1 files changed, 1030 insertions, 423 deletions

diff --git a/tools/perf/util/probe-finder.c b/tools/perf/util/probe-finder.c
index 32b81f707ff5..3b9d0b800d5c 100644
--- a/tools/perf/util/probe-finder.c
+++ b/tools/perf/util/probe-finder.c
@@ -33,6 +33,7 @@
 #include <ctype.h>
 #include <dwarf-regs.h>
 
+#include <linux/bitops.h>
 #include "event.h"
 #include "debug.h"
 #include "util.h"
@@ -116,6 +117,126 @@ static void line_list__free(struct list_head *head)
         }
 }
 
+/* Dwarf FL wrappers */
+static char *debuginfo_path;    /* Currently dummy */
+
+static const Dwfl_Callbacks offline_callbacks = {
+        .find_debuginfo = dwfl_standard_find_debuginfo,
+        .debuginfo_path = &debuginfo_path,
+
+        .section_address = dwfl_offline_section_address,
+
+        /* We use this table for core files too.  */
+        .find_elf = dwfl_build_id_find_elf,
+};
+
+/* Get a Dwarf from offline image */
+static Dwarf *dwfl_init_offline_dwarf(int fd, Dwfl **dwflp, Dwarf_Addr *bias)
+{
+        Dwfl_Module *mod;
+        Dwarf *dbg = NULL;
+
+        if (!dwflp)
+                return NULL;
+
+        *dwflp = dwfl_begin(&offline_callbacks);
+        if (!*dwflp)
+                return NULL;
+
+        mod = dwfl_report_offline(*dwflp, "", "", fd);
+        if (!mod)
+                goto error;
+
+        dbg = dwfl_module_getdwarf(mod, bias);
+        if (!dbg) {
+error:
+                dwfl_end(*dwflp);
+                *dwflp = NULL;
+        }
+        return dbg;
+}
+
+#if _ELFUTILS_PREREQ(0, 148)
+/* This method is buggy if elfutils is older than 0.148 */
+static int __linux_kernel_find_elf(Dwfl_Module *mod,
+                                   void **userdata,
+                                   const char *module_name,
+                                   Dwarf_Addr base,
+                                   char **file_name, Elf **elfp)
+{
+        int fd;
+        const char *path = kernel_get_module_path(module_name);
+
+        pr_debug2("Use file %s for %s\n", path, module_name);
+        if (path) {
+                fd = open(path, O_RDONLY);
+                if (fd >= 0) {
+                        *file_name = strdup(path);
+                        return fd;
+                }
+        }
+        /* If failed, try to call standard method */
+        return dwfl_linux_kernel_find_elf(mod, userdata, module_name, base,
+                                          file_name, elfp);
+}
+
+static const Dwfl_Callbacks kernel_callbacks = {
+        .find_debuginfo = dwfl_standard_find_debuginfo,
+        .debuginfo_path = &debuginfo_path,
+
+        .find_elf = __linux_kernel_find_elf,
+        .section_address = dwfl_linux_kernel_module_section_address,
+};
+
+/* Get a Dwarf from live kernel image */
+static Dwarf *dwfl_init_live_kernel_dwarf(Dwarf_Addr addr, Dwfl **dwflp,
+                                          Dwarf_Addr *bias)
+{
+        Dwarf *dbg;
+
+        if (!dwflp)
+                return NULL;
+
+        *dwflp = dwfl_begin(&kernel_callbacks);
+        if (!*dwflp)
+                return NULL;
+
+        /* Load the kernel dwarves: Don't care the result here */
+        dwfl_linux_kernel_report_kernel(*dwflp);
+        dwfl_linux_kernel_report_modules(*dwflp);
+
+        dbg = dwfl_addrdwarf(*dwflp, addr, bias);
+        /* Here, check whether we could get a real dwarf */
+        if (!dbg) {
+                pr_debug("Failed to find kernel dwarf at %lx\n",
+                         (unsigned long)addr);
+                dwfl_end(*dwflp);
+                *dwflp = NULL;
+        }
+        return dbg;
+}
+#else
+/* With older elfutils, this just support kernel module... */
+static Dwarf *dwfl_init_live_kernel_dwarf(Dwarf_Addr addr __used, Dwfl **dwflp,
+                                          Dwarf_Addr *bias)
+{
+        int fd;
+        const char *path = kernel_get_module_path("kernel");
+
+        if (!path) {
+                pr_err("Failed to find vmlinux path\n");
+                return NULL;
+        }
+
+        pr_debug2("Use file %s for debuginfo\n", path);
+        fd = open(path, O_RDONLY);
+        if (fd < 0)
+                return NULL;
+
+        return dwfl_init_offline_dwarf(fd, dwflp, bias);
+}
+#endif
+
 /* Dwarf wrappers */
 
 /* Find the realpath of the target file. */
@@ -152,6 +273,25 @@ static const char *cu_get_comp_dir(Dwarf_Die *cu_die)
         return dwarf_formstring(&attr);
 }
 
+/* Get a line number and file name for given address */
+static int cu_find_lineinfo(Dwarf_Die *cudie, unsigned long addr,
+                            const char **fname, int *lineno)
+{
+        Dwarf_Line *line;
+        Dwarf_Addr laddr;
+
+        line = dwarf_getsrc_die(cudie, (Dwarf_Addr)addr);
+        if (line && dwarf_lineaddr(line, &laddr) == 0 &&
+            addr == (unsigned long)laddr && dwarf_lineno(line, lineno) == 0) {
+                *fname = dwarf_linesrc(line, NULL, NULL);
+                if (!*fname)
+                        /* line number is useless without filename */
+                        *lineno = 0;
+        }
+
+        return *lineno ?: -ENOENT;
+}
+
 /* Compare diename and tname */
 static bool die_compare_name(Dwarf_Die *dw_die, const char *tname)
 {
@@ -160,35 +300,76 @@ static bool die_compare_name(Dwarf_Die *dw_die, const char *tname)
         return name ? (strcmp(tname, name) == 0) : false;
 }
 
-/* Get type die, but skip qualifiers and typedef */
-static Dwarf_Die *die_get_real_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem)
+/* Get callsite line number of inline-function instance */
+static int die_get_call_lineno(Dwarf_Die *in_die)
 {
         Dwarf_Attribute attr;
+        Dwarf_Word ret;
+
+        if (!dwarf_attr(in_die, DW_AT_call_line, &attr))
+                return -ENOENT;
+
+        dwarf_formudata(&attr, &ret);
+        return (int)ret;
+}
+
+/* Get type die */
+static Dwarf_Die *die_get_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem)
+{
+        Dwarf_Attribute attr;
+
+        if (dwarf_attr_integrate(vr_die, DW_AT_type, &attr) &&
+            dwarf_formref_die(&attr, die_mem))
+                return die_mem;
+        else
+                return NULL;
+}
+
+/* Get a type die, but skip qualifiers */
+static Dwarf_Die *__die_get_real_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem)
+{
         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;
+                vr_die = die_get_type(vr_die, die_mem);
+                if (!vr_die)
+                        break;
+                tag = dwarf_tag(vr_die);
         } 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);
+                 tag == DW_TAG_shared_type);
 
