2 * probe-finder.c : C expression to kprobe event converter
4 * Written by Masami Hiramatsu <mhiramat@redhat.com>
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.
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.
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.
22 #include <sys/utsname.h>
23 #include <sys/types.h>
32 #include <dwarf-regs.h>
34 #include <linux/bitops.h>
41 #include "probe-finder.h"
43 /* Kprobe tracer basic type is up to u64 */
44 #define MAX_BASIC_TYPE_BITS 64
46 /* Dwarf FL wrappers */
47 static char *debuginfo_path
; /* Currently dummy */
49 static const Dwfl_Callbacks offline_callbacks
= {
50 .find_debuginfo
= dwfl_standard_find_debuginfo
,
51 .debuginfo_path
= &debuginfo_path
,
53 .section_address
= dwfl_offline_section_address
,
55 /* We use this table for core files too. */
56 .find_elf
= dwfl_build_id_find_elf
,
59 /* Get a Dwarf from offline image */
60 static int debuginfo__init_offline_dwarf(struct debuginfo
*dbg
,
65 fd
= open(path
, O_RDONLY
);
69 dbg
->dwfl
= dwfl_begin(&offline_callbacks
);
73 dbg
->mod
= dwfl_report_offline(dbg
->dwfl
, "", "", fd
);
77 dbg
->dbg
= dwfl_module_getdwarf(dbg
->mod
, &dbg
->bias
);
87 memset(dbg
, 0, sizeof(*dbg
));
92 static struct debuginfo
*__debuginfo__new(const char *path
)
94 struct debuginfo
*dbg
= zalloc(sizeof(*dbg
));
98 if (debuginfo__init_offline_dwarf(dbg
, path
) < 0)
101 pr_debug("Open Debuginfo file: %s\n", path
);
105 enum dso_binary_type distro_dwarf_types
[] = {
106 DSO_BINARY_TYPE__FEDORA_DEBUGINFO
,
107 DSO_BINARY_TYPE__UBUNTU_DEBUGINFO
,
108 DSO_BINARY_TYPE__OPENEMBEDDED_DEBUGINFO
,
109 DSO_BINARY_TYPE__BUILDID_DEBUGINFO
,
110 DSO_BINARY_TYPE__NOT_FOUND
,
113 struct debuginfo
*debuginfo__new(const char *path
)
115 enum dso_binary_type
*type
;
116 char buf
[PATH_MAX
], nil
= '\0';
118 struct debuginfo
*dinfo
= NULL
;
120 /* Try to open distro debuginfo files */
121 dso
= dso__new(path
);
125 for (type
= distro_dwarf_types
;
126 !dinfo
&& *type
!= DSO_BINARY_TYPE__NOT_FOUND
;
128 if (dso__read_binary_type_filename(dso
, *type
, &nil
,
131 dinfo
= __debuginfo__new(buf
);
136 /* if failed to open all distro debuginfo, open given binary */
137 return dinfo
? : __debuginfo__new(path
);
140 void debuginfo__delete(struct debuginfo
*dbg
)
150 * Probe finder related functions
153 static struct probe_trace_arg_ref
*alloc_trace_arg_ref(long offs
)
155 struct probe_trace_arg_ref
*ref
;
156 ref
= zalloc(sizeof(struct probe_trace_arg_ref
));
163 * Convert a location into trace_arg.
164 * If tvar == NULL, this just checks variable can be converted.
165 * If fentry == true and vr_die is a parameter, do huristic search
166 * for the location fuzzed by function entry mcount.
168 static int convert_variable_location(Dwarf_Die
*vr_die
, Dwarf_Addr addr
,
169 Dwarf_Op
*fb_ops
, Dwarf_Die
*sp_die
,
170 struct probe_trace_arg
*tvar
)
172 Dwarf_Attribute attr
;
182 if (dwarf_attr(vr_die
, DW_AT_external
, &attr
) != NULL
)
185 /* TODO: handle more than 1 exprs */
186 if (dwarf_attr(vr_die
, DW_AT_location
, &attr
) == NULL
)
187 return -EINVAL
; /* Broken DIE ? */
188 if (dwarf_getlocation_addr(&attr
, addr
, &op
, &nops
, 1) <= 0) {
189 ret
= dwarf_entrypc(sp_die
, &tmp
);
190 if (ret
|| addr
!= tmp
||
191 dwarf_tag(vr_die
) != DW_TAG_formal_parameter
||
192 dwarf_highpc(sp_die
, &tmp
))
195 * This is fuzzed by fentry mcount. We try to find the
196 * parameter location at the earliest address.
