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 int bsize
, boffs
, total
;
287 /* TODO: check all types */
288 if (cast
&& strcmp(cast
, "string") != 0) {
289 /* Non string type is OK */
290 tvar
->type
= strdup(cast
);
291 return (tvar
->type
== NULL
) ? -ENOMEM
: 0;
294 bsize
= dwarf_bitsize(vr_die
);
296 /* This is a bitfield */
297 boffs
= dwarf_bitoffset(vr_die
);
298 total
= dwarf_bytesize(vr_die
);
299 if (boffs
< 0 || total
< 0)
301 ret
= snprintf(buf
, 16, "b%d@%d/%zd", bsize
, boffs
,
302 BYTES_TO_BITS(total
));
306 if (die_get_real_type(vr_die
, &type
) == NULL
) {
307 pr_warning("Failed to get a type information of %s.\n",
308 dwarf_diename(vr_die
));
312 pr_debug("%s type is %s.\n",
313 dwarf_diename(vr_die
), dwarf_diename(&type
));
315 if (cast
&& strcmp(cast
, "string") == 0) { /* String type */
316 ret
= dwarf_tag(&type
);
317 if (ret
!= DW_TAG_pointer_type
&&
318 ret
!= DW_TAG_array_type
) {
319 pr_warning("Failed to cast into string: "
320 "%s(%s) is not a pointer nor array.\n",
321 dwarf_diename(vr_die
), dwarf_diename(&type
));
324 if (die_get_real_type(&type
, &type
) == NULL
) {
325 pr_warning("Failed to get a type"
329 if (ret
== DW_TAG_pointer_type
) {
331 ref_ptr
= &(*ref_ptr
)->next
;
332 /* Add new reference with offset +0 */
333 *ref_ptr
= zalloc(sizeof(struct probe_trace_arg_ref
));
334 if (*ref_ptr
== NULL
) {
335 pr_warning("Out of memory error\n");
339 if (!die_compare_name(&type
, "char") &&
340 !die_compare_name(&type
, "unsigned char")) {
341 pr_warning("Failed to cast into string: "
342 "%s is not (unsigned) char *.\n",
343 dwarf_diename(vr_die
));
346 tvar
->type
= strdup(cast
);
347 return (tvar
->type
== NULL
) ? -ENOMEM
: 0;
350 ret
= dwarf_bytesize(&type
);
352 /* No size ... try to use default type */
354 ret
= BYTES_TO_BITS(ret
);
356 /* Check the bitwidth */
357 if (ret
> MAX_BASIC_TYPE_BITS
) {
358 pr_info("%s exceeds max-bitwidth. Cut down to %d bits.\n",
359 dwarf_diename(&type
), MAX_BASIC_TYPE_BITS
);
360 ret
= MAX_BASIC_TYPE_BITS
;
362 ret
= snprintf(buf
, 16, "%c%d",
363 die_is_signed_type(&type
) ? 's' : 'u', ret
);
366 if (ret
< 0 || ret
>= 16) {
369 pr_warning("Failed to convert variable type: %s\n",
373 tvar
->type
= strdup(buf
);
374 if (tvar
->type
== NULL
)
379 static int convert_variable_fields(Dwarf_Die
*vr_die
, const char *varname
,
380 struct perf_probe_arg_field
*field
,
381 struct probe_trace_arg_ref
**ref_ptr
,
384 struct probe_trace_arg_ref
*ref
= *ref_ptr
;
389 pr_debug("converting %s in %s\n", field
->name
, varname
);
390 if (die_get_real_type(vr_die
, &type
) == NULL
) {
391 pr_warning("Failed to get the type of %s.\n", varname
);
394 pr_debug2("Var real type: (%x)\n", (unsigned)dwarf_dieoffset(&type
));
395 tag
= dwarf_tag(&type
);
397 if (field
->name
[0] == '[' &&
398 (tag
== DW_TAG_array_type
|| tag
== DW_TAG_pointer_type
)) {
400 /* Save original type for next field */
401 memcpy(die_mem
, &type
, sizeof(*die_mem
));
402 /* Get the type of this array */
403 if (die_get_real_type(&type
, &type
) == NULL
) {
404 pr_warning("Failed to get the type of %s.\n", varname
);
407 pr_debug2("Array real type: (%x)\n",
408 (unsigned)dwarf_dieoffset(&type
));
409 if (tag
== DW_TAG_pointer_type
) {
410 ref
= zalloc(sizeof(struct probe_trace_arg_ref
));
414 (*ref_ptr
)->next
= ref
;
418 ref
->offset
+= dwarf_bytesize(&type
) * field
->index
;
420 /* Save vr_die for converting types */
421 memcpy(die_mem
, vr_die
, sizeof(*die_mem
));
423 } else if (tag
== DW_TAG_pointer_type
) {
424 /* Check the pointer and dereference */
426 pr_err("Semantic error: %s must be referred by '->'\n",
430 /* Get the type pointed by this pointer */
431 if (die_get_real_type(&type
