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