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>
40 #include "probe-finder.h"
42 /* Kprobe tracer basic type is up to u64 */
43 #define MAX_BASIC_TYPE_BITS 64
45 /* Line number list operations */
47 /* Add a line to line number list */
48 static int line_list__add_line(struct list_head
*head
, int line
)
53 /* Reverse search, because new line will be the last one */
54 list_for_each_entry_reverse(ln
, head
, list
) {
55 if (ln
->line
< line
) {
58 } else if (ln
->line
== line
) /* Already exist */
61 /* List is empty, or the smallest entry */
64 pr_debug("line list: add a line %u\n", line
);
65 ln
= zalloc(sizeof(struct line_node
));
69 INIT_LIST_HEAD(&ln
->list
);
70 list_add(&ln
->list
, p
);
74 /* Check if the line in line number list */
75 static int line_list__has_line(struct list_head
*head
, int line
)
79 /* Reverse search, because new line will be the last one */
80 list_for_each_entry(ln
, head
, list
)
87 /* Init line number list */
88 static void line_list__init(struct list_head
*head
)
93 /* Free line number list */
94 static void line_list__free(struct list_head
*head
)
97 while (!list_empty(head
)) {
98 ln
= list_first_entry(head
, struct line_node
, list
);
104 /* Dwarf FL wrappers */
105 static char *debuginfo_path
; /* Currently dummy */
107 static const Dwfl_Callbacks offline_callbacks
= {
108 .find_debuginfo
= dwfl_standard_find_debuginfo
,
109 .debuginfo_path
= &debuginfo_path
,
111 .section_address
= dwfl_offline_section_address
,
113 /* We use this table for core files too. */
114 .find_elf
= dwfl_build_id_find_elf
,
117 /* Get a Dwarf from offline image */
118 static int debuginfo__init_offline_dwarf(struct debuginfo
*self
,
124 fd
= open(path
, O_RDONLY
);
128 self
->dwfl
= dwfl_begin(&offline_callbacks
);
132 mod
= dwfl_report_offline(self
->dwfl
, "", "", fd
);
136 self
->dbg
= dwfl_module_getdwarf(mod
, &self
->bias
);
143 dwfl_end(self
->dwfl
);
146 memset(self
, 0, sizeof(*self
));
151 #if _ELFUTILS_PREREQ(0, 148)
152 /* This method is buggy if elfutils is older than 0.148 */
153 static int __linux_kernel_find_elf(Dwfl_Module
*mod
,
155 const char *module_name
,
157 char **file_name
, Elf
**elfp
)
160 const char *path
= kernel_get_module_path(module_name
);
162 pr_debug2("Use file %s for %s\n", path
, module_name
);
164 fd
= open(path
, O_RDONLY
);
166 *file_name
= strdup(path
);
170 /* If failed, try to call standard method */
171 return dwfl_linux_kernel_find_elf(mod
, userdata
, module_name
, base
,
175 static const Dwfl_Callbacks kernel_callbacks
= {
176 .find_debuginfo
= dwfl_standard_find_debuginfo
,
177 .debuginfo_path
= &debuginfo_path
,
179 .find_elf
= __linux_kernel_find_elf
,
180 .section_address
= dwfl_linux_kernel_module_section_address
,
183 /* Get a Dwarf from live kernel image */
184 static int debuginfo__init_online_kernel_dwarf(struct debuginfo
*self
,
187 self
->dwfl
= dwfl_begin(&kernel_callbacks
);
191 /* Load the kernel dwarves: Don't care the result here */
192 dwfl_linux_kernel_report_kernel(self
->dwfl
);
193 dwfl_linux_kernel_report_modules(self
->dwfl
);
195 self
->dbg
= dwfl_addrdwarf(self
->dwfl
, addr
, &self
->bias
);
196 /* Here, check whether we could get a real dwarf */
198 pr_debug("Failed to find kernel dwarf at %lx\n",
199 (unsigned long)addr
);
200 dwfl_end(self
->dwfl
);
201 memset(self
, 0, sizeof(*self
));
208 /* With older elfutils, this just support kernel module... */
209 static int debuginfo__init_online_kernel_dwarf(struct debuginfo
*self
,
210 Dwarf_Addr addr __used
)
212 const char *path
= kernel_get_module_path("kernel");
215 pr_err("Failed to find vmlinux path\n");
219 pr_debug2("Use file %s for debuginfo\n", path
);
220 return debuginfo__init_offline_dwarf(self
, path
);
224 struct debuginfo
*debuginfo__new(const char *path
)
226 struct debuginfo
*self
= zalloc(sizeof(struct debuginfo
));
230 if (debuginfo__init_offline_dwarf(self
, path
) < 0) {
238 struct debuginfo
*debuginfo__new_online_kernel(unsigned long addr
)
240 struct debuginfo
*self
= zalloc(sizeof(struct debuginfo
));
244 if (debuginfo__init_online_kernel_dwarf(self
, (Dwarf_Addr
)addr
) < 0) {
252 void debuginfo__delete(struct debuginfo
*self
)
256 dwfl_end(self
->dwfl
);
262 * Probe finder related functions
265 static struct probe_trace_arg_ref
*alloc_trace_arg_ref(long offs
)
267 struct probe_trace_arg_ref
*ref
;
268 ref
= zalloc(sizeof(struct probe_trace_arg_ref
));
275 * Convert a location into trace_arg.
276 * If tvar == NULL, this just checks variable can be converted.
