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	Version: linux-6.0.1 spark-3.0.0 hadoop-3.2.0-src hadoop-3.3.0-src spark-2.4.7 linux-4.15.13 hadoop-2.7.4-src Revert   Change

 // SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * probe-finder.c : C expression to kprobe event converter
  *
  * Written by Masami Hiramatsu <mhiramat@redhat.com>
  */
 
 #include <inttypes.h>
 #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 <stdlib.h>
 #include <string.h>
 #include <stdarg.h>
 #include <dwarf-regs.h>
 
 #include <linux/bitops.h>
 #include <linux/zalloc.h>
 #include "event.h"
 #include "dso.h"
 #include "debug.h"
 #include "intlist.h"
 #include "strbuf.h"
 #include "strlist.h"
 #include "symbol.h"
 #include "probe-finder.h"
 #include "probe-file.h"
 #include "string2.h"
 
 #ifdef HAVE_DEBUGINFOD_SUPPORT
 #include <elfutils/debuginfod.h>
 #endif
 
 /* Kprobe tracer basic type is up to u64 */
 #define MAX_BASIC_TYPE_BITS 64
 
 /* 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)
 {
     GElf_Addr dummy;
     int fd;
 
     fd = open(path, O_RDONLY);
     if (fd < 0)
         return fd;
 
     dbg->dwfl = dwfl_begin(&offline_callbacks);
     if (!dbg->dwfl)
         goto error;
 
     dwfl_report_begin(dbg->dwfl);
     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;
 
     dwfl_module_build_id(dbg->mod, &dbg->build_id, &dummy);
 
     dwfl_report_end(dbg->dwfl, NULL, NULL);
 
     return 0;
 error:
     if (dbg->dwfl)
         dwfl_end(dbg->dwfl);
     else
         close(fd);
     memset(dbg, 0, sizeof(*dbg));
 
     return -ENOENT;
 }
 
 static 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);
     if (dbg)
         pr_debug("Open Debuginfo file: %s\n", path);
     return dbg;
 }
 
 enum dso_binary_type distro_dwarf_types[] = {
     DSO_BINARY_TYPE__FEDORA_DEBUGINFO,
     DSO_BINARY_TYPE__UBUNTU_DEBUGINFO,
     DSO_BINARY_TYPE__OPENEMBEDDED_DEBUGINFO,
     DSO_BINARY_TYPE__BUILDID_DEBUGINFO,
     DSO_BINARY_TYPE__MIXEDUP_UBUNTU_DEBUGINFO,
     DSO_BINARY_TYPE__NOT_FOUND,
 };
 
 struct debuginfo *debuginfo__new(const char *path)
 {
     enum dso_binary_type *type;
     char buf[PATH_MAX], nil = '\0';
     struct dso *dso;
     struct debuginfo *dinfo = NULL;
     struct build_id bid;
 
     /* Try to open distro debuginfo files */
     dso = dso__new(path);
     if (!dso)
         goto out;
 
     /* Set the build id for DSO_BINARY_TYPE__BUILDID_DEBUGINFO */
     if (is_regular_file(path) && filename__read_build_id(path, &bid) > 0)
         dso__set_build_id(dso, &bid);
 
     for (type = distro_dwarf_types;
          !dinfo && *type != DSO_BINARY_TYPE__NOT_FOUND;
          type++) {
         if (dso__read_binary_type_filename(dso, *type, &nil,
                            buf, PATH_MAX) < 0)
             continue;
         dinfo = __debuginfo__new(buf);
     }
     dso__put(dso);
 
 out:
     /* if failed to open all distro debuginfo, open given binary */
     return dinfo ? : __debuginfo__new(path);
 }
 
 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 heuristic 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,
                      unsigned int machine,
                      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, ret2 = 0;
 
     if (dwarf_attr(vr_die, DW_AT_external, &attr) != NULL)
         goto static_var;
 
     /* Constant value */
     if (dwarf_attr(vr_die, DW_AT_const_value, &attr) &&
         immediate_value_is_supported()) {
         Dwarf_Sword snum;
 
         if (!tvar)
             return 0;
 
         dwarf_formsdata(&attr, &snum);
         ret = asprintf(&tvar->value, "\\%ld", (long)snum);
 
         return ret < 0 ? -ENOMEM : 0;
     }
 
     /* 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)
             return -ENOENT;
 
         if (probe_conf.show_location_range &&
             (dwarf_tag(vr_die) == DW_TAG_variable)) {
             ret2 = -ERANGE;
         } else if (addr != tmp ||
             dwarf_tag(vr_die) != DW_TAG_formal_parameter) {
             return -ENOENT;
         }
 
         ret = dwarf_highpc(sp_die, &tmp);
         if (ret)
             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 ret2;
         /* 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 ret2;
     }
 
