perf probe: Remove die() from probe-finder code
authorMasami Hiramatsu <mhiramat@redhat.com>
Mon, 12 Apr 2010 17:17:35 +0000 (13:17 -0400)
committerArnaldo Carvalho de Melo <acme@redhat.com>
Wed, 14 Apr 2010 20:28:30 +0000 (17:28 -0300)
Remove die() and DIE_IF() code from util/probe-finder.c since
these 'sudden death' in utility functions make reusing it from
other code (especially tui/gui) difficult.

Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <20100412171735.3790.88853.stgit@localhost6.localdomain6>
Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
tools/perf/util/probe-event.c
tools/perf/util/probe-finder.c

index bef280527e60d334dacd28aeae64cbb98fa1fac7..7893b3207dbec2b28191259cbbecb5a28d50d511 100644 (file)
@@ -151,10 +151,10 @@ static int try_to_find_kprobe_trace_events(struct perf_probe_event *pev,
 
        /* Error path */
        if (need_dwarf) {
-               if (ntevs == -ENOENT)
+               if (ntevs == -EBADF)
                        pr_warning("No dwarf info found in the vmlinux - "
                                "please rebuild with CONFIG_DEBUG_INFO=y.\n");
-               die("Could not analyze debuginfo.");
+               die("Failed to analyze debuginfo.");
        }
        pr_debug("An error occurred in debuginfo analysis."
                 " Try to use symbols.\n");
index 1f4528555d4209ed7a065b1db06487fa4d6d998d..54daa91e901d68117c911591bb1c30f2354ad179 100644 (file)
@@ -196,19 +196,7 @@ 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;
+       return name ? strcmp(tname, name) : -1;
 }
 
 /* Get type die, but skip qualifiers and typedef */
@@ -390,7 +378,7 @@ static Dwarf_Die *die_find_member(Dwarf_Die *st_die, const char *name,
  */
 
 /* Show a location */
-static void convert_location(Dwarf_Op *op, struct probe_finder *pf)
+static int convert_location(Dwarf_Op *op, struct probe_finder *pf)
 {
        unsigned int regn;
        Dwarf_Word offs = 0;
@@ -400,8 +388,11 @@ static void convert_location(Dwarf_Op *op, struct probe_finder *pf)
 
        /* 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");
+               if (pf->fb_ops == NULL) {
+                       pr_warning("The attribute of frame base is not "
+                                  "supported.\n");
+                       return -ENOTSUP;
+               }
                ref = true;
                offs = op->number;
                op = &pf->fb_ops[0];
@@ -419,50 +410,63 @@ static void convert_location(Dwarf_Op *op, struct probe_finder *pf)
                ref = true;
        } else if (op->atom == DW_OP_regx) {
                regn = op->number;
-       } else
-               die("DW_OP %d is not supported.", op->atom);
+       } else {
+               pr_warning("DW_OP %x is not supported.\n", op->atom);
+               return -ENOTSUP;
+       }
 
        regs = get_arch_regstr(regn);
-       if (!regs)
-               die("%u exceeds max register number.", regn);
+       if (!regs) {
+               pr_warning("%u exceeds max register number.\n", regn);
+               return -ERANGE;
+       }
 
        tvar->value = xstrdup(regs);
        if (ref) {
                tvar->ref = xzalloc(sizeof(struct kprobe_trace_arg_ref));
                tvar->ref->offset = (long)offs;
        }
+       return 0;
 }
 
-static void convert_variable_type(Dwarf_Die *vr_die,
-                                 struct kprobe_trace_arg *targ)
+static int convert_variable_type(Dwarf_Die *vr_die,
+                                struct kprobe_trace_arg *targ)
 {
        Dwarf_Die type;
        char buf[16];
        int ret;
 
