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fs/ext4/inode.c: use pr_warn_ratelimited()
[linux/fpc-iii.git] / tools / perf / util / probe-finder.c
blobab83b6ac5d657c80af1e67790c1ace15d7592578
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 static char *debuginfo_path; /* Currently dummy */
121
122 static const Dwfl_Callbacks offline_callbacks = {
123 .find_debuginfo = dwfl_standard_find_debuginfo,
124 .debuginfo_path = &debuginfo_path,
125
126 .section_address = dwfl_offline_section_address,
127
128 /* We use this table for core files too. */
129 .find_elf = dwfl_build_id_find_elf,
130 };
131
132 /* Get a Dwarf from offline image */
133 static Dwarf *dwfl_init_offline_dwarf(int fd, Dwfl **dwflp, Dwarf_Addr *bias)
134 {
135 Dwfl_Module *mod;
136 Dwarf *dbg = NULL;
137
138 if (!dwflp)
139 return NULL;
140
141 *dwflp = dwfl_begin(&offline_callbacks);
142 if (!*dwflp)
143 return NULL;
144
145 mod = dwfl_report_offline(*dwflp, "", "", fd);
146 if (!mod)
147 goto error;
148
149 dbg = dwfl_module_getdwarf(mod, bias);
150 if (!dbg) {
151 error:
152 dwfl_end(*dwflp);
153 *dwflp = NULL;
154 }
155 return dbg;
156 }
157
158 #if _ELFUTILS_PREREQ(0, 148)
159 /* This method is buggy if elfutils is older than 0.148 */
160 static int __linux_kernel_find_elf(Dwfl_Module *mod,
161 void **userdata,
162 const char *module_name,
163 Dwarf_Addr base,
164 char **file_name, Elf **elfp)
165 {
166 int fd;
167 const char *path = kernel_get_module_path(module_name);
168
169 pr_debug2("Use file %s for %s\n", path, module_name);
170 if (path) {
171 fd = open(path, O_RDONLY);
172 if (fd >= 0) {
173 *file_name = strdup(path);
174 return fd;
175 }
176 }
177 /* If failed, try to call standard method */
178 return dwfl_linux_kernel_find_elf(mod, userdata, module_name, base,
179 file_name, elfp);
180 }
181
182 static const Dwfl_Callbacks kernel_callbacks = {
183 .find_debuginfo = dwfl_standard_find_debuginfo,
184 .debuginfo_path = &debuginfo_path,
185
186 .find_elf = __linux_kernel_find_elf,
187 .section_address = dwfl_linux_kernel_module_section_address,
188 };
189
190 /* Get a Dwarf from live kernel image */
191 static Dwarf *dwfl_init_live_kernel_dwarf(Dwarf_Addr addr, Dwfl **dwflp,
192 Dwarf_Addr *bias)
193 {
194 Dwarf *dbg;
195
196 if (!dwflp)
197 return NULL;
198
199 *dwflp = dwfl_begin(&kernel_callbacks);
200 if (!*dwflp)
201 return NULL;
202
203 /* Load the kernel dwarves: Don't care the result here */
204 dwfl_linux_kernel_report_kernel(*dwflp);
205 dwfl_linux_kernel_report_modules(*dwflp);
206
207 dbg = dwfl_addrdwarf(*dwflp, addr, bias);
208 /* Here, check whether we could get a real dwarf */
209 if (!dbg) {
210 pr_debug("Failed to find kernel dwarf at %lx\n",
211 (unsigned long)addr);
212 dwfl_end(*dwflp);
213 *dwflp = NULL;
214 }
215 return dbg;
216 }
217 #else
218 /* With older elfutils, this just support kernel module... */
219 static Dwarf *dwfl_init_live_kernel_dwarf(Dwarf_Addr addr __used, Dwfl **dwflp,
220 Dwarf_Addr *bias)
221 {
222 int fd;
223 const char *path = kernel_get_module_path("kernel");
224
225 if (!path) {
226 pr_err("Failed to find vmlinux path\n");
227 return NULL;
228 }
229
230 pr_debug2("Use file %s for debuginfo\n", path);
231 fd = open(path, O_RDONLY);
232 if (fd < 0)
233 return NULL;
234
235 return dwfl_init_offline_dwarf(fd, dwflp, bias);
236 }
237 #endif
238
239 /* Dwarf wrappers */
240
241 /* Find the realpath of the target file. */
242 static const char *cu_find_realpath(Dwarf_Die *cu_die, const char *fname)
243 {
244 Dwarf_Files *files;
245 size_t nfiles, i;
246 const char *src = NULL;
247 int ret;
248
249 if (!fname)
250 return NULL;
251
252 ret = dwarf_getsrcfiles(cu_die, &files, &nfiles);
253 if (ret != 0)
254 return NULL;
255
256 for (i = 0; i < nfiles; i++) {
257 src = dwarf_filesrc(files, i, NULL, NULL);
258 if (strtailcmp(src, fname) == 0)
259 break;
260 }
261 if (i == nfiles)
262 return NULL;
263 return src;
264 }
265
266 /* Get DW_AT_comp_dir (should be NULL with older gcc) */
267 static const char *cu_get_comp_dir(Dwarf_Die *cu_die)
268 {
269 Dwarf_Attribute attr;
270 if (dwarf_attr(cu_die, DW_AT_comp_dir, &attr) == NULL)
271 return NULL;
272 return dwarf_formstring(&attr);
273 }
274
275 /* Compare diename and tname */
276 static bool die_compare_name(Dwarf_Die *dw_die, const char *tname)
277 {
278 const char *name;
279 name = dwarf_diename(dw_die);
280 return name ? (strcmp(tname, name) == 0) : false;
281 }
282
283 /* Get type die */
284 static Dwarf_Die *die_get_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem)
285 {
286 Dwarf_Attribute attr;
287
288 if (dwarf_attr_integrate(vr_die, DW_AT_type, &attr) &&
289 dwarf_formref_die(&attr, die_mem))
290 return die_mem;
291 else
292 return NULL;
293 }
294
295 /* Get a type die, but skip qualifiers */
296 static Dwarf_Die *__die_get_real_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem)
297 {
298 int tag;
299
300 do {
301 vr_die = die_get_type(vr_die, die_mem);
302 if (!vr_die)
303 break;
304 tag = dwarf_tag(vr_die);
305 } while (tag == DW_TAG_const_type ||
306 tag == DW_TAG_restrict_type ||
307 tag == DW_TAG_volatile_type ||
308 tag == DW_TAG_shared_type);
309
310 return vr_die;
311 }
312
313 /* Get a type die, but skip qualifiers and typedef */
314 static Dwarf_Die *die_get_real_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem)
315 {
316 do {
317 vr_die = __die_get_real_type(vr_die, die_mem);
318 } while (vr_die && dwarf_tag(vr_die) == DW_TAG_typedef);
319
320 return vr_die;
321 }
322
323 static bool die_is_signed_type(Dwarf_Die *tp_die)
324 {
325 Dwarf_Attribute attr;
326 Dwarf_Word ret;
327
328 if (dwarf_attr(tp_die, DW_AT_encoding, &attr) == NULL ||
329 dwarf_formudata(&attr, &ret) != 0)
330 return false;
331
332 return (ret == DW_ATE_signed_char || ret == DW_ATE_signed ||
333 ret == DW_ATE_signed_fixed);
334 }
335
336 static int die_get_byte_size(Dwarf_Die *tp_die)
337 {
338 Dwarf_Attribute attr;
339 Dwarf_Word ret;
340
341 if (dwarf_attr(tp_die, DW_AT_byte_size, &attr) == NULL ||
342 dwarf_formudata(&attr, &ret) != 0)
343 return 0;
344
345 return (int)ret;
346 }
347
348 /* Get data_member_location offset */
349 static int die_get_data_member_location(Dwarf_Die *mb_die, Dwarf_Word *offs)
350 {
351 Dwarf_Attribute attr;
352 Dwarf_Op *expr;
353 size_t nexpr;
354 int ret;
355
