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>
33 #include <dwarf-regs.h>
35 #include <linux/bitops.h>
42 #include "probe-finder.h"
44 /* Kprobe tracer basic type is up to u64 */
45 #define MAX_BASIC_TYPE_BITS 64
47 /* Dwarf FL wrappers */
48 static char *debuginfo_path
; /* Currently dummy */
50 static const Dwfl_Callbacks offline_callbacks
= {
51 .find_debuginfo
= dwfl_standard_find_debuginfo
,
52 .debuginfo_path
= &debuginfo_path
,
54 .section_address
= dwfl_offline_section_address
,
56 /* We use this table for core files too. */
57 .find_elf
= dwfl_build_id_find_elf
,
60 /* Get a Dwarf from offline image */
61 static int debuginfo__init_offline_dwarf(struct debuginfo
*dbg
,
66 fd
= open(path
, O_RDONLY
);
70 dbg
->dwfl
= dwfl_begin(&offline_callbacks
);
74 dbg
->mod
= dwfl_report_offline(dbg
->dwfl
, "", "", fd
);
78 dbg
->dbg
= dwfl_module_getdwarf(dbg
->mod
, &dbg
->bias
);
88 memset(dbg
, 0, sizeof(*dbg
));
93 static struct debuginfo
*__debuginfo__new(const char *path
)
95 struct debuginfo
*dbg
= zalloc(sizeof(*dbg
));
99 if (debuginfo__init_offline_dwarf(dbg
, path
) < 0)
102 pr_debug("Open Debuginfo file: %s\n", path
);
106 enum dso_binary_type distro_dwarf_types
[] = {
107 DSO_BINARY_TYPE__FEDORA_DEBUGINFO
,
108 DSO_BINARY_TYPE__UBUNTU_DEBUGINFO
,
109 DSO_BINARY_TYPE__OPENEMBEDDED_DEBUGINFO
,
110 DSO_BINARY_TYPE__BUILDID_DEBUGINFO
,
111 DSO_BINARY_TYPE__NOT_FOUND
,
114 struct debuginfo
*debuginfo__new(const char *path
)
116 enum dso_binary_type
*type
;
117 char buf
[PATH_MAX
], nil
= '\0';
119 struct debuginfo
*dinfo
= NULL
;
121 /* Try to open distro debuginfo files */
122 dso
= dso__new(path
);
126 for (type
= distro_dwarf_types
;
127 !dinfo
&& *type
!= DSO_BINARY_TYPE__NOT_FOUND
;
129 if (dso__read_binary_type_filename(dso
, *type
, &nil
,
132 dinfo
= __debuginfo__new(buf
);
137 /* if failed to open all distro debuginfo, open given binary */
138 return dinfo
? : __debuginfo__new(path
);
141 void debuginfo__delete(struct debuginfo
*dbg
)
151 * Probe finder related functions
154 static struct probe_trace_arg_ref
*alloc_trace_arg_ref(long offs
)
156 struct probe_trace_arg_ref
*ref
;
157 ref
= zalloc(sizeof(struct probe_trace_arg_ref
));
164 * Convert a location into trace_arg.
165 * If tvar == NULL, this just checks variable can be converted.
166 * If fentry == true and vr_die is a parameter, do huristic search
167 * for the location fuzzed by function entry mcount.
169 static int convert_variable_location(Dwarf_Die
*vr_die
, Dwarf_Addr addr
,
170 Dwarf_Op
*fb_ops
, Dwarf_Die
*sp_die
,
171 struct probe_trace_arg
*tvar
)
173 Dwarf_Attribute attr
;
183 if (dwarf_attr(vr_die
, DW_AT_external
, &attr
) != NULL
)
186 /* TODO: handle more than 1 exprs */
187 if (dwarf_attr(vr_die
, DW_AT_location
, &attr
) == NULL
)
188 return -EINVAL
; /* Broken DIE ? */
189 if (dwarf_getlocation_addr(&attr
, addr
, &op
, &nops
, 1) <= 0) {
190 ret
= dwarf_entrypc(sp_die
, &tmp
);
191 if (ret
|| addr
!= tmp
||
192 dwarf_tag(vr_die
) != DW_TAG_formal_parameter
||
193 dwarf_highpc(sp_die
, &tmp
))
196 * This is fuzzed by fentry mcount. We try to find the
197 * parameter location at the earliest address.