-       if (die_get_real_type(vr_die, &type) == NULL)
-               die("Failed to get a type information of %s.",
-                   dwarf_diename(vr_die));
+       if (die_get_real_type(vr_die, &type) == NULL) {
+               pr_warning("Failed to get a type information of %s.\n",
+                          dwarf_diename(vr_die));
+               return -ENOENT;
+       }
 
        ret = die_get_byte_size(&type) * 8;
        if (ret) {
                /* Check the bitwidth */
                if (ret > MAX_BASIC_TYPE_BITS) {
-                       pr_warning("  Warning: %s exceeds max-bitwidth."
-                                  " Cut down to %d bits.\n",
-                                  dwarf_diename(&type), MAX_BASIC_TYPE_BITS);
+                       pr_info("%s exceeds max-bitwidth."
+                               " Cut down to %d bits.\n",
+                               dwarf_diename(&type), MAX_BASIC_TYPE_BITS);
                        ret = MAX_BASIC_TYPE_BITS;
                }
 
                ret = snprintf(buf, 16, "%c%d",
                               die_is_signed_type(&type) ? 's' : 'u', ret);
-               if (ret < 0 || ret >= 16)
-                       die("Failed to convert variable type.");
+               if (ret < 0 || ret >= 16) {
+                       if (ret >= 16)
+                               ret = -E2BIG;
+                       pr_warning("Failed to convert variable type: %s\n",
+                                  strerror(-ret));
+                       return ret;
+               }
                targ->type = xstrdup(buf);
        }
+       return 0;
 }
 
-static void convert_variable_fields(Dwarf_Die *vr_die, const char *varname,
+static int convert_variable_fields(Dwarf_Die *vr_die, const char *varname,
                                    struct perf_probe_arg_field *field,
                                    struct kprobe_trace_arg_ref **ref_ptr,
                                    Dwarf_Die *die_mem)
@@ -473,21 +477,28 @@ static void convert_variable_fields(Dwarf_Die *vr_die, const char *varname,
        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);
+       if (die_get_real_type(vr_die, &type) == NULL) {
+               pr_warning("Failed to get the type of %s.\n", varname);
+               return -ENOENT;
+       }
 
        /* 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);
+               if (!field->ref) {
+                       pr_err("Semantic error: %s must be referred by '->'\n",
+                              field->name);
+                       return -EINVAL;
+               }
                /* 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);
-
+               if (die_get_real_type(&type, &type) == NULL) {
+                       pr_warning("Failed to get the type of %s.\n", varname);
+                       return -ENOENT;
+               }
                /* Verify it is a data structure  */
-               if (dwarf_tag(&type) != DW_TAG_structure_type)
-                       die("%s is not a data structure.", varname);
+               if (dwarf_tag(&type) != DW_TAG_structure_type) {
+                       pr_warning("%s is not a data structure.\n", varname);
+                       return -EINVAL;
+               }
 
                ref = xzalloc(sizeof(struct kprobe_trace_arg_ref));
                if (*ref_ptr)
@@ -496,34 +507,46 @@ static void convert_variable_fields(Dwarf_Die *vr_die, const char *varname,
                        *ref_ptr = ref;
        } else {
                /* Verify it is a data structure  */
-               if (dwarf_tag(&type) != DW_TAG_structure_type)
-                       die("%s is not a data structure.", varname);
-
-               if (field->ref)
-                       die("Semantic error: %s must be referred by '.'",
-                           field->name);
-               if (!ref)
-                       die("Structure on a register is not supported yet.");
+               if (dwarf_tag(&type) != DW_TAG_structure_type) {
+                       pr_warning("%s is not a data structure.\n", varname);
+                       return -EINVAL;
+               }
+               if (field->ref) {
+                       pr_err("Semantic error: %s must be referred by '.'\n",
+                              field->name);
+                       return -EINVAL;
+               }
+               if (!ref) {
+                       pr_warning("Structure on a register is not "
+                                  "supported yet.\n");
+                       return -ENOTSUP;
+               }
        }
 
-       if (die_find_member(&type, field->name, die_mem) == NULL)
-               die("%s(tyep:%s) has no member %s.", varname,
-                   dwarf_diename(&type), field->name);
+       if (die_find_member(&type, field->name, die_mem) == NULL) {
+               pr_warning("%s(tyep:%s) has no member %s.\n", varname,
+                          dwarf_diename(&type), field->name);
+               return -EINVAL;
+       }
 
