perf probe: Remove xzalloc() 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 = xstrdup(regs);
428         if (ref) {
429                 tvar->ref = zalloc(sizeof(struct kprobe_trace_arg_ref));
430                 if (tvar->ref == NULL)
431                         return -ENOMEM;
432                 tvar->ref->offset = (long)offs;
433         }
434         return 0;
435 }
436
437 static int convert_variable_type(Dwarf_Die *vr_die,
438                                  struct kprobe_trace_arg *targ)
439 {
440         Dwarf_Die type;
441         char buf[16];
442         int ret;
443
444         if (die_get_real_type(vr_die, &type) == NULL) {
445                 pr_warning("Failed to get a type information of %s.\n",
446                            dwarf_diename(vr_die));
447                 return -ENOENT;
448         }
449
450         ret = die_get_byte_size(&type) * 8;
451         if (ret) {
452                 /* Check the bitwidth */
453                 if (ret > MAX_BASIC_TYPE_BITS) {
454                         pr_info("%s exceeds max-bitwidth."
455                                 " Cut down to %d bits.\n",
456                                 dwarf_diename(&type), MAX_BASIC_TYPE_BITS);
457                         ret = MAX_BASIC_TYPE_BITS;
458                 }
459
460                 ret = snprintf(buf, 16, "%c%d",
461                                die_is_signed_type(&type) ? 's' : 'u', ret);
462                 if (ret < 0 || ret >= 16) {
463                         if (ret >= 16)
464                                 ret = -E2BIG;
465                         pr_warning("Failed to convert variable type: %s\n",
466                                    strerror(-ret));
467                         return ret;
468                 }
469                 targ->type = xstrdup(buf);
470         }
471         return 0;
472 }
473
474 static int convert_variable_fields(Dwarf_Die *vr_die, const char *varname,
475                                     struct perf_probe_arg_field *field,
476                                     struct kprobe_trace_arg_ref **ref_ptr,
477                                     Dwarf_Die *die_mem)
478 {
479         struct kprobe_trace_arg_ref *ref = *ref_ptr;
480         Dwarf_Attribute attr;
481         Dwarf_Die type;
482         Dwarf_Word offs;
483
484         pr_debug("converting %s in %s\n", field->name, varname);
485         if (die_get_real_type(vr_die, &type) == NULL) {
486                 pr_warning("Failed to get the type of %s.\n", varname);
487                 return -ENOENT;
488         }
489
490         /* Check the pointer and dereference */
491         if (dwarf_tag(&type) == DW_TAG_pointer_type) {
492                 if (!field->ref) {
493                         pr_err("Semantic error: %s must be referred by '->'\n",
494                                field->name);
495                         return -EINVAL;
496                 }
497                 /* Get the type pointed by this pointer */
498                 if (die_get_real_type(&type, &type) == NULL) {
499                         pr_warning("Failed to get the type of %s.\n", varname);
500                         return -ENOENT;
501                 }
502                 /* Verify it is a data structure  */
503                 if (dwarf_tag(&type) != DW_TAG_structure_type) {
504                         pr_warning("%s is not a data structure.\n", varname);
505                         return -EINVAL;
506                 }
507
508                 ref = zalloc(sizeof(struct kprobe_trace_arg_ref));
509                 if (ref == NULL)
510                         return -ENOMEM;
511                 if (*ref_ptr)
512                         (*ref_ptr)->next = ref;
513                 else
514                         *ref_ptr = ref;
515         } else {
516                 /* Verify it is a data structure  */
517                 if (dwarf_tag(&type) != DW_TAG_structure_type) {
518                         pr_warning("%s is not a data structure.\n", varname);
519                         return -EINVAL;
520                 }
521                 if (field->ref) {