199 for (addr
+= 1; addr
<= tmp
; addr
++) {
200 if (dwarf_getlocation_addr(&attr
, addr
, &op
,
208 /* TODO: Support const_value */
211 if (op
->atom
== DW_OP_addr
) {
215 /* Static variables on memory (not stack), make @varname */
216 ret
= strlen(dwarf_diename(vr_die
));
217 tvar
->value
= zalloc(ret
+ 2);
218 if (tvar
->value
== NULL
)
220 snprintf(tvar
->value
, ret
+ 2, "@%s", dwarf_diename(vr_die
));
221 tvar
->ref
= alloc_trace_arg_ref((long)offs
);
222 if (tvar
->ref
== NULL
)
227 /* If this is based on frame buffer, set the offset */
228 if (op
->atom
== DW_OP_fbreg
) {
236 if (op
->atom
>= DW_OP_breg0
&& op
->atom
<= DW_OP_breg31
) {
237 regn
= op
->atom
- DW_OP_breg0
;
240 } else if (op
->atom
>= DW_OP_reg0
&& op
->atom
<= DW_OP_reg31
) {
241 regn
= op
->atom
- DW_OP_reg0
;
242 } else if (op
->atom
== DW_OP_bregx
) {
246 } else if (op
->atom
== DW_OP_regx
) {
249 pr_debug("DW_OP %x is not supported.\n", op
->atom
);
256 regs
= get_arch_regstr(regn
);
258 /* This should be a bug in DWARF or this tool */
259 pr_warning("Mapping for the register number %u "
260 "missing on this architecture.\n", regn
);
264 tvar
->value
= strdup(regs
);
265 if (tvar
->value
== NULL
)
269 tvar
->ref
= alloc_trace_arg_ref((long)offs
);
270 if (tvar
->ref
== NULL
)
276 #define BYTES_TO_BITS(nb) ((nb) * BITS_PER_LONG / sizeof(long))
278 static int convert_variable_type(Dwarf_Die
*vr_die
,
279 struct probe_trace_arg
*tvar
,
282 struct probe_trace_arg_ref
**ref_ptr
= &tvar
->ref
;
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",
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 pointor"
460 " nor array.\n", varname
);
464 pr_err("Semantic error: %s must be referred by '.'\n",
469 pr_warning("Structure on a register is not "
475 if (die_find_member(&type
, field
->name
, die_mem
) == NULL
) {
476 pr_warning("%s(type:%s) has no member %s.\n", varname
,
477 dwarf_diename(&type
), field
->name
);
481 /* Get the offset of the field */
482 if (tag
== DW_TAG_union_type
) {
485 ret
= die_get_data_member_location(die_mem
, &offs
);
487 pr_warning("Failed to get the offset of %s.\n",
492 ref
->offset
+= (long)offs
;
495 /* Converting next field */
497 return convert_variable_fields(die_mem
, field
->name
,
498 field
->next
, &ref
, die_mem
);
503 /* Show a variables in kprobe event format */
504 static int convert_variable(Dwarf_Die
*vr_die
, struct probe_finder
*pf
)
509 pr_debug("Converting variable %s into trace event.\n",
510 dwarf_diename(vr_die
));
512 ret
= convert_variable_location(vr_die
, pf
->addr
, pf
->fb_ops
,
513 &pf
->sp_die
, pf
->tvar
);
515 pr_err("Failed to find the location of %s at this address.\n"
516 " Perhaps, it has been optimized out.\n", pf
->pvar
->var
);
517 else if (ret
== -ENOTSUP
)
518 pr_err("Sorry, we don't support this variable location yet.\n");
519 else if (pf
->pvar
->field
) {
520 ret
= convert_variable_fields(vr_die
, pf
->pvar
->var
,
521 pf
->pvar
->field
, &pf
->tvar
->ref
,
526 ret
= convert_variable_type(vr_die
, pf
->tvar
, pf
->pvar
->type
);
527 /* *expr will be cached in libdw. Don't free it. */
531 /* Find a variable in a scope DIE */
532 static int find_variable(Dwarf_Die
*sc_die
, struct probe_finder
*pf
)
538 if (!is_c_varname(pf
->pvar
->var
)) {
539 /* Copy raw parameters */
540 pf
->tvar
->value
= strdup(pf
->pvar
->var
);
541 if (pf
->tvar
->value
== NULL
)
543 if (pf
->pvar
->type
) {
544 pf
->tvar
->type
= strdup(pf
->pvar
->type
);
545 if (pf
->tvar
->type
== NULL
)
548 if (pf
->pvar
->name
) {
549 pf
->tvar
->name
= strdup(pf
->pvar
->name
);
550 if (pf
->tvar
->name
== NULL
)
553 pf
->tvar
->name
= NULL
;
558 pf
->tvar
->name
= strdup(pf
->pvar
->name
);
560 ret
= synthesize_perf_probe_arg(pf
->pvar
, buf
, 32);
563 ptr
= strchr(buf
