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gpio: rcar: Fix runtime PM imbalance on error
[linux/fpc-iii.git] / tools / perf / util / probe-finder.c
blobe4cff49384f411e6c6d0e34d94bd869fadc88f06
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 /* Kprobe tracer basic type is up to u64 */
35 #define MAX_BASIC_TYPE_BITS 64
36
37 /* Dwarf FL wrappers */
38 static char *debuginfo_path; /* Currently dummy */
39
40 static const Dwfl_Callbacks offline_callbacks = {
41 .find_debuginfo = dwfl_standard_find_debuginfo,
42 .debuginfo_path = &debuginfo_path,
43
44 .section_address = dwfl_offline_section_address,
45
46 /* We use this table for core files too. */
47 .find_elf = dwfl_build_id_find_elf,
48 };
49
50 /* Get a Dwarf from offline image */
51 static int debuginfo__init_offline_dwarf(struct debuginfo *dbg,
52 const char *path)
53 {
54 int fd;
55
56 fd = open(path, O_RDONLY);
57 if (fd < 0)
58 return fd;
59
60 dbg->dwfl = dwfl_begin(&offline_callbacks);
61 if (!dbg->dwfl)
62 goto error;
63
64 dwfl_report_begin(dbg->dwfl);
65 dbg->mod = dwfl_report_offline(dbg->dwfl, "", "", fd);
66 if (!dbg->mod)
67 goto error;
68
69 dbg->dbg = dwfl_module_getdwarf(dbg->mod, &dbg->bias);
70 if (!dbg->dbg)
71 goto error;
72
73 dwfl_report_end(dbg->dwfl, NULL, NULL);
74
75 return 0;
76 error:
77 if (dbg->dwfl)
78 dwfl_end(dbg->dwfl);
79 else
80 close(fd);
81 memset(dbg, 0, sizeof(*dbg));
82
83 return -ENOENT;
84 }
85
86 static struct debuginfo *__debuginfo__new(const char *path)
87 {
88 struct debuginfo *dbg = zalloc(sizeof(*dbg));
89 if (!dbg)
90 return NULL;
91
92 if (debuginfo__init_offline_dwarf(dbg, path) < 0)
93 zfree(&dbg);
94 if (dbg)
95 pr_debug("Open Debuginfo file: %s\n", path);
96 return dbg;
97 }
98
99 enum dso_binary_type distro_dwarf_types[] = {
100 DSO_BINARY_TYPE__FEDORA_DEBUGINFO,
101 DSO_BINARY_TYPE__UBUNTU_DEBUGINFO,
102 DSO_BINARY_TYPE__OPENEMBEDDED_DEBUGINFO,
103 DSO_BINARY_TYPE__BUILDID_DEBUGINFO,
104 DSO_BINARY_TYPE__NOT_FOUND,
105 };
106
107 struct debuginfo *debuginfo__new(const char *path)
108 {
109 enum dso_binary_type *type;
110 char buf[PATH_MAX], nil = '\0';
111 struct dso *dso;
112 struct debuginfo *dinfo = NULL;
113
114 /* Try to open distro debuginfo files */
115 dso = dso__new(path);
116 if (!dso)
117 goto out;
118
119 for (type = distro_dwarf_types;
120 !dinfo && *type != DSO_BINARY_TYPE__NOT_FOUND;
121 type++) {
122 if (dso__read_binary_type_filename(dso, *type, &nil,
123 buf, PATH_MAX) < 0)
124 continue;
125 dinfo = __debuginfo__new(buf);
126 }
127 dso__put(dso);
128
129 out:
130 /* if failed to open all distro debuginfo, open given binary */
131 return dinfo ? : __debuginfo__new(path);
132 }
133
134 void debuginfo__delete(struct debuginfo *dbg)
135 {
136 if (dbg) {
137 if (dbg->dwfl)
138 dwfl_end(dbg->dwfl);
139 free(dbg);
140 }
141 }
142
143 /*
144 * Probe finder related functions
145 */
146
147 static struct probe_trace_arg_ref *alloc_trace_arg_ref(long offs)
148 {
149 struct probe_trace_arg_ref *ref;
150 ref = zalloc(sizeof(struct probe_trace_arg_ref));
151 if (ref != NULL)
152 ref->offset = offs;
153 return ref;
154 }
155
156 /*
157 * Convert a location into trace_arg.
158 * If tvar == NULL, this just checks variable can be converted.
159 * If fentry == true and vr_die is a parameter, do huristic search
160 * for the location fuzzed by function entry mcount.
161 */
162 static int convert_variable_location(Dwarf_Die *vr_die, Dwarf_Addr addr,
163 Dwarf_Op *fb_ops, Dwarf_Die *sp_die,
164 unsigned int machine,
165 struct probe_trace_arg *tvar)
166 {
167 Dwarf_Attribute attr;
168 Dwarf_Addr tmp = 0;
169 Dwarf_Op *op;
170 size_t nops;
171 unsigned int regn;
172 Dwarf_Word offs = 0;
173 bool ref = false;
174 const char *regs;
175 int ret, ret2 = 0;
176
177 if (dwarf_attr(vr_die, DW_AT_external, &attr) != NULL)
178 goto static_var;
179
180 /* Constant value */
181 if (dwarf_attr(vr_die, DW_AT_const_value, &attr) &&
182 immediate_value_is_supported()) {
183 Dwarf_Sword snum;
184
185 dwarf_formsdata(&attr, &snum);
186 ret = asprintf(&tvar->value, "\\%ld", (long)snum);
187
188 return ret < 0 ? -ENOMEM : 0;
189 }
190
191 /* TODO: handle more than 1 exprs */
192 if (dwarf_attr(vr_die, DW_AT_location, &attr) == NULL)
193 return -EINVAL; /* Broken DIE ? */
194 if (dwarf_getlocation_addr(&attr, addr, &op, &nops, 1) <= 0) {
195 ret = dwarf_entrypc(sp_die, &tmp);
196 if (ret)
197 return -ENOENT;
198
199 if (probe_conf.show_location_range &&
200 (dwarf_tag(vr_die) == DW_TAG_variable)) {
201 ret2 = -ERANGE;
202 } else if (addr != tmp ||
203 dwarf_tag(vr_die) != DW_TAG_formal_parameter) {
204 return -ENOENT;
205 }
206
207 ret = dwarf_highpc(sp_die, &tmp);
208 if (ret)
209 return -ENOENT;
210 /*
211 * This is fuzzed by fentry mcount. We try to find the
212 * parameter location at the earliest address.