278 static int convert_variable_location(Dwarf_Die
*vr_die
, Dwarf_Addr addr
,
280 struct probe_trace_arg
*tvar
)
282 Dwarf_Attribute attr
;
291 if (dwarf_attr(vr_die
, DW_AT_external
, &attr
) != NULL
)
294 /* TODO: handle more than 1 exprs */
295 if (dwarf_attr(vr_die
, DW_AT_location
, &attr
) == NULL
||
296 dwarf_getlocation_addr(&attr
, addr
, &op
, &nops
, 1) <= 0 ||
298 /* TODO: Support const_value */
302 if (op
->atom
== DW_OP_addr
) {
306 /* Static variables on memory (not stack), make @varname */
307 ret
= strlen(dwarf_diename(vr_die
));
308 tvar
->value
= zalloc(ret
+ 2);
309 if (tvar
->value
== NULL
)
311 snprintf(tvar
->value
, ret
+ 2, "@%s", dwarf_diename(vr_die
));
312 tvar
->ref
= alloc_trace_arg_ref((long)offs
);
313 if (tvar
->ref
== NULL
)
318 /* If this is based on frame buffer, set the offset */
319 if (op
->atom
== DW_OP_fbreg
) {
327 if (op
->atom
>= DW_OP_breg0
&& op
->atom
<= DW_OP_breg31
) {
328 regn
= op
->atom
- DW_OP_breg0
;
331 } else if (op
->atom
>= DW_OP_reg0
&& op
->atom
<= DW_OP_reg31
) {
332 regn
= op
->atom
- DW_OP_reg0
;
333 } else if (op
->atom
== DW_OP_bregx
) {
337 } else if (op
->atom
== DW_OP_regx
) {
340 pr_debug("DW_OP %x is not supported.\n", op
->atom
);
347 regs
= get_arch_regstr(regn
);
349 /* This should be a bug in DWARF or this tool */
350 pr_warning("Mapping for the register number %u "
351 "missing on this architecture.\n", regn
);
355 tvar
->value
= strdup(regs
);
356 if (tvar
->value
== NULL
)
360 tvar
->ref
= alloc_trace_arg_ref((long)offs
);
361 if (tvar
->ref
== NULL
)
367 #define BYTES_TO_BITS(nb) ((nb) * BITS_PER_LONG / sizeof(long))
369 static int convert_variable_type(Dwarf_Die
*vr_die
,
370 struct probe_trace_arg
*tvar
,
373 struct probe_trace_arg_ref
**ref_ptr
= &tvar
->ref
;
376 int bsize
, boffs
, total
;
379 /* TODO: check all types */
380 if (cast
&& strcmp(cast
, "string") != 0) {
381 /* Non string type is OK */
382 tvar
->type
= strdup(cast
);
383 return (tvar
->type
== NULL
) ? -ENOMEM
: 0;
386 bsize
= dwarf_bitsize(vr_die
);
388 /* This is a bitfield */
389 boffs
= dwarf_bitoffset(vr_die
);
390 total
= dwarf_bytesize(vr_die
);
391 if (boffs
< 0 || total
< 0)
393 ret
= snprintf(buf
, 16, "b%d@%d/%zd", bsize
, boffs
,
394 BYTES_TO_BITS(total
));
398 if (die_get_real_type(vr_die
, &type
) == NULL
) {
399 pr_warning("Failed to get a type information of %s.\n",
400 dwarf_diename(vr_die
));
404 pr_debug("%s type is %s.\n",
405 dwarf_diename(vr_die
), dwarf_diename(&type
));
407 if (cast
&& strcmp(cast
, "string") == 0) { /* String type */
408 ret
= dwarf_tag(&type
);
409 if (ret
!= DW_TAG_pointer_type
&&
410 ret
!= DW_TAG_array_type
) {
411 pr_warning("Failed to cast into string: "
412 "%s(%s) is not a pointer nor array.\n",
413 dwarf_diename(vr_die
), dwarf_diename(&type
));
416 if (ret
== DW_TAG_pointer_type
) {
417 if (die_get_real_type(&type
, &type
) == NULL
) {
418 pr_warning("Failed to get a type"
423 ref_ptr
= &(*ref_ptr
)->next
;
424 /* Add new reference with offset +0 */
425 *ref_ptr
= zalloc(sizeof(struct probe_trace_arg_ref
));
426 if (*ref_ptr
== NULL
) {
427 pr_warning("Out of memory error\n");
431 if (!die_compare_name(&type
, "char") &&
432 !die_compare_name(&type
, "unsigned char")) {
433 pr_warning("Failed to cast into string: "
434 "%s is not (unsigned) char *.\n",
435 dwarf_diename(vr_die
));
438 tvar
->type
= strdup(cast
);
439 return (tvar
->type
== NULL
) ? -ENOMEM
: 0;
442 ret
= dwarf_bytesize(&type
);
444 /* No size ... try to use default type */
446 ret
= BYTES_TO_BITS(ret
);
448 /* Check the bitwidth */
449 if (ret
> MAX_BASIC_TYPE_BITS
) {
450 pr_info("%s exceeds max-bitwidth. Cut down to %d bits.\n",
451 dwarf_diename(&type
), MAX_BASIC_TYPE_BITS
);
452 ret
= MAX_BASIC_TYPE_BITS
;
454 ret
= snprintf(buf
, 16, "%c%d",
455 die_is_signed_type(&type
) ? 's' : 'u', ret
);
458 if (ret
< 0 || ret
>= 16) {
461 pr_warning("Failed to convert variable type: %s\n",
465 tvar
->type
= strdup(buf
);
466 if (tvar
->type
== NULL
)
471 static int convert_variable_fields(Dwarf_Die
