perf probe: Remove xstrdup()/xstrndup() from util/probe-{event, finder}.c
[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
35 #include "string.h"
36 #include "event.h"
37 #include "debug.h"
38 #include "util.h"
39 #include "probe-finder.h"
40
41
42 /*
43  * Generic dwarf analysis helpers
44  */
45
46 #define X86_32_MAX_REGS 8
47 const char *x86_32_regs_table[X86_32_MAX_REGS] = {
48         "%ax",
49         "%cx",
50         "%dx",
51         "%bx",
52         "$stack",       /* Stack address instead of %sp */
53         "%bp",
54         "%si",
55         "%di",
56 };
57
58 #define X86_64_MAX_REGS 16
59 const char *x86_64_regs_table[X86_64_MAX_REGS] = {
60         "%ax",
61         "%dx",
62         "%cx",
63         "%bx",
64         "%si",
65         "%di",
66         "%bp",
67         "%sp",
68         "%r8",
69         "%r9",
70         "%r10",
71         "%r11",
72         "%r12",
73         "%r13",
74         "%r14",
75         "%r15",
76 };
77
78 /* TODO: switching by dwarf address size */
79 #ifdef __x86_64__
80 #define ARCH_MAX_REGS X86_64_MAX_REGS
81 #define arch_regs_table x86_64_regs_table
82 #else
83 #define ARCH_MAX_REGS X86_32_MAX_REGS
84 #define arch_regs_table x86_32_regs_table
85 #endif
86
87 /* Kprobe tracer basic type is up to u64 */
88 #define MAX_BASIC_TYPE_BITS     64
89
90 /* Return architecture dependent register string (for kprobe-tracer) */
91 static const char *get_arch_regstr(unsigned int n)
92 {
93         return (n <= ARCH_MAX_REGS) ? arch_regs_table[n] : NULL;
94 }
95
96 /*
97  * Compare the tail of two strings.
98  * Return 0 if whole of either string is same as another's tail part.
99  */
100 static int strtailcmp(const char *s1, const char *s2)
101 {
102         int i1 = strlen(s1);
103         int i2 = strlen(s2);
104         while (--i1 >= 0 && --i2 >= 0) {
105                 if (s1[i1] != s2[i2])
106                         return s1[i1] - s2[i2];
107         }
108         return 0;
109 }
110
111 /* Line number list operations */
112
113 /* Add a line to line number list */
114 static int line_list__add_line(struct list_head *head, unsigned int line)
115 {
116         struct line_node *ln;
117         struct list_head *p;
118
119         /* Reverse search, because new line will be the last one */
120         list_for_each_entry_reverse(ln, head, list) {
121                 if (ln->line < line) {
122                         p = &ln->list;
123                         goto found;
124                 } else if (ln->line == line)    /* Already exist */
125                         return 1;
126         }
127         /* List is empty, or the smallest entry */
128         p = head;
129 found:
130         pr_debug("line list: add a line %u\n", line);
131         ln = zalloc(sizeof(struct line_node));
132         if (ln == NULL)
133                 return -ENOMEM;
134         ln->line = line;
135         INIT_LIST_HEAD(&ln->list);
136         list_add(&ln->list, p);
137         return 0;
138 }
139
140 /* Check if the line in line number list */
141 static int line_list__has_line(struct list_head *head, unsigned int line)
142 {
143         struct line_node *ln;
144
145         /* Reverse search, because new line will be the last one */
146         list_for_each_entry(ln, head, list)
147                 if (ln->line == line)
148                         return 1;
149
150         return 0;
151 }
152
153 /* Init line number list */
154 static void line_list__init(struct list_head *head)
155 {
156         INIT_LIST_HEAD(head);
157 }
158
159 /* Free line number list */
160 static void line_list__free(struct list_head *head)
161 {
162         struct line_node *ln;
163         while (!list_empty(head)) {
164                 ln = list_first_entry(head, struct line_node, list);
165                 list_del(&ln->list);
166                 free(ln);
167         }
168 }
169
170 /* Dwarf wrappers */
171
172 /* Find the realpath of the target file. */
173 static const char *cu_find_realpath(Dwarf_Die *cu_die, const char *fname)
174 {
175         Dwarf_Files *files;
176         size_t nfiles, i;
177         const char *src = NULL;
178         int ret;
179
180         if (!fname)
181                 return NULL;
182
183         ret = dwarf_getsrcfiles(cu_die, &files, &nfiles);
184         if (ret != 0)
185                 return NULL;
186
187         for (i = 0; i < nfiles; i++) {
188                 src = dwarf_filesrc(files, i, NULL, NULL);
189                 if (strtailcmp(src, fname) == 0)
190                         break;
191         }
192         if (i == nfiles)
193                 return NULL;
194         return src;
195 }
196
197 /* Compare diename and tname */
198 static bool die_compare_name(Dwarf_Die *dw_die, const char *tname)
199 {
200         const char *name;
201         name = dwarf_diename(dw_die);
202         return name ? strcmp(tname, name) : -1;
203 }
204
205 /* Get type die, but skip qualifiers and typedef */
206 static Dwarf_Die *die_get_real_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem)
207 {
208         Dwarf_Attribute attr;
209         int tag;
210
211         do {
212                 if (dwarf_attr(vr_die, DW_AT_type, &attr) == NULL ||
213                     dwarf_formref_die(&attr, die_mem) == NULL)
214                         return NULL;
215
216                 tag = dwarf_tag(die_mem);
217                 vr_die = die_mem;
218         } while (tag == DW_TAG_const_type ||
219                  tag == DW_TAG_restrict_type ||
220                  tag == DW_TAG_volatile_type ||
221                  tag == DW_TAG_shared_type ||
222                  tag == DW_TAG_typedef);
223
224         return die_mem;
225 }
226
227 static bool die_is_signed_type(Dwarf_Die *tp_die)
228 {
229         Dwarf_Attribute attr;
230         Dwarf_Word ret;
231
232         if (dwarf_attr(tp_die, DW_AT_encoding, &attr) == NULL ||