-        return die_mem;
+        return vr_die;
 }
 
-static bool die_is_signed_type(Dwarf_Die *tp_die)
+/* Get a type die, but skip qualifiers and typedef */
+static Dwarf_Die *die_get_real_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem)
+{
+        do {
+                vr_die = __die_get_real_type(vr_die, die_mem);
+        } while (vr_die && dwarf_tag(vr_die) == DW_TAG_typedef);
+
+        return vr_die;
+}
+
+static int die_get_attr_udata(Dwarf_Die *tp_die, unsigned int attr_name,
+                              Dwarf_Word *result)
 {
         Dwarf_Attribute attr;
+
+        if (dwarf_attr(tp_die, attr_name, &attr) == NULL ||
+            dwarf_formudata(&attr, result) != 0)
+                return -ENOENT;
+
+        return 0;
+}
+
+static bool die_is_signed_type(Dwarf_Die *tp_die)
+{
         Dwarf_Word ret;
 
-        if (dwarf_attr(tp_die, DW_AT_encoding, &attr) == NULL ||
-            dwarf_formudata(&attr, &ret) != 0)
+        if (die_get_attr_udata(tp_die, DW_AT_encoding, &ret))
                 return false;
 
         return (ret == DW_ATE_signed_char || ret == DW_ATE_signed ||
@@ -197,11 +378,29 @@ static bool die_is_signed_type(Dwarf_Die *tp_die)
 
 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)
+        if (die_get_attr_udata(tp_die, DW_AT_byte_size, &ret))
+                return 0;
+
+        return (int)ret;
+}
+
+static int die_get_bit_size(Dwarf_Die *tp_die)
+{
+        Dwarf_Word ret;
+
+        if (die_get_attr_udata(tp_die, DW_AT_bit_size, &ret))
+                return 0;
+
+        return (int)ret;
+}
+
+static int die_get_bit_offset(Dwarf_Die *tp_die)
+{
+        Dwarf_Word ret;
+
+        if (die_get_attr_udata(tp_die, DW_AT_bit_offset, &ret))
                 return 0;
 
         return (int)ret;
@@ -317,28 +516,196 @@ static int __die_find_inline_cb(Dwarf_Die *die_mem, void *data)
 static Dwarf_Die *die_find_inlinefunc(Dwarf_Die *sp_die, Dwarf_Addr addr,
                                       Dwarf_Die *die_mem)
 {
-        return die_find_child(sp_die, __die_find_inline_cb, &addr, die_mem);
+        Dwarf_Die tmp_die;
+
+        sp_die = die_find_child(sp_die, __die_find_inline_cb, &addr, &tmp_die);
+        if (!sp_die)
+                return NULL;
+
+        /* Inlined function could be recursive. Trace it until fail */
+        while (sp_die) {
+                memcpy(die_mem, sp_die, sizeof(Dwarf_Die));
+                sp_die = die_find_child(sp_die, __die_find_inline_cb, &addr,
+                                        &tmp_die);
+        }
+
+        return die_mem;
+}
+
+/* Walker on lines (Note: line number will not be sorted) */
+typedef int (* line_walk_handler_t) (const char *fname, int lineno,
+                                     Dwarf_Addr addr, void *data);
+
+struct __line_walk_param {
+        const char *fname;
+        line_walk_handler_t handler;
+        void *data;
+        int retval;
+};
+
+static int __die_walk_funclines_cb(Dwarf_Die *in_die, void *data)
+{
+        struct __line_walk_param *lw = data;
+        Dwarf_Addr addr;
+        int lineno;
+
+        if (dwarf_tag(in_die) == DW_TAG_inlined_subroutine) {
+                lineno = die_get_call_lineno(in_die);
+                if (lineno > 0 && dwarf_entrypc(in_die, &addr) == 0) {
+                        lw->retval = lw->handler(lw->fname, lineno, addr,
+                                                 lw->data);
+                        if (lw->retval != 0)
+                                return DIE_FIND_CB_FOUND;
+                }
+        }
+        return DIE_FIND_CB_SIBLING;
+}
+
+/* Walk on lines of blocks included in given DIE */
+static int __die_walk_funclines(Dwarf_Die *sp_die,
+                                line_walk_handler_t handler, void *data)
+{
+        struct __line_walk_param lw = {
+                .handler = handler,
+                .data = data,
+                .retval = 0,
+        };
+        Dwarf_Die die_mem;
+        Dwarf_Addr addr;
+        int lineno;
+
+        /* Handle function declaration line */
+        lw.fname = dwarf_decl_file(sp_die);
+        if (lw.fname && dwarf_decl_line(sp_die, &lineno) == 0 &&
+            dwarf_entrypc(sp_die, &addr) == 0) {
+                lw.retval = handler(lw.fname, lineno, addr, data);
+                if (lw.retval != 0)
+                        goto done;
+        }
+        die_find_child(sp_die, __die_walk_funclines_cb, &lw, &die_mem);
+done:
+        return lw.retval;
+}
+
+static int __die_walk_culines_cb(Dwarf_Die *sp_die, void *data)
+{
+        struct __line_walk_param *lw = data;
+
+        lw->retval = __die_walk_funclines(sp_die, lw->handler, lw->data);
+        if (lw->retval != 0)
+                return DWARF_CB_ABORT;
+
+        return DWARF_CB_OK;
 }
 
+/*
+ * Walk on lines inside given PDIE. If the PDIE is subprogram, walk only on
+ * the lines inside the subprogram, otherwise PDIE must be a CU DIE.
+ */
+static int die_walk_lines(Dwarf_Die *pdie, line_walk_handler_t handler,
+                          void *data)
+{
+        Dwarf_Lines *lines;
+        Dwarf_Line *line;
+        Dwarf_Addr addr;
+        const char *fname;
+        int lineno, ret = 0;
+        Dwarf_Die die_mem, *cu_die;
+        size_t nlines, i;
+
+        /* Get the CU die */
+        if (dwarf_tag(pdie) == DW_TAG_subprogram)
+                cu_die = dwarf_diecu(pdie, &die_mem, NULL, NULL);
+        else
+                cu_die = pdie;
+        if (!cu_die) {
+                pr_debug2("Failed to get CU from subprogram\n");
+                return -EINVAL;
+        }
+
+        /* Get lines list in the CU */
+        if (dwarf_getsrclines(cu_die, &lines, &nlines) != 0) {
+                pr_debug2("Failed to get source lines on this CU.\n");
+                return -ENOENT;
+        }
+        pr_debug2("Get %zd lines from this CU\n", nlines);
+
+        /* Walk on the lines on lines list */
+        for (i = 0; i < nlines; i++) {
+                line = dwarf_onesrcline(lines, i);
+                if (line == NULL ||
+                    dwarf_lineno(line, &lineno) != 0 ||
+                    dwarf_lineaddr(line, &addr) != 0) {
+                        pr_debug2("Failed to get line info. "
+                                  "Possible error in debuginfo.\n");
+                        continue;
+                }
+                /* Filter lines based on address */
+                if (pdie != cu_die)
+                        /*
+                         * Address filtering
+                         * The line is included in given function, and
+                         * no inline block includes it.
+                         */
+                        if (!dwarf_haspc(pdie, addr) ||
+                            die_find_inlinefunc(pdie, addr, &die_mem))
+                                continue;
+                /* Get source line */
+                fname = dwarf_linesrc(line, NULL, NULL);
+
+                ret = handler(fname, lineno, addr, data);
+                if (ret != 0)
+                        return ret;
+        }
+
+        /*
+         * Dwarf lines doesn't include function declarations and inlined
+         * subroutines. We have to check functions list or given function.
+         */
+        if (pdie != cu_die)
+                ret = __die_walk_funclines(pdie, handler, data);
+        else {
+                struct __line_walk_param param = {
+                        .handler = handler,
+                        .data = data,
+                        .retval = 0,
+                };
+                dwarf_getfuncs(cu_die, __die_walk_culines_cb, &param, 0);
+                ret = param.retval;
+        }
+
+        return ret;
+}
+
+struct __find_variable_param {
+        const char *name;
+        Dwarf_Addr addr;
+};
+
 static int __die_find_variable_cb(Dwarf_Die *die_mem, void *data)
 {
-        const char *name = data;
+        struct __find_variable_param *fvp = data;
         int tag;
 
         tag = dwarf_tag(die_mem);
         if ((tag == DW_TAG_formal_parameter ||
              tag == DW_TAG_variable) &&
-            die_compare_name(die_mem, name))
+            die_compare_name(die_mem, fvp->name))
                 return DIE_FIND_CB_FOUND;
 