*vr_die
, const char *varname
,
472 struct perf_probe_arg_field
*field
,
473 struct probe_trace_arg_ref
**ref_ptr
,
476 struct probe_trace_arg_ref
*ref
= *ref_ptr
;
481 pr_debug("converting %s in %s\n", field
->name
, varname
);
482 if (die_get_real_type(vr_die
, &type
) == NULL
) {
483 pr_warning("Failed to get the type of %s.\n", varname
);
486 pr_debug2("Var real type: (%x)\n", (unsigned)dwarf_dieoffset(&type
));
487 tag
= dwarf_tag(&type
);
489 if (field
->name
[0] == '[' &&
490 (tag
== DW_TAG_array_type
|| tag
== DW_TAG_pointer_type
)) {
492 /* Save original type for next field */
493 memcpy(die_mem
, &type
, sizeof(*die_mem
));
494 /* Get the type of this array */
495 if (die_get_real_type(&type
, &type
) == NULL
) {
496 pr_warning("Failed to get the type of %s.\n", varname
);
499 pr_debug2("Array real type: (%x)\n",
500 (unsigned)dwarf_dieoffset(&type
));
501 if (tag
== DW_TAG_pointer_type
) {
502 ref
= zalloc(sizeof(struct probe_trace_arg_ref
));
506 (*ref_ptr
)->next
= ref
;
510 ref
->offset
+= dwarf_bytesize(&type
) * field
->index
;
512 /* Save vr_die for converting types */
513 memcpy(die_mem
, vr_die
, sizeof(*die_mem
));
515 } else if (tag
== DW_TAG_pointer_type
) {
516 /* Check the pointer and dereference */
518 pr_err("Semantic error: %s must be referred by '->'\n",
522 /* Get the type pointed by this pointer */
523 if (die_get_real_type(&type
, &type
) == NULL
) {
524 pr_warning("Failed to get the type of %s.\n", varname
);
527 /* Verify it is a data structure */
528 if (dwarf_tag(&type
) != DW_TAG_structure_type
) {
529 pr_warning("%s is not a data structure.\n", varname
);
533 ref
= zalloc(sizeof(struct probe_trace_arg_ref
));
537 (*ref_ptr
)->next
= ref
;
541 /* Verify it is a data structure */
542 if (tag
!= DW_TAG_structure_type
) {
543 pr_warning("%s is not a data structure.\n", varname
);
546 if (field
->name
[0] == '[') {
547 pr_err("Semantic error: %s is not a pointor"
548 " nor array.\n", varname
);
552 pr_err("Semantic error: %s must be referred by '.'\n",
557 pr_warning("Structure on a register is not "
563 if (die_find_member(&type
, field
->name
, die_mem
) == NULL
) {
564 pr_warning("%s(tyep:%s) has no member %s.\n", varname
,
565 dwarf_diename(&type
), field
->name
);
569 /* Get the offset of the field */
570 ret
= die_get_data_member_location(die_mem
, &offs
);
572 pr_warning("Failed to get the offset of %s.\n", field
->name
);
575 ref
->offset
+= (long)offs
;
578 /* Converting next field */
580 return convert_variable_fields(die_mem
, field
->name
,
581 field
->next
, &ref
, die_mem
);
586 /* Show a variables in kprobe event format */
587 static int convert_variable(Dwarf_Die
*vr_die
, struct probe_finder
*pf
)
592 pr_debug("Converting variable %s into trace event.\n",
593 dwarf_diename(vr_die
));
595 ret
= convert_variable_location(vr_die
, pf
->addr
, pf
->fb_ops
,
598 pr_err("Failed to find the location of %s at this address.\n"
599 " Perhaps, it has been optimized out.\n", pf
->pvar
->var
);
600 else if (ret
== -ENOTSUP
)
601 pr_err("Sorry, we don't support this variable location yet.\n");
602 else if (pf
->pvar
->field
) {
603 ret
= convert_variable_fields(vr_die
, pf
->pvar
->var
,
604 pf
->pvar
->field
, &pf
->tvar
->ref
,
609 ret
= convert_variable_type(vr_die
, pf
->tvar
, pf
->pvar
->type
);
610 /* *expr will be cached in libdw. Don't free it. */
614 /* Find a variable in a scope DIE */
615 static int find_variable(Dwarf_Die
*sc_die
, struct probe_finder
*pf
)
621 if (!is_c_varname(pf
->pvar
->var
)) {
622 /* Copy raw parameters */
623 pf
->tvar
->value
= strdup(pf
->pvar
->var
);
624 if (pf
->tvar
->value
== NULL
)
626 if (pf
->pvar
->type
) {
627 pf
->tvar
->type
= strdup(pf
->pvar
->type
);
628 if (pf
->tvar
->type
== NULL
)
631 if (pf
->pvar
->name
) {
632 pf
->tvar
->name
= strdup(pf
->pvar
->name
);
633 if (pf
->tvar
->name
== NULL
)
636 pf
->tvar
->name
= NULL
;
641 pf
->tvar
->name
= strdup(pf
->pvar
->name
);
643 ret
= synthesize_perf_probe_arg(pf
->pvar
, buf