213 */
214 for (addr += 1; addr <= tmp; addr++) {
215 if (dwarf_getlocation_addr(&attr, addr, &op,
216 &nops, 1) > 0)
217 goto found;
218 }
219 return -ENOENT;
220 }
221 found:
222 if (nops == 0)
223 /* TODO: Support const_value */
224 return -ENOENT;
225
226 if (op->atom == DW_OP_addr) {
227 static_var:
228 if (!tvar)
229 return ret2;
230 /* Static variables on memory (not stack), make @varname */
231 ret = strlen(dwarf_diename(vr_die));
232 tvar->value = zalloc(ret + 2);
233 if (tvar->value == NULL)
234 return -ENOMEM;
235 snprintf(tvar->value, ret + 2, "@%s", dwarf_diename(vr_die));
236 tvar->ref = alloc_trace_arg_ref((long)offs);
237 if (tvar->ref == NULL)
238 return -ENOMEM;
239 return ret2;
240 }
241
242 /* If this is based on frame buffer, set the offset */
243 if (op->atom == DW_OP_fbreg) {
244 if (fb_ops == NULL)
245 return -ENOTSUP;
246 ref = true;
247 offs = op->number;
248 op = &fb_ops[0];
249 }
250
251 if (op->atom >= DW_OP_breg0 && op->atom <= DW_OP_breg31) {
252 regn = op->atom - DW_OP_breg0;
253 offs += op->number;
254 ref = true;
255 } else if (op->atom >= DW_OP_reg0 && op->atom <= DW_OP_reg31) {
256 regn = op->atom - DW_OP_reg0;
257 } else if (op->atom == DW_OP_bregx) {
258 regn = op->number;
259 offs += op->number2;
260 ref = true;
261 } else if (op->atom == DW_OP_regx) {
262 regn = op->number;
263 } else {
264 pr_debug("DW_OP %x is not supported.\n", op->atom);
265 return -ENOTSUP;
266 }
267
268 if (!tvar)
269 return ret2;
270
271 regs = get_dwarf_regstr(regn, machine);
272 if (!regs) {
273 /* This should be a bug in DWARF or this tool */
274 pr_warning("Mapping for the register number %u "
275 "missing on this architecture.\n", regn);
276 return -ENOTSUP;
277 }
278
279 tvar->value = strdup(regs);
280 if (tvar->value == NULL)
281 return -ENOMEM;
282
283 if (ref) {
284 tvar->ref = alloc_trace_arg_ref((long)offs);
285 if (tvar->ref == NULL)
286 return -ENOMEM;
287 }
288 return ret2;
289 }
290
291 #define BYTES_TO_BITS(nb) ((nb) * BITS_PER_LONG / sizeof(long))
292
293 static int convert_variable_type(Dwarf_Die *vr_die,
294 struct probe_trace_arg *tvar,
295 const char *cast, bool user_access)
296 {
297 struct probe_trace_arg_ref **ref_ptr = &tvar->ref;
298 Dwarf_Die type;
299 char buf[16];
300 char sbuf[STRERR_BUFSIZE];
301 int bsize, boffs, total;
302 int ret;
303 char prefix;
304
305 /* TODO: check all types */
306 if (cast && strcmp(cast, "string") != 0 && strcmp(cast, "ustring") &&
307 strcmp(cast, "x") != 0 &&
308 strcmp(cast, "s") != 0 && strcmp(cast, "u") != 0) {
309 /* Non string type is OK */
310 /* and respect signedness/hexadecimal cast */
311 tvar->type = strdup(cast);
312 return (tvar->type == NULL) ? -ENOMEM : 0;
313 }
314
315 bsize = dwarf_bitsize(vr_die);
316 if (bsize > 0) {
317 /* This is a bitfield */
318 boffs = dwarf_bitoffset(vr_die);
319 total = dwarf_bytesize(vr_die);
320 if (boffs < 0 || total < 0)
321 return -ENOENT;
322 ret = snprintf(buf, 16, "b%d@%d/%zd", bsize, boffs,
323 BYTES_TO_BITS(total));
324 goto formatted;
325 }
326
327 if (die_get_real_type(vr_die, &type) == NULL) {
328 pr_warning("Failed to get a type information of %s.\n",
329 dwarf_diename(vr_die));
330 return -ENOENT;
331 }
332
333 pr_debug("%s type is %s.\n",
334 dwarf_diename(vr_die), dwarf_diename(&type));
335
336 if (cast && (!strcmp(cast, "string") || !strcmp(cast, "ustring"))) {
337 /* String type */
338 ret = dwarf_tag(&type);
339 if (ret != DW_TAG_pointer_type &&
340 ret != DW_TAG_array_type) {
341 pr_warning("Failed to cast into string: "
342 "%s(%s) is not a pointer nor array.\n",
343 dwarf_diename(vr_die), dwarf_diename(&type));
344 return -EINVAL;
345 }
346 if (die_get_real_type(&type, &type) == NULL) {
347 pr_warning("Failed to get a type"
348 " information.\n");
349 return -ENOENT;
350 }
351 if (ret == DW_TAG_pointer_type) {
352 while (*ref_ptr)
353 ref_ptr = &(*ref_ptr)->next;
354 /* Add new reference with offset +0 */
355 *ref_ptr = zalloc(sizeof(struct probe_trace_arg_ref));
356 if (*ref_ptr == NULL) {
357 pr_warning("Out of memory error\n");
358 return -ENOMEM;
359 }
360 (*ref_ptr)->user_access = user_access;
361 }
362 if (!die_compare_name(&type, "char") &&
363 !die_compare_name(&type, "unsigned char")) {
364 pr_warning("Failed to cast into string: "
365 "%s is not (unsigned) char *.\n",
366 dwarf_diename(vr_die));
367 return -EINVAL;
368 }
369 tvar->type = strdup(cast);
370 return (tvar->type == NULL) ? -ENOMEM : 0;
371 }
372
373 if (cast && (strcmp(cast, "u") == 0))
374 prefix = 'u';
375 else if (cast && (strcmp(cast, "s") == 0))
376 prefix = 's';
377 else if (cast && (strcmp(cast, "x") == 0) &&
378 probe_type_is_available(PROBE_TYPE_X))
379 prefix = 'x';
380 else
381 prefix = die_is_signed_type(&type) ? 's' :
382 probe_type_is_available(PROBE_TYPE_X) ? 'x' : 'u';
383
384 ret = dwarf_bytesize(&type);
385 if (ret <= 0)
386 /* No size ... try to use default type */
387 return 0;
388 ret = BYTES_TO_BITS(ret);
389
390 /* Check the bitwidth */
391 if (ret > MAX_BASIC_TYPE_BITS) {
392 pr_info("%s exceeds max-bitwidth. Cut down to %d bits.\n",
393 dwarf_diename(&type), MAX_BASIC_TYPE_BITS);
394 ret = MAX_BASIC_TYPE_BITS;
395 }
396 ret = snprintf(buf, 16, "%c%d", prefix, ret);
397
398 formatted:
399 if (ret < 0 || ret >= 16) {
400 if (ret >= 16)
401 ret = -E2BIG;
402 pr_warning("Failed to convert variable type: %s\n",
403 str_error_r(-ret, sbuf, sizeof(sbuf)));
404 return ret;
405 }
406 tvar->type = strdup(buf);
407 if (tvar->type == NULL)
408 return -ENOMEM;
409 return 0;
410 }
411
412 static int convert_variable_fields(Dwarf_Die *vr_die, const char *varname,
413 struct perf_probe_arg_field *field,
414 struct probe_trace_arg_ref **ref_ptr,
415 Dwarf_Die *die_mem, bool user_access)
416 {
417 struct probe_trace_arg_ref *ref = *ref_ptr;
418 Dwarf_Die type;
419 Dwarf_Word offs;
420 int ret, tag;
421
422 pr_debug("converting %s in %s\n", field->name, varname);
423 if (die_get_real_type(vr_die, &type) == NULL) {
424 pr_warning("Failed to get the type of %s.\n", varname);
425 return -ENOENT;
426 }
427 pr_debug2("Var real type: %s (%x)\n", dwarf_diename(&type),
428 (unsigned)dwarf_dieoffset(&type));
429 tag = dwarf_tag(&type);
430
431 if (field->name[0] == '[' &&
432 (tag == DW_TAG_array_type || tag == DW_TAG_pointer_type)) {
433 /* Save original type for next field or type */
434 memcpy(die_mem, &type, sizeof(*die_mem));
435 /* Get the type of this array */
436 if (die_get_real_type(&type, &type) == NULL) {
437 pr_warning("Failed to get the type of %s.\n", varname);
438 return -ENOENT;
439 }
440 pr_debug2("Array real type: %s (%x)\n", dwarf_diename(&type),
441 (unsigned)dwarf_dieoffset(&type));
442 if (tag == DW_TAG_pointer_type) {
443 ref = zalloc(sizeof(struct probe_trace_arg_ref));
444 if (ref == NULL)
445 return -ENOMEM;
446 if (*ref_ptr)
447 (*ref_ptr)->next = ref;
448 else
449 *ref_ptr = ref;
450 }
451 ref->offset += dwarf_bytesize(&type) * field->index;
452 ref->user_access = user_access;
453 goto next;
454 } else if (tag == DW_TAG_pointer_type) {
455 /* Check the pointer and dereference */
456 if (!field->ref) {
457 pr_err("Semantic error: %s must be referred by '->'\n",
458 field->name);
459 return -EINVAL;
460 }
461 /* Get the type pointed by this pointer */
462 if (die_get_real_type(&type, &type) == NULL) {
463 pr_warning("Failed to get the type of %s.\n", varname);
464 return -ENOENT;
465 }
466 /* Verify it is a data structure */
467 tag = dwarf_tag(&type);
468 if (tag != DW_TAG_structure_type && tag != DW_TAG_union_type) {
469 pr_warning("%s is not a data structure nor a union.\n",
470 varname);
471 return -EINVAL;
472 }
473
474 ref = zalloc(sizeof(struct probe_trace_arg_ref));
475 if (ref == NULL)
476 return -ENOMEM;
477 if (*ref_ptr)
478 (*ref_ptr)->next = ref;
479 else
480 *ref_ptr = ref;
481 } else {
482 /* Verify it is a data structure */
483 if (tag != DW_TAG_structure_type && tag != DW_TAG_union_type) {
484 pr_warning("%s is not a data structure nor a union.\n",
485 varname);
