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perf probe: Add basic module support
[linux-2.6.git] / tools / perf / util / probe-finder.c
blobc20bd52833aae6efc30dde0c87b04111230e5d0a
1 /*
2 * probe-finder.c : C expression to kprobe event converter
3 *
4 * Written by Masami Hiramatsu <mhiramat@redhat.com>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
19 *
20 */
21
22 #include <sys/utsname.h>
23 #include <sys/types.h>
24 #include <sys/stat.h>
25 #include <fcntl.h>
26 #include <errno.h>
27 #include <stdio.h>
28 #include <unistd.h>
29 #include <getopt.h>
30 #include <stdlib.h>
31 #include <string.h>
32 #include <stdarg.h>
33 #include <ctype.h>
34 #include <dwarf-regs.h>
35
36 #include "event.h"
37 #include "debug.h"
38 #include "util.h"
39 #include "symbol.h"
40 #include "probe-finder.h"
41
42 /* Kprobe tracer basic type is up to u64 */
43 #define MAX_BASIC_TYPE_BITS 64
44
45 /*
46 * Compare the tail of two strings.
47 * Return 0 if whole of either string is same as another's tail part.
48 */
49 static int strtailcmp(const char *s1, const char *s2)
50 {
51 int i1 = strlen(s1);
52 int i2 = strlen(s2);
53 while (--i1 >= 0 && --i2 >= 0) {
54 if (s1[i1] != s2[i2])
55 return s1[i1] - s2[i2];
56 }
57 return 0;
58 }
59
60 /* Line number list operations */
61
62 /* Add a line to line number list */
63 static int line_list__add_line(struct list_head *head, int line)
64 {
65 struct line_node *ln;
66 struct list_head *p;
67
68 /* Reverse search, because new line will be the last one */
69 list_for_each_entry_reverse(ln, head, list) {
70 if (ln->line < line) {
71 p = &ln->list;
72 goto found;
73 } else if (ln->line == line) /* Already exist */
74 return 1;
75 }
76 /* List is empty, or the smallest entry */
77 p = head;
78 found:
79 pr_debug("line list: add a line %u\n", line);
80 ln = zalloc(sizeof(struct line_node));
81 if (ln == NULL)
82 return -ENOMEM;
83 ln->line = line;
84 INIT_LIST_HEAD(&ln->list);
85 list_add(&ln->list, p);
86 return 0;
87 }
88
89 /* Check if the line in line number list */
90 static int line_list__has_line(struct list_head *head, int line)
91 {
92 struct line_node *ln;
93
94 /* Reverse search, because new line will be the last one */
95 list_for_each_entry(ln, head, list)
96 if (ln->line == line)
97 return 1;
98
99 return 0;
100 }
101
102 /* Init line number list */
103 static void line_list__init(struct list_head *head)
104 {
105 INIT_LIST_HEAD(head);
106 }
107
108 /* Free line number list */
109 static void line_list__free(struct list_head *head)
110 {
111 struct line_node *ln;
112 while (!list_empty(head)) {
113 ln = list_first_entry(head, struct line_node, list);
114 list_del(&ln->list);
115 free(ln);
116 }
117 }
118
119 /* Dwarf FL wrappers */
120
121 static int __linux_kernel_find_elf(Dwfl_Module *mod,
122 void **userdata,
123 const char *module_name,
124 Dwarf_Addr base,
125 char **file_name, Elf **elfp)
126 {
127 int fd;
128 const char *path = kernel_get_module_path(module_name);
129
130 if (path) {
131 fd = open(path, O_RDONLY);
132 if (fd >= 0) {
133 *file_name = strdup(path);
134 return fd;
135 }
136 }
137 /* If failed, try to call standard method */
138 return dwfl_linux_kernel_find_elf(mod, userdata, module_name, base,
139 file_name, elfp);
140 }
141
142 static char *debuginfo_path; /* Currently dummy */
143
144 static const Dwfl_Callbacks offline_callbacks = {
145 .find_debuginfo = dwfl_standard_find_debuginfo,
146 .debuginfo_path = &debuginfo_path,
147
148 .section_address = dwfl_offline_section_address,
149
150 /* We use this table for core files too. */
151 .find_elf = dwfl_build_id_find_elf,
152 };
153
154 static const Dwfl_Callbacks kernel_callbacks = {
155 .find_debuginfo = dwfl_standard_find_debuginfo,
156 .debuginfo_path = &debuginfo_path,
157
158 .find_elf = __linux_kernel_find_elf,
159 .section_address = dwfl_linux_kernel_module_section_address,
160 };
161
162 /* Get a Dwarf from offline image */
163 static Dwarf *dwfl_init_offline_dwarf(int fd, Dwfl **dwflp, Dwarf_Addr *bias)
164 {
165 Dwfl_Module *mod;
166 Dwarf *dbg = NULL;
167
168 if (!dwflp)
169 return NULL;
170
171 *dwflp = dwfl_begin(&offline_callbacks);
172 if (!*dwflp)
173 return NULL;
174
175 mod = dwfl_report_offline(*dwflp, "", "", fd);
176 if (!mod)
177 goto error;
178
179 dbg = dwfl_module_getdwarf(mod, bias);
180 if (!dbg) {
181 error:
182 dwfl_end(*dwflp);
183 *dwflp = NULL;
184 }
185 return dbg;
186 }
187
188 /* Get a Dwarf from live kernel image */
189 static Dwarf *dwfl_init_live_kernel_dwarf(Dwarf_Addr addr, Dwfl **dwflp,
190 Dwarf_Addr *bias)
191 {
192 Dwarf *dbg;
193
194 if (!dwflp)
195 return NULL;
196
197 *dwflp = dwfl_begin(&kernel_callbacks);
198 if (!*dwflp)
199 return NULL;
200
201 /* Load the kernel dwarves: Don't care the result here */
202 dwfl_linux_kernel_report_kernel(*dwflp);
203 dwfl_linux_kernel_report_modules(*dwflp);
204
205 dbg = dwfl_addrdwarf(*dwflp, addr, bias);
206 /* Here, check whether we could get a real dwarf */
207 if (!dbg) {
208 dwfl_end(*dwflp);
209 *dwflp = NULL;
210 }
211 return dbg;
212 }
213
214 /* Dwarf wrappers */
215
216 /* Find the realpath of the target file. */
217 static const char *cu_find_realpath(Dwarf_Die *cu_die, const char *fname)
218 {
219 Dwarf_Files *files;
220 size_t nfiles, i;
221 const char *src = NULL;
222 int ret;
223
224 if (!fname)
225 return NULL;
226
227 ret = dwarf_getsrcfiles(cu_die, &files, &nfiles);
228 if (ret != 0)
229 return NULL;
230
231 for (i = 0; i < nfiles; i++) {
232 src = dwarf_filesrc(files, i, NULL, NULL);
233 if (strtailcmp(src, fname) == 0)
234 break;
235 }
236 if (i == nfiles)
237 return NULL;
238 return src;
239 }
240
241 /* Get DW_AT_comp_dir (should be NULL with older gcc) */
242 static const char *cu_get_comp_dir(Dwarf_Die *cu_die)
243 {
244 Dwarf_Attribute attr;
245 if (dwarf_attr(cu_die, DW_AT_comp_dir, &attr) == NULL)
246 return NULL;
247 return dwarf_formstring(&attr);
248 }
249
250 /* Compare diename and tname */
251 static bool die_compare_name(Dwarf_Die *dw_die, const char *tname)
252 {
253 const char *name;
254 name = dwarf_diename(dw_die);
255 return name ? (strcmp(tname, name) == 0) : false;
256 }
257
258 /* Get type die */
259 static Dwarf_Die *die_get_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem)
260 {
261 Dwarf_Attribute attr;
262
263 if (dwarf_attr_integrate(vr_die, DW_AT_type, &attr) &&
264 dwarf_formref_die(&attr, die_mem))
265 return die_mem;
266 else
267 return NULL;
268 }
269
270 /* Get a type die, but skip qualifiers */
271 static Dwarf_Die *__die_get_real_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem)
272 {
273 int tag;
274
275 do {
276 vr_die = die_get_type(vr_die, die_mem);
277 if (!vr_die)
278 break;
279 tag = dwarf_tag(vr_die);
280 } while (tag == DW_TAG_const_type ||
281 tag == DW_TAG_restrict_type ||
282 tag == DW_TAG_volatile_type ||
283 tag == DW_TAG_shared_type);
284
285 return vr_die;
286 }
287
288 /* Get a type die, but skip qualifiers and typedef */
289 static Dwarf_Die *die_get_real_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem)
290 {
291 do {
292 vr_die = __die_get_real_type(vr_die, die_mem);
293 } while (vr_die && dwarf_tag(vr_die) == DW_TAG_typedef);
