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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * dwarf-aux.c : libdw auxiliary interfaces
4 */
5
6#include <errno.h>
7#include <inttypes.h>
8#include <stdbool.h>
9#include <stdlib.h>
10#include "debug.h"
11#include "dwarf-aux.h"
12#include "strbuf.h"
13#include "string2.h"
14
15/**
16 * cu_find_realpath - Find the realpath of the target file
17 * @cu_die: A DIE(dwarf information entry) of CU(compilation Unit)
18 * @fname: The tail filename of the target file
19 *
20 * Find the real(long) path of @fname in @cu_die.
21 */
22const char *cu_find_realpath(Dwarf_Die *cu_die, const char *fname)
23{
24 Dwarf_Files *files;
25 size_t nfiles, i;
26 const char *src = NULL;
27 int ret;
28
29 if (!fname)
30 return NULL;
31
32 ret = dwarf_getsrcfiles(cu_die, &files, &nfiles);
33 if (ret != 0)
34 return NULL;
35
36 for (i = 0; i < nfiles; i++) {
37 src = dwarf_filesrc(files, i, NULL, NULL);
38 if (strtailcmp(src, fname) == 0)
39 break;
40 }
41 if (i == nfiles)
42 return NULL;
43 return src;
44}
45
46/**
47 * cu_get_comp_dir - Get the path of compilation directory
48 * @cu_die: a CU DIE
49 *
50 * Get the path of compilation directory of given @cu_die.
51 * Since this depends on DW_AT_comp_dir, older gcc will not
52 * embedded it. In that case, this returns NULL.
53 */
54const char *cu_get_comp_dir(Dwarf_Die *cu_die)
55{
56 Dwarf_Attribute attr;
57 if (dwarf_attr(cu_die, DW_AT_comp_dir, &attr) == NULL)
58 return NULL;
59 return dwarf_formstring(&attr);
60}
61
62/**
63 * cu_find_lineinfo - Get a line number and file name for given address
64 * @cu_die: a CU DIE
65 * @addr: An address
66 * @fname: a pointer which returns the file name string
67 * @lineno: a pointer which returns the line number
68 *
69 * Find a line number and file name for @addr in @cu_die.
70 */
71int cu_find_lineinfo(Dwarf_Die *cu_die, unsigned long addr,
72 const char **fname, int *lineno)
73{
74 Dwarf_Line *line;
75 Dwarf_Addr laddr;
76
77 line = dwarf_getsrc_die(cu_die, (Dwarf_Addr)addr);
78 if (line && dwarf_lineaddr(line, &laddr) == 0 &&
79 addr == (unsigned long)laddr && dwarf_lineno(line, lineno) == 0) {
80 *fname = dwarf_linesrc(line, NULL, NULL);
81 if (!*fname)
82 /* line number is useless without filename */
83 *lineno = 0;
84 }
85
86 return *lineno ?: -ENOENT;
87}
88
89static int __die_find_inline_cb(Dwarf_Die *die_mem, void *data);
90
91/**
92 * cu_walk_functions_at - Walk on function DIEs at given address
93 * @cu_die: A CU DIE
94 * @addr: An address
95 * @callback: A callback which called with found DIEs
96 * @data: A user data
97 *
98 * Walk on function DIEs at given @addr in @cu_die. Passed DIEs
99 * should be subprogram or inlined-subroutines.
100 */
101int cu_walk_functions_at(Dwarf_Die *cu_die, Dwarf_Addr addr,
102 int (*callback)(Dwarf_Die *, void *), void *data)
103{
104 Dwarf_Die die_mem;
105 Dwarf_Die *sc_die;
106 int ret = -ENOENT;
107
108 /* Inlined function could be recursive. Trace it until fail */
109 for (sc_die = die_find_realfunc(cu_die, addr, &die_mem);
110 sc_die != NULL;
111 sc_die = die_find_child(sc_die, __die_find_inline_cb, &addr,
112 &die_mem)) {
113 ret = callback(sc_die, data);
114 if (ret)
115 break;
116 }
117
118 return ret;
119
120}
121
122/**
123 * die_get_linkage_name - Get the linkage name of the object
124 * @dw_die: A DIE of the object
125 *
126 * Get the linkage name attiribute of given @dw_die.
127 * For C++ binary, the linkage name will be the mangled symbol.
128 */
129const char *die_get_linkage_name(Dwarf_Die *dw_die)
130{
131 Dwarf_Attribute attr;
132
133 if (dwarf_attr_integrate(dw_die, DW_AT_linkage_name, &attr) == NULL)
134 return NULL;
135 return dwarf_formstring(&attr);
136}
137
138/**
139 * die_compare_name - Compare diename and tname
140 * @dw_die: a DIE
141 * @tname: a string of target name
142 *
143 * Compare the name of @dw_die and @tname. Return false if @dw_die has no name.
144 */
145bool die_compare_name(Dwarf_Die *dw_die, const char *tname)
146{
147 const char *name;
148
149 name = dwarf_diename(dw_die);
150 return name ? (strcmp(tname, name) == 0) : false;
151}
152
153/**
154 * die_match_name - Match diename/linkage name and glob
155 * @dw_die: a DIE
156 * @glob: a string of target glob pattern
157 *
158 * Glob matching the name of @dw_die and @glob. Return false if matching fail.
159 * This also match linkage name.
160 */
161bool die_match_name(Dwarf_Die *dw_die, const char *glob)
162{
163 const char *name;
164
165 name = dwarf_diename(dw_die);
166 if (name && strglobmatch(name, glob))
167 return true;
168 /* fall back to check linkage name */
169 name = die_get_linkage_name(dw_die);
170 if (name && strglobmatch(name, glob))
171 return true;
172
173 return false;
174}
175
176/**
177 * die_get_call_lineno - Get callsite line number of inline-function instance
178 * @in_die: a DIE of an inlined function instance
179 *
180 * Get call-site line number of @in_die. This means from where the inline
181 * function is called.
182 */
183int die_get_call_lineno(Dwarf_Die *in_die)
184{
185 Dwarf_Attribute attr;
186 Dwarf_Word ret;
187
188 if (!dwarf_attr(in_die, DW_AT_call_line, &attr))
189 return -ENOENT;
190
191 dwarf_formudata(&attr, &ret);
192 return (int)ret;
193}
194
195/**
196 * die_get_type - Get type DIE
197 * @vr_die: a DIE of a variable
198 * @die_mem: where to store a type DIE
199 *
200 * Get a DIE of the type of given variable (@vr_die), and store
201 * it to die_mem. Return NULL if fails to get a type DIE.
202 */
203Dwarf_Die *die_get_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem)
204{
205 Dwarf_Attribute attr;
206
207 if (dwarf_attr_integrate(vr_die, DW_AT_type, &attr) &&
208 dwarf_formref_die(&attr, die_mem))
209 return die_mem;
210 else
211 return NULL;
212}
213
214/* Get a type die, but skip qualifiers */
215static Dwarf_Die *__die_get_real_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem)
216{
217 int tag;
218
219 do {
220 vr_die = die_get_type(vr_die, die_mem);
221 if (!vr_die)
222 break;
223 tag = dwarf_tag(vr_die);
224 } while (tag == DW_TAG_const_type ||
225 tag == DW_TAG_restrict_type ||
226 tag == DW_TAG_volatile_type ||
227 tag == DW_TAG_shared_type);
228
229 return vr_die;
230}
231
232/**
233 * die_get_real_type - Get a type die, but skip qualifiers and typedef
234 * @vr_die: a DIE of a variable
235 * @die_mem: where to store a type DIE
236 *
237 * Get a DIE of the type of given variable (@vr_die), and store
238 * it to die_mem. Return NULL if fails to get a type DIE.
239 * If the type is qualifiers (e.g. const) or typedef, this skips it
240 * and tries to find real type (structure or basic types, e.g. int).
241 */
242Dwarf_Die *die_get_real_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem)
243{
244 do {
245 vr_die = __die_get_real_type(vr_die, die_mem);
246 } while (vr_die && dwarf_tag(vr_die) == DW_TAG_typedef);
247
248 return vr_die;
249}
250
251/* Get attribute and translate it as a udata */
252static int die_get_attr_udata(Dwarf_Die *tp_die, unsigned int attr_name,
253 Dwarf_Word *result)
254{
255 Dwarf_Attribute attr;
256
257 if (dwarf_attr(tp_die, attr_name, &attr) == NULL ||
258 dwarf_formudata(&attr, result) != 0)
259 return -ENOENT;
260
261 return 0;
262}
263
264/* Get attribute and translate it as a sdata */
265static int die_get_attr_sdata(Dwarf_Die *tp_die, unsigned int attr_name,
266 Dwarf_Sword *result)
267{
268 Dwarf_Attribute attr;
269
270 if (dwarf_attr(tp_die, attr_name, &attr) == NULL ||
271 dwarf_formsdata(&attr, result) != 0)
272 return -ENOENT;
273
274 return 0;
275}
276
277/**
278 * die_is_signed_type - Check whether a type DIE is signed or not
279 * @tp_die: a DIE of a type
280 *
281 * Get the encoding of @tp_die and return true if the encoding
282 * is signed.
283 */
284bool die_is_signed_type(Dwarf_Die *tp_die)
285{
286 Dwarf_Word ret;
287
288 if (die_get_attr_udata(tp_die, DW_AT_encoding, &ret))
289 return false;
290
291 return (ret == DW_ATE_signed_char || ret == DW_ATE_signed ||
292 ret == DW_ATE_signed_fixed);
293}
294
295/**
296 * die_is_func_def - Ensure that this DIE is a subprogram and definition
297 * @dw_die: a DIE
298 *
299 * Ensure that this DIE is a subprogram and NOT a declaration. This
300 * returns true if @dw_die is a function definition.
301 **/
302bool die_is_func_def(Dwarf_Die *dw_die)
303{
304 Dwarf_Attribute attr;
305
306 return (dwarf_tag(dw_die) == DW_TAG_subprogram &&
307 dwarf_attr(dw_die, DW_AT_declaration, &attr) == NULL);
308}
309
310/**
311 * die_is_func_instance - Ensure that this DIE is an instance of a subprogram
312 * @dw_die: a DIE
313 *
314 * Ensure that this DIE is an instance (which has an entry address).
315 * This returns true if @dw_die is a function instance. If not, you need to
316 * call die_walk_instances() to find actual instances.
317 **/
318bool die_is_func_instance(Dwarf_Die *dw_die)
319{
320 Dwarf_Addr tmp;
321
322 /* Actually gcc optimizes non-inline as like as inlined */
323 return !dwarf_func_inline(dw_die) && dwarf_entrypc(dw_die, &tmp) == 0;
324}
325/**
326 * die_get_data_member_location - Get the data-member offset
327 * @mb_die: a DIE of a member of a data structure
328 * @offs: The offset of the member in the data structure
329 *
330 * Get the offset of @mb_die in the data structure including @mb_die, and
331 * stores result offset to @offs. If any error occurs this returns errno.
