Merge tag 'v4.11-rc6' into perf/core, to pick up fixes

[mirror_ubuntu-bionic-kernel.git] / tools / perf / util / probe-event.c

/*
 * probe-event.c : perf-probe definition to probe_events format 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 <stdlib.h>
#include <string.h>
#include <stdarg.h>
#include <limits.h>
#include <elf.h>

#include "util.h"
#include "event.h"
#include "strlist.h"
#include "debug.h"
#include "cache.h"
#include "color.h"
#include "symbol.h"
#include "thread.h"
#include <api/fs/fs.h>
#include "trace-event.h"        /* For __maybe_unused */
#include "probe-event.h"
#include "probe-finder.h"
#include "probe-file.h"
#include "session.h"

#define PERFPROBE_GROUP "probe"

bool probe_event_dry_run;       /* Dry run flag */
struct probe_conf probe_conf;

#define semantic_error(msg ...) pr_err("Semantic error :" msg)

int e_snprintf(char *str, size_t size, const char *format, ...)
{
        int ret;
        va_list ap;
        va_start(ap, format);
        ret = vsnprintf(str, size, format, ap);
        va_end(ap);
        if (ret >= (int)size)
                ret = -E2BIG;
        return ret;
}

static struct machine *host_machine;

/* Initialize symbol maps and path of vmlinux/modules */
int init_probe_symbol_maps(bool user_only)
{
        int ret;

        symbol_conf.sort_by_name = true;
        symbol_conf.allow_aliases = true;
        ret = symbol__init(NULL);
        if (ret < 0) {
                pr_debug("Failed to init symbol map.\n");
                goto out;
        }

        if (host_machine || user_only)  /* already initialized */
                return 0;

        if (symbol_conf.vmlinux_name)
                pr_debug("Use vmlinux: %s\n", symbol_conf.vmlinux_name);

        host_machine = machine__new_host();
        if (!host_machine) {
                pr_debug("machine__new_host() failed.\n");
                symbol__exit();
                ret = -1;
        }
out:
        if (ret < 0)
                pr_warning("Failed to init vmlinux path.\n");
        return ret;
}

void exit_probe_symbol_maps(void)
{
        machine__delete(host_machine);
        host_machine = NULL;
        symbol__exit();
}

static struct symbol *__find_kernel_function_by_name(const char *name,
                                                     struct map **mapp)
{
        return machine__find_kernel_function_by_name(host_machine, name, mapp);
}

static struct symbol *__find_kernel_function(u64 addr, struct map **mapp)
{
        return machine__find_kernel_function(host_machine, addr, mapp);
}

static struct ref_reloc_sym *kernel_get_ref_reloc_sym(void)
{
        /* kmap->ref_reloc_sym should be set if host_machine is initialized */
        struct kmap *kmap;
        struct map *map = machine__kernel_map(host_machine);

        if (map__load(map) < 0)
                return NULL;

        kmap = map__kmap(map);
        if (!kmap)
                return NULL;
        return kmap->ref_reloc_sym;
}

static int kernel_get_symbol_address_by_name(const char *name, u64 *addr,
                                             bool reloc, bool reladdr)
{
        struct ref_reloc_sym *reloc_sym;
        struct symbol *sym;
        struct map *map;

        /* ref_reloc_sym is just a label. Need a special fix*/
        reloc_sym = kernel_get_ref_reloc_sym();
        if (reloc_sym && strcmp(name, reloc_sym->name) == 0)
                *addr = (reloc) ? reloc_sym->addr : reloc_sym->unrelocated_addr;
        else {
                sym = __find_kernel_function_by_name(name, &map);
                if (!sym)
                        return -ENOENT;
                *addr = map->unmap_ip(map, sym->start) -
                        ((reloc) ? 0 : map->reloc) -
                        ((reladdr) ? map->start : 0);
        }
        return 0;
}

static struct map *kernel_get_module_map(const char *module)
{
        struct map_groups *grp = &host_machine->kmaps;
        struct maps *maps = &grp->maps[MAP__FUNCTION];
        struct map *pos;

        /* A file path -- this is an offline module */
        if (module && strchr(module, '/'))
                return dso__new_map(module);

        if (!module)
                module = "kernel";

        for (pos = maps__first(maps); pos; pos = map__next(pos)) {
                /* short_name is "[module]" */
                if (strncmp(pos->dso->short_name + 1, module,
                            pos->dso->short_name_len - 2) == 0 &&
                    module[pos->dso->short_name_len - 2] == '\0') {
                        map__get(pos);
                        return pos;
                }
        }
        return NULL;
}

struct map *get_target_map(const char *target, bool user)
{
        /* Init maps of given executable or kernel */
        if (user)
                return dso__new_map(target);
        else
                return kernel_get_module_map(target);
}

static int convert_exec_to_group(const char *exec, char **result)
{
        char *ptr1, *ptr2, *exec_copy;
        char buf[64];
        int ret;

        exec_copy = strdup(exec);
        if (!exec_copy)
                return -ENOMEM;

        ptr1 = basename(exec_copy);
        if (!ptr1) {
                ret = -EINVAL;
                goto out;
        }

        for (ptr2 = ptr1; *ptr2 != '\0'; ptr2++) {
                if (!isalnum(*ptr2) && *ptr2 != '_') {
                        *ptr2 = '\0';
                        break;
                }
        }

        ret = e_snprintf(buf, 64, "%s_%s", PERFPROBE_GROUP, ptr1);
        if (ret < 0)
                goto out;

        *result = strdup(buf);
        ret = *result ? 0 : -ENOMEM;

out:
        free(exec_copy);
        return ret;
}

static void clear_perf_probe_point(struct perf_probe_point *pp)
{
        free(pp->file);
        free(pp->function);
        free(pp->lazy_line);
}

static void clear_probe_trace_events(struct probe_trace_event *tevs, int ntevs)
{
        int i;

        for (i = 0; i < ntevs; i++)
                clear_probe_trace_event(tevs + i);
}

static bool kprobe_blacklist__listed(unsigned long address);
static bool kprobe_warn_out_range(const char *symbol, unsigned long address)
{
        u64 etext_addr = 0;
        int ret;

        /* Get the address of _etext for checking non-probable text symbol */
        ret = kernel_get_symbol_address_by_name("_etext", &etext_addr,
                                                false, false);

        if (ret == 0 && etext_addr < address)
                pr_warning("%s is out of .text, skip it.\n", symbol);
        else if (kprobe_blacklist__listed(address))
                pr_warning("%s is blacklisted function, skip it.\n", symbol);
        else
                return false;

        return true;
}

/*
 * @module can be module name of module file path. In case of path,
 * inspect elf and find out what is actual module name.
 * Caller has to free mod_name after using it.
 */
static char *find_module_name(const char *module)
{
        int fd;
        Elf *elf;
        GElf_Ehdr ehdr;
        GElf_Shdr shdr;
        Elf_Data *data;
        Elf_Scn *sec;
        char *mod_name = NULL;
        int name_offset;

        fd = open(module, O_RDONLY);
        if (fd < 0)
                return NULL;

        elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
        if (elf == NULL)
                goto elf_err;

        if (gelf_getehdr(elf, &ehdr) == NULL)
                goto ret_err;

        sec = elf_section_by_name(elf, &ehdr, &shdr,
                        ".gnu.linkonce.this_module", NULL);
        if (!sec)
                goto ret_err;

        data = elf_getdata(sec, NULL);
        if (!data || !data->d_buf)
                goto ret_err;

        /*
         * NOTE:
         * '.gnu.linkonce.this_module' section of kernel module elf directly
         * maps to 'struct module' from linux/module.h. This section contains
         * actual module name which will be used by kernel after loading it.
         * But, we cannot use 'struct module' here since linux/module.h is not
         * exposed to user-space. Offset of 'name' has remained same from long
         * time, so hardcoding it here.
         */
        if (ehdr.e_ident[EI_CLASS] == ELFCLASS32)
                name_offset = 12;
        else    /* expect ELFCLASS64 by default */
                name_offset = 24;

        mod_name = strdup((char *)data->d_buf + name_offset);

ret_err:
        elf_end(elf);
elf_err:
        close(fd);
        return mod_name;
}

#ifdef HAVE_DWARF_SUPPORT

static int kernel_get_module_dso(const char *module, struct dso **pdso)
{
        struct dso *dso;
        struct map *map;
        const char *vmlinux_name;
        int ret = 0;

        if (module) {
                char module_name[128];

                snprintf(module_name, sizeof(module_name), "[%s]", module);
                map = map_groups__find_by_name(&host_machine->kmaps, MAP__FUNCTION, module_name);
                if (map) {
                        dso = map->dso;
                        goto found;
                }
                pr_debug("Failed to find module %s.\n", module);
                return -ENOENT;
        }

        map = machine__kernel_map(host_machine);
        dso = map->dso;

        vmlinux_name = symbol_conf.vmlinux_name;
        dso->load_errno = 0;
        if (vmlinux_name)
                ret = dso__load_vmlinux(dso, map, vmlinux_name, false);
        else
                ret = dso__load_vmlinux_path(dso, map);
found:
        *pdso = dso;
        return ret;
}

/*
 * Some binaries like glibc have special symbols which are on the symbol
 * table, but not in the debuginfo. If we can find the address of the
 * symbol from map, we can translate the address back to the probe point.
 */
static int find_alternative_probe_point(struct debuginfo *dinfo,
                                        struct perf_probe_point *pp,
                                        struct perf_probe_point *result,
                                        const char *target, bool uprobes)
{
        struct map *map = NULL;
        struct symbol *sym;
        u64 address = 0;
        int ret = -ENOENT;

        /* This can work only for function-name based one */
        if (!pp->function || pp->file)
                return -ENOTSUP;

        map = get_target_map(target, uprobes);
        if (!map)
                return -EINVAL;

        /* Find the address of given function */
        map__for_each_symbol_by_name(map, pp->function, sym) {
                if (uprobes)
                        address = sym->start;
                else
                        address = map->unmap_ip(map, sym->start) - map->reloc;
                break;
        }
        if (!address) {
                ret = -ENOENT;
                goto out;
        }
        pr_debug("Symbol %s address found : %" PRIx64 "\n",
                        pp->function, address);

        ret = debuginfo__find_probe_point(dinfo, (unsigned long)address,
                                          result);
        if (ret <= 0)
                ret = (!ret) ? -ENOENT : ret;
        else {
                result->offset += pp->offset;
                result->line += pp->line;
                result->retprobe = pp->retprobe;
                ret = 0;
        }

out:
        map__put(map);
        return ret;

}

static int get_alternative_probe_event(struct debuginfo *dinfo,
                                       struct perf_probe_event *pev,
                                       struct perf_probe_point *tmp)
{
        int ret;

        memcpy(tmp, &pev->point, sizeof(*tmp));
        memset(&pev->point, 0, sizeof(pev->point));
        ret = find_alternative_probe_point(dinfo, tmp, &pev->point,
                                           pev->target, pev->uprobes);
        if (ret < 0)
                memcpy(&pev->point, tmp, sizeof(*tmp));

        return ret;
}

static int get_alternative_line_range(struct debuginfo *dinfo,
                                      struct line_range *lr,
                                      const char *target, bool user)
{
        struct perf_probe_point pp = { .function = lr->function,
                                       .file = lr->file,
                                       .line = lr->start };
        struct perf_probe_point result;
        int ret, len = 0;

        memset(&result, 0, sizeof(result));

        if (lr->end != INT_MAX)
                len = lr->end - lr->start;
        ret = find_alternative_probe_point(dinfo, &pp, &result,
                                           target, user);
        if (!ret) {
                lr->function = result.function;
                lr->file = result.file;
                lr->start = result.line;
                if (lr->end != INT_MAX)
                        lr->end = lr->start + len;
                clear_perf_probe_point(&pp);
        }
        return ret;
}

