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perf probe: Fix to support libdwfl older than 0.148
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / tools / perf / util / probe-finder.c
blobddf4d45563218ad9e2d8971d32f2a8f25097c502
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 DWARF register number %u "
656 "missing on this architecture.", 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.",
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 information.");
709 return -ENOENT;
710 }
711 while (*ref_ptr)
712 ref_ptr = &(*ref_ptr)->next;
713 /* Add new reference with offset +0 */
714 *ref_ptr = zalloc(sizeof(struct probe_trace_arg_ref));
715 if (*ref_ptr == NULL) {
716 pr_warning("Out of memory error\n");
717 return -ENOMEM;
718 }
719 }
720 if (!die_compare_name(&type, "char") &&
721 !die_compare_name(&type, "unsigned char")) {
722 pr_warning("Failed to cast into string: "
723 "%s is not (unsigned) char *.",
724 dwarf_diename(vr_die));
725 return -EINVAL;
726 }
727 tvar->type = strdup(cast);
728 return (tvar->type == NULL) ? -ENOMEM : 0;
729 }
730
731 ret = die_get_byte_size(&type) * 8;
732 if (ret) {
733 /* Check the bitwidth */
734 if (ret > MAX_BASIC_TYPE_BITS) {
735 pr_info("%s exceeds max-bitwidth."
736 " Cut down to %d bits.\n",
737 dwarf_diename(&type), MAX_BASIC_TYPE_BITS);
738 ret = MAX_BASIC_TYPE_BITS;
739 }
740
741 ret = snprintf(buf, 16, "%c%d",
742 die_is_signed_type(&type) ? 's' : 'u', ret);
743 if (ret < 0 || ret >= 16) {
744 if (ret >= 16)
745 ret = -E2BIG;
746 pr_warning("Failed to convert variable type: %s\n",
747 strerror(-ret));
748 return ret;
749 }
750 tvar->type = strdup(buf);
751 if (tvar->type == NULL)
752 return -ENOMEM;
753 }
754 return 0;
755 }
756
757 static int convert_variable_fields(Dwarf_Die *vr_die, const char *varname,
758 struct perf_probe_arg_field *field,
759 struct probe_trace_arg_ref **ref_ptr,
760 Dwarf_Die *die_mem)
761 {
762 struct probe_trace_arg_ref *ref = *ref_ptr;
763 Dwarf_Die type;
764 Dwarf_Word offs;
765 int ret, tag;
766
767 pr_debug("converting %s in %s\n", field->name, varname);
768 if (die_get_real_type(vr_die, &type) == NULL) {
769 pr_warning("Failed to get the type of %s.\n", varname);
770 return -ENOENT;
771 }
772 pr_debug2("Var real type: (%x)\n", (unsigned)dwarf_dieoffset(&type));
773 tag = dwarf_tag(&type);
774
775 if (field->name[0] == '[' &&
776 (tag == DW_TAG_array_type || tag == DW_TAG_pointer_type)) {
777 if (field->next)
778 /* Save original type for next field */
779 memcpy(die_mem, &type, sizeof(*die_mem));
780 /* Get the type of this array */
781 if (die_get_real_type(&type, &type) == NULL) {
782 pr_warning("Failed to get the type of %s.\n", varname);
783 return -ENOENT;
784 }
785 pr_debug2("Array real type: (%x)\n",
786 (unsigned)dwarf_dieoffset(&type));
787 if (tag == DW_TAG_pointer_type) {
788 ref = zalloc(sizeof(struct probe_trace_arg_ref));
789 if (ref == NULL)
790 return -ENOMEM;
791 if (*ref_ptr)
792 (*ref_ptr)->next = ref;
793 else
794 *ref_ptr = ref;
795 }
796 ref->offset += die_get_byte_size(&type) * field->index;
797 if (!field->next)
798 /* Save vr_die for converting types */
799 memcpy(die_mem, vr_die, sizeof(*die_mem));
800 goto next;
801 } else if (tag == DW_TAG_pointer_type) {
802 /* Check the pointer and dereference */
803 if (!field->ref) {
804 pr_err("Semantic error: %s must be referred by '->'\n",
805 field->name);
806 return -EINVAL;
807 }
808 /* Get the type pointed by this pointer */
809 if (die_get_real_type(&type, &type) == NULL) {
810 pr_warning("Failed to get the type of %s.\n", varname);
811 return -ENOENT;
812 }
813 /* Verify it is a data structure */
814 if (dwarf_tag(&type) != DW_TAG_structure_type) {
815 pr_warning("%s is not a data structure.\n", varname);
816 return -EINVAL;
817 }
818
819 ref = zalloc(sizeof(struct probe_trace_arg_ref));
820 if (ref == NULL)
821 return -ENOMEM;
822 if (*ref_ptr)
823 (*ref_ptr)->next = ref;
824 else
825 *ref_ptr = ref;
826 } else {
827 /* Verify it is a data structure */
828 if (tag != DW_TAG_structure_type) {
829 pr_warning("%s is not a data structure.\n", varname);
830 return -EINVAL;
831 }
832 if (field->name[0] == '[') {
