Merge tag 'linux-kselftest-kunit-5.15-rc1' of git://git.kernel.org/pub/scm/linux...
[linux-2.6-microblaze.git] / tools / perf / util / probe-finder.c
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * probe-finder.c : C expression to kprobe event converter
4  *
5  * Written by Masami Hiramatsu <mhiramat@redhat.com>
6  */
7
8 #include <inttypes.h>
9 #include <sys/utsname.h>
10 #include <sys/types.h>
11 #include <sys/stat.h>
12 #include <fcntl.h>
13 #include <errno.h>
14 #include <stdio.h>
15 #include <unistd.h>
16 #include <stdlib.h>
17 #include <string.h>
18 #include <stdarg.h>
19 #include <dwarf-regs.h>
20
21 #include <linux/bitops.h>
22 #include <linux/zalloc.h>
23 #include "event.h"
24 #include "dso.h"
25 #include "debug.h"
26 #include "intlist.h"
27 #include "strbuf.h"
28 #include "strlist.h"
29 #include "symbol.h"
30 #include "probe-finder.h"
31 #include "probe-file.h"
32 #include "string2.h"
33
34 #ifdef HAVE_DEBUGINFOD_SUPPORT
35 #include <elfutils/debuginfod.h>
36 #endif
37
38 /* Kprobe tracer basic type is up to u64 */
39 #define MAX_BASIC_TYPE_BITS     64
40
41 /* Dwarf FL wrappers */
42 static char *debuginfo_path;    /* Currently dummy */
43
44 static const Dwfl_Callbacks offline_callbacks = {
45         .find_debuginfo = dwfl_standard_find_debuginfo,
46         .debuginfo_path = &debuginfo_path,
47
48         .section_address = dwfl_offline_section_address,
49
50         /* We use this table for core files too.  */
51         .find_elf = dwfl_build_id_find_elf,
52 };
53
54 /* Get a Dwarf from offline image */
55 static int debuginfo__init_offline_dwarf(struct debuginfo *dbg,
56                                          const char *path)
57 {
58         GElf_Addr dummy;
59         int fd;
60
61         fd = open(path, O_RDONLY);
62         if (fd < 0)
63                 return fd;
64
65         dbg->dwfl = dwfl_begin(&offline_callbacks);
66         if (!dbg->dwfl)
67                 goto error;
68
69         dwfl_report_begin(dbg->dwfl);
70         dbg->mod = dwfl_report_offline(dbg->dwfl, "", "", fd);
71         if (!dbg->mod)
72                 goto error;
73
74         dbg->dbg = dwfl_module_getdwarf(dbg->mod, &dbg->bias);
75         if (!dbg->dbg)
76                 goto error;
77
78         dwfl_module_build_id(dbg->mod, &dbg->build_id, &dummy);
79
80         dwfl_report_end(dbg->dwfl, NULL, NULL);
81
82         return 0;
83 error:
84         if (dbg->dwfl)
85                 dwfl_end(dbg->dwfl);
86         else
87                 close(fd);
88         memset(dbg, 0, sizeof(*dbg));
89
90         return -ENOENT;
91 }
92
93 static struct debuginfo *__debuginfo__new(const char *path)
94 {
95         struct debuginfo *dbg = zalloc(sizeof(*dbg));
96         if (!dbg)
97                 return NULL;
98
99         if (debuginfo__init_offline_dwarf(dbg, path) < 0)
100                 zfree(&dbg);
101         if (dbg)
102                 pr_debug("Open Debuginfo file: %s\n", path);
103         return dbg;
104 }
105
106 enum dso_binary_type distro_dwarf_types[] = {
107         DSO_BINARY_TYPE__FEDORA_DEBUGINFO,
108         DSO_BINARY_TYPE__UBUNTU_DEBUGINFO,
109         DSO_BINARY_TYPE__OPENEMBEDDED_DEBUGINFO,
110         DSO_BINARY_TYPE__BUILDID_DEBUGINFO,
111         DSO_BINARY_TYPE__MIXEDUP_UBUNTU_DEBUGINFO,
112         DSO_BINARY_TYPE__NOT_FOUND,
113 };
114
115 struct debuginfo *debuginfo__new(const char *path)
116 {
117         enum dso_binary_type *type;
118         char buf[PATH_MAX], nil = '\0';
119         struct dso *dso;
120         struct debuginfo *dinfo = NULL;
121         struct build_id bid;
122
123         /* Try to open distro debuginfo files */
124         dso = dso__new(path);
125         if (!dso)
126                 goto out;
127
128         /* Set the build id for DSO_BINARY_TYPE__BUILDID_DEBUGINFO */
129         if (is_regular_file(path) && filename__read_build_id(path, &bid) > 0)
130                 dso__set_build_id(dso, &bid);
131
132         for (type = distro_dwarf_types;
133              !dinfo && *type != DSO_BINARY_TYPE__NOT_FOUND;
134              type++) {
135                 if (dso__read_binary_type_filename(dso, *type, &nil,
136                                                    buf, PATH_MAX) < 0)
137                         continue;
138                 dinfo = __debuginfo__new(buf);
139         }
140         dso__put(dso);
141
142 out:
143         /* if failed to open all distro debuginfo, open given binary */
144         return dinfo ? : __debuginfo__new(path);
145 }
146
147 void debuginfo__delete(struct debuginfo *dbg)
148 {
149         if (dbg) {
150                 if (dbg->dwfl)
151                         dwfl_end(dbg->dwfl);
152                 free(dbg);
153         }
154 }
155
156 /*
157  * Probe finder related functions
158  */
159
160 static struct probe_trace_arg_ref *alloc_trace_arg_ref(long offs)
161 {
162         struct probe_trace_arg_ref *ref;
163         ref = zalloc(sizeof(struct probe_trace_arg_ref));
164         if (ref != NULL)
165                 ref->offset = offs;
166         return ref;
167 }
168
169 /*
170  * Convert a location into trace_arg.
171  * If tvar == NULL, this just checks variable can be converted.
172  * If fentry == true and vr_die is a parameter, do heuristic search
173  * for the location fuzzed by function entry mcount.
174  */
175 static int convert_variable_location(Dwarf_Die *vr_die, Dwarf_Addr addr,
176                                      Dwarf_Op *fb_ops, Dwarf_Die *sp_die,
177                                      unsigned int machine,
178                                      struct probe_trace_arg *tvar)
179 {
180         Dwarf_Attribute attr;
181         Dwarf_Addr tmp = 0;
182         Dwarf_Op *op;
183         size_t nops;
184         unsigned int regn;
185         Dwarf_Word offs = 0;
186         bool ref = false;
187         const char *regs;
188         int ret, ret2 = 0;
189
190         if (dwarf_attr(vr_die, DW_AT_external, &attr) != NULL)
191                 goto static_var;
192
193         /* Constant value */
194         if (dwarf_attr(vr_die, DW_AT_const_value, &attr) &&
195             immediate_value_is_supported()) {
196                 Dwarf_Sword snum;
197
198                 if (!tvar)
199                         return 0;
200
201                 dwarf_formsdata(&attr, &snum);
202                 ret = asprintf(&tvar->value, "\\%ld", (long)snum);
203
204                 return ret < 0 ? -ENOMEM : 0;
205         }
206
207         /* TODO: handle more than 1 exprs */
208         if (dwarf_attr(vr_die, DW_AT_location, &attr) == NULL)
209                 return -EINVAL; /* Broken DIE ? */
210         if (dwarf_getlocation_addr(&attr, addr, &op, &nops, 1) <= 0) {
211                 ret = dwarf_entrypc(sp_die, &tmp);
212                 if (ret)
213                         return -ENOENT;
214
215                 if (probe_conf.show_location_range &&
216                         (dwarf_tag(vr_die) == DW_TAG_variable)) {
217                         ret2 = -ERANGE;
218                 } else if (addr != tmp ||
219                         dwarf_tag(vr_die) != DW_TAG_formal_parameter) {
220                         return -ENOENT;
221                 }
222
223                 ret = dwarf_highpc(sp_die, &tmp);
224                 if (ret)
225                         return -ENOENT;
226                 /*
227                  * This is fuzzed by fentry mcount. We try to find the
228                  * parameter location at the earliest address.