332 */
333int die_get_data_member_location(Dwarf_Die *mb_die, Dwarf_Word *offs)
334{
335 Dwarf_Attribute attr;
336 Dwarf_Op *expr;
337 size_t nexpr;
338 int ret;
339
340 if (dwarf_attr(mb_die, DW_AT_data_member_location, &attr) == NULL)
341 return -ENOENT;
342
343 if (dwarf_formudata(&attr, offs) != 0) {
344 /* DW_AT_data_member_location should be DW_OP_plus_uconst */
345 ret = dwarf_getlocation(&attr, &expr, &nexpr);
346 if (ret < 0 || nexpr == 0)
347 return -ENOENT;
348
349 if (expr[0].atom != DW_OP_plus_uconst || nexpr != 1) {
350 pr_debug("Unable to get offset:Unexpected OP %x (%zd)\n",
351 expr[0].atom, nexpr);
352 return -ENOTSUP;
353 }
354 *offs = (Dwarf_Word)expr[0].number;
355 }
356 return 0;
357}
358
359/* Get the call file index number in CU DIE */
360static int die_get_call_fileno(Dwarf_Die *in_die)
361{
362 Dwarf_Sword idx;
363
364 if (die_get_attr_sdata(in_die, DW_AT_call_file, &idx) == 0)
365 return (int)idx;
366 else
367 return -ENOENT;
368}
369
370/* Get the declared file index number in CU DIE */
371static int die_get_decl_fileno(Dwarf_Die *pdie)
372{
373 Dwarf_Sword idx;
374
375 if (die_get_attr_sdata(pdie, DW_AT_decl_file, &idx) == 0)
376 return (int)idx;
377 else
378 return -ENOENT;
379}
380
381/**
382 * die_get_call_file - Get callsite file name of inlined function instance
383 * @in_die: a DIE of an inlined function instance
384 *
385 * Get call-site file name of @in_die. This means from which file the inline
386 * function is called.
387 */
388const char *die_get_call_file(Dwarf_Die *in_die)
389{
390 Dwarf_Die cu_die;
391 Dwarf_Files *files;
392 int idx;
393
394 idx = die_get_call_fileno(in_die);
395 if (idx < 0 || !dwarf_diecu(in_die, &cu_die, NULL, NULL) ||
396 dwarf_getsrcfiles(&cu_die, &files, NULL) != 0)
397 return NULL;
398
399 return dwarf_filesrc(files, idx, NULL, NULL);
400}
401
402
403/**
404 * die_find_child - Generic DIE search function in DIE tree
405 * @rt_die: a root DIE
406 * @callback: a callback function
407 * @data: a user data passed to the callback function
408 * @die_mem: a buffer for result DIE
409 *
410 * Trace DIE tree from @rt_die and call @callback for each child DIE.
411 * If @callback returns DIE_FIND_CB_END, this stores the DIE into
412 * @die_mem and returns it. If @callback returns DIE_FIND_CB_CONTINUE,
413 * this continues to trace the tree. Optionally, @callback can return
414 * DIE_FIND_CB_CHILD and DIE_FIND_CB_SIBLING, those means trace only
415 * the children and trace only the siblings respectively.
416 * Returns NULL if @callback can't find any appropriate DIE.
417 */
418Dwarf_Die *die_find_child(Dwarf_Die *rt_die,
419 int (*callback)(Dwarf_Die *, void *),
420 void *data, Dwarf_Die *die_mem)
421{
422 Dwarf_Die child_die;
423 int ret;
424
425 ret = dwarf_child(rt_die, die_mem);
426 if (ret != 0)
427 return NULL;
428
429 do {
430 ret = callback(die_mem, data);
431 if (ret == DIE_FIND_CB_END)
432 return die_mem;
433
434 if ((ret & DIE_FIND_CB_CHILD) &&
435 die_find_child(die_mem, callback, data, &child_die)) {
436 memcpy(die_mem, &child_die, sizeof(Dwarf_Die));
437 return die_mem;
438 }
439 } while ((ret & DIE_FIND_CB_SIBLING) &&
440 dwarf_siblingof(die_mem, die_mem) == 0);
441
442 return NULL;
443}
444
445struct __addr_die_search_param {
446 Dwarf_Addr addr;
447 Dwarf_Die *die_mem;
448};
449
450static int __die_search_func_tail_cb(Dwarf_Die *fn_die, void *data)
451{
452 struct __addr_die_search_param *ad = data;
453 Dwarf_Addr addr = 0;
454
455 if (dwarf_tag(fn_die) == DW_TAG_subprogram &&
456 !dwarf_highpc(fn_die, &addr) &&
457 addr == ad->addr) {
458 memcpy(ad->die_mem, fn_die, sizeof(Dwarf_Die));
459 return DWARF_CB_ABORT;
460 }
461 return DWARF_CB_OK;
462}
463
464/**
465 * die_find_tailfunc - Search for a non-inlined function with tail call at
466 * given address
467 * @cu_die: a CU DIE which including @addr
468 * @addr: target address
469 * @die_mem: a buffer for result DIE
470 *
471 * Search for a non-inlined function DIE with tail call at @addr. Stores the
472 * DIE to @die_mem and returns it if found. Returns NULL if failed.
473 */
474Dwarf_Die *die_find_tailfunc(Dwarf_Die *cu_die, Dwarf_Addr addr,
475 Dwarf_Die *die_mem)
476{
477 struct __addr_die_search_param ad;
478 ad.addr = addr;
479 ad.die_mem = die_mem;
480 /* dwarf_getscopes can't find subprogram. */
481 if (!dwarf_getfuncs(cu_die, __die_search_func_tail_cb, &ad, 0))
482 return NULL;
483 else
484 return die_mem;
485}
486
487/* die_find callback for non-inlined function search */
488static int __die_search_func_cb(Dwarf_Die *fn_die, void *data)
489{
490 struct __addr_die_search_param *ad = data;
491
492 /*
493 * Since a declaration entry doesn't has given pc, this always returns
494 * function definition entry.
495 */
496 if (dwarf_tag(fn_die) == DW_TAG_subprogram &&
497 dwarf_haspc(fn_die, ad->addr)) {
498 memcpy(ad->die_mem, fn_die, sizeof(Dwarf_Die));
499 return DWARF_CB_ABORT;
500 }
501 return DWARF_CB_OK;
502}
503
504/**
505 * die_find_realfunc - Search a non-inlined function at given address
506 * @cu_die: a CU DIE which including @addr
507 * @addr: target address
508 * @die_mem: a buffer for result DIE
509 *
510 * Search a non-inlined function DIE which includes @addr. Stores the
511 * DIE to @die_mem and returns it if found. Returns NULL if failed.
512 */
513Dwarf_Die *die_find_realfunc(Dwarf_Die *cu_die, Dwarf_Addr addr,
514 Dwarf_Die *die_mem)
515{
516 struct __addr_die_search_param ad;
517 ad.addr = addr;
518 ad.die_mem = die_mem;
519 /* dwarf_getscopes can't find subprogram. */
520 if (!dwarf_getfuncs(cu_die, __die_search_func_cb, &ad, 0))
521 return NULL;
522 else
523 return die_mem;
524}
525
526/* die_find callback for inline function search */
527static int __die_find_inline_cb(Dwarf_Die *die_mem, void *data)
528{
529 Dwarf_Addr *addr = data;
530
531 if (dwarf_tag(die_mem) == DW_TAG_inlined_subroutine &&
532 dwarf_haspc(die_mem, *addr))
533 return DIE_FIND_CB_END;
534
535 return DIE_FIND_CB_CONTINUE;
536}
537
538/**
539 * die_find_top_inlinefunc - Search the top inlined function at given address
540 * @sp_die: a subprogram DIE which including @addr
541 * @addr: target address
542 * @die_mem: a buffer for result DIE
543 *
544 * Search an inlined function DIE which includes @addr. Stores the
545 * DIE to @die_mem and returns it if found. Returns NULL if failed.
546 * Even if several inlined functions are expanded recursively, this
547 * doesn't trace it down, and returns the topmost one.
548 */
549Dwarf_Die *die_find_top_inlinefunc(Dwarf_Die *sp_die, Dwarf_Addr addr,
550 Dwarf_Die *die_mem)
551{
552 return die_find_child(sp_die, __die_find_inline_cb, &addr, die_mem);
553}
554
555/**
556 * die_find_inlinefunc - Search an inlined function at given address
557 * @sp_die: a subprogram DIE which including @addr
558 * @addr: target address
559 * @die_mem: a buffer for result DIE
560 *
561 * Search an inlined function DIE which includes @addr. Stores the
562 * DIE to @die_mem and returns it if found. Returns NULL if failed.
563 * If several inlined functions are expanded recursively, this trace
564 * it down and returns deepest one.
565 */
566Dwarf_Die *die_find_inlinefunc(Dwarf_Die *sp_die, Dwarf_Addr addr,
567 Dwarf_Die *die_mem)
568{
569 Dwarf_Die tmp_die;
570
571 sp_die = die_find_child(sp_die, __die_find_inline_cb, &addr, &tmp_die);
572 if (!sp_die)
573 return NULL;
574
575 /* Inlined function could be recursive. Trace it until fail */
576 while (sp_die) {
577 memcpy(die_mem, sp_die, sizeof(Dwarf_Die));
578 sp_die = die_find_child(sp_die, __die_find_inline_cb, &addr,
579 &tmp_die);
580 }
581
582 return die_mem;
583}
584
585struct __instance_walk_param {
586 void *addr;
587 int (*callback)(Dwarf_Die *, void *);
588 void *data;
589 int retval;
590};
591
592static int __die_walk_instances_cb(Dwarf_Die *inst, void *data)
593{
594 struct __instance_walk_param *iwp = data;
595 Dwarf_Attribute attr_mem;
596 Dwarf_Die origin_mem;
597 Dwarf_Attribute *attr;
598 Dwarf_Die *origin;
599 int tmp;
600
601 attr = dwarf_attr(inst, DW_AT_abstract_origin, &attr_mem);
602 if (attr == NULL)
603 return DIE_FIND_CB_CONTINUE;
604
605 origin = dwarf_formref_die(attr, &origin_mem);
606 if (origin == NULL || origin->addr != iwp->addr)
607 return DIE_FIND_CB_CONTINUE;
608
609 /* Ignore redundant instances */
610 if (dwarf_tag(inst) == DW_TAG_inlined_subroutine) {
611 dwarf_decl_line(origin, &tmp);
612 if (die_get_call_lineno(inst) == tmp) {
613 tmp = die_get_decl_fileno(origin);
614 if (die_get_call_fileno(inst) == tmp)
615 return DIE_FIND_CB_CONTINUE;
616 }
617 }
618
619 iwp->retval = iwp->callback(inst, iwp->data);
620
621 return (iwp->retval) ? DIE_FIND_CB_END : DIE_FIND_CB_CONTINUE;
622}
623
624/**
625 * die_walk_instances - Walk on instances of given DIE
626 * @or_die: an abstract original DIE
627 * @callback: a callback function which is called with instance DIE
628 * @data: user data
629 *
630 * Walk on the instances of give @in_die. @in_die must be an inlined function
631 * declartion. This returns the return value of @callback if it returns
632 * non-zero value, or -ENOENT if there is no instance.