     /* 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.\n", op->atom);
         return -ENOTSUP;
     }
 
     if (!tvar)
         return ret2;
 
     regs = get_dwarf_regstr(regn, machine);
     if (!regs) {
         /* 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 -ENOTSUP;
     }
 
     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 ret2;
 }
 
 #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, bool user_access)
 {
     struct probe_trace_arg_ref **ref_ptr = &tvar->ref;
     Dwarf_Die type;
     char buf[16];
     char sbuf[STRERR_BUFSIZE];
     int bsize, boffs, total;
     int ret;
     char prefix;
 
     /* TODO: check all types */
     if (cast && strcmp(cast, "string") != 0 && strcmp(cast, "ustring") &&
         strcmp(cast, "x") != 0 &&
         strcmp(cast, "s") != 0 && strcmp(cast, "u") != 0) {
         /* Non string type is OK */
         /* and respect signedness/hexadecimal cast */
         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.\n",
                dwarf_diename(vr_die));
         return -ENOENT;
     }
 
     pr_debug("%s type is %s.\n",
          dwarf_diename(vr_die), dwarf_diename(&type));
 
     if (cast && (!strcmp(cast, "string") || !strcmp(cast, "ustring"))) {
         /* 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.\n",
                    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.\n");
             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\n");
                 return -ENOMEM;
             }
             (*ref_ptr)->user_access = user_access;
         }
         if (!die_compare_name(&type, "char") &&
             !die_compare_name(&type, "unsigned char")) {
             pr_warning("Failed to cast into string: "
                    "%s is not (unsigned) char *.\n",
                    dwarf_diename(vr_die));
             return -EINVAL;
         }
         tvar->type = strdup(cast);
         return (tvar->type == NULL) ? -ENOMEM : 0;
     }
 
     if (cast && (strcmp(cast, "u") == 0))
         prefix = 'u';
     else if (cast && (strcmp(cast, "s") == 0))
         prefix = 's';
     else if (cast && (strcmp(cast, "x") == 0) &&
          probe_type_is_available(PROBE_TYPE_X))
         prefix = 'x';
     else
         prefix = die_is_signed_type(&type) ? 's' :
              probe_type_is_available(PROBE_TYPE_X) ? 'x' : 'u';
 
     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.\n",
             dwarf_diename(&type), MAX_BASIC_TYPE_BITS);
         ret = MAX_BASIC_TYPE_BITS;
     }
     ret = snprintf(buf, 16, "%c%d", prefix, ret);
 
 formatted:
     if (ret < 0 || ret >= 16) {
         if (ret >= 16)
             ret = -E2BIG;
         pr_warning("Failed to convert variable type: %s\n",
                str_error_r(-ret, sbuf, sizeof(sbuf)));
         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, bool user_access)
 {
     struct probe_trace_arg_ref *ref = *ref_ptr;
     Dwarf_Die type;
     Dwarf_Word offs;
     int ret, tag;
 
     pr_debug("converting %s in %s\n", field->name, varname);
     if (die_get_real_type(vr_die, &type) == NULL) {
         pr_warning("Failed to get the type of %s.\n", varname);
         return -ENOENT;
     }
     pr_debug2("Var real type: %s (%x)\n", dwarf_diename(&type),
           (unsigned)dwarf_dieoffset(&type));
     tag = dwarf_tag(&type);
 
     if (field->name[0] == '[' &&
         (tag == DW_TAG_array_type || tag == DW_TAG_pointer_type)) {
         /* Save original type for next field or type */
         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.\n", varname);
             return -ENOENT;
         }
         pr_debug2("Array real type: %s (%x)\n", dwarf_diename(&type),
              (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;
         ref->user_access = user_access;
         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 '->'\n",
                    field->name);
             return -EINVAL;
         }
         /* Get the type pointed by this pointer */
         if (die_get_real_type(&type, &type) == NULL) {
             pr_warning("Failed to get the type of %s.\n", varname);
             return -ENOENT;
         }
         /* Verify it is a data structure  */
         tag = dwarf_tag(&type);
         if (tag != DW_TAG_structure_type && tag != DW_TAG_union_type) {
             pr_warning("%s is not a data structure nor a union.\n",
                    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 a union.\n",
                    varname);
             return -EINVAL;
         }
         if (field->name[0] == '[') {
             pr_err("Semantic error: %s is not a pointer"
                    " nor array.\n", varname);
             return -EINVAL;
         }
         /* While processing unnamed field, we don't care about this */
         if (field->ref && dwarf_diename(vr_die)) {
             pr_err("Semantic error: %s must be referred by '.'\n",
                    field->name);
             return -EINVAL;
         }
         if (!ref) {
             pr_warning("Structure on a register is not "
                    "supported yet.\n");
             return -ENOTSUP;
         }
     }
 
     if (die_find_member(&type, field->name, die_mem) == NULL) {
         pr_warning("%s(type:%s) has no member %s.\n", 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.\n",
                    field->name);
             return ret;
         }
     }
     ref->offset += (long)offs;
     ref->user_access = user_access;
 