486 return -EINVAL;
487 }
488 if (field->name[0] == '[') {
489 pr_err("Semantic error: %s is not a pointer"
490 " nor array.\n", varname);
491 return -EINVAL;
492 }
493 /* While prcessing unnamed field, we don't care about this */
494 if (field->ref && dwarf_diename(vr_die)) {
495 pr_err("Semantic error: %s must be referred by '.'\n",
496 field->name);
497 return -EINVAL;
498 }
499 if (!ref) {
500 pr_warning("Structure on a register is not "
501 "supported yet.\n");
502 return -ENOTSUP;
503 }
504 }
505
506 if (die_find_member(&type, field->name, die_mem) == NULL) {
507 pr_warning("%s(type:%s) has no member %s.\n", varname,
508 dwarf_diename(&type), field->name);
509 return -EINVAL;
510 }
511
512 /* Get the offset of the field */
513 if (tag == DW_TAG_union_type) {
514 offs = 0;
515 } else {
516 ret = die_get_data_member_location(die_mem, &offs);
517 if (ret < 0) {
518 pr_warning("Failed to get the offset of %s.\n",
519 field->name);
520 return ret;
521 }
522 }
523 ref->offset += (long)offs;
524 ref->user_access = user_access;
525
526 /* If this member is unnamed, we need to reuse this field */
527 if (!dwarf_diename(die_mem))
528 return convert_variable_fields(die_mem, varname, field,
529 &ref, die_mem, user_access);
530
531 next:
532 /* Converting next field */
533 if (field->next)
534 return convert_variable_fields(die_mem, field->name,
535 field->next, &ref, die_mem, user_access);
536 else
537 return 0;
538 }
539
540 static void print_var_not_found(const char *varname)
541 {
542 pr_err("Failed to find the location of the '%s' variable at this address.\n"
543 " Perhaps it has been optimized out.\n"
544 " Use -V with the --range option to show '%s' location range.\n",
545 varname, varname);
546 }
547
548 /* Show a variables in kprobe event format */
549 static int convert_variable(Dwarf_Die *vr_die, struct probe_finder *pf)
550 {
551 Dwarf_Die die_mem;
552 int ret;
553
554 pr_debug("Converting variable %s into trace event.\n",
555 dwarf_diename(vr_die));
556
557 ret = convert_variable_location(vr_die, pf->addr, pf->fb_ops,
558 &pf->sp_die, pf->machine, pf->tvar);
559 if (ret == -ENOENT && pf->skip_empty_arg)
560 /* This can be found in other place. skip it */
561 return 0;
562 if (ret == -ENOENT || ret == -EINVAL) {
563 print_var_not_found(pf->pvar->var);
564 } else if (ret == -ENOTSUP)
565 pr_err("Sorry, we don't support this variable location yet.\n");
566 else if (ret == 0 && pf->pvar->field) {
567 ret = convert_variable_fields(vr_die, pf->pvar->var,
568 pf->pvar->field, &pf->tvar->ref,
569 &die_mem, pf->pvar->user_access);
570 vr_die = &die_mem;
571 }
572 if (ret == 0)
573 ret = convert_variable_type(vr_die, pf->tvar, pf->pvar->type,
574 pf->pvar->user_access);
575 /* *expr will be cached in libdw. Don't free it. */
576 return ret;
577 }
578
579 /* Find a variable in a scope DIE */
580 static int find_variable(Dwarf_Die *sc_die, struct probe_finder *pf)
581 {
582 Dwarf_Die vr_die;
583 char *buf, *ptr;
584 int ret = 0;
585
586 /* Copy raw parameters */
587 if (!is_c_varname(pf->pvar->var))
588 return copy_to_probe_trace_arg(pf->tvar, pf->pvar);
589
590 if (pf->pvar->name)
591 pf->tvar->name = strdup(pf->pvar->name);
592 else {
593 buf = synthesize_perf_probe_arg(pf->pvar);
594 if (!buf)
595 return -ENOMEM;
596 ptr = strchr(buf, ':'); /* Change type separator to _ */
597 if (ptr)
598 *ptr = '_';
599 pf->tvar->name = buf;
600 }
601 if (pf->tvar->name == NULL)
602 return -ENOMEM;
603
604 pr_debug("Searching '%s' variable in context.\n", pf->pvar->var);
605 /* Search child die for local variables and parameters. */
606 if (!die_find_variable_at(sc_die, pf->pvar->var, pf->addr, &vr_die)) {
607 /* Search again in global variables */
608 if (!die_find_variable_at(&pf->cu_die, pf->pvar->var,
609 0, &vr_die)) {
610 if (pf->skip_empty_arg)
611 return 0;
612 pr_warning("Failed to find '%s' in this function.\n",
613 pf->pvar->var);
614 ret = -ENOENT;
615 }
616 }
617 if (ret >= 0)
618 ret = convert_variable(&vr_die, pf);
619
620 return ret;
621 }
622
623 /* Convert subprogram DIE to trace point */
624 static int convert_to_trace_point(Dwarf_Die *sp_die, Dwfl_Module *mod,
625 Dwarf_Addr paddr, bool retprobe,
626 const char *function,
627 struct probe_trace_point *tp)
628 {
629 Dwarf_Addr eaddr;
630 GElf_Sym sym;
631 const char *symbol;
632
633 /* Verify the address is correct */
634 if (!dwarf_haspc(sp_die, paddr)) {
635 pr_warning("Specified offset is out of %s\n",
636 dwarf_diename(sp_die));
637 return -EINVAL;
638 }
639
640 if (dwarf_entrypc(sp_die, &eaddr) == 0) {
641 /* If the DIE has entrypc, use it. */
642 symbol = dwarf_diename(sp_die);
643 } else {
644 /* Try to get actual symbol name and address from symtab */
645 symbol = dwfl_module_addrsym(mod, paddr, &sym, NULL);
646 eaddr = sym.st_value;
647 }
648 if (!symbol) {
649 pr_warning("Failed to find symbol at 0x%lx\n",
650 (unsigned long)paddr);
651 return -ENOENT;
652 }
653
654 tp->offset = (unsigned long)(paddr - eaddr);
655 tp->address = (unsigned long)paddr;
656 tp->symbol = strdup(symbol);
657 if (!tp->symbol)
658 return -ENOMEM;
659
660 /* Return probe must be on the head of a subprogram */
661 if (retprobe) {
662 if (eaddr != paddr) {
663 pr_warning("Failed to find \"%s%%return\",\n"
664 " because %s is an inlined function and"
665 " has no return point.\n", function,
666 function);
667 return -EINVAL;
668 }
669 tp->retprobe = true;
670 }
671
672 return 0;
673 }
674
675 /* Call probe_finder callback with scope DIE */
676 static int call_probe_finder(Dwarf_Die *sc_die, struct probe_finder *pf)
677 {
678 Dwarf_Attribute fb_attr;
679 Dwarf_Frame *frame = NULL;
680 size_t nops;
681 int ret;
682
683 if (!sc_die) {
684 pr_err("Caller must pass a scope DIE. Program error.\n");
685 return -EINVAL;
686 }
687
688 /* If not a real subprogram, find a real one */
689 if (!die_is_func_def(sc_die)) {
690 if (!die_find_realfunc(&pf->cu_die, pf->addr, &pf->sp_die)) {
691 if (die_find_tailfunc(&pf->cu_die, pf->addr, &pf->sp_die)) {
692 pr_warning("Ignoring tail call from %s\n",
693 dwarf_diename(&pf->sp_die));
694 return 0;
695 } else {
696 pr_warning("Failed to find probe point in any "
697 "functions.\n");
698 return -ENOENT;
699 }
700 }
701 } else
702 memcpy(&pf->sp_die, sc_die, sizeof(Dwarf_Die));
703
704 /* Get the frame base attribute/ops from subprogram */
705 dwarf_attr(&pf->sp_die, DW_AT_frame_base, &fb_attr);
706 ret = dwarf_getlocation_addr(&fb_attr, pf->addr, &pf->fb_ops, &nops, 1);
707 if (ret <= 0 || nops == 0) {
708 pf->fb_ops = NULL;
709 #if _ELFUTILS_PREREQ(0, 142)
710 } else if (nops == 1 && pf->fb_ops[0].atom == DW_OP_call_frame_cfa &&
711 (pf->cfi_eh != NULL || pf->cfi_dbg != NULL)) {
712 if ((dwarf_cfi_addrframe(pf->cfi_eh, pf->addr, &frame) != 0 &&
713 (dwarf_cfi_addrframe(pf->cfi_dbg, pf->addr, &frame) != 0)) ||
714 dwarf_frame_cfa(frame, &pf->fb_ops, &nops) != 0) {
715 pr_warning("Failed to get call frame on 0x%jx\n",
716 (uintmax_t)pf->addr);
717 free(frame);
718 return -ENOENT;
719 }
720 #endif
721 }
722
723 /* Call finder's callback handler */
724 ret = pf->callback(sc_die, pf);
725
726 /* Since *pf->fb_ops can be a part of frame. we should free it here. */
727 free(frame);
728 pf->fb_ops = NULL;
729
730 return ret;
731 }
732
733 struct find_scope_param {
734 const char *function;
735 const char *file;
736 int line;
737 int diff;
738 Dwarf_Die *die_mem;
739 bool found;
740 };
741
742 static int find_best_scope_cb(Dwarf_Die *fn_die, void *data)
743 {
744 struct find_scope_param *fsp = data;
745 const char *file;
746 int lno;
747
748 /* Skip if declared file name does not match */
749 if (fsp->file) {
750 file = dwarf_decl_file(fn_die);
751 if (!file || strcmp(fsp->file, file) != 0)
752 return 0;
753 }
754 /* If the function name is given, that's what user expects */
755 if (fsp->function) {
756 if (die_match_name(fn_die, fsp->function)) {
757 memcpy(fsp->die_mem, fn_die, sizeof(Dwarf_Die));
758 fsp->found = true;
759 return 1;
760 }
761 } else {
