perf probe: Search concrete out-of-line instances
[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;
619         char buf[32], *ptr;
620         int ret = 0;
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", pf->pvar->var);
656         /* Search child die for local variables and parameters. */
657         if (!die_find_variable_at(sc_die, pf->pvar->var, pf->addr, &vr_die)) {
658                 /* Search again in global variables */
659                 if (!die_find_variable_at(&pf->cu_die, pf->pvar->var, 0, &vr_die))
660                         ret = -ENOENT;
661         }
662         if (ret == 0)
663                 ret = convert_variable(&vr_die, pf);
664
665         if (ret < 0)
666                 pr_warning("Failed to find '%s' in this function.\n",
667                            pf->pvar->var);
668         return ret;
669 }
670
671 /* Convert subprogram DIE to trace point */
672 static int convert_to_trace_point(Dwarf_Die *sp_die, Dwarf_Addr paddr,
673                                   bool retprobe, struct probe_trace_point *tp)
674 {
675         Dwarf_Addr eaddr;
676         const char *name;
677
678         /* Copy the name of probe point */
679         name = dwarf_diename(sp_die);
680         if (name) {
681                 if (dwarf_entrypc(sp_die, &eaddr) != 0) {
682                         pr_warning("Failed to get entry address of %s\n",
683                                    dwarf_diename(sp_die));
684                         return -ENOENT;
685                 }
686                 tp->symbol = strdup(name);
687                 if (tp->symbol == NULL)
688                         return -ENOMEM;
689                 tp->offset = (unsigned long)(paddr - eaddr);
690         } else
691                 /* This function has no name. */
692                 tp->offset = (unsigned long)paddr;
693
694         /* Return probe must be on the head of a subprogram */
695         if (retprobe) {
696                 if (eaddr != paddr) {
697                         pr_warning("Return probe must be on the head of"
698                                    " a real function.\n");
699                         return -EINVAL;
700                 }
701                 tp->retprobe = true;
702         }
703
704         return 0;
705 }
706
707 /* Call probe_finder callback with scope DIE */
708 static int call_probe_finder(Dwarf_Die *sc_die, struct probe_finder *pf)
709 {
710         Dwarf_Attribute fb_attr;
711         size_t nops;
712         int ret;
713
714         if (!sc_die) {
715                 pr_err("Caller must pass a scope DIE. Program error.\n");
716                 return -EINVAL;
717         }
718
719         /* If not a real subprogram, find a real one */
720         if (dwarf_tag(sc_die) != DW_TAG_subprogram) {
721                 if (!die_find_realfunc(&pf->cu_die, pf->addr, &pf->sp_die)) {
722                         pr_warning("Failed to find probe point in any "
723                                    "functions.\n");
724                         return -ENOENT;
725                 }
726         } else
727                 memcpy(&pf->sp_die, sc_die, sizeof(Dwarf_Die));
728
729         /* Get the frame base attribute/ops from subprogram */
730         dwarf_attr(&pf->sp_die, DW_AT_frame_base, &fb_attr);
731         ret = dwarf_getlocation_addr(&fb_attr, pf->addr, &pf->fb_ops, &nops, 1);
732         if (ret <= 0 || nops == 0) {
733                 pf->fb_ops = NULL;
734 #if _ELFUTILS_PREREQ(0, 142)
735         } else if (nops == 1 && pf->fb_ops[0].atom == DW_OP_call_frame_cfa &&
736                    pf->cfi != NULL) {
737                 Dwarf_Frame *frame;
738                 if (dwarf_cfi_addrframe(pf->cfi, pf->addr, &frame) != 0 ||
739                     dwarf_frame_cfa(frame, &pf->fb_ops, &nops) != 0) {
740                         pr_warning("Failed to get call frame on 0x%jx\n",
741                                    (uintmax_t)pf->addr);
742                         return -ENOENT;
743                 }
744 #endif
745         }
746
747         /* Call finder's callback handler */
748         ret = pf->callback(sc_die, pf);
749
750         /* *pf->fb_ops will be cached in libdw. Don't free it. */
751         pf->fb_ops = NULL;
752
753         return ret;
754 }
755
756 struct find_scope_param {
757         const char *function;
758         const char *file;
759         int line;
760         int diff;
761         Dwarf_Die *die_mem;
762         bool found;
763 };
764