233             dwarf_formudata(&attr, &ret) != 0)
234                 return false;
235
236         return (ret == DW_ATE_signed_char || ret == DW_ATE_signed ||
237                 ret == DW_ATE_signed_fixed);
238 }
239
240 static int die_get_byte_size(Dwarf_Die *tp_die)
241 {
242         Dwarf_Attribute attr;
243         Dwarf_Word ret;
244
245         if (dwarf_attr(tp_die, DW_AT_byte_size, &attr) == NULL ||
246             dwarf_formudata(&attr, &ret) != 0)
247                 return 0;
248
249         return (int)ret;
250 }
251
252 /* Return values for die_find callbacks */
253 enum {
254         DIE_FIND_CB_FOUND = 0,          /* End of Search */
255         DIE_FIND_CB_CHILD = 1,          /* Search only children */
256         DIE_FIND_CB_SIBLING = 2,        /* Search only siblings */
257         DIE_FIND_CB_CONTINUE = 3,       /* Search children and siblings */
258 };
259
260 /* Search a child die */
261 static Dwarf_Die *die_find_child(Dwarf_Die *rt_die,
262                                  int (*callback)(Dwarf_Die *, void *),
263                                  void *data, Dwarf_Die *die_mem)
264 {
265         Dwarf_Die child_die;
266         int ret;
267
268         ret = dwarf_child(rt_die, die_mem);
269         if (ret != 0)
270                 return NULL;
271
272         do {
273                 ret = callback(die_mem, data);
274                 if (ret == DIE_FIND_CB_FOUND)
275                         return die_mem;
276
277                 if ((ret & DIE_FIND_CB_CHILD) &&
278                     die_find_child(die_mem, callback, data, &child_die)) {
279                         memcpy(die_mem, &child_die, sizeof(Dwarf_Die));
280                         return die_mem;
281                 }
282         } while ((ret & DIE_FIND_CB_SIBLING) &&
283                  dwarf_siblingof(die_mem, die_mem) == 0);
284
285         return NULL;
286 }
287
288 struct __addr_die_search_param {
289         Dwarf_Addr      addr;
290         Dwarf_Die       *die_mem;
291 };
292
293 static int __die_search_func_cb(Dwarf_Die *fn_die, void *data)
294 {
295         struct __addr_die_search_param *ad = data;
296
297         if (dwarf_tag(fn_die) == DW_TAG_subprogram &&
298             dwarf_haspc(fn_die, ad->addr)) {
299                 memcpy(ad->die_mem, fn_die, sizeof(Dwarf_Die));
300                 return DWARF_CB_ABORT;
301         }
302         return DWARF_CB_OK;
303 }
304
305 /* Search a real subprogram including this line, */
306 static Dwarf_Die *die_find_real_subprogram(Dwarf_Die *cu_die, Dwarf_Addr addr,
307                                            Dwarf_Die *die_mem)
308 {
309         struct __addr_die_search_param ad;
310         ad.addr = addr;
311         ad.die_mem = die_mem;
312         /* dwarf_getscopes can't find subprogram. */
313         if (!dwarf_getfuncs(cu_die, __die_search_func_cb, &ad, 0))
314                 return NULL;
315         else
316                 return die_mem;
317 }
318
319 /* die_find callback for inline function search */
320 static int __die_find_inline_cb(Dwarf_Die *die_mem, void *data)
321 {
322         Dwarf_Addr *addr = data;
323
324         if (dwarf_tag(die_mem) == DW_TAG_inlined_subroutine &&
325             dwarf_haspc(die_mem, *addr))
326                 return DIE_FIND_CB_FOUND;
327
328         return DIE_FIND_CB_CONTINUE;
329 }
330
331 /* Similar to dwarf_getfuncs, but returns inlined_subroutine if exists. */
332 static Dwarf_Die *die_find_inlinefunc(Dwarf_Die *sp_die, Dwarf_Addr addr,
333                                       Dwarf_Die *die_mem)
334 {
335         return die_find_child(sp_die, __die_find_inline_cb, &addr, die_mem);
336 }
337
338 static int __die_find_variable_cb(Dwarf_Die *die_mem, void *data)
339 {
340         const char *name = data;
341         int tag;
342
343         tag = dwarf_tag(die_mem);
344         if ((tag == DW_TAG_formal_parameter ||
345              tag == DW_TAG_variable) &&
346             (die_compare_name(die_mem, name) == 0))
347                 return DIE_FIND_CB_FOUND;
348
349         return DIE_FIND_CB_CONTINUE;
350 }
351
352 /* Find a variable called 'name' */
353 static Dwarf_Die *die_find_variable(Dwarf_Die *sp_die, const char *name,
354                                     Dwarf_Die *die_mem)
355 {
356         return die_find_child(sp_die, __die_find_variable_cb, (void *)name,
357                               die_mem);
358 }
359
360 static int __die_find_member_cb(Dwarf_Die *die_mem, void *data)
361 {
362         const char *name = data;
363
364         if ((dwarf_tag(die_mem) == DW_TAG_member) &&
365             (die_compare_name(die_mem, name) == 0))
366                 return DIE_FIND_CB_FOUND;
367
368         return DIE_FIND_CB_SIBLING;
369 }
370
371 /* Find a member called 'name' */
372 static Dwarf_Die *die_find_member(Dwarf_Die *st_die, const char *name,
373                                   Dwarf_Die *die_mem)
374 {
375         return die_find_child(st_die, __die_find_member_cb, (void *)name,
376                               die_mem);
377 }
378
379 /*
380  * Probe finder related functions
381  */
382
383 /* Show a location */
384 static int convert_location(Dwarf_Op *op, struct probe_finder *pf)
385 {
386         unsigned int regn;
387         Dwarf_Word offs = 0;
388         bool ref = false;
389         const char *regs;
390         struct kprobe_trace_arg *tvar = pf->tvar;
391
392         /* If this is based on frame buffer, set the offset */
393         if (op->atom == DW_OP_fbreg) {
394                 if (pf->fb_ops == NULL) {
395                         pr_warning("The attribute of frame base is not "
396                                    "supported.\n");
397                         return -ENOTSUP;
398                 }
399                 ref = true;
400                 offs = op->number;
401                 op = &pf->fb_ops[0];
