/*
   * probe-finder.c : C expression to kprobe event converter
   *
   * Written by Masami Hiramatsu <mhiramat@redhat.com>
   *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License as published by
   * the Free Software Foundation; either version 2 of the License, or
   * (at your option) any later version.
   *
   * This program is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU General Public License for more details.
   *
   * You should have received a copy of the GNU General Public License
   * along with this program; if not, write to the Free Software
   * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
   *
   */
  
  #include <sys/utsname.h>
  #include <sys/types.h>
  #include <sys/stat.h>
  #include <fcntl.h>
  #include <errno.h>
  #include <stdio.h>
  #include <unistd.h>
  #include <getopt.h>
  #include <stdlib.h>
  #include <string.h>
  #include <stdarg.h>
  #include <dwarf-regs.h>
  
  #include <linux/bitops.h>
  #include "event.h"
  #include "debug.h"
  #include "util.h"
  #include "symbol.h"
  #include "probe-finder.h"
  
  /* Kprobe tracer basic type is up to u64 */
  #define MAX_BASIC_TYPE_BITS	64
  
  /* Line number list operations */
  
  /* Add a line to line number list */
  static int line_list__add_line(struct list_head *head, int line)
  {
  	struct line_node *ln;
  	struct list_head *p;
  
  	/* Reverse search, because new line will be the last one */
  	list_for_each_entry_reverse(ln, head, list) {
  		if (ln->line < line) {
  			p = &ln->list;
  			goto found;
  		} else if (ln->line == line)	/* Already exist */
  			return 1;
  	}
  	/* List is empty, or the smallest entry */
  	p = head;
  found:
  	pr_debug("line list: add a line %u
  ", line);
  	ln = zalloc(sizeof(struct line_node));
  	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, int line)
  {
  	struct line_node *ln;
  
  	/* Reverse search, because new line will be the last one */
  	list_for_each_entry(ln, head, list)
  		if (ln->line == line)
  			return 1;
  
  	return 0;
  }
  
  /* Init line number list */
  static void line_list__init(struct list_head *head)
  {
  	INIT_LIST_HEAD(head);
  }
  
  /* Free line number list */
  static void line_list__free(struct list_head *head)
  {
  	struct line_node *ln;
  	while (!list_empty(head)) {
  		ln = list_first_entry(head, struct line_node, list);
  		list_del(&ln->list);
  		free(ln);
  	}
  }
  
  /* Dwarf 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 int debuginfo__init_offline_dwarf(struct debuginfo *dbg,
  					 const char *path)
  {
  	int fd;
  
  	fd = open(path, O_RDONLY);
  	if (fd < 0)
  		return fd;
  
  	dbg->dwfl = dwfl_begin(&offline_callbacks);
  	if (!dbg->dwfl)
  		goto error;
  
  	dbg->mod = dwfl_report_offline(dbg->dwfl, "", "", fd);
  	if (!dbg->mod)
  		goto error;
  
  	dbg->dbg = dwfl_module_getdwarf(dbg->mod, &dbg->bias);
  	if (!dbg->dbg)
  		goto error;
  
  	return 0;
  error:
  	if (dbg->dwfl)
  		dwfl_end(dbg->dwfl);
  	else
  		close(fd);
  	memset(dbg, 0, sizeof(*dbg));
  
  	return -ENOENT;
  }
  
  #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
  ", 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 int debuginfo__init_online_kernel_dwarf(struct debuginfo *dbg,
  					       Dwarf_Addr addr)
  {
  	dbg->dwfl = dwfl_begin(&kernel_callbacks);
  	if (!dbg->dwfl)
  		return -EINVAL;
  
  	/* Load the kernel dwarves: Don't care the result here */
  	dwfl_linux_kernel_report_kernel(dbg->dwfl);
  	dwfl_linux_kernel_report_modules(dbg->dwfl);
  
  	dbg->dbg = dwfl_addrdwarf(dbg->dwfl, addr, &dbg->bias);
  	/* Here, check whether we could get a real dwarf */
  	if (!dbg->dbg) {
  		pr_debug("Failed to find kernel dwarf at %lx
  ",
  			 (unsigned long)addr);
  		dwfl_end(dbg->dwfl);
  		memset(dbg, 0, sizeof(*dbg));
  		return -ENOENT;
  	}
  
  	return 0;
  }
  #else
  /* With older elfutils, this just support kernel module... */
  static int debuginfo__init_online_kernel_dwarf(struct debuginfo *dbg,
  					       Dwarf_Addr addr __maybe_unused)
  {
  	const char *path = kernel_get_module_path("kernel");
  
  	if (!path) {
  		pr_err("Failed to find vmlinux path
  ");
  		return -ENOENT;
  	}
  
  	pr_debug2("Use file %s for debuginfo
  ", path);
  	return debuginfo__init_offline_dwarf(dbg, path);
  }
  #endif
  
  struct debuginfo *debuginfo__new(const char *path)
  {
  	struct debuginfo *dbg = zalloc(sizeof(*dbg));
  	if (!dbg)
  		return NULL;
  
  	if (debuginfo__init_offline_dwarf(dbg, path) < 0)
  		zfree(&dbg);
  
  	return dbg;
  }
  
  struct debuginfo *debuginfo__new_online_kernel(unsigned long addr)
  {
  	struct debuginfo *dbg = zalloc(sizeof(*dbg));
  
  	if (!dbg)
  		return NULL;
  
  	if (debuginfo__init_online_kernel_dwarf(dbg, (Dwarf_Addr)addr) < 0)
  		zfree(&dbg);
  
  	return dbg;
  }
  
  void debuginfo__delete(struct debuginfo *dbg)
  {
  	if (dbg) {
  		if (dbg->dwfl)
  			dwfl_end(dbg->dwfl);
  		free(dbg);
  	}
  }
  
