perf probe: Fix to search local variables in appropriate scope
[linux-2.6.git] / tools / perf / util / probe-finder.c
1 /*
2  * probe-finder.c : C expression to kprobe event converter
3  *
4  * Written by Masami Hiramatsu <mhiramat@redhat.com>
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation; either version 2 of the License, or
9  * (at your option) any later version.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  * GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program; if not, write to the Free Software
18  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
19  *
20  */
21
22 #include <sys/utsname.h>
23 #include <sys/types.h>
24 #include <sys/stat.h>
25 #include <fcntl.h>
26 #include <errno.h>
27 #include <stdio.h>
28 #include <unistd.h>
29 #include <getopt.h>
30 #include <stdlib.h>
31 #include <string.h>
32 #include <stdarg.h>
33 #include <ctype.h>
34 #include <dwarf-regs.h>
35
36 #include <linux/bitops.h>
37 #include "event.h"
38 #include "debug.h"
39 #include "util.h"
40 #include "symbol.h"
41 #include "probe-finder.h"
42
43 /* Kprobe tracer basic type is up to u64 */
44 #define MAX_BASIC_TYPE_BITS     64
45
46 /* Line number list operations */
47
48 /* Add a line to line number list */
49 static int line_list__add_line(struct list_head *head, int line)
50 {
51         struct line_node *ln;
52         struct list_head *p;
53
54         /* Reverse search, because new line will be the last one */
55         list_for_each_entry_reverse(ln, head, list) {
56                 if (ln->line < line) {
57                         p = &ln->list;
58                         goto found;
59                 } else if (ln->line == line)    /* Already exist */
60                         return 1;
61         }
62         /* List is empty, or the smallest entry */
63         p = head;
64 found:
65         pr_debug("line list: add a line %u\n", line);
66         ln = zalloc(sizeof(struct line_node));
67         if (ln == NULL)
68                 return -ENOMEM;
69         ln->line = line;
70         INIT_LIST_HEAD(&ln->list);
71         list_add(&ln->list, p);
72         return 0;
73 }
74
75 /* Check if the line in line number list */
76 static int line_list__has_line(struct list_head *head, int line)
77 {
78         struct line_node *ln;
79
80         /* Reverse search, because new line will be the last one */
81         list_for_each_entry(ln, head, list)
82                 if (ln->line == line)
83                         return 1;
84
85         return 0;
86 }
87
88 /* Init line number list */
89 static void line_list__init(struct list_head *head)
90 {
91         INIT_LIST_HEAD(head);
92 }
93
94 /* Free line number list */
95 static void line_list__free(struct list_head *head)
96 {
97         struct line_node *ln;
98         while (!list_empty(head)) {
99                 ln = list_first_entry(head, struct line_node, list);
100                 list_del(&ln->list);
101                 free(ln);
102         }
103 }
104
105 /* Dwarf FL wrappers */
106 static char *debuginfo_path;    /* Currently dummy */
107
108 static const Dwfl_Callbacks offline_callbacks = {
109         .find_debuginfo = dwfl_standard_find_debuginfo,
110         .debuginfo_path = &debuginfo_path,
111
112         .section_address = dwfl_offline_section_address,
113
114         /* We use this table for core files too.  */
115         .find_elf = dwfl_build_id_find_elf,
116 };
117
118 /* Get a Dwarf from offline image */
119 static int debuginfo__init_offline_dwarf(struct debuginfo *self,
120                                          const char *path)
121 {
122         Dwfl_Module *mod;
123         int fd;
124
125         fd = open(path, O_RDONLY);
126         if (fd < 0)
127                 return fd;
128
129         self->dwfl = dwfl_begin(&offline_callbacks);
130         if (!self->dwfl)
131                 goto error;
132
133         mod = dwfl_report_offline(self->dwfl, "", "", fd);
134         if (!mod)
135                 goto error;
136
137         self->dbg = dwfl_module_getdwarf(mod, &self->bias);
138         if (!self->dbg)
139                 goto error;
140
141         return 0;
142 error:
143         if (self->dwfl)
144                 dwfl_end(self->dwfl);
145         else
146                 close(fd);
147         memset(self, 0, sizeof(*self));
148
149         return -ENOENT;
150 }
151
152 #if _ELFUTILS_PREREQ(0, 148)
153 /* This method is buggy if elfutils is older than 0.148 */
154 static int __linux_kernel_find_elf(Dwfl_Module *mod,
155                                    void **userdata,
156                                    const char *module_name,
157                                    Dwarf_Addr base,
158                                    char **file_name, Elf **elfp)
159 {
160         int fd;
161         const char *path = kernel_get_module_path(module_name);
162
163         pr_debug2("Use file %s for %s\n", path, module_name);
164         if (path) {
165                 fd = open(path, O_RDONLY);
166                 if (fd >= 0) {
167                         *file_name = strdup(path);
168                         return fd;
169                 }
170         }
171         /* If failed, try to call standard method */
172         return dwfl_linux_kernel_find_elf(mod, userdata, module_name, base,
173                                           file_name, elfp);
174 }
175
176 static const Dwfl_Callbacks kernel_callbacks = {
177         .find_debuginfo = dwfl_standard_find_debuginfo,
178         .debuginfo_path = &debuginfo_path,
179
180         .find_elf = __linux_kernel_find_elf,
181         .section_address = dwfl_linux_kernel_module_section_address,
182 };
183
184 /* Get a Dwarf from live kernel image */
185 static int debuginfo__init_online_kernel_dwarf(struct debuginfo *self,
186                                                Dwarf_Addr addr)
187 {
188         self->dwfl = dwfl_begin(&kernel_callbacks);
189         if (!self->dwfl)
190                 return -EINVAL;
191
192         /* Load the kernel dwarves: Don't care the result here */
193         dwfl_linux_kernel_report_kernel(self->dwfl);
194         dwfl_linux_kernel_report_modules(self->dwfl);
195
196         self->dbg = dwfl_addrdwarf(self->dwfl, addr, &self->bias);
197         /* Here, check whether we could get a real dwarf */
198         if (!self->dbg) {
199                 pr_debug("Failed to find kernel dwarf at %lx\n",
200                          (unsigned long)addr);
201                 dwfl_end(self->dwfl);
202                 memset(self, 0, sizeof(*self));
203                 return -ENOENT;
204         }
205
206         return 0;
207 }
208 #else
209 /* With older elfutils, this just support kernel module... */
210 static int debuginfo__init_online_kernel_dwarf(struct debuginfo *self,
211                                                Dwarf_Addr addr __used)
212 {
213         const char *path = kernel_get_module_path("kernel");
214
215         if (!path) {
216                 pr_err("Failed to find vmlinux path\n");
217                 return -ENOENT;
218         }
219
220         pr_debug2("Use file %s for debuginfo\n", path);
221         return debuginfo__init_offline_dwarf(self, path);
222 }
223 #endif
224
225 struct debuginfo *debuginfo__new(const char *path)
226 {
227         struct debuginfo *self = zalloc(sizeof(struct debuginfo));
228         if (!self)
229                 return NULL;
230
231         if (debuginfo__init_offline_dwarf(self, path) < 0) {
232                 free(self);
233                 self = NULL;
234         }
235
236         return self;
237 }
238
239 struct debuginfo *debuginfo__new_online_kernel(unsigned long addr)
240 {
241         struct debuginfo *self = zalloc(sizeof(struct debuginfo));
242         if (!self)
243                 return NULL;
244
245         if (debuginfo__init_online_kernel_dwarf(self, (Dwarf_Addr)addr) < 0) {
246                 free(self);
247                 self = NULL;
248         }
249
250         return self;
251 }
252
253 void debuginfo__delete(struct debuginfo *self)
254 {
255         if (self) {
256                 if (self->dwfl)
257                         dwfl_end(self->dwfl);
258                 free(self);
259         }
260 }
261
262 /*
263  * Probe finder related functions
264  */
265
266 static struct probe_trace_arg_ref *alloc_trace_arg_ref(long offs)
267 {
268         struct probe_trace_arg_ref *ref;
269         ref = zalloc(sizeof(struct probe_trace_arg_ref));
270         if (ref != NULL)
271                 ref->offset = offs;
272         return ref;
273 }
274
275 /*
276  * Convert a location into trace_arg.