, &type
) == NULL
) {
432 pr_warning("Failed to get the type of %s.\n", varname
);
435 /* Verify it is a data structure */
436 tag
= dwarf_tag(&type
);
437 if (tag
!= DW_TAG_structure_type
&& tag
!= DW_TAG_union_type
) {
438 pr_warning("%s is not a data structure nor an union.\n",
443 ref
= zalloc(sizeof(struct probe_trace_arg_ref
));
447 (*ref_ptr
)->next
= ref
;
451 /* Verify it is a data structure */
452 if (tag
!= DW_TAG_structure_type
&& tag
!= DW_TAG_union_type
) {
453 pr_warning("%s is not a data structure nor an union.\n",
457 if (field
->name
[0] == '[') {
458 pr_err("Semantic error: %s is not a pointor"
459 " nor array.\n", varname
);
463 pr_err("Semantic error: %s must be referred by '.'\n",
468 pr_warning("Structure on a register is not "
474 if (die_find_member(&type
, field
->name
, die_mem
) == NULL
) {
475 pr_warning("%s(type:%s) has no member %s.\n", varname
,
476 dwarf_diename(&type
), field
->name
);
480 /* Get the offset of the field */
481 if (tag
== DW_TAG_union_type
) {
484 ret
= die_get_data_member_location(die_mem
, &offs
);
486 pr_warning("Failed to get the offset of %s.\n",
491 ref
->offset
+= (long)offs
;
494 /* Converting next field */
496 return convert_variable_fields(die_mem
, field
->name
,
497 field
->next
, &ref
, die_mem
);
502 /* Show a variables in kprobe event format */
503 static int convert_variable(Dwarf_Die
*vr_die
, struct probe_finder
*pf
)
508 pr_debug("Converting variable %s into trace event.\n",
509 dwarf_diename(vr_die
));
511 ret
= convert_variable_location(vr_die
, pf
->addr
, pf
->fb_ops
,
512 &pf
->sp_die
, pf
->tvar
);
513 if (ret
== -ENOENT
|| ret
== -EINVAL
)
514 pr_err("Failed to find the location of %s at this address.\n"
515 " Perhaps, it has been optimized out.\n", pf
->pvar
->var
);
516 else if (ret
== -ENOTSUP
)
517 pr_err("Sorry, we don't support this variable location yet.\n");
518 else if (ret
== 0 && pf
->pvar
->field
) {
519 ret
= convert_variable_fields(vr_die
, pf
->pvar
->var
,
520 pf
->pvar
->field
, &pf
->tvar
->ref
,
525 ret
= convert_variable_type(vr_die
, pf
->tvar
, pf
->pvar
->type
);
526 /* *expr will be cached in libdw. Don't free it. */
530 /* Find a variable in a scope DIE */
531 static int find_variable(Dwarf_Die
*sc_die
, struct probe_finder
*pf
)
537 if (!is_c_varname(pf
->pvar
->var
)) {
538 /* Copy raw parameters */
539 pf
->tvar
->value
= strdup(pf
->pvar
->var
);
540 if (pf
->tvar
->value
== NULL
)
542 if (pf
->pvar
->type
) {
543 pf
->tvar
->type
= strdup(pf
->pvar
->type
);
544 if (pf
->tvar
->type
== NULL
)
547 if (pf
->pvar
->name
) {
548 pf
->tvar
->name
= strdup(pf
->pvar
->name
);
549 if (pf
->tvar
->name
== NULL
)
552 pf
->tvar
->name
= NULL
;
557 pf
->tvar
->name
= strdup(pf
->pvar
->name
);
559 ret
= synthesize_perf_probe_arg(pf
->pvar
, buf
, 32);
562 ptr
= strchr(buf
, ':'); /* Change type separator to _ */
565 pf
->tvar
->name
= strdup(buf
);
567 if (pf
->tvar
->name
== NULL
)
570 pr_debug("Searching '%s' variable in context.\n", pf
->pvar
->var
);
571 /* Search child die for local variables and parameters. */
572 if (!die_find_variable_at(sc_die
, pf
->pvar
->var
, pf
->addr
, &vr_die
)) {
573 /* Search again in global variables */
574 if (!die_find_variable_at(&pf
->cu_die
, pf
->pvar
->var
, 0, &vr_die
))
575 pr_warning("Failed to find '%s' in this function.\n",
580 ret
= convert_variable(&vr_die
, pf
);
585 /* Convert subprogram DIE to trace point */
586 static int convert_to_trace_point(Dwarf_Die
*sp_die
, Dwfl_Module
*mod
,
587 Dwarf_Addr paddr
, bool retprobe
,
588 struct probe_trace_point
*tp
)
590 Dwarf_Addr eaddr
, highaddr
;
594 /* Verify the address is correct */
595 if (dwarf_entrypc(sp_die