, ':'); /* Change type separator to _ */
566 pf
->tvar
->name
= strdup(buf
);
568 if (pf
->tvar
->name
== NULL
)
571 pr_debug("Searching '%s' variable in context.\n", pf
->pvar
->var
);
572 /* Search child die for local variables and parameters. */
573 if (!die_find_variable_at(sc_die
, pf
->pvar
->var
, pf
->addr
, &vr_die
)) {
574 /* Search again in global variables */
575 if (!die_find_variable_at(&pf
->cu_die
, pf
->pvar
->var
, 0, &vr_die
))
579 ret
= convert_variable(&vr_die
, pf
);
582 pr_warning("Failed to find '%s' in this function.\n",
587 /* Convert subprogram DIE to trace point */
588 static int convert_to_trace_point(Dwarf_Die
*sp_die
, Dwfl_Module
*mod
,
589 Dwarf_Addr paddr
, bool retprobe
,
590 struct probe_trace_point
*tp
)
592 Dwarf_Addr eaddr
, highaddr
;
596 /* Verify the address is correct */
597 if (dwarf_entrypc(sp_die
, &eaddr
) != 0) {
598 pr_warning("Failed to get entry address of %s\n",
599 dwarf_diename(sp_die
));
602 if (dwarf_highpc(sp_die
, &highaddr
) != 0) {
603 pr_warning("Failed to get end address of %s\n",
604 dwarf_diename(sp_die
));
607 if (paddr
> highaddr
) {
608 pr_warning("Offset specified is greater than size of %s\n",
609 dwarf_diename(sp_die
));
613 /* Get an appropriate symbol from symtab */
614 symbol
= dwfl_module_addrsym(mod
, paddr
, &sym
, NULL
);
616 pr_warning("Failed to find symbol at 0x%lx\n",
617 (unsigned long)paddr
);
620 tp
->offset
= (unsigned long)(paddr
- sym
.st_value
);
621 tp
->address
= (unsigned long)paddr
;
622 tp
->symbol
= strdup(symbol
);
626 /* Return probe must be on the head of a subprogram */
628 if (eaddr
!= paddr
) {
629 pr_warning("Return probe must be on the head of"
630 " a real function.\n");
639 /* Call probe_finder callback with scope DIE */
640 static int call_probe_finder(Dwarf_Die
*sc_die
, struct probe_finder
*pf
)
642 Dwarf_Attribute fb_attr
;
647 pr_err("Caller must pass a scope DIE. Program error.\n");
651 /* If not a real subprogram, find a real one */
652 if (!die_is_func_def(sc_die
)) {
653 if (!die_find_realfunc(&pf
->cu_die
, pf
->addr
, &pf
->sp_die
)) {
654 pr_warning("Failed to find probe point in any "
659 memcpy(&pf
->sp_die
, sc_die
, sizeof(Dwarf_Die
));
661 /* Get the frame base attribute/ops from subprogram */
662 dwarf_attr(&pf
->sp_die
, DW_AT_frame_base
, &fb_attr
);
663 ret
= dwarf_getlocation_addr(&fb_attr
, pf
->addr
, &pf
->fb_ops
, &nops
, 1);
664 if (ret
<= 0 || nops
== 0) {
666 #if _ELFUTILS_PREREQ(0, 142)
667 } else if (nops
== 1 && pf
->fb_ops
[0].atom
== DW_OP_call_frame_cfa
&&
670 if (dwarf_cfi_addrframe(pf
->cfi
, pf
->addr
, &frame
) != 0 ||
671 dwarf_frame_cfa(frame
, &pf
->fb_ops
, &nops
) != 0) {
672 pr_warning("Failed to get call frame on 0x%jx\n",
673 (uintmax_t)pf
->addr
);
679 /* Call finder's callback handler */
680 ret
= pf
->callback(sc_die
, pf
);
682 /* *pf->fb_ops will be cached in libdw. Don't free it. */
688 struct find_scope_param
{
689 const char *function
;
697 static int find_best_scope_cb(Dwarf_Die
*fn_die
, void *data
)
699 struct find_scope_param
*fsp
= data
;
703 /* Skip if declared file name does not match */
705 file
= dwarf_decl_file(fn_die
);
706 if (!file
|| strcmp(fsp
->file
, file
) != 0)
709 /* If the function name is given, that's what user expects */
711 if (die_compare_name(fn_die
, fsp
->function
)) {
712 memcpy(fsp
->die_mem
, fn_die
, sizeof(Dwarf_Die
));
717 /* With the line number, find the nearest declared DIE */
718 dwarf_decl_line(fn_die
, &lno
);
719 if (lno
< fsp
->line
&& fsp
->diff
> fsp
->line
- lno
) {
720 /* Keep a candidate and continue */
721 fsp
->diff
= fsp
->line
- lno
;
722 memcpy(fsp
->die_mem
, fn_die
, sizeof(Dwarf_Die
));
729 /* Find an appropriate scope fits to given conditions */
730 static Dwarf_Die
*find_best_scope(struct probe_finder
*pf