762 /* With the line number, find the nearest declared DIE */
763 dwarf_decl_line(fn_die, &lno);
764 if (lno < fsp->line && fsp->diff > fsp->line - lno) {
765 /* Keep a candidate and continue */
766 fsp->diff = fsp->line - lno;
767 memcpy(fsp->die_mem, fn_die, sizeof(Dwarf_Die));
768 fsp->found = true;
769 }
770 }
771 return 0;
772 }
773
774 /* Return innermost DIE */
775 static int find_inner_scope_cb(Dwarf_Die *fn_die, void *data)
776 {
777 struct find_scope_param *fsp = data;
778
779 memcpy(fsp->die_mem, fn_die, sizeof(Dwarf_Die));
780 fsp->found = true;
781 return 1;
782 }
783
784 /* Find an appropriate scope fits to given conditions */
785 static Dwarf_Die *find_best_scope(struct probe_finder *pf, Dwarf_Die *die_mem)
786 {
787 struct find_scope_param fsp = {
788 .function = pf->pev->point.function,
789 .file = pf->fname,
790 .line = pf->lno,
791 .diff = INT_MAX,
792 .die_mem = die_mem,
793 .found = false,
794 };
795 int ret;
796
797 ret = cu_walk_functions_at(&pf->cu_die, pf->addr, find_best_scope_cb,
798 &fsp);
799 if (!ret && !fsp.found)
800 cu_walk_functions_at(&pf->cu_die, pf->addr,
801 find_inner_scope_cb, &fsp);
802
803 return fsp.found ? die_mem : NULL;
804 }
805
806 static int verify_representive_line(struct probe_finder *pf, const char *fname,
807 int lineno, Dwarf_Addr addr)
808 {
809 const char *__fname, *__func = NULL;
810 Dwarf_Die die_mem;
811 int __lineno;
812
813 /* Verify line number and address by reverse search */
814 if (cu_find_lineinfo(&pf->cu_die, addr, &__fname, &__lineno) < 0)
815 return 0;
816
817 pr_debug2("Reversed line: %s:%d\n", __fname, __lineno);
818 if (strcmp(fname, __fname) || lineno == __lineno)
819 return 0;
820
821 pr_warning("This line is sharing the address with other lines.\n");
822
823 if (pf->pev->point.function) {
824 /* Find best match function name and lines */
825 pf->addr = addr;
826 if (find_best_scope(pf, &die_mem)
827 && die_match_name(&die_mem, pf->pev->point.function)
828 && dwarf_decl_line(&die_mem, &lineno) == 0) {
829 __func = dwarf_diename(&die_mem);
830 __lineno -= lineno;
831 }
832 }
833 pr_warning("Please try to probe at %s:%d instead.\n",
834 __func ? : __fname, __lineno);
835
836 return -ENOENT;
837 }
838
839 static int probe_point_line_walker(const char *fname, int lineno,
840 Dwarf_Addr addr, void *data)
841 {
842 struct probe_finder *pf = data;
843 Dwarf_Die *sc_die, die_mem;
844 int ret;
845
846 if (lineno != pf->lno || strtailcmp(fname, pf->fname) != 0)
847 return 0;
848
849 if (verify_representive_line(pf, fname, lineno, addr))
850 return -ENOENT;
851
852 pf->addr = addr;
853 sc_die = find_best_scope(pf, &die_mem);
854 if (!sc_die) {
855 pr_warning("Failed to find scope of probe point.\n");
856 return -ENOENT;
857 }
858
859 ret = call_probe_finder(sc_die, pf);
860
861 /* Continue if no error, because the line will be in inline function */
862 return ret < 0 ? ret : 0;
863 }
864
865 /* Find probe point from its line number */
866 static int find_probe_point_by_line(struct probe_finder *pf)
867 {
868 return die_walk_lines(&pf->cu_die, probe_point_line_walker, pf);
869 }
870
871 /* Find lines which match lazy pattern */
872 static int find_lazy_match_lines(struct intlist *list,
873 const char *fname, const char *pat)
874 {
875 FILE *fp;
876 char *line = NULL;
877 size_t line_len;
878 ssize_t len;
879 int count = 0, linenum = 1;
880 char sbuf[STRERR_BUFSIZE];
881
882 fp = fopen(fname, "r");
883 if (!fp) {
884 pr_warning("Failed to open %s: %s\n", fname,
885 str_error_r(errno, sbuf, sizeof(sbuf)));
886 return -errno;
887 }
888
889 while ((len = getline(&line, &line_len, fp)) > 0) {
890
891 if (line[len - 1] == '\n')
892 line[len - 1] = '\0';
893
894 if (strlazymatch(line, pat)) {
895 intlist__add(list, linenum);
896 count++;
897 }
898 linenum++;
899 }
900
901 if (ferror(fp))
902 count = -errno;
903 free(line);
904 fclose(fp);
905
906 if (count == 0)
907 pr_debug("No matched lines found in %s.\n", fname);
908 return count;
909 }
910
911 static int probe_point_lazy_walker(const char *fname, int lineno,
912 Dwarf_Addr addr, void *data)
913 {
914 struct probe_finder *pf = data;
915 Dwarf_Die *sc_die, die_mem;
916 int ret;
917
918 if (!intlist__has_entry(pf->lcache, lineno) ||
919 strtailcmp(fname, pf->fname) != 0)
920 return 0;
921
922 pr_debug("Probe line found: line:%d addr:0x%llx\n",
923 lineno, (unsigned long long)addr);
924 pf->addr = addr;
925 pf->lno = lineno;
926 sc_die = find_best_scope(pf, &die_mem);
927 if (!sc_die) {
928 pr_warning("Failed to find scope of probe point.\n");
929 return -ENOENT;
930 }
931
932 ret = call_probe_finder(sc_die, pf);
933
934 /*
935 * Continue if no error, because the lazy pattern will match
936 * to other lines
937 */
938 return ret < 0 ? ret : 0;
939 }
940
941 /* Find probe points from lazy pattern */
942 static int find_probe_point_lazy(Dwarf_Die *sp_die, struct probe_finder *pf)
943 {
944 int ret = 0;
945 char *fpath;
946
947 if (intlist__empty(pf->lcache)) {
948 const char *comp_dir;
949
950 comp_dir = cu_get_comp_dir(&pf->cu_die);
951 ret = get_real_path(pf->fname, comp_dir, &fpath);
952 if (ret < 0) {
953 pr_warning("Failed to find source file path.\n");
954 return ret;
955 }
956
957 /* Matching lazy line pattern */
958 ret = find_lazy_match_lines(pf->lcache, fpath,
959 pf->pev->point.lazy_line);
960 free(fpath);
961 if (ret <= 0)
962 return ret;
963 }
964
965 return die_walk_lines(sp_die, probe_point_lazy_walker, pf);
966 }
967
968 static void skip_prologue(Dwarf_Die *sp_die, struct probe_finder *pf)
969 {
970 struct perf_probe_point *pp = &pf->pev->point;
971
972 /* Not uprobe? */
973 if (!pf->pev->uprobes)
974 return;
975
976 /* Compiled with optimization? */
977 if (die_is_optimized_target(&pf->cu_die))
978 return;
979
980 /* Don't know entrypc? */
981 if (!pf->addr)
982 return;
983
984 /* Only FUNC and FUNC@SRC are eligible. */
985 if (!pp->function || pp->line || pp->retprobe || pp->lazy_line ||
986 pp->offset || pp->abs_address)
987 return;
988
989 /* Not interested in func parameter? */
990 if (!perf_probe_with_var(pf->pev))
991 return;
992
993 pr_info("Target program is compiled without optimization. Skipping prologue.\n"
994 "Probe on address 0x%" PRIx64 " to force probing at the function entry.\n\n",
995 pf->addr);
996
997 die_skip_prologue(sp_die, &pf->cu_die, &pf->addr);
998 }
999
1000 static int probe_point_inline_cb(Dwarf_Die *in_die, void *data)
1001 {
1002 struct probe_finder *pf = data;
1003 struct perf_probe_point *pp = &pf->pev->point;
1004 Dwarf_Addr addr;
1005 int ret;
1006
1007 if (pp->lazy_line)
1008 ret = find_probe_point_lazy(in_die, pf);
1009 else {
1010 /* Get probe address */
1011 if (die_entrypc(in_die, &addr) != 0) {
1012 pr_warning("Failed to get entry address of %s.\n",
1013 dwarf_diename(in_die));
1014 return -ENOENT;
1015 }
1016 if (addr == 0) {
1017 pr_debug("%s has no valid entry address. skipped.\n",
1018 dwarf_diename(in_die));
1019 return -ENOENT;
1020 }
1021 pf->addr = addr;
1022 pf->addr += pp->offset;
1023 pr_debug("found inline addr: 0x%jx\n",
1024 (uintmax_t)pf->addr);
1025
1026 ret = call_probe_finder(in_die, pf);
1027 }
1028
1029 return ret;
1030 }
1031
1032 /* Callback parameter with return value for libdw */
1033 struct dwarf_callback_param {
1034 void *data;
1035 int retval;
1036 };
1037
1038 /* Search function from function name */
1039 static int probe_point_search_cb(Dwarf_Die *sp_die, void *data)
1040 {
1041 struct dwarf_callback_param *param = data;
1042 struct probe_finder *pf = param->data;
1043 struct perf_probe_point *pp = &pf->pev->point;
1044
1045 /* Check tag and diename */
1046 if (!die_is_func_def(sp_die) ||
1047 !die_match_name(sp_die, pp->function))
1048 return DWARF_CB_OK;
1049
1050 /* Check declared file */
1051 if (pp->file && strtailcmp(pp->file, dwarf_decl_file(sp_die)))
1052 return DWARF_CB_OK;
1053
1054 pr_debug("Matched function: %s [%lx]\n", dwarf_diename(sp_die),
1055 (unsigned long)dwarf_dieoffset(sp_die));
1056 pf->fname = dwarf_decl_file(sp_die);