522                         pr_err("Semantic error: %s must be referred by '.'\n",
523                                field->name);
524                         return -EINVAL;
525                 }
526                 if (!ref) {
527                         pr_warning("Structure on a register is not "
528                                    "supported yet.\n");
529                         return -ENOTSUP;
530                 }
531         }
532
533         if (die_find_member(&type, field->name, die_mem) == NULL) {
534                 pr_warning("%s(tyep:%s) has no member %s.\n", varname,
535                            dwarf_diename(&type), field->name);
536                 return -EINVAL;
537         }
538
539         /* Get the offset of the field */
540         if (dwarf_attr(die_mem, DW_AT_data_member_location, &attr) == NULL ||
541             dwarf_formudata(&attr, &offs) != 0) {
542                 pr_warning("Failed to get the offset of %s.\n", field->name);
543                 return -ENOENT;
544         }
545         ref->offset += (long)offs;
546
547         /* Converting next field */
548         if (field->next)
549                 return convert_variable_fields(die_mem, field->name,
550                                                field->next, &ref, die_mem);
551         else
552                 return 0;
553 }
554
555 /* Show a variables in kprobe event format */
556 static int convert_variable(Dwarf_Die *vr_die, struct probe_finder *pf)
557 {
558         Dwarf_Attribute attr;
559         Dwarf_Die die_mem;
560         Dwarf_Op *expr;
561         size_t nexpr;
562         int ret;
563
564         if (dwarf_attr(vr_die, DW_AT_location, &attr) == NULL)
565                 goto error;
566         /* TODO: handle more than 1 exprs */
567         ret = dwarf_getlocation_addr(&attr, pf->addr, &expr, &nexpr, 1);
568         if (ret <= 0 || nexpr == 0)
569                 goto error;
570
571         ret = convert_location(expr, pf);
572         if (ret == 0 && pf->pvar->field) {
573                 ret = convert_variable_fields(vr_die, pf->pvar->var,
574                                               pf->pvar->field, &pf->tvar->ref,
575                                               &die_mem);
576                 vr_die = &die_mem;
577         }
578         if (ret == 0) {
579                 if (pf->pvar->type)
580                         pf->tvar->type = xstrdup(pf->pvar->type);
581                 else
582                         ret = convert_variable_type(vr_die, pf->tvar);
583         }
584         /* *expr will be cached in libdw. Don't free it. */
585         return ret;
586 error:
587         /* TODO: Support const_value */
588         pr_err("Failed to find the location of %s at this address.\n"
589                " Perhaps, it has been optimized out.\n", pf->pvar->var);
590         return -ENOENT;
591 }
592
593 /* Find a variable in a subprogram die */
594 static int find_variable(Dwarf_Die *sp_die, struct probe_finder *pf)
595 {
596         Dwarf_Die vr_die;
597         char buf[32], *ptr;
598
599         /* TODO: Support arrays */
600         if (pf->pvar->name)
601                 pf->tvar->name = xstrdup(pf->pvar->name);
602         else {
603                 synthesize_perf_probe_arg(pf->pvar, buf, 32);
604                 ptr = strchr(buf, ':'); /* Change type separator to _ */
605                 if (ptr)
606                         *ptr = '_';
607                 pf->tvar->name = xstrdup(buf);
608         }
609
610         if (!is_c_varname(pf->pvar->var)) {
611                 /* Copy raw parameters */
612                 pf->tvar->value = xstrdup(pf->pvar->var);
613                 return 0;
614         }
615
616         pr_debug("Searching '%s' variable in context.\n",
617                  pf->pvar->var);
618         /* Search child die for local variables and parameters. */
619         if (!die_find_variable(sp_die, pf->pvar->var, &vr_die)) {
620                 pr_warning("Failed to find '%s' in this function.\n",
621                            pf->pvar->var);
622                 return -ENOENT;
623         }
624         return convert_variable(&vr_die, pf);