, Dwarf_Die
*die_mem
)
732 struct find_scope_param fsp
= {
733 .function
= pf
->pev
->point
.function
,
741 cu_walk_functions_at(&pf
->cu_die
, pf
->addr
, find_best_scope_cb
, &fsp
);
743 return fsp
.found
? die_mem
: NULL
;
746 static int probe_point_line_walker(const char *fname
, int lineno
,
747 Dwarf_Addr addr
, void *data
)
749 struct probe_finder
*pf
= data
;
750 Dwarf_Die
*sc_die
, die_mem
;
753 if (lineno
!= pf
->lno
|| strtailcmp(fname
, pf
->fname
) != 0)
757 sc_die
= find_best_scope(pf
, &die_mem
);
759 pr_warning("Failed to find scope of probe point.\n");
763 ret
= call_probe_finder(sc_die
, pf
);
765 /* Continue if no error, because the line will be in inline function */
766 return ret
< 0 ? ret
: 0;
769 /* Find probe point from its line number */
770 static int find_probe_point_by_line(struct probe_finder
*pf
)
772 return die_walk_lines(&pf
->cu_die
, probe_point_line_walker
, pf
);
775 /* Find lines which match lazy pattern */
776 static int find_lazy_match_lines(struct intlist
*list
,
777 const char *fname
, const char *pat
)
783 int count
= 0, linenum
= 1;
785 fp
= fopen(fname
, "r");
787 pr_warning("Failed to open %s: %s\n", fname
, strerror(errno
));
791 while ((len
= getline(&line
, &line_len
, fp
)) > 0) {
793 if (line
[len
- 1] == '\n')
794 line
[len
- 1] = '\0';
796 if (strlazymatch(line
, pat
)) {
797 intlist__add(list
, linenum
);
809 pr_debug("No matched lines found in %s.\n", fname
);
813 static int probe_point_lazy_walker(const char *fname
, int lineno
,
814 Dwarf_Addr addr
, void *data
)
816 struct probe_finder
*pf
= data
;
817 Dwarf_Die
*sc_die
, die_mem
;
820 if (!intlist__has_entry(pf
->lcache
, lineno
) ||
821 strtailcmp(fname
, pf
->fname
) != 0)
824 pr_debug("Probe line found: line:%d addr:0x%llx\n",
825 lineno
, (unsigned long long)addr
);
828 sc_die
= find_best_scope(pf
, &die_mem
);
830 pr_warning("Failed to find scope of probe point.\n");
834 ret
= call_probe_finder(sc_die
, pf
);
837 * Continue if no error, because the lazy pattern will match
840 return ret
< 0 ? ret
: 0;
843 /* Find probe points from lazy pattern */
844 static int find_probe_point_lazy(Dwarf_Die
*sp_die
, struct probe_finder
*pf
)
848 if (intlist__empty(pf
->lcache
)) {
849 /* Matching lazy line pattern */
850 ret
= find_lazy_match_lines(pf
->lcache
, pf
->fname
,
851 pf
->pev
->point
.lazy_line
);
856 return die_walk_lines(sp_die
, probe_point_lazy_walker
, pf
);
859 static int probe_point_inline_cb(Dwarf_Die
*in_die
, void *data
)
861 struct probe_finder
*pf
= data
;
862 struct perf_probe_point
*pp
= &pf
->pev
->point
;
867 ret
= find_probe_point_lazy(in_die
, pf
);
869 /* Get probe address */
870 if (dwarf_entrypc(in_die
, &addr
) != 0) {
871 pr_warning("Failed to get entry address of %s.\n",
872 dwarf_diename(in_die
));
876 pf
->addr
+= pp
->offset
;
877 pr_debug("found inline addr: 0x%jx\n",
878 (uintmax_t)pf
->addr
);
880 ret
= call_probe_finder(in_die
, pf
);
886 /* Callback parameter with return value for libdw */
887 struct dwarf_callback_param
{
892 /* Search function from function name */
893 static int probe_point_search_cb(Dwarf_Die
*sp_die
, void *data
)
895 struct dwarf_callback_param
*param
= data
;
896 struct probe_finder
*pf
= param
->data
;
897 struct perf_probe_point
*pp
= &pf
->pev
->point
;
899 /* Check tag and diename */
900 if (!die_is_func_def(sp_die
) ||
901 !die_compare_name(sp_die
, pp
->function
))
904 /* Check declared file */
905 if (pp
->file
&& strtailcmp(pp
->file
, dwarf_decl_file(sp_die
)))
908 pf
->fname
= dwarf_decl_file(sp_die
);
909 if (pp
->line
) { /* Function relative line */
910 dwarf_decl_line(sp_die
, &pf
->lno
);
912 param
->retval
= find_probe_point_by_line(pf
);
913 } else if (!dwarf_func_inline(sp_die
)) {
916 param
->retval
= find_probe_point_lazy(sp_die