-        return DIE_FIND_CB_CONTINUE;
+        if (dwarf_haspc(die_mem, fvp->addr))
+                return DIE_FIND_CB_CONTINUE;
+        else
+                return DIE_FIND_CB_SIBLING;
 }
 
-/* Find a variable called 'name' */
-static Dwarf_Die *die_find_variable(Dwarf_Die *sp_die, const char *name,
-                                    Dwarf_Die *die_mem)
+/* Find a variable called 'name' at given address */
+static Dwarf_Die *die_find_variable_at(Dwarf_Die *sp_die, const char *name,
+                                       Dwarf_Addr addr, Dwarf_Die *die_mem)
 {
-        return die_find_child(sp_die, __die_find_variable_cb, (void *)name,
+        struct __find_variable_param fvp = { .name = name, .addr = addr};
+
+        return die_find_child(sp_die, __die_find_variable_cb, (void *)&fvp,
                               die_mem);
 }
 
@@ -361,6 +728,60 @@ static Dwarf_Die *die_find_member(Dwarf_Die *st_die, const char *name,
                               die_mem);
 }
 
+/* Get the name of given variable DIE */
+static int die_get_typename(Dwarf_Die *vr_die, char *buf, int len)
+{
+        Dwarf_Die type;
+        int tag, ret, ret2;
+        const char *tmp = "";
+
+        if (__die_get_real_type(vr_die, &type) == NULL)
+                return -ENOENT;
+
+        tag = dwarf_tag(&type);
+        if (tag == DW_TAG_array_type || tag == DW_TAG_pointer_type)
+                tmp = "*";
+        else if (tag == DW_TAG_subroutine_type) {
+                /* Function pointer */
+                ret = snprintf(buf, len, "(function_type)");
+                return (ret >= len) ? -E2BIG : ret;
+        } else {
+                if (!dwarf_diename(&type))
+                        return -ENOENT;
+                if (tag == DW_TAG_union_type)
+                        tmp = "union ";
+                else if (tag == DW_TAG_structure_type)
+                        tmp = "struct ";
+                /* Write a base name */
+                ret = snprintf(buf, len, "%s%s", tmp, dwarf_diename(&type));
+                return (ret >= len) ? -E2BIG : ret;
+        }
+        ret = die_get_typename(&type, buf, len);
+        if (ret > 0) {
+                ret2 = snprintf(buf + ret, len - ret, "%s", tmp);
+                ret = (ret2 >= len - ret) ? -E2BIG : ret2 + ret;
+        }
+        return ret;
+}
+
+/* Get the name and type of given variable DIE, stored as "type\tname" */
+static int die_get_varname(Dwarf_Die *vr_die, char *buf, int len)
+{
+        int ret, ret2;
+
+        ret = die_get_typename(vr_die, buf, len);
+        if (ret < 0) {
+                pr_debug("Failed to get type, make it unknown.\n");
+                ret = snprintf(buf, len, "(unknown_type)");
+        }
+        if (ret > 0) {
+                ret2 = snprintf(buf + ret, len - ret, "\t%s",
+                                dwarf_diename(vr_die));
+                ret = (ret2 >= len - ret) ? -E2BIG : ret2 + ret;
+        }
+        return ret;
+}
+
 /*
  * Probe finder related functions
  */
@@ -374,8 +795,13 @@ static struct probe_trace_arg_ref *alloc_trace_arg_ref(long offs)
         return ref;
 }
 
-/* Show a location */
-static int convert_variable_location(Dwarf_Die *vr_die, struct probe_finder *pf)
+/*
+ * Convert a location into trace_arg.
+ * If tvar == NULL, this just checks variable can be converted.
+ */
+static int convert_variable_location(Dwarf_Die *vr_die, Dwarf_Addr addr,
+                                     Dwarf_Op *fb_ops,
+                                     struct probe_trace_arg *tvar)
 {
         Dwarf_Attribute attr;
         Dwarf_Op *op;
@@ -384,20 +810,23 @@ static int convert_variable_location(Dwarf_Die *vr_die, struct probe_finder *pf)
         Dwarf_Word offs = 0;
         bool ref = false;
         const char *regs;
-        struct probe_trace_arg *tvar = pf->tvar;
         int ret;
 
+        if (dwarf_attr(vr_die, DW_AT_external, &attr) != NULL)
+                goto static_var;
+
         /* TODO: handle more than 1 exprs */
         if (dwarf_attr(vr_die, DW_AT_location, &attr) == NULL ||
-            dwarf_getlocation_addr(&attr, pf->addr, &op, &nops, 1) <= 0 ||
+            dwarf_getlocation_addr(&attr, addr, &op, &nops, 1) <= 0 ||
             nops == 0) {
                 /* TODO: Support const_value */
-                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;
         }
 
         if (op->atom == DW_OP_addr) {
+static_var:
+                if (!tvar)
+                        return 0;
                 /* Static variables on memory (not stack), make @varname */
                 ret = strlen(dwarf_diename(vr_die));
                 tvar->value = zalloc(ret + 2);
@@ -412,14 +841,11 @@ static int convert_variable_location(Dwarf_Die *vr_die, struct probe_finder *pf)
 
         /* If this is based on frame buffer, set the offset */
         if (op->atom == DW_OP_fbreg) {
-                if (pf->fb_ops == NULL) {
-                        pr_warning("The attribute of frame base is not "
-                                   "supported.\n");
+                if (fb_ops == NULL)
                         return -ENOTSUP;
-                }
                 ref = true;
                 offs = op->number;
-                op = &pf->fb_ops[0];
+                op = &fb_ops[0];
         }
 
         if (op->atom >= DW_OP_breg0 && op->atom <= DW_OP_breg31) {
@@ -435,13 +861,18 @@ static int convert_variable_location(Dwarf_Die *vr_die, struct probe_finder *pf)
         } else if (op->atom == DW_OP_regx) {
                 regn = op->number;
         } else {
-                pr_warning("DW_OP %x is not supported.\n", op->atom);
+                pr_debug("DW_OP %x is not supported.\n", op->atom);
                 return -ENOTSUP;
         }
 
+        if (!tvar)
+                return 0;
+
         regs = get_arch_regstr(regn);
         if (!regs) {
-                pr_warning("Mapping for DWARF register number %u missing on this architecture.", regn);
+                /* This should be a bug in DWARF or this tool */
+                pr_warning("Mapping for the register number %u "
+                           "missing on this architecture.\n", regn);
                 return -ERANGE;
         }
 
@@ -457,6 +888,8 @@ static int convert_variable_location(Dwarf_Die *vr_die, struct probe_finder *pf)
         return 0;
 }
 
+#define BYTES_TO_BITS(nb)       ((nb) * BITS_PER_LONG / sizeof(long))
+
 static int convert_variable_type(Dwarf_Die *vr_die,
                                  struct probe_trace_arg *tvar,
                                  const char *cast)
@@ -473,6 +906,14 @@ static int convert_variable_type(Dwarf_Die *vr_die,
                 return (tvar->type == NULL) ? -ENOMEM : 0;
         }
 