, &eaddr
) != 0) {
596 pr_warning("Failed to get entry address of %s\n",
597 dwarf_diename(sp_die
));
600 if (dwarf_highpc(sp_die
, &highaddr
) != 0) {
601 pr_warning("Failed to get end address of %s\n",
602 dwarf_diename(sp_die
));
605 if (paddr
> highaddr
) {
606 pr_warning("Offset specified is greater than size of %s\n",
607 dwarf_diename(sp_die
));
611 /* Get an appropriate symbol from symtab */
612 symbol
= dwfl_module_addrsym(mod
, paddr
, &sym
, NULL
);
614 pr_warning("Failed to find symbol at 0x%lx\n",
615 (unsigned long)paddr
);
618 tp
->offset
= (unsigned long)(paddr
- sym
.st_value
);
619 tp
->address
= (unsigned long)paddr
;
620 tp
->symbol
= strdup(symbol
);
624 /* Return probe must be on the head of a subprogram */
626 if (eaddr
!= paddr
) {
627 pr_warning("Return probe must be on the head of"
628 " a real function.\n");
637 /* Call probe_finder callback with scope DIE */
638 static int call_probe_finder(Dwarf_Die
*sc_die
, struct probe_finder
*pf
)
640 Dwarf_Attribute fb_attr
;
645 pr_err("Caller must pass a scope DIE. Program error.\n");
649 /* If not a real subprogram, find a real one */
650 if (!die_is_func_def(sc_die
)) {
651 if (!die_find_realfunc(&pf
->cu_die
, pf
->addr
, &pf
->sp_die
)) {
652 pr_warning("Failed to find probe point in any "
657 memcpy(&pf
->sp_die
, sc_die
, sizeof(Dwarf_Die
));
659 /* Get the frame base attribute/ops from subprogram */
660 dwarf_attr(&pf
->sp_die
, DW_AT_frame_base
, &fb_attr
);
661 ret
= dwarf_getlocation_addr(&fb_attr
, pf
->addr
, &pf
->fb_ops
, &nops
, 1);
662 if (ret
<= 0 || nops
== 0) {
664 #if _ELFUTILS_PREREQ(0, 142)
665 } else if (nops
== 1 && pf
->fb_ops
[0].atom
== DW_OP_call_frame_cfa
&&
668 if (dwarf_cfi_addrframe(pf
->cfi
, pf
->addr
, &frame
) != 0 ||
669 dwarf_frame_cfa(frame
, &pf
->fb_ops
, &nops
) != 0) {
670 pr_warning("Failed to get call frame on 0x%jx\n",
671 (uintmax_t)pf
->addr
);
677 /* Call finder's callback handler */
678 ret
= pf
->callback(sc_die
, pf
);
680 /* *pf->fb_ops will be cached in libdw. Don't free it. */
686 struct find_scope_param
{
687 const char *function
;
695 static int find_best_scope_cb(Dwarf_Die
*fn_die
, void *data
)
697 struct find_scope_param
*fsp
= data
;
701 /* Skip if declared file name does not match */
703 file
= dwarf_decl_file(fn_die
);
704 if (!file
|| strcmp(fsp
->file
, file
) != 0)
707 /* If the function name is given, that's what user expects */
709 if (die_compare_name(fn_die
, fsp
->function
)) {
710 memcpy(fsp
->die_mem
, fn_die
, sizeof(Dwarf_Die
));
715 /* With the line number, find the nearest declared DIE */
716 dwarf_decl_line(fn_die
, &lno
);
717 if (lno
< fsp
->line
&& fsp
->diff
> fsp
->line
- lno
) {
718 /* Keep a candidate and continue */
719 fsp
->diff
= fsp
->line
- lno
;
720 memcpy(fsp
->die_mem
, fn_die
, sizeof(Dwarf_Die
));
727 /* Find an appropriate scope fits to given conditions */
728 static Dwarf_Die
*find_best_scope(struct probe_finder
*pf
, Dwarf_Die
*die_mem
)
730 struct find_scope_param fsp
= {
731 .function
= pf
->pev
->point
.function
,
739 cu_walk_functions_at(&pf
->cu_die
, pf
->addr
, find_best_scope_cb
, &fsp
);
741 return fsp
.found
? die_mem
: NULL
;
744 static int probe_point_line_walker(const char *fname
, int lineno
,
745 Dwarf_Addr addr
, void *data
)
747 struct probe_finder
*pf
= data
;
748 Dwarf_Die
*sc_die
, die_mem
;
751 if (lineno
!= pf
->lno
|| strtailcmp(fname
, pf
->fname
) != 0)
755 sc_die
= find_best_scope(pf
, &die_mem
);
757 pr_warning("Failed to find scope of probe point.\n");
761 ret
= call_probe_finder(sc_die
, pf
);
763 /* Continue if no error, because the line will be in inline function */
764 return ret
< 0 ? ret
: 0;