277  * If tvar == NULL, this just checks variable can be converted.
278  */
279 static int convert_variable_location(Dwarf_Die *vr_die, Dwarf_Addr addr,
280                                      Dwarf_Op *fb_ops,
281                                      struct probe_trace_arg *tvar)
282 {
283         Dwarf_Attribute attr;
284         Dwarf_Op *op;
285         size_t nops;
286         unsigned int regn;
287         Dwarf_Word offs = 0;
288         bool ref = false;
289         const char *regs;
290         int ret;
291
292         if (dwarf_attr(vr_die, DW_AT_external, &attr) != NULL)
293                 goto static_var;
294
295         /* TODO: handle more than 1 exprs */
296         if (dwarf_attr(vr_die, DW_AT_location, &attr) == NULL ||
297             dwarf_getlocation_addr(&attr, addr, &op, &nops, 1) <= 0 ||
298             nops == 0) {
299                 /* TODO: Support const_value */
300                 return -ENOENT;
301         }
302
303         if (op->atom == DW_OP_addr) {
304 static_var:
305                 if (!tvar)
306                         return 0;
307                 /* Static variables on memory (not stack), make @varname */
308                 ret = strlen(dwarf_diename(vr_die));
309                 tvar->value = zalloc(ret + 2);
310                 if (tvar->value == NULL)
311                         return -ENOMEM;
312                 snprintf(tvar->value, ret + 2, "@%s", dwarf_diename(vr_die));
313                 tvar->ref = alloc_trace_arg_ref((long)offs);
314                 if (tvar->ref == NULL)
315                         return -ENOMEM;
316                 return 0;
317         }
318
319         /* If this is based on frame buffer, set the offset */
320         if (op->atom == DW_OP_fbreg) {
321                 if (fb_ops == NULL)
322                         return -ENOTSUP;
323                 ref = true;
324                 offs = op->number;
325                 op = &fb_ops[0];
326         }
327
328         if (op->atom >= DW_OP_breg0 && op->atom <= DW_OP_breg31) {
329                 regn = op->atom - DW_OP_breg0;
330                 offs += op->number;
331                 ref = true;
332         } else if (op->atom >= DW_OP_reg0 && op->atom <= DW_OP_reg31) {
333                 regn = op->atom - DW_OP_reg0;
334         } else if (op->atom == DW_OP_bregx) {
335                 regn = op->number;
336                 offs += op->number2;
337                 ref = true;
338         } else if (op->atom == DW_OP_regx) {
339                 regn = op->number;
340         } else {
341                 pr_debug("DW_OP %x is not supported.\n", op->atom);
342                 return -ENOTSUP;
343         }
344
345         if (!tvar)
346                 return 0;
347
348         regs = get_arch_regstr(regn);
349         if (!regs) {
350                 /* This should be a bug in DWARF or this tool */
351                 pr_warning("Mapping for the register number %u "
352                            "missing on this architecture.\n", regn);
353                 return -ERANGE;
354         }
355
356         tvar->value = strdup(regs);
357         if (tvar->value == NULL)
358                 return -ENOMEM;
359
360         if (ref) {
361                 tvar->ref = alloc_trace_arg_ref((long)offs);
362                 if (tvar->ref == NULL)
363                         return -ENOMEM;
364         }
365         return 0;
366 }
367
368 #define BYTES_TO_BITS(nb)       ((nb) * BITS_PER_LONG / sizeof(long))
369
370 static int convert_variable_type(Dwarf_Die *vr_die,
371                                  struct probe_trace_arg *tvar,
372                                  const char *cast)
373 {
374         struct probe_trace_arg_ref **ref_ptr = &tvar->ref;
375         Dwarf_Die type;
376         char buf[16];
377         int bsize, boffs, total;
378         int ret;
379
380         /* TODO: check all types */
381         if (cast && strcmp(cast, "string") != 0) {
382                 /* Non string type is OK */
383                 tvar->type = strdup(cast);
384                 return (tvar->type == NULL) ? -ENOMEM : 0;
385         }
386
387         bsize = dwarf_bitsize(vr_die);
388         if (bsize > 0) {
389                 /* This is a bitfield */
390                 boffs = dwarf_bitoffset(vr_die);
391                 total = dwarf_bytesize(vr_die);
392                 if (boffs < 0 || total < 0)
393                         return -ENOENT;
394                 ret = snprintf(buf, 16, "b%d@%d/%zd", bsize, boffs,
395                                 BYTES_TO_BITS(total));
396                 goto formatted;
397         }
398
399         if (die_get_real_type(vr_die, &type) == NULL) {
400                 pr_warning("Failed to get a type information of %s.\n",
401                            dwarf_diename(vr_die));
402                 return -ENOENT;
403         }
404
405         pr_debug("%s type is %s.\n",
406                  dwarf_diename(vr_die), dwarf_diename(&type));
407
408         if (cast && strcmp(cast, "string") == 0) {      /* String type */
409                 ret = dwarf_tag(&type);
410                 if (ret != DW_TAG_pointer_type &&
411                     ret != DW_TAG_array_type) {
412                         pr_warning("Failed to cast into string: "
413                                    "%s(%s) is not a pointer nor array.\n",
414                                    dwarf_diename(vr_die), dwarf_diename(&type));
415                         return -EINVAL;
416                 }
417                 if (ret == DW_TAG_pointer_type) {
418                         if (die_get_real_type(&type, &type) == NULL) {
419                                 pr_warning("Failed to get a type"
420                                            " information.\n");
421                                 return -ENOENT;
422                         }
423                         while (*ref_ptr)
424                                 ref_ptr = &(*ref_ptr)->next;
425                         /* Add new reference with offset +0 */
426                         *ref_ptr = zalloc(sizeof(struct probe_trace_arg_ref));
427                         if (*ref_ptr == NULL) {
428                                 pr_warning("Out of memory error\n");
429                                 return -ENOMEM;
430                         }
431                 }
432                 if (!die_compare_name(&type, "char") &&
433                     !die_compare_name(&type, "unsigned char")) {
434                         pr_warning("Failed to cast into string: "
435                                    "%s is not (unsigned) char *.\n",
436                                    dwarf_diename(vr_die));
437                         return -EINVAL;
438                 }
439                 tvar->type = strdup(cast);
440                 return (tvar->type == NULL) ? -ENOMEM : 0;
441         }
442
443         ret = dwarf_bytesize(&type);
444         if (ret <= 0)
445                 /* No size ... try to use default type */
446                 return 0;
447         ret = BYTES_TO_BITS(ret);
448
449         /* Check the bitwidth */
450         if (ret > MAX_BASIC_TYPE_BITS) {
451                 pr_info("%s exceeds max-bitwidth. Cut down to %d bits.\n",
452                         dwarf_diename(&type), MAX_BASIC_TYPE_BITS);
453                 ret = MAX_BASIC_TYPE_BITS;
454         }
455         ret = snprintf(buf, 16, "%c%d",
456                        die_is_signed_type(&type) ? 's' : 'u', ret);
