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>
34 #include <dwarf-regs.h>
36 #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 /* Line number list operations */
48 /* Add a line to line number list */
49 static int line_list__add_line(struct list_head
*head
, int line
)
54 /* Reverse search, because new line will be the last one */
55 list_for_each_entry_reverse(ln
, head
, list
) {
56 if (ln
->line
< line
) {
59 } else if (ln
->line
== line
) /* Already exist */
62 /* List is empty, or the smallest entry */
65 pr_debug("line list: add a line %u\n", line
);
66 ln
= zalloc(sizeof(struct line_node
));
70 INIT_LIST_HEAD(&ln
->list
);
71 list_add(&ln
->list
, p
);
75 /* Check if the line in line number list */
76 static int line_list__has_line(struct list_head
*head
, int line
)
80 /* Reverse search, because new line will be the last one */
81 list_for_each_entry(ln
, head
, list
)
88 /* Init line number list */
89 static void line_list__init(struct list_head
*head
)
94 /* Free line number list */
95 static void line_list__free(struct list_head
*head
)
98 while (!list_empty(head
)) {
99 ln
= list_first_entry(head
, struct line_node
, list
);
105 /* Dwarf FL wrappers */
106 static char *debuginfo_path
; /* Currently dummy */
108 static const Dwfl_Callbacks offline_callbacks
= {
109 .find_debuginfo
= dwfl_standard_find_debuginfo
,
110 .debuginfo_path
= &debuginfo_path
,
112 .section_address
= dwfl_offline_section_address
,
114 /* We use this table for core files too. */
115 .find_elf
= dwfl_build_id_find_elf
,
118 /* Get a Dwarf from offline image */
119 static int debuginfo__init_offline_dwarf(struct debuginfo
*self
,
125 fd
= open(path
, O_RDONLY
);
129 self
->dwfl
= dwfl_begin(&offline_callbacks
);
133 mod
= dwfl_report_offline(self
->dwfl
, "", "", fd
);
137 self
->dbg
= dwfl_module_getdwarf(mod
, &self
->bias
);
144 dwfl_end(self
->dwfl
);
147 memset(self
, 0, sizeof(*self
));
152 #if _ELFUTILS_PREREQ(0, 148)
153 /* This method is buggy if elfutils is older than 0.148 */
154 static int __linux_kernel_find_elf(Dwfl_Module
*mod
,
156 const char *module_name
,
158 char **file_name
, Elf
**elfp
)
161 const char *path
= kernel_get_module_path(module_name
);
163 pr_debug2("Use file %s for %s\n", path
, module_name
);
165 fd
= open(path
, O_RDONLY
);
167 *file_name
= strdup(path
);
171 /* If failed, try to call standard method */
172 return dwfl_linux_kernel_find_elf(mod
, userdata
, module_name
, base
,
176 static const Dwfl_Callbacks kernel_callbacks
= {
177 .find_debuginfo
= dwfl_standard_find_debuginfo
,
178 .debuginfo_path
= &debuginfo_path
,
180 .find_elf
= __linux_kernel_find_elf
,
181 .section_address
= dwfl_linux_kernel_module_section_address
,
184 /* Get a Dwarf from live kernel image */
185 static int debuginfo__init_online_kernel_dwarf(struct debuginfo
*self
,
188 self
->dwfl
= dwfl_begin(&kernel_callbacks
);
192 /* Load the kernel dwarves: Don't care the result here */
193 dwfl_linux_kernel_report_kernel(self
->dwfl
);
194 dwfl_linux_kernel_report_modules(self
->dwfl
);
196 self
->dbg
= dwfl_addrdwarf(self
->dwfl
, addr
, &self
->bias
);
197 /* Here, check whether we could get a real dwarf */
199 pr_debug("Failed to find kernel dwarf at %lx\n",
200 (unsigned long)addr
);
201 dwfl_end(self
->dwfl
);
202 memset(self
, 0, sizeof(*self
));
209 /* With older elfutils, this just support kernel module... */
210 static int debuginfo__init_online_kernel_dwarf(struct debuginfo
*self
,
211 Dwarf_Addr addr __used
)
213 const char *path
= kernel_get_module_path("kernel");
216 pr_err("Failed to find vmlinux path\n");
220 pr_debug2("Use file %s for debuginfo\n", path
);
221 return debuginfo__init_offline_dwarf(self
, path
);
225 struct debuginfo
*debuginfo__new(const char *path
)
227 struct debuginfo
*self
= zalloc(sizeof(struct debuginfo
));
231 if (debuginfo__init_offline_dwarf(self
, path
) < 0) {
239 struct debuginfo
*debuginfo__new_online_kernel(unsigned long addr
)
241 struct debuginfo
*self
= zalloc(sizeof(struct debuginfo
));
245 if (debuginfo__init_online_kernel_dwarf(self
, (Dwarf_Addr
)addr
) < 0) {
253 void debuginfo__delete(struct debuginfo
*self
)
257 dwfl_end(self
->dwfl
);
263 * Probe finder related functions
266 static struct probe_trace_arg_ref
*alloc_trace_arg_ref(long offs
)
268 struct probe_trace_arg_ref
*ref
;
269 ref
= zalloc(sizeof(struct probe_trace_arg_ref
));
276 * Convert a location into trace_arg.