402         }
403
404         if (op->atom >= DW_OP_breg0 && op->atom <= DW_OP_breg31) {
405                 regn = op->atom - DW_OP_breg0;
406                 offs += op->number;
407                 ref = true;
408         } else if (op->atom >= DW_OP_reg0 && op->atom <= DW_OP_reg31) {
409                 regn = op->atom - DW_OP_reg0;
410         } else if (op->atom == DW_OP_bregx) {
411                 regn = op->number;
412                 offs += op->number2;
413                 ref = true;
414         } else if (op->atom == DW_OP_regx) {
415                 regn = op->number;
416         } else {
417                 pr_warning("DW_OP %x is not supported.\n", op->atom);
418                 return -ENOTSUP;
419         }
420
421         regs = get_arch_regstr(regn);
422         if (!regs) {
423                 pr_warning("%u exceeds max register number.\n", regn);
424                 return -ERANGE;
425         }
426
427         tvar->value = strdup(regs);
428         if (tvar->value == NULL)
429                 return -ENOMEM;
430
431         if (ref) {
432                 tvar->ref = zalloc(sizeof(struct kprobe_trace_arg_ref));
433                 if (tvar->ref == NULL)
434                         return -ENOMEM;
435                 tvar->ref->offset = (long)offs;
436         }
437         return 0;
438 }
439
440 static int convert_variable_type(Dwarf_Die *vr_die,
441                                  struct kprobe_trace_arg *targ)
442 {
443         Dwarf_Die type;
444         char buf[16];
445         int ret;
446
447         if (die_get_real_type(vr_die, &type) == NULL) {
448                 pr_warning("Failed to get a type information of %s.\n",
449                            dwarf_diename(vr_die));
450                 return -ENOENT;
451         }
452
453         ret = die_get_byte_size(&type) * 8;
454         if (ret) {
455                 /* Check the bitwidth */
456                 if (ret > MAX_BASIC_TYPE_BITS) {
457                         pr_info("%s exceeds max-bitwidth."
458                                 " Cut down to %d bits.\n",
459                                 dwarf_diename(&type), MAX_BASIC_TYPE_BITS);
460                         ret = MAX_BASIC_TYPE_BITS;
461                 }
462
463                 ret = snprintf(buf, 16, "%c%d",
464                                die_is_signed_type(&type) ? 's' : 'u', ret);
465                 if (ret < 0 || ret >= 16) {
466                         if (ret >= 16)
467                                 ret = -E2BIG;
468                         pr_warning("Failed to convert variable type: %s\n",
469                                    strerror(-ret));
470                         return ret;
471                 }
472                 targ->type = strdup(buf);
473                 if (targ->type == NULL)
474                         return -ENOMEM;
475         }
476         return 0;
477 }
478
479 static int convert_variable_fields(Dwarf_Die *vr_die, const char *varname,
480                                     struct perf_probe_arg_field *field,
481                                     struct kprobe_trace_arg_ref **ref_ptr,
482                                     Dwarf_Die *die_mem)
483 {
484         struct kprobe_trace_arg_ref *ref = *ref_ptr;
485         Dwarf_Attribute attr;
486         Dwarf_Die type;
487         Dwarf_Word offs;
488
489         pr_debug("converting %s in %s\n", field->name, varname);
490         if (die_get_real_type(vr_die, &type) == NULL) {
491                 pr_warning("Failed to get the type of %s.\n", varname);
492                 return -ENOENT;
493         }
494
495         /* Check the pointer and dereference */
496         if (dwarf_tag(&type) == DW_TAG_pointer_type) {
497                 if (!field->ref) {
498                         pr_err("Semantic error: %s must be referred by '->'\n",
499                                field->name);
500                         return -EINVAL;
501                 }
502                 /* Get the type pointed by this pointer */
503                 if (die_get_real_type(&type, &type) == NULL) {
504                         pr_warning("Failed to get the type of %s.\n", varname);
505                         return -ENOENT;
506                 }
507                 /* Verify it is a data structure  */
508                 if (dwarf_tag(&type) != DW_TAG_structure_type) {
509                         pr_warning("%s is not a data structure.\n", varname);
510                         return -EINVAL;
511                 }
512
513                 ref = zalloc(sizeof(struct kprobe_trace_arg_ref));
514                 if (ref == NULL)
515                         return -ENOMEM;
516                 if (*ref_ptr)
517                         (*ref_ptr)->next = ref;
518                 else
519                         *ref_ptr = ref;
520         } else {
521                 /* Verify it is a data structure  */
522                 if (dwarf_tag(&type) != DW_TAG_structure_type) {
523                         pr_warning("%s is not a data structure.\n", varname);
524                         return -EINVAL;
525                 }
526                 if (field->ref) {
527                         pr_err("Semantic error: %s must be referred by '.'\n",
528                                field->name);
529                         return -EINVAL;
530                 }
531                 if (!ref) {
532                         pr_warning("Structure on a register is not "
533                                    "supported yet.\n");
534                         return -ENOTSUP;
535                 }
536         }
537
538         if (die_find_member(&type, field->name, die_mem) == NULL) {
539                 pr_warning("%s(tyep:%s) has no member %s.\n", varname,
540                            dwarf_diename(&type), field->name);