625 }
626
627 /* Show a probe point to output buffer */
628 static int convert_probe_point(Dwarf_Die *sp_die, struct probe_finder *pf)
629 {
630         struct kprobe_trace_event *tev;
631         Dwarf_Addr eaddr;
632         Dwarf_Die die_mem;
633         const char *name;
634         int ret, i;
635         Dwarf_Attribute fb_attr;
636         size_t nops;
637
638         if (pf->ntevs == MAX_PROBES) {
639                 pr_warning("Too many( > %d) probe point found.\n", MAX_PROBES);
640                 return -ERANGE;
641         }
642         tev = &pf->tevs[pf->ntevs++];
643
644         /* If no real subprogram, find a real one */
645         if (!sp_die || dwarf_tag(sp_die) != DW_TAG_subprogram) {
646                 sp_die = die_find_real_subprogram(&pf->cu_die,
647                                                  pf->addr, &die_mem);
648                 if (!sp_die) {
649                         pr_warning("Failed to find probe point in any "
650                                    "functions.\n");
651                         return -ENOENT;
652                 }
653         }
654
655         /* Copy the name of probe point */
656         name = dwarf_diename(sp_die);
657         if (name) {
658                 if (dwarf_entrypc(sp_die, &eaddr) != 0) {
659                         pr_warning("Failed to get entry pc of %s\n",
660                                    dwarf_diename(sp_die));
661                         return -ENOENT;
662                 }
663                 tev->point.symbol = xstrdup(name);
664                 tev->point.offset = (unsigned long)(pf->addr - eaddr);
665         } else
666                 /* This function has no name. */
667                 tev->point.offset = (unsigned long)pf->addr;
668
669         pr_debug("Probe point found: %s+%lu\n", tev->point.symbol,
670                  tev->point.offset);
671
672         /* Get the frame base attribute/ops */
673         dwarf_attr(sp_die, DW_AT_frame_base, &fb_attr);
674         ret = dwarf_getlocation_addr(&fb_attr, pf->addr, &pf->fb_ops, &nops, 1);
675         if (ret <= 0 || nops == 0) {
676                 pf->fb_ops = NULL;
677         } else if (nops == 1 && pf->fb_ops[0].atom == DW_OP_call_frame_cfa &&
678                    pf->cfi != NULL) {
679                 Dwarf_Frame *frame;
680                 if (dwarf_cfi_addrframe(pf->cfi, pf->addr, &frame) != 0 ||
681                     dwarf_frame_cfa(frame, &pf->fb_ops, &nops) != 0) {
682                         pr_warning("Failed to get CFA on 0x%jx\n",
683                                    (uintmax_t)pf->addr);
684                         return -ENOENT;
685                 }
686         }
687
688         /* Find each argument */
689         tev->nargs = pf->pev->nargs;
690         tev->args = zalloc(sizeof(struct kprobe_trace_arg) * tev->nargs);
691         if (tev->args == NULL)
692                 return -ENOMEM;
693         for (i = 0; i < pf->pev->nargs; i++) {
694                 pf->pvar = &pf->pev->args[i];
695                 pf->tvar = &tev->args[i];
696                 ret = find_variable(sp_die, pf);
697                 if (ret != 0)
698                         return ret;
699         }
700
701         /* *pf->fb_ops will be cached in libdw. Don't free it. */
702         pf->fb_ops = NULL;
703         return 0;
704 }
705
706 /* Find probe point from its line number */
707 static int find_probe_point_by_line(struct probe_finder *pf)
708 {
709         Dwarf_Lines *lines;
710         Dwarf_Line *line;
711         size_t nlines, i;
712         Dwarf_Addr addr;
713         int lineno;
714         int ret = 0;
715
716         if (dwarf_getsrclines(&pf->cu_die, &lines, &nlines) != 0) {
717                 pr_warning("No source lines found in this CU.\n");
718                 return -ENOENT;
719         }
720
721         for (i = 0; i < nlines && ret == 0; i++) {
722                 line = dwarf_onesrcline(lines, i);
723                 if (dwarf_lineno(line, &lineno) != 0 ||
724                     lineno != pf->lno)
725                         continue;
726