229                  */
230                 for (addr += 1; addr <= tmp; addr++) {
231                         if (dwarf_getlocation_addr(&attr, addr, &op,
232                                                    &nops, 1) > 0)
233                                 goto found;
234                 }
235                 return -ENOENT;
236         }
237 found:
238         if (nops == 0)
239                 /* TODO: Support const_value */
240                 return -ENOENT;
241
242         if (op->atom == DW_OP_addr) {
243 static_var:
244                 if (!tvar)
245                         return ret2;
246                 /* Static variables on memory (not stack), make @varname */
247                 ret = strlen(dwarf_diename(vr_die));
248                 tvar->value = zalloc(ret + 2);
249                 if (tvar->value == NULL)
250                         return -ENOMEM;
251                 snprintf(tvar->value, ret + 2, "@%s", dwarf_diename(vr_die));
252                 tvar->ref = alloc_trace_arg_ref((long)offs);
253                 if (tvar->ref == NULL)
254                         return -ENOMEM;
255                 return ret2;
256         }
257
258         /* If this is based on frame buffer, set the offset */
259         if (op->atom == DW_OP_fbreg) {
260                 if (fb_ops == NULL)
261                         return -ENOTSUP;
262                 ref = true;
263                 offs = op->number;
264                 op = &fb_ops[0];
265         }
266
267         if (op->atom >= DW_OP_breg0 && op->atom <= DW_OP_breg31) {
268                 regn = op->atom - DW_OP_breg0;
269                 offs += op->number;
270                 ref = true;
271         } else if (op->atom >= DW_OP_reg0 && op->atom <= DW_OP_reg31) {
272                 regn = op->atom - DW_OP_reg0;
273         } else if (op->atom == DW_OP_bregx) {
274                 regn = op->number;
275                 offs += op->number2;
276                 ref = true;
277         } else if (op->atom == DW_OP_regx) {
278                 regn = op->number;
279         } else {
280                 pr_debug("DW_OP %x is not supported.\n", op->atom);
281                 return -ENOTSUP;
282         }
283
284         if (!tvar)
285                 return ret2;
286
287         regs = get_dwarf_regstr(regn, machine);
288         if (!regs) {
289                 /* This should be a bug in DWARF or this tool */
290                 pr_warning("Mapping for the register number %u "
291                            "missing on this architecture.\n", regn);
292                 return -ENOTSUP;
293         }
294
295         tvar->value = strdup(regs);
296         if (tvar->value == NULL)
297                 return -ENOMEM;
298
299         if (ref) {
300                 tvar->ref = alloc_trace_arg_ref((long)offs);
301                 if (tvar->ref == NULL)
302                         return -ENOMEM;
303         }
304         return ret2;
305 }
306
307 #define BYTES_TO_BITS(nb)       ((nb) * BITS_PER_LONG / sizeof(long))
308
309 static int convert_variable_type(Dwarf_Die *vr_die,
310                                  struct probe_trace_arg *tvar,
311                                  const char *cast, bool user_access)
312 {
313         struct probe_trace_arg_ref **ref_ptr = &tvar->ref;
314         Dwarf_Die type;
315         char buf[16];
316         char sbuf[STRERR_BUFSIZE];
317         int bsize, boffs, total;
318         int ret;
319         char prefix;
320
321         /* TODO: check all types */
322         if (cast && strcmp(cast, "string") != 0 && strcmp(cast, "ustring") &&
323             strcmp(cast, "x") != 0 &&
324             strcmp(cast, "s") != 0 && strcmp(cast, "u") != 0) {
325                 /* Non string type is OK */
326                 /* and respect signedness/hexadecimal cast */
327                 tvar->type = strdup(cast);
328                 return (tvar->type == NULL) ? -ENOMEM : 0;
329         }
330
331         bsize = dwarf_bitsize(vr_die);
332         if (bsize > 0) {
333                 /* This is a bitfield */
334                 boffs = dwarf_bitoffset(vr_die);
335                 total = dwarf_bytesize(vr_die);
336                 if (boffs < 0 || total < 0)
337                         return -ENOENT;
338                 ret = snprintf(buf, 16, "b%d@%d/%zd", bsize, boffs,
339                                 BYTES_TO_BITS(total));
340                 goto formatted;
341         }
342
343         if (die_get_real_type(vr_die, &type) == NULL) {
344                 pr_warning("Failed to get a type information of %s.\n",
345                            dwarf_diename(vr_die));
346                 return -ENOENT;
347         }
348
349         pr_debug("%s type is %s.\n",
350                  dwarf_diename(vr_die), dwarf_diename(&type));
351
352         if (cast && (!strcmp(cast, "string") || !strcmp(cast, "ustring"))) {
353                 /* String type */
354                 ret = dwarf_tag(&type);
355                 if (ret != DW_TAG_pointer_type &&
356                     ret != DW_TAG_array_type) {
357                         pr_warning("Failed to cast into string: "
358                                    "%s(%s) is not a pointer nor array.\n",
359                                    dwarf_diename(vr_die), dwarf_diename(&type));
360                         return -EINVAL;
361                 }
362                 if (die_get_real_type(&type, &type) == NULL) {
363                         pr_warning("Failed to get a type"
364                                    " information.\n");
365                         return -ENOENT;
366                 }
367                 if (ret == DW_TAG_pointer_type) {
368                         while (*ref_ptr)
369                                 ref_ptr = &(*ref_ptr)->next;
370                         /* Add new reference with offset +0 */
371                         *ref_ptr = zalloc(sizeof(struct probe_trace_arg_ref));
372                         if (*ref_ptr == NULL) {
373                                 pr_warning("Out of memory error\n");
374                                 return -ENOMEM;
375                         }
376                         (*ref_ptr)->user_access = user_access;
377                 }
378                 if (!die_compare_name(&type, "char") &&
379                     !die_compare_name(&type, "unsigned char")) {
380                         pr_warning("Failed to cast into string: "
381                                    "%s is not (unsigned) char *.\n",
382                                    dwarf_diename(vr_die));
383                         return -EINVAL;
384                 }
385                 tvar->type = strdup(cast);
386                 return (tvar->type == NULL) ? -ENOMEM : 0;
387         }
388
389         if (cast && (strcmp(cast, "u") == 0))
390                 prefix = 'u';
391         else if (cast && (strcmp(cast, "s") == 0))
392                 prefix = 's';
393         else if (cast && (strcmp(cast, "x") == 0) &&
394                  probe_type_is_available(PROBE_TYPE_X))
395                 prefix = 'x';
396         else
397                 prefix = die_is_signed_type(&type) ? 's' :
398                          probe_type_is_available(PROBE_TYPE_X) ? 'x' : 'u';
399
400         ret = dwarf_bytesize(&type);
401         if (ret <= 0)
402                 /* No size ... try to use default type */
403                 return 0;
404         ret = BYTES_TO_BITS(ret);
405
406         /* Check the bitwidth */
407         if (ret > MAX_BASIC_TYPE_BITS) {
408                 pr_info("%s exceeds max-bitwidth. Cut down to %d bits.\n",
409                         dwarf_diename(&type), MAX_BASIC_TYPE_BITS);
410                 ret = MAX_BASIC_TYPE_BITS;
411         }
412         ret = snprintf(buf, 16, "%c%d", prefix, ret);
413
414 formatted:
415         if (ret < 0 || ret >= 16) {
416                 if (ret >= 16)
417                         ret = -E2BIG;
418                 pr_warning("Failed to convert variable type: %s\n",
419                            str_error_r(-ret, sbuf, sizeof(sbuf)));
420                 return ret;
421         }
422         tvar->type = strdup(buf);
423         if (tvar->type == NULL)
424                 return -ENOMEM;
425         return 0;
426 }
427
428 static int convert_variable_fields(Dwarf_Die *vr_die, const char *varname,
429                                     struct perf_probe_arg_field *field,
430                                     struct probe_trace_arg_ref **ref_ptr,
431                                     Dwarf_Die *die_mem, bool user_access)
432 {
433         struct probe_trace_arg_ref *ref = *ref_ptr;
434         Dwarf_Die type;
435         Dwarf_Word offs;
436         int ret, tag;
437
438         pr_debug("converting %s in %s\n", field->name, varname);
439         if (die_get_real_type(vr_die, &type) == NULL) {
440                 pr_warning("Failed to get the type of %s.\n", varname);
441                 return -ENOENT;
442         }
443         pr_debug2("Var real type: %s (%x)\n", dwarf_diename(&type),
444                   (unsigned)dwarf_dieoffset(&type));
445         tag = dwarf_tag(&type);
446
447         if (field->name[0] == '[' &&
448             (tag == DW_TAG_array_type || tag == DW_TAG_pointer_type)) {
449                 /* Save original type for next field or type */
450                 memcpy(die_mem, &type, sizeof(*die_mem));
451                 /* Get the type of this array */
452                 if (die_get_real_type(&type, &type) == NULL) {
453                         pr_warning("Failed to get the type of %s.\n", varname);
454                         return -ENOENT;
455                 }
456                 pr_debug2("Array real type: %s (%x)\n", dwarf_diename(&type),
457                          (unsigned)dwarf_dieoffset(&type));
458                 if (tag == DW_TAG_pointer_type) {
459                         ref = zalloc(sizeof(struct probe_trace_arg_ref));
460                         if (ref == NULL)
461                                 return -ENOMEM;
462                         if (*ref_ptr)
463                                 (*ref_ptr)->next = ref;
464                         else
465                                 *ref_ptr = ref;
466                 }
467                 ref->offset += dwarf_bytesize(&type) * field->index;
468                 ref->user_access = user_access;
469                 goto next;
470         } else if (tag == DW_TAG_pointer_type) {
471                 /* Check the pointer and dereference */
472                 if (!field->ref) {
473                         pr_err("Semantic error: %s must be referred by '->'\n",
474                                field->name);
475                         return -EINVAL;
476                 }
477                 /* Get the type pointed by this pointer */
478                 if (die_get_real_type(&type, &type) == NULL) {
479                         pr_warning("Failed to get the type of %s.\n", varname);
480                         return -ENOENT;
481                 }
482                 /* Verify it is a data structure  */
483                 tag = dwarf_tag(&type);
484                 if (tag != DW_TAG_structure_type && tag != DW_TAG_union_type) {
485                         pr_warning("%s is not a data structure nor a union.\n",
486                                    varname);
487                         return -EINVAL;
488                 }
489
490                 ref = zalloc(sizeof(struct probe_trace_arg_ref));
