1 files changed, 829 insertions, 0 deletions

diff --git a/tools/perf/util/probe-finder.c b/tools/perf/util/probe-finder.c
new file mode 100644
index 000000000000..c171a243d05b
--- /dev/null
+++ b/tools/perf/util/probe-finder.c
@@ -0,0 +1,829 @@
+/*
+ * 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 = zalloc(sizeof(struct line_node));
+        DIE_IF(ln == NULL);
+        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;
+}
+
+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_get_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;
+}
+
+/* Similar to dwarf_getfuncs, but returns inlined_subroutine if exists. */
+static Dwarf_Die *die_get_inlinefunc(Dwarf_Die *sp_die, Dwarf_Addr addr,
+                                     Dwarf_Die *die_mem)
+{
+        Dwarf_Die child_die;
+        int ret;
+
+        ret = dwarf_child(sp_die, die_mem);
+        if (ret != 0)
+                return NULL;
+
+        do {
+                if (dwarf_tag(die_mem) == DW_TAG_inlined_subroutine &&
+                    dwarf_haspc(die_mem, addr))
+                        return die_mem;
+
+                if (die_get_inlinefunc(die_mem, addr, &child_die)) {
+                        memcpy(die_mem, &child_die, sizeof(Dwarf_Die));
+                        return die_mem;
+                }
+        } while (dwarf_siblingof(die_mem, die_mem) == 0);
+
+        return NULL;
+}
+
+/* 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 a variable die */
+static Dwarf_Die *die_find_variable(Dwarf_Die *sp_die, const char *name,
+                                    Dwarf_Die *die_mem)
+{
+        Dwarf_Die child_die;
+        int tag;
+        int ret;
+
+        ret = dwarf_child(sp_die, die_mem);
+        if (ret != 0)
+                return NULL;
+
+        do {
+                tag = dwarf_tag(die_mem);
+                if ((tag == DW_TAG_formal_parameter ||
+                     tag == DW_TAG_variable) &&
+                    (die_compare_name(die_mem, name) == 0))
+                        return die_mem;
+
+                if (die_find_variable(die_mem, name, &child_die)) {
+                        memcpy(die_mem, &child_die, sizeof(Dwarf_Die));
+                        return die_mem;
+                }
+        } while (dwarf_siblingof(die_mem, die_mem) == 0);
+
+        return NULL;
+}
+
+/*
+ * Probe finder related functions
+ */
+
+/* Show a location */
+static void show_location(Dwarf_Op *op, struct probe_finder *pf)
+{
+        unsigned int regn;
+        Dwarf_Word offs = 0;
+        int deref = 0, ret;
+        const char *regs;
+
+        /* 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");
+                deref = 1;
+                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;
+                deref = 1;
+        } 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;
+                deref = 1;
+        } 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);
+
+        if (deref)
+                ret = snprintf(pf->buf, pf->len, " %s=%+jd(%s)",
+                               pf->var, (intmax_t)offs, regs);
+        else
+                ret = snprintf(pf->buf, pf->len, " %s=%s", pf->var, regs);
+        DIE_IF(ret < 0);
+        DIE_IF(ret >= pf->len);
+}
+
+/* Show a variables in kprobe event format */
+static void show_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;
+
+        show_location(expr, pf);
+        /* *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->var);
+}
+
+/* Find a variable in a subprogram die */
+static void find_variable(Dwarf_Die *sp_die, struct probe_finder *pf)
+{
+        int ret;
+        Dwarf_Die vr_die;
+
+        /* TODO: Support struct members and arrays */
+        if (!is_c_varname(pf->var)) {
+                /* Output raw parameters */
+                ret = snprintf(pf->buf, pf->len, " %s", pf->var);
+                DIE_IF(ret < 0);
+                DIE_IF(ret >= pf->len);
+                return ;
+        }
+
+        pr_debug("Searching '%s' variable in context.\n", pf->var);
+        /* Search child die for local variables and parameters. */
+        if (!die_find_variable(sp_die, pf->var, &vr_die))
+                die("Failed to find '%s' in this function.", pf->var);
+
+        show_variable(&vr_die, pf);
+}
+
+/* Show a probe point to output buffer */
+static void show_probe_point(Dwarf_Die *sp_die, struct probe_finder *pf)
+{
+        struct probe_point *pp = pf->pp;
+        Dwarf_Addr eaddr;
+        Dwarf_Die die_mem;
+        const char *name;
+        char tmp[MAX_PROBE_BUFFER];
+        int ret, i, len;
+        Dwarf_Attribute fb_attr;
+        size_t nops;
+
+        /* If no real subprogram, find a real one */
+        if (!sp_die || dwarf_tag(sp_die) != DW_TAG_subprogram) {
+                sp_die = die_get_real_subprogram(&pf->cu_die,
+                                                 pf->addr, &die_mem);
+                if (!sp_die)
+                        die("Probe point is not found in subprograms.");
+        }
+
+        /* Output name of probe point */
+        name = dwarf_diename(sp_die);
+        if (name) {
+                dwarf_entrypc(sp_die, &eaddr);
+                ret = snprintf(tmp, MAX_PROBE_BUFFER, "%s+%lu", name,
+                                (unsigned long)(pf->addr - eaddr));
+                /* Copy the function name if possible */
+                if (!pp->function) {
+                        pp->function = strdup(name);
+                        pp->offset = (size_t)(pf->addr - eaddr);
+                }
+        } else {
+                /* This function has no name. */
+                ret = snprintf(tmp, MAX_PROBE_BUFFER, "0x%jx",
+                               (uintmax_t)pf->addr);
+                if (!pp->function) {
+                        /* TODO: Use _stext */
+                        pp->function = strdup("");
+                        pp->offset = (size_t)pf->addr;
+                }
+        }
+        DIE_IF(ret < 0);
+        DIE_IF(ret >= MAX_PROBE_BUFFER);
+        len = ret;
+        pr_debug("Probe point found: %s\n", tmp);
+
+        /* 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 */
+        for (i = 0; i < pp->nr_args; i++) {
+                pf->var = pp->args[i];
+                pf->buf = &tmp[len];
+                pf->len = MAX_PROBE_BUFFER - len;
+                find_variable(sp_die, pf);
+                len += strlen(pf->buf);
+        }
+
+        /* *pf->fb_ops will be cached in libdw. Don't free it. */
+        pf->fb_ops = NULL;
+
+        if (pp->found == MAX_PROBES)
+                die("Too many( > %d) probe point found.\n", MAX_PROBES);
+
+        pp->probes[pp->found] = strdup(tmp);
+        pp->found++;
+}
+
+/* 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;
+
+                show_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 = malloc(st.st_size + 2);
+        DIE_IF(fbuf == NULL);
+        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->pp->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_get_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;
+
+                show_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 probe_point *pp = pf->pp;
+
+        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);
+
+                show_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 probe_point *pp = pf->pp;
+
+        /* 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 */
+                        show_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 a probe point */
+int find_probe_point(int fd, struct probe_point *pp)
+{
+        struct probe_finder pf = {.pp = pp};
+        Dwarf_Off off, noff;
+        size_t cuhl;
+        Dwarf_Die *diep;
+        Dwarf *dbg;
+
+        dbg = dwarf_begin(fd, DWARF_C_READ);
+        if (!dbg)
+                return -ENOENT;
+
+        pp->found = 0;
+        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 pp->found;
+}
+
+/* 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_get_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 = strdup(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;
+}
+