perf probe: Fix local variable searching loop
[linux-2.6.git] / tools / perf / util / probe-finder.c
1 /*
2  * probe-finder.c : C expression to kprobe event converter
3  *
4  * Written by Masami Hiramatsu <mhiramat@redhat.com>
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation; either version 2 of the License, or
9  * (at your option) any later version.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  * GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program; if not, write to the Free Software
18  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
19  *
20  */
21
22 #include <sys/utsname.h>
23 #include <sys/types.h>
24 #include <sys/stat.h>
25 #include <fcntl.h>
26 #include <errno.h>
27 #include <stdio.h>
28 #include <unistd.h>
29 #include <getopt.h>
30 #include <stdlib.h>
31 #include <string.h>
32 #include <stdarg.h>
33 #include <ctype.h>
34 #include <dwarf-regs.h>
35
36 #include "event.h"
37 #include "debug.h"
38 #include "util.h"
39 #include "symbol.h"
40 #include "probe-finder.h"
41
42 /* Kprobe tracer basic type is up to u64 */
43 #define MAX_BASIC_TYPE_BITS     64
44
45 /*
46  * Compare the tail of two strings.
47  * Return 0 if whole of either string is same as another's tail part.
48  */
49 static int strtailcmp(const char *s1, const char *s2)
50 {
51         int i1 = strlen(s1);
52         int i2 = strlen(s2);
53         while (--i1 >= 0 && --i2 >= 0) {
54                 if (s1[i1] != s2[i2])
55                         return s1[i1] - s2[i2];
56         }
57         return 0;
58 }
59
60 /* Line number list operations */
61
62 /* Add a line to line number list */
63 static int line_list__add_line(struct list_head *head, int line)
64 {
65         struct line_node *ln;
66         struct list_head *p;
67
68         /* Reverse search, because new line will be the last one */
69         list_for_each_entry_reverse(ln, head, list) {
70                 if (ln->line < line) {
71                         p = &ln->list;
72                         goto found;
73                 } else if (ln->line == line)    /* Already exist */
74                         return 1;
75         }
76         /* List is empty, or the smallest entry */
77         p = head;
78 found:
79         pr_debug("line list: add a line %u\n", line);
80         ln = zalloc(sizeof(struct line_node));
81         if (ln == NULL)
82                 return -ENOMEM;
83         ln->line = line;
84         INIT_LIST_HEAD(&ln->list);
85         list_add(&ln->list, p);
86         return 0;
87 }
88
89 /* Check if the line in line number list */
90 static int line_list__has_line(struct list_head *head, int line)
91 {
92         struct line_node *ln;
93
94         /* Reverse search, because new line will be the last one */
95         list_for_each_entry(ln, head, list)
96                 if (ln->line == line)
97                         return 1;
98
99         return 0;
100 }
101
102 /* Init line number list */
103 static void line_list__init(struct list_head *head)
104 {
105         INIT_LIST_HEAD(head);
106 }
107
108 /* Free line number list */
109 static void line_list__free(struct list_head *head)
110 {
111         struct line_node *ln;
112         while (!list_empty(head)) {
113                 ln = list_first_entry(head, struct line_node, list);
114                 list_del(&ln->list);
115                 free(ln);
116         }
117 }
118
119 /* Dwarf wrappers */
120
121 /* Find the realpath of the target file. */
122 static const char *cu_find_realpath(Dwarf_Die *cu_die, const char *fname)
123 {
124         Dwarf_Files *files;
125         size_t nfiles, i;
126         const char *src = NULL;
127         int ret;
128
129         if (!fname)
130                 return NULL;
131
132         ret = dwarf_getsrcfiles(cu_die, &files, &nfiles);
133         if (ret != 0)
134                 return NULL;
135
136         for (i = 0; i < nfiles; i++) {
137                 src = dwarf_filesrc(files, i, NULL, NULL);
138                 if (strtailcmp(src, fname) == 0)
139                         break;
140         }
141         if (i == nfiles)
142                 return NULL;
143         return src;
144 }
145
146 /* Get DW_AT_comp_dir (should be NULL with older gcc) */
147 static const char *cu_get_comp_dir(Dwarf_Die *cu_die)
148 {
149         Dwarf_Attribute attr;
150         if (dwarf_attr(cu_die, DW_AT_comp_dir, &attr) == NULL)
151                 return NULL;
152         return dwarf_formstring(&attr);
153 }
154
155 /* Compare diename and tname */
156 static bool die_compare_name(Dwarf_Die *dw_die, const char *tname)
157 {
158         const char *name;
159         name = dwarf_diename(dw_die);
160         return name ? (strcmp(tname, name) == 0) : false;
161 }
162
163 /* Get type die */
164 static Dwarf_Die *die_get_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem)
165 {
166         Dwarf_Attribute attr;
167
168         if (dwarf_attr_integrate(vr_die, DW_AT_type, &attr) &&
169             dwarf_formref_die(&attr, die_mem))
170                 return die_mem;
171         else
172                 return NULL;
173 }
174
175 /* Get type die, but skip qualifiers and typedef */
176 static Dwarf_Die *die_get_real_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem)
177 {
178         int tag;
179
180         do {
181                 vr_die = die_get_type(vr_die, die_mem);
182                 if (!vr_die)
183                         break;
184                 tag = dwarf_tag(vr_die);
185         } while (tag == DW_TAG_const_type ||
186                  tag == DW_TAG_restrict_type ||
187                  tag == DW_TAG_volatile_type ||
188                  tag == DW_TAG_shared_type ||
189                  tag == DW_TAG_typedef);
190
191         return vr_die;
192 }
193
194 static bool die_is_signed_type(Dwarf_Die *tp_die)
195 {
196         Dwarf_Attribute attr;
197         Dwarf_Word ret;
198
199         if (dwarf_attr(tp_die, DW_AT_encoding, &attr) == NULL ||
200             dwarf_formudata(&attr, &ret) != 0)
201                 return false;
202
203         return (ret == DW_ATE_signed_char || ret == DW_ATE_signed ||
204                 ret == DW_ATE_signed_fixed);
205 }
206
207 static int die_get_byte_size(Dwarf_Die *tp_die)
208 {
209         Dwarf_Attribute attr;
210         Dwarf_Word ret;
211
212         if (dwarf_attr(tp_die, DW_AT_byte_size, &attr) == NULL ||