767 /* Find probe point from its line number */
768 static int find_probe_point_by_line(struct probe_finder
*pf
)
770 return die_walk_lines(&pf
->cu_die
, probe_point_line_walker
, pf
);
773 /* Find lines which match lazy pattern */
774 static int find_lazy_match_lines(struct intlist
*list
,
775 const char *fname
, const char *pat
)
781 int count
= 0, linenum
= 1;
783 fp
= fopen(fname
, "r");
785 pr_warning("Failed to open %s: %s\n", fname
, strerror(errno
));
789 while ((len
= getline(&line
, &line_len
, fp
)) > 0) {
791 if (line
[len
- 1] == '\n')
792 line
[len
- 1] = '\0';
794 if (strlazymatch(line
, pat
)) {
795 intlist__add(list
, linenum
);
807 pr_debug("No matched lines found in %s.\n", fname
);
811 static int probe_point_lazy_walker(const char *fname
, int lineno
,
812 Dwarf_Addr addr
, void *data
)
814 struct probe_finder
*pf
= data
;
815 Dwarf_Die
*sc_die
, die_mem
;
818 if (!intlist__has_entry(pf
->lcache
, lineno
) ||
819 strtailcmp(fname
, pf
->fname
) != 0)
822 pr_debug("Probe line found: line:%d addr:0x%llx\n",
823 lineno
, (unsigned long long)addr
);
826 sc_die
= find_best_scope(pf
, &die_mem
);
828 pr_warning("Failed to find scope of probe point.\n");
832 ret
= call_probe_finder(sc_die
, pf
);
835 * Continue if no error, because the lazy pattern will match
838 return ret
< 0 ? ret
: 0;
841 /* Find probe points from lazy pattern */
842 static int find_probe_point_lazy(Dwarf_Die
*sp_die
, struct probe_finder
*pf
)
846 if (intlist__empty(pf
->lcache
)) {
847 /* Matching lazy line pattern */
848 ret
= find_lazy_match_lines(pf
->lcache
, pf
->fname
,
849 pf
->pev
->point
.lazy_line
);
854 return die_walk_lines(sp_die
, probe_point_lazy_walker
, pf
);
857 static int probe_point_inline_cb(Dwarf_Die
*in_die
, void *data
)
859 struct probe_finder
*pf
= data
;
860 struct perf_probe_point
*pp
= &pf
->pev
->point
;
865 ret
= find_probe_point_lazy(in_die
, pf
);
867 /* Get probe address */
868 if (dwarf_entrypc(in_die
, &addr
) != 0) {
869 pr_warning("Failed to get entry address of %s.\n",
870 dwarf_diename(in_die
));
874 pf
->addr
+= pp
->offset
;
875 pr_debug("found inline addr: 0x%jx\n",
876 (uintmax_t)pf
->addr
);
878 ret
= call_probe_finder(in_die
, pf
);
884 /* Callback parameter with return value for libdw */
885 struct dwarf_callback_param
{
890 /* Search function from function name */
891 static int probe_point_search_cb(Dwarf_Die
*sp_die
, void *data
)
893 struct dwarf_callback_param
*param
= data
;
894 struct probe_finder
*pf
= param
->data
;
895 struct perf_probe_point
*pp
= &pf
->pev
->point
;
897 /* Check tag and diename */
898 if (!die_is_func_def(sp_die
) ||
899 !die_compare_name(sp_die
, pp
->function
))
902 /* Check declared file */
903 if (pp
->file
&& strtailcmp(pp
->file
, dwarf_decl_file(sp_die
)))
906 pf
->fname
= dwarf_decl_file(sp_die
);
907 if (pp
->line
) { /* Function relative line */
908 dwarf_decl_line(sp_die
, &pf
->lno
);
910 param
->retval
= find_probe_point_by_line(pf
);
911 } else if (!dwarf_func_inline(sp_die
)) {
914 param
->retval
= find_probe_point_lazy(sp_die
, pf
);
916 if (dwarf_entrypc(sp_die
, &pf
->addr
) != 0) {
917 pr_warning("Failed to get entry address of "
918 "%s.\n", dwarf_diename(sp_die
));
919 param
->retval
= -ENOENT
;
920 return DWARF_CB_ABORT
;
922 pf
->addr
+= pp
->offset
;
923 /* TODO: Check the address in this function */
924 param
->retval
= call_probe_finder(sp_die
, pf
);
927 /* Inlined function: search instances */
928 param
->retval
= die_walk_instances(sp_die
,
929 probe_point_inline_cb
, (void *)pf
);
931 return DWARF_CB_ABORT
; /* Exit; no same symbol in this CU. */
934 static int find_probe_point_by_func(struct probe_finder
*pf
)
936 struct dwarf_callback_param _param