294
295 return vr_die;
296 }
297
298 static bool die_is_signed_type(Dwarf_Die *tp_die)
299 {
300 Dwarf_Attribute attr;
301 Dwarf_Word ret;
302
303 if (dwarf_attr(tp_die, DW_AT_encoding, &attr) == NULL ||
304 dwarf_formudata(&attr, &ret) != 0)
305 return false;
306
307 return (ret == DW_ATE_signed_char || ret == DW_ATE_signed ||
308 ret == DW_ATE_signed_fixed);
309 }
310
311 static int die_get_byte_size(Dwarf_Die *tp_die)
312 {
313 Dwarf_Attribute attr;
314 Dwarf_Word ret;
315
316 if (dwarf_attr(tp_die, DW_AT_byte_size, &attr) == NULL ||
317 dwarf_formudata(&attr, &ret) != 0)
318 return 0;
319
320 return (int)ret;
321 }
322
323 /* Get data_member_location offset */
324 static int die_get_data_member_location(Dwarf_Die *mb_die, Dwarf_Word *offs)
325 {
326 Dwarf_Attribute attr;
327 Dwarf_Op *expr;
328 size_t nexpr;
329 int ret;
330
331 if (dwarf_attr(mb_die, DW_AT_data_member_location, &attr) == NULL)
332 return -ENOENT;
333
334 if (dwarf_formudata(&attr, offs) != 0) {
335 /* DW_AT_data_member_location should be DW_OP_plus_uconst */
336 ret = dwarf_getlocation(&attr, &expr, &nexpr);
337 if (ret < 0 || nexpr == 0)
338 return -ENOENT;
339
340 if (expr[0].atom != DW_OP_plus_uconst || nexpr != 1) {
341 pr_debug("Unable to get offset:Unexpected OP %x (%zd)\n",
342 expr[0].atom, nexpr);
343 return -ENOTSUP;
344 }
345 *offs = (Dwarf_Word)expr[0].number;
346 }
347 return 0;
348 }
349
350 /* Return values for die_find callbacks */
351 enum {
352 DIE_FIND_CB_FOUND = 0, /* End of Search */
353 DIE_FIND_CB_CHILD = 1, /* Search only children */
354 DIE_FIND_CB_SIBLING = 2, /* Search only siblings */
355 DIE_FIND_CB_CONTINUE = 3, /* Search children and siblings */
356 };
357
358 /* Search a child die */
359 static Dwarf_Die *die_find_child(Dwarf_Die *rt_die,
360 int (*callback)(Dwarf_Die *, void *),
361 void *data, Dwarf_Die *die_mem)
362 {
363 Dwarf_Die child_die;
364 int ret;
365
366 ret = dwarf_child(rt_die, die_mem);
367 if (ret != 0)
368 return NULL;
369
370 do {
371 ret = callback(die_mem, data);
372 if (ret == DIE_FIND_CB_FOUND)
373 return die_mem;
374
375 if ((ret & DIE_FIND_CB_CHILD) &&
376 die_find_child(die_mem, callback, data, &child_die)) {
377 memcpy(die_mem, &child_die, sizeof(Dwarf_Die));
378 return die_mem;
379 }
380 } while ((ret & DIE_FIND_CB_SIBLING) &&
381 dwarf_siblingof(die_mem, die_mem) == 0);
382
383 return NULL;
384 }
385
386 struct __addr_die_search_param {
387 Dwarf_Addr addr;
388 Dwarf_Die *die_mem;
389 };
390
391 static int __die_search_func_cb(Dwarf_Die *fn_die, void *data)
392 {
393 struct __addr_die_search_param *ad = data;
394
395 if (dwarf_tag(fn_die) == DW_TAG_subprogram &&
396 dwarf_haspc(fn_die, ad->addr)) {
397 memcpy(ad->die_mem, fn_die, sizeof(Dwarf_Die));
398 return DWARF_CB_ABORT;
399 }
400 return DWARF_CB_OK;
401 }
402
403 /* Search a real subprogram including this line, */
404 static Dwarf_Die *die_find_real_subprogram(Dwarf_Die *cu_die, Dwarf_Addr addr,
405 Dwarf_Die *die_mem)
406 {
407 struct __addr_die_search_param ad;
408 ad.addr = addr;
409 ad.die_mem = die_mem;
410 /* dwarf_getscopes can't find subprogram. */
411 if (!dwarf_getfuncs(cu_die, __die_search_func_cb, &ad, 0))
412 return NULL;
413 else
414 return die_mem;
415 }
416
417 /* die_find callback for inline function search */
418 static int __die_find_inline_cb(Dwarf_Die *die_mem, void *data)
419 {
420 Dwarf_Addr *addr = data;
421
422 if (dwarf_tag(die_mem) == DW_TAG_inlined_subroutine &&
423 dwarf_haspc(die_mem, *addr))
424 return DIE_FIND_CB_FOUND;
425
426 return DIE_FIND_CB_CONTINUE;
427 }
428
429 /* Similar to dwarf_getfuncs, but returns inlined_subroutine if exists. */
430 static Dwarf_Die *die_find_inlinefunc(Dwarf_Die *sp_die, Dwarf_Addr addr,
431 Dwarf_Die *die_mem)
432 {
433 return die_find_child(sp_die, __die_find_inline_cb, &addr, die_mem);
434 }
435
436 struct __find_variable_param {
437 const char *name;
438 Dwarf_Addr addr;
439 };
440
441 static int __die_find_variable_cb(Dwarf_Die *die_mem, void *data)
442 {
443 struct __find_variable_param *fvp = data;
444 int tag;
445
446 tag = dwarf_tag(die_mem);
447 if ((tag == DW_TAG_formal_parameter ||
448 tag == DW_TAG_variable) &&
449 die_compare_name(die_mem, fvp->name))
450 return DIE_FIND_CB_FOUND;
451
452 if (dwarf_haspc(die_mem, fvp->addr))
453 return DIE_FIND_CB_CONTINUE;
454 else
455 return DIE_FIND_CB_SIBLING;
456 }
457
458 /* Find a variable called 'name' at given address */
459 static Dwarf_Die *die_find_variable_at(Dwarf_Die *sp_die, const char *name,
460 Dwarf_Addr addr, Dwarf_Die *die_mem)
461 {
462 struct __find_variable_param fvp = { .name = name, .addr = addr};
463
464 return die_find_child(sp_die, __die_find_variable_cb, (void *)&fvp,
465 die_mem);
466 }
467
468 static int __die_find_member_cb(Dwarf_Die *die_mem, void *data)
469 {
470 const char *name = data;
471
472 if ((dwarf_tag(die_mem) == DW_TAG_member) &&
473 die_compare_name(die_mem, name))
474 return DIE_FIND_CB_FOUND;
475
476 return DIE_FIND_CB_SIBLING;
477 }
478
479 /* Find a member called 'name' */
480 static Dwarf_Die *die_find_member(Dwarf_Die *st_die, const char *name,
481 Dwarf_Die *die_mem)
482 {
483 return die_find_child(st_die, __die_find_member_cb, (void *)name,
484 die_mem);
485 }
486
487 /* Get the name of given variable DIE */
488 static int die_get_typename(Dwarf_Die *vr_die, char *buf, int len)
489 {
490 Dwarf_Die type;
491 int tag, ret, ret2;
492 const char *tmp = "";
493
494 if (__die_get_real_type(vr_die, &type) == NULL)
495 return -ENOENT;
496
497 tag = dwarf_tag(&type);
498 if (tag == DW_TAG_array_type || tag == DW_TAG_pointer_type)
499 tmp = "*";
500 else if (tag == DW_TAG_subroutine_type) {
501 /* Function pointer */
502 ret = snprintf(buf, len, "(function_type)");
503 return (ret >= len) ? -E2BIG : ret;
504 } else {
505 if (!dwarf_diename(&type))
506 return -ENOENT;
507 if (tag == DW_TAG_union_type)
508 tmp = "union ";
509 else if (tag == DW_TAG_structure_type)
510 tmp = "struct ";
511 /* Write a base name */
512 ret = snprintf(buf, len, "%s%s", tmp, dwarf_diename(&type));
513 return (ret >= len) ? -E2BIG : ret;
514 }
515 ret = die_get_typename(&type, buf, len);
516 if (ret > 0) {
517 ret2 = snprintf(buf + ret, len - ret, "%s", tmp);
518 ret = (ret2 >= len - ret) ? -E2BIG : ret2 + ret;
519 }
520 return ret;
521 }
522
523 /* Get the name and type of given variable DIE, stored as "type\tname" */
524 static int die_get_varname(Dwarf_Die *vr_die, char *buf, int len)
525 {
526 int ret, ret2;
527
528 ret = die_get_typename(vr_die, buf, len);
529 if (ret < 0) {
530 pr_debug("Failed to get type, make it unknown.\n");
531 ret = snprintf(buf, len, "(unknown_type)");
532 }
533 if (ret > 0) {
534 ret2 = snprintf(buf + ret, len - ret, "\t%s",
535 dwarf_diename(vr_die));
536 ret = (ret2 >= len - ret) ? -E2BIG : ret2 + ret;
537 }
538 return ret;
539 }
540
541 /*
542 * Probe finder related functions
543 */
544
545 static struct probe_trace_arg_ref *alloc_trace_arg_ref(long offs)
546 {
547 struct probe_trace_arg_ref *ref;
548 ref = zalloc(sizeof(struct probe_trace_arg_ref));
549 if (ref != NULL)
550 ref->offset = offs;
551 return ref;
552 }
553
554 /*
555 * Convert a location into trace_arg.