457
458 formatted:
459         if (ret < 0 || ret >= 16) {
460                 if (ret >= 16)
461                         ret = -E2BIG;
462                 pr_warning("Failed to convert variable type: %s\n",
463                            strerror(-ret));
464                 return ret;
465         }
466         tvar->type = strdup(buf);
467         if (tvar->type == NULL)
468                 return -ENOMEM;
469         return 0;
470 }
471
472 static int convert_variable_fields(Dwarf_Die *vr_die, const char *varname,
473                                     struct perf_probe_arg_field *field,
474                                     struct probe_trace_arg_ref **ref_ptr,
475                                     Dwarf_Die *die_mem)
476 {
477         struct probe_trace_arg_ref *ref = *ref_ptr;
478         Dwarf_Die type;
479         Dwarf_Word offs;
480         int ret, tag;
481
482         pr_debug("converting %s in %s\n", field->name, varname);
483         if (die_get_real_type(vr_die, &type) == NULL) {
484                 pr_warning("Failed to get the type of %s.\n", varname);
485                 return -ENOENT;
486         }
487         pr_debug2("Var real type: (%x)\n", (unsigned)dwarf_dieoffset(&type));
488         tag = dwarf_tag(&type);
489
490         if (field->name[0] == '[' &&
491             (tag == DW_TAG_array_type || tag == DW_TAG_pointer_type)) {
492                 if (field->next)
493                         /* Save original type for next field */
494                         memcpy(die_mem, &type, sizeof(*die_mem));
495                 /* Get the type of this array */
496                 if (die_get_real_type(&type, &type) == NULL) {
497                         pr_warning("Failed to get the type of %s.\n", varname);
498                         return -ENOENT;
499                 }
500                 pr_debug2("Array real type: (%x)\n",
501                          (unsigned)dwarf_dieoffset(&type));
502                 if (tag == DW_TAG_pointer_type) {
503                         ref = zalloc(sizeof(struct probe_trace_arg_ref));
504                         if (ref == NULL)
505                                 return -ENOMEM;
506                         if (*ref_ptr)
507                                 (*ref_ptr)->next = ref;
508                         else
509                                 *ref_ptr = ref;
510                 }
511                 ref->offset += dwarf_bytesize(&type) * field->index;
512                 if (!field->next)
513                         /* Save vr_die for converting types */
514                         memcpy(die_mem, vr_die, sizeof(*die_mem));
515                 goto next;
516         } else if (tag == DW_TAG_pointer_type) {
517                 /* Check the pointer and dereference */
518                 if (!field->ref) {
519                         pr_err("Semantic error: %s must be referred by '->'\n",
520                                field->name);
521                         return -EINVAL;
522                 }
523                 /* Get the type pointed by this pointer */
524                 if (die_get_real_type(&type, &type) == NULL) {
525                         pr_warning("Failed to get the type of %s.\n", varname);
526                         return -ENOENT;
527                 }
528                 /* Verify it is a data structure  */
529                 if (dwarf_tag(&type) != DW_TAG_structure_type) {
530                         pr_warning("%s is not a data structure.\n", varname);
531                         return -EINVAL;
532                 }
533
534                 ref = zalloc(sizeof(struct probe_trace_arg_ref));
535                 if (ref == NULL)
536                         return -ENOMEM;
537                 if (*ref_ptr)
538                         (*ref_ptr)->next = ref;
539                 else
540                         *ref_ptr = ref;
541         } else {
542                 /* Verify it is a data structure  */
543                 if (tag != DW_TAG_structure_type) {
544                         pr_warning("%s is not a data structure.\n", varname);
545                         return -EINVAL;
546                 }
547                 if (field->name[0] == '[') {
548                         pr_err("Semantic error: %s is not a pointor"
549                                " nor array.\n", varname);
550                         return -EINVAL;
551                 }
552                 if (field->ref) {
553                         pr_err("Semantic error: %s must be referred by '.'\n",
554                                field->name);
555                         return -EINVAL;
556                 }
557                 if (!ref) {
558                         pr_warning("Structure on a register is not "
559                                    "supported yet.\n");
560                         return -ENOTSUP;
561                 }
562         }
563
564         if (die_find_member(&type, field->name, die_mem) == NULL) {
565                 pr_warning("%s(tyep:%s) has no member %s.\n", varname,
566                            dwarf_diename(&type), field->name);
567                 return -EINVAL;
568         }
569
570         /* Get the offset of the field */
571         ret = die_get_data_member_location(die_mem, &offs);
572         if (ret < 0) {
573                 pr_warning("Failed to get the offset of %s.\n", field->name);
574                 return ret;
575         }
576         ref->offset += (long)offs;
577
578 next:
579         /* Converting next field */
580         if (field->next)
581                 return convert_variable_fields(die_mem, field->name,
582                                         field->next, &ref, die_mem);
583         else
584                 return 0;
585 }
586
587 /* Show a variables in kprobe event format */
588 static int convert_variable(Dwarf_Die *vr_die, struct probe_finder *pf)
589 {
590         Dwarf_Die die_mem;
591         int ret;
592
593         pr_debug("Converting variable %s into trace event.\n",
594                  dwarf_diename(vr_die));
595
596         ret = convert_variable_location(vr_die, pf->addr, pf->fb_ops,
597                                         pf->tvar);
598         if (ret == -ENOENT)
599                 pr_err("Failed to find the location of %s at this address.\n"
600                        " Perhaps, it has been optimized out.\n", pf->pvar->var);
601         else if (ret == -ENOTSUP)
602                 pr_err("Sorry, we don't support this variable location yet.\n");
603         else if (pf->pvar->field) {
604                 ret = convert_variable_fields(vr_die, pf->pvar->var,
605                                               pf->pvar->field, &pf->tvar->ref,
606                                               &die_mem);
607                 vr_die = &die_mem;
608         }
609         if (ret == 0)
610                 ret = convert_variable_type(vr_die, pf->tvar, pf->pvar->type);
611         /* *expr will be cached in libdw. Don't free it. */
612         return ret;
613 }
614
615 /* Find a variable in a scope DIE */
616 static int find_variable(Dwarf_Die *sc_die, struct probe_finder *pf)
617 {
618         Dwarf_Die vr_die, *scopes;
619         char buf[32], *ptr;
620         int ret, nscopes;
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                 if (pf->pvar->type) {
628                         pf->tvar->type = strdup(pf->pvar->type);