633 */
634int die_walk_instances(Dwarf_Die *or_die, int (*callback)(Dwarf_Die *, void *),
635 void *data)
636{
637 Dwarf_Die cu_die;
638 Dwarf_Die die_mem;
639 struct __instance_walk_param iwp = {
640 .addr = or_die->addr,
641 .callback = callback,
642 .data = data,
643 .retval = -ENOENT,
644 };
645
646 if (dwarf_diecu(or_die, &cu_die, NULL, NULL) == NULL)
647 return -ENOENT;
648
649 die_find_child(&cu_die, __die_walk_instances_cb, &iwp, &die_mem);
650
651 return iwp.retval;
652}
653
654/* Line walker internal parameters */
655struct __line_walk_param {
656 bool recursive;
657 line_walk_callback_t callback;
658 void *data;
659 int retval;
660};
661
662static int __die_walk_funclines_cb(Dwarf_Die *in_die, void *data)
663{
664 struct __line_walk_param *lw = data;
665 Dwarf_Addr addr = 0;
666 const char *fname;
667 int lineno;
668
669 if (dwarf_tag(in_die) == DW_TAG_inlined_subroutine) {
670 fname = die_get_call_file(in_die);
671 lineno = die_get_call_lineno(in_die);
672 if (fname && lineno > 0 && dwarf_entrypc(in_die, &addr) == 0) {
673 lw->retval = lw->callback(fname, lineno, addr, lw->data);
674 if (lw->retval != 0)
675 return DIE_FIND_CB_END;
676 }
677 }
678 if (!lw->recursive)
679 /* Don't need to search recursively */
680 return DIE_FIND_CB_SIBLING;
681
682 if (addr) {
683 fname = dwarf_decl_file(in_die);
684 if (fname && dwarf_decl_line(in_die, &lineno) == 0) {
685 lw->retval = lw->callback(fname, lineno, addr, lw->data);
686 if (lw->retval != 0)
687 return DIE_FIND_CB_END;
688 }
689 }
690
691 /* Continue to search nested inlined function call-sites */
692 return DIE_FIND_CB_CONTINUE;
693}
694
695/* Walk on lines of blocks included in given DIE */
696static int __die_walk_funclines(Dwarf_Die *sp_die, bool recursive,
697 line_walk_callback_t callback, void *data)
698{
699 struct __line_walk_param lw = {
700 .recursive = recursive,
701 .callback = callback,
702 .data = data,
703 .retval = 0,
704 };
705 Dwarf_Die die_mem;
706 Dwarf_Addr addr;
707 const char *fname;
708 int lineno;
709
710 /* Handle function declaration line */
711 fname = dwarf_decl_file(sp_die);
712 if (fname && dwarf_decl_line(sp_die, &lineno) == 0 &&
713 dwarf_entrypc(sp_die, &addr) == 0) {
714 lw.retval = callback(fname, lineno, addr, data);
715 if (lw.retval != 0)
716 goto done;
717 }
718 die_find_child(sp_die, __die_walk_funclines_cb, &lw, &die_mem);
719done:
720 return lw.retval;
721}
722
723static int __die_walk_culines_cb(Dwarf_Die *sp_die, void *data)
724{
725 struct __line_walk_param *lw = data;
726
727 lw->retval = __die_walk_funclines(sp_die, true, lw->callback, lw->data);
728 if (lw->retval != 0)
729 return DWARF_CB_ABORT;
730
731 return DWARF_CB_OK;
732}
733
734/**
735 * die_walk_lines - Walk on lines inside given DIE
736 * @rt_die: a root DIE (CU, subprogram or inlined_subroutine)
737 * @callback: callback routine
738 * @data: user data
739 *
740 * Walk on all lines inside given @rt_die and call @callback on each line.
741 * If the @rt_die is a function, walk only on the lines inside the function,
742 * otherwise @rt_die must be a CU DIE.
743 * Note that this walks not only dwarf line list, but also function entries
744 * and inline call-site.
745 */
746int die_walk_lines(Dwarf_Die *rt_die, line_walk_callback_t callback, void *data)
747{
748 Dwarf_Lines *lines;
749 Dwarf_Line *line;
750 Dwarf_Addr addr;
751 const char *fname, *decf = NULL;
752 int lineno, ret = 0;
753 int decl = 0, inl;
754 Dwarf_Die die_mem, *cu_die;
755 size_t nlines, i;
756
757 /* Get the CU die */
758 if (dwarf_tag(rt_die) != DW_TAG_compile_unit) {
759 cu_die = dwarf_diecu(rt_die, &die_mem, NULL, NULL);
760 dwarf_decl_line(rt_die, &decl);
761 decf = dwarf_decl_file(rt_die);
762 } else
763 cu_die = rt_die;
764 if (!cu_die) {
765 pr_debug2("Failed to get CU from given DIE.\n");
766 return -EINVAL;
767 }
768
769 /* Get lines list in the CU */
770 if (dwarf_getsrclines(cu_die, &lines, &nlines) != 0) {
771 pr_debug2("Failed to get source lines on this CU.\n");
772 return -ENOENT;
773 }
774 pr_debug2("Get %zd lines from this CU\n", nlines);
775
776 /* Walk on the lines on lines list */
777 for (i = 0; i < nlines; i++) {
778 line = dwarf_onesrcline(lines, i);
779 if (line == NULL ||
780 dwarf_lineno(line, &lineno) != 0 ||
781 dwarf_lineaddr(line, &addr) != 0) {
782 pr_debug2("Failed to get line info. "
783 "Possible error in debuginfo.\n");
784 continue;
785 }
786 /* Filter lines based on address */
787 if (rt_die != cu_die) {
788 /*
789 * Address filtering
790 * The line is included in given function, and
791 * no inline block includes it.
792 */
793 if (!dwarf_haspc(rt_die, addr))
794 continue;
795 if (die_find_inlinefunc(rt_die, addr, &die_mem)) {
796 dwarf_decl_line(&die_mem, &inl);
797 if (inl != decl ||
798 decf != dwarf_decl_file(&die_mem))
799 continue;
800 }
801 }
802 /* Get source line */
803 fname = dwarf_linesrc(line, NULL, NULL);
804
805 ret = callback(fname, lineno, addr, data);
806 if (ret != 0)
807 return ret;
808 }
809
810 /*
811 * Dwarf lines doesn't include function declarations and inlined
812 * subroutines. We have to check functions list or given function.
813 */
814 if (rt_die != cu_die)
815 /*
816 * Don't need walk functions recursively, because nested
817 * inlined functions don't have lines of the specified DIE.
818 */
819 ret = __die_walk_funclines(rt_die, false, callback, data);
820 else {
821 struct __line_walk_param param = {
822 .callback = callback,
823 .data = data,
824 .retval = 0,
825 };
826 dwarf_getfuncs(cu_die, __die_walk_culines_cb, ¶m, 0);
827 ret = param.retval;
828 }
829
830 return ret;
831}
832
833struct __find_variable_param {
834 const char *name;
835 Dwarf_Addr addr;
836};
837
838static int __die_find_variable_cb(Dwarf_Die *die_mem, void *data)
839{
840 struct __find_variable_param *fvp = data;
841 Dwarf_Attribute attr;
842 int tag;
843
844 tag = dwarf_tag(die_mem);
845 if ((tag == DW_TAG_formal_parameter ||
846 tag == DW_TAG_variable) &&
847 die_compare_name(die_mem, fvp->name) &&
848 /* Does the DIE have location information or external instance? */
849 (dwarf_attr(die_mem, DW_AT_external, &attr) ||
850 dwarf_attr(die_mem, DW_AT_location, &attr)))
851 return DIE_FIND_CB_END;
852 if (dwarf_haspc(die_mem, fvp->addr))
853 return DIE_FIND_CB_CONTINUE;
854 else
855 return DIE_FIND_CB_SIBLING;
856}
857
858/**
859 * die_find_variable_at - Find a given name variable at given address
860 * @sp_die: a function DIE
861 * @name: variable name
862 * @addr: address
863 * @die_mem: a buffer for result DIE
864 *
865 * Find a variable DIE called @name at @addr in @sp_die.
866 */
867Dwarf_Die *die_find_variable_at(Dwarf_Die *sp_die, const char *name,
868 Dwarf_Addr addr, Dwarf_Die *die_mem)
869{
870 struct __find_variable_param fvp = { .name = name, .addr = addr};
871
872 return die_find_child(sp_die, __die_find_variable_cb, (void *)&fvp,
873 die_mem);
874}
875
876static int __die_find_member_cb(Dwarf_Die *die_mem, void *data)
877{
878 const char *name = data;
879
880 if (dwarf_tag(die_mem) == DW_TAG_member) {
881 if (die_compare_name(die_mem, name))
882 return DIE_FIND_CB_END;
883 else if (!dwarf_diename(die_mem)) { /* Unnamed structure */
884 Dwarf_Die type_die, tmp_die;
885 if (die_get_type(die_mem, &type_die) &&
886 die_find_member(&type_die, name, &tmp_die))
887 return DIE_FIND_CB_END;
888 }
889 }
890 return DIE_FIND_CB_SIBLING;
891}
892
893/**
894 * die_find_member - Find a given name member in a data structure
895 * @st_die: a data structure type DIE
896 * @name: member name
897 * @die_mem: a buffer for result DIE
898 *
899 * Find a member DIE called @name in @st_die.
900 */
901Dwarf_Die *die_find_member(Dwarf_Die *st_die, const char *name,
902 Dwarf_Die *die_mem)
903{
904 return die_find_child(st_die, __die_find_member_cb, (void *)name,
905 die_mem);
906}
907
908/**
909 * die_get_typename - Get the name of given variable DIE
910 * @vr_die: a variable DIE
911 * @buf: a strbuf for result type name
912 *
913 * Get the name of @vr_die and stores it to @buf. Return 0 if succeeded.
914 * and Return -ENOENT if failed to find type name.
915 * Note that the result will stores typedef name if possible, and stores
916 * "*(function_type)" if the type is a function pointer.
917 */
918int die_get_typename(Dwarf_Die *vr_die, struct strbuf *buf)
919{
920 Dwarf_Die type;
921 int tag, ret;
922 const char *tmp = "";
923
924 if (__die_get_real_type(vr_die, &type) == NULL)
925 return -ENOENT;
926
927 tag = dwarf_tag(&type);
928 if (tag == DW_TAG_array_type || tag == DW_TAG_pointer_type)
929 tmp = "*";
930 else if (tag == DW_TAG_subroutine_type) {
931 /* Function pointer */
932 return strbuf_add(buf, "(function_type)", 15);
933 } else {
934 if (!dwarf_diename(&type))
935 return -ENOENT;
936 if (tag == DW_TAG_union_type)
937 tmp = "union ";
938 else if (tag == DW_TAG_structure_type)
939 tmp = "struct ";
940 else if (tag == DW_TAG_enumeration_type)
941 tmp = "enum ";
942 /* Write a base name */
943 return strbuf_addf(buf, "%s%s", tmp, dwarf_diename(&type));
944 }
945 ret = die_get_typename(&type, buf);
946 return ret ? ret : strbuf_addstr(buf, tmp);
947}
948
949/**
950 * die_get_varname - Get the name and type of given variable DIE
951 * @vr_die: a variable DIE
952 * @buf: a strbuf for type and variable name
953 *
954 * Get the name and type of @vr_die and stores it in @buf as "type\tname".
955 */
956int die_get_varname(Dwarf_Die *vr_die, struct strbuf *buf)
957{
958 int ret;
959
960 ret = die_get_typename(vr_die, buf);
961 if (ret < 0) {
962 pr_debug("Failed to get type, make it unknown.\n");
963 ret = strbuf_add(buf, " (unknown_type)", 14);
964 }
965
966 return ret < 0 ? ret : strbuf_addf(buf, "\t%s", dwarf_diename(vr_die));
967}
968
969#ifdef HAVE_DWARF_GETLOCATIONS_SUPPORT
970/**
971 * die_get_var_innermost_scope - Get innermost scope range of given variable DIE
972 * @sp_die: a subprogram DIE
973 * @vr_die: a variable DIE
974 * @buf: a strbuf for variable byte offset range
975 *
976 * Get the innermost scope range of @vr_die and stores it in @buf as
977 * "@<function_name+[NN-NN,NN-NN]>".