765 static int find_best_scope_cb(Dwarf_Die *fn_die, void *data)
766 {
767         struct find_scope_param *fsp = data;
768         const char *file;
769         int lno;
770
771         /* Skip if declared file name does not match */
772         if (fsp->file) {
773                 file = dwarf_decl_file(fn_die);
774                 if (!file || strcmp(fsp->file, file) != 0)
775                         return 0;
776         }
777         /* If the function name is given, that's what user expects */
778         if (fsp->function) {
779                 if (die_compare_name(fn_die, fsp->function)) {
780                         memcpy(fsp->die_mem, fn_die, sizeof(Dwarf_Die));
781                         fsp->found = true;
782                         return 1;
783                 }
784         } else {
785                 /* With the line number, find the nearest declared DIE */
786                 dwarf_decl_line(fn_die, &lno);
787                 if (lno < fsp->line && fsp->diff > fsp->line - lno) {
788                         /* Keep a candidate and continue */
789                         fsp->diff = fsp->line - lno;
790                         memcpy(fsp->die_mem, fn_die, sizeof(Dwarf_Die));
791                         fsp->found = true;
792                 }
793         }
794         return 0;
795 }
796
797 /* Find an appropriate scope fits to given conditions */
798 static Dwarf_Die *find_best_scope(struct probe_finder *pf, Dwarf_Die *die_mem)
799 {
800         struct find_scope_param fsp = {
801                 .function = pf->pev->point.function,
802                 .file = pf->fname,
803                 .line = pf->lno,
804                 .diff = INT_MAX,
805                 .die_mem = die_mem,
806                 .found = false,
807         };
808
809         cu_walk_functions_at(&pf->cu_die, pf->addr, find_best_scope_cb, &fsp);
810
811         return fsp.found ? die_mem : NULL;
812 }
813
814 static int probe_point_line_walker(const char *fname, int lineno,
815                                    Dwarf_Addr addr, void *data)
816 {
817         struct probe_finder *pf = data;
818         Dwarf_Die *sc_die, die_mem;
819         int ret;
820
821         if (lineno != pf->lno || strtailcmp(fname, pf->fname) != 0)
822                 return 0;
823
824         pf->addr = addr;
825         sc_die = find_best_scope(pf, &die_mem);
826         if (!sc_die) {
827                 pr_warning("Failed to find scope of probe point.\n");
828                 return -ENOENT;
829         }
830
831         ret = call_probe_finder(sc_die, pf);
832
833         /* Continue if no error, because the line will be in inline function */
834         return ret < 0 ? ret : 0;
835 }
836
837 /* Find probe point from its line number */
838 static int find_probe_point_by_line(struct probe_finder *pf)
839 {
840         return die_walk_lines(&pf->cu_die, probe_point_line_walker, pf);
841 }
842
843 /* Find lines which match lazy pattern */
844 static int find_lazy_match_lines(struct list_head *head,
845                                  const char *fname, const char *pat)
846 {
847         FILE *fp;
848         char *line = NULL;
849         size_t line_len;
850         ssize_t len;
851         int count = 0, linenum = 1;
852
853         fp = fopen(fname, "r");
854         if (!fp) {
855                 pr_warning("Failed to open %s: %s\n", fname, strerror(errno));
856                 return -errno;
857         }
858
859         while ((len = getline(&line, &line_len, fp)) > 0) {
860
861                 if (line[len - 1] == '\n')
862                         line[len - 1] = '\0';
863
864                 if (strlazymatch(line, pat)) {
865                         line_list__add_line(head, linenum);
866                         count++;
867                 }
868                 linenum++;
869         }
870
871         if (ferror(fp))
872                 count = -errno;
873         free(line);
874         fclose(fp);
875
876         if (count == 0)
877                 pr_debug("No matched lines found in %s.\n", fname);
878         return count;
879 }
880
881 static int probe_point_lazy_walker(const char *fname, int lineno,
882                                    Dwarf_Addr addr, void *data)
883 {
884         struct probe_finder *pf = data;
885         Dwarf_Die *sc_die, die_mem;
886         int ret;
887
888         if (!line_list__has_line(&pf->lcache, lineno) ||
889             strtailcmp(fname, pf->fname) != 0)
890                 return 0;
891