491                 if (ref == NULL)
492                         return -ENOMEM;
493                 if (*ref_ptr)
494                         (*ref_ptr)->next = ref;
495                 else
496                         *ref_ptr = ref;
497         } else {
498                 /* Verify it is a data structure  */
499                 if (tag != DW_TAG_structure_type && tag != DW_TAG_union_type) {
500                         pr_warning("%s is not a data structure nor a union.\n",
501                                    varname);
502                         return -EINVAL;
503                 }
504                 if (field->name[0] == '[') {
505                         pr_err("Semantic error: %s is not a pointer"
506                                " nor array.\n", varname);
507                         return -EINVAL;
508                 }
509                 /* While processing unnamed field, we don't care about this */
510                 if (field->ref && dwarf_diename(vr_die)) {
511                         pr_err("Semantic error: %s must be referred by '.'\n",
512                                field->name);
513                         return -EINVAL;
514                 }
515                 if (!ref) {
516                         pr_warning("Structure on a register is not "
517                                    "supported yet.\n");
518                         return -ENOTSUP;
519                 }
520         }
521
522         if (die_find_member(&type, field->name, die_mem) == NULL) {
523                 pr_warning("%s(type:%s) has no member %s.\n", varname,
524                            dwarf_diename(&type), field->name);
525                 return -EINVAL;
526         }
527
528         /* Get the offset of the field */
529         if (tag == DW_TAG_union_type) {
530                 offs = 0;
531         } else {
532                 ret = die_get_data_member_location(die_mem, &offs);
533                 if (ret < 0) {
534                         pr_warning("Failed to get the offset of %s.\n",
535                                    field->name);
536                         return ret;
537                 }
538         }
539         ref->offset += (long)offs;
540         ref->user_access = user_access;
541
542         /* If this member is unnamed, we need to reuse this field */
543         if (!dwarf_diename(die_mem))
544                 return convert_variable_fields(die_mem, varname, field,
545                                                 &ref, die_mem, user_access);
546
547 next:
548         /* Converting next field */
549         if (field->next)
550                 return convert_variable_fields(die_mem, field->name,
551                                 field->next, &ref, die_mem, user_access);
552         else
553                 return 0;
554 }
555
556 static void print_var_not_found(const char *varname)
557 {
558         pr_err("Failed to find the location of the '%s' variable at this address.\n"
559                " Perhaps it has been optimized out.\n"
560                " Use -V with the --range option to show '%s' location range.\n",
561                 varname, varname);
562 }
563
564 /* Show a variables in kprobe event format */
565 static int convert_variable(Dwarf_Die *vr_die, struct probe_finder *pf)
566 {
567         Dwarf_Die die_mem;
568         int ret;
569
570         pr_debug("Converting variable %s into trace event.\n",
571                  dwarf_diename(vr_die));
572
573         ret = convert_variable_location(vr_die, pf->addr, pf->fb_ops,
574                                         &pf->sp_die, pf->machine, pf->tvar);
575         if (ret == -ENOENT && pf->skip_empty_arg)
576                 /* This can be found in other place. skip it */
577                 return 0;
578         if (ret == -ENOENT || ret == -EINVAL) {
579                 print_var_not_found(pf->pvar->var);
580         } else if (ret == -ENOTSUP)
581                 pr_err("Sorry, we don't support this variable location yet.\n");
582         else if (ret == 0 && pf->pvar->field) {
583                 ret = convert_variable_fields(vr_die, pf->pvar->var,
584                                               pf->pvar->field, &pf->tvar->ref,
585                                               &die_mem, pf->pvar->user_access);
586                 vr_die = &die_mem;
587         }
588         if (ret == 0)
589                 ret = convert_variable_type(vr_die, pf->tvar, pf->pvar->type,
590                                             pf->pvar->user_access);
591         /* *expr will be cached in libdw. Don't free it. */
592         return ret;
593 }
594
595 /* Find a variable in a scope DIE */
596 static int find_variable(Dwarf_Die *sc_die, struct probe_finder *pf)
597 {
598         Dwarf_Die vr_die;
599         char *buf, *ptr;
600         int ret = 0;
601
602         /* Copy raw parameters */
603         if (!is_c_varname(pf->pvar->var))
604                 return copy_to_probe_trace_arg(pf->tvar, pf->pvar);
605
606         if (pf->pvar->name)
607                 pf->tvar->name = strdup(pf->pvar->name);
608         else {
609                 buf = synthesize_perf_probe_arg(pf->pvar);
610                 if (!buf)
611                         return -ENOMEM;
612                 ptr = strchr(buf, ':'); /* Change type separator to _ */
613                 if (ptr)
614                         *ptr = '_';
615                 pf->tvar->name = buf;
616         }
617         if (pf->tvar->name == NULL)
618                 return -ENOMEM;
619
620         pr_debug("Searching '%s' variable in context.\n", pf->pvar->var);
621         /* Search child die for local variables and parameters. */
622         if (!die_find_variable_at(sc_die, pf->pvar->var, pf->addr, &vr_die)) {
623                 /* Search again in global variables */
624                 if (!die_find_variable_at(&pf->cu_die, pf->pvar->var,
625                                                 0, &vr_die)) {
626                         if (pf->skip_empty_arg)
627                                 return 0;
628                         pr_warning("Failed to find '%s' in this function.\n",
629                                    pf->pvar->var);
630                         ret = -ENOENT;
631                 }
632         }
633         if (ret >= 0)
634                 ret = convert_variable(&vr_die, pf);
635
636         return ret;
637 }
638
639 /* Convert subprogram DIE to trace point */
640 static int convert_to_trace_point(Dwarf_Die *sp_die, Dwfl_Module *mod,
641                                   Dwarf_Addr paddr, bool retprobe,
642                                   const char *function,
643                                   struct probe_trace_point *tp)
644 {
645         Dwarf_Addr eaddr;
646         GElf_Sym sym;
647         const char *symbol;
648
649         /* Verify the address is correct */
650         if (!dwarf_haspc(sp_die, paddr)) {
651                 pr_warning("Specified offset is out of %s\n",
652                            dwarf_diename(sp_die));
653                 return -EINVAL;
654         }
655
656         if (dwarf_entrypc(sp_die, &eaddr) == 0) {
657                 /* If the DIE has entrypc, use it. */
658                 symbol = dwarf_diename(sp_die);
659         } else {
660                 /* Try to get actual symbol name and address from symtab */
661                 symbol = dwfl_module_addrsym(mod, paddr, &sym, NULL);
662                 eaddr = sym.st_value;
663         }
664         if (!symbol) {
665                 pr_warning("Failed to find symbol at 0x%lx\n",
666                            (unsigned long)paddr);
667                 return -ENOENT;
668         }
669
670         tp->offset = (unsigned long)(paddr - eaddr);
671         tp->address = paddr;
672         tp->symbol = strdup(symbol);
673         if (!tp->symbol)
674                 return -ENOMEM;
675
676         /* Return probe must be on the head of a subprogram */
677         if (retprobe) {
678                 if (eaddr != paddr) {
679                         pr_warning("Failed to find \"%s%%return\",\n"
680                                    " because %s is an inlined function and"
681                                    " has no return point.\n", function,
682                                    function);
683                         return -EINVAL;
684                 }
685                 tp->retprobe = true;
686         }
687
688         return 0;
689 }
690
691 /* Call probe_finder callback with scope DIE */
692 static int call_probe_finder(Dwarf_Die *sc_die, struct probe_finder *pf)
693 {
694         Dwarf_Attribute fb_attr;
695         Dwarf_Frame *frame = NULL;
696         size_t nops;
697         int ret;
698
699         if (!sc_die) {
700                 pr_err("Caller must pass a scope DIE. Program error.\n");
701                 return -EINVAL;
702         }
703
704         /* If not a real subprogram, find a real one */
705         if (!die_is_func_def(sc_die)) {
706                 if (!die_find_realfunc(&pf->cu_die, pf->addr, &pf->sp_die)) {
707                         if (die_find_tailfunc(&pf->cu_die, pf->addr, &pf->sp_die)) {
708                                 pr_warning("Ignoring tail call from %s\n",
709                                                 dwarf_diename(&pf->sp_die));
710                                 return 0;
711                         } else {
712                                 pr_warning("Failed to find probe point in any "
713                                            "functions.\n");
714                                 return -ENOENT;
715                         }
716                 }
717         } else
718                 memcpy(&pf->sp_die, sc_die, sizeof(Dwarf_Die));
719
720         /* Get the frame base attribute/ops from subprogram */
721         dwarf_attr(&pf->sp_die, DW_AT_frame_base, &fb_attr);
722         ret = dwarf_getlocation_addr(&fb_attr, pf->addr, &pf->fb_ops, &nops, 1);
723         if (ret <= 0 || nops == 0) {
724                 pf->fb_ops = NULL;
725 #if _ELFUTILS_PREREQ(0, 142)
726         } else if (nops == 1 && pf->fb_ops[0].atom == DW_OP_call_frame_cfa &&
727                    (pf->cfi_eh != NULL || pf->cfi_dbg != NULL)) {
728                 if ((dwarf_cfi_addrframe(pf->cfi_eh, pf->addr, &frame) != 0 &&
729                      (dwarf_cfi_addrframe(pf->cfi_dbg, pf->addr, &frame) != 0)) ||
730                     dwarf_frame_cfa(frame, &pf->fb_ops, &nops) != 0) {
731                         pr_warning("Failed to get call frame on 0x%jx\n",
732                                    (uintmax_t)pf->addr);
733                         free(frame);
734                         return -ENOENT;
735                 }
736 #endif
737         }
738
739         /* Call finder's callback handler */
740         ret = pf->callback(sc_die, pf);
741
742         /* Since *pf->fb_ops can be a part of frame. we should free it here. */
743         free(frame);
744         pf->fb_ops = NULL;
745
746         return ret;
747 }
748
749 struct find_scope_param {
750         const char *function;
751         const char *file;
752         int line;
753         int diff;
754         Dwarf_Die *die_mem;
755         bool found;
756 };
757
758 static int find_best_scope_cb(Dwarf_Die *fn_die, void *data)
759 {
760         struct find_scope_param *fsp = data;
761         const char *file;
762         int lno;
763
764         /* Skip if declared file name does not match */
765         if (fsp->file) {