541                 return -EINVAL;
542         }
543
544         /* Get the offset of the field */
545         if (dwarf_attr(die_mem, DW_AT_data_member_location, &attr) == NULL ||
546             dwarf_formudata(&attr, &offs) != 0) {
547                 pr_warning("Failed to get the offset of %s.\n", field->name);
548                 return -ENOENT;
549         }
550         ref->offset += (long)offs;
551
552         /* Converting next field */
553         if (field->next)
554                 return convert_variable_fields(die_mem, field->name,
555                                                field->next, &ref, die_mem);
556         else
557                 return 0;
558 }
559
560 /* Show a variables in kprobe event format */
561 static int convert_variable(Dwarf_Die *vr_die, struct probe_finder *pf)
562 {
563         Dwarf_Attribute attr;
564         Dwarf_Die die_mem;
565         Dwarf_Op *expr;
566         size_t nexpr;
567         int ret;
568
569         if (dwarf_attr(vr_die, DW_AT_location, &attr) == NULL)
570                 goto error;
571         /* TODO: handle more than 1 exprs */
572         ret = dwarf_getlocation_addr(&attr, pf->addr, &expr, &nexpr, 1);
573         if (ret <= 0 || nexpr == 0)
574                 goto error;
575
576         ret = convert_location(expr, pf);
577         if (ret == 0 && pf->pvar->field) {
578                 ret = convert_variable_fields(vr_die, pf->pvar->var,
579                                               pf->pvar->field, &pf->tvar->ref,
580                                               &die_mem);
581                 vr_die = &die_mem;
582         }
583         if (ret == 0) {
584                 if (pf->pvar->type) {
585                         pf->tvar->type = strdup(pf->pvar->type);
586                         if (pf->tvar->type == NULL)
587                                 ret = -ENOMEM;
588                 } else
589                         ret = convert_variable_type(vr_die, pf->tvar);
590         }
591         /* *expr will be cached in libdw. Don't free it. */
592         return ret;
593 error:
594         /* TODO: Support const_value */
595         pr_err("Failed to find the location of %s at this address.\n"
596                " Perhaps, it has been optimized out.\n", pf->pvar->var);
597         return -ENOENT;
598 }
599
600 /* Find a variable in a subprogram die */
601 static int find_variable(Dwarf_Die *sp_die, struct probe_finder *pf)
602 {
603         Dwarf_Die vr_die;
604         char buf[32], *ptr;
605         int ret;
606
607         /* TODO: Support arrays */
608         if (pf->pvar->name)
609                 pf->tvar->name = strdup(pf->pvar->name);
610         else {
611                 ret = synthesize_perf_probe_arg(pf->pvar, buf, 32);
612                 if (ret < 0)
613                         return ret;
614                 ptr = strchr(buf, ':'); /* Change type separator to _ */
615                 if (ptr)
616                         *ptr = '_';
617                 pf->tvar->name = strdup(buf);
618         }
619         if (pf->tvar->name == NULL)
620                 return -ENOMEM;
621
622         if (!is_c_varname(pf->pvar->var)) {
623                 /* Copy raw parameters */
624                 pf->tvar->value = strdup(pf->pvar->var);
625                 if (pf->tvar->value == NULL)
626                         return -ENOMEM;
627                 else
628                         return 0;
629         }
630
631         pr_debug("Searching '%s' variable in context.\n",
632                  pf->pvar->var);
633         /* Search child die for local variables and parameters. */
634         if (!die_find_variable(sp_die, pf->pvar->var, &vr_die)) {
635                 pr_warning("Failed to find '%s' in this function.\n",
636                            pf->pvar->var);
637                 return -ENOENT;
638         }
639         return convert_variable(&vr_die, pf);
640 }
641
642 /* Show a probe point to output buffer */
643 static int convert_probe_point(Dwarf_Die *sp_die, struct probe_finder *pf)
644 {
645         struct kprobe_trace_event *tev;
646         Dwarf_Addr eaddr;
647         Dwarf_Die die_mem;
648         const char *name;
649         int ret, i;
650         Dwarf_Attribute fb_attr;
651         size_t nops;
652
653         if (pf->ntevs == MAX_PROBES) {
654                 pr_warning("Too many( > %d) probe point found.\n", MAX_PROBES);
655                 return -ERANGE;
656         }
657         tev = &pf->tevs[pf->ntevs++];
658
659         /* If no real subprogram, find a real one */
660         if (!sp_die || dwarf_tag(sp_die) != DW_TAG_subprogram) {
661                 sp_die = die_find_real_subprogram(&pf->cu_die,
662                                                  pf->addr, &die_mem);
663                 if (!sp_die) {
664                         pr_warning("Failed to find probe point in any "
665                                    "functions.\n");
666                         return -ENOENT;
667                 }
668         }
669
670         /* Copy the name of probe point */
671         name = dwarf_diename(sp_die);
672         if (name) {
673                 if (dwarf_entrypc(sp_die, &eaddr) != 0) {
674                         pr_warning("Failed to get entry pc of %s\n",
675                                    dwarf_diename(sp_die));
676                         return -ENOENT;
677                 }
678                 tev->point.symbol = strdup(name);
679                 if (tev->point.symbol == NULL)
680                         return -ENOMEM;
681                 tev->point.offset = (unsigned long)(pf->addr - eaddr);
682         } else
683                 /* This function has no name. */
684                 tev->point.offset = (unsigned long)pf->addr;
685
686         pr_debug("Probe point found: %s+%lu\n", tev->point.symbol,
687                  tev->point.offset);