        /* Get the offset of the field */
        if (dwarf_attr(die_mem, DW_AT_data_member_location, &attr) == NULL ||
-           dwarf_formudata(&attr, &offs) != 0)
-               die("Failed to get the offset of %s.", field->name);
+           dwarf_formudata(&attr, &offs) != 0) {
+               pr_warning("Failed to get the offset of %s.\n", field->name);
+               return -ENOENT;
+       }
        ref->offset += (long)offs;
 
        /* Converting next field */
        if (field->next)
-               convert_variable_fields(die_mem, field->name, field->next,
-                                       &ref, die_mem);
+               return convert_variable_fields(die_mem, field->name,
+                                              field->next, &ref, die_mem);
+       else
+               return 0;
 }
 
 /* Show a variables in kprobe event format */
-static void convert_variable(Dwarf_Die *vr_die, struct probe_finder *pf)
+static int convert_variable(Dwarf_Die *vr_die, struct probe_finder *pf)
 {
        Dwarf_Attribute attr;
        Dwarf_Die die_mem;
@@ -538,28 +561,30 @@ static void convert_variable(Dwarf_Die *vr_die, struct probe_finder *pf)
        if (ret <= 0 || nexpr == 0)
                goto error;
 
-       convert_location(expr, pf);
-
-       if (pf->pvar->field) {
-               convert_variable_fields(vr_die, pf->pvar->var,
-                                       pf->pvar->field, &pf->tvar->ref,
-                                       &die_mem);
+       ret = convert_location(expr, pf);
+       if (ret == 0 && pf->pvar->field) {
+               ret = convert_variable_fields(vr_die, pf->pvar->var,
+                                             pf->pvar->field, &pf->tvar->ref,
+                                             &die_mem);
                vr_die = &die_mem;
        }
-       if (pf->pvar->type)
-               pf->tvar->type = xstrdup(pf->pvar->type);
-       else
-               convert_variable_type(vr_die, pf->tvar);
+       if (ret == 0) {
+               if (pf->pvar->type)
+                       pf->tvar->type = xstrdup(pf->pvar->type);
+               else
+                       ret = convert_variable_type(vr_die, pf->tvar);
+       }
        /* *expr will be cached in libdw. Don't free it. */
-       return ;
+       return ret;
 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->var);
+       pr_err("Failed to find the location of %s at this address.\n"
+              " Perhaps, it has been optimized out.\n", pf->pvar->var);
+       return -ENOENT;
 }
 
 /* Find a variable in a subprogram die */
-static void find_variable(Dwarf_Die *sp_die, struct probe_finder *pf)
+static int find_variable(Dwarf_Die *sp_die, struct probe_finder *pf)
 {
        Dwarf_Die vr_die;
        char buf[32], *ptr;
@@ -578,19 +603,22 @@ static void find_variable(Dwarf_Die *sp_die, struct probe_finder *pf)
        if (!is_c_varname(pf->pvar->var)) {
                /* Copy raw parameters */
                pf->tvar->value = xstrdup(pf->pvar->var);
-       } else {
-               pr_debug("Searching '%s' variable in context.\n",
-                        pf->pvar->var);
-               /* Search child die for local variables and parameters. */
-               if (!die_find_variable(sp_die, pf->pvar->var, &vr_die))
-                       die("Failed to find '%s' in this function.",
-                           pf->pvar->var);
-               convert_variable(&vr_die, pf);
+               return 0;
        }
+
+       pr_debug("Searching '%s' variable in context.\n",
+                pf->pvar->var);
+       /* Search child die for local variables and parameters. */
+       if (!die_find_variable(sp_die, pf->pvar->var, &vr_die)) {
+               pr_warning("Failed to find '%s' in this function.\n",
+                          pf->pvar->var);
+               return -ENOENT;
+       }
+       return 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)
+static int convert_probe_point(Dwarf_Die *sp_die, struct probe_finder *pf)
 {
        struct kprobe_trace_event *tev;
        Dwarf_Addr eaddr;
@@ -600,22 +628,31 @@ static void convert_probe_point(Dwarf_Die *sp_die, struct probe_finder *pf)
        Dwarf_Attribute fb_attr;
        size_t nops;
 