556 * If tvar == NULL, this just checks variable can be converted.
557 */
558 static int convert_variable_location(Dwarf_Die *vr_die, Dwarf_Addr addr,
559 Dwarf_Op *fb_ops,
560 struct probe_trace_arg *tvar)
561 {
562 Dwarf_Attribute attr;
563 Dwarf_Op *op;
564 size_t nops;
565 unsigned int regn;
566 Dwarf_Word offs = 0;
567 bool ref = false;
568 const char *regs;
569 int ret;
570
571 if (dwarf_attr(vr_die, DW_AT_external, &attr) != NULL)
572 goto static_var;
573
574 /* TODO: handle more than 1 exprs */
575 if (dwarf_attr(vr_die, DW_AT_location, &attr) == NULL ||
576 dwarf_getlocation_addr(&attr, addr, &op, &nops, 1) <= 0 ||
577 nops == 0) {
578 /* TODO: Support const_value */
579 return -ENOENT;
580 }
581
582 if (op->atom == DW_OP_addr) {
583 static_var:
584 if (!tvar)
585 return 0;
586 /* Static variables on memory (not stack), make @varname */
587 ret = strlen(dwarf_diename(vr_die));
588 tvar->value = zalloc(ret + 2);
589 if (tvar->value == NULL)
590 return -ENOMEM;
591 snprintf(tvar->value, ret + 2, "@%s", dwarf_diename(vr_die));
592 tvar->ref = alloc_trace_arg_ref((long)offs);
593 if (tvar->ref == NULL)
594 return -ENOMEM;
595 return 0;
596 }
597
598 /* If this is based on frame buffer, set the offset */
599 if (op->atom == DW_OP_fbreg) {
600 if (fb_ops == NULL)
601 return -ENOTSUP;
602 ref = true;
603 offs = op->number;
604 op = &fb_ops[0];
605 }
606
607 if (op->atom >= DW_OP_breg0 && op->atom <= DW_OP_breg31) {
608 regn = op->atom - DW_OP_breg0;
609 offs += op->number;
610 ref = true;
611 } else if (op->atom >= DW_OP_reg0 && op->atom <= DW_OP_reg31) {
612 regn = op->atom - DW_OP_reg0;
613 } else if (op->atom == DW_OP_bregx) {
614 regn = op->number;
615 offs += op->number2;
616 ref = true;
617 } else if (op->atom == DW_OP_regx) {
618 regn = op->number;
619 } else {
620 pr_debug("DW_OP %x is not supported.\n", op->atom);
621 return -ENOTSUP;
622 }
623
624 if (!tvar)
625 return 0;
626
627 regs = get_arch_regstr(regn);
628 if (!regs) {
629 /* This should be a bug in DWARF or this tool */
630 pr_warning("Mapping for DWARF register number %u "
631 "missing on this architecture.", regn);
632 return -ERANGE;
633 }
634
635 tvar->value = strdup(regs);
636 if (tvar->value == NULL)
637 return -ENOMEM;
638
639 if (ref) {
640 tvar->ref = alloc_trace_arg_ref((long)offs);
641 if (tvar->ref == NULL)
642 return -ENOMEM;
643 }
644 return 0;
645 }
646
647 static int convert_variable_type(Dwarf_Die *vr_die,
648 struct probe_trace_arg *tvar,
649 const char *cast)
650 {
651 struct probe_trace_arg_ref **ref_ptr = &tvar->ref;
652 Dwarf_Die type;
653 char buf[16];
654 int ret;
655
656 /* TODO: check all types */
657 if (cast && strcmp(cast, "string") != 0) {
658 /* Non string type is OK */
659 tvar->type = strdup(cast);
660 return (tvar->type == NULL) ? -ENOMEM : 0;
661 }
662
663 if (die_get_real_type(vr_die, &type) == NULL) {
664 pr_warning("Failed to get a type information of %s.\n",
665 dwarf_diename(vr_die));
666 return -ENOENT;
667 }
668
669 pr_debug("%s type is %s.\n",
670 dwarf_diename(vr_die), dwarf_diename(&type));
671
672 if (cast && strcmp(cast, "string") == 0) { /* String type */
673 ret = dwarf_tag(&type);
674 if (ret != DW_TAG_pointer_type &&
675 ret != DW_TAG_array_type) {
676 pr_warning("Failed to cast into string: "
677 "%s(%s) is not a pointer nor array.",
678 dwarf_diename(vr_die), dwarf_diename(&type));
679 return -EINVAL;
680 }
681 if (ret == DW_TAG_pointer_type) {
682 if (die_get_real_type(&type, &type) == NULL) {
683 pr_warning("Failed to get a type information.");
684 return -ENOENT;
685 }
686 while (*ref_ptr)
687 ref_ptr = &(*ref_ptr)->next;
688 /* Add new reference with offset +0 */
689 *ref_ptr = zalloc(sizeof(struct probe_trace_arg_ref));
690 if (*ref_ptr == NULL) {
691 pr_warning("Out of memory error\n");
692 return -ENOMEM;
693 }
694 }
695 if (!die_compare_name(&type, "char") &&
696 !die_compare_name(&type, "unsigned char")) {
697 pr_warning("Failed to cast into string: "
698 "%s is not (unsigned) char *.",
699 dwarf_diename(vr_die));
700 return -EINVAL;
701 }
702 tvar->type = strdup(cast);
703 return (tvar->type == NULL) ? -ENOMEM : 0;
704 }
705
706 ret = die_get_byte_size(&type) * 8;
707 if (ret) {
708 /* Check the bitwidth */
709 if (ret > MAX_BASIC_TYPE_BITS) {
710 pr_info("%s exceeds max-bitwidth."