, 32);
646 ptr
= strchr(buf
, ':'); /* Change type separator to _ */
649 pf
->tvar
->name
= strdup(buf
);
651 if (pf
->tvar
->name
== NULL
)
654 pr_debug("Searching '%s' variable in context.\n", pf
->pvar
->var
);
655 /* Search child die for local variables and parameters. */
656 if (!die_find_variable_at(sc_die
, pf
->pvar
->var
, pf
->addr
, &vr_die
)) {
657 /* Search again in global variables */
658 if (!die_find_variable_at(&pf
->cu_die
, pf
->pvar
->var
, 0, &vr_die
))
662 ret
= convert_variable(&vr_die
, pf
);
665 pr_warning("Failed to find '%s' in this function.\n",
670 /* Convert subprogram DIE to trace point */
671 static int convert_to_trace_point(Dwarf_Die
*sp_die
, Dwarf_Addr paddr
,
672 bool retprobe
, struct probe_trace_point
*tp
)
674 Dwarf_Addr eaddr
, highaddr
;
677 /* Copy the name of probe point */
678 name
= dwarf_diename(sp_die
);
680 if (dwarf_entrypc(sp_die
, &eaddr
) != 0) {
681 pr_warning("Failed to get entry address of %s\n",
682 dwarf_diename(sp_die
));
685 if (dwarf_highpc(sp_die
, &highaddr
) != 0) {
686 pr_warning("Failed to get end address of %s\n",
687 dwarf_diename(sp_die
));
690 if (paddr
> highaddr
) {
691 pr_warning("Offset specified is greater than size of %s\n",
692 dwarf_diename(sp_die
));
695 tp
->symbol
= strdup(name
);
696 if (tp
->symbol
== NULL
)
698 tp
->offset
= (unsigned long)(paddr
- eaddr
);
700 /* This function has no name. */
701 tp
->offset
= (unsigned long)paddr
;
703 /* Return probe must be on the head of a subprogram */
705 if (eaddr
!= paddr
) {
706 pr_warning("Return probe must be on the head of"
707 " a real function.\n");
716 /* Call probe_finder callback with scope DIE */
717 static int call_probe_finder(Dwarf_Die
*sc_die
, struct probe_finder
*pf
)
719 Dwarf_Attribute fb_attr
;
724 pr_err("Caller must pass a scope DIE. Program error.\n");
728 /* If not a real subprogram, find a real one */
729 if (dwarf_tag(sc_die
) != DW_TAG_subprogram
) {
730 if (!die_find_realfunc(&pf
->cu_die
, pf
->addr
, &pf
->sp_die
)) {
731 pr_warning("Failed to find probe point in any "
736 memcpy(&pf
->sp_die
, sc_die
, sizeof(Dwarf_Die
));
738 /* Get the frame base attribute/ops from subprogram */
739 dwarf_attr(&pf
->sp_die
, DW_AT_frame_base
, &fb_attr
);
740 ret
= dwarf_getlocation_addr(&fb_attr
, pf
->addr
, &pf
->fb_ops
, &nops
, 1);
741 if (ret
<= 0 || nops
== 0) {
743 #if _ELFUTILS_PREREQ(0, 142)
744 } else if (nops
== 1 && pf
->fb_ops
[0].atom
== DW_OP_call_frame_cfa
&&
747 if (dwarf_cfi_addrframe(pf
->cfi
, pf
->addr
, &frame
) != 0 ||
748 dwarf_frame_cfa(frame
, &pf
->fb_ops
, &nops
) != 0) {
749 pr_warning("Failed to get call frame on 0x%jx\n",
750 (uintmax_t)pf
->addr
);
756 /* Call finder's callback handler */
757 ret
= pf
->callback(sc_die
, pf
);
759 /* *pf->fb_ops will be cached in libdw. Don't free it. */
765 struct find_scope_param
{
766 const char *function
;
774 static int find_best_scope_cb(Dwarf_Die
*fn_die
, void *data
)
776 struct find_scope_param
*fsp
= data
;
780 /* Skip if declared file name does not match */
782 file
= dwarf_decl_file(fn_die
);
783 if (!file
|| strcmp(fsp
->file
, file
) != 0)
786 /* If the function name is given, that's what user expects */
788 if (die_compare_name(fn_die
, fsp
->function
)) {
789 memcpy(fsp
->die_mem
, fn_die
, sizeof(Dwarf_Die
));
794 /* With the line number, find the nearest declared DIE */
795 dwarf_decl_line(fn_die
, &lno
);
796 if (lno
< fsp
->line
&& fsp
->diff
> fsp
->line
- lno
) {
797 /* Keep a candidate and continue */
798 fsp
->diff
= fsp
->line
- lno
;
799 memcpy(fsp
->die_mem
, fn_die
, sizeof(Dwarf_Die
));
806 /* Find an appropriate scope fits to given conditions */
807 static Dwarf_Die
*find_best_scope(struct probe_finder
*pf
, Dwarf_Die
*die_mem
)
809 struct find_scope_param fsp
= {
810 .function
= pf
->pev
->point
.function
,
818 cu_walk_functions_at(&pf
->cu_die
, pf
->addr
, find_best_scope_cb
, &fsp
);
820 return fsp
.found
? die_mem
: NULL
;
823 static int probe_point_line_walker(const char *fname
, int lineno
,