+        if (die_get_bit_size(vr_die) != 0) {
+                /* This is a bitfield */
+                ret = snprintf(buf, 16, "b%d@%d/%zd", die_get_bit_size(vr_die),
+                                die_get_bit_offset(vr_die),
+                                BYTES_TO_BITS(die_get_byte_size(vr_die)));
+                goto formatted;
+        }
+
         if (die_get_real_type(vr_die, &type) == NULL) {
                 pr_warning("Failed to get a type information of %s.\n",
                            dwarf_diename(vr_die));
@@ -487,13 +928,14 @@ static int convert_variable_type(Dwarf_Die *vr_die,
                 if (ret != DW_TAG_pointer_type &&
                     ret != DW_TAG_array_type) {
                         pr_warning("Failed to cast into string: "
-                                   "%s(%s) is not a pointer nor array.",
+                                   "%s(%s) is not a pointer nor array.\n",
                                    dwarf_diename(vr_die), dwarf_diename(&type));
                         return -EINVAL;
                 }
                 if (ret == DW_TAG_pointer_type) {
                         if (die_get_real_type(&type, &type) == NULL) {
-                                pr_warning("Failed to get a type information.");
+                                pr_warning("Failed to get a type"
+                                           " information.\n");
                                 return -ENOENT;
                         }
                         while (*ref_ptr)
@@ -508,7 +950,7 @@ static int convert_variable_type(Dwarf_Die *vr_die,
                 if (!die_compare_name(&type, "char") &&
                     !die_compare_name(&type, "unsigned char")) {
                         pr_warning("Failed to cast into string: "
-                                   "%s is not (unsigned) char *.",
+                                   "%s is not (unsigned) char *.\n",
                                    dwarf_diename(vr_die));
                         return -EINVAL;
                 }
@@ -516,29 +958,31 @@ static int convert_variable_type(Dwarf_Die *vr_die,
                 return (tvar->type == NULL) ? -ENOMEM : 0;
         }
 
-        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 = BYTES_TO_BITS(die_get_byte_size(&type));
+        if (!ret)
+                /* No size ... try to use default type */
+                return 0;
 
-                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;
-                }
-                tvar->type = strdup(buf);
-                if (tvar->type == NULL)
-                        return -ENOMEM;
+        /* 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);
+
+formatted:
+        if (ret < 0 || ret >= 16) {
+                if (ret >= 16)
+                        ret = -E2BIG;
+                pr_warning("Failed to convert variable type: %s\n",
+                           strerror(-ret));
+                return ret;
+        }
+        tvar->type = strdup(buf);
+        if (tvar->type == NULL)
+                return -ENOMEM;
         return 0;
 }
 
@@ -618,8 +1062,8 @@ static int convert_variable_fields(Dwarf_Die *vr_die, const char *varname,
                         return -EINVAL;
                 }
                 if (field->name[0] == '[') {
-                        pr_err("Semantic error: %s is not a pointor nor array.",
-                               varname);
+                        pr_err("Semantic error: %s is not a pointor"
+                               " nor array.\n", varname);
                         return -EINVAL;
                 }
                 if (field->ref) {
@@ -666,8 +1110,14 @@ static int convert_variable(Dwarf_Die *vr_die, struct probe_finder *pf)
         pr_debug("Converting variable %s into trace event.\n",
                  dwarf_diename(vr_die));
 
-        ret = convert_variable_location(vr_die, pf);
-        if (ret == 0 && pf->pvar->field) {
+        ret = convert_variable_location(vr_die, pf->addr, pf->fb_ops,
+                                        pf->tvar);
+        if (ret == -ENOENT)
+                pr_err("Failed to find the location of %s at this address.\n"
+                       " Perhaps, it has been optimized out.\n", pf->pvar->var);
+        else if (ret == -ENOTSUP)
+                pr_err("Sorry, we don't support this variable location yet.\n");
+        else if (pf->pvar->field) {
                 ret = convert_variable_fields(vr_die, pf->pvar->var,
                                               pf->pvar->field, &pf->tvar->ref,
                                               &die_mem);
@@ -722,85 +1172,87 @@ static int find_variable(Dwarf_Die *sp_die, struct probe_finder *pf)
         pr_debug("Searching '%s' variable in context.\n",
                  pf->pvar->var);
         /* Search child die for local variables and parameters. */
-        if (die_find_variable(sp_die, pf->pvar->var, &vr_die))
+        if (die_find_variable_at(sp_die, pf->pvar->var, pf->addr, &vr_die))
                 ret = convert_variable(&vr_die, pf);
         else {
                 /* Search upper class */
                 nscopes = dwarf_getscopes_die(sp_die, &scopes);
-                if (nscopes > 0) {
-                        ret = dwarf_getscopevar(scopes, nscopes, pf->pvar->var,
-                                                0, NULL, 0, 0, &vr_die);
-                        if (ret >= 0)
+                while (nscopes-- > 1) {
+                        pr_debug("Searching variables in %s\n",
+                                 dwarf_diename(&scopes[nscopes]));
+                        /* We should check this scope, so give dummy address */
+                        if (die_find_variable_at(&scopes[nscopes],
+                                                 pf->pvar->var, 0,
+                                                 &vr_die)) {
                                 ret = convert_variable(&vr_die, pf);
-                        else
-                                ret = -ENOENT;
+                                goto found;
+                        }
+                }
+                if (scopes)
                         free(scopes);
-                } else
-                        ret = -ENOENT;
+                ret = -ENOENT;
         }
+found:
         if (ret < 0)
                 pr_warning("Failed to find '%s' in this function.\n",
                            pf->pvar->var);
         return ret;
 }
 
-/* Show a probe point to output buffer */
-static int convert_probe_point(Dwarf_Die *sp_die, struct probe_finder *pf)
+/* Convert subprogram DIE to trace point */
+static int convert_to_trace_point(Dwarf_Die *sp_die, Dwarf_Addr paddr,
+                                  bool retprobe, struct probe_trace_point *tp)
 {
-        struct probe_trace_event *tev;
         Dwarf_Addr eaddr;
-        Dwarf_Die die_mem;
         const char *name;
-        int ret, i;
-        Dwarf_Attribute fb_attr;
-        size_t nops;
-
-        if (pf->ntevs == 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_find_real_subprogram(&pf->cu_die,
-                                                 pf->addr, &die_mem);
-                if (!sp_die) {
-                        pr_warning("Failed to find probe point in any "
-                                   "functions.\n");
-                        return -ENOENT;
-                }
-        }
 
         /* Copy the name of probe point */
         name = dwarf_diename(sp_die);
         if (name) {
                 if (dwarf_entrypc(sp_die, &eaddr) != 0) {
-                        pr_warning("Failed to get entry pc of %s\n",
+                        pr_warning("Failed to get entry address of %s\n",
                                    dwarf_diename(sp_die));
                         return -ENOENT;
                 }
-                tev->point.symbol = strdup(name);
-                if (tev->point.symbol == NULL)
+                tp->symbol = strdup(name);
+                if (tp->symbol == NULL)
                         return -ENOMEM;
-                tev->point.offset = (unsigned long)(pf->addr - eaddr);
+                tp->offset = (unsigned long)(paddr - eaddr);
         } else
                 /* This function has no name. */
-                tev->point.offset = (unsigned long)pf->addr;
+                tp->offset = (unsigned long)paddr;
 
         /* Return probe must be on the head of a subprogram */
-        if (pf->pev->point.retprobe) {
-                if (tev->point.offset != 0) {
+        if (retprobe) {
+                if (eaddr != paddr) {
                         pr_warning("Return probe must be on the head of"
-                                   " a real function\n");
+                                   " a real function.\n");
                         return -EINVAL;
                 }
-                tev->point.retprobe = true;
+                tp->retprobe = true;
         }
 