277 * If tvar == NULL, this just checks variable can be converted.
279 static int convert_variable_location(Dwarf_Die
*vr_die
, Dwarf_Addr addr
,
281 struct probe_trace_arg
*tvar
)
283 Dwarf_Attribute attr
;
292 if (dwarf_attr(vr_die
, DW_AT_external
, &attr
) != NULL
)
295 /* TODO: handle more than 1 exprs */
296 if (dwarf_attr(vr_die
, DW_AT_location
, &attr
) == NULL
||
297 dwarf_getlocation_addr(&attr
, addr
, &op
, &nops
, 1) <= 0 ||
299 /* TODO: Support const_value */
303 if (op
->atom
== DW_OP_addr
) {
307 /* Static variables on memory (not stack), make @varname */
308 ret
= strlen(dwarf_diename(vr_die
));
309 tvar
->value
= zalloc(ret
+ 2);
310 if (tvar
->value
== NULL
)
312 snprintf(tvar
->value
, ret
+ 2, "@%s", dwarf_diename(vr_die
));
313 tvar
->ref
= alloc_trace_arg_ref((long)offs
);
314 if (tvar
->ref
== NULL
)
319 /* If this is based on frame buffer, set the offset */
320 if (op
->atom
== DW_OP_fbreg
) {
328 if (op
->atom
>= DW_OP_breg0
&& op
->atom
<= DW_OP_breg31
) {
329 regn
= op
->atom
- DW_OP_breg0
;
332 } else if (op
->atom
>= DW_OP_reg0
&& op
->atom
<= DW_OP_reg31
) {
333 regn
= op
->atom
- DW_OP_reg0
;
334 } else if (op
->atom
== DW_OP_bregx
) {
338 } else if (op
->atom
== DW_OP_regx
) {
341 pr_debug("DW_OP %x is not supported.\n", op
->atom
);
348 regs
= get_arch_regstr(regn
);
350 /* This should be a bug in DWARF or this tool */
351 pr_warning("Mapping for the register number %u "
352 "missing on this architecture.\n", regn
);
356 tvar
->value
= strdup(regs
);
357 if (tvar
->value
== NULL
)
361 tvar
->ref
= alloc_trace_arg_ref((long)offs
);
362 if (tvar
->ref
== NULL
)
368 #define BYTES_TO_BITS(nb) ((nb) * BITS_PER_LONG / sizeof(long))
370 static int convert_variable_type(Dwarf_Die
*vr_die
,
371 struct probe_trace_arg
*tvar
,
374 struct probe_trace_arg_ref
**ref_ptr
= &tvar
->ref
;
377 int bsize
, boffs
, total
;
380 /* TODO: check all types */
381 if (cast
&& strcmp(cast
, "string") != 0) {
382 /* Non string type is OK */
383 tvar
->type
= strdup(cast
);
384 return (tvar
->type
== NULL
) ? -ENOMEM
: 0;
387 bsize
= dwarf_bitsize(vr_die
);
389 /* This is a bitfield */
390 boffs
= dwarf_bitoffset(vr_die
);
391 total
= dwarf_bytesize(vr_die
);
392 if (boffs
< 0 || total
< 0)
394 ret
= snprintf(buf
, 16, "b%d@%d/%zd", bsize
, boffs
,
395 BYTES_TO_BITS(total
));
399 if (die_get_real_type(vr_die
, &type
) == NULL
) {
400 pr_warning("Failed to get a type information of %s.\n",
401 dwarf_diename(vr_die
));
405 pr_debug("%s type is %s.\n",
406 dwarf_diename(vr_die
), dwarf_diename(&type
));
408 if (cast
&& strcmp(cast
, "string") == 0) { /* String type */
409 ret
= dwarf_tag(&type
);
410 if (ret
!= DW_TAG_pointer_type
&&
411 ret
!= DW_TAG_array_type
) {
412 pr_warning("Failed to cast into string: "
413 "%s(%s) is not a pointer nor array.\n",
414 dwarf_diename(vr_die
), dwarf_diename(&type
));
417 if (ret
== DW_TAG_pointer_type
) {
418 if (die_get_real_type(&type
, &type
) == NULL
) {
419 pr_warning("Failed to get a type"
424 ref_ptr
= &(*ref_ptr
)->next
;
425 /* Add new reference with offset +0 */
426 *ref_ptr
= zalloc(sizeof(struct probe_trace_arg_ref
));
427 if (*ref_ptr
== NULL
) {
428 pr_warning("Out of memory error\n");
432 if (!die_compare_name(&type
, "char") &&
433 !die_compare_name(&type
, "unsigned char")) {
434 pr_warning("Failed to cast into string: "
435 "%s is not (unsigned) char *.\n",
436 dwarf_diename(vr_die
));
439 tvar
->type
= strdup(cast
);
440 return (tvar
->type
== NULL
) ? -ENOMEM
: 0;
443 ret
= dwarf_bytesize(&type
);
445 /* No size ... try to use default type */
447 ret
= BYTES_TO_BITS(ret
);
449 /* Check the bitwidth */
450 if (ret
> MAX_BASIC_TYPE_BITS
) {
451 pr_info("%s exceeds max-bitwidth. Cut down to %d bits.\n",
452 dwarf_diename(&type
), MAX_BASIC_TYPE_BITS