824 Dwarf_Addr addr
, void *data
)
826 struct probe_finder
*pf
= data
;
827 Dwarf_Die
*sc_die
, die_mem
;
830 if (lineno
!= pf
->lno
|| strtailcmp(fname
, pf
->fname
) != 0)
834 sc_die
= find_best_scope(pf
, &die_mem
);
836 pr_warning("Failed to find scope of probe point.\n");
840 ret
= call_probe_finder(sc_die
, pf
);
842 /* Continue if no error, because the line will be in inline function */
843 return ret
< 0 ? ret
: 0;
846 /* Find probe point from its line number */
847 static int find_probe_point_by_line(struct probe_finder
*pf
)
849 return die_walk_lines(&pf
->cu_die
, probe_point_line_walker
, pf
);
852 /* Find lines which match lazy pattern */
853 static int find_lazy_match_lines(struct list_head
*head
,
854 const char *fname
, const char *pat
)
860 int count
= 0, linenum
= 1;
862 fp
= fopen(fname
, "r");
864 pr_warning("Failed to open %s: %s\n", fname
, strerror(errno
));
868 while ((len
= getline(&line
, &line_len
, fp
)) > 0) {
870 if (line
[len
- 1] == '\n')
871 line
[len
- 1] = '\0';
873 if (strlazymatch(line
, pat
)) {
874 line_list__add_line(head
, linenum
);
886 pr_debug("No matched lines found in %s.\n", fname
);
890 static int probe_point_lazy_walker(const char *fname
, int lineno
,
891 Dwarf_Addr addr
, void *data
)
893 struct probe_finder
*pf
= data
;
894 Dwarf_Die
*sc_die
, die_mem
;
897 if (!line_list__has_line(&pf
->lcache
, lineno
) ||
898 strtailcmp(fname
, pf
->fname
) != 0)
901 pr_debug("Probe line found: line:%d addr:0x%llx\n",
902 lineno
, (unsigned long long)addr
);
905 sc_die
= find_best_scope(pf
, &die_mem
);
907 pr_warning("Failed to find scope of probe point.\n");
911 ret
= call_probe_finder(sc_die
, pf
);
914 * Continue if no error, because the lazy pattern will match
917 return ret
< 0 ? ret
: 0;
920 /* Find probe points from lazy pattern */
921 static int find_probe_point_lazy(Dwarf_Die
*sp_die
, struct probe_finder
*pf
)
925 if (list_empty(&pf
->lcache
)) {
926 /* Matching lazy line pattern */
927 ret
= find_lazy_match_lines(&pf
->lcache
, pf
->fname
,
928 pf
->pev
->point
.lazy_line
);
933 return die_walk_lines(sp_die
, probe_point_lazy_walker
, pf
);
936 static int probe_point_inline_cb(Dwarf_Die
*in_die
, void *data
)
938 struct probe_finder
*pf
= data
;
939 struct perf_probe_point
*pp
= &pf
->pev
->point
;
944 ret
= find_probe_point_lazy(in_die
, pf
);
946 /* Get probe address */
947 if (dwarf_entrypc(in_die
, &addr
) != 0) {
948 pr_warning("Failed to get entry address of %s.\n",
949 dwarf_diename(in_die
));
953 pf
->addr
+= pp
->offset
;
954 pr_debug("found inline addr: 0x%jx\n",
955 (uintmax_t)pf
->addr
);
957 ret
= call_probe_finder(in_die
, pf
);
963 /* Callback parameter with return value for libdw */
964 struct dwarf_callback_param
{
969 /* Search function from function name */
970 static int probe_point_search_cb(Dwarf_Die
*sp_die
, void *data
)
972 struct dwarf_callback_param
*param
= data
;
973 struct probe_finder
*pf
= param
->data
;
974 struct perf_probe_point
*pp
= &pf
->pev
->point
;
976 /* Check tag and diename */
977 if (dwarf_tag(sp_die
) != DW_TAG_subprogram
||
978 !die_compare_name(sp_die
, pp
->function
))
981 /* Check declared file */
982 if (pp
->file
&& strtailcmp(pp
->file
, dwarf_decl_file(sp_die
)))
985 pf
->fname
= dwarf_decl_file(sp_die
);
986 if (pp
->line
) { /* Function relative line */
987 dwarf_decl_line(sp_die
, &pf
->lno
);
989 param
->retval
= find_probe_point_by_line(pf
);
990 } else if (!dwarf_func_inline(sp_die
)) {
993 param
->retval
= find_probe_point_lazy(sp_die
, pf
);
995 if (dwarf_entrypc(sp_die
, &pf
->addr
) != 0) {
996 pr_warning("Failed to get entry address of "
997 "%s.\n", dwarf_diename(sp_die
));
998 param
->retval
= -ENOENT
;
999 return DWARF_CB_ABORT
;
1001 pf
->addr
+= pp
->offset
;
1002 /* TODO: Check the address in this function */
1003 param
->retval
= call_probe_finder(sp_die
, pf
);
1006 /* Inlined function: search instances */
1007 param
->retval
= die_walk_instances(sp_die
,
1008 probe_point_inline_cb
, (void *)pf
);
1010 return DWARF_CB_ABORT