1057 if (pp->line) { /* Function relative line */
1058 dwarf_decl_line(sp_die, &pf->lno);
1059 pf->lno += pp->line;
1060 param->retval = find_probe_point_by_line(pf);
1061 } else if (die_is_func_instance(sp_die)) {
1062 /* Instances always have the entry address */
1063 die_entrypc(sp_die, &pf->addr);
1064 /* But in some case the entry address is 0 */
1065 if (pf->addr == 0) {
1066 pr_debug("%s has no entry PC. Skipped\n",
1067 dwarf_diename(sp_die));
1068 param->retval = 0;
1069 /* Real function */
1070 } else if (pp->lazy_line)
1071 param->retval = find_probe_point_lazy(sp_die, pf);
1072 else {
1073 skip_prologue(sp_die, pf);
1074 pf->addr += pp->offset;
1075 /* TODO: Check the address in this function */
1076 param->retval = call_probe_finder(sp_die, pf);
1077 }
1078 } else if (!probe_conf.no_inlines) {
1079 /* Inlined function: search instances */
1080 param->retval = die_walk_instances(sp_die,
1081 probe_point_inline_cb, (void *)pf);
1082 /* This could be a non-existed inline definition */
1083 if (param->retval == -ENOENT)
1084 param->retval = 0;
1085 }
1086
1087 /* We need to find other candidates */
1088 if (strisglob(pp->function) && param->retval >= 0) {
1089 param->retval = 0; /* We have to clear the result */
1090 return DWARF_CB_OK;
1091 }
1092
1093 return DWARF_CB_ABORT; /* Exit; no same symbol in this CU. */
1094 }
1095
1096 static int find_probe_point_by_func(struct probe_finder *pf)
1097 {
1098 struct dwarf_callback_param _param = {.data = (void *)pf,
1099 .retval = 0};
1100 dwarf_getfuncs(&pf->cu_die, probe_point_search_cb, &_param, 0);
1101 return _param.retval;
1102 }
1103
1104 struct pubname_callback_param {
1105 char *function;
1106 char *file;
1107 Dwarf_Die *cu_die;
1108 Dwarf_Die *sp_die;
1109 int found;
1110 };
1111
1112 static int pubname_search_cb(Dwarf *dbg, Dwarf_Global *gl, void *data)
1113 {
1114 struct pubname_callback_param *param = data;
1115
1116 if (dwarf_offdie(dbg, gl->die_offset, param->sp_die)) {
1117 if (dwarf_tag(param->sp_die) != DW_TAG_subprogram)
1118 return DWARF_CB_OK;
1119
1120 if (die_match_name(param->sp_die, param->function)) {
1121 if (!dwarf_offdie(dbg, gl->cu_offset, param->cu_die))
1122 return DWARF_CB_OK;
1123
1124 if (param->file &&
1125 strtailcmp(param->file, dwarf_decl_file(param->sp_die)))
1126 return DWARF_CB_OK;
1127
1128 param->found = 1;
1129 return DWARF_CB_ABORT;
1130 }
1131 }
1132
1133 return DWARF_CB_OK;
1134 }
1135
1136 static int debuginfo__find_probe_location(struct debuginfo *dbg,
1137 struct probe_finder *pf)
1138 {
1139 struct perf_probe_point *pp = &pf->pev->point;
1140 Dwarf_Off off, noff;
1141 size_t cuhl;
1142 Dwarf_Die *diep;
1143 int ret = 0;
1144
1145 off = 0;
1146 pf->lcache = intlist__new(NULL);
1147 if (!pf->lcache)
1148 return -ENOMEM;
1149
1150 /* Fastpath: lookup by function name from .debug_pubnames section */
1151 if (pp->function && !strisglob(pp->function)) {
1152 struct pubname_callback_param pubname_param = {
1153 .function = pp->function,
1154 .file = pp->file,
1155 .cu_die = &pf->cu_die,
1156 .sp_die = &pf->sp_die,
1157 .found = 0,
1158 };
1159 struct dwarf_callback_param probe_param = {
1160 .data = pf,
1161 };
1162
1163 dwarf_getpubnames(dbg->dbg, pubname_search_cb,
1164 &pubname_param, 0);
1165 if (pubname_param.found) {
1166 ret = probe_point_search_cb(&pf->sp_die, &probe_param);
1167 if (ret)
1168 goto found;
1169 }
1170 }
1171
1172 /* Loop on CUs (Compilation Unit) */
1173 while (!dwarf_nextcu(dbg->dbg, off, &noff, &cuhl, NULL, NULL, NULL)) {
1174 /* Get the DIE(Debugging Information Entry) of this CU */
1175 diep = dwarf_offdie(dbg->dbg, off + cuhl, &pf->cu_die);
1176 if (!diep)
1177 continue;
1178
1179 /* Check if target file is included. */
1180 if (pp->file)
1181 pf->fname = cu_find_realpath(&pf->cu_die, pp->file);
1182 else
1183 pf->fname = NULL;
1184
1185 if (!pp->file || pf->fname) {
1186 if (pp->function)
1187 ret = find_probe_point_by_func(pf);
1188 else if (pp->lazy_line)
1189 ret = find_probe_point_lazy(&pf->cu_die, pf);
1190 else {
1191 pf->lno = pp->line;
1192 ret = find_probe_point_by_line(pf);
1193 }
1194 if (ret < 0)
1195 break;
1196 }
1197 off = noff;
1198 }
1199
1200 found:
1201 intlist__delete(pf->lcache);
1202 pf->lcache = NULL;
1203
1204 return ret;
1205 }
1206
1207 /* Find probe points from debuginfo */
1208 static int debuginfo__find_probes(struct debuginfo *dbg,
1209 struct probe_finder *pf)
1210 {
1211 int ret = 0;
1212 Elf *elf;
1213 GElf_Ehdr ehdr;
1214
1215 if (pf->cfi_eh || pf->cfi_dbg)
1216 return debuginfo__find_probe_location(dbg, pf);
1217
1218 /* Get the call frame information from this dwarf */
1219 elf = dwarf_getelf(dbg->dbg);
1220 if (elf == NULL)
1221 return -EINVAL;
1222
1223 if (gelf_getehdr(elf, &ehdr) == NULL)
1224 return -EINVAL;
1225
1226 pf->machine = ehdr.e_machine;
1227
1228 #if _ELFUTILS_PREREQ(0, 142)
1229 do {
1230 GElf_Shdr shdr;
1231
1232 if (elf_section_by_name(elf, &ehdr, &shdr, ".eh_frame", NULL) &&
1233 shdr.sh_type == SHT_PROGBITS)
1234 pf->cfi_eh = dwarf_getcfi_elf(elf);
1235
1236 pf->cfi_dbg = dwarf_getcfi(dbg->dbg);
1237 } while (0);
1238 #endif
1239
1240 ret = debuginfo__find_probe_location(dbg, pf);
1241 return ret;
1242 }
1243
1244 struct local_vars_finder {
1245 struct probe_finder *pf;
1246 struct perf_probe_arg *args;
1247 bool vars;
1248 int max_args;
1249 int nargs;
1250 int ret;
1251 };
1252
1253 /* Collect available variables in this scope */
1254 static int copy_variables_cb(Dwarf_Die *die_mem, void *data)
1255 {
1256 struct local_vars_finder *vf = data;
1257 struct probe_finder *pf = vf->pf;
1258 int tag;
1259
1260 tag = dwarf_tag(die_mem);
1261 if (tag == DW_TAG_formal_parameter ||
1262 (tag == DW_TAG_variable && vf->vars)) {
1263 if (convert_variable_location(die_mem, vf->pf->addr,
1264 vf->pf->fb_ops, &pf->sp_die,
1265 pf->machine, NULL) == 0) {
1266 vf->args[vf->nargs].var = (char *)dwarf_diename(die_mem);
1267 if (vf->args[vf->nargs].var == NULL) {
1268 vf->ret = -ENOMEM;
1269 return DIE_FIND_CB_END;
1270 }
1271 pr_debug(" %s", vf->args[vf->nargs].var);
1272 vf->nargs++;
1273 }
1274 }
1275
1276 if (dwarf_haspc(die_mem, vf->pf->addr))
1277 return DIE_FIND_CB_CONTINUE;
1278 else
1279 return DIE_FIND_CB_SIBLING;
1280 }
1281
1282 static int expand_probe_args(Dwarf_Die *sc_die, struct probe_finder *pf,
1283 struct perf_probe_arg *args)
1284 {
1285 Dwarf_Die die_mem;
1286 int i;
1287 int n = 0;
1288 struct local_vars_finder vf = {.pf = pf, .args = args, .vars = false,
1289 .max_args = MAX_PROBE_ARGS, .ret = 0};
1290
1291 for (i = 0; i < pf->pev->nargs; i++) {
1292 /* var never be NULL */
1293 if (strcmp(pf->pev->args[i].var, PROBE_ARG_VARS) == 0)
1294 vf.vars = true;
1295 else if (strcmp(pf->pev->args[i].var, PROBE_ARG_PARAMS) != 0) {
1296 /* Copy normal argument */
1297 args[n] = pf->pev->args[i];
1298 n++;
1299 continue;
1300 }
1301 pr_debug("Expanding %s into:", pf->pev->args[i].var);
1302 vf.nargs = n;
1303 /* Special local variables */
1304 die_find_child(sc_die, copy_variables_cb, (void *)&vf,
1305 &die_mem);
1306 pr_debug(" (%d)\n", vf.nargs - n);
1307 if (vf.ret < 0)
1308 return vf.ret;
1309 n = vf.nargs;
1310 }
1311 return n;
1312 }
1313
1314 static bool trace_event_finder_overlap(struct trace_event_finder *tf)
1315 {
1316 int i;
1317
1318 for (i = 0; i < tf->ntevs; i++) {
1319 if (tf->pf.addr == tf->tevs[i].point.address)
1320 return true;
1321 }
1322 return false;
1323 }
1324
1325 /* Add a found probe point into trace event list */
1326 static int add_probe_trace_event(Dwarf_Die *sc_die, struct probe_finder *pf)
1327 {
1328 struct trace_event_finder *tf =
1329 container_of(pf, struct trace_event_finder, pf);
1330 struct perf_probe_point *pp = &pf->pev->point;
1331 struct probe_trace_event *tev;
1332 struct perf_probe_arg *args = NULL;
1333 int ret, i;
1334
1335 /*
1336 * For some reason (e.g. different column assigned to same address)
1337 * This callback can be called with the address which already passed.
