linux/tools/perf/util/probe-finder.c

1011 lines
24 KiB
C

/*
* probe-finder.c : C expression to kprobe event converter
*
* Written by Masami Hiramatsu <mhiramat@redhat.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*
*/
#include <sys/utsname.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <errno.h>
#include <stdio.h>
#include <unistd.h>
#include <getopt.h>
#include <stdlib.h>
#include <string.h>
#include <stdarg.h>
#include <ctype.h>
#include "string.h"
#include "event.h"
#include "debug.h"
#include "util.h"
#include "probe-finder.h"
/*
* Generic dwarf analysis helpers
*/
#define X86_32_MAX_REGS 8
const char *x86_32_regs_table[X86_32_MAX_REGS] = {
"%ax",
"%cx",
"%dx",
"%bx",
"$stack", /* Stack address instead of %sp */
"%bp",
"%si",
"%di",
};
#define X86_64_MAX_REGS 16
const char *x86_64_regs_table[X86_64_MAX_REGS] = {
"%ax",
"%dx",
"%cx",
"%bx",
"%si",
"%di",
"%bp",
"%sp",
"%r8",
"%r9",
"%r10",
"%r11",
"%r12",
"%r13",
"%r14",
"%r15",
};
/* TODO: switching by dwarf address size */
#ifdef __x86_64__
#define ARCH_MAX_REGS X86_64_MAX_REGS
#define arch_regs_table x86_64_regs_table
#else
#define ARCH_MAX_REGS X86_32_MAX_REGS
#define arch_regs_table x86_32_regs_table
#endif
/* Return architecture dependent register string (for kprobe-tracer) */
static const char *get_arch_regstr(unsigned int n)
{
return (n <= ARCH_MAX_REGS) ? arch_regs_table[n] : NULL;
}
/*
* Compare the tail of two strings.
* Return 0 if whole of either string is same as another's tail part.
*/
static int strtailcmp(const char *s1, const char *s2)
{
int i1 = strlen(s1);
int i2 = strlen(s2);
while (--i1 >= 0 && --i2 >= 0) {
if (s1[i1] != s2[i2])
return s1[i1] - s2[i2];
}
return 0;
}
/* Line number list operations */
/* Add a line to line number list */
static void line_list__add_line(struct list_head *head, unsigned int line)
{
struct line_node *ln;
struct list_head *p;
/* Reverse search, because new line will be the last one */
list_for_each_entry_reverse(ln, head, list) {
if (ln->line < line) {
p = &ln->list;
goto found;
} else if (ln->line == line) /* Already exist */
return ;
}
/* List is empty, or the smallest entry */
p = head;
found:
pr_debug("line list: add a line %u\n", line);
ln = xzalloc(sizeof(struct line_node));
ln->line = line;
INIT_LIST_HEAD(&ln->list);
list_add(&ln->list, p);
}
/* Check if the line in line number list */
static int line_list__has_line(struct list_head *head, unsigned int line)
{
struct line_node *ln;
/* Reverse search, because new line will be the last one */
list_for_each_entry(ln, head, list)
if (ln->line == line)
return 1;
return 0;
}
/* Init line number list */
static void line_list__init(struct list_head *head)
{
INIT_LIST_HEAD(head);
}
/* Free line number list */
static void line_list__free(struct list_head *head)
{
struct line_node *ln;
while (!list_empty(head)) {
ln = list_first_entry(head, struct line_node, list);
list_del(&ln->list);
free(ln);
}
}
/* Dwarf wrappers */
/* Find the realpath of the target file. */
static const char *cu_find_realpath(Dwarf_Die *cu_die, const char *fname)
{
Dwarf_Files *files;
size_t nfiles, i;
const char *src = NULL;
int ret;
if (!fname)
return NULL;
ret = dwarf_getsrcfiles(cu_die, &files, &nfiles);
if (ret != 0)
return NULL;
for (i = 0; i < nfiles; i++) {