711 " Cut down to %d bits.\n",
712 dwarf_diename(&type), MAX_BASIC_TYPE_BITS);
713 ret = MAX_BASIC_TYPE_BITS;
714 }
715
716 ret = snprintf(buf, 16, "%c%d",
717 die_is_signed_type(&type) ? 's' : 'u', ret);
718 if (ret < 0 || ret >= 16) {
719 if (ret >= 16)
720 ret = -E2BIG;
721 pr_warning("Failed to convert variable type: %s\n",
722 strerror(-ret));
723 return ret;
724 }
725 tvar->type = strdup(buf);
726 if (tvar->type == NULL)
727 return -ENOMEM;
728 }
729 return 0;
730 }
731
732 static int convert_variable_fields(Dwarf_Die *vr_die, const char *varname,
733 struct perf_probe_arg_field *field,
734 struct probe_trace_arg_ref **ref_ptr,
735 Dwarf_Die *die_mem)
736 {
737 struct probe_trace_arg_ref *ref = *ref_ptr;
738 Dwarf_Die type;
739 Dwarf_Word offs;
740 int ret, tag;
741
742 pr_debug("converting %s in %s\n", field->name, varname);
743 if (die_get_real_type(vr_die, &type) == NULL) {
744 pr_warning("Failed to get the type of %s.\n", varname);
745 return -ENOENT;
746 }
747 pr_debug2("Var real type: (%x)\n", (unsigned)dwarf_dieoffset(&type));
748 tag = dwarf_tag(&type);
749
750 if (field->name[0] == '[' &&
751 (tag == DW_TAG_array_type || tag == DW_TAG_pointer_type)) {
752 if (field->next)
753 /* Save original type for next field */
754 memcpy(die_mem, &type, sizeof(*die_mem));
755 /* Get the type of this array */
756 if (die_get_real_type(&type, &type) == NULL) {
757 pr_warning("Failed to get the type of %s.\n", varname);
758 return -ENOENT;
759 }
760 pr_debug2("Array real type: (%x)\n",
761 (unsigned)dwarf_dieoffset(&type));
762 if (tag == DW_TAG_pointer_type) {
763 ref = zalloc(sizeof(struct probe_trace_arg_ref));
764 if (ref == NULL)
765 return -ENOMEM;
766 if (*ref_ptr)
767 (*ref_ptr)->next = ref;
768 else
769 *ref_ptr = ref;
770 }
771 ref->offset += die_get_byte_size(&type) * field->index;
772 if (!field->next)
773 /* Save vr_die for converting types */
774 memcpy(die_mem, vr_die, sizeof(*die_mem));
775 goto next;
776 } else if (tag == DW_TAG_pointer_type) {
777 /* Check the pointer and dereference */
778 if (!field->ref) {
779 pr_err("Semantic error: %s must be referred by '->'\n",
780 field->name);
781 return -EINVAL;
782 }
783 /* Get the type pointed by this pointer */
784 if (die_get_real_type(&type, &type) == NULL) {
785 pr_warning("Failed to get the type of %s.\n", varname);
786 return -ENOENT;
787 }
788 /* Verify it is a data structure */
789 if (dwarf_tag(&type) != DW_TAG_structure_type) {
790 pr_warning("%s is not a data structure.\n", varname);
791 return -EINVAL;
792 }
793
794 ref = zalloc(sizeof(struct probe_trace_arg_ref));
795 if (ref == NULL)
796 return -ENOMEM;
797 if (*ref_ptr)
798 (*ref_ptr)->next = ref;
799 else
800 *ref_ptr = ref;
801 } else {
802 /* Verify it is a data structure */
803 if (tag != DW_TAG_structure_type) {
804 pr_warning("%s is not a data structure.\n", varname);
805 return -EINVAL;
806 }
807 if (field->name[0] == '[') {
808 pr_err("Semantic error: %s is not a pointor nor array.",
809 varname);
810 return -EINVAL;
811 }
812 if (field->ref) {
813 pr_err("Semantic error: %s must be referred by '.'\n",
814 field->name);
815 return -EINVAL;
816 }
817 if (!ref) {
818 pr_warning("Structure on a register is not "
819 "supported yet.\n");
820 return -ENOTSUP;
821 }
822 }
823
824 if (die_find_member(&type, field->name, die_mem) == NULL) {
825 pr_warning("%s(tyep:%s) has no member %s.\n", varname,
826 dwarf_diename(&type), field->name);
827 return -EINVAL;
828 }
829
830 /* Get the offset of the field */
831 ret = die_get_data_member_location(die_mem, &offs);
832 if (ret < 0) {
833 pr_warning("Failed to get the offset of %s.\n", field->name);
834 return ret;
835 }
836 ref->offset += (long)offs;
837
838 next:
839 /* Converting next field */
840 if (field->next)
841 return convert_variable_fields(die_mem, field->name,
842 field->next, &ref, die_mem);
843 else
844 return 0;
845 }
846
847 /* Show a variables in kprobe event format */
848 static int convert_variable(Dwarf_Die *vr_die, struct probe_finder *pf)
849 {
850 Dwarf_Die die_mem;
851 int ret;
852
853 pr_debug("Converting variable %s into trace event.\n",
854 dwarf_diename(vr_die));
855
856 ret = convert_variable_location(vr_die, pf->addr, pf->fb_ops,
857 pf->tvar);
858 if (ret == -ENOENT)
859 pr_err("Failed to find the location of %s at this address.\n"
860 " Perhaps, it has been optimized out.\n", pf->pvar->var);
861 else if (ret == -ENOTSUP)
862 pr_err("Sorry, we don't support this variable location yet.\n");
863 else if (pf->pvar->field) {
864 ret = convert_variable_fields(vr_die, pf->pvar->var,
865 pf->pvar->field, &pf->tvar->ref,
866 &die_mem);
867 vr_die = &die_mem;
868 }
869 if (ret == 0)
870 ret = convert_variable_type(vr_die, pf->tvar, pf->pvar->type);
871 /* *expr will be cached in libdw. Don't free it. */
872 return ret;
873 }
874
875 /* Find a variable in a subprogram die */
876 static int find_variable(Dwarf_Die *sp_die, struct probe_finder *pf)
877 {
878 Dwarf_Die vr_die, *scopes;
879 char buf[32], *ptr;
880 int ret, nscopes;
881
882 if (!is_c_varname(pf->pvar->var)) {
883 /* Copy raw parameters */
884 pf->tvar->value = strdup(pf->pvar->var);
885 if (pf->tvar->value == NULL)
886 return -ENOMEM;
887 if (pf->pvar->type) {
888 pf->tvar->type = strdup(pf->pvar->type);
889 if (pf->tvar->type == NULL)
890 return -ENOMEM;
891 }
892 if (pf->pvar->name) {
893 pf->tvar->name = strdup(pf->pvar->name);
894 if (pf->tvar->name == NULL)
895 return -ENOMEM;
896 } else
897 pf->tvar->name = NULL;
898 return 0;
899 }
900
901 if (pf->pvar->name)
902 pf->tvar->name = strdup(pf->pvar->name);
903 else {
904 ret = synthesize_perf_probe_arg(pf->pvar, buf, 32);
905 if (ret < 0)
906 return ret;
907 ptr = strchr(buf, ':'); /* Change type separator to _ */
908 if (ptr)
909 *ptr = '_';
910 pf->tvar->name = strdup(buf);
911 }
912 if (pf->tvar->name == NULL)
913 return -ENOMEM;
914
915 pr_debug("Searching '%s' variable in context.\n",
916 pf->pvar->var);
917 /* Search child die for local variables and parameters. */
918 if (die_find_variable_at(sp_die, pf->pvar->var, pf->addr, &vr_die))
919 ret = convert_variable(&vr_die, pf);
920 else {
921 /* Search upper class */
922 nscopes = dwarf_getscopes_die(sp_die, &scopes);
923 while (nscopes-- > 1) {
924 pr_debug("Searching variables in %s\n",
925 dwarf_diename(&scopes[nscopes]));
926 /* We should check this scope, so give dummy address */