1338 * Ignore it first.
1339 */
1340 if (trace_event_finder_overlap(tf))
1341 return 0;
1342
1343 /* Check number of tevs */
1344 if (tf->ntevs == tf->max_tevs) {
1345 pr_warning("Too many( > %d) probe point found.\n",
1346 tf->max_tevs);
1347 return -ERANGE;
1348 }
1349 tev = &tf->tevs[tf->ntevs++];
1350
1351 /* Trace point should be converted from subprogram DIE */
1352 ret = convert_to_trace_point(&pf->sp_die, tf->mod, pf->addr,
1353 pp->retprobe, pp->function, &tev->point);
1354 if (ret < 0)
1355 goto end;
1356
1357 tev->point.realname = strdup(dwarf_diename(sc_die));
1358 if (!tev->point.realname) {
1359 ret = -ENOMEM;
1360 goto end;
1361 }
1362
1363 pr_debug("Probe point found: %s+%lu\n", tev->point.symbol,
1364 tev->point.offset);
1365
1366 /* Expand special probe argument if exist */
1367 args = zalloc(sizeof(struct perf_probe_arg) * MAX_PROBE_ARGS);
1368 if (args == NULL) {
1369 ret = -ENOMEM;
1370 goto end;
1371 }
1372
1373 ret = expand_probe_args(sc_die, pf, args);
1374 if (ret < 0)
1375 goto end;
1376
1377 tev->nargs = ret;
1378 tev->args = zalloc(sizeof(struct probe_trace_arg) * tev->nargs);
1379 if (tev->args == NULL) {
1380 ret = -ENOMEM;
1381 goto end;
1382 }
1383
1384 /* Find each argument */
1385 for (i = 0; i < tev->nargs; i++) {
1386 pf->pvar = &args[i];
1387 pf->tvar = &tev->args[i];
1388 /* Variable should be found from scope DIE */
1389 ret = find_variable(sc_die, pf);
1390 if (ret != 0)
1391 break;
1392 }
1393
1394 end:
1395 if (ret) {
1396 clear_probe_trace_event(tev);
1397 tf->ntevs--;
1398 }
1399 free(args);
1400 return ret;
1401 }
1402
1403 static int fill_empty_trace_arg(struct perf_probe_event *pev,
1404 struct probe_trace_event *tevs, int ntevs)
1405 {
1406 char **valp;
1407 char *type;
1408 int i, j, ret;
1409
1410 for (i = 0; i < pev->nargs; i++) {
1411 type = NULL;
1412 for (j = 0; j < ntevs; j++) {
1413 if (tevs[j].args[i].value) {
1414 type = tevs[j].args[i].type;
1415 break;
1416 }
1417 }
1418 if (j == ntevs) {
1419 print_var_not_found(pev->args[i].var);
1420 return -ENOENT;
1421 }
1422 for (j = 0; j < ntevs; j++) {
1423 valp = &tevs[j].args[i].value;
1424 if (*valp)
1425 continue;
1426
1427 ret = asprintf(valp, "\\%lx", probe_conf.magic_num);
1428 if (ret < 0)
1429 return -ENOMEM;
1430 /* Note that type can be NULL */
1431 if (type) {
1432 tevs[j].args[i].type = strdup(type);
1433 if (!tevs[j].args[i].type)
1434 return -ENOMEM;
1435 }
1436 }
1437 }
1438 return 0;
1439 }
1440
1441 /* Find probe_trace_events specified by perf_probe_event from debuginfo */
1442 int debuginfo__find_trace_events(struct debuginfo *dbg,
1443 struct perf_probe_event *pev,
1444 struct probe_trace_event **tevs)
1445 {
1446 struct trace_event_finder tf = {
1447 .pf = {.pev = pev, .callback = add_probe_trace_event},
1448 .max_tevs = probe_conf.max_probes, .mod = dbg->mod};
1449 int ret, i;
1450
1451 /* Allocate result tevs array */
1452 *tevs = zalloc(sizeof(struct probe_trace_event) * tf.max_tevs);
1453 if (*tevs == NULL)
1454 return -ENOMEM;
1455
1456 tf.tevs = *tevs;
1457 tf.ntevs = 0;
1458
1459 if (pev->nargs != 0 && immediate_value_is_supported())
1460 tf.pf.skip_empty_arg = true;
1461
1462 ret = debuginfo__find_probes(dbg, &tf.pf);
1463 if (ret >= 0 && tf.pf.skip_empty_arg)
1464 ret = fill_empty_trace_arg(pev, tf.tevs, tf.ntevs);
1465
1466 if (ret < 0) {
1467 for (i = 0; i < tf.ntevs; i++)
1468 clear_probe_trace_event(&tf.tevs[i]);
1469 zfree(tevs);
1470 return ret;
1471 }
1472
1473 return (ret < 0) ? ret : tf.ntevs;
1474 }
1475
1476 /* Collect available variables in this scope */
1477 static int collect_variables_cb(Dwarf_Die *die_mem, void *data)
1478 {
1479 struct available_var_finder *af = data;
1480 struct variable_list *vl;
1481 struct strbuf buf = STRBUF_INIT;
1482 int tag, ret;
1483
1484 vl = &af->vls[af->nvls - 1];
1485
1486 tag = dwarf_tag(die_mem);
1487 if (tag == DW_TAG_formal_parameter ||
1488 tag == DW_TAG_variable) {
1489 ret = convert_variable_location(die_mem, af->pf.addr,
1490 af->pf.fb_ops, &af->pf.sp_die,
1491 af->pf.machine, NULL);
1492 if (ret == 0 || ret == -ERANGE) {
1493 int ret2;
1494 bool externs = !af->child;
1495
1496 if (strbuf_init(&buf, 64) < 0)
1497 goto error;
1498
1499 if (probe_conf.show_location_range) {
1500 if (!externs)
1501 ret2 = strbuf_add(&buf,
1502 ret ? "[INV]\t" : "[VAL]\t", 6);
1503 else
1504 ret2 = strbuf_add(&buf, "[EXT]\t", 6);
1505 if (ret2)
1506 goto error;
1507 }
1508
1509 ret2 = die_get_varname(die_mem, &buf);
1510
1511 if (!ret2 && probe_conf.show_location_range &&
1512 !externs) {
1513 if (strbuf_addch(&buf, '\t') < 0)
1514 goto error;
1515 ret2 = die_get_var_range(&af->pf.sp_die,
1516 die_mem, &buf);
1517 }
1518
1519 pr_debug("Add new var: %s\n", buf.buf);
1520 if (ret2 == 0) {
1521 strlist__add(vl->vars,
1522 strbuf_detach(&buf, NULL));
1523 }
1524 strbuf_release(&buf);
1525 }
1526 }
1527
1528 if (af->child && dwarf_haspc(die_mem, af->pf.addr))
1529 return DIE_FIND_CB_CONTINUE;
1530 else
1531 return DIE_FIND_CB_SIBLING;
1532 error:
1533 strbuf_release(&buf);
1534 pr_debug("Error in strbuf\n");
1535 return DIE_FIND_CB_END;
1536 }
1537
1538 static bool available_var_finder_overlap(struct available_var_finder *af)
1539 {
1540 int i;
1541
1542 for (i = 0; i < af->nvls; i++) {
1543 if (af->pf.addr == af->vls[i].point.address)
1544 return true;
1545 }
1546 return false;
1547
1548 }
1549
1550 /* Add a found vars into available variables list */
1551 static int add_available_vars(Dwarf_Die *sc_die, struct probe_finder *pf)
1552 {
1553 struct available_var_finder *af =
1554 container_of(pf, struct available_var_finder, pf);
1555 struct perf_probe_point *pp = &pf->pev->point;
1556 struct variable_list *vl;
1557 Dwarf_Die die_mem;
1558 int ret;
1559
1560 /*
1561 * For some reason (e.g. different column assigned to same address),
1562 * this callback can be called with the address which already passed.