766                 file = dwarf_decl_file(fn_die);
767                 if (!file || strcmp(fsp->file, file) != 0)
768                         return 0;
769         }
770         /* If the function name is given, that's what user expects */
771         if (fsp->function) {
772                 if (die_match_name(fn_die, fsp->function)) {
773                         memcpy(fsp->die_mem, fn_die, sizeof(Dwarf_Die));
774                         fsp->found = true;
775                         return 1;
776                 }
777         } else {
778                 /* With the line number, find the nearest declared DIE */
779                 dwarf_decl_line(fn_die, &lno);
780                 if (lno < fsp->line && fsp->diff > fsp->line - lno) {
781                         /* Keep a candidate and continue */
782                         fsp->diff = fsp->line - lno;
783                         memcpy(fsp->die_mem, fn_die, sizeof(Dwarf_Die));
784                         fsp->found = true;
785                 }
786         }
787         return 0;
788 }
789
790 /* Return innermost DIE */
791 static int find_inner_scope_cb(Dwarf_Die *fn_die, void *data)
792 {
793         struct find_scope_param *fsp = data;
794
795         memcpy(fsp->die_mem, fn_die, sizeof(Dwarf_Die));
796         fsp->found = true;
797         return 1;
798 }
799
800 /* Find an appropriate scope fits to given conditions */
801 static Dwarf_Die *find_best_scope(struct probe_finder *pf, Dwarf_Die *die_mem)
802 {
803         struct find_scope_param fsp = {
804                 .function = pf->pev->point.function,
805                 .file = pf->fname,
806                 .line = pf->lno,
807                 .diff = INT_MAX,
808                 .die_mem = die_mem,
809                 .found = false,
810         };
811         int ret;
812
813         ret = cu_walk_functions_at(&pf->cu_die, pf->addr, find_best_scope_cb,
814                                    &fsp);
815         if (!ret && !fsp.found)
816                 cu_walk_functions_at(&pf->cu_die, pf->addr,
817                                      find_inner_scope_cb, &fsp);
818
819         return fsp.found ? die_mem : NULL;
820 }
821
822 static int verify_representive_line(struct probe_finder *pf, const char *fname,
823                                 int lineno, Dwarf_Addr addr)
824 {
825         const char *__fname, *__func = NULL;
826         Dwarf_Die die_mem;
827         int __lineno;
828
829         /* Verify line number and address by reverse search */
830         if (cu_find_lineinfo(&pf->cu_die, addr, &__fname, &__lineno) < 0)
831                 return 0;
832
833         pr_debug2("Reversed line: %s:%d\n", __fname, __lineno);
834         if (strcmp(fname, __fname) || lineno == __lineno)
835                 return 0;
836
837         pr_warning("This line is sharing the address with other lines.\n");
838
839         if (pf->pev->point.function) {
840                 /* Find best match function name and lines */
841                 pf->addr = addr;
842                 if (find_best_scope(pf, &die_mem)
843                     && die_match_name(&die_mem, pf->pev->point.function)
844                     && dwarf_decl_line(&die_mem, &lineno) == 0) {
845                         __func = dwarf_diename(&die_mem);
846                         __lineno -= lineno;
847                 }
848         }
849         pr_warning("Please try to probe at %s:%d instead.\n",
850                    __func ? : __fname, __lineno);
851
852         return -ENOENT;
853 }
854
855 static int probe_point_line_walker(const char *fname, int lineno,
856                                    Dwarf_Addr addr, void *data)
857 {
858         struct probe_finder *pf = data;
859         Dwarf_Die *sc_die, die_mem;
860         int ret;
861
862         if (lineno != pf->lno || strtailcmp(fname, pf->fname) != 0)
863                 return 0;
864
865         if (verify_representive_line(pf, fname, lineno, addr))
866                 return -ENOENT;
867
868         pf->addr = addr;
869         sc_die = find_best_scope(pf, &die_mem);
870         if (!sc_die) {
871                 pr_warning("Failed to find scope of probe point.\n");
872                 return -ENOENT;
873         }
874
875         ret = call_probe_finder(sc_die, pf);
876
877         /* Continue if no error, because the line will be in inline function */
878         return ret < 0 ? ret : 0;
879 }
880
881 /* Find probe point from its line number */
882 static int find_probe_point_by_line(struct probe_finder *pf)
883 {
884         return die_walk_lines(&pf->cu_die, probe_point_line_walker, pf);
885 }
886
887 /* Find lines which match lazy pattern */
888 static int find_lazy_match_lines(struct intlist *list,
889                                  const char *fname, const char *pat)
890 {
891         FILE *fp;
892         char *line = NULL;
893         size_t line_len;
894         ssize_t len;
895         int count = 0, linenum = 1;
896         char sbuf[STRERR_BUFSIZE];
897
898         fp = fopen(fname, "r");
899         if (!fp) {
900                 pr_warning("Failed to open %s: %s\n", fname,
901                            str_error_r(errno, sbuf, sizeof(sbuf)));
902                 return -errno;
903         }
904
905         while ((len = getline(&line, &line_len, fp)) > 0) {
906
907                 if (line[len - 1] == '\n')
908                         line[len - 1] = '\0';
909
910                 if (strlazymatch(line, pat)) {
911                         intlist__add(list, linenum);
912                         count++;
913                 }
914                 linenum++;
915         }
916
917         if (ferror(fp))
918                 count = -errno;
919         free(line);
920         fclose(fp);
921
922         if (count == 0)
923                 pr_debug("No matched lines found in %s.\n", fname);
924         return count;
925 }
926
927 static int probe_point_lazy_walker(const char *fname, int lineno,
928                                    Dwarf_Addr addr, void *data)
929 {
930         struct probe_finder *pf = data;
931         Dwarf_Die *sc_die, die_mem;
932         int ret;
933
934         if (!intlist__has_entry(pf->lcache, lineno) ||
935             strtailcmp(fname, pf->fname) != 0)
936                 return 0;
937
938         pr_debug("Probe line found: line:%d addr:0x%llx\n",
939                  lineno, (unsigned long long)addr);
940         pf->addr = addr;
941         pf->lno = lineno;
942         sc_die = find_best_scope(pf, &die_mem);
943         if (!sc_die) {
944                 pr_warning("Failed to find scope of probe point.\n");
945                 return -ENOENT;
946         }
947
948         ret = call_probe_finder(sc_die, pf);
949
950         /*
951          * Continue if no error, because the lazy pattern will match
952          * to other lines
953          */
954         return ret < 0 ? ret : 0;
955 }
956
957 /* Find probe points from lazy pattern  */
958 static int find_probe_point_lazy(Dwarf_Die *sp_die, struct probe_finder *pf)
959 {
960         struct build_id bid;
961         char sbuild_id[SBUILD_ID_SIZE] = "";
962         int ret = 0;
963         char *fpath;
964
965         if (intlist__empty(pf->lcache)) {
966                 const char *comp_dir;
967
968                 comp_dir = cu_get_comp_dir(&pf->cu_die);
969                 if (pf->dbg->build_id) {
970                         build_id__init(&bid, pf->dbg->build_id, BUILD_ID_SIZE);
971                         build_id__sprintf(&bid, sbuild_id);
972                 }
973                 ret = find_source_path(pf->fname, sbuild_id, comp_dir, &fpath);
974                 if (ret < 0) {
975                         pr_warning("Failed to find source file path.\n");
976                         return ret;
977                 }
978
979                 /* Matching lazy line pattern */
980                 ret = find_lazy_match_lines(pf->lcache, fpath,
981                                             pf->pev->point.lazy_line);
982                 free(fpath);
983                 if (ret <= 0)
984                         return ret;
985         }
986
987         return die_walk_lines(sp_die, probe_point_lazy_walker, pf);
988 }
989
990 static void skip_prologue(Dwarf_Die *sp_die, struct probe_finder *pf)
991 {
992         struct perf_probe_point *pp = &pf->pev->point;
993
994         /* Not uprobe? */
995         if (!pf->pev->uprobes)
996                 return;
997
998         /* Compiled with optimization? */
999         if (die_is_optimized_target(&pf->cu_die))
1000                 return;
1001
1002         /* Don't know entrypc? */
1003         if (!pf->addr)
1004                 return;
1005
1006         /* Only FUNC and FUNC@SRC are eligible. */
1007         if (!pp->function || pp->line || pp->retprobe || pp->lazy_line ||
1008             pp->offset || pp->abs_address)
1009                 return;
1010
1011         /* Not interested in func parameter? */
1012         if (!perf_probe_with_var(pf->pev))
1013                 return;
1014
1015         pr_info("Target program is compiled without optimization. Skipping prologue.\n"
1016                 "Probe on address 0x%" PRIx64 " to force probing at the function entry.\n\n",
1017                 pf->addr);
1018
1019         die_skip_prologue(sp_die, &pf->cu_die, &pf->addr);
1020 }
1021
1022 static int probe_point_inline_cb(Dwarf_Die *in_die, void *data)
1023 {
1024         struct probe_finder *pf = data;
1025         struct perf_probe_point *pp = &pf->pev->point;
1026         Dwarf_Addr addr;
1027         int ret;
1028
1029         if (pp->lazy_line)
1030                 ret = find_probe_point_lazy(in_die, pf);
1031         else {
1032                 /* Get probe address */
1033                 if (die_entrypc(in_die, &addr) != 0) {
1034                         pr_warning("Failed to get entry address of %s.\n",
1035                                    dwarf_diename(in_die));
1036                         return -ENOENT;
1037                 }
1038                 if (addr == 0) {
1039                         pr_debug("%s has no valid entry address. skipped.\n",
1040                                  dwarf_diename(in_die));
1041                         return -ENOENT;
1042                 }
1043                 pf->addr = addr;
1044                 pf->addr += pp->offset;
1045                 pr_debug("found inline addr: 0x%jx\n",
1046                          (uintmax_t)pf->addr);
1047
1048                 ret = call_probe_finder(in_die, pf);
1049         }
1050
1051         return ret;
1052 }
1053
1054 /* Callback parameter with return value for libdw */
1055 struct dwarf_callback_param {
1056         void *data;
1057         int retval;
1058 };
1059
1060 /* Search function from function name */
1061 static int probe_point_search_cb(Dwarf_Die *sp_die, void *data)
1062 {
1063         struct dwarf_callback_param *param = data;
1064         struct probe_finder *pf = param->data;
1065         struct perf_probe_point *pp = &pf->pev->point;
1066
1067         /* Check tag and diename */
1068         if (!die_is_func_def(sp_die) ||
1069             !die_match_name(sp_die, pp->function))
1070                 return DWARF_CB_OK;
1071
1072         /* Check declared file */
1073         if (pp->file && strtailcmp(pp->file, dwarf_decl_file(sp_die)))
1074                 return DWARF_CB_OK;
1075
1076         pr_debug("Matched function: %s [%lx]\n", dwarf_diename(sp_die),
1077                  (unsigned long)dwarf_dieoffset(sp_die));