; /* Exit; no same symbol in this CU. */
1013 static int find_probe_point_by_func(struct probe_finder
*pf
)
1015 struct dwarf_callback_param _param
= {.data
= (void *)pf
,
1017 dwarf_getfuncs(&pf
->cu_die
, probe_point_search_cb
, &_param
, 0);
1018 return _param
.retval
;
1021 struct pubname_callback_param
{
1029 static int pubname_search_cb(Dwarf
*dbg
, Dwarf_Global
*gl
, void *data
)
1031 struct pubname_callback_param
*param
= data
;
1033 if (dwarf_offdie(dbg
, gl
->die_offset
, param
->sp_die
)) {
1034 if (dwarf_tag(param
->sp_die
) != DW_TAG_subprogram
)
1037 if (die_compare_name(param
->sp_die
, param
->function
)) {
1038 if (!dwarf_offdie(dbg
, gl
->cu_offset
, param
->cu_die
))
1042 strtailcmp(param
->file
, dwarf_decl_file(param
->sp_die
)))
1046 return DWARF_CB_ABORT
;
1053 /* Find probe points from debuginfo */
1054 static int debuginfo__find_probes(struct debuginfo
*self
,
1055 struct probe_finder
*pf
)
1057 struct perf_probe_point
*pp
= &pf
->pev
->point
;
1058 Dwarf_Off off
, noff
;
1063 #if _ELFUTILS_PREREQ(0, 142)
1064 /* Get the call frame information from this dwarf */
1065 pf
->cfi
= dwarf_getcfi(self
->dbg
);
1069 line_list__init(&pf
->lcache
);
1071 /* Fastpath: lookup by function name from .debug_pubnames section */
1073 struct pubname_callback_param pubname_param
= {
1074 .function
= pp
->function
,
1076 .cu_die
= &pf
->cu_die
,
1077 .sp_die
= &pf
->sp_die
,
1080 struct dwarf_callback_param probe_param
= {
1084 dwarf_getpubnames(self
->dbg
, pubname_search_cb
,
1086 if (pubname_param
.found
) {
1087 ret
= probe_point_search_cb(&pf
->sp_die
, &probe_param
);
1093 /* Loop on CUs (Compilation Unit) */
1094 while (!dwarf_nextcu(self
->dbg
, off
, &noff
, &cuhl
, NULL
, NULL
, NULL
)) {
1095 /* Get the DIE(Debugging Information Entry) of this CU */
1096 diep
= dwarf_offdie(self
->dbg
, off
+ cuhl
, &pf
->cu_die
);
1100 /* Check if target file is included. */
1102 pf
->fname
= cu_find_realpath(&pf
->cu_die
, pp
->file
);
1106 if (!pp
->file
|| pf
->fname
) {
1108 ret
= find_probe_point_by_func(pf
);
1109 else if (pp
->lazy_line
)
1110 ret
= find_probe_point_lazy(NULL
, pf
);
1113 ret
= find_probe_point_by_line(pf
);
1122 line_list__free(&pf
->lcache
);
1127 /* Add a found probe point into trace event list */
1128 static int add_probe_trace_event(Dwarf_Die
*sc_die
, struct probe_finder
*pf
)
1130 struct trace_event_finder
*tf
=
1131 container_of(pf
, struct trace_event_finder
, pf
);
1132 struct probe_trace_event
*tev
;
1135 /* Check number of tevs */
1136 if (tf
->ntevs
== tf
->max_tevs
) {
1137 pr_warning("Too many( > %d) probe point found.\n",
1141 tev
= &tf
->tevs
[tf
->ntevs
++];
1143 /* Trace point should be converted from subprogram DIE */
1144 ret
= convert_to_trace_point(&pf
->sp_die
, pf
->addr
,
1145 pf
->pev
->point
.retprobe
, &tev
->point
);
1149 pr_debug("Probe point found: %s+%lu\n", tev
->point
.symbol
,
1152 /* Find each argument */
1153 tev
->nargs
= pf
->pev
->nargs
;
1154 tev
->args
= zalloc(sizeof(struct probe_trace_arg
) * tev
->nargs
);
1155 if (tev
->args
== NULL
)
1157 for (i
= 0; i
< pf
->pev
->nargs
; i
++) {
1158 pf
->pvar
= &pf
->pev
->args
[i
];
1159 pf
->tvar
= &tev
->args
[i
];
1160 /* Variable should be found from scope DIE */
1161 ret
= find_variable(sc_die
, pf
);
1169 /* Find probe_trace_events specified by perf_probe_event from debuginfo */
1170 int debuginfo__find_trace_events(struct debuginfo
*self
,
1171 struct perf_probe_event
*pev
,
1172 struct probe_trace_event
**tevs
, int max_tevs
)
1174 struct trace_event_finder tf
= {
1175 .pf
= {.pev
= pev
, .callback
= add_probe_trace_event
},
1176 .max_tevs
= max_tevs
};
1179 /* Allocate result tevs array */
1180 *tevs
= zalloc(sizeof(struct probe_trace_event
) * max_tevs
);
1187 ret
= debuginfo__find_probes(self
, &tf
.pf
);
1194 return (ret
< 0) ? ret
: tf
.ntevs
;
1197 #define MAX_VAR_LEN 64
1199 /* Collect available variables in this scope */
1200 static int collect_variables_cb(Dwarf_Die
*die_mem
, void *data
)