213             dwarf_formudata(&attr, &ret) != 0)
214                 return 0;
215
216         return (int)ret;
217 }
218
219 /* Get data_member_location offset */
220 static int die_get_data_member_location(Dwarf_Die *mb_die, Dwarf_Word *offs)
221 {
222         Dwarf_Attribute attr;
223         Dwarf_Op *expr;
224         size_t nexpr;
225         int ret;
226
227         if (dwarf_attr(mb_die, DW_AT_data_member_location, &attr) == NULL)
228                 return -ENOENT;
229
230         if (dwarf_formudata(&attr, offs) != 0) {
231                 /* DW_AT_data_member_location should be DW_OP_plus_uconst */
232                 ret = dwarf_getlocation(&attr, &expr, &nexpr);
233                 if (ret < 0 || nexpr == 0)
234                         return -ENOENT;
235
236                 if (expr[0].atom != DW_OP_plus_uconst || nexpr != 1) {
237                         pr_debug("Unable to get offset:Unexpected OP %x (%zd)\n",
238                                  expr[0].atom, nexpr);
239                         return -ENOTSUP;
240                 }
241                 *offs = (Dwarf_Word)expr[0].number;
242         }
243         return 0;
244 }
245
246 /* Return values for die_find callbacks */
247 enum {
248         DIE_FIND_CB_FOUND = 0,          /* End of Search */
249         DIE_FIND_CB_CHILD = 1,          /* Search only children */
250         DIE_FIND_CB_SIBLING = 2,        /* Search only siblings */
251         DIE_FIND_CB_CONTINUE = 3,       /* Search children and siblings */
252 };
253
254 /* Search a child die */
255 static Dwarf_Die *die_find_child(Dwarf_Die *rt_die,
256                                  int (*callback)(Dwarf_Die *, void *),
257                                  void *data, Dwarf_Die *die_mem)
258 {
259         Dwarf_Die child_die;
260         int ret;
261
262         ret = dwarf_child(rt_die, die_mem);
263         if (ret != 0)
264                 return NULL;
265
266         do {
267                 ret = callback(die_mem, data);
268                 if (ret == DIE_FIND_CB_FOUND)
269                         return die_mem;
270
271                 if ((ret & DIE_FIND_CB_CHILD) &&
272                     die_find_child(die_mem, callback, data, &child_die)) {
273                         memcpy(die_mem, &child_die, sizeof(Dwarf_Die));
274                         return die_mem;
275                 }
276         } while ((ret & DIE_FIND_CB_SIBLING) &&
277                  dwarf_siblingof(die_mem, die_mem) == 0);
278
279         return NULL;
280 }
281
282 struct __addr_die_search_param {
283         Dwarf_Addr      addr;
284         Dwarf_Die       *die_mem;
285 };
286
287 static int __die_search_func_cb(Dwarf_Die *fn_die, void *data)
288 {
289         struct __addr_die_search_param *ad = data;
290
291         if (dwarf_tag(fn_die) == DW_TAG_subprogram &&
292             dwarf_haspc(fn_die, ad->addr)) {
293                 memcpy(ad->die_mem, fn_die, sizeof(Dwarf_Die));
294                 return DWARF_CB_ABORT;
295         }
296         return DWARF_CB_OK;
297 }
298
299 /* Search a real subprogram including this line, */
300 static Dwarf_Die *die_find_real_subprogram(Dwarf_Die *cu_die, Dwarf_Addr addr,
301                                            Dwarf_Die *die_mem)
302 {
303         struct __addr_die_search_param ad;
304         ad.addr = addr;
305         ad.die_mem = die_mem;
306         /* dwarf_getscopes can't find subprogram. */
307         if (!dwarf_getfuncs(cu_die, __die_search_func_cb, &ad, 0))
308                 return NULL;
309         else
310                 return die_mem;
311 }
312
313 /* die_find callback for inline function search */
314 static int __die_find_inline_cb(Dwarf_Die *die_mem, void *data)
315 {
316         Dwarf_Addr *addr = data;
317
318         if (dwarf_tag(die_mem) == DW_TAG_inlined_subroutine &&
319             dwarf_haspc(die_mem, *addr))
320                 return DIE_FIND_CB_FOUND;
321
322         return DIE_FIND_CB_CONTINUE;
323 }
324
325 /* Similar to dwarf_getfuncs, but returns inlined_subroutine if exists. */
326 static Dwarf_Die *die_find_inlinefunc(Dwarf_Die *sp_die, Dwarf_Addr addr,
327                                       Dwarf_Die *die_mem)
328 {
329         return die_find_child(sp_die, __die_find_inline_cb, &addr, die_mem);
330 }
331
332 struct __find_variable_param {
333         const char *name;
334         Dwarf_Addr addr;
335 };
336
337 static int __die_find_variable_cb(Dwarf_Die *die_mem, void *data)
338 {
339         struct __find_variable_param *fvp = data;
340         int tag;
341
342         tag = dwarf_tag(die_mem);
343         if ((tag == DW_TAG_formal_parameter ||
344              tag == DW_TAG_variable) &&
345             die_compare_name(die_mem, fvp->name))
346                 return DIE_FIND_CB_FOUND;
347
348         if (dwarf_haspc(die_mem, fvp->addr))
349                 return DIE_FIND_CB_CONTINUE;
350         else
351                 return DIE_FIND_CB_SIBLING;
352 }
353
354 /* Find a variable called 'name' at given address */
355 static Dwarf_Die *die_find_variable_at(Dwarf_Die *sp_die, const char *name,
356                                        Dwarf_Addr addr, Dwarf_Die *die_mem)
357 {
358         struct __find_variable_param fvp = { .name = name, .addr = addr};
359
360         return die_find_child(sp_die, __die_find_variable_cb, (void *)&fvp,
361                               die_mem);
362 }
363
364 static int __die_find_member_cb(Dwarf_Die *die_mem, void *data)
365 {
366         const char *name = data;
367
368         if ((dwarf_tag(die_mem) == DW_TAG_member) &&
369             die_compare_name(die_mem, name))
370                 return DIE_FIND_CB_FOUND;
371
372         return DIE_FIND_CB_SIBLING;
373 }
374
375 /* Find a member called 'name' */
376 static Dwarf_Die *die_find_member(Dwarf_Die *st_die, const char *name,
377                                   Dwarf_Die *die_mem)
378 {
379         return die_find_child(st_die, __die_find_member_cb, (void *)name,
380                               die_mem);
381 }
382
383 /*
384  * Probe finder related functions
385  */
386
387 static struct probe_trace_arg_ref *alloc_trace_arg_ref(long offs)
388 {
389         struct probe_trace_arg_ref *ref;
390         ref = zalloc(sizeof(struct probe_trace_arg_ref));
391         if (ref != NULL)
392                 ref->offset = offs;