892         pr_debug("Probe line found: line:%d addr:0x%llx\n",
893                  lineno, (unsigned long long)addr);
894         pf->addr = addr;
895         pf->lno = lineno;
896         sc_die = find_best_scope(pf, &die_mem);
897         if (!sc_die) {
898                 pr_warning("Failed to find scope of probe point.\n");
899                 return -ENOENT;
900         }
901
902         ret = call_probe_finder(sc_die, pf);
903
904         /*
905          * Continue if no error, because the lazy pattern will match
906          * to other lines
907          */
908         return ret < 0 ? ret : 0;
909 }
910
911 /* Find probe points from lazy pattern  */
912 static int find_probe_point_lazy(Dwarf_Die *sp_die, struct probe_finder *pf)
913 {
914         int ret = 0;
915
916         if (list_empty(&pf->lcache)) {
917                 /* Matching lazy line pattern */
918                 ret = find_lazy_match_lines(&pf->lcache, pf->fname,
919                                             pf->pev->point.lazy_line);
920                 if (ret <= 0)
921                         return ret;
922         }
923
924         return die_walk_lines(sp_die, probe_point_lazy_walker, pf);
925 }
926
927 static int probe_point_inline_cb(Dwarf_Die *in_die, void *data)
928 {
929         struct probe_finder *pf = data;
930         struct perf_probe_point *pp = &pf->pev->point;
931         Dwarf_Addr addr;
932         int ret;
933
934         if (pp->lazy_line)
935                 ret = find_probe_point_lazy(in_die, pf);
936         else {
937                 /* Get probe address */
938                 if (dwarf_entrypc(in_die, &addr) != 0) {
939                         pr_warning("Failed to get entry address of %s.\n",
940                                    dwarf_diename(in_die));
941                         return -ENOENT;
942                 }
943                 pf->addr = addr;
944                 pf->addr += pp->offset;
945                 pr_debug("found inline addr: 0x%jx\n",
946                          (uintmax_t)pf->addr);
947
948                 ret = call_probe_finder(in_die, pf);
949         }
950
951         return ret;
952 }
953
954 /* Callback parameter with return value for libdw */
955 struct dwarf_callback_param {
956         void *data;
957         int retval;
958 };
959
960 /* Search function from function name */
961 static int probe_point_search_cb(Dwarf_Die *sp_die, void *data)
962 {
963         struct dwarf_callback_param *param = data;
964         struct probe_finder *pf = param->data;
965         struct perf_probe_point *pp = &pf->pev->point;
966
967         /* Check tag and diename */
968         if (dwarf_tag(sp_die) != DW_TAG_subprogram ||
969             !die_compare_name(sp_die, pp->function))
970                 return DWARF_CB_OK;
971
972         /* Check declared file */
973         if (pp->file && strtailcmp(pp->file, dwarf_decl_file(sp_die)))
974                 return DWARF_CB_OK;
975
976         pf->fname = dwarf_decl_file(sp_die);
977         if (pp->line) { /* Function relative line */
978                 dwarf_decl_line(sp_die, &pf->lno);
979                 pf->lno += pp->line;
980                 param->retval = find_probe_point_by_line(pf);
981         } else if (!dwarf_func_inline(sp_die)) {
982                 /* Real function */
983                 if (pp->lazy_line)
984                         param->retval = find_probe_point_lazy(sp_die, pf);
985                 else {
986                         if (dwarf_entrypc(sp_die, &pf->addr) != 0) {
987                                 pr_warning("Failed to get entry address of "
988                                            "%s.\n", dwarf_diename(sp_die));
989                                 param->retval = -ENOENT;
990                                 return DWARF_CB_ABORT;
991                         }
992                         pf->addr += pp->offset;
993                         /* TODO: Check the address in this function */
994                         param->retval = call_probe_finder(sp_die, pf);
995                 }
996         } else
997                 /* Inlined function: search instances */
998                 param->retval = die_walk_instances(sp_die,
999                                         probe_point_inline_cb, (void *)pf);
1000
1001         return DWARF_CB_ABORT; /* Exit; no same symbol in this CU. */
1002 }
1003
1004 static int find_probe_point_by_func(struct probe_finder *pf)
1005 {
1006         struct dwarf_callback_param _param = {.data = (void *)pf,
