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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/* 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 Dwarf_Attribute attr_mem;
482
483 if (idx < 0 || !dwarf_attr_integrate(dw_die, DW_AT_decl_file, &attr_mem) ||
484 !dwarf_cu_die(attr_mem.cu, &cu_die, NULL, NULL, NULL, NULL, NULL, NULL) ||
485 dwarf_getsrcfiles(&cu_die, &files, NULL) != 0)
486 return NULL;
487
488 return dwarf_filesrc(files, idx, NULL, NULL);
489}
490
491/**
492 * die_get_call_file - Get callsite file name of inlined function instance
493 * @in_die: a DIE of an inlined function instance
494 *
495 * Get call-site file name of @in_die. This means from which file the inline
496 * function is called.
497 */
498const char *die_get_call_file(Dwarf_Die *in_die)
499{
500 return die_get_file_name(in_die, die_get_call_fileno(in_die));
501}
502
503/**
504 * die_get_decl_file - Find the declared file name of this DIE
505 * @dw_die: a DIE for something declared.
506 *
507 * Get declared file name of @dw_die.
508 * NOTE: Since some version of clang DWARF5 implementation incorrectly uses
509 * file index 0 for DW_AT_decl_file, die_get_decl_file() will return NULL for
510 * such cases. Use this function instead.
511 */
512const char *die_get_decl_file(Dwarf_Die *dw_die)
513{
514 return die_get_file_name(dw_die, die_get_decl_fileno(dw_die));
515}
516
517/**
518 * die_find_child - Generic DIE search function in DIE tree
519 * @rt_die: a root DIE
520 * @callback: a callback function
521 * @data: a user data passed to the callback function
522 * @die_mem: a buffer for result DIE
523 *
524 * Trace DIE tree from @rt_die and call @callback for each child DIE.
525 * If @callback returns DIE_FIND_CB_END, this stores the DIE into
526 * @die_mem and returns it. If @callback returns DIE_FIND_CB_CONTINUE,
527 * this continues to trace the tree. Optionally, @callback can return
528 * DIE_FIND_CB_CHILD and DIE_FIND_CB_SIBLING, those means trace only
529 * the children and trace only the siblings respectively.
530 * Returns NULL if @callback can't find any appropriate DIE.
531 */
532Dwarf_Die *die_find_child(Dwarf_Die *rt_die,
533 int (*callback)(Dwarf_Die *, void *),
534 void *data, Dwarf_Die *die_mem)
535{
536 Dwarf_Die child_die;
537 int ret;
538
539 ret = dwarf_child(rt_die, die_mem);
540 if (ret != 0)
541 return NULL;
542
543 do {
544 ret = callback(die_mem, data);
545 if (ret == DIE_FIND_CB_END)
546 return die_mem;
547
548 if ((ret & DIE_FIND_CB_CHILD) &&
549 die_find_child(die_mem, callback, data, &child_die)) {
550 memcpy(die_mem, &child_die, sizeof(Dwarf_Die));
551 return die_mem;
552 }
553 } while ((ret & DIE_FIND_CB_SIBLING) &&
554 dwarf_siblingof(die_mem, die_mem) == 0);
555
556 return NULL;
557}
558
559struct __addr_die_search_param {
560 Dwarf_Addr addr;
561 Dwarf_Die *die_mem;
562};
563
564static int __die_search_func_tail_cb(Dwarf_Die *fn_die, void *data)
565{
566 struct __addr_die_search_param *ad = data;
567 Dwarf_Addr addr = 0;
568
569 if (dwarf_tag(fn_die) == DW_TAG_subprogram &&
570 !dwarf_highpc(fn_die, &addr) &&
571 addr == ad->addr) {
572 memcpy(ad->die_mem, fn_die, sizeof(Dwarf_Die));
573 return DWARF_CB_ABORT;
574 }
575 return DWARF_CB_OK;
576}
577
578/**
579 * die_find_tailfunc - Search for a non-inlined function with tail call at
580 * given address
581 * @cu_die: a CU DIE which including @addr
582 * @addr: target address
583 * @die_mem: a buffer for result DIE
584 *
585 * Search for a non-inlined function DIE with tail call at @addr. Stores the
586 * DIE to @die_mem and returns it if found. Returns NULL if failed.
587 */
588Dwarf_Die *die_find_tailfunc(Dwarf_Die *cu_die, Dwarf_Addr addr,
589 Dwarf_Die *die_mem)
590{
591 struct __addr_die_search_param ad;
592 ad.addr = addr;
593 ad.die_mem = die_mem;
594 /* dwarf_getscopes can't find subprogram. */
595 if (!dwarf_getfuncs(cu_die, __die_search_func_tail_cb, &ad, 0))
596 return NULL;
597 else
598 return die_mem;
599}
600
601/* die_find callback for non-inlined function search */
602static int __die_search_func_cb(Dwarf_Die *fn_die, void *data)
603{
604 struct __addr_die_search_param *ad = data;
605
606 /*
607 * Since a declaration entry doesn't has given pc, this always returns
608 * function definition entry.
609 */
610 if (dwarf_tag(fn_die) == DW_TAG_subprogram &&
611 dwarf_haspc(fn_die, ad->addr)) {
612 memcpy(ad->die_mem, fn_die, sizeof(Dwarf_Die));
613 return DWARF_CB_ABORT;
614 }
615 return DWARF_CB_OK;
616}
617
618/**
619 * die_find_realfunc - Search a non-inlined function at given address
620 * @cu_die: a CU DIE which including @addr
621 * @addr: target address
622 * @die_mem: a buffer for result DIE
623 *
624 * Search a non-inlined function DIE which includes @addr. Stores the
625 * DIE to @die_mem and returns it if found. Returns NULL if failed.
626 */
627Dwarf_Die *die_find_realfunc(Dwarf_Die *cu_die, Dwarf_Addr addr,
628 Dwarf_Die *die_mem)
629{
630 struct __addr_die_search_param ad;
631 ad.addr = addr;
632 ad.die_mem = die_mem;
633 /* dwarf_getscopes can't find subprogram. */
634 if (!dwarf_getfuncs(cu_die, __die_search_func_cb, &ad, 0))
635 return NULL;
636 else
637 return die_mem;
638}
639
640/* die_find callback for inline function search */
641static int __die_find_inline_cb(Dwarf_Die *die_mem, void *data)
642{
643 Dwarf_Addr *addr = data;
644
645 if (dwarf_tag(die_mem) == DW_TAG_inlined_subroutine &&
646 dwarf_haspc(die_mem, *addr))
647 return DIE_FIND_CB_END;
648
649 return DIE_FIND_CB_CONTINUE;
650}
651
652/**
653 * die_find_top_inlinefunc - Search the top inlined function at given address
654 * @sp_die: a subprogram DIE which including @addr
655 * @addr: target address
656 * @die_mem: a buffer for result DIE
657 *
658 * Search an inlined function DIE which includes @addr. Stores the
659 * DIE to @die_mem and returns it if found. Returns NULL if failed.
660 * Even if several inlined functions are expanded recursively, this
661 * doesn't trace it down, and returns the topmost one.
662 */
663Dwarf_Die *die_find_top_inlinefunc(Dwarf_Die *sp_die, Dwarf_Addr addr,
664 Dwarf_Die *die_mem)
665{
666 return die_find_child(sp_die, __die_find_inline_cb, &addr, die_mem);
667}
668
669/**
670 * die_find_inlinefunc - Search an inlined function at given address
671 * @sp_die: a subprogram DIE which including @addr
672 * @addr: target address
673 * @die_mem: a buffer for result DIE
674 *
675 * Search an inlined function DIE which includes @addr. Stores the
676 * DIE to @die_mem and returns it if found. Returns NULL if failed.
677 * If several inlined functions are expanded recursively, this trace
678 * it down and returns deepest one.