  /*
   * Probe finder related functions
   */
  
  static struct probe_trace_arg_ref *alloc_trace_arg_ref(long offs)
  {
  	struct probe_trace_arg_ref *ref;
  	ref = zalloc(sizeof(struct probe_trace_arg_ref));
  	if (ref != NULL)
  		ref->offset = offs;
  	return ref;
  }
  
  /*
   * Convert a location into trace_arg.
   * If tvar == NULL, this just checks variable can be converted.
   * If fentry == true and vr_die is a parameter, do huristic search
   * for the location fuzzed by function entry mcount.
   */
  static int convert_variable_location(Dwarf_Die *vr_die, Dwarf_Addr addr,
  				     Dwarf_Op *fb_ops, Dwarf_Die *sp_die,
  				     struct probe_trace_arg *tvar)
  {
  	Dwarf_Attribute attr;
  	Dwarf_Addr tmp = 0;
  	Dwarf_Op *op;
  	size_t nops;
  	unsigned int regn;
  	Dwarf_Word offs = 0;
  	bool ref = false;
  	const char *regs;
  	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)
  		return -EINVAL;	/* Broken DIE ? */
  	if (dwarf_getlocation_addr(&attr, addr, &op, &nops, 1) <= 0) {
  		ret = dwarf_entrypc(sp_die, &tmp);
  		if (ret || addr != tmp ||
  		    dwarf_tag(vr_die) != DW_TAG_formal_parameter ||
  		    dwarf_highpc(sp_die, &tmp))
  			return -ENOENT;
  		/*
  		 * This is fuzzed by fentry mcount. We try to find the
  		 * parameter location at the earliest address.
  		 */
  		for (addr += 1; addr <= tmp; addr++) {
  			if (dwarf_getlocation_addr(&attr, addr, &op,
  						   &nops, 1) > 0)
  				goto found;
  		}
  		return -ENOENT;
  	}
  found:
  	if (nops == 0)
  		/* TODO: Support const_value */
  		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);
  		if (tvar->value == NULL)
  			return -ENOMEM;
  		snprintf(tvar->value, ret + 2, "@%s", dwarf_diename(vr_die));
  		tvar->ref = alloc_trace_arg_ref((long)offs);
  		if (tvar->ref == NULL)
  			return -ENOMEM;
  		return 0;
  	}
  
  	/* If this is based on frame buffer, set the offset */
  	if (op->atom == DW_OP_fbreg) {
  		if (fb_ops == NULL)
  			return -ENOTSUP;
  		ref = true;
  		offs = op->number;
  		op = &fb_ops[0];
  	}
  
  	if (op->atom >= DW_OP_breg0 && op->atom <= DW_OP_breg31) {
  		regn = op->atom - DW_OP_breg0;
  		offs += op->number;
  		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;
  		ref = true;
  	} else if (op->atom == DW_OP_regx) {
  		regn = op->number;
  	} else {
  		pr_debug("DW_OP %x is not supported.
  ", op->atom);
  		return -ENOTSUP;
  	}
  
  	if (!tvar)
  		return 0;
  
  	regs = get_arch_regstr(regn);
  	if (!regs) {
  		/* This should be a bug in DWARF or this tool */
  		pr_warning("Mapping for the register number %u "
  			   "missing on this architecture.
  ", regn);
  		return -ERANGE;
  	}
  
  	tvar->value = strdup(regs);
  	if (tvar->value == NULL)
  		return -ENOMEM;
  
  	if (ref) {
  		tvar->ref = alloc_trace_arg_ref((long)offs);
  		if (tvar->ref == NULL)
  			return -ENOMEM;
  	}
  	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)
  {
  	struct probe_trace_arg_ref **ref_ptr = &tvar->ref;
  	Dwarf_Die type;
  	char buf[16];
  	int bsize, boffs, total;
  	int ret;
  
  	/* TODO: check all types */
  	if (cast && strcmp(cast, "string") != 0) {
  		/* Non string type is OK */
  		tvar->type = strdup(cast);
  		return (tvar->type == NULL) ? -ENOMEM : 0;
  	}
  
  	bsize = dwarf_bitsize(vr_die);
  	if (bsize > 0) {
  		/* This is a bitfield */
  		boffs = dwarf_bitoffset(vr_die);
  		total = dwarf_bytesize(vr_die);
  		if (boffs < 0 || total < 0)
  			return -ENOENT;
  		ret = snprintf(buf, 16, "b%d@%d/%zd", bsize, boffs,
  				BYTES_TO_BITS(total));
  		goto formatted;
  	}
  
  	if (die_get_real_type(vr_die, &type) == NULL) {
  		pr_warning("Failed to get a type information of %s.
  ",
  			   dwarf_diename(vr_die));
  		return -ENOENT;
  	}
  
  	pr_debug("%s type is %s.
  ",
  		 dwarf_diename(vr_die), dwarf_diename(&type));
  
