die: a variable DIE
962 * @buf: a strbuf for type and variable name
963 *
964 * Get the name and type of @vr_die and stores it in @buf as "type\tname".
965 */
966int die_get_varname(Dwarf_Die *vr_die, struct strbuf *buf)
967{
968 int ret;
969
970 ret = die_get_typename(vr_die, buf);
971 if (ret < 0) {
972 pr_debug("Failed to get type, make it unknown.\n");
973 ret = strbuf_add(buf, " (unknown_type)", 14);
974 }
975
976 return ret < 0 ? ret : strbuf_addf(buf, "\t%s", dwarf_diename(vr_die));
977}
978
979#ifdef HAVE_DWARF_GETLOCATIONS
980/**
981 * die_get_var_innermost_scope - Get innermost scope range of given variable DIE
982 * @sp_die: a subprogram DIE
983 * @vr_die: a variable DIE
984 * @buf: a strbuf for variable byte offset range
985 *
986 * Get the innermost scope range of @vr_die and stores it in @buf as
987 * "@<function_name+[NN-NN,NN-NN]>".
988 */
989static int die_get_var_innermost_scope(Dwarf_Die *sp_die, Dwarf_Die *vr_die,
990 struct strbuf *buf)
991{
992 Dwarf_Die *scopes;
993 int count;
994 size_t offset = 0;
995 Dwarf_Addr base;
996 Dwarf_Addr start, end;
997 Dwarf_Addr entry;
998 int ret;
999 bool first = true;
1000 const char *name;
1001
1002 ret = dwarf_entrypc(sp_die, &entry);
1003 if (ret)
1004 return ret;
1005
1006 name = dwarf_diename(sp_die);
1007 if (!name)
1008 return -ENOENT;
1009
1010 count = dwarf_getscopes_die(vr_die, &scopes);
1011
1012 /* (*SCOPES)[1] is the DIE for the scope containing that scope */
1013 if (count <= 1) {
1014 ret = -EINVAL;
1015 goto out;
1016 }
1017
1018 while ((offset = dwarf_ranges(&scopes[1], offset, &base,
1019 &start, &end)) > 0) {
1020 start -= entry;
1021 end -= entry;
1022
1023 if (first) {
1024 ret = strbuf_addf(buf, "@<%s+[%" PRIu64 "-%" PRIu64,
1025 name, start, end);
1026 first = false;
1027 } else {
1028 ret = strbuf_addf(buf, ",%" PRIu64 "-%" PRIu64,
1029 start, end);
1030 }
1031 if (ret < 0)
1032 goto out;
1033 }
1034
1035 if (!first)
1036 ret = strbuf_add(buf, "]>", 2);
1037
1038out:
1039 free(scopes);
1040 return ret;
1041}
1042
1043/**
1044 * die_get_var_range - Get byte offset range of given variable DIE
1045 * @sp_die: a subprogram DIE
1046 * @vr_die: a variable DIE
1047 * @buf: a strbuf for type and variable name and byte offset range
1048 *
1049 * Get the byte offset range of @vr_die and stores it in @buf as
1050 * "@<function_name+[NN-NN,NN-NN]>".
1051 */
1052int die_get_var_range(Dwarf_Die *sp_die, Dwarf_Die *vr_die, struct strbuf *buf)
1053{
1054 int ret = 0;
1055 Dwarf_Addr base;
1056 Dwarf_Addr start, end;
1057 Dwarf_Addr entry;
1058 Dwarf_Op *op;
1059 size_t nops;
1060 size_t offset = 0;
1061 Dwarf_Attribute attr;
1062 bool first = true;
1063 const char *name;
1064
1065 ret = dwarf_entrypc(sp_die, &entry);
1066 if (ret)
1067 return ret;
1068
1069 name = dwarf_diename(sp_die);
1070 if (!name)
1071 return -ENOENT;
1072
1073 if (dwarf_attr(vr_die, DW_AT_location, &attr) == NULL)
1074 return -EINVAL;
1075
1076 while ((offset = dwarf_getlocations(&attr, offset, &base,
1077 &start, &end, &op, &nops)) > 0) {
1078 if (start == 0) {
1079 /* Single Location Descriptions */
1080 ret = die_get_var_innermost_scope(sp_die, vr_die, buf);
1081 goto out;
1082 }
1083
1084 /* Location Lists */
1085 start -= entry;
1086 end -= entry;
1087 if (first) {
1088 ret = strbuf_addf(buf, "@<%s+[%" PRIu64 "-%" PRIu64,
1089 name, start, end);
1090 first = false;
1091 } else {
1092 ret = strbuf_addf(buf, ",%" PRIu64 "-%" PRIu64,
1093 start, end);
1094 }
1095 if (ret < 0)
1096 goto out;
1097 }
1098
1099 if (!first)
1100 ret = strbuf_add(buf, "]>", 2);
1101out:
1102 return ret;
1103}
1104#else
1105int die_get_var_range(Dwarf_Die *sp_die __maybe_unused,
1106 Dwarf_Die *vr_die __maybe_unused,
1107 struct strbuf *buf __maybe_unused)
1108{
1109 return -ENOTSUP;
1110}
1111#endif
1112
1113/*
1114 * die_has_loclist - Check if DW_AT_location of @vr_die is a location list
1115 * @vr_die: a variable DIE
1116 */
1117static bool die_has_loclist(Dwarf_Die *vr_die)
1118{
1119 Dwarf_Attribute loc;
1120 int tag = dwarf_tag(vr_die);
1121
1122 if (tag != DW_TAG_formal_parameter &&
1123 tag != DW_TAG_variable)
1124 return false;
1125
1126 return (dwarf_attr_integrate(vr_die, DW_AT_location, &loc) &&
1127 dwarf_whatform(&loc) == DW_FORM_sec_offset);
1128}
1129
1130/*
1131 * die_is_optimized_target - Check if target program is compiled with
1132 * optimization
1133 * @cu_die: a CU DIE
1134 *
1135 * For any object in given CU whose DW_AT_location is a location list,
1136 * target program is compiled with optimization. This is applicable to
1137 * clang as well.