393         return ref;
394 }
395
396 /* Show a location */
397 static int convert_variable_location(Dwarf_Die *vr_die, struct probe_finder *pf)
398 {
399         Dwarf_Attribute attr;
400         Dwarf_Op *op;
401         size_t nops;
402         unsigned int regn;
403         Dwarf_Word offs = 0;
404         bool ref = false;
405         const char *regs;
406         struct probe_trace_arg *tvar = pf->tvar;
407         int ret;
408
409         /* TODO: handle more than 1 exprs */
410         if (dwarf_attr(vr_die, DW_AT_location, &attr) == NULL ||
411             dwarf_getlocation_addr(&attr, pf->addr, &op, &nops, 1) <= 0 ||
412             nops == 0) {
413                 /* TODO: Support const_value */
414                 pr_err("Failed to find the location of %s at this address.\n"
415                        " Perhaps, it has been optimized out.\n", pf->pvar->var);
416                 return -ENOENT;
417         }
418
419         if (op->atom == DW_OP_addr) {
420                 /* Static variables on memory (not stack), make @varname */
421                 ret = strlen(dwarf_diename(vr_die));
422                 tvar->value = zalloc(ret + 2);
423                 if (tvar->value == NULL)
424                         return -ENOMEM;
425                 snprintf(tvar->value, ret + 2, "@%s", dwarf_diename(vr_die));
426                 tvar->ref = alloc_trace_arg_ref((long)offs);
427                 if (tvar->ref == NULL)
428                         return -ENOMEM;
429                 return 0;
430         }
431
432         /* If this is based on frame buffer, set the offset */
433         if (op->atom == DW_OP_fbreg) {
434                 if (pf->fb_ops == NULL) {
435                         pr_warning("The attribute of frame base is not "
436                                    "supported.\n");
437                         return -ENOTSUP;
438                 }
439                 ref = true;
440                 offs = op->number;
441                 op = &pf->fb_ops[0];
442         }
443
444         if (op->atom >= DW_OP_breg0 && op->atom <= DW_OP_breg31) {
445                 regn = op->atom - DW_OP_breg0;
446                 offs += op->number;
447                 ref = true;
448         } else if (op->atom >= DW_OP_reg0 && op->atom <= DW_OP_reg31) {
449                 regn = op->atom - DW_OP_reg0;
450         } else if (op->atom == DW_OP_bregx) {
451                 regn = op->number;
452                 offs += op->number2;
453                 ref = true;
454         } else if (op->atom == DW_OP_regx) {
455                 regn = op->number;
456         } else {
457                 pr_warning("DW_OP %x is not supported.\n", op->atom);
458                 return -ENOTSUP;
459         }
460
461         regs = get_arch_regstr(regn);
462         if (!regs) {
463                 pr_warning("Mapping for DWARF register number %u missing on this architecture.", regn);
464                 return -ERANGE;
465         }
466
467         tvar->value = strdup(regs);
468         if (tvar->value == NULL)
469                 return -ENOMEM;
470
471         if (ref) {
472                 tvar->ref = alloc_trace_arg_ref((long)offs);
473                 if (tvar->ref == NULL)
474                         return -ENOMEM;
475         }
476         return 0;
477 }
478
479 static int convert_variable_type(Dwarf_Die *vr_die,
480                                  struct probe_trace_arg *tvar,
481                                  const char *cast)
482 {
483         struct probe_trace_arg_ref **ref_ptr = &tvar->ref;
484         Dwarf_Die type;
485         char buf[16];
486         int ret;
487
488         /* TODO: check all types */
489         if (cast && strcmp(cast, "string") != 0) {
490                 /* Non string type is OK */
491                 tvar->type = strdup(cast);
492                 return (tvar->type == NULL) ? -ENOMEM : 0;
493         }
494
495         if (die_get_real_type(vr_die, &type) == NULL) {
496                 pr_warning("Failed to get a type information of %s.\n",
497                            dwarf_diename(vr_die));
498                 return -ENOENT;
499         }
500
501         pr_debug("%s type is %s.\n",
502                  dwarf_diename(vr_die), dwarf_diename(&type));
503
504         if (cast && strcmp(cast, "string") == 0) {      /* String type */
505                 ret = dwarf_tag(&type);
506                 if (ret != DW_TAG_pointer_type &&
507                     ret != DW_TAG_array_type) {
508                         pr_warning("Failed to cast into string: "
509                                    "%s(%s) is not a pointer nor array.",
510                                    dwarf_diename(vr_die), dwarf_diename(&type));
511                         return -EINVAL;
512                 }
513                 if (ret == DW_TAG_pointer_type) {
514                         if (die_get_real_type(&type, &type) == NULL) {
515                                 pr_warning("Failed to get a type information.");
516                                 return -ENOENT;
517                         }
518                         while (*ref_ptr)
519                                 ref_ptr = &(*ref_ptr)->next;
520                         /* Add new reference with offset +0 */
521                         *ref_ptr = zalloc(sizeof(struct probe_trace_arg_ref));
522                         if (*ref_ptr == NULL) {
523                                 pr_warning("Out of memory error\n");
524                                 return -ENOMEM;
525                         }
526                 }
527                 if (!die_compare_name(&type, "char") &&
528                     !die_compare_name(&type, "unsigned char")) {
529                         pr_warning("Failed to cast into string: "
530                                    "%s is not (unsigned) char *.",
531                                    dwarf_diename(vr_die));
532                         return -EINVAL;
533                 }
534                 tvar->type = strdup(cast);
535                 return (tvar->type == NULL) ? -ENOMEM : 0;
536         }
537
538         ret = die_get_byte_size(&type) * 8;
539         if (ret) {
540                 /* Check the bitwidth */
541                 if (ret > MAX_BASIC_TYPE_BITS) {
542                         pr_info("%s exceeds max-bitwidth."