833 pr_err("Semantic error: %s is not a pointor nor array.",
834 varname);
835 return -EINVAL;
836 }
837 if (field->ref) {
838 pr_err("Semantic error: %s must be referred by '.'\n",
839 field->name);
840 return -EINVAL;
841 }
842 if (!ref) {
843 pr_warning("Structure on a register is not "
844 "supported yet.\n");
845 return -ENOTSUP;
846 }
847 }
848
849 if (die_find_member(&type, field->name, die_mem) == NULL) {
850 pr_warning("%s(tyep:%s) has no member %s.\n", varname,
851 dwarf_diename(&type), field->name);
852 return -EINVAL;
853 }
854
855 /* Get the offset of the field */
856 ret = die_get_data_member_location(die_mem, &offs);
857 if (ret < 0) {
858 pr_warning("Failed to get the offset of %s.\n", field->name);
859 return ret;
860 }
861 ref->offset += (long)offs;
862
863 next:
864 /* Converting next field */
865 if (field->next)
866 return convert_variable_fields(die_mem, field->name,
867 field->next, &ref, die_mem);
868 else
869 return 0;
870 }
871
872 /* Show a variables in kprobe event format */
873 static int convert_variable(Dwarf_Die *vr_die, struct probe_finder *pf)
874 {
875 Dwarf_Die die_mem;
876 int ret;
877
878 pr_debug("Converting variable %s into trace event.\n",
879 dwarf_diename(vr_die));
880
881 ret = convert_variable_location(vr_die, pf->addr, pf->fb_ops,
882 pf->tvar);
883 if (ret == -ENOENT)
884 pr_err("Failed to find the location of %s at this address.\n"
885 " Perhaps, it has been optimized out.\n", pf->pvar->var);
886 else if (ret == -ENOTSUP)
887 pr_err("Sorry, we don't support this variable location yet.\n");
888 else if (pf->pvar->field) {
889 ret = convert_variable_fields(vr_die, pf->pvar->var,
890 pf->pvar->field, &pf->tvar->ref,
891 &die_mem);
892 vr_die = &die_mem;
893 }
894 if (ret == 0)
895 ret = convert_variable_type(vr_die, pf->tvar, pf->pvar->type);
896 /* *expr will be cached in libdw. Don't free it. */
897 return ret;
898 }
899
900 /* Find a variable in a subprogram die */
901 static int find_variable(Dwarf_Die *sp_die, struct probe_finder *pf)
902 {
903 Dwarf_Die vr_die, *scopes;
904 char buf[32], *ptr;
905 int ret, nscopes;
906
907 if (!is_c_varname(pf->pvar->var)) {
908 /* Copy raw parameters */
909 pf->tvar->value = strdup(pf->pvar->var);
910 if (pf->tvar->value == NULL)
911 return -ENOMEM;
912 if (pf->pvar->type) {
913 pf->tvar->type = strdup(pf->pvar->type);
914 if (pf->tvar->type == NULL)
915 return -ENOMEM;
916 }
917 if (pf->pvar->name) {
918 pf->tvar->name = strdup(pf->pvar->name);
919 if (pf->tvar->name == NULL)
920 return -ENOMEM;
921 } else
922 pf->tvar->name = NULL;
923 return 0;
924 }
925
926 if (pf->pvar->name)
927 pf->tvar->name = strdup(pf->pvar->name);
928 else {
929 ret = synthesize_perf_probe_arg(pf->pvar, buf, 32);
930 if (ret < 0)
931 return ret;
932 ptr = strchr(buf, ':'); /* Change type separator to _ */
933 if (ptr)
934 *ptr = '_';
935 pf->tvar->name = strdup(buf);
936 }
937 if (pf->tvar->name == NULL)
938 return -ENOMEM;
939
940 pr_debug("Searching '%s' variable in context.\n",
941 pf->pvar->var);
942 /* Search child die for local variables and parameters. */
943 if (die_find_variable_at(sp_die, pf->pvar->var, pf->addr, &vr_die))
944 ret = convert_variable(&vr_die, pf);
945 else {
946 /* Search upper class */
947 nscopes = dwarf_getscopes_die(sp_die, &scopes);
948 while (nscopes-- > 1) {
949 pr_debug("Searching variables in %s\n",
950 dwarf_diename(&scopes[nscopes]));
951 /* We should check this scope, so give dummy address */
952 if (die_find_variable_at(&scopes[nscopes],
953 pf->pvar->var, 0,
954 &vr_die)) {
955 ret = convert_variable(&vr_die, pf);
956 goto found;
957 }
958 }
959 if (scopes)
960 free(scopes);
961 ret = -ENOENT;
962 }
963 found:
964 if (ret < 0)
965 pr_warning("Failed to find '%s' in this function.\n",
966 pf->pvar->var);
967 return ret;
968 }
969
970 /* Convert subprogram DIE to trace point */
971 static int convert_to_trace_point(Dwarf_Die *sp_die, Dwarf_Addr paddr,
972 bool retprobe, struct probe_trace_point *tp)
973 {
974 Dwarf_Addr eaddr;
975 const char *name;
976
977 /* Copy the name of probe point */
978 name = dwarf_diename(sp_die);
979 if (name) {
980 if (dwarf_entrypc(sp_die, &eaddr) != 0) {