-       if (pf->ntevs == MAX_PROBES)
-               die("Too many( > %d) probe point found.\n", MAX_PROBES);
+       if (pf->ntevs == MAX_PROBES) {
+               pr_warning("Too many( > %d) probe point found.\n", MAX_PROBES);
+               return -ERANGE;
+       }
        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.");
+               if (!sp_die) {
+                       pr_warning("Failed to find probe point in any "
+                                  "functions.\n");
+                       return -ENOENT;
+               }
        }
 
        /* Copy the name of probe point */
        name = dwarf_diename(sp_die);
        if (name) {
-               dwarf_entrypc(sp_die, &eaddr);
+               if (dwarf_entrypc(sp_die, &eaddr) != 0) {
+                       pr_warning("Failed to get entry pc of %s\n",
+                                  dwarf_diename(sp_die));
+                       return -ENOENT;
+               }
                tev->point.symbol = xstrdup(name);
                tev->point.offset = (unsigned long)(pf->addr - eaddr);
        } else
@@ -633,9 +670,12 @@ static void convert_probe_point(Dwarf_Die *sp_die, struct probe_finder *pf)
        } else if (nops == 1 && pf->fb_ops[0].atom == DW_OP_call_frame_cfa &&
                   pf->cfi != NULL) {
                Dwarf_Frame *frame;
-               ret = dwarf_cfi_addrframe(pf->cfi, pf->addr, &frame);
-               DIE_IF(ret != 0);
-               dwarf_frame_cfa(frame, &pf->fb_ops, &nops);
+               if (dwarf_cfi_addrframe(pf->cfi, pf->addr, &frame) != 0 ||
+                   dwarf_frame_cfa(frame, &pf->fb_ops, &nops) != 0) {
+                       pr_warning("Failed to get CFA on 0x%jx\n",
+                                  (uintmax_t)pf->addr);
+                       return -ENOENT;
+               }
        }
 
        /* Find each argument */
@@ -644,45 +684,53 @@ static void convert_probe_point(Dwarf_Die *sp_die, struct probe_finder *pf)
        for (i = 0; i < pf->pev->nargs; i++) {
                pf->pvar = &pf->pev->args[i];
                pf->tvar = &tev->args[i];
-               find_variable(sp_die, pf);
+               ret = find_variable(sp_die, pf);
+               if (ret != 0)
+                       return ret;
        }
 
        /* *pf->fb_ops will be cached in libdw. Don't free it. */
        pf->fb_ops = NULL;
+       return 0;
 }
 
 /* Find probe point from its line number */
-static void find_probe_point_by_line(struct probe_finder *pf)
+static int 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;
+       int ret = 0;
 
-       ret = dwarf_getsrclines(&pf->cu_die, &lines, &nlines);
-       DIE_IF(ret != 0);
+       if (dwarf_getsrclines(&pf->cu_die, &lines, &nlines) != 0) {
+               pr_warning("No source lines found in this CU.\n");
+               return -ENOENT;
+       }
 
-       for (i = 0; i < nlines; i++) {
+       for (i = 0; i < nlines && ret == 0; i++) {
                line = dwarf_onesrcline(lines, i);
-               dwarf_lineno(line, &lineno);
-               if (lineno != pf->lno)
+               if (dwarf_lineno(line, &lineno) != 0 ||
+                   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);
+               if (dwarf_lineaddr(line, &addr) != 0) {
+                       pr_warning("Failed to get the address of the line.\n");
+                       return -ENOENT;
+               }
                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);
+               ret = convert_probe_point(NULL, pf);
                /* Continuing, because target line might be inlined. */
        }
+       return ret;
 }
 