  	if (cast && strcmp(cast, "string") == 0) {	/* String type */
  		ret = dwarf_tag(&type);
  		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.
  ",
  				   dwarf_diename(vr_die), dwarf_diename(&type));
  			return -EINVAL;
  		}
  		if (die_get_real_type(&type, &type) == NULL) {
  			pr_warning("Failed to get a type"
  				   " information.
  ");
  			return -ENOENT;
  		}
  		if (ret == DW_TAG_pointer_type) {
  			while (*ref_ptr)
  				ref_ptr = &(*ref_ptr)->next;
  			/* Add new reference with offset +0 */
  			*ref_ptr = zalloc(sizeof(struct probe_trace_arg_ref));
  			if (*ref_ptr == NULL) {
  				pr_warning("Out of memory error
  ");
  				return -ENOMEM;
  			}
  		}
  		if (!die_compare_name(&type, "char") &&
  		    !die_compare_name(&type, "unsigned char")) {
  			pr_warning("Failed to cast into string: "
  				   "%s is not (unsigned) char *.
  ",
  				   dwarf_diename(vr_die));
  			return -EINVAL;
  		}
  		tvar->type = strdup(cast);
  		return (tvar->type == NULL) ? -ENOMEM : 0;
  	}
  
  	ret = dwarf_bytesize(&type);
  	if (ret <= 0)
  		/* No size ... try to use default type */
  		return 0;
  	ret = BYTES_TO_BITS(ret);
  
  	/* Check the bitwidth */
  	if (ret > MAX_BASIC_TYPE_BITS) {
  		pr_info("%s exceeds max-bitwidth. Cut down to %d bits.
  ",
  			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
  ",
  			   strerror(-ret));
  		return ret;
  	}
  	tvar->type = strdup(buf);
  	if (tvar->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 probe_trace_arg_ref **ref_ptr,
  				    Dwarf_Die *die_mem)
  {
  	struct probe_trace_arg_ref *ref = *ref_ptr;
  	Dwarf_Die type;
  	Dwarf_Word offs;
  	int ret, tag;
  
  	pr_debug("converting %s in %s
  ", field->name, varname);
  	if (die_get_real_type(vr_die, &type) == NULL) {
  		pr_warning("Failed to get the type of %s.
  ", varname);
  		return -ENOENT;
  	}
  	pr_debug2("Var real type: (%x)
  ", (unsigned)dwarf_dieoffset(&type));
  	tag = dwarf_tag(&type);
  
  	if (field->name[0] == '[' &&
  	    (tag == DW_TAG_array_type || tag == DW_TAG_pointer_type)) {
  		if (field->next)
  			/* Save original type for next field */
  			memcpy(die_mem, &type, sizeof(*die_mem));
  		/* Get the type of this array */
  		if (die_get_real_type(&type, &type) == NULL) {
  			pr_warning("Failed to get the type of %s.
  ", varname);
  			return -ENOENT;
  		}
  		pr_debug2("Array real type: (%x)
  ",
  			 (unsigned)dwarf_dieoffset(&type));
  		if (tag == DW_TAG_pointer_type) {
  			ref = zalloc(sizeof(struct probe_trace_arg_ref));
  			if (ref == NULL)
  				return -ENOMEM;
  			if (*ref_ptr)
  				(*ref_ptr)->next = ref;
  			else
  				*ref_ptr = ref;
  		}
  		ref->offset += dwarf_bytesize(&type) * field->index;
  		if (!field->next)
  			/* Save vr_die for converting types */
  			memcpy(die_mem, vr_die, sizeof(*die_mem));
  		goto next;
  	} else if (tag == DW_TAG_pointer_type) {
  		/* Check the pointer and dereference */
  		if (!field->ref) {
  			pr_err("Semantic error: %s must be referred by '->'
  ",
  			       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.
  ", varname);
  			return -ENOENT;
  		}
  		/* Verify it is a data structure  */
  		tag = dwarf_tag(&type);
  		if (tag != DW_TAG_structure_type && tag != DW_TAG_union_type) {
  			pr_warning("%s is not a data structure nor an union.
  ",
  				   varname);
  			return -EINVAL;
  		}
  
  		ref = zalloc(sizeof(struct probe_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 (tag != DW_TAG_structure_type && tag != DW_TAG_union_type) {
  			pr_warning("%s is not a data structure nor an union.
  ",
  				   varname);
  			return -EINVAL;
  		}
  		if (field->name[0] == '[') {
  			pr_err("Semantic error: %s is not a pointor"
  			       " nor array.
  ", varname);
  			return -EINVAL;
  		}
  		if (field->ref) {
  			pr_err("Semantic error: %s must be referred by '.'
  ",
  			       field->name);
  			return -EINVAL;
  		}
  		if (!ref) {
  			pr_warning("Structure on a register is not "
  				   "supported yet.
  ");
  			return -ENOTSUP;
  		}
  	}
  
  	if (die_find_member(&type, field->name, die_mem) == NULL) {
  		pr_warning("%s(type:%s) has no member %s.
  ", varname,
  			   dwarf_diename(&type), field->name);
  		return -EINVAL;
  	}
  
  	/* Get the offset of the field */
  	if (tag == DW_TAG_union_type) {
  		offs = 0;
  	} else {
  		ret = die_get_data_member_location(die_mem, &offs);
  		if (ret < 0) {
  			pr_warning("Failed to get the offset of %s.
  ",
  				   field->name);
  			return ret;
  		}
  	}
  	ref->offset += (long)offs;
  
  next:
  	/* Converting next field */
  	if (field->next)
  		return convert_variable_fields(die_mem, field->name,
  					field->next, &ref, die_mem);
  	else
  		return 0;
  }
  