679 */
680Dwarf_Die *die_find_inlinefunc(Dwarf_Die *sp_die, Dwarf_Addr addr,
681 Dwarf_Die *die_mem)
682{
683 Dwarf_Die tmp_die;
684
685 sp_die = die_find_child(sp_die, __die_find_inline_cb, &addr, &tmp_die);
686 if (!sp_die)
687 return NULL;
688
689 /* Inlined function could be recursive. Trace it until fail */
690 while (sp_die) {
691 memcpy(die_mem, sp_die, sizeof(Dwarf_Die));
692 sp_die = die_find_child(sp_die, __die_find_inline_cb, &addr,
693 &tmp_die);
694 }
695
696 return die_mem;
697}
698
699struct __instance_walk_param {
700 void *addr;
701 int (*callback)(Dwarf_Die *, void *);
702 void *data;
703 int retval;
704};
705
706static int __die_walk_instances_cb(Dwarf_Die *inst, void *data)
707{
708 struct __instance_walk_param *iwp = data;
709 Dwarf_Attribute attr_mem;
710 Dwarf_Die origin_mem;
711 Dwarf_Attribute *attr;
712 Dwarf_Die *origin;
713 int tmp;
714
715 if (!die_is_func_instance(inst))
716 return DIE_FIND_CB_CONTINUE;
717
718 attr = dwarf_attr(inst, DW_AT_abstract_origin, &attr_mem);
719 if (attr == NULL)
720 return DIE_FIND_CB_CONTINUE;
721
722 origin = dwarf_formref_die(attr, &origin_mem);
723 if (origin == NULL || origin->addr != iwp->addr)
724 return DIE_FIND_CB_CONTINUE;
725
726 /* Ignore redundant instances */
727 if (dwarf_tag(inst) == DW_TAG_inlined_subroutine) {
728 dwarf_decl_line(origin, &tmp);
729 if (die_get_call_lineno(inst) == tmp) {
730 tmp = die_get_decl_fileno(origin);
731 if (die_get_call_fileno(inst) == tmp)
732 return DIE_FIND_CB_CONTINUE;
733 }
734 }
735
736 iwp->retval = iwp->callback(inst, iwp->data);
737
738 return (iwp->retval) ? DIE_FIND_CB_END : DIE_FIND_CB_CONTINUE;
739}
740
741/**
742 * die_walk_instances - Walk on instances of given DIE
743 * @or_die: an abstract original DIE
744 * @callback: a callback function which is called with instance DIE
745 * @data: user data
746 *
747 * Walk on the instances of give @in_die. @in_die must be an inlined function
748 * declaration. This returns the return value of @callback if it returns
749 * non-zero value, or -ENOENT if there is no instance.
750 */
751int die_walk_instances(Dwarf_Die *or_die, int (*callback)(Dwarf_Die *, void *),
752 void *data)
753{
754 Dwarf_Die cu_die;
755 Dwarf_Die die_mem;
756 struct __instance_walk_param iwp = {
757 .addr = or_die->addr,
758 .callback = callback,
759 .data = data,
760 .retval = -ENOENT,
761 };
762
763 if (dwarf_diecu(or_die, &cu_die, NULL, NULL) == NULL)
764 return -ENOENT;
765
766 die_find_child(&cu_die, __die_walk_instances_cb, &iwp, &die_mem);
767
768 return iwp.retval;
769}
770
771/* Line walker internal parameters */
772struct __line_walk_param {
773 bool recursive;
774 line_walk_callback_t callback;
775 void *data;
776 int retval;
777};
778
779static int __die_walk_funclines_cb(Dwarf_Die *in_die, void *data)
780{
781 struct __line_walk_param *lw = data;
782 Dwarf_Addr addr = 0;
783 const char *fname;
784 int lineno;
785
786 if (dwarf_tag(in_die) == DW_TAG_inlined_subroutine) {
787 fname = die_get_call_file(in_die);
788 lineno = die_get_call_lineno(in_die);
789 if (fname && lineno > 0 && die_entrypc(in_die, &addr) == 0) {
790 lw->retval = lw->callback(fname, lineno, addr, lw->data);
791 if (lw->retval != 0)
792 return DIE_FIND_CB_END;
793 }
794 if (!lw->recursive)
795 return DIE_FIND_CB_SIBLING;
796 }
797
798 if (addr) {
799 fname = die_get_decl_file(in_die);
800 if (fname && dwarf_decl_line(in_die, &lineno) == 0) {
801 lw->retval = lw->callback(fname, lineno, addr, lw->data);
802 if (lw->retval != 0)
803 return DIE_FIND_CB_END;
804 }
805 }
806
807 /* Continue to search nested inlined function call-sites */
808 return DIE_FIND_CB_CONTINUE;
809}
810
811/* Walk on lines of blocks included in given DIE */
812static int __die_walk_funclines(Dwarf_Die *sp_die, bool recursive,
813 line_walk_callback_t callback, void *data)
814{
815 struct __line_walk_param lw = {
816 .recursive = recursive,
817 .callback = callback,
818 .data = data,
819 .retval = 0,
820 };
821 Dwarf_Die die_mem;
822 Dwarf_Addr addr;
823 const char *fname;
824 int lineno;
825
826 /* Handle function declaration line */
827 fname = die_get_decl_file(sp_die);
828 if (fname && dwarf_decl_line(sp_die, &lineno) == 0 &&
829 die_entrypc(sp_die, &addr) == 0) {
830 lw.retval = callback(fname, lineno, addr, data);
831 if (lw.retval != 0)
832 goto done;
833 }
834 die_find_child(sp_die, __die_walk_funclines_cb, &lw, &die_mem);
835done:
836 return lw.retval;
837}
838
839static int __die_walk_culines_cb(Dwarf_Die *sp_die, void *data)
840{
841 struct __line_walk_param *lw = data;
842
843 /*
844 * Since inlined function can include another inlined function in
845 * the same file, we need to walk in it recursively.
846 */
847 lw->retval = __die_walk_funclines(sp_die, true, lw->callback, lw->data);
848 if (lw->retval != 0)
849 return DWARF_CB_ABORT;
850
851 return DWARF_CB_OK;
852}
853
854/**
855 * die_walk_lines - Walk on lines inside given DIE
856 * @rt_die: a root DIE (CU, subprogram or inlined_subroutine)
857 * @callback: callback routine
858 * @data: user data
859 *
860 * Walk on all lines inside given @rt_die and call @callback on each line.
861 * If the @rt_die is a function, walk only on the lines inside the function,
862 * otherwise @rt_die must be a CU DIE.
863 * Note that this walks not only dwarf line list, but also function entries
864 * and inline call-site.
865 */
866int die_walk_lines(Dwarf_Die *rt_die, line_walk_callback_t callback, void *data)
867{
868 Dwarf_Lines *lines;
869 Dwarf_Line *line;
870 Dwarf_Addr addr;
871 const char *fname, *decf = NULL, *inf = NULL;
872 int lineno, ret = 0;
873 int decl = 0, inl;
874 Dwarf_Die die_mem, *cu_die;
875 size_t nlines, i;
876 bool flag;
877
878 /* Get the CU die */
879 if (dwarf_tag(rt_die) != DW_TAG_compile_unit) {
880 cu_die = dwarf_diecu(rt_die, &die_mem, NULL, NULL);
881 dwarf_decl_line(rt_die, &decl);
882 decf = die_get_decl_file(rt_die);
883 if (!decf) {
884 pr_debug2("Failed to get the declared file name of %s\n",
885 dwarf_diename(rt_die));
886 return -EINVAL;
887 }
888 } else
889 cu_die = rt_die;
890 if (!cu_die) {
891 pr_debug2("Failed to get CU from given DIE.\n");
892 return -EINVAL;
893 }
894
895 /* Get lines list in the CU */
896 if (dwarf_getsrclines(cu_die, &lines, &nlines) != 0) {
897 pr_debug2("Failed to get source lines on this CU.\n");
898 return -ENOENT;
899 }
900 pr_debug2("Get %zd lines from this CU\n", nlines);
901
902 /* Walk on the lines on lines list */
903 for (i = 0; i < nlines; i++) {
904 line = dwarf_onesrcline(lines, i);
905 if (line == NULL ||
906 dwarf_lineno(line, &lineno) != 0 ||
907 dwarf_lineaddr(line, &addr) != 0) {
908 pr_debug2("Failed to get line info. "
909 "Possible error in debuginfo.\n");
910 continue;
911 }
912 /* Skip end-of-sequence */
913 if (dwarf_lineendsequence(line, &flag) != 0 || flag)
914 continue;
915 /* Skip Non statement line-info */
916 if (dwarf_linebeginstatement(line, &flag) != 0 || !flag)
917 continue;
918 /* Filter lines based on address */
919 if (rt_die != cu_die) {
920 /*
921 * Address filtering
922 * The line is included in given function, and
923 * no inline block includes it.
924 */
925 if (!dwarf_haspc(rt_die, addr))
926 continue;
927
928 if (die_find_inlinefunc(rt_die, addr, &die_mem)) {
929 /* Call-site check */
930 inf = die_get_call_file(&die_mem);
931 if ((inf && !strcmp(inf, decf)) &&
932 die_get_call_lineno(&die_mem) == lineno)
933 goto found;
934
935 dwarf_decl_line(&die_mem, &inl);
936 if (inl != decl ||
937 decf != die_get_decl_file(&die_mem))
938 continue;
939 }
940 }
941found:
942 /* Get source line */
943 fname = dwarf_linesrc(line, NULL, NULL);
944
945 ret = callback(fname, lineno, addr, data);
946 if (ret != 0)
947 return ret;
948 }
949
950 /*
951 * Dwarf lines doesn't include function declarations and inlined
952 * subroutines. We have to check functions list or given function.
953 */
954 if (rt_die != cu_die)
955 /*
956 * Don't need walk inlined functions recursively, because
957 * inner inlined functions don't have the lines of the
958 * specified function.