);
453 ret
= MAX_BASIC_TYPE_BITS
;
455 ret
= snprintf(buf
, 16, "%c%d",
456 die_is_signed_type(&type
) ? 's' : 'u', ret
);
459 if (ret
< 0 || ret
>= 16) {
462 pr_warning("Failed to convert variable type: %s\n",
466 tvar
->type
= strdup(buf
);
467 if (tvar
->type
== NULL
)
472 static int convert_variable_fields(Dwarf_Die
*vr_die
, const char *varname
,
473 struct perf_probe_arg_field
*field
,
474 struct probe_trace_arg_ref
**ref_ptr
,
477 struct probe_trace_arg_ref
*ref
= *ref_ptr
;
482 pr_debug("converting %s in %s\n", field
->name
, varname
);
483 if (die_get_real_type(vr_die
, &type
) == NULL
) {
484 pr_warning("Failed to get the type of %s.\n", varname
);
487 pr_debug2("Var real type: (%x)\n", (unsigned)dwarf_dieoffset(&type
));
488 tag
= dwarf_tag(&type
);
490 if (field
->name
[0] == '[' &&
491 (tag
== DW_TAG_array_type
|| tag
== DW_TAG_pointer_type
)) {
493 /* Save original type for next field */
494 memcpy(die_mem
, &type
, sizeof(*die_mem
));
495 /* Get the type of this array */
496 if (die_get_real_type(&type
, &type
) == NULL
) {
497 pr_warning("Failed to get the type of %s.\n", varname
);
500 pr_debug2("Array real type: (%x)\n",
501 (unsigned)dwarf_dieoffset(&type
));
502 if (tag
== DW_TAG_pointer_type
) {
503 ref
= zalloc(sizeof(struct probe_trace_arg_ref
));
507 (*ref_ptr
)->next
= ref
;
511 ref
->offset
+= dwarf_bytesize(&type
) * field
->index
;
513 /* Save vr_die for converting types */
514 memcpy(die_mem
, vr_die
, sizeof(*die_mem
));
516 } else if (tag
== DW_TAG_pointer_type
) {
517 /* Check the pointer and dereference */
519 pr_err("Semantic error: %s must be referred by '->'\n",
523 /* Get the type pointed by this pointer */
524 if (die_get_real_type(&type
, &type
) == NULL
) {
525 pr_warning("Failed to get the type of %s.\n", varname
);
528 /* Verify it is a data structure */
529 if (dwarf_tag(&type
) != DW_TAG_structure_type
) {
530 pr_warning("%s is not a data structure.\n", varname
);
534 ref
= zalloc(sizeof(struct probe_trace_arg_ref
));
538 (*ref_ptr
)->next
= ref
;
542 /* Verify it is a data structure */
543 if (tag
!= DW_TAG_structure_type
) {
544 pr_warning("%s is not a data structure.\n", varname
);
547 if (field
->name
[0] == '[') {
548 pr_err("Semantic error: %s is not a pointor"
549 " nor array.\n", varname
);
553 pr_err("Semantic error: %s must be referred by '.'\n",
558 pr_warning("Structure on a register is not "
564 if (die_find_member(&type
, field
->name
, die_mem
) == NULL
) {
565 pr_warning("%s(tyep:%s) has no member %s.\n", varname
,
566 dwarf_diename(&type
), field
->name
);
570 /* Get the offset of the field */
571 ret
= die_get_data_member_location(die_mem
, &offs
);
573 pr_warning("Failed to get the offset of %s.\n", field
->name
);
576 ref
->offset
+= (long)offs
;
579 /* Converting next field */
581 return convert_variable_fields(die_mem
, field
->name
,
582 field
->next
, &ref
, die_mem
);
587 /* Show a variables in kprobe event format */
588 static int convert_variable(Dwarf_Die
*vr_die
, struct probe_finder
*pf
)
593 pr_debug("Converting variable %s into trace event.\n",
594 dwarf_diename(vr_die
));
596 ret
= convert_variable_location(vr_die
, pf
->addr
, pf
->fb_ops
,
599 pr_err("Failed to find the location of %s at this address.\n"
600 " Perhaps, it has been optimized out.\n", pf
->pvar
->var
);
601 else if (ret
== -ENOTSUP
)
602 pr_err("Sorry, we don't support this variable location yet.\n");
603 else if (pf
->pvar
->field
) {
604 ret
= convert_variable_fields(vr_die
, pf
->pvar
->var
,
605 pf
->pvar
->field
, &pf
->tvar
->ref
,
610 ret
= convert_variable_type(vr_die
, pf
->tvar
, pf
->pvar
->type
);
611 /* *expr will be cached in libdw. Don't free it. */
615 /* Find a variable in a subprogram die */
616 static int find_variable(Dwarf_Die
*sp_die