, pf
);
918 if (dwarf_entrypc(sp_die
, &pf
->addr
) != 0) {
919 pr_warning("Failed to get entry address of "
920 "%s.\n", dwarf_diename(sp_die
));
921 param
->retval
= -ENOENT
;
922 return DWARF_CB_ABORT
;
924 pf
->addr
+= pp
->offset
;
925 /* TODO: Check the address in this function */
926 param
->retval
= call_probe_finder(sp_die
, pf
);
929 /* Inlined function: search instances */
930 param
->retval
= die_walk_instances(sp_die
,
931 probe_point_inline_cb
, (void *)pf
);
933 return DWARF_CB_ABORT
; /* Exit; no same symbol in this CU. */
936 static int find_probe_point_by_func(struct probe_finder
*pf
)
938 struct dwarf_callback_param _param
= {.data
= (void *)pf
,
940 dwarf_getfuncs(&pf
->cu_die
, probe_point_search_cb
, &_param
, 0);
941 return _param
.retval
;
944 struct pubname_callback_param
{
952 static int pubname_search_cb(Dwarf
*dbg
, Dwarf_Global
*gl
, void *data
)
954 struct pubname_callback_param
*param
= data
;
956 if (dwarf_offdie(dbg
, gl
->die_offset
, param
->sp_die
)) {
957 if (dwarf_tag(param
->sp_die
) != DW_TAG_subprogram
)
960 if (die_compare_name(param
->sp_die
, param
->function
)) {
961 if (!dwarf_offdie(dbg
, gl
->cu_offset
, param
->cu_die
))
965 strtailcmp(param
->file
, dwarf_decl_file(param
->sp_die
)))
969 return DWARF_CB_ABORT
;
976 /* Find probe points from debuginfo */
977 static int debuginfo__find_probes(struct debuginfo
*dbg
,
978 struct probe_finder
*pf
)
980 struct perf_probe_point
*pp
= &pf
->pev
->point
;
986 #if _ELFUTILS_PREREQ(0, 142)
987 /* Get the call frame information from this dwarf */
988 pf
->cfi
= dwarf_getcfi(dbg
->dbg
);
992 pf
->lcache
= intlist__new(NULL
);
996 /* Fastpath: lookup by function name from .debug_pubnames section */
998 struct pubname_callback_param pubname_param
= {
999 .function
= pp
->function
,
1001 .cu_die
= &pf
->cu_die
,
1002 .sp_die
= &pf
->sp_die
,
1005 struct dwarf_callback_param probe_param
= {
1009 dwarf_getpubnames(dbg
->dbg
, pubname_search_cb
,
1011 if (pubname_param
.found
) {
1012 ret
= probe_point_search_cb(&pf
->sp_die
, &probe_param
);
1018 /* Loop on CUs (Compilation Unit) */
1019 while (!dwarf_nextcu(dbg
->dbg
, off
, &noff
, &cuhl
, NULL
, NULL
, NULL
)) {
1020 /* Get the DIE(Debugging Information Entry) of this CU */
1021 diep
= dwarf_offdie(dbg
->dbg
, off
+ cuhl
, &pf
->cu_die
);
1025 /* Check if target file is included. */
1027 pf
->fname
= cu_find_realpath(&pf
->cu_die
, pp
->file
);
1031 if (!pp
->file
|| pf
->fname
) {
1033 ret
= find_probe_point_by_func(pf
);
1034 else if (pp
->lazy_line
)
1035 ret
= find_probe_point_lazy(NULL
, pf
);
1038 ret
= find_probe_point_by_line(pf
);
1047 intlist__delete(pf
->lcache
);
1053 struct local_vars_finder
{
1054 struct probe_finder
*pf
;
1055 struct perf_probe_arg
*args
;
1061 /* Collect available variables in this scope */
1062 static int copy_variables_cb(Dwarf_Die
*die_mem
, void *data
)
1064 struct local_vars_finder
*vf
= data
;
1065 struct probe_finder
*pf
= vf
->pf
;
1068 tag
= dwarf_tag(die_mem
);
1069 if (tag
== DW_TAG_formal_parameter
||
1070 tag
== DW_TAG_variable
) {
1071 if (convert_variable_location(die_mem
, vf
->pf
->addr
,
1072 vf
->pf
->fb_ops
, &pf
->sp_die
,
1074 vf
->args
[vf
->nargs
].var
= (char *)dwarf_diename(die_mem
);
1075 if (vf
->args
[vf
->nargs
].var
== NULL
) {
1077 return DIE_FIND_CB_END
;
1079 pr_debug(" %s", vf
->args
[vf
->nargs
].var
);
1084 if (dwarf_haspc(die_mem
, vf
->pf
->addr
))
1085 return DIE_FIND_CB_CONTINUE
;
1087 return DIE_FIND_CB_SIBLING
;
1090 static int expand_probe_args(Dwarf_Die
*sc_die
, struct probe_finder
*pf
,
1091 struct perf_probe_arg
*args
)
1096 struct local_vars_finder vf
= {.pf
= pf
, .args
= args
,
1097 .max_args
= MAX_PROBE_ARGS
, .ret
= 0};
1099 for (i
= 0; i
< pf
->pev
->nargs
; i
++) {