198 for (addr
+= 1; addr
<= tmp
; addr
++) {
199 if (dwarf_getlocation_addr(&attr
, addr
, &op
,
207 /* TODO: Support const_value */
210 if (op
->atom
== DW_OP_addr
) {
214 /* Static variables on memory (not stack), make @varname */
215 ret
= strlen(dwarf_diename(vr_die
));
216 tvar
->value
= zalloc(ret
+ 2);
217 if (tvar
->value
== NULL
)
219 snprintf(tvar
->value
, ret
+ 2, "@%s", dwarf_diename(vr_die
));
220 tvar
->ref
= alloc_trace_arg_ref((long)offs
);
221 if (tvar
->ref
== NULL
)
226 /* If this is based on frame buffer, set the offset */
227 if (op
->atom
== DW_OP_fbreg
) {
235 if (op
->atom
>= DW_OP_breg0
&& op
->atom
<= DW_OP_breg31
) {
236 regn
= op
->atom
- DW_OP_breg0
;
239 } else if (op
->atom
>= DW_OP_reg0
&& op
->atom
<= DW_OP_reg31
) {
240 regn
= op
->atom
- DW_OP_reg0
;
241 } else if (op
->atom
== DW_OP_bregx
) {
245 } else if (op
->atom
== DW_OP_regx
) {
248 pr_debug("DW_OP %x is not supported.\n", op
->atom
);
255 regs
= get_arch_regstr(regn
);
257 /* This should be a bug in DWARF or this tool */
258 pr_warning("Mapping for the register number %u "
259 "missing on this architecture.\n", regn
);
263 tvar
->value
= strdup(regs
);
264 if (tvar
->value
== NULL
)
268 tvar
->ref
= alloc_trace_arg_ref((long)offs
);
269 if (tvar
->ref
== NULL
)
275 #define BYTES_TO_BITS(nb) ((nb) * BITS_PER_LONG / sizeof(long))
277 static int convert_variable_type(Dwarf_Die
*vr_die
,
278 struct probe_trace_arg
*tvar
,
281 struct probe_trace_arg_ref
**ref_ptr
= &tvar
->ref
;
284 char sbuf
[STRERR_BUFSIZE
];
285 int bsize
, boffs
, total
;
288 /* TODO: check all types */
289 if (cast
&& strcmp(cast
, "string") != 0) {
290 /* Non string type is OK */
291 tvar
->type
= strdup(cast
);
292 return (tvar
->type
== NULL
) ? -ENOMEM
: 0;
295 bsize
= dwarf_bitsize(vr_die
);
297 /* This is a bitfield */
298 boffs
= dwarf_bitoffset(vr_die
);
299 total
= dwarf_bytesize(vr_die
);
300 if (boffs
< 0 || total
< 0)
302 ret
= snprintf(buf
, 16, "b%d@%d/%zd", bsize
, boffs
,
303 BYTES_TO_BITS(total
));
307 if (die_get_real_type(vr_die
, &type
) == NULL
) {
308 pr_warning("Failed to get a type information of %s.\n",
309 dwarf_diename(vr_die
));
313 pr_debug("%s type is %s.\n",
314 dwarf_diename(vr_die
), dwarf_diename(&type
));
316 if (cast
&& strcmp(cast
, "string") == 0) { /* String type */
317 ret
= dwarf_tag(&type
);
318 if (ret
!= DW_TAG_pointer_type
&&
319 ret
!= DW_TAG_array_type
) {
320 pr_warning("Failed to cast into string: "
321 "%s(%s) is not a pointer nor array.\n",
322 dwarf_diename(vr_die
), dwarf_diename(&type
));
325 if (die_get_real_type(&type
, &type
) == NULL
) {
326 pr_warning("Failed to get a type"
330 if (ret
== DW_TAG_pointer_type
) {
332 ref_ptr
= &(*ref_ptr
)->next
;
333 /* Add new reference with offset +0 */
334 *ref_ptr
= zalloc(sizeof(struct probe_trace_arg_ref
));
335 if (*ref_ptr
== NULL
) {
336 pr_warning("Out of memory error\n");
340 if (!die_compare_name(&type
, "char") &&
341 !die_compare_name(&type
, "unsigned char")) {
342 pr_warning("Failed to cast into string: "
343 "%s is not (unsigned) char *.\n",
344 dwarf_diename(vr_die
));
347 tvar
->type
= strdup(cast
);
348 return (tvar
->type
== NULL
) ? -ENOMEM
: 0;
351 ret
= dwarf_bytesize(&type
);
353 /* No size ... try to use default type */
355 ret
= BYTES_TO_BITS(ret
);
357 /* Check the bitwidth */
358 if (ret
> MAX_BASIC_TYPE_BITS
) {
359 pr_info("%s exceeds max-bitwidth. Cut down to %d bits.\n",
360 dwarf_diename(&type
), MAX_BASIC_TYPE_BITS
);
361 ret
= MAX_BASIC_TYPE_BITS
;
363 ret
= snprintf(buf
, 16, "%c%d",
364 die_is_signed_type(&type
) ? 's' : 'u', ret
);
367 if (ret
< 0 || ret
>= 16) {
370 pr_warning("Failed to convert variable type: %s\n",
371 strerror_r(-ret
, sbuf
, sizeof(sbuf
)));
374 tvar
->type
= strdup(buf
);
375 if (tvar
->type
== NULL
)
380 static int convert_variable_fields(Dwarf_Die
*vr_die
, const char *varname
,
381 struct perf_probe_arg_field
*field
,
382 struct probe_trace_arg_ref
**ref_ptr
,
385 struct probe_trace_arg_ref
*ref
= *ref_ptr
;
390 pr_debug("converting %s in %s\n", field
->name
, varname
);
391 if (die_get_real_type(vr_die
, &type
) == NULL
) {
392 pr_warning("Failed to get the type of %s.\n", varname
);
395 pr_debug2("Var real type: (%x)\n", (unsigned)dwarf_dieoffset(&type
));
396 tag
= dwarf_tag(&type
);
398 if (field
->name
[0] == '[' &&
399 (tag
== DW_TAG_array_type
|| tag
== DW_TAG_pointer_type
)) {
401 /* Save original type for next field */