981 pr_warning("Failed to get entry pc of %s\n",
982 dwarf_diename(sp_die));
983 return -ENOENT;
984 }
985 tp->symbol = strdup(name);
986 if (tp->symbol == NULL)
987 return -ENOMEM;
988 tp->offset = (unsigned long)(paddr - eaddr);
989 } else
990 /* This function has no name. */
991 tp->offset = (unsigned long)paddr;
992
993 /* Return probe must be on the head of a subprogram */
994 if (retprobe) {
995 if (eaddr != paddr) {
996 pr_warning("Return probe must be on the head of"
997 " a real function\n");
998 return -EINVAL;
999 }
1000 tp->retprobe = true;
1001 }
1002
1003 return 0;
1004 }
1005
1006 /* Call probe_finder callback with real subprogram DIE */
1007 static int call_probe_finder(Dwarf_Die *sp_die, struct probe_finder *pf)
1008 {
1009 Dwarf_Die die_mem;
1010 Dwarf_Attribute fb_attr;
1011 size_t nops;
1012 int ret;
1013
1014 /* If no real subprogram, find a real one */
1015 if (!sp_die || dwarf_tag(sp_die) != DW_TAG_subprogram) {
1016 sp_die = die_find_real_subprogram(&pf->cu_die,
1017 pf->addr, &die_mem);
1018 if (!sp_die) {
1019 pr_warning("Failed to find probe point in any "
1020 "functions.\n");
1021 return -ENOENT;
1022 }
1023 }
1024
1025 /* Get the frame base attribute/ops */
1026 dwarf_attr(sp_die, DW_AT_frame_base, &fb_attr);
1027 ret = dwarf_getlocation_addr(&fb_attr, pf->addr, &pf->fb_ops, &nops, 1);
1028 if (ret <= 0 || nops == 0) {
1029 pf->fb_ops = NULL;
1030 #if _ELFUTILS_PREREQ(0, 142)
1031 } else if (nops == 1 && pf->fb_ops[0].atom == DW_OP_call_frame_cfa &&
1032 pf->cfi != NULL) {
1033 Dwarf_Frame *frame;
1034 if (dwarf_cfi_addrframe(pf->cfi, pf->addr, &frame) != 0 ||
1035 dwarf_frame_cfa(frame, &pf->fb_ops, &nops) != 0) {
1036 pr_warning("Failed to get CFA on 0x%jx\n",
1037 (uintmax_t)pf->addr);
1038 return -ENOENT;
1039 }
1040 #endif
1041 }
1042
1043 /* Call finder's callback handler */
1044 ret = pf->callback(sp_die, pf);
1045
1046 /* *pf->fb_ops will be cached in libdw. Don't free it. */
1047 pf->fb_ops = NULL;
1048
1049 return ret;
1050 }
1051
1052 /* Find probe point from its line number */
1053 static int find_probe_point_by_line(struct probe_finder *pf)
1054 {
1055 Dwarf_Lines *lines;
1056 Dwarf_Line *line;
1057 size_t nlines, i;
1058 Dwarf_Addr addr;
1059 int lineno;
1060 int ret = 0;
1061
1062 if (dwarf_getsrclines(&pf->cu_die, &lines, &nlines) != 0) {
1063 pr_warning("No source lines found in this CU.\n");
1064 return -ENOENT;
1065 }
1066
1067 for (i = 0; i < nlines && ret == 0; i++) {
1068 line = dwarf_onesrcline(lines, i);
1069 if (dwarf_lineno(line, &lineno) != 0 ||
1070 lineno != pf->lno)
1071 continue;
1072
1073 /* TODO: Get fileno from line, but how? */
1074 if (strtailcmp(dwarf_linesrc(line, NULL, NULL), pf->fname) != 0)
1075 continue;
1076
1077 if (dwarf_lineaddr(line, &addr) != 0) {
1078 pr_warning("Failed to get the address of the line.\n");
1079 return -ENOENT;
1080 }
1081 pr_debug("Probe line found: line[%d]:%d addr:0x%jx\n",
1082 (int)i, lineno, (uintmax_t)addr);
1083 pf->addr = addr;
1084
1085 ret = call_probe_finder(NULL, pf);
1086 /* Continuing, because target line might be inlined. */
1087 }
1088 return ret;
1089 }
1090
1091 /* Find lines which match lazy pattern */
1092 static int find_lazy_match_lines(struct list_head *head,
1093 const char *fname, const char *pat)
1094 {
1095 char *fbuf, *p1, *p2;
1096 int fd, line, nlines = -1;
1097 struct stat st;
1098
1099 fd = open(fname, O_RDONLY);
1100 if (fd < 0) {
1101 pr_warning("Failed to open %s: %s\n", fname, strerror(-fd));
1102 return -errno;
1103 }
1104
1105 if (fstat(fd, &st) < 0) {
1106 pr_warning("Failed to get the size of %s: %s\n",
1107 fname, strerror(errno));
1108 nlines = -errno;
1109 goto out_close;
1110 }
1111
1112 nlines = -ENOMEM;
1113 fbuf = malloc(st.st_size + 2);
1114 if (fbuf == NULL)
1115 goto out_close;
1116 if (read(fd, fbuf, st.st_size) < 0) {
1117 pr_warning("Failed to read %s: %s\n", fname, strerror(errno));
1118 nlines = -errno;
1119 goto out_free_fbuf;
1120 }
1121 fbuf[st.st_size] = '\n'; /* Dummy line */
1122 fbuf[st.st_size + 1] = '\0';
1123 p1 = fbuf;
1124 line = 1;
1125 nlines = 0;
1126 while ((p2 = strchr(p1, '\n')) != NULL) {
1127 *p2 = '\0';
1128 if (strlazymatch(p1, pat)) {