543                                 " Cut down to %d bits.\n",
544                                 dwarf_diename(&type), MAX_BASIC_TYPE_BITS);
545                         ret = MAX_BASIC_TYPE_BITS;
546                 }
547
548                 ret = snprintf(buf, 16, "%c%d",
549                                die_is_signed_type(&type) ? 's' : 'u', ret);
550                 if (ret < 0 || ret >= 16) {
551                         if (ret >= 16)
552                                 ret = -E2BIG;
553                         pr_warning("Failed to convert variable type: %s\n",
554                                    strerror(-ret));
555                         return ret;
556                 }
557                 tvar->type = strdup(buf);
558                 if (tvar->type == NULL)
559                         return -ENOMEM;
560         }
561         return 0;
562 }
563
564 static int convert_variable_fields(Dwarf_Die *vr_die, const char *varname,
565                                     struct perf_probe_arg_field *field,
566                                     struct probe_trace_arg_ref **ref_ptr,
567                                     Dwarf_Die *die_mem)
568 {
569         struct probe_trace_arg_ref *ref = *ref_ptr;
570         Dwarf_Die type;
571         Dwarf_Word offs;
572         int ret, tag;
573
574         pr_debug("converting %s in %s\n", field->name, varname);
575         if (die_get_real_type(vr_die, &type) == NULL) {
576                 pr_warning("Failed to get the type of %s.\n", varname);
577                 return -ENOENT;
578         }
579         pr_debug2("Var real type: (%x)\n", (unsigned)dwarf_dieoffset(&type));
580         tag = dwarf_tag(&type);
581
582         if (field->name[0] == '[' &&
583             (tag == DW_TAG_array_type || tag == DW_TAG_pointer_type)) {
584                 if (field->next)
585                         /* Save original type for next field */
586                         memcpy(die_mem, &type, sizeof(*die_mem));
587                 /* Get the type of this array */
588                 if (die_get_real_type(&type, &type) == NULL) {
589                         pr_warning("Failed to get the type of %s.\n", varname);
590                         return -ENOENT;
591                 }
592                 pr_debug2("Array real type: (%x)\n",
593                          (unsigned)dwarf_dieoffset(&type));
594                 if (tag == DW_TAG_pointer_type) {
595                         ref = zalloc(sizeof(struct probe_trace_arg_ref));
596                         if (ref == NULL)
597                                 return -ENOMEM;
598                         if (*ref_ptr)
599                                 (*ref_ptr)->next = ref;
600                         else
601                                 *ref_ptr = ref;
602                 }
603                 ref->offset += die_get_byte_size(&type) * field->index;
604                 if (!field->next)
605                         /* Save vr_die for converting types */
606                         memcpy(die_mem, vr_die, sizeof(*die_mem));
607                 goto next;
608         } else if (tag == DW_TAG_pointer_type) {
609                 /* Check the pointer and dereference */
610                 if (!field->ref) {
611                         pr_err("Semantic error: %s must be referred by '->'\n",
612                                field->name);
613                         return -EINVAL;
614                 }
615                 /* Get the type pointed by this pointer */
616                 if (die_get_real_type(&type, &type) == NULL) {
617                         pr_warning("Failed to get the type of %s.\n", varname);
618                         return -ENOENT;
619                 }
620                 /* Verify it is a data structure  */
621                 if (dwarf_tag(&type) != DW_TAG_structure_type) {
622                         pr_warning("%s is not a data structure.\n", varname);
623                         return -EINVAL;
624                 }
625
626                 ref = zalloc(sizeof(struct probe_trace_arg_ref));
627                 if (ref == NULL)
628                         return -ENOMEM;
629                 if (*ref_ptr)
630                         (*ref_ptr)->next = ref;
631                 else
632                         *ref_ptr = ref;
633         } else {
634                 /* Verify it is a data structure  */
635                 if (tag != DW_TAG_structure_type) {
636                         pr_warning("%s is not a data structure.\n", varname);
637                         return -EINVAL;
638                 }
639                 if (field->name[0] == '[') {
640                         pr_err("Semantic error: %s is not a pointor nor array.",
641                                varname);
642                         return -EINVAL;
643                 }
644                 if (field->ref) {
645                         pr_err("Semantic error: %s must be referred by '.'\n",
646                                field->name);
647                         return -EINVAL;
648                 }
649                 if (!ref) {
650                         pr_warning("Structure on a register is not "
651                                    "supported yet.\n");
652                         return -ENOTSUP;
653                 }
654         }
655
656         if (die_find_member(&type, field->name, die_mem) == NULL) {
657                 pr_warning("%s(tyep:%s) has no member %s.\n", varname,
658                            dwarf_diename(&type), field->name);
659                 return -EINVAL;
660         }
661
662         /* Get the offset of the field */
663         ret = die_get_data_member_location(die_mem, &offs);
664         if (ret < 0) {
665                 pr_warning("Failed to get the offset of %s.\n", field->name);
666                 return ret;
667         }
668         ref->offset += (long)offs;
669
670 next:
671         /* Converting next field */
672         if (field->next)
673                 return convert_variable_fields(die_mem, field->name,
674                                         field->next, &ref, die_mem);
675         else
676                 return 0;
677 }
678
679 /* Show a variables in kprobe event format */
680 static int convert_variable(Dwarf_Die *vr_die, struct probe_finder *pf)
681 {
682         Dwarf_Die die_mem;
683         int ret;
684
685         pr_debug("Converting variable %s into trace event.\n",
686                  dwarf_diename(vr_die));
687
688         ret = convert_variable_location(vr_die, pf);
689         if (ret == 0 && pf->pvar->field) {
690                 ret = convert_variable_fields(vr_die, pf->pvar->var,
691                                               pf->pvar->field, &pf->tvar->ref,
692                                               &die_mem);
693                 vr_die = &die_mem;
694         }
695         if (ret == 0)
696                 ret = convert_variable_type(vr_die, pf->tvar, pf->pvar->type);
697         /* *expr will be cached in libdw. Don't free it. */
698         return ret;
699 }
700
701 /* Find a variable in a subprogram die */
702 static int find_variable(Dwarf_Die *sp_die, struct probe_finder *pf)
703 {
704         Dwarf_Die vr_die, *scopes;
705         char buf[32], *ptr;
706         int ret, nscopes;
707
708         if (!is_c_varname(pf->pvar->var)) {
709                 /* Copy raw parameters */
710                 pf->tvar->value = strdup(pf->pvar->var);
711                 if (pf->tvar->value == NULL)
712                         return -ENOMEM;
713                 if (pf->pvar->type) {
714                         pf->tvar->type = strdup(pf->pvar->type);
715                         if (pf->tvar->type == NULL)
716                                 return -ENOMEM;
717                 }
718                 if (pf->pvar->name) {
719                         pf->tvar->name = strdup(pf->pvar->name);
720                         if (pf->tvar->name == NULL)
721                                 return -ENOMEM;
722                 } else
723                         pf->tvar->name = NULL;
724                 return 0;
725         }
726
727         if (pf->pvar->name)
728                 pf->tvar->name = strdup(pf->pvar->name);
729         else {
730                 ret = synthesize_perf_probe_arg(pf->pvar, buf, 32);