/* Open new debuginfo of given module */
static struct debuginfo *open_debuginfo(const char *module, bool silent)
{
        const char *path = module;
        char reason[STRERR_BUFSIZE];
        struct debuginfo *ret = NULL;
        struct dso *dso = NULL;
        int err;

        if (!module || !strchr(module, '/')) {
                err = kernel_get_module_dso(module, &dso);
                if (err < 0) {
                        if (!dso || dso->load_errno == 0) {
                                if (!str_error_r(-err, reason, STRERR_BUFSIZE))
                                        strcpy(reason, "(unknown)");
                        } else
                                dso__strerror_load(dso, reason, STRERR_BUFSIZE);
                        if (!silent)
                                pr_err("Failed to find the path for %s: %s\n",
                                        module ?: "kernel", reason);
                        return NULL;
                }
                path = dso->long_name;
        }
        ret = debuginfo__new(path);
        if (!ret && !silent) {
                pr_warning("The %s file has no debug information.\n", path);
                if (!module || !strtailcmp(path, ".ko"))
                        pr_warning("Rebuild with CONFIG_DEBUG_INFO=y, ");
                else
                        pr_warning("Rebuild with -g, ");
                pr_warning("or install an appropriate debuginfo package.\n");
        }
        return ret;
}

/* For caching the last debuginfo */
static struct debuginfo *debuginfo_cache;
static char *debuginfo_cache_path;

static struct debuginfo *debuginfo_cache__open(const char *module, bool silent)
{
        const char *path = module;

        /* If the module is NULL, it should be the kernel. */
        if (!module)
                path = "kernel";

        if (debuginfo_cache_path && !strcmp(debuginfo_cache_path, path))
                goto out;

        /* Copy module path */
        free(debuginfo_cache_path);
        debuginfo_cache_path = strdup(path);
        if (!debuginfo_cache_path) {
                debuginfo__delete(debuginfo_cache);
                debuginfo_cache = NULL;
                goto out;
        }

        debuginfo_cache = open_debuginfo(module, silent);
        if (!debuginfo_cache)
                zfree(&debuginfo_cache_path);
out:
        return debuginfo_cache;
}

static void debuginfo_cache__exit(void)
{
        debuginfo__delete(debuginfo_cache);
        debuginfo_cache = NULL;
        zfree(&debuginfo_cache_path);
}


static int get_text_start_address(const char *exec, unsigned long *address)
{
        Elf *elf;
        GElf_Ehdr ehdr;
        GElf_Shdr shdr;
        int fd, ret = -ENOENT;

        fd = open(exec, O_RDONLY);
        if (fd < 0)
                return -errno;

        elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
        if (elf == NULL) {
                ret = -EINVAL;
                goto out_close;
        }

        if (gelf_getehdr(elf, &ehdr) == NULL)
                goto out;

        if (!elf_section_by_name(elf, &ehdr, &shdr, ".text", NULL))
                goto out;

        *address = shdr.sh_addr - shdr.sh_offset;
        ret = 0;
out:
        elf_end(elf);
out_close:
        close(fd);

        return ret;
}

/*
 * Convert trace point to probe point with debuginfo
 */
static int find_perf_probe_point_from_dwarf(struct probe_trace_point *tp,
                                            struct perf_probe_point *pp,
                                            bool is_kprobe)
{
        struct debuginfo *dinfo = NULL;
        unsigned long stext = 0;
        u64 addr = tp->address;
        int ret = -ENOENT;

        /* convert the address to dwarf address */
        if (!is_kprobe) {
                if (!addr) {
                        ret = -EINVAL;
                        goto error;
                }
                ret = get_text_start_address(tp->module, &stext);
                if (ret < 0)
                        goto error;
                addr += stext;
        } else if (tp->symbol) {
                /* If the module is given, this returns relative address */
                ret = kernel_get_symbol_address_by_name(tp->symbol, &addr,
                                                        false, !!tp->module);
                if (ret != 0)
                        goto error;
                addr += tp->offset;
        }

        pr_debug("try to find information at %" PRIx64 " in %s\n", addr,
                 tp->module ? : "kernel");

        dinfo = debuginfo_cache__open(tp->module, verbose <= 0);
        if (dinfo)
                ret = debuginfo__find_probe_point(dinfo,
                                                 (unsigned long)addr, pp);
        else
                ret = -ENOENT;

        if (ret > 0) {
                pp->retprobe = tp->retprobe;
                return 0;
        }
error:
        pr_debug("Failed to find corresponding probes from debuginfo.\n");
        return ret ? : -ENOENT;
}

/* Adjust symbol name and address */
static int post_process_probe_trace_point(struct probe_trace_point *tp,
                                           struct map *map, unsigned long offs)
{
        struct symbol *sym;
        u64 addr = tp->address + tp->offset - offs;

        sym = map__find_symbol(map, addr);
        if (!sym)
                return -ENOENT;

        if (strcmp(sym->name, tp->symbol)) {
                /* If we have no realname, use symbol for it */
                if (!tp->realname)
                        tp->realname = tp->symbol;
                else
                        free(tp->symbol);
                tp->symbol = strdup(sym->name);
                if (!tp->symbol)
                        return -ENOMEM;
        }
        tp->offset = addr - sym->start;
        tp->address -= offs;

        return 0;
}

/*
 * Rename DWARF symbols to ELF symbols -- gcc sometimes optimizes functions
 * and generate new symbols with suffixes such as .constprop.N or .isra.N
 * etc. Since those symbols are not recorded in DWARF, we have to find
 * correct generated symbols from offline ELF binary.
 * For online kernel or uprobes we don't need this because those are
 * rebased on _text, or already a section relative address.
 */
static int
post_process_offline_probe_trace_events(struct probe_trace_event *tevs,
                                        int ntevs, const char *pathname)
{
        struct map *map;
        unsigned long stext = 0;
        int i, ret = 0;

        /* Prepare a map for offline binary */
        map = dso__new_map(pathname);
        if (!map || get_text_start_address(pathname, &stext) < 0) {
                pr_warning("Failed to get ELF symbols for %s\n", pathname);
                return -EINVAL;
        }

        for (i = 0; i < ntevs; i++) {
                ret = post_process_probe_trace_point(&tevs[i].point,
                                                     map, stext);
                if (ret < 0)
                        break;
        }
        map__put(map);

        return ret;
}

static int add_exec_to_probe_trace_events(struct probe_trace_event *tevs,
                                          int ntevs, const char *exec)
{
        int i, ret = 0;
        unsigned long stext = 0;

        if (!exec)
                return 0;

        ret = get_text_start_address(exec, &stext);
        if (ret < 0)
                return ret;

        for (i = 0; i < ntevs && ret >= 0; i++) {
                /* point.address is the addres of point.symbol + point.offset */
                tevs[i].point.address -= stext;
                tevs[i].point.module = strdup(exec);
                if (!tevs[i].point.module) {
                        ret = -ENOMEM;
                        break;
                }
                tevs[i].uprobes = true;
        }

        return ret;
}

static int
post_process_module_probe_trace_events(struct probe_trace_event *tevs,
                                       int ntevs, const char *module,
                                       struct debuginfo *dinfo)
{
        Dwarf_Addr text_offs = 0;
        int i, ret = 0;
        char *mod_name = NULL;
        struct map *map;

        if (!module)
                return 0;

        map = get_target_map(module, false);
        if (!map || debuginfo__get_text_offset(dinfo, &text_offs, true) < 0) {
                pr_warning("Failed to get ELF symbols for %s\n", module);
                return -EINVAL;
        }

        mod_name = find_module_name(module);
        for (i = 0; i < ntevs; i++) {
                ret = post_process_probe_trace_point(&tevs[i].point,
                                                map, (unsigned long)text_offs);
                if (ret < 0)
                        break;
                tevs[i].point.module =
                        strdup(mod_name ? mod_name : module);
                if (!tevs[i].point.module) {
                        ret = -ENOMEM;
                        break;
                }
        }

        free(mod_name);
        map__put(map);

        return ret;
}

static int
post_process_kernel_probe_trace_events(struct probe_trace_event *tevs,
                                       int ntevs)
{
        struct ref_reloc_sym *reloc_sym;
        char *tmp;
        int i, skipped = 0;

        /* Skip post process if the target is an offline kernel */
        if (symbol_conf.ignore_vmlinux_buildid)
                return post_process_offline_probe_trace_events(tevs, ntevs,
                                                symbol_conf.vmlinux_name);

        reloc_sym = kernel_get_ref_reloc_sym();
        if (!reloc_sym) {
                pr_warning("Relocated base symbol is not found!\n");
                return -EINVAL;
        }

        for (i = 0; i < ntevs; i++) {
                if (!tevs[i].point.address)
                        continue;
                if (tevs[i].point.retprobe && !kretprobe_offset_is_supported())
                        continue;
                /* If we found a wrong one, mark it by NULL symbol */
                if (kprobe_warn_out_range(tevs[i].point.symbol,
                                          tevs[i].point.address)) {
                        tmp = NULL;
                        skipped++;
                } else {
                        tmp = strdup(reloc_sym->name);
                        if (!tmp)
                                return -ENOMEM;
                }
                /* If we have no realname, use symbol for it */
                if (!tevs[i].point.realname)
                        tevs[i].point.realname = tevs[i].point.symbol;
                else
                        free(tevs[i].point.symbol);
                tevs[i].point.symbol = tmp;
                tevs[i].point.offset = tevs[i].point.address -
                                       reloc_sym->unrelocated_addr;
        }
        return skipped;
}

void __weak
arch__post_process_probe_trace_events(struct perf_probe_event *pev __maybe_unused,
                                      int ntevs __maybe_unused)
{
}

/* Post processing the probe events */
static int post_process_probe_trace_events(struct perf_probe_event *pev,
                                           struct probe_trace_event *tevs,
                                           int ntevs, const char *module,
                                           bool uprobe, struct debuginfo *dinfo)
{
        int ret;

        if (uprobe)
                ret = add_exec_to_probe_trace_events(tevs, ntevs, module);
        else if (module)
                /* Currently ref_reloc_sym based probe is not for drivers */
                ret = post_process_module_probe_trace_events(tevs, ntevs,
                                                             module, dinfo);
        else
                ret = post_process_kernel_probe_trace_events(tevs, ntevs);

        if (ret >= 0)
                arch__post_process_probe_trace_events(pev, ntevs);

        return ret;
}

/* Try to find perf_probe_event with debuginfo */
static int try_to_find_probe_trace_events(struct perf_probe_event *pev,
                                          struct probe_trace_event **tevs)
{
        bool need_dwarf = perf_probe_event_need_dwarf(pev);
        struct perf_probe_point tmp;
        struct debuginfo *dinfo;
        int ntevs, ret = 0;

        dinfo = open_debuginfo(pev->target, !need_dwarf);
        if (!dinfo) {
                if (need_dwarf)
                        return -ENOENT;
                pr_debug("Could not open debuginfo. Try to use symbols.\n");
                return 0;
        }

        pr_debug("Try to find probe point from debuginfo.\n");
        /* Searching trace events corresponding to a probe event */
        ntevs = debuginfo__find_trace_events(dinfo, pev, tevs);

        if (ntevs == 0) {  /* Not found, retry with an alternative */
                ret = get_alternative_probe_event(dinfo, pev, &tmp);
                if (!ret) {
                        ntevs = debuginfo__find_trace_events(dinfo, pev, tevs);
                        /*
                         * Write back to the original probe_event for
                         * setting appropriate (user given) event name
                         */
                        clear_perf_probe_point(&pev->point);
                        memcpy(&pev->point, &tmp, sizeof(tmp));
                }
        }

        if (ntevs > 0) {        /* Succeeded to find trace events */
                pr_debug("Found %d probe_trace_events.\n", ntevs);
                ret = post_process_probe_trace_events(pev, *tevs, ntevs,
                                        pev->target, pev->uprobes, dinfo);
                if (ret < 0 || ret == ntevs) {
                        pr_debug("Post processing failed or all events are skipped. (%d)\n", ret);
                        clear_probe_trace_events(*tevs, ntevs);
                        zfree(tevs);
                        ntevs = 0;
                }
        }

        debuginfo__delete(dinfo);

        if (ntevs == 0) {       /* No error but failed to find probe point. */
                pr_warning("Probe point '%s' not found.\n",
                           synthesize_perf_probe_point(&pev->point));
                return -ENOENT;
        } else if (ntevs < 0) {
                /* Error path : ntevs < 0 */
                pr_debug("An error occurred in debuginfo analysis (%d).\n", ntevs);
                if (ntevs == -EBADF)
                        pr_warning("Warning: No dwarf info found in the vmlinux - "
                                "please rebuild kernel with CONFIG_DEBUG_INFO=y.\n");
                if (!need_dwarf) {
                        pr_debug("Trying to use symbols.\n");
                        return 0;
                }
        }
        return ntevs;
}