1563 * Ignore it first.
1564 */
1565 if (available_var_finder_overlap(af))
1566 return 0;
1567
1568 /* Check number of tevs */
1569 if (af->nvls == af->max_vls) {
1570 pr_warning("Too many( > %d) probe point found.\n", af->max_vls);
1571 return -ERANGE;
1572 }
1573 vl = &af->vls[af->nvls++];
1574
1575 /* Trace point should be converted from subprogram DIE */
1576 ret = convert_to_trace_point(&pf->sp_die, af->mod, pf->addr,
1577 pp->retprobe, pp->function, &vl->point);
1578 if (ret < 0)
1579 return ret;
1580
1581 pr_debug("Probe point found: %s+%lu\n", vl->point.symbol,
1582 vl->point.offset);
1583
1584 /* Find local variables */
1585 vl->vars = strlist__new(NULL, NULL);
1586 if (vl->vars == NULL)
1587 return -ENOMEM;
1588 af->child = true;
1589 die_find_child(sc_die, collect_variables_cb, (void *)af, &die_mem);
1590
1591 /* Find external variables */
1592 if (!probe_conf.show_ext_vars)
1593 goto out;
1594 /* Don't need to search child DIE for external vars. */
1595 af->child = false;
1596 die_find_child(&pf->cu_die, collect_variables_cb, (void *)af, &die_mem);
1597
1598 out:
1599 if (strlist__empty(vl->vars)) {
1600 strlist__delete(vl->vars);
1601 vl->vars = NULL;
1602 }
1603
1604 return ret;
1605 }
1606
1607 /*
1608 * Find available variables at given probe point
1609 * Return the number of found probe points. Return 0 if there is no
1610 * matched probe point. Return <0 if an error occurs.
1611 */
1612 int debuginfo__find_available_vars_at(struct debuginfo *dbg,
1613 struct perf_probe_event *pev,
1614 struct variable_list **vls)
1615 {
1616 struct available_var_finder af = {
1617 .pf = {.pev = pev, .callback = add_available_vars},
1618 .mod = dbg->mod,
1619 .max_vls = probe_conf.max_probes};
1620 int ret;
1621
1622 /* Allocate result vls array */
1623 *vls = zalloc(sizeof(struct variable_list) * af.max_vls);
1624 if (*vls == NULL)
1625 return -ENOMEM;
1626
1627 af.vls = *vls;
1628 af.nvls = 0;
1629
1630 ret = debuginfo__find_probes(dbg, &af.pf);
1631 if (ret < 0) {
1632 /* Free vlist for error */
1633 while (af.nvls--) {
1634 zfree(&af.vls[af.nvls].point.symbol);
1635 strlist__delete(af.vls[af.nvls].vars);
1636 }
1637 zfree(vls);
1638 return ret;
1639 }
1640
1641 return (ret < 0) ? ret : af.nvls;
1642 }
1643
1644 /* For the kernel module, we need a special code to get a DIE */
1645 int debuginfo__get_text_offset(struct debuginfo *dbg, Dwarf_Addr *offs,
1646 bool adjust_offset)
1647 {
1648 int n, i;
1649 Elf32_Word shndx;
1650 Elf_Scn *scn;
1651 Elf *elf;
1652 GElf_Shdr mem, *shdr;
1653 const char *p;
1654
1655 elf = dwfl_module_getelf(dbg->mod, &dbg->bias);
1656 if (!elf)
1657 return -EINVAL;
1658
1659 /* Get the number of relocations */
1660 n = dwfl_module_relocations(dbg->mod);
1661 if (n < 0)
1662 return -ENOENT;
1663 /* Search the relocation related .text section */
1664 for (i = 0; i < n; i++) {
1665 p = dwfl_module_relocation_info(dbg->mod, i, &shndx);
1666 if (strcmp(p, ".text") == 0) {
1667 /* OK, get the section header */
1668 scn = elf_getscn(elf, shndx);
1669 if (!scn)
1670 return -ENOENT;
1671 shdr = gelf_getshdr(scn, &mem);
1672 if (!shdr)
1673 return -ENOENT;
1674 *offs = shdr->sh_addr;
1675 if (adjust_offset)
1676 *offs -= shdr->sh_offset;
1677 }
1678 }
1679 return 0;
1680 }
1681
1682 /* Reverse search */
1683 int debuginfo__find_probe_point(struct debuginfo *dbg, unsigned long addr,
1684 struct perf_probe_point *ppt)
1685 {
1686 Dwarf_Die cudie, spdie, indie;
1687 Dwarf_Addr _addr = 0, baseaddr = 0;
1688 const char *fname = NULL, *func = NULL, *basefunc = NULL, *tmp;
1689 int baseline = 0, lineno = 0, ret = 0;
1690
1691 /* We always need to relocate the address for aranges */
1692 if (debuginfo__get_text_offset(dbg, &baseaddr, false) == 0)
1693 addr += baseaddr;
1694 /* Find cu die */
1695 if (!dwarf_addrdie(dbg->dbg, (Dwarf_Addr)addr, &cudie)) {
1696 pr_warning("Failed to find debug information for address %lx\n",
1697 addr);
1698 ret = -EINVAL;
1699 goto end;
1700 }
1701
1702 /* Find a corresponding line (filename and lineno) */
1703 cu_find_lineinfo(&cudie, addr, &fname, &lineno);
1704 /* Don't care whether it failed or not */
1705
1706 /* Find a corresponding function (name, baseline and baseaddr) */
1707 if (die_find_realfunc(&cudie, (Dwarf_Addr)addr, &spdie)) {
1708 /* Get function entry information */
1709 func = basefunc = dwarf_diename(&spdie);
1710 if (!func ||
1711 die_entrypc(&spdie, &baseaddr) != 0 ||
1712 dwarf_decl_line(&spdie, &baseline) != 0) {
1713 lineno = 0;
1714 goto post;
1715 }
1716
1717 fname = dwarf_decl_file(&spdie);
1718 if (addr == (unsigned long)baseaddr) {
1719 /* Function entry - Relative line number is 0 */
1720 lineno = baseline;
1721 goto post;
1722 }
1723
1724 /* Track down the inline functions step by step */
1725 while (die_find_top_inlinefunc(&spdie, (Dwarf_Addr)addr,
1726 &indie)) {
1727 /* There is an inline function */
1728 if (die_entrypc(&indie, &_addr) == 0 &&
1729 _addr == addr) {
1730 /*
1731 * addr is at an inline function entry.
1732 * In this case, lineno should be the call-site
1733 * line number. (overwrite lineinfo)
1734 */
1735 lineno = die_get_call_lineno(&indie);
1736 fname = die_get_call_file(&indie);
1737 break;
1738 } else {
1739 /*
1740 * addr is in an inline function body.
1741 * Since lineno points one of the lines
1742 * of the inline function, baseline should
1743 * be the entry line of the inline function.