356 if (dwarf_attr(mb_die, DW_AT_data_member_location, &attr) == NULL)
357 return -ENOENT;
358
359 if (dwarf_formudata(&attr, offs) != 0) {
360 /* DW_AT_data_member_location should be DW_OP_plus_uconst */
361 ret = dwarf_getlocation(&attr, &expr, &nexpr);
362 if (ret < 0 || nexpr == 0)
363 return -ENOENT;
364
365 if (expr[0].atom != DW_OP_plus_uconst || nexpr != 1) {
366 pr_debug("Unable to get offset:Unexpected OP %x (%zd)\n",
367 expr[0].atom, nexpr);
368 return -ENOTSUP;
369 }
370 *offs = (Dwarf_Word)expr[0].number;
371 }
372 return 0;
373 }
374
375 /* Return values for die_find callbacks */
376 enum {
377 DIE_FIND_CB_FOUND = 0, /* End of Search */
378 DIE_FIND_CB_CHILD = 1, /* Search only children */
379 DIE_FIND_CB_SIBLING = 2, /* Search only siblings */
380 DIE_FIND_CB_CONTINUE = 3, /* Search children and siblings */
381 };
382
383 /* Search a child die */
384 static Dwarf_Die *die_find_child(Dwarf_Die *rt_die,
385 int (*callback)(Dwarf_Die *, void *),
386 void *data, Dwarf_Die *die_mem)
387 {
388 Dwarf_Die child_die;
389 int ret;
390
391 ret = dwarf_child(rt_die, die_mem);
392 if (ret != 0)
393 return NULL;
394
395 do {
396 ret = callback(die_mem, data);
397 if (ret == DIE_FIND_CB_FOUND)
398 return die_mem;
399
400 if ((ret & DIE_FIND_CB_CHILD) &&
401 die_find_child(die_mem, callback, data, &child_die)) {
402 memcpy(die_mem, &child_die, sizeof(Dwarf_Die));
403 return die_mem;
404 }
405 } while ((ret & DIE_FIND_CB_SIBLING) &&
406 dwarf_siblingof(die_mem, die_mem) == 0);
407
408 return NULL;
409 }
410
411 struct __addr_die_search_param {
412 Dwarf_Addr addr;
413 Dwarf_Die *die_mem;
414 };
415
416 static int __die_search_func_cb(Dwarf_Die *fn_die, void *data)
417 {
418 struct __addr_die_search_param *ad = data;
419
420 if (dwarf_tag(fn_die) == DW_TAG_subprogram &&
421 dwarf_haspc(fn_die, ad->addr)) {
422 memcpy(ad->die_mem, fn_die, sizeof(Dwarf_Die));
423 return DWARF_CB_ABORT;
424 }
425 return DWARF_CB_OK;
426 }
427
428 /* Search a real subprogram including this line, */
429 static Dwarf_Die *die_find_real_subprogram(Dwarf_Die *cu_die, Dwarf_Addr addr,
430 Dwarf_Die *die_mem)
431 {
432 struct __addr_die_search_param ad;
433 ad.addr = addr;
434 ad.die_mem = die_mem;
435 /* dwarf_getscopes can't find subprogram. */
436 if (!dwarf_getfuncs(cu_die, __die_search_func_cb, &ad, 0))
437 return NULL;
438 else
439 return die_mem;
440 }
441
442 /* die_find callback for inline function search */
443 static int __die_find_inline_cb(Dwarf_Die *die_mem, void *data)
444 {
445 Dwarf_Addr *addr = data;
446
447 if (dwarf_tag(die_mem) == DW_TAG_inlined_subroutine &&
448 dwarf_haspc(die_mem, *addr))
449 return DIE_FIND_CB_FOUND;
450
451 return DIE_FIND_CB_CONTINUE;
452 }
453
454 /* Similar to dwarf_getfuncs, but returns inlined_subroutine if exists. */
455 static Dwarf_Die *die_find_inlinefunc(Dwarf_Die *sp_die, Dwarf_Addr addr,
456 Dwarf_Die *die_mem)
457 {
458 return die_find_child(sp_die, __die_find_inline_cb, &addr, die_mem);
459 }
460
461 struct __find_variable_param {
462 const char *name;
463 Dwarf_Addr addr;
464 };
465
466 static int __die_find_variable_cb(Dwarf_Die *die_mem, void *data)
467 {
468 struct __find_variable_param *fvp = data;
469 int tag;
470
471 tag = dwarf_tag(die_mem);
472 if ((tag == DW_TAG_formal_parameter ||
473 tag == DW_TAG_variable) &&
474 die_compare_name(die_mem, fvp->name))
475 return DIE_FIND_CB_FOUND;
476
477 if (dwarf_haspc(die_mem, fvp->addr))
478 return DIE_FIND_CB_CONTINUE;
479 else
480 return DIE_FIND_CB_SIBLING;
481 }
482
483 /* Find a variable called 'name' at given address */
484 static Dwarf_Die *die_find_variable_at(Dwarf_Die *sp_die, const char *name,
485 Dwarf_Addr addr, Dwarf_Die *die_mem)
486 {
487 struct __find_variable_param fvp = { .name = name, .addr = addr};
488
489 return die_find_child(sp_die, __die_find_variable_cb, (void *)&fvp,
490 die_mem);
491 }
492
493 static int __die_find_member_cb(Dwarf_Die *die_mem, void *data)
494 {
495 const char *name = data;
496
497 if ((dwarf_tag(die_mem) == DW_TAG_member) &&
498 die_compare_name(die_mem, name))
499 return DIE_FIND_CB_FOUND;
500
501 return DIE_FIND_CB_SIBLING;
502 }
503
504 /* Find a member called 'name' */
505 static Dwarf_Die *die_find_member(Dwarf_Die *st_die, const char *name,
506 Dwarf_Die *die_mem)
507 {
508 return die_find_child(st_die, __die_find_member_cb, (void *)name,
509 die_mem);
510 }
511
512 /* Get the name of given variable DIE */
513 static int die_get_typename(Dwarf_Die *vr_die, char *buf, int len)
514 {
515 Dwarf_Die type;
516 int tag, ret, ret2;
517 const char *tmp = "";
518
519 if (__die_get_real_type(vr_die, &type) == NULL)
520 return -ENOENT;
521
522 tag = dwarf_tag(&type);
523 if (tag == DW_TAG_array_type || tag == DW_TAG_pointer_type)
524 tmp = "*";
525 else if (tag == DW_TAG_subroutine_type) {
526 /* Function pointer */
527 ret = snprintf(buf, len, "(function_type)");
528 return (ret >= len) ? -E2BIG : ret;
529 } else {
530 if (!dwarf_diename(&type))
531 return -ENOENT;
532 if (tag == DW_TAG_union_type)
533 tmp = "union ";
534 else if (tag == DW_TAG_structure_type)
535 tmp = "struct ";
536 /* Write a base name */
537 ret = snprintf(buf, len, "%s%s", tmp, dwarf_diename(&type));
538 return (ret >= len) ? -E2BIG : ret;
539 }
540 ret = die_get_typename(&type, buf, len);
541 if (ret > 0) {
542 ret2 = snprintf(buf + ret, len - ret, "%s", tmp);
543 ret = (ret2 >= len - ret) ? -E2BIG : ret2 + ret;
544 }
545 return ret;
546 }
547
548 /* Get the name and type of given variable DIE, stored as "type\tname" */
549 static int die_get_varname(Dwarf_Die *vr_die, char *buf, int len)
550 {
551 int ret, ret2;
552
553 ret = die_get_typename(vr_die, buf, len);
554 if (ret < 0) {
555 pr_debug("Failed to get type, make it unknown.\n");
556 ret = snprintf(buf, len, "(unknown_type)");
557 }
558 if (ret > 0) {
559 ret2 = snprintf(buf + ret, len - ret, "\t%s",
560 dwarf_diename(vr_die));
561 ret = (ret2 >= len - ret) ? -E2BIG : ret2 + ret;
562 }
563 return ret;
564 }
565
566 /*
567 * Probe finder related functions
568 */
569
570 static struct probe_trace_arg_ref *alloc_trace_arg_ref(long offs)
571 {
572 struct probe_trace_arg_ref *ref;
573 ref = zalloc(sizeof(struct probe_trace_arg_ref));
574 if (ref != NULL)
575 ref->offset = offs;
576 return ref;
577 }
578
579 /*
580 * Convert a location into trace_arg.