     /* If this member is unnamed, we need to reuse this field */
     if (!dwarf_diename(die_mem))
         return convert_variable_fields(die_mem, varname, field,
                         &ref, die_mem, user_access);
 
 next:
     /* Converting next field */
     if (field->next)
         return convert_variable_fields(die_mem, field->name,
                 field->next, &ref, die_mem, user_access);
     else
         return 0;
 }
 
 static void print_var_not_found(const char *varname)
 {
     pr_err("Failed to find the location of the '%s' variable at this address.\n"
            " Perhaps it has been optimized out.\n"
            " Use -V with the --range option to show '%s' location range.\n",
         varname, varname);
 }
 
 /* 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.\n",
          dwarf_diename(vr_die));
 
     ret = convert_variable_location(vr_die, pf->addr, pf->fb_ops,
                     &pf->sp_die, pf->machine, pf->tvar);
     if (ret == -ENOENT && pf->skip_empty_arg)
         /* This can be found in other place. skip it */
         return 0;
     if (ret == -ENOENT || ret == -EINVAL) {
         print_var_not_found(pf->pvar->var);
     } else if (ret == -ENOTSUP)
         pr_err("Sorry, we don't support this variable location yet.\n");
     else if (ret == 0 && pf->pvar->field) {
         ret = convert_variable_fields(vr_die, pf->pvar->var,
                           pf->pvar->field, &pf->tvar->ref,
                           &die_mem, pf->pvar->user_access);
         vr_die = &die_mem;
     }
     if (ret == 0)
         ret = convert_variable_type(vr_die, pf->tvar, pf->pvar->type,
                         pf->pvar->user_access);
     /* *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, *ptr;
     int ret = 0;
 
     /* Copy raw parameters */
     if (!is_c_varname(pf->pvar->var))
         return copy_to_probe_trace_arg(pf->tvar, pf->pvar);
 
     if (pf->pvar->name)
         pf->tvar->name = strdup(pf->pvar->name);
     else {
         buf = synthesize_perf_probe_arg(pf->pvar);
         if (!buf)
             return -ENOMEM;
         ptr = strchr(buf, ':'); /* Change type separator to _ */
         if (ptr)
             *ptr = '_';
         pf->tvar->name = buf;
     }
     if (pf->tvar->name == NULL)
         return -ENOMEM;
 
     pr_debug("Searching '%s' variable in context.\n", 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)) {
             if (pf->skip_empty_arg)
                 return 0;
             pr_warning("Failed to find '%s' in this function.\n",
                    pf->pvar->var);
             ret = -ENOENT;
         }
     }
     if (ret >= 0)
         ret = convert_variable(&vr_die, pf);
 
     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,
                   const char *function,
                   struct probe_trace_point *tp)
 {
     Dwarf_Addr eaddr;
     GElf_Sym sym;
     const char *symbol;
 
     /* Verify the address is correct */
     if (!dwarf_haspc(sp_die, paddr)) {
         pr_warning("Specified offset is out of %s\n",
                dwarf_diename(sp_die));
         return -EINVAL;
     }
 
     if (dwarf_entrypc(sp_die, &eaddr) == 0) {
         /* If the DIE has entrypc, use it. */
         symbol = dwarf_diename(sp_die);
     } else {
         /* Try to get actual symbol name and address from symtab */
         symbol = dwfl_module_addrsym(mod, paddr, &sym, NULL);
         eaddr = sym.st_value;
     }
     if (!symbol) {
         pr_warning("Failed to find symbol at 0x%lx\n",
                (unsigned long)paddr);
         return -ENOENT;
     }
 
     tp->offset = (unsigned long)(paddr - eaddr);
     tp->address = 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("Failed to find \"%s%%return\",\n"
                    " because %s is an inlined function and"
                    " has no return point.\n", function,
                    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;
     Dwarf_Frame *frame = NULL;
     size_t nops;
     int ret;
 
     if (!sc_die) {
         pr_err("Caller must pass a scope DIE. Program error.\n");
         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)) {
             if (die_find_tailfunc(&pf->cu_die, pf->addr, &pf->sp_die)) {
                 pr_warning("Ignoring tail call from %s\n",
                         dwarf_diename(&pf->sp_die));
                 return 0;
             } else {
                 pr_warning("Failed to find probe point in any "
                        "functions.\n");
                 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_eh != NULL || pf->cfi_dbg != NULL)) {
         if ((dwarf_cfi_addrframe(pf->cfi_eh, pf->addr, &frame) != 0 &&
              (dwarf_cfi_addrframe(pf->cfi_dbg, pf->addr, &frame) != 0)) ||
             dwarf_frame_cfa(frame, &pf->fb_ops, &nops) != 0) {
             pr_warning("Failed to get call frame on 0x%jx\n",
                    (uintmax_t)pf->addr);
             free(frame);
             return -ENOENT;
         }
 #endif
     }
 