 /* Find lines which match lazy pattern */
@@ -690,15 +738,27 @@ 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;
+       int fd, ret, 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);
+       if (fd < 0) {
+               pr_warning("Failed to open %s: %s\n", fname, strerror(-fd));
+               return fd;
+       }
+
+       ret = fstat(fd, &st);
+       if (ret < 0) {
+               pr_warning("Failed to get the size of %s: %s\n",
+                          fname, strerror(errno));
+               return ret;
+       }
        fbuf = xmalloc(st.st_size + 2);
-       DIE_IF(read(fd, fbuf, st.st_size) < 0);
+       ret = read(fd, fbuf, st.st_size);
+       if (ret < 0) {
+               pr_warning("Failed to read %s: %s\n", fname, strerror(errno));
+               return ret;
+       }
        close(fd);
        fbuf[st.st_size] = '\n';        /* Dummy line */
        fbuf[st.st_size + 1] = '\0';
@@ -718,7 +778,7 @@ static int find_lazy_match_lines(struct list_head *head,
 }
 
 /* Find probe points from lazy pattern  */
-static void find_probe_point_lazy(Dwarf_Die *sp_die, struct probe_finder *pf)
+static int find_probe_point_lazy(Dwarf_Die *sp_die, struct probe_finder *pf)
 {
        Dwarf_Lines *lines;
        Dwarf_Line *line;
@@ -726,31 +786,40 @@ static void find_probe_point_lazy(Dwarf_Die *sp_die, struct probe_finder *pf)
        Dwarf_Addr addr;
        Dwarf_Die die_mem;
        int lineno;
-       int ret;
+       int ret = 0;
 
        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);
+               if (ret == 0) {
+                       pr_debug("No matched lines found in %s.\n", pf->fname);
+                       return 0;
+               } else if (ret < 0)
+                       return ret;
        }
 
-       ret = dwarf_getsrclines(&pf->cu_die, &lines, &nlines);
-       DIE_IF(ret != 0);
-       for (i = 0; i < nlines; i++) {
+       if (dwarf_getsrclines(&pf->cu_die, &lines, &nlines) != 0) {
+               pr_warning("No source lines found in this CU.\n");
+               return -ENOENT;
+       }
+
+       for (i = 0; i < nlines && ret >= 0; i++) {
                line = dwarf_onesrcline(lines, i);
 
-               dwarf_lineno(line, &lineno);
-               if (!line_list__has_line(&pf->lcache, lineno))
+               if (dwarf_lineno(line, &lineno) != 0 ||
+                   !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 (dwarf_lineaddr(line, &addr) != 0) {
+                       pr_debug("Failed to get the address of line %d.\n",
+                                lineno);
+                       continue;
+               }
                if (sp_die) {
                        /* Address filtering 1: does sp_die include addr? */
                        if (!dwarf_haspc(sp_die, addr))
@@ -764,27 +833,42 @@ static void find_probe_point_lazy(Dwarf_Die *sp_die, struct probe_finder *pf)
                         (int)i, lineno, (unsigned long long)addr);
                pf->addr = addr;
 
-               convert_probe_point(sp_die, pf);
+               ret = convert_probe_point(sp_die, pf);
                /* Continuing, because target line might be inlined. */
        }
        /* TODO: deallocate lines, but how? */
+       return ret;
 }
 
+/* Callback parameter with return value */
+struct dwarf_callback_param {
+       void *data;
+       int retval;
+};
+
 static int probe_point_inline_cb(Dwarf_Die *in_die, void *data)
 {
-       struct probe_finder *pf = (struct probe_finder *)data;
+       struct dwarf_callback_param *param = data;
+       struct probe_finder *pf = param->data;
        struct perf_probe_point *pp = &pf->pev->point;
+       Dwarf_Addr addr;
 
        if (pp->lazy_line)
-               find_probe_point_lazy(in_die, pf);
+               param->retval = find_probe_point_lazy(in_die, pf);
        else {
                /* Get probe address */
-               pf->addr = die_get_entrypc(in_die);
+               if (dwarf_entrypc(in_die, &addr) != 0) {
+                       pr_warning("Failed to get entry pc of %s.\n",
+                                  dwarf_diename(in_die));
+                       param->retval = -ENOENT;
+                       return DWARF_CB_ABORT;
+               }
+               pf->addr = addr;
                pf->addr += pp->offset;
                pr_debug("found inline addr: 0x%jx\n",
                         (uintmax_t)pf->addr);
 