581 * If tvar == NULL, this just checks variable can be converted.
582 */
583 static int convert_variable_location(Dwarf_Die *vr_die, Dwarf_Addr addr,
584 Dwarf_Op *fb_ops,
585 struct probe_trace_arg *tvar)
586 {
587 Dwarf_Attribute attr;
588 Dwarf_Op *op;
589 size_t nops;
590 unsigned int regn;
591 Dwarf_Word offs = 0;
592 bool ref = false;
593 const char *regs;
594 int ret;
595
596 if (dwarf_attr(vr_die, DW_AT_external, &attr) != NULL)
597 goto static_var;
598
599 /* TODO: handle more than 1 exprs */
600 if (dwarf_attr(vr_die, DW_AT_location, &attr) == NULL ||
601 dwarf_getlocation_addr(&attr, addr, &op, &nops, 1) <= 0 ||
602 nops == 0) {
603 /* TODO: Support const_value */
604 return -ENOENT;
605 }
606
607 if (op->atom == DW_OP_addr) {
608 static_var:
609 if (!tvar)
610 return 0;
611 /* Static variables on memory (not stack), make @varname */
612 ret = strlen(dwarf_diename(vr_die));
613 tvar->value = zalloc(ret + 2);
614 if (tvar->value == NULL)
615 return -ENOMEM;
616 snprintf(tvar->value, ret + 2, "@%s", dwarf_diename(vr_die));
617 tvar->ref = alloc_trace_arg_ref((long)offs);
618 if (tvar->ref == NULL)
619 return -ENOMEM;
620 return 0;
621 }
622
623 /* If this is based on frame buffer, set the offset */
624 if (op->atom == DW_OP_fbreg) {
625 if (fb_ops == NULL)
626 return -ENOTSUP;
627 ref = true;
628 offs = op->number;
629 op = &fb_ops[0];
630 }
631
632 if (op->atom >= DW_OP_breg0 && op->atom <= DW_OP_breg31) {
633 regn = op->atom - DW_OP_breg0;
634 offs += op->number;
635 ref = true;
636 } else if (op->atom >= DW_OP_reg0 && op->atom <= DW_OP_reg31) {
637 regn = op->atom - DW_OP_reg0;
638 } else if (op->atom == DW_OP_bregx) {
639 regn = op->number;
640 offs += op->number2;
641 ref = true;
642 } else if (op->atom == DW_OP_regx) {
643 regn = op->number;
644 } else {
645 pr_debug("DW_OP %x is not supported.\n", op->atom);
646 return -ENOTSUP;
647 }
648
649 if (!tvar)
650 return 0;
651
652 regs = get_arch_regstr(regn);
653 if (!regs) {
654 /* This should be a bug in DWARF or this tool */
655 pr_warning("Mapping for the register number %u "
656 "missing on this architecture.\n", regn);
657 return -ERANGE;
658 }
659
660 tvar->value = strdup(regs);
661 if (tvar->value == NULL)
662 return -ENOMEM;
663
664 if (ref) {
665 tvar->ref = alloc_trace_arg_ref((long)offs);
666 if (tvar->ref == NULL)
667 return -ENOMEM;
668 }
669 return 0;
670 }
671
672 static int convert_variable_type(Dwarf_Die *vr_die,
673 struct probe_trace_arg *tvar,
674 const char *cast)
675 {
676 struct probe_trace_arg_ref **ref_ptr = &tvar->ref;
677 Dwarf_Die type;
678 char buf[16];
679 int ret;
680
681 /* TODO: check all types */
682 if (cast && strcmp(cast, "string") != 0) {
683 /* Non string type is OK */
684 tvar->type = strdup(cast);
685 return (tvar->type == NULL) ? -ENOMEM : 0;
686 }
687
688 if (die_get_real_type(vr_die, &type) == NULL) {
689 pr_warning("Failed to get a type information of %s.\n",
690 dwarf_diename(vr_die));
691 return -ENOENT;
692 }
693
694 pr_debug("%s type is %s.\n",
695 dwarf_diename(vr_die), dwarf_diename(&type));
696
697 if (cast && strcmp(cast, "string") == 0) { /* String type */
698 ret = dwarf_tag(&type);
699 if (ret != DW_TAG_pointer_type &&
700 ret != DW_TAG_array_type) {
701 pr_warning("Failed to cast into string: "
702 "%s(%s) is not a pointer nor array.\n",
703 dwarf_diename(vr_die), dwarf_diename(&type));
704 return -EINVAL;
705 }
706 if (ret == DW_TAG_pointer_type) {
707 if (die_get_real_type(&type, &type) == NULL) {
708 pr_warning("Failed to get a type"
709 " information.\n");
710 return -ENOENT;
711 }
712 while (*ref_ptr)
713 ref_ptr = &(*ref_ptr)->next;
714 /* Add new reference with offset +0 */
715 *ref_ptr = zalloc(sizeof(struct probe_trace_arg_ref));
716 if (*ref_ptr == NULL) {
717 pr_warning("Out of memory error\n");
718 return -ENOMEM;
719 }
720 }
721 if (!die_compare_name(&type, "char") &&
722 !die_compare_name(&type, "unsigned char")) {
723 pr_warning("Failed to cast into string: "
724 "%s is not (unsigned) char *.\n",
725 dwarf_diename(vr_die));
726 return -EINVAL;
727 }
728 tvar->type = strdup(cast);
729 return (tvar->type == NULL) ? -ENOMEM : 0;
730 }
731
732 ret = die_get_byte_size(&type) * 8;
733 if (ret) {
734 /* Check the bitwidth */
735 if (ret > MAX_BASIC_TYPE_BITS) {
736 pr_info("%s exceeds max-bitwidth."