     /* Call finder's callback handler */
     ret = pf->callback(sc_die, pf);
 
     /* Since *pf->fb_ops can be a part of frame. we should free it here. */
     free(frame);
     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_match_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;
 }
 
 /* Return innermost DIE */
 static int find_inner_scope_cb(Dwarf_Die *fn_die, void *data)
 {
     struct find_scope_param *fsp = data;
 
     memcpy(fsp->die_mem, fn_die, sizeof(Dwarf_Die));
     fsp->found = true;
     return 1;
 }
 
 /* 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,
     };
     int ret;
 
     ret = cu_walk_functions_at(&pf->cu_die, pf->addr, find_best_scope_cb,
                    &fsp);
     if (!ret && !fsp.found)
         cu_walk_functions_at(&pf->cu_die, pf->addr,
                      find_inner_scope_cb, &fsp);
 
     return fsp.found ? die_mem : NULL;
 }
 
 static int verify_representive_line(struct probe_finder *pf, const char *fname,
                 int lineno, Dwarf_Addr addr)
 {
     const char *__fname, *__func = NULL;
     Dwarf_Die die_mem;
     int __lineno;
 
     /* Verify line number and address by reverse search */
     if (cu_find_lineinfo(&pf->cu_die, addr, &__fname, &__lineno) < 0)
         return 0;
 
     pr_debug2("Reversed line: %s:%d\n", __fname, __lineno);
     if (strcmp(fname, __fname) || lineno == __lineno)
         return 0;
 
     pr_warning("This line is sharing the address with other lines.\n");
 
     if (pf->pev->point.function) {
         /* Find best match function name and lines */
         pf->addr = addr;
         if (find_best_scope(pf, &die_mem)
             && die_match_name(&die_mem, pf->pev->point.function)
             && dwarf_decl_line(&die_mem, &lineno) == 0) {
             __func = dwarf_diename(&die_mem);
             __lineno -= lineno;
         }
     }
     pr_warning("Please try to probe at %s:%d instead.\n",
            __func ? : __fname, __lineno);
 
     return -ENOENT;
 }
 
 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;
 
     if (verify_representive_line(pf, fname, lineno, addr))
         return -ENOENT;
 
     pf->addr = addr;
     sc_die = find_best_scope(pf, &die_mem);
     if (!sc_die) {
         pr_warning("Failed to find scope of probe point.\n");
         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 intlist *list,
                  const char *fname, const char *pat)
 {
     FILE *fp;
     char *line = NULL;
     size_t line_len;
     ssize_t len;
     int count = 0, linenum = 1;
     char sbuf[STRERR_BUFSIZE];
 
     fp = fopen(fname, "r");
     if (!fp) {
         pr_warning("Failed to open %s: %s\n", fname,
                str_error_r(errno, sbuf, sizeof(sbuf)));
         return -errno;
     }
 
     while ((len = getline(&line, &line_len, fp)) > 0) {
 
         if (line[len - 1] == '\n')
             line[len - 1] = '\0';
 
         if (strlazymatch(line, pat)) {
             intlist__add(list, linenum);
             count++;
         }
         linenum++;
     }
 
     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;
     Dwarf_Die *sc_die, die_mem;
     int ret;
 
     if (!intlist__has_entry(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;
     pf->lno = lineno;
     sc_die = find_best_scope(pf, &die_mem);
     if (!sc_die) {
         pr_warning("Failed to find scope of probe point.\n");
         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)
 {
     struct build_id bid;
     char sbuild_id[SBUILD_ID_SIZE] = "";
     int ret = 0;
     char *fpath;
 
     if (intlist__empty(pf->lcache)) {
         const char *comp_dir;
 
         comp_dir = cu_get_comp_dir(&pf->cu_die);
         if (pf->dbg->build_id) {
             build_id__init(&bid, pf->dbg->build_id, BUILD_ID_SIZE);
             build_id__sprintf(&bid, sbuild_id);
         }
         ret = find_source_path(pf->fname, sbuild_id, comp_dir, &fpath);
         if (ret < 0) {
             pr_warning("Failed to find source file path.\n");
             return ret;
         }
 
         /* Matching lazy line pattern */
         ret = find_lazy_match_lines(pf->lcache, fpath,
                         pf->pev->point.lazy_line);
         free(fpath);
         if (ret <= 0)
             return ret;
     }
 
     return die_walk_lines(sp_die, probe_point_lazy_walker, pf);
 }
 
 static void skip_prologue(Dwarf_Die *sp_die, struct probe_finder *pf)
 {
     struct perf_probe_point *pp = &pf->pev->point;
 