1202 struct available_var_finder
*af
= data
;
1203 struct variable_list
*vl
;
1204 char buf
[MAX_VAR_LEN
];
1207 vl
= &af
->vls
[af
->nvls
- 1];
1209 tag
= dwarf_tag(die_mem
);
1210 if (tag
== DW_TAG_formal_parameter
||
1211 tag
== DW_TAG_variable
) {
1212 ret
= convert_variable_location(die_mem
, af
->pf
.addr
,
1213 af
->pf
.fb_ops
, NULL
);
1215 ret
= die_get_varname(die_mem
, buf
, MAX_VAR_LEN
);
1216 pr_debug2("Add new var: %s\n", buf
);
1218 strlist__add(vl
->vars
, buf
);
1222 if (af
->child
&& dwarf_haspc(die_mem
, af
->pf
.addr
))
1223 return DIE_FIND_CB_CONTINUE
;
1225 return DIE_FIND_CB_SIBLING
;
1228 /* Add a found vars into available variables list */
1229 static int add_available_vars(Dwarf_Die
*sc_die
, struct probe_finder
*pf
)
1231 struct available_var_finder
*af
=
1232 container_of(pf
, struct available_var_finder
, pf
);
1233 struct variable_list
*vl
;
1237 /* Check number of tevs */
1238 if (af
->nvls
== af
->max_vls
) {
1239 pr_warning("Too many( > %d) probe point found.\n", af
->max_vls
);
1242 vl
= &af
->vls
[af
->nvls
++];
1244 /* Trace point should be converted from subprogram DIE */
1245 ret
= convert_to_trace_point(&pf
->sp_die
, pf
->addr
,
1246 pf
->pev
->point
.retprobe
, &vl
->point
);
1250 pr_debug("Probe point found: %s+%lu\n", vl
->point
.symbol
,
1253 /* Find local variables */
1254 vl
->vars
= strlist__new(true, NULL
);
1255 if (vl
->vars
== NULL
)
1258 die_find_child(sc_die
, collect_variables_cb
, (void *)af
, &die_mem
);
1260 /* Find external variables */
1263 /* Don't need to search child DIE for externs. */
1265 die_find_child(&pf
->cu_die
, collect_variables_cb
, (void *)af
, &die_mem
);
1268 if (strlist__empty(vl
->vars
)) {
1269 strlist__delete(vl
->vars
);
1276 /* Find available variables at given probe point */
1277 int debuginfo__find_available_vars_at(struct debuginfo
*self
,
1278 struct perf_probe_event
*pev
,
1279 struct variable_list
**vls
,
1280 int max_vls
, bool externs
)
1282 struct available_var_finder af
= {
1283 .pf
= {.pev
= pev
, .callback
= add_available_vars
},
1284 .max_vls
= max_vls
, .externs
= externs
};
1287 /* Allocate result vls array */
1288 *vls
= zalloc(sizeof(struct variable_list
) * max_vls
);
1295 ret
= debuginfo__find_probes(self
, &af
.pf
);
1297 /* Free vlist for error */
1299 if (af
.vls
[af
.nvls
].point
.symbol
)
1300 free(af
.vls
[af
.nvls
].point
.symbol
);
1301 if (af
.vls
[af
.nvls
].vars
)
1302 strlist__delete(af
.vls
[af
.nvls
].vars
);
1309 return (ret
< 0) ? ret
: af
.nvls
;
1312 /* Reverse search */
1313 int debuginfo__find_probe_point(struct debuginfo
*self
, unsigned long addr
,
1314 struct perf_probe_point
*ppt
)
1316 Dwarf_Die cudie
, spdie
, indie
;
1317 Dwarf_Addr _addr
, baseaddr
;
1318 const char *fname
= NULL
, *func
= NULL
, *tmp
;
1319 int baseline
= 0, lineno
= 0, ret
= 0;
1321 /* Adjust address with bias */
1325 if (!dwarf_addrdie(self
->dbg
, (Dwarf_Addr
)addr
- self
->bias
, &cudie
)) {
1326 pr_warning("Failed to find debug information for address %lx\n",
1332 /* Find a corresponding line (filename and lineno) */
1333 cu_find_lineinfo(&cudie
, addr
, &fname
, &lineno
);
1334 /* Don't care whether it failed or not */
1336 /* Find a corresponding function (name, baseline and baseaddr) */
1337 if (die_find_realfunc(&cudie
, (Dwarf_Addr
)addr
, &spdie
)) {
1338 /* Get function entry information */
1339 tmp
= dwarf_diename(&spdie
);
1341 dwarf_entrypc(&spdie
, &baseaddr
) != 0 ||
1342 dwarf_decl_line(&spdie
, &baseline
) != 0)
1346 if (addr
== (unsigned long)baseaddr
)
1347 /* Function entry - Relative line number is 0 */
1349 else if (die_find_inlinefunc(&spdie
, (Dwarf_Addr
)addr
,
1351 if (dwarf_entrypc(&indie
, &_addr
) == 0 &&
1354 * addr is at an inline function entry.
1355 * In this case, lineno should be the call-site
1358 lineno
= die_get_call_lineno(&indie
);
1361 * addr is in an inline function body.
1362 * Since lineno points one of the lines
1363 * of the inline function, baseline should
1364 * be the entry line of the inline function.