737 " Cut down to %d bits.\n",
738 dwarf_diename(&type), MAX_BASIC_TYPE_BITS);
739 ret = MAX_BASIC_TYPE_BITS;
740 }
741
742 ret = snprintf(buf, 16, "%c%d",
743 die_is_signed_type(&type) ? 's' : 'u', ret);
744 if (ret < 0 || ret >= 16) {
745 if (ret >= 16)
746 ret = -E2BIG;
747 pr_warning("Failed to convert variable type: %s\n",
748 strerror(-ret));
749 return ret;
750 }
751 tvar->type = strdup(buf);
752 if (tvar->type == NULL)
753 return -ENOMEM;
754 }
755 return 0;
756 }
757
758 static int convert_variable_fields(Dwarf_Die *vr_die, const char *varname,
759 struct perf_probe_arg_field *field,
760 struct probe_trace_arg_ref **ref_ptr,
761 Dwarf_Die *die_mem)
762 {
763 struct probe_trace_arg_ref *ref = *ref_ptr;
764 Dwarf_Die type;
765 Dwarf_Word offs;
766 int ret, tag;
767
768 pr_debug("converting %s in %s\n", field->name, varname);
769 if (die_get_real_type(vr_die, &type) == NULL) {
770 pr_warning("Failed to get the type of %s.\n", varname);
771 return -ENOENT;
772 }
773 pr_debug2("Var real type: (%x)\n", (unsigned)dwarf_dieoffset(&type));
774 tag = dwarf_tag(&type);
775
776 if (field->name[0] == '[' &&
777 (tag == DW_TAG_array_type || tag == DW_TAG_pointer_type)) {
778 if (field->next)
779 /* Save original type for next field */
780 memcpy(die_mem, &type, sizeof(*die_mem));
781 /* Get the type of this array */
782 if (die_get_real_type(&type, &type) == NULL) {
783 pr_warning("Failed to get the type of %s.\n", varname);
784 return -ENOENT;
785 }
786 pr_debug2("Array real type: (%x)\n",
787 (unsigned)dwarf_dieoffset(&type));
788 if (tag == DW_TAG_pointer_type) {
789 ref = zalloc(sizeof(struct probe_trace_arg_ref));
790 if (ref == NULL)
791 return -ENOMEM;
792 if (*ref_ptr)
793 (*ref_ptr)->next = ref;
794 else
795 *ref_ptr = ref;
796 }
797 ref->offset += die_get_byte_size(&type) * field->index;
798 if (!field->next)
799 /* Save vr_die for converting types */
800 memcpy(die_mem, vr_die, sizeof(*die_mem));
801 goto next;
802 } else if (tag == DW_TAG_pointer_type) {
803 /* Check the pointer and dereference */
804 if (!field->ref) {
805 pr_err("Semantic error: %s must be referred by '->'\n",
806 field->name);
807 return -EINVAL;
808 }
809 /* Get the type pointed by this pointer */
810 if (die_get_real_type(&type, &type) == NULL) {
811 pr_warning("Failed to get the type of %s.\n", varname);
812 return -ENOENT;
813 }
814 /* Verify it is a data structure */
815 if (dwarf_tag(&type) != DW_TAG_structure_type) {
816 pr_warning("%s is not a data structure.\n", varname);
817 return -EINVAL;
818 }
819
820 ref = zalloc(sizeof(struct probe_trace_arg_ref));
821 if (ref == NULL)
822 return -ENOMEM;
823 if (*ref_ptr)
824 (*ref_ptr)->next = ref;
825 else
826 *ref_ptr = ref;
827 } else {
828 /* Verify it is a data structure */
829 if (tag != DW_TAG_structure_type) {
830 pr_warning("%s is not a data structure.\n", varname);
831 return -EINVAL;
832 }
833 if (field->name[0] == '[') {
834 pr_err("Semantic error: %s is not a pointor"
835 " nor array.\n", varname);
836 return -EINVAL;
837 }
838 if (field->ref) {
839 pr_err("Semantic error: %s must be referred by '.'\n",
840 field->name);
841 return -EINVAL;
842 }
843 if (!ref) {
844 pr_warning("Structure on a register is not "
845 "supported yet.\n");
846 return -ENOTSUP;
847 }
848 }
849
850 if (die_find_member(&type, field->name, die_mem) == NULL) {
851 pr_warning("%s(tyep:%s) has no member %s.\n", varname,
852 dwarf_diename(&type), field->name);
853 return -EINVAL;
854 }
855
856 /* Get the offset of the field */
857 ret = die_get_data_member_location(die_mem, &offs);
858 if (ret < 0) {
859 pr_warning("Failed to get the offset of %s.\n", field->name);
860 return ret;
861 }
862 ref->offset += (long)offs;
863
864 next:
865 /* Converting next field */
866 if (field->next)
867 return convert_variable_fields(die_mem, field->name,
868 field->next, &ref, die_mem);
869 else
870 return 0;
871 }
872
873 /* Show a variables in kprobe event format */
874 static int convert_variable(Dwarf_Die *vr_die, struct probe_finder *pf)
875 {
876 Dwarf_Die die_mem;
877 int ret;
878
879 pr_debug("Converting variable %s into trace event.\n",
880 dwarf_diename(vr_die));
881
882 ret = convert_variable_location(vr_die, pf->addr, pf->fb_ops,
883 pf->tvar);
884 if (ret == -ENOENT)
885 pr_err("Failed to find the location of %s at this address.\n"
886 " Perhaps, it has been optimized out.\n", pf->pvar->var);
887 else if (ret == -ENOTSUP)
888 pr_err("Sorry, we don't support this variable location yet.\n");
889 else if (pf->pvar->field) {
890 ret = convert_variable_fields(vr_die, pf->pvar->var,
891 pf->pvar->field, &pf->tvar->ref,
892 &die_mem);
893 vr_die = &die_mem;
894 }
895 if (ret == 0)
896 ret = convert_variable_type(vr_die, pf->tvar, pf->pvar->type);
897 /* *expr will be cached in libdw. Don't free it. */
898 return ret;
899 }
900
901 /* Find a variable in a subprogram die */
902 static int find_variable(Dwarf_Die *sp_die, struct probe_finder *pf)
903 {
904 Dwarf_Die vr_die, *scopes;
905 char buf[32], *ptr;
906 int ret, nscopes;
907
908 if (!is_c_varname(pf->pvar->var)) {
909 /* Copy raw parameters */
910 pf->tvar->value = strdup(pf->pvar->var);
911 if (pf->tvar->value == NULL)
912 return -ENOMEM;
913 if (pf->pvar->type) {
914 pf->tvar->type = strdup(pf->pvar->type);
915 if (pf->tvar->type == NULL)
916 return -ENOMEM;
917 }
918 if (pf->pvar->name) {
919 pf->tvar->name = strdup(pf->pvar->name);
920 if (pf->tvar->name == NULL)
921 return -ENOMEM;
922 } else
923 pf->tvar->name = NULL;
924 return 0;
925 }
926
927 if (pf->pvar->name)
928 pf->tvar->name = strdup(pf->pvar->name);
929 else {
930 ret = synthesize_perf_probe_arg(pf->pvar, buf, 32);
931 if (ret < 0)
932 return ret;
933 ptr = strchr(buf, ':'); /* Change type separator to _ */
934 if (ptr)
935 *ptr = '_';
936 pf->tvar->name = strdup(buf);
937 }
938 if (pf->tvar->name == NULL)
939 return -ENOMEM;
940
941 pr_debug("Searching '%s' variable in context.\n",
942 pf->pvar->var);
943 /* Search child die for local variables and parameters. */
944 if (die_find_variable_at(sp_die, pf->pvar->var, pf->addr, &vr_die))
945 ret = convert_variable(&vr_die, pf);
946 else {
947 /* Search upper class */
948 nscopes = dwarf_getscopes_die(sp_die, &scopes);
949 while (nscopes-- > 1) {
950 pr_debug("Searching variables in %s\n",
951 dwarf_diename(&scopes[nscopes]));
952 /* We should check this scope, so give dummy address */