402 memcpy(die_mem
, &type
, sizeof(*die_mem
));
403 /* Get the type of this array */
404 if (die_get_real_type(&type
, &type
) == NULL
) {
405 pr_warning("Failed to get the type of %s.\n", varname
);
408 pr_debug2("Array real type: (%x)\n",
409 (unsigned)dwarf_dieoffset(&type
));
410 if (tag
== DW_TAG_pointer_type
) {
411 ref
= zalloc(sizeof(struct probe_trace_arg_ref
));
415 (*ref_ptr
)->next
= ref
;
419 ref
->offset
+= dwarf_bytesize(&type
) * field
->index
;
421 /* Save vr_die for converting types */
422 memcpy(die_mem
, vr_die
, sizeof(*die_mem
));
424 } else if (tag
== DW_TAG_pointer_type
) {
425 /* Check the pointer and dereference */
427 pr_err("Semantic error: %s must be referred by '->'\n",
431 /* Get the type pointed by this pointer */
432 if (die_get_real_type(&type
, &type
) == NULL
) {
433 pr_warning("Failed to get the type of %s.\n", varname
);
436 /* Verify it is a data structure */
437 tag
= dwarf_tag(&type
);
438 if (tag
!= DW_TAG_structure_type
&& tag
!= DW_TAG_union_type
) {
439 pr_warning("%s is not a data structure nor an union.\n",
444 ref
= zalloc(sizeof(struct probe_trace_arg_ref
));
448 (*ref_ptr
)->next
= ref
;
452 /* Verify it is a data structure */
453 if (tag
!= DW_TAG_structure_type
&& tag
!= DW_TAG_union_type
) {
454 pr_warning("%s is not a data structure nor an union.\n",
458 if (field
->name
[0] == '[') {
459 pr_err("Semantic error: %s is not a pointer"
460 " nor array.\n", varname
);
463 /* While prcessing unnamed field, we don't care about this */
464 if (field
->ref
&& dwarf_diename(vr_die
)) {
465 pr_err("Semantic error: %s must be referred by '.'\n",
470 pr_warning("Structure on a register is not "
476 if (die_find_member(&type
, field
->name
, die_mem
) == NULL
) {
477 pr_warning("%s(type:%s) has no member %s.\n", varname
,
478 dwarf_diename(&type
), field
->name
);
482 /* Get the offset of the field */
483 if (tag
== DW_TAG_union_type
) {
486 ret
= die_get_data_member_location(die_mem
, &offs
);
488 pr_warning("Failed to get the offset of %s.\n",
493 ref
->offset
+= (long)offs
;
495 /* If this member is unnamed, we need to reuse this field */
496 if (!dwarf_diename(die_mem
))
497 return convert_variable_fields(die_mem
, varname
, field
,
501 /* Converting next field */
503 return convert_variable_fields(die_mem
, field
->name
,
504 field
->next
, &ref
, die_mem
);
509 /* Show a variables in kprobe event format */
510 static int convert_variable(Dwarf_Die
*vr_die
, struct probe_finder
*pf
)
515 pr_debug("Converting variable %s into trace event.\n",
516 dwarf_diename(vr_die
));
518 ret
= convert_variable_location(vr_die
, pf
->addr
, pf
->fb_ops
,
519 &pf
->sp_die
, pf
->tvar
);
520 if (ret
== -ENOENT
|| ret
== -EINVAL
)
521 pr_err("Failed to find the location of %s at this address.\n"
522 " Perhaps, it has been optimized out.\n", pf
->pvar
->var
);
523 else if (ret
== -ENOTSUP
)
524 pr_err("Sorry, we don't support this variable location yet.\n");
525 else if (ret
== 0 && pf
->pvar
->field
) {
526 ret
= convert_variable_fields(vr_die
, pf
->pvar
->var
,
527 pf
->pvar
->field
, &pf
->tvar
->ref
,
532 ret
= convert_variable_type(vr_die
, pf
->tvar
, pf
->pvar
->type
);
533 /* *expr will be cached in libdw. Don't free it. */
537 /* Find a variable in a scope DIE */
538 static int find_variable(Dwarf_Die
*sc_die
, struct probe_finder
*pf
)
544 if (!is_c_varname(pf
->pvar
->var
)) {
545 /* Copy raw parameters */
546 pf
->tvar
->value
= strdup(pf
->pvar
->var
);
547 if (pf
->tvar
->value
== NULL
)
549 if (pf
->pvar
->type
) {
550 pf
->tvar
->type
= strdup(pf
->pvar
->type
);
551 if (pf
->tvar
->type
== NULL
)
554 if (pf
->pvar
->name
) {
555 pf
->tvar
->name
= strdup(pf
->pvar
->name
);
556 if (pf
->tvar
->name
== NULL
)
559 pf
->tvar
->name
= NULL
;
564 pf
->tvar
->name
= strdup(pf
->pvar
->name
);
566 ret
= synthesize_perf_probe_arg(pf
->pvar
, buf
, 32);
569 ptr
= strchr(buf
, ':'); /* Change type separator to _ */
572 pf
->tvar
->name
= strdup(buf
);
574 if (pf
->tvar
->name
== NULL
)
577 pr_debug("Searching '%s' variable in context.\n", pf
->pvar
->var
);
578 /* Search child die for local variables and parameters. */
579 if (!die_find_variable_at(sc_die
, pf
->pvar
->var
, pf
->addr
, &vr_die
)) {
580 /* Search again in global variables */
581 if (!die_find_variable_at(&pf
->cu_die
, pf
->pvar
->var
, 0, &vr_die
))
582 pr_warning("Failed to find '%s' in this function.\n",
587 ret