#define LINEBUF_SIZE 256
#define NR_ADDITIONAL_LINES 2

static int __show_one_line(FILE *fp, int l, bool skip, bool show_num)
{
        char buf[LINEBUF_SIZE], sbuf[STRERR_BUFSIZE];
        const char *color = show_num ? "" : PERF_COLOR_BLUE;
        const char *prefix = NULL;

        do {
                if (fgets(buf, LINEBUF_SIZE, fp) == NULL)
                        goto error;
                if (skip)
                        continue;
                if (!prefix) {
                        prefix = show_num ? "%7d  " : "         ";
                        color_fprintf(stdout, color, prefix, l);
                }
                color_fprintf(stdout, color, "%s", buf);

        } while (strchr(buf, '\n') == NULL);

        return 1;
error:
        if (ferror(fp)) {
                pr_warning("File read error: %s\n",
                           str_error_r(errno, sbuf, sizeof(sbuf)));
                return -1;
        }
        return 0;
}

static int _show_one_line(FILE *fp, int l, bool skip, bool show_num)
{
        int rv = __show_one_line(fp, l, skip, show_num);
        if (rv == 0) {
                pr_warning("Source file is shorter than expected.\n");
                rv = -1;
        }
        return rv;
}

#define show_one_line_with_num(f,l)     _show_one_line(f,l,false,true)
#define show_one_line(f,l)              _show_one_line(f,l,false,false)
#define skip_one_line(f,l)              _show_one_line(f,l,true,false)
#define show_one_line_or_eof(f,l)       __show_one_line(f,l,false,false)

/*
 * Show line-range always requires debuginfo to find source file and
 * line number.
 */
static int __show_line_range(struct line_range *lr, const char *module,
                             bool user)
{
        int l = 1;
        struct int_node *ln;
        struct debuginfo *dinfo;
        FILE *fp;
        int ret;
        char *tmp;
        char sbuf[STRERR_BUFSIZE];

        /* Search a line range */
        dinfo = open_debuginfo(module, false);
        if (!dinfo)
                return -ENOENT;

        ret = debuginfo__find_line_range(dinfo, lr);
        if (!ret) {     /* Not found, retry with an alternative */
                ret = get_alternative_line_range(dinfo, lr, module, user);
                if (!ret)
                        ret = debuginfo__find_line_range(dinfo, lr);
        }
        debuginfo__delete(dinfo);
        if (ret == 0 || ret == -ENOENT) {
                pr_warning("Specified source line is not found.\n");
                return -ENOENT;
        } else if (ret < 0) {
                pr_warning("Debuginfo analysis failed.\n");
                return ret;
        }

        /* Convert source file path */
        tmp = lr->path;
        ret = get_real_path(tmp, lr->comp_dir, &lr->path);

        /* Free old path when new path is assigned */
        if (tmp != lr->path)
                free(tmp);

        if (ret < 0) {
                pr_warning("Failed to find source file path.\n");
                return ret;
        }

        setup_pager();

        if (lr->function)
                fprintf(stdout, "<%s@%s:%d>\n", lr->function, lr->path,
                        lr->start - lr->offset);
        else
                fprintf(stdout, "<%s:%d>\n", lr->path, lr->start);

        fp = fopen(lr->path, "r");
        if (fp == NULL) {
                pr_warning("Failed to open %s: %s\n", lr->path,
                           str_error_r(errno, sbuf, sizeof(sbuf)));
                return -errno;
        }
        /* Skip to starting line number */
        while (l < lr->start) {
                ret = skip_one_line(fp, l++);
                if (ret < 0)
                        goto end;
        }

        intlist__for_each_entry(ln, lr->line_list) {
                for (; ln->i > l; l++) {
                        ret = show_one_line(fp, l - lr->offset);
                        if (ret < 0)
                                goto end;
                }
                ret = show_one_line_with_num(fp, l++ - lr->offset);
                if (ret < 0)
                        goto end;
        }

        if (lr->end == INT_MAX)
                lr->end = l + NR_ADDITIONAL_LINES;
        while (l <= lr->end) {
                ret = show_one_line_or_eof(fp, l++ - lr->offset);
                if (ret <= 0)
                        break;
        }
end:
        fclose(fp);
        return ret;
}

int show_line_range(struct line_range *lr, const char *module, bool user)
{
        int ret;

        ret = init_probe_symbol_maps(user);
        if (ret < 0)
                return ret;
        ret = __show_line_range(lr, module, user);
        exit_probe_symbol_maps();

        return ret;
}

static int show_available_vars_at(struct debuginfo *dinfo,
                                  struct perf_probe_event *pev,
                                  struct strfilter *_filter)
{
        char *buf;
        int ret, i, nvars;
        struct str_node *node;
        struct variable_list *vls = NULL, *vl;
        struct perf_probe_point tmp;
        const char *var;

        buf = synthesize_perf_probe_point(&pev->point);
        if (!buf)
                return -EINVAL;
        pr_debug("Searching variables at %s\n", buf);

        ret = debuginfo__find_available_vars_at(dinfo, pev, &vls);
        if (!ret) {  /* Not found, retry with an alternative */
                ret = get_alternative_probe_event(dinfo, pev, &tmp);
                if (!ret) {
                        ret = debuginfo__find_available_vars_at(dinfo, pev,
                                                                &vls);
                        /* Release the old probe_point */
                        clear_perf_probe_point(&tmp);
                }
        }
        if (ret <= 0) {
                if (ret == 0 || ret == -ENOENT) {
                        pr_err("Failed to find the address of %s\n", buf);
                        ret = -ENOENT;
                } else
                        pr_warning("Debuginfo analysis failed.\n");
                goto end;
        }

        /* Some variables are found */
        fprintf(stdout, "Available variables at %s\n", buf);
        for (i = 0; i < ret; i++) {
                vl = &vls[i];
                /*
                 * A probe point might be converted to
                 * several trace points.
                 */
                fprintf(stdout, "\t@<%s+%lu>\n", vl->point.symbol,
                        vl->point.offset);
                zfree(&vl->point.symbol);
                nvars = 0;
                if (vl->vars) {
                        strlist__for_each_entry(node, vl->vars) {
                                var = strchr(node->s, '\t') + 1;
                                if (strfilter__compare(_filter, var)) {
                                        fprintf(stdout, "\t\t%s\n", node->s);
                                        nvars++;
                                }
                        }
                        strlist__delete(vl->vars);
                }
                if (nvars == 0)
                        fprintf(stdout, "\t\t(No matched variables)\n");
        }
        free(vls);
end:
        free(buf);
        return ret;
}

/* Show available variables on given probe point */
int show_available_vars(struct perf_probe_event *pevs, int npevs,
                        struct strfilter *_filter)
{
        int i, ret = 0;
        struct debuginfo *dinfo;

        ret = init_probe_symbol_maps(pevs->uprobes);
        if (ret < 0)
                return ret;

        dinfo = open_debuginfo(pevs->target, false);
        if (!dinfo) {
                ret = -ENOENT;
                goto out;
        }

        setup_pager();

        for (i = 0; i < npevs && ret >= 0; i++)
                ret = show_available_vars_at(dinfo, &pevs[i], _filter);

        debuginfo__delete(dinfo);
out:
        exit_probe_symbol_maps();
        return ret;
}

#else   /* !HAVE_DWARF_SUPPORT */

static void debuginfo_cache__exit(void)
{
}

static int
find_perf_probe_point_from_dwarf(struct probe_trace_point *tp __maybe_unused,
                                 struct perf_probe_point *pp __maybe_unused,
                                 bool is_kprobe __maybe_unused)
{
        return -ENOSYS;
}

static int try_to_find_probe_trace_events(struct perf_probe_event *pev,
                                struct probe_trace_event **tevs __maybe_unused)
{
        if (perf_probe_event_need_dwarf(pev)) {
                pr_warning("Debuginfo-analysis is not supported.\n");
                return -ENOSYS;
        }

        return 0;
}

int show_line_range(struct line_range *lr __maybe_unused,
                    const char *module __maybe_unused,
                    bool user __maybe_unused)
{
        pr_warning("Debuginfo-analysis is not supported.\n");
        return -ENOSYS;
}

int show_available_vars(struct perf_probe_event *pevs __maybe_unused,
                        int npevs __maybe_unused,
                        struct strfilter *filter __maybe_unused)
{
        pr_warning("Debuginfo-analysis is not supported.\n");
        return -ENOSYS;
}
#endif

void line_range__clear(struct line_range *lr)
{
        free(lr->function);
        free(lr->file);
        free(lr->path);
        free(lr->comp_dir);
        intlist__delete(lr->line_list);
        memset(lr, 0, sizeof(*lr));
}

int line_range__init(struct line_range *lr)
{
        memset(lr, 0, sizeof(*lr));
        lr->line_list = intlist__new(NULL);
        if (!lr->line_list)
                return -ENOMEM;
        else
                return 0;
}

static int parse_line_num(char **ptr, int *val, const char *what)
{
        const char *start = *ptr;

        errno = 0;
        *val = strtol(*ptr, ptr, 0);
        if (errno || *ptr == start) {
                semantic_error("'%s' is not a valid number.\n", what);
                return -EINVAL;
        }
        return 0;
}

/* Check the name is good for event, group or function */
static bool is_c_func_name(const char *name)
{
        if (!isalpha(*name) && *name != '_')
                return false;
        while (*++name != '\0') {
                if (!isalpha(*name) && !isdigit(*name) && *name != '_')
                        return false;
        }
        return true;
}

/*
 * Stuff 'lr' according to the line range described by 'arg'.
 * The line range syntax is described by:
 *
 *         SRC[:SLN[+NUM|-ELN]]
 *         FNC[@SRC][:SLN[+NUM|-ELN]]
 */
int parse_line_range_desc(const char *arg, struct line_range *lr)
{
        char *range, *file, *name = strdup(arg);
        int err;

        if (!name)
                return -ENOMEM;

        lr->start = 0;
        lr->end = INT_MAX;

        range = strchr(name, ':');
        if (range) {
                *range++ = '\0';

                err = parse_line_num(&range, &lr->start, "start line");
                if (err)
                        goto err;

                if (*range == '+' || *range == '-') {
                        const char c = *range++;

                        err = parse_line_num(&range, &lr->end, "end line");
                        if (err)
                                goto err;

                        if (c == '+') {
                                lr->end += lr->start;
                                /*
                                 * Adjust the number of lines here.
                                 * If the number of lines == 1, the
                                 * the end of line should be equal to
                                 * the start of line.
                                 */
                                lr->end--;
                        }
                }

                pr_debug("Line range is %d to %d\n", lr->start, lr->end);

                err = -EINVAL;
                if (lr->start > lr->end) {
                        semantic_error("Start line must be smaller"
                                       " than end line.\n");
                        goto err;
                }
                if (*range != '\0') {
                        semantic_error("Tailing with invalid str '%s'.\n", range);
                        goto err;
                }
        }

        file = strchr(name, '@');
        if (file) {
                *file = '\0';
                lr->file = strdup(++file);
                if (lr->file == NULL) {
                        err = -ENOMEM;
                        goto err;
                }
                lr->function = name;
        } else if (strchr(name, '/') || strchr(name, '.'))
                lr->file = name;
        else if (is_c_func_name(name))/* We reuse it for checking funcname */
                lr->function = name;
        else {  /* Invalid name */
                semantic_error("'%s' is not a valid function name.\n", name);
                err = -EINVAL;
                goto err;
        }

        return 0;
err:
        free(name);
        return err;
}

static int parse_perf_probe_event_name(char **arg, struct perf_probe_event *pev)
{
        char *ptr;

        ptr = strchr(*arg, ':');
        if (ptr) {
                *ptr = '\0';
                if (!pev->sdt && !is_c_func_name(*arg))
                        goto ng_name;
                pev->group = strdup(*arg);
                if (!pev->group)
                        return -ENOMEM;
                *arg = ptr + 1;
        } else
                pev->group = NULL;
        if (!pev->sdt && !is_c_func_name(*arg)) {
ng_name:
                semantic_error("%s is bad for event name -it must "
                               "follow C symbol-naming rule.\n", *arg);
                return -EINVAL;
        }
        pev->event = strdup(*arg);
        if (pev->event == NULL)
                return -ENOMEM;

        return 0;
}

/* Parse probepoint definition. */
static int parse_perf_probe_point(char *arg, struct perf_probe_event *pev)
{
        struct perf_probe_point *pp = &pev->point;
        char *ptr, *tmp;
        char c, nc = 0;
        bool file_spec = false;
        int ret;