959 */
960 ret = __die_walk_funclines(rt_die, false, callback, data);
961 else {
962 struct __line_walk_param param = {
963 .callback = callback,
964 .data = data,
965 .retval = 0,
966 };
967 dwarf_getfuncs(cu_die, __die_walk_culines_cb, ¶m, 0);
968 ret = param.retval;
969 }
970
971 return ret;
972}
973
974struct __find_variable_param {
975 const char *name;
976 Dwarf_Addr addr;
977};
978
979static int __die_find_variable_cb(Dwarf_Die *die_mem, void *data)
980{
981 struct __find_variable_param *fvp = data;
982 Dwarf_Attribute attr;
983 int tag;
984
985 tag = dwarf_tag(die_mem);
986 if ((tag == DW_TAG_formal_parameter ||
987 tag == DW_TAG_variable) &&
988 die_compare_name(die_mem, fvp->name) &&
989 /*
990 * Does the DIE have location information or const value
991 * or external instance?
992 */
993 (dwarf_attr(die_mem, DW_AT_external, &attr) ||
994 dwarf_attr(die_mem, DW_AT_location, &attr) ||
995 dwarf_attr(die_mem, DW_AT_const_value, &attr)))
996 return DIE_FIND_CB_END;
997 if (dwarf_haspc(die_mem, fvp->addr))
998 return DIE_FIND_CB_CONTINUE;
999 else
1000 return DIE_FIND_CB_SIBLING;
1001}
1002
1003/**
1004 * die_find_variable_at - Find a given name variable at given address
1005 * @sp_die: a function DIE
1006 * @name: variable name
1007 * @addr: address
1008 * @die_mem: a buffer for result DIE
1009 *
1010 * Find a variable DIE called @name at @addr in @sp_die.
1011 */
1012Dwarf_Die *die_find_variable_at(Dwarf_Die *sp_die, const char *name,
1013 Dwarf_Addr addr, Dwarf_Die *die_mem)
1014{
1015 struct __find_variable_param fvp = { .name = name, .addr = addr};
1016
1017 return die_find_child(sp_die, __die_find_variable_cb, (void *)&fvp,
1018 die_mem);
1019}
1020
1021static int __die_find_member_cb(Dwarf_Die *die_mem, void *data)
1022{
1023 const char *name = data;
1024
1025 if (dwarf_tag(die_mem) == DW_TAG_member) {
1026 if (die_compare_name(die_mem, name))
1027 return DIE_FIND_CB_END;
1028 else if (!dwarf_diename(die_mem)) { /* Unnamed structure */
1029 Dwarf_Die type_die, tmp_die;
1030 if (die_get_type(die_mem, &type_die) &&
1031 die_find_member(&type_die, name, &tmp_die))
1032 return DIE_FIND_CB_END;
1033 }
1034 }
1035 return DIE_FIND_CB_SIBLING;
1036}
1037
1038/**
1039 * die_find_member - Find a given name member in a data structure
1040 * @st_die: a data structure type DIE
1041 * @name: member name
1042 * @die_mem: a buffer for result DIE
1043 *
1044 * Find a member DIE called @name in @st_die.
1045 */
1046Dwarf_Die *die_find_member(Dwarf_Die *st_die, const char *name,
1047 Dwarf_Die *die_mem)
1048{
1049 return die_find_child(st_die, __die_find_member_cb, (void *)name,
1050 die_mem);
1051}
1052
1053/**
1054 * die_get_typename_from_type - Get the name of given type DIE
1055 * @type_die: a type DIE
1056 * @buf: a strbuf for result type name
1057 *
1058 * Get the name of @type_die and stores it to @buf. Return 0 if succeeded.
1059 * and Return -ENOENT if failed to find type name.
1060 * Note that the result will stores typedef name if possible, and stores
1061 * "*(function_type)" if the type is a function pointer.
1062 */
1063int die_get_typename_from_type(Dwarf_Die *type_die, struct strbuf *buf)
1064{
1065 int tag, ret;
1066 const char *tmp = "";
1067
1068 tag = dwarf_tag(type_die);
1069 if (tag == DW_TAG_array_type || tag == DW_TAG_pointer_type)
1070 tmp = "*";
1071 else if (tag == DW_TAG_subroutine_type) {
1072 /* Function pointer */
1073 return strbuf_add(buf, "(function_type)", 15);
1074 } else {
1075 const char *name = dwarf_diename(type_die);
1076
1077 if (tag == DW_TAG_union_type)
1078 tmp = "union ";
1079 else if (tag == DW_TAG_structure_type)
1080 tmp = "struct ";
1081 else if (tag == DW_TAG_enumeration_type)
1082 tmp = "enum ";
1083 else if (name == NULL)
1084 return -ENOENT;
1085 /* Write a base name */
1086 return strbuf_addf(buf, "%s%s", tmp, name ?: "");
1087 }
1088 ret = die_get_typename(type_die, buf);
1089 if (ret < 0) {
1090 /* void pointer has no type attribute */
1091 if (tag == DW_TAG_pointer_type && ret == -ENOENT)
1092 return strbuf_addf(buf, "void*");
1093
1094 return ret;
1095 }
1096 return strbuf_addstr(buf, tmp);
1097}
1098
1099/**
1100 * die_get_typename - Get the name of given variable DIE
1101 * @vr_die: a variable DIE
1102 * @buf: a strbuf for result type name
1103 *
1104 * Get the name of @vr_die and stores it to @buf. Return 0 if succeeded.
1105 * and Return -ENOENT if failed to find type name.
1106 * Note that the result will stores typedef name if possible, and stores
1107 * "*(function_type)" if the type is a function pointer.
1108 */
1109int die_get_typename(Dwarf_Die *vr_die, struct strbuf *buf)
1110{
1111 Dwarf_Die type;
1112
1113 if (__die_get_real_type(vr_die, &type) == NULL)
1114 return -ENOENT;
1115
1116 return die_get_typename_from_type(&type, buf);
1117}
1118
1119/**
1120 * die_get_varname - Get the name and type of given variable DIE
1121 * @vr_die: a variable DIE
1122 * @buf: a strbuf for type and variable name
1123 *
1124 * Get the name and type of @vr_die and stores it in @buf as "type\tname".
1125 */
1126int die_get_varname(Dwarf_Die *vr_die, struct strbuf *buf)
1127{
1128 int ret;
1129
1130 ret = die_get_typename(vr_die, buf);
1131 if (ret < 0) {
1132 pr_debug("Failed to get type, make it unknown.\n");
1133 ret = strbuf_add(buf, "(unknown_type)", 14);
1134 }
1135
1136 return ret < 0 ? ret : strbuf_addf(buf, "\t%s", dwarf_diename(vr_die));
1137}
1138
1139#ifdef HAVE_DWARF_GETLOCATIONS_SUPPORT
1140/**
1141 * die_get_var_innermost_scope - Get innermost scope range of given variable DIE
1142 * @sp_die: a subprogram DIE
1143 * @vr_die: a variable DIE
1144 * @buf: a strbuf for variable byte offset range
1145 *
1146 * Get the innermost scope range of @vr_die and stores it in @buf as
1147 * "@<function_name+[NN-NN,NN-NN]>".
1148 */
1149static int die_get_var_innermost_scope(Dwarf_Die *sp_die, Dwarf_Die *vr_die,
1150 struct strbuf *buf)
1151{
1152 Dwarf_Die *scopes;
1153 int count;
1154 size_t offset = 0;
1155 Dwarf_Addr base;
1156 Dwarf_Addr start, end;
1157 Dwarf_Addr entry;
1158 int ret;
1159 bool first = true;
1160 const char *name;
1161
1162 ret = die_entrypc(sp_die, &entry);
1163 if (ret)
1164 return ret;
1165
1166 name = dwarf_diename(sp_die);
1167 if (!name)
1168 return -ENOENT;
1169
1170 count = dwarf_getscopes_die(vr_die, &scopes);
1171
1172 /* (*SCOPES)[1] is the DIE for the scope containing that scope */
1173 if (count <= 1) {
1174 ret = -EINVAL;
1175 goto out;
1176 }
1177
1178 while ((offset = dwarf_ranges(&scopes[1], offset, &base,
1179 &start, &end)) > 0) {
1180 start -= entry;
1181 end -= entry;
1182
1183 if (first) {
1184 ret = strbuf_addf(buf, "@<%s+[%" PRIu64 "-%" PRIu64,
1185 name, start, end);
1186 first = false;
1187 } else {
1188 ret = strbuf_addf(buf, ",%" PRIu64 "-%" PRIu64,
1189 start, end);
1190 }
1191 if (ret < 0)
1192 goto out;
1193 }
1194
1195 if (!first)
1196 ret = strbuf_add(buf, "]>", 2);
1197
1198out:
1199 free(scopes);
1200 return ret;
1201}
1202
1203/**
1204 * die_get_var_range - Get byte offset range of given variable DIE
1205 * @sp_die: a subprogram DIE
1206 * @vr_die: a variable DIE
1207 * @buf: a strbuf for type and variable name and byte offset range
1208 *
1209 * Get the byte offset range of @vr_die and stores it in @buf as
1210 * "@<function_name+[NN-NN,NN-NN]>".