     /* Not uprobe? */
     if (!pf->pev->uprobes)
         return;
 
     /* Compiled with optimization? */
     if (die_is_optimized_target(&pf->cu_die))
         return;
 
     /* Don't know entrypc? */
     if (!pf->addr)
         return;
 
     /* Only FUNC and FUNC@SRC are eligible. */
     if (!pp->function || pp->line || pp->retprobe || pp->lazy_line ||
         pp->offset || pp->abs_address)
         return;
 
     /* Not interested in func parameter? */
     if (!perf_probe_with_var(pf->pev))
         return;
 
     pr_info("Target program is compiled without optimization. Skipping prologue.\n"
         "Probe on address 0x%" PRIx64 " to force probing at the function entry.\n\n",
         pf->addr);
 
     die_skip_prologue(sp_die, &pf->cu_die, &pf->addr);
 }
 
 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 (die_entrypc(in_die, &addr) != 0) {
             pr_warning("Failed to get entry address of %s.\n",
                    dwarf_diename(in_die));
             return -ENOENT;
         }
         if (addr == 0) {
             pr_debug("%s has no valid entry address. skipped.\n",
                  dwarf_diename(in_die));
             return -ENOENT;
         }
         pf->addr = addr;
         pf->addr += pp->offset;
         pr_debug("found inline addr: 0x%jx\n",
              (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_match_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;
 
     pr_debug("Matched function: %s [%lx]\n", dwarf_diename(sp_die),
          (unsigned long)dwarf_dieoffset(sp_die));
     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 (die_is_func_instance(sp_die)) {
         /* Instances always have the entry address */
         die_entrypc(sp_die, &pf->addr);
         /* But in some case the entry address is 0 */
         if (pf->addr == 0) {
             pr_debug("%s has no entry PC. Skipped\n",
                  dwarf_diename(sp_die));
             param->retval = 0;
         /* Real function */
         } else if (pp->lazy_line)
             param->retval = find_probe_point_lazy(sp_die, pf);
         else {
             skip_prologue(sp_die, pf);
             pf->addr += pp->offset;
             /* TODO: Check the address in this function */
             param->retval = call_probe_finder(sp_die, pf);
         }
     } else if (!probe_conf.no_inlines) {
         /* Inlined function: search instances */
         param->retval = die_walk_instances(sp_die,
                     probe_point_inline_cb, (void *)pf);
         /* This could be a non-existed inline definition */
         if (param->retval == -ENOENT)
             param->retval = 0;
     }
 
     /* We need to find other candidates */
     if (strisglob(pp->function) && param->retval >= 0) {
         param->retval = 0;  /* We have to clear the result */
         return DWARF_CB_OK;
     }
 
     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_match_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;
 }
 
 static int debuginfo__find_probe_location(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;
 
     off = 0;
     pf->lcache = intlist__new(NULL);
     if (!pf->lcache)
         return -ENOMEM;
 
     /* Fastpath: lookup by function name from .debug_pubnames section */
     if (pp->function && !strisglob(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) {
             off = noff;
             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(&pf->cu_die, pf);
             else {
                 pf->lno = pp->line;
                 ret = find_probe_point_by_line(pf);
             }
             if (ret < 0)
                 break;
         }
         off = noff;
     }
 
 found:
     intlist__delete(pf->lcache);
     pf->lcache = NULL;
 
     return ret;
 }
 
 /* Find probe points from debuginfo */
 static int debuginfo__find_probes(struct debuginfo *dbg,
                   struct probe_finder *pf)
 {
     int ret = 0;
     Elf *elf;
     GElf_Ehdr ehdr;
 
     if (pf->cfi_eh || pf->cfi_dbg)
         return debuginfo__find_probe_location(dbg, pf);
 
     /* Get the call frame information from this dwarf */
     elf = dwarf_getelf(dbg->dbg);
     if (elf == NULL)
         return -EINVAL;
 
     if (gelf_getehdr(elf, &ehdr) == NULL)
         return -EINVAL;
 
     pf->machine = ehdr.e_machine;
 