731                 if (ret < 0)
732                         return ret;
733                 ptr = strchr(buf, ':'); /* Change type separator to _ */
734                 if (ptr)
735                         *ptr = '_';
736                 pf->tvar->name = strdup(buf);
737         }
738         if (pf->tvar->name == NULL)
739                 return -ENOMEM;
740
741         pr_debug("Searching '%s' variable in context.\n",
742                  pf->pvar->var);
743         /* Search child die for local variables and parameters. */
744         if (die_find_variable_at(sp_die, pf->pvar->var, pf->addr, &vr_die))
745                 ret = convert_variable(&vr_die, pf);
746         else {
747                 /* Search upper class */
748                 nscopes = dwarf_getscopes_die(sp_die, &scopes);
749                 if (nscopes > 0) {
750                         ret = dwarf_getscopevar(scopes, nscopes, pf->pvar->var,
751                                                 0, NULL, 0, 0, &vr_die);
752                         if (ret >= 0)
753                                 ret = convert_variable(&vr_die, pf);
754                         else
755                                 ret = -ENOENT;
756                         free(scopes);
757                 } else
758                         ret = -ENOENT;
759         }
760         if (ret < 0)
761                 pr_warning("Failed to find '%s' in this function.\n",
762                            pf->pvar->var);
763         return ret;
764 }
765
766 /* Show a probe point to output buffer */
767 static int convert_probe_point(Dwarf_Die *sp_die, struct probe_finder *pf)
768 {
769         struct probe_trace_event *tev;
770         Dwarf_Addr eaddr;
771         Dwarf_Die die_mem;
772         const char *name;
773         int ret, i;
774         Dwarf_Attribute fb_attr;
775         size_t nops;
776
777         if (pf->ntevs == pf->max_tevs) {
778                 pr_warning("Too many( > %d) probe point found.\n",
779                            pf->max_tevs);
780                 return -ERANGE;
781         }
782         tev = &pf->tevs[pf->ntevs++];
783
784         /* If no real subprogram, find a real one */
785         if (!sp_die || dwarf_tag(sp_die) != DW_TAG_subprogram) {
786                 sp_die = die_find_real_subprogram(&pf->cu_die,
787                                                  pf->addr, &die_mem);
788                 if (!sp_die) {
789                         pr_warning("Failed to find probe point in any "
790                                    "functions.\n");
791                         return -ENOENT;
792                 }
793         }
794
795         /* Copy the name of probe point */
796         name = dwarf_diename(sp_die);
797         if (name) {
798                 if (dwarf_entrypc(sp_die, &eaddr) != 0) {
799                         pr_warning("Failed to get entry pc of %s\n",
800                                    dwarf_diename(sp_die));
801                         return -ENOENT;
802                 }
803                 tev->point.symbol = strdup(name);
804                 if (tev->point.symbol == NULL)
805                         return -ENOMEM;
806                 tev->point.offset = (unsigned long)(pf->addr - eaddr);
807         } else
808                 /* This function has no name. */
809                 tev->point.offset = (unsigned long)pf->addr;
810
811         /* Return probe must be on the head of a subprogram */
812         if (pf->pev->point.retprobe) {
813                 if (tev->point.offset != 0) {
814                         pr_warning("Return probe must be on the head of"
815                                    " a real function\n");
816                         return -EINVAL;
817                 }
818                 tev->point.retprobe = true;
819         }
820
821         pr_debug("Probe point found: %s+%lu\n", tev->point.symbol,
822                  tev->point.offset);
823
824         /* Get the frame base attribute/ops */
825         dwarf_attr(sp_die, DW_AT_frame_base, &fb_attr);
826         ret = dwarf_getlocation_addr(&fb_attr, pf->addr, &pf->fb_ops, &nops, 1);
827         if (ret <= 0 || nops == 0) {
828                 pf->fb_ops = NULL;
829 #if _ELFUTILS_PREREQ(0, 142)
830         } else if (nops == 1 && pf->fb_ops[0].atom == DW_OP_call_frame_cfa &&
831                    pf->cfi != NULL) {
832                 Dwarf_Frame *frame;
833                 if (dwarf_cfi_addrframe(pf->cfi, pf->addr, &frame) != 0 ||
834                     dwarf_frame_cfa(frame, &pf->fb_ops, &nops) != 0) {
835                         pr_warning("Failed to get CFA on 0x%jx\n",
836                                    (uintmax_t)pf->addr);
837                         return -ENOENT;
838                 }
839 #endif
840         }
841
842         /* Find each argument */
843         tev->nargs = pf->pev->nargs;
844         tev->args = zalloc(sizeof(struct probe_trace_arg) * tev->nargs);
845         if (tev->args == NULL)
846                 return -ENOMEM;
847         for (i = 0; i < pf->pev->nargs; i++) {
848                 pf->pvar = &pf->pev->args[i];
849                 pf->tvar = &tev->args[i];
850                 ret = find_variable(sp_die, pf);
851                 if (ret != 0)
852                         return ret;
853         }
854
855         /* *pf->fb_ops will be cached in libdw. Don't free it. */
856         pf->fb_ops = NULL;
857         return 0;
858 }
859
860 /* Find probe point from its line number */
861 static int find_probe_point_by_line(struct probe_finder *pf)
862 {
863         Dwarf_Lines *lines;
864         Dwarf_Line *line;
865         size_t nlines, i;
866         Dwarf_Addr addr;
867         int lineno;
868         int ret = 0;
869
870         if (dwarf_getsrclines(&pf->cu_die, &lines, &nlines) != 0) {
871                 pr_warning("No source lines found in this CU.\n");
872                 return -ENOENT;
873         }
874
875         for (i = 0; i < nlines && ret == 0; i++) {
876                 line = dwarf_onesrcline(lines, i);
877                 if (dwarf_lineno(line, &lineno) != 0 ||
878                     lineno != pf->lno)
879                         continue;
880
881                 /* TODO: Get fileno from line, but how? */
882                 if (strtailcmp(dwarf_linesrc(line, NULL, NULL), pf->fname) != 0)
883                         continue;
884
885                 if (dwarf_lineaddr(line, &addr) != 0) {
886                         pr_warning("Failed to get the address of the line.\n");
887                         return -ENOENT;
888                 }
889                 pr_debug("Probe line found: line[%d]:%d addr:0x%jx\n",
890                          (int)i, lineno, (uintmax_t)addr);
891                 pf->addr = addr;
892
893                 ret = convert_probe_point(NULL, pf);
894                 /* Continuing, because target line might be inlined. */
895         }
896         return ret;
897 }
898
899 /* Find lines which match lazy pattern */
900 static int find_lazy_match_lines(struct list_head *head,
901                                  const char *fname, const char *pat)
902 {
903         char *fbuf, *p1, *p2;
904         int fd, line, nlines = -1;
905         struct stat st;
906
907         fd = open(fname, O_RDONLY);
908         if (fd < 0) {
909                 pr_warning("Failed to open %s: %s\n", fname, strerror(-fd));
910                 return -errno;
911         }
912
913         if (fstat(fd, &st) < 0) {
914                 pr_warning("Failed to get the size of %s: %s\n",
915                            fname, strerror(errno));
916                 nlines = -errno;
917                 goto out_close;
918         }
919
920         nlines = -ENOMEM;
921         fbuf = malloc(st.st_size + 2);
922         if (fbuf == NULL)
923                 goto out_close;
924         if (read(fd, fbuf, st.st_size) < 0) {
925                 pr_warning("Failed to read %s: %s\n", fname, strerror(errno));
926                 nlines = -errno;
927                 goto out_free_fbuf;
928         }
929         fbuf[st.st_size] = '\n';        /* Dummy line */
930         fbuf[st.st_size + 1] = '\0';
931         p1 = fbuf;
932         line = 1;
933         nlines = 0;
934         while ((p2 = strchr(p1, '\n')) != NULL) {
935                 *p2 = '\0';