629                         if (pf->tvar->type == NULL)
630                                 return -ENOMEM;
631                 }
632                 if (pf->pvar->name) {
633                         pf->tvar->name = strdup(pf->pvar->name);
634                         if (pf->tvar->name == NULL)
635                                 return -ENOMEM;
636                 } else
637                         pf->tvar->name = NULL;
638                 return 0;
639         }
640
641         if (pf->pvar->name)
642                 pf->tvar->name = strdup(pf->pvar->name);
643         else {
644                 ret = synthesize_perf_probe_arg(pf->pvar, buf, 32);
645                 if (ret < 0)
646                         return ret;
647                 ptr = strchr(buf, ':'); /* Change type separator to _ */
648                 if (ptr)
649                         *ptr = '_';
650                 pf->tvar->name = strdup(buf);
651         }
652         if (pf->tvar->name == NULL)
653                 return -ENOMEM;
654
655         pr_debug("Searching '%s' variable in context.\n",
656                  pf->pvar->var);
657         /* Search child die for local variables and parameters. */
658         if (die_find_variable_at(sc_die, pf->pvar->var, pf->addr, &vr_die))
659                 ret = convert_variable(&vr_die, pf);
660         else {
661                 /* Search upper class */
662                 nscopes = dwarf_getscopes_die(sc_die, &scopes);
663                 ret = -ENOENT;
664                 while (nscopes-- > 1) {
665                         pr_debug("Searching variables in %s\n",
666                                  dwarf_diename(&scopes[nscopes]));
667                         /* We should check this scope, so give dummy address */
668                         if (die_find_variable_at(&scopes[nscopes],
669                                                  pf->pvar->var, 0,
670                                                  &vr_die)) {
671                                 ret = convert_variable(&vr_die, pf);
672                                 break;
673                         }
674                 }
675                 if (scopes)
676                         free(scopes);
677         }
678         if (ret < 0)
679                 pr_warning("Failed to find '%s' in this function.\n",
680                            pf->pvar->var);
681         return ret;
682 }
683
684 /* Convert subprogram DIE to trace point */
685 static int convert_to_trace_point(Dwarf_Die *sp_die, Dwarf_Addr paddr,
686                                   bool retprobe, struct probe_trace_point *tp)
687 {
688         Dwarf_Addr eaddr;
689         const char *name;
690
691         /* Copy the name of probe point */
692         name = dwarf_diename(sp_die);
693         if (name) {
694                 if (dwarf_entrypc(sp_die, &eaddr) != 0) {
695                         pr_warning("Failed to get entry address of %s\n",
696                                    dwarf_diename(sp_die));
697                         return -ENOENT;
698                 }
699                 tp->symbol = strdup(name);
700                 if (tp->symbol == NULL)
701                         return -ENOMEM;
702                 tp->offset = (unsigned long)(paddr - eaddr);
703         } else
704                 /* This function has no name. */
705                 tp->offset = (unsigned long)paddr;
706
707         /* Return probe must be on the head of a subprogram */
708         if (retprobe) {
709                 if (eaddr != paddr) {
710                         pr_warning("Return probe must be on the head of"
711                                    " a real function.\n");
712                         return -EINVAL;
713                 }
714                 tp->retprobe = true;
715         }
716
717         return 0;
718 }
719
720 /* Call probe_finder callback with scope DIE */
721 static int call_probe_finder(Dwarf_Die *sc_die, struct probe_finder *pf)
722 {
723         Dwarf_Attribute fb_attr;
724         size_t nops;
725         int ret;
726
727         if (!sc_die) {
728                 pr_err("Caller must pass a scope DIE. Program error.\n");
729                 return -EINVAL;
730         }
731
732         /* If not a real subprogram, find a real one */
733         if (dwarf_tag(sc_die) != DW_TAG_subprogram) {
734                 if (!die_find_realfunc(&pf->cu_die, pf->addr, &pf->sp_die)) {
735                         pr_warning("Failed to find probe point in any "
736                                    "functions.\n");
737                         return -ENOENT;
738                 }
739         } else
740                 memcpy(&pf->sp_die, sc_die, sizeof(Dwarf_Die));
741
742         /* Get the frame base attribute/ops from subprogram */
743         dwarf_attr(&pf->sp_die, DW_AT_frame_base, &fb_attr);
744         ret = dwarf_getlocation_addr(&fb_attr, pf->addr, &pf->fb_ops, &nops, 1);
745         if (ret <= 0 || nops == 0) {
746                 pf->fb_ops = NULL;
747 #if _ELFUTILS_PREREQ(0, 142)
748         } else if (nops == 1 && pf->fb_ops[0].atom == DW_OP_call_frame_cfa &&
749                    pf->cfi != NULL) {
750                 Dwarf_Frame *frame;
751                 if (dwarf_cfi_addrframe(pf->cfi, pf->addr, &frame) != 0 ||
752                     dwarf_frame_cfa(frame, &pf->fb_ops, &nops) != 0) {
753                         pr_warning("Failed to get call frame on 0x%jx\n",
754                                    (uintmax_t)pf->addr);
755                         return -ENOENT;
756                 }
757 #endif
758         }
759
760         /* Call finder's callback handler */
761         ret = pf->callback(sc_die, pf);
762
763         /* *pf->fb_ops will be cached in libdw. Don't free it. */
764         pf->fb_ops = NULL;
765
766         return ret;
767 }
768
769 struct find_scope_param {
770         const char *function;
771         const char *file;
772         int line;
773         int diff;
774         Dwarf_Die *die_mem;
775         bool found;
776 };
777
778 static int find_best_scope_cb(Dwarf_Die *fn_die, void *data)
779 {
780         struct find_scope_param *fsp = data;
781         const char *file;
782         int lno;
783
784         /* Skip if declared file name does not match */
785         if (fsp->file) {
786                 file = dwarf_decl_file(fn_die);
787                 if (!file || strcmp(fsp->file, file) != 0)
788                         return 0;
789         }
790         /* If the function name is given, that's what user expects */
791         if (fsp->function) {
792                 if (die_compare_name(fn_die, fsp->function)) {
793                         memcpy(fsp->die_mem, fn_die, sizeof(Dwarf_Die));
794                         fsp->found = true;
795                         return 1;
796                 }
797         } else {
798                 /* With the line number, find the nearest declared DIE */
799                 dwarf_decl_line(fn_die, &lno);
800                 if (lno < fsp->line && fsp->diff > fsp->line - lno) {
801                         /* Keep a candidate and continue */
802                         fsp->diff = fsp->line - lno;
803                         memcpy(fsp->die_mem, fn_die, sizeof(Dwarf_Die));
804                         fsp->found = true;
805                 }
806         }
807         return 0;
808 }
809
810 /* Find an appropriate scope fits to given conditions */
811 static Dwarf_Die *find_best_scope(struct probe_finder *pf, Dwarf_Die *die_mem)
