Merge branch 'master' of /home/davem/src/GIT/linux-2.6/

Conflicts:
	include/linux/mod_devicetable.h
	scripts/mod/file2alias.c

1 files changed, 755 insertions, 291 deletions

diff --git a/tools/perf/util/probe-finder.c b/tools/perf/util/probe-finder.c
index c171a243d05b..562b1443e785 100644
--- a/tools/perf/util/probe-finder.c
+++ b/tools/perf/util/probe-finder.c
@@ -31,6 +31,7 @@
 #include <string.h>
 #include <stdarg.h>
 #include <ctype.h>
+#include <dwarf-regs.h>
 
 #include "string.h"
 #include "event.h"
@@ -38,57 +39,8 @@
 #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;
-}
+/* Kprobe tracer basic type is up to u64 */
+#define MAX_BASIC_TYPE_BITS     64
 
 /*
  * Compare the tail of two strings.
@@ -108,7 +60,7 @@ static int strtailcmp(const char *s1, const char *s2)
 /* Line number list operations */
 
 /* Add a line to line number list */
-static void line_list__add_line(struct list_head *head, unsigned int line)
+static int line_list__add_line(struct list_head *head, int line)
 {
         struct line_node *ln;
         struct list_head *p;
@@ -119,21 +71,23 @@ static void line_list__add_line(struct list_head *head, unsigned int line)
                         p = &ln->list;
                         goto found;
                 } else if (ln->line == line)    /* Already exist */
-                        return ;
+                        return 1;
         }
         /* 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);
+        if (ln == NULL)
+                return -ENOMEM;
         ln->line = line;
         INIT_LIST_HEAD(&ln->list);
         list_add(&ln->list, p);
+        return 0;
 }
 
 /* Check if the line in line number list */
-static int line_list__has_line(struct list_head *head, unsigned int line)
+static int line_list__has_line(struct list_head *head, int line)
 {
         struct line_node *ln;
 
@@ -184,9 +138,129 @@ static const char *cu_find_realpath(Dwarf_Die *cu_die, const char *fname)
                 if (strtailcmp(src, fname) == 0)
                         break;
         }
+        if (i == nfiles)
+                return NULL;
         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);
+        return name ? strcmp(tname, name) : -1;
+}
+
+/* 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;
+}
+
+static bool die_is_signed_type(Dwarf_Die *tp_die)
+{
+        Dwarf_Attribute attr;
+        Dwarf_Word ret;
+
+        if (dwarf_attr(tp_die, DW_AT_encoding, &attr) == NULL ||
+            dwarf_formudata(&attr, &ret) != 0)
+                return false;
+
+        return (ret == DW_ATE_signed_char || ret == DW_ATE_signed ||
+                ret == DW_ATE_signed_fixed);
+}
+
+static int die_get_byte_size(Dwarf_Die *tp_die)
+{
+        Dwarf_Attribute attr;
+        Dwarf_Word ret;
+
+        if (dwarf_attr(tp_die, DW_AT_byte_size, &attr) == NULL ||
+            dwarf_formudata(&attr, &ret) != 0)
+                return 0;
+
+        return (int)ret;
+}
+
+/* Get data_member_location offset */
+static int die_get_data_member_location(Dwarf_Die *mb_die, Dwarf_Word *offs)
+{
+        Dwarf_Attribute attr;
+        Dwarf_Op *expr;
+        size_t nexpr;
+        int ret;
+
+        if (dwarf_attr(mb_die, DW_AT_data_member_location, &attr) == NULL)
+                return -ENOENT;
+
+        if (dwarf_formudata(&attr, offs) != 0) {
+                /* DW_AT_data_member_location should be DW_OP_plus_uconst */
+                ret = dwarf_getlocation(&attr, &expr, &nexpr);
+                if (ret < 0 || nexpr == 0)
+                        return -ENOENT;
+
+                if (expr[0].atom != DW_OP_plus_uconst || nexpr != 1) {
+                        pr_debug("Unable to get offset:Unexpected OP %x (%zd)\n",
+                                 expr[0].atom, nexpr);
+                        return -ENOTSUP;
+                }
+                *offs = (Dwarf_Word)expr[0].number;
+        }
+        return 0;
+}
+
+/* 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;
@@ -205,8 +279,8 @@ static int __die_search_func_cb(Dwarf_Die *fn_die, void *data)
 }
 