1211 */
1212int die_get_var_range(Dwarf_Die *sp_die, Dwarf_Die *vr_die, struct strbuf *buf)
1213{
1214 int ret = 0;
1215 Dwarf_Addr base;
1216 Dwarf_Addr start, end;
1217 Dwarf_Addr entry;
1218 Dwarf_Op *op;
1219 size_t nops;
1220 size_t offset = 0;
1221 Dwarf_Attribute attr;
1222 bool first = true;
1223 const char *name;
1224
1225 ret = die_entrypc(sp_die, &entry);
1226 if (ret)
1227 return ret;
1228
1229 name = dwarf_diename(sp_die);
1230 if (!name)
1231 return -ENOENT;
1232
1233 if (dwarf_attr(vr_die, DW_AT_location, &attr) == NULL)
1234 return -EINVAL;
1235
1236 while ((offset = dwarf_getlocations(&attr, offset, &base,
1237 &start, &end, &op, &nops)) > 0) {
1238 if (start == 0) {
1239 /* Single Location Descriptions */
1240 ret = die_get_var_innermost_scope(sp_die, vr_die, buf);
1241 goto out;
1242 }
1243
1244 /* Location Lists */
1245 start -= entry;
1246 end -= entry;
1247 if (first) {
1248 ret = strbuf_addf(buf, "@<%s+[%" PRIu64 "-%" PRIu64,
1249 name, start, end);
1250 first = false;
1251 } else {
1252 ret = strbuf_addf(buf, ",%" PRIu64 "-%" PRIu64,
1253 start, end);
1254 }
1255 if (ret < 0)
1256 goto out;
1257 }
1258
1259 if (!first)
1260 ret = strbuf_add(buf, "]>", 2);
1261out:
1262 return ret;
1263}
1264
1265/* Interval parameters for __die_find_var_reg_cb() */
1266struct find_var_data {
1267 /* Target instruction address */
1268 Dwarf_Addr pc;
1269 /* Target memory address (for global data) */
1270 Dwarf_Addr addr;
1271 /* Target register */
1272 unsigned reg;
1273 /* Access offset, set for global data */
1274 int offset;
1275};
1276
1277/* Max number of registers DW_OP_regN supports */
1278#define DWARF_OP_DIRECT_REGS 32
1279
1280/* Only checks direct child DIEs in the given scope. */
1281static int __die_find_var_reg_cb(Dwarf_Die *die_mem, void *arg)
1282{
1283 struct find_var_data *data = arg;
1284 int tag = dwarf_tag(die_mem);
1285 ptrdiff_t off = 0;
1286 Dwarf_Attribute attr;
1287 Dwarf_Addr base, start, end;
1288 Dwarf_Op *ops;
1289 size_t nops;
1290
1291 if (tag != DW_TAG_variable && tag != DW_TAG_formal_parameter)
1292 return DIE_FIND_CB_SIBLING;
1293
1294 if (dwarf_attr(die_mem, DW_AT_location, &attr) == NULL)
1295 return DIE_FIND_CB_SIBLING;
1296
1297 while ((off = dwarf_getlocations(&attr, off, &base, &start, &end, &ops, &nops)) > 0) {
1298 /* Assuming the location list is sorted by address */
1299 if (end < data->pc)
1300 continue;
1301 if (start > data->pc)
1302 break;
1303
1304 /* Only match with a simple case */
1305 if (data->reg < DWARF_OP_DIRECT_REGS) {
1306 if (ops->atom == (DW_OP_reg0 + data->reg) && nops == 1)
1307 return DIE_FIND_CB_END;
1308 } else {
1309 if (ops->atom == DW_OP_regx && ops->number == data->reg &&
1310 nops == 1)
1311 return DIE_FIND_CB_END;
1312 }
1313 }
1314 return DIE_FIND_CB_SIBLING;
1315}
1316
1317/**
1318 * die_find_variable_by_reg - Find a variable saved in a register
1319 * @sc_die: a scope DIE
1320 * @pc: the program address to find
1321 * @reg: the register number to find
1322 * @die_mem: a buffer to save the resulting DIE
1323 *
1324 * Find the variable DIE accessed by the given register.
1325 */
1326Dwarf_Die *die_find_variable_by_reg(Dwarf_Die *sc_die, Dwarf_Addr pc, int reg,
1327 Dwarf_Die *die_mem)
1328{
1329 struct find_var_data data = {
1330 .pc = pc,
1331 .reg = reg,
1332 };
1333 return die_find_child(sc_die, __die_find_var_reg_cb, &data, die_mem);
1334}
1335
1336/* Only checks direct child DIEs in the given scope */
1337static int __die_find_var_addr_cb(Dwarf_Die *die_mem, void *arg)
1338{
1339 struct find_var_data *data = arg;
1340 int tag = dwarf_tag(die_mem);
1341 ptrdiff_t off = 0;
1342 Dwarf_Attribute attr;
1343 Dwarf_Addr base, start, end;
1344 Dwarf_Word size;
1345 Dwarf_Die type_die;
1346 Dwarf_Op *ops;
1347 size_t nops;
1348
1349 if (tag != DW_TAG_variable)
1350 return DIE_FIND_CB_SIBLING;
1351
1352 if (dwarf_attr(die_mem, DW_AT_location, &attr) == NULL)
1353 return DIE_FIND_CB_SIBLING;
1354
1355 while ((off = dwarf_getlocations(&attr, off, &base, &start, &end, &ops, &nops)) > 0) {
1356 if (ops->atom != DW_OP_addr)
1357 continue;
1358
1359 if (data->addr < ops->number)
1360 continue;
1361
1362 if (data->addr == ops->number) {
1363 /* Update offset relative to the start of the variable */
1364 data->offset = 0;
1365 return DIE_FIND_CB_END;
1366 }
1367
1368 if (die_get_real_type(die_mem, &type_die) == NULL)
1369 continue;
1370
1371 if (dwarf_aggregate_size(&type_die, &size) < 0)
1372 continue;
1373
1374 if (data->addr >= ops->number + size)
1375 continue;
1376
1377 /* Update offset relative to the start of the variable */
1378 data->offset = data->addr - ops->number;
1379 return DIE_FIND_CB_END;
1380 }
1381 return DIE_FIND_CB_SIBLING;
1382}
1383
1384/**
1385 * die_find_variable_by_addr - Find variable located at given address
1386 * @sc_die: a scope DIE
1387 * @pc: the program address to find
1388 * @addr: the data address to find
1389 * @die_mem: a buffer to save the resulting DIE
1390 * @offset: the offset in the resulting type
1391 *
1392 * Find the variable DIE located at the given address (in PC-relative mode).
1393 * This is usually for global variables.
1394 */
1395Dwarf_Die *die_find_variable_by_addr(Dwarf_Die *sc_die, Dwarf_Addr pc,
1396 Dwarf_Addr addr, Dwarf_Die *die_mem,
1397 int *offset)
1398{
1399 struct find_var_data data = {
1400 .pc = pc,
1401 .addr = addr,
1402 };
1403 Dwarf_Die *result;
1404
1405 result = die_find_child(sc_die, __die_find_var_addr_cb, &data, die_mem);
1406 if (result)
1407 *offset = data.offset;
1408 return result;
1409}
1410#endif
1411
1412/*
1413 * die_has_loclist - Check if DW_AT_location of @vr_die is a location list
1414 * @vr_die: a variable DIE
1415 */
1416static bool die_has_loclist(Dwarf_Die *vr_die)
1417{
1418 Dwarf_Attribute loc;
1419 int tag = dwarf_tag(vr_die);
1420
1421 if (tag != DW_TAG_formal_parameter &&
1422 tag != DW_TAG_variable)
1423 return false;
1424
1425 return (dwarf_attr_integrate(vr_die, DW_AT_location, &loc) &&
1426 dwarf_whatform(&loc) == DW_FORM_sec_offset);
1427}
1428
1429/*
1430 * die_is_optimized_target - Check if target program is compiled with
1431 * optimization
1432 * @cu_die: a CU DIE
1433 *
1434 * For any object in given CU whose DW_AT_location is a location list,
1435 * target program is compiled with optimization. This is applicable to
1436 * clang as well.
1437 */
1438bool die_is_optimized_target(Dwarf_Die *cu_die)
1439{
1440 Dwarf_Die tmp_die;
1441
1442 if (die_has_loclist(cu_die))
1443 return true;
1444
1445 if (!dwarf_child(cu_die, &tmp_die) &&
1446 die_is_optimized_target(&tmp_die))
1447 return true;
1448
1449 if (!dwarf_siblingof(cu_die, &tmp_die) &&
1450 die_is_optimized_target(&tmp_die))
1451 return true;
1452
1453 return false;
1454}
1455
1456/*
1457 * die_search_idx - Search index of given line address
1458 * @lines: Line records of single CU
1459 * @nr_lines: Number of @lines
1460 * @addr: address we are looking for
1461 * @idx: index to be set by this function (return value)
1462 *
1463 * Search for @addr by looping over every lines of CU. If address
1464 * matches, set index of that line in @idx. Note that single source
1465 * line can have multiple line records. i.e. single source line can
1466 * have multiple index.