927 if (die_find_variable_at(&scopes[nscopes],
928 pf->pvar->var, 0,
929 &vr_die)) {
930 ret = convert_variable(&vr_die, pf);
931 goto found;
932 }
933 }
934 if (scopes)
935 free(scopes);
936 ret = -ENOENT;
937 }
938 found:
939 if (ret < 0)
940 pr_warning("Failed to find '%s' in this function.\n",
941 pf->pvar->var);
942 return ret;
943 }
944
945 /* Convert subprogram DIE to trace point */
946 static int convert_to_trace_point(Dwarf_Die *sp_die, Dwarf_Addr paddr,
947 bool retprobe, struct probe_trace_point *tp)
948 {
949 Dwarf_Addr eaddr;
950 const char *name;
951
952 /* Copy the name of probe point */
953 name = dwarf_diename(sp_die);
954 if (name) {
955 if (dwarf_entrypc(sp_die, &eaddr) != 0) {
956 pr_warning("Failed to get entry pc of %s\n",
957 dwarf_diename(sp_die));
958 return -ENOENT;
959 }
960 tp->symbol = strdup(name);
961 if (tp->symbol == NULL)
962 return -ENOMEM;
963 tp->offset = (unsigned long)(paddr - eaddr);
964 } else
965 /* This function has no name. */
966 tp->offset = (unsigned long)paddr;
967
968 /* Return probe must be on the head of a subprogram */
969 if (retprobe) {
970 if (eaddr != paddr) {
971 pr_warning("Return probe must be on the head of"
972 " a real function\n");
973 return -EINVAL;
974 }
975 tp->retprobe = true;
976 }
977
978 return 0;
979 }
980
981 /* Call probe_finder callback with real subprogram DIE */
982 static int call_probe_finder(Dwarf_Die *sp_die, struct probe_finder *pf)
983 {
984 Dwarf_Die die_mem;
985 Dwarf_Attribute fb_attr;
986 size_t nops;
987 int ret;
988
989 /* If no real subprogram, find a real one */
990 if (!sp_die || dwarf_tag(sp_die) != DW_TAG_subprogram) {
991 sp_die = die_find_real_subprogram(&pf->cu_die,
992 pf->addr, &die_mem);
993 if (!sp_die) {
994 pr_warning("Failed to find probe point in any "
995 "functions.\n");
996 return -ENOENT;
997 }
998 }
999
1000 /* Get the frame base attribute/ops */
1001 dwarf_attr(sp_die, DW_AT_frame_base, &fb_attr);
1002 ret = dwarf_getlocation_addr(&fb_attr, pf->addr, &pf->fb_ops, &nops, 1);
1003 if (ret <= 0 || nops == 0) {
1004 pf->fb_ops = NULL;
1005 #if _ELFUTILS_PREREQ(0, 142)
1006 } else if (nops == 1 && pf->fb_ops[0].atom == DW_OP_call_frame_cfa &&
1007 pf->cfi != NULL) {
1008 Dwarf_Frame *frame;
1009 if (dwarf_cfi_addrframe(pf->cfi, pf->addr, &frame) != 0 ||
1010 dwarf_frame_cfa(frame, &pf->fb_ops, &nops) != 0) {
1011 pr_warning("Failed to get CFA on 0x%jx\n",
1012 (uintmax_t)pf->addr);
1013 return -ENOENT;
1014 }
1015 #endif
1016 }
1017
1018 /* Call finder's callback handler */
1019 ret = pf->callback(sp_die, pf);
1020
1021 /* *pf->fb_ops will be cached in libdw. Don't free it. */
1022 pf->fb_ops = NULL;
1023
1024 return ret;
1025 }
1026
1027 /* Find probe point from its line number */
1028 static int find_probe_point_by_line(struct probe_finder *pf)
1029 {
1030 Dwarf_Lines *lines;
1031 Dwarf_Line *line;
1032 size_t nlines, i;
1033 Dwarf_Addr addr;
1034 int lineno;
1035 int ret = 0;
1036
1037 if (dwarf_getsrclines(&pf->cu_die, &lines, &nlines) != 0) {
1038 pr_warning("No source lines found in this CU.\n");
1039 return -ENOENT;
1040 }
1041
1042 for (i = 0; i < nlines && ret == 0; i++) {
1043 line = dwarf_onesrcline(lines, i);
1044 if (dwarf_lineno(line, &lineno) != 0 ||
1045 lineno != pf->lno)
1046 continue;
1047
1048 /* TODO: Get fileno from line, but how? */
1049 if (strtailcmp(dwarf_linesrc(line, NULL, NULL), pf->fname) != 0)
1050 continue;
1051
1052 if (dwarf_lineaddr(line, &addr) != 0) {
1053 pr_warning("Failed to get the address of the line.\n");
1054 return -ENOENT;
1055 }
1056 pr_debug("Probe line found: line[%d]:%d addr:0x%jx\n",
1057 (int)i, lineno, (uintmax_t)addr);
1058 pf->addr = addr;
1059
1060 ret = call_probe_finder(NULL, pf);
1061 /* Continuing, because target line might be inlined. */
1062 }
1063 return ret;
1064 }
1065
1066 /* Find lines which match lazy pattern */
1067 static int find_lazy_match_lines(struct list_head *head,
1068 const char *fname, const char *pat)
1069 {
1070 char *fbuf, *p1, *p2;
1071 int fd, line, nlines = -1;
1072 struct stat st;
1073
1074 fd = open(fname, O_RDONLY);
1075 if (fd < 0) {
1076 pr_warning("Failed to open %s: %s\n", fname, strerror(-fd));
1077 return -errno;
1078 }
1079
1080 if (fstat(fd, &st) < 0) {
1081 pr_warning("Failed to get the size of %s: %s\n",
1082 fname, strerror(errno));
1083 nlines = -errno;
1084 goto out_close;
1085 }
1086
1087 nlines = -ENOMEM;
1088 fbuf = malloc(st.st_size + 2);
1089 if (fbuf == NULL)
1090 goto out_close;
1091 if (read(fd, fbuf, st.st_size) < 0) {
1092 pr_warning("Failed to read %s: %s\n", fname, strerror(errno));
1093 nlines = -errno;
1094 goto out_free_fbuf;
1095 }
1096 fbuf[st.st_size] = '\n'; /* Dummy line */
1097 fbuf[st.st_size + 1] = '\0';
1098 p1 = fbuf;
1099 line = 1;
1100 nlines = 0;
1101 while ((p2 = strchr(p1, '\n')) != NULL) {
1102 *p2 = '\0';
1103 if (strlazymatch(p1, pat)) {
1104 line_list__add_line(head, line);
1105 nlines++;
1106 }
1107 line++;
1108 p1 = p2 + 1;
1109 }
1110 out_free_fbuf:
1111 free(fbuf);
1112 out_close:
1113 close(fd);
1114 return nlines;
1115 }
1116
1117 /* Find probe points from lazy pattern */
1118 static int find_probe_point_lazy(Dwarf_Die *sp_die, struct probe_finder *pf)
1119 {
1120 Dwarf_Lines *lines;
1121 Dwarf_Line *line;
1122 size_t nlines, i;
1123 Dwarf_Addr addr;
1124 Dwarf_Die die_mem;
1125 int lineno;
1126 int ret = 0;
1127
1128 if (list_empty(&pf->lcache)) {
1129 /* Matching lazy line pattern */
1130 ret = find_lazy_match_lines(&pf->lcache, pf->fname,
1131 pf->pev->point.lazy_line);
1132 if (ret == 0) {
1133 pr_debug("No matched lines found in %s.\n", pf->fname);
1134 return 0;
1135 } else if (ret < 0)
1136 return ret;
1137 }
1138
1139 if (dwarf_getsrclines(&pf->cu_die, &lines, &nlines) != 0) {
1140 pr_warning("No source lines found in this CU.\n");
1141 return -ENOENT;
1142 }
1143
1144 for (i = 0; i < nlines && ret >= 0; i++) {
1145 line = dwarf_onesrcline(lines, i);
1146
1147 if (dwarf_lineno(line, &lineno) != 0 ||
1148 !line_list__has_line(&pf->lcache, lineno))
1149 continue;
1150
1151 /* TODO: Get fileno from line, but how? */
1152 if (strtailcmp(dwarf_linesrc(line, NULL, NULL), pf->fname) != 0)
1153 continue;
1154
1155 if (dwarf_lineaddr(line, &addr) != 0) {
1156 pr_debug("Failed to get the address of line %d.\n",
1157 lineno);
1158 continue;
1159 }
1160 if (sp_die) {
1161 /* Address filtering 1: does sp_die include addr? */