936                 if (strlazymatch(p1, pat)) {
937                         line_list__add_line(head, line);
938                         nlines++;
939                 }
940                 line++;
941                 p1 = p2 + 1;
942         }
943 out_free_fbuf:
944         free(fbuf);
945 out_close:
946         close(fd);
947         return nlines;
948 }
949
950 /* Find probe points from lazy pattern  */
951 static int find_probe_point_lazy(Dwarf_Die *sp_die, struct probe_finder *pf)
952 {
953         Dwarf_Lines *lines;
954         Dwarf_Line *line;
955         size_t nlines, i;
956         Dwarf_Addr addr;
957         Dwarf_Die die_mem;
958         int lineno;
959         int ret = 0;
960
961         if (list_empty(&pf->lcache)) {
962                 /* Matching lazy line pattern */
963                 ret = find_lazy_match_lines(&pf->lcache, pf->fname,
964                                             pf->pev->point.lazy_line);
965                 if (ret == 0) {
966                         pr_debug("No matched lines found in %s.\n", pf->fname);
967                         return 0;
968                 } else if (ret < 0)
969                         return ret;
970         }
971
972         if (dwarf_getsrclines(&pf->cu_die, &lines, &nlines) != 0) {
973                 pr_warning("No source lines found in this CU.\n");
974                 return -ENOENT;
975         }
976
977         for (i = 0; i < nlines && ret >= 0; i++) {
978                 line = dwarf_onesrcline(lines, i);
979
980                 if (dwarf_lineno(line, &lineno) != 0 ||
981                     !line_list__has_line(&pf->lcache, lineno))
982                         continue;
983
984                 /* TODO: Get fileno from line, but how? */
985                 if (strtailcmp(dwarf_linesrc(line, NULL, NULL), pf->fname) != 0)
986                         continue;
987
988                 if (dwarf_lineaddr(line, &addr) != 0) {
989                         pr_debug("Failed to get the address of line %d.\n",
990                                  lineno);
991                         continue;
992                 }
993                 if (sp_die) {
994                         /* Address filtering 1: does sp_die include addr? */
995                         if (!dwarf_haspc(sp_die, addr))
996                                 continue;
997                         /* Address filtering 2: No child include addr? */
998                         if (die_find_inlinefunc(sp_die, addr, &die_mem))
999                                 continue;
1000                 }
1001
1002                 pr_debug("Probe line found: line[%d]:%d addr:0x%llx\n",
1003                          (int)i, lineno, (unsigned long long)addr);
1004                 pf->addr = addr;
1005
1006                 ret = convert_probe_point(sp_die, pf);
1007                 /* Continuing, because target line might be inlined. */
1008         }
1009         /* TODO: deallocate lines, but how? */
1010         return ret;
1011 }
1012
1013 /* Callback parameter with return value */
1014 struct dwarf_callback_param {
1015         void *data;
1016         int retval;
1017 };
1018
1019 static int probe_point_inline_cb(Dwarf_Die *in_die, void *data)
1020 {
1021         struct dwarf_callback_param *param = data;
1022         struct probe_finder *pf = param->data;
1023         struct perf_probe_point *pp = &pf->pev->point;
1024         Dwarf_Addr addr;
1025
1026         if (pp->lazy_line)
1027                 param->retval = find_probe_point_lazy(in_die, pf);
1028         else {
1029                 /* Get probe address */
1030                 if (dwarf_entrypc(in_die, &addr) != 0) {
1031                         pr_warning("Failed to get entry pc of %s.\n",
1032                                    dwarf_diename(in_die));
1033                         param->retval = -ENOENT;
1034                         return DWARF_CB_ABORT;
1035                 }
1036                 pf->addr = addr;
1037                 pf->addr += pp->offset;
1038                 pr_debug("found inline addr: 0x%jx\n",
1039                          (uintmax_t)pf->addr);
1040
1041                 param->retval = convert_probe_point(in_die, pf);
1042                 if (param->retval < 0)
1043                         return DWARF_CB_ABORT;
1044         }
1045
1046         return DWARF_CB_OK;
1047 }
1048
1049 /* Search function from function name */
1050 static int probe_point_search_cb(Dwarf_Die *sp_die, void *data)
1051 {
1052         struct dwarf_callback_param *param = data;
1053         struct probe_finder *pf = param->data;
1054         struct perf_probe_point *pp = &pf->pev->point;
1055
1056         /* Check tag and diename */
1057         if (dwarf_tag(sp_die) != DW_TAG_subprogram ||
1058             !die_compare_name(sp_die, pp->function))
1059                 return DWARF_CB_OK;
1060
1061         pf->fname = dwarf_decl_file(sp_die);
1062         if (pp->line) { /* Function relative line */
1063                 dwarf_decl_line(sp_die, &pf->lno);
1064                 pf->lno += pp->line;
1065                 param->retval = find_probe_point_by_line(pf);
1066         } else if (!dwarf_func_inline(sp_die)) {
1067                 /* Real function */
1068                 if (pp->lazy_line)
1069                         param->retval = find_probe_point_lazy(sp_die, pf);
1070                 else {
1071                         if (dwarf_entrypc(sp_die, &pf->addr) != 0) {
1072                                 pr_warning("Failed to get entry pc of %s.\n",
1073                                            dwarf_diename(sp_die));
1074                                 param->retval = -ENOENT;
1075                                 return DWARF_CB_ABORT;
1076                         }
1077                         pf->addr += pp->offset;
1078                         /* TODO: Check the address in this function */
1079                         param->retval = convert_probe_point(sp_die, pf);
1080                 }
1081         } else {
1082                 struct dwarf_callback_param _param = {.data = (void *)pf,
1083                                                       .retval = 0};
1084                 /* Inlined function: search instances */
1085                 dwarf_func_inline_instances(sp_die, probe_point_inline_cb,
1086                                             &_param);
1087                 param->retval = _param.retval;
1088         }
1089
1090         return DWARF_CB_ABORT; /* Exit; no same symbol in this CU. */
1091 }
1092
1093 static int find_probe_point_by_func(struct probe_finder *pf)
1094 {
1095         struct dwarf_callback_param _param = {.data = (void *)pf,
1096                                               .retval = 0};
1097         dwarf_getfuncs(&pf->cu_die, probe_point_search_cb, &_param, 0);
1098         return _param.retval;
1099 }
1100
1101 /* Find probe_trace_events specified by perf_probe_event from debuginfo */
1102 int find_probe_trace_events(int fd, struct perf_probe_event *pev,
1103                              struct probe_trace_event **tevs, int max_tevs)
1104 {
1105         struct probe_finder pf = {.pev = pev, .max_tevs = max_tevs};
1106         struct perf_probe_point *pp = &pev->point;
1107         Dwarf_Off off, noff;
1108         size_t cuhl;
1109         Dwarf_Die *diep;
1110         Dwarf *dbg;
1111         int ret = 0;
1112
1113         pf.tevs = zalloc(sizeof(struct probe_trace_event) * max_tevs);
1114         if (pf.tevs == NULL)
1115                 return -ENOMEM;
1116         *tevs = pf.tevs;
1117         pf.ntevs = 0;
1118
1119         dbg = dwarf_begin(fd, DWARF_C_READ);
1120         if (!dbg) {
1121                 pr_warning("No dwarf info found in the vmlinux - "
1122                         "please rebuild with CONFIG_DEBUG_INFO=y.\n");
1123                 free(pf.tevs);
1124                 *tevs = NULL;
1125                 return -EBADF;
1126         }
1127
1128 #if _ELFUTILS_PREREQ(0, 142)
1129         /* Get the call frame information from this dwarf */
1130         pf.cfi = dwarf_getcfi(dbg);
1131 #endif
1132
1133         off = 0;
1134         line_list__init(&pf.lcache);
1135         /* Loop on CUs (Compilation Unit) */
1136         while (!dwarf_nextcu(dbg, off, &noff, &cuhl, NULL, NULL, NULL) &&
1137                ret >= 0) {