1467 */
1468static bool die_search_idx(Dwarf_Lines *lines, unsigned long nr_lines,
1469 Dwarf_Addr addr, unsigned long *idx)
1470{
1471 unsigned long i;
1472 Dwarf_Addr tmp;
1473
1474 for (i = 0; i < nr_lines; i++) {
1475 if (dwarf_lineaddr(dwarf_onesrcline(lines, i), &tmp))
1476 return false;
1477
1478 if (tmp == addr) {
1479 *idx = i;
1480 return true;
1481 }
1482 }
1483 return false;
1484}
1485
1486/*
1487 * die_get_postprologue_addr - Search next address after function prologue
1488 * @entrypc_idx: entrypc index
1489 * @lines: Line records of single CU
1490 * @nr_lines: Number of @lines
1491 * @hignpc: high PC address of function
1492 * @postprologue_addr: Next address after function prologue (return value)
1493 *
1494 * Look for prologue-end marker. If there is no explicit marker, return
1495 * address of next line record or next source line.
1496 */
1497static bool die_get_postprologue_addr(unsigned long entrypc_idx,
1498 Dwarf_Lines *lines,
1499 unsigned long nr_lines,
1500 Dwarf_Addr highpc,
1501 Dwarf_Addr *postprologue_addr)
1502{
1503 unsigned long i;
1504 int entrypc_lno, lno;
1505 Dwarf_Line *line;
1506 Dwarf_Addr addr;
1507 bool p_end;
1508
1509 /* entrypc_lno is actual source line number */
1510 line = dwarf_onesrcline(lines, entrypc_idx);
1511 if (dwarf_lineno(line, &entrypc_lno))
1512 return false;
1513
1514 for (i = entrypc_idx; i < nr_lines; i++) {
1515 line = dwarf_onesrcline(lines, i);
1516
1517 if (dwarf_lineaddr(line, &addr) ||
1518 dwarf_lineno(line, &lno) ||
1519 dwarf_lineprologueend(line, &p_end))
1520 return false;
1521
1522 /* highpc is exclusive. [entrypc,highpc) */
1523 if (addr >= highpc)
1524 break;
1525
1526 /* clang supports prologue-end marker */
1527 if (p_end)
1528 break;
1529
1530 /* Actual next line in source */
1531 if (lno != entrypc_lno)
1532 break;
1533
1534 /*
1535 * Single source line can have multiple line records.
1536 * For Example,
1537 * void foo() { printf("hello\n"); }
1538 * contains two line records. One points to declaration and
1539 * other points to printf() line. Variable 'lno' won't get
1540 * incremented in this case but 'i' will.
1541 */
1542 if (i != entrypc_idx)
1543 break;
1544 }
1545
1546 dwarf_lineaddr(line, postprologue_addr);
1547 if (*postprologue_addr >= highpc)
1548 dwarf_lineaddr(dwarf_onesrcline(lines, i - 1),
1549 postprologue_addr);
1550
1551 return true;
1552}
1553
1554/*
1555 * die_skip_prologue - Use next address after prologue as probe location
1556 * @sp_die: a subprogram DIE
1557 * @cu_die: a CU DIE
1558 * @entrypc: entrypc of the function
1559 *
1560 * Function prologue prepares stack and registers before executing function
1561 * logic. When target program is compiled without optimization, function
1562 * parameter information is only valid after prologue. When we probe entrypc
1563 * of the function, and try to record function parameter, it contains
1564 * garbage value.
1565 */
1566void die_skip_prologue(Dwarf_Die *sp_die, Dwarf_Die *cu_die,
1567 Dwarf_Addr *entrypc)
1568{
1569 size_t nr_lines = 0;
1570 unsigned long entrypc_idx = 0;
1571 Dwarf_Lines *lines = NULL;
1572 Dwarf_Addr postprologue_addr;
1573 Dwarf_Addr highpc;
1574
1575 if (dwarf_highpc(sp_die, &highpc))
1576 return;
1577
1578 if (dwarf_getsrclines(cu_die, &lines, &nr_lines))
1579 return;
1580
1581 if (!die_search_idx(lines, nr_lines, *entrypc, &entrypc_idx))
1582 return;
1583
1584 if (!die_get_postprologue_addr(entrypc_idx, lines, nr_lines,
1585 highpc, &postprologue_addr))
1586 return;
1587
1588 *entrypc = postprologue_addr;
1589}
1590
1591/* Internal parameters for __die_find_scope_cb() */
1592struct find_scope_data {
1593 /* Target instruction address */
1594 Dwarf_Addr pc;
1595 /* Number of scopes found [output] */
1596 int nr;
1597 /* Array of scopes found, 0 for the outermost one. [output] */
1598 Dwarf_Die *scopes;
1599};
1600
1601static int __die_find_scope_cb(Dwarf_Die *die_mem, void *arg)
1602{
1603 struct find_scope_data *data = arg;
1604
1605 if (dwarf_haspc(die_mem, data->pc)) {
1606 Dwarf_Die *tmp;
1607
1608 tmp = realloc(data->scopes, (data->nr + 1) * sizeof(*tmp));
1609 if (tmp == NULL)
1610 return DIE_FIND_CB_END;
1611
1612 memcpy(tmp + data->nr, die_mem, sizeof(*die_mem));
1613 data->scopes = tmp;
1614 data->nr++;
1615 return DIE_FIND_CB_CHILD;
1616 }
1617 return DIE_FIND_CB_SIBLING;
1618}
1619
1620/**
1621 * die_get_scopes - Return a list of scopes including the address
1622 * @cu_die: a compile unit DIE
1623 * @pc: the address to find
1624 * @scopes: the array of DIEs for scopes (result)
1625 *
1626 * This function does the same as the dwarf_getscopes() but doesn't follow
1627 * the origins of inlined functions. It returns the number of scopes saved
1628 * in the @scopes argument. The outer scope will be saved first (index 0) and
1629 * the last one is the innermost scope at the @pc.
1630 */
1631int die_get_scopes(Dwarf_Die *cu_die, Dwarf_Addr pc, Dwarf_Die **scopes)
1632{
1633 struct find_scope_data data = {
1634 .pc = pc,
1635 };
1636 Dwarf_Die die_mem;
1637
1638 die_find_child(cu_die, __die_find_scope_cb, &data, &die_mem);
1639
1640 *scopes = data.scopes;
1641 return data.nr;
1642}
1/*
2 * dwarf-aux.c : libdw auxiliary interfaces
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
17 *
18 */
19
20#include <stdbool.h>
21#include "util.h"
22#include "debug.h"
23#include "dwarf-aux.h"
24
25/**
26 * cu_find_realpath - Find the realpath of the target file
27 * @cu_die: A DIE(dwarf information entry) of CU(compilation Unit)
28 * @fname: The tail filename of the target file
29 *
30 * Find the real(long) path of @fname in @cu_die.
31 */
32const char *cu_find_realpath(Dwarf_Die *cu_die, const char *fname)
33{
34 Dwarf_Files *files;
35 size_t nfiles, i;
36 const char *src = NULL;
37 int ret;
38
39 if (!fname)
40 return NULL;
41
42 ret = dwarf_getsrcfiles(cu_die, &files, &nfiles);
43 if (ret != 0)
44 return NULL;
45
46 for (i = 0; i < nfiles; i++) {
47 src = dwarf_filesrc(files, i, NULL, NULL);
48 if (strtailcmp(src, fname) == 0)
49 break;
50 }
51 if (i == nfiles)
52 return NULL;
53 return src;
54}
55
56/**
57 * cu_get_comp_dir - Get the path of compilation directory
58 * @cu_die: a CU DIE
59 *
60 * Get the path of compilation directory of given @cu_die.
61 * Since this depends on DW_AT_comp_dir, older gcc will not
62 * embedded it. In that case, this returns NULL.
63 */
64const char *cu_get_comp_dir(Dwarf_Die *cu_die)
65{
66 Dwarf_Attribute attr;
67 if (dwarf_attr(cu_die, DW_AT_comp_dir, &attr) == NULL)
68 return NULL;
69 return dwarf_formstring(&attr);
70}
71
72/**
73 * cu_find_lineinfo - Get a line number and file name for given address
74 * @cu_die: a CU DIE
75 * @addr: An address
76 * @fname: a pointer which returns the file name string
77 * @lineno: a pointer which returns the line number
78 *
79 * Find a line number and file name for @addr in @cu_die.