  /* Show a variables in kprobe event format */
  static int convert_variable(Dwarf_Die *vr_die, struct probe_finder *pf)
  {
  	Dwarf_Die die_mem;
  	int ret;
  
  	pr_debug("Converting variable %s into trace event.
  ",
  		 dwarf_diename(vr_die));
  
  	ret = convert_variable_location(vr_die, pf->addr, pf->fb_ops,
  					&pf->sp_die, pf->tvar);
  	if (ret == -ENOENT)
  		pr_err("Failed to find the location of %s at this address.
  "
  		       " Perhaps, it has been optimized out.
  ", pf->pvar->var);
  	else if (ret == -ENOTSUP)
  		pr_err("Sorry, we don't support this variable location yet.
  ");
  	else if (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)
  		ret = convert_variable_type(vr_die, pf->tvar, pf->pvar->type);
  	/* *expr will be cached in libdw. Don't free it. */
  	return ret;
  }
  
  /* Find a variable in a scope DIE */
  static int find_variable(Dwarf_Die *sc_die, struct probe_finder *pf)
  {
  	Dwarf_Die vr_die;
  	char buf[32], *ptr;
  	int ret = 0;
  
  	if (!is_c_varname(pf->pvar->var)) {
  		/* Copy raw parameters */
  		pf->tvar->value = strdup(pf->pvar->var);
  		if (pf->tvar->value == NULL)
  			return -ENOMEM;
  		if (pf->pvar->type) {
  			pf->tvar->type = strdup(pf->pvar->type);
  			if (pf->tvar->type == NULL)
  				return -ENOMEM;
  		}
  		if (pf->pvar->name) {
  			pf->tvar->name = strdup(pf->pvar->name);
  			if (pf->tvar->name == NULL)
  				return -ENOMEM;
  		} else
  			pf->tvar->name = NULL;
  		return 0;
  	}
  
  	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;
  
  	pr_debug("Searching '%s' variable in context.
  ", pf->pvar->var);
  	/* Search child die for local variables and parameters. */
  	if (!die_find_variable_at(sc_die, pf->pvar->var, pf->addr, &vr_die)) {
  		/* Search again in global variables */
  		if (!die_find_variable_at(&pf->cu_die, pf->pvar->var, 0, &vr_die))
  			ret = -ENOENT;
  	}
  	if (ret >= 0)
  		ret = convert_variable(&vr_die, pf);
  
  	if (ret < 0)
  		pr_warning("Failed to find '%s' in this function.
  ",
  			   pf->pvar->var);
  	return ret;
  }
  
  /* Convert subprogram DIE to trace point */
  static int convert_to_trace_point(Dwarf_Die *sp_die, Dwfl_Module *mod,
  				  Dwarf_Addr paddr, bool retprobe,
  				  struct probe_trace_point *tp)
  {
  	Dwarf_Addr eaddr, highaddr;
  	GElf_Sym sym;
  	const char *symbol;
  
  	/* Verify the address is correct */
  	if (dwarf_entrypc(sp_die, &eaddr) != 0) {
  		pr_warning("Failed to get entry address of %s
  ",
  			   dwarf_diename(sp_die));
  		return -ENOENT;
  	}
  	if (dwarf_highpc(sp_die, &highaddr) != 0) {
  		pr_warning("Failed to get end address of %s
  ",
  			   dwarf_diename(sp_die));
  		return -ENOENT;
  	}
  	if (paddr > highaddr) {
  		pr_warning("Offset specified is greater than size of %s
  ",
  			   dwarf_diename(sp_die));
  		return -EINVAL;
  	}
  
  	/* Get an appropriate symbol from symtab */
  	symbol = dwfl_module_addrsym(mod, paddr, &sym, NULL);
  	if (!symbol) {
  		pr_warning("Failed to find symbol at 0x%lx
  ",
  			   (unsigned long)paddr);
  		return -ENOENT;
  	}
  	tp->offset = (unsigned long)(paddr - sym.st_value);
  	tp->address = (unsigned long)paddr;
  	tp->symbol = strdup(symbol);
  	if (!tp->symbol)
  		return -ENOMEM;
  
  	/* Return probe must be on the head of a subprogram */
  	if (retprobe) {
  		if (eaddr != paddr) {
  			pr_warning("Return probe must be on the head of"
  				   " a real function.
  ");
  			return -EINVAL;
  		}
  		tp->retprobe = true;
  	}
  
  	return 0;
  }
  
  /* Call probe_finder callback with scope DIE */
  static int call_probe_finder(Dwarf_Die *sc_die, struct probe_finder *pf)
  {
  	Dwarf_Attribute fb_attr;
  	size_t nops;
  	int ret;
  
  	if (!sc_die) {
  		pr_err("Caller must pass a scope DIE. Program error.
  ");
  		return -EINVAL;
  	}
  
  	/* If not a real subprogram, find a real one */
  	if (!die_is_func_def(sc_die)) {
  		if (!die_find_realfunc(&pf->cu_die, pf->addr, &pf->sp_die)) {
  			pr_warning("Failed to find probe point in any "
  				   "functions.
  ");
  			return -ENOENT;
  		}
  	} else
  		memcpy(&pf->sp_die, sc_die, sizeof(Dwarf_Die));
  
  	/* Get the frame base attribute/ops from subprogram */
  	dwarf_attr(&pf->sp_die, DW_AT_frame_base, &fb_attr);
  	ret = dwarf_getlocation_addr(&fb_attr, pf->addr, &pf->fb_ops, &nops, 1);
  	if (ret <= 0 || nops == 0) {
  		pf->fb_ops = NULL;
  #if _ELFUTILS_PREREQ(0, 142)
  	} 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 call frame on 0x%jx
  ",
  				   (uintmax_t)pf->addr);
  			return -ENOENT;
  		}
  #endif
  	}
  