 /* 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)
+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;
@@ -218,77 +292,64 @@ static Dwarf_Die *die_get_real_subprogram(Dwarf_Die *cu_die, Dwarf_Addr addr,
                 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)
+/* die_find callback for inline function search */
+static int __die_find_inline_cb(Dwarf_Die *die_mem, void *data)
 {
-        Dwarf_Die child_die;
-        int ret;
+        Dwarf_Addr *addr = data;
 
-        ret = dwarf_child(sp_die, die_mem);
-        if (ret != 0)
-                return NULL;
+        if (dwarf_tag(die_mem) == DW_TAG_inlined_subroutine &&
+            dwarf_haspc(die_mem, *addr))
+                return DIE_FIND_CB_FOUND;
 
-        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;
+        return DIE_FIND_CB_CONTINUE;
 }
 
-/* Compare diename and tname */
-static bool die_compare_name(Dwarf_Die *dw_die, const char *tname)
+/* 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)
 {
-        const char *name;
-        name = dwarf_diename(dw_die);
-        DIE_IF(name == NULL);
-        return strcmp(tname, name);
+        return die_find_child(sp_die, __die_find_inline_cb, &addr, die_mem);
 }
 
-/* Get entry pc(or low pc, 1st entry of ranges)  of the die */
-static Dwarf_Addr die_get_entrypc(Dwarf_Die *dw_die)
+static int __die_find_variable_cb(Dwarf_Die *die_mem, void *data)
 {
-        Dwarf_Addr epc;
-        int ret;
+        const char *name = data;
+        int tag;
 
-        ret = dwarf_entrypc(dw_die, &epc);
-        DIE_IF(ret == -1);
-        return epc;
+        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;
 }
 
-/* Get a variable die */
+/* Find a variable called 'name' */
 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;
+        return die_find_child(sp_die, __die_find_variable_cb, (void *)name,
+                              die_mem);
+}
 
-        ret = dwarf_child(sp_die, die_mem);
-        if (ret != 0)
-                return NULL;
+static int __die_find_member_cb(Dwarf_Die *die_mem, void *data)
+{
+        const char *name = data;
 
-        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 ((dwarf_tag(die_mem) == DW_TAG_member) &&
+            (die_compare_name(die_mem, name) == 0))
+                return DIE_FIND_CB_FOUND;
 
-                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 DIE_FIND_CB_SIBLING;
+}
 
-        return NULL;
+/* 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);
 }
 
 /*
@@ -296,19 +357,22 @@ static Dwarf_Die *die_find_variable(Dwarf_Die *sp_die, const char *name,
  */
 
 /* Show a location */
-static void show_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;
-        int deref = 0, ret;
+        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");
-                deref = 1;
+                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];
         }
@@ -316,35 +380,164 @@ static void show_location(Dwarf_Op *op, struct probe_finder *pf)
         if (op->atom >= DW_OP_breg0 && op->atom <= DW_OP_breg31) {
                 regn = op->atom - DW_OP_breg0;
                 offs += op->number;
-                deref = 1;
+                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;
-                deref = 1;
+                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("Mapping for DWARF register number %u missing on this architecture.", regn);
+                return -ERANGE;
+        }
+
+        tvar->value = strdup(regs);
+        if (tvar->value == NULL)
+                return -ENOMEM;
+
+        if (ref) {
+                tvar->ref = zalloc(sizeof(struct kprobe_trace_arg_ref));
+                if (tvar->ref == NULL)
+                        return -ENOMEM;
+                tvar->ref->offset = (long)offs;
+        }
+        return 0;
+}
+
+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) {
+                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_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) {
+                        if (ret >= 16)
+                                ret = -E2BIG;
+                        pr_warning("Failed to convert variable type: %s\n",
+                                   strerror(-ret));
+                        return ret;
+                }
+                targ->type = strdup(buf);
+                if (targ->type == NULL)
+                        return -ENOMEM;
+        }
+        return 0;
+}
+
+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)
+{
+        struct kprobe_trace_arg_ref *ref = *ref_ptr;
+        Dwarf_Die type;
+        Dwarf_Word offs;
+        int ret;
+
+        pr_debug("converting %s in %s\n", field->name, 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) {
+                        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) {
+                        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) {
+                        pr_warning("%s is not a data structure.\n", varname);
+                        return -EINVAL;
+                }
+
+                ref = zalloc(sizeof(struct kprobe_trace_arg_ref));
+                if (ref == NULL)
+                        return -ENOMEM;
+                if (*ref_ptr)
+                        (*ref_ptr)->next = ref;
+                else
+                        *ref_ptr = ref;
+        } else {
+                /* Verify it is a data structure  */
+                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) {
+                pr_warning("%s(tyep:%s) has no member %s.\n", varname,
+                           dwarf_diename(&type), field->name);
+                return -EINVAL;
+        }
 