-               convert_probe_point(in_die, pf);
+               param->retval = convert_probe_point(in_die, pf);
        }
 
        return DWARF_CB_OK;
@@ -793,39 +877,53 @@ static int probe_point_inline_cb(Dwarf_Die *in_die, void *data)
 /* 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 dwarf_callback_param *param = data;
+       struct probe_finder *pf = param->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;
+               return DWARF_CB_OK;
 
        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);
+               param->retval = 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);
+                       param->retval = find_probe_point_lazy(sp_die, pf);
                else {
-                       pf->addr = die_get_entrypc(sp_die);
+                       if (dwarf_entrypc(sp_die, &pf->addr) != 0) {
+                               pr_warning("Failed to get entry pc of %s.\n",
+                                          dwarf_diename(sp_die));
+                               param->retval = -ENOENT;
+                               return DWARF_CB_ABORT;
+                       }
                        pf->addr += pp->offset;
                        /* TODO: Check the address in this function */
-                       convert_probe_point(sp_die, pf);
+                       param->retval = convert_probe_point(sp_die, pf);
                }
-       } else
+       } else {
+               struct dwarf_callback_param _param = {.data = (void *)pf,
+                                                     .retval = 0};
                /* Inlined function: search instances */
-               dwarf_func_inline_instances(sp_die, probe_point_inline_cb, pf);
+               dwarf_func_inline_instances(sp_die, probe_point_inline_cb,
+                                           &_param);
+               param->retval = _param.retval;
+       }
 
-       return 1; /* Exit; no same symbol in this CU. */
+       return DWARF_CB_ABORT; /* Exit; no same symbol in this CU. */
 }
 
-static void find_probe_point_by_func(struct probe_finder *pf)
+static int find_probe_point_by_func(struct probe_finder *pf)
 {
-       dwarf_getfuncs(&pf->cu_die, probe_point_search_cb, pf, 0);
+       struct dwarf_callback_param _param = {.data = (void *)pf,
+                                             .retval = 0};
+       dwarf_getfuncs(&pf->cu_die, probe_point_search_cb, &_param, 0);
+       return _param.retval;
 }
 
 /* Find kprobe_trace_events specified by perf_probe_event from debuginfo */
@@ -838,14 +936,18 @@ int find_kprobe_trace_events(int fd, struct perf_probe_event *pev,
        size_t cuhl;
        Dwarf_Die *diep;
        Dwarf *dbg;
+       int ret = 0;
 
        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;
+       if (!dbg) {
+               pr_warning("No dwarf info found in the vmlinux - "
+                       "please rebuild with CONFIG_DEBUG_INFO=y.\n");
+               return -EBADF;
+       }
 
        /* Get the call frame information from this dwarf */
        pf.cfi = dwarf_getcfi(dbg);
@@ -853,7 +955,8 @@ int find_kprobe_trace_events(int fd, struct perf_probe_event *pev,
        off = 0;
        line_list__init(&pf.lcache);
        /* Loop on CUs (Compilation Unit) */
-       while (!dwarf_nextcu(dbg, off, &noff, &cuhl, NULL, NULL, NULL)) {
+       while (!dwarf_nextcu(dbg, off, &noff, &cuhl, NULL, NULL, NULL) &&
+              ret >= 0) {
                /* Get the DIE(Debugging Information Entry) of this CU */
                diep = dwarf_offdie(dbg, off + cuhl, &pf.cu_die);
                if (!diep)
@@ -867,12 +970,12 @@ int find_kprobe_trace_events(int fd, struct perf_probe_event *pev,
 