-        pr_debug("Probe point found: %s+%lu\n", tev->point.symbol,
-                 tev->point.offset);
+        return 0;
+}
+
+/* Call probe_finder callback with real subprogram DIE */
+static int call_probe_finder(Dwarf_Die *sp_die, struct probe_finder *pf)
+{
+        Dwarf_Die die_mem;
+        Dwarf_Attribute fb_attr;
+        size_t nops;
+        int ret;
+
+        /* If no real subprogram, find a real one */
+        if (!sp_die || dwarf_tag(sp_die) != DW_TAG_subprogram) {
+                sp_die = die_find_real_subprogram(&pf->cu_die,
+                                                  pf->addr, &die_mem);
+                if (!sp_die) {
+                        pr_warning("Failed to find probe point in any "
+                                   "functions.\n");
+                        return -ENOENT;
+                }
+        }
 
         /* Get the frame base attribute/ops */
         dwarf_attr(sp_die, DW_AT_frame_base, &fb_attr);
@@ -813,182 +1265,118 @@ static int convert_probe_point(Dwarf_Die *sp_die, struct probe_finder *pf)
                 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",
+                        pr_warning("Failed to get call frame on 0x%jx\n",
                                    (uintmax_t)pf->addr);
                         return -ENOENT;
                 }
 #endif
         }
 
-        /* Find each argument */
-        tev->nargs = pf->pev->nargs;
-        tev->args = zalloc(sizeof(struct probe_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;
-        }
+        /* Call finder's callback handler */
+        ret = pf->callback(sp_die, pf);
 
         /* *pf->fb_ops will be cached in libdw. Don't free it. */
         pf->fb_ops = NULL;
-        return 0;
+
+        return ret;
 }
 
-/* Find probe point from its line number */
-static int find_probe_point_by_line(struct probe_finder *pf)
+static int probe_point_line_walker(const char *fname, int lineno,
+                                   Dwarf_Addr addr, void *data)
 {
-        Dwarf_Lines *lines;
-        Dwarf_Line *line;
-        size_t nlines, i;
-        Dwarf_Addr addr;
-        int lineno;
-        int ret = 0;
-
-        if (dwarf_getsrclines(&pf->cu_die, &lines, &nlines) != 0) {
-                pr_warning("No source lines found in this CU.\n");
-                return -ENOENT;
-        }
+        struct probe_finder *pf = data;
+        int ret;
 
-        for (i = 0; i < nlines && ret == 0; i++) {
-                line = dwarf_onesrcline(lines, i);
-                if (dwarf_lineno(line, &lineno) != 0 ||
-                    lineno != pf->lno)
-                        continue;
+        if (lineno != pf->lno || strtailcmp(fname, pf->fname) != 0)
+                return 0;
 
-                /* TODO: Get fileno from line, but how? */
-                if (strtailcmp(dwarf_linesrc(line, NULL, NULL), pf->fname) != 0)
-                        continue;
+        pf->addr = addr;
+        ret = call_probe_finder(NULL, pf);
 
-                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;
+        /* Continue if no error, because the line will be in inline function */
+        return ret < 0 ? ret : 0;
+}
 
-                ret = convert_probe_point(NULL, pf);
-                /* Continuing, because target line might be inlined. */
-        }
-        return ret;
+/* Find probe point from its line number */
+static int find_probe_point_by_line(struct probe_finder *pf)
+{
+        return die_walk_lines(&pf->cu_die, probe_point_line_walker, pf);
 }
 
 /* Find lines which match lazy pattern */
 static int find_lazy_match_lines(struct list_head *head,
                                  const char *fname, const char *pat)
 {
-        char *fbuf, *p1, *p2;
-        int fd, line, nlines = -1;
-        struct stat st;
-
-        fd = open(fname, O_RDONLY);
-        if (fd < 0) {
-                pr_warning("Failed to open %s: %s\n", fname, strerror(-fd));
+        FILE *fp;
+        char *line = NULL;
+        size_t line_len;
+        ssize_t len;
+        int count = 0, linenum = 1;
+
+        fp = fopen(fname, "r");
+        if (!fp) {
+                pr_warning("Failed to open %s: %s\n", fname, strerror(errno));
                 return -errno;
         }
 
-        if (fstat(fd, &st) < 0) {
-                pr_warning("Failed to get the size of %s: %s\n",
-                           fname, strerror(errno));
-                nlines = -errno;
-                goto out_close;
-        }
-
-        nlines = -ENOMEM;
-        fbuf = malloc(st.st_size + 2);
-        if (fbuf == NULL)
-                goto out_close;
-        if (read(fd, fbuf, st.st_size) < 0) {
-                pr_warning("Failed to read %s: %s\n", fname, strerror(errno));
-                nlines = -errno;
-                goto out_free_fbuf;
-        }
-        fbuf[st.st_size] = '\n';        /* Dummy line */
-        fbuf[st.st_size + 1] = '\0';
-        p1 = fbuf;
-        line = 1;
-        nlines = 0;
-        while ((p2 = strchr(p1, '\n')) != NULL) {
-                *p2 = '\0';
-                if (strlazymatch(p1, pat)) {
-                        line_list__add_line(head, line);
-                        nlines++;
+        while ((len = getline(&line, &line_len, fp)) > 0) {
+
+                if (line[len - 1] == '\n')
+                        line[len - 1] = '\0';
+
+                if (strlazymatch(line, pat)) {
+                        line_list__add_line(head, linenum);
+                        count++;
                 }
-                line++;
-                p1 = p2 + 1;
+                linenum++;
         }
-out_free_fbuf:
-        free(fbuf);
-out_close:
-        close(fd);
-        return nlines;
+
+        if (ferror(fp))
+                count = -errno;
+        free(line);
+        fclose(fp);
+
+        if (count == 0)
+                pr_debug("No matched lines found in %s.\n", fname);
+        return count;
+}
+
+static int probe_point_lazy_walker(const char *fname, int lineno,
+                                   Dwarf_Addr addr, void *data)
+{
+        struct probe_finder *pf = data;
+        int ret;
+
+        if (!line_list__has_line(&pf->lcache, lineno) ||
+            strtailcmp(fname, pf->fname) != 0)
+                return 0;
+
+        pr_debug("Probe line found: line:%d addr:0x%llx\n",
+                 lineno, (unsigned long long)addr);
+        pf->addr = addr;
+        ret = call_probe_finder(NULL, pf);
+
+        /*
+         * Continue if no error, because the lazy pattern will match
+         * to other lines
+         */
+        return ret < 0 ? ret : 0;
 }
 
 /* Find probe points from lazy pattern  */
 static int find_probe_point_lazy(Dwarf_Die *sp_die, struct probe_finder *pf)
 {
-        Dwarf_Lines *lines;
-        Dwarf_Line *line;
-        size_t nlines, i;
-        Dwarf_Addr addr;
-        Dwarf_Die die_mem;
-        int lineno;
         int ret = 0;
 
         if (list_empty(&pf->lcache)) {
                 /* Matching lazy line pattern */
                 ret = find_lazy_match_lines(&pf->lcache, pf->fname,
                                             pf->pev->point.lazy_line);
-                if (ret == 0) {
-                        pr_debug("No matched lines found in %s.\n", pf->fname);
-                        return 0;
-                } else if (ret < 0)
+                if (ret <= 0)
                         return ret;
         }
 