1129 line_list__add_line(head, line);
1130 nlines++;
1131 }
1132 line++;
1133 p1 = p2 + 1;
1134 }
1135 out_free_fbuf:
1136 free(fbuf);
1137 out_close:
1138 close(fd);
1139 return nlines;
1140 }
1141
1142 /* Find probe points from lazy pattern */
1143 static int find_probe_point_lazy(Dwarf_Die *sp_die, struct probe_finder *pf)
1144 {
1145 Dwarf_Lines *lines;
1146 Dwarf_Line *line;
1147 size_t nlines, i;
1148 Dwarf_Addr addr;
1149 Dwarf_Die die_mem;
1150 int lineno;
1151 int ret = 0;
1152
1153 if (list_empty(&pf->lcache)) {
1154 /* Matching lazy line pattern */
1155 ret = find_lazy_match_lines(&pf->lcache, pf->fname,
1156 pf->pev->point.lazy_line);
1157 if (ret == 0) {
1158 pr_debug("No matched lines found in %s.\n", pf->fname);
1159 return 0;
1160 } else if (ret < 0)
1161 return ret;
1162 }
1163
1164 if (dwarf_getsrclines(&pf->cu_die, &lines, &nlines) != 0) {
1165 pr_warning("No source lines found in this CU.\n");
1166 return -ENOENT;
1167 }
1168
1169 for (i = 0; i < nlines && ret >= 0; i++) {
1170 line = dwarf_onesrcline(lines, i);
1171
1172 if (dwarf_lineno(line, &lineno) != 0 ||
1173 !line_list__has_line(&pf->lcache, lineno))
1174 continue;
1175
1176 /* TODO: Get fileno from line, but how? */
1177 if (strtailcmp(dwarf_linesrc(line, NULL, NULL), pf->fname) != 0)
1178 continue;
1179
1180 if (dwarf_lineaddr(line, &addr) != 0) {
1181 pr_debug("Failed to get the address of line %d.\n",
1182 lineno);
1183 continue;
1184 }
1185 if (sp_die) {
1186 /* Address filtering 1: does sp_die include addr? */
1187 if (!dwarf_haspc(sp_die, addr))
1188 continue;
1189 /* Address filtering 2: No child include addr? */
1190 if (die_find_inlinefunc(sp_die, addr, &die_mem))
1191 continue;
1192 }
1193
1194 pr_debug("Probe line found: line[%d]:%d addr:0x%llx\n",
1195 (int)i, lineno, (unsigned long long)addr);
1196 pf->addr = addr;
1197
1198 ret = call_probe_finder(sp_die, pf);
1199 /* Continuing, because target line might be inlined. */
1200 }
1201 /* TODO: deallocate lines, but how? */
1202 return ret;
1203 }
1204
1205 /* Callback parameter with return value */
1206 struct dwarf_callback_param {
1207 void *data;
1208 int retval;
1209 };
1210
1211 static int probe_point_inline_cb(Dwarf_Die *in_die, void *data)
1212 {
1213 struct dwarf_callback_param *param = data;
1214 struct probe_finder *pf = param->data;
1215 struct perf_probe_point *pp = &pf->pev->point;
1216 Dwarf_Addr addr;
1217
1218 if (pp->lazy_line)
1219 param->retval = find_probe_point_lazy(in_die, pf);
1220 else {
1221 /* Get probe address */
1222 if (dwarf_entrypc(in_die, &addr) != 0) {
1223 pr_warning("Failed to get entry pc of %s.\n",
1224 dwarf_diename(in_die));
1225 param->retval = -ENOENT;
1226 return DWARF_CB_ABORT;
1227 }
1228 pf->addr = addr;
1229 pf->addr += pp->offset;
1230 pr_debug("found inline addr: 0x%jx\n",
1231 (uintmax_t)pf->addr);
1232
1233 param->retval = call_probe_finder(in_die, pf);
1234 if (param->retval < 0)
1235 return DWARF_CB_ABORT;
1236 }
1237
1238 return DWARF_CB_OK;
1239 }
1240
1241 /* Search function from function name */
1242 static int probe_point_search_cb(Dwarf_Die *sp_die, void *data)
1243 {
1244 struct dwarf_callback_param *param = data;
1245 struct probe_finder *pf = param->data;
1246 struct perf_probe_point *pp = &pf->pev->point;
1247
1248 /* Check tag and diename */
1249 if (dwarf_tag(sp_die) != DW_TAG_subprogram ||
1250 !die_compare_name(sp_die, pp->function))
1251 return DWARF_CB_OK;
1252
1253 pf->fname = dwarf_decl_file(sp_die);
1254 if (pp->line) { /* Function relative line */
1255 dwarf_decl_line(sp_die, &pf->lno);
1256 pf->lno += pp->line;
1257 param->retval = find_probe_point_by_line(pf);
1258 } else if (!dwarf_func_inline(sp_die)) {
1259 /* Real function */
1260 if (pp->lazy_line)
1261 param->retval = find_probe_point_lazy(sp_die, pf);
1262 else {
1263 if (dwarf_entrypc(sp_die, &pf->addr) != 0) {
1264 pr_warning("Failed to get entry pc of %s.\n",
1265 dwarf_diename(sp_die));
1266 param->retval = -ENOENT;
1267 return DWARF_CB_ABORT;
1268 }
1269 pf->addr += pp->offset;
1270 /* TODO: Check the address in this function */
1271 param->retval = call_probe_finder(sp_die, pf);
1272 }
1273 } else {