1162 if (!dwarf_haspc(sp_die, addr))
1163 continue;
1164 /* Address filtering 2: No child include addr? */
1165 if (die_find_inlinefunc(sp_die, addr, &die_mem))
1166 continue;
1167 }
1168
1169 pr_debug("Probe line found: line[%d]:%d addr:0x%llx\n",
1170 (int)i, lineno, (unsigned long long)addr);
1171 pf->addr = addr;
1172
1173 ret = call_probe_finder(sp_die, pf);
1174 /* Continuing, because target line might be inlined. */
1175 }
1176 /* TODO: deallocate lines, but how? */
1177 return ret;
1178 }
1179
1180 /* Callback parameter with return value */
1181 struct dwarf_callback_param {
1182 void *data;
1183 int retval;
1184 };
1185
1186 static int probe_point_inline_cb(Dwarf_Die *in_die, void *data)
1187 {
1188 struct dwarf_callback_param *param = data;
1189 struct probe_finder *pf = param->data;
1190 struct perf_probe_point *pp = &pf->pev->point;
1191 Dwarf_Addr addr;
1192
1193 if (pp->lazy_line)
1194 param->retval = find_probe_point_lazy(in_die, pf);
1195 else {
1196 /* Get probe address */
1197 if (dwarf_entrypc(in_die, &addr) != 0) {
1198 pr_warning("Failed to get entry pc of %s.\n",
1199 dwarf_diename(in_die));
1200 param->retval = -ENOENT;
1201 return DWARF_CB_ABORT;
1202 }
1203 pf->addr = addr;
1204 pf->addr += pp->offset;
1205 pr_debug("found inline addr: 0x%jx\n",
1206 (uintmax_t)pf->addr);
1207
1208 param->retval = call_probe_finder(in_die, pf);
1209 if (param->retval < 0)
1210 return DWARF_CB_ABORT;
1211 }
1212
1213 return DWARF_CB_OK;
1214 }
1215
1216 /* Search function from function name */
1217 static int probe_point_search_cb(Dwarf_Die *sp_die, void *data)
1218 {
1219 struct dwarf_callback_param *param = data;
1220 struct probe_finder *pf = param->data;
1221 struct perf_probe_point *pp = &pf->pev->point;
1222
1223 /* Check tag and diename */
1224 if (dwarf_tag(sp_die) != DW_TAG_subprogram ||
1225 !die_compare_name(sp_die, pp->function))
1226 return DWARF_CB_OK;
1227
1228 pf->fname = dwarf_decl_file(sp_die);
1229 if (pp->line) { /* Function relative line */
1230 dwarf_decl_line(sp_die, &pf->lno);
1231 pf->lno += pp->line;
1232 param->retval = find_probe_point_by_line(pf);
1233 } else if (!dwarf_func_inline(sp_die)) {
1234 /* Real function */
1235 if (pp->lazy_line)
1236 param->retval = find_probe_point_lazy(sp_die, pf);
1237 else {
1238 if (dwarf_entrypc(sp_die, &pf->addr) != 0) {
1239 pr_warning("Failed to get entry pc of %s.\n",
1240 dwarf_diename(sp_die));
1241 param->retval = -ENOENT;
1242 return DWARF_CB_ABORT;
1243 }
1244 pf->addr += pp->offset;
1245 /* TODO: Check the address in this function */
1246 param->retval = call_probe_finder(sp_die, pf);
1247 }
1248 } else {
1249 struct dwarf_callback_param _param = {.data = (void *)pf,
1250 .retval = 0};
1251 /* Inlined function: search instances */
1252 dwarf_func_inline_instances(sp_die, probe_point_inline_cb,
1253 &_param);
1254 param->retval = _param.retval;
1255 }
1256
1257 return DWARF_CB_ABORT; /* Exit; no same symbol in this CU. */
1258 }
1259
1260 static int find_probe_point_by_func(struct probe_finder *pf)
1261 {
1262 struct dwarf_callback_param _param = {.data = (void *)pf,
1263 .retval = 0};
1264 dwarf_getfuncs(&pf->cu_die, probe_point_search_cb, &_param, 0);
1265 return _param.retval;
1266 }
1267
1268 /* Find probe points from debuginfo */
1269 static int find_probes(int fd, struct probe_finder *pf)
1270 {
1271 struct perf_probe_point *pp = &pf->pev->point;
1272 Dwarf_Off off, noff;
1273 size_t cuhl;
1274 Dwarf_Die *diep;
1275 Dwarf *dbg = NULL;
1276 Dwfl *dwfl;
1277 Dwarf_Addr bias; /* Currently ignored */
1278 int ret = 0;
1279
1280 dbg = dwfl_init_offline_dwarf(fd, &dwfl, &bias);
1281 if (!dbg) {
1282 pr_warning("No dwarf info found in the vmlinux - "
1283 "please rebuild with CONFIG_DEBUG_INFO=y.\n");
1284 return -EBADF;
1285 }
1286
1287 #if _ELFUTILS_PREREQ(0, 142)
1288 /* Get the call frame information from this dwarf */
1289 pf->cfi = dwarf_getcfi(dbg);
1290 #endif
1291
1292 off = 0;
1293 line_list__init(&pf->lcache);
1294 /* Loop on CUs (Compilation Unit) */
1295 while (!dwarf_nextcu(dbg, off, &noff, &cuhl, NULL, NULL, NULL) &&
1296 ret >= 0) {
1297 /* Get the DIE(Debugging Information Entry) of this CU */
1298 diep = dwarf_offdie(dbg, off + cuhl, &pf->cu_die);
1299 if (!diep)
1300 continue;
1301
1302 /* Check if target file is included. */
1303 if (pp->file)
1304 pf->fname = cu_find_realpath(&pf->cu_die, pp->file);
1305 else
1306 pf->fname = NULL;
1307
1308 if (!pp->file || pf->fname) {
1309 if (pp->function)
1310 ret = find_probe_point_by_func(pf);
1311 else if (pp->lazy_line)
1312 ret = find_probe_point_lazy(NULL, pf);
1313 else {
1314 pf->lno = pp->line;
1315 ret = find_probe_point_by_line(pf);
1316 }
1317 }
1318 off = noff;
1319 }
1320 line_list__free(&pf->lcache);
1321 if (dwfl)
1322 dwfl_end(dwfl);
1323
1324 return ret;
1325 }
1326
1327 /* Add a found probe point into trace event list */
1328 static int add_probe_trace_event(Dwarf_Die *sp_die, struct probe_finder *pf)
1329 {
1330 struct trace_event_finder *tf =
1331 container_of(pf, struct trace_event_finder, pf);
1332 struct probe_trace_event *tev;
1333 int ret, i;
1334
1335 /* Check number of tevs */
1336 if (tf->ntevs == tf->max_tevs) {
1337 pr_warning("Too many( > %d) probe point found.\n",
1338 tf->max_tevs);
1339 return -ERANGE;
1340 }
1341 tev = &tf->tevs[tf->ntevs++];
1342
1343 ret = convert_to_trace_point(sp_die, pf->addr, pf->pev->point.retprobe,
1344 &tev->point);
1345 if (ret < 0)
1346 return ret;
1347
1348 pr_debug("Probe point found: %s+%lu\n", tev->point.symbol,
1349 tev->point.offset);
1350
1351 /* Find each argument */
1352 tev->nargs = pf->pev->nargs;
1353 tev->args = zalloc(sizeof(struct probe_trace_arg) * tev->nargs);
1354 if (tev->args == NULL)
1355 return -ENOMEM;
1356 for (i = 0; i < pf->pev->nargs; i++) {
1357 pf->pvar = &pf->pev->args[i];
1358 pf->tvar = &tev->args[i];
1359 ret = find_variable(sp_die, pf);
1360 if (ret != 0)
1361 return ret;
1362 }
1363
1364 return 0;
1365 }
1366
1367 /* Find probe_trace_events specified by perf_probe_event from debuginfo */
1368 int find_probe_trace_events(int fd, struct perf_probe_event *pev,
1369 struct probe_trace_event **tevs, int max_tevs)
1370 {
1371 struct trace_event_finder tf = {
1372 .pf = {.pev = pev, .callback = add_probe_trace_event},
1373 .max_tevs = max_tevs};
1374 int ret;
1375
1376 /* Allocate result tevs array */