727                 /* TODO: Get fileno from line, but how? */
728                 if (strtailcmp(dwarf_linesrc(line, NULL, NULL), pf->fname) != 0)
729                         continue;
730
731                 if (dwarf_lineaddr(line, &addr) != 0) {
732                         pr_warning("Failed to get the address of the line.\n");
733                         return -ENOENT;
734                 }
735                 pr_debug("Probe line found: line[%d]:%d addr:0x%jx\n",
736                          (int)i, lineno, (uintmax_t)addr);
737                 pf->addr = addr;
738
739                 ret = convert_probe_point(NULL, pf);
740                 /* Continuing, because target line might be inlined. */
741         }
742         return ret;
743 }
744
745 /* Find lines which match lazy pattern */
746 static int find_lazy_match_lines(struct list_head *head,
747                                  const char *fname, const char *pat)
748 {
749         char *fbuf, *p1, *p2;
750         int fd, ret, line, nlines = 0;
751         struct stat st;
752
753         fd = open(fname, O_RDONLY);
754         if (fd < 0) {
755                 pr_warning("Failed to open %s: %s\n", fname, strerror(-fd));
756                 return fd;
757         }
758
759         ret = fstat(fd, &st);
760         if (ret < 0) {
761                 pr_warning("Failed to get the size of %s: %s\n",
762                            fname, strerror(errno));
763                 return ret;
764         }
765         fbuf = xmalloc(st.st_size + 2);
766         ret = read(fd, fbuf, st.st_size);
767         if (ret < 0) {
768                 pr_warning("Failed to read %s: %s\n", fname, strerror(errno));
769                 return ret;
770         }
771         close(fd);
772         fbuf[st.st_size] = '\n';        /* Dummy line */
773         fbuf[st.st_size + 1] = '\0';
774         p1 = fbuf;
775         line = 1;
776         while ((p2 = strchr(p1, '\n')) != NULL) {
777                 *p2 = '\0';
778                 if (strlazymatch(p1, pat)) {
779                         line_list__add_line(head, line);
780                         nlines++;
781                 }
782                 line++;
783                 p1 = p2 + 1;
784         }
785         free(fbuf);
786         return nlines;
787 }
788
789 /* Find probe points from lazy pattern  */
790 static int find_probe_point_lazy(Dwarf_Die *sp_die, struct probe_finder *pf)
791 {
792         Dwarf_Lines *lines;
793         Dwarf_Line *line;
794         size_t nlines, i;
795         Dwarf_Addr addr;
796         Dwarf_Die die_mem;
797         int lineno;
798         int ret = 0;
799
800         if (list_empty(&pf->lcache)) {
801                 /* Matching lazy line pattern */
802                 ret = find_lazy_match_lines(&pf->lcache, pf->fname,
803                                             pf->pev->point.lazy_line);
804                 if (ret == 0) {
805                         pr_debug("No matched lines found in %s.\n", pf->fname);
806                         return 0;
807                 } else if (ret < 0)
808                         return ret;
809         }
810
811         if (dwarf_getsrclines(&pf->cu_die, &lines, &nlines) != 0) {
812                 pr_warning("No source lines found in this CU.\n");
813                 return -ENOENT;
814         }
815
816         for (i = 0; i < nlines && ret >= 0; i++) {
817                 line = dwarf_onesrcline(lines, i);
818
819                 if (dwarf_lineno(line, &lineno) != 0 ||
820                     !line_list__has_line(&pf->lcache, lineno))
821                         continue;
822
823                 /* TODO: Get fileno from line, but how? */
824                 if (strtailcmp(dwarf_linesrc(line, NULL, NULL), pf->fname) != 0)
825                         continue;
826
827                 if (dwarf_lineaddr(line, &addr) != 0) {
828                         pr_debug("Failed to get the address of line %d.\n",
829                                  lineno);
830                         continue;
831                 }
832                 if (sp_die) {
833                         /* Address filtering 1: does sp_die include addr? */
