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