  	/* Call finder's callback handler */
  	ret = pf->callback(sc_die, pf);
  
  	/* *pf->fb_ops will be cached in libdw. Don't free it. */
  	pf->fb_ops = NULL;
  
  	return ret;
  }
  
  struct find_scope_param {
  	const char *function;
  	const char *file;
  	int line;
  	int diff;
  	Dwarf_Die *die_mem;
  	bool found;
  };
  
  static int find_best_scope_cb(Dwarf_Die *fn_die, void *data)
  {
  	struct find_scope_param *fsp = data;
  	const char *file;
  	int lno;
  
  	/* Skip if declared file name does not match */
  	if (fsp->file) {
  		file = dwarf_decl_file(fn_die);
  		if (!file || strcmp(fsp->file, file) != 0)
  			return 0;
  	}
  	/* If the function name is given, that's what user expects */
  	if (fsp->function) {
  		if (die_compare_name(fn_die, fsp->function)) {
  			memcpy(fsp->die_mem, fn_die, sizeof(Dwarf_Die));
  			fsp->found = true;
  			return 1;
  		}
  	} else {
  		/* With the line number, find the nearest declared DIE */
  		dwarf_decl_line(fn_die, &lno);
  		if (lno < fsp->line && fsp->diff > fsp->line - lno) {
  			/* Keep a candidate and continue */
  			fsp->diff = fsp->line - lno;
  			memcpy(fsp->die_mem, fn_die, sizeof(Dwarf_Die));
  			fsp->found = true;
  		}
  	}
  	return 0;
  }
  
  /* Find an appropriate scope fits to given conditions */
  static Dwarf_Die *find_best_scope(struct probe_finder *pf, Dwarf_Die *die_mem)
  {
  	struct find_scope_param fsp = {
  		.function = pf->pev->point.function,
  		.file = pf->fname,
  		.line = pf->lno,
  		.diff = INT_MAX,
  		.die_mem = die_mem,
  		.found = false,
  	};
  
  	cu_walk_functions_at(&pf->cu_die, pf->addr, find_best_scope_cb, &fsp);
  
  	return fsp.found ? die_mem : NULL;
  }
  
  static int probe_point_line_walker(const char *fname, int lineno,
  				   Dwarf_Addr addr, void *data)
  {
  	struct probe_finder *pf = data;
  	Dwarf_Die *sc_die, die_mem;
  	int ret;
  
  	if (lineno != pf->lno || strtailcmp(fname, pf->fname) != 0)
  		return 0;
  
  	pf->addr = addr;
  	sc_die = find_best_scope(pf, &die_mem);
  	if (!sc_die) {
  		pr_warning("Failed to find scope of probe point.
  ");
  		return -ENOENT;
  	}
  
  	ret = call_probe_finder(sc_die, pf);
  
  	/* Continue if no error, because the line will be in inline function */
  	return ret < 0 ? ret : 0;
  }
  
  /* 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)
  {
  	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
  ", fname, strerror(errno));
  		return -errno;
  	}
  
  	while ((len = getline(&line, &line_len, fp)) > 0) {
  
  		if (line[len - 1] == '
  ')
  			line[len - 1] = '\0';
  
  		if (strlazymatch(line, pat)) {
  			line_list__add_line(head, linenum);
  			count++;
  		}
  		linenum++;
  	}
  
  	if (ferror(fp))
  		count = -errno;
  	free(line);
  	fclose(fp);
  
  	if (count == 0)
  		pr_debug("No matched lines found in %s.
  ", fname);
  	return count;
  }
  
  static int probe_point_lazy_walker(const char *fname, int lineno,
  				   Dwarf_Addr addr, void *data)
  {
  	struct probe_finder *pf = data;
  	Dwarf_Die *sc_die, die_mem;
  	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
  ",
  		 lineno, (unsigned long long)addr);
  	pf->addr = addr;
  	pf->lno = lineno;
  	sc_die = find_best_scope(pf, &die_mem);
  	if (!sc_die) {
  		pr_warning("Failed to find scope of probe point.
  ");
  		return -ENOENT;
  	}
  
  	ret = call_probe_finder(sc_die, 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)
  {
  	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)
  			return ret;
  	}
  
  	return die_walk_lines(sp_die, probe_point_lazy_walker, pf);
  }
  
  static int probe_point_inline_cb(Dwarf_Die *in_die, void *data)
  {
  	struct probe_finder *pf = data;
  	struct perf_probe_point *pp = &pf->pev->point;
  	Dwarf_Addr addr;
  	int ret;
  
  	if (pp->lazy_line)
  		ret = find_probe_point_lazy(in_die, pf);
  	else {
  		/* Get probe address */
  		if (dwarf_entrypc(in_die, &addr) != 0) {
  			pr_warning("Failed to get entry address of %s.
  ",
  				   dwarf_diename(in_die));
  			return -ENOENT;
  		}
  		pf->addr = addr;
  		pf->addr += pp->offset;
  		pr_debug("found inline addr: 0x%jx
  ",
  			 (uintmax_t)pf->addr);
  
  		ret = call_probe_finder(in_die, pf);
  	}
  
  	return ret;
  }
  
  /* Callback parameter with return value for libdw */
  struct dwarf_callback_param {
  	void *data;
  	int retval;
  };
  
  /* Search function from function name */
  static int probe_point_search_cb(Dwarf_Die *sp_die, void *data)
  {
  	struct dwarf_callback_param *param = data;
  	struct probe_finder *pf = param->data;
  	struct perf_probe_point *pp = &pf->pev->point;
  