1138                 /* Get the DIE(Debugging Information Entry) of this CU */
1139                 diep = dwarf_offdie(dbg, off + cuhl, &pf.cu_die);
1140                 if (!diep)
1141                         continue;
1142
1143                 /* Check if target file is included. */
1144                 if (pp->file)
1145                         pf.fname = cu_find_realpath(&pf.cu_die, pp->file);
1146                 else
1147                         pf.fname = NULL;
1148
1149                 if (!pp->file || pf.fname) {
1150                         if (pp->function)
1151                                 ret = find_probe_point_by_func(&pf);
1152                         else if (pp->lazy_line)
1153                                 ret = find_probe_point_lazy(NULL, &pf);
1154                         else {
1155                                 pf.lno = pp->line;
1156                                 ret = find_probe_point_by_line(&pf);
1157                         }
1158                 }
1159                 off = noff;
1160         }
1161         line_list__free(&pf.lcache);
1162         dwarf_end(dbg);
1163
1164         return (ret < 0) ? ret : pf.ntevs;
1165 }
1166
1167 /* Reverse search */
1168 int find_perf_probe_point(int fd, unsigned long addr,
1169                           struct perf_probe_point *ppt)
1170 {
1171         Dwarf_Die cudie, spdie, indie;
1172         Dwarf *dbg;
1173         Dwarf_Line *line;
1174         Dwarf_Addr laddr, eaddr;
1175         const char *tmp;
1176         int lineno, ret = 0;
1177         bool found = false;
1178
1179         dbg = dwarf_begin(fd, DWARF_C_READ);
1180         if (!dbg)
1181                 return -EBADF;
1182
1183         /* Find cu die */
1184         if (!dwarf_addrdie(dbg, (Dwarf_Addr)addr, &cudie)) {
1185                 ret = -EINVAL;
1186                 goto end;
1187         }
1188
1189         /* Find a corresponding line */
1190         line = dwarf_getsrc_die(&cudie, (Dwarf_Addr)addr);
1191         if (line) {
1192                 if (dwarf_lineaddr(line, &laddr) == 0 &&
1193                     (Dwarf_Addr)addr == laddr &&
1194                     dwarf_lineno(line, &lineno) == 0) {
1195                         tmp = dwarf_linesrc(line, NULL, NULL);
1196                         if (tmp) {
1197                                 ppt->line = lineno;
1198                                 ppt->file = strdup(tmp);
1199                                 if (ppt->file == NULL) {
1200                                         ret = -ENOMEM;
1201                                         goto end;
1202                                 }
1203                                 found = true;
1204                         }
1205                 }
1206         }
1207
1208         /* Find a corresponding function */
1209         if (die_find_real_subprogram(&cudie, (Dwarf_Addr)addr, &spdie)) {
1210                 tmp = dwarf_diename(&spdie);
1211                 if (!tmp || dwarf_entrypc(&spdie, &eaddr) != 0)
1212                         goto end;
1213
1214                 if (ppt->line) {
1215                         if (die_find_inlinefunc(&spdie, (Dwarf_Addr)addr,
1216                                                 &indie)) {
1217                                 /* addr in an inline function */
1218                                 tmp = dwarf_diename(&indie);
1219                                 if (!tmp)
1220                                         goto end;
1221                                 ret = dwarf_decl_line(&indie, &lineno);
1222                         } else {
1223                                 if (eaddr == addr) {    /* Function entry */
1224                                         lineno = ppt->line;
1225                                         ret = 0;
1226                                 } else
1227                                         ret = dwarf_decl_line(&spdie, &lineno);
1228                         }
1229                         if (ret == 0) {
1230                                 /* Make a relative line number */
1231                                 ppt->line -= lineno;
1232                                 goto found;
1233                         }
1234                 }
1235                 /* We don't have a line number, let's use offset */
1236                 ppt->offset = addr - (unsigned long)eaddr;
1237 found:
1238                 ppt->function = strdup(tmp);
1239                 if (ppt->function == NULL) {
1240                         ret = -ENOMEM;
1241                         goto end;
1242                 }
1243                 found = true;
1244         }
1245
1246 end:
1247         dwarf_end(dbg);
1248         if (ret >= 0)
1249                 ret = found ? 1 : 0;
1250         return ret;
1251 }
1252
1253 /* Add a line and store the src path */
1254 static int line_range_add_line(const char *src, unsigned int lineno,
1255                                struct line_range *lr)
1256 {
1257         /* Copy source path */
1258         if (!lr->path) {
1259                 lr->path = strdup(src);
1260                 if (lr->path == NULL)
1261                         return -ENOMEM;
1262         }
1263         return line_list__add_line(&lr->line_list, lineno);
1264 }
1265
1266 /* Search function declaration lines */
1267 static int line_range_funcdecl_cb(Dwarf_Die *sp_die, void *data)
1268 {
1269         struct dwarf_callback_param *param = data;
1270         struct line_finder *lf = param->data;
1271         const char *src;
1272         int lineno;
1273
1274         src = dwarf_decl_file(sp_die);
1275         if (src && strtailcmp(src, lf->fname) != 0)
1276                 return DWARF_CB_OK;
1277
1278         if (dwarf_decl_line(sp_die, &lineno) != 0 ||
1279             (lf->lno_s > lineno || lf->lno_e < lineno))
1280                 return DWARF_CB_OK;
1281
1282         param->retval = line_range_add_line(src, lineno, lf->lr);
1283         if (param->retval < 0)
1284                 return DWARF_CB_ABORT;
1285         return DWARF_CB_OK;
1286 }
1287
1288 static int find_line_range_func_decl_lines(struct line_finder *lf)
1289 {
1290         struct dwarf_callback_param param = {.data = (void *)lf, .retval = 0};
1291         dwarf_getfuncs(&lf->cu_die, line_range_funcdecl_cb, &param, 0);
1292         return param.retval;
1293 }
1294
1295 /* Find line range from its line number */
1296 static int find_line_range_by_line(Dwarf_Die *sp_die, struct line_finder *lf)
1297 {
1298         Dwarf_Lines *lines;
1299         Dwarf_Line *line;
1300         size_t nlines, i;
1301         Dwarf_Addr addr;
1302         int lineno, ret = 0;
1303         const char *src;
1304         Dwarf_Die die_mem;
1305
1306         line_list__init(&lf->lr->line_list);
1307         if (dwarf_getsrclines(&lf->cu_die, &lines, &nlines) != 0) {
1308                 pr_warning("No source lines found in this CU.\n");
1309                 return -ENOENT;
1310         }
1311
1312         /* Search probable lines on lines list */
1313         for (i = 0; i < nlines; i++) {
1314                 line = dwarf_onesrcline(lines, i);
1315                 if (dwarf_lineno(line, &lineno) != 0 ||
1316                     (lf->lno_s > lineno || lf->lno_e < lineno))
1317                         continue;
1318
1319                 if (sp_die) {
1320                         /* Address filtering 1: does sp_die include addr? */
1321                         if (dwarf_lineaddr(line, &addr) != 0 ||
1322                             !dwarf_haspc(sp_die, addr))
1323                                 continue;
1324
1325                         /* Address filtering 2: No child include addr? */
1326                         if (die_find_inlinefunc(sp_die, addr, &die_mem))
1327                                 continue;
1328                 }
1329
1330                 /* TODO: Get fileno from line, but how? */
1331                 src = dwarf_linesrc(line, NULL, NULL);
1332                 if (strtailcmp(src, lf->fname) != 0)
1333                         continue;
1334
1335                 ret = line_range_add_line(src, lineno, lf->lr);
1336                 if (ret < 0)
1337                         return ret;
1338         }
1339
1340         /*
1341          * Dwarf lines doesn't include function declarations. We have to
1342          * check functions list or given function.