= {.data
= (void *)pf
,
938 dwarf_getfuncs(&pf
->cu_die
, probe_point_search_cb
, &_param
, 0);
939 return _param
.retval
;
942 struct pubname_callback_param
{
950 static int pubname_search_cb(Dwarf
*dbg
, Dwarf_Global
*gl
, void *data
)
952 struct pubname_callback_param
*param
= data
;
954 if (dwarf_offdie(dbg
, gl
->die_offset
, param
->sp_die
)) {
955 if (dwarf_tag(param
->sp_die
) != DW_TAG_subprogram
)
958 if (die_compare_name(param
->sp_die
, param
->function
)) {
959 if (!dwarf_offdie(dbg
, gl
->cu_offset
, param
->cu_die
))
963 strtailcmp(param
->file
, dwarf_decl_file(param
->sp_die
)))
967 return DWARF_CB_ABORT
;
974 /* Find probe points from debuginfo */
975 static int debuginfo__find_probes(struct debuginfo
*dbg
,
976 struct probe_finder
*pf
)
978 struct perf_probe_point
*pp
= &pf
->pev
->point
;
984 #if _ELFUTILS_PREREQ(0, 142)
985 /* Get the call frame information from this dwarf */
986 pf
->cfi
= dwarf_getcfi_elf(dwarf_getelf(dbg
->dbg
));
990 pf
->lcache
= intlist__new(NULL
);
994 /* Fastpath: lookup by function name from .debug_pubnames section */
996 struct pubname_callback_param pubname_param
= {
997 .function
= pp
->function
,
999 .cu_die
= &pf
->cu_die
,
1000 .sp_die
= &pf
->sp_die
,
1003 struct dwarf_callback_param probe_param
= {
1007 dwarf_getpubnames(dbg
->dbg
, pubname_search_cb
,
1009 if (pubname_param
.found
) {
1010 ret
= probe_point_search_cb(&pf
->sp_die
, &probe_param
);
1016 /* Loop on CUs (Compilation Unit) */
1017 while (!dwarf_nextcu(dbg
->dbg
, off
, &noff
, &cuhl
, NULL
, NULL
, NULL
)) {
1018 /* Get the DIE(Debugging Information Entry) of this CU */
1019 diep
= dwarf_offdie(dbg
->dbg
, off
+ cuhl
, &pf
->cu_die
);
1023 /* Check if target file is included. */
1025 pf
->fname
= cu_find_realpath(&pf
->cu_die
, pp
->file
);
1029 if (!pp
->file
|| pf
->fname
) {
1031 ret
= find_probe_point_by_func(pf
);
1032 else if (pp
->lazy_line
)
1033 ret
= find_probe_point_lazy(NULL
, pf
);
1036 ret
= find_probe_point_by_line(pf
);
1045 intlist__delete(pf
->lcache
);
1051 struct local_vars_finder
{
1052 struct probe_finder
*pf
;
1053 struct perf_probe_arg
*args
;
1059 /* Collect available variables in this scope */
1060 static int copy_variables_cb(Dwarf_Die
*die_mem
, void *data
)
1062 struct local_vars_finder
*vf
= data
;
1063 struct probe_finder
*pf
= vf
->pf
;
1066 tag
= dwarf_tag(die_mem
);
1067 if (tag
== DW_TAG_formal_parameter
||
1068 tag
== DW_TAG_variable
) {
1069 if (convert_variable_location(die_mem
, vf
->pf
->addr
,
1070 vf
->pf
->fb_ops
, &pf
->sp_die
,
1072 vf
->args
[vf
->nargs
].var
= (char *)dwarf_diename(die_mem
);
1073 if (vf
->args
[vf
->nargs
].var
== NULL
) {
1075 return DIE_FIND_CB_END
;
1077 pr_debug(" %s", vf
->args
[vf
->nargs
].var
);
1082 if (dwarf_haspc(die_mem
, vf
->pf
->addr
))
1083 return DIE_FIND_CB_CONTINUE
;
1085 return DIE_FIND_CB_SIBLING
;
1088 static int expand_probe_args(Dwarf_Die
*sc_die
, struct probe_finder
*pf
,
1089 struct perf_probe_arg
*args
)
1094 struct local_vars_finder vf
= {.pf
= pf
, .args
= args
,
1095 .max_args
= MAX_PROBE_ARGS
, .ret
= 0};
1097 for (i
= 0; i
< pf
->pev
->nargs
; i
++) {
1098 /* var never be NULL */
1099 if (strcmp(pf
->pev
->args
[i
].var
, "$vars") == 0) {
1100 pr_debug("Expanding $vars into:");
1102 /* Special local variables */
1103 die_find_child(sc_die
, copy_variables_cb
, (void *)&vf
,
1105 pr_debug(" (%d)\n", vf
.nargs
- n
);
1110 /* Copy normal argument */
1111 args
[n
] = pf
->pev
->args
[i
];
1118 /* Add a found probe point into trace event list */
1119 static int add_probe_trace_event(Dwarf_Die
*sc_die
, struct probe_finder
*pf
)
1121 struct trace_event_finder
*tf
=
1122 container_of(pf
, struct trace_event_finder