1078         pf->fname = dwarf_decl_file(sp_die);
1079         if (pp->line) { /* Function relative line */
1080                 dwarf_decl_line(sp_die, &pf->lno);
1081                 pf->lno += pp->line;
1082                 param->retval = find_probe_point_by_line(pf);
1083         } else if (die_is_func_instance(sp_die)) {
1084                 /* Instances always have the entry address */
1085                 die_entrypc(sp_die, &pf->addr);
1086                 /* But in some case the entry address is 0 */
1087                 if (pf->addr == 0) {
1088                         pr_debug("%s has no entry PC. Skipped\n",
1089                                  dwarf_diename(sp_die));
1090                         param->retval = 0;
1091                 /* Real function */
1092                 } else if (pp->lazy_line)
1093                         param->retval = find_probe_point_lazy(sp_die, pf);
1094                 else {
1095                         skip_prologue(sp_die, pf);
1096                         pf->addr += pp->offset;
1097                         /* TODO: Check the address in this function */
1098                         param->retval = call_probe_finder(sp_die, pf);
1099                 }
1100         } else if (!probe_conf.no_inlines) {
1101                 /* Inlined function: search instances */
1102                 param->retval = die_walk_instances(sp_die,
1103                                         probe_point_inline_cb, (void *)pf);
1104                 /* This could be a non-existed inline definition */
1105                 if (param->retval == -ENOENT)
1106                         param->retval = 0;
1107         }
1108
1109         /* We need to find other candidates */
1110         if (strisglob(pp->function) && param->retval >= 0) {
1111                 param->retval = 0;      /* We have to clear the result */
1112                 return DWARF_CB_OK;
1113         }
1114
1115         return DWARF_CB_ABORT; /* Exit; no same symbol in this CU. */
1116 }
1117
1118 static int find_probe_point_by_func(struct probe_finder *pf)
1119 {
1120         struct dwarf_callback_param _param = {.data = (void *)pf,
1121                                               .retval = 0};
1122         dwarf_getfuncs(&pf->cu_die, probe_point_search_cb, &_param, 0);
1123         return _param.retval;
1124 }
1125
1126 struct pubname_callback_param {
1127         char *function;
1128         char *file;
1129         Dwarf_Die *cu_die;
1130         Dwarf_Die *sp_die;
1131         int found;
1132 };
1133
1134 static int pubname_search_cb(Dwarf *dbg, Dwarf_Global *gl, void *data)
1135 {
1136         struct pubname_callback_param *param = data;
1137
1138         if (dwarf_offdie(dbg, gl->die_offset, param->sp_die)) {
1139                 if (dwarf_tag(param->sp_die) != DW_TAG_subprogram)
1140                         return DWARF_CB_OK;
1141
1142                 if (die_match_name(param->sp_die, param->function)) {
1143                         if (!dwarf_offdie(dbg, gl->cu_offset, param->cu_die))
1144                                 return DWARF_CB_OK;
1145
1146                         if (param->file &&
1147                             strtailcmp(param->file, dwarf_decl_file(param->sp_die)))
1148                                 return DWARF_CB_OK;
1149
1150                         param->found = 1;
1151                         return DWARF_CB_ABORT;
1152                 }
1153         }
1154
1155         return DWARF_CB_OK;
1156 }
1157
1158 static int debuginfo__find_probe_location(struct debuginfo *dbg,
1159                                   struct probe_finder *pf)
1160 {
1161         struct perf_probe_point *pp = &pf->pev->point;
1162         Dwarf_Off off, noff;
1163         size_t cuhl;
1164         Dwarf_Die *diep;
1165         int ret = 0;
1166
1167         off = 0;
1168         pf->lcache = intlist__new(NULL);
1169         if (!pf->lcache)
1170                 return -ENOMEM;
1171
1172         /* Fastpath: lookup by function name from .debug_pubnames section */
1173         if (pp->function && !strisglob(pp->function)) {
1174                 struct pubname_callback_param pubname_param = {
1175                         .function = pp->function,
1176                         .file     = pp->file,
1177                         .cu_die   = &pf->cu_die,
1178                         .sp_die   = &pf->sp_die,
1179                         .found    = 0,
1180                 };
1181                 struct dwarf_callback_param probe_param = {
1182                         .data = pf,
1183                 };
1184
1185                 dwarf_getpubnames(dbg->dbg, pubname_search_cb,
1186                                   &pubname_param, 0);
1187                 if (pubname_param.found) {
1188                         ret = probe_point_search_cb(&pf->sp_die, &probe_param);
1189                         if (ret)
1190                                 goto found;
1191                 }
1192         }
1193
1194         /* Loop on CUs (Compilation Unit) */
1195         while (!dwarf_nextcu(dbg->dbg, off, &noff, &cuhl, NULL, NULL, NULL)) {
1196                 /* Get the DIE(Debugging Information Entry) of this CU */
1197                 diep = dwarf_offdie(dbg->dbg, off + cuhl, &pf->cu_die);
1198                 if (!diep) {
1199                         off = noff;
1200                         continue;
1201                 }
1202
1203                 /* Check if target file is included. */
1204                 if (pp->file)
1205                         pf->fname = cu_find_realpath(&pf->cu_die, pp->file);
1206                 else
1207                         pf->fname = NULL;
1208
1209                 if (!pp->file || pf->fname) {
1210                         if (pp->function)
1211                                 ret = find_probe_point_by_func(pf);
1212                         else if (pp->lazy_line)
1213                                 ret = find_probe_point_lazy(&pf->cu_die, pf);
1214                         else {
1215                                 pf->lno = pp->line;
1216                                 ret = find_probe_point_by_line(pf);
1217                         }
1218                         if (ret < 0)
1219                                 break;
1220                 }
1221                 off = noff;
1222         }
1223
1224 found:
1225         intlist__delete(pf->lcache);
1226         pf->lcache = NULL;
1227
1228         return ret;
1229 }
1230
1231 /* Find probe points from debuginfo */
1232 static int debuginfo__find_probes(struct debuginfo *dbg,
1233                                   struct probe_finder *pf)
1234 {
1235         int ret = 0;
1236         Elf *elf;
1237         GElf_Ehdr ehdr;
1238
1239         if (pf->cfi_eh || pf->cfi_dbg)
1240                 return debuginfo__find_probe_location(dbg, pf);
1241
1242         /* Get the call frame information from this dwarf */
1243         elf = dwarf_getelf(dbg->dbg);
1244         if (elf == NULL)
1245                 return -EINVAL;
1246
1247         if (gelf_getehdr(elf, &ehdr) == NULL)
1248                 return -EINVAL;
1249
1250         pf->machine = ehdr.e_machine;
1251
1252 #if _ELFUTILS_PREREQ(0, 142)
1253         do {
1254                 GElf_Shdr shdr;
1255
1256                 if (elf_section_by_name(elf, &ehdr, &shdr, ".eh_frame", NULL) &&
1257                     shdr.sh_type == SHT_PROGBITS)
1258                         pf->cfi_eh = dwarf_getcfi_elf(elf);
1259
1260                 pf->cfi_dbg = dwarf_getcfi(dbg->dbg);
1261         } while (0);
1262 #endif
1263
1264         ret = debuginfo__find_probe_location(dbg, pf);
1265         return ret;
1266 }
1267
1268 struct local_vars_finder {
1269         struct probe_finder *pf;
1270         struct perf_probe_arg *args;
1271         bool vars;
1272         int max_args;
1273         int nargs;
1274         int ret;
1275 };
1276
1277 /* Collect available variables in this scope */
1278 static int copy_variables_cb(Dwarf_Die *die_mem, void *data)
1279 {
1280         struct local_vars_finder *vf = data;
1281         struct probe_finder *pf = vf->pf;
1282         int tag;
1283
1284         tag = dwarf_tag(die_mem);
1285         if (tag == DW_TAG_formal_parameter ||
1286             (tag == DW_TAG_variable && vf->vars)) {
1287                 if (convert_variable_location(die_mem, vf->pf->addr,
1288                                               vf->pf->fb_ops, &pf->sp_die,
1289                                               pf->machine, NULL) == 0) {
1290                         vf->args[vf->nargs].var = (char *)dwarf_diename(die_mem);
1291                         if (vf->args[vf->nargs].var == NULL) {
1292                                 vf->ret = -ENOMEM;
1293                                 return DIE_FIND_CB_END;
1294                         }
1295                         pr_debug(" %s", vf->args[vf->nargs].var);
1296                         vf->nargs++;
1297                 }
1298         }
1299
1300         if (dwarf_haspc(die_mem, vf->pf->addr))
1301                 return DIE_FIND_CB_CONTINUE;
1302         else
1303                 return DIE_FIND_CB_SIBLING;
1304 }
1305
1306 static int expand_probe_args(Dwarf_Die *sc_die, struct probe_finder *pf,
1307                              struct perf_probe_arg *args)
1308 {
1309         Dwarf_Die die_mem;
1310         int i;
1311         int n = 0;
1312         struct local_vars_finder vf = {.pf = pf, .args = args, .vars = false,
1313                                 .max_args = MAX_PROBE_ARGS, .ret = 0};
1314
1315         for (i = 0; i < pf->pev->nargs; i++) {
1316                 /* var never be NULL */
1317                 if (strcmp(pf->pev->args[i].var, PROBE_ARG_VARS) == 0)
1318                         vf.vars = true;
1319                 else if (strcmp(pf->pev->args[i].var, PROBE_ARG_PARAMS) != 0) {
1320                         /* Copy normal argument */
1321                         args[n] = pf->pev->args[i];
1322                         n++;
1323                         continue;
1324                 }
1325                 pr_debug("Expanding %s into:", pf->pev->args[i].var);
1326                 vf.nargs = n;
1327                 /* Special local variables */
1328                 die_find_child(sc_die, copy_variables_cb, (void *)&vf,
1329                                &die_mem);
1330                 pr_debug(" (%d)\n", vf.nargs - n);
1331                 if (vf.ret < 0)
1332                         return vf.ret;
1333                 n = vf.nargs;
1334         }
1335         return n;
1336 }
1337
1338 static bool trace_event_finder_overlap(struct trace_event_finder *tf)
1339 {
1340         int i;
1341
1342         for (i = 0; i < tf->ntevs; i++) {
1343                 if (tf->pf.addr == tf->tevs[i].point.address)
1344                         return true;
1345         }
1346         return false;
1347 }
1348
1349 /* Add a found probe point into trace event list */
1350 static int add_probe_trace_event(Dwarf_Die *sc_die, struct probe_finder *pf)
1351 {
1352         struct trace_event_finder *tf =
1353                         container_of(pf, struct trace_event_finder, pf);
1354         struct perf_probe_point *pp = &pf->pev->point;
1355         struct probe_trace_event *tev;
1356         struct perf_probe_arg *args = NULL;
1357         int ret, i;
1358
1359         /*
1360          * For some reason (e.g. different column assigned to same address)
1361          * This callback can be called with the address which already passed.