, struct probe_finder
*pf
)
618 Dwarf_Die vr_die
, *scopes
;
622 if (!is_c_varname(pf
->pvar
->var
)) {
623 /* Copy raw parameters */
624 pf
->tvar
->value
= strdup(pf
->pvar
->var
);
625 if (pf
->tvar
->value
== NULL
)
627 if (pf
->pvar
->type
) {
628 pf
->tvar
->type
= strdup(pf
->pvar
->type
);
629 if (pf
->tvar
->type
== NULL
)
632 if (pf
->pvar
->name
) {
633 pf
->tvar
->name
= strdup(pf
->pvar
->name
);
634 if (pf
->tvar
->name
== NULL
)
637 pf
->tvar
->name
= NULL
;
642 pf
->tvar
->name
= strdup(pf
->pvar
->name
);
644 ret
= synthesize_perf_probe_arg(pf
->pvar
, buf
, 32);
647 ptr
= strchr(buf
, ':'); /* Change type separator to _ */
650 pf
->tvar
->name
= strdup(buf
);
652 if (pf
->tvar
->name
== NULL
)
655 pr_debug("Searching '%s' variable in context.\n",
657 /* Search child die for local variables and parameters. */
658 if (die_find_variable_at(sp_die
, pf
->pvar
->var
, pf
->addr
, &vr_die
))
659 ret
= convert_variable(&vr_die
, pf
);
661 /* Search upper class */
662 nscopes
= dwarf_getscopes_die(sp_die
, &scopes
);
663 while (nscopes
-- > 1) {
664 pr_debug("Searching variables in %s\n",
665 dwarf_diename(&scopes
[nscopes
]));
666 /* We should check this scope, so give dummy address */
667 if (die_find_variable_at(&scopes
[nscopes
],
670 ret
= convert_variable(&vr_die
, pf
);
680 pr_warning("Failed to find '%s' in this function.\n",
685 /* Convert subprogram DIE to trace point */
686 static int convert_to_trace_point(Dwarf_Die
*sp_die
, Dwarf_Addr paddr
,
687 bool retprobe
, struct probe_trace_point
*tp
)
692 /* Copy the name of probe point */
693 name
= dwarf_diename(sp_die
);
695 if (dwarf_entrypc(sp_die
, &eaddr
) != 0) {
696 pr_warning("Failed to get entry address of %s\n",
697 dwarf_diename(sp_die
));
700 tp
->symbol
= strdup(name
);
701 if (tp
->symbol
== NULL
)
703 tp
->offset
= (unsigned long)(paddr
- eaddr
);
705 /* This function has no name. */
706 tp
->offset
= (unsigned long)paddr
;
708 /* Return probe must be on the head of a subprogram */
710 if (eaddr
!= paddr
) {
711 pr_warning("Return probe must be on the head of"
712 " a real function.\n");
721 /* Call probe_finder callback with real subprogram DIE */
722 static int call_probe_finder(Dwarf_Die
*sp_die
, struct probe_finder
*pf
)
725 Dwarf_Attribute fb_attr
;
729 /* If no real subprogram, find a real one */
730 if (!sp_die
|| dwarf_tag(sp_die
) != DW_TAG_subprogram
) {
731 sp_die
= die_find_realfunc(&pf
->cu_die
, pf
->addr
, &die_mem
);
733 pr_warning("Failed to find probe point in any "
739 /* Get the frame base attribute/ops */
740 dwarf_attr(sp_die
, DW_AT_frame_base
, &fb_attr
);
741 ret
= dwarf_getlocation_addr(&fb_attr
, pf
->addr
, &pf
->fb_ops
, &nops
, 1);
742 if (ret
<= 0 || nops
== 0) {
744 #if _ELFUTILS_PREREQ(0, 142)
745 } else if (nops
== 1 && pf
->fb_ops
[0].atom
== DW_OP_call_frame_cfa
&&
748 if (dwarf_cfi_addrframe(pf
->cfi
, pf
->addr
, &frame
) != 0 ||
749 dwarf_frame_cfa(frame
, &pf
->fb_ops
, &nops
) != 0) {
750 pr_warning("Failed to get call frame on 0x%jx\n",
751 (uintmax_t)pf
->addr
);
757 /* Call finder's callback handler */
758 ret
= pf
->callback(sp_die
, pf
);
760 /* *pf->fb_ops will be cached in libdw. Don't free it. */
766 static int probe_point_line_walker(const char *fname
, int lineno
,
767 Dwarf_Addr addr
, void *data
)
769 struct probe_finder
*pf
= data
;
772 if (lineno
!= pf
->lno
|| strtailcmp(fname
, pf
->fname
) != 0)
776 ret
= call_probe_finder(NULL
, pf
);
778 /* Continue if no error, because the line will be in inline function */
779 return ret
< 0 ? ret
: 0;
782 /* Find probe point from its line number */
783 static int find_probe_point_by_line(struct probe_finder
*pf
)
785 return die_walk_lines(&pf
->cu_die
, probe_point_line_walker
, pf
);
788 /* Find lines which match lazy pattern */