1100 /* var never be NULL */
1101 if (strcmp(pf
->pev
->args
[i
].var
, "$vars") == 0) {
1102 pr_debug("Expanding $vars into:");
1104 /* Special local variables */
1105 die_find_child(sc_die
, copy_variables_cb
, (void *)&vf
,
1107 pr_debug(" (%d)\n", vf
.nargs
- n
);
1112 /* Copy normal argument */
1113 args
[n
] = pf
->pev
->args
[i
];
1120 /* Add a found probe point into trace event list */
1121 static int add_probe_trace_event(Dwarf_Die
*sc_die
, struct probe_finder
*pf
)
1123 struct trace_event_finder
*tf
=
1124 container_of(pf
, struct trace_event_finder
, pf
);
1125 struct probe_trace_event
*tev
;
1126 struct perf_probe_arg
*args
;
1129 /* Check number of tevs */
1130 if (tf
->ntevs
== tf
->max_tevs
) {
1131 pr_warning("Too many( > %d) probe point found.\n",
1135 tev
= &tf
->tevs
[tf
->ntevs
++];
1137 /* Trace point should be converted from subprogram DIE */
1138 ret
= convert_to_trace_point(&pf
->sp_die
, tf
->mod
, pf
->addr
,
1139 pf
->pev
->point
.retprobe
, &tev
->point
);
1143 pr_debug("Probe point found: %s+%lu\n", tev
->point
.symbol
,
1146 /* Expand special probe argument if exist */
1147 args
= zalloc(sizeof(struct perf_probe_arg
) * MAX_PROBE_ARGS
);
1151 ret
= expand_probe_args(sc_die
, pf
, args
);
1156 tev
->args
= zalloc(sizeof(struct probe_trace_arg
) * tev
->nargs
);
1157 if (tev
->args
== NULL
) {
1162 /* Find each argument */
1163 for (i
= 0; i
< tev
->nargs
; i
++) {
1164 pf
->pvar
= &args
[i
];
1165 pf
->tvar
= &tev
->args
[i
];
1166 /* Variable should be found from scope DIE */
1167 ret
= find_variable(sc_die
, pf
);
1177 /* Find probe_trace_events specified by perf_probe_event from debuginfo */
1178 int debuginfo__find_trace_events(struct debuginfo
*dbg
,
1179 struct perf_probe_event
*pev
,
1180 struct probe_trace_event
**tevs
, int max_tevs
)
1182 struct trace_event_finder tf
= {
1183 .pf
= {.pev
= pev
, .callback
= add_probe_trace_event
},
1184 .mod
= dbg
->mod
, .max_tevs
= max_tevs
};
1187 /* Allocate result tevs array */
1188 *tevs
= zalloc(sizeof(struct probe_trace_event
) * max_tevs
);
1195 ret
= debuginfo__find_probes(dbg
, &tf
.pf
);
1201 return (ret
< 0) ? ret
: tf
.ntevs
;
1204 #define MAX_VAR_LEN 64
1206 /* Collect available variables in this scope */
1207 static int collect_variables_cb(Dwarf_Die
*die_mem
, void *data
)
1209 struct available_var_finder
*af
= data
;
1210 struct variable_list
*vl
;
1211 char buf
[MAX_VAR_LEN
];
1214 vl
= &af
->vls
[af
->nvls
- 1];
1216 tag
= dwarf_tag(die_mem
);
1217 if (tag
== DW_TAG_formal_parameter
||
1218 tag
== DW_TAG_variable
) {
1219 ret
= convert_variable_location(die_mem
, af
->pf
.addr
,
1220 af
->pf
.fb_ops
, &af
->pf
.sp_die
,
1223 ret
= die_get_varname(die_mem
, buf
, MAX_VAR_LEN
);
1224 pr_debug2("Add new var: %s\n", buf
);
1226 strlist__add(vl
->vars
, buf
);
1230 if (af
->child
&& dwarf_haspc(die_mem
, af
->pf
.addr
))
1231 return DIE_FIND_CB_CONTINUE
;
1233 return DIE_FIND_CB_SIBLING
;
1236 /* Add a found vars into available variables list */
1237 static int add_available_vars(Dwarf_Die
*sc_die
, struct probe_finder
*pf
)
1239 struct available_var_finder
*af
=
1240 container_of(pf
, struct available_var_finder
, pf
);
1241 struct variable_list
*vl
;
1245 /* Check number of tevs */
1246 if (af
->nvls
== af
->max_vls
) {
1247 pr_warning("Too many( > %d) probe point found.\n", af
->max_vls
);
1250 vl
= &af
->vls
[af
->nvls
++];
1252 /* Trace point should be converted from subprogram DIE */
1253 ret
= convert_to_trace_point(&pf
->sp_die
, af
->mod
, pf
->addr
,
1254 pf
->pev
->point
.retprobe
, &vl
->point
);
1258 pr_debug("Probe point found: %s+%lu\n", vl
->point
.symbol
,
1261 /* Find local variables */
1262 vl
->vars
= strlist__new(true, NULL
);
1263 if (vl
->vars
== NULL
)
1266 die_find_child(sc_die
, collect_variables_cb