1007                                               .retval = 0};
1008         dwarf_getfuncs(&pf->cu_die, probe_point_search_cb, &_param, 0);
1009         return _param.retval;
1010 }
1011
1012 struct pubname_callback_param {
1013         char *function;
1014         char *file;
1015         Dwarf_Die *cu_die;
1016         Dwarf_Die *sp_die;
1017         int found;
1018 };
1019
1020 static int pubname_search_cb(Dwarf *dbg, Dwarf_Global *gl, void *data)
1021 {
1022         struct pubname_callback_param *param = data;
1023
1024         if (dwarf_offdie(dbg, gl->die_offset, param->sp_die)) {
1025                 if (dwarf_tag(param->sp_die) != DW_TAG_subprogram)
1026                         return DWARF_CB_OK;
1027
1028                 if (die_compare_name(param->sp_die, param->function)) {
1029                         if (!dwarf_offdie(dbg, gl->cu_offset, param->cu_die))
1030                                 return DWARF_CB_OK;
1031
1032                         if (param->file &&
1033                             strtailcmp(param->file, dwarf_decl_file(param->sp_die)))
1034                                 return DWARF_CB_OK;
1035
1036                         param->found = 1;
1037                         return DWARF_CB_ABORT;
1038                 }
1039         }
1040
1041         return DWARF_CB_OK;
1042 }
1043
1044 /* Find probe points from debuginfo */
1045 static int debuginfo__find_probes(struct debuginfo *self,
1046                                   struct probe_finder *pf)
1047 {
1048         struct perf_probe_point *pp = &pf->pev->point;
1049         Dwarf_Off off, noff;
1050         size_t cuhl;
1051         Dwarf_Die *diep;
1052         int ret = 0;
1053
1054 #if _ELFUTILS_PREREQ(0, 142)
1055         /* Get the call frame information from this dwarf */
1056         pf->cfi = dwarf_getcfi(self->dbg);
1057 #endif
1058
1059         off = 0;
1060         line_list__init(&pf->lcache);
1061
1062         /* Fastpath: lookup by function name from .debug_pubnames section */
1063         if (pp->function) {
1064                 struct pubname_callback_param pubname_param = {
1065                         .function = pp->function,
1066                         .file     = pp->file,
1067                         .cu_die   = &pf->cu_die,
1068                         .sp_die   = &pf->sp_die,
1069                         .found    = 0,
1070                 };
1071                 struct dwarf_callback_param probe_param = {
1072                         .data = pf,
1073                 };
1074
1075                 dwarf_getpubnames(self->dbg, pubname_search_cb,
1076                                   &pubname_param, 0);
1077                 if (pubname_param.found) {
1078                         ret = probe_point_search_cb(&pf->sp_die, &probe_param);
1079                         if (ret)
1080                                 goto found;
1081                 }
1082         }
1083
1084         /* Loop on CUs (Compilation Unit) */
1085         while (!dwarf_nextcu(self->dbg, off, &noff, &cuhl, NULL, NULL, NULL)) {
1086                 /* Get the DIE(Debugging Information Entry) of this CU */
1087                 diep = dwarf_offdie(self->dbg, off + cuhl, &pf->cu_die);
1088                 if (!diep)
1089                         continue;
1090
1091                 /* Check if target file is included. */
1092                 if (pp->file)
1093                         pf->fname = cu_find_realpath(&pf->cu_die, pp->file);
1094                 else
1095                         pf->fname = NULL;
1096
1097                 if (!pp->file || pf->fname) {
1098                         if (pp->function)
1099                                 ret = find_probe_point_by_func(pf);
1100                         else if (pp->lazy_line)
1101                                 ret = find_probe_point_lazy(NULL, pf);
1102                         else {
1103                                 pf->lno = pp->line;
1104                                 ret = find_probe_point_by_line(pf);
1105                         }
1106                         if (ret < 0)
1107                                 break;
1108                 }
1109                 off = noff;
1110         }
1111
1112 found:
1113         line_list__free(&pf->lcache);
1114
1115         return ret;
1116 }
1117
1118 /* Add a found probe point into trace event list */
1119 static int add_probe_trace_event(Dwarf_Die *sc_die, struct probe_finder *pf)
1120 {
1121         struct trace_event_finder *tf =