953 if (die_find_variable_at(&scopes[nscopes],
954 pf->pvar->var, 0,
955 &vr_die)) {
956 ret = convert_variable(&vr_die, pf);
957 goto found;
958 }
959 }
960 if (scopes)
961 free(scopes);
962 ret = -ENOENT;
963 }
964 found:
965 if (ret < 0)
966 pr_warning("Failed to find '%s' in this function.\n",
967 pf->pvar->var);
968 return ret;
969 }
970
971 /* Convert subprogram DIE to trace point */
972 static int convert_to_trace_point(Dwarf_Die *sp_die, Dwarf_Addr paddr,
973 bool retprobe, struct probe_trace_point *tp)
974 {
975 Dwarf_Addr eaddr;
976 const char *name;
977
978 /* Copy the name of probe point */
979 name = dwarf_diename(sp_die);
980 if (name) {
981 if (dwarf_entrypc(sp_die, &eaddr) != 0) {
982 pr_warning("Failed to get entry address of %s\n",
983 dwarf_diename(sp_die));
984 return -ENOENT;
985 }
986 tp->symbol = strdup(name);
987 if (tp->symbol == NULL)
988 return -ENOMEM;
989 tp->offset = (unsigned long)(paddr - eaddr);
990 } else
991 /* This function has no name. */
992 tp->offset = (unsigned long)paddr;
993
994 /* Return probe must be on the head of a subprogram */
995 if (retprobe) {
996 if (eaddr != paddr) {
997 pr_warning("Return probe must be on the head of"
998 " a real function.\n");
999 return -EINVAL;
1000 }
1001 tp->retprobe = true;
1002 }
1003
1004 return 0;
1005 }
1006
1007 /* Call probe_finder callback with real subprogram DIE */
1008 static int call_probe_finder(Dwarf_Die *sp_die, struct probe_finder *pf)
1009 {
1010 Dwarf_Die die_mem;
1011 Dwarf_Attribute fb_attr;
1012 size_t nops;
1013 int ret;
1014
1015 /* If no real subprogram, find a real one */
1016 if (!sp_die || dwarf_tag(sp_die) != DW_TAG_subprogram) {
1017 sp_die = die_find_real_subprogram(&pf->cu_die,
1018 pf->addr, &die_mem);
1019 if (!sp_die) {
1020 pr_warning("Failed to find probe point in any "
1021 "functions.\n");
1022 return -ENOENT;
1023 }
1024 }
1025
1026 /* Get the frame base attribute/ops */
1027 dwarf_attr(sp_die, DW_AT_frame_base, &fb_attr);
1028 ret = dwarf_getlocation_addr(&fb_attr, pf->addr, &pf->fb_ops, &nops, 1);
1029 if (ret <= 0 || nops == 0) {
1030 pf->fb_ops = NULL;
1031 #if _ELFUTILS_PREREQ(0, 142)
1032 } else if (nops == 1 && pf->fb_ops[0].atom == DW_OP_call_frame_cfa &&
1033 pf->cfi != NULL) {
1034 Dwarf_Frame *frame;
1035 if (dwarf_cfi_addrframe(pf->cfi, pf->addr, &frame) != 0 ||
1036 dwarf_frame_cfa(frame, &pf->fb_ops, &nops) != 0) {
1037 pr_warning("Failed to get call frame on 0x%jx\n",
1038 (uintmax_t)pf->addr);
1039 return -ENOENT;
1040 }
1041 #endif
1042 }
1043
1044 /* Call finder's callback handler */
1045 ret = pf->callback(sp_die, pf);
1046
1047 /* *pf->fb_ops will be cached in libdw. Don't free it. */
1048 pf->fb_ops = NULL;
1049
1050 return ret;
1051 }
1052
1053 /* Find probe point from its line number */
1054 static int find_probe_point_by_line(struct probe_finder *pf)
1055 {
1056 Dwarf_Lines *lines;
1057 Dwarf_Line *line;
1058 size_t nlines, i;
1059 Dwarf_Addr addr;
1060 int lineno;
1061 int ret = 0;
1062
1063 if (dwarf_getsrclines(&pf->cu_die, &lines, &nlines) != 0) {
1064 pr_warning("No source lines found.\n");
1065 return -ENOENT;
1066 }
1067
1068 for (i = 0; i < nlines && ret == 0; i++) {
1069 line = dwarf_onesrcline(lines, i);
1070 if (dwarf_lineno(line, &lineno) != 0 ||
1071 lineno != pf->lno)
1072 continue;
1073
1074 /* TODO: Get fileno from line, but how? */
1075 if (strtailcmp(dwarf_linesrc(line, NULL, NULL), pf->fname) != 0)
1076 continue;
1077
1078 if (dwarf_lineaddr(line, &addr) != 0) {
1079 pr_warning("Failed to get the address of the line.\n");
1080 return -ENOENT;
1081 }
1082 pr_debug("Probe line found: line[%d]:%d addr:0x%jx\n",
1083 (int)i, lineno, (uintmax_t)addr);
1084 pf->addr = addr;
1085
1086 ret = call_probe_finder(NULL, pf);
1087 /* Continuing, because target line might be inlined. */
1088 }
1089 return ret;
1090 }
1091
1092 /* Find lines which match lazy pattern */
1093 static int find_lazy_match_lines(struct list_head *head,
1094 const char *fname, const char *pat)
1095 {
1096 char *fbuf, *p1, *p2;
1097 int fd, line, nlines = -1;
1098 struct stat st;
1099
1100 fd = open(fname, O_RDONLY);
1101 if (fd < 0) {
1102 pr_warning("Failed to open %s: %s\n", fname, strerror(-fd));
1103 return -errno;
1104 }
1105
1106 if (fstat(fd, &st) < 0) {
1107 pr_warning("Failed to get the size of %s: %s\n",
1108 fname, strerror(errno));
1109 nlines = -errno;
1110 goto out_close;
1111 }
1112
1113 nlines = -ENOMEM;
1114 fbuf = malloc(st.st_size + 2);
1115 if (fbuf == NULL)
1116 goto out_close;
1117 if (read(fd, fbuf, st.st_size) < 0) {
1118 pr_warning("Failed to read %s: %s\n", fname, strerror(errno));
1119 nlines = -errno;
1120 goto out_free_fbuf;
1121 }
1122 fbuf[st.st_size] = '\n'; /* Dummy line */
1123 fbuf[st.st_size + 1] = '\0';
1124 p1 = fbuf;
1125 line = 1;
1126 nlines = 0;
1127 while ((p2 = strchr(p1, '\n')) != NULL) {
1128 *p2 = '\0';
1129 if (strlazymatch(p1, pat)) {
1130 line_list__add_line(head, line);
1131 nlines++;
1132 }
1133 line++;
1134 p1 = p2 + 1;
1135 }
1136 out_free_fbuf:
1137 free(fbuf);
1138 out_close:
1139 close(fd);
1140 return nlines;
1141 }
1142
1143 /* Find probe points from lazy pattern */
1144 static int find_probe_point_lazy(Dwarf_Die *sp_die, struct probe_finder *pf)
1145 {
1146 Dwarf_Lines *lines;
1147 Dwarf_Line *line;
1148 size_t nlines, i;
1149 Dwarf_Addr addr;
1150 Dwarf_Die die_mem;
1151 int lineno;
1152 int ret = 0;
1153
1154 if (list_empty(&pf->lcache)) {
1155 /* Matching lazy line pattern */
1156 ret = find_lazy_match_lines(&pf->lcache, pf->fname,
1157 pf->pev->point.lazy_line);
1158 if (ret == 0) {
1159 pr_debug("No matched lines found in %s.\n", pf->fname);
1160 return 0;
1161 } else if (ret < 0)
1162 return ret;
1163 }
1164
1165 if (dwarf_getsrclines(&pf->cu_die, &lines, &nlines) != 0) {
1166 pr_warning("No source lines found.\n");
1167 return -ENOENT;
1168 }
1169
1170 for (i = 0; i < nlines && ret >= 0; i++) {
1171 line = dwarf_onesrcline(lines, i);
1172
1173 if (dwarf_lineno(line, &lineno) != 0 ||
1174 !line_list__has_line(&pf->lcache, lineno))
1175 continue;
1176
1177 /* TODO: Get fileno from line, but how? */
1178 if (strtailcmp(dwarf_linesrc(line, NULL, NULL), pf->fname) != 0)
1179 continue;
1180
1181 if (dwarf_lineaddr(line, &addr) != 0) {
1182 pr_debug("Failed to get the address of line %d.\n",
1183 lineno);
1184 continue;
1185 }
1186 if (sp_die) {
1187 /* Address filtering 1: does sp_die include addr? */