812 {
813         struct find_scope_param fsp = {
814                 .function = pf->pev->point.function,
815                 .file = pf->fname,
816                 .line = pf->lno,
817                 .diff = INT_MAX,
818                 .die_mem = die_mem,
819                 .found = false,
820         };
821
822         cu_walk_functions_at(&pf->cu_die, pf->addr, find_best_scope_cb, &fsp);
823
824         return fsp.found ? die_mem : NULL;
825 }
826
827 static int probe_point_line_walker(const char *fname, int lineno,
828                                    Dwarf_Addr addr, void *data)
829 {
830         struct probe_finder *pf = data;
831         Dwarf_Die *sc_die, die_mem;
832         int ret;
833
834         if (lineno != pf->lno || strtailcmp(fname, pf->fname) != 0)
835                 return 0;
836
837         pf->addr = addr;
838         sc_die = find_best_scope(pf, &die_mem);
839         if (!sc_die) {
840                 pr_warning("Failed to find scope of probe point.\n");
841                 return -ENOENT;
842         }
843
844         ret = call_probe_finder(sc_die, pf);
845
846         /* Continue if no error, because the line will be in inline function */
847         return ret < 0 ? ret : 0;
848 }
849
850 /* Find probe point from its line number */
851 static int find_probe_point_by_line(struct probe_finder *pf)
852 {
853         return die_walk_lines(&pf->cu_die, probe_point_line_walker, pf);
854 }
855
856 /* Find lines which match lazy pattern */
857 static int find_lazy_match_lines(struct list_head *head,
858                                  const char *fname, const char *pat)
859 {
860         FILE *fp;
861         char *line = NULL;
862         size_t line_len;
863         ssize_t len;
864         int count = 0, linenum = 1;
865
866         fp = fopen(fname, "r");
867         if (!fp) {
868                 pr_warning("Failed to open %s: %s\n", fname, strerror(errno));
869                 return -errno;
870         }
871
872         while ((len = getline(&line, &line_len, fp)) > 0) {
873
874                 if (line[len - 1] == '\n')
875                         line[len - 1] = '\0';
876
877                 if (strlazymatch(line, pat)) {
878                         line_list__add_line(head, linenum);
879                         count++;
880                 }
881                 linenum++;
882         }
883
884         if (ferror(fp))
885                 count = -errno;
886         free(line);
887         fclose(fp);
888
889         if (count == 0)
890                 pr_debug("No matched lines found in %s.\n", fname);
891         return count;
892 }
893
894 static int probe_point_lazy_walker(const char *fname, int lineno,
895                                    Dwarf_Addr addr, void *data)
896 {
897         struct probe_finder *pf = data;
898         Dwarf_Die *sc_die, die_mem;
899         int ret;
900
901         if (!line_list__has_line(&pf->lcache, lineno) ||
902             strtailcmp(fname, pf->fname) != 0)
903                 return 0;
904
905         pr_debug("Probe line found: line:%d addr:0x%llx\n",
906                  lineno, (unsigned long long)addr);
907         pf->addr = addr;
908         pf->lno = lineno;
909         sc_die = find_best_scope(pf, &die_mem);
910         if (!sc_die) {
911                 pr_warning("Failed to find scope of probe point.\n");
912                 return -ENOENT;
913         }
914
915         ret = call_probe_finder(sc_die, pf);
916
917         /*
918          * Continue if no error, because the lazy pattern will match
919          * to other lines
920          */
921         return ret < 0 ? ret : 0;
922 }
923
924 /* Find probe points from lazy pattern  */
925 static int find_probe_point_lazy(Dwarf_Die *sp_die, struct probe_finder *pf)
926 {
927         int ret = 0;
928
929         if (list_empty(&pf->lcache)) {
930                 /* Matching lazy line pattern */
931                 ret = find_lazy_match_lines(&pf->lcache, pf->fname,
932                                             pf->pev->point.lazy_line);
933                 if (ret <= 0)
934                         return ret;
935         }
936
937         return die_walk_lines(sp_die, probe_point_lazy_walker, pf);
938 }
939
940 /* Callback parameter with return value */
941 struct dwarf_callback_param {
942         void *data;
943         int retval;
944 };
945
946 static int probe_point_inline_cb(Dwarf_Die *in_die, void *data)
947 {
948         struct dwarf_callback_param *param = data;
949         struct probe_finder *pf = param->data;
950         struct perf_probe_point *pp = &pf->pev->point;
951         Dwarf_Addr addr;
952
953         if (pp->lazy_line)
954                 param->retval = find_probe_point_lazy(in_die, pf);
955         else {
956                 /* Get probe address */
957                 if (dwarf_entrypc(in_die, &addr) != 0) {
958                         pr_warning("Failed to get entry address of %s.\n",
959                                    dwarf_diename(in_die));
960                         param->retval = -ENOENT;
961                         return DWARF_CB_ABORT;
962                 }
963                 pf->addr = addr;
964                 pf->addr += pp->offset;
965                 pr_debug("found inline addr: 0x%jx\n",
966                          (uintmax_t)pf->addr);
967
968                 param->retval = call_probe_finder(in_die, pf);
969                 if (param->retval < 0)
970                         return DWARF_CB_ABORT;
971         }
972
973         return DWARF_CB_OK;
974 }
975
976 /* Search function from function name */
977 static int probe_point_search_cb(Dwarf_Die *sp_die, void *data)
978 {
979         struct dwarf_callback_param *param = data;
980         struct probe_finder *pf = param->data;
981         struct perf_probe_point *pp = &pf->pev->point;
982
983         /* Check tag and diename */
984         if (dwarf_tag(sp_die) != DW_TAG_subprogram ||
985             !die_compare_name(sp_die, pp->function))
986                 return DWARF_CB_OK;
987
988         /* Check declared file */
989         if (pp->file && strtailcmp(pp->file, dwarf_decl_file(sp_die)))
990                 return DWARF_CB_OK;
991
992         pf->fname = dwarf_decl_file(sp_die);
993         if (pp->line) { /* Function relative line */
994                 dwarf_decl_line(sp_die, &pf->lno);
995                 pf->lno += pp->line;
996                 param->retval = find_probe_point_by_line(pf);
997         } else if (!dwarf_func_inline(sp_die)) {
998                 /* Real function */
999                 if (pp->lazy_line)
1000                         param->retval = find_probe_point_lazy(sp_die, pf);
1001                 else {
1002                         if (dwarf_entrypc(sp_die, &pf->addr) != 0) {
1003                                 pr_warning("Failed to get entry address of "
1004                                            "%s.\n", dwarf_diename(sp_die));
1005                                 param->retval = -ENOENT;
1006                                 return DWARF_CB_ABORT;
1007                         }
1008                         pf->addr += pp->offset;
1009                         /* TODO: Check the address in this function */
1010                         param->retval = call_probe_finder(sp_die, pf);
1011                 }
1012         } else {
1013                 struct dwarf_callback_param _param = {.data = (void *)pf,