, pf
);
1123 struct probe_trace_event
*tev
;
1124 struct perf_probe_arg
*args
;
1127 /* Check number of tevs */
1128 if (tf
->ntevs
== tf
->max_tevs
) {
1129 pr_warning("Too many( > %d) probe point found.\n",
1133 tev
= &tf
->tevs
[tf
->ntevs
++];
1135 /* Trace point should be converted from subprogram DIE */
1136 ret
= convert_to_trace_point(&pf
->sp_die
, tf
->mod
, pf
->addr
,
1137 pf
->pev
->point
.retprobe
, &tev
->point
);
1141 pr_debug("Probe point found: %s+%lu\n", tev
->point
.symbol
,
1144 /* Expand special probe argument if exist */
1145 args
= zalloc(sizeof(struct perf_probe_arg
) * MAX_PROBE_ARGS
);
1149 ret
= expand_probe_args(sc_die
, pf
, args
);
1154 tev
->args
= zalloc(sizeof(struct probe_trace_arg
) * tev
->nargs
);
1155 if (tev
->args
== NULL
) {
1160 /* Find each argument */
1161 for (i
= 0; i
< tev
->nargs
; i
++) {
1162 pf
->pvar
= &args
[i
];
1163 pf
->tvar
= &tev
->args
[i
];
1164 /* Variable should be found from scope DIE */
1165 ret
= find_variable(sc_die
, pf
);
1175 /* Find probe_trace_events specified by perf_probe_event from debuginfo */
1176 int debuginfo__find_trace_events(struct debuginfo
*dbg
,
1177 struct perf_probe_event
*pev
,
1178 struct probe_trace_event
**tevs
, int max_tevs
)
1180 struct trace_event_finder tf
= {
1181 .pf
= {.pev
= pev
, .callback
= add_probe_trace_event
},
1182 .mod
= dbg
->mod
, .max_tevs
= max_tevs
};
1185 /* Allocate result tevs array */
1186 *tevs
= zalloc(sizeof(struct probe_trace_event
) * max_tevs
);
1193 ret
= debuginfo__find_probes(dbg
, &tf
.pf
);
1199 return (ret
< 0) ? ret
: tf
.ntevs
;
1202 #define MAX_VAR_LEN 64
1204 /* Collect available variables in this scope */
1205 static int collect_variables_cb(Dwarf_Die
*die_mem
, void *data
)
1207 struct available_var_finder
*af
= data
;
1208 struct variable_list
*vl
;
1209 char buf
[MAX_VAR_LEN
];
1212 vl
= &af
->vls
[af
->nvls
- 1];
1214 tag
= dwarf_tag(die_mem
);
1215 if (tag
== DW_TAG_formal_parameter
||
1216 tag
== DW_TAG_variable
) {
1217 ret
= convert_variable_location(die_mem
, af
->pf
.addr
,
1218 af
->pf
.fb_ops
, &af
->pf
.sp_die
,
1221 ret
= die_get_varname(die_mem
, buf
, MAX_VAR_LEN
);
1222 pr_debug2("Add new var: %s\n", buf
);
1224 strlist__add(vl
->vars
, buf
);
1228 if (af
->child
&& dwarf_haspc(die_mem
, af
->pf
.addr
))
1229 return DIE_FIND_CB_CONTINUE
;
1231 return DIE_FIND_CB_SIBLING
;
1234 /* Add a found vars into available variables list */
1235 static int add_available_vars(Dwarf_Die
*sc_die
, struct probe_finder
*pf
)
1237 struct available_var_finder
*af
=
1238 container_of(pf
, struct available_var_finder
, pf
);
1239 struct variable_list
*vl
;
1243 /* Check number of tevs */
1244 if (af
->nvls
== af
->max_vls
) {
1245 pr_warning("Too many( > %d) probe point found.\n", af
->max_vls
);
1248 vl
= &af
->vls
[af
->nvls
++];
1250 /* Trace point should be converted from subprogram DIE */
1251 ret
= convert_to_trace_point(&pf
->sp_die
, af
->mod
, pf
->addr
,
1252 pf
->pev
->point
.retprobe
, &vl
->point
);
1256 pr_debug("Probe point found: %s+%lu\n", vl
->point
.symbol
,
1259 /* Find local variables */
1260 vl
->vars
= strlist__new(true, NULL
);
1261 if (vl
->vars
== NULL
)
1264 die_find_child(sc_die
, collect_variables_cb
, (void *)af
, &die_mem
);
1266 /* Find external variables */
1269 /* Don't need to search child DIE for externs. */
1271 die_find_child(&pf
->cu_die
, collect_variables_cb
, (void *)af
, &die_mem
);
1274 if (strlist__empty(vl
->vars
)) {
1275 strlist__delete(vl
->vars
);
1283 * Find available variables at given probe point
1284 * Return the number of found probe points. Return 0 if there is no
1285 * matched probe point. Return <0 if an error occurs.