1188 if (!dwarf_haspc(sp_die, addr))
1189 continue;
1190 /* Address filtering 2: No child include addr? */
1191 if (die_find_inlinefunc(sp_die, addr, &die_mem))
1192 continue;
1193 }
1194
1195 pr_debug("Probe line found: line[%d]:%d addr:0x%llx\n",
1196 (int)i, lineno, (unsigned long long)addr);
1197 pf->addr = addr;
1198
1199 ret = call_probe_finder(sp_die, pf);
1200 /* Continuing, because target line might be inlined. */
1201 }
1202 /* TODO: deallocate lines, but how? */
1203 return ret;
1204 }
1205
1206 /* Callback parameter with return value */
1207 struct dwarf_callback_param {
1208 void *data;
1209 int retval;
1210 };
1211
1212 static int probe_point_inline_cb(Dwarf_Die *in_die, void *data)
1213 {
1214 struct dwarf_callback_param *param = data;
1215 struct probe_finder *pf = param->data;
1216 struct perf_probe_point *pp = &pf->pev->point;
1217 Dwarf_Addr addr;
1218
1219 if (pp->lazy_line)
1220 param->retval = find_probe_point_lazy(in_die, pf);
1221 else {
1222 /* Get probe address */
1223 if (dwarf_entrypc(in_die, &addr) != 0) {
1224 pr_warning("Failed to get entry address of %s.\n",
1225 dwarf_diename(in_die));
1226 param->retval = -ENOENT;
1227 return DWARF_CB_ABORT;
1228 }
1229 pf->addr = addr;
1230 pf->addr += pp->offset;
1231 pr_debug("found inline addr: 0x%jx\n",
1232 (uintmax_t)pf->addr);
1233
1234 param->retval = call_probe_finder(in_die, pf);
1235 if (param->retval < 0)
1236 return DWARF_CB_ABORT;
1237 }
1238
1239 return DWARF_CB_OK;
1240 }
1241
1242 /* Search function from function name */
1243 static int probe_point_search_cb(Dwarf_Die *sp_die, void *data)
1244 {
1245 struct dwarf_callback_param *param = data;
1246 struct probe_finder *pf = param->data;
1247 struct perf_probe_point *pp = &pf->pev->point;
1248
1249 /* Check tag and diename */
1250 if (dwarf_tag(sp_die) != DW_TAG_subprogram ||
1251 !die_compare_name(sp_die, pp->function))
1252 return DWARF_CB_OK;
1253
1254 pf->fname = dwarf_decl_file(sp_die);
1255 if (pp->line) { /* Function relative line */
1256 dwarf_decl_line(sp_die, &pf->lno);
1257 pf->lno += pp->line;
1258 param->retval = find_probe_point_by_line(pf);
1259 } else if (!dwarf_func_inline(sp_die)) {
1260 /* Real function */
1261 if (pp->lazy_line)
1262 param->retval = find_probe_point_lazy(sp_die, pf);
1263 else {
1264 if (dwarf_entrypc(sp_die, &pf->addr) != 0) {
1265 pr_warning("Failed to get entry address of "
1266 "%s.\n", dwarf_diename(sp_die));
1267 param->retval = -ENOENT;
1268 return DWARF_CB_ABORT;
1269 }
1270 pf->addr += pp->offset;
1271 /* TODO: Check the address in this function */
1272 param->retval = call_probe_finder(sp_die, pf);
1273 }
1274 } else {
1275 struct dwarf_callback_param _param = {.data = (void *)pf,
1276 .retval = 0};
1277 /* Inlined function: search instances */
1278 dwarf_func_inline_instances(sp_die, probe_point_inline_cb,
1279 &_param);
1280 param->retval = _param.retval;
1281 }
1282
1283 return DWARF_CB_ABORT; /* Exit; no same symbol in this CU. */
1284 }
1285
1286 static int find_probe_point_by_func(struct probe_finder *pf)
1287 {
1288 struct dwarf_callback_param _param = {.data = (void *)pf,
1289 .retval = 0};
1290 dwarf_getfuncs(&pf->cu_die, probe_point_search_cb, &_param, 0);
1291 return _param.retval;
1292 }
1293
1294 /* Find probe points from debuginfo */
1295 static int find_probes(int fd, struct probe_finder *pf)
1296 {
1297 struct perf_probe_point *pp = &pf->pev->point;
1298 Dwarf_Off off, noff;
1299 size_t cuhl;
1300 Dwarf_Die *diep;
1301 Dwarf *dbg = NULL;
1302 Dwfl *dwfl;
1303 Dwarf_Addr bias; /* Currently ignored */
1304 int ret = 0;
1305
1306 dbg = dwfl_init_offline_dwarf(fd, &dwfl, &bias);
1307 if (!dbg) {
1308 pr_warning("No debug information found in the vmlinux - "
1309 "please rebuild with CONFIG_DEBUG_INFO=y.\n");
1310 return -EBADF;
1311 }
1312
1313 #if _ELFUTILS_PREREQ(0, 142)
1314 /* Get the call frame information from this dwarf */
1315 pf->cfi = dwarf_getcfi(dbg);
1316 #endif
1317
1318 off = 0;
1319 line_list__init(&pf->lcache);
1320 /* Loop on CUs (Compilation Unit) */
1321 while (!dwarf_nextcu(dbg, off, &noff, &cuhl, NULL, NULL, NULL) &&
1322 ret >= 0) {
1323 /* Get the DIE(Debugging Information Entry) of this CU */
1324 diep = dwarf_offdie(dbg, off + cuhl, &pf->cu_die);
1325 if (!diep)
1326 continue;
1327
1328 /* Check if target file is included. */
1329 if (pp->file)
1330 pf->fname = cu_find_realpath(&pf->cu_die, pp->file);
1331 else
1332 pf->fname = NULL;
1333
1334 if (!pp->file || pf->fname) {
1335 if (pp->function)
1336 ret = find_probe_point_by_func(pf);
1337 else if (pp->lazy_line)
1338 ret = find_probe_point_lazy(NULL, pf);
1339 else {
1340 pf->lno = pp->line;
1341 ret = find_probe_point_by_line(pf);
1342 }
1343 }
1344 off = noff;
1345 }
1346 line_list__free(&pf->lcache);
1347 if (dwfl)
1348 dwfl_end(dwfl);
1349
1350 return ret;
1351 }
1352
1353 /* Add a found probe point into trace event list */
1354 static int add_probe_trace_event(Dwarf_Die *sp_die, struct probe_finder *pf)
1355 {
1356 struct trace_event_finder *tf =
1357 container_of(pf, struct trace_event_finder, pf);
1358 struct probe_trace_event *tev;
1359 int ret, i;
1360
1361 /* Check number of tevs */
1362 if (tf->ntevs == tf->max_tevs) {
1363 pr_warning("Too many( > %d) probe point found.\n",
1364 tf->max_tevs);
1365 return -ERANGE;
1366 }
1367 tev = &tf->tevs[tf->ntevs++];
1368
1369 ret = convert_to_trace_point(sp_die, pf->addr, pf->pev->point.retprobe,
1370 &tev->point);
1371 if (ret < 0)
1372 return ret;
1373
1374 pr_debug("Probe point found: %s+%lu\n", tev->point.symbol,
1375 tev->point.offset);
1376
1377 /* Find each argument */
1378 tev->nargs = pf->pev->nargs;
1379 tev->args = zalloc(sizeof(struct probe_trace_arg) * tev->nargs);
1380 if (tev->args == NULL)
1381 return -ENOMEM;
1382 for (i = 0; i < pf->pev->nargs; i++) {
1383 pf->pvar = &pf->pev->args[i];
1384 pf->tvar = &tev->args[i];
1385 ret = find_variable(sp_die, pf);
1386 if (ret != 0)
1387 return ret;
1388 }
1389
1390 return 0;
1391 }
1392
1393 /* Find probe_trace_events specified by perf_probe_event from debuginfo */
1394 int find_probe_trace_events(int fd, struct perf_probe_event *pev,
1395 struct probe_trace_event **tevs, int max_tevs)
1396 {
1397 struct trace_event_finder tf = {
1398 .pf = {.pev = pev, .callback = add_probe_trace_event},
1399 .max_tevs = max_tevs};
1400 int ret;
1401
1402 /* Allocate result tevs array */
1403 *tevs = zalloc(sizeof(struct probe_trace_event) * max_tevs);