  	/* Check tag and diename */
  	if (!die_is_func_def(sp_die) ||
  	    !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);
  		pf->lno += pp->line;
  		param->retval = find_probe_point_by_line(pf);
  	} else if (!dwarf_func_inline(sp_die)) {
  		/* Real function */
  		if (pp->lazy_line)
  			param->retval = find_probe_point_lazy(sp_die, pf);
  		else {
  			if (dwarf_entrypc(sp_die, &pf->addr) != 0) {
  				pr_warning("Failed to get entry address of "
  					   "%s.
  ", dwarf_diename(sp_die));
  				param->retval = -ENOENT;
  				return DWARF_CB_ABORT;
  			}
  			pf->addr += pp->offset;
  			/* TODO: Check the address in this function */
  			param->retval = call_probe_finder(sp_die, pf);
  		}
  	} else
  		/* Inlined function: search instances */
  		param->retval = die_walk_instances(sp_die,
  					probe_point_inline_cb, (void *)pf);
  
  	return DWARF_CB_ABORT; /* Exit; no same symbol in this CU. */
  }
  
  static int find_probe_point_by_func(struct probe_finder *pf)
  {
  	struct dwarf_callback_param _param = {.data = (void *)pf,
  					      .retval = 0};
  	dwarf_getfuncs(&pf->cu_die, probe_point_search_cb, &_param, 0);
  	return _param.retval;
  }
  
  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 debuginfo__find_probes(struct debuginfo *dbg,
  				  struct probe_finder *pf)
  {
  	struct perf_probe_point *pp = &pf->pev->point;
  	Dwarf_Off off, noff;
  	size_t cuhl;
  	Dwarf_Die *diep;
  	int ret = 0;
  
  #if _ELFUTILS_PREREQ(0, 142)
  	/* Get the call frame information from this dwarf */
  	pf->cfi = dwarf_getcfi(dbg->dbg);
  #endif
  
  	off = 0;
  	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->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->dbg, off, &noff, &cuhl, NULL, NULL, NULL)) {
  		/* Get the DIE(Debugging Information Entry) of this CU */
  		diep = dwarf_offdie(dbg->dbg, off + cuhl, &pf->cu_die);
  		if (!diep)
  			continue;
  
  		/* Check if target file is included. */
  		if (pp->file)
  			pf->fname = cu_find_realpath(&pf->cu_die, pp->file);
  		else
  			pf->fname = NULL;
  
  		if (!pp->file || pf->fname) {
  			if (pp->function)
  				ret = find_probe_point_by_func(pf);
  			else if (pp->lazy_line)
  				ret = find_probe_point_lazy(NULL, pf);
  			else {
  				pf->lno = pp->line;
  				ret = find_probe_point_by_line(pf);
  			}
  			if (ret < 0)
  				break;
  		}
  		off = noff;
  	}
  
  found:
  	line_list__free(&pf->lcache);
  
  	return ret;
  }
  
  struct local_vars_finder {
  	struct probe_finder *pf;
  	struct perf_probe_arg *args;
  	int max_args;
  	int nargs;
  	int ret;
  };
  
  /* Collect available variables in this scope */
  static int copy_variables_cb(Dwarf_Die *die_mem, void *data)
  {
  	struct local_vars_finder *vf = data;
  	struct probe_finder *pf = vf->pf;
  	int tag;
  
  	tag = dwarf_tag(die_mem);
  	if (tag == DW_TAG_formal_parameter ||
  	    tag == DW_TAG_variable) {
  		if (convert_variable_location(die_mem, vf->pf->addr,
  					      vf->pf->fb_ops, &pf->sp_die,
  					      NULL) == 0) {
  			vf->args[vf->nargs].var = (char *)dwarf_diename(die_mem);
  			if (vf->args[vf->nargs].var == NULL) {
  				vf->ret = -ENOMEM;
  				return DIE_FIND_CB_END;
  			}
  			pr_debug(" %s", vf->args[vf->nargs].var);
  			vf->nargs++;
  		}
  	}
  
  	if (dwarf_haspc(die_mem, vf->pf->addr))
  		return DIE_FIND_CB_CONTINUE;
  	else
  		return DIE_FIND_CB_SIBLING;
  }
  
  static int expand_probe_args(Dwarf_Die *sc_die, struct probe_finder *pf,
  			     struct perf_probe_arg *args)
  {
  	Dwarf_Die die_mem;
  	int i;
  	int n = 0;
  	struct local_vars_finder vf = {.pf = pf, .args = args,
  				.max_args = MAX_PROBE_ARGS, .ret = 0};
  
  	for (i = 0; i < pf->pev->nargs; i++) {
  		/* var never be NULL */
  		if (strcmp(pf->pev->args[i].var, "$vars") == 0) {
  			pr_debug("Expanding $vars into:");
  			vf.nargs = n;
  			/* Special local variables */
  			die_find_child(sc_die, copy_variables_cb, (void *)&vf,
  				       &die_mem);
  			pr_debug(" (%d)
  ", vf.nargs - n);
  			if (vf.ret < 0)
  				return vf.ret;
  			n = vf.nargs;
  		} else {
  			/* Copy normal argument */
  			args[n] = pf->pev->args[i];
  			n++;
  		}
  	}
  	return n;
  }
  
  /* Add a found probe point into trace event list */
  static int add_probe_trace_event(Dwarf_Die *sc_die, struct probe_finder *pf)
  {
  	struct trace_event_finder *tf =
  			container_of(pf, struct trace_event_finder, pf);
  	struct probe_trace_event *tev;
  	struct perf_probe_arg *args;
  	int ret, i;
  