688
689         /* Get the frame base attribute/ops */
690         dwarf_attr(sp_die, DW_AT_frame_base, &fb_attr);
691         ret = dwarf_getlocation_addr(&fb_attr, pf->addr, &pf->fb_ops, &nops, 1);
692         if (ret <= 0 || nops == 0) {
693                 pf->fb_ops = NULL;
694         } else if (nops == 1 && pf->fb_ops[0].atom == DW_OP_call_frame_cfa &&
695                    pf->cfi != NULL) {
696                 Dwarf_Frame *frame;
697                 if (dwarf_cfi_addrframe(pf->cfi, pf->addr, &frame) != 0 ||
698                     dwarf_frame_cfa(frame, &pf->fb_ops, &nops) != 0) {
699                         pr_warning("Failed to get CFA on 0x%jx\n",
700                                    (uintmax_t)pf->addr);
701                         return -ENOENT;
702                 }
703         }
704
705         /* Find each argument */
706         tev->nargs = pf->pev->nargs;
707         tev->args = zalloc(sizeof(struct kprobe_trace_arg) * tev->nargs);
708         if (tev->args == NULL)
709                 return -ENOMEM;
710         for (i = 0; i < pf->pev->nargs; i++) {
711                 pf->pvar = &pf->pev->args[i];
712                 pf->tvar = &tev->args[i];
713                 ret = find_variable(sp_die, pf);
714                 if (ret != 0)
715                         return ret;
716         }
717
718         /* *pf->fb_ops will be cached in libdw. Don't free it. */
719         pf->fb_ops = NULL;
720         return 0;
721 }
722
723 /* Find probe point from its line number */
724 static int find_probe_point_by_line(struct probe_finder *pf)
725 {
726         Dwarf_Lines *lines;
727         Dwarf_Line *line;
728         size_t nlines, i;
729         Dwarf_Addr addr;
730         int lineno;
731         int ret = 0;
732
733         if (dwarf_getsrclines(&pf->cu_die, &lines, &nlines) != 0) {
734                 pr_warning("No source lines found in this CU.\n");
735                 return -ENOENT;
736         }
737
738         for (i = 0; i < nlines && ret == 0; i++) {
739                 line = dwarf_onesrcline(lines, i);
740                 if (dwarf_lineno(line, &lineno) != 0 ||
741                     lineno != pf->lno)
742                         continue;
743
744                 /* TODO: Get fileno from line, but how? */
745                 if (strtailcmp(dwarf_linesrc(line, NULL, NULL), pf->fname) != 0)
746                         continue;
747
748                 if (dwarf_lineaddr(line, &addr) != 0) {
749                         pr_warning("Failed to get the address of the line.\n");
750                         return -ENOENT;
751                 }
752                 pr_debug("Probe line found: line[%d]:%d addr:0x%jx\n",
753                          (int)i, lineno, (uintmax_t)addr);
754                 pf->addr = addr;
755
756                 ret = convert_probe_point(NULL, pf);
757                 /* Continuing, because target line might be inlined. */
758         }
759         return ret;
760 }
761
762 /* Find lines which match lazy pattern */
763 static int find_lazy_match_lines(struct list_head *head,
764                                  const char *fname, const char *pat)
765 {
766         char *fbuf, *p1, *p2;
767         int fd, ret, line, nlines = 0;
768         struct stat st;
769
770         fd = open(fname, O_RDONLY);
771         if (fd < 0) {
772                 pr_warning("Failed to open %s: %s\n", fname, strerror(-fd));
773                 return fd;
774         }
775
776         ret = fstat(fd, &st);
777         if (ret < 0) {
778                 pr_warning("Failed to get the size of %s: %s\n",
779                            fname, strerror(errno));
780                 return ret;
781         }
782         fbuf = xmalloc(st.st_size + 2);
783         ret = read(fd, fbuf, st.st_size);
784         if (ret < 0) {
785                 pr_warning("Failed to read %s: %s\n", fname, strerror(errno));
786                 return ret;
787         }
788         close(fd);
789         fbuf[st.st_size] = '\n';        /* Dummy line */
790         fbuf[st.st_size + 1] = '\0';
791         p1 = fbuf;
792         line = 1;
793         while ((p2 = strchr(p1, '\n')) != NULL) {
794                 *p2 = '\0';
795                 if (strlazymatch(p1, pat)) {
796                         line_list__add_line(head, line);
797                         nlines++;
798                 }
799                 line++;
800                 p1 = p2 + 1;
801         }
802         free(fbuf);
803         return nlines;
804 }
805
806 /* Find probe points from lazy pattern  */
807 static int find_probe_point_lazy(Dwarf_Die *sp_die, struct probe_finder *pf)
808 {
809         Dwarf_Lines *lines;
810         Dwarf_Line *line;
811         size_t nlines, i;
812         Dwarf_Addr addr;
813         Dwarf_Die die_mem;
814         int lineno;
815         int ret = 0;
816
817         if (list_empty(&pf->lcache)) {
818                 /* Matching lazy line pattern */
819                 ret = find_lazy_match_lines(&pf->lcache, pf->fname,
820                                             pf->pev->point.lazy_line);
821                 if (ret == 0) {
822                         pr_debug("No matched lines found in %s.\n", pf->fname);
823                         return 0;
824                 } else if (ret < 0)
825                         return ret;
826         }
827
828         if (dwarf_getsrclines(&pf->cu_die, &lines, &nlines) != 0) {
829                 pr_warning("No source lines found in this CU.\n");
830                 return -ENOENT;
831         }
832
833         for (i = 0; i < nlines && ret >= 0; i++) {
834                 line = dwarf_onesrcline(lines, i);
835
836                 if (dwarf_lineno(line, &lineno) != 0 ||
837                     !line_list__has_line(&pf->lcache, lineno))
838                         continue;
839