1362          * Ignore it first.
1363          */
1364         if (trace_event_finder_overlap(tf))
1365                 return 0;
1366
1367         /* Check number of tevs */
1368         if (tf->ntevs == tf->max_tevs) {
1369                 pr_warning("Too many( > %d) probe point found.\n",
1370                            tf->max_tevs);
1371                 return -ERANGE;
1372         }
1373         tev = &tf->tevs[tf->ntevs++];
1374
1375         /* Trace point should be converted from subprogram DIE */
1376         ret = convert_to_trace_point(&pf->sp_die, tf->mod, pf->addr,
1377                                      pp->retprobe, pp->function, &tev->point);
1378         if (ret < 0)
1379                 goto end;
1380
1381         tev->point.realname = strdup(dwarf_diename(sc_die));
1382         if (!tev->point.realname) {
1383                 ret = -ENOMEM;
1384                 goto end;
1385         }
1386
1387         pr_debug("Probe point found: %s+%lu\n", tev->point.symbol,
1388                  tev->point.offset);
1389
1390         /* Expand special probe argument if exist */
1391         args = zalloc(sizeof(struct perf_probe_arg) * MAX_PROBE_ARGS);
1392         if (args == NULL) {
1393                 ret = -ENOMEM;
1394                 goto end;
1395         }
1396
1397         ret = expand_probe_args(sc_die, pf, args);
1398         if (ret < 0)
1399                 goto end;
1400
1401         tev->nargs = ret;
1402         tev->args = zalloc(sizeof(struct probe_trace_arg) * tev->nargs);
1403         if (tev->args == NULL) {
1404                 ret = -ENOMEM;
1405                 goto end;
1406         }
1407
1408         /* Find each argument */
1409         for (i = 0; i < tev->nargs; i++) {
1410                 pf->pvar = &args[i];
1411                 pf->tvar = &tev->args[i];
1412                 /* Variable should be found from scope DIE */
1413                 ret = find_variable(sc_die, pf);
1414                 if (ret != 0)
1415                         break;
1416         }
1417
1418 end:
1419         if (ret) {
1420                 clear_probe_trace_event(tev);
1421                 tf->ntevs--;
1422         }
1423         free(args);
1424         return ret;
1425 }
1426
1427 static int fill_empty_trace_arg(struct perf_probe_event *pev,
1428                                 struct probe_trace_event *tevs, int ntevs)
1429 {
1430         char **valp;
1431         char *type;
1432         int i, j, ret;
1433
1434         if (!ntevs)
1435                 return -ENOENT;
1436
1437         for (i = 0; i < pev->nargs; i++) {
1438                 type = NULL;
1439                 for (j = 0; j < ntevs; j++) {
1440                         if (tevs[j].args[i].value) {
1441                                 type = tevs[j].args[i].type;
1442                                 break;
1443                         }
1444                 }
1445                 if (j == ntevs) {
1446                         print_var_not_found(pev->args[i].var);
1447                         return -ENOENT;
1448                 }
1449                 for (j = 0; j < ntevs; j++) {
1450                         valp = &tevs[j].args[i].value;
1451                         if (*valp)
1452                                 continue;
1453
1454                         ret = asprintf(valp, "\\%lx", probe_conf.magic_num);
1455                         if (ret < 0)
1456                                 return -ENOMEM;
1457                         /* Note that type can be NULL */
1458                         if (type) {
1459                                 tevs[j].args[i].type = strdup(type);
1460                                 if (!tevs[j].args[i].type)
1461                                         return -ENOMEM;
1462                         }
1463                 }
1464         }
1465         return 0;
1466 }
1467
1468 /* Find probe_trace_events specified by perf_probe_event from debuginfo */
1469 int debuginfo__find_trace_events(struct debuginfo *dbg,
1470                                  struct perf_probe_event *pev,
1471                                  struct probe_trace_event **tevs)
1472 {
1473         struct trace_event_finder tf = {
1474                         .pf = {.pev = pev, .dbg = dbg, .callback = add_probe_trace_event},
1475                         .max_tevs = probe_conf.max_probes, .mod = dbg->mod};
1476         int ret, i;
1477
1478         /* Allocate result tevs array */
1479         *tevs = zalloc(sizeof(struct probe_trace_event) * tf.max_tevs);
1480         if (*tevs == NULL)
1481                 return -ENOMEM;
1482
1483         tf.tevs = *tevs;
1484         tf.ntevs = 0;
1485
1486         if (pev->nargs != 0 && immediate_value_is_supported())
1487                 tf.pf.skip_empty_arg = true;
1488
1489         ret = debuginfo__find_probes(dbg, &tf.pf);
1490         if (ret >= 0 && tf.pf.skip_empty_arg)
1491                 ret = fill_empty_trace_arg(pev, tf.tevs, tf.ntevs);
1492
1493         if (ret < 0 || tf.ntevs == 0) {
1494                 for (i = 0; i < tf.ntevs; i++)
1495                         clear_probe_trace_event(&tf.tevs[i]);
1496                 zfree(tevs);
1497                 return ret;
1498         }
1499
1500         return (ret < 0) ? ret : tf.ntevs;
1501 }
1502
1503 /* Collect available variables in this scope */
1504 static int collect_variables_cb(Dwarf_Die *die_mem, void *data)
1505 {
1506         struct available_var_finder *af = data;
1507         struct variable_list *vl;
1508         struct strbuf buf = STRBUF_INIT;
1509         int tag, ret;
1510
1511         vl = &af->vls[af->nvls - 1];
1512
1513         tag = dwarf_tag(die_mem);
1514         if (tag == DW_TAG_formal_parameter ||
1515             tag == DW_TAG_variable) {
1516                 ret = convert_variable_location(die_mem, af->pf.addr,
1517                                                 af->pf.fb_ops, &af->pf.sp_die,
1518                                                 af->pf.machine, NULL);
1519                 if (ret == 0 || ret == -ERANGE) {
1520                         int ret2;
1521                         bool externs = !af->child;
1522
1523                         if (strbuf_init(&buf, 64) < 0)
1524                                 goto error;
1525
1526                         if (probe_conf.show_location_range) {
1527                                 if (!externs)
1528                                         ret2 = strbuf_add(&buf,
1529                                                 ret ? "[INV]\t" : "[VAL]\t", 6);
1530                                 else
1531                                         ret2 = strbuf_add(&buf, "[EXT]\t", 6);
1532                                 if (ret2)
1533                                         goto error;
1534                         }
1535
1536                         ret2 = die_get_varname(die_mem, &buf);
1537
1538                         if (!ret2 && probe_conf.show_location_range &&
1539                                 !externs) {
1540                                 if (strbuf_addch(&buf, '\t') < 0)
1541                                         goto error;
1542                                 ret2 = die_get_var_range(&af->pf.sp_die,
1543                                                         die_mem, &buf);
1544                         }
1545
1546                         pr_debug("Add new var: %s\n", buf.buf);
1547                         if (ret2 == 0) {
1548                                 strlist__add(vl->vars,
1549                                         strbuf_detach(&buf, NULL));
1550                         }
1551                         strbuf_release(&buf);
1552                 }
1553         }
1554
1555         if (af->child && dwarf_haspc(die_mem, af->pf.addr))
1556                 return DIE_FIND_CB_CONTINUE;
1557         else
1558                 return DIE_FIND_CB_SIBLING;
1559 error:
1560         strbuf_release(&buf);
1561         pr_debug("Error in strbuf\n");
1562         return DIE_FIND_CB_END;
1563 }
1564
1565 static bool available_var_finder_overlap(struct available_var_finder *af)
1566 {
1567         int i;
1568
1569         for (i = 0; i < af->nvls; i++) {
1570                 if (af->pf.addr == af->vls[i].point.address)
1571                         return true;
1572         }
1573         return false;
1574
1575 }
1576
1577 /* Add a found vars into available variables list */
1578 static int add_available_vars(Dwarf_Die *sc_die, struct probe_finder *pf)
1579 {
1580         struct available_var_finder *af =
1581                         container_of(pf, struct available_var_finder, pf);
1582         struct perf_probe_point *pp = &pf->pev->point;
1583         struct variable_list *vl;
1584         Dwarf_Die die_mem;
1585         int ret;
1586
1587         /*
1588          * For some reason (e.g. different column assigned to same address),
1589          * this callback can be called with the address which already passed.