1744 */
1745 tmp = dwarf_diename(&indie);
1746 if (!tmp ||
1747 dwarf_decl_line(&indie, &baseline) != 0)
1748 break;
1749 func = tmp;
1750 spdie = indie;
1751 }
1752 }
1753 /* Verify the lineno and baseline are in a same file */
1754 tmp = dwarf_decl_file(&spdie);
1755 if (!tmp || strcmp(tmp, fname) != 0)
1756 lineno = 0;
1757 }
1758
1759 post:
1760 /* Make a relative line number or an offset */
1761 if (lineno)
1762 ppt->line = lineno - baseline;
1763 else if (basefunc) {
1764 ppt->offset = addr - (unsigned long)baseaddr;
1765 func = basefunc;
1766 }
1767
1768 /* Duplicate strings */
1769 if (func) {
1770 ppt->function = strdup(func);
1771 if (ppt->function == NULL) {
1772 ret = -ENOMEM;
1773 goto end;
1774 }
1775 }
1776 if (fname) {
1777 ppt->file = strdup(fname);
1778 if (ppt->file == NULL) {
1779 zfree(&ppt->function);
1780 ret = -ENOMEM;
1781 goto end;
1782 }
1783 }
1784 end:
1785 if (ret == 0 && (fname || func))
1786 ret = 1; /* Found a point */
1787 return ret;
1788 }
1789
1790 /* Add a line and store the src path */
1791 static int line_range_add_line(const char *src, unsigned int lineno,
1792 struct line_range *lr)
1793 {
1794 /* Copy source path */
1795 if (!lr->path) {
1796 lr->path = strdup(src);
1797 if (lr->path == NULL)
1798 return -ENOMEM;
1799 }
1800 return intlist__add(lr->line_list, lineno);
1801 }
1802
1803 static int line_range_walk_cb(const char *fname, int lineno,
1804 Dwarf_Addr addr __maybe_unused,
1805 void *data)
1806 {
1807 struct line_finder *lf = data;
1808 const char *__fname;
1809 int __lineno;
1810 int err;
1811
1812 if ((strtailcmp(fname, lf->fname) != 0) ||
1813 (lf->lno_s > lineno || lf->lno_e < lineno))
1814 return 0;
1815
1816 /* Make sure this line can be reversable */
1817 if (cu_find_lineinfo(&lf->cu_die, addr, &__fname, &__lineno) > 0
1818 && (lineno != __lineno || strcmp(fname, __fname)))
1819 return 0;
1820
1821 err = line_range_add_line(fname, lineno, lf->lr);
1822 if (err < 0 && err != -EEXIST)
1823 return err;
1824
1825 return 0;
1826 }
1827
1828 /* Find line range from its line number */
1829 static int find_line_range_by_line(Dwarf_Die *sp_die, struct line_finder *lf)
1830 {
1831 int ret;
1832
1833 ret = die_walk_lines(sp_die ?: &lf->cu_die, line_range_walk_cb, lf);
1834
1835 /* Update status */
1836 if (ret >= 0)
1837 if (!intlist__empty(lf->lr->line_list))
1838 ret = lf->found = 1;
1839 else
1840 ret = 0; /* Lines are not found */
1841 else {
1842 zfree(&lf->lr->path);
1843 }
1844 return ret;
1845 }
1846
1847 static int line_range_inline_cb(Dwarf_Die *in_die, void *data)
1848 {
1849 int ret = find_line_range_by_line(in_die, data);
1850
1851 /*
1852 * We have to check all instances of inlined function, because
1853 * some execution paths can be optimized out depends on the
1854 * function argument of instances. However, if an error occurs,
1855 * it should be handled by the caller.
1856 */
1857 return ret < 0 ? ret : 0;
1858 }
1859
1860 /* Search function definition from function name */
1861 static int line_range_search_cb(Dwarf_Die *sp_die, void *data)
1862 {
1863 struct dwarf_callback_param *param = data;
1864 struct line_finder *lf = param->data;
1865 struct line_range *lr = lf->lr;
1866
1867 /* Check declared file */
1868 if (lr->file && strtailcmp(lr->file, dwarf_decl_file(sp_die)))
1869 return DWARF_CB_OK;
1870
1871 if (die_is_func_def(sp_die) &&
1872 die_match_name(sp_die, lr->function)) {
1873 lf->fname = dwarf_decl_file(sp_die);
1874 dwarf_decl_line(sp_die, &lr->offset);
1875 pr_debug("fname: %s, lineno:%d\n", lf->fname, lr->offset);
1876 lf->lno_s = lr->offset + lr->start;
1877 if (lf->lno_s < 0) /* Overflow */
1878 lf->lno_s = INT_MAX;
1879 lf->lno_e = lr->offset + lr->end;
1880 if (lf->lno_e < 0) /* Overflow */
1881 lf->lno_e = INT_MAX;
1882 pr_debug("New line range: %d to %d\n", lf->lno_s, lf->lno_e);
1883 lr->start = lf->lno_s;
1884 lr->end = lf->lno_e;
1885 if (!die_is_func_instance(sp_die))
1886 param->retval = die_walk_instances(sp_die,
1887 line_range_inline_cb, lf);
1888 else
1889 param->retval = find_line_range_by_line(sp_die, lf);
1890 return DWARF_CB_ABORT;
1891 }
1892 return DWARF_CB_OK;
1893 }
1894
1895 static int find_line_range_by_func(struct line_finder *lf)
1896 {
1897 struct dwarf_callback_param param = {.data = (void *)lf, .retval = 0};
1898 dwarf_getfuncs(&lf->cu_die, line_range_search_cb, &param, 0);
1899 return param.retval;
1900 }
1901
1902 int debuginfo__find_line_range(struct debuginfo *dbg, struct line_range *lr)
1903 {
1904 struct line_finder lf = {.lr = lr, .found = 0};
1905 int ret = 0;
1906 Dwarf_Off off = 0, noff;
1907 size_t cuhl;
1908 Dwarf_Die *diep;
1909 const char *comp_dir;
1910
1911 /* Fastpath: lookup by function name from .debug_pubnames section */
1912 if (lr->function) {
1913 struct pubname_callback_param pubname_param = {
1914 .function = lr->function, .file = lr->file,
1915 .cu_die = &lf.cu_die, .sp_die = &lf.sp_die, .found = 0};
1916 struct dwarf_callback_param line_range_param = {
1917 .data = (void *)&lf, .retval = 0};
1918
1919 dwarf_getpubnames(dbg->dbg, pubname_search_cb,
1920 &pubname_param, 0);
1921 if (pubname_param.found) {
1922 line_range_search_cb(&lf.sp_die, &line_range_param);
1923 if (lf.found)
1924 goto found;
1925 }
1926 }
1927
1928 /* Loop on CUs (Compilation Unit) */
1929 while (!lf.found && ret >= 0) {
1930 if (dwarf_nextcu(dbg->dbg, off, &noff, &cuhl,
1931 NULL, NULL, NULL) != 0)
1932 break;
1933
1934 /* Get the DIE(Debugging Information Entry) of this CU */
1935 diep = dwarf_offdie(dbg->dbg, off + cuhl, &lf.cu_die);
1936 if (!diep)
1937 continue;
1938
1939 /* Check if target file is included. */
1940 if (lr->file)
1941 lf.fname = cu_find_realpath(&lf.cu_die, lr->file);
1942 else
1943 lf.fname = 0;
1944
1945 if (!lr->file || lf.fname) {
1946 if (lr->function)
1947 ret = find_line_range_by_func(&lf);
1948 else {
1949 lf.lno_s = lr->start;
1950 lf.lno_e = lr->end;
1951 ret = find_line_range_by_line(NULL, &lf);
1952 }
1953 }
1954 off = noff;
1955 }
1956
1957 found:
1958 /* Store comp_dir */
1959 if (lf.found) {
1960 comp_dir = cu_get_comp_dir(&lf.cu_die);
1961 if (comp_dir) {
1962 lr->comp_dir = strdup(comp_dir);
1963 if (!lr->comp_dir)
1964 ret = -ENOMEM;
1965 }
1966 }
1967
1968 pr_debug("path: %s\n", lr->path);
1969 return (ret < 0) ? ret : lf.found;
1970 }
1971
1972 /*
1973 * Find a src file from a DWARF tag path. Prepend optional source path prefix
1974 * and chop off leading directories that do not exist. Result is passed back as
1975 * a newly allocated path on success.
1976 * Return 0 if file was found and readable, -errno otherwise.
1977 */
1978 int get_real_path(const char *raw_path, const char *comp_dir,
1979 char **new_path)
1980 {
1981 const char *prefix = symbol_conf.source_prefix;
1982
1983 if (!prefix) {
1984 if (raw_path[0] != '/' && comp_dir)
1985 /* If not an absolute path, try to use comp_dir */
1986 prefix = comp_dir;
1987 else {
1988 if (access(raw_path, R_OK) == 0) {
1989 *new_path = strdup(raw_path);
1990 return *new_path ? 0 : -ENOMEM;
1991 } else
1992 return -errno;
1993 }
1994 }
1995
1996 *new_path = malloc((strlen(prefix) + strlen(raw_path) + 2));
1997 if (!*new_path)
1998 return -ENOMEM;
1999
2000 for (;;) {
2001 sprintf(*new_path, "%s/%s", prefix, raw_path);
2002
2003 if (access(*new_path, R_OK) == 0)
2004 return 0;
2005
2006 if (!symbol_conf.source_prefix) {
2007 /* In case of searching comp_dir, don't retry */
2008 zfree(new_path);
2009 return -errno;
2010 }
2011
2012 switch (errno) {
2013 case ENAMETOOLONG:
2014 case ENOENT:
2015 case EROFS:
2016 case EFAULT:
2017 raw_path = strchr(++raw_path, '/');
2018 if (!raw_path) {
2019 zfree(new_path);
2020 return -ENOENT;
2021 }
2022 continue;
2023
2024 default:
2025 zfree(new_path);
2026 return -errno;
2027 }
2028 }
2029 }
Linux with added FPC-III support