840                 /* TODO: Get fileno from line, but how? */
841                 if (strtailcmp(dwarf_linesrc(line, NULL, NULL), pf->fname) != 0)
842                         continue;
843
844                 if (dwarf_lineaddr(line, &addr) != 0) {
845                         pr_debug("Failed to get the address of line %d.\n",
846                                  lineno);
847                         continue;
848                 }
849                 if (sp_die) {
850                         /* Address filtering 1: does sp_die include addr? */
851                         if (!dwarf_haspc(sp_die, addr))
852                                 continue;
853                         /* Address filtering 2: No child include addr? */
854                         if (die_find_inlinefunc(sp_die, addr, &die_mem))
855                                 continue;
856                 }
857
858                 pr_debug("Probe line found: line[%d]:%d addr:0x%llx\n",
859                          (int)i, lineno, (unsigned long long)addr);
860                 pf->addr = addr;
861
862                 ret = convert_probe_point(sp_die, pf);
863                 /* Continuing, because target line might be inlined. */
864         }
865         /* TODO: deallocate lines, but how? */
866         return ret;
867 }
868
869 /* Callback parameter with return value */
870 struct dwarf_callback_param {
871         void *data;
872         int retval;
873 };
874
875 static int probe_point_inline_cb(Dwarf_Die *in_die, void *data)
876 {
877         struct dwarf_callback_param *param = data;
878         struct probe_finder *pf = param->data;
879         struct perf_probe_point *pp = &pf->pev->point;
880         Dwarf_Addr addr;
881
882         if (pp->lazy_line)
883                 param->retval = find_probe_point_lazy(in_die, pf);
884         else {
885                 /* Get probe address */
886                 if (dwarf_entrypc(in_die, &addr) != 0) {
887                         pr_warning("Failed to get entry pc of %s.\n",
888                                    dwarf_diename(in_die));
889                         param->retval = -ENOENT;
890                         return DWARF_CB_ABORT;
891                 }
892                 pf->addr = addr;
893                 pf->addr += pp->offset;
894                 pr_debug("found inline addr: 0x%jx\n",
895                          (uintmax_t)pf->addr);
896
897                 param->retval = convert_probe_point(in_die, pf);
898         }
899
900         return DWARF_CB_OK;
901 }
902
903 /* Search function from function name */
904 static int probe_point_search_cb(Dwarf_Die *sp_die, void *data)
905 {
906         struct dwarf_callback_param *param = data;
907         struct probe_finder *pf = param->data;
908         struct perf_probe_point *pp = &pf->pev->point;
909
910         /* Check tag and diename */
911         if (dwarf_tag(sp_die) != DW_TAG_subprogram ||
912             die_compare_name(sp_die, pp->function) != 0)
913                 return DWARF_CB_OK;
914
915         pf->fname = dwarf_decl_file(sp_die);
916         if (pp->line) { /* Function relative line */
917                 dwarf_decl_line(sp_die, &pf->lno);
918                 pf->lno += pp->line;
919                 param->retval = find_probe_point_by_line(pf);
920         } else if (!dwarf_func_inline(sp_die)) {
921                 /* Real function */
922                 if (pp->lazy_line)
923                         param->retval = find_probe_point_lazy(sp_die, pf);
924                 else {
925                         if (dwarf_entrypc(sp_die, &pf->addr) != 0) {
926                                 pr_warning("Failed to get entry pc of %s.\n",
927                                            dwarf_diename(sp_die));
928                                 param->retval = -ENOENT;
929                                 return DWARF_CB_ABORT;
930                         }
931                         pf->addr += pp->offset;
932                         /* TODO: Check the address in this function */
933                         param->retval = convert_probe_point(sp_die, pf);
934                 }
935         } else {
936                 struct dwarf_callback_param _param = {.data = (void *)pf,
937                                                       .retval = 0};
938                 /* Inlined function: search instances */
939                 dwarf_func_inline_instances(sp_die, probe_point_inline_cb,
940                                             &_param);
941                 param->retval = _param.retval;
942         }
943
944         return DWARF_CB_ABORT; /* Exit; no same symbol in this CU. */
945 }
946
947 static int find_probe_point_by_func(struct probe_finder *pf)
948 {
949         struct dwarf_callback_param _param = {.data = (void *)pf,
950                                               .retval = 0};
951         dwarf_getfuncs(&pf->cu_die, probe_point_search_cb, &_param, 0);
952         return _param.retval;
953 }
954
955 /* Find kprobe_trace_events specified by perf_probe_event from debuginfo */
956 int find_kprobe_trace_events(int fd, struct perf_probe_event *pev,
957                              struct kprobe_trace_event **tevs)
958 {
959         struct probe_finder pf = {.pev = pev};
960         struct perf_probe_point *pp = &pev->point;
961         Dwarf_Off off, noff;
962         size_t cuhl;
963         Dwarf_Die *diep;
964         Dwarf *dbg;
965         int ret = 0;
966
967         pf.tevs = zalloc(sizeof(struct kprobe_trace_event) * MAX_PROBES);
968         if (pf.tevs == NULL)
969                 return -ENOMEM;
970         *tevs = pf.tevs;
971         pf.ntevs = 0;
972
973         dbg = dwarf_begin(fd, DWARF_C_READ);
974         if (!dbg) {
975                 pr_warning("No dwarf info found in the vmlinux - "
976                         "please rebuild with CONFIG_DEBUG_INFO=y.\n");