834                         if (!dwarf_haspc(sp_die, addr))
835                                 continue;
836                         /* Address filtering 2: No child include addr? */
837                         if (die_find_inlinefunc(sp_die, addr, &die_mem))
838                                 continue;
839                 }
840
841                 pr_debug("Probe line found: line[%d]:%d addr:0x%llx\n",
842                          (int)i, lineno, (unsigned long long)addr);
843                 pf->addr = addr;
844
845                 ret = convert_probe_point(sp_die, pf);
846                 /* Continuing, because target line might be inlined. */
847         }
848         /* TODO: deallocate lines, but how? */
849         return ret;
850 }
851
852 /* Callback parameter with return value */
853 struct dwarf_callback_param {
854         void *data;
855         int retval;
856 };
857
858 static int probe_point_inline_cb(Dwarf_Die *in_die, void *data)
859 {
860         struct dwarf_callback_param *param = data;
861         struct probe_finder *pf = param->data;
862         struct perf_probe_point *pp = &pf->pev->point;
863         Dwarf_Addr addr;
864
865         if (pp->lazy_line)
866                 param->retval = find_probe_point_lazy(in_die, pf);
867         else {
868                 /* Get probe address */
869                 if (dwarf_entrypc(in_die, &addr) != 0) {
870                         pr_warning("Failed to get entry pc of %s.\n",
871                                    dwarf_diename(in_die));
872                         param->retval = -ENOENT;
873                         return DWARF_CB_ABORT;
874                 }
875                 pf->addr = addr;
876                 pf->addr += pp->offset;
877                 pr_debug("found inline addr: 0x%jx\n",
878                          (uintmax_t)pf->addr);
879
880                 param->retval = convert_probe_point(in_die, pf);
881         }
882
883         return DWARF_CB_OK;
884 }
885
886 /* Search function from function name */
887 static int probe_point_search_cb(Dwarf_Die *sp_die, void *data)
888 {
889         struct dwarf_callback_param *param = data;
890         struct probe_finder *pf = param->data;
891         struct perf_probe_point *pp = &pf->pev->point;
892
893         /* Check tag and diename */
894         if (dwarf_tag(sp_die) != DW_TAG_subprogram ||
895             die_compare_name(sp_die, pp->function) != 0)
896                 return DWARF_CB_OK;
897
898         pf->fname = dwarf_decl_file(sp_die);
899         if (pp->line) { /* Function relative line */
900                 dwarf_decl_line(sp_die, &pf->lno);
901                 pf->lno += pp->line;
902                 param->retval = find_probe_point_by_line(pf);
903         } else if (!dwarf_func_inline(sp_die)) {
904                 /* Real function */
905                 if (pp->lazy_line)
906                         param->retval = find_probe_point_lazy(sp_die, pf);
907                 else {
908                         if (dwarf_entrypc(sp_die, &pf->addr) != 0) {
909                                 pr_warning("Failed to get entry pc of %s.\n",
910                                            dwarf_diename(sp_die));
911                                 param->retval = -ENOENT;
912                                 return DWARF_CB_ABORT;
913                         }
914                         pf->addr += pp->offset;
915                         /* TODO: Check the address in this function */
916                         param->retval = convert_probe_point(sp_die, pf);
917                 }
918         } else {
919                 struct dwarf_callback_param _param = {.data = (void *)pf,
920                                                       .retval = 0};
921                 /* Inlined function: search instances */
922                 dwarf_func_inline_instances(sp_die, probe_point_inline_cb,
923                                             &_param);
924                 param->retval = _param.retval;
925         }
926
927         return DWARF_CB_ABORT; /* Exit; no same symbol in this CU. */
928 }
929