1122                         container_of(pf, struct trace_event_finder, pf);
1123         struct probe_trace_event *tev;
1124         int ret, i;
1125
1126         /* Check number of tevs */
1127         if (tf->ntevs == tf->max_tevs) {
1128                 pr_warning("Too many( > %d) probe point found.\n",
1129                            tf->max_tevs);
1130                 return -ERANGE;
1131         }
1132         tev = &tf->tevs[tf->ntevs++];
1133
1134         /* Trace point should be converted from subprogram DIE */
1135         ret = convert_to_trace_point(&pf->sp_die, pf->addr,
1136                                      pf->pev->point.retprobe, &tev->point);
1137         if (ret < 0)
1138                 return ret;
1139
1140         pr_debug("Probe point found: %s+%lu\n", tev->point.symbol,
1141                  tev->point.offset);
1142
1143         /* Find each argument */
1144         tev->nargs = pf->pev->nargs;
1145         tev->args = zalloc(sizeof(struct probe_trace_arg) * tev->nargs);
1146         if (tev->args == NULL)
1147                 return -ENOMEM;
1148         for (i = 0; i < pf->pev->nargs; i++) {
1149                 pf->pvar = &pf->pev->args[i];
1150                 pf->tvar = &tev->args[i];
1151                 /* Variable should be found from scope DIE */
1152                 ret = find_variable(sc_die, pf);
1153                 if (ret != 0)
1154                         return ret;
1155         }
1156
1157         return 0;
1158 }
1159
1160 /* Find probe_trace_events specified by perf_probe_event from debuginfo */
1161 int debuginfo__find_trace_events(struct debuginfo *self,
1162                                  struct perf_probe_event *pev,
1163                                  struct probe_trace_event **tevs, int max_tevs)
1164 {
1165         struct trace_event_finder tf = {
1166                         .pf = {.pev = pev, .callback = add_probe_trace_event},
1167                         .max_tevs = max_tevs};
1168         int ret;
1169
1170         /* Allocate result tevs array */
1171         *tevs = zalloc(sizeof(struct probe_trace_event) * max_tevs);
1172         if (*tevs == NULL)
1173                 return -ENOMEM;
1174
1175         tf.tevs = *tevs;
1176         tf.ntevs = 0;
1177
1178         ret = debuginfo__find_probes(self, &tf.pf);
1179         if (ret < 0) {
1180                 free(*tevs);
1181                 *tevs = NULL;
1182                 return ret;
1183         }
1184
1185         return (ret < 0) ? ret : tf.ntevs;
1186 }
1187
1188 #define MAX_VAR_LEN 64
1189
1190 /* Collect available variables in this scope */
1191 static int collect_variables_cb(Dwarf_Die *die_mem, void *data)
1192 {
1193         struct available_var_finder *af = data;
1194         struct variable_list *vl;
1195         char buf[MAX_VAR_LEN];
1196         int tag, ret;
1197
1198         vl = &af->vls[af->nvls - 1];
1199
1200         tag = dwarf_tag(die_mem);
1201         if (tag == DW_TAG_formal_parameter ||
1202             tag == DW_TAG_variable) {
1203                 ret = convert_variable_location(die_mem, af->pf.addr,
1204                                                 af->pf.fb_ops, NULL);
1205                 if (ret == 0) {
1206                         ret = die_get_varname(die_mem, buf, MAX_VAR_LEN);
1207                         pr_debug2("Add new var: %s\n", buf);
1208                         if (ret > 0)
1209                                 strlist__add(vl->vars, buf);
1210                 }
1211         }
1212
1213         if (af->child && dwarf_haspc(die_mem, af->pf.addr))
1214                 return DIE_FIND_CB_CONTINUE;
1215         else
1216                 return DIE_FIND_CB_SIBLING;
1217 }
1218
1219 /* Add a found vars into available variables list */
1220 static int add_available_vars(Dwarf_Die *sc_die, struct probe_finder *pf)
1221 {
1222         struct available_var_finder *af =
1223                         container_of(pf, struct available_var_finder, pf);
1224         struct variable_list *vl;
1225         Dwarf_Die die_mem;
1226         int ret;
1227
1228         /* Check number of tevs */
1229         if (af->nvls == af->max_vls) {
1230                 pr_warning("Too many( > %d) probe point found.\n", af->max_vls);
1231                 return -ERANGE;
1232         }
1233         vl = &af->vls[af->nvls++];
1234
1235         /* Trace point should be converted from subprogram DIE */
1236         ret = convert_to_trace_point(&pf->sp_die, pf->addr,