1590          * Ignore it first.
1591          */
1592         if (available_var_finder_overlap(af))
1593                 return 0;
1594
1595         /* Check number of tevs */
1596         if (af->nvls == af->max_vls) {
1597                 pr_warning("Too many( > %d) probe point found.\n", af->max_vls);
1598                 return -ERANGE;
1599         }
1600         vl = &af->vls[af->nvls++];
1601
1602         /* Trace point should be converted from subprogram DIE */
1603         ret = convert_to_trace_point(&pf->sp_die, af->mod, pf->addr,
1604                                      pp->retprobe, pp->function, &vl->point);
1605         if (ret < 0)
1606                 return ret;
1607
1608         pr_debug("Probe point found: %s+%lu\n", vl->point.symbol,
1609                  vl->point.offset);
1610
1611         /* Find local variables */
1612         vl->vars = strlist__new(NULL, NULL);
1613         if (vl->vars == NULL)
1614                 return -ENOMEM;
1615         af->child = true;
1616         die_find_child(sc_die, collect_variables_cb, (void *)af, &die_mem);
1617
1618         /* Find external variables */
1619         if (!probe_conf.show_ext_vars)
1620                 goto out;
1621         /* Don't need to search child DIE for external vars. */
1622         af->child = false;
1623         die_find_child(&pf->cu_die, collect_variables_cb, (void *)af, &die_mem);
1624
1625 out:
1626         if (strlist__empty(vl->vars)) {
1627                 strlist__delete(vl->vars);
1628                 vl->vars = NULL;
1629         }
1630
1631         return ret;
1632 }
1633
1634 /*
1635  * Find available variables at given probe point
1636  * Return the number of found probe points. Return 0 if there is no
1637  * matched probe point. Return <0 if an error occurs.
1638  */
1639 int debuginfo__find_available_vars_at(struct debuginfo *dbg,
1640                                       struct perf_probe_event *pev,
1641                                       struct variable_list **vls)
1642 {
1643         struct available_var_finder af = {
1644                         .pf = {.pev = pev, .dbg = dbg, .callback = add_available_vars},
1645                         .mod = dbg->mod,
1646                         .max_vls = probe_conf.max_probes};
1647         int ret;
1648
1649         /* Allocate result vls array */
1650         *vls = zalloc(sizeof(struct variable_list) * af.max_vls);
1651         if (*vls == NULL)
1652                 return -ENOMEM;
1653
1654         af.vls = *vls;
1655         af.nvls = 0;
1656
1657         ret = debuginfo__find_probes(dbg, &af.pf);
1658         if (ret < 0) {
1659                 /* Free vlist for error */
1660                 while (af.nvls--) {
1661                         zfree(&af.vls[af.nvls].point.symbol);
1662                         strlist__delete(af.vls[af.nvls].vars);
1663                 }
1664                 zfree(vls);
1665                 return ret;
1666         }
1667
1668         return (ret < 0) ? ret : af.nvls;
1669 }
1670
1671 /* For the kernel module, we need a special code to get a DIE */
1672 int debuginfo__get_text_offset(struct debuginfo *dbg, Dwarf_Addr *offs,
1673                                 bool adjust_offset)
1674 {
1675         int n, i;
1676         Elf32_Word shndx;
1677         Elf_Scn *scn;
1678         Elf *elf;
1679         GElf_Shdr mem, *shdr;
1680         const char *p;
1681
1682         elf = dwfl_module_getelf(dbg->mod, &dbg->bias);
1683         if (!elf)
1684                 return -EINVAL;
1685
1686         /* Get the number of relocations */
1687         n = dwfl_module_relocations(dbg->mod);
1688         if (n < 0)
1689                 return -ENOENT;
1690         /* Search the relocation related .text section */
1691         for (i = 0; i < n; i++) {
1692                 p = dwfl_module_relocation_info(dbg->mod, i, &shndx);
1693                 if (strcmp(p, ".text") == 0) {
1694                         /* OK, get the section header */
1695                         scn = elf_getscn(elf, shndx);
1696                         if (!scn)
1697                                 return -ENOENT;
1698                         shdr = gelf_getshdr(scn, &mem);
1699                         if (!shdr)
1700                                 return -ENOENT;
1701                         *offs = shdr->sh_addr;
1702                         if (adjust_offset)
1703                                 *offs -= shdr->sh_offset;
1704                 }
1705         }
1706         return 0;
1707 }
1708
1709 /* Reverse search */
1710 int debuginfo__find_probe_point(struct debuginfo *dbg, u64 addr,
1711                                 struct perf_probe_point *ppt)
1712 {
1713         Dwarf_Die cudie, spdie, indie;
1714         Dwarf_Addr _addr = 0, baseaddr = 0;
1715         const char *fname = NULL, *func = NULL, *basefunc = NULL, *tmp;
1716         int baseline = 0, lineno = 0, ret = 0;
1717
1718         /* We always need to relocate the address for aranges */
1719         if (debuginfo__get_text_offset(dbg, &baseaddr, false) == 0)
1720                 addr += baseaddr;
1721         /* Find cu die */
1722         if (!dwarf_addrdie(dbg->dbg, (Dwarf_Addr)addr, &cudie)) {
1723                 pr_warning("Failed to find debug information for address %" PRIx64 "\n",
1724                            addr);
1725                 ret = -EINVAL;
1726                 goto end;
1727         }
1728
1729         /* Find a corresponding line (filename and lineno) */
1730         cu_find_lineinfo(&cudie, (Dwarf_Addr)addr, &fname, &lineno);
1731         /* Don't care whether it failed or not */
1732
1733         /* Find a corresponding function (name, baseline and baseaddr) */
1734         if (die_find_realfunc(&cudie, (Dwarf_Addr)addr, &spdie)) {
1735                 /* Get function entry information */
1736                 func = basefunc = dwarf_diename(&spdie);
1737                 if (!func ||
1738                     die_entrypc(&spdie, &baseaddr) != 0 ||
1739                     dwarf_decl_line(&spdie, &baseline) != 0) {
1740                         lineno = 0;
1741                         goto post;
1742                 }
1743
1744                 fname = dwarf_decl_file(&spdie);
1745                 if (addr == baseaddr) {
1746                         /* Function entry - Relative line number is 0 */
1747                         lineno = baseline;
1748                         goto post;
1749                 }
1750
1751                 /* Track down the inline functions step by step */
1752                 while (die_find_top_inlinefunc(&spdie, (Dwarf_Addr)addr,
1753                                                 &indie)) {
1754                         /* There is an inline function */
1755                         if (die_entrypc(&indie, &_addr) == 0 &&
1756                             _addr == addr) {
1757                                 /*
1758                                  * addr is at an inline function entry.
1759                                  * In this case, lineno should be the call-site
1760                                  * line number. (overwrite lineinfo)
1761                                  */
1762                                 lineno = die_get_call_lineno(&indie);
1763                                 fname = die_get_call_file(&indie);
1764                                 break;
1765                         } else {
1766                                 /*
1767                                  * addr is in an inline function body.
1768                                  * Since lineno points one of the lines
1769                                  * of the inline function, baseline should
1770                                  * be the entry line of the inline function.
1771                                  */
1772                                 tmp = dwarf_diename(&indie);
1773                                 if (!tmp ||
1774                                     dwarf_decl_line(&indie, &baseline) != 0)
1775                                         break;
1776                                 func = tmp;
1777                                 spdie = indie;
1778                         }
1779                 }
1780                 /* Verify the lineno and baseline are in a same file */
1781                 tmp = dwarf_decl_file(&spdie);
1782                 if (!tmp || strcmp(tmp, fname) != 0)
1783                         lineno = 0;
1784         }
1785
1786 post:
1787         /* Make a relative line number or an offset */
1788         if (lineno)
1789                 ppt->line = lineno - baseline;
1790         else if (basefunc) {
1791                 ppt->offset = addr - baseaddr;
1792                 func = basefunc;
1793         }
1794
1795         /* Duplicate strings */
1796         if (func) {
1797                 ppt->function = strdup(func);
1798                 if (ppt->function == NULL) {
1799                         ret = -ENOMEM;
1800                         goto end;
1801                 }
1802         }
1803         if (fname) {
1804                 ppt->file = strdup(fname);
1805                 if (ppt->file == NULL) {
1806                         zfree(&ppt->function);
1807                         ret = -ENOMEM;
1808                         goto end;
1809                 }
1810         }
1811 end:
1812         if (ret == 0 && (fname || func))
1813                 ret = 1;        /* Found a point */
1814         return ret;
1815 }
1816
1817 /* Add a line and store the src path */
1818 static int line_range_add_line(const char *src, unsigned int lineno,
1819                                struct line_range *lr)
1820 {
1821         /* Copy source path */
1822         if (!lr->path) {
1823                 lr->path = strdup(src);
1824                 if (lr->path == NULL)
1825                         return -ENOMEM;
1826         }
1827         return intlist__add(lr->line_list, lineno);
1828 }
1829
1830 static int line_range_walk_cb(const char *fname, int lineno,
1831                               Dwarf_Addr addr, void *data)
1832 {
1833         struct line_finder *lf = data;
1834         const char *__fname;
1835         int __lineno;
1836         int err;
1837
1838         if ((strtailcmp(fname, lf->fname) != 0) ||
1839             (lf->lno_s > lineno || lf->lno_e < lineno))
1840                 return 0;
1841
1842         /* Make sure this line can be reversible */
1843         if (cu_find_lineinfo(&lf->cu_die, addr, &__fname, &__lineno) > 0
1844             && (lineno != __lineno || strcmp(fname, __fname)))
1845                 return 0;
1846
1847         err = line_range_add_line(fname, lineno, lf->lr);
1848         if (err < 0 && err != -EEXIST)
1849                 return err;
1850
1851         return 0;
1852 }
1853
1854 /* Find line range from its line number */
1855 static int find_line_range_by_line(Dwarf_Die *sp_die, struct line_finder *lf)
1856 {
1857         int ret;
1858
1859         ret = die_walk_lines(sp_die ?: &lf->cu_die, line_range_walk_cb, lf);
1860
1861         /* Update status */
1862         if (ret >= 0)
1863                 if (!intlist__empty(lf->lr->line_list))
1864                         ret = lf->found = 1;
1865                 else
1866                         ret = 0;        /* Lines are not found */
1867         else {
1868                 zfree(&lf->lr->path);
1869         }
1870         return ret;
1871 }
1872
1873 static int line_range_inline_cb(Dwarf_Die *in_die, void *data)
1874 {
1875         int ret = find_line_range_by_line(in_die, data);
1876
1877         /*
1878          * We have to check all instances of inlined function, because
1879          * some execution paths can be optimized out depends on the
1880          * function argument of instances. However, if an error occurs,
1881          * it should be handled by the caller.