930 static int find_probe_point_by_func(struct probe_finder *pf)
931 {
932         struct dwarf_callback_param _param = {.data = (void *)pf,
933                                               .retval = 0};
934         dwarf_getfuncs(&pf->cu_die, probe_point_search_cb, &_param, 0);
935         return _param.retval;
936 }
937
938 /* Find kprobe_trace_events specified by perf_probe_event from debuginfo */
939 int find_kprobe_trace_events(int fd, struct perf_probe_event *pev,
940                              struct kprobe_trace_event **tevs)
941 {
942         struct probe_finder pf = {.pev = pev};
943         struct perf_probe_point *pp = &pev->point;
944         Dwarf_Off off, noff;
945         size_t cuhl;
946         Dwarf_Die *diep;
947         Dwarf *dbg;
948         int ret = 0;
949
950         pf.tevs = zalloc(sizeof(struct kprobe_trace_event) * MAX_PROBES);
951         if (pf.tevs == NULL)
952                 return -ENOMEM;
953         *tevs = pf.tevs;
954         pf.ntevs = 0;
955
956         dbg = dwarf_begin(fd, DWARF_C_READ);
957         if (!dbg) {
958                 pr_warning("No dwarf info found in the vmlinux - "
959                         "please rebuild with CONFIG_DEBUG_INFO=y.\n");
960                 return -EBADF;
961         }
962
963         /* Get the call frame information from this dwarf */
964         pf.cfi = dwarf_getcfi(dbg);
965
966         off = 0;
967         line_list__init(&pf.lcache);
968         /* Loop on CUs (Compilation Unit) */
969         while (!dwarf_nextcu(dbg, off, &noff, &cuhl, NULL, NULL, NULL) &&
970                ret >= 0) {
971                 /* Get the DIE(Debugging Information Entry) of this CU */
972                 diep = dwarf_offdie(dbg, off + cuhl, &pf.cu_die);
973                 if (!diep)
974                         continue;
975
976                 /* Check if target file is included. */
977                 if (pp->file)
978                         pf.fname = cu_find_realpath(&pf.cu_die, pp->file);
979                 else
980                         pf.fname = NULL;
981
982                 if (!pp->file || pf.fname) {
983                         if (pp->function)
984                                 ret = find_probe_point_by_func(&pf);
985                         else if (pp->lazy_line)
986                                 ret = find_probe_point_lazy(NULL, &pf);
987                         else {
988                                 pf.lno = pp->line;
989                                 ret = find_probe_point_by_line(&pf);
990                         }
991                 }
992                 off = noff;
993         }
994         line_list__free(&pf.lcache);
995         dwarf_end(dbg);
996
997         return (ret < 0) ? ret : pf.ntevs;
998 }
999
1000 /* Reverse search */
1001 int find_perf_probe_point(int fd, unsigned long addr,
1002                           struct perf_probe_point *ppt)
1003 {
1004         Dwarf_Die cudie, spdie, indie;
1005         Dwarf *dbg;
1006         Dwarf_Line *line;
1007         Dwarf_Addr laddr, eaddr;
1008         const char *tmp;
1009         int lineno, ret = 0;
1010         bool found = false;
1011
1012         dbg = dwarf_begin(fd, DWARF_C_READ);
1013         if (!dbg)
1014                 return -EBADF;
1015
1016         /* Find cu die */
1017         if (!dwarf_addrdie(dbg, (Dwarf_Addr)addr, &cudie)) {
1018                 ret = -EINVAL;
1019                 goto end;
1020         }
1021
1022         /* Find a corresponding line */
1023         line = dwarf_getsrc_die(&cudie, (Dwarf_Addr)addr);
1024         if (line) {
1025                 if (dwarf_lineaddr(line, &laddr) == 0 &&
1026                     (Dwarf_Addr)addr == laddr &&
1027                     dwarf_lineno(line, &lineno) == 0) {
1028                         tmp = dwarf_linesrc(line, NULL, NULL);
1029                         if (tmp) {
1030                                 ppt->line = lineno;
1031                                 ppt->file = xstrdup(tmp);
1032                                 found = true;
1033                         }
1034                 }
1035         }
1036
1037         /* Find a corresponding function */