1274 struct dwarf_callback_param _param = {.data = (void *)pf,
1275 .retval = 0};
1276 /* Inlined function: search instances */
1277 dwarf_func_inline_instances(sp_die, probe_point_inline_cb,
1278 &_param);
1279 param->retval = _param.retval;
1280 }
1281
1282 return DWARF_CB_ABORT; /* Exit; no same symbol in this CU. */
1283 }
1284
1285 static int find_probe_point_by_func(struct probe_finder *pf)
1286 {
1287 struct dwarf_callback_param _param = {.data = (void *)pf,
1288 .retval = 0};
1289 dwarf_getfuncs(&pf->cu_die, probe_point_search_cb, &_param, 0);
1290 return _param.retval;
1291 }
1292
1293 /* Find probe points from debuginfo */
1294 static int find_probes(int fd, struct probe_finder *pf)
1295 {
1296 struct perf_probe_point *pp = &pf->pev->point;
1297 Dwarf_Off off, noff;
1298 size_t cuhl;
1299 Dwarf_Die *diep;
1300 Dwarf *dbg = NULL;
1301 Dwfl *dwfl;
1302 Dwarf_Addr bias; /* Currently ignored */
1303 int ret = 0;
1304
1305 dbg = dwfl_init_offline_dwarf(fd, &dwfl, &bias);
1306 if (!dbg) {
1307 pr_warning("No dwarf info found in the vmlinux - "
1308 "please rebuild with CONFIG_DEBUG_INFO=y.\n");
1309 return -EBADF;
1310 }
1311
1312 #if _ELFUTILS_PREREQ(0, 142)
1313 /* Get the call frame information from this dwarf */
1314 pf->cfi = dwarf_getcfi(dbg);
1315 #endif
1316
1317 off = 0;
1318 line_list__init(&pf->lcache);
1319 /* Loop on CUs (Compilation Unit) */
1320 while (!dwarf_nextcu(dbg, off, &noff, &cuhl, NULL, NULL, NULL) &&
1321 ret >= 0) {
1322 /* Get the DIE(Debugging Information Entry) of this CU */
1323 diep = dwarf_offdie(dbg, off + cuhl, &pf->cu_die);
1324 if (!diep)
1325 continue;
1326
1327 /* Check if target file is included. */
1328 if (pp->file)
1329 pf->fname = cu_find_realpath(&pf->cu_die, pp->file);
1330 else
1331 pf->fname = NULL;
1332
1333 if (!pp->file || pf->fname) {
1334 if (pp->function)
1335 ret = find_probe_point_by_func(pf);
1336 else if (pp->lazy_line)
1337 ret = find_probe_point_lazy(NULL, pf);
1338 else {
1339 pf->lno = pp->line;
1340 ret = find_probe_point_by_line(pf);
1341 }
1342 }
1343 off = noff;
1344 }
1345 line_list__free(&pf->lcache);
1346 if (dwfl)
1347 dwfl_end(dwfl);
1348
1349 return ret;
1350 }
1351
1352 /* Add a found probe point into trace event list */
1353 static int add_probe_trace_event(Dwarf_Die *sp_die, struct probe_finder *pf)
1354 {
1355 struct trace_event_finder *tf =
1356 container_of(pf, struct trace_event_finder, pf);
1357 struct probe_trace_event *tev;
1358 int ret, i;
1359
1360 /* Check number of tevs */
1361 if (tf->ntevs == tf->max_tevs) {
1362 pr_warning("Too many( > %d) probe point found.\n",
1363 tf->max_tevs);
1364 return -ERANGE;
1365 }
1366 tev = &tf->tevs[tf->ntevs++];
1367
1368 ret = convert_to_trace_point(sp_die, pf->addr, pf->pev->point.retprobe,
1369 &tev->point);
1370 if (ret < 0)
1371 return ret;
1372
1373 pr_debug("Probe point found: %s+%lu\n", tev->point.symbol,
1374 tev->point.offset);
1375
1376 /* Find each argument */
1377 tev->nargs = pf->pev->nargs;
1378 tev->args = zalloc(sizeof(struct probe_trace_arg) * tev->nargs);
1379 if (tev->args == NULL)
1380 return -ENOMEM;
1381 for (i = 0; i < pf->pev->nargs; i++) {
1382 pf->pvar = &pf->pev->args[i];
1383 pf->tvar = &tev->args[i];
1384 ret = find_variable(sp_die, pf);
1385 if (ret != 0)
1386 return ret;
1387 }
1388
1389 return 0;
1390 }
1391
1392 /* Find probe_trace_events specified by perf_probe_event from debuginfo */
1393 int find_probe_trace_events(int fd, struct perf_probe_event *pev,
1394 struct probe_trace_event **tevs, int max_tevs)
1395 {
1396 struct trace_event_finder tf = {
1397 .pf = {.pev = pev, .callback = add_probe_trace_event},
1398 .max_tevs = max_tevs};
1399 int ret;
1400
1401 /* Allocate result tevs array */
1402 *tevs = zalloc(sizeof(struct probe_trace_event) * max_tevs);
1403 if (*tevs == NULL)
1404 return -ENOMEM;
1405
1406 tf.tevs = *tevs;
1407 tf.ntevs = 0;
1408
1409 ret = find_probes(fd, &tf.pf);
1410 if (ret < 0) {
1411 free(*tevs);
1412 *tevs = NULL;
1413 return ret;
1414 }
1415
1416 return (ret < 0) ? ret : tf.ntevs;
1417 }
1418
1419 #define MAX_VAR_LEN 64
1420
1421 /* Collect available variables in this scope */