                if (!pp->file || pf.fname) {
                        if (pp->function)
-                               find_probe_point_by_func(&pf);
+                               ret = find_probe_point_by_func(&pf);
                        else if (pp->lazy_line)
-                               find_probe_point_lazy(NULL, &pf);
+                               ret = find_probe_point_lazy(NULL, &pf);
                        else {
                                pf.lno = pp->line;
-                               find_probe_point_by_line(&pf);
+                               ret = find_probe_point_by_line(&pf);
                        }
                }
                off = noff;
@@ -880,7 +983,7 @@ int find_kprobe_trace_events(int fd, struct perf_probe_event *pev,
        line_list__free(&pf.lcache);
        dwarf_end(dbg);
 
-       return pf.ntevs;
+       return (ret < 0) ? ret : pf.ntevs;
 }
 
 /* Reverse search */
@@ -893,10 +996,11 @@ int find_perf_probe_point(int fd, unsigned long addr,
        Dwarf_Addr laddr, eaddr;
        const char *tmp;
        int lineno, ret = 0;
+       bool found = false;
 
        dbg = dwarf_begin(fd, DWARF_C_READ);
        if (!dbg)
-               return -ENOENT;
+               return -EBADF;
 
        /* Find cu die */
        if (!dwarf_addrdie(dbg, (Dwarf_Addr)addr, &cudie)) {
@@ -907,82 +1011,87 @@ int find_perf_probe_point(int fd, unsigned long addr,
        /* 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;
-
+               if (dwarf_lineaddr(line, &laddr) == 0 &&
+                   (Dwarf_Addr)addr == laddr &&
+                   dwarf_lineno(line, &lineno) == 0) {
                        tmp = dwarf_linesrc(line, NULL, NULL);
-                       DIE_IF(!tmp);
-                       ppt->file = xstrdup(tmp);
-                       ret = 1;
+                       if (tmp) {
+                               ppt->line = lineno;
+                               ppt->file = xstrdup(tmp);
+                               found = true;
+                       }
                }
        }
 
        /* Find a corresponding function */
        if (die_find_real_subprogram(&cudie, (Dwarf_Addr)addr, &spdie)) {
                tmp = dwarf_diename(&spdie);
-               if (!tmp)
+               if (!tmp || dwarf_entrypc(&spdie, &eaddr) != 0)
                        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);
+               if (ppt->line) {
+                       if (die_find_inlinefunc(&spdie, (Dwarf_Addr)addr,
+                                               &indie)) {
+                               /* addr in an inline function */
+                               tmp = dwarf_diename(&indie);
+                               if (!tmp)
+                                       goto end;
+                               ret = dwarf_decl_line(&indie, &lineno);
+                       } else {
+                               if (eaddr == addr) {    /* Function entry */
+                                       lineno = ppt->line;
+                                       ret = 0;
+                               } else
+                                       ret = dwarf_decl_line(&spdie, &lineno);
+                       }
+                       if (ret == 0) {
+                               /* Make a relative line number */
+                               ppt->line -= lineno;
+                               goto found;
+                       }
                }
+               /* We don't have a line number, let's use offset */
+               ppt->offset = addr - (unsigned long)eaddr;
+found:
                ppt->function = xstrdup(tmp);
-               ppt->line -= lineno;    /* Make a relative line number */
+               found = true;
        }
 
 end:
        dwarf_end(dbg);
+       if (ret >= 0)
+               ret = found ? 1 : 0;
        return ret;
 }
 
 
 /* Find line range from its line number */
-static void find_line_range_by_line(Dwarf_Die *sp_die, struct line_finder *lf)
+static int 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);
+       if (dwarf_getsrclines(&lf->cu_die, &lines, &nlines) != 0) {
+               pr_warning("No source lines found in this CU.\n");
+               return -ENOENT;
+       }
 