, (void *)af
, &die_mem
);
1268 /* Find external variables */
1271 /* Don't need to search child DIE for externs. */
1273 die_find_child(&pf
->cu_die
, collect_variables_cb
, (void *)af
, &die_mem
);
1276 if (strlist__empty(vl
->vars
)) {
1277 strlist__delete(vl
->vars
);
1284 /* Find available variables at given probe point */
1285 int debuginfo__find_available_vars_at(struct debuginfo
*dbg
,
1286 struct perf_probe_event
*pev
,
1287 struct variable_list
**vls
,
1288 int max_vls
, bool externs
)
1290 struct available_var_finder af
= {
1291 .pf
= {.pev
= pev
, .callback
= add_available_vars
},
1293 .max_vls
= max_vls
, .externs
= externs
};
1296 /* Allocate result vls array */
1297 *vls
= zalloc(sizeof(struct variable_list
) * max_vls
);
1304 ret
= debuginfo__find_probes(dbg
, &af
.pf
);
1306 /* Free vlist for error */
1308 zfree(&af
.vls
[af
.nvls
].point
.symbol
);
1309 strlist__delete(af
.vls
[af
.nvls
].vars
);
1315 return (ret
< 0) ? ret
: af
.nvls
;
1318 /* Reverse search */
1319 int debuginfo__find_probe_point(struct debuginfo
*dbg
, unsigned long addr
,
1320 struct perf_probe_point
*ppt
)
1322 Dwarf_Die cudie
, spdie
, indie
;
1323 Dwarf_Addr _addr
= 0, baseaddr
= 0;
1324 const char *fname
= NULL
, *func
= NULL
, *basefunc
= NULL
, *tmp
;
1325 int baseline
= 0, lineno
= 0, ret
= 0;
1327 /* Adjust address with bias */
1331 if (!dwarf_addrdie(dbg
->dbg
, (Dwarf_Addr
)addr
- dbg
->bias
, &cudie
)) {
1332 pr_warning("Failed to find debug information for address %lx\n",
1338 /* Find a corresponding line (filename and lineno) */
1339 cu_find_lineinfo(&cudie
, addr
, &fname
, &lineno
);
1340 /* Don't care whether it failed or not */
1342 /* Find a corresponding function (name, baseline and baseaddr) */
1343 if (die_find_realfunc(&cudie
, (Dwarf_Addr
)addr
, &spdie
)) {
1344 /* Get function entry information */
1345 func
= basefunc
= dwarf_diename(&spdie
);
1347 dwarf_entrypc(&spdie
, &baseaddr
) != 0 ||
1348 dwarf_decl_line(&spdie
, &baseline
) != 0) {
1353 fname
= dwarf_decl_file(&spdie
);
1354 if (addr
== (unsigned long)baseaddr
) {
1355 /* Function entry - Relative line number is 0 */
1360 /* Track down the inline functions step by step */
1361 while (die_find_top_inlinefunc(&spdie
, (Dwarf_Addr
)addr
,
1363 /* There is an inline function */
1364 if (dwarf_entrypc(&indie
, &_addr
) == 0 &&
1367 * addr is at an inline function entry.
1368 * In this case, lineno should be the call-site
1369 * line number. (overwrite lineinfo)
1371 lineno
= die_get_call_lineno(&indie
);
1372 fname
= die_get_call_file(&indie
);
1376 * addr is in an inline function body.
1377 * Since lineno points one of the lines
1378 * of the inline function, baseline should
1379 * be the entry line of the inline function.
1381 tmp
= dwarf_diename(&indie
);
1383 dwarf_decl_line(&indie
, &baseline
) != 0)
1389 /* Verify the lineno and baseline are in a same file */
1390 tmp
= dwarf_decl_file(&spdie
);
1391 if (!tmp
|| strcmp(tmp
, fname
) != 0)
1396 /* Make a relative line number or an offset */
1398 ppt
->line
= lineno
- baseline
;
1399 else if (basefunc
) {
1400 ppt
->offset
= addr
- (unsigned long)baseaddr
;
1404 /* Duplicate strings */
1406 ppt
->function
= strdup(func
);
1407 if (ppt
->function
== NULL
) {
1413 ppt
->file
= strdup(fname
);
1414 if (ppt
->file
== NULL
) {
1415 zfree(&ppt
->function
);
1421 if (ret
== 0 && (fname
|| func
))
1422 ret
= 1; /* Found a point */
1426 /* Add a line and store the src path */
1427 static int line_range_add_line(const char *src
, unsigned int lineno
,
1428 struct line_range
*lr
)
1430 /* Copy source path */
1432 lr
->path
= strdup(src
);
1433 if (lr
->path
== NULL
)
1436 return intlist__add(lr
->line_list
, lineno
);
1439 static int line_range_walk_cb(const char *fname
, int lineno