977                 return -EBADF;
978         }
979
980         /* Get the call frame information from this dwarf */
981         pf.cfi = dwarf_getcfi(dbg);
982
983         off = 0;
984         line_list__init(&pf.lcache);
985         /* Loop on CUs (Compilation Unit) */
986         while (!dwarf_nextcu(dbg, off, &noff, &cuhl, NULL, NULL, NULL) &&
987                ret >= 0) {
988                 /* Get the DIE(Debugging Information Entry) of this CU */
989                 diep = dwarf_offdie(dbg, off + cuhl, &pf.cu_die);
990                 if (!diep)
991                         continue;
992
993                 /* Check if target file is included. */
994                 if (pp->file)
995                         pf.fname = cu_find_realpath(&pf.cu_die, pp->file);
996                 else
997                         pf.fname = NULL;
998
999                 if (!pp->file || pf.fname) {
1000                         if (pp->function)
1001                                 ret = find_probe_point_by_func(&pf);
1002                         else if (pp->lazy_line)
1003                                 ret = find_probe_point_lazy(NULL, &pf);
1004                         else {
1005                                 pf.lno = pp->line;
1006                                 ret = find_probe_point_by_line(&pf);
1007                         }
1008                 }
1009                 off = noff;
1010         }
1011         line_list__free(&pf.lcache);
1012         dwarf_end(dbg);
1013
1014         return (ret < 0) ? ret : pf.ntevs;
1015 }
1016
1017 /* Reverse search */
1018 int find_perf_probe_point(int fd, unsigned long addr,
1019                           struct perf_probe_point *ppt)
1020 {
1021         Dwarf_Die cudie, spdie, indie;
1022         Dwarf *dbg;
1023         Dwarf_Line *line;
1024         Dwarf_Addr laddr, eaddr;
1025         const char *tmp;
1026         int lineno, ret = 0;
1027         bool found = false;
1028
1029         dbg = dwarf_begin(fd, DWARF_C_READ);
1030         if (!dbg)
1031                 return -EBADF;
1032
1033         /* Find cu die */
1034         if (!dwarf_addrdie(dbg, (Dwarf_Addr)addr, &cudie)) {
1035                 ret = -EINVAL;
1036                 goto end;
1037         }
1038
1039         /* Find a corresponding line */
1040         line = dwarf_getsrc_die(&cudie, (Dwarf_Addr)addr);
1041         if (line) {
1042                 if (dwarf_lineaddr(line, &laddr) == 0 &&
1043                     (Dwarf_Addr)addr == laddr &&
1044                     dwarf_lineno(line, &lineno) == 0) {
1045                         tmp = dwarf_linesrc(line, NULL, NULL);
1046                         if (tmp) {
1047                                 ppt->line = lineno;
1048                                 ppt->file = strdup(tmp);
1049                                 if (ppt->file == NULL) {
1050                                         ret = -ENOMEM;
1051                                         goto end;
1052                                 }
1053                                 found = true;
1054                         }
1055                 }
1056         }
1057
1058         /* Find a corresponding function */
1059         if (die_find_real_subprogram(&cudie, (Dwarf_Addr)addr, &spdie)) {
1060                 tmp = dwarf_diename(&spdie);
1061                 if (!tmp || dwarf_entrypc(&spdie, &eaddr) != 0)
1062                         goto end;
1063
1064                 if (ppt->line) {
1065                         if (die_find_inlinefunc(&spdie, (Dwarf_Addr)addr,
1066                                                 &indie)) {
1067                                 /* addr in an inline function */
1068                                 tmp = dwarf_diename(&indie);
1069                                 if (!tmp)
1070                                         goto end;
1071                                 ret = dwarf_decl_line(&indie, &lineno);
1072                         } else {
1073                                 if (eaddr == addr) {    /* Function entry */
1074                                         lineno = ppt->line;
1075                                         ret = 0;
1076                                 } else
1077                                         ret = dwarf_decl_line(&spdie, &lineno);
1078                         }
1079                         if (ret == 0) {
1080                                 /* Make a relative line number */
1081                                 ppt->line -= lineno;
1082                                 goto found;
1083                         }
1084                 }
1085                 /* We don't have a line number, let's use offset */
1086                 ppt->offset = addr - (unsigned long)eaddr;
1087 found:
1088                 ppt->function = strdup(tmp);
1089                 if (ppt->function == NULL) {
1090                         ret = -ENOMEM;
1091                         goto end;
1092                 }
1093                 found = true;
1094         }
1095
1096 end:
1097         dwarf_end(dbg);
1098         if (ret >= 0)
1099                 ret = found ? 1 : 0;
1100         return ret;
1101 }
1102
1103
1104 /* Find line range from its line number */
1105 static int find_line_range_by_line(Dwarf_Die *sp_die, struct line_finder *lf)
1106 {
1107         Dwarf_Lines *lines;
1108         Dwarf_Line *line;
1109         size_t nlines, i;
1110         Dwarf_Addr addr;
1111         int lineno;
1112         const char *src;
1113         Dwarf_Die die_mem;
1114
1115         line_list__init(&lf->lr->line_list);
1116         if (dwarf_getsrclines(&lf->cu_die, &lines, &nlines) != 0) {
1117                 pr_warning("No source lines found in this CU.\n");
1118                 return -ENOENT;
1119         }
1120
1121         for (i = 0; i < nlines; i++) {
1122                 line = dwarf_onesrcline(lines, i);