789 static int find_lazy_match_lines(struct list_head
*head
,
790 const char *fname
, const char *pat
)
796 int count
= 0, linenum
= 1;
798 fp
= fopen(fname
, "r");
800 pr_warning("Failed to open %s: %s\n", fname
, strerror(errno
));
804 while ((len
= getline(&line
, &line_len
, fp
)) > 0) {
806 if (line
[len
- 1] == '\n')
807 line
[len
- 1] = '\0';
809 if (strlazymatch(line
, pat
)) {
810 line_list__add_line(head
, linenum
);
822 pr_debug("No matched lines found in %s.\n", fname
);
826 static int probe_point_lazy_walker(const char *fname
, int lineno
,
827 Dwarf_Addr addr
, void *data
)
829 struct probe_finder
*pf
= data
;
832 if (!line_list__has_line(&pf
->lcache
, lineno
) ||
833 strtailcmp(fname
, pf
->fname
) != 0)
836 pr_debug("Probe line found: line:%d addr:0x%llx\n",
837 lineno
, (unsigned long long)addr
);
839 ret
= call_probe_finder(NULL
, pf
);
842 * Continue if no error, because the lazy pattern will match
845 return ret
< 0 ? ret
: 0;
848 /* Find probe points from lazy pattern */
849 static int find_probe_point_lazy(Dwarf_Die
*sp_die
, struct probe_finder
*pf
)
853 if (list_empty(&pf
->lcache
)) {
854 /* Matching lazy line pattern */
855 ret
= find_lazy_match_lines(&pf
->lcache
, pf
->fname
,
856 pf
->pev
->point
.lazy_line
);
861 return die_walk_lines(sp_die
, probe_point_lazy_walker
, pf
);
864 /* Callback parameter with return value */
865 struct dwarf_callback_param
{
870 static int probe_point_inline_cb(Dwarf_Die
*in_die
, void *data
)
872 struct dwarf_callback_param
*param
= data
;
873 struct probe_finder
*pf
= param
->data
;
874 struct perf_probe_point
*pp
= &pf
->pev
->point
;
878 param
->retval
= find_probe_point_lazy(in_die
, pf
);
880 /* Get probe address */
881 if (dwarf_entrypc(in_die
, &addr
) != 0) {
882 pr_warning("Failed to get entry address of %s.\n",
883 dwarf_diename(in_die
));
884 param
->retval
= -ENOENT
;
885 return DWARF_CB_ABORT
;
888 pf
->addr
+= pp
->offset
;
889 pr_debug("found inline addr: 0x%jx\n",
890 (uintmax_t)pf
->addr
);
892 param
->retval
= call_probe_finder(in_die
, pf
);
893 if (param
->retval
< 0)
894 return DWARF_CB_ABORT
;
900 /* Search function from function name */
901 static int probe_point_search_cb(Dwarf_Die
*sp_die
, void *data
)
903 struct dwarf_callback_param
*param
= data
;
904 struct probe_finder
*pf
= param
->data
;
905 struct perf_probe_point
*pp
= &pf
->pev
->point
;
907 /* Check tag and diename */
908 if (dwarf_tag(sp_die
) != DW_TAG_subprogram
||
909 !die_compare_name(sp_die
, pp
->function
))
912 /* Check declared file */
913 if (pp
->file
&& strtailcmp(pp
->file
, dwarf_decl_file(sp_die
)))
916 pf
->fname
= dwarf_decl_file(sp_die
);
917 if (pp
->line
) { /* Function relative line */
918 dwarf_decl_line(sp_die
, &pf
->lno
);
920 param
->retval
= find_probe_point_by_line(pf
);
921 } else if (!dwarf_func_inline(sp_die
)) {
924 param
->retval
= find_probe_point_lazy(sp_die
, pf
);
926 if (dwarf_entrypc(sp_die
, &pf
->addr
) != 0) {
927 pr_warning("Failed to get entry address of "
928 "%s.\n", dwarf_diename(sp_die
));
929 param
->retval
= -ENOENT
;
930 return DWARF_CB_ABORT
;
932 pf
->addr
+= pp
->offset
;
933 /* TODO: Check the address in this function */
934 param
->retval
= call_probe_finder(sp_die
, pf
);
937 struct dwarf_callback_param _param
= {.data
= (void *)pf
,
939 /* Inlined function: search instances */
940 dwarf_func_inline_instances(sp_die
, probe_point_inline_cb
,
942 param
->retval
= _param
.retval
;
945 return DWARF_CB_ABORT
; /* Exit; no same symbol in this CU. */
948 static int find_probe_point_by_func(struct probe_finder
*pf
)
950 struct dwarf_callback_param _param
= {.data
= (void *)pf
,
952 dwarf_getfuncs(&pf
->cu_die
, probe_point_search_cb
, &_param
, 0);
953 return _param
.retval
;
956 struct pubname_callback_param
{