978 */
979static int die_get_var_innermost_scope(Dwarf_Die *sp_die, Dwarf_Die *vr_die,
980 struct strbuf *buf)
981{
982 Dwarf_Die *scopes;
983 int count;
984 size_t offset = 0;
985 Dwarf_Addr base;
986 Dwarf_Addr start, end;
987 Dwarf_Addr entry;
988 int ret;
989 bool first = true;
990 const char *name;
991
992 ret = dwarf_entrypc(sp_die, &entry);
993 if (ret)
994 return ret;
995
996 name = dwarf_diename(sp_die);
997 if (!name)
998 return -ENOENT;
999
1000 count = dwarf_getscopes_die(vr_die, &scopes);
1001
1002 /* (*SCOPES)[1] is the DIE for the scope containing that scope */
1003 if (count <= 1) {
1004 ret = -EINVAL;
1005 goto out;
1006 }
1007
1008 while ((offset = dwarf_ranges(&scopes[1], offset, &base,
1009 &start, &end)) > 0) {
1010 start -= entry;
1011 end -= entry;
1012
1013 if (first) {
1014 ret = strbuf_addf(buf, "@<%s+[%" PRIu64 "-%" PRIu64,
1015 name, start, end);
1016 first = false;
1017 } else {
1018 ret = strbuf_addf(buf, ",%" PRIu64 "-%" PRIu64,
1019 start, end);
1020 }
1021 if (ret < 0)
1022 goto out;
1023 }
1024
1025 if (!first)
1026 ret = strbuf_add(buf, "]>", 2);
1027
1028out:
1029 free(scopes);
1030 return ret;
1031}
1032
1033/**
1034 * die_get_var_range - Get byte offset range of given variable DIE
1035 * @sp_die: a subprogram DIE
1036 * @vr_die: a variable DIE
1037 * @buf: a strbuf for type and variable name and byte offset range
1038 *
1039 * Get the byte offset range of @vr_die and stores it in @buf as
1040 * "@<function_name+[NN-NN,NN-NN]>".
1041 */
1042int die_get_var_range(Dwarf_Die *sp_die, Dwarf_Die *vr_die, struct strbuf *buf)
1043{
1044 int ret = 0;
1045 Dwarf_Addr base;
1046 Dwarf_Addr start, end;
1047 Dwarf_Addr entry;
1048 Dwarf_Op *op;
1049 size_t nops;
1050 size_t offset = 0;
1051 Dwarf_Attribute attr;
1052 bool first = true;
1053 const char *name;
1054
1055 ret = dwarf_entrypc(sp_die, &entry);
1056 if (ret)
1057 return ret;
1058
1059 name = dwarf_diename(sp_die);
1060 if (!name)
1061 return -ENOENT;
1062
1063 if (dwarf_attr(vr_die, DW_AT_location, &attr) == NULL)
1064 return -EINVAL;
1065
1066 while ((offset = dwarf_getlocations(&attr, offset, &base,
1067 &start, &end, &op, &nops)) > 0) {
1068 if (start == 0) {
1069 /* Single Location Descriptions */
1070 ret = die_get_var_innermost_scope(sp_die, vr_die, buf);
1071 goto out;
1072 }
1073
1074 /* Location Lists */
1075 start -= entry;
1076 end -= entry;
1077 if (first) {
1078 ret = strbuf_addf(buf, "@<%s+[%" PRIu64 "-%" PRIu64,
1079 name, start, end);
1080 first = false;
1081 } else {
1082 ret = strbuf_addf(buf, ",%" PRIu64 "-%" PRIu64,
1083 start, end);
1084 }
1085 if (ret < 0)
1086 goto out;
1087 }
1088
1089 if (!first)
1090 ret = strbuf_add(buf, "]>", 2);
1091out:
1092 return ret;
1093}
1094#else
1095int die_get_var_range(Dwarf_Die *sp_die __maybe_unused,
1096 Dwarf_Die *vr_die __maybe_unused,
1097 struct strbuf *buf __maybe_unused)
1098{
1099 return -ENOTSUP;
1100}
1101#endif
1102
1103/*
1104 * die_has_loclist - Check if DW_AT_location of @vr_die is a location list
1105 * @vr_die: a variable DIE
1106 */
1107static bool die_has_loclist(Dwarf_Die *vr_die)
1108{
1109 Dwarf_Attribute loc;
1110 int tag = dwarf_tag(vr_die);
1111
1112 if (tag != DW_TAG_formal_parameter &&
1113 tag != DW_TAG_variable)
1114 return false;
1115
1116 return (dwarf_attr_integrate(vr_die, DW_AT_location, &loc) &&
1117 dwarf_whatform(&loc) == DW_FORM_sec_offset);
1118}
1119
1120/*
1121 * die_is_optimized_target - Check if target program is compiled with
1122 * optimization
1123 * @cu_die: a CU DIE
1124 *
1125 * For any object in given CU whose DW_AT_location is a location list,
1126 * target program is compiled with optimization. This is applicable to
1127 * clang as well.
1128 */
1129bool die_is_optimized_target(Dwarf_Die *cu_die)
1130{
1131 Dwarf_Die tmp_die;
1132
1133 if (die_has_loclist(cu_die))
1134 return true;
1135
1136 if (!dwarf_child(cu_die, &tmp_die) &&
1137 die_is_optimized_target(&tmp_die))
1138 return true;
1139
1140 if (!dwarf_siblingof(cu_die, &tmp_die) &&
1141 die_is_optimized_target(&tmp_die))
1142 return true;
1143
1144 return false;
1145}
1146
1147/*
1148 * die_search_idx - Search index of given line address
1149 * @lines: Line records of single CU
1150 * @nr_lines: Number of @lines
1151 * @addr: address we are looking for
1152 * @idx: index to be set by this function (return value)
1153 *
1154 * Search for @addr by looping over every lines of CU. If address
1155 * matches, set index of that line in @idx. Note that single source
1156 * line can have multiple line records. i.e. single source line can
1157 * have multiple index.
1158 */
1159static bool die_search_idx(Dwarf_Lines *lines, unsigned long nr_lines,
1160 Dwarf_Addr addr, unsigned long *idx)
1161{
1162 unsigned long i;
1163 Dwarf_Addr tmp;
1164
1165 for (i = 0; i < nr_lines; i++) {
1166 if (dwarf_lineaddr(dwarf_onesrcline(lines, i), &tmp))
1167 return false;
1168
1169 if (tmp == addr) {
1170 *idx = i;
1171 return true;
1172 }
1173 }
1174 return false;
1175}
1176
1177/*
1178 * die_get_postprologue_addr - Search next address after function prologue
1179 * @entrypc_idx: entrypc index
1180 * @lines: Line records of single CU
1181 * @nr_lines: Number of @lines
1182 * @hignpc: high PC address of function
1183 * @postprologue_addr: Next address after function prologue (return value)
1184 *
1185 * Look for prologue-end marker. If there is no explicit marker, return
1186 * address of next line record or next source line.
1187 */
1188static bool die_get_postprologue_addr(unsigned long entrypc_idx,
1189 Dwarf_Lines *lines,
1190 unsigned long nr_lines,
1191 Dwarf_Addr highpc,
1192 Dwarf_Addr *postprologue_addr)
1193{
1194 unsigned long i;
1195 int entrypc_lno, lno;
1196 Dwarf_Line *line;
1197 Dwarf_Addr addr;
1198 bool p_end;
1199
1200 /* entrypc_lno is actual source line number */
1201 line = dwarf_onesrcline(lines, entrypc_idx);
1202 if (dwarf_lineno(line, &entrypc_lno))
1203 return false;
1204
1205 for (i = entrypc_idx; i < nr_lines; i++) {
1206 line = dwarf_onesrcline(lines, i);
1207
1208 if (dwarf_lineaddr(line, &addr) ||
1209 dwarf_lineno(line, &lno) ||
1210 dwarf_lineprologueend(line, &p_end))
1211 return false;
1212
1213 /* highpc is exclusive. [entrypc,highpc) */
1214 if (addr >= highpc)
1215 break;
1216
1217 /* clang supports prologue-end marker */
1218 if (p_end)
1219 break;
1220
1221 /* Actual next line in source */
1222 if (lno != entrypc_lno)
1223 break;
1224
1225 /*
1226 * Single source line can have multiple line records.
1227 * For Example,
1228 * void foo() { printf("hello\n"); }
1229 * contains two line records. One points to declaration and
1230 * other points to printf() line. Variable 'lno' won't get
1231 * incremented in this case but 'i' will.
1232 */
1233 if (i != entrypc_idx)
1234 break;
1235 }
1236
1237 dwarf_lineaddr(line, postprologue_addr);
1238 if (*postprologue_addr >= highpc)
1239 dwarf_lineaddr(dwarf_onesrcline(lines, i - 1),
1240 postprologue_addr);
1241
1242 return true;
1243}
1244
1245/*
1246 * die_skip_prologue - Use next address after prologue as probe location
1247 * @sp_die: a subprogram DIE
1248 * @cu_die: a CU DIE
1249 * @entrypc: entrypc of the function
1250 *
1251 * Function prologue prepares stack and registers before executing function
1252 * logic. When target program is compiled without optimization, function
1253 * parameter information is only valid after prologue. When we probe entrypc
1254 * of the function, and try to record function parameter, it contains
1255 * garbage value.
1256 */
1257void die_skip_prologue(Dwarf_Die *sp_die, Dwarf_Die *cu_die,
1258 Dwarf_Addr *entrypc)
1259{
1260 size_t nr_lines = 0;
1261 unsigned long entrypc_idx = 0;
1262 Dwarf_Lines *lines = NULL;
1263 Dwarf_Addr postprologue_addr;
1264 Dwarf_Addr highpc;
1265
1266 if (dwarf_highpc(sp_die, &highpc))
1267 return;
1268
1269 if (dwarf_getsrclines(cu_die, &lines, &nr_lines))
1270 return;
1271
1272 if (!die_search_idx(lines, nr_lines, *entrypc, &entrypc_idx))
1273 return;
1274
1275 if (!die_get_postprologue_addr(entrypc_idx, lines, nr_lines,
1276 highpc, &postprologue_addr))
1277 return;
1278
1279 *entrypc = postprologue_addr;
1280}
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * dwarf-aux.c : libdw auxiliary interfaces
4 */
5
6#include <errno.h>
7#include <inttypes.h>
8#include <stdbool.h>
9#include <stdlib.h>
10#include "debug.h"
11#include "dwarf-aux.h"
12#include "strbuf.h"
13#include "string2.h"
14
15/**
16 * cu_find_realpath - Find the realpath of the target file
17 * @cu_die: A DIE(dwarf information entry) of CU(compilation Unit)
18 * @fname: The tail filename of the target file
19 *
20 * Find the real(long) path of @fname in @cu_die.
21 */
22const char *cu_find_realpath(Dwarf_Die *cu_die, const char *fname)
23{
24 Dwarf_Files *files;
25 size_t nfiles, i;
26 const char *src = NULL;
27 int ret;
28
29 if (!fname)
30 return NULL;
31
32 ret = dwarf_getsrcfiles(cu_die, &files, &nfiles);
33 if (ret != 0)
34 return NULL;
35
36 for (i = 0; i < nfiles; i++) {
37 src = dwarf_filesrc(files, i, NULL, NULL);
38 if (strtailcmp(src, fname) == 0)
39 break;
40 }
41 if (i == nfiles)
42 return NULL;
43 return src;
44}
45
46/**
47 * cu_get_comp_dir - Get the path of compilation directory
48 * @cu_die: a CU DIE
49 *
50 * Get the path of compilation directory of given @cu_die.
51 * Since this depends on DW_AT_comp_dir, older gcc will not
52 * embedded it. In that case, this returns NULL.