-        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);
-
-                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;
-
-                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_find_inlinefunc(sp_die, addr, &die_mem))
-                                continue;
-                }
-
-                pr_debug("Probe line found: line[%d]:%d addr:0x%llx\n",
-                         (int)i, lineno, (unsigned long long)addr);
-                pf->addr = addr;
-
-                ret = convert_probe_point(sp_die, pf);
-                /* Continuing, because target line might be inlined. */
-        }
-        /* TODO: deallocate lines, but how? */
-        return ret;
+        return die_walk_lines(sp_die, probe_point_lazy_walker, pf);
 }
 
 /* Callback parameter with return value */
@@ -1009,7 +1397,7 @@ static int probe_point_inline_cb(Dwarf_Die *in_die, void *data)
         else {
                 /* Get probe address */
                 if (dwarf_entrypc(in_die, &addr) != 0) {
-                        pr_warning("Failed to get entry pc of %s.\n",
+                        pr_warning("Failed to get entry address of %s.\n",
                                    dwarf_diename(in_die));
                         param->retval = -ENOENT;
                         return DWARF_CB_ABORT;
@@ -1019,7 +1407,7 @@ static int probe_point_inline_cb(Dwarf_Die *in_die, void *data)
                 pr_debug("found inline addr: 0x%jx\n",
                          (uintmax_t)pf->addr);
 
-                param->retval = convert_probe_point(in_die, pf);
+                param->retval = call_probe_finder(in_die, pf);
                 if (param->retval < 0)
                         return DWARF_CB_ABORT;
         }
@@ -1039,6 +1427,10 @@ static int probe_point_search_cb(Dwarf_Die *sp_die, void *data)
             !die_compare_name(sp_die, pp->function))
                 return DWARF_CB_OK;
 
+        /* Check declared file */
+        if (pp->file && strtailcmp(pp->file, dwarf_decl_file(sp_die)))
+                return DWARF_CB_OK;
+
         pf->fname = dwarf_decl_file(sp_die);
         if (pp->line) { /* Function relative line */
                 dwarf_decl_line(sp_die, &pf->lno);
@@ -1050,14 +1442,14 @@ static int probe_point_search_cb(Dwarf_Die *sp_die, void *data)
                         param->retval = find_probe_point_lazy(sp_die, pf);
                 else {
                         if (dwarf_entrypc(sp_die, &pf->addr) != 0) {
-                                pr_warning("Failed to get entry pc of %s.\n",
-                                           dwarf_diename(sp_die));
+                                pr_warning("Failed to get entry address 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 */
-                        param->retval = convert_probe_point(sp_die, pf);
+                        param->retval = call_probe_finder(sp_die, pf);
                 }
         } else {
                 struct dwarf_callback_param _param = {.data = (void *)pf,
@@ -1079,155 +1471,410 @@ static int find_probe_point_by_func(struct probe_finder *pf)
         return _param.retval;
 }
 
-/* Find probe_trace_events specified by perf_probe_event from debuginfo */
-int find_probe_trace_events(int fd, struct perf_probe_event *pev,
-                             struct probe_trace_event **tevs, int max_tevs)
+struct pubname_callback_param {
+        char *function;
+        char *file;
+        Dwarf_Die *cu_die;
+        Dwarf_Die *sp_die;
+        int found;
+};
+
+static int pubname_search_cb(Dwarf *dbg, Dwarf_Global *gl, void *data)
+{
+        struct pubname_callback_param *param = data;
+
+        if (dwarf_offdie(dbg, gl->die_offset, param->sp_die)) {
+                if (dwarf_tag(param->sp_die) != DW_TAG_subprogram)
+                        return DWARF_CB_OK;
+
+                if (die_compare_name(param->sp_die, param->function)) {
+                        if (!dwarf_offdie(dbg, gl->cu_offset, param->cu_die))
+                                return DWARF_CB_OK;
+
+                        if (param->file &&
+                            strtailcmp(param->file, dwarf_decl_file(param->sp_die)))
+                                return DWARF_CB_OK;
+
+                        param->found = 1;
+                        return DWARF_CB_ABORT;
+                }
+        }
+
+        return DWARF_CB_OK;
+}
+
+/* Find probe points from debuginfo */
+static int find_probes(int fd, struct probe_finder *pf)
 {
-        struct probe_finder pf = {.pev = pev, .max_tevs = max_tevs};
-        struct perf_probe_point *pp = &pev->point;
+        struct perf_probe_point *pp = &pf->pev->point;
         Dwarf_Off off, noff;
         size_t cuhl;
         Dwarf_Die *diep;
-        Dwarf *dbg;
+        Dwarf *dbg = NULL;
+        Dwfl *dwfl;
+        Dwarf_Addr bias;        /* Currently ignored */
         int ret = 0;
 
-        pf.tevs = zalloc(sizeof(struct probe_trace_event) * max_tevs);
-        if (pf.tevs == NULL)
-                return -ENOMEM;
-        *tevs = pf.tevs;
-        pf.ntevs = 0;
-
-        dbg = dwarf_begin(fd, DWARF_C_READ);
+        dbg = dwfl_init_offline_dwarf(fd, &dwfl, &bias);
         if (!dbg) {
-                pr_warning("No dwarf info found in the vmlinux - "
+                pr_warning("No debug information found in the vmlinux - "
                         "please rebuild with CONFIG_DEBUG_INFO=y.\n");
-                free(pf.tevs);
-                *tevs = NULL;
+                close(fd);      /* Without dwfl_end(), fd isn't closed. */
                 return -EBADF;
         }
 
 #if _ELFUTILS_PREREQ(0, 142)
         /* Get the call frame information from this dwarf */
-        pf.cfi = dwarf_getcfi(dbg);
+        pf->cfi = dwarf_getcfi(dbg);
 #endif
 
         off = 0;
-        line_list__init(&pf.lcache);
+        line_list__init(&pf->lcache);
+
+        /* Fastpath: lookup by function name from .debug_pubnames section */
+        if (pp->function) {
+                struct pubname_callback_param pubname_param = {
+                        .function = pp->function,
+                        .file     = pp->file,
+                        .cu_die   = &pf->cu_die,
+                        .sp_die   = &pf->sp_die,
+                        .found    = 0,
+                };
+                struct dwarf_callback_param probe_param = {
+                        .data = pf,
+                };
+
+                dwarf_getpubnames(dbg, pubname_search_cb, &pubname_param, 0);
+                if (pubname_param.found) {
+                        ret = probe_point_search_cb(&pf->sp_die, &probe_param);
+                        if (ret)
+                                goto found;
+                }
+        }
+
         /* Loop on CUs (Compilation Unit) */
-        while (!dwarf_nextcu(dbg, off, &noff, &cuhl, NULL, NULL, NULL) &&
-               ret >= 0) {
+        while (!dwarf_nextcu(dbg, off, &noff, &cuhl, NULL, NULL, NULL)) {
                 /* Get the DIE(Debugging Information Entry) of this CU */
-                diep = dwarf_offdie(dbg, off + cuhl, &pf.cu_die);
+                diep = dwarf_offdie(dbg, off + cuhl, &pf->cu_die);
                 if (!diep)
                         continue;
 
                 /* Check if target file is included. */
                 if (pp->file)
-                        pf.fname = cu_find_realpath(&pf.cu_die, pp->file);
+                        pf->fname = cu_find_realpath(&pf->cu_die, pp->file);
                 else
-                        pf.fname = NULL;
+                        pf->fname = NULL;
 