1237                                      pf->pev->point.retprobe, &vl->point);
1238         if (ret < 0)
1239                 return ret;
1240
1241         pr_debug("Probe point found: %s+%lu\n", vl->point.symbol,
1242                  vl->point.offset);
1243
1244         /* Find local variables */
1245         vl->vars = strlist__new(true, NULL);
1246         if (vl->vars == NULL)
1247                 return -ENOMEM;
1248         af->child = true;
1249         die_find_child(sc_die, collect_variables_cb, (void *)af, &die_mem);
1250
1251         /* Find external variables */
1252         if (!af->externs)
1253                 goto out;
1254         /* Don't need to search child DIE for externs. */
1255         af->child = false;
1256         die_find_child(&pf->cu_die, collect_variables_cb, (void *)af, &die_mem);
1257
1258 out:
1259         if (strlist__empty(vl->vars)) {
1260                 strlist__delete(vl->vars);
1261                 vl->vars = NULL;
1262         }
1263
1264         return ret;
1265 }
1266
1267 /* Find available variables at given probe point */
1268 int debuginfo__find_available_vars_at(struct debuginfo *self,
1269                                       struct perf_probe_event *pev,
1270                                       struct variable_list **vls,
1271                                       int max_vls, bool externs)
1272 {
1273         struct available_var_finder af = {
1274                         .pf = {.pev = pev, .callback = add_available_vars},
1275                         .max_vls = max_vls, .externs = externs};
1276         int ret;
1277
1278         /* Allocate result vls array */
1279         *vls = zalloc(sizeof(struct variable_list) * max_vls);
1280         if (*vls == NULL)
1281                 return -ENOMEM;
1282
1283         af.vls = *vls;
1284         af.nvls = 0;
1285
1286         ret = debuginfo__find_probes(self, &af.pf);
1287         if (ret < 0) {
1288                 /* Free vlist for error */
1289                 while (af.nvls--) {
1290                         if (af.vls[af.nvls].point.symbol)
1291                                 free(af.vls[af.nvls].point.symbol);
1292                         if (af.vls[af.nvls].vars)
1293                                 strlist__delete(af.vls[af.nvls].vars);
1294                 }
1295                 free(af.vls);
1296                 *vls = NULL;
1297                 return ret;
1298         }
1299
1300         return (ret < 0) ? ret : af.nvls;
1301 }
1302
1303 /* Reverse search */
1304 int debuginfo__find_probe_point(struct debuginfo *self, unsigned long addr,
1305                                 struct perf_probe_point *ppt)
1306 {
1307         Dwarf_Die cudie, spdie, indie;
1308         Dwarf_Addr _addr, baseaddr;
1309         const char *fname = NULL, *func = NULL, *tmp;
1310         int baseline = 0, lineno = 0, ret = 0;
1311
1312         /* Adjust address with bias */
1313         addr += self->bias;
1314
1315         /* Find cu die */
1316         if (!dwarf_addrdie(self->dbg, (Dwarf_Addr)addr - self->bias, &cudie)) {
1317                 pr_warning("Failed to find debug information for address %lx\n",
1318                            addr);
1319                 ret = -EINVAL;
1320                 goto end;
1321         }
1322
1323         /* Find a corresponding line (filename and lineno) */
1324         cu_find_lineinfo(&cudie, addr, &fname, &lineno);
1325         /* Don't care whether it failed or not */
1326
1327         /* Find a corresponding function (name, baseline and baseaddr) */
1328         if (die_find_realfunc(&cudie, (Dwarf_Addr)addr, &spdie)) {
1329                 /* Get function entry information */
1330                 tmp = dwarf_diename(&spdie);
1331                 if (!tmp ||
1332                     dwarf_entrypc(&spdie, &baseaddr) != 0 ||
1333                     dwarf_decl_line(&spdie, &baseline) != 0)
1334                         goto post;
1335                 func = tmp;
1336
1337                 if (addr == (unsigned long)baseaddr)
1338                         /* Function entry - Relative line number is 0 */
1339                         lineno = baseline;
1340                 else if (die_find_inlinefunc(&spdie, (Dwarf_Addr)addr,
1341                                              &indie)) {
1342                         if (dwarf_entrypc(&indie, &_addr) == 0 &&
1343                             _addr == addr)
1344                                 /*
1345                                  * addr is at an inline function entry.