,
1440 Dwarf_Addr addr __maybe_unused
,
1443 struct line_finder
*lf
= data
;
1446 if ((strtailcmp(fname
, lf
->fname
) != 0) ||
1447 (lf
->lno_s
> lineno
|| lf
->lno_e
< lineno
))
1450 err
= line_range_add_line(fname
, lineno
, lf
->lr
);
1451 if (err
< 0 && err
!= -EEXIST
)
1457 /* Find line range from its line number */
1458 static int find_line_range_by_line(Dwarf_Die
*sp_die
, struct line_finder
*lf
)
1462 ret
= die_walk_lines(sp_die
?: &lf
->cu_die
, line_range_walk_cb
, lf
);
1466 if (!intlist__empty(lf
->lr
->line_list
))
1467 ret
= lf
->found
= 1;
1469 ret
= 0; /* Lines are not found */
1471 zfree(&lf
->lr
->path
);
1476 static int line_range_inline_cb(Dwarf_Die
*in_die
, void *data
)
1478 find_line_range_by_line(in_die
, data
);
1481 * We have to check all instances of inlined function, because
1482 * some execution paths can be optimized out depends on the
1483 * function argument of instances
1488 /* Search function definition from function name */
1489 static int line_range_search_cb(Dwarf_Die
*sp_die
, void *data
)
1491 struct dwarf_callback_param
*param
= data
;
1492 struct line_finder
*lf
= param
->data
;
1493 struct line_range
*lr
= lf
->lr
;
1495 /* Check declared file */
1496 if (lr
->file
&& strtailcmp(lr
->file
, dwarf_decl_file(sp_die
)))
1499 if (die_is_func_def(sp_die
) &&
1500 die_compare_name(sp_die
, lr
->function
)) {
1501 lf
->fname
= dwarf_decl_file(sp_die
);
1502 dwarf_decl_line(sp_die
, &lr
->offset
);
1503 pr_debug("fname: %s, lineno:%d\n", lf
->fname
, lr
->offset
);
1504 lf
->lno_s
= lr
->offset
+ lr
->start
;
1505 if (lf
->lno_s
< 0) /* Overflow */
1506 lf
->lno_s
= INT_MAX
;
1507 lf
->lno_e
= lr
->offset
+ lr
->end
;
1508 if (lf
->lno_e
< 0) /* Overflow */
1509 lf
->lno_e
= INT_MAX
;
1510 pr_debug("New line range: %d to %d\n", lf
->lno_s
, lf
->lno_e
);
1511 lr
->start
= lf
->lno_s
;
1512 lr
->end
= lf
->lno_e
;
1513 if (dwarf_func_inline(sp_die
))
1514 param
->retval
= die_walk_instances(sp_die
,
1515 line_range_inline_cb
, lf
);
1517 param
->retval
= find_line_range_by_line(sp_die
, lf
);
1518 return DWARF_CB_ABORT
;
1523 static int find_line_range_by_func(struct line_finder
*lf
)
1525 struct dwarf_callback_param param
= {.data
= (void *)lf
, .retval
= 0};
1526 dwarf_getfuncs(&lf
->cu_die
, line_range_search_cb
, ¶m
, 0);
1527 return param
.retval
;
1530 int debuginfo__find_line_range(struct debuginfo
*dbg
, struct line_range
*lr
)
1532 struct line_finder lf
= {.lr
= lr
, .found
= 0};
1534 Dwarf_Off off
= 0, noff
;
1537 const char *comp_dir
;
1539 /* Fastpath: lookup by function name from .debug_pubnames section */
1541 struct pubname_callback_param pubname_param
= {
1542 .function
= lr
->function
, .file
= lr
->file
,
1543 .cu_die
= &lf
.cu_die
, .sp_die
= &lf
.sp_die
, .found
= 0};
1544 struct dwarf_callback_param line_range_param
= {
1545 .data
= (void *)&lf
, .retval
= 0};
1547 dwarf_getpubnames(dbg
->dbg
, pubname_search_cb
,
1549 if (pubname_param
.found
) {
1550 line_range_search_cb(&lf
.sp_die
, &line_range_param
);
1556 /* Loop on CUs (Compilation Unit) */
1557 while (!lf
.found
&& ret
>= 0) {
1558 if (dwarf_nextcu(dbg
->dbg
, off
, &noff
, &cuhl
,
1559 NULL
, NULL
, NULL
) != 0)
1562 /* Get the DIE(Debugging Information Entry) of this CU */
1563 diep
= dwarf_offdie(dbg
->dbg
, off
+ cuhl
, &lf
.cu_die
);
1567 /* Check if target file is included. */
1569 lf
.fname
= cu_find_realpath(&lf
.cu_die
, lr
->file
);
1573 if (!lr
->file
|| lf
.fname
) {
1575 ret
= find_line_range_by_func(&lf
);
1577 lf
.lno_s
= lr
->start
;
1579 ret
= find_line_range_by_line(NULL
, &lf
);
1586 /* Store comp_dir */
1588 comp_dir
= cu_get_comp_dir(&lf
.cu_die
);
1590 lr
->comp_dir
= strdup(comp_dir
);
1596 pr_debug("path: %s\n", lr
->path
);
1597 return (ret
< 0) ? ret
: lf
.found
;