1404 if (*tevs == NULL)
1405 return -ENOMEM;
1406
1407 tf.tevs = *tevs;
1408 tf.ntevs = 0;
1409
1410 ret = find_probes(fd, &tf.pf);
1411 if (ret < 0) {
1412 free(*tevs);
1413 *tevs = NULL;
1414 return ret;
1415 }
1416
1417 return (ret < 0) ? ret : tf.ntevs;
1418 }
1419
1420 #define MAX_VAR_LEN 64
1421
1422 /* Collect available variables in this scope */
1423 static int collect_variables_cb(Dwarf_Die *die_mem, void *data)
1424 {
1425 struct available_var_finder *af = data;
1426 struct variable_list *vl;
1427 char buf[MAX_VAR_LEN];
1428 int tag, ret;
1429
1430 vl = &af->vls[af->nvls - 1];
1431
1432 tag = dwarf_tag(die_mem);
1433 if (tag == DW_TAG_formal_parameter ||
1434 tag == DW_TAG_variable) {
1435 ret = convert_variable_location(die_mem, af->pf.addr,
1436 af->pf.fb_ops, NULL);
1437 if (ret == 0) {
1438 ret = die_get_varname(die_mem, buf, MAX_VAR_LEN);
1439 pr_debug2("Add new var: %s\n", buf);
1440 if (ret > 0)
1441 strlist__add(vl->vars, buf);
1442 }
1443 }
1444
1445 if (af->child && dwarf_haspc(die_mem, af->pf.addr))
1446 return DIE_FIND_CB_CONTINUE;
1447 else
1448 return DIE_FIND_CB_SIBLING;
1449 }
1450
1451 /* Add a found vars into available variables list */
1452 static int add_available_vars(Dwarf_Die *sp_die, struct probe_finder *pf)
1453 {
1454 struct available_var_finder *af =
1455 container_of(pf, struct available_var_finder, pf);
1456 struct variable_list *vl;
1457 Dwarf_Die die_mem, *scopes = NULL;
1458 int ret, nscopes;
1459
1460 /* Check number of tevs */
1461 if (af->nvls == af->max_vls) {
1462 pr_warning("Too many( > %d) probe point found.\n", af->max_vls);
1463 return -ERANGE;
1464 }
1465 vl = &af->vls[af->nvls++];
1466
1467 ret = convert_to_trace_point(sp_die, pf->addr, pf->pev->point.retprobe,
1468 &vl->point);
1469 if (ret < 0)
1470 return ret;
1471
1472 pr_debug("Probe point found: %s+%lu\n", vl->point.symbol,
1473 vl->point.offset);
1474
1475 /* Find local variables */
1476 vl->vars = strlist__new(true, NULL);
1477 if (vl->vars == NULL)
1478 return -ENOMEM;
1479 af->child = true;
1480 die_find_child(sp_die, collect_variables_cb, (void *)af, &die_mem);
1481
1482 /* Find external variables */
1483 if (!af->externs)
1484 goto out;
1485 /* Don't need to search child DIE for externs. */
1486 af->child = false;
1487 nscopes = dwarf_getscopes_die(sp_die, &scopes);
1488 while (nscopes-- > 1)
1489 die_find_child(&scopes[nscopes], collect_variables_cb,
1490 (void *)af, &die_mem);
1491 if (scopes)
1492 free(scopes);
1493
1494 out:
1495 if (strlist__empty(vl->vars)) {
1496 strlist__delete(vl->vars);
1497 vl->vars = NULL;
1498 }
1499
1500 return ret;
1501 }
1502
1503 /* Find available variables at given probe point */
1504 int find_available_vars_at(int fd, struct perf_probe_event *pev,
1505 struct variable_list **vls, int max_vls,
1506 bool externs)
1507 {
1508 struct available_var_finder af = {
1509 .pf = {.pev = pev, .callback = add_available_vars},
1510 .max_vls = max_vls, .externs = externs};
1511 int ret;
1512
1513 /* Allocate result vls array */
1514 *vls = zalloc(sizeof(struct variable_list) * max_vls);
1515 if (*vls == NULL)
1516 return -ENOMEM;
1517
1518 af.vls = *vls;
1519 af.nvls = 0;
1520
1521 ret = find_probes(fd, &af.pf);
1522 if (ret < 0) {
1523 /* Free vlist for error */
1524 while (af.nvls--) {
1525 if (af.vls[af.nvls].point.symbol)
1526 free(af.vls[af.nvls].point.symbol);
1527 if (af.vls[af.nvls].vars)
1528 strlist__delete(af.vls[af.nvls].vars);
1529 }
1530 free(af.vls);
1531 *vls = NULL;
1532 return ret;
1533 }
1534
1535 return (ret < 0) ? ret : af.nvls;
1536 }
1537
1538 /* Reverse search */
1539 int find_perf_probe_point(unsigned long addr, struct perf_probe_point *ppt)
1540 {
1541 Dwarf_Die cudie, spdie, indie;
1542 Dwarf *dbg = NULL;
1543 Dwfl *dwfl = NULL;
1544 Dwarf_Line *line;
1545 Dwarf_Addr laddr, eaddr, bias = 0;
1546 const char *tmp;
1547 int lineno, ret = 0;
1548 bool found = false;
1549
1550 /* Open the live linux kernel */
1551 dbg = dwfl_init_live_kernel_dwarf(addr, &dwfl, &bias);
1552 if (!dbg) {
1553 pr_warning("No debug information found in the vmlinux - "
1554 "please rebuild with CONFIG_DEBUG_INFO=y.\n");
1555 ret = -EINVAL;
1556 goto end;
1557 }
1558
1559 /* Adjust address with bias */
1560 addr += bias;
1561 /* Find cu die */
1562 if (!dwarf_addrdie(dbg, (Dwarf_Addr)addr - bias, &cudie)) {
1563 pr_warning("Failed to find debug information for address %lx\n",
1564 addr);
1565 ret = -EINVAL;
1566 goto end;
1567 }
1568
1569 /* Find a corresponding line */
1570 line = dwarf_getsrc_die(&cudie, (Dwarf_Addr)addr);
1571 if (line) {
1572 if (dwarf_lineaddr(line, &laddr) == 0 &&
1573 (Dwarf_Addr)addr == laddr &&
1574 dwarf_lineno(line, &lineno) == 0) {
1575 tmp = dwarf_linesrc(line, NULL, NULL);
1576 if (tmp) {
1577 ppt->line = lineno;
1578 ppt->file = strdup(tmp);
1579 if (ppt->file == NULL) {
1580 ret = -ENOMEM;
1581 goto end;
1582 }
1583 found = true;
1584 }
1585 }
1586 }
1587
1588 /* Find a corresponding function */
1589 if (die_find_real_subprogram(&cudie, (Dwarf_Addr)addr, &spdie)) {
1590 tmp = dwarf_diename(&spdie);
1591 if (!tmp || dwarf_entrypc(&spdie, &eaddr) != 0)
1592 goto end;
1593
1594 if (ppt->line) {
1595 if (die_find_inlinefunc(&spdie, (Dwarf_Addr)addr,
1596 &indie)) {
1597 /* addr in an inline function */
1598 tmp = dwarf_diename(&indie);
1599 if (!tmp)
1600 goto end;
1601 ret = dwarf_decl_line(&indie, &lineno);
1602 } else {
1603 if (eaddr == addr) { /* Function entry */
1604 lineno = ppt->line;
1605 ret = 0;
1606 } else
1607 ret = dwarf_decl_line(&spdie, &lineno);
1608 }
1609 if (ret == 0) {
1610 /* Make a relative line number */
1611 ppt->line -= lineno;
1612 goto found;
1613 }
1614 }
1615 /* We don't have a line number, let's use offset */
1616 ppt->offset = addr - (unsigned long)eaddr;
1617 found:
1618 ppt->function = strdup(tmp);
1619 if (ppt->function == NULL) {
1620 ret = -ENOMEM;
1621 goto end;
1622 }
1623 found = true;
1624 }
1625
1626 end:
1627 if (dwfl)
1628 dwfl_end(dwfl);
1629 if (ret >= 0)
1630 ret = found ? 1 : 0;
1631 return ret;
1632 }
1633
1634 /* Add a line and store the src path */
1635 static int line_range_add_line(const char *src, unsigned int lineno,
1636 struct line_range *lr)
1637 {
1638 /* Copy source path */
1639 if (!lr->path) {
1640 lr->path = strdup(src);
1641 if (lr->path == NULL)
1642 return -ENOMEM;
1643 }
1644 return line_list__add_line(&lr->line_list, lineno);