  	/* Check number of tevs */
  	if (tf->ntevs == tf->max_tevs) {
  		pr_warning("Too many( > %d) probe point found.
  ",
  			   tf->max_tevs);
  		return -ERANGE;
  	}
  	tev = &tf->tevs[tf->ntevs++];
  
  	/* Trace point should be converted from subprogram DIE */
  	ret = convert_to_trace_point(&pf->sp_die, tf->mod, pf->addr,
  				     pf->pev->point.retprobe, &tev->point);
  	if (ret < 0)
  		return ret;
  
  	pr_debug("Probe point found: %s+%lu
  ", tev->point.symbol,
  		 tev->point.offset);
  
  	/* Expand special probe argument if exist */
  	args = zalloc(sizeof(struct perf_probe_arg) * MAX_PROBE_ARGS);
  	if (args == NULL)
  		return -ENOMEM;
  
  	ret = expand_probe_args(sc_die, pf, args);
  	if (ret < 0)
  		goto end;
  
  	tev->nargs = ret;
  	tev->args = zalloc(sizeof(struct probe_trace_arg) * tev->nargs);
  	if (tev->args == NULL) {
  		ret = -ENOMEM;
  		goto end;
  	}
  
  	/* Find each argument */
  	for (i = 0; i < tev->nargs; i++) {
  		pf->pvar = &args[i];
  		pf->tvar = &tev->args[i];
  		/* Variable should be found from scope DIE */
  		ret = find_variable(sc_die, pf);
  		if (ret != 0)
  			break;
  	}
  
  end:
  	free(args);
  	return ret;
  }
  
  /* Find probe_trace_events specified by perf_probe_event from debuginfo */
  int debuginfo__find_trace_events(struct debuginfo *dbg,
  				 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},
  			.mod = dbg->mod, .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 = debuginfo__find_probes(dbg, &tf.pf);
  	if (ret < 0) {
  		zfree(tevs);
  		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, &af->pf.sp_die,
  						NULL);
  		if (ret == 0) {
  			ret = die_get_varname(die_mem, buf, MAX_VAR_LEN);
  			pr_debug2("Add new var: %s
  ", 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 *sc_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;
  	int ret;
  
  	/* Check number of tevs */
  	if (af->nvls == af->max_vls) {
  		pr_warning("Too many( > %d) probe point found.
  ", af->max_vls);
  		return -ERANGE;
  	}
  	vl = &af->vls[af->nvls++];
  
  	/* Trace point should be converted from subprogram DIE */
  	ret = convert_to_trace_point(&pf->sp_die, af->mod, pf->addr,
  				     pf->pev->point.retprobe, &vl->point);
  	if (ret < 0)
  		return ret;
  
  	pr_debug("Probe point found: %s+%lu
  ", 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(sc_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;
  	die_find_child(&pf->cu_die, collect_variables_cb, (void *)af, &die_mem);
  
  out:
  	if (strlist__empty(vl->vars)) {
  		strlist__delete(vl->vars);
  		vl->vars = NULL;
  	}
  
  	return ret;
  }
  
  /* Find available variables at given probe point */
  int debuginfo__find_available_vars_at(struct debuginfo *dbg,
  				      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},
  			.mod = dbg->mod,
  			.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 = debuginfo__find_probes(dbg, &af.pf);
  	if (ret < 0) {
  		/* Free vlist for error */
  		while (af.nvls--) {
  			zfree(&af.vls[af.nvls].point.symbol);
  			strlist__delete(af.vls[af.nvls].vars);
  		}
  		zfree(vls);
  		return ret;
  	}
  
  	return (ret < 0) ? ret : af.nvls;
  }
  
  /* Reverse search */
  int debuginfo__find_probe_point(struct debuginfo *dbg, unsigned long addr,
  				struct perf_probe_point *ppt)
  {
  	Dwarf_Die cudie, spdie, indie;
  	Dwarf_Addr _addr = 0, baseaddr = 0;
  	const char *fname = NULL, *func = NULL, *basefunc = NULL, *tmp;
  	int baseline = 0, lineno = 0, ret = 0;
  
  	/* Adjust address with bias */
  	addr += dbg->bias;
  
  	/* Find cu die */
  	if (!dwarf_addrdie(dbg->dbg, (Dwarf_Addr)addr - dbg->bias, &cudie)) {
  		pr_warning("Failed to find debug information for address %lx
  ",
  			   addr);
  		ret = -EINVAL;
  		goto end;
  	}
  
  	/* 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 (name, baseline and baseaddr) */
  	if (die_find_realfunc(&cudie, (Dwarf_Addr)addr, &spdie)) {
  		/* Get function entry information */
  		func = basefunc = dwarf_diename(&spdie);
  		if (!func ||
  		    dwarf_entrypc(&spdie, &baseaddr) != 0 ||
  		    dwarf_decl_line(&spdie, &baseline) != 0) {
  			lineno = 0;
  			goto post;
  		}
  
  		fname = dwarf_decl_file(&spdie);
  		if (addr == (unsigned long)baseaddr) {
  			/* Function entry - Relative line number is 0 */
  			lineno = baseline;
  			goto post;
  		}
  