53 */
54const char *cu_get_comp_dir(Dwarf_Die *cu_die)
55{
56 Dwarf_Attribute attr;
57 if (dwarf_attr(cu_die, DW_AT_comp_dir, &attr) == NULL)
58 return NULL;
59 return dwarf_formstring(&attr);
60}
61
62/* Unlike dwarf_getsrc_die(), cu_getsrc_die() only returns statement line */
63static Dwarf_Line *cu_getsrc_die(Dwarf_Die *cu_die, Dwarf_Addr addr)
64{
65 Dwarf_Addr laddr;
66 Dwarf_Lines *lines;
67 Dwarf_Line *line;
68 size_t nlines, l, u, n;
69 bool flag;
70
71 if (dwarf_getsrclines(cu_die, &lines, &nlines) != 0 ||
72 nlines == 0)
73 return NULL;
74
75 /* Lines are sorted by address, use binary search */
76 l = 0; u = nlines - 1;
77 while (l < u) {
78 n = u - (u - l) / 2;
79 line = dwarf_onesrcline(lines, n);
80 if (!line || dwarf_lineaddr(line, &laddr) != 0)
81 return NULL;
82 if (addr < laddr)
83 u = n - 1;
84 else
85 l = n;
86 }
87 /* Going backward to find the lowest line */
88 do {
89 line = dwarf_onesrcline(lines, --l);
90 if (!line || dwarf_lineaddr(line, &laddr) != 0)
91 return NULL;
92 } while (laddr == addr);
93 l++;
94 /* Going forward to find the statement line */
95 do {
96 line = dwarf_onesrcline(lines, l++);
97 if (!line || dwarf_lineaddr(line, &laddr) != 0 ||
98 dwarf_linebeginstatement(line, &flag) != 0)
99 return NULL;
100 if (laddr > addr)
101 return NULL;
102 } while (!flag);
103
104 return line;
105}
106
107/**
108 * cu_find_lineinfo - Get a line number and file name for given address
109 * @cu_die: a CU DIE
110 * @addr: An address
111 * @fname: a pointer which returns the file name string
112 * @lineno: a pointer which returns the line number
113 *
114 * Find a line number and file name for @addr in @cu_die.
115 */
116int cu_find_lineinfo(Dwarf_Die *cu_die, Dwarf_Addr addr,
117 const char **fname, int *lineno)
118{
119 Dwarf_Line *line;
120 Dwarf_Die die_mem;
121 Dwarf_Addr faddr;
122
123 if (die_find_realfunc(cu_die, addr, &die_mem)
124 && die_entrypc(&die_mem, &faddr) == 0 &&
125 faddr == addr) {
126 *fname = die_get_decl_file(&die_mem);
127 dwarf_decl_line(&die_mem, lineno);
128 goto out;
129 }
130
131 line = cu_getsrc_die(cu_die, addr);
132 if (line && dwarf_lineno(line, lineno) == 0) {
133 *fname = dwarf_linesrc(line, NULL, NULL);
134 if (!*fname)
135 /* line number is useless without filename */
136 *lineno = 0;
137 }
138
139out:
140 return (*lineno && *fname) ? *lineno : -ENOENT;
141}
142
143static int __die_find_inline_cb(Dwarf_Die *die_mem, void *data);
144
145/**
146 * cu_walk_functions_at - Walk on function DIEs at given address
147 * @cu_die: A CU DIE
148 * @addr: An address
149 * @callback: A callback which called with found DIEs
150 * @data: A user data
151 *
152 * Walk on function DIEs at given @addr in @cu_die. Passed DIEs
153 * should be subprogram or inlined-subroutines.
154 */
155int cu_walk_functions_at(Dwarf_Die *cu_die, Dwarf_Addr addr,
156 int (*callback)(Dwarf_Die *, void *), void *data)
157{
158 Dwarf_Die die_mem;
159 Dwarf_Die *sc_die;
160 int ret = -ENOENT;
161
162 /* Inlined function could be recursive. Trace it until fail */
163 for (sc_die = die_find_realfunc(cu_die, addr, &die_mem);
164 sc_die != NULL;
165 sc_die = die_find_child(sc_die, __die_find_inline_cb, &addr,
166 &die_mem)) {
167 ret = callback(sc_die, data);
168 if (ret)
169 break;
170 }
171
172 return ret;
173
174}
175
176/**
177 * die_get_linkage_name - Get the linkage name of the object
178 * @dw_die: A DIE of the object
179 *
180 * Get the linkage name attribute of given @dw_die.
181 * For C++ binary, the linkage name will be the mangled symbol.
182 */
183const char *die_get_linkage_name(Dwarf_Die *dw_die)
184{
185 Dwarf_Attribute attr;
186
187 if (dwarf_attr_integrate(dw_die, DW_AT_linkage_name, &attr) == NULL)
188 return NULL;
189 return dwarf_formstring(&attr);
190}
191
192/**
193 * die_compare_name - Compare diename and tname
194 * @dw_die: a DIE
195 * @tname: a string of target name
196 *
197 * Compare the name of @dw_die and @tname. Return false if @dw_die has no name.
198 */
199bool die_compare_name(Dwarf_Die *dw_die, const char *tname)
200{
201 const char *name;
202
203 name = dwarf_diename(dw_die);
204 return name ? (strcmp(tname, name) == 0) : false;
205}
206
207/**
208 * die_match_name - Match diename/linkage name and glob
209 * @dw_die: a DIE
210 * @glob: a string of target glob pattern
211 *
212 * Glob matching the name of @dw_die and @glob. Return false if matching fail.
213 * This also match linkage name.
214 */
215bool die_match_name(Dwarf_Die *dw_die, const char *glob)
216{
217 const char *name;
218
219 name = dwarf_diename(dw_die);
220 if (name && strglobmatch(name, glob))
221 return true;
222 /* fall back to check linkage name */
223 name = die_get_linkage_name(dw_die);
224 if (name && strglobmatch(name, glob))
225 return true;
226
227 return false;
228}
229
230/**
231 * die_get_call_lineno - Get callsite line number of inline-function instance
232 * @in_die: a DIE of an inlined function instance
233 *
234 * Get call-site line number of @in_die. This means from where the inline
235 * function is called.
236 */
237int die_get_call_lineno(Dwarf_Die *in_die)
238{
239 Dwarf_Attribute attr;
240 Dwarf_Word ret;
241
242 if (!dwarf_attr(in_die, DW_AT_call_line, &attr))
243 return -ENOENT;
244
245 dwarf_formudata(&attr, &ret);
246 return (int)ret;
247}
248
249/**
250 * die_get_type - Get type DIE
251 * @vr_die: a DIE of a variable
252 * @die_mem: where to store a type DIE
253 *
254 * Get a DIE of the type of given variable (@vr_die), and store
255 * it to die_mem. Return NULL if fails to get a type DIE.
256 */
257Dwarf_Die *die_get_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem)
258{
259 Dwarf_Attribute attr;
260
261 if (dwarf_attr_integrate(vr_die, DW_AT_type, &attr) &&
262 dwarf_formref_die(&attr, die_mem))
263 return die_mem;
264 else
265 return NULL;
266}
267
268/* Get a type die, but skip qualifiers */
269static Dwarf_Die *__die_get_real_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem)
270{
271 int tag;
272
273 do {
274 vr_die = die_get_type(vr_die, die_mem);
275 if (!vr_die)
276 break;
277 tag = dwarf_tag(vr_die);
278 } while (tag == DW_TAG_const_type ||
279 tag == DW_TAG_restrict_type ||
280 tag == DW_TAG_volatile_type ||
281 tag == DW_TAG_shared_type);
282
283 return vr_die;
284}
285
286/**
287 * die_get_real_type - Get a type die, but skip qualifiers and typedef
288 * @vr_die: a DIE of a variable
289 * @die_mem: where to store a type DIE
290 *
291 * Get a DIE of the type of given variable (@vr_die), and store
292 * it to die_mem. Return NULL if fails to get a type DIE.
293 * If the type is qualifiers (e.g. const) or typedef, this skips it
294 * and tries to find real type (structure or basic types, e.g. int).
295 */
296Dwarf_Die *die_get_real_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem)
297{
298 do {
299 vr_die = __die_get_real_type(vr_die, die_mem);
300 } while (vr_die && dwarf_tag(vr_die) == DW_TAG_typedef);
301
302 return vr_die;
303}
304
305/* Get attribute and translate it as a udata */
306static int die_get_attr_udata(Dwarf_Die *tp_die, unsigned int attr_name,
307 Dwarf_Word *result)
308{
309 Dwarf_Attribute attr;
310
311 if (dwarf_attr_integrate(tp_die, attr_name, &attr) == NULL ||
312 dwarf_formudata(&attr, result) != 0)
313 return -ENOENT;
314
315 return 0;
316}
317
318/**
319 * die_is_signed_type - Check whether a type DIE is signed or not
320 * @tp_die: a DIE of a type
321 *
322 * Get the encoding of @tp_die and return true if the encoding
323 * is signed.
324 */
325bool die_is_signed_type(Dwarf_Die *tp_die)
326{
327 Dwarf_Word ret;
328
329 if (die_get_attr_udata(tp_die, DW_AT_encoding, &ret))
330 return false;
331
332 return (ret == DW_ATE_signed_char || ret == DW_ATE_signed ||
333 ret == DW_ATE_signed_fixed);
334}
335
336/**
337 * die_is_func_def - Ensure that this DIE is a subprogram and definition
338 * @dw_die: a DIE
339 *
340 * Ensure that this DIE is a subprogram and NOT a declaration. This
341 * returns true if @dw_die is a function definition.
342 **/
343bool die_is_func_def(Dwarf_Die *dw_die)
344{
345 Dwarf_Attribute attr;
346 Dwarf_Addr addr = 0;
347
348 if (dwarf_tag(dw_die) != DW_TAG_subprogram)
349 return false;
350
351 if (dwarf_attr(dw_die, DW_AT_declaration, &attr))
352 return false;
353
354 /*
355 * DW_AT_declaration can be lost from function declaration
356 * by gcc's bug #97060.
357 * So we need to check this subprogram DIE has DW_AT_inline
358 * or an entry address.
359 */
360 if (!dwarf_attr(dw_die, DW_AT_inline, &attr) &&
361 die_entrypc(dw_die, &addr) < 0)
362 return false;
363
364 return true;
365}
366
367/**
368 * die_entrypc - Returns entry PC (the lowest address) of a DIE
369 * @dw_die: a DIE
370 * @addr: where to store entry PC
371 *
372 * Since dwarf_entrypc() does not return entry PC if the DIE has only address
373 * range, we have to use this to retrieve the lowest address from the address
374 * range attribute.
375 */
376int die_entrypc(Dwarf_Die *dw_die, Dwarf_Addr *addr)
377{
378 Dwarf_Addr base, end;
379 Dwarf_Attribute attr;
380
381 if (!addr)
382 return -EINVAL;
383
384 if (dwarf_entrypc(dw_die, addr) == 0)
385 return 0;
386
387 /*
388 * Since the dwarf_ranges() will return 0 if there is no
389 * DW_AT_ranges attribute, we should check it first.
390 */
391 if (!dwarf_attr(dw_die, DW_AT_ranges, &attr))
392 return -ENOENT;
393
394 return dwarf_ranges(dw_die, 0, &base, addr, &end) < 0 ? -ENOENT : 0;
395}
396
397/**
398 * die_is_func_instance - Ensure that this DIE is an instance of a subprogram
399 * @dw_die: a DIE
400 *
401 * Ensure that this DIE is an instance (which has an entry address).
402 * This returns true if @dw_die is a function instance. If not, the @dw_die
403 * must be a prototype. You can use die_walk_instances() to find actual
404 * instances.
405 **/
406bool die_is_func_instance(Dwarf_Die *dw_die)
407{
408 Dwarf_Addr tmp;
409 Dwarf_Attribute attr_mem;
410 int tag = dwarf_tag(dw_die);
411
412 if (tag != DW_TAG_subprogram &&
413 tag != DW_TAG_inlined_subroutine)
414 return false;
415
416 return dwarf_entrypc(dw_die, &tmp) == 0 ||
417 dwarf_attr(dw_die, DW_AT_ranges, &attr_mem) != NULL;
418}
419
420/**
421 * die_get_data_member_location - Get the data-member offset
422 * @mb_die: a DIE of a member of a data structure
423 * @offs: The offset of the member in the data structure
424 *
425 * Get the offset of @mb_die in the data structure including @mb_die, and
426 * stores result offset to @offs. If any error occurs this returns errno.