        /*
         * <Syntax>
         * perf probe [GRP:][EVENT=]SRC[:LN|;PTN]
         * perf probe [GRP:][EVENT=]FUNC[@SRC][+OFFS|%return|:LN|;PAT]
         * perf probe %[GRP:]SDT_EVENT
         */
        if (!arg)
                return -EINVAL;

        if (is_sdt_event(arg)) {
                pev->sdt = true;
                if (arg[0] == '%')
                        arg++;
        }

        ptr = strpbrk(arg, ";=@+%");
        if (pev->sdt) {
                if (ptr) {
                        if (*ptr != '@') {
                                semantic_error("%s must be an SDT name.\n",
                                               arg);
                                return -EINVAL;
                        }
                        /* This must be a target file name or build id */
                        tmp = build_id_cache__complement(ptr + 1);
                        if (tmp) {
                                pev->target = build_id_cache__origname(tmp);
                                free(tmp);
                        } else
                                pev->target = strdup(ptr + 1);
                        if (!pev->target)
                                return -ENOMEM;
                        *ptr = '\0';
                }
                ret = parse_perf_probe_event_name(&arg, pev);
                if (ret == 0) {
                        if (asprintf(&pev->point.function, "%%%s", pev->event) < 0)
                                ret = -errno;
                }
                return ret;
        }

        if (ptr && *ptr == '=') {       /* Event name */
                *ptr = '\0';
                tmp = ptr + 1;
                ret = parse_perf_probe_event_name(&arg, pev);
                if (ret < 0)
                        return ret;

                arg = tmp;
        }

        /*
         * Check arg is function or file name and copy it.
         *
         * We consider arg to be a file spec if and only if it satisfies
         * all of the below criteria::
         * - it does not include any of "+@%",
         * - it includes one of ":;", and
         * - it has a period '.' in the name.
         *
         * Otherwise, we consider arg to be a function specification.
         */
        if (!strpbrk(arg, "+@%") && (ptr = strpbrk(arg, ";:")) != NULL) {
                /* This is a file spec if it includes a '.' before ; or : */
                if (memchr(arg, '.', ptr - arg))
                        file_spec = true;
        }

        ptr = strpbrk(arg, ";:+@%");
        if (ptr) {
                nc = *ptr;
                *ptr++ = '\0';
        }

        if (arg[0] == '\0')
                tmp = NULL;
        else {
                tmp = strdup(arg);
                if (tmp == NULL)
                        return -ENOMEM;
        }

        if (file_spec)
                pp->file = tmp;
        else {
                pp->function = tmp;

                /*
                 * Keep pp->function even if this is absolute address,
                 * so it can mark whether abs_address is valid.
                 * Which make 'perf probe lib.bin 0x0' possible.
                 *
                 * Note that checking length of tmp is not needed
                 * because when we access tmp[1] we know tmp[0] is '0',
                 * so tmp[1] should always valid (but could be '\0').
                 */
                if (tmp && !strncmp(tmp, "0x", 2)) {
                        pp->abs_address = strtoul(pp->function, &tmp, 0);
                        if (*tmp != '\0') {
                                semantic_error("Invalid absolute address.\n");
                                return -EINVAL;
                        }
                }
        }

        /* Parse other options */
        while (ptr) {
                arg = ptr;
                c = nc;
                if (c == ';') { /* Lazy pattern must be the last part */
                        pp->lazy_line = strdup(arg);
                        if (pp->lazy_line == NULL)
                                return -ENOMEM;
                        break;
                }
                ptr = strpbrk(arg, ";:+@%");
                if (ptr) {
                        nc = *ptr;
                        *ptr++ = '\0';
                }
                switch (c) {
                case ':':       /* Line number */
                        pp->line = strtoul(arg, &tmp, 0);
                        if (*tmp != '\0') {
                                semantic_error("There is non-digit char"
                                               " in line number.\n");
                                return -EINVAL;
                        }
                        break;
                case '+':       /* Byte offset from a symbol */
                        pp->offset = strtoul(arg, &tmp, 0);
                        if (*tmp != '\0') {
                                semantic_error("There is non-digit character"
                                                " in offset.\n");
                                return -EINVAL;
                        }
                        break;
                case '@':       /* File name */
                        if (pp->file) {
                                semantic_error("SRC@SRC is not allowed.\n");
                                return -EINVAL;
                        }
                        pp->file = strdup(arg);
                        if (pp->file == NULL)
                                return -ENOMEM;
                        break;
                case '%':       /* Probe places */
                        if (strcmp(arg, "return") == 0) {
                                pp->retprobe = 1;
                        } else {        /* Others not supported yet */
                                semantic_error("%%%s is not supported.\n", arg);
                                return -ENOTSUP;
                        }
                        break;
                default:        /* Buggy case */
                        pr_err("This program has a bug at %s:%d.\n",
                                __FILE__, __LINE__);
                        return -ENOTSUP;
                        break;
                }
        }

        /* Exclusion check */
        if (pp->lazy_line && pp->line) {
                semantic_error("Lazy pattern can't be used with"
                               " line number.\n");
                return -EINVAL;
        }

        if (pp->lazy_line && pp->offset) {
                semantic_error("Lazy pattern can't be used with offset.\n");
                return -EINVAL;
        }

        if (pp->line && pp->offset) {
                semantic_error("Offset can't be used with line number.\n");
                return -EINVAL;
        }

        if (!pp->line && !pp->lazy_line && pp->file && !pp->function) {
                semantic_error("File always requires line number or "
                               "lazy pattern.\n");
                return -EINVAL;
        }

        if (pp->offset && !pp->function) {
                semantic_error("Offset requires an entry function.\n");
                return -EINVAL;
        }

        if ((pp->offset || pp->line || pp->lazy_line) && pp->retprobe) {
                semantic_error("Offset/Line/Lazy pattern can't be used with "
                               "return probe.\n");
                return -EINVAL;
        }

        pr_debug("symbol:%s file:%s line:%d offset:%lu return:%d lazy:%s\n",
                 pp->function, pp->file, pp->line, pp->offset, pp->retprobe,
                 pp->lazy_line);
        return 0;
}

/* Parse perf-probe event argument */
static int parse_perf_probe_arg(char *str, struct perf_probe_arg *arg)
{
        char *tmp, *goodname;
        struct perf_probe_arg_field **fieldp;

        pr_debug("parsing arg: %s into ", str);

        tmp = strchr(str, '=');
        if (tmp) {
                arg->name = strndup(str, tmp - str);
                if (arg->name == NULL)
                        return -ENOMEM;
                pr_debug("name:%s ", arg->name);
                str = tmp + 1;
        }

        tmp = strchr(str, ':');
        if (tmp) {      /* Type setting */
                *tmp = '\0';
                arg->type = strdup(tmp + 1);
                if (arg->type == NULL)
                        return -ENOMEM;
                pr_debug("type:%s ", arg->type);
        }

        tmp = strpbrk(str, "-.[");
        if (!is_c_varname(str) || !tmp) {
                /* A variable, register, symbol or special value */
                arg->var = strdup(str);
                if (arg->var == NULL)
                        return -ENOMEM;
                pr_debug("%s\n", arg->var);
                return 0;
        }

        /* Structure fields or array element */
        arg->var = strndup(str, tmp - str);
        if (arg->var == NULL)
                return -ENOMEM;
        goodname = arg->var;
        pr_debug("%s, ", arg->var);
        fieldp = &arg->field;

        do {
                *fieldp = zalloc(sizeof(struct perf_probe_arg_field));
                if (*fieldp == NULL)
                        return -ENOMEM;
                if (*tmp == '[') {      /* Array */
                        str = tmp;
                        (*fieldp)->index = strtol(str + 1, &tmp, 0);
                        (*fieldp)->ref = true;
                        if (*tmp != ']' || tmp == str + 1) {
                                semantic_error("Array index must be a"
                                                " number.\n");
                                return -EINVAL;
                        }
                        tmp++;
                        if (*tmp == '\0')
                                tmp = NULL;
                } else {                /* Structure */
                        if (*tmp == '.') {
                                str = tmp + 1;
                                (*fieldp)->ref = false;
                        } else if (tmp[1] == '>') {
                                str = tmp + 2;
                                (*fieldp)->ref = true;
                        } else {
                                semantic_error("Argument parse error: %s\n",
                                               str);
                                return -EINVAL;
                        }
                        tmp = strpbrk(str, "-.[");
                }
                if (tmp) {
                        (*fieldp)->name = strndup(str, tmp - str);
                        if ((*fieldp)->name == NULL)
                                return -ENOMEM;
                        if (*str != '[')
                                goodname = (*fieldp)->name;
                        pr_debug("%s(%d), ", (*fieldp)->name, (*fieldp)->ref);
                        fieldp = &(*fieldp)->next;
                }
        } while (tmp);
        (*fieldp)->name = strdup(str);
        if ((*fieldp)->name == NULL)
                return -ENOMEM;
        if (*str != '[')
                goodname = (*fieldp)->name;
        pr_debug("%s(%d)\n", (*fieldp)->name, (*fieldp)->ref);

        /* If no name is specified, set the last field name (not array index)*/
        if (!arg->name) {
                arg->name = strdup(goodname);
                if (arg->name == NULL)
                        return -ENOMEM;
        }
        return 0;
}

/* Parse perf-probe event command */
int parse_perf_probe_command(const char *cmd, struct perf_probe_event *pev)
{
        char **argv;
        int argc, i, ret = 0;

        argv = argv_split(cmd, &argc);
        if (!argv) {
                pr_debug("Failed to split arguments.\n");
                return -ENOMEM;
        }
        if (argc - 1 > MAX_PROBE_ARGS) {
                semantic_error("Too many probe arguments (%d).\n", argc - 1);
                ret = -ERANGE;
                goto out;
        }
        /* Parse probe point */
        ret = parse_perf_probe_point(argv[0], pev);
        if (ret < 0)
                goto out;

        /* Copy arguments and ensure return probe has no C argument */
        pev->nargs = argc - 1;
        pev->args = zalloc(sizeof(struct perf_probe_arg) * pev->nargs);
        if (pev->args == NULL) {
                ret = -ENOMEM;
                goto out;
        }
        for (i = 0; i < pev->nargs && ret >= 0; i++) {
                ret = parse_perf_probe_arg(argv[i + 1], &pev->args[i]);
                if (ret >= 0 &&
                    is_c_varname(pev->args[i].var) && pev->point.retprobe) {
                        semantic_error("You can't specify local variable for"
                                       " kretprobe.\n");
                        ret = -EINVAL;
                }
        }
out:
        argv_free(argv);

        return ret;
}

/* Returns true if *any* ARG is either C variable, $params or $vars. */
bool perf_probe_with_var(struct perf_probe_event *pev)
{
        int i = 0;

        for (i = 0; i < pev->nargs; i++)
                if (is_c_varname(pev->args[i].var)              ||
                    !strcmp(pev->args[i].var, PROBE_ARG_PARAMS) ||
                    !strcmp(pev->args[i].var, PROBE_ARG_VARS))
                        return true;
        return false;
}