  		/* Track down the inline functions step by step */
  		while (die_find_top_inlinefunc(&spdie, (Dwarf_Addr)addr,
  						&indie)) {
  			/* There is an inline function */
  			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. (overwrite lineinfo)
  				 */
  				lineno = die_get_call_lineno(&indie);
  				fname = die_get_call_file(&indie);
  				break;
  			} 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 ||
  				    dwarf_decl_line(&indie, &baseline) != 0)
  					break;
  				func = tmp;
  				spdie = indie;
  			}
  		}
  		/* Verify the lineno and baseline are in a same file */
  		tmp = dwarf_decl_file(&spdie);
  		if (!tmp || strcmp(tmp, fname) != 0)
  			lineno = 0;
  	}
  
  post:
  	/* Make a relative line number or an offset */
  	if (lineno)
  		ppt->line = lineno - baseline;
  	else if (basefunc) {
  		ppt->offset = addr - (unsigned long)baseaddr;
  		func = basefunc;
  	}
  
  	/* Duplicate strings */
  	if (func) {
  		ppt->function = strdup(func);
  		if (ppt->function == NULL) {
  			ret = -ENOMEM;
  			goto end;
  		}
  	}
  	if (fname) {
  		ppt->file = strdup(fname);
  		if (ppt->file == NULL) {
  			zfree(&ppt->function);
  			ret = -ENOMEM;
  			goto end;
  		}
  	}
  end:
  	if (ret == 0 && (fname || func))
  		ret = 1;	/* Found a point */
  	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 source path */
  	if (!lr->path) {
  		lr->path = strdup(src);
  		if (lr->path == NULL)
  			return -ENOMEM;
  	}
  	return line_list__add_line(&lr->line_list, lineno);
  }
  
  static int line_range_walk_cb(const char *fname, int lineno,
  			      Dwarf_Addr addr __maybe_unused,
  			      void *data)
  {
  	struct line_finder *lf = data;
  
  	if ((strtailcmp(fname, lf->fname) != 0) ||
  	    (lf->lno_s > lineno || lf->lno_e < lineno))
  		return 0;
  
  	if (line_range_add_line(fname, lineno, lf->lr) < 0)
  		return -EINVAL;
  
  	return 0;
  }
  
  /* Find line range from its line number */
  static int find_line_range_by_line(Dwarf_Die *sp_die, struct line_finder *lf)
  {
  	int ret;
  
  	ret = die_walk_lines(sp_die ?: &lf->cu_die, line_range_walk_cb, lf);
  
  	/* Update status */
  	if (ret >= 0)
  		if (!list_empty(&lf->lr->line_list))
  			ret = lf->found = 1;
  		else
  			ret = 0;	/* Lines are not found */
  	else {
  		zfree(&lf->lr->path);
  	}
  	return ret;
  }
  
  static int line_range_inline_cb(Dwarf_Die *in_die, void *data)
  {
  	find_line_range_by_line(in_die, data);
  
  	/*
  	 * We have to check all instances of inlined function, because
  	 * some execution paths can be optimized out depends on the
  	 * function argument of instances
  	 */
  	return 0;
  }
  
  /* Search function definition from function name */
  static int line_range_search_cb(Dwarf_Die *sp_die, void *data)
  {
  	struct dwarf_callback_param *param = 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 (die_is_func_def(sp_die) &&
  	    die_compare_name(sp_die, lr->function)) {
  		lf->fname = dwarf_decl_file(sp_die);
  		dwarf_decl_line(sp_die, &lr->offset);
  		pr_debug("fname: %s, lineno:%d
  ", lf->fname, lr->offset);
  		lf->lno_s = lr->offset + lr->start;
  		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;
  		pr_debug("New line range: %d to %d
  ", lf->lno_s, lf->lno_e);
  		lr->start = lf->lno_s;
  		lr->end = lf->lno_e;
  		if (dwarf_func_inline(sp_die))
  			param->retval = die_walk_instances(sp_die,
  						line_range_inline_cb, lf);
  		else
  			param->retval = find_line_range_by_line(sp_die, lf);
  		return DWARF_CB_ABORT;
  	}
  	return DWARF_CB_OK;
  }
  
  static int find_line_range_by_func(struct line_finder *lf)
  {
  	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 debuginfo__find_line_range(struct debuginfo *dbg, struct line_range *lr)
  {
  	struct line_finder lf = {.lr = lr, .found = 0};
  	int ret = 0;
  	Dwarf_Off off = 0, noff;
  	size_t cuhl;
  	Dwarf_Die *diep;
  	const char *comp_dir;
  
  	/* 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->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->dbg, off, &noff, &cuhl,
  				 NULL, NULL, NULL) != 0)
  			break;
  
  		/* Get the DIE(Debugging Information Entry) of this CU */
  		diep = dwarf_offdie(dbg->dbg, off + cuhl, &lf.cu_die);
  		if (!diep)
  			continue;
  
  		/* Check if target file is included. */
  		if (lr->file)
  			lf.fname = cu_find_realpath(&lf.cu_die, lr->file);
  		else
  			lf.fname = 0;
  
  		if (!lr->file || lf.fname) {
  			if (lr->function)
  				ret = find_line_range_by_func(&lf);
  			else {
  				lf.lno_s = lr->start;
  				lf.lno_e = lr->end;
  				ret = find_line_range_by_line(NULL, &lf);
  			}
  		}
  		off = noff;
  	}
  
  found:
  	/* Store comp_dir */
  	if (lf.found) {
  		comp_dir = cu_get_comp_dir(&lf.cu_die);
  		if (comp_dir) {
  			lr->comp_dir = strdup(comp_dir);
  			if (!lr->comp_dir)
  				ret = -ENOMEM;
  		}
  	}
  
  	pr_debug("path: %s
  ", lr->path);
  	return (ret < 0) ? ret : lf.found;
  }