964 static int pubname_search_cb(Dwarf
*dbg
, Dwarf_Global
*gl
, void *data
)
966 struct pubname_callback_param
*param
= data
;
968 if (dwarf_offdie(dbg
, gl
->die_offset
, param
->sp_die
)) {
969 if (dwarf_tag(param
->sp_die
) != DW_TAG_subprogram
)
972 if (die_compare_name(param
->sp_die
, param
->function
)) {
973 if (!dwarf_offdie(dbg
, gl
->cu_offset
, param
->cu_die
))
977 strtailcmp(param
->file
, dwarf_decl_file(param
->sp_die
)))
981 return DWARF_CB_ABORT
;
988 /* Find probe points from debuginfo */
989 static int debuginfo__find_probes(struct debuginfo
*self
,
990 struct probe_finder
*pf
)
992 struct perf_probe_point
*pp
= &pf
->pev
->point
;
998 #if _ELFUTILS_PREREQ(0, 142)
999 /* Get the call frame information from this dwarf */
1000 pf
->cfi
= dwarf_getcfi(self
->dbg
);
1004 line_list__init(&pf
->lcache
);
1006 /* Fastpath: lookup by function name from .debug_pubnames section */
1008 struct pubname_callback_param pubname_param
= {
1009 .function
= pp
->function
,
1011 .cu_die
= &pf
->cu_die
,
1012 .sp_die
= &pf
->sp_die
,
1015 struct dwarf_callback_param probe_param
= {
1019 dwarf_getpubnames(self
->dbg
, pubname_search_cb
,
1021 if (pubname_param
.found
) {
1022 ret
= probe_point_search_cb(&pf
->sp_die
, &probe_param
);
1028 /* Loop on CUs (Compilation Unit) */
1029 while (!dwarf_nextcu(self
->dbg
, off
, &noff
, &cuhl
, NULL
, NULL
, NULL
)) {
1030 /* Get the DIE(Debugging Information Entry) of this CU */
1031 diep
= dwarf_offdie(self
->dbg
, off
+ cuhl
, &pf
->cu_die
);
1035 /* Check if target file is included. */
1037 pf
->fname
= cu_find_realpath(&pf
->cu_die
, pp
->file
);
1041 if (!pp
->file
|| pf
->fname
) {
1043 ret
= find_probe_point_by_func(pf
);
1044 else if (pp
->lazy_line
)
1045 ret
= find_probe_point_lazy(NULL
, pf
);
1048 ret
= find_probe_point_by_line(pf
);
1057 line_list__free(&pf
->lcache
);
1062 /* Add a found probe point into trace event list */
1063 static int add_probe_trace_event(Dwarf_Die
*sp_die
, struct probe_finder
*pf
)
1065 struct trace_event_finder
*tf
=
1066 container_of(pf
, struct trace_event_finder
, pf
);
1067 struct probe_trace_event
*tev
;
1070 /* Check number of tevs */
1071 if (tf
->ntevs
== tf
->max_tevs
) {
1072 pr_warning("Too many( > %d) probe point found.\n",
1076 tev
= &tf
->tevs
[tf
->ntevs
++];
1078 ret
= convert_to_trace_point(sp_die
, pf
->addr
, pf
->pev
->point
.retprobe
,
1083 pr_debug("Probe point found: %s+%lu\n", tev
->point
.symbol
,
1086 /* Find each argument */
1087 tev
->nargs
= pf
->pev
->nargs
;
1088 tev
->args
= zalloc(sizeof(struct probe_trace_arg
) * tev
->nargs
);
1089 if (tev
->args
== NULL
)
1091 for (i
= 0; i
< pf
->pev
->nargs
; i
++) {
1092 pf
->pvar
= &pf
->pev
->args
[i
];
1093 pf
->tvar
= &tev
->args
[i
];
1094 ret
= find_variable(sp_die
, pf
);
1102 /* Find probe_trace_events specified by perf_probe_event from debuginfo */
1103 int debuginfo__find_trace_events(struct debuginfo
*self
,
1104 struct perf_probe_event
*pev
,
1105 struct probe_trace_event
**tevs
, int max_tevs
)
1107 struct trace_event_finder tf
= {
1108 .pf
= {.pev
= pev
, .callback
= add_probe_trace_event
},
1109 .max_tevs
= max_tevs
};
1112 /* Allocate result tevs array */
1113 *tevs
= zalloc(sizeof(struct probe_trace_event
) * max_tevs
);
1120 ret
= debuginfo__find_probes(self
, &tf
.pf
);
1127 return (ret
< 0) ? ret
: tf
.ntevs
;
1130 #define MAX_VAR_LEN 64
1132 /* Collect available variables in this scope */
1133 static int collect_variables_cb(Dwarf_Die
*die_mem
, void *data
)
1135 struct available_var_finder
*af
= data
;
1136 struct variable_list
*vl
;
1137 char buf
[MAX_VAR_LEN
];
1140 vl
= &af
->vls
[af
->nvls
- 1];
1142 tag
= dwarf_tag(die_mem
);
1143 if (tag
== DW_TAG_formal_parameter
||
1144 tag
== DW_TAG_variable
) {
1145 ret
= convert_variable_location(die_mem