1014                                                       .retval = 0};
1015                 /* Inlined function: search instances */
1016                 dwarf_func_inline_instances(sp_die, probe_point_inline_cb,
1017                                             &_param);
1018                 param->retval = _param.retval;
1019         }
1020
1021         return DWARF_CB_ABORT; /* Exit; no same symbol in this CU. */
1022 }
1023
1024 static int find_probe_point_by_func(struct probe_finder *pf)
1025 {
1026         struct dwarf_callback_param _param = {.data = (void *)pf,
1027                                               .retval = 0};
1028         dwarf_getfuncs(&pf->cu_die, probe_point_search_cb, &_param, 0);
1029         return _param.retval;
1030 }
1031
1032 struct pubname_callback_param {
1033         char *function;
1034         char *file;
1035         Dwarf_Die *cu_die;
1036         Dwarf_Die *sp_die;
1037         int found;
1038 };
1039
1040 static int pubname_search_cb(Dwarf *dbg, Dwarf_Global *gl, void *data)
1041 {
1042         struct pubname_callback_param *param = data;
1043
1044         if (dwarf_offdie(dbg, gl->die_offset, param->sp_die)) {
1045                 if (dwarf_tag(param->sp_die) != DW_TAG_subprogram)
1046                         return DWARF_CB_OK;
1047
1048                 if (die_compare_name(param->sp_die, param->function)) {
1049                         if (!dwarf_offdie(dbg, gl->cu_offset, param->cu_die))
1050                                 return DWARF_CB_OK;
1051
1052                         if (param->file &&
1053                             strtailcmp(param->file, dwarf_decl_file(param->sp_die)))
1054                                 return DWARF_CB_OK;
1055
1056                         param->found = 1;
1057                         return DWARF_CB_ABORT;
1058                 }
1059         }
1060
1061         return DWARF_CB_OK;
1062 }
1063
1064 /* Find probe points from debuginfo */
1065 static int debuginfo__find_probes(struct debuginfo *self,
1066                                   struct probe_finder *pf)
1067 {
1068         struct perf_probe_point *pp = &pf->pev->point;
1069         Dwarf_Off off, noff;
1070         size_t cuhl;
1071         Dwarf_Die *diep;
1072         int ret = 0;
1073
1074 #if _ELFUTILS_PREREQ(0, 142)
1075         /* Get the call frame information from this dwarf */
1076         pf->cfi = dwarf_getcfi(self->dbg);
1077 #endif
1078
1079         off = 0;
1080         line_list__init(&pf->lcache);
1081
1082         /* Fastpath: lookup by function name from .debug_pubnames section */
1083         if (pp->function) {
1084                 struct pubname_callback_param pubname_param = {
1085                         .function = pp->function,
1086                         .file     = pp->file,
1087                         .cu_die   = &pf->cu_die,
1088                         .sp_die   = &pf->sp_die,
1089                         .found    = 0,
1090                 };
1091                 struct dwarf_callback_param probe_param = {
1092                         .data = pf,
1093                 };
1094
1095                 dwarf_getpubnames(self->dbg, pubname_search_cb,
1096                                   &pubname_param, 0);
1097                 if (pubname_param.found) {
1098                         ret = probe_point_search_cb(&pf->sp_die, &probe_param);
1099                         if (ret)
1100                                 goto found;
1101                 }
1102         }
1103
1104         /* Loop on CUs (Compilation Unit) */
1105         while (!dwarf_nextcu(self->dbg, off, &noff, &cuhl, NULL, NULL, NULL)) {
1106                 /* Get the DIE(Debugging Information Entry) of this CU */
1107                 diep = dwarf_offdie(self->dbg, off + cuhl, &pf->cu_die);
1108                 if (!diep)
1109                         continue;
1110
1111                 /* Check if target file is included. */
1112                 if (pp->file)
1113                         pf->fname = cu_find_realpath(&pf->cu_die, pp->file);
1114                 else
1115                         pf->fname = NULL;
1116
1117                 if (!pp->file || pf->fname) {
1118                         if (pp->function)
1119                                 ret = find_probe_point_by_func(pf);
1120                         else if (pp->lazy_line)
1121                                 ret = find_probe_point_lazy(NULL, pf);
1122                         else {
1123                                 pf->lno = pp->line;
1124                                 ret = find_probe_point_by_line(pf);
1125                         }
1126                         if (ret < 0)
1127                                 break;
1128                 }
1129                 off = noff;
1130         }
1131
1132 found:
1133         line_list__free(&pf->lcache);
1134
1135         return ret;
1136 }
1137
1138 /* Add a found probe point into trace event list */
1139 static int add_probe_trace_event(Dwarf_Die *sc_die, struct probe_finder *pf)
1140 {
1141         struct trace_event_finder *tf =
1142                         container_of(pf, struct trace_event_finder, pf);
1143         struct probe_trace_event *tev;
1144         int ret, i;
1145
1146         /* Check number of tevs */
1147         if (tf->ntevs == tf->max_tevs) {
1148                 pr_warning("Too many( > %d) probe point found.\n",
1149                            tf->max_tevs);
1150                 return -ERANGE;
1151         }
1152         tev = &tf->tevs[tf->ntevs++];
1153
1154         /* Trace point should be converted from subprogram DIE */
1155         ret = convert_to_trace_point(&pf->sp_die, pf->addr,
1156                                      pf->pev->point.retprobe, &tev->point);
1157         if (ret < 0)
1158                 return ret;
1159
1160         pr_debug("Probe point found: %s+%lu\n", tev->point.symbol,
1161                  tev->point.offset);
1162
1163         /* Find each argument */
1164         tev->nargs = pf->pev->nargs;
1165         tev->args = zalloc(sizeof(struct probe_trace_arg) * tev->nargs);
1166         if (tev->args == NULL)
1167                 return -ENOMEM;
1168         for (i = 0; i < pf->pev->nargs; i++) {
1169                 pf->pvar = &pf->pev->args[i];
1170                 pf->tvar = &tev->args[i];
1171                 /* Variable should be found from scope DIE */
1172                 ret = find_variable(sc_die, pf);
1173                 if (ret != 0)
1174                         return ret;
1175         }
1176
1177         return 0;
1178 }
1179
1180 /* Find probe_trace_events specified by perf_probe_event from debuginfo */
1181 int debuginfo__find_trace_events(struct debuginfo *self,
1182                                  struct perf_probe_event *pev,
1183                                  struct probe_trace_event **tevs, int max_tevs)
1184 {
1185         struct trace_event_finder tf = {
1186                         .pf = {.pev = pev, .callback = add_probe_trace_event},
1187                         .max_tevs = max_tevs};
1188         int ret;
1189
1190         /* Allocate result tevs array */
1191         *tevs = zalloc(sizeof(struct probe_trace_event) * max_tevs);
1192         if (*tevs == NULL)
1193                 return -ENOMEM;
1194
1195         tf.tevs = *tevs;
1196         tf.ntevs = 0;
1197
1198         ret = debuginfo__find_probes(self, &tf.pf);
1199         if (ret < 0) {
1200                 free(*tevs);
1201                 *tevs = NULL;