-        if (deref)
-                ret = snprintf(pf->buf, pf->len, " %s=%+jd(%s)",
-                               pf->var, (intmax_t)offs, regs);
+        /* Get the offset of the field */
+        ret = die_get_data_member_location(die_mem, &offs);
+        if (ret < 0) {
+                pr_warning("Failed to get the offset of %s.\n", field->name);
+                return ret;
+        }
+        ref->offset += (long)offs;
+
+        /* Converting next field */
+        if (field->next)
+                return convert_variable_fields(die_mem, field->name,
+                                        field->next, &ref, die_mem);
         else
-                ret = snprintf(pf->buf, pf->len, " %s=%s", pf->var, regs);
-        DIE_IF(ret < 0);
-        DIE_IF(ret >= pf->len);
+                return 0;
 }
 
 /* Show a variables in kprobe event format */
-static void show_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;
         Dwarf_Op *expr;
         size_t nexpr;
         int ret;
@@ -356,142 +549,191 @@ static void show_variable(Dwarf_Die *vr_die, struct probe_finder *pf)
         if (ret <= 0 || nexpr == 0)
                 goto error;
 
-        show_location(expr, pf);
+        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 (ret == 0) {
+                if (pf->pvar->type) {
+                        pf->tvar->type = strdup(pf->pvar->type);
+                        if (pf->tvar->type == NULL)
+                                ret = -ENOMEM;
+                } 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->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)
 {
-        int ret;
         Dwarf_Die vr_die;
+        char buf[32], *ptr;
+        int ret;
 
-        /* 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 ;
+        /* TODO: Support arrays */
+        if (pf->pvar->name)
+                pf->tvar->name = strdup(pf->pvar->name);
+        else {
+                ret = synthesize_perf_probe_arg(pf->pvar, buf, 32);
+                if (ret < 0)
+                        return ret;
+                ptr = strchr(buf, ':'); /* Change type separator to _ */
+                if (ptr)
+                        *ptr = '_';
+                pf->tvar->name = strdup(buf);
+        }
+        if (pf->tvar->name == NULL)
+                return -ENOMEM;
+
+        if (!is_c_varname(pf->pvar->var)) {
+                /* Copy raw parameters */
+                pf->tvar->value = strdup(pf->pvar->var);
+                if (pf->tvar->value == NULL)
+                        return -ENOMEM;
+                else
+                        return 0;
         }
 
-        pr_debug("Searching '%s' variable in context.\n", pf->var);
+        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->var, &vr_die))
-                die("Failed to find '%s' in this function.", pf->var);
-
-        show_variable(&vr_die, pf);
+        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 show_probe_point(Dwarf_Die *sp_die, struct probe_finder *pf)
+static int convert_probe_point(Dwarf_Die *sp_die, struct probe_finder *pf)
 {
-        struct probe_point *pp = pf->pp;
+        struct kprobe_trace_event *tev;
         Dwarf_Addr eaddr;
         Dwarf_Die die_mem;
         const char *name;
-        char tmp[MAX_PROBE_BUFFER];
-        int ret, i, len;
+        int ret, i;
         Dwarf_Attribute fb_attr;
         size_t nops;
 
+        if (pf->ntevs == pf->max_tevs) {
+                pr_warning("Too many( > %d) probe point found.\n",
+                           pf->max_tevs);
+                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_get_real_subprogram(&pf->cu_die,
+                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;
+                }
         }
 