 #if _ELFUTILS_PREREQ(0, 142)
     do {
         GElf_Shdr shdr;
 
         if (elf_section_by_name(elf, &ehdr, &shdr, ".eh_frame", NULL) &&
             shdr.sh_type == SHT_PROGBITS)
             pf->cfi_eh = dwarf_getcfi_elf(elf);
 
         pf->cfi_dbg = dwarf_getcfi(dbg->dbg);
     } while (0);
 #endif
 
     ret = debuginfo__find_probe_location(dbg, pf);
     return ret;
 }
 
 struct local_vars_finder {
     struct probe_finder *pf;
     struct perf_probe_arg *args;
     bool vars;
     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 && vf->vars)) {
         if (convert_variable_location(die_mem, vf->pf->addr,
                           vf->pf->fb_ops, &pf->sp_die,
                           pf->machine, 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, .vars = false,
                 .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, PROBE_ARG_VARS) == 0)
             vf.vars = true;
         else if (strcmp(pf->pev->args[i].var, PROBE_ARG_PARAMS) != 0) {
             /* Copy normal argument */
             args[n] = pf->pev->args[i];
             n++;
             continue;
         }
         pr_debug("Expanding %s into:", pf->pev->args[i].var);
         vf.nargs = n;
         /* Special local variables */
         die_find_child(sc_die, copy_variables_cb, (void *)&vf,
                    &die_mem);
         pr_debug(" (%d)\n", vf.nargs - n);
         if (vf.ret < 0)
             return vf.ret;
         n = vf.nargs;
     }
     return n;
 }
 
 static bool trace_event_finder_overlap(struct trace_event_finder *tf)
 {
     int i;
 
     for (i = 0; i < tf->ntevs; i++) {
         if (tf->pf.addr == tf->tevs[i].point.address)
             return true;
     }
     return false;
 }
 
 /* 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 perf_probe_point *pp = &pf->pev->point;
     struct probe_trace_event *tev;
     struct perf_probe_arg *args = NULL;
     int ret, i;
 
     /*
      * For some reason (e.g. different column assigned to same address)
      * This callback can be called with the address which already passed.
      * Ignore it first.
      */
     if (trace_event_finder_overlap(tf))
         return 0;
 
     /* 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++];
 
     /* Trace point should be converted from subprogram DIE */
     ret = convert_to_trace_point(&pf->sp_die, tf->mod, pf->addr,
                      pp->retprobe, pp->function, &tev->point);
     if (ret < 0)
         goto end;
 
     tev->point.realname = strdup(dwarf_diename(sc_die));
     if (!tev->point.realname) {
         ret = -ENOMEM;
         goto end;
     }
 
     pr_debug("Probe point found: %s+%lu\n", 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) {
         ret = -ENOMEM;
         goto end;
     }
 
     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:
     if (ret) {
         clear_probe_trace_event(tev);
         tf->ntevs--;
     }
     free(args);
     return ret;
 }
 
 static int fill_empty_trace_arg(struct perf_probe_event *pev,
                 struct probe_trace_event *tevs, int ntevs)
 {
     char **valp;
     char *type;
     int i, j, ret;
 
     if (!ntevs)
         return -ENOENT;
 
     for (i = 0; i < pev->nargs; i++) {
         type = NULL;
         for (j = 0; j < ntevs; j++) {
             if (tevs[j].args[i].value) {
                 type = tevs[j].args[i].type;
                 break;
             }
         }
         if (j == ntevs) {
             print_var_not_found(pev->args[i].var);
             return -ENOENT;
         }
         for (j = 0; j < ntevs; j++) {
             valp = &tevs[j].args[i].value;
             if (*valp)
                 continue;
 
             ret = asprintf(valp, "\\%lx", probe_conf.magic_num);
             if (ret < 0)
                 return -ENOMEM;
             /* Note that type can be NULL */
             if (type) {
                 tevs[j].args[i].type = strdup(type);
                 if (!tevs[j].args[i].type)
                     return -ENOMEM;
             }
         }
     }
     return 0;
 }
 
 /* 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)
 {
     struct trace_event_finder tf = {
             .pf = {.pev = pev, .dbg = dbg, .callback = add_probe_trace_event},
             .max_tevs = probe_conf.max_probes, .mod = dbg->mod};
     int ret, i;
 
     /* Allocate result tevs array */
     *tevs = zalloc(sizeof(struct probe_trace_event) * tf.max_tevs);
     if (*tevs == NULL)
         return -ENOMEM;
 
     tf.tevs = *tevs;
     tf.ntevs = 0;
 
     if (pev->nargs != 0 && immediate_value_is_supported())
         tf.pf.skip_empty_arg = true;
 
     ret = debuginfo__find_probes(dbg, &tf.pf);
     if (ret >= 0 && tf.pf.skip_empty_arg)
         ret = fill_empty_trace_arg(pev, tf.tevs, tf.ntevs);
 
     if (ret < 0 || tf.ntevs == 0) {
         for (i = 0; i < tf.ntevs; i++)
             clear_probe_trace_event(&tf.tevs[i]);
         zfree(tevs);
         return ret;
     }
 
     return (ret < 0) ? ret : tf.ntevs;
 }
 
 /* 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;
     struct strbuf buf = STRBUF_INIT;
     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,
                         af->pf.machine, NULL);
         if (ret == 0 || ret == -ERANGE) {
             int ret2;
             bool externs = !af->child;
 