        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)
+               if (dwarf_lineno(line, &lineno) != 0 ||
+                   (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))
+                       if (dwarf_lineaddr(line, &addr) != 0 ||
+                           !dwarf_haspc(sp_die, addr))
                                continue;
 
                        /* Address filtering 2: No child include addr? */
@@ -1007,18 +1116,22 @@ static void find_line_range_by_line(Dwarf_Die *sp_die, struct line_finder *lf)
                free(lf->lr->path);
                lf->lr->path = NULL;
        }
+       return lf->found;
 }
 
 static int line_range_inline_cb(Dwarf_Die *in_die, void *data)
 {
-       find_line_range_by_line(in_die, (struct line_finder *)data);
+       struct dwarf_callback_param *param = data;
+
+       param->retval = find_line_range_by_line(in_die, param->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 dwarf_callback_param *param = data;
+       struct line_finder *lf = param->data;
        struct line_range *lr = lf->lr;
 
        if (dwarf_tag(sp_die) == DW_TAG_subprogram &&
@@ -1033,38 +1146,47 @@ static int line_range_search_cb(Dwarf_Die *sp_die, void *data)
                        lf->lno_e = lr->offset + lr->end;
                lr->start = lf->lno_s;
                lr->end = lf->lno_e;
-               if (dwarf_func_inline(sp_die))
+               if (dwarf_func_inline(sp_die)) {
+                       struct dwarf_callback_param _param;
+                       _param.data = (void *)lf;
+                       _param.retval = 0;
                        dwarf_func_inline_instances(sp_die,
-                                                   line_range_inline_cb, lf);
-               else
-                       find_line_range_by_line(sp_die, lf);
-               return 1;
+                                                   line_range_inline_cb,
+                                                   &_param);
+                       param->retval = _param.retval;
+               } else
+                       param->retval = find_line_range_by_line(sp_die, lf);
+               return DWARF_CB_ABORT;
        }
-       return 0;
+       return DWARF_CB_OK;
 }
 
-static void find_line_range_by_func(struct line_finder *lf)
+static int find_line_range_by_func(struct line_finder *lf)
 {
-       dwarf_getfuncs(&lf->cu_die, line_range_search_cb, lf, 0);
+       struct dwarf_callback_param param = {.data = (void *)lf, .retval = 0};
+       dwarf_getfuncs(&lf->cu_die, line_range_search_cb, &param, 0);
+       return param.retval;
 }
 
 int find_line_range(int fd, struct line_range *lr)
 {
        struct line_finder lf = {.lr = lr, .found = 0};
-       int ret;
+       int ret = 0;
        Dwarf_Off off = 0, noff;
        size_t cuhl;
        Dwarf_Die *diep;
        Dwarf *dbg;
 
        dbg = dwarf_begin(fd, DWARF_C_READ);
-       if (!dbg)
-               return -ENOENT;
+       if (!dbg) {
+               pr_warning("No dwarf info found in the vmlinux - "
+                       "please rebuild with CONFIG_DEBUG_INFO=y.\n");
+               return -EBADF;
+       }
 
        /* Loop on CUs (Compilation Unit) */
-       while (!lf.found) {
-               ret = dwarf_nextcu(dbg, off, &noff, &cuhl, NULL, NULL, NULL);
-               if (ret != 0)
+       while (!lf.found && ret >= 0) {
+               if (dwarf_nextcu(dbg, off, &noff, &cuhl, NULL, NULL, NULL) != 0)
                        break;
 
                /* Get the DIE(Debugging Information Entry) of this CU */
@@ -1080,20 +1202,21 @@ int find_line_range(int fd, struct line_range *lr)
 
                if (!lr->file || lf.fname) {
                        if (lr->function)
-                               find_line_range_by_func(&lf);
+                               ret = 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);
+                               ret = find_line_range_by_line(NULL, &lf);
                        }
                }
                off = noff;
        }
        pr_debug("path: %lx\n", (unsigned long)lr->path);
        dwarf_end(dbg);
-       return lf.found;
+
+       return (ret < 0) ? ret : lf.found;
 }