1882          */
1883         return ret < 0 ? ret : 0;
1884 }
1885
1886 /* Search function definition from function name */
1887 static int line_range_search_cb(Dwarf_Die *sp_die, void *data)
1888 {
1889         struct dwarf_callback_param *param = data;
1890         struct line_finder *lf = param->data;
1891         struct line_range *lr = lf->lr;
1892
1893         /* Check declared file */
1894         if (lr->file && strtailcmp(lr->file, dwarf_decl_file(sp_die)))
1895                 return DWARF_CB_OK;
1896
1897         if (die_match_name(sp_die, lr->function) && die_is_func_def(sp_die)) {
1898                 lf->fname = dwarf_decl_file(sp_die);
1899                 dwarf_decl_line(sp_die, &lr->offset);
1900                 pr_debug("fname: %s, lineno:%d\n", lf->fname, lr->offset);
1901                 lf->lno_s = lr->offset + lr->start;
1902                 if (lf->lno_s < 0)      /* Overflow */
1903                         lf->lno_s = INT_MAX;
1904                 lf->lno_e = lr->offset + lr->end;
1905                 if (lf->lno_e < 0)      /* Overflow */
1906                         lf->lno_e = INT_MAX;
1907                 pr_debug("New line range: %d to %d\n", lf->lno_s, lf->lno_e);
1908                 lr->start = lf->lno_s;
1909                 lr->end = lf->lno_e;
1910                 if (!die_is_func_instance(sp_die))
1911                         param->retval = die_walk_instances(sp_die,
1912                                                 line_range_inline_cb, lf);
1913                 else
1914                         param->retval = find_line_range_by_line(sp_die, lf);
1915                 return DWARF_CB_ABORT;
1916         }
1917         return DWARF_CB_OK;
1918 }
1919
1920 static int find_line_range_by_func(struct line_finder *lf)
1921 {
1922         struct dwarf_callback_param param = {.data = (void *)lf, .retval = 0};
1923         dwarf_getfuncs(&lf->cu_die, line_range_search_cb, &param, 0);
1924         return param.retval;
1925 }
1926
1927 int debuginfo__find_line_range(struct debuginfo *dbg, struct line_range *lr)
1928 {
1929         struct line_finder lf = {.lr = lr, .found = 0};
1930         int ret = 0;
1931         Dwarf_Off off = 0, noff;
1932         size_t cuhl;
1933         Dwarf_Die *diep;
1934         const char *comp_dir;
1935
1936         /* Fastpath: lookup by function name from .debug_pubnames section */
1937         if (lr->function) {
1938                 struct pubname_callback_param pubname_param = {
1939                         .function = lr->function, .file = lr->file,
1940                         .cu_die = &lf.cu_die, .sp_die = &lf.sp_die, .found = 0};
1941                 struct dwarf_callback_param line_range_param = {
1942                         .data = (void *)&lf, .retval = 0};
1943
1944                 dwarf_getpubnames(dbg->dbg, pubname_search_cb,
1945                                   &pubname_param, 0);
1946                 if (pubname_param.found) {
1947                         line_range_search_cb(&lf.sp_die, &line_range_param);
1948                         if (lf.found)
1949                                 goto found;
1950                 }
1951         }
1952
1953         /* Loop on CUs (Compilation Unit) */
1954         while (!lf.found && ret >= 0) {
1955                 if (dwarf_nextcu(dbg->dbg, off, &noff, &cuhl,
1956                                  NULL, NULL, NULL) != 0)
1957                         break;
1958
1959                 /* Get the DIE(Debugging Information Entry) of this CU */
1960                 diep = dwarf_offdie(dbg->dbg, off + cuhl, &lf.cu_die);
1961                 if (!diep) {
1962                         off = noff;
1963                         continue;
1964                 }
1965
1966                 /* Check if target file is included. */
1967                 if (lr->file)
1968                         lf.fname = cu_find_realpath(&lf.cu_die, lr->file);
1969                 else
1970                         lf.fname = 0;
1971
1972                 if (!lr->file || lf.fname) {
1973                         if (lr->function)
1974                                 ret = find_line_range_by_func(&lf);
1975                         else {
1976                                 lf.lno_s = lr->start;
1977                                 lf.lno_e = lr->end;
1978                                 ret = find_line_range_by_line(NULL, &lf);
1979                         }
1980                 }
1981                 off = noff;
1982         }
1983
1984 found:
1985         /* Store comp_dir */
1986         if (lf.found) {
1987                 comp_dir = cu_get_comp_dir(&lf.cu_die);
1988                 if (comp_dir) {
1989                         lr->comp_dir = strdup(comp_dir);
1990                         if (!lr->comp_dir)
1991                                 ret = -ENOMEM;
1992                 }
1993         }
1994
1995         pr_debug("path: %s\n", lr->path);
1996         return (ret < 0) ? ret : lf.found;
1997 }
1998
1999 #ifdef HAVE_DEBUGINFOD_SUPPORT
2000 /* debuginfod doesn't require the comp_dir but buildid is required */
2001 static int get_source_from_debuginfod(const char *raw_path,
2002                                 const char *sbuild_id, char **new_path)
2003 {
2004         debuginfod_client *c = debuginfod_begin();
2005         const char *p = raw_path;
2006         int fd;
2007
2008         if (!c)
2009                 return -ENOMEM;
2010
2011         fd = debuginfod_find_source(c, (const unsigned char *)sbuild_id,
2012                                 0, p, new_path);
2013         pr_debug("Search %s from debuginfod -> %d\n", p, fd);
2014         if (fd >= 0)
2015                 close(fd);
2016         debuginfod_end(c);
2017         if (fd < 0) {
2018                 pr_debug("Failed to find %s in debuginfod (%s)\n",
2019                         raw_path, sbuild_id);
2020                 return -ENOENT;
2021         }
2022         pr_debug("Got a source %s\n", *new_path);
2023
2024         return 0;
2025 }
2026 #else
2027 static inline int get_source_from_debuginfod(const char *raw_path __maybe_unused,
2028                                 const char *sbuild_id __maybe_unused,
2029                                 char **new_path __maybe_unused)
2030 {
2031         return -ENOTSUP;
2032 }
2033 #endif
2034 /*
2035  * Find a src file from a DWARF tag path. Prepend optional source path prefix
2036  * and chop off leading directories that do not exist. Result is passed back as
2037  * a newly allocated path on success.
2038  * Return 0 if file was found and readable, -errno otherwise.
2039  */
2040 int find_source_path(const char *raw_path, const char *sbuild_id,
2041                 const char *comp_dir, char **new_path)
2042 {
2043         const char *prefix = symbol_conf.source_prefix;
2044
2045         if (sbuild_id && !prefix) {
2046                 if (!get_source_from_debuginfod(raw_path, sbuild_id, new_path))
2047                         return 0;
2048         }
2049
2050         if (!prefix) {
2051                 if (raw_path[0] != '/' && comp_dir)
2052                         /* If not an absolute path, try to use comp_dir */
2053                         prefix = comp_dir;
2054                 else {
2055                         if (access(raw_path, R_OK) == 0) {
2056                                 *new_path = strdup(raw_path);
2057                                 return *new_path ? 0 : -ENOMEM;
2058                         } else
2059                                 return -errno;
2060                 }
2061         }
2062
2063         *new_path = malloc((strlen(prefix) + strlen(raw_path) + 2));
2064         if (!*new_path)
2065                 return -ENOMEM;
2066
2067         for (;;) {
2068                 sprintf(*new_path, "%s/%s", prefix, raw_path);
2069
2070                 if (access(*new_path, R_OK) == 0)
2071                         return 0;
2072
2073                 if (!symbol_conf.source_prefix) {
2074                         /* In case of searching comp_dir, don't retry */
2075                         zfree(new_path);
2076                         return -errno;
2077                 }
2078
2079                 switch (errno) {
2080                 case ENAMETOOLONG:
2081                 case ENOENT:
2082                 case EROFS:
2083                 case EFAULT:
2084                         raw_path = strchr(++raw_path, '/');
2085                         if (!raw_path) {
2086                                 zfree(new_path);
2087                                 return -ENOENT;
2088                         }
2089                         continue;
2090
2091                 default:
2092                         zfree(new_path);
2093                         return -errno;
2094                 }
2095         }
2096 }