             if (strbuf_init(&buf, 64) < 0)
                 goto error;
 
             if (probe_conf.show_location_range) {
                 if (!externs)
                     ret2 = strbuf_add(&buf,
                         ret ? "[INV]\t" : "[VAL]\t", 6);
                 else
                     ret2 = strbuf_add(&buf, "[EXT]\t", 6);
                 if (ret2)
                     goto error;
             }
 
             ret2 = die_get_varname(die_mem, &buf);
 
             if (!ret2 && probe_conf.show_location_range &&
                 !externs) {
                 if (strbuf_addch(&buf, '\t') < 0)
                     goto error;
                 ret2 = die_get_var_range(&af->pf.sp_die,
                             die_mem, &buf);
             }
 
             pr_debug("Add new var: %s\n", buf.buf);
             if (ret2 == 0) {
                 strlist__add(vl->vars,
                     strbuf_detach(&buf, NULL));
             }
             strbuf_release(&buf);
         }
     }
 
     if (af->child && dwarf_haspc(die_mem, af->pf.addr))
         return DIE_FIND_CB_CONTINUE;
     else
         return DIE_FIND_CB_SIBLING;
 error:
     strbuf_release(&buf);
     pr_debug("Error in strbuf\n");
     return DIE_FIND_CB_END;
 }
 
 static bool available_var_finder_overlap(struct available_var_finder *af)
 {
     int i;
 
     for (i = 0; i < af->nvls; i++) {
         if (af->pf.addr == af->vls[i].point.address)
             return true;
     }
     return false;
 
 }
 
 /* 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 perf_probe_point *pp = &pf->pev->point;
     struct variable_list *vl;
     Dwarf_Die die_mem;
     int ret;
 
     /*
      * For some reason (e.g. different column assigned to same address),
      * this callback can be called with the address which already passed.
      * Ignore it first.
      */
     if (available_var_finder_overlap(af))
         return 0;
 
     /* 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++];
 
     /* Trace point should be converted from subprogram DIE */
     ret = convert_to_trace_point(&pf->sp_die, af->mod, pf->addr,
                      pp->retprobe, pp->function, &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(NULL, 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 (!probe_conf.show_ext_vars)
         goto out;
     /* Don't need to search child DIE for external vars. */
     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
  * Return the number of found probe points. Return 0 if there is no
  * matched probe point. Return <0 if an error occurs.
  */
 int debuginfo__find_available_vars_at(struct debuginfo *dbg,
                       struct perf_probe_event *pev,
                       struct variable_list **vls)
 {
     struct available_var_finder af = {
             .pf = {.pev = pev, .dbg = dbg, .callback = add_available_vars},
             .mod = dbg->mod,
             .max_vls = probe_conf.max_probes};
     int ret;
 
     /* Allocate result vls array */
     *vls = zalloc(sizeof(struct variable_list) * af.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;
 }
 
 /* For the kernel module, we need a special code to get a DIE */
 int debuginfo__get_text_offset(struct debuginfo *dbg, Dwarf_Addr *offs,
                 bool adjust_offset)
 {
     int n, i;
     Elf32_Word shndx;
     Elf_Scn *scn;
     Elf *elf;
     GElf_Shdr mem, *shdr;
     const char *p;
 
     elf = dwfl_module_getelf(dbg->mod, &dbg->bias);
     if (!elf)
         return -EINVAL;
 
     /* Get the number of relocations */
     n = dwfl_module_relocations(dbg->mod);
     if (n < 0)
         return -ENOENT;
     /* Search the relocation related .text section */
     for (i = 0; i < n; i++) {
         p = dwfl_module_relocation_info(dbg->mod, i, &shndx);
         if (strcmp(p, ".text") == 0) {
             /* OK, get the section header */
             scn = elf_getscn(elf, shndx);
             if (!scn)
                 return -ENOENT;
             shdr = gelf_getshdr(scn, &mem);
             if (!shdr)
                 return -ENOENT;
             *offs = shdr->sh_addr;
             if (adjust_offset)
                 *offs -= shdr->sh_offset;
         }
     }
     return 0;
 }
 
 /* Reverse search */
 int debuginfo__find_probe_point(struct debuginfo *dbg, u64 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;
 
     /* We always need to relocate the address for aranges */
     if (debuginfo__get_text_offset(dbg, &baseaddr, false) == 0)
         addr += baseaddr;
     /* Find cu die */
     if (!dwarf_addrdie(dbg->dbg, (Dwarf_Addr)addr, &cudie)) {
         pr_warning("Failed to find debug information for address %" PRIx64 "\n",
                addr);
         ret = -EINVAL;
         goto end;
     }
 