/* Return true if this perf_probe_event requires debuginfo */
bool perf_probe_event_need_dwarf(struct perf_probe_event *pev)
{
        if (pev->point.file || pev->point.line || pev->point.lazy_line)
                return true;

        if (perf_probe_with_var(pev))
                return true;

        return false;
}

/* Parse probe_events event into struct probe_point */
int parse_probe_trace_command(const char *cmd, struct probe_trace_event *tev)
{
        struct probe_trace_point *tp = &tev->point;
        char pr;
        char *p;
        char *argv0_str = NULL, *fmt, *fmt1_str, *fmt2_str, *fmt3_str;
        int ret, i, argc;
        char **argv;

        pr_debug("Parsing probe_events: %s\n", cmd);
        argv = argv_split(cmd, &argc);
        if (!argv) {
                pr_debug("Failed to split arguments.\n");
                return -ENOMEM;
        }
        if (argc < 2) {
                semantic_error("Too few probe arguments.\n");
                ret = -ERANGE;
                goto out;
        }

        /* Scan event and group name. */
        argv0_str = strdup(argv[0]);
        if (argv0_str == NULL) {
                ret = -ENOMEM;
                goto out;
        }
        fmt1_str = strtok_r(argv0_str, ":", &fmt);
        fmt2_str = strtok_r(NULL, "/", &fmt);
        fmt3_str = strtok_r(NULL, " \t", &fmt);
        if (fmt1_str == NULL || strlen(fmt1_str) != 1 || fmt2_str == NULL
            || fmt3_str == NULL) {
                semantic_error("Failed to parse event name: %s\n", argv[0]);
                ret = -EINVAL;
                goto out;
        }
        pr = fmt1_str[0];
        tev->group = strdup(fmt2_str);
        tev->event = strdup(fmt3_str);
        if (tev->group == NULL || tev->event == NULL) {
                ret = -ENOMEM;
                goto out;
        }
        pr_debug("Group:%s Event:%s probe:%c\n", tev->group, tev->event, pr);

        tp->retprobe = (pr == 'r');

        /* Scan module name(if there), function name and offset */
        p = strchr(argv[1], ':');
        if (p) {
                tp->module = strndup(argv[1], p - argv[1]);
                if (!tp->module) {
                        ret = -ENOMEM;
                        goto out;
                }
                tev->uprobes = (tp->module[0] == '/');
                p++;
        } else
                p = argv[1];
        fmt1_str = strtok_r(p, "+", &fmt);
        /* only the address started with 0x */
        if (fmt1_str[0] == '0') {
                /*
                 * Fix a special case:
                 * if address == 0, kernel reports something like:
                 * p:probe_libc/abs_0 /lib/libc-2.18.so:0x          (null) arg1=%ax
                 * Newer kernel may fix that, but we want to
                 * support old kernel also.
                 */
                if (strcmp(fmt1_str, "0x") == 0) {
                        if (!argv[2] || strcmp(argv[2], "(null)")) {
                                ret = -EINVAL;
                                goto out;
                        }
                        tp->address = 0;

                        free(argv[2]);
                        for (i = 2; argv[i + 1] != NULL; i++)
                                argv[i] = argv[i + 1];

                        argv[i] = NULL;
                        argc -= 1;
                } else
                        tp->address = strtoul(fmt1_str, NULL, 0);
        } else {
                /* Only the symbol-based probe has offset */
                tp->symbol = strdup(fmt1_str);
                if (tp->symbol == NULL) {
                        ret = -ENOMEM;
                        goto out;
                }
                fmt2_str = strtok_r(NULL, "", &fmt);
                if (fmt2_str == NULL)
                        tp->offset = 0;
                else
                        tp->offset = strtoul(fmt2_str, NULL, 10);
        }

        tev->nargs = argc - 2;
        tev->args = zalloc(sizeof(struct probe_trace_arg) * tev->nargs);
        if (tev->args == NULL) {
                ret = -ENOMEM;
                goto out;
        }
        for (i = 0; i < tev->nargs; i++) {
                p = strchr(argv[i + 2], '=');
                if (p)  /* We don't need which register is assigned. */
                        *p++ = '\0';
                else
                        p = argv[i + 2];
                tev->args[i].name = strdup(argv[i + 2]);
                /* TODO: parse regs and offset */
                tev->args[i].value = strdup(p);
                if (tev->args[i].name == NULL || tev->args[i].value == NULL) {
                        ret = -ENOMEM;
                        goto out;
                }
        }
        ret = 0;
out:
        free(argv0_str);
        argv_free(argv);
        return ret;
}

/* Compose only probe arg */
char *synthesize_perf_probe_arg(struct perf_probe_arg *pa)
{
        struct perf_probe_arg_field *field = pa->field;
        struct strbuf buf;
        char *ret = NULL;
        int err;

        if (strbuf_init(&buf, 64) < 0)
                return NULL;

        if (pa->name && pa->var)
                err = strbuf_addf(&buf, "%s=%s", pa->name, pa->var);
        else
                err = strbuf_addstr(&buf, pa->name ?: pa->var);
        if (err)
                goto out;

        while (field) {
                if (field->name[0] == '[')
                        err = strbuf_addstr(&buf, field->name);
                else
                        err = strbuf_addf(&buf, "%s%s", field->ref ? "->" : ".",
                                          field->name);
                field = field->next;
                if (err)
                        goto out;
        }

        if (pa->type)
                if (strbuf_addf(&buf, ":%s", pa->type) < 0)
                        goto out;

        ret = strbuf_detach(&buf, NULL);
out:
        strbuf_release(&buf);
        return ret;
}

/* Compose only probe point (not argument) */
char *synthesize_perf_probe_point(struct perf_probe_point *pp)
{
        struct strbuf buf;
        char *tmp, *ret = NULL;
        int len, err = 0;

        if (strbuf_init(&buf, 64) < 0)
                return NULL;

        if (pp->function) {
                if (strbuf_addstr(&buf, pp->function) < 0)
                        goto out;
                if (pp->offset)
                        err = strbuf_addf(&buf, "+%lu", pp->offset);
                else if (pp->line)
                        err = strbuf_addf(&buf, ":%d", pp->line);
                else if (pp->retprobe)
                        err = strbuf_addstr(&buf, "%return");
                if (err)
                        goto out;
        }
        if (pp->file) {
                tmp = pp->file;
                len = strlen(tmp);
                if (len > 30) {
                        tmp = strchr(pp->file + len - 30, '/');
                        tmp = tmp ? tmp + 1 : pp->file + len - 30;
                }
                err = strbuf_addf(&buf, "@%s", tmp);
                if (!err && !pp->function && pp->line)
                        err = strbuf_addf(&buf, ":%d", pp->line);
        }
        if (!err)
                ret = strbuf_detach(&buf, NULL);
out:
        strbuf_release(&buf);
        return ret;
}

char *synthesize_perf_probe_command(struct perf_probe_event *pev)
{
        struct strbuf buf;
        char *tmp, *ret = NULL;
        int i;

        if (strbuf_init(&buf, 64))
                return NULL;
        if (pev->event)
                if (strbuf_addf(&buf, "%s:%s=", pev->group ?: PERFPROBE_GROUP,
                                pev->event) < 0)
                        goto out;

        tmp = synthesize_perf_probe_point(&pev->point);
        if (!tmp || strbuf_addstr(&buf, tmp) < 0)
                goto out;
        free(tmp);

        for (i = 0; i < pev->nargs; i++) {
                tmp = synthesize_perf_probe_arg(pev->args + i);
                if (!tmp || strbuf_addf(&buf, " %s", tmp) < 0)
                        goto out;
                free(tmp);
        }

        ret = strbuf_detach(&buf, NULL);
out:
        strbuf_release(&buf);
        return ret;
}

static int __synthesize_probe_trace_arg_ref(struct probe_trace_arg_ref *ref,
                                            struct strbuf *buf, int depth)
{
        int err;
        if (ref->next) {
                depth = __synthesize_probe_trace_arg_ref(ref->next, buf,
                                                         depth + 1);
                if (depth < 0)
                        return depth;
        }
        err = strbuf_addf(buf, "%+ld(", ref->offset);
        return (err < 0) ? err : depth;
}

static int synthesize_probe_trace_arg(struct probe_trace_arg *arg,
                                      struct strbuf *buf)
{
        struct probe_trace_arg_ref *ref = arg->ref;
        int depth = 0, err;

        /* Argument name or separator */
        if (arg->name)
                err = strbuf_addf(buf, " %s=", arg->name);
        else
                err = strbuf_addch(buf, ' ');
        if (err)
                return err;

        /* Special case: @XXX */
        if (arg->value[0] == '@' && arg->ref)
                        ref = ref->next;

        /* Dereferencing arguments */
        if (ref) {
                depth = __synthesize_probe_trace_arg_ref(ref, buf, 1);
                if (depth < 0)
                        return depth;
        }

        /* Print argument value */
        if (arg->value[0] == '@' && arg->ref)
                err = strbuf_addf(buf, "%s%+ld", arg->value, arg->ref->offset);
        else
                err = strbuf_addstr(buf, arg->value);

        /* Closing */
        while (!err && depth--)
                err = strbuf_addch(buf, ')');

        /* Print argument type */
        if (!err && arg->type)
                err = strbuf_addf(buf, ":%s", arg->type);

        return err;
}

char *synthesize_probe_trace_command(struct probe_trace_event *tev)
{
        struct probe_trace_point *tp = &tev->point;
        struct strbuf buf;
        char *ret = NULL;
        int i, err;

        /* Uprobes must have tp->module */
        if (tev->uprobes && !tp->module)
                return NULL;

        if (strbuf_init(&buf, 32) < 0)
                return NULL;

        if (strbuf_addf(&buf, "%c:%s/%s ", tp->retprobe ? 'r' : 'p',
                        tev->group, tev->event) < 0)
                goto error;
        /*
         * If tp->address == 0, then this point must be a
         * absolute address uprobe.
         * try_to_find_absolute_address() should have made
         * tp->symbol to "0x0".
         */
        if (tev->uprobes && !tp->address) {
                if (!tp->symbol || strcmp(tp->symbol, "0x0"))
                        goto error;
        }

        /* Use the tp->address for uprobes */
        if (tev->uprobes)
                err = strbuf_addf(&buf, "%s:0x%lx", tp->module, tp->address);
        else if (!strncmp(tp->symbol, "0x", 2))
                /* Absolute address. See try_to_find_absolute_address() */
                err = strbuf_addf(&buf, "%s%s0x%lx", tp->module ?: "",
                                  tp->module ? ":" : "", tp->address);
        else
                err = strbuf_addf(&buf, "%s%s%s+%lu", tp->module ?: "",
                                tp->module ? ":" : "", tp->symbol, tp->offset);
        if (err)
                goto error;

        for (i = 0; i < tev->nargs; i++)
                if (synthesize_probe_trace_arg(&tev->args[i], &buf) < 0)
                        goto error;

        ret = strbuf_detach(&buf, NULL);
error:
        strbuf_release(&buf);
        return ret;
}

static int find_perf_probe_point_from_map(struct probe_trace_point *tp,
                                          struct perf_probe_point *pp,
                                          bool is_kprobe)
{
        struct symbol *sym = NULL;
        struct map *map = NULL;
        u64 addr = tp->address;
        int ret = -ENOENT;

        if (!is_kprobe) {
                map = dso__new_map(tp->module);
                if (!map)
                        goto out;
                sym = map__find_symbol(map, addr);
        } else {
                if (tp->symbol && !addr) {
                        if (kernel_get_symbol_address_by_name(tp->symbol,
                                                &addr, true, false) < 0)
                                goto out;
                }
                if (addr) {
                        addr += tp->offset;
                        sym = __find_kernel_function(addr, &map);
                }
        }

        if (!sym)
                goto out;

        pp->retprobe = tp->retprobe;
        pp->offset = addr - map->unmap_ip(map, sym->start);
        pp->function = strdup(sym->name);
        ret = pp->function ? 0 : -ENOMEM;

out:
        if (map && !is_kprobe) {
                map__put(map);
        }

        return ret;
}

static int convert_to_perf_probe_point(struct probe_trace_point *tp,
                                       struct perf_probe_point *pp,
                                       bool is_kprobe)
{
        char buf[128];
        int ret;

        ret = find_perf_probe_point_from_dwarf(tp, pp, is_kprobe);
        if (!ret)
                return 0;
        ret = find_perf_probe_point_from_map(tp, pp, is_kprobe);
        if (!ret)
                return 0;

        pr_debug("Failed to find probe point from both of dwarf and map.\n");

        if (tp->symbol) {
                pp->function = strdup(tp->symbol);
                pp->offset = tp->offset;
        } else {
                ret = e_snprintf(buf, 128, "0x%" PRIx64, (u64)tp->address);
                if (ret < 0)
                        return ret;
                pp->function = strdup(buf);
                pp->offset = 0;
        }
        if (pp->function == NULL)
                return -ENOMEM;

        pp->retprobe = tp->retprobe;

        return 0;
}

static int convert_to_perf_probe_event(struct probe_trace_event *tev,
                               struct perf_probe_event *pev, bool is_kprobe)
{
        struct strbuf buf = STRBUF_INIT;
        int i, ret;