1038         if (die_find_real_subprogram(&cudie, (Dwarf_Addr)addr, &spdie)) {
1039                 tmp = dwarf_diename(&spdie);
1040                 if (!tmp || dwarf_entrypc(&spdie, &eaddr) != 0)
1041                         goto end;
1042
1043                 if (ppt->line) {
1044                         if (die_find_inlinefunc(&spdie, (Dwarf_Addr)addr,
1045                                                 &indie)) {
1046                                 /* addr in an inline function */
1047                                 tmp = dwarf_diename(&indie);
1048                                 if (!tmp)
1049                                         goto end;
1050                                 ret = dwarf_decl_line(&indie, &lineno);
1051                         } else {
1052                                 if (eaddr == addr) {    /* Function entry */
1053                                         lineno = ppt->line;
1054                                         ret = 0;
1055                                 } else
1056                                         ret = dwarf_decl_line(&spdie, &lineno);
1057                         }
1058                         if (ret == 0) {
1059                                 /* Make a relative line number */
1060                                 ppt->line -= lineno;
1061                                 goto found;
1062                         }
1063                 }
1064                 /* We don't have a line number, let's use offset */
1065                 ppt->offset = addr - (unsigned long)eaddr;
1066 found:
1067                 ppt->function = xstrdup(tmp);
1068                 found = true;
1069         }
1070
1071 end:
1072         dwarf_end(dbg);
1073         if (ret >= 0)
1074                 ret = found ? 1 : 0;
1075         return ret;
1076 }
1077
1078
1079 /* Find line range from its line number */
1080 static int find_line_range_by_line(Dwarf_Die *sp_die, struct line_finder *lf)
1081 {
1082         Dwarf_Lines *lines;
1083         Dwarf_Line *line;
1084         size_t nlines, i;
1085         Dwarf_Addr addr;
1086         int lineno;
1087         const char *src;
1088         Dwarf_Die die_mem;
1089
1090         line_list__init(&lf->lr->line_list);
1091         if (dwarf_getsrclines(&lf->cu_die, &lines, &nlines) != 0) {
1092                 pr_warning("No source lines found in this CU.\n");
1093                 return -ENOENT;
1094         }
1095
1096         for (i = 0; i < nlines; i++) {
1097                 line = dwarf_onesrcline(lines, i);
1098                 if (dwarf_lineno(line, &lineno) != 0 ||
1099                     (lf->lno_s > lineno || lf->lno_e < lineno))
1100                         continue;
1101
1102                 if (sp_die) {
1103                         /* Address filtering 1: does sp_die include addr? */
1104                         if (dwarf_lineaddr(line, &addr) != 0 ||
1105                             !dwarf_haspc(sp_die, addr))
1106                                 continue;
1107
1108                         /* Address filtering 2: No child include addr? */
1109                         if (die_find_inlinefunc(sp_die, addr, &die_mem))
1110                                 continue;
1111                 }
1112
1113                 /* TODO: Get fileno from line, but how? */
1114                 src = dwarf_linesrc(line, NULL, NULL);
1115                 if (strtailcmp(src, lf->fname) != 0)
1116                         continue;
1117
1118                 /* Copy real path */
1119                 if (!lf->lr->path)
1120                         lf->lr->path = xstrdup(src);
1121                 line_list__add_line(&lf->lr->line_list, (unsigned int)lineno);
1122         }
1123         /* Update status */
1124         if (!list_empty(&lf->lr->line_list))
1125                 lf->found = 1;
1126         else {
1127                 free(lf->lr->path);
1128                 lf->lr->path = NULL;
1129         }
1130         return lf->found;
1131 }
1132
1133 static int line_range_inline_cb(Dwarf_Die *in_die, void *data)
1134 {
1135         struct dwarf_callback_param *param = data;
1136