, af
->pf
.addr
,
1146 af
->pf
.fb_ops
, NULL
);
1148 ret
= die_get_varname(die_mem
, buf
, MAX_VAR_LEN
);
1149 pr_debug2("Add new var: %s\n", buf
);
1151 strlist__add(vl
->vars
, buf
);
1155 if (af
->child
&& dwarf_haspc(die_mem
, af
->pf
.addr
))
1156 return DIE_FIND_CB_CONTINUE
;
1158 return DIE_FIND_CB_SIBLING
;
1161 /* Add a found vars into available variables list */
1162 static int add_available_vars(Dwarf_Die
*sp_die
, struct probe_finder
*pf
)
1164 struct available_var_finder
*af
=
1165 container_of(pf
, struct available_var_finder
, pf
);
1166 struct variable_list
*vl
;
1167 Dwarf_Die die_mem
, *scopes
= NULL
;
1170 /* Check number of tevs */
1171 if (af
->nvls
== af
->max_vls
) {
1172 pr_warning("Too many( > %d) probe point found.\n", af
->max_vls
);
1175 vl
= &af
->vls
[af
->nvls
++];
1177 ret
= convert_to_trace_point(sp_die
, pf
->addr
, pf
->pev
->point
.retprobe
,
1182 pr_debug("Probe point found: %s+%lu\n", vl
->point
.symbol
,
1185 /* Find local variables */
1186 vl
->vars
= strlist__new(true, NULL
);
1187 if (vl
->vars
== NULL
)
1190 die_find_child(sp_die
, collect_variables_cb
, (void *)af
, &die_mem
);
1192 /* Find external variables */
1195 /* Don't need to search child DIE for externs. */
1197 nscopes
= dwarf_getscopes_die(sp_die
, &scopes
);
1198 while (nscopes
-- > 1)
1199 die_find_child(&scopes
[nscopes
], collect_variables_cb
,
1200 (void *)af
, &die_mem
);
1205 if (strlist__empty(vl
->vars
)) {
1206 strlist__delete(vl
->vars
);
1213 /* Find available variables at given probe point */
1214 int debuginfo__find_available_vars_at(struct debuginfo
*self
,
1215 struct perf_probe_event
*pev
,
1216 struct variable_list
**vls
,
1217 int max_vls
, bool externs
)
1219 struct available_var_finder af
= {
1220 .pf
= {.pev
= pev
, .callback
= add_available_vars
},
1221 .max_vls
= max_vls
, .externs
= externs
};
1224 /* Allocate result vls array */
1225 *vls
= zalloc(sizeof(struct variable_list
) * max_vls
);
1232 ret
= debuginfo__find_probes(self
, &af
.pf
);
1234 /* Free vlist for error */
1236 if (af
.vls
[af
.nvls
].point
.symbol
)
1237 free(af
.vls
[af
.nvls
].point
.symbol
);
1238 if (af
.vls
[af
.nvls
].vars
)
1239 strlist__delete(af
.vls
[af
.nvls
].vars
);
1246 return (ret
< 0) ? ret
: af
.nvls
;
1249 /* Reverse search */
1250 int debuginfo__find_probe_point(struct debuginfo
*self
, unsigned long addr
,
1251 struct perf_probe_point
*ppt
)
1253 Dwarf_Die cudie
, spdie
, indie
;
1254 Dwarf_Addr _addr
, baseaddr
;
1255 const char *fname
= NULL
, *func
= NULL
, *tmp
;
1256 int baseline
= 0, lineno
= 0, ret
= 0;
1258 /* Adjust address with bias */
1262 if (!dwarf_addrdie(self
->dbg
, (Dwarf_Addr
)addr
- self
->bias
, &cudie
)) {
1263 pr_warning("Failed to find debug information for address %lx\n",
1269 /* Find a corresponding line (filename and lineno) */
1270 cu_find_lineinfo(&cudie
, addr
, &fname
, &lineno
);
1271 /* Don't care whether it failed or not */
1273 /* Find a corresponding function (name, baseline and baseaddr) */
1274 if (die_find_realfunc(&cudie
, (Dwarf_Addr
)addr
, &spdie
)) {
1275 /* Get function entry information */
1276 tmp
= dwarf_diename(&spdie
);
1278 dwarf_entrypc(&spdie
, &baseaddr
) != 0 ||
1279 dwarf_decl_line(&spdie
, &baseline
) != 0)
1283 if (addr
== (unsigned long)baseaddr
)
1284 /* Function entry - Relative line number is 0 */
1286 else if (die_find_inlinefunc(&spdie
, (Dwarf_Addr
)addr
,
1288 if (dwarf_entrypc(&indie
, &_addr
) == 0 &&
1291 * addr is at an inline function entry.
1292 * In this case, lineno should be the call-site
1295 lineno
= die_get_call_lineno(&indie
);
1298 * addr is in an inline function body.
1299 * Since lineno points one of the lines
1300 * of the inline function, baseline should
1301 * be the entry line of the inline function.