1343          */
1344         if (sp_die) {
1345                 src = dwarf_decl_file(sp_die);
1346                 if (src && dwarf_decl_line(sp_die, &lineno) == 0 &&
1347                     (lf->lno_s <= lineno && lf->lno_e >= lineno))
1348                         ret = line_range_add_line(src, lineno, lf->lr);
1349         } else
1350                 ret = find_line_range_func_decl_lines(lf);
1351
1352         /* Update status */
1353         if (ret >= 0)
1354                 if (!list_empty(&lf->lr->line_list))
1355                         ret = lf->found = 1;
1356                 else
1357                         ret = 0;        /* Lines are not found */
1358         else {
1359                 free(lf->lr->path);
1360                 lf->lr->path = NULL;
1361         }
1362         return ret;
1363 }
1364
1365 static int line_range_inline_cb(Dwarf_Die *in_die, void *data)
1366 {
1367         struct dwarf_callback_param *param = data;
1368
1369         param->retval = find_line_range_by_line(in_die, param->data);
1370         return DWARF_CB_ABORT;  /* No need to find other instances */
1371 }
1372
1373 /* Search function from function name */
1374 static int line_range_search_cb(Dwarf_Die *sp_die, void *data)
1375 {
1376         struct dwarf_callback_param *param = data;
1377         struct line_finder *lf = param->data;
1378         struct line_range *lr = lf->lr;
1379
1380         if (dwarf_tag(sp_die) == DW_TAG_subprogram &&
1381             die_compare_name(sp_die, lr->function)) {
1382                 lf->fname = dwarf_decl_file(sp_die);
1383                 dwarf_decl_line(sp_die, &lr->offset);
1384                 pr_debug("fname: %s, lineno:%d\n", lf->fname, lr->offset);
1385                 lf->lno_s = lr->offset + lr->start;
1386                 if (lf->lno_s < 0)      /* Overflow */
1387                         lf->lno_s = INT_MAX;
1388                 lf->lno_e = lr->offset + lr->end;
1389                 if (lf->lno_e < 0)      /* Overflow */
1390                         lf->lno_e = INT_MAX;
1391                 pr_debug("New line range: %d to %d\n", lf->lno_s, lf->lno_e);
1392                 lr->start = lf->lno_s;
1393                 lr->end = lf->lno_e;
1394                 if (dwarf_func_inline(sp_die)) {
1395                         struct dwarf_callback_param _param;
1396                         _param.data = (void *)lf;
1397                         _param.retval = 0;
1398                         dwarf_func_inline_instances(sp_die,
1399                                                     line_range_inline_cb,
1400                                                     &_param);
1401                         param->retval = _param.retval;
1402                 } else
1403                         param->retval = find_line_range_by_line(sp_die, lf);
1404                 return DWARF_CB_ABORT;
1405         }
1406         return DWARF_CB_OK;
1407 }
1408
1409 static int find_line_range_by_func(struct line_finder *lf)
1410 {
1411         struct dwarf_callback_param param = {.data = (void *)lf, .retval = 0};
1412         dwarf_getfuncs(&lf->cu_die, line_range_search_cb, &param, 0);
1413         return param.retval;
1414 }
1415
1416 int find_line_range(int fd, struct line_range *lr)
1417 {
1418         struct line_finder lf = {.lr = lr, .found = 0};
1419         int ret = 0;
1420         Dwarf_Off off = 0, noff;
1421         size_t cuhl;
1422         Dwarf_Die *diep;
1423         Dwarf *dbg;
1424         const char *comp_dir;
1425
1426         dbg = dwarf_begin(fd, DWARF_C_READ);
1427         if (!dbg) {
1428                 pr_warning("No dwarf info found in the vmlinux - "
1429                         "please rebuild with CONFIG_DEBUG_INFO=y.\n");
1430                 return -EBADF;
1431         }
1432
1433         /* Loop on CUs (Compilation Unit) */
1434         while (!lf.found && ret >= 0) {
1435                 if (dwarf_nextcu(dbg, off, &noff, &cuhl, NULL, NULL, NULL) != 0)
1436                         break;
1437
1438                 /* Get the DIE(Debugging Information Entry) of this CU */
1439                 diep = dwarf_offdie(dbg, off + cuhl, &lf.cu_die);
1440                 if (!diep)
1441                         continue;
1442
1443                 /* Check if target file is included. */
1444                 if (lr->file)
1445                         lf.fname = cu_find_realpath(&lf.cu_die, lr->file);
1446                 else
1447                         lf.fname = 0;
1448
1449                 if (!lr->file || lf.fname) {
1450                         if (lr->function)
1451                                 ret = find_line_range_by_func(&lf);
1452                         else {
1453                                 lf.lno_s = lr->start;
1454                                 lf.lno_e = lr->end;
1455                                 ret = find_line_range_by_line(NULL, &lf);
1456                         }
1457                 }
1458                 off = noff;
1459         }
1460
1461         /* Store comp_dir */
1462         if (lf.found) {
1463                 comp_dir = cu_get_comp_dir(&lf.cu_die);
1464                 if (comp_dir) {
1465                         lr->comp_dir = strdup(comp_dir);
1466                         if (!lr->comp_dir)
1467                                 ret = -ENOMEM;
1468                 }
1469         }
1470
1471         pr_debug("path: %s\n", lr->path);
1472         dwarf_end(dbg);
1473
1474         return (ret < 0) ? ret : lf.found;
1475 }
1476