427 */
428int die_get_data_member_location(Dwarf_Die *mb_die, Dwarf_Word *offs)
429{
430 Dwarf_Attribute attr;
431 Dwarf_Op *expr;
432 size_t nexpr;
433 int ret;
434
435 if (dwarf_attr(mb_die, DW_AT_data_member_location, &attr) == NULL)
436 return -ENOENT;
437
438 if (dwarf_formudata(&attr, offs) != 0) {
439 /* DW_AT_data_member_location should be DW_OP_plus_uconst */
440 ret = dwarf_getlocation(&attr, &expr, &nexpr);
441 if (ret < 0 || nexpr == 0)
442 return -ENOENT;
443
444 if (expr[0].atom != DW_OP_plus_uconst || nexpr != 1) {
445 pr_debug("Unable to get offset:Unexpected OP %x (%zd)\n",
446 expr[0].atom, nexpr);
447 return -ENOTSUP;
448 }
449 *offs = (Dwarf_Word)expr[0].number;
450 }
451 return 0;
452}
453
454/* Get the call file index number in CU DIE */
455static int die_get_call_fileno(Dwarf_Die *in_die)
456{
457 Dwarf_Word idx;
458
459 if (die_get_attr_udata(in_die, DW_AT_call_file, &idx) == 0)
460 return (int)idx;
461 else
462 return -ENOENT;
463}
464
465/* Get the declared file index number in CU DIE */
466static int die_get_decl_fileno(Dwarf_Die *pdie)
467{
468 Dwarf_Word idx;
469
470 if (die_get_attr_udata(pdie, DW_AT_decl_file, &idx) == 0)
471 return (int)idx;
472 else
473 return -ENOENT;
474}
475
476/* Return the file name by index */
477static const char *die_get_file_name(Dwarf_Die *dw_die, int idx)
478{
479 Dwarf_Die cu_die;
480 Dwarf_Files *files;
481
482 if (idx < 0 || !dwarf_diecu(dw_die, &cu_die, NULL, NULL) ||
483 dwarf_getsrcfiles(&cu_die, &files, NULL) != 0)
484 return NULL;
485
486 return dwarf_filesrc(files, idx, NULL, NULL);
487}
488
489/**
490 * die_get_call_file - Get callsite file name of inlined function instance
491 * @in_die: a DIE of an inlined function instance
492 *
493 * Get call-site file name of @in_die. This means from which file the inline
494 * function is called.
495 */
496const char *die_get_call_file(Dwarf_Die *in_die)
497{
498 return die_get_file_name(in_die, die_get_call_fileno(in_die));
499}
500
501/**
502 * die_get_decl_file - Find the declared file name of this DIE
503 * @dw_die: a DIE for something declared.
504 *
505 * Get declared file name of @dw_die.
506 * NOTE: Since some version of clang DWARF5 implementation incorrectly uses
507 * file index 0 for DW_AT_decl_file, die_get_decl_file() will return NULL for
508 * such cases. Use this function instead.
509 */
510const char *die_get_decl_file(Dwarf_Die *dw_die)
511{
512 return die_get_file_name(dw_die, die_get_decl_fileno(dw_die));
513}
514
515/**
516 * die_find_child - Generic DIE search function in DIE tree
517 * @rt_die: a root DIE
518 * @callback: a callback function
519 * @data: a user data passed to the callback function
520 * @die_mem: a buffer for result DIE
521 *
522 * Trace DIE tree from @rt_die and call @callback for each child DIE.
523 * If @callback returns DIE_FIND_CB_END, this stores the DIE into
524 * @die_mem and returns it. If @callback returns DIE_FIND_CB_CONTINUE,
525 * this continues to trace the tree. Optionally, @callback can return
526 * DIE_FIND_CB_CHILD and DIE_FIND_CB_SIBLING, those means trace only
527 * the children and trace only the siblings respectively.
528 * Returns NULL if @callback can't find any appropriate DIE.
529 */
530Dwarf_Die *die_find_child(Dwarf_Die *rt_die,
531 int (*callback)(Dwarf_Die *, void *),
532 void *data, Dwarf_Die *die_mem)
533{
534 Dwarf_Die child_die;
535 int ret;
536
537 ret = dwarf_child(rt_die, die_mem);
538 if (ret != 0)
539 return NULL;
540
541 do {
542 ret = callback(die_mem, data);
543 if (ret == DIE_FIND_CB_END)
544 return die_mem;
545
546 if ((ret & DIE_FIND_CB_CHILD) &&
547 die_find_child(die_mem, callback, data, &child_die)) {
548 memcpy(die_mem, &child_die, sizeof(Dwarf_Die));
549 return die_mem;
550 }
551 } while ((ret & DIE_FIND_CB_SIBLING) &&
552 dwarf_siblingof(die_mem, die_mem) == 0);
553
554 return NULL;
555}
556
557struct __addr_die_search_param {
558 Dwarf_Addr addr;
559 Dwarf_Die *die_mem;
560};
561
562static int __die_search_func_tail_cb(Dwarf_Die *fn_die, void *data)
563{
564 struct __addr_die_search_param *ad = data;
565 Dwarf_Addr addr = 0;
566
567 if (dwarf_tag(fn_die) == DW_TAG_subprogram &&
568 !dwarf_highpc(fn_die, &addr) &&
569 addr == ad->addr) {
570 memcpy(ad->die_mem, fn_die, sizeof(Dwarf_Die));
571 return DWARF_CB_ABORT;
572 }
573 return DWARF_CB_OK;
574}
575
576/**
577 * die_find_tailfunc - Search for a non-inlined function with tail call at
578 * given address
579 * @cu_die: a CU DIE which including @addr
580 * @addr: target address
581 * @die_mem: a buffer for result DIE
582 *
583 * Search for a non-inlined function DIE with tail call at @addr. Stores the
584 * DIE to @die_mem and returns it if found. Returns NULL if failed.
585 */
586Dwarf_Die *die_find_tailfunc(Dwarf_Die *cu_die, Dwarf_Addr addr,
587 Dwarf_Die *die_mem)
588{
589 struct __addr_die_search_param ad;
590 ad.addr = addr;
591 ad.die_mem = die_mem;
592 /* dwarf_getscopes can't find subprogram. */
593 if (!dwarf_getfuncs(cu_die, __die_search_func_tail_cb, &ad, 0))
594 return NULL;
595 else
596 return die_mem;
597}
598
599/* die_find callback for non-inlined function search */
600static int __die_search_func_cb(Dwarf_Die *fn_die, void *data)
601{
602 struct __addr_die_search_param *ad = data;
603
604 /*
605 * Since a declaration entry doesn't has given pc, this always returns
606 * function definition entry.
607 */
608 if (dwarf_tag(fn_die) == DW_TAG_subprogram &&
609 dwarf_haspc(fn_die, ad->addr)) {
610 memcpy(ad->die_mem, fn_die, sizeof(Dwarf_Die));
611 return DWARF_CB_ABORT;
612 }
613 return DWARF_CB_OK;
614}
615
616/**
617 * die_find_realfunc - Search a non-inlined function at given address
618 * @cu_die: a CU DIE which including @addr
619 * @addr: target address
620 * @die_mem: a buffer for result DIE
621 *
622 * Search a non-inlined function DIE which includes @addr. Stores the
623 * DIE to @die_mem and returns it if found. Returns NULL if failed.
624 */
625Dwarf_Die *die_find_realfunc(Dwarf_Die *cu_die, Dwarf_Addr addr,
626 Dwarf_Die *die_mem)
627{
628 struct __addr_die_search_param ad;
629 ad.addr = addr;
630 ad.die_mem = die_mem;
631 /* dwarf_getscopes can't find subprogram. */
632 if (!dwarf_getfuncs(cu_die, __die_search_func_cb, &ad, 0))
633 return NULL;
634 else
635 return die_mem;
636}
637
638/* die_find callback for inline function search */
639static int __die_find_inline_cb(Dwarf_Die *die_mem, void *data)
640{
641 Dwarf_Addr *addr = data;
642
643 if (dwarf_tag(die_mem) == DW_TAG_inlined_subroutine &&
644 dwarf_haspc(die_mem, *addr))
645 return DIE_FIND_CB_END;
646
647 return DIE_FIND_CB_CONTINUE;
648}
649
650/**
651 * die_find_top_inlinefunc - Search the top inlined function at given address
652 * @sp_die: a subprogram DIE which including @addr
653 * @addr: target address
654 * @die_mem: a buffer for result DIE
655 *
656 * Search an inlined function DIE which includes @addr. Stores the
657 * DIE to @die_mem and returns it if found. Returns NULL if failed.
658 * Even if several inlined functions are expanded recursively, this
659 * doesn't trace it down, and returns the topmost one.
660 */
661Dwarf_Die *die_find_top_inlinefunc(Dwarf_Die *sp_die, Dwarf_Addr addr,
662 Dwarf_Die *die_mem)
663{
664 return die_find_child(sp_die, __die_find_inline_cb, &addr, die_mem);
665}
666
667/**
668 * die_find_inlinefunc - Search an inlined function at given address
669 * @sp_die: a subprogram DIE which including @addr
670 * @addr: target address
671 * @die_mem: a buffer for result DIE
672 *
673 * Search an inlined function DIE which includes @addr. Stores the
674 * DIE to @die_mem and returns it if found. Returns NULL if failed.
675 * If several inlined functions are expanded recursively, this trace
676 * it down and returns deepest one.
677 */
678Dwarf_Die *die_find_inlinefunc(Dwarf_Die *sp_die, Dwarf_Addr addr,
679 Dwarf_Die *die_mem)
680{
681 Dwarf_Die tmp_die;
682
683 sp_die = die_find_child(sp_die, __die_find_inline_cb, &addr, &tmp_die);
684 if (!sp_die)
685 return NULL;
686
687 /* Inlined function could be recursive. Trace it until fail */
688 while (sp_die) {
689 memcpy(die_mem, sp_die, sizeof(Dwarf_Die));
690 sp_die = die_find_child(sp_die, __die_find_inline_cb, &addr,
691 &tmp_die);
692 }
693
694 return die_mem;
695}
696
697struct __instance_walk_param {
698 void *addr;
699 int (*callback)(Dwarf_Die *, void *);
700 void *data;
701 int retval;
702};
703
704static int __die_walk_instances_cb(Dwarf_Die *inst, void *data)
705{
706 struct __instance_walk_param *iwp = data;
707 Dwarf_Attribute attr_mem;
708 Dwarf_Die origin_mem;
709 Dwarf_Attribute *attr;
710 Dwarf_Die *origin;
711 int tmp;
712
713 if (!die_is_func_instance(inst))
714 return DIE_FIND_CB_CONTINUE;
715
716 attr = dwarf_attr(inst, DW_AT_abstract_origin, &attr_mem);
717 if (attr == NULL)
718 return DIE_FIND_CB_CONTINUE;
719
720 origin = dwarf_formref_die(attr, &origin_mem);
721 if (origin == NULL || origin->addr != iwp->addr)
722 return DIE_FIND_CB_CONTINUE;
723
724 /* Ignore redundant instances */
725 if (dwarf_tag(inst) == DW_TAG_inlined_subroutine) {
726 dwarf_decl_line(origin, &tmp);
727 if (die_get_call_lineno(inst) == tmp) {
728 tmp = die_get_decl_fileno(origin);
729 if (die_get_call_fileno(inst) == tmp)
730 return DIE_FIND_CB_CONTINUE;
731 }
732 }
733
734 iwp->retval = iwp->callback(inst, iwp->data);
735
736 return (iwp->retval) ? DIE_FIND_CB_END : DIE_FIND_CB_CONTINUE;
737}
738
739/**
740 * die_walk_instances - Walk on instances of given DIE
741 * @or_die: an abstract original DIE
742 * @callback: a callback function which is called with instance DIE
743 * @data: user data
744 *
745 * Walk on the instances of give @in_die. @in_die must be an inlined function
746 * declaration. This returns the return value of @callback if it returns
747 * non-zero value, or -ENOENT if there is no instance.