1287 int debuginfo__find_available_vars_at(struct debuginfo
*dbg
,
1288 struct perf_probe_event
*pev
,
1289 struct variable_list
**vls
,
1290 int max_vls
, bool externs
)
1292 struct available_var_finder af
= {
1293 .pf
= {.pev
= pev
, .callback
= add_available_vars
},
1295 .max_vls
= max_vls
, .externs
= externs
};
1298 /* Allocate result vls array */
1299 *vls
= zalloc(sizeof(struct variable_list
) * max_vls
);
1306 ret
= debuginfo__find_probes(dbg
, &af
.pf
);
1308 /* Free vlist for error */
1310 zfree(&af
.vls
[af
.nvls
].point
.symbol
);
1311 strlist__delete(af
.vls
[af
.nvls
].vars
);
1317 return (ret
< 0) ? ret
: af
.nvls
;
1320 /* Reverse search */
1321 int debuginfo__find_probe_point(struct debuginfo
*dbg
, unsigned long addr
,
1322 struct perf_probe_point
*ppt
)
1324 Dwarf_Die cudie
, spdie
, indie
;
1325 Dwarf_Addr _addr
= 0, baseaddr
= 0;
1326 const char *fname
= NULL
, *func
= NULL
, *basefunc
= NULL
, *tmp
;
1327 int baseline
= 0, lineno
= 0, ret
= 0;
1329 /* Adjust address with bias */
1333 if (!dwarf_addrdie(dbg
->dbg
, (Dwarf_Addr
)addr
- dbg
->bias
, &cudie
)) {
1334 pr_warning("Failed to find debug information for address %lx\n",
1340 /* Find a corresponding line (filename and lineno) */
1341 cu_find_lineinfo(&cudie
, addr
, &fname
, &lineno
);
1342 /* Don't care whether it failed or not */
1344 /* Find a corresponding function (name, baseline and baseaddr) */
1345 if (die_find_realfunc(&cudie
, (Dwarf_Addr
)addr
, &spdie
)) {
1346 /* Get function entry information */
1347 func
= basefunc
= dwarf_diename(&spdie
);
1349 dwarf_entrypc(&spdie
, &baseaddr
) != 0 ||
1350 dwarf_decl_line(&spdie
, &baseline
) != 0) {
1355 fname
= dwarf_decl_file(&spdie
);
1356 if (addr
== (unsigned long)baseaddr
) {
1357 /* Function entry - Relative line number is 0 */
1362 /* Track down the inline functions step by step */
1363 while (die_find_top_inlinefunc(&spdie
, (Dwarf_Addr
)addr
,
1365 /* There is an inline function */
1366 if (dwarf_entrypc(&indie
, &_addr
) == 0 &&
1369 * addr is at an inline function entry.
1370 * In this case, lineno should be the call-site
1371 * line number. (overwrite lineinfo)
1373 lineno
= die_get_call_lineno(&indie
);
1374 fname
= die_get_call_file(&indie
);
1378 * addr is in an inline function body.
1379 * Since lineno points one of the lines
1380 * of the inline function, baseline should
1381 * be the entry line of the inline function.
1383 tmp
= dwarf_diename(&indie
);
1385 dwarf_decl_line(&indie
, &baseline
) != 0)
1391 /* Verify the lineno and baseline are in a same file */
1392 tmp
= dwarf_decl_file(&spdie
);
1393 if (!tmp
|| strcmp(tmp
, fname
) != 0)
1398 /* Make a relative line number or an offset */
1400 ppt
->line
= lineno
- baseline
;
1401 else if (basefunc
) {
1402 ppt
->offset
= addr
- (unsigned long)baseaddr
;
1406 /* Duplicate strings */
1408 ppt
->function
= strdup(func
);
1409 if (ppt
->function
== NULL
) {
1415 ppt
->file
= strdup(fname
);
1416 if (ppt
->file
== NULL
) {
1417 zfree(&ppt
->function
);
1423 if (ret
== 0 && (fname
|| func
))
1424 ret
= 1; /* Found a point */
1428 /* Add a line and store the src path */
1429 static int line_range_add_line(const char *src
, unsigned int lineno
,
1430 struct line_range
*lr
)
1432 /* Copy source path */
1434 lr
->path
= strdup(src
);
1435 if (lr
->path
== NULL
)
1438 return intlist__add(lr
->line_list
, lineno
);
1441 static int line_range_walk_cb(const char *fname
, int lineno
,
1442 Dwarf_Addr addr __maybe_unused
,
1445 struct line_finder
*lf
= data
;
1448 if ((strtailcmp(fname
, lf
->fname
) != 0) ||
1449 (lf
->lno_s
> lineno
|| lf
->lno_e
< lineno
))
1452 err
= line_range_add_line(fname
, lineno
, lf
->lr
);
1453 if (err
< 0 && err
!= -EEXIST
)
1459 /* Find line range from its line number */
1460 static int find_line_range_by_line(Dwarf_Die
*sp_die
, struct line_finder
*lf
)
1464 ret
= die_walk_lines(sp_die
?: &lf
->cu_die
, line_range_walk_cb
, lf
);
1468 if (!intlist__empty(lf
->lr
->line_list
))
1469 ret
= lf
->found
= 1;
1471 ret
= 0; /* Lines are not found */
1473 zfree(&lf
->lr
->path
);
1478 static int line_range_inline_cb(Dwarf_Die
*in_die
, void *data
)
1480 int ret
= find_line_range_by_line(in_die
, data
);
1483 * We have to check all instances of inlined function, because
1484 * some execution paths can be optimized out depends on the
1485 * function argument of instances. However, if an error occurs,
1486 * it should be handled by the caller.