-                if (!pp->file || pf.fname) {
+                if (!pp->file || pf->fname) {
                         if (pp->function)
-                                ret = find_probe_point_by_func(&pf);
+                                ret = find_probe_point_by_func(pf);
                         else if (pp->lazy_line)
-                                ret = find_probe_point_lazy(NULL, &pf);
+                                ret = find_probe_point_lazy(NULL, pf);
                         else {
-                                pf.lno = pp->line;
-                                ret = find_probe_point_by_line(&pf);
+                                pf->lno = pp->line;
+                                ret = find_probe_point_by_line(pf);
                         }
+                        if (ret < 0)
+                                break;
                 }
                 off = noff;
         }
-        line_list__free(&pf.lcache);
-        dwarf_end(dbg);
 
-        return (ret < 0) ? ret : pf.ntevs;
+found:
+        line_list__free(&pf->lcache);
+        if (dwfl)
+                dwfl_end(dwfl);
+
+        return ret;
+}
+
+/* Add a found probe point into trace event list */
+static int add_probe_trace_event(Dwarf_Die *sp_die, struct probe_finder *pf)
+{
+        struct trace_event_finder *tf =
+                        container_of(pf, struct trace_event_finder, pf);
+        struct probe_trace_event *tev;
+        int ret, i;
+
+        /* Check number of tevs */
+        if (tf->ntevs == tf->max_tevs) {
+                pr_warning("Too many( > %d) probe point found.\n",
+                           tf->max_tevs);
+                return -ERANGE;
+        }
+        tev = &tf->tevs[tf->ntevs++];
+
+        ret = convert_to_trace_point(sp_die, pf->addr, pf->pev->point.retprobe,
+                                     &tev->point);
+        if (ret < 0)
+                return ret;
+
+        pr_debug("Probe point found: %s+%lu\n", tev->point.symbol,
+                 tev->point.offset);
+
+        /* Find each argument */
+        tev->nargs = pf->pev->nargs;
+        tev->args = zalloc(sizeof(struct probe_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;
+        }
+
+        return 0;
+}
+
+/* Find probe_trace_events specified by perf_probe_event from debuginfo */
+int find_probe_trace_events(int fd, struct perf_probe_event *pev,
+                            struct probe_trace_event **tevs, int max_tevs)
+{
+        struct trace_event_finder tf = {
+                        .pf = {.pev = pev, .callback = add_probe_trace_event},
+                        .max_tevs = max_tevs};
+        int ret;
+
+        /* Allocate result tevs array */
+        *tevs = zalloc(sizeof(struct probe_trace_event) * max_tevs);
+        if (*tevs == NULL)
+                return -ENOMEM;
+
+        tf.tevs = *tevs;
+        tf.ntevs = 0;
+
+        ret = find_probes(fd, &tf.pf);
+        if (ret < 0) {
+                free(*tevs);
+                *tevs = NULL;
+                return ret;
+        }
+
+        return (ret < 0) ? ret : tf.ntevs;
+}
+
+#define MAX_VAR_LEN 64
+
+/* Collect available variables in this scope */
+static int collect_variables_cb(Dwarf_Die *die_mem, void *data)
+{
+        struct available_var_finder *af = data;
+        struct variable_list *vl;
+        char buf[MAX_VAR_LEN];
+        int tag, ret;
+
+        vl = &af->vls[af->nvls - 1];
+
+        tag = dwarf_tag(die_mem);
+        if (tag == DW_TAG_formal_parameter ||
+            tag == DW_TAG_variable) {
+                ret = convert_variable_location(die_mem, af->pf.addr,
+                                                af->pf.fb_ops, NULL);
+                if (ret == 0) {
+                        ret = die_get_varname(die_mem, buf, MAX_VAR_LEN);
+                        pr_debug2("Add new var: %s\n", buf);
+                        if (ret > 0)
+                                strlist__add(vl->vars, buf);
+                }
+        }
+
+        if (af->child && dwarf_haspc(die_mem, af->pf.addr))
+                return DIE_FIND_CB_CONTINUE;
+        else
+                return DIE_FIND_CB_SIBLING;
+}
+
+/* Add a found vars into available variables list */
+static int add_available_vars(Dwarf_Die *sp_die, struct probe_finder *pf)
+{
+        struct available_var_finder *af =
+                        container_of(pf, struct available_var_finder, pf);
+        struct variable_list *vl;
+        Dwarf_Die die_mem, *scopes = NULL;
+        int ret, nscopes;
+
+        /* Check number of tevs */
+        if (af->nvls == af->max_vls) {
+                pr_warning("Too many( > %d) probe point found.\n", af->max_vls);
+                return -ERANGE;
+        }
+        vl = &af->vls[af->nvls++];
+
+        ret = convert_to_trace_point(sp_die, pf->addr, pf->pev->point.retprobe,
+                                     &vl->point);
+        if (ret < 0)
+                return ret;
+
+        pr_debug("Probe point found: %s+%lu\n", vl->point.symbol,
+                 vl->point.offset);
+
+        /* Find local variables */
+        vl->vars = strlist__new(true, NULL);
+        if (vl->vars == NULL)
+                return -ENOMEM;
+        af->child = true;
+        die_find_child(sp_die, collect_variables_cb, (void *)af, &die_mem);
+
+        /* Find external variables */
+        if (!af->externs)
+                goto out;
+        /* Don't need to search child DIE for externs. */
+        af->child = false;
+        nscopes = dwarf_getscopes_die(sp_die, &scopes);
+        while (nscopes-- > 1)
+                die_find_child(&scopes[nscopes], collect_variables_cb,
+                               (void *)af, &die_mem);
+        if (scopes)
+                free(scopes);
+
+out:
+        if (strlist__empty(vl->vars)) {
+                strlist__delete(vl->vars);
+                vl->vars = NULL;
+        }
+
+        return ret;
+}
+
+/* Find available variables at given probe point */
+int find_available_vars_at(int fd, struct perf_probe_event *pev,
+                           struct variable_list **vls, int max_vls,
+                           bool externs)
+{
+        struct available_var_finder af = {
+                        .pf = {.pev = pev, .callback = add_available_vars},
+                        .max_vls = max_vls, .externs = externs};
+        int ret;
+
+        /* Allocate result vls array */
+        *vls = zalloc(sizeof(struct variable_list) * max_vls);
+        if (*vls == NULL)
+                return -ENOMEM;
+
+        af.vls = *vls;
+        af.nvls = 0;
+
+        ret = find_probes(fd, &af.pf);
+        if (ret < 0) {
+                /* Free vlist for error */
+                while (af.nvls--) {
+                        if (af.vls[af.nvls].point.symbol)
+                                free(af.vls[af.nvls].point.symbol);
+                        if (af.vls[af.nvls].vars)
+                                strlist__delete(af.vls[af.nvls].vars);
+                }
+                free(af.vls);
+                *vls = NULL;
+                return ret;
+        }
+
+        return (ret < 0) ? ret : af.nvls;
 }
 
 /* Reverse search */
-int find_perf_probe_point(int fd, unsigned long addr,
-                          struct perf_probe_point *ppt)
+int find_perf_probe_point(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;
+        Dwarf *dbg = NULL;
+        Dwfl *dwfl = NULL;
+        Dwarf_Addr _addr, baseaddr, bias = 0;
+        const char *fname = NULL, *func = NULL, *tmp;
+        int baseline = 0, lineno = 0, ret = 0;
+
+        /* Open the live linux kernel */
+        dbg = dwfl_init_live_kernel_dwarf(addr, &dwfl, &bias);
+        if (!dbg) {
+                pr_warning("No debug information found in the vmlinux - "
+                        "please rebuild with CONFIG_DEBUG_INFO=y.\n");
+                ret = -EINVAL;
+                goto end;
+        }
 