1366 tmp
= dwarf_diename(&indie
);
1368 dwarf_decl_line(&spdie
, &baseline
) == 0)
1375 /* Make a relative line number or an offset */
1377 ppt
->line
= lineno
- baseline
;
1379 ppt
->offset
= addr
- (unsigned long)baseaddr
;
1381 /* Duplicate strings */
1383 ppt
->function
= strdup(func
);
1384 if (ppt
->function
== NULL
) {
1390 ppt
->file
= strdup(fname
);
1391 if (ppt
->file
== NULL
) {
1392 if (ppt
->function
) {
1393 free(ppt
->function
);
1394 ppt
->function
= NULL
;
1401 if (ret
== 0 && (fname
|| func
))
1402 ret
= 1; /* Found a point */
1406 /* Add a line and store the src path */
1407 static int line_range_add_line(const char *src
, unsigned int lineno
,
1408 struct line_range
*lr
)
1410 /* Copy source path */
1412 lr
->path
= strdup(src
);
1413 if (lr
->path
== NULL
)
1416 return line_list__add_line(&lr
->line_list
, lineno
);
1419 static int line_range_walk_cb(const char *fname
, int lineno
,
1420 Dwarf_Addr addr __used
,
1423 struct line_finder
*lf
= data
;
1425 if ((strtailcmp(fname
, lf
->fname
) != 0) ||
1426 (lf
->lno_s
> lineno
|| lf
->lno_e
< lineno
))
1429 if (line_range_add_line(fname
, lineno
, lf
->lr
) < 0)
1435 /* Find line range from its line number */
1436 static int find_line_range_by_line(Dwarf_Die
*sp_die
, struct line_finder
*lf
)
1440 ret
= die_walk_lines(sp_die
?: &lf
->cu_die
, line_range_walk_cb
, lf
);
1444 if (!list_empty(&lf
->lr
->line_list
))
1445 ret
= lf
->found
= 1;
1447 ret
= 0; /* Lines are not found */
1450 lf
->lr
->path
= NULL
;
1455 static int line_range_inline_cb(Dwarf_Die
*in_die
, void *data
)
1457 find_line_range_by_line(in_die
, data
);
1460 * We have to check all instances of inlined function, because
1461 * some execution paths can be optimized out depends on the
1462 * function argument of instances
1467 /* Search function from function name */
1468 static int line_range_search_cb(Dwarf_Die
*sp_die
, void *data
)
1470 struct dwarf_callback_param
*param
= data
;
1471 struct line_finder
*lf
= param
->data
;
1472 struct line_range
*lr
= lf
->lr
;
1474 /* Check declared file */
1475 if (lr
->file
&& strtailcmp(lr
->file
, dwarf_decl_file(sp_die
)))
1478 if (dwarf_tag(sp_die
) == DW_TAG_subprogram
&&
1479 die_compare_name(sp_die
, lr
->function
)) {
1480 lf
->fname
= dwarf_decl_file(sp_die
);
1481 dwarf_decl_line(sp_die
, &lr
->offset
);
1482 pr_debug("fname: %s, lineno:%d\n", lf
->fname
, lr
->offset
);
1483 lf
->lno_s
= lr
->offset
+ lr
->start
;
1484 if (lf
->lno_s
< 0) /* Overflow */
1485 lf
->lno_s
= INT_MAX
;
1486 lf
->lno_e
= lr
->offset
+ lr
->end
;
1487 if (lf
->lno_e
< 0) /* Overflow */
1488 lf
->lno_e
= INT_MAX
;
1489 pr_debug("New line range: %d to %d\n", lf
->lno_s
, lf
->lno_e
);
1490 lr
->start
= lf
->lno_s
;
1491 lr
->end
= lf
->lno_e
;
1492 if (dwarf_func_inline(sp_die
))
1493 param
->retval
= die_walk_instances(sp_die
,
1494 line_range_inline_cb
, lf
);
1496 param
->retval
= find_line_range_by_line(sp_die
, lf
);
1497 return DWARF_CB_ABORT
;
1502 static int find_line_range_by_func(struct line_finder
*lf
)
1504 struct dwarf_callback_param param
= {.data
= (void *)lf
, .retval
= 0};
1505 dwarf_getfuncs(&lf
->cu_die
, line_range_search_cb
, ¶m
, 0);
1506 return param
.retval
;
1509 int debuginfo__find_line_range(struct debuginfo
*self
, struct line_range
*lr
)
1511 struct line_finder lf
= {.lr
= lr
, .found
= 0};
1513 Dwarf_Off off
= 0, noff
;
1516 const char *comp_dir
;
1518 /* Fastpath: lookup by function name from .debug_pubnames section */
1520 struct pubname_callback_param pubname_param
= {
1521 .function
= lr
->function
, .file
= lr
->file
,
1522 .cu_die
= &lf
.cu_die
, .sp_die
= &lf
.sp_die
, .found
= 0};
1523 struct dwarf_callback_param line_range_param
= {
1524 .data
= (void *)&lf
, .retval
= 0};
1526 dwarf_getpubnames(self
->dbg
, pubname_search_cb
,
1528 if (pubname_param
.found
) {
1529 line_range_search_cb(&lf
.sp_die
, &line_range_param
);
1535 /* Loop on CUs (Compilation Unit) */
1536 while (!lf
.found
&& ret
>= 0) {
1537 if (dwarf_nextcu(self
->dbg
, off
, &noff
, &cuhl
,
1538 NULL
, NULL
, NULL
) != 0)
1541 /* Get the DIE(Debugging Information Entry) of this CU */
1542 diep
= dwarf_offdie(self
->dbg
, off
+ cuhl
, &lf
.cu_die
);
1546 /* Check if target file is included. */
1548 lf
.fname
= cu_find_realpath(&lf
.cu_die
, lr
->file
);
1552 if (!lr
->file
|| lf
.fname
) {
1554 ret
= find_line_range_by_func(&lf
);
1556 lf
.lno_s
= lr
->start
;
1558 ret
= find_line_range_by_line(NULL
, &lf
);
1565 /* Store comp_dir */
1567 comp_dir
= cu_get_comp_dir(&lf
.cu_die
);
1569 lr
->comp_dir
= strdup(comp_dir
);
1575 pr_debug("path: %s\n", lr
->path
);
1576 return (ret
< 0) ? ret
: lf
.found
;