        /* Convert event/group name */
        pev->event = strdup(tev->event);
        pev->group = strdup(tev->group);
        if (pev->event == NULL || pev->group == NULL)
                return -ENOMEM;

        /* Convert trace_point to probe_point */
        ret = convert_to_perf_probe_point(&tev->point, &pev->point, is_kprobe);
        if (ret < 0)
                return ret;

        /* Convert trace_arg to probe_arg */
        pev->nargs = tev->nargs;
        pev->args = zalloc(sizeof(struct perf_probe_arg) * pev->nargs);
        if (pev->args == NULL)
                return -ENOMEM;
        for (i = 0; i < tev->nargs && ret >= 0; i++) {
                if (tev->args[i].name)
                        pev->args[i].name = strdup(tev->args[i].name);
                else {
                        if ((ret = strbuf_init(&buf, 32)) < 0)
                                goto error;
                        ret = synthesize_probe_trace_arg(&tev->args[i], &buf);
                        pev->args[i].name = strbuf_detach(&buf, NULL);
                }
                if (pev->args[i].name == NULL && ret >= 0)
                        ret = -ENOMEM;
        }
error:
        if (ret < 0)
                clear_perf_probe_event(pev);

        return ret;
}

void clear_perf_probe_event(struct perf_probe_event *pev)
{
        struct perf_probe_arg_field *field, *next;
        int i;

        free(pev->event);
        free(pev->group);
        free(pev->target);
        clear_perf_probe_point(&pev->point);

        for (i = 0; i < pev->nargs; i++) {
                free(pev->args[i].name);
                free(pev->args[i].var);
                free(pev->args[i].type);
                field = pev->args[i].field;
                while (field) {
                        next = field->next;
                        zfree(&field->name);
                        free(field);
                        field = next;
                }
        }
        free(pev->args);
        memset(pev, 0, sizeof(*pev));
}

#define strdup_or_goto(str, label)      \
({ char *__p = NULL; if (str && !(__p = strdup(str))) goto label; __p; })

static int perf_probe_point__copy(struct perf_probe_point *dst,
                                  struct perf_probe_point *src)
{
        dst->file = strdup_or_goto(src->file, out_err);
        dst->function = strdup_or_goto(src->function, out_err);
        dst->lazy_line = strdup_or_goto(src->lazy_line, out_err);
        dst->line = src->line;
        dst->retprobe = src->retprobe;
        dst->offset = src->offset;
        return 0;

out_err:
        clear_perf_probe_point(dst);
        return -ENOMEM;
}

static int perf_probe_arg__copy(struct perf_probe_arg *dst,
                                struct perf_probe_arg *src)
{
        struct perf_probe_arg_field *field, **ppfield;

        dst->name = strdup_or_goto(src->name, out_err);
        dst->var = strdup_or_goto(src->var, out_err);
        dst->type = strdup_or_goto(src->type, out_err);

        field = src->field;
        ppfield = &(dst->field);
        while (field) {
                *ppfield = zalloc(sizeof(*field));
                if (!*ppfield)
                        goto out_err;
                (*ppfield)->name = strdup_or_goto(field->name, out_err);
                (*ppfield)->index = field->index;
                (*ppfield)->ref = field->ref;
                field = field->next;
                ppfield = &((*ppfield)->next);
        }
        return 0;
out_err:
        return -ENOMEM;
}

int perf_probe_event__copy(struct perf_probe_event *dst,
                           struct perf_probe_event *src)
{
        int i;

        dst->event = strdup_or_goto(src->event, out_err);
        dst->group = strdup_or_goto(src->group, out_err);
        dst->target = strdup_or_goto(src->target, out_err);
        dst->uprobes = src->uprobes;

        if (perf_probe_point__copy(&dst->point, &src->point) < 0)
                goto out_err;

        dst->args = zalloc(sizeof(struct perf_probe_arg) * src->nargs);
        if (!dst->args)
                goto out_err;
        dst->nargs = src->nargs;

        for (i = 0; i < src->nargs; i++)
                if (perf_probe_arg__copy(&dst->args[i], &src->args[i]) < 0)
                        goto out_err;
        return 0;

out_err:
        clear_perf_probe_event(dst);
        return -ENOMEM;
}

void clear_probe_trace_event(struct probe_trace_event *tev)
{
        struct probe_trace_arg_ref *ref, *next;
        int i;

        free(tev->event);
        free(tev->group);
        free(tev->point.symbol);
        free(tev->point.realname);
        free(tev->point.module);
        for (i = 0; i < tev->nargs; i++) {
                free(tev->args[i].name);
                free(tev->args[i].value);
                free(tev->args[i].type);
                ref = tev->args[i].ref;
                while (ref) {
                        next = ref->next;
                        free(ref);
                        ref = next;
                }
        }
        free(tev->args);
        memset(tev, 0, sizeof(*tev));
}

struct kprobe_blacklist_node {
        struct list_head list;
        unsigned long start;
        unsigned long end;
        char *symbol;
};

static void kprobe_blacklist__delete(struct list_head *blacklist)
{
        struct kprobe_blacklist_node *node;

        while (!list_empty(blacklist)) {
                node = list_first_entry(blacklist,
                                        struct kprobe_blacklist_node, list);
                list_del(&node->list);
                free(node->symbol);
                free(node);
        }
}

static int kprobe_blacklist__load(struct list_head *blacklist)
{
        struct kprobe_blacklist_node *node;
        const char *__debugfs = debugfs__mountpoint();
        char buf[PATH_MAX], *p;
        FILE *fp;
        int ret;

        if (__debugfs == NULL)
                return -ENOTSUP;

        ret = e_snprintf(buf, PATH_MAX, "%s/kprobes/blacklist", __debugfs);
        if (ret < 0)
                return ret;

        fp = fopen(buf, "r");
        if (!fp)
                return -errno;

        ret = 0;
        while (fgets(buf, PATH_MAX, fp)) {
                node = zalloc(sizeof(*node));
                if (!node) {
                        ret = -ENOMEM;
                        break;
                }
                INIT_LIST_HEAD(&node->list);
                list_add_tail(&node->list, blacklist);
                if (sscanf(buf, "0x%lx-0x%lx", &node->start, &node->end) != 2) {
                        ret = -EINVAL;
                        break;
                }
                p = strchr(buf, '\t');
                if (p) {
                        p++;
                        if (p[strlen(p) - 1] == '\n')
                                p[strlen(p) - 1] = '\0';
                } else
                        p = (char *)"unknown";
                node->symbol = strdup(p);
                if (!node->symbol) {
                        ret = -ENOMEM;
                        break;
                }
                pr_debug2("Blacklist: 0x%lx-0x%lx, %s\n",
                          node->start, node->end, node->symbol);
                ret++;
        }
        if (ret < 0)
                kprobe_blacklist__delete(blacklist);
        fclose(fp);

        return ret;
}

static struct kprobe_blacklist_node *
kprobe_blacklist__find_by_address(struct list_head *blacklist,
                                  unsigned long address)
{
        struct kprobe_blacklist_node *node;

        list_for_each_entry(node, blacklist, list) {
                if (node->start <= address && address <= node->end)
                        return node;
        }

        return NULL;
}

static LIST_HEAD(kprobe_blacklist);

static void kprobe_blacklist__init(void)
{
        if (!list_empty(&kprobe_blacklist))
                return;

        if (kprobe_blacklist__load(&kprobe_blacklist) < 0)
                pr_debug("No kprobe blacklist support, ignored\n");
}

static void kprobe_blacklist__release(void)
{
        kprobe_blacklist__delete(&kprobe_blacklist);
}

static bool kprobe_blacklist__listed(unsigned long address)
{
        return !!kprobe_blacklist__find_by_address(&kprobe_blacklist, address);
}

static int perf_probe_event__sprintf(const char *group, const char *event,
                                     struct perf_probe_event *pev,
                                     const char *module,
                                     struct strbuf *result)
{
        int i, ret;
        char *buf;

        if (asprintf(&buf, "%s:%s", group, event) < 0)
                return -errno;
        ret = strbuf_addf(result, "  %-20s (on ", buf);
        free(buf);
        if (ret)
                return ret;

        /* Synthesize only event probe point */
        buf = synthesize_perf_probe_point(&pev->point);
        if (!buf)
                return -ENOMEM;
        ret = strbuf_addstr(result, buf);
        free(buf);

        if (!ret && module)
                ret = strbuf_addf(result, " in %s", module);

        if (!ret && pev->nargs > 0) {
                ret = strbuf_add(result, " with", 5);
                for (i = 0; !ret && i < pev->nargs; i++) {
                        buf = synthesize_perf_probe_arg(&pev->args[i]);
                        if (!buf)
                                return -ENOMEM;
                        ret = strbuf_addf(result, " %s", buf);
                        free(buf);
                }
        }
        if (!ret)
                ret = strbuf_addch(result, ')');

        return ret;
}

/* Show an event */
int show_perf_probe_event(const char *group, const char *event,
                          struct perf_probe_event *pev,
                          const char *module, bool use_stdout)
{
        struct strbuf buf = STRBUF_INIT;
        int ret;

        ret = perf_probe_event__sprintf(group, event, pev, module, &buf);
        if (ret >= 0) {
                if (use_stdout)
                        printf("%s\n", buf.buf);
                else
                        pr_info("%s\n", buf.buf);
        }
        strbuf_release(&buf);

        return ret;
}

static bool filter_probe_trace_event(struct probe_trace_event *tev,
                                     struct strfilter *filter)
{
        char tmp[128];

        /* At first, check the event name itself */
        if (strfilter__compare(filter, tev->event))
                return true;

        /* Next, check the combination of name and group */
        if (e_snprintf(tmp, 128, "%s:%s", tev->group, tev->event) < 0)
                return false;
        return strfilter__compare(filter, tmp);
}

static int __show_perf_probe_events(int fd, bool is_kprobe,
                                    struct strfilter *filter)
{
        int ret = 0;
        struct probe_trace_event tev;
        struct perf_probe_event pev;
        struct strlist *rawlist;
        struct str_node *ent;

        memset(&tev, 0, sizeof(tev));
        memset(&pev, 0, sizeof(pev));

        rawlist = probe_file__get_rawlist(fd);
        if (!rawlist)
                return -ENOMEM;

        strlist__for_each_entry(ent, rawlist) {
                ret = parse_probe_trace_command(ent->s, &tev);
                if (ret >= 0) {
                        if (!filter_probe_trace_event(&tev, filter))
                                goto next;
                        ret = convert_to_perf_probe_event(&tev, &pev,
                                                                is_kprobe);
                        if (ret < 0)
                                goto next;
                        ret = show_perf_probe_event(pev.group, pev.event,
                                                    &pev, tev.point.module,
                                                    true);
                }
next:
                clear_perf_probe_event(&pev);
                clear_probe_trace_event(&tev);
                if (ret < 0)
                        break;
        }
        strlist__delete(rawlist);
        /* Cleanup cached debuginfo if needed */
        debuginfo_cache__exit();

        return ret;
}

/* List up current perf-probe events */
int show_perf_probe_events(struct strfilter *filter)
{
        int kp_fd, up_fd, ret;

        setup_pager();

        if (probe_conf.cache)
                return probe_cache__show_all_caches(filter);

        ret = init_probe_symbol_maps(false);
        if (ret < 0)
                return ret;

        ret = probe_file__open_both(&kp_fd, &up_fd, 0);
        if (ret < 0)
                return ret;

        if (kp_fd >= 0)
                ret = __show_perf_probe_events(kp_fd, true, filter);
        if (up_fd >= 0 && ret >= 0)
                ret = __show_perf_probe_events(up_fd, false, filter);
        if (kp_fd > 0)
                close(kp_fd);
        if (up_fd > 0)
                close(up_fd);
        exit_probe_symbol_maps();

        return ret;
}

static int get_new_event_name(char *buf, size_t len, const char *base,
                              struct strlist *namelist, bool allow_suffix)
{
        int i, ret;
        char *p, *nbase;

        if (*base == '.')
                base++;
        nbase = strdup(base);
        if (!nbase)
                return -ENOMEM;