= convert_variable(&vr_die
, pf
);
592 /* Convert subprogram DIE to trace point */
593 static int convert_to_trace_point(Dwarf_Die
*sp_die
, Dwfl_Module
*mod
,
594 Dwarf_Addr paddr
, bool retprobe
,
595 struct probe_trace_point
*tp
)
597 Dwarf_Addr eaddr
, highaddr
;
601 /* Verify the address is correct */
602 if (dwarf_entrypc(sp_die
, &eaddr
) != 0) {
603 pr_warning("Failed to get entry address of %s\n",
604 dwarf_diename(sp_die
));
607 if (dwarf_highpc(sp_die
, &highaddr
) != 0) {
608 pr_warning("Failed to get end address of %s\n",
609 dwarf_diename(sp_die
));
612 if (paddr
> highaddr
) {
613 pr_warning("Offset specified is greater than size of %s\n",
614 dwarf_diename(sp_die
));
618 symbol
= dwarf_diename(sp_die
);
620 /* Try to get the symbol name from symtab */
621 symbol
= dwfl_module_addrsym(mod
, paddr
, &sym
, NULL
);
623 pr_warning("Failed to find symbol at 0x%lx\n",
624 (unsigned long)paddr
);
627 eaddr
= sym
.st_value
;
629 tp
->offset
= (unsigned long)(paddr
- eaddr
);
630 tp
->address
= (unsigned long)paddr
;
631 tp
->symbol
= strdup(symbol
);
635 /* Return probe must be on the head of a subprogram */
637 if (eaddr
!= paddr
) {
638 pr_warning("Return probe must be on the head of"
639 " a real function.\n");
648 /* Call probe_finder callback with scope DIE */
649 static int call_probe_finder(Dwarf_Die
*sc_die
, struct probe_finder
*pf
)
651 Dwarf_Attribute fb_attr
;
656 pr_err("Caller must pass a scope DIE. Program error.\n");
660 /* If not a real subprogram, find a real one */
661 if (!die_is_func_def(sc_die
)) {
662 if (!die_find_realfunc(&pf
->cu_die
, pf
->addr
, &pf
->sp_die
)) {
663 pr_warning("Failed to find probe point in any "
668 memcpy(&pf
->sp_die
, sc_die
, sizeof(Dwarf_Die
));
670 /* Get the frame base attribute/ops from subprogram */
671 dwarf_attr(&pf
->sp_die
, DW_AT_frame_base
, &fb_attr
);
672 ret
= dwarf_getlocation_addr(&fb_attr
, pf
->addr
, &pf
->fb_ops
, &nops
, 1);
673 if (ret
<= 0 || nops
== 0) {
675 #if _ELFUTILS_PREREQ(0, 142)
676 } else if (nops
== 1 && pf
->fb_ops
[0].atom
== DW_OP_call_frame_cfa
&&
679 if (dwarf_cfi_addrframe(pf
->cfi
, pf
->addr
, &frame
) != 0 ||
680 dwarf_frame_cfa(frame
, &pf
->fb_ops
, &nops
) != 0) {
681 pr_warning("Failed to get call frame on 0x%jx\n",
682 (uintmax_t)pf
->addr
);
688 /* Call finder's callback handler */
689 ret
= pf
->callback(sc_die
, pf
);
691 /* *pf->fb_ops will be cached in libdw. Don't free it. */
697 struct find_scope_param
{
698 const char *function
;
706 static int find_best_scope_cb(Dwarf_Die
*fn_die
, void *data
)
708 struct find_scope_param
*fsp
= data
;
712 /* Skip if declared file name does not match */
714 file
= dwarf_decl_file(fn_die
);
715 if (!file
|| strcmp(fsp
->file
, file
) != 0)
718 /* If the function name is given, that's what user expects */
720 if (die_compare_name(fn_die
, fsp
->function
)) {
721 memcpy(fsp
->die_mem
, fn_die
, sizeof(Dwarf_Die
));
726 /* With the line number, find the nearest declared DIE */
727 dwarf_decl_line(fn_die
, &lno
);
728 if (lno
< fsp
->line
&& fsp
->diff
> fsp
->line
- lno
) {
729 /* Keep a candidate and continue */
730 fsp
->diff
= fsp
->line
- lno
;
731 memcpy(fsp
->die_mem
, fn_die
, sizeof(Dwarf_Die
));
738 /* Find an appropriate scope fits to given conditions */
739 static Dwarf_Die
*find_best_scope(struct probe_finder
*pf
, Dwarf_Die
*die_mem
)
741 struct find_scope_param fsp
= {
742 .function
= pf
->pev
->point
.function
,
750 cu_walk_functions_at(&pf
->cu_die
, pf
->addr
, find_best_scope_cb
, &fsp
);
752 return fsp
.found
? die_mem
: NULL
;
755 static int probe_point_line_walker(const char *fname
, int lineno
,
756 Dwarf_Addr addr
, void *data
)
758 struct probe_finder
*pf
= data
;
759 Dwarf_Die
*sc_die
, die_mem
;
762 if (lineno
!= pf
->lno
|| strtailcmp(fname
, pf
->fname
) != 0)
766 sc_die
= find_best_scope(pf
, &die_mem
);
768 pr_warning("Failed to find scope of probe point.\n");
772 ret
= call_probe_finder(sc_die
, pf
);
774 /* Continue if no error, because the line will be in inline function */
775 return ret
< 0 ? ret
: 0;
778 /* Find probe point from its line number */
779 static int find_probe_point_by_line(struct probe_finder
*pf
)
781 return die_walk_lines(&pf
->cu_die
, probe_point_line_walker
, pf
);
784 /* Find lines which match lazy pattern */
785 static int find_lazy_match_lines(struct intlist
*list
,
786 const char *fname
, const char *pat
)
792 int count
= 0, linenum
