1 files changed, 755 insertions, 291 deletions

diff --git a/tools/perf/util/probe-finder.c b/tools/perf/util/probe-finder.c
index c171a24..562b144 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;
 }