1422 static int collect_variables_cb(Dwarf_Die *die_mem, void *data)
1423 {
1424 struct available_var_finder *af = data;
1425 struct variable_list *vl;
1426 char buf[MAX_VAR_LEN];
1427 int tag, ret;
1428
1429 vl = &af->vls[af->nvls - 1];
1430
1431 tag = dwarf_tag(die_mem);
1432 if (tag == DW_TAG_formal_parameter ||
1433 tag == DW_TAG_variable) {
1434 ret = convert_variable_location(die_mem, af->pf.addr,
1435 af->pf.fb_ops, NULL);
1436 if (ret == 0) {
1437 ret = die_get_varname(die_mem, buf, MAX_VAR_LEN);
1438 pr_debug2("Add new var: %s\n", buf);
1439 if (ret > 0)
1440 strlist__add(vl->vars, buf);
1441 }
1442 }
1443
1444 if (af->child && dwarf_haspc(die_mem, af->pf.addr))
1445 return DIE_FIND_CB_CONTINUE;
1446 else
1447 return DIE_FIND_CB_SIBLING;
1448 }
1449
1450 /* Add a found vars into available variables list */
1451 static int add_available_vars(Dwarf_Die *sp_die, struct probe_finder *pf)
1452 {
1453 struct available_var_finder *af =
1454 container_of(pf, struct available_var_finder, pf);
1455 struct variable_list *vl;
1456 Dwarf_Die die_mem, *scopes = NULL;
1457 int ret, nscopes;
1458
1459 /* Check number of tevs */
1460 if (af->nvls == af->max_vls) {
1461 pr_warning("Too many( > %d) probe point found.\n", af->max_vls);
1462 return -ERANGE;
1463 }
1464 vl = &af->vls[af->nvls++];
1465
1466 ret = convert_to_trace_point(sp_die, pf->addr, pf->pev->point.retprobe,
1467 &vl->point);
1468 if (ret < 0)
1469 return ret;
1470
1471 pr_debug("Probe point found: %s+%lu\n", vl->point.symbol,
1472 vl->point.offset);
1473
1474 /* Find local variables */
1475 vl->vars = strlist__new(true, NULL);
1476 if (vl->vars == NULL)
1477 return -ENOMEM;
1478 af->child = true;
1479 die_find_child(sp_die, collect_variables_cb, (void *)af, &die_mem);
1480
1481 /* Find external variables */
1482 if (!af->externs)
1483 goto out;
1484 /* Don't need to search child DIE for externs. */
1485 af->child = false;
1486 nscopes = dwarf_getscopes_die(sp_die, &scopes);
1487 while (nscopes-- > 1)
1488 die_find_child(&scopes[nscopes], collect_variables_cb,
1489 (void *)af, &die_mem);
1490 if (scopes)
1491 free(scopes);
1492
1493 out:
1494 if (strlist__empty(vl->vars)) {
1495 strlist__delete(vl->vars);
1496 vl->vars = NULL;
1497 }
1498
1499 return ret;
1500 }
1501
1502 /* Find available variables at given probe point */
1503 int find_available_vars_at(int fd, struct perf_probe_event *pev,
1504 struct variable_list **vls, int max_vls,
1505 bool externs)
1506 {
1507 struct available_var_finder af = {
1508 .pf = {.pev = pev, .callback = add_available_vars},
1509 .max_vls = max_vls, .externs = externs};
1510 int ret;
1511
1512 /* Allocate result vls array */
1513 *vls = zalloc(sizeof(struct variable_list) * max_vls);
1514 if (*vls == NULL)
1515 return -ENOMEM;
1516
1517 af.vls = *vls;
1518 af.nvls = 0;
1519
1520 ret = find_probes(fd, &af.pf);
1521 if (ret < 0) {
1522 /* Free vlist for error */
1523 while (af.nvls--) {
1524 if (af.vls[af.nvls].point.symbol)
1525 free(af.vls[af.nvls].point.symbol);
1526 if (af.vls[af.nvls].vars)
1527 strlist__delete(af.vls[af.nvls].vars);
1528 }
1529 free(af.vls);
1530 *vls = NULL;
1531 return ret;
1532 }
1533
1534 return (ret < 0) ? ret : af.nvls;
1535 }
1536
1537 /* Reverse search */
1538 int find_perf_probe_point(unsigned long addr, struct perf_probe_point *ppt)
1539 {
1540 Dwarf_Die cudie, spdie, indie;
1541 Dwarf *dbg = NULL;
1542 Dwfl *dwfl = NULL;
1543 Dwarf_Line *line;
1544 Dwarf_Addr laddr, eaddr, bias = 0;
1545 const char *tmp;
1546 int lineno, ret = 0;
1547 bool found = false;
1548
1549 /* Open the live linux kernel */
1550 dbg = dwfl_init_live_kernel_dwarf(addr, &dwfl, &bias);
1551 if (!dbg) {
1552 pr_warning("No dwarf info found in the vmlinux - "
1553 "please rebuild with CONFIG_DEBUG_INFO=y.\n");
1554 ret = -EINVAL;
1555 goto end;
1556 }
1557
1558 /* Adjust address with bias */
1559 addr += bias;
1560 /* Find cu die */
1561 if (!dwarf_addrdie(dbg, (Dwarf_Addr)addr - bias, &cudie)) {
1562 pr_warning("No CU DIE is found at %lx\n", addr);
1563 ret = -EINVAL;
1564 goto end;
1565 }
1566
1567 /* Find a corresponding line */
1568 line = dwarf_getsrc_die(&cudie, (Dwarf_Addr)addr);
1569 if (line) {