= 1;
793 char sbuf
[STRERR_BUFSIZE
];
795 fp
= fopen(fname
, "r");
797 pr_warning("Failed to open %s: %s\n", fname
,
798 strerror_r(errno
, sbuf
, sizeof(sbuf
)));
802 while ((len
= getline(&line
, &line_len
, fp
)) > 0) {
804 if (line
[len
- 1] == '\n')
805 line
[len
- 1] = '\0';
807 if (strlazymatch(line
, pat
)) {
808 intlist__add(list
, linenum
);
820 pr_debug("No matched lines found in %s.\n", fname
);
824 static int probe_point_lazy_walker(const char *fname
, int lineno
,
825 Dwarf_Addr addr
, void *data
)
827 struct probe_finder
*pf
= data
;
828 Dwarf_Die
*sc_die
, die_mem
;
831 if (!intlist__has_entry(pf
->lcache
, lineno
) ||
832 strtailcmp(fname
, pf
->fname
) != 0)
835 pr_debug("Probe line found: line:%d addr:0x%llx\n",
836 lineno
, (unsigned long long)addr
);
839 sc_die
= find_best_scope(pf
, &die_mem
);
841 pr_warning("Failed to find scope of probe point.\n");
845 ret
= call_probe_finder(sc_die
, pf
);
848 * Continue if no error, because the lazy pattern will match
851 return ret
< 0 ? ret
: 0;
854 /* Find probe points from lazy pattern */
855 static int find_probe_point_lazy(Dwarf_Die
*sp_die
, struct probe_finder
*pf
)
859 if (intlist__empty(pf
->lcache
)) {
860 /* Matching lazy line pattern */
861 ret
= find_lazy_match_lines(pf
->lcache
, pf
->fname
,
862 pf
->pev
->point
.lazy_line
);
867 return die_walk_lines(sp_die
, probe_point_lazy_walker
, pf
);
870 static int probe_point_inline_cb(Dwarf_Die
*in_die
, void *data
)
872 struct probe_finder
*pf
= data
;
873 struct perf_probe_point
*pp
= &pf
->pev
->point
;
878 ret
= find_probe_point_lazy(in_die
, pf
);
880 /* Get probe address */
881 if (dwarf_entrypc(in_die
, &addr
) != 0) {
882 pr_warning("Failed to get entry address of %s.\n",
883 dwarf_diename(in_die
));
887 pf
->addr
+= pp
->offset
;
888 pr_debug("found inline addr: 0x%jx\n",
889 (uintmax_t)pf
->addr
);
891 ret
= call_probe_finder(in_die
, pf
);
897 /* Callback parameter with return value for libdw */
898 struct dwarf_callback_param
{
903 /* Search function from function name */
904 static int probe_point_search_cb(Dwarf_Die
*sp_die
, void *data
)
906 struct dwarf_callback_param
*param
= data
;
907 struct probe_finder
*pf
= param
->data
;
908 struct perf_probe_point
*pp
= &pf
->pev
->point
;
910 /* Check tag and diename */
911 if (!die_is_func_def(sp_die
) ||
912 !die_compare_name(sp_die
, pp
->function
))
915 /* Check declared file */
916 if (pp
->file
&& strtailcmp(pp
->file
, dwarf_decl_file(sp_die
)))
919 pf
->fname
= dwarf_decl_file(sp_die
);
920 if (pp
->line
) { /* Function relative line */
921 dwarf_decl_line(sp_die
, &pf
->lno
);
923 param
->retval
= find_probe_point_by_line(pf
);
924 } else if (die_is_func_instance(sp_die
)) {
925 /* Instances always have the entry address */
926 dwarf_entrypc(sp_die
, &pf
->addr
);
929 param
->retval
= find_probe_point_lazy(sp_die
, pf
);
931 pf
->addr
+= pp
->offset
;
932 /* TODO: Check the address in this function */
933 param
->retval
= call_probe_finder(sp_die
, pf
);
936 /* Inlined function: search instances */
937 param
->retval
= die_walk_instances(sp_die
,
938 probe_point_inline_cb
, (void *)pf
);
940 return DWARF_CB_ABORT
; /* Exit; no same symbol in this CU. */
943 static int find_probe_point_by_func(struct probe_finder
*pf
)
945 struct dwarf_callback_param _param
= {.data
= (void *)pf
,
947 dwarf_getfuncs(&pf
->cu_die
, probe_point_search_cb
, &_param
, 0);
948 return _param
.retval
;
951 struct pubname_callback_param
{
959 static int pubname_search_cb(Dwarf
*dbg
, Dwarf_Global
*gl
, void *data
)
961 struct pubname_callback_param
*param
= data
;
963 if (dwarf_offdie(dbg
, gl
->die_offset
, param
->sp_die
)) {
964 if (dwarf_tag(param
->sp_die
) != DW_TAG_subprogram
)
967 if (die_compare_name(param
->sp_die
, param
->function
)) {
968 if (!dwarf_offdie(dbg
, gl
->cu_offset
, param
->cu_die
))
972 strtailcmp(param
->file
, dwarf_decl_file(param
->sp_die
)))
976 return DWARF_CB_ABORT
;
983 /* Find probe points from debuginfo */
984 static int debuginfo__find_probes(struct debuginfo
*dbg
,
985 struct probe_finder
*pf
)
987 struct perf_probe_point
*pp
= &pf
->pev
->point
;
993 #if _ELFUTILS_PREREQ(0, 142)
998 /* Get the call frame information from this dwarf */
999 elf
= dwarf_getelf(dbg
->dbg
);
1003 if (gelf_getehdr(elf
, &ehdr
) == NULL
)
1006 if (elf_section_by_name(elf
, &ehdr
, &shdr
, ".eh_frame", NULL
) &&
1007 shdr
.sh_type
== SHT_PROGBITS
) {
1008 pf