-        /* Output name of probe point */
+        /* Copy the 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);
+                if (dwarf_entrypc(sp_die, &eaddr) != 0) {
+                        pr_warning("Failed to get entry pc of %s\n",
+                                   dwarf_diename(sp_die));
+                        return -ENOENT;
                 }
-        } else {
+                tev->point.symbol = strdup(name);
+                if (tev->point.symbol == NULL)
+                        return -ENOMEM;
+                tev->point.offset = (unsigned long)(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);
+                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)
+        if (ret <= 0 || nops == 0) {
                 pf->fb_ops = NULL;
+        } else if (nops == 1 && pf->fb_ops[0].atom == DW_OP_call_frame_cfa &&
+                   pf->cfi != NULL) {
+                Dwarf_Frame *frame;
+                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 */
-        /* 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);
+        tev->nargs = pf->pev->nargs;
+        tev->args = zalloc(sizeof(struct kprobe_trace_arg) * tev->nargs);
+        if (tev->args == NULL)
+                return -ENOMEM;
+        for (i = 0; i < pf->pev->nargs; i++) {
+                pf->pvar = &pf->pev->args[i];
+                pf->tvar = &tev->args[i];
+                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;
-
-        if (pp->found == MAX_PROBES)
-                die("Too many( > %d) probe point found.\n", MAX_PROBES);
-
-        pp->probes[pp->found] = strdup(tmp);
-        pp->found++;
+        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;
 
-                show_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 */
@@ -499,16 +741,27 @@ 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);
-        fbuf = malloc(st.st_size + 2);
-        DIE_IF(fbuf == NULL);
-        DIE_IF(read(fd, fbuf, st.st_size) < 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);
+        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';
@@ -528,7 +781,7 @@ 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;
@@ -536,37 +789,46 @@ 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->pp->lazy_line);
-                if (ret <= 0)
-                        die("No matched lines found in %s.", pf->fname);
+                                            pf->pev->point.lazy_line);
+                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))
                                 continue;
                         /* Address filtering 2: No child include addr? */
-                        if (die_get_inlinefunc(sp_die, addr, &die_mem))
+                        if (die_find_inlinefunc(sp_die, addr, &die_mem))
                                 continue;
                 }
 
@@ -574,27 +836,44 @@ static void find_probe_point_lazy(Dwarf_Die *sp_die, struct probe_finder *pf)
                          (int)i, lineno, (unsigned long long)addr);
                 pf->addr = addr;
 
-                show_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 probe_point *pp = pf->pp;
+        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);
 
-                show_probe_point(in_die, pf);
+                param->retval = convert_probe_point(in_die, pf);
+                if (param->retval < 0)
+                        return DWARF_CB_ABORT;
         }
 
         return DWARF_CB_OK;
@@ -603,59 +882,88 @@ 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 probe_point *pp = pf->pp;
+        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 */
-                        show_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 a probe point */
-int find_probe_point(int fd, struct probe_point *pp)
+/* 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, int max_tevs)
 {
-        struct probe_finder pf = {.pp = pp};
+        struct probe_finder pf = {.pev = pev, .max_tevs = max_tevs};
+        struct perf_probe_point *pp = &pev->point;
         Dwarf_Off off, noff;
         size_t cuhl;
         Dwarf_Die *diep;
         Dwarf *dbg;
+        int ret = 0;
+
+        pf.tevs = zalloc(sizeof(struct kprobe_trace_event) * max_tevs);
+        if (pf.tevs == NULL)
+                return -ENOMEM;
+        *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);
 
-        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)) {
+        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)
@@ -669,12 +977,12 @@ int find_probe_point(int fd, struct probe_point *pp)
 
                 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;
@@ -682,41 +990,169 @@ int find_probe_point(int fd, struct probe_point *pp)
         line_list__free(&pf.lcache);
         dwarf_end(dbg);
 