1303 tmp
= dwarf_diename(&indie
);
1305 dwarf_decl_line(&spdie
, &baseline
) == 0)
1312 /* Make a relative line number or an offset */
1314 ppt
->line
= lineno
- baseline
;
1316 ppt
->offset
= addr
- (unsigned long)baseaddr
;
1318 /* Duplicate strings */
1320 ppt
->function
= strdup(func
);
1321 if (ppt
->function
== NULL
) {
1327 ppt
->file
= strdup(fname
);
1328 if (ppt
->file
== NULL
) {
1329 if (ppt
->function
) {
1330 free(ppt
->function
);
1331 ppt
->function
= NULL
;
1338 if (ret
== 0 && (fname
|| func
))
1339 ret
= 1; /* Found a point */
1343 /* Add a line and store the src path */
1344 static int line_range_add_line(const char *src
, unsigned int lineno
,
1345 struct line_range
*lr
)
1347 /* Copy source path */
1349 lr
->path
= strdup(src
);
1350 if (lr
->path
== NULL
)
1353 return line_list__add_line(&lr
->line_list
, lineno
);
1356 static int line_range_walk_cb(const char *fname
, int lineno
,
1357 Dwarf_Addr addr __used
,
1360 struct line_finder
*lf
= data
;
1362 if ((strtailcmp(fname
, lf
->fname
) != 0) ||
1363 (lf
->lno_s
> lineno
|| lf
->lno_e
< lineno
))
1366 if (line_range_add_line(fname
, lineno
, lf
->lr
) < 0)
1372 /* Find line range from its line number */
1373 static int find_line_range_by_line(Dwarf_Die
*sp_die
, struct line_finder
*lf
)
1377 ret
= die_walk_lines(sp_die
?: &lf
->cu_die
, line_range_walk_cb
, lf
);
1381 if (!list_empty(&lf
->lr
->line_list
))
1382 ret
= lf
->found
= 1;
1384 ret
= 0; /* Lines are not found */
1387 lf
->lr
->path
= NULL
;
1392 static int line_range_inline_cb(Dwarf_Die
*in_die
, void *data
)
1394 struct dwarf_callback_param
*param
= data
;
1396 param
->retval
= find_line_range_by_line(in_die
, param
->data
);
1397 return DWARF_CB_ABORT
; /* No need to find other instances */
1400 /* Search function from function name */
1401 static int line_range_search_cb(Dwarf_Die
*sp_die
, void *data
)
1403 struct dwarf_callback_param
*param
= data
;
1404 struct line_finder
*lf
= param
->data
;
1405 struct line_range
*lr
= lf
->lr
;
1407 /* Check declared file */
1408 if (lr
->file
&& strtailcmp(lr
->file
, dwarf_decl_file(sp_die
)))
1411 if (dwarf_tag(sp_die
) == DW_TAG_subprogram
&&
1412 die_compare_name(sp_die
, lr
->function
)) {
1413 lf
->fname
= dwarf_decl_file(sp_die
);
1414 dwarf_decl_line(sp_die
, &lr
->offset
);
1415 pr_debug("fname: %s, lineno:%d\n", lf
->fname
, lr
->offset
);
1416 lf
->lno_s
= lr
->offset
+ lr
->start
;
1417 if (lf
->lno_s
< 0) /* Overflow */
1418 lf
->lno_s
= INT_MAX
;
1419 lf
->lno_e
= lr
->offset
+ lr
->end
;
1420 if (lf
->lno_e
< 0) /* Overflow */
1421 lf
->lno_e
= INT_MAX
;
1422 pr_debug("New line range: %d to %d\n", lf
->lno_s
, lf
->lno_e
);
1423 lr
->start
= lf
->lno_s
;
1424 lr
->end
= lf
->lno_e
;
1425 if (dwarf_func_inline(sp_die
)) {
1426 struct dwarf_callback_param _param
;
1427 _param
.data
= (void *)lf
;
1429 dwarf_func_inline_instances(sp_die
,
1430 line_range_inline_cb
,
1432 param
->retval
= _param
.retval
;
1434 param
->retval
= find_line_range_by_line(sp_die
, lf
);
1435 return DWARF_CB_ABORT
;
1440 static int find_line_range_by_func(struct line_finder
*lf
)
1442 struct dwarf_callback_param param
= {.data
= (void *)lf
, .retval
= 0};
1443 dwarf_getfuncs(&lf
->cu_die
, line_range_search_cb
, ¶m
, 0);
1444 return param
.retval
;
1447 int debuginfo__find_line_range(struct debuginfo
*self
, struct line_range
*lr
)
1449 struct line_finder lf
= {.lr
= lr
, .found
= 0};
1451 Dwarf_Off off
= 0, noff
;
1454 const char *comp_dir
;
1456 /* Fastpath: lookup by function name from .debug_pubnames section */
1458 struct pubname_callback_param pubname_param
= {
1459 .function
= lr
->function
, .file
= lr
->file
,
1460 .cu_die
= &lf
.cu_die
, .sp_die
= &lf
.sp_die
, .found
= 0};
1461 struct dwarf_callback_param line_range_param
= {
1462 .data
= (void *)&lf
, .retval
= 0};
1464 dwarf_getpubnames(self
->dbg
, pubname_search_cb
,
1466 if (pubname_param
.found
) {
1467 line_range_search_cb(&lf
.sp_die
, &line_range_param
);
1473 /* Loop on CUs (Compilation Unit) */
1474 while (!lf
.found
&& ret
>= 0) {
1475 if (dwarf_nextcu(self
->dbg
, off
, &noff
, &cuhl
,
1476 NULL
, NULL
, NULL
) != 0)
1479 /* Get the DIE(Debugging Information Entry) of this CU */
1480 diep
= dwarf_offdie(self
->dbg
, off
+ cuhl
, &lf
.cu_die
);
1484 /* Check if target file is included. */
1486 lf
.fname
= cu_find_realpath(&lf
.cu_die
, lr
->file
);
1490 if (!lr
->file
|| lf
.fname
) {
1492 ret
= find_line_range_by_func(&lf
);
1494 lf
.lno_s
= lr
->start
;
1496 ret
= find_line_range_by_line(NULL
, &lf
);
1503 /* Store comp_dir */
1505 comp_dir
= cu_get_comp_dir(&lf
.cu_die
);
1507 lr
->comp_dir
= strdup(comp_dir
);
1513 pr_debug("path: %s\n", lr
->path
);
1514 return (ret
< 0) ? ret
: lf
.found
;