1346                                  * In this case, lineno should be the call-site
1347                                  * line number.
1348                                  */
1349                                 lineno = die_get_call_lineno(&indie);
1350                         else {
1351                                 /*
1352                                  * addr is in an inline function body.
1353                                  * Since lineno points one of the lines
1354                                  * of the inline function, baseline should
1355                                  * be the entry line of the inline function.
1356                                  */
1357                                 tmp = dwarf_diename(&indie);
1358                                 if (tmp &&
1359                                     dwarf_decl_line(&spdie, &baseline) == 0)
1360                                         func = tmp;
1361                         }
1362                 }
1363         }
1364
1365 post:
1366         /* Make a relative line number or an offset */
1367         if (lineno)
1368                 ppt->line = lineno - baseline;
1369         else if (func)
1370                 ppt->offset = addr - (unsigned long)baseaddr;
1371
1372         /* Duplicate strings */
1373         if (func) {
1374                 ppt->function = strdup(func);
1375                 if (ppt->function == NULL) {
1376                         ret = -ENOMEM;
1377                         goto end;
1378                 }
1379         }
1380         if (fname) {
1381                 ppt->file = strdup(fname);
1382                 if (ppt->file == NULL) {
1383                         if (ppt->function) {
1384                                 free(ppt->function);
1385                                 ppt->function = NULL;
1386                         }
1387                         ret = -ENOMEM;
1388                         goto end;
1389                 }
1390         }
1391 end:
1392         if (ret == 0 && (fname || func))
1393                 ret = 1;        /* Found a point */
1394         return ret;
1395 }
1396
1397 /* Add a line and store the src path */
1398 static int line_range_add_line(const char *src, unsigned int lineno,
1399                                struct line_range *lr)
1400 {
1401         /* Copy source path */
1402         if (!lr->path) {
1403                 lr->path = strdup(src);
1404                 if (lr->path == NULL)
1405                         return -ENOMEM;
1406         }
1407         return line_list__add_line(&lr->line_list, lineno);
1408 }
1409
1410 static int line_range_walk_cb(const char *fname, int lineno,
1411                               Dwarf_Addr addr __used,
1412                               void *data)
1413 {
1414         struct line_finder *lf = data;
1415
1416         if ((strtailcmp(fname, lf->fname) != 0) ||
1417             (lf->lno_s > lineno || lf->lno_e < lineno))
1418                 return 0;
1419
1420         if (line_range_add_line(fname, lineno, lf->lr) < 0)
1421                 return -EINVAL;
1422
1423         return 0;
1424 }
1425
1426 /* Find line range from its line number */
1427 static int find_line_range_by_line(Dwarf_Die *sp_die, struct line_finder *lf)
1428 {
1429         int ret;
1430
1431         ret = die_walk_lines(sp_die ?: &lf->cu_die, line_range_walk_cb, lf);
1432
1433         /* Update status */
1434         if (ret >= 0)
1435                 if (!list_empty(&lf->lr->line_list))
1436                         ret = lf->found = 1;
1437                 else
1438                         ret = 0;        /* Lines are not found */
1439         else {
1440                 free(lf->lr->path);
1441                 lf->lr->path = NULL;
1442         }
1443         return ret;
1444 }
1445
1446 static int line_range_inline_cb(Dwarf_Die *in_die, void *data)
1447 {
1448         find_line_range_by_line(in_die, data);
1449
1450         /*
1451          * We have to check all instances of inlined function, because
1452          * some execution paths can be optimized out depends on the
1453          * function argument of instances
1454          */
1455         return 0;
1456 }
1457
1458 /* Search function from function name */
1459 static int line_range_search_cb(Dwarf_Die *sp_die, void *data)
1460 {
1461         struct dwarf_callback_param *param = data;
1462         struct line_finder *lf = param->data;
1463         struct line_range *lr = lf->lr;
1464
1465         /* Check declared file */