-        return pp->found;
+        return (ret < 0) ? ret : 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;
+        bool found = false;
+
+        dbg = dwarf_begin(fd, DWARF_C_READ);
+        if (!dbg)
+                return -EBADF;
+
+        /* Find cu die */
+        if (!dwarf_addrdie(dbg, (Dwarf_Addr)addr, &cudie)) {
+                ret = -EINVAL;
+                goto end;
+        }
+
+        /* Find a corresponding line */
+        line = dwarf_getsrc_die(&cudie, (Dwarf_Addr)addr);
+        if (line) {
+                if (dwarf_lineaddr(line, &laddr) == 0 &&
+                    (Dwarf_Addr)addr == laddr &&
+                    dwarf_lineno(line, &lineno) == 0) {
+                        tmp = dwarf_linesrc(line, NULL, NULL);
+                        if (tmp) {
+                                ppt->line = lineno;
+                                ppt->file = strdup(tmp);
+                                if (ppt->file == NULL) {
+                                        ret = -ENOMEM;
+                                        goto end;
+                                }
+                                found = true;
+                        }
+                }
+        }
+
+        /* Find a corresponding function */
+        if (die_find_real_subprogram(&cudie, (Dwarf_Addr)addr, &spdie)) {
+                tmp = dwarf_diename(&spdie);
+                if (!tmp || dwarf_entrypc(&spdie, &eaddr) != 0)
+                        goto end;
+
+                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 = strdup(tmp);
+                if (ppt->function == NULL) {
+                        ret = -ENOMEM;
+                        goto end;
+                }
+                found = true;
+        }
+
+end:
+        dwarf_end(dbg);
+        if (ret >= 0)
+                ret = found ? 1 : 0;
+        return ret;
+}
+
+/* Add a line and store the src path */
+static int line_range_add_line(const char *src, unsigned int lineno,
+                               struct line_range *lr)
+{
+        /* Copy real path */
+        if (!lr->path) {
+                lr->path = strdup(src);
+                if (lr->path == NULL)
+                        return -ENOMEM;
+        }
+        return line_list__add_line(&lr->line_list, lineno);
+}
+
+/* Search function declaration lines */
+static int line_range_funcdecl_cb(Dwarf_Die *sp_die, void *data)
+{
+        struct dwarf_callback_param *param = data;
+        struct line_finder *lf = param->data;
+        const char *src;
+        int lineno;
+
+        src = dwarf_decl_file(sp_die);
+        if (src && strtailcmp(src, lf->fname) != 0)
+                return DWARF_CB_OK;
+
+        if (dwarf_decl_line(sp_die, &lineno) != 0 ||
+            (lf->lno_s > lineno || lf->lno_e < lineno))
+                return DWARF_CB_OK;
+
+        param->retval = line_range_add_line(src, lineno, lf->lr);
+        if (param->retval < 0)
+                return DWARF_CB_ABORT;
+        return DWARF_CB_OK;
+}
+
+static int find_line_range_func_decl_lines(struct line_finder *lf)
+{
+        struct dwarf_callback_param param = {.data = (void *)lf, .retval = 0};
+        dwarf_getfuncs(&lf->cu_die, line_range_funcdecl_cb, &param, 0);
+        return param.retval;
 }
 
 /* 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;
+        int lineno, ret = 0;
         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;
+        }
 
+        /* Search probable lines on lines list */
         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? */
-                        if (die_get_inlinefunc(sp_die, addr, &die_mem))
+                        if (die_find_inlinefunc(sp_die, addr, &die_mem))
                                 continue;
                 }
 
@@ -725,30 +1161,49 @@ static void find_line_range_by_line(Dwarf_Die *sp_die, struct line_finder *lf)
                 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);
+                ret = line_range_add_line(src, lineno, lf->lr);
+                if (ret < 0)
+                        return ret;
         }
+
+        /*
+         * Dwarf lines doesn't include function declarations. We have to
+         * check functions list or given function.
+         */
+        if (sp_die) {
+                src = dwarf_decl_file(sp_die);
+                if (src && dwarf_decl_line(sp_die, &lineno) == 0 &&
+                    (lf->lno_s <= lineno && lf->lno_e >= lineno))
+                        ret = line_range_add_line(src, lineno, lf->lr);
+        } else
+                ret = find_line_range_func_decl_lines(lf);
+
         /* Update status */
-        if (!list_empty(&lf->lr->line_list))
-                lf->found = 1;
+        if (ret >= 0)
+                if (!list_empty(&lf->lr->line_list))
+                        ret = lf->found = 1;
+                else
+                        ret = 0;        /* Lines are not found */
         else {
                 free(lf->lr->path);
                 lf->lr->path = NULL;
         }
+        return ret;
 }
 
 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 &&
@@ -757,44 +1212,55 @@ static int line_range_search_cb(Dwarf_Die *sp_die, void *data)
                 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)
+                if (lf->lno_s < 0)      /* Overflow */
+                        lf->lno_s = INT_MAX;
+                lf->lno_e = lr->offset + lr->end;
+                if (lf->lno_e < 0)      /* Overflow */
                         lf->lno_e = INT_MAX;
-                else
-                        lf->lno_e = lr->offset + lr->end;
+                pr_debug("New line range: %d to %d\n", lf->lno_s, lf->lno_e);
                 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 */
@@ -810,20 +1276,18 @@ 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);
+                                lf.lno_e = lr->end;
+                                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;
 }