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