1377 *tevs = zalloc(sizeof(struct probe_trace_event) * max_tevs);
1378 if (*tevs == NULL)
1379 return -ENOMEM;
1380
1381 tf.tevs = *tevs;
1382 tf.ntevs = 0;
1383
1384 ret = find_probes(fd, &tf.pf);
1385 if (ret < 0) {
1386 free(*tevs);
1387 *tevs = NULL;
1388 return ret;
1389 }
1390
1391 return (ret < 0) ? ret : tf.ntevs;
1392 }
1393
1394 #define MAX_VAR_LEN 64
1395
1396 /* Collect available variables in this scope */
1397 static int collect_variables_cb(Dwarf_Die *die_mem, void *data)
1398 {
1399 struct available_var_finder *af = data;
1400 struct variable_list *vl;
1401 char buf[MAX_VAR_LEN];
1402 int tag, ret;
1403
1404 vl = &af->vls[af->nvls - 1];
1405
1406 tag = dwarf_tag(die_mem);
1407 if (tag == DW_TAG_formal_parameter ||
1408 tag == DW_TAG_variable) {
1409 ret = convert_variable_location(die_mem, af->pf.addr,
1410 af->pf.fb_ops, NULL);
1411 if (ret == 0) {
1412 ret = die_get_varname(die_mem, buf, MAX_VAR_LEN);
1413 pr_debug2("Add new var: %s\n", buf);
1414 if (ret > 0)
1415 strlist__add(vl->vars, buf);
1416 }
1417 }
1418
1419 if (af->child && dwarf_haspc(die_mem, af->pf.addr))
1420 return DIE_FIND_CB_CONTINUE;
1421 else
1422 return DIE_FIND_CB_SIBLING;
1423 }
1424
1425 /* Add a found vars into available variables list */
1426 static int add_available_vars(Dwarf_Die *sp_die, struct probe_finder *pf)
1427 {
1428 struct available_var_finder *af =
1429 container_of(pf, struct available_var_finder, pf);
1430 struct variable_list *vl;
1431 Dwarf_Die die_mem, *scopes = NULL;
1432 int ret, nscopes;
1433
1434 /* Check number of tevs */
1435 if (af->nvls == af->max_vls) {
1436 pr_warning("Too many( > %d) probe point found.\n", af->max_vls);
1437 return -ERANGE;
1438 }
1439 vl = &af->vls[af->nvls++];
1440
1441 ret = convert_to_trace_point(sp_die, pf->addr, pf->pev->point.retprobe,
1442 &vl->point);
1443 if (ret < 0)
1444 return ret;
1445
1446 pr_debug("Probe point found: %s+%lu\n", vl->point.symbol,
1447 vl->point.offset);
1448
1449 /* Find local variables */
1450 vl->vars = strlist__new(true, NULL);
1451 if (vl->vars == NULL)
1452 return -ENOMEM;
1453 af->child = true;
1454 die_find_child(sp_die, collect_variables_cb, (void *)af, &die_mem);
1455
1456 /* Find external variables */
1457 if (!af->externs)
1458 goto out;
1459 /* Don't need to search child DIE for externs. */
1460 af->child = false;
1461 nscopes = dwarf_getscopes_die(sp_die, &scopes);
1462 while (nscopes-- > 1)
1463 die_find_child(&scopes[nscopes], collect_variables_cb,
1464 (void *)af, &die_mem);
1465 if (scopes)
1466 free(scopes);
1467
1468 out:
1469 if (strlist__empty(vl->vars)) {
1470 strlist__delete(vl->vars);
1471 vl->vars = NULL;
1472 }
1473
1474 return ret;
1475 }
1476
1477 /* Find available variables at given probe point */
1478 int find_available_vars_at(int fd, struct perf_probe_event *pev,
1479 struct variable_list **vls, int max_vls,
1480 bool externs)
1481 {
1482 struct available_var_finder af = {
1483 .pf = {.pev = pev, .callback = add_available_vars},
1484 .max_vls = max_vls, .externs = externs};
1485 int ret;
1486
1487 /* Allocate result vls array */
1488 *vls = zalloc(sizeof(struct variable_list) * max_vls);
1489 if (*vls == NULL)
1490 return -ENOMEM;
1491
1492 af.vls = *vls;
1493 af.nvls = 0;
1494
1495 ret = find_probes(fd, &af.pf);
1496 if (ret < 0) {
1497 /* Free vlist for error */
1498 while (af.nvls--) {
1499 if (af.vls[af.nvls].point.symbol)
1500 free(af.vls[af.nvls].point.symbol);
1501 if (af.vls[af.nvls].vars)
1502 strlist__delete(af.vls[af.nvls].vars);
1503 }
1504 free(af.vls);
1505 *vls = NULL;
1506 return ret;
1507 }
1508
1509 return (ret < 0) ? ret : af.nvls;
1510 }
1511
1512 /* Reverse search */
1513 int find_perf_probe_point(unsigned long addr, struct perf_probe_point *ppt)
1514 {
1515 Dwarf_Die cudie, spdie, indie;
1516 Dwarf *dbg = NULL;
1517 Dwfl *dwfl = NULL;
1518 Dwarf_Line *line;
1519 Dwarf_Addr laddr, eaddr, bias = 0;
1520 const char *tmp;
1521 int lineno, ret = 0;
1522 bool found = false;
1523
1524 /* Open the live linux kernel */
1525 dbg = dwfl_init_live_kernel_dwarf(addr, &dwfl, &bias);
1526 if (!dbg) {
1527 pr_warning("No dwarf info found in the vmlinux - "
1528 "please rebuild with CONFIG_DEBUG_INFO=y.\n");
1529 ret = -EINVAL;
1530 goto end;
1531 }
1532
1533 /* Adjust address with bias */
1534 addr += bias;
1535 /* Find cu die */
1536 if (!dwarf_addrdie(dbg, (Dwarf_Addr)addr - bias, &cudie)) {
1537 pr_warning("No CU DIE is found at %lx\n", addr);
1538 ret = -EINVAL;
1539 goto end;
1540 }
1541
1542 /* Find a corresponding line */
1543 line = dwarf_getsrc_die(&cudie, (Dwarf_Addr)addr);
1544 if (line) {
1545 if (dwarf_lineaddr(line, &laddr) == 0 &&
1546 (Dwarf_Addr)addr == laddr &&
1547 dwarf_lineno(line, &lineno) == 0) {
1548 tmp = dwarf_linesrc(line, NULL, NULL);
1549 if (tmp) {
1550 ppt->line = lineno;
1551 ppt->file = strdup(tmp);
1552 if (ppt->file == NULL) {
1553 ret = -ENOMEM;
1554 goto end;
1555 }
1556 found = true;
1557 }
1558 }
1559 }
1560
1561 /* Find a corresponding function */
1562 if (die_find_real_subprogram(&cudie, (Dwarf_Addr)addr, &spdie)) {
1563 tmp = dwarf_diename(&spdie);
1564 if (!tmp || dwarf_entrypc(&spdie, &eaddr) != 0)
1565 goto end;
1566
1567 if (ppt->line) {
1568 if (die_find_inlinefunc(&spdie, (Dwarf_Addr)addr,
1569 &indie)) {
1570 /* addr in an inline function */
1571 tmp = dwarf_diename(&indie);
1572 if (!tmp)
1573 goto end;
1574 ret = dwarf_decl_line(&indie, &lineno);
1575 } else {
1576 if (eaddr == addr) { /* Function entry */
1577 lineno = ppt->line;
1578 ret = 0;
1579 } else
1580 ret = dwarf_decl_line(&spdie, &lineno);
1581 }
1582 if (ret == 0) {
1583 /* Make a relative line number */
1584 ppt->line -= lineno;
1585 goto found;
1586 }
1587 }
1588 /* We don't have a line number, let's use offset */
1589 ppt->offset = addr - (unsigned long)eaddr;
1590 found:
1591 ppt->function = strdup(tmp);
1592 if (ppt->function == NULL) {
1593 ret = -ENOMEM;
1594 goto end;
1595 }
1596 found = true;
1597 }
1598
1599 end:
1600 if (dwfl)
1601 dwfl_end(dwfl);
1602 if (ret >= 0)
1603 ret = found ? 1 : 0;
1604 return ret;
1605 }
1606
1607 /* Add a line and store the src path */
1608 static int line_range_add_line(const char *src, unsigned int lineno,
1609 struct line_range *lr)
1610 {
1611 /* Copy source path */
1612 if (!lr->path) {
1613 lr->path = strdup(src);
1614 if (lr->path == NULL)
1615 return -ENOMEM;
1616 }
1617 return line_list__add_line(&lr->line_list, lineno);