+        /* Adjust address with bias */
+        addr += bias;
         /* Find cu die */
-        if (!dwarf_addrdie(dbg, (Dwarf_Addr)addr, &cudie)) {
+        if (!dwarf_addrdie(dbg, (Dwarf_Addr)addr - bias, &cudie)) {
+                pr_warning("Failed to find debug information for address %lx\n",
+                           addr);
                 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 line (filename and lineno) */
+        cu_find_lineinfo(&cudie, addr, &fname, &lineno);
+        /* Don't care whether it failed or not */
 
-        /* Find a corresponding function */
+        /* Find a corresponding function (name, baseline and baseaddr) */
         if (die_find_real_subprogram(&cudie, (Dwarf_Addr)addr, &spdie)) {
+                /* Get function entry information */
                 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 */
+                if (!tmp ||
+                    dwarf_entrypc(&spdie, &baseaddr) != 0 ||
+                    dwarf_decl_line(&spdie, &baseline) != 0)
+                        goto post;
+                func = tmp;
+
+                if (addr == (unsigned long)baseaddr)
+                        /* Function entry - Relative line number is 0 */
+                        lineno = baseline;
+                else if (die_find_inlinefunc(&spdie, (Dwarf_Addr)addr,
+                                             &indie)) {
+                        if (dwarf_entrypc(&indie, &_addr) == 0 &&
+                            _addr == addr)
+                                /*
+                                 * addr is at an inline function entry.
+                                 * In this case, lineno should be the call-site
+                                 * line number.
+                                 */
+                                lineno = die_get_call_lineno(&indie);
+                        else {
+                                /*
+                                 * addr is in an inline function body.
+                                 * Since lineno points one of the lines
+                                 * of the inline function, baseline should
+                                 * be the entry line of the 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;
+                                if (tmp &&
+                                    dwarf_decl_line(&spdie, &baseline) == 0)
+                                        func = tmp;
                         }
                 }
-                /* We don't have a line number, let's use offset */
-                ppt->offset = addr - (unsigned long)eaddr;
-found:
-                ppt->function = strdup(tmp);
+        }
+
+post:
+        /* Make a relative line number or an offset */
+        if (lineno)
+                ppt->line = lineno - baseline;
+        else if (func)
+                ppt->offset = addr - (unsigned long)baseaddr;
+
+        /* Duplicate strings */
+        if (func) {
+                ppt->function = strdup(func);
                 if (ppt->function == NULL) {
                         ret = -ENOMEM;
                         goto end;
                 }
-                found = true;
         }
-
+        if (fname) {
+                ppt->file = strdup(fname);
+                if (ppt->file == NULL) {
+                        if (ppt->function) {
+                                free(ppt->function);
+                                ppt->function = NULL;
+                        }
+                        ret = -ENOMEM;
+                        goto end;
+                }
+        }
 end:
-        dwarf_end(dbg);
-        if (ret >= 0)
-                ret = found ? 1 : 0;
+        if (dwfl)
+                dwfl_end(dwfl);
+        if (ret == 0 && (fname || func))
+                ret = 1;        /* Found a point */
         return ret;
 }
 
@@ -1244,91 +1891,28 @@ static int line_range_add_line(const char *src, unsigned int lineno,
         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)
+static int line_range_walk_cb(const char *fname, int lineno,
+                              Dwarf_Addr addr __used,
+                              void *data)
 {
-        struct dwarf_callback_param *param = data;
-        struct line_finder *lf = param->data;
-        const char *src;
-        int lineno;
+        struct line_finder *lf = data;
 
-        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 ||
+        if ((strtailcmp(fname, lf->fname) != 0) ||
             (lf->lno_s > lineno || lf->lno_e < lineno))
-                return DWARF_CB_OK;
+                return 0;
 
-        param->retval = line_range_add_line(src, lineno, lf->lr);
-        if (param->retval < 0)
-                return DWARF_CB_ABORT;
-        return DWARF_CB_OK;
-}
+        if (line_range_add_line(fname, lineno, lf->lr) < 0)
+                return -EINVAL;
 
-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;
+        return 0;
 }
 
 /* Find line range from its line number */
 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, ret = 0;
-        const char *src;
-        Dwarf_Die die_mem;
-
-        line_list__init(&lf->lr->line_list);
-        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);
-                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? */
-                        if (dwarf_lineaddr(line, &addr) != 0 ||
-                            !dwarf_haspc(sp_die, addr))
-                                continue;
-
-                        /* Address filtering 2: No child include addr? */
-                        if (die_find_inlinefunc(sp_die, addr, &die_mem))
-                                continue;
-                }
-
-                /* TODO: Get fileno from line, but how? */
-                src = dwarf_linesrc(line, NULL, NULL);
-                if (strtailcmp(src, lf->fname) != 0)
-                        continue;
+        int ret;
 
-                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);
+        ret = die_walk_lines(sp_die ?: &lf->cu_die, line_range_walk_cb, lf);
 
         /* Update status */
         if (ret >= 0)
@@ -1358,6 +1942,10 @@ static int line_range_search_cb(Dwarf_Die *sp_die, void *data)
         struct line_finder *lf = param->data;
         struct line_range *lr = lf->lr;
 
+        /* Check declared file */
+        if (lr->file && strtailcmp(lr->file, dwarf_decl_file(sp_die)))
+                return DWARF_CB_OK;
+
         if (dwarf_tag(sp_die) == DW_TAG_subprogram &&
             die_compare_name(sp_die, lr->function)) {
                 lf->fname = dwarf_decl_file(sp_die);
@@ -1401,16 +1989,35 @@ int find_line_range(int fd, struct line_range *lr)
         Dwarf_Off off = 0, noff;
         size_t cuhl;
         Dwarf_Die *diep;
-        Dwarf *dbg;
+        Dwarf *dbg = NULL;
+        Dwfl *dwfl;
+        Dwarf_Addr bias;        /* Currently ignored */
         const char *comp_dir;
 
-        dbg = dwarf_begin(fd, DWARF_C_READ);
+        dbg = dwfl_init_offline_dwarf(fd, &dwfl, &bias);
         if (!dbg) {
-                pr_warning("No dwarf info found in the vmlinux - "
+                pr_warning("No debug information found in the vmlinux - "
                         "please rebuild with CONFIG_DEBUG_INFO=y.\n");
+                close(fd);      /* Without dwfl_end(), fd isn't closed. */
                 return -EBADF;
         }
 
+        /* Fastpath: lookup by function name from .debug_pubnames section */
+        if (lr->function) {
+                struct pubname_callback_param pubname_param = {
+                        .function = lr->function, .file = lr->file,
+                        .cu_die = &lf.cu_die, .sp_die = &lf.sp_die, .found = 0};
+                struct dwarf_callback_param line_range_param = {
+                        .data = (void *)&lf, .retval = 0};
+
+                dwarf_getpubnames(dbg, pubname_search_cb, &pubname_param, 0);
+                if (pubname_param.found) {
+                        line_range_search_cb(&lf.sp_die, &line_range_param);
+                        if (lf.found)
+                                goto found;
+                }
+        }
+
         /* Loop on CUs (Compilation Unit) */
         while (!lf.found && ret >= 0) {
                 if (dwarf_nextcu(dbg, off, &noff, &cuhl, NULL, NULL, NULL) != 0)
@@ -1439,6 +2046,7 @@ int find_line_range(int fd, struct line_range *lr)
                 off = noff;
         }
 
+found:
         /* Store comp_dir */
         if (lf.found) {
                 comp_dir = cu_get_comp_dir(&lf.cu_die);
@@ -1450,8 +2058,7 @@ int find_line_range(int fd, struct line_range *lr)
         }
 
         pr_debug("path: %s\n", lr->path);
-        dwarf_end(dbg);
-
+        dwfl_end(dwfl);
         return (ret < 0) ? ret : lf.found;
 }