        /* Cut off the dot suffixes (e.g. .const, .isra)*/
        p = strchr(nbase, '.');
        if (p && p != nbase)
                *p = '\0';

        /* Try no suffix number */
        ret = e_snprintf(buf, len, "%s", nbase);
        if (ret < 0) {
                pr_debug("snprintf() failed: %d\n", ret);
                goto out;
        }
        if (!strlist__has_entry(namelist, buf))
                goto out;

        if (!allow_suffix) {
                pr_warning("Error: event \"%s\" already exists.\n"
                           " Hint: Remove existing event by 'perf probe -d'\n"
                           "       or force duplicates by 'perf probe -f'\n"
                           "       or set 'force=yes' in BPF source.\n",
                           buf);
                ret = -EEXIST;
                goto out;
        }

        /* Try to add suffix */
        for (i = 1; i < MAX_EVENT_INDEX; i++) {
                ret = e_snprintf(buf, len, "%s_%d", nbase, i);
                if (ret < 0) {
                        pr_debug("snprintf() failed: %d\n", ret);
                        goto out;
                }
                if (!strlist__has_entry(namelist, buf))
                        break;
        }
        if (i == MAX_EVENT_INDEX) {
                pr_warning("Too many events are on the same function.\n");
                ret = -ERANGE;
        }

out:
        free(nbase);
        return ret;
}

/* Warn if the current kernel's uprobe implementation is old */
static void warn_uprobe_event_compat(struct probe_trace_event *tev)
{
        int i;
        char *buf = synthesize_probe_trace_command(tev);

        /* Old uprobe event doesn't support memory dereference */
        if (!tev->uprobes || tev->nargs == 0 || !buf)
                goto out;

        for (i = 0; i < tev->nargs; i++)
                if (strglobmatch(tev->args[i].value, "[$@+-]*")) {
                        pr_warning("Please upgrade your kernel to at least "
                                   "3.14 to have access to feature %s\n",
                                   tev->args[i].value);
                        break;
                }
out:
        free(buf);
}

/* Set new name from original perf_probe_event and namelist */
static int probe_trace_event__set_name(struct probe_trace_event *tev,
                                       struct perf_probe_event *pev,
                                       struct strlist *namelist,
                                       bool allow_suffix)
{
        const char *event, *group;
        char buf[64];
        int ret;

        /* If probe_event or trace_event already have the name, reuse it */
        if (pev->event && !pev->sdt)
                event = pev->event;
        else if (tev->event)
                event = tev->event;
        else {
                /* Or generate new one from probe point */
                if (pev->point.function &&
                        (strncmp(pev->point.function, "0x", 2) != 0) &&
                        !strisglob(pev->point.function))
                        event = pev->point.function;
                else
                        event = tev->point.realname;
        }
        if (pev->group && !pev->sdt)
                group = pev->group;
        else if (tev->group)
                group = tev->group;
        else
                group = PERFPROBE_GROUP;

        /* Get an unused new event name */
        ret = get_new_event_name(buf, 64, event,
                                 namelist, allow_suffix);
        if (ret < 0)
                return ret;

        event = buf;

        tev->event = strdup(event);
        tev->group = strdup(group);
        if (tev->event == NULL || tev->group == NULL)
                return -ENOMEM;

        /* Add added event name to namelist */
        strlist__add(namelist, event);
        return 0;
}

static int __open_probe_file_and_namelist(bool uprobe,
                                          struct strlist **namelist)
{
        int fd;

        fd = probe_file__open(PF_FL_RW | (uprobe ? PF_FL_UPROBE : 0));
        if (fd < 0)
                return fd;

        /* Get current event names */
        *namelist = probe_file__get_namelist(fd);
        if (!(*namelist)) {
                pr_debug("Failed to get current event list.\n");
                close(fd);
                return -ENOMEM;
        }
        return fd;
}

static int __add_probe_trace_events(struct perf_probe_event *pev,
                                     struct probe_trace_event *tevs,
                                     int ntevs, bool allow_suffix)
{
        int i, fd[2] = {-1, -1}, up, ret;
        struct probe_trace_event *tev = NULL;
        struct probe_cache *cache = NULL;
        struct strlist *namelist[2] = {NULL, NULL};

        up = pev->uprobes ? 1 : 0;
        fd[up] = __open_probe_file_and_namelist(up, &namelist[up]);
        if (fd[up] < 0)
                return fd[up];

        ret = 0;
        for (i = 0; i < ntevs; i++) {
                tev = &tevs[i];
                up = tev->uprobes ? 1 : 0;
                if (fd[up] == -1) {     /* Open the kprobe/uprobe_events */
                        fd[up] = __open_probe_file_and_namelist(up,
                                                                &namelist[up]);
                        if (fd[up] < 0)
                                goto close_out;
                }
                /* Skip if the symbol is out of .text or blacklisted */
                if (!tev->point.symbol && !pev->uprobes)
                        continue;

                /* Set new name for tev (and update namelist) */
                ret = probe_trace_event__set_name(tev, pev, namelist[up],
                                                  allow_suffix);
                if (ret < 0)
                        break;

                ret = probe_file__add_event(fd[up], tev);
                if (ret < 0)
                        break;

                /*
                 * Probes after the first probe which comes from same
                 * user input are always allowed to add suffix, because
                 * there might be several addresses corresponding to
                 * one code line.
                 */
                allow_suffix = true;
        }
        if (ret == -EINVAL && pev->uprobes)
                warn_uprobe_event_compat(tev);
        if (ret == 0 && probe_conf.cache) {
                cache = probe_cache__new(pev->target);
                if (!cache ||
                    probe_cache__add_entry(cache, pev, tevs, ntevs) < 0 ||
                    probe_cache__commit(cache) < 0)
                        pr_warning("Failed to add event to probe cache\n");
                probe_cache__delete(cache);
        }

close_out:
        for (up = 0; up < 2; up++) {
                strlist__delete(namelist[up]);
                if (fd[up] >= 0)
                        close(fd[up]);
        }
        return ret;
}

static int find_probe_functions(struct map *map, char *name,
                                struct symbol **syms)
{
        int found = 0;
        struct symbol *sym;
        struct rb_node *tmp;

        if (map__load(map) < 0)
                return 0;

        map__for_each_symbol(map, sym, tmp) {
                if (strglobmatch(sym->name, name)) {
                        found++;
                        if (syms && found < probe_conf.max_probes)
                                syms[found - 1] = sym;
                }
        }

        return found;
}

void __weak arch__fix_tev_from_maps(struct perf_probe_event *pev __maybe_unused,
                                struct probe_trace_event *tev __maybe_unused,
                                struct map *map __maybe_unused,
                                struct symbol *sym __maybe_unused) { }

/*
 * Find probe function addresses from map.
 * Return an error or the number of found probe_trace_event
 */
static int find_probe_trace_events_from_map(struct perf_probe_event *pev,
                                            struct probe_trace_event **tevs)
{
        struct map *map = NULL;
        struct ref_reloc_sym *reloc_sym = NULL;
        struct symbol *sym;
        struct symbol **syms = NULL;
        struct probe_trace_event *tev;
        struct perf_probe_point *pp = &pev->point;
        struct probe_trace_point *tp;
        int num_matched_functions;
        int ret, i, j, skipped = 0;
        char *mod_name;

        map = get_target_map(pev->target, pev->uprobes);
        if (!map) {
                ret = -EINVAL;
                goto out;
        }

        syms = malloc(sizeof(struct symbol *) * probe_conf.max_probes);
        if (!syms) {
                ret = -ENOMEM;
                goto out;
        }

        /*
         * Load matched symbols: Since the different local symbols may have
         * same name but different addresses, this lists all the symbols.
         */
        num_matched_functions = find_probe_functions(map, pp->function, syms);
        if (num_matched_functions == 0) {
                pr_err("Failed to find symbol %s in %s\n", pp->function,
                        pev->target ? : "kernel");
                ret = -ENOENT;
                goto out;
        } else if (num_matched_functions > probe_conf.max_probes) {
                pr_err("Too many functions matched in %s\n",
                        pev->target ? : "kernel");
                ret = -E2BIG;
                goto out;
        }

        /* Note that the symbols in the kmodule are not relocated */
        if (!pev->uprobes && !pev->target &&
                        (!pp->retprobe || kretprobe_offset_is_supported())) {
                reloc_sym = kernel_get_ref_reloc_sym();
                if (!reloc_sym) {
                        pr_warning("Relocated base symbol is not found!\n");
                        ret = -EINVAL;
                        goto out;
                }
        }

        /* Setup result trace-probe-events */
        *tevs = zalloc(sizeof(*tev) * num_matched_functions);
        if (!*tevs) {
                ret = -ENOMEM;
                goto out;
        }

        ret = 0;

        for (j = 0; j < num_matched_functions; j++) {
                sym = syms[j];

                tev = (*tevs) + ret;
                tp = &tev->point;
                if (ret == num_matched_functions) {
                        pr_warning("Too many symbols are listed. Skip it.\n");
                        break;
                }
                ret++;

                if (pp->offset > sym->end - sym->start) {
                        pr_warning("Offset %ld is bigger than the size of %s\n",
                                   pp->offset, sym->name);
                        ret = -ENOENT;
                        goto err_out;
                }
                /* Add one probe point */
                tp->address = map->unmap_ip(map, sym->start) + pp->offset;

                /* Check the kprobe (not in module) is within .text  */
                if (!pev->uprobes && !pev->target &&
                    kprobe_warn_out_range(sym->name, tp->address)) {
                        tp->symbol = NULL;      /* Skip it */
                        skipped++;
                } else if (reloc_sym) {
                        tp->symbol = strdup_or_goto(reloc_sym->name, nomem_out);
                        tp->offset = tp->address - reloc_sym->addr;
                } else {
                        tp->symbol = strdup_or_goto(sym->name, nomem_out);
                        tp->offset = pp->offset;
                }
                tp->realname = strdup_or_goto(sym->name, nomem_out);

                tp->retprobe = pp->retprobe;
                if (pev->target) {
                        if (pev->uprobes) {
                                tev->point.module = strdup_or_goto(pev->target,
                                                                   nomem_out);
                        } else {
                                mod_name = find_module_name(pev->target);
                                tev->point.module =
                                        strdup(mod_name ? mod_name : pev->target);
                                free(mod_name);
                                if (!tev->point.module)
                                        goto nomem_out;
                        }
                }
                tev->uprobes = pev->uprobes;
                tev->nargs = pev->nargs;
                if (tev->nargs) {
                        tev->args = zalloc(sizeof(struct probe_trace_arg) *
                                           tev->nargs);
                        if (tev->args == NULL)
                                goto nomem_out;
                }
                for (i = 0; i < tev->nargs; i++) {
                        if (pev->args[i].name)
                                tev->args[i].name =
                                        strdup_or_goto(pev->args[i].name,
                                                        nomem_out);