->cfi
= dwarf_getcfi_elf(elf
);
1010 pf
->cfi
= dwarf_getcfi(dbg
->dbg
);
1015 pf
->lcache
= intlist__new(NULL
);
1019 /* Fastpath: lookup by function name from .debug_pubnames section */
1021 struct pubname_callback_param pubname_param
= {
1022 .function
= pp
->function
,
1024 .cu_die
= &pf
->cu_die
,
1025 .sp_die
= &pf
->sp_die
,
1028 struct dwarf_callback_param probe_param
= {
1032 dwarf_getpubnames(dbg
->dbg
, pubname_search_cb
,
1034 if (pubname_param
.found
) {
1035 ret
= probe_point_search_cb(&pf
->sp_die
, &probe_param
);
1041 /* Loop on CUs (Compilation Unit) */
1042 while (!dwarf_nextcu(dbg
->dbg
, off
, &noff
, &cuhl
, NULL
, NULL
, NULL
)) {
1043 /* Get the DIE(Debugging Information Entry) of this CU */
1044 diep
= dwarf_offdie(dbg
->dbg
, off
+ cuhl
, &pf
->cu_die
);
1048 /* Check if target file is included. */
1050 pf
->fname
= cu_find_realpath(&pf
->cu_die
, pp
->file
);
1054 if (!pp
->file
|| pf
->fname
) {
1056 ret
= find_probe_point_by_func(pf
);
1057 else if (pp
->lazy_line
)
1058 ret
= find_probe_point_lazy(NULL
, pf
);
1061 ret
= find_probe_point_by_line(pf
);
1070 intlist__delete(pf
->lcache
);
1076 struct local_vars_finder
{
1077 struct probe_finder
*pf
;
1078 struct perf_probe_arg
*args
;
1084 /* Collect available variables in this scope */
1085 static int copy_variables_cb(Dwarf_Die
*die_mem
, void *data
)
1087 struct local_vars_finder
*vf
= data
;
1088 struct probe_finder
*pf
= vf
->pf
;
1091 tag
= dwarf_tag(die_mem
);
1092 if (tag
== DW_TAG_formal_parameter
||
1093 tag
== DW_TAG_variable
) {
1094 if (convert_variable_location(die_mem
, vf
->pf
->addr
,
1095 vf
->pf
->fb_ops
, &pf
->sp_die
,
1097 vf
->args
[vf
->nargs
].var
= (char *)dwarf_diename(die_mem
);
1098 if (vf
->args
[vf
->nargs
].var
== NULL
) {
1100 return DIE_FIND_CB_END
;
1102 pr_debug(" %s", vf
->args
[vf
->nargs
].var
);
1107 if (dwarf_haspc(die_mem
, vf
->pf
->addr
))
1108 return DIE_FIND_CB_CONTINUE
;
1110 return DIE_FIND_CB_SIBLING
;
1113 static int expand_probe_args(Dwarf_Die
*sc_die
, struct probe_finder
*pf
,
1114 struct perf_probe_arg
*args
)
1119 struct local_vars_finder vf
= {.pf
= pf
, .args
= args
,
1120 .max_args
= MAX_PROBE_ARGS
, .ret
= 0};
1122 for (i
= 0; i
< pf
->pev
->nargs
; i
++) {
1123 /* var never be NULL */
1124 if (strcmp(pf
->pev
->args
[i
].var
, "$vars") == 0) {
1125 pr_debug("Expanding $vars into:");
1127 /* Special local variables */
1128 die_find_child(sc_die
, copy_variables_cb
, (void *)&vf
,
1130 pr_debug(" (%d)\n", vf
.nargs
- n
);
1135 /* Copy normal argument */
1136 args
[n
] = pf
->pev
->args
[i
];
1143 /* Add a found probe point into trace event list */
1144 static int add_probe_trace_event(Dwarf_Die
*sc_die
, struct probe_finder
*pf
)
1146 struct trace_event_finder
*tf
=
1147 container_of(pf
, struct trace_event_finder
, pf
);
1148 struct probe_trace_event
*tev
;
1149 struct perf_probe_arg
*args
;
1152 /* Check number of tevs */
1153 if (tf
->ntevs
== tf
->max_tevs
) {
1154 pr_warning("Too many( > %d) probe point found.\n",
1158 tev
= &tf
->tevs
[tf
->ntevs
++];
1160 /* Trace point should be converted from subprogram DIE */
1161 ret
= convert_to_trace_point(&pf
->sp_die
, tf
->mod
, pf
->addr
,
1162 pf
->pev
->point
.retprobe
, &tev
->point
);
1166 pr_debug("Probe point found: %s+%lu\n", tev
->point
.symbol
,
1169 /* Expand special probe argument if exist */
1170 args
= zalloc(sizeof(struct perf_probe_arg
) * MAX_PROBE_ARGS
);
1174 ret
= expand_probe_args(sc_die
, pf
, args
);
1179 tev
->args
= zalloc(sizeof(struct probe_trace_arg
) * tev
->nargs
);
1180 if (tev
->args
== NULL
) {
1185 /* Find each argument */
1186 for (i
= 0; i
< tev
->nargs
; i
++) {
1187 pf
->pvar
= &args
[i
];
1188 pf
->tvar
= &tev
->args
[i
];
1189 /* Variable should be found from scope DIE */
1190 ret
= find_variable(sc_die
, pf
);
1200 /* Find probe_trace_events specified by perf_probe_event from debuginfo */
1201 int debuginfo__find_trace_events(struct debuginfo
*dbg
,
1202 struct perf_probe_event
*pev
,
1203 struct probe_trace_event
**tevs
, int max_tevs
)
1205 struct trace_event_finder tf
= {
1206 .pf
= {.pev
= pev
, .callback
= add_probe_trace_event
},
1207 .mod
= dbg
->mod
, .max_tevs
= max_tevs
};
1210 /* Allocate result tevs array */
1211 *tevs
= zalloc(sizeof(struct probe_trace_event
) * max_tevs
);
1218 ret
= debuginfo__find_probes(dbg
, &tf
.pf
);
1224 return (ret
< 0) ? ret
: tf
.ntevs
;
1227 #define MAX_VAR_LEN 64