1618 }
1619
1620 /* Search function declaration lines */
1621 static int line_range_funcdecl_cb(Dwarf_Die *sp_die, void *data)
1622 {
1623 struct dwarf_callback_param *param = data;
1624 struct line_finder *lf = param->data;
1625 const char *src;
1626 int lineno;
1627
1628 src = dwarf_decl_file(sp_die);
1629 if (src && strtailcmp(src, lf->fname) != 0)
1630 return DWARF_CB_OK;
1631
1632 if (dwarf_decl_line(sp_die, &lineno) != 0 ||
1633 (lf->lno_s > lineno || lf->lno_e < lineno))
1634 return DWARF_CB_OK;
1635
1636 param->retval = line_range_add_line(src, lineno, lf->lr);
1637 if (param->retval < 0)
1638 return DWARF_CB_ABORT;
1639 return DWARF_CB_OK;
1640 }
1641
1642 static int find_line_range_func_decl_lines(struct line_finder *lf)
1643 {
1644 struct dwarf_callback_param param = {.data = (void *)lf, .retval = 0};
1645 dwarf_getfuncs(&lf->cu_die, line_range_funcdecl_cb, &param, 0);
1646 return param.retval;
1647 }
1648
1649 /* Find line range from its line number */
1650 static int find_line_range_by_line(Dwarf_Die *sp_die, struct line_finder *lf)
1651 {
1652 Dwarf_Lines *lines;
1653 Dwarf_Line *line;
1654 size_t nlines, i;
1655 Dwarf_Addr addr;
1656 int lineno, ret = 0;
1657 const char *src;
1658 Dwarf_Die die_mem;
1659
1660 line_list__init(&lf->lr->line_list);
1661 if (dwarf_getsrclines(&lf->cu_die, &lines, &nlines) != 0) {
1662 pr_warning("No source lines found in this CU.\n");
1663 return -ENOENT;
1664 }
1665
1666 /* Search probable lines on lines list */
1667 for (i = 0; i < nlines; i++) {
1668 line = dwarf_onesrcline(lines, i);
1669 if (dwarf_lineno(line, &lineno) != 0 ||
1670 (lf->lno_s > lineno || lf->lno_e < lineno))
1671 continue;
1672
1673 if (sp_die) {
1674 /* Address filtering 1: does sp_die include addr? */
1675 if (dwarf_lineaddr(line, &addr) != 0 ||
1676 !dwarf_haspc(sp_die, addr))
1677 continue;
1678
1679 /* Address filtering 2: No child include addr? */
1680 if (die_find_inlinefunc(sp_die, addr, &die_mem))
1681 continue;
1682 }
1683
1684 /* TODO: Get fileno from line, but how? */
1685 src = dwarf_linesrc(line, NULL, NULL);
1686 if (strtailcmp(src, lf->fname) != 0)
1687 continue;
1688
1689 ret = line_range_add_line(src, lineno, lf->lr);
1690 if (ret < 0)
1691 return ret;
1692 }
1693
1694 /*
1695 * Dwarf lines doesn't include function declarations. We have to
1696 * check functions list or given function.
1697 */
1698 if (sp_die) {
1699 src = dwarf_decl_file(sp_die);
1700 if (src && dwarf_decl_line(sp_die, &lineno) == 0 &&
1701 (lf->lno_s <= lineno && lf->lno_e >= lineno))
1702 ret = line_range_add_line(src, lineno, lf->lr);
1703 } else
1704 ret = find_line_range_func_decl_lines(lf);
1705
1706 /* Update status */
1707 if (ret >= 0)
1708 if (!list_empty(&lf->lr->line_list))
1709 ret = lf->found = 1;
1710 else
1711 ret = 0; /* Lines are not found */
1712 else {
1713 free(lf->lr->path);
1714 lf->lr->path = NULL;
1715 }
1716 return ret;
1717 }
1718
1719 static int line_range_inline_cb(Dwarf_Die *in_die, void *data)
1720 {
1721 struct dwarf_callback_param *param = data;
1722
1723 param->retval = find_line_range_by_line(in_die, param->data);
1724 return DWARF_CB_ABORT; /* No need to find other instances */
1725 }
1726
1727 /* Search function from function name */
1728 static int line_range_search_cb(Dwarf_Die *sp_die, void *data)
1729 {
1730 struct dwarf_callback_param *param = data;
1731 struct line_finder *lf = param->data;
1732 struct line_range *lr = lf->lr;
1733
1734 pr_debug("find (%lx) %s\n", dwarf_dieoffset(sp_die),
1735 dwarf_diename(sp_die));
1736 if (dwarf_tag(sp_die) == DW_TAG_subprogram &&
1737 die_compare_name(sp_die, lr->function)) {
1738 lf->fname = dwarf_decl_file(sp_die);
1739 dwarf_decl_line(sp_die, &lr->offset);
1740 pr_debug("fname: %s, lineno:%d\n", lf->fname, lr->offset);
1741 lf->lno_s = lr->offset + lr->start;
1742 if (lf->lno_s < 0) /* Overflow */
1743 lf->lno_s = INT_MAX;
1744 lf->lno_e = lr->offset + lr->end;
1745 if (lf->lno_e < 0) /* Overflow */
1746 lf->lno_e = INT_MAX;
1747 pr_debug("New line range: %d to %d\n", lf->lno_s, lf->lno_e);
1748 lr->start = lf->lno_s;
1749 lr->end = lf->lno_e;
1750 if (dwarf_func_inline(sp_die)) {
1751 struct dwarf_callback_param _param;
1752 _param.data = (void *)lf;
1753 _param.retval = 0;
1754 dwarf_func_inline_instances(sp_die,
1755 line_range_inline_cb,
1756 &_param);
1757 param->retval = _param.retval;
1758 } else
1759 param->retval = find_line_range_by_line(sp_die, lf);
1760 return DWARF_CB_ABORT;
1761 }
1762 return DWARF_CB_OK;
1763 }
1764
1765 static int find_line_range_by_func(struct line_finder *lf)
1766 {
1767 struct dwarf_callback_param param = {.data = (void *)lf, .retval = 0};
1768 dwarf_getfuncs(&lf->cu_die, line_range_search_cb, &param, 0);
1769 return param.retval;
1770 }
1771
1772 int find_line_range(int fd, struct line_range *lr)
1773 {
1774 struct line_finder lf = {.lr = lr, .found = 0};
1775 int ret = 0;
1776 Dwarf_Off off = 0, noff;
1777 size_t cuhl;
1778 Dwarf_Die *diep;
1779 Dwarf *dbg = NULL;
1780 Dwfl *dwfl;
1781 Dwarf_Addr bias; /* Currently ignored */
1782 const char *comp_dir;
1783
1784 dbg = dwfl_init_offline_dwarf(fd, &dwfl, &bias);
1785 if (!dbg) {
1786 pr_warning("No dwarf info found in the vmlinux - "
1787 "please rebuild with CONFIG_DEBUG_INFO=y.\n");
1788 return -EBADF;
1789 }
1790
1791 /* Loop on CUs (Compilation Unit) */
1792 while (!lf.found && ret >= 0) {
1793 if (dwarf_nextcu(dbg, off, &noff, &cuhl, NULL, NULL, NULL) != 0)
1794 break;
1795
1796 /* Get the DIE(Debugging Information Entry) of this CU */
1797 diep = dwarf_offdie(dbg, off + cuhl, &lf.cu_die);
1798 if (!diep)
1799 continue;
1800
1801 /* Check if target file is included. */
1802 if (lr->file)
1803 lf.fname = cu_find_realpath(&lf.cu_die, lr->file);
1804 else
1805 lf.fname = 0;
1806
1807 if (!lr->file || lf.fname) {
1808 if (lr->function)
1809 ret = find_line_range_by_func(&lf);
1810 else {
1811 lf.lno_s = lr->start;
1812 lf.lno_e = lr->end;
1813 ret = find_line_range_by_line(NULL, &lf);
1814 }
1815 }
1816 off = noff;
1817 }
1818
1819 /* Store comp_dir */
1820 if (lf.found) {
1821 comp_dir = cu_get_comp_dir(&lf.cu_die);
1822 if (comp_dir) {
1823 lr->comp_dir = strdup(comp_dir);
1824 if (!lr->comp_dir)
1825 ret = -ENOMEM;
1826 }
1827 }
1828
1829 pr_debug("path: %s\n", lr->path);
1830 dwfl_end(dwfl);
1831 return (ret < 0) ? ret : lf.found;
1832 }
1833
Linus' kernel tree