1123                 if (dwarf_lineno(line, &lineno) != 0 ||
1124                     (lf->lno_s > lineno || lf->lno_e < lineno))
1125                         continue;
1126
1127                 if (sp_die) {
1128                         /* Address filtering 1: does sp_die include addr? */
1129                         if (dwarf_lineaddr(line, &addr) != 0 ||
1130                             !dwarf_haspc(sp_die, addr))
1131                                 continue;
1132
1133                         /* Address filtering 2: No child include addr? */
1134                         if (die_find_inlinefunc(sp_die, addr, &die_mem))
1135                                 continue;
1136                 }
1137
1138                 /* TODO: Get fileno from line, but how? */
1139                 src = dwarf_linesrc(line, NULL, NULL);
1140                 if (strtailcmp(src, lf->fname) != 0)
1141                         continue;
1142
1143                 /* Copy real path */
1144                 if (!lf->lr->path) {
1145                         lf->lr->path = strdup(src);
1146                         if (lf->lr->path == NULL)
1147                                 return -ENOMEM;
1148                 }
1149                 line_list__add_line(&lf->lr->line_list, (unsigned int)lineno);
1150         }
1151         /* Update status */
1152         if (!list_empty(&lf->lr->line_list))
1153                 lf->found = 1;
1154         else {
1155                 free(lf->lr->path);
1156                 lf->lr->path = NULL;
1157         }
1158         return lf->found;
1159 }
1160
1161 static int line_range_inline_cb(Dwarf_Die *in_die, void *data)
1162 {
1163         struct dwarf_callback_param *param = data;
1164
1165         param->retval = find_line_range_by_line(in_die, param->data);
1166         return DWARF_CB_ABORT;  /* No need to find other instances */
1167 }
1168
1169 /* Search function from function name */
1170 static int line_range_search_cb(Dwarf_Die *sp_die, void *data)
1171 {
1172         struct dwarf_callback_param *param = data;
1173         struct line_finder *lf = param->data;
1174         struct line_range *lr = lf->lr;
1175
1176         if (dwarf_tag(sp_die) == DW_TAG_subprogram &&
1177             die_compare_name(sp_die, lr->function) == 0) {
1178                 lf->fname = dwarf_decl_file(sp_die);
1179                 dwarf_decl_line(sp_die, &lr->offset);
1180                 pr_debug("fname: %s, lineno:%d\n", lf->fname, lr->offset);
1181                 lf->lno_s = lr->offset + lr->start;
1182                 if (!lr->end)
1183                         lf->lno_e = INT_MAX;
1184                 else
1185                         lf->lno_e = lr->offset + lr->end;
1186                 lr->start = lf->lno_s;
1187                 lr->end = lf->lno_e;
1188                 if (dwarf_func_inline(sp_die)) {
1189                         struct dwarf_callback_param _param;
1190                         _param.data = (void *)lf;
1191                         _param.retval = 0;
1192                         dwarf_func_inline_instances(sp_die,
1193                                                     line_range_inline_cb,
1194                                                     &_param);
1195                         param->retval = _param.retval;
1196                 } else
1197                         param->retval = find_line_range_by_line(sp_die, lf);
1198                 return DWARF_CB_ABORT;
1199         }
1200         return DWARF_CB_OK;
1201 }
1202
1203 static int find_line_range_by_func(struct line_finder *lf)
1204 {
1205         struct dwarf_callback_param param = {.data = (void *)lf, .retval = 0};
1206         dwarf_getfuncs(&lf->cu_die, line_range_search_cb, &param, 0);
1207         return param.retval;
1208 }
1209
1210 int find_line_range(int fd, struct line_range *lr)
1211 {
1212         struct line_finder lf = {.lr = lr, .found = 0};
1213         int ret = 0;
1214         Dwarf_Off off = 0, noff;
1215         size_t cuhl;
1216         Dwarf_Die *diep;
1217         Dwarf *dbg;
1218
1219         dbg = dwarf_begin(fd, DWARF_C_READ);
1220         if (!dbg) {
1221                 pr_warning("No dwarf info found in the vmlinux - "
1222                         "please rebuild with CONFIG_DEBUG_INFO=y.\n");
1223                 return -EBADF;
1224         }
1225
1226         /* Loop on CUs (Compilation Unit) */
1227         while (!lf.found && ret >= 0) {
1228                 if (dwarf_nextcu(dbg, off, &noff, &cuhl, NULL, NULL, NULL) != 0)
1229                         break;
1230
1231                 /* Get the DIE(Debugging Information Entry) of this CU */
1232                 diep = dwarf_offdie(dbg, off + cuhl, &lf.cu_die);
1233                 if (!diep)
1234                         continue;
1235
1236                 /* Check if target file is included. */
1237                 if (lr->file)
1238                         lf.fname = cu_find_realpath(&lf.cu_die, lr->file);
1239                 else
1240                         lf.fname = 0;
1241
1242                 if (!lr->file || lf.fname) {
1243                         if (lr->function)
1244                                 ret = find_line_range_by_func(&lf);
1245                         else {
1246                                 lf.lno_s = lr->start;
1247                                 if (!lr->end)
1248                                         lf.lno_e = INT_MAX;
1249                                 else
1250                                         lf.lno_e = lr->end;
1251                                 ret = find_line_range_by_line(NULL, &lf);
1252                         }
1253                 }
1254                 off = noff;
1255         }
1256         pr_debug("path: %lx\n", (unsigned long)lr->path);
1257         dwarf_end(dbg);
1258
1259         return (ret < 0) ? ret : lf.found;
1260 }
1261