1466         if (lr->file && strtailcmp(lr->file, dwarf_decl_file(sp_die)))
1467                 return DWARF_CB_OK;
1468
1469         if (dwarf_tag(sp_die) == DW_TAG_subprogram &&
1470             die_compare_name(sp_die, lr->function)) {
1471                 lf->fname = dwarf_decl_file(sp_die);
1472                 dwarf_decl_line(sp_die, &lr->offset);
1473                 pr_debug("fname: %s, lineno:%d\n", lf->fname, lr->offset);
1474                 lf->lno_s = lr->offset + lr->start;
1475                 if (lf->lno_s < 0)      /* Overflow */
1476                         lf->lno_s = INT_MAX;
1477                 lf->lno_e = lr->offset + lr->end;
1478                 if (lf->lno_e < 0)      /* Overflow */
1479                         lf->lno_e = INT_MAX;
1480                 pr_debug("New line range: %d to %d\n", lf->lno_s, lf->lno_e);
1481                 lr->start = lf->lno_s;
1482                 lr->end = lf->lno_e;
1483                 if (dwarf_func_inline(sp_die))
1484                         param->retval = die_walk_instances(sp_die,
1485                                                 line_range_inline_cb, lf);
1486                 else
1487                         param->retval = find_line_range_by_line(sp_die, lf);
1488                 return DWARF_CB_ABORT;
1489         }
1490         return DWARF_CB_OK;
1491 }
1492
1493 static int find_line_range_by_func(struct line_finder *lf)
1494 {
1495         struct dwarf_callback_param param = {.data = (void *)lf, .retval = 0};
1496         dwarf_getfuncs(&lf->cu_die, line_range_search_cb, &param, 0);
1497         return param.retval;
1498 }
1499
1500 int debuginfo__find_line_range(struct debuginfo *self, struct line_range *lr)
1501 {
1502         struct line_finder lf = {.lr = lr, .found = 0};
1503         int ret = 0;
1504         Dwarf_Off off = 0, noff;
1505         size_t cuhl;
1506         Dwarf_Die *diep;
1507         const char *comp_dir;
1508
1509         /* Fastpath: lookup by function name from .debug_pubnames section */
1510         if (lr->function) {
1511                 struct pubname_callback_param pubname_param = {
1512                         .function = lr->function, .file = lr->file,
1513                         .cu_die = &lf.cu_die, .sp_die = &lf.sp_die, .found = 0};
1514                 struct dwarf_callback_param line_range_param = {
1515                         .data = (void *)&lf, .retval = 0};
1516
1517                 dwarf_getpubnames(self->dbg, pubname_search_cb,
1518                                   &pubname_param, 0);
1519                 if (pubname_param.found) {
1520                         line_range_search_cb(&lf.sp_die, &line_range_param);
1521                         if (lf.found)
1522                                 goto found;
1523                 }
1524         }
1525
1526         /* Loop on CUs (Compilation Unit) */
1527         while (!lf.found && ret >= 0) {
1528                 if (dwarf_nextcu(self->dbg, off, &noff, &cuhl,
1529                                  NULL, NULL, NULL) != 0)
1530                         break;
1531
1532                 /* Get the DIE(Debugging Information Entry) of this CU */
1533                 diep = dwarf_offdie(self->dbg, off + cuhl, &lf.cu_die);
1534                 if (!diep)
1535                         continue;
1536
1537                 /* Check if target file is included. */
1538                 if (lr->file)
1539                         lf.fname = cu_find_realpath(&lf.cu_die, lr->file);
1540                 else
1541                         lf.fname = 0;
1542
1543                 if (!lr->file || lf.fname) {
1544                         if (lr->function)
1545                                 ret = find_line_range_by_func(&lf);
1546                         else {
1547                                 lf.lno_s = lr->start;
1548                                 lf.lno_e = lr->end;
1549                                 ret = find_line_range_by_line(NULL, &lf);
1550                         }
1551                 }
1552                 off = noff;
1553         }
1554
1555 found:
1556         /* Store comp_dir */
1557         if (lf.found) {
1558                 comp_dir = cu_get_comp_dir(&lf.cu_die);
1559                 if (comp_dir) {
1560                         lr->comp_dir = strdup(comp_dir);
1561                         if (!lr->comp_dir)
1562                                 ret = -ENOMEM;
1563                 }
1564         }
1565
1566         pr_debug("path: %s\n", lr->path);
1567         return (ret < 0) ? ret : lf.found;
1568 }
1569