1570 if (dwarf_lineaddr(line, &laddr) == 0 &&
1571 (Dwarf_Addr)addr == laddr &&
1572 dwarf_lineno(line, &lineno) == 0) {
1573 tmp = dwarf_linesrc(line, NULL, NULL);
1574 if (tmp) {
1575 ppt->line = lineno;
1576 ppt->file = strdup(tmp);
1577 if (ppt->file == NULL) {
1578 ret = -ENOMEM;
1579 goto end;
1580 }
1581 found = true;
1582 }
1583 }
1584 }
1585
1586 /* Find a corresponding function */
1587 if (die_find_real_subprogram(&cudie, (Dwarf_Addr)addr, &spdie)) {
1588 tmp = dwarf_diename(&spdie);
1589 if (!tmp || dwarf_entrypc(&spdie, &eaddr) != 0)
1590 goto end;
1591
1592 if (ppt->line) {
1593 if (die_find_inlinefunc(&spdie, (Dwarf_Addr)addr,
1594 &indie)) {
1595 /* addr in an inline function */
1596 tmp = dwarf_diename(&indie);
1597 if (!tmp)
1598 goto end;
1599 ret = dwarf_decl_line(&indie, &lineno);
1600 } else {
1601 if (eaddr == addr) { /* Function entry */
1602 lineno = ppt->line;
1603 ret = 0;
1604 } else
1605 ret = dwarf_decl_line(&spdie, &lineno);
1606 }
1607 if (ret == 0) {
1608 /* Make a relative line number */
1609 ppt->line -= lineno;
1610 goto found;
1611 }
1612 }
1613 /* We don't have a line number, let's use offset */
1614 ppt->offset = addr - (unsigned long)eaddr;
1615 found:
1616 ppt->function = strdup(tmp);
1617 if (ppt->function == NULL) {
1618 ret = -ENOMEM;
1619 goto end;
1620 }
1621 found = true;
1622 }
1623
1624 end:
1625 if (dwfl)
1626 dwfl_end(dwfl);
1627 if (ret >= 0)
1628 ret = found ? 1 : 0;
1629 return ret;
1630 }
1631
1632 /* Add a line and store the src path */
1633 static int line_range_add_line(const char *src, unsigned int lineno,
1634 struct line_range *lr)
1635 {
1636 /* Copy source path */
1637 if (!lr->path) {
1638 lr->path = strdup(src);
1639 if (lr->path == NULL)
1640 return -ENOMEM;
1641 }
1642 return line_list__add_line(&lr->line_list, lineno);
1643 }
1644
1645 /* Search function declaration lines */
1646 static int line_range_funcdecl_cb(Dwarf_Die *sp_die, void *data)
1647 {
1648 struct dwarf_callback_param *param = data;
1649 struct line_finder *lf = param->data;
1650 const char *src;
1651 int lineno;
1652
1653 src = dwarf_decl_file(sp_die);
1654 if (src && strtailcmp(src, lf->fname) != 0)
1655 return DWARF_CB_OK;
1656
1657 if (dwarf_decl_line(sp_die, &lineno) != 0 ||
1658 (lf->lno_s > lineno || lf->lno_e < lineno))
1659 return DWARF_CB_OK;
1660
1661 param->retval = line_range_add_line(src, lineno, lf->lr);
1662 if (param->retval < 0)
1663 return DWARF_CB_ABORT;
1664 return DWARF_CB_OK;
1665 }
1666
1667 static int find_line_range_func_decl_lines(struct line_finder *lf)
1668 {
1669 struct dwarf_callback_param param = {.data = (void *)lf, .retval = 0};
1670 dwarf_getfuncs(&lf->cu_die, line_range_funcdecl_cb, &param, 0);
1671 return param.retval;
1672 }
1673
1674 /* Find line range from its line number */
1675 static int find_line_range_by_line(Dwarf_Die *sp_die, struct line_finder *lf)
1676 {
1677 Dwarf_Lines *lines;
1678 Dwarf_Line *line;
1679 size_t nlines, i;
1680 Dwarf_Addr addr;
1681 int lineno, ret = 0;
1682 const char *src;
1683 Dwarf_Die die_mem;
1684
1685 line_list__init(&lf->lr->line_list);
1686 if (dwarf_getsrclines(&lf->cu_die, &lines, &nlines) != 0) {
1687 pr_warning("No source lines found in this CU.\n");
1688 return -ENOENT;
1689 }
1690
1691 /* Search probable lines on lines list */
1692 for (i = 0; i < nlines; i++) {
1693 line = dwarf_onesrcline(lines, i);
1694 if (dwarf_lineno(line, &lineno) != 0 ||
1695 (lf->lno_s > lineno || lf->lno_e < lineno))
1696 continue;
1697
1698 if (sp_die) {
1699 /* Address filtering 1: does sp_die include addr? */
1700 if (dwarf_lineaddr(line, &addr) != 0 ||
1701 !dwarf_haspc(sp_die, addr))
1702 continue;
1703
1704 /* Address filtering 2: No child include addr? */
1705 if (die_find_inlinefunc(sp_die, addr, &die_mem))
1706 continue;
1707 }
1708
1709 /* TODO: Get fileno from line, but how? */
1710 src = dwarf_linesrc(line, NULL, NULL);
1711 if (strtailcmp(src, lf->fname) != 0)
1712 continue;
1713
1714 ret = line_range_add_line(src, lineno, lf->lr);
1715 if (ret < 0)
1716 return ret;
1717 }
1718
1719 /*
1720 * Dwarf lines doesn't include function declarations. We have to
1721 * check functions list or given function.