1202                 return ret;
1203         }
1204
1205         return (ret < 0) ? ret : tf.ntevs;
1206 }
1207
1208 #define MAX_VAR_LEN 64
1209
1210 /* Collect available variables in this scope */
1211 static int collect_variables_cb(Dwarf_Die *die_mem, void *data)
1212 {
1213         struct available_var_finder *af = data;
1214         struct variable_list *vl;
1215         char buf[MAX_VAR_LEN];
1216         int tag, ret;
1217
1218         vl = &af->vls[af->nvls - 1];
1219
1220         tag = dwarf_tag(die_mem);
1221         if (tag == DW_TAG_formal_parameter ||
1222             tag == DW_TAG_variable) {
1223                 ret = convert_variable_location(die_mem, af->pf.addr,
1224                                                 af->pf.fb_ops, NULL);
1225                 if (ret == 0) {
1226                         ret = die_get_varname(die_mem, buf, MAX_VAR_LEN);
1227                         pr_debug2("Add new var: %s\n", buf);
1228                         if (ret > 0)
1229                                 strlist__add(vl->vars, buf);
1230                 }
1231         }
1232
1233         if (af->child && dwarf_haspc(die_mem, af->pf.addr))
1234                 return DIE_FIND_CB_CONTINUE;
1235         else
1236                 return DIE_FIND_CB_SIBLING;
1237 }
1238
1239 /* Add a found vars into available variables list */
1240 static int add_available_vars(Dwarf_Die *sc_die, struct probe_finder *pf)
1241 {
1242         struct available_var_finder *af =
1243                         container_of(pf, struct available_var_finder, pf);
1244         struct variable_list *vl;
1245         Dwarf_Die die_mem, *scopes = NULL;
1246         int ret, nscopes;
1247
1248         /* Check number of tevs */
1249         if (af->nvls == af->max_vls) {
1250                 pr_warning("Too many( > %d) probe point found.\n", af->max_vls);
1251                 return -ERANGE;
1252         }
1253         vl = &af->vls[af->nvls++];
1254
1255         /* Trace point should be converted from subprogram DIE */
1256         ret = convert_to_trace_point(&pf->sp_die, pf->addr,
1257                                      pf->pev->point.retprobe, &vl->point);
1258         if (ret < 0)
1259                 return ret;
1260
1261         pr_debug("Probe point found: %s+%lu\n", vl->point.symbol,
1262                  vl->point.offset);
1263
1264         /* Find local variables */
1265         vl->vars = strlist__new(true, NULL);
1266         if (vl->vars == NULL)
1267                 return -ENOMEM;
1268         af->child = true;
1269         die_find_child(sc_die, collect_variables_cb, (void *)af, &die_mem);
1270
1271         /* Find external variables */
1272         if (!af->externs)
1273                 goto out;
1274         /* Don't need to search child DIE for externs. */
1275         af->child = false;
1276         nscopes = dwarf_getscopes_die(sc_die, &scopes);
1277         while (nscopes-- > 1)
1278                 die_find_child(&scopes[nscopes], collect_variables_cb,
1279                                (void *)af, &die_mem);
1280         if (scopes)
1281                 free(scopes);
1282
1283 out:
1284         if (strlist__empty(vl->vars)) {
1285                 strlist__delete(vl->vars);
1286                 vl->vars = NULL;
1287         }
1288
1289         return ret;
1290 }
1291
1292 /* Find available variables at given probe point */
1293 int debuginfo__find_available_vars_at(struct debuginfo *self,
1294                                       struct perf_probe_event *pev,
1295                                       struct variable_list **vls,
1296                                       int max_vls, bool externs)
1297 {
1298         struct available_var_finder af = {
1299                         .pf = {.pev = pev, .callback = add_available_vars},
1300                         .max_vls = max_vls, .externs = externs};
1301         int ret;
1302
1303         /* Allocate result vls array */
1304         *vls = zalloc(sizeof(struct variable_list) * max_vls);
1305         if (*vls == NULL)
1306                 return -ENOMEM;
1307
1308         af.vls = *vls;
1309         af.nvls = 0;
1310
1311         ret = debuginfo__find_probes(self, &af.pf);
1312         if (ret < 0) {
1313                 /* Free vlist for error */
1314                 while (af.nvls--) {
1315                         if (af.vls[af.nvls].point.symbol)
1316                                 free(af.vls[af.nvls].point.symbol);
1317                         if (af.vls[af.nvls].vars)
1318                                 strlist__delete(af.vls[af.nvls].vars);
1319                 }
1320                 free(af.vls);
1321                 *vls = NULL;
1322                 return ret;
1323         }
1324
1325         return (ret < 0) ? ret : af.nvls;
1326 }
1327
1328 /* Reverse search */
1329 int debuginfo__find_probe_point(struct debuginfo *self, unsigned long addr,
1330                                 struct perf_probe_point *ppt)
1331 {
1332         Dwarf_Die cudie, spdie, indie;
1333         Dwarf_Addr _addr, baseaddr;
1334         const char *fname = NULL, *func = NULL, *tmp;
1335         int baseline = 0, lineno = 0, ret = 0;
1336
1337         /* Adjust address with bias */
1338         addr += self->bias;
1339
1340         /* Find cu die */
1341         if (!dwarf_addrdie(self->dbg, (Dwarf_Addr)addr - self->bias, &cudie)) {
1342                 pr_warning("Failed to find debug information for address %lx\n",
1343                            addr);
1344                 ret = -EINVAL;
1345                 goto end;
1346         }
1347
1348         /* Find a corresponding line (filename and lineno) */
1349         cu_find_lineinfo(&cudie, addr, &fname, &lineno);
1350         /* Don't care whether it failed or not */
1351
1352         /* Find a corresponding function (name, baseline and baseaddr) */
1353         if (die_find_realfunc(&cudie, (Dwarf_Addr)addr, &spdie)) {
1354                 /* Get function entry information */
1355                 tmp = dwarf_diename(&spdie);
1356                 if (!tmp ||
1357                     dwarf_entrypc(&spdie, &baseaddr) != 0 ||
1358                     dwarf_decl_line(&spdie, &baseline) != 0)
1359                         goto post;
1360                 func = tmp;
1361
1362                 if (addr == (unsigned long)baseaddr)
1363                         /* Function entry - Relative line number is 0 */
1364                         lineno = baseline;
1365                 else if (die_find_inlinefunc(&spdie, (Dwarf_Addr)addr,
1366                                              &indie)) {
1367                         if (dwarf_entrypc(&indie, &_addr) == 0 &&
1368                             _addr == addr)
1369                                 /*
1370                                  * addr is at an inline function entry.
1371                                  * In this case, lineno should be the call-site
1372                                  * line number.
1373                                  */
1374                                 lineno = die_get_call_lineno(&indie);
1375                         else {
1376                                 /*
1377                                  * addr is in an inline function body.
1378                                  * Since lineno points one of the lines
1379                                  * of the inline function, baseline should
1380                                  * be the entry line of the inline function.