80 */
81int cu_find_lineinfo(Dwarf_Die *cu_die, unsigned long addr,
82 const char **fname, int *lineno)
83{
84 Dwarf_Line *line;
85 Dwarf_Addr laddr;
86
87 line = dwarf_getsrc_die(cu_die, (Dwarf_Addr)addr);
88 if (line && dwarf_lineaddr(line, &laddr) == 0 &&
89 addr == (unsigned long)laddr && dwarf_lineno(line, lineno) == 0) {
90 *fname = dwarf_linesrc(line, NULL, NULL);
91 if (!*fname)
92 /* line number is useless without filename */
93 *lineno = 0;
94 }
95
96 return *lineno ?: -ENOENT;
97}
98
99static int __die_find_inline_cb(Dwarf_Die *die_mem, void *data);
100
101/**
102 * cu_walk_functions_at - Walk on function DIEs at given address
103 * @cu_die: A CU DIE
104 * @addr: An address
105 * @callback: A callback which called with found DIEs
106 * @data: A user data
107 *
108 * Walk on function DIEs at given @addr in @cu_die. Passed DIEs
109 * should be subprogram or inlined-subroutines.
110 */
111int cu_walk_functions_at(Dwarf_Die *cu_die, Dwarf_Addr addr,
112 int (*callback)(Dwarf_Die *, void *), void *data)
113{
114 Dwarf_Die die_mem;
115 Dwarf_Die *sc_die;
116 int ret = -ENOENT;
117
118 /* Inlined function could be recursive. Trace it until fail */
119 for (sc_die = die_find_realfunc(cu_die, addr, &die_mem);
120 sc_die != NULL;
121 sc_die = die_find_child(sc_die, __die_find_inline_cb, &addr,
122 &die_mem)) {
123 ret = callback(sc_die, data);
124 if (ret)
125 break;
126 }
127
128 return ret;
129
130}
131
132/**
133 * die_compare_name - Compare diename and tname
134 * @dw_die: a DIE
135 * @tname: a string of target name
136 *
137 * Compare the name of @dw_die and @tname. Return false if @dw_die has no name.
138 */
139bool die_compare_name(Dwarf_Die *dw_die, const char *tname)
140{
141 const char *name;
142 name = dwarf_diename(dw_die);
143 return name ? (strcmp(tname, name) == 0) : false;
144}
145
146/**
147 * die_get_call_lineno - Get callsite line number of inline-function instance
148 * @in_die: a DIE of an inlined function instance
149 *
150 * Get call-site line number of @in_die. This means from where the inline
151 * function is called.
152 */
153int die_get_call_lineno(Dwarf_Die *in_die)
154{
155 Dwarf_Attribute attr;
156 Dwarf_Word ret;
157
158 if (!dwarf_attr(in_die, DW_AT_call_line, &attr))
159 return -ENOENT;
160
161 dwarf_formudata(&attr, &ret);
162 return (int)ret;
163}
164
165/**
166 * die_get_type - Get type DIE
167 * @vr_die: a DIE of a variable
168 * @die_mem: where to store a type DIE
169 *
170 * Get a DIE of the type of given variable (@vr_die), and store
171 * it to die_mem. Return NULL if fails to get a type DIE.
172 */
173Dwarf_Die *die_get_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem)
174{
175 Dwarf_Attribute attr;
176
177 if (dwarf_attr_integrate(vr_die, DW_AT_type, &attr) &&
178 dwarf_formref_die(&attr, die_mem))
179 return die_mem;
180 else
181 return NULL;
182}
183
184/* Get a type die, but skip qualifiers */
185static Dwarf_Die *__die_get_real_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem)
186{
187 int tag;
188
189 do {
190 vr_die = die_get_type(vr_die, die_mem);
191 if (!vr_die)
192 break;
193 tag = dwarf_tag(vr_die);
194 } while (tag == DW_TAG_const_type ||
195 tag == DW_TAG_restrict_type ||
196 tag == DW_TAG_volatile_type ||
197 tag == DW_TAG_shared_type);
198
199 return vr_die;
200}
201
202/**
203 * die_get_real_type - Get a type die, but skip qualifiers and typedef
204 * @vr_die: a DIE of a variable
205 * @die_mem: where to store a type DIE
206 *
207 * Get a DIE of the type of given variable (@vr_die), and store
208 * it to die_mem. Return NULL if fails to get a type DIE.
209 * If the type is qualifiers (e.g. const) or typedef, this skips it
210 * and tries to find real type (structure or basic types, e.g. int).
211 */
212Dwarf_Die *die_get_real_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem)
213{
214 do {
215 vr_die = __die_get_real_type(vr_die, die_mem);
216 } while (vr_die && dwarf_tag(vr_die) == DW_TAG_typedef);
217
218 return vr_die;
219}
220
221/* Get attribute and translate it as a udata */
222static int die_get_attr_udata(Dwarf_Die *tp_die, unsigned int attr_name,
223 Dwarf_Word *result)
224{
225 Dwarf_Attribute attr;
226
227 if (dwarf_attr(tp_die, attr_name, &attr) == NULL ||
228 dwarf_formudata(&attr, result) != 0)
229 return -ENOENT;
230
231 return 0;
232}
233
234/* Get attribute and translate it as a sdata */
235static int die_get_attr_sdata(Dwarf_Die *tp_die, unsigned int attr_name,
236 Dwarf_Sword *result)
237{
238 Dwarf_Attribute attr;
239
240 if (dwarf_attr(tp_die, attr_name, &attr) == NULL ||
241 dwarf_formsdata(&attr, result) != 0)
242 return -ENOENT;
243
244 return 0;
245}
246
247/**
248 * die_is_signed_type - Check whether a type DIE is signed or not
249 * @tp_die: a DIE of a type
250 *
251 * Get the encoding of @tp_die and return true if the encoding
252 * is signed.
253 */
254bool die_is_signed_type(Dwarf_Die *tp_die)
255{
256 Dwarf_Word ret;
257
258 if (die_get_attr_udata(tp_die, DW_AT_encoding, &ret))
259 return false;
260
261 return (ret == DW_ATE_signed_char || ret == DW_ATE_signed ||
262 ret == DW_ATE_signed_fixed);
263}
264
265/**
266 * die_get_data_member_location - Get the data-member offset
267 * @mb_die: a DIE of a member of a data structure
268 * @offs: The offset of the member in the data structure
269 *
270 * Get the offset of @mb_die in the data structure including @mb_die, and
271 * stores result offset to @offs. If any error occurs this returns errno.
272 */
273int die_get_data_member_location(Dwarf_Die *mb_die, Dwarf_Word *offs)
274{
275 Dwarf_Attribute attr;
276 Dwarf_Op *expr;
277 size_t nexpr;
278 int ret;
279
280 if (dwarf_attr(mb_die, DW_AT_data_member_location, &attr) == NULL)
281 return -ENOENT;
282
283 if (dwarf_formudata(&attr, offs) != 0) {
284 /* DW_AT_data_member_location should be DW_OP_plus_uconst */
285 ret = dwarf_getlocation(&attr, &expr, &nexpr);
286 if (ret < 0 || nexpr == 0)
287 return -ENOENT;
288
289 if (expr[0].atom != DW_OP_plus_uconst || nexpr != 1) {
290 pr_debug("Unable to get offset:Unexpected OP %x (%zd)\n",
291 expr[0].atom, nexpr);
292 return -ENOTSUP;
293 }
294 *offs = (Dwarf_Word)expr[0].number;
295 }
296 return 0;
297}
298
299/* Get the call file index number in CU DIE */
300static int die_get_call_fileno(Dwarf_Die *in_die)
301{
302 Dwarf_Sword idx;
303
304 if (die_get_attr_sdata(in_die, DW_AT_call_file, &idx) == 0)
305 return (int)idx;
306 else
307 return -ENOENT;
308}
309
310/* Get the declared file index number in CU DIE */
311static int die_get_decl_fileno(Dwarf_Die *pdie)
312{
313 Dwarf_Sword idx;
314
315 if (die_get_attr_sdata(pdie, DW_AT_decl_file, &idx) == 0)
316 return (int)idx;
317 else
318 return -ENOENT;
319}
320
321/**
322 * die_get_call_file - Get callsite file name of inlined function instance
323 * @in_die: a DIE of an inlined function instance
324 *
325 * Get call-site file name of @in_die. This means from which file the inline
326 * function is called.
327 */
328const char *die_get_call_file(Dwarf_Die *in_die)
329{
330 Dwarf_Die cu_die;
331 Dwarf_Files *files;
332 int idx;
333
334 idx = die_get_call_fileno(in_die);
335 if (idx < 0 || !dwarf_diecu(in_die, &cu_die, NULL, NULL) ||
336 dwarf_getsrcfiles(&cu_die, &files, NULL) != 0)
337 return NULL;
338
339 return dwarf_filesrc(files, idx, NULL, NULL);
340}
341
342
343/**
344 * die_find_child - Generic DIE search function in DIE tree
345 * @rt_die: a root DIE
346 * @callback: a callback function
347 * @data: a user data passed to the callback function
348 * @die_mem: a buffer for result DIE
349 *
350 * Trace DIE tree from @rt_die and call @callback for each child DIE.