1229 /* Collect available variables in this scope */
1230 static int collect_variables_cb(Dwarf_Die
*die_mem
, void *data
)
1232 struct available_var_finder
*af
= data
;
1233 struct variable_list
*vl
;
1234 char buf
[MAX_VAR_LEN
];
1237 vl
= &af
->vls
[af
->nvls
- 1];
1239 tag
= dwarf_tag(die_mem
);
1240 if (tag
== DW_TAG_formal_parameter
||
1241 tag
== DW_TAG_variable
) {
1242 ret
= convert_variable_location(die_mem
, af
->pf
.addr
,
1243 af
->pf
.fb_ops
, &af
->pf
.sp_die
,
1246 ret
= die_get_varname(die_mem
, buf
, MAX_VAR_LEN
);
1247 pr_debug2("Add new var: %s\n", buf
);
1249 strlist__add(vl
->vars
, buf
);
1253 if (af
->child
&& dwarf_haspc(die_mem
, af
->pf
.addr
))
1254 return DIE_FIND_CB_CONTINUE
;
1256 return DIE_FIND_CB_SIBLING
;
1259 /* Add a found vars into available variables list */
1260 static int add_available_vars(Dwarf_Die
*sc_die
, struct probe_finder
*pf
)
1262 struct available_var_finder
*af
=
1263 container_of(pf
, struct available_var_finder
, pf
);
1264 struct variable_list
*vl
;
1268 /* Check number of tevs */
1269 if (af
->nvls
== af
->max_vls
) {
1270 pr_warning("Too many( > %d) probe point found.\n", af
->max_vls
);
1273 vl
= &af
->vls
[af
->nvls
++];
1275 /* Trace point should be converted from subprogram DIE */
1276 ret
= convert_to_trace_point(&pf
->sp_die
, af
->mod
, pf
->addr
,
1277 pf
->pev
->point
.retprobe
, &vl
->point
);
1281 pr_debug("Probe point found: %s+%lu\n", vl
->point
.symbol
,
1284 /* Find local variables */
1285 vl
->vars
= strlist__new(true, NULL
);
1286 if (vl
->vars
== NULL
)
1289 die_find_child(sc_die
, collect_variables_cb
, (void *)af
, &die_mem
);
1291 /* Find external variables */
1294 /* Don't need to search child DIE for externs. */
1296 die_find_child(&pf
->cu_die
, collect_variables_cb
, (void *)af
, &die_mem
);
1299 if (strlist__empty(vl
->vars
)) {
1300 strlist__delete(vl
->vars
);
1308 * Find available variables at given probe point
1309 * Return the number of found probe points. Return 0 if there is no
1310 * matched probe point. Return <0 if an error occurs.
1312 int debuginfo__find_available_vars_at(struct debuginfo
*dbg
,
1313 struct perf_probe_event
*pev
,
1314 struct variable_list
**vls
,
1315 int max_vls
, bool externs
)
1317 struct available_var_finder af
= {
1318 .pf
= {.pev
= pev
, .callback
= add_available_vars
},
1320 .max_vls
= max_vls
, .externs
= externs
};
1323 /* Allocate result vls array */
1324 *vls
= zalloc(sizeof(struct variable_list
) * max_vls
);
1331 ret
= debuginfo__find_probes(dbg
, &af
.pf
);
1333 /* Free vlist for error */
1335 zfree(&af
.vls
[af
.nvls
].point
.symbol
);
1336 strlist__delete(af
.vls
[af
.nvls
].vars
);
1342 return (ret
< 0) ? ret
: af
.nvls
;
1345 /* Reverse search */
1346 int debuginfo__find_probe_point(struct debuginfo
*dbg
, unsigned long addr
,
1347 struct perf_probe_point
*ppt
)
1349 Dwarf_Die cudie
, spdie
, indie
;
1350 Dwarf_Addr _addr
= 0, baseaddr
= 0;
1351 const char *fname
= NULL
, *func
= NULL
, *basefunc
= NULL
, *tmp
;
1352 int baseline
= 0, lineno
= 0, ret
= 0;
1355 if (!dwarf_addrdie(dbg
->dbg
, (Dwarf_Addr
)addr
, &cudie
)) {
1356 pr_warning("Failed to find debug information for address %lx\n",
1362 /* Find a corresponding line (filename and lineno) */
1363 cu_find_lineinfo(&cudie
, addr
, &fname
, &lineno
);
1364 /* Don't care whether it failed or not */
1366 /* Find a corresponding function (name, baseline and baseaddr) */
1367 if (die_find_realfunc(&cudie
, (Dwarf_Addr
)addr
, &spdie
)) {
1368 /* Get function entry information */
1369 func
= basefunc
= dwarf_diename(&spdie
);
1371 dwarf_entrypc(&spdie
, &baseaddr
) != 0 ||
1372 dwarf_decl_line(&spdie
, &baseline
) != 0) {
1377 fname
= dwarf_decl_file(&spdie
);
1378 if (addr
== (unsigned long)baseaddr
) {
1379 /* Function entry - Relative line number is 0 */
1384 /* Track down the inline functions step by step */
1385 while (die_find_top_inlinefunc(&spdie
, (Dwarf_Addr
)addr
,
1387 /* There is an inline function */
1388 if (dwarf_entrypc(&indie
, &_addr
) == 0 &&
1391 * addr is at an inline function entry.
1392 * In this case, lineno should be the call-site
1393 * line number. (overwrite lineinfo)
1395 lineno
= die_get_call_lineno(&indie
);
1396 fname
= die_get_call_file(&indie
);
1400 * addr is in an inline function body.
1401 * Since lineno points one of the lines
1402 * of the inline function, baseline should
1403 * be the entry line of the inline function.