1645 }
1646
1647 /* Search function declaration lines */
1648 static int line_range_funcdecl_cb(Dwarf_Die *sp_die, void *data)
1649 {
1650 struct dwarf_callback_param *param = data;
1651 struct line_finder *lf = param->data;
1652 const char *src;
1653 int lineno;
1654
1655 src = dwarf_decl_file(sp_die);
1656 if (src && strtailcmp(src, lf->fname) != 0)
1657 return DWARF_CB_OK;
1658
1659 if (dwarf_decl_line(sp_die, &lineno) != 0 ||
1660 (lf->lno_s > lineno || lf->lno_e < lineno))
1661 return DWARF_CB_OK;
1662
1663 param->retval = line_range_add_line(src, lineno, lf->lr);
1664 if (param->retval < 0)
1665 return DWARF_CB_ABORT;
1666 return DWARF_CB_OK;
1667 }
1668
1669 static int find_line_range_func_decl_lines(struct line_finder *lf)
1670 {
1671 struct dwarf_callback_param param = {.data = (void *)lf, .retval = 0};
1672 dwarf_getfuncs(&lf->cu_die, line_range_funcdecl_cb, &param, 0);
1673 return param.retval;
1674 }
1675
1676 /* Find line range from its line number */
1677 static int find_line_range_by_line(Dwarf_Die *sp_die, struct line_finder *lf)
1678 {
1679 Dwarf_Lines *lines;
1680 Dwarf_Line *line;
1681 size_t nlines, i;
1682 Dwarf_Addr addr;
1683 int lineno, ret = 0;
1684 const char *src;
1685 Dwarf_Die die_mem;
1686
1687 line_list__init(&lf->lr->line_list);
1688 if (dwarf_getsrclines(&lf->cu_die, &lines, &nlines) != 0) {
1689 pr_warning("No source lines found.\n");
1690 return -ENOENT;
1691 }
1692
1693 /* Search probable lines on lines list */
1694 for (i = 0; i < nlines; i++) {
1695 line = dwarf_onesrcline(lines, i);
1696 if (dwarf_lineno(line, &lineno) != 0 ||
1697 (lf->lno_s > lineno || lf->lno_e < lineno))
1698 continue;
1699
1700 if (sp_die) {
1701 /* Address filtering 1: does sp_die include addr? */
1702 if (dwarf_lineaddr(line, &addr) != 0 ||
1703 !dwarf_haspc(sp_die, addr))
1704 continue;
1705
1706 /* Address filtering 2: No child include addr? */
1707 if (die_find_inlinefunc(sp_die, addr, &die_mem))
1708 continue;
1709 }
1710
1711 /* TODO: Get fileno from line, but how? */
1712 src = dwarf_linesrc(line, NULL, NULL);
1713 if (strtailcmp(src, lf->fname) != 0)
1714 continue;
1715
1716 ret = line_range_add_line(src, lineno, lf->lr);
1717 if (ret < 0)
1718 return ret;
1719 }
1720
1721 /*
1722 * Dwarf lines doesn't include function declarations. We have to
1723 * check functions list or given function.
1724 */
1725 if (sp_die) {
1726 src = dwarf_decl_file(sp_die);
1727 if (src && dwarf_decl_line(sp_die, &lineno) == 0 &&
1728 (lf->lno_s <= lineno && lf->lno_e >= lineno))
1729 ret = line_range_add_line(src, lineno, lf->lr);
1730 } else
1731 ret = find_line_range_func_decl_lines(lf);
1732
1733 /* Update status */
1734 if (ret >= 0)
1735 if (!list_empty(&lf->lr->line_list))
1736 ret = lf->found = 1;
1737 else
1738 ret = 0; /* Lines are not found */
1739 else {
1740 free(lf->lr->path);
1741 lf->lr->path = NULL;
1742 }
1743 return ret;
1744 }
1745
1746 static int line_range_inline_cb(Dwarf_Die *in_die, void *data)
1747 {
1748 struct dwarf_callback_param *param = data;
1749
1750 param->retval = find_line_range_by_line(in_die, param->data);
1751 return DWARF_CB_ABORT; /* No need to find other instances */
1752 }
1753
1754 /* Search function from function name */
1755 static int line_range_search_cb(Dwarf_Die *sp_die, void *data)
1756 {
1757 struct dwarf_callback_param *param = data;
1758 struct line_finder *lf = param->data;
1759 struct line_range *lr = lf->lr;
1760
1761 pr_debug("find (%llx) %s\n",
1762 (unsigned long long)dwarf_dieoffset(sp_die),
1763 dwarf_diename(sp_die));
1764 if (dwarf_tag(sp_die) == DW_TAG_subprogram &&
1765 die_compare_name(sp_die, lr->function)) {
1766 lf->fname = dwarf_decl_file(sp_die);
1767 dwarf_decl_line(sp_die, &lr->offset);
1768 pr_debug("fname: %s, lineno:%d\n", lf->fname, lr->offset);
1769 lf->lno_s = lr->offset + lr->start;
1770 if (lf->lno_s < 0) /* Overflow */
1771 lf->lno_s = INT_MAX;
1772 lf->lno_e = lr->offset + lr->end;
1773 if (lf->lno_e < 0) /* Overflow */
1774 lf->lno_e = INT_MAX;
1775 pr_debug("New line range: %d to %d\n", lf->lno_s, lf->lno_e);
1776 lr->start = lf->lno_s;
1777 lr->end = lf->lno_e;
1778 if (dwarf_func_inline(sp_die)) {
1779 struct dwarf_callback_param _param;
1780 _param.data = (void *)lf;
1781 _param.retval = 0;
1782 dwarf_func_inline_instances(sp_die,
1783 line_range_inline_cb,
1784 &_param);
1785 param->retval = _param.retval;
1786 } else
1787 param->retval = find_line_range_by_line(sp_die, lf);
1788 return DWARF_CB_ABORT;
1789 }
1790 return DWARF_CB_OK;
1791 }
1792
1793 static int find_line_range_by_func(struct line_finder *lf)
1794 {
1795 struct dwarf_callback_param param = {.data = (void *)lf, .retval = 0};
1796 dwarf_getfuncs(&lf->cu_die, line_range_search_cb, &param, 0);
1797 return param.retval;
1798 }
1799
1800 int find_line_range(int fd, struct line_range *lr)
1801 {
1802 struct line_finder lf = {.lr = lr, .found = 0};
1803 int ret = 0;
1804 Dwarf_Off off = 0, noff;
1805 size_t cuhl;
1806 Dwarf_Die *diep;
1807 Dwarf *dbg = NULL;
1808 Dwfl *dwfl;
1809 Dwarf_Addr bias; /* Currently ignored */
1810 const char *comp_dir;
1811
1812 dbg = dwfl_init_offline_dwarf(fd, &dwfl, &bias);
1813 if (!dbg) {
1814 pr_warning("No debug information found in the vmlinux - "
1815 "please rebuild with CONFIG_DEBUG_INFO=y.\n");
1816 return -EBADF;
1817 }
1818
1819 /* Loop on CUs (Compilation Unit) */
1820 while (!lf.found && ret >= 0) {
1821 if (dwarf_nextcu(dbg, off, &noff, &cuhl, NULL, NULL, NULL) != 0)
1822 break;
1823
1824 /* Get the DIE(Debugging Information Entry) of this CU */
1825 diep = dwarf_offdie(dbg, off + cuhl, &lf.cu_die);
1826 if (!diep)
1827 continue;
1828
1829 /* Check if target file is included. */
1830 if (lr->file)
1831 lf.fname = cu_find_realpath(&lf.cu_die, lr->file);
1832 else
1833 lf.fname = 0;
1834
1835 if (!lr->file || lf.fname) {
1836 if (lr->function)
1837 ret = find_line_range_by_func(&lf);
1838 else {
1839 lf.lno_s = lr->start;
1840 lf.lno_e = lr->end;
1841 ret = find_line_range_by_line(NULL, &lf);
1842 }
1843 }
1844 off = noff;
1845 }
1846
1847 /* Store comp_dir */
1848 if (lf.found) {
1849 comp_dir = cu_get_comp_dir(&lf.cu_die);
1850 if (comp_dir) {
1851 lr->comp_dir = strdup(comp_dir);
1852 if (!lr->comp_dir)
1853 ret = -ENOMEM;
1854 }
1855 }
1856
1857 pr_debug("path: %s\n", lr->path);
1858 dwfl_end(dwfl);
1859 return (ret < 0) ? ret : lf.found;
1860 }
1861
Linux with added FPC-III support