1138 */
1139bool die_is_optimized_target(Dwarf_Die *cu_die)
1140{
1141 Dwarf_Die tmp_die;
1142
1143 if (die_has_loclist(cu_die))
1144 return true;
1145
1146 if (!dwarf_child(cu_die, &tmp_die) &&
1147 die_is_optimized_target(&tmp_die))
1148 return true;
1149
1150 if (!dwarf_siblingof(cu_die, &tmp_die) &&
1151 die_is_optimized_target(&tmp_die))
1152 return true;
1153
1154 return false;
1155}
1156
1157/*
1158 * die_search_idx - Search index of given line address
1159 * @lines: Line records of single CU
1160 * @nr_lines: Number of @lines
1161 * @addr: address we are looking for
1162 * @idx: index to be set by this function (return value)
1163 *
1164 * Search for @addr by looping over every lines of CU. If address
1165 * matches, set index of that line in @idx. Note that single source
1166 * line can have multiple line records. i.e. single source line can
1167 * have multiple index.
1168 */
1169static bool die_search_idx(Dwarf_Lines *lines, unsigned long nr_lines,
1170 Dwarf_Addr addr, unsigned long *idx)
1171{
1172 unsigned long i;
1173 Dwarf_Addr tmp;
1174
1175 for (i = 0; i < nr_lines; i++) {
1176 if (dwarf_lineaddr(dwarf_onesrcline(lines, i), &tmp))
1177 return false;
1178
1179 if (tmp == addr) {
1180 *idx = i;
1181 return true;
1182 }
1183 }
1184 return false;
1185}
1186
1187/*
1188 * die_get_postprologue_addr - Search next address after function prologue
1189 * @entrypc_idx: entrypc index
1190 * @lines: Line records of single CU
1191 * @nr_lines: Number of @lines
1192 * @hignpc: high PC address of function
1193 * @postprologue_addr: Next address after function prologue (return value)
1194 *
1195 * Look for prologue-end marker. If there is no explicit marker, return
1196 * address of next line record or next source line.
1197 */
1198static bool die_get_postprologue_addr(unsigned long entrypc_idx,
1199 Dwarf_Lines *lines,
1200 unsigned long nr_lines,
1201 Dwarf_Addr highpc,
1202 Dwarf_Addr *postprologue_addr)
1203{
1204 unsigned long i;
1205 int entrypc_lno, lno;
1206 Dwarf_Line *line;
1207 Dwarf_Addr addr;
1208 bool p_end;
1209
1210 /* entrypc_lno is actual source line number */
1211 line = dwarf_onesrcline(lines, entrypc_idx);
1212 if (dwarf_lineno(line, &entrypc_lno))
1213 return false;
1214
1215 for (i = entrypc_idx; i < nr_lines; i++) {
1216 line = dwarf_onesrcline(lines, i);
1217
1218 if (dwarf_lineaddr(line, &addr) ||
1219 dwarf_lineno(line, &lno) ||
1220 dwarf_lineprologueend(line, &p_end))
1221 return false;
1222
1223 /* highpc is exclusive. [entrypc,highpc) */
1224 if (addr >= highpc)
1225 break;
1226
1227 /* clang supports prologue-end marker */
1228 if (p_end)
1229 break;
1230
1231 /* Actual next line in source */
1232 if (lno != entrypc_lno)
1233 break;
1234
1235 /*
1236 * Single source line can have multiple line records.
1237 * For Example,
1238 * void foo() { printf("hello\n"); }
1239 * contains two line records. One points to declaration and
1240 * other points to printf() line. Variable 'lno' won't get
1241 * incremented in this case but 'i' will.
1242 */
1243 if (i != entrypc_idx)
1244 break;
1245 }
1246
1247 dwarf_lineaddr(line, postprologue_addr);
1248 if (*postprologue_addr >= highpc)
1249 dwarf_lineaddr(dwarf_onesrcline(lines, i - 1),
1250 postprologue_addr);
1251
1252 return true;
1253}
1254
1255/*
1256 * die_skip_prologue - Use next address after prologue as probe location
1257 * @sp_die: a subprogram DIE
1258 * @cu_die: a CU DIE
1259 * @entrypc: entrypc of the function
1260 *
1261 * Function prologue prepares stack and registers before executing function
1262 * logic. When target program is compiled without optimization, function
1263 * parameter information is only valid after prologue. When we probe entrypc
1264 * of the function, and try to record function parameter, it contains
1265 * garbage value.
1266 */
1267void die_skip_prologue(Dwarf_Die *sp_die, Dwarf_Die *cu_die,
1268 Dwarf_Addr *entrypc)
1269{
1270 size_t nr_lines = 0;
1271 unsigned long entrypc_idx = 0;
1272 Dwarf_Lines *lines = NULL;
1273 Dwarf_Addr postprologue_addr;
1274 Dwarf_Addr highpc;
1275
1276 if (dwarf_highpc(sp_die, &highpc))
1277 return;
1278
1279 if (dwarf_getsrclines(cu_die, &lines, &nr_lines))
1280 return;
1281
1282 if (!die_search_idx(lines, nr_lines, *entrypc, &entrypc_idx))
1283 return;
1284
1285 if (!die_get_postprologue_addr(entrypc_idx, lines, nr_lines,
1286 highpc, &postprologue_addr))
1287 return;
1288
1289 *entrypc = postprologue_addr;
1290}