     /* Find a corresponding line (filename and lineno) */
     cu_find_lineinfo(&cudie, (Dwarf_Addr)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 ||
             die_entrypc(&spdie, &baseaddr) != 0 ||
             dwarf_decl_line(&spdie, &baseline) != 0) {
             lineno = 0;
             goto post;
         }
 
         fname = dwarf_decl_file(&spdie);
         if (addr == 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 (die_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 - 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 intlist__add(lr->line_list, lineno);
 }
 
 static int line_range_walk_cb(const char *fname, int lineno,
                   Dwarf_Addr addr, void *data)
 {
     struct line_finder *lf = data;
     const char *__fname;
     int __lineno;
     int err;
 
     if ((strtailcmp(fname, lf->fname) != 0) ||
         (lf->lno_s > lineno || lf->lno_e < lineno))
         return 0;
 
     /* Make sure this line can be reversible */
     if (cu_find_lineinfo(&lf->cu_die, addr, &__fname, &__lineno) > 0
         && (lineno != __lineno || strcmp(fname, __fname)))
         return 0;
 
     err = line_range_add_line(fname, lineno, lf->lr);
     if (err < 0 && err != -EEXIST)
         return err;
 
     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 (!intlist__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)
 {
     int ret = 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. However, if an error occurs,
      * it should be handled by the caller.
      */
     return ret < 0 ? ret : 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_match_name(sp_die, lr->function) && die_is_func_def(sp_die)) {
         lf->fname = dwarf_decl_file(sp_die);
         dwarf_decl_line(sp_die, &lr->offset);
         pr_debug("fname: %s, lineno:%d\n", lf->fname, lr->offset);
         lf->lno_s = lr->offset + lr->start;
         if (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\n", lf->lno_s, lf->lno_e);
         lr->start = lf->lno_s;
         lr->end = lf->lno_e;
         if (!die_is_func_instance(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) {
             off = noff;
             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\n", lr->path);
     return (ret < 0) ? ret : lf.found;
 }
 
 #ifdef HAVE_DEBUGINFOD_SUPPORT
 /* debuginfod doesn't require the comp_dir but buildid is required */
 static int get_source_from_debuginfod(const char *raw_path,
                 const char *sbuild_id, char **new_path)
 {
     debuginfod_client *c = debuginfod_begin();
     const char *p = raw_path;
     int fd;
 
     if (!c)
         return -ENOMEM;
 
     fd = debuginfod_find_source(c, (const unsigned char *)sbuild_id,
                 0, p, new_path);
     pr_debug("Search %s from debuginfod -> %d\n", p, fd);
     if (fd >= 0)
         close(fd);
     debuginfod_end(c);
     if (fd < 0) {
         pr_debug("Failed to find %s in debuginfod (%s)\n",
             raw_path, sbuild_id);
         return -ENOENT;
     }
     pr_debug("Got a source %s\n", *new_path);
 
     return 0;
 }
 #else
 static inline int get_source_from_debuginfod(const char *raw_path __maybe_unused,
                 const char *sbuild_id __maybe_unused,
                 char **new_path __maybe_unused)
 {
     return -ENOTSUP;
 }
 #endif
 /*
  * Find a src file from a DWARF tag path. Prepend optional source path prefix
  * and chop off leading directories that do not exist. Result is passed back as
  * a newly allocated path on success.
  * Return 0 if file was found and readable, -errno otherwise.
  */
 int find_source_path(const char *raw_path, const char *sbuild_id,
         const char *comp_dir, char **new_path)
 {
     const char *prefix = symbol_conf.source_prefix;
 
     if (sbuild_id && !prefix) {
         if (!get_source_from_debuginfod(raw_path, sbuild_id, new_path))
             return 0;
     }
 
     if (!prefix) {
         if (raw_path[0] != '/' && comp_dir)
             /* If not an absolute path, try to use comp_dir */
             prefix = comp_dir;
         else {
             if (access(raw_path, R_OK) == 0) {
                 *new_path = strdup(raw_path);
                 return *new_path ? 0 : -ENOMEM;
             } else
                 return -errno;
         }
     }
 
     *new_path = malloc((strlen(prefix) + strlen(raw_path) + 2));
     if (!*new_path)
         return -ENOMEM;
 
     for (;;) {
         sprintf(*new_path, "%s/%s", prefix, raw_path);
 
         if (access(*new_path, R_OK) == 0)
             return 0;
 
         if (!symbol_conf.source_prefix) {
             /* In case of searching comp_dir, don't retry */
             zfree(new_path);
             return -errno;
         }
 
         switch (errno) {
         case ENAMETOOLONG:
         case ENOENT:
         case EROFS:
         case EFAULT:
             raw_path = strchr(++raw_path, '/');
             if (!raw_path) {
                 zfree(new_path);
                 return -ENOENT;
             }
             continue;
 
         default:
             zfree(new_path);
             return -errno;
         }
     }
 }

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