1405 tmp
= dwarf_diename(&indie
);
1407 dwarf_decl_line(&indie
, &baseline
) != 0)
1413 /* Verify the lineno and baseline are in a same file */
1414 tmp
= dwarf_decl_file(&spdie
);
1415 if (!tmp
|| strcmp(tmp
, fname
) != 0)
1420 /* Make a relative line number or an offset */
1422 ppt
->line
= lineno
- baseline
;
1423 else if (basefunc
) {
1424 ppt
->offset
= addr
- (unsigned long)baseaddr
;
1428 /* Duplicate strings */
1430 ppt
->function
= strdup(func
);
1431 if (ppt
->function
== NULL
) {
1437 ppt
->file
= strdup(fname
);
1438 if (ppt
->file
== NULL
) {
1439 zfree(&ppt
->function
);
1445 if (ret
== 0 && (fname
|| func
))
1446 ret
= 1; /* Found a point */
1450 /* Add a line and store the src path */
1451 static int line_range_add_line(const char *src
, unsigned int lineno
,
1452 struct line_range
*lr
)
1454 /* Copy source path */
1456 lr
->path
= strdup(src
);
1457 if (lr
->path
== NULL
)
1460 return intlist__add(lr
->line_list
, lineno
);
1463 static int line_range_walk_cb(const char *fname
, int lineno
,
1464 Dwarf_Addr addr __maybe_unused
,
1467 struct line_finder
*lf
= data
;
1470 if ((strtailcmp(fname
, lf
->fname
) != 0) ||
1471 (lf
->lno_s
> lineno
|| lf
->lno_e
< lineno
))
1474 err
= line_range_add_line(fname
, lineno
, lf
->lr
);
1475 if (err
< 0 && err
!= -EEXIST
)
1481 /* Find line range from its line number */
1482 static int find_line_range_by_line(Dwarf_Die
*sp_die
, struct line_finder
*lf
)
1486 ret
= die_walk_lines(sp_die
?: &lf
->cu_die
, line_range_walk_cb
, lf
);
1490 if (!intlist__empty(lf
->lr
->line_list
))
1491 ret
= lf
->found
= 1;
1493 ret
= 0; /* Lines are not found */
1495 zfree(&lf
->lr
->path
);
1500 static int line_range_inline_cb(Dwarf_Die
*in_die
, void *data
)
1502 int ret
= find_line_range_by_line(in_die
, data
);
1505 * We have to check all instances of inlined function, because
1506 * some execution paths can be optimized out depends on the
1507 * function argument of instances. However, if an error occurs,
1508 * it should be handled by the caller.
1510 return ret
< 0 ? ret
: 0;
1513 /* Search function definition from function name */
1514 static int line_range_search_cb(Dwarf_Die
*sp_die
, void *data
)
1516 struct dwarf_callback_param
*param
= data
;
1517 struct line_finder
*lf
= param
->data
;
1518 struct line_range
*lr
= lf
->lr
;
1520 /* Check declared file */
1521 if (lr
->file
&& strtailcmp(lr
->file
, dwarf_decl_file(sp_die
)))
1524 if (die_is_func_def(sp_die
) &&
1525 die_compare_name(sp_die
, lr
->function
)) {
1526 lf
->fname
= dwarf_decl_file(sp_die
);
1527 dwarf_decl_line(sp_die
, &lr
->offset
);
1528 pr_debug("fname: %s, lineno:%d\n", lf
->fname
, lr
->offset
);
1529 lf
->lno_s
= lr
->offset
+ lr
->start
;
1530 if (lf
->lno_s
< 0) /* Overflow */
1531 lf
->lno_s
= INT_MAX
;
1532 lf
->lno_e
= lr
->offset
+ lr
->end
;
1533 if (lf
->lno_e
< 0) /* Overflow */
1534 lf
->lno_e
= INT_MAX
;
1535 pr_debug("New line range: %d to %d\n", lf
->lno_s
, lf
->lno_e
);
1536 lr
->start
= lf
->lno_s
;
1537 lr
->end
= lf
->lno_e
;
1538 if (!die_is_func_instance(sp_die
))
1539 param
->retval
= die_walk_instances(sp_die
,
1540 line_range_inline_cb
, lf
);
1542 param
->retval
= find_line_range_by_line(sp_die
, lf
);
1543 return DWARF_CB_ABORT
;
1548 static int find_line_range_by_func(struct line_finder
*lf
)
1550 struct dwarf_callback_param param
= {.data
= (void *)lf
, .retval
= 0};
1551 dwarf_getfuncs(&lf
->cu_die
, line_range_search_cb
, ¶m
, 0);
1552 return param
.retval
;
1555 int debuginfo__find_line_range(struct debuginfo
*dbg
, struct line_range
*lr
)
1557 struct line_finder lf
= {.lr
= lr
, .found
= 0};
1559 Dwarf_Off off
= 0, noff
;
1562 const char *comp_dir
;
1564 /* Fastpath: lookup by function name from .debug_pubnames section */
1566 struct pubname_callback_param pubname_param
= {
1567 .function
= lr
->function
, .file
= lr
->file
,
1568 .cu_die
= &lf
.cu_die
, .sp_die
= &lf
.sp_die
, .found
= 0};
1569 struct dwarf_callback_param line_range_param
= {
1570 .data
= (void *)&lf
, .retval
= 0};
1572 dwarf_getpubnames(dbg
->dbg
, pubname_search_cb
,
1574 if (pubname_param
.found
) {
1575 line_range_search_cb(&lf
.sp_die
, &line_range_param
);
1581 /* Loop on CUs (Compilation Unit) */
1582 while (!lf
.found
&& ret
>= 0) {
1583 if (dwarf_nextcu(dbg
->dbg
, off
, &noff
, &cuhl
,
1584 NULL
, NULL
, NULL
) != 0)
1587 /* Get the DIE(Debugging Information Entry) of this CU */
1588 diep
= dwarf_offdie(dbg
->dbg
, off
+ cuhl
, &lf
.cu_die
);
1592 /* Check if target file is included. */
1594 lf
.fname
= cu_find_realpath(&lf
.cu_die
, lr
->file
);
1598 if (!lr
->file
|| lf
.fname
) {
1600 ret
= find_line_range_by_func(&lf
);
1602 lf
.lno_s
= lr
->start
;
1604 ret
= find_line_range_by_line(NULL
, &lf
);
1611 /* Store comp_dir */
1613 comp_dir
= cu_get_comp_dir(&lf
.cu_die
);
1615 lr
->comp_dir
= strdup(comp_dir
);
1621 pr_debug("path: %s\n", lr
->path
);
1622 return (ret
< 0) ? ret
: lf
.found
;