1381                                  */
1382                                 tmp = dwarf_diename(&indie);
1383                                 if (tmp &&
1384                                     dwarf_decl_line(&spdie, &baseline) == 0)
1385                                         func = tmp;
1386                         }
1387                 }
1388         }
1389
1390 post:
1391         /* Make a relative line number or an offset */
1392         if (lineno)
1393                 ppt->line = lineno - baseline;
1394         else if (func)
1395                 ppt->offset = addr - (unsigned long)baseaddr;
1396
1397         /* Duplicate strings */
1398         if (func) {
1399                 ppt->function = strdup(func);
1400                 if (ppt->function == NULL) {
1401                         ret = -ENOMEM;
1402                         goto end;
1403                 }
1404         }
1405         if (fname) {
1406                 ppt->file = strdup(fname);
1407                 if (ppt->file == NULL) {
1408                         if (ppt->function) {
1409                                 free(ppt->function);
1410                                 ppt->function = NULL;
1411                         }
1412                         ret = -ENOMEM;
1413                         goto end;
1414                 }
1415         }
1416 end:
1417         if (ret == 0 && (fname || func))
1418                 ret = 1;        /* Found a point */
1419         return ret;
1420 }
1421
1422 /* Add a line and store the src path */
1423 static int line_range_add_line(const char *src, unsigned int lineno,
1424                                struct line_range *lr)
1425 {
1426         /* Copy source path */
1427         if (!lr->path) {
1428                 lr->path = strdup(src);
1429                 if (lr->path == NULL)
1430                         return -ENOMEM;
1431         }
1432         return line_list__add_line(&lr->line_list, lineno);
1433 }
1434
1435 static int line_range_walk_cb(const char *fname, int lineno,
1436                               Dwarf_Addr addr __used,
1437                               void *data)
1438 {
1439         struct line_finder *lf = data;
1440
1441         if ((strtailcmp(fname, lf->fname) != 0) ||
1442             (lf->lno_s > lineno || lf->lno_e < lineno))
1443                 return 0;
1444
1445         if (line_range_add_line(fname, lineno, lf->lr) < 0)
1446                 return -EINVAL;
1447
1448         return 0;
1449 }
1450
1451 /* Find line range from its line number */
1452 static int find_line_range_by_line(Dwarf_Die *sp_die, struct line_finder *lf)
1453 {
1454         int ret;
1455
1456         ret = die_walk_lines(sp_die ?: &lf->cu_die, line_range_walk_cb, lf);
1457
1458         /* Update status */
1459         if (ret >= 0)
1460                 if (!list_empty(&lf->lr->line_list))
1461                         ret = lf->found = 1;
1462                 else
1463                         ret = 0;        /* Lines are not found */
1464         else {
1465                 free(lf->lr->path);
1466                 lf->lr->path = NULL;
1467         }
1468         return ret;
1469 }
1470
1471 static int line_range_inline_cb(Dwarf_Die *in_die, void *data)
1472 {
1473         struct dwarf_callback_param *param = data;
1474
1475         param->retval = find_line_range_by_line(in_die, param->data);
1476
1477         /*
1478          * We have to check all instances of inlined function, because
1479          * some execution paths can be optimized out depends on the
1480          * function argument of instances
1481          */
1482         return DWARF_CB_OK;
1483 }
1484
1485 /* Search function from function name */
1486 static int line_range_search_cb(Dwarf_Die *sp_die, void *data)
1487 {
1488         struct dwarf_callback_param *param = data;
1489         struct line_finder *lf = param->data;
1490         struct line_range *lr = lf->lr;
1491
1492         /* Check declared file */
1493         if (lr->file && strtailcmp(lr->file, dwarf_decl_file(sp_die)))
1494                 return DWARF_CB_OK;
1495
1496         if (dwarf_tag(sp_die) == DW_TAG_subprogram &&
1497             die_compare_name(sp_die, lr->function)) {
1498                 lf->fname = dwarf_decl_file(sp_die);
1499                 dwarf_decl_line(sp_die, &lr->offset);
1500                 pr_debug("fname: %s, lineno:%d\n", lf->fname, lr->offset);
1501                 lf->lno_s = lr->offset + lr->start;
1502                 if (lf->lno_s < 0)      /* Overflow */
1503                         lf->lno_s = INT_MAX;
1504                 lf->lno_e = lr->offset + lr->end;
1505                 if (lf->lno_e < 0)      /* Overflow */
1506                         lf->lno_e = INT_MAX;
1507                 pr_debug("New line range: %d to %d\n", lf->lno_s, lf->lno_e);
1508                 lr->start = lf->lno_s;
1509                 lr->end = lf->lno_e;
1510                 if (dwarf_func_inline(sp_die)) {
1511                         struct dwarf_callback_param _param;
1512                         _param.data = (void *)lf;
1513                         _param.retval = 0;
1514                         dwarf_func_inline_instances(sp_die,
1515                                                     line_range_inline_cb,
1516                                                     &_param);
1517                         param->retval = _param.retval;
1518                 } else
1519                         param->retval = find_line_range_by_line(sp_die, lf);
1520                 return DWARF_CB_ABORT;
1521         }
1522         return DWARF_CB_OK;
1523 }
1524
1525 static int find_line_range_by_func(struct line_finder *lf)
1526 {
1527         struct dwarf_callback_param param = {.data = (void *)lf, .retval = 0};
1528         dwarf_getfuncs(&lf->cu_die, line_range_search_cb, &param, 0);
1529         return param.retval;
1530 }
1531
1532 int debuginfo__find_line_range(struct debuginfo *self, struct line_range *lr)
1533 {
1534         struct line_finder lf = {.lr = lr, .found = 0};
1535         int ret = 0;
1536         Dwarf_Off off = 0, noff;
1537         size_t cuhl;
1538         Dwarf_Die *diep;
1539         const char *comp_dir;
1540
1541         /* Fastpath: lookup by function name from .debug_pubnames section */
1542         if (lr->function) {
1543                 struct pubname_callback_param pubname_param = {
1544                         .function = lr->function, .file = lr->file,
1545                         .cu_die = &lf.cu_die, .sp_die = &lf.sp_die, .found = 0};
1546                 struct dwarf_callback_param line_range_param = {
1547                         .data = (void *)&lf, .retval = 0};
1548
1549                 dwarf_getpubnames(self->dbg, pubname_search_cb,
1550                                   &pubname_param, 0);
1551                 if (pubname_param.found) {
1552                         line_range_search_cb(&lf.sp_die, &line_range_param);
1553                         if (lf.found)
1554                                 goto found;
1555                 }
1556         }
1557
1558         /* Loop on CUs (Compilation Unit) */
1559         while (!lf.found && ret >= 0) {
1560                 if (dwarf_nextcu(self->dbg, off, &noff, &cuhl,
1561                                  NULL, NULL, NULL) != 0)
1562                         break;
1563
1564                 /* Get the DIE(Debugging Information Entry) of this CU */
1565                 diep = dwarf_offdie(self->dbg, off + cuhl, &lf.cu_die);
1566                 if (!diep)
1567                         continue;
1568
1569                 /* Check if target file is included. */
1570                 if (lr->file)
1571                         lf.fname = cu_find_realpath(&lf.cu_die, lr->file);
1572                 else
1573                         lf.fname = 0;
1574
1575                 if (!lr->file || lf.fname) {
1576                         if (lr->function)
1577                                 ret = find_line_range_by_func(&lf);
1578                         else {
1579                                 lf.lno_s = lr->start;
1580                                 lf.lno_e = lr->end;
1581                                 ret = find_line_range_by_line(NULL, &lf);
1582                         }
1583                 }
1584                 off = noff;
1585         }
1586
1587 found:
1588         /* Store comp_dir */
1589         if (lf.found) {
1590                 comp_dir = cu_get_comp_dir(&lf.cu_die);
1591                 if (comp_dir) {
1592                         lr->comp_dir = strdup(comp_dir);
1593                         if (!lr->comp_dir)
1594                                 ret = -ENOMEM;
1595                 }
1596         }
1597
1598         pr_debug("path: %s\n", lr->path);
1599         return (ret < 0) ? ret : lf.found;
1600 }
1601