1137         param->retval = find_line_range_by_line(in_die, param->data);
1138         return DWARF_CB_ABORT;  /* No need to find other instances */
1139 }
1140
1141 /* Search function from function name */
1142 static int line_range_search_cb(Dwarf_Die *sp_die, void *data)
1143 {
1144         struct dwarf_callback_param *param = data;
1145         struct line_finder *lf = param->data;
1146         struct line_range *lr = lf->lr;
1147
1148         if (dwarf_tag(sp_die) == DW_TAG_subprogram &&
1149             die_compare_name(sp_die, lr->function) == 0) {
1150                 lf->fname = dwarf_decl_file(sp_die);
1151                 dwarf_decl_line(sp_die, &lr->offset);
1152                 pr_debug("fname: %s, lineno:%d\n", lf->fname, lr->offset);
1153                 lf->lno_s = lr->offset + lr->start;
1154                 if (!lr->end)
1155                         lf->lno_e = INT_MAX;
1156                 else
1157                         lf->lno_e = lr->offset + lr->end;
1158                 lr->start = lf->lno_s;
1159                 lr->end = lf->lno_e;
1160                 if (dwarf_func_inline(sp_die)) {
1161                         struct dwarf_callback_param _param;
1162                         _param.data = (void *)lf;
1163                         _param.retval = 0;
1164                         dwarf_func_inline_instances(sp_die,
1165                                                     line_range_inline_cb,
1166                                                     &_param);
1167                         param->retval = _param.retval;
1168                 } else
1169                         param->retval = find_line_range_by_line(sp_die, lf);
1170                 return DWARF_CB_ABORT;
1171         }
1172         return DWARF_CB_OK;
1173 }
1174
1175 static int find_line_range_by_func(struct line_finder *lf)
1176 {
1177         struct dwarf_callback_param param = {.data = (void *)lf, .retval = 0};
1178         dwarf_getfuncs(&lf->cu_die, line_range_search_cb, &param, 0);
1179         return param.retval;
1180 }
1181
1182 int find_line_range(int fd, struct line_range *lr)
1183 {
1184         struct line_finder lf = {.lr = lr, .found = 0};
1185         int ret = 0;
1186         Dwarf_Off off = 0, noff;
1187         size_t cuhl;
1188         Dwarf_Die *diep;
1189         Dwarf *dbg;
1190
1191         dbg = dwarf_begin(fd, DWARF_C_READ);
1192         if (!dbg) {
1193                 pr_warning("No dwarf info found in the vmlinux - "
1194                         "please rebuild with CONFIG_DEBUG_INFO=y.\n");
1195                 return -EBADF;
1196         }
1197
1198         /* Loop on CUs (Compilation Unit) */
1199         while (!lf.found && ret >= 0) {
1200                 if (dwarf_nextcu(dbg, off, &noff, &cuhl, NULL, NULL, NULL) != 0)
1201                         break;
1202
1203                 /* Get the DIE(Debugging Information Entry) of this CU */
1204                 diep = dwarf_offdie(dbg, off + cuhl, &lf.cu_die);
1205                 if (!diep)
1206                         continue;
1207
1208                 /* Check if target file is included. */
1209                 if (lr->file)
1210                         lf.fname = cu_find_realpath(&lf.cu_die, lr->file);
1211                 else
1212                         lf.fname = 0;
1213
1214                 if (!lr->file || lf.fname) {
1215                         if (lr->function)
1216                                 ret = find_line_range_by_func(&lf);
1217                         else {
1218                                 lf.lno_s = lr->start;
1219                                 if (!lr->end)
1220                                         lf.lno_e = INT_MAX;
1221                                 else
1222                                         lf.lno_e = lr->end;
1223                                 ret = find_line_range_by_line(NULL, &lf);
1224                         }
1225                 }
1226                 off = noff;
1227         }
1228         pr_debug("path: %lx\n", (unsigned long)lr->path);
1229         dwarf_end(dbg);
1230
1231         return (ret < 0) ? ret : lf.found;
1232 }
1233