748 */
749int die_walk_instances(Dwarf_Die *or_die, int (*callback)(Dwarf_Die *, void *),
750 void *data)
751{
752 Dwarf_Die cu_die;
753 Dwarf_Die die_mem;
754 struct __instance_walk_param iwp = {
755 .addr = or_die->addr,
756 .callback = callback,
757 .data = data,
758 .retval = -ENOENT,
759 };
760
761 if (dwarf_diecu(or_die, &cu_die, NULL, NULL) == NULL)
762 return -ENOENT;
763
764 die_find_child(&cu_die, __die_walk_instances_cb, &iwp, &die_mem);
765
766 return iwp.retval;
767}
768
769/* Line walker internal parameters */
770struct __line_walk_param {
771 bool recursive;
772 line_walk_callback_t callback;
773 void *data;
774 int retval;
775};
776
777static int __die_walk_funclines_cb(Dwarf_Die *in_die, void *data)
778{
779 struct __line_walk_param *lw = data;
780 Dwarf_Addr addr = 0;
781 const char *fname;
782 int lineno;
783
784 if (dwarf_tag(in_die) == DW_TAG_inlined_subroutine) {
785 fname = die_get_call_file(in_die);
786 lineno = die_get_call_lineno(in_die);
787 if (fname && lineno > 0 && die_entrypc(in_die, &addr) == 0) {
788 lw->retval = lw->callback(fname, lineno, addr, lw->data);
789 if (lw->retval != 0)
790 return DIE_FIND_CB_END;
791 }
792 if (!lw->recursive)
793 return DIE_FIND_CB_SIBLING;
794 }
795
796 if (addr) {
797 fname = die_get_decl_file(in_die);
798 if (fname && dwarf_decl_line(in_die, &lineno) == 0) {
799 lw->retval = lw->callback(fname, lineno, addr, lw->data);
800 if (lw->retval != 0)
801 return DIE_FIND_CB_END;
802 }
803 }
804
805 /* Continue to search nested inlined function call-sites */
806 return DIE_FIND_CB_CONTINUE;
807}
808
809/* Walk on lines of blocks included in given DIE */
810static int __die_walk_funclines(Dwarf_Die *sp_die, bool recursive,
811 line_walk_callback_t callback, void *data)
812{
813 struct __line_walk_param lw = {
814 .recursive = recursive,
815 .callback = callback,
816 .data = data,
817 .retval = 0,
818 };
819 Dwarf_Die die_mem;
820 Dwarf_Addr addr;
821 const char *fname;
822 int lineno;
823
824 /* Handle function declaration line */
825 fname = die_get_decl_file(sp_die);
826 if (fname && dwarf_decl_line(sp_die, &lineno) == 0 &&
827 die_entrypc(sp_die, &addr) == 0) {
828 lw.retval = callback(fname, lineno, addr, data);
829 if (lw.retval != 0)
830 goto done;
831 }
832 die_find_child(sp_die, __die_walk_funclines_cb, &lw, &die_mem);
833done:
834 return lw.retval;
835}
836
837static int __die_walk_culines_cb(Dwarf_Die *sp_die, void *data)
838{
839 struct __line_walk_param *lw = data;
840
841 /*
842 * Since inlined function can include another inlined function in
843 * the same file, we need to walk in it recursively.
844 */
845 lw->retval = __die_walk_funclines(sp_die, true, lw->callback, lw->data);
846 if (lw->retval != 0)
847 return DWARF_CB_ABORT;
848
849 return DWARF_CB_OK;
850}
851
852/**
853 * die_walk_lines - Walk on lines inside given DIE
854 * @rt_die: a root DIE (CU, subprogram or inlined_subroutine)
855 * @callback: callback routine
856 * @data: user data
857 *
858 * Walk on all lines inside given @rt_die and call @callback on each line.
859 * If the @rt_die is a function, walk only on the lines inside the function,
860 * otherwise @rt_die must be a CU DIE.
861 * Note that this walks not only dwarf line list, but also function entries
862 * and inline call-site.
863 */
864int die_walk_lines(Dwarf_Die *rt_die, line_walk_callback_t callback, void *data)
865{
866 Dwarf_Lines *lines;
867 Dwarf_Line *line;
868 Dwarf_Addr addr;
869 const char *fname, *decf = NULL, *inf = NULL;
870 int lineno, ret = 0;
871 int decl = 0, inl;
872 Dwarf_Die die_mem, *cu_die;
873 size_t nlines, i;
874 bool flag;
875
876 /* Get the CU die */
877 if (dwarf_tag(rt_die) != DW_TAG_compile_unit) {
878 cu_die = dwarf_diecu(rt_die, &die_mem, NULL, NULL);
879 dwarf_decl_line(rt_die, &decl);
880 decf = die_get_decl_file(rt_die);
881 if (!decf) {
882 pr_debug2("Failed to get the declared file name of %s\n",
883 dwarf_diename(rt_die));
884 return -EINVAL;
885 }
886 } else
887 cu_die = rt_die;
888 if (!cu_die) {
889 pr_debug2("Failed to get CU from given DIE.\n");
890 return -EINVAL;
891 }
892
893 /* Get lines list in the CU */
894 if (dwarf_getsrclines(cu_die, &lines, &nlines) != 0) {
895 pr_debug2("Failed to get source lines on this CU.\n");
896 return -ENOENT;
897 }
898 pr_debug2("Get %zd lines from this CU\n", nlines);
899
900 /* Walk on the lines on lines list */
901 for (i = 0; i < nlines; i++) {
902 line = dwarf_onesrcline(lines, i);
903 if (line == NULL ||
904 dwarf_lineno(line, &lineno) != 0 ||
905 dwarf_lineaddr(line, &addr) != 0) {
906 pr_debug2("Failed to get line info. "
907 "Possible error in debuginfo.\n");
908 continue;
909 }
910 /* Skip end-of-sequence */
911 if (dwarf_lineendsequence(line, &flag) != 0 || flag)
912 continue;
913 /* Skip Non statement line-info */
914 if (dwarf_linebeginstatement(line, &flag) != 0 || !flag)
915 continue;
916 /* Filter lines based on address */
917 if (rt_die != cu_die) {
918 /*
919 * Address filtering
920 * The line is included in given function, and
921 * no inline block includes it.
922 */
923 if (!dwarf_haspc(rt_die, addr))
924 continue;
925
926 if (die_find_inlinefunc(rt_die, addr, &die_mem)) {
927 /* Call-site check */
928 inf = die_get_call_file(&die_mem);
929 if ((inf && !strcmp(inf, decf)) &&
930 die_get_call_lineno(&die_mem) == lineno)
931 goto found;
932
933 dwarf_decl_line(&die_mem, &inl);
934 if (inl != decl ||
935 decf != die_get_decl_file(&die_mem))
936 continue;
937 }
938 }
939found:
940 /* Get source line */
941 fname = dwarf_linesrc(line, NULL, NULL);
942
943 ret = callback(fname, lineno, addr, data);
944 if (ret != 0)
945 return ret;
946 }
947
948 /*
949 * Dwarf lines doesn't include function declarations and inlined
950 * subroutines. We have to check functions list or given function.
951 */
952 if (rt_die != cu_die)
953 /*
954 * Don't need walk inlined functions recursively, because
955 * inner inlined functions don't have the lines of the
956 * specified function.
957 */
958 ret = __die_walk_funclines(rt_die, false, callback, data);
959 else {
960 struct __line_walk_param param = {
961 .callback = callback,
962 .data = data,
963 .retval = 0,
964 };
965 dwarf_getfuncs(cu_die, __die_walk_culines_cb, ¶m, 0);
966 ret = param.retval;
967 }
968
969 return ret;
970}
971
972struct __find_variable_param {
973 const char *name;
974 Dwarf_Addr addr;
975};
976
977static int __die_find_variable_cb(Dwarf_Die *die_mem, void *data)
978{
979 struct __find_variable_param *fvp = data;
980 Dwarf_Attribute attr;
981 int tag;
982
983 tag = dwarf_tag(die_mem);
984 if ((tag == DW_TAG_formal_parameter ||
985 tag == DW_TAG_variable) &&
986 die_compare_name(die_mem, fvp->name) &&
987 /*
988 * Does the DIE have location information or const value
989 * or external instance?
990 */
991 (dwarf_attr(die_mem, DW_AT_external, &attr) ||
992 dwarf_attr(die_mem, DW_AT_location, &attr) ||
993 dwarf_attr(die_mem, DW_AT_const_value, &attr)))
994 return DIE_FIND_CB_END;
995 if (dwarf_haspc(die_mem, fvp->addr))
996 return DIE_FIND_CB_CONTINUE;
997 else
998 return DIE_FIND_CB_SIBLING;
999}
1000
1001/**
1002 * die_find_variable_at - Find a given name variable at given address
1003 * @sp_die: a function DIE
1004 * @name: variable name
1005 * @addr: address
1006 * @die_mem: a buffer for result DIE
1007 *
1008 * Find a variable DIE called @name at @addr in @sp_die.
1009 */
1010Dwarf_Die *die_find_variable_at(Dwarf_Die *sp_die, const char *name,
1011 Dwarf_Addr addr, Dwarf_Die *die_mem)
1012{
1013 struct __find_variable_param fvp = { .name = name, .addr = addr};
1014
1015 return die_find_child(sp_die, __die_find_variable_cb, (void *)&fvp,
1016 die_mem);
1017}
1018
1019static int __die_find_member_cb(Dwarf_Die *die_mem, void *data)
1020{
1021 const char *name = data;
1022
1023 if (dwarf_tag(die_mem) == DW_TAG_member) {
1024 if (die_compare_name(die_mem, name))
1025 return DIE_FIND_CB_END;
1026 else if (!dwarf_diename(die_mem)) { /* Unnamed structure */
1027 Dwarf_Die type_die, tmp_die;
1028 if (die_get_type(die_mem, &type_die) &&
1029 die_find_member(&type_die, name, &tmp_die))
1030 return DIE_FIND_CB_END;
1031 }
1032 }
1033 return DIE_FIND_CB_SIBLING;
1034}
1035
1036/**
1037 * die_find_member - Find a given name member in a data structure
1038 * @st_die: a data structure type DIE
1039 * @name: member name
1040 * @die_mem: a buffer for result DIE
1041 *
1042 * Find a member DIE called @name in @st_die.
1043 */
1044Dwarf_Die *die_find_member(Dwarf_Die *st_die, const char *name,
1045 Dwarf_Die *die_mem)
1046{
1047 return die_find_child(st_die, __die_find_member_cb, (void *)name,
1048 die_mem);
1049}
1050
1051/**
1052 * die_get_typename - Get the name of given variable DIE
1053 * @vr_die: a variable DIE
1054 * @buf: a strbuf for result type name
1055 *
1056 * Get the name of @vr_die and stores it to @buf. Return 0 if succeeded.
1057 * and Return -ENOENT if failed to find type name.
1058 * Note that the result will stores typedef name if possible, and stores
1059 * "*(function_type)" if the type is a function pointer.
1060 */
1061int die_get_typename(Dwarf_Die *vr_die, struct strbuf *buf)
1062{
1063 Dwarf_Die type;
1064 int tag, ret;
1065 const char *tmp = "";
1066
1067 if (__die_get_real_type(vr_die, &type) == NULL)
1068 return -ENOENT;
1069
1070 tag = dwarf_tag(&type);
1071 if (tag == DW_TAG_array_type || tag == DW_TAG_pointer_type)
1072 tmp = "*";
1073 else if (tag == DW_TAG_subroutine_type) {
1074 /* Function pointer */
1075 return strbuf_add(buf, "(function_type)", 15);
1076 } else {
1077 if (!dwarf_diename(&type))
1078 return -ENOENT;
1079 if (tag == DW_TAG_union_type)
1080 tmp = "union ";
1081 else if (tag == DW_TAG_structure_type)
1082 tmp = "struct ";
1083 else if (tag == DW_TAG_enumeration_type)
1084 tmp = "enum ";
1085 /* Write a base name */
1086 return strbuf_addf(buf, "%s%s", tmp, dwarf_diename(&type));
1087 }
1088 ret = die_get_typename(&type, buf);
1089 return ret ? ret : strbuf_addstr(buf, tmp);
1090}
1091
1092/**
1093 * die_get_varname - Get the name and type of given variable DIE
1094 * @vr_die: a variable DIE
1095 * @buf: a strbuf for type and variable name
1096 *
1097 * Get the name and type of @vr_die and stores it in @buf as "type\tname".