1722 */
1723 if (sp_die) {
1724 src = dwarf_decl_file(sp_die);
1725 if (src && dwarf_decl_line(sp_die, &lineno) == 0 &&
1726 (lf->lno_s <= lineno && lf->lno_e >= lineno))
1727 ret = line_range_add_line(src, lineno, lf->lr);
1728 } else
1729 ret = find_line_range_func_decl_lines(lf);
1730
1731 /* Update status */
1732 if (ret >= 0)
1733 if (!list_empty(&lf->lr->line_list))
1734 ret = lf->found = 1;
1735 else
1736 ret = 0; /* Lines are not found */
1737 else {
1738 free(lf->lr->path);
1739 lf->lr->path = NULL;
1740 }
1741 return ret;
1742 }
1743
1744 static int line_range_inline_cb(Dwarf_Die *in_die, void *data)
1745 {
1746 struct dwarf_callback_param *param = data;
1747
1748 param->retval = find_line_range_by_line(in_die, param->data);
1749 return DWARF_CB_ABORT; /* No need to find other instances */
1750 }
1751
1752 /* Search function from function name */
1753 static int line_range_search_cb(Dwarf_Die *sp_die, void *data)
1754 {
1755 struct dwarf_callback_param *param = data;
1756 struct line_finder *lf = param->data;
1757 struct line_range *lr = lf->lr;
1758
1759 pr_debug("find (%llx) %s\n",
1760 (unsigned long long)dwarf_dieoffset(sp_die),
1761 dwarf_diename(sp_die));
1762 if (dwarf_tag(sp_die) == DW_TAG_subprogram &&
1763 die_compare_name(sp_die, lr->function)) {
1764 lf->fname = dwarf_decl_file(sp_die);
1765 dwarf_decl_line(sp_die, &lr->offset);
1766 pr_debug("fname: %s, lineno:%d\n", lf->fname, lr->offset);
1767 lf->lno_s = lr->offset + lr->start;
1768 if (lf->lno_s < 0) /* Overflow */
1769 lf->lno_s = INT_MAX;
1770 lf->lno_e = lr->offset + lr->end;
1771 if (lf->lno_e < 0) /* Overflow */
1772 lf->lno_e = INT_MAX;
1773 pr_debug("New line range: %d to %d\n", lf->lno_s, lf->lno_e);
1774 lr->start = lf->lno_s;
1775 lr->end = lf->lno_e;
1776 if (dwarf_func_inline(sp_die)) {
1777 struct dwarf_callback_param _param;
1778 _param.data = (void *)lf;
1779 _param.retval = 0;
1780 dwarf_func_inline_instances(sp_die,
1781 line_range_inline_cb,
1782 &_param);
1783 param->retval = _param.retval;
1784 } else
1785 param->retval = find_line_range_by_line(sp_die, lf);
1786 return DWARF_CB_ABORT;
1787 }
1788 return DWARF_CB_OK;
1789 }
1790
1791 static int find_line_range_by_func(struct line_finder *lf)
1792 {
1793 struct dwarf_callback_param param = {.data = (void *)lf, .retval = 0};
1794 dwarf_getfuncs(&lf->cu_die, line_range_search_cb, &param, 0);
1795 return param.retval;
1796 }
1797
1798 int find_line_range(int fd, struct line_range *lr)
1799 {
1800 struct line_finder lf = {.lr = lr, .found = 0};
1801 int ret = 0;
1802 Dwarf_Off off = 0, noff;
1803 size_t cuhl;
1804 Dwarf_Die *diep;
1805 Dwarf *dbg = NULL;
1806 Dwfl *dwfl;
1807 Dwarf_Addr bias; /* Currently ignored */
1808 const char *comp_dir;
1809
1810 dbg = dwfl_init_offline_dwarf(fd, &dwfl, &bias);
1811 if (!dbg) {
1812 pr_warning("No dwarf info found in the vmlinux - "
1813 "please rebuild with CONFIG_DEBUG_INFO=y.\n");
1814 return -EBADF;
1815 }
1816
1817 /* Loop on CUs (Compilation Unit) */
1818 while (!lf.found && ret >= 0) {
1819 if (dwarf_nextcu(dbg, off, &noff, &cuhl, NULL, NULL, NULL) != 0)
1820 break;
1821
1822 /* Get the DIE(Debugging Information Entry) of this CU */
1823 diep = dwarf_offdie(dbg, off + cuhl, &lf.cu_die);
1824 if (!diep)
1825 continue;
1826
1827 /* Check if target file is included. */
1828 if (lr->file)
1829 lf.fname = cu_find_realpath(&lf.cu_die, lr->file);
1830 else
1831 lf.fname = 0;
1832
1833 if (!lr->file || lf.fname) {
1834 if (lr->function)
1835 ret = find_line_range_by_func(&lf);
1836 else {
1837 lf.lno_s = lr->start;
1838 lf.lno_e = lr->end;
1839 ret = find_line_range_by_line(NULL, &lf);
1840 }
1841 }
1842 off = noff;
1843 }
1844
1845 /* Store comp_dir */
1846 if (lf.found) {
1847 comp_dir = cu_get_comp_dir(&lf.cu_die);
1848 if (comp_dir) {
1849 lr->comp_dir = strdup(comp_dir);
1850 if (!lr->comp_dir)
1851 ret = -ENOMEM;
1852 }
1853 }
1854
1855 pr_debug("path: %s\n", lr->path);
1856 dwfl_end(dwfl);
1857 return (ret < 0) ? ret : lf.found;
1858 }
1859
Linux 2.6 ibm-acpi/thinkpad-acpi driver git tree