                        tev->args[i].value = strdup_or_goto(pev->args[i].var,
                                                            nomem_out);
                        if (pev->args[i].type)
                                tev->args[i].type =
                                        strdup_or_goto(pev->args[i].type,
                                                        nomem_out);
                }
                arch__fix_tev_from_maps(pev, tev, map, sym);
        }
        if (ret == skipped) {
                ret = -ENOENT;
                goto err_out;
        }

out:
        map__put(map);
        free(syms);
        return ret;

nomem_out:
        ret = -ENOMEM;
err_out:
        clear_probe_trace_events(*tevs, num_matched_functions);
        zfree(tevs);
        goto out;
}

static int try_to_find_absolute_address(struct perf_probe_event *pev,
                                        struct probe_trace_event **tevs)
{
        struct perf_probe_point *pp = &pev->point;
        struct probe_trace_event *tev;
        struct probe_trace_point *tp;
        int i, err;

        if (!(pev->point.function && !strncmp(pev->point.function, "0x", 2)))
                return -EINVAL;
        if (perf_probe_event_need_dwarf(pev))
                return -EINVAL;

        /*
         * This is 'perf probe /lib/libc.so 0xabcd'. Try to probe at
         * absolute address.
         *
         * Only one tev can be generated by this.
         */
        *tevs = zalloc(sizeof(*tev));
        if (!*tevs)
                return -ENOMEM;

        tev = *tevs;
        tp = &tev->point;

        /*
         * Don't use tp->offset, use address directly, because
         * in synthesize_probe_trace_command() address cannot be
         * zero.
         */
        tp->address = pev->point.abs_address;
        tp->retprobe = pp->retprobe;
        tev->uprobes = pev->uprobes;

        err = -ENOMEM;
        /*
         * Give it a '0x' leading symbol name.
         * In __add_probe_trace_events, a NULL symbol is interpreted as
         * invalud.
         */
        if (asprintf(&tp->symbol, "0x%lx", tp->address) < 0)
                goto errout;

        /* For kprobe, check range */
        if ((!tev->uprobes) &&
            (kprobe_warn_out_range(tev->point.symbol,
                                   tev->point.address))) {
                err = -EACCES;
                goto errout;
        }

        if (asprintf(&tp->realname, "abs_%lx", tp->address) < 0)
                goto errout;

        if (pev->target) {
                tp->module = strdup(pev->target);
                if (!tp->module)
                        goto errout;
        }

        if (tev->group) {
                tev->group = strdup(pev->group);
                if (!tev->group)
                        goto errout;
        }

        if (pev->event) {
                tev->event = strdup(pev->event);
                if (!tev->event)
                        goto errout;
        }

        tev->nargs = pev->nargs;
        tev->args = zalloc(sizeof(struct probe_trace_arg) * tev->nargs);
        if (!tev->args)
                goto errout;

        for (i = 0; i < tev->nargs; i++)
                copy_to_probe_trace_arg(&tev->args[i], &pev->args[i]);

        return 1;

errout:
        clear_probe_trace_events(*tevs, 1);
        *tevs = NULL;
        return err;
}

/* Concatinate two arrays */
static void *memcat(void *a, size_t sz_a, void *b, size_t sz_b)
{
        void *ret;

        ret = malloc(sz_a + sz_b);
        if (ret) {
                memcpy(ret, a, sz_a);
                memcpy(ret + sz_a, b, sz_b);
        }
        return ret;
}

static int
concat_probe_trace_events(struct probe_trace_event **tevs, int *ntevs,
                          struct probe_trace_event **tevs2, int ntevs2)
{
        struct probe_trace_event *new_tevs;
        int ret = 0;

        if (*ntevs == 0) {
                *tevs = *tevs2;
                *ntevs = ntevs2;
                *tevs2 = NULL;
                return 0;
        }

        if (*ntevs + ntevs2 > probe_conf.max_probes)
                ret = -E2BIG;
        else {
                /* Concatinate the array of probe_trace_event */
                new_tevs = memcat(*tevs, (*ntevs) * sizeof(**tevs),
                                  *tevs2, ntevs2 * sizeof(**tevs2));
                if (!new_tevs)
                        ret = -ENOMEM;
                else {
                        free(*tevs);
                        *tevs = new_tevs;
                        *ntevs += ntevs2;
                }
        }
        if (ret < 0)
                clear_probe_trace_events(*tevs2, ntevs2);
        zfree(tevs2);

        return ret;
}

/*
 * Try to find probe_trace_event from given probe caches. Return the number
 * of cached events found, if an error occurs return the error.
 */
static int find_cached_events(struct perf_probe_event *pev,
                              struct probe_trace_event **tevs,
                              const char *target)
{
        struct probe_cache *cache;
        struct probe_cache_entry *entry;
        struct probe_trace_event *tmp_tevs = NULL;
        int ntevs = 0;
        int ret = 0;

        cache = probe_cache__new(target);
        /* Return 0 ("not found") if the target has no probe cache. */
        if (!cache)
                return 0;

        for_each_probe_cache_entry(entry, cache) {
                /* Skip the cache entry which has no name */
                if (!entry->pev.event || !entry->pev.group)
                        continue;
                if ((!pev->group || strglobmatch(entry->pev.group, pev->group)) &&
                    strglobmatch(entry->pev.event, pev->event)) {
                        ret = probe_cache_entry__get_event(entry, &tmp_tevs);
                        if (ret > 0)
                                ret = concat_probe_trace_events(tevs, &ntevs,
                                                                &tmp_tevs, ret);
                        if (ret < 0)
                                break;
                }
        }
        probe_cache__delete(cache);
        if (ret < 0) {
                clear_probe_trace_events(*tevs, ntevs);
                zfree(tevs);
        } else {
                ret = ntevs;
                if (ntevs > 0 && target && target[0] == '/')
                        pev->uprobes = true;
        }

        return ret;
}

/* Try to find probe_trace_event from all probe caches */
static int find_cached_events_all(struct perf_probe_event *pev,
                                   struct probe_trace_event **tevs)
{
        struct probe_trace_event *tmp_tevs = NULL;
        struct strlist *bidlist;
        struct str_node *nd;
        char *pathname;
        int ntevs = 0;
        int ret;

        /* Get the buildid list of all valid caches */
        bidlist = build_id_cache__list_all(true);
        if (!bidlist) {
                ret = -errno;
                pr_debug("Failed to get buildids: %d\n", ret);
                return ret;
        }

        ret = 0;
        strlist__for_each_entry(nd, bidlist) {
                pathname = build_id_cache__origname(nd->s);
                ret = find_cached_events(pev, &tmp_tevs, pathname);
                /* In the case of cnt == 0, we just skip it */
                if (ret > 0)
                        ret = concat_probe_trace_events(tevs, &ntevs,
                                                        &tmp_tevs, ret);
                free(pathname);
                if (ret < 0)
                        break;
        }
        strlist__delete(bidlist);

        if (ret < 0) {
                clear_probe_trace_events(*tevs, ntevs);
                zfree(tevs);
        } else
                ret = ntevs;

        return ret;
}

static int find_probe_trace_events_from_cache(struct perf_probe_event *pev,
                                              struct probe_trace_event **tevs)
{
        struct probe_cache *cache;
        struct probe_cache_entry *entry;
        struct probe_trace_event *tev;
        struct str_node *node;
        int ret, i;

        if (pev->sdt) {
                /* For SDT/cached events, we use special search functions */
                if (!pev->target)
                        return find_cached_events_all(pev, tevs);
                else
                        return find_cached_events(pev, tevs, pev->target);
        }
        cache = probe_cache__new(pev->target);
        if (!cache)
                return 0;

        entry = probe_cache__find(cache, pev);
        if (!entry) {
                /* SDT must be in the cache */
                ret = pev->sdt ? -ENOENT : 0;
                goto out;
        }

        ret = strlist__nr_entries(entry->tevlist);
        if (ret > probe_conf.max_probes) {
                pr_debug("Too many entries matched in the cache of %s\n",
                         pev->target ? : "kernel");
                ret = -E2BIG;
                goto out;
        }

        *tevs = zalloc(ret * sizeof(*tev));
        if (!*tevs) {
                ret = -ENOMEM;
                goto out;
        }

        i = 0;
        strlist__for_each_entry(node, entry->tevlist) {
                tev = &(*tevs)[i++];
                ret = parse_probe_trace_command(node->s, tev);
                if (ret < 0)
                        goto out;
                /* Set the uprobes attribute as same as original */
                tev->uprobes = pev->uprobes;
        }
        ret = i;

out:
        probe_cache__delete(cache);
        return ret;
}

static int convert_to_probe_trace_events(struct perf_probe_event *pev,
                                         struct probe_trace_event **tevs)
{
        int ret;

        if (!pev->group && !pev->sdt) {
                /* Set group name if not given */
                if (!pev->uprobes) {
                        pev->group = strdup(PERFPROBE_GROUP);
                        ret = pev->group ? 0 : -ENOMEM;
                } else
                        ret = convert_exec_to_group(pev->target, &pev->group);
                if (ret != 0) {
                        pr_warning("Failed to make a group name.\n");
                        return ret;
                }
        }

        ret = try_to_find_absolute_address(pev, tevs);
        if (ret > 0)
                return ret;

        /* At first, we need to lookup cache entry */
        ret = find_probe_trace_events_from_cache(pev, tevs);
        if (ret > 0 || pev->sdt)        /* SDT can be found only in the cache */
                return ret == 0 ? -ENOENT : ret; /* Found in probe cache */

        /* Convert perf_probe_event with debuginfo */
        ret = try_to_find_probe_trace_events(pev, tevs);
        if (ret != 0)
                return ret;     /* Found in debuginfo or got an error */

        return find_probe_trace_events_from_map(pev, tevs);
}

int convert_perf_probe_events(struct perf_probe_event *pevs, int npevs)
{
        int i, ret;

        /* Loop 1: convert all events */
        for (i = 0; i < npevs; i++) {
                /* Init kprobe blacklist if needed */
                if (!pevs[i].uprobes)
                        kprobe_blacklist__init();
                /* Convert with or without debuginfo */
                ret  = convert_to_probe_trace_events(&pevs[i], &pevs[i].tevs);
                if (ret < 0)
                        return ret;
                pevs[i].ntevs = ret;
        }
        /* This just release blacklist only if allocated */
        kprobe_blacklist__release();

        return 0;
}

static int show_probe_trace_event(struct probe_trace_event *tev)
{
        char *buf = synthesize_probe_trace_command(tev);

        if (!buf) {
                pr_debug("Failed to synthesize probe trace event.\n");
                return -EINVAL;
        }

        /* Showing definition always go stdout */
        printf("%s\n", buf);
        free(buf);

        return 0;
}

int show_probe_trace_events(struct perf_probe_event *pevs, int npevs)
{
        struct strlist *namelist = strlist__new(NULL, NULL);
        struct probe_trace_event *tev;
        struct perf_probe_event *pev;
        int i, j, ret = 0;

        if (!namelist)
                return -ENOMEM;

        for (j = 0; j < npevs && !ret; j++) {
                pev = &pevs[j];
                for (i = 0; i < pev->ntevs && !ret; i++) {
                        tev = &pev->tevs[i];
                        /* Skip if the symbol is out of .text or blacklisted */
                        if (!tev->point.symbol && !pev->uprobes)
                                continue;

                        /* Set new name for tev (and update namelist) */
                        ret = probe_trace_event__set_name(tev, pev,
                                                          namelist, true);
                        if (!ret)
                                ret = show_probe_trace_event(tev);
                }
        }
        strlist__delete(namelist);

        return ret;
}

int apply_perf_probe_events(struct perf_probe_event *pevs, int npevs)
{
        int i, ret = 0;

        /* Loop 2: add all events */
        for (i = 0; i < npevs; i++) {
                ret = __add_probe_trace_events(&pevs[i], pevs[i].tevs,
                                               pevs[i].ntevs,
                                               probe_conf.force_add);
                if (ret < 0)
                        break;
        }
        return ret;
}

void cleanup_perf_probe_events(struct perf_probe_event *pevs, int npevs)
{
        int i, j;

        /* Loop 3: cleanup and free trace events  */
        for (i = 0; i < npevs; i++) {
                for (j = 0; j < pevs[i].ntevs; j++)
                        clear_probe_trace_event(&pevs[i].tevs[j]);
                zfree(&pevs[i].tevs);
                pevs[i].ntevs = 0;
                clear_perf_probe_event(&pevs[i]);
        }
}

int add_perf_probe_events(struct perf_probe_event *pevs, int npevs)
{
        int ret;

        ret = init_probe_symbol_maps(pevs->uprobes);
        if (