1098 */
1099int die_get_varname(Dwarf_Die *vr_die, struct strbuf *buf)
1100{
1101 int ret;
1102
1103 ret = die_get_typename(vr_die, buf);
1104 if (ret < 0) {
1105 pr_debug("Failed to get type, make it unknown.\n");
1106 ret = strbuf_add(buf, " (unknown_type)", 14);
1107 }
1108
1109 return ret < 0 ? ret : strbuf_addf(buf, "\t%s", dwarf_diename(vr_die));
1110}
1111
1112#ifdef HAVE_DWARF_GETLOCATIONS_SUPPORT
1113/**
1114 * die_get_var_innermost_scope - Get innermost scope range of given variable DIE
1115 * @sp_die: a subprogram DIE
1116 * @vr_die: a variable DIE
1117 * @buf: a strbuf for variable byte offset range
1118 *
1119 * Get the innermost scope range of @vr_die and stores it in @buf as
1120 * "@<function_name+[NN-NN,NN-NN]>".
1121 */
1122static int die_get_var_innermost_scope(Dwarf_Die *sp_die, Dwarf_Die *vr_die,
1123 struct strbuf *buf)
1124{
1125 Dwarf_Die *scopes;
1126 int count;
1127 size_t offset = 0;
1128 Dwarf_Addr base;
1129 Dwarf_Addr start, end;
1130 Dwarf_Addr entry;
1131 int ret;
1132 bool first = true;
1133 const char *name;
1134
1135 ret = die_entrypc(sp_die, &entry);
1136 if (ret)
1137 return ret;
1138
1139 name = dwarf_diename(sp_die);
1140 if (!name)
1141 return -ENOENT;
1142
1143 count = dwarf_getscopes_die(vr_die, &scopes);
1144
1145 /* (*SCOPES)[1] is the DIE for the scope containing that scope */
1146 if (count <= 1) {
1147 ret = -EINVAL;
1148 goto out;
1149 }
1150
1151 while ((offset = dwarf_ranges(&scopes[1], offset, &base,
1152 &start, &end)) > 0) {
1153 start -= entry;
1154 end -= entry;
1155
1156 if (first) {
1157 ret = strbuf_addf(buf, "@<%s+[%" PRIu64 "-%" PRIu64,
1158 name, start, end);
1159 first = false;
1160 } else {
1161 ret = strbuf_addf(buf, ",%" PRIu64 "-%" PRIu64,
1162 start, end);
1163 }
1164 if (ret < 0)
1165 goto out;
1166 }
1167
1168 if (!first)
1169 ret = strbuf_add(buf, "]>", 2);
1170
1171out:
1172 free(scopes);
1173 return ret;
1174}
1175
1176/**
1177 * die_get_var_range - Get byte offset range of given variable DIE
1178 * @sp_die: a subprogram DIE
1179 * @vr_die: a variable DIE
1180 * @buf: a strbuf for type and variable name and byte offset range
1181 *
1182 * Get the byte offset range of @vr_die and stores it in @buf as
1183 * "@<function_name+[NN-NN,NN-NN]>".
1184 */
1185int die_get_var_range(Dwarf_Die *sp_die, Dwarf_Die *vr_die, struct strbuf *buf)
1186{
1187 int ret = 0;
1188 Dwarf_Addr base;
1189 Dwarf_Addr start, end;
1190 Dwarf_Addr entry;
1191 Dwarf_Op *op;
1192 size_t nops;
1193 size_t offset = 0;
1194 Dwarf_Attribute attr;
1195 bool first = true;
1196 const char *name;
1197
1198 ret = die_entrypc(sp_die, &entry);
1199 if (ret)
1200 return ret;
1201
1202 name = dwarf_diename(sp_die);
1203 if (!name)
1204 return -ENOENT;
1205
1206 if (dwarf_attr(vr_die, DW_AT_location, &attr) == NULL)
1207 return -EINVAL;
1208
1209 while ((offset = dwarf_getlocations(&attr, offset, &base,
1210 &start, &end, &op, &nops)) > 0) {
1211 if (start == 0) {
1212 /* Single Location Descriptions */
1213 ret = die_get_var_innermost_scope(sp_die, vr_die, buf);
1214 goto out;
1215 }
1216
1217 /* Location Lists */
1218 start -= entry;
1219 end -= entry;
1220 if (first) {
1221 ret = strbuf_addf(buf, "@<%s+[%" PRIu64 "-%" PRIu64,
1222 name, start, end);
1223 first = false;
1224 } else {
1225 ret = strbuf_addf(buf, ",%" PRIu64 "-%" PRIu64,
1226 start, end);
1227 }
1228 if (ret < 0)
1229 goto out;
1230 }
1231
1232 if (!first)
1233 ret = strbuf_add(buf, "]>", 2);
1234out:
1235 return ret;
1236}
1237#else
1238int die_get_var_range(Dwarf_Die *sp_die __maybe_unused,
1239 Dwarf_Die *vr_die __maybe_unused,
1240 struct strbuf *buf __maybe_unused)
1241{
1242 return -ENOTSUP;
1243}
1244#endif
1245
1246/*
1247 * die_has_loclist - Check if DW_AT_location of @vr_die is a location list
1248 * @vr_die: a variable DIE
1249 */
1250static bool die_has_loclist(Dwarf_Die *vr_die)
1251{
1252 Dwarf_Attribute loc;
1253 int tag = dwarf_tag(vr_die);
1254
1255 if (tag != DW_TAG_formal_parameter &&
1256 tag != DW_TAG_variable)
1257 return false;
1258
1259 return (dwarf_attr_integrate(vr_die, DW_AT_location, &loc) &&
1260 dwarf_whatform(&loc) == DW_FORM_sec_offset);
1261}
1262
1263/*
1264 * die_is_optimized_target - Check if target program is compiled with
1265 * optimization
1266 * @cu_die: a CU DIE
1267 *
1268 * For any object in given CU whose DW_AT_location is a location list,
1269 * target program is compiled with optimization. This is applicable to
1270 * clang as well.
1271 */
1272bool die_is_optimized_target(Dwarf_Die *cu_die)
1273{
1274 Dwarf_Die tmp_die;
1275
1276 if (die_has_loclist(cu_die))
1277 return true;
1278
1279 if (!dwarf_child(cu_die, &tmp_die) &&
1280 die_is_optimized_target(&tmp_die))
1281 return true;
1282
1283 if (!dwarf_siblingof(cu_die, &tmp_die) &&
1284 die_is_optimized_target(&tmp_die))
1285 return true;
1286
1287 return false;
1288}
1289
1290/*
1291 * die_search_idx - Search index of given line address
1292 * @lines: Line records of single CU
1293 * @nr_lines: Number of @lines
1294 * @addr: address we are looking for
1295 * @idx: index to be set by this function (return value)
1296 *
1297 * Search for @addr by looping over every lines of CU. If address
1298 * matches, set index of that line in @idx. Note that single source
1299 * line can have multiple line records. i.e. single source line can
1300 * have multiple index.
1301 */
1302static bool die_search_idx(Dwarf_Lines *lines, unsigned long nr_lines,
1303 Dwarf_Addr addr, unsigned long *idx)
1304{
1305 unsigned long i;
1306 Dwarf_Addr tmp;
1307
1308 for (i = 0; i < nr_lines; i++) {
1309 if (dwarf_lineaddr(dwarf_onesrcline(lines, i), &tmp))
1310 return false;
1311
1312 if (tmp == addr) {
1313 *idx = i;
1314 return true;
1315 }
1316 }
1317 return false;
1318}
1319
1320/*
1321 * die_get_postprologue_addr - Search next address after function prologue
1322 * @entrypc_idx: entrypc index
1323 * @lines: Line records of single CU
1324 * @nr_lines: Number of @lines
1325 * @hignpc: high PC address of function
1326 * @postprologue_addr: Next address after function prologue (return value)
1327 *
1328 * Look for prologue-end marker. If there is no explicit marker, return
1329 * address of next line record or next source line.
1330 */
1331static bool die_get_postprologue_addr(unsigned long entrypc_idx,
1332 Dwarf_Lines *lines,
1333 unsigned long nr_lines,
1334 Dwarf_Addr highpc,
1335 Dwarf_Addr *postprologue_addr)
1336{
1337 unsigned long i;
1338 int entrypc_lno, lno;
1339 Dwarf_Line *line;
1340 Dwarf_Addr addr;
1341 bool p_end;
1342
1343 /* entrypc_lno is actual source line number */
1344 line = dwarf_onesrcline(lines, entrypc_idx);
1345 if (dwarf_lineno(line, &entrypc_lno))
1346 return false;
1347
1348 for (i = entrypc_idx; i < nr_lines; i++) {
1349 line = dwarf_onesrcline(lines, i);
1350
1351 if (dwarf_lineaddr(line, &addr) ||
1352 dwarf_lineno(line, &lno) ||
1353 dwarf_lineprologueend(line, &p_end))
1354 return false;
1355
1356 /* highpc is exclusive. [entrypc,highpc) */
1357 if (addr >= highpc)
1358 break;
1359
1360 /* clang supports prologue-end marker */
1361 if (p_end)
1362 break;
1363
1364 /* Actual next line in source */
1365 if (lno != entrypc_lno)
1366 break;
1367
1368 /*
1369 * Single source line can have multiple line records.
1370 * For Example,
1371 * void foo() { printf("hello\n"); }
1372 * contains two line records. One points to declaration and
1373 * other points to printf() line. Variable 'lno' won't get
1374 * incremented in this case but 'i' will.
1375 */
1376 if (i != entrypc_idx)
1377 break;
1378 }
1379
1380 dwarf_lineaddr(line, postprologue_addr);
1381 if (*postprologue_addr >= highpc)
1382 dwarf_lineaddr(dwarf_onesrcline(lines, i - 1),
1383 postprologue_addr);
1384
1385 return true;
1386}
1387
1388/*
1389 * die_skip_prologue - Use next address after prologue as probe location
1390 * @sp_die: a subprogram DIE
1391 * @cu_die: a CU DIE
1392 * @entrypc: entrypc of the function
1393 *
1394 * Function prologue prepares stack and registers before executing function
1395 * logic. When target program is compiled without optimization, function
1396 * parameter information is only valid after prologue. When we probe entrypc
1397 * of the function, and try to record function parameter, it contains
1398 * garbage value.
1399 */
1400void die_skip_prologue(Dwarf_Die *sp_die, Dwarf_Die *cu_die,
1401 Dwarf_Addr *entrypc)
1402{
1403 size_t nr_lines = 0;
1404 unsigned long entrypc_idx = 0;
1405 Dwarf_Lines *lines = NULL;
1406 Dwarf_Addr postprologue_addr;
1407 Dwarf_Addr highpc;
1408
1409 if (dwarf_highpc(sp_die, &highpc))
1410 return;
1411
1412 if (dwarf_getsrclines(cu_die, &lines, &nr_lines))
1413 return;
1414
1415 if (!die_search_idx(lines, nr_lines, *entrypc, &entrypc_idx))
1416 return;
1417
1418 if (!die_get_postprologue_addr(entrypc_idx, lines, nr_lines,
1419 highpc, &postprologue_addr))
1420 return;
1421
1422 *entrypc = postprologue_addr;
1423}