351 * If @callback returns DIE_FIND_CB_END, this stores the DIE into
352 * @die_mem and returns it. If @callback returns DIE_FIND_CB_CONTINUE,
353 * this continues to trace the tree. Optionally, @callback can return
354 * DIE_FIND_CB_CHILD and DIE_FIND_CB_SIBLING, those means trace only
355 * the children and trace only the siblings respectively.
356 * Returns NULL if @callback can't find any appropriate DIE.
357 */
358Dwarf_Die *die_find_child(Dwarf_Die *rt_die,
359 int (*callback)(Dwarf_Die *, void *),
360 void *data, Dwarf_Die *die_mem)
361{
362 Dwarf_Die child_die;
363 int ret;
364
365 ret = dwarf_child(rt_die, die_mem);
366 if (ret != 0)
367 return NULL;
368
369 do {
370 ret = callback(die_mem, data);
371 if (ret == DIE_FIND_CB_END)
372 return die_mem;
373
374 if ((ret & DIE_FIND_CB_CHILD) &&
375 die_find_child(die_mem, callback, data, &child_die)) {
376 memcpy(die_mem, &child_die, sizeof(Dwarf_Die));
377 return die_mem;
378 }
379 } while ((ret & DIE_FIND_CB_SIBLING) &&
380 dwarf_siblingof(die_mem, die_mem) == 0);
381
382 return NULL;
383}
384
385struct __addr_die_search_param {
386 Dwarf_Addr addr;
387 Dwarf_Die *die_mem;
388};
389
390/* die_find callback for non-inlined function search */
391static int __die_search_func_cb(Dwarf_Die *fn_die, void *data)
392{
393 struct __addr_die_search_param *ad = data;
394
395 if (dwarf_tag(fn_die) == DW_TAG_subprogram &&
396 dwarf_haspc(fn_die, ad->addr)) {
397 memcpy(ad->die_mem, fn_die, sizeof(Dwarf_Die));
398 return DWARF_CB_ABORT;
399 }
400 return DWARF_CB_OK;
401}
402
403/**
404 * die_find_realfunc - Search a non-inlined function at given address
405 * @cu_die: a CU DIE which including @addr
406 * @addr: target address
407 * @die_mem: a buffer for result DIE
408 *
409 * Search a non-inlined function DIE which includes @addr. Stores the
410 * DIE to @die_mem and returns it if found. Returns NULl if failed.
411 */
412Dwarf_Die *die_find_realfunc(Dwarf_Die *cu_die, Dwarf_Addr addr,
413 Dwarf_Die *die_mem)
414{
415 struct __addr_die_search_param ad;
416 ad.addr = addr;
417 ad.die_mem = die_mem;
418 /* dwarf_getscopes can't find subprogram. */
419 if (!dwarf_getfuncs(cu_die, __die_search_func_cb, &ad, 0))
420 return NULL;
421 else
422 return die_mem;
423}
424
425/* die_find callback for inline function search */
426static int __die_find_inline_cb(Dwarf_Die *die_mem, void *data)
427{
428 Dwarf_Addr *addr = data;
429
430 if (dwarf_tag(die_mem) == DW_TAG_inlined_subroutine &&
431 dwarf_haspc(die_mem, *addr))
432 return DIE_FIND_CB_END;
433
434 return DIE_FIND_CB_CONTINUE;
435}
436
437/**
438 * die_find_inlinefunc - Search an inlined function at given address
439 * @cu_die: a CU DIE which including @addr
440 * @addr: target address
441 * @die_mem: a buffer for result DIE
442 *
443 * Search an inlined function DIE which includes @addr. Stores the
444 * DIE to @die_mem and returns it if found. Returns NULl if failed.
445 * If several inlined functions are expanded recursively, this trace
446 * it and returns deepest one.
447 */
448Dwarf_Die *die_find_inlinefunc(Dwarf_Die *sp_die, Dwarf_Addr addr,
449 Dwarf_Die *die_mem)
450{
451 Dwarf_Die tmp_die;
452
453 sp_die = die_find_child(sp_die, __die_find_inline_cb, &addr, &tmp_die);
454 if (!sp_die)
455 return NULL;
456
457 /* Inlined function could be recursive. Trace it until fail */
458 while (sp_die) {
459 memcpy(die_mem, sp_die, sizeof(Dwarf_Die));
460 sp_die = die_find_child(sp_die, __die_find_inline_cb, &addr,
461 &tmp_die);
462 }
463
464 return die_mem;
465}
466
467struct __instance_walk_param {
468 void *addr;
469 int (*callback)(Dwarf_Die *, void *);
470 void *data;
471 int retval;
472};
473
474static int __die_walk_instances_cb(Dwarf_Die *inst, void *data)
475{
476 struct __instance_walk_param *iwp = data;
477 Dwarf_Attribute attr_mem;
478 Dwarf_Die origin_mem;
479 Dwarf_Attribute *attr;
480 Dwarf_Die *origin;
481 int tmp;
482
483 attr = dwarf_attr(inst, DW_AT_abstract_origin, &attr_mem);
484 if (attr == NULL)
485 return DIE_FIND_CB_CONTINUE;
486
487 origin = dwarf_formref_die(attr, &origin_mem);
488 if (origin == NULL || origin->addr != iwp->addr)
489 return DIE_FIND_CB_CONTINUE;
490
491 /* Ignore redundant instances */
492 if (dwarf_tag(inst) == DW_TAG_inlined_subroutine) {
493 dwarf_decl_line(origin, &tmp);
494 if (die_get_call_lineno(inst) == tmp) {
495 tmp = die_get_decl_fileno(origin);
496 if (die_get_call_fileno(inst) == tmp)
497 return DIE_FIND_CB_CONTINUE;
498 }
499 }
500
501 iwp->retval = iwp->callback(inst, iwp->data);
502
503 return (iwp->retval) ? DIE_FIND_CB_END : DIE_FIND_CB_CONTINUE;
504}
505
506/**
507 * die_walk_instances - Walk on instances of given DIE
508 * @or_die: an abstract original DIE
509 * @callback: a callback function which is called with instance DIE
510 * @data: user data
511 *
512 * Walk on the instances of give @in_die. @in_die must be an inlined function
513 * declartion. This returns the return value of @callback if it returns
514 * non-zero value, or -ENOENT if there is no instance.
515 */
516int die_walk_instances(Dwarf_Die *or_die, int (*callback)(Dwarf_Die *, void *),
517 void *data)
518{
519 Dwarf_Die cu_die;
520 Dwarf_Die die_mem;
521 struct __instance_walk_param iwp = {
522 .addr = or_die->addr,
523 .callback = callback,
524 .data = data,
525 .retval = -ENOENT,
526 };
527
528 if (dwarf_diecu(or_die, &cu_die, NULL, NULL) == NULL)
529 return -ENOENT;
530
531 die_find_child(&cu_die, __die_walk_instances_cb, &iwp, &die_mem);
532
533 return iwp.retval;
534}
535
536/* Line walker internal parameters */
537struct __line_walk_param {
538 bool recursive;
539 line_walk_callback_t callback;
540 void *data;
541 int retval;
542};
543
544static int __die_walk_funclines_cb(Dwarf_Die *in_die, void *data)
545{
546 struct __line_walk_param *lw = data;
547 Dwarf_Addr addr = 0;
548 const char *fname;
549 int lineno;
550
551 if (dwarf_tag(in_die) == DW_TAG_inlined_subroutine) {
552 fname = die_get_call_file(in_die);
553 lineno = die_get_call_lineno(in_die);
554 if (fname && lineno > 0 && dwarf_entrypc(in_die, &addr) == 0) {
555 lw->retval = lw->callback(fname, lineno, addr, lw->data);
556 if (lw->retval != 0)
557 return DIE_FIND_CB_END;
558 }
559 }
560 if (!lw->recursive)
561 /* Don't need to search recursively */
562 return DIE_FIND_CB_SIBLING;
563
564 if (addr) {
565 fname = dwarf_decl_file(in_die);
566 if (fname && dwarf_decl_line(in_die, &lineno) == 0) {
567 lw->retval = lw->callback(fname, lineno, addr, lw->data);
568 if (lw->retval != 0)
569 return DIE_FIND_CB_END;
570 }
571 }
572
573 /* Continue to search nested inlined function call-sites */
574 return DIE_FIND_CB_CONTINUE;
575}
576
577/* Walk on lines of blocks included in given DIE */
578static int __die_walk_funclines(Dwarf_Die *sp_die, bool recursive,
579 line_walk_callback_t callback, void *data)
580{
581 struct __line_walk_param lw = {
582 .recursive = recursive,
583 .callback = callback,
584 .data = data,
585 .retval = 0,
586 };
587 Dwarf_Die die_mem;
588 Dwarf_Addr addr;
589 const char *fname;
590 int lineno;
591
592 /* Handle function declaration line */
593 fname = dwarf_decl_file(sp_die);
594 if (fname && dwarf_decl_line(sp_die, &lineno) == 0 &&
595 dwarf_entrypc(sp_die, &addr) == 0) {
596 lw.retval = callback(fname, lineno, addr, data);
597 if (lw.retval != 0)
598 goto done;
599 }
600 die_find_child(sp_die, __die_walk_funclines_cb, &lw, &die_mem);
601done:
602 return lw.retval;
603}
604
605static int __die_walk_culines_cb(Dwarf_Die *sp_die, void *data)
606{
607 struct __line_walk_param *lw = data;
608
609 lw->retval = __die_walk_funclines(sp_die, true, lw->callback, lw->data);
610 if (lw->retval != 0)
611 return DWARF_CB_ABORT;
612
613 return DWARF_CB_OK;
614}
615
616/**
617 * die_walk_lines - Walk on lines inside given DIE
618 * @rt_die: a root DIE (CU, subprogram or inlined_subroutine)
619 * @callback: callback routine
620 * @data: user data
621 *
622 * Walk on all lines inside given @rt_die and call @callback on each line.
623 * If the @rt_die is a function, walk only on the lines inside the function,
624 * otherwise @rt_die must be a CU DIE.
625 * Note that this walks not only dwarf line list, but also function entries
626 * and inline call-site.
627 */
628int die_walk_lines(Dwarf_Die *rt_die, line_walk_callback_t callback, void *data)
629{
630 Dwarf_Lines *lines;
631 Dwarf_Line *line;
632 Dwarf_Addr addr;
633 const char *fname;
634 int lineno, ret = 0;
635 Dwarf_Die die_mem, *cu_die;
636 size_t nlines, i;
637
638 /* Get the CU die */
639 if (dwarf_tag(rt_die) != DW_TAG_compile_unit)
640 cu_die = dwarf_diecu(rt_die, &die_mem, NULL, NULL);
641 else
642 cu_die = rt_die;
643 if (!cu_die) {
644 pr_debug2("Failed to get CU from given DIE.\n");
645 return -EINVAL;
646 }
647
648 /* Get lines list in the CU */
649 if (dwarf_getsrclines(cu_die, &lines, &nlines) != 0) {
650 pr_debug2("Failed to get source lines on this CU.\n");
651 return -ENOENT;
652 }
653 pr_debug2("Get %zd lines from this CU\n", nlines);
654
655 /* Walk on the lines on lines list */
656 for (i = 0; i < nlines; i++) {
657 line = dwarf_onesrcline(lines, i);
658 if (line == NULL ||
659 dwarf_lineno(line, &lineno) != 0 ||
660 dwarf_lineaddr(line, &addr) != 0) {
661 pr_debug2("Failed to get line info. "
662 "Possible error in debuginfo.\n");
663 continue;
664 }
665 /* Filter lines based on address */
666 if (rt_die != cu_die)
667 /*
668 * Address filtering
669 * The line is included in given function, and
670 * no inline block includes it.
671 */
672 if (!dwarf_haspc(rt_die, addr) ||
673 die_find_inlinefunc(rt_die, addr, &die_mem))
674 continue;
675 /* Get source line */
676 fname = dwarf_linesrc(line, NULL, NULL);
677
678 ret = callback(fname, lineno, addr, data);
679 if (ret != 0)
680 return ret;
681 }
682
683 /*
684 * Dwarf lines doesn't include function declarations and inlined
685 * subroutines. We have to check functions list or given function.
686 */
687 if (rt_die != cu_die)
688 /*
689 * Don't need walk functions recursively, because nested
690 * inlined functions don't have lines of the specified DIE.
691 */
692 ret = __die_walk_funclines(rt_die, false, callback, data);
693 else {
694 struct __line_walk_param param = {
695 .callback = callback,
696 .data = data,
697 .retval = 0,
698 };
699 dwarf_getfuncs(cu_die, __die_walk_culines_cb, ¶m, 0);
700 ret = param.retval;
701 }
702
703 return ret;
704}
705
706struct __find_variable_param {
707 const char *name;
708 Dwarf_Addr addr;
709};
710
711static int __die_find_variable_cb(Dwarf_Die *die_mem, void *data)
712{
713 struct __find_variable_param *fvp = data;
714 int tag;
715
716 tag = dwarf_tag(die_mem);
717 if ((tag == DW_TAG_formal_parameter ||
718 tag == DW_TAG_variable) &&
719 die_compare_name(die_mem, fvp->name))
720 return DIE_FIND_CB_END;
721
722 if (dwarf_haspc(die_mem, fvp->addr))
723 return DIE_FIND_CB_CONTINUE;
724 else
725 return DIE_FIND_CB_SIBLING;
726}
727
728/**
729 * die_find_variable_at - Find a given name variable at given address
730 * @sp_die: a function DIE
731 * @name: variable name
732 * @addr: address
733 * @die_mem: a buffer for result DIE
734 *
735 * Find a variable DIE called @name at @addr in @sp_die.
736 */
737Dwarf_Die *die_find_variable_at(Dwarf_Die *sp_die, const char *name,
738 Dwarf_Addr addr, Dwarf_Die *die_mem)
739{
740 struct __find_variable_param fvp = { .name = name, .addr = addr};
741
742 return die_find_child(sp_die, __die_find_variable_cb, (void *)&fvp,
743 die_mem);
744}
745
746static int __die_find_member_cb(Dwarf_Die *die_mem, void *data)
747{
748 const char *name = data;
749
750 if ((dwarf_tag(die_mem) == DW_TAG_member) &&
751 die_compare_name(die_mem, name))
752 return DIE_FIND_CB_END;
753
754 return DIE_FIND_CB_SIBLING;
755}
756
757/**
758 * die_find_member - Find a given name member in a data structure
759 * @st_die: a data structure type DIE
760 * @name: member name
761 * @die_mem: a buffer for result DIE
762 *
763 * Find a member DIE called @name in @st_die.
764 */
765Dwarf_Die *die_find_member(Dwarf_Die *st_die, const char *name,
766 Dwarf_Die *die_mem)
767{
768 return die_find_child(st_die, __die_find_member_cb, (void *)name,
769 die_mem);
770}
771
772/**
773 * die_get_typename - Get the name of given variable DIE
774 * @vr_die: a variable DIE
775 * @buf: a buffer for result type name
776 * @len: a max-length of @buf
777 *
778 * Get the name of @vr_die and stores it to @buf. Return the actual length
779 * of type name if succeeded. Return -E2BIG if @len is not enough long, and
780 * Return -ENOENT if failed to find type name.
781 * Note that the result will stores typedef name if possible, and stores
782 * "*(function_type)" if the type is a function pointer.
783 */
784int die_get_typename(Dwarf_Die *vr_die, char *buf, int len)
785{
786 Dwarf_Die type;
787 int tag, ret, ret2;
788 const char *tmp = "";
789
790 if (__die_get_real_type(vr_die, &type) == NULL)
791 return -ENOENT;
792
793 tag = dwarf_tag(&type);
794 if (tag == DW_TAG_array_type || tag == DW_TAG_pointer_type)
795 tmp = "*";
796 else if (tag == DW_TAG_subroutine_type) {
797 /* Function pointer */
798 ret = snprintf(buf, len, "(function_type)");
799 return (ret >= len) ? -E2BIG : ret;
800 } else {
801 if (!dwarf_diename(&type))
802 return -ENOENT;
803 if (tag == DW_TAG_union_type)
804 tmp = "union ";
805 else if (tag == DW_TAG_structure_type)
806 tmp = "struct ";
807 /* Write a base name */
808 ret = snprintf(buf, len, "%s%s", tmp, dwarf_diename(&type));
809 return (ret >= len) ? -E2BIG : ret;
810 }
811 ret = die_get_typename(&type, buf, len);
812 if (ret > 0) {
813 ret2 = snprintf(buf + ret, len - ret, "%s", tmp);
814 ret = (ret2 >= len - ret) ? -E2BIG : ret2 + ret;
815 }
816 return ret;
817}
818
819/**
820 * die_get_varname - Get the name and type of given variable DIE
821 * @vr_die: a variable DIE
822 * @buf: a buffer for type and variable name
823 * @len: the max-length of @buf
824 *
825 * Get the name and type of @vr_die and stores it in @buf as "type\tname".
826 */
827int die_get_varname(Dwarf_Die *vr_die, char *buf, int len)
828{
829 int ret, ret2;
830
831 ret = die_get_typename(vr_die, buf, len);
832 if (ret < 0) {
833 pr_debug("Failed to get type, make it unknown.\n");
834 ret = snprintf(buf, len, "(unknown_type)");
835 }
836 if (ret > 0) {
837 ret2 = snprintf(buf + ret, len - ret, "\t%s",
838 dwarf_diename(vr_die));
839 ret = (ret2 >= len - ret) ? -E2BIG : ret2 + ret;
840 }
841 return ret;
842}
843