1488 return ret
< 0 ? ret
: 0;
1491 /* Search function definition from function name */
1492 static int line_range_search_cb(Dwarf_Die
*sp_die
, void *data
)
1494 struct dwarf_callback_param
*param
= data
;
1495 struct line_finder
*lf
= param
->data
;
1496 struct line_range
*lr
= lf
->lr
;
1498 /* Check declared file */
1499 if (lr
->file
&& strtailcmp(lr
->file
, dwarf_decl_file(sp_die
)))
1502 if (die_is_func_def(sp_die
) &&
1503 die_compare_name(sp_die
, lr
->function
)) {
1504 lf
->fname
= dwarf_decl_file(sp_die
);
1505 dwarf_decl_line(sp_die
, &lr
->offset
);
1506 pr_debug("fname: %s, lineno:%d\n", lf
->fname
, lr
->offset
);
1507 lf
->lno_s
= lr
->offset
+ lr
->start
;
1508 if (lf
->lno_s
< 0) /* Overflow */
1509 lf
->lno_s
= INT_MAX
;
1510 lf
->lno_e
= lr
->offset
+ lr
->end
;
1511 if (lf
->lno_e
< 0) /* Overflow */
1512 lf
->lno_e
= INT_MAX
;
1513 pr_debug("New line range: %d to %d\n", lf
->lno_s
, lf
->lno_e
);
1514 lr
->start
= lf
->lno_s
;
1515 lr
->end
= lf
->lno_e
;
1516 if (dwarf_func_inline(sp_die
))
1517 param
->retval
= die_walk_instances(sp_die
,
1518 line_range_inline_cb
, lf
);
1520 param
->retval
= find_line_range_by_line(sp_die
, lf
);
1521 return DWARF_CB_ABORT
;
1526 static int find_line_range_by_func(struct line_finder
*lf
)
1528 struct dwarf_callback_param param
= {.data
= (void *)lf
, .retval
= 0};
1529 dwarf_getfuncs(&lf
->cu_die
, line_range_search_cb
, ¶m
, 0);
1530 return param
.retval
;
1533 int debuginfo__find_line_range(struct debuginfo
*dbg
, struct line_range
*lr
)
1535 struct line_finder lf
= {.lr
= lr
, .found
= 0};
1537 Dwarf_Off off
= 0, noff
;
1540 const char *comp_dir
;
1542 /* Fastpath: lookup by function name from .debug_pubnames section */
1544 struct pubname_callback_param pubname_param
= {
1545 .function
= lr
->function
, .file
= lr
->file
,
1546 .cu_die
= &lf
.cu_die
, .sp_die
= &lf
.sp_die
, .found
= 0};
1547 struct dwarf_callback_param line_range_param
= {
1548 .data
= (void *)&lf
, .retval
= 0};
1550 dwarf_getpubnames(dbg
->dbg
, pubname_search_cb
,
1552 if (pubname_param
.found
) {
1553 line_range_search_cb(&lf
.sp_die
, &line_range_param
);
1559 /* Loop on CUs (Compilation Unit) */
1560 while (!lf
.found
&& ret
>= 0) {
1561 if (dwarf_nextcu(dbg
->dbg
, off
, &noff
, &cuhl
,
1562 NULL
, NULL
, NULL
) != 0)
1565 /* Get the DIE(Debugging Information Entry) of this CU */
1566 diep
= dwarf_offdie(dbg
->dbg
, off
+ cuhl
, &lf
.cu_die
);
1570 /* Check if target file is included. */
1572 lf
.fname
= cu_find_realpath(&lf
.cu_die
, lr
->file
);
1576 if (!lr
->file
|| lf
.fname
) {
1578 ret
= find_line_range_by_func(&lf
);
1580 lf
.lno_s
= lr
->start
;
1582 ret
= find_line_range_by_line(NULL
, &lf
);
1589 /* Store comp_dir */
1591 comp_dir
= cu_get_comp_dir(&lf
.cu_die
);
1593 lr
->comp_dir
= strdup(comp_dir
);
1599 pr_debug("path: %s\n", lr
->path
);
1600 return (ret
< 0) ? ret
: lf
.found
;