src = dwarf_filesrc(files, i, NULL, NULL);
if (strtailcmp(src, fname) == 0)
break;
}
return src;
}
/* Compare diename and tname */
static bool die_compare_name(Dwarf_Die *dw_die, const char *tname)
{
const char *name;
name = dwarf_diename(dw_die);
DIE_IF(name == NULL);
return strcmp(tname, name);
}
/* Get entry pc(or low pc, 1st entry of ranges) of the die */
static Dwarf_Addr die_get_entrypc(Dwarf_Die *dw_die)
{
Dwarf_Addr epc;
int ret;
ret = dwarf_entrypc(dw_die, &epc);
DIE_IF(ret == -1);
return epc;
}
/* Get type die, but skip qualifiers and typedef */
static Dwarf_Die *die_get_real_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem)
{
Dwarf_Attribute attr;
int tag;
do {
if (dwarf_attr(vr_die, DW_AT_type, &attr) == NULL ||
dwarf_formref_die(&attr, die_mem) == NULL)
return NULL;
tag = dwarf_tag(die_mem);
vr_die = die_mem;
} while (tag == DW_TAG_const_type ||
tag == DW_TAG_restrict_type ||
tag == DW_TAG_volatile_type ||
tag == DW_TAG_shared_type ||
tag == DW_TAG_typedef);
return die_mem;
}
/* Return values for die_find callbacks */
enum {
DIE_FIND_CB_FOUND = 0, /* End of Search */
DIE_FIND_CB_CHILD = 1, /* Search only children */
DIE_FIND_CB_SIBLING = 2, /* Search only siblings */
DIE_FIND_CB_CONTINUE = 3, /* Search children and siblings */
};
/* Search a child die */
static Dwarf_Die *die_find_child(Dwarf_Die *rt_die,
int (*callback)(Dwarf_Die *, void *),
void *data, Dwarf_Die *die_mem)
{
Dwarf_Die child_die;
int ret;
ret = dwarf_child(rt_die, die_mem);
if (ret != 0)
return NULL;
do {
ret = callback(die_mem, data);
if (ret == DIE_FIND_CB_FOUND)
return die_mem;
if ((ret & DIE_FIND_CB_CHILD) &&
die_find_child(die_mem, callback, data, &child_die)) {
memcpy(die_mem, &child_die, sizeof(Dwarf_Die));
return die_mem;
}
} while ((ret & DIE_FIND_CB_SIBLING) &&
dwarf_siblingof(die_mem, die_mem) == 0);
return NULL;
}
struct __addr_die_search_param {
Dwarf_Addr addr;
Dwarf_Die *die_mem;
};
static int __die_search_func_cb(Dwarf_Die *fn_die, void *data)
{
struct __addr_die_search_param *ad = data;
if (dwarf_tag(fn_die) == DW_TAG_subprogram &&
dwarf_haspc(fn_die, ad->addr)) {
memcpy(ad->die_mem, fn_die, sizeof(Dwarf_Die));
return DWARF_CB_ABORT;
}
return DWARF_CB_OK;
}
/* Search a real subprogram including this line, */
static Dwarf_Die *die_find_real_subprogram(Dwarf_Die *cu_die, Dwarf_Addr addr,
Dwarf_Die *die_mem)
{
struct __addr_die_search_param ad;
ad.addr = addr;
ad.die_mem = die_mem;
/* dwarf_getscopes can't find subprogram. */
if (!dwarf_getfuncs(cu_die, __die_search_func_cb, &ad, 0))
return NULL;
else
return die_mem;
}
/* die_find callback for inline function search */
static int __die_find_inline_cb(Dwarf_Die *die_mem, void *data)
{
Dwarf_Addr *addr = data;
if (dwarf_tag(die_mem) == DW_TAG_inlined_subroutine &&
dwarf_haspc(die_mem, *addr))
return DIE_FIND_CB_FOUND;
return DIE_FIND_CB_CONTINUE;
}
/* Similar to dwarf_getfuncs, but returns inlined_subroutine if exists. */
static Dwarf_Die *die_find_inlinefunc(Dwarf_Die *sp_die, Dwarf_Addr addr,
Dwarf_Die *die_mem)
{
return die_find_child(sp_die, __die_find_inline_cb, &addr, die_mem);
}
static int __die_find_variable_cb(Dwarf_Die *die_mem, void *data)
{
const char *name = data;
int tag;
tag = dwarf_tag(die_mem);
if ((tag == DW_TAG_formal_parameter ||
tag == DW_TAG_variable) &&
(die_compare_name(die_mem, name) == 0))
return DIE_FIND_CB_FOUND;
return DIE_FIND_CB_CONTINUE;
}
/* Find a variable called 'name' */
static Dwarf_Die *die_find_variable(Dwarf_Die *sp_die, const char *name,
Dwarf_Die *die_mem)
{
return die_find_child(sp_die, __die_find_variable_cb, (void *)name,
die_mem);
}
static int __die_find_member_cb(Dwarf_Die *die_mem, void *data)
{
const char *name = data;
if ((dwarf_tag(die_mem) == DW_TAG_member) &&
(die_compare_name(die_mem, name) == 0))
return DIE_FIND_CB_FOUND;
return DIE_FIND_CB_SIBLING;
}
/* Find a member called 'name' */
static Dwarf_Die *die_find_member(Dwarf_Die *st_die, const char *name,
Dwarf_Die *die_mem)
{
return die_find_child(st_die, __die_find_member_cb, (void *)name,
die_mem);
}
/*
* Probe finder related functions
*/
/* Show a location */
static void convert_location(Dwarf_Op *op, struct probe_finder *pf)
{
unsigned int regn;
Dwarf_Word offs = 0;
bool ref = false;
const char *regs;
struct kprobe_trace_arg *tvar = pf->tvar;
/* TODO: support CFA */
/* If this is based on frame buffer, set the offset */
if (op->atom == DW_OP_fbreg) {
if (pf->fb_ops == NULL)
die("The attribute of frame base is not supported.\n");
ref = true;
offs = op->number;
op = &pf->fb_ops[0];
}
if (op->atom >= DW_OP_breg0 && op->atom <= DW_OP_breg31) {
regn = op->atom - DW_OP_breg0;
offs += op->number;
ref = true;
} else if (op->atom >= DW_OP_reg0 && op->atom <= DW_OP_reg31) {
regn = op->atom - DW_OP_reg0;
} else if (op->atom == DW_OP_bregx) {
regn = op->number;
offs += op->number2;
ref = true;
} else if (op->atom == DW_OP_regx) {
regn = op->number;
} else
die("DW_OP %d is not supported.", op->atom);
regs = get_arch_regstr(regn);
if (!regs)
die("%u exceeds max register number.", regn);
tvar->value = xstrdup(regs);
if (ref) {
tvar->ref = xzalloc(sizeof(struct kprobe_trace_arg_ref));
tvar->ref->offset = (long)offs;
}
}
static void convert_variable_fields(Dwarf_Die *vr_die, const char *varname,
struct perf_probe_arg_field *field,
struct kprobe_trace_arg_ref **ref_ptr)
{
struct kprobe_trace_arg_ref *ref = *ref_ptr;
Dwarf_Attribute attr;
Dwarf_Die member;
Dwarf_Die type;
Dwarf_Word offs;
pr_debug("converting %s in %s\n", field->name, varname);
if (die_get_real_type(vr_die, &type) == NULL)
die("Failed to get a type information of %s.", varname);
/* Check the pointer and dereference */
if (dwarf_tag(&type) == DW_TAG_pointer_type) {
if (!field->ref)
die("Semantic error: %s must be referred by '->'",
field->name);
/* Get the type pointed by this pointer */
if (die_get_real_type(&type, &type) == NULL)
die("Failed to get a type information of %s.", varname);
ref = xzalloc(sizeof(struct kprobe_trace_arg_ref));
if (*ref_ptr)
(*ref_ptr)->next = ref;
else
*ref_ptr = ref;
} else {
if (field->ref)
die("Semantic error: %s must be referred by '.'",
field->name);
if (!ref)
die("Structure on a register is not supported yet.");
}
/* Verify it is a data structure */
if (dwarf_tag(&type) != DW_TAG_structure_type)
die("%s is not a data structure.", varname);
if (die_find_member(&type, field->name, &member) == NULL)
die("%s(tyep:%s) has no member %s.", varname,
dwarf_diename(&type), field->name);
/* Get the offset of the field */
if (dwarf_attr(&member, DW_AT_data_member_location, &attr) == NULL ||
dwarf_formudata(&attr, &offs) != 0)
die("Failed to get the offset of %s.", field->name);
ref->offset += (long)offs;
/* Converting next field */
if (field->next)
convert_variable_fields(&member, field->name, field->next,
&ref);
}
/* Show a variables in kprobe event format */
static void convert_variable(Dwarf_Die *vr_die, struct probe_finder *pf)
{
Dwarf_Attribute attr;
Dwarf_Op *expr;
size_t nexpr;
int ret;
if (dwarf_attr(vr_die, DW_AT_location, &attr) == NULL)
goto error;
/* TODO: handle more than 1 exprs */
ret = dwarf_getlocation_addr(&attr, pf->addr, &expr, &nexpr, 1);
if (ret <= 0 || nexpr == 0)
goto error;
convert_location(expr, pf);
if (pf->pvar->field)
convert_variable_fields(vr_die, pf->pvar->name,
pf->pvar->field, &pf->tvar->ref);
/* *expr will be cached in libdw. Don't free it. */
return ;
error:
/* TODO: Support const_value */
die("Failed to find the location of %s at this address.\n"
" Perhaps, it has been optimized out.", pf->pvar->name);
}
/* Find a variable in a subprogram die */
static void find_variable(Dwarf_Die *sp_die, struct probe_finder *pf)
{
Dwarf_Die vr_die;
char buf[128];
/* TODO: Support struct members and arrays */
if (!is_c_varname(pf->pvar->name)) {
/* Copy raw parameters */
pf->tvar->value = xstrdup(pf->pvar->name);
} else {
synthesize_perf_probe_arg(pf->pvar, buf, 128);
pf->tvar->name = xstrdup(buf);
pr_debug("Searching '%s' variable in context.\n",
pf->pvar->name);
/* Search child die for local variables and parameters. */
if (!die_find_variable(sp_die, pf->pvar->name, &vr_die))
die("Failed to find '%s' in this function.",
pf->pvar->name);
convert_variable(&vr_die, pf);
}
}
/* Show a probe point to output buffer */
static void convert_probe_point(Dwarf_Die *sp_die, struct probe_finder *pf)
{
struct kprobe_trace_event *tev;
Dwarf_Addr eaddr;
Dwarf_Die die_mem;
const char *name;
int ret, i;
Dwarf_Attribute fb_attr;
size_t nops;
if (pf->ntevs == MAX_PROBES)
die("Too many( > %d) probe point found.\n", MAX_PROBES);
tev = &pf->tevs[pf->ntevs++];
/* If no real subprogram, find a real one */
if (!sp_die || dwarf_tag(sp_die) != DW_TAG_subprogram) {
sp_die = die_find_real_subprogram(&pf->cu_die,
pf->addr, &die_mem);
if (!sp_die)
die("Probe point is not found in subprograms.");
}
/* Copy the name of probe point */
name = dwarf_diename(sp_die);
if (name) {
dwarf_entrypc(sp_die, &eaddr);
tev->point.symbol = xstrdup(name);
tev->point.offset = (unsigned long)(pf->addr - eaddr);
} else
/* This function has no name. */
tev->point.offset = (unsigned long)pf->addr;
pr_debug("Probe point found: %s+%lu\n", tev->point.symbol,
tev->point.offset);
/* Get the frame base attribute/ops */
dwarf_attr(sp_die, DW_AT_frame_base, &fb_attr);
ret = dwarf_getlocation_addr(&fb_attr, pf->addr, &pf->fb_ops, &nops, 1);
if (ret <= 0 || nops == 0)
pf->fb_ops = NULL;
/* Find each argument */
/* TODO: use dwarf_cfi_addrframe */
tev->nargs = pf->pev->nargs;
tev->args = xzalloc(sizeof(struct kprobe_trace_arg) * tev->nargs);
for (i = 0; i < pf->pev->nargs; i++) {
pf->pvar = &pf->pev->args[i];
pf->tvar = &tev->args[i];
find_variable(sp_die, pf);
}
/* *pf->fb_ops will be cached in libdw. Don't free it. */
pf->fb_ops = NULL;
}
/* Find probe point from its line number */
static void find_probe_point_by_line(struct probe_finder *pf)
{
Dwarf_Lines *lines;
Dwarf_Line *line;
size_t nlines, i;
Dwarf_Addr addr;
int lineno;
int ret;
ret = dwarf_getsrclines(&pf->cu_die, &lines, &nlines);
DIE_IF(ret != 0);
for (i = 0; i < nlines; i++) {
line = dwarf_onesrcline(lines, i);
dwarf_lineno(line, &lineno);
if (lineno != pf->lno)
continue;
/* TODO: Get fileno from line, but how? */
if (strtailcmp(dwarf_linesrc(line, NULL, NULL), pf->fname) != 0)
continue;
ret = dwarf_lineaddr(line, &addr);
DIE_IF(ret != 0);
pr_debug("Probe line found: line[%d]:%d addr:0x%jx\n",
(int)i, lineno, (uintmax_t)addr);
pf->addr = addr;
convert_probe_point(NULL, pf);
/* Continuing, because target line might be inlined. */
}
}
/* Find lines which match lazy pattern */
static int find_lazy_match_lines(struct list_head *head,
const char *fname, const char *pat)
{
char *fbuf, *p1, *p2;
int fd, line, nlines = 0;
struct stat st;
fd = open(fname, O_RDONLY);
if (fd < 0)
die("failed to open %s", fname);
DIE_IF(fstat(fd, &st) < 0);
fbuf = xmalloc(st.st_size + 2);
DIE_IF(read(fd, fbuf, st.st_size) < 0);
close(fd);
fbuf[st.st_size] = '\n'; /* Dummy line */
fbuf[st.st_size + 1] = '\0';
p1 = fbuf;
line = 1;
while ((p2 = strchr(p1, '\n')) != NULL) {
*p2 = '\0';
if (strlazymatch(p1, pat)) {
line_list__add_line(head, line);
nlines++;
}
line++;
p1 = p2 + 1;
}
free(fbuf);
return nlines;
}
/* Find probe points from lazy pattern */
static void find_probe_point_lazy(Dwarf_Die *sp_die, struct probe_finder *pf)
{
Dwarf_Lines *lines;
Dwarf_Line *line;
size_t nlines, i;
Dwarf_Addr addr;
Dwarf_Die die_mem;
int lineno;
int ret;
if (list_empty(&pf->lcache)) {
/* Matching lazy line pattern */
ret = find_lazy_match_lines(&pf->lcache, pf->fname,
pf->pev->point.lazy_line);
if (ret <= 0)
die("No matched lines found in %s.", pf->fname);
}
ret = dwarf_getsrclines(&pf->cu_die, &lines, &nlines);
DIE_IF(ret != 0);
for (i = 0; i < nlines; i++) {
line = dwarf_onesrcline(lines, i);
dwarf_lineno(line, &lineno);
if (!line_list__has_line(&pf->lcache, lineno))
continue;
/* TODO: Get fileno from line, but how? */
if (strtailcmp(dwarf_linesrc(line, NULL, NULL), pf->fname) != 0)
continue;
ret = dwarf_lineaddr(line, &addr);
DIE_IF(ret != 0);
if (sp_die) {
/* Address filtering 1: does sp_die include addr? */
if (!dwarf_haspc(sp_die, addr))
continue;
/* Address filtering 2: No child include addr? */
if (die_find_inlinefunc(sp_die, addr, &die_mem))
continue;
}
pr_debug("Probe line found: line[%d]:%d addr:0x%llx\n",
(int)i, lineno, (unsigned long long)addr);
pf->addr = addr;
convert_probe_point(sp_die, pf);
/* Continuing, because target line might be inlined. */
}
/* TODO: deallocate lines, but how? */
}
static int probe_point_inline_cb(Dwarf_Die *in_die, void *data)
{
struct probe_finder *pf = (struct probe_finder *)data;
struct perf_probe_point *pp = &pf->pev->point;
if (pp->lazy_line)
find_probe_point_lazy(in_die, pf);
else {
/* Get probe address */
pf->addr = die_get_entrypc(in_die);
pf->addr += pp->offset;
pr_debug("found inline addr: 0x%jx\n",
(uintmax_t)pf->addr);
convert_probe_point(in_die, pf);
}
return DWARF_CB_OK;
}
/* Search function from function name */
static int probe_point_search_cb(Dwarf_Die *sp_die, void *data)
{
struct probe_finder *pf = (struct probe_finder *)data;
struct perf_probe_point *pp = &pf->pev->point;
/* Check tag and diename */
if (dwarf_tag(sp_die) != DW_TAG_subprogram ||
die_compare_name(sp_die, pp->function) != 0)
return 0;
pf->fname = dwarf_decl_file(sp_die);
if (pp->line) { /* Function relative line */
dwarf_decl_line(sp_die, &pf->lno);
pf->lno += pp->line;
find_probe_point_by_line(pf);
} else if (!dwarf_func_inline(sp_die)) {
/* Real function */
if (pp->lazy_line)
find_probe_point_lazy(sp_die, pf);
else {
pf->addr = die_get_entrypc(sp_die);
pf->addr += pp->offset;
/* TODO: Check the address in this function */
convert_probe_point(sp_die, pf);
}
} else
/* Inlined function: search instances */
dwarf_func_inline_instances(sp_die, probe_point_inline_cb, pf);
return 1; /* Exit; no same symbol in this CU. */
}
static void find_probe_point_by_func(struct probe_finder *pf)
{
dwarf_getfuncs(&pf->cu_die, probe_point_search_cb, pf, 0);
}
/* Find kprobe_trace_events specified by perf_probe_event from debuginfo */
int find_kprobe_trace_events(int fd, struct perf_probe_event *pev,
struct kprobe_trace_event **tevs)
{
struct probe_finder pf = {.pev = pev};
struct perf_probe_point *pp = &pev->point;
Dwarf_Off off, noff;
size_t cuhl;
Dwarf_Die *diep;
Dwarf *dbg;
pf.tevs = xzalloc(sizeof(struct kprobe_trace_event) * MAX_PROBES);
*tevs = pf.tevs;
pf.ntevs = 0;
dbg = dwarf_begin(fd, DWARF_C_READ);
if (!dbg)
return -ENOENT;
off = 0;
line_list__init(&pf.lcache);
/* Loop on CUs (Compilation Unit) */
while (!dwarf_nextcu(dbg, off, &noff, &cuhl, NULL, NULL, NULL)) {
/* Get the DIE(Debugging Information Entry) of this CU */
diep = dwarf_offdie(dbg, off + cuhl, &pf.cu_die);
if (!diep)
continue;
/* Check if target file is included. */
if (pp->file)
pf.fname = cu_find_realpath(&pf.cu_die, pp->file);
else
pf.fname = NULL;
if (!pp->file || pf.fname) {
if (pp->function)
find_probe_point_by_func(&pf);
else if (pp->lazy_line)
find_probe_point_lazy(NULL, &pf);
else {
pf.lno = pp->line;
find_probe_point_by_line(&pf);
}
}
off = noff;
}
line_list__free(&pf.lcache);
dwarf_end(dbg);
return pf.ntevs;
}
/* Reverse search */
int find_perf_probe_point(int fd, unsigned long addr,
struct perf_probe_point *ppt)
{
Dwarf_Die cudie, spdie, indie;
Dwarf *dbg;
Dwarf_Line *line;
Dwarf_Addr laddr, eaddr;
const char *tmp;
int lineno, ret = 0;
dbg = dwarf_begin(fd, DWARF_C_READ);
if (!dbg)
return -ENOENT;
/* Find cu die */
if (!dwarf_addrdie(dbg, (Dwarf_Addr)addr, &cudie))
return -EINVAL;
/* Find a corresponding line */
line = dwarf_getsrc_die(&cudie, (Dwarf_Addr)addr);
if (line) {
dwarf_lineaddr(line, &laddr);
if ((Dwarf_Addr)addr == laddr) {
dwarf_lineno(line, &lineno);
ppt->line = lineno;
tmp = dwarf_linesrc(line, NULL, NULL);
DIE_IF(!tmp);
ppt->file = xstrdup(tmp);
ret = 1;
}
}
/* Find a corresponding function */
if (die_find_real_subprogram(&cudie, (Dwarf_Addr)addr, &spdie)) {
tmp = dwarf_diename(&spdie);
if (!tmp)
goto end;
dwarf_entrypc(&spdie, &eaddr);
if (!lineno) {
/* We don't have a line number, let's use offset */
ppt->function = xstrdup(tmp);
ppt->offset = addr - (unsigned long)eaddr;
ret = 1;
goto end;
}
if (die_find_inlinefunc(&spdie, (Dwarf_Addr)addr, &indie)) {
/* addr in an inline function */
tmp = dwarf_diename(&indie);
if (!tmp)
goto end;
dwarf_decl_line(&indie, &lineno);
} else {
if (eaddr == addr) /* No offset: function entry */
lineno = ppt->line;
else
dwarf_decl_line(&spdie, &lineno);
}
ppt->function = xstrdup(tmp);
ppt->line -= lineno; /* Make a relative line number */
}
end:
dwarf_end(dbg);
return ret;
}
/* Find line range from its line number */
static void find_line_range_by_line(Dwarf_Die *sp_die, struct line_finder *lf)
{
Dwarf_Lines *lines;
Dwarf_Line *line;
size_t nlines, i;
Dwarf_Addr addr;
int lineno;
int ret;
const char *src;
Dwarf_Die die_mem;
line_list__init(&lf->lr->line_list);
ret = dwarf_getsrclines(&lf->cu_die, &lines, &nlines);
DIE_IF(ret != 0);
for (i = 0; i < nlines; i++) {
line = dwarf_onesrcline(lines, i);
ret = dwarf_lineno(line, &lineno);
DIE_IF(ret != 0);
if (lf->lno_s > lineno || lf->lno_e < lineno)
continue;
if (sp_die) {
/* Address filtering 1: does sp_die include addr? */
ret = dwarf_lineaddr(line, &addr);
DIE_IF(ret != 0);
if (!dwarf_haspc(sp_die, addr))
continue;
/* Address filtering 2: No child include addr? */
if (die_find_inlinefunc(sp_die, addr, &die_mem))
continue;
}
/* TODO: Get fileno from line, but how? */
src = dwarf_linesrc(line, NULL, NULL);
if (strtailcmp(src, lf->fname) != 0)
continue;
/* Copy real path */
if (!lf->lr->path)
lf->lr->path = xstrdup(src);
line_list__add_line(&lf->lr->line_list, (unsigned int)lineno);
}
/* Update status */
if (!list_empty(&lf->lr->line_list))
lf->found = 1;
else {
free(lf->lr->path);
lf->lr->path = NULL;
}
}
static int line_range_inline_cb(Dwarf_Die *in_die, void *data)
{
find_line_range_by_line(in_die, (struct line_finder *)data);
return DWARF_CB_ABORT; /* No need to find other instances */
}
/* Search function from function name */
static int line_range_search_cb(Dwarf_Die *sp_die, void *data)
{
struct line_finder *lf = (struct line_finder *)data;
struct line_range *lr = lf->lr;
if (dwarf_tag(sp_die) == DW_TAG_subprogram &&
die_compare_name(sp_die, lr->function) == 0) {
lf->fname = dwarf_decl_file(sp_die);
dwarf_decl_line(sp_die, &lr->offset);
pr_debug("fname: %s, lineno:%d\n", lf->fname, lr->offset);
lf->lno_s = lr->offset + lr->start;
if (!lr->end)
lf->lno_e = INT_MAX;
else
lf->lno_e = lr->offset + lr->end;
lr->start = lf->lno_s;
lr->end = lf->lno_e;
if (dwarf_func_inline(sp_die))
dwarf_func_inline_instances(sp_die,
line_range_inline_cb, lf);
else
find_line_range_by_line(sp_die, lf);
return 1;
}
return 0;
}
static void find_line_range_by_func(struct line_finder *lf)
{
dwarf_getfuncs(&lf->cu_die, line_range_search_cb, lf, 0);
}
int find_line_range(int fd, struct line_range *lr)
{
struct line_finder lf = {.lr = lr, .found = 0};
int ret;
Dwarf_Off off = 0, noff;
size_t cuhl;
Dwarf_Die *diep;
Dwarf *dbg;
dbg = dwarf_begin(fd, DWARF_C_READ);
if (!dbg)
return -ENOENT;
/* Loop on CUs (Compilation Unit) */
while (!lf.found) {
ret = dwarf_nextcu(dbg, off, &noff, &cuhl, NULL, NULL, NULL);
if (ret != 0)
break;
/* Get the DIE(Debugging Information Entry) of this CU */
diep = dwarf_offdie(dbg, off + cuhl, &lf.cu_die);
if (!diep)
continue;
/* Check if target file is included. */
if (lr->file)
lf.fname = cu_find_realpath(&lf.cu_die, lr->file);
else
lf.fname = 0;
if (!lr->file || lf.fname) {
if (lr->function)
find_line_range_by_func(&lf);
else {
lf.lno_s = lr->start;
if (!lr->end)
lf.lno_e = INT_MAX;
else
lf.lno_e = lr->end;
find_line_range_by_line(NULL, &lf);
}
}
off = noff;
}
pr_debug("path: %lx\n", (unsigned long)lr->path);
dwarf_end(dbg);
return lf.found;
}