~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

TOMOYO Linux Cross Reference
Linux/tools/perf/util/dwarf-aux.c

Version: ~ [ linux-5.13-rc5 ] ~ [ linux-5.12.9 ] ~ [ linux-5.11.22 ] ~ [ linux-5.10.42 ] ~ [ linux-5.9.16 ] ~ [ linux-5.8.18 ] ~ [ linux-5.7.19 ] ~ [ linux-5.6.19 ] ~ [ linux-5.5.19 ] ~ [ linux-5.4.124 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.193 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.235 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.271 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.271 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.18.140 ] ~ [ linux-3.16.85 ] ~ [ linux-3.14.79 ] ~ [ linux-3.12.74 ] ~ [ linux-3.10.108 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  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  */
 32 const 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  */
 64 const 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  */
 81 int 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 
 99 static 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  */
111 int 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  */
139 bool die_compare_name(Dwarf_Die *dw_die, const char *tname)
140 {
141         const char *name;
142 
143         name = dwarf_diename(dw_die);
144         return name ? (strcmp(tname, name) == 0) : false;
145 }
146 
147 /**
148  * die_match_name - Match diename and glob
149  * @dw_die: a DIE
150  * @glob: a string of target glob pattern
151  *
152  * Glob matching the name of @dw_die and @glob. Return false if matching fail.
153  */
154 bool die_match_name(Dwarf_Die *dw_die, const char *glob)
155 {
156         const char *name;
157 
158         name = dwarf_diename(dw_die);
159         return name ? strglobmatch(name, glob) : false;
160 }
161 
162 /**
163  * die_get_call_lineno - Get callsite line number of inline-function instance
164  * @in_die: a DIE of an inlined function instance
165  *
166  * Get call-site line number of @in_die. This means from where the inline
167  * function is called.
168  */
169 int die_get_call_lineno(Dwarf_Die *in_die)
170 {
171         Dwarf_Attribute attr;
172         Dwarf_Word ret;
173 
174         if (!dwarf_attr(in_die, DW_AT_call_line, &attr))
175                 return -ENOENT;
176 
177         dwarf_formudata(&attr, &ret);
178         return (int)ret;
179 }
180 
181 /**
182  * die_get_type - Get type DIE
183  * @vr_die: a DIE of a variable
184  * @die_mem: where to store a type DIE
185  *
186  * Get a DIE of the type of given variable (@vr_die), and store
187  * it to die_mem. Return NULL if fails to get a type DIE.
188  */
189 Dwarf_Die *die_get_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem)
190 {
191         Dwarf_Attribute attr;
192 
193         if (dwarf_attr_integrate(vr_die, DW_AT_type, &attr) &&
194             dwarf_formref_die(&attr, die_mem))
195                 return die_mem;
196         else
197                 return NULL;
198 }
199 
200 /* Get a type die, but skip qualifiers */
201 static Dwarf_Die *__die_get_real_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem)
202 {
203         int tag;
204 
205         do {
206                 vr_die = die_get_type(vr_die, die_mem);
207                 if (!vr_die)
208                         break;
209                 tag = dwarf_tag(vr_die);
210         } while (tag == DW_TAG_const_type ||
211                  tag == DW_TAG_restrict_type ||
212                  tag == DW_TAG_volatile_type ||
213                  tag == DW_TAG_shared_type);
214 
215         return vr_die;
216 }
217 
218 /**
219  * die_get_real_type - Get a type die, but skip qualifiers and typedef
220  * @vr_die: a DIE of a variable
221  * @die_mem: where to store a type DIE
222  *
223  * Get a DIE of the type of given variable (@vr_die), and store
224  * it to die_mem. Return NULL if fails to get a type DIE.
225  * If the type is qualifiers (e.g. const) or typedef, this skips it
226  * and tries to find real type (structure or basic types, e.g. int).
227  */
228 Dwarf_Die *die_get_real_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem)
229 {
230         do {
231                 vr_die = __die_get_real_type(vr_die, die_mem);
232         } while (vr_die && dwarf_tag(vr_die) == DW_TAG_typedef);
233 
234         return vr_die;
235 }
236 
237 /* Get attribute and translate it as a udata */
238 static int die_get_attr_udata(Dwarf_Die *tp_die, unsigned int attr_name,
239                               Dwarf_Word *result)
240 {
241         Dwarf_Attribute attr;
242 
243         if (dwarf_attr(tp_die, attr_name, &attr) == NULL ||
244             dwarf_formudata(&attr, result) != 0)
245                 return -ENOENT;
246 
247         return 0;
248 }
249 
250 /* Get attribute and translate it as a sdata */
251 static int die_get_attr_sdata(Dwarf_Die *tp_die, unsigned int attr_name,
252                               Dwarf_Sword *result)
253 {
254         Dwarf_Attribute attr;
255 
256         if (dwarf_attr(tp_die, attr_name, &attr) == NULL ||
257             dwarf_formsdata(&attr, result) != 0)
258                 return -ENOENT;
259 
260         return 0;
261 }
262 
263 /**
264  * die_is_signed_type - Check whether a type DIE is signed or not
265  * @tp_die: a DIE of a type
266  *
267  * Get the encoding of @tp_die and return true if the encoding
268  * is signed.
269  */
270 bool die_is_signed_type(Dwarf_Die *tp_die)
271 {
272         Dwarf_Word ret;
273 
274         if (die_get_attr_udata(tp_die, DW_AT_encoding, &ret))
275                 return false;
276 
277         return (ret == DW_ATE_signed_char || ret == DW_ATE_signed ||
278                 ret == DW_ATE_signed_fixed);
279 }
280 
281 /**
282  * die_is_func_def - Ensure that this DIE is a subprogram and definition
283  * @dw_die: a DIE
284  *
285  * Ensure that this DIE is a subprogram and NOT a declaration. This
286  * returns true if @dw_die is a function definition.
287  **/
288 bool die_is_func_def(Dwarf_Die *dw_die)
289 {
290         Dwarf_Attribute attr;
291 
292         return (dwarf_tag(dw_die) == DW_TAG_subprogram &&
293                 dwarf_attr(dw_die, DW_AT_declaration, &attr) == NULL);
294 }
295 
296 /**
297  * die_is_func_instance - Ensure that this DIE is an instance of a subprogram
298  * @dw_die: a DIE
299  *
300  * Ensure that this DIE is an instance (which has an entry address).
301  * This returns true if @dw_die is a function instance. If not, you need to
302  * call die_walk_instances() to find actual instances.
303  **/
304 bool die_is_func_instance(Dwarf_Die *dw_die)
305 {
306         Dwarf_Addr tmp;
307 
308         /* Actually gcc optimizes non-inline as like as inlined */
309         return !dwarf_func_inline(dw_die) && dwarf_entrypc(dw_die, &tmp) == 0;
310 }
311 /**
312  * die_get_data_member_location - Get the data-member offset
313  * @mb_die: a DIE of a member of a data structure
314  * @offs: The offset of the member in the data structure
315  *
316  * Get the offset of @mb_die in the data structure including @mb_die, and
317  * stores result offset to @offs. If any error occurs this returns errno.
318  */
319 int die_get_data_member_location(Dwarf_Die *mb_die, Dwarf_Word *offs)
320 {
321         Dwarf_Attribute attr;
322         Dwarf_Op *expr;
323         size_t nexpr;
324         int ret;
325 
326         if (dwarf_attr(mb_die, DW_AT_data_member_location, &attr) == NULL)
327                 return -ENOENT;
328 
329         if (dwarf_formudata(&attr, offs) != 0) {
330                 /* DW_AT_data_member_location should be DW_OP_plus_uconst */
331                 ret = dwarf_getlocation(&attr, &expr, &nexpr);
332                 if (ret < 0 || nexpr == 0)
333                         return -ENOENT;
334 
335                 if (expr[0].atom != DW_OP_plus_uconst || nexpr != 1) {
336                         pr_debug("Unable to get offset:Unexpected OP %x (%zd)\n",
337                                  expr[0].atom, nexpr);
338                         return -ENOTSUP;
339                 }
340                 *offs = (Dwarf_Word)expr[0].number;
341         }
342         return 0;
343 }
344 
345 /* Get the call file index number in CU DIE */
346 static int die_get_call_fileno(Dwarf_Die *in_die)
347 {
348         Dwarf_Sword idx;
349 
350         if (die_get_attr_sdata(in_die, DW_AT_call_file, &idx) == 0)
351                 return (int)idx;
352         else
353                 return -ENOENT;
354 }
355 
356 /* Get the declared file index number in CU DIE */
357 static int die_get_decl_fileno(Dwarf_Die *pdie)
358 {
359         Dwarf_Sword idx;
360 
361         if (die_get_attr_sdata(pdie, DW_AT_decl_file, &idx) == 0)
362                 return (int)idx;
363         else
364                 return -ENOENT;
365 }
366 
367 /**
368  * die_get_call_file - Get callsite file name of inlined function instance
369  * @in_die: a DIE of an inlined function instance
370  *
371  * Get call-site file name of @in_die. This means from which file the inline
372  * function is called.
373  */
374 const char *die_get_call_file(Dwarf_Die *in_die)
375 {
376         Dwarf_Die cu_die;
377         Dwarf_Files *files;
378         int idx;
379 
380         idx = die_get_call_fileno(in_die);
381         if (idx < 0 || !dwarf_diecu(in_die, &cu_die, NULL, NULL) ||
382             dwarf_getsrcfiles(&cu_die, &files, NULL) != 0)
383                 return NULL;
384 
385         return dwarf_filesrc(files, idx, NULL, NULL);
386 }
387 
388 
389 /**
390  * die_find_child - Generic DIE search function in DIE tree
391  * @rt_die: a root DIE
392  * @callback: a callback function
393  * @data: a user data passed to the callback function
394  * @die_mem: a buffer for result DIE
395  *
396  * Trace DIE tree from @rt_die and call @callback for each child DIE.
397  * If @callback returns DIE_FIND_CB_END, this stores the DIE into
398  * @die_mem and returns it. If @callback returns DIE_FIND_CB_CONTINUE,
399  * this continues to trace the tree. Optionally, @callback can return
400  * DIE_FIND_CB_CHILD and DIE_FIND_CB_SIBLING, those means trace only
401  * the children and trace only the siblings respectively.
402  * Returns NULL if @callback can't find any appropriate DIE.
403  */
404 Dwarf_Die *die_find_child(Dwarf_Die *rt_die,
405                           int (*callback)(Dwarf_Die *, void *),
406                           void *data, Dwarf_Die *die_mem)
407 {
408         Dwarf_Die child_die;
409         int ret;
410 
411         ret = dwarf_child(rt_die, die_mem);
412         if (ret != 0)
413                 return NULL;
414 
415         do {
416                 ret = callback(die_mem, data);
417                 if (ret == DIE_FIND_CB_END)
418                         return die_mem;
419 
420                 if ((ret & DIE_FIND_CB_CHILD) &&
421                     die_find_child(die_mem, callback, data, &child_die)) {
422                         memcpy(die_mem, &child_die, sizeof(Dwarf_Die));
423                         return die_mem;
424                 }
425         } while ((ret & DIE_FIND_CB_SIBLING) &&
426                  dwarf_siblingof(die_mem, die_mem) == 0);
427 
428         return NULL;
429 }
430 
431 struct __addr_die_search_param {
432         Dwarf_Addr      addr;
433         Dwarf_Die       *die_mem;
434 };
435 
436 static int __die_search_func_tail_cb(Dwarf_Die *fn_die, void *data)
437 {
438         struct __addr_die_search_param *ad = data;
439         Dwarf_Addr addr = 0;
440 
441         if (dwarf_tag(fn_die) == DW_TAG_subprogram &&
442             !dwarf_highpc(fn_die, &addr) &&
443             addr == ad->addr) {
444                 memcpy(ad->die_mem, fn_die, sizeof(Dwarf_Die));
445                 return DWARF_CB_ABORT;
446         }
447         return DWARF_CB_OK;
448 }
449 
450 /**
451  * die_find_tailfunc - Search for a non-inlined function with tail call at
452  * given address
453  * @cu_die: a CU DIE which including @addr
454  * @addr: target address
455  * @die_mem: a buffer for result DIE
456  *
457  * Search for a non-inlined function DIE with tail call at @addr. Stores the
458  * DIE to @die_mem and returns it if found. Returns NULL if failed.
459  */
460 Dwarf_Die *die_find_tailfunc(Dwarf_Die *cu_die, Dwarf_Addr addr,
461                                     Dwarf_Die *die_mem)
462 {
463         struct __addr_die_search_param ad;
464         ad.addr = addr;
465         ad.die_mem = die_mem;
466         /* dwarf_getscopes can't find subprogram. */
467         if (!dwarf_getfuncs(cu_die, __die_search_func_tail_cb, &ad, 0))
468                 return NULL;
469         else
470                 return die_mem;
471 }
472 
473 /* die_find callback for non-inlined function search */
474 static int __die_search_func_cb(Dwarf_Die *fn_die, void *data)
475 {
476         struct __addr_die_search_param *ad = data;
477 
478         /*
479          * Since a declaration entry doesn't has given pc, this always returns
480          * function definition entry.
481          */
482         if (dwarf_tag(fn_die) == DW_TAG_subprogram &&
483             dwarf_haspc(fn_die, ad->addr)) {
484                 memcpy(ad->die_mem, fn_die, sizeof(Dwarf_Die));
485                 return DWARF_CB_ABORT;
486         }
487         return DWARF_CB_OK;
488 }
489 
490 /**
491  * die_find_realfunc - Search a non-inlined function at given address
492  * @cu_die: a CU DIE which including @addr
493  * @addr: target address
494  * @die_mem: a buffer for result DIE
495  *
496  * Search a non-inlined function DIE which includes @addr. Stores the
497  * DIE to @die_mem and returns it if found. Returns NULL if failed.
498  */
499 Dwarf_Die *die_find_realfunc(Dwarf_Die *cu_die, Dwarf_Addr addr,
500                                     Dwarf_Die *die_mem)
501 {
502         struct __addr_die_search_param ad;
503         ad.addr = addr;
504         ad.die_mem = die_mem;
505         /* dwarf_getscopes can't find subprogram. */
506         if (!dwarf_getfuncs(cu_die, __die_search_func_cb, &ad, 0))
507                 return NULL;
508         else
509                 return die_mem;
510 }
511 
512 /* die_find callback for inline function search */
513 static int __die_find_inline_cb(Dwarf_Die *die_mem, void *data)
514 {
515         Dwarf_Addr *addr = data;
516 
517         if (dwarf_tag(die_mem) == DW_TAG_inlined_subroutine &&
518             dwarf_haspc(die_mem, *addr))
519                 return DIE_FIND_CB_END;
520 
521         return DIE_FIND_CB_CONTINUE;
522 }
523 
524 /**
525  * die_find_top_inlinefunc - Search the top inlined function at given address
526  * @sp_die: a subprogram DIE which including @addr
527  * @addr: target address
528  * @die_mem: a buffer for result DIE
529  *
530  * Search an inlined function DIE which includes @addr. Stores the
531  * DIE to @die_mem and returns it if found. Returns NULL if failed.
532  * Even if several inlined functions are expanded recursively, this
533  * doesn't trace it down, and returns the topmost one.
534  */
535 Dwarf_Die *die_find_top_inlinefunc(Dwarf_Die *sp_die, Dwarf_Addr addr,
536                                    Dwarf_Die *die_mem)
537 {
538         return die_find_child(sp_die, __die_find_inline_cb, &addr, die_mem);
539 }
540 
541 /**
542  * die_find_inlinefunc - Search an inlined function at given address
543  * @sp_die: a subprogram DIE which including @addr
544  * @addr: target address
545  * @die_mem: a buffer for result DIE
546  *
547  * Search an inlined function DIE which includes @addr. Stores the
548  * DIE to @die_mem and returns it if found. Returns NULL if failed.
549  * If several inlined functions are expanded recursively, this trace
550  * it down and returns deepest one.
551  */
552 Dwarf_Die *die_find_inlinefunc(Dwarf_Die *sp_die, Dwarf_Addr addr,
553                                Dwarf_Die *die_mem)
554 {
555         Dwarf_Die tmp_die;
556 
557         sp_die = die_find_child(sp_die, __die_find_inline_cb, &addr, &tmp_die);
558         if (!sp_die)
559                 return NULL;
560 
561         /* Inlined function could be recursive. Trace it until fail */
562         while (sp_die) {
563                 memcpy(die_mem, sp_die, sizeof(Dwarf_Die));
564                 sp_die = die_find_child(sp_die, __die_find_inline_cb, &addr,
565                                         &tmp_die);
566         }
567 
568         return die_mem;
569 }
570 
571 struct __instance_walk_param {
572         void    *addr;
573         int     (*callback)(Dwarf_Die *, void *);
574         void    *data;
575         int     retval;
576 };
577 
578 static int __die_walk_instances_cb(Dwarf_Die *inst, void *data)
579 {
580         struct __instance_walk_param *iwp = data;
581         Dwarf_Attribute attr_mem;
582         Dwarf_Die origin_mem;
583         Dwarf_Attribute *attr;
584         Dwarf_Die *origin;
585         int tmp;
586 
587         attr = dwarf_attr(inst, DW_AT_abstract_origin, &attr_mem);
588         if (attr == NULL)
589                 return DIE_FIND_CB_CONTINUE;
590 
591         origin = dwarf_formref_die(attr, &origin_mem);
592         if (origin == NULL || origin->addr != iwp->addr)
593                 return DIE_FIND_CB_CONTINUE;
594 
595         /* Ignore redundant instances */
596         if (dwarf_tag(inst) == DW_TAG_inlined_subroutine) {
597                 dwarf_decl_line(origin, &tmp);
598                 if (die_get_call_lineno(inst) == tmp) {
599                         tmp = die_get_decl_fileno(origin);
600                         if (die_get_call_fileno(inst) == tmp)
601                                 return DIE_FIND_CB_CONTINUE;
602                 }
603         }
604 
605         iwp->retval = iwp->callback(inst, iwp->data);
606 
607         return (iwp->retval) ? DIE_FIND_CB_END : DIE_FIND_CB_CONTINUE;
608 }
609 
610 /**
611  * die_walk_instances - Walk on instances of given DIE
612  * @or_die: an abstract original DIE
613  * @callback: a callback function which is called with instance DIE
614  * @data: user data
615  *
616  * Walk on the instances of give @in_die. @in_die must be an inlined function
617  * declartion. This returns the return value of @callback if it returns
618  * non-zero value, or -ENOENT if there is no instance.
619  */
620 int die_walk_instances(Dwarf_Die *or_die, int (*callback)(Dwarf_Die *, void *),
621                        void *data)
622 {
623         Dwarf_Die cu_die;
624         Dwarf_Die die_mem;
625         struct __instance_walk_param iwp = {
626                 .addr = or_die->addr,
627                 .callback = callback,
628                 .data = data,
629                 .retval = -ENOENT,
630         };
631 
632         if (dwarf_diecu(or_die, &cu_die, NULL, NULL) == NULL)
633                 return -ENOENT;
634 
635         die_find_child(&cu_die, __die_walk_instances_cb, &iwp, &die_mem);
636 
637         return iwp.retval;
638 }
639 
640 /* Line walker internal parameters */
641 struct __line_walk_param {
642         bool recursive;
643         line_walk_callback_t callback;
644         void *data;
645         int retval;
646 };
647 
648 static int __die_walk_funclines_cb(Dwarf_Die *in_die, void *data)
649 {
650         struct __line_walk_param *lw = data;
651         Dwarf_Addr addr = 0;
652         const char *fname;
653         int lineno;
654 
655         if (dwarf_tag(in_die) == DW_TAG_inlined_subroutine) {
656                 fname = die_get_call_file(in_die);
657                 lineno = die_get_call_lineno(in_die);
658                 if (fname && lineno > 0 && dwarf_entrypc(in_die, &addr) == 0) {
659                         lw->retval = lw->callback(fname, lineno, addr, lw->data);
660                         if (lw->retval != 0)
661                                 return DIE_FIND_CB_END;
662                 }
663         }
664         if (!lw->recursive)
665                 /* Don't need to search recursively */
666                 return DIE_FIND_CB_SIBLING;
667 
668         if (addr) {
669                 fname = dwarf_decl_file(in_die);
670                 if (fname && dwarf_decl_line(in_die, &lineno) == 0) {
671                         lw->retval = lw->callback(fname, lineno, addr, lw->data);
672                         if (lw->retval != 0)
673                                 return DIE_FIND_CB_END;
674                 }
675         }
676 
677         /* Continue to search nested inlined function call-sites */
678         return DIE_FIND_CB_CONTINUE;
679 }
680 
681 /* Walk on lines of blocks included in given DIE */
682 static int __die_walk_funclines(Dwarf_Die *sp_die, bool recursive,
683                                 line_walk_callback_t callback, void *data)
684 {
685         struct __line_walk_param lw = {
686                 .recursive = recursive,
687                 .callback = callback,
688                 .data = data,
689                 .retval = 0,
690         };
691         Dwarf_Die die_mem;
692         Dwarf_Addr addr;
693         const char *fname;
694         int lineno;
695 
696         /* Handle function declaration line */
697         fname = dwarf_decl_file(sp_die);
698         if (fname && dwarf_decl_line(sp_die, &lineno) == 0 &&
699             dwarf_entrypc(sp_die, &addr) == 0) {
700                 lw.retval = callback(fname, lineno, addr, data);
701                 if (lw.retval != 0)
702                         goto done;
703         }
704         die_find_child(sp_die, __die_walk_funclines_cb, &lw, &die_mem);
705 done:
706         return lw.retval;
707 }
708 
709 static int __die_walk_culines_cb(Dwarf_Die *sp_die, void *data)
710 {
711         struct __line_walk_param *lw = data;
712 
713         lw->retval = __die_walk_funclines(sp_die, true, lw->callback, lw->data);
714         if (lw->retval != 0)
715                 return DWARF_CB_ABORT;
716 
717         return DWARF_CB_OK;
718 }
719 
720 /**
721  * die_walk_lines - Walk on lines inside given DIE
722  * @rt_die: a root DIE (CU, subprogram or inlined_subroutine)
723  * @callback: callback routine
724  * @data: user data
725  *
726  * Walk on all lines inside given @rt_die and call @callback on each line.
727  * If the @rt_die is a function, walk only on the lines inside the function,
728  * otherwise @rt_die must be a CU DIE.
729  * Note that this walks not only dwarf line list, but also function entries
730  * and inline call-site.
731  */
732 int die_walk_lines(Dwarf_Die *rt_die, line_walk_callback_t callback, void *data)
733 {
734         Dwarf_Lines *lines;
735         Dwarf_Line *line;
736         Dwarf_Addr addr;
737         const char *fname;
738         int lineno, ret = 0;
739         Dwarf_Die die_mem, *cu_die;
740         size_t nlines, i;
741 
742         /* Get the CU die */
743         if (dwarf_tag(rt_die) != DW_TAG_compile_unit)
744                 cu_die = dwarf_diecu(rt_die, &die_mem, NULL, NULL);
745         else
746                 cu_die = rt_die;
747         if (!cu_die) {
748                 pr_debug2("Failed to get CU from given DIE.\n");
749                 return -EINVAL;
750         }
751 
752         /* Get lines list in the CU */
753         if (dwarf_getsrclines(cu_die, &lines, &nlines) != 0) {
754                 pr_debug2("Failed to get source lines on this CU.\n");
755                 return -ENOENT;
756         }
757         pr_debug2("Get %zd lines from this CU\n", nlines);
758 
759         /* Walk on the lines on lines list */
760         for (i = 0; i < nlines; i++) {
761                 line = dwarf_onesrcline(lines, i);
762                 if (line == NULL ||
763                     dwarf_lineno(line, &lineno) != 0 ||
764                     dwarf_lineaddr(line, &addr) != 0) {
765                         pr_debug2("Failed to get line info. "
766                                   "Possible error in debuginfo.\n");
767                         continue;
768                 }
769                 /* Filter lines based on address */
770                 if (rt_die != cu_die)
771                         /*
772                          * Address filtering
773                          * The line is included in given function, and
774                          * no inline block includes it.
775                          */
776                         if (!dwarf_haspc(rt_die, addr) ||
777                             die_find_inlinefunc(rt_die, addr, &die_mem))
778                                 continue;
779                 /* Get source line */
780                 fname = dwarf_linesrc(line, NULL, NULL);
781 
782                 ret = callback(fname, lineno, addr, data);
783                 if (ret != 0)
784                         return ret;
785         }
786 
787         /*
788          * Dwarf lines doesn't include function declarations and inlined
789          * subroutines. We have to check functions list or given function.
790          */
791         if (rt_die != cu_die)
792                 /*
793                  * Don't need walk functions recursively, because nested
794                  * inlined functions don't have lines of the specified DIE.
795                  */
796                 ret = __die_walk_funclines(rt_die, false, callback, data);
797         else {
798                 struct __line_walk_param param = {
799                         .callback = callback,
800                         .data = data,
801                         .retval = 0,
802                 };
803                 dwarf_getfuncs(cu_die, __die_walk_culines_cb, &param, 0);
804                 ret = param.retval;
805         }
806 
807         return ret;
808 }
809 
810 struct __find_variable_param {
811         const char *name;
812         Dwarf_Addr addr;
813 };
814 
815 static int __die_find_variable_cb(Dwarf_Die *die_mem, void *data)
816 {
817         struct __find_variable_param *fvp = data;
818         Dwarf_Attribute attr;
819         int tag;
820 
821         tag = dwarf_tag(die_mem);
822         if ((tag == DW_TAG_formal_parameter ||
823              tag == DW_TAG_variable) &&
824             die_compare_name(die_mem, fvp->name) &&
825         /* Does the DIE have location information or external instance? */
826             (dwarf_attr(die_mem, DW_AT_external, &attr) ||
827              dwarf_attr(die_mem, DW_AT_location, &attr)))
828                 return DIE_FIND_CB_END;
829         if (dwarf_haspc(die_mem, fvp->addr))
830                 return DIE_FIND_CB_CONTINUE;
831         else
832                 return DIE_FIND_CB_SIBLING;
833 }
834 
835 /**
836  * die_find_variable_at - Find a given name variable at given address
837  * @sp_die: a function DIE
838  * @name: variable name
839  * @addr: address
840  * @die_mem: a buffer for result DIE
841  *
842  * Find a variable DIE called @name at @addr in @sp_die.
843  */
844 Dwarf_Die *die_find_variable_at(Dwarf_Die *sp_die, const char *name,
845                                 Dwarf_Addr addr, Dwarf_Die *die_mem)
846 {
847         struct __find_variable_param fvp = { .name = name, .addr = addr};
848 
849         return die_find_child(sp_die, __die_find_variable_cb, (void *)&fvp,
850                               die_mem);
851 }
852 
853 static int __die_find_member_cb(Dwarf_Die *die_mem, void *data)
854 {
855         const char *name = data;
856 
857         if (dwarf_tag(die_mem) == DW_TAG_member) {
858                 if (die_compare_name(die_mem, name))
859                         return DIE_FIND_CB_END;
860                 else if (!dwarf_diename(die_mem)) {     /* Unnamed structure */
861                         Dwarf_Die type_die, tmp_die;
862                         if (die_get_type(die_mem, &type_die) &&
863                             die_find_member(&type_die, name, &tmp_die))
864                                 return DIE_FIND_CB_END;
865                 }
866         }
867         return DIE_FIND_CB_SIBLING;
868 }
869 
870 /**
871  * die_find_member - Find a given name member in a data structure
872  * @st_die: a data structure type DIE
873  * @name: member name
874  * @die_mem: a buffer for result DIE
875  *
876  * Find a member DIE called @name in @st_die.
877  */
878 Dwarf_Die *die_find_member(Dwarf_Die *st_die, const char *name,
879                            Dwarf_Die *die_mem)
880 {
881         return die_find_child(st_die, __die_find_member_cb, (void *)name,
882                               die_mem);
883 }
884 
885 /**
886  * die_get_typename - Get the name of given variable DIE
887  * @vr_die: a variable DIE
888  * @buf: a strbuf for result type name
889  *
890  * Get the name of @vr_die and stores it to @buf. Return 0 if succeeded.
891  * and Return -ENOENT if failed to find type name.
892  * Note that the result will stores typedef name if possible, and stores
893  * "*(function_type)" if the type is a function pointer.
894  */
895 int die_get_typename(Dwarf_Die *vr_die, struct strbuf *buf)
896 {
897         Dwarf_Die type;
898         int tag, ret;
899         const char *tmp = "";
900 
901         if (__die_get_real_type(vr_die, &type) == NULL)
902                 return -ENOENT;
903 
904         tag = dwarf_tag(&type);
905         if (tag == DW_TAG_array_type || tag == DW_TAG_pointer_type)
906                 tmp = "*";
907         else if (tag == DW_TAG_subroutine_type) {
908                 /* Function pointer */
909                 strbuf_addf(buf, "(function_type)");
910                 return 0;
911         } else {
912                 if (!dwarf_diename(&type))
913                         return -ENOENT;
914                 if (tag == DW_TAG_union_type)
915                         tmp = "union ";
916                 else if (tag == DW_TAG_structure_type)
917                         tmp = "struct ";
918                 else if (tag == DW_TAG_enumeration_type)
919                         tmp = "enum ";
920                 /* Write a base name */
921                 strbuf_addf(buf, "%s%s", tmp, dwarf_diename(&type));
922                 return 0;
923         }
924         ret = die_get_typename(&type, buf);
925         if (ret == 0)
926                 strbuf_addf(buf, "%s", tmp);
927 
928         return ret;
929 }
930 
931 /**
932  * die_get_varname - Get the name and type of given variable DIE
933  * @vr_die: a variable DIE
934  * @buf: a strbuf for type and variable name
935  *
936  * Get the name and type of @vr_die and stores it in @buf as "type\tname".
937  */
938 int die_get_varname(Dwarf_Die *vr_die, struct strbuf *buf)
939 {
940         int ret;
941 
942         ret = die_get_typename(vr_die, buf);
943         if (ret < 0) {
944                 pr_debug("Failed to get type, make it unknown.\n");
945                 strbuf_addf(buf, "(unknown_type)");
946         }
947 
948         strbuf_addf(buf, "\t%s", dwarf_diename(vr_die));
949 
950         return 0;
951 }
952 
953 /**
954  * die_get_var_innermost_scope - Get innermost scope range of given variable DIE
955  * @sp_die: a subprogram DIE
956  * @vr_die: a variable DIE
957  * @buf: a strbuf for variable byte offset range
958  *
959  * Get the innermost scope range of @vr_die and stores it in @buf as
960  * "@<function_name+[NN-NN,NN-NN]>".
961  */
962 static int die_get_var_innermost_scope(Dwarf_Die *sp_die, Dwarf_Die *vr_die,
963                                 struct strbuf *buf)
964 {
965         Dwarf_Die *scopes;
966         int count;
967         size_t offset = 0;
968         Dwarf_Addr base;
969         Dwarf_Addr start, end;
970         Dwarf_Addr entry;
971         int ret;
972         bool first = true;
973         const char *name;
974 
975         ret = dwarf_entrypc(sp_die, &entry);
976         if (ret)
977                 return ret;
978 
979         name = dwarf_diename(sp_die);
980         if (!name)
981                 return -ENOENT;
982 
983         count = dwarf_getscopes_die(vr_die, &scopes);
984 
985         /* (*SCOPES)[1] is the DIE for the scope containing that scope */
986         if (count <= 1) {
987                 ret = -EINVAL;
988                 goto out;
989         }
990 
991         while ((offset = dwarf_ranges(&scopes[1], offset, &base,
992                                 &start, &end)) > 0) {
993                 start -= entry;
994                 end -= entry;
995 
996                 if (first) {
997                         strbuf_addf(buf, "@<%s+[%" PRIu64 "-%" PRIu64,
998                                 name, start, end);
999                         first = false;
1000                 } else {
1001                         strbuf_addf(buf, ",%" PRIu64 "-%" PRIu64,
1002                                 start, end);
1003                 }
1004         }
1005 
1006         if (!first)
1007                 strbuf_addf(buf, "]>");
1008 
1009 out:
1010         free(scopes);
1011         return ret;
1012 }
1013 
1014 /**
1015  * die_get_var_range - Get byte offset range of given variable DIE
1016  * @sp_die: a subprogram DIE
1017  * @vr_die: a variable DIE
1018  * @buf: a strbuf for type and variable name and byte offset range
1019  *
1020  * Get the byte offset range of @vr_die and stores it in @buf as
1021  * "@<function_name+[NN-NN,NN-NN]>".
1022  */
1023 int die_get_var_range(Dwarf_Die *sp_die, Dwarf_Die *vr_die, struct strbuf *buf)
1024 {
1025         int ret = 0;
1026         Dwarf_Addr base;
1027         Dwarf_Addr start, end;
1028         Dwarf_Addr entry;
1029         Dwarf_Op *op;
1030         size_t nops;
1031         size_t offset = 0;
1032         Dwarf_Attribute attr;
1033         bool first = true;
1034         const char *name;
1035 
1036         ret = dwarf_entrypc(sp_die, &entry);
1037         if (ret)
1038                 return ret;
1039 
1040         name = dwarf_diename(sp_die);
1041         if (!name)
1042                 return -ENOENT;
1043 
1044         if (dwarf_attr(vr_die, DW_AT_location, &attr) == NULL)
1045                 return -EINVAL;
1046 
1047         while ((offset = dwarf_getlocations(
1048                                 &attr, offset, &base,
1049                                 &start, &end, &op, &nops)) > 0) {
1050                 if (start == 0) {
1051                         /* Single Location Descriptions */
1052                         ret = die_get_var_innermost_scope(sp_die, vr_die, buf);
1053                         return ret;
1054                 }
1055 
1056                 /* Location Lists */
1057                 start -= entry;
1058                 end -= entry;
1059                 if (first) {
1060                         strbuf_addf(buf, "@<%s+[%" PRIu64 "-%" PRIu64,
1061                                 name, start, end);
1062                         first = false;
1063                 } else {
1064                         strbuf_addf(buf, ",%" PRIu64 "-%" PRIu64,
1065                                 start, end);
1066                 }
1067         }
1068 
1069         if (!first)
1070                 strbuf_addf(buf, "]>");
1071 
1072         return ret;
1073 }
1074 

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

kernel.org | git.kernel.org | LWN.net | Project Home | Wiki (Japanese) | Wiki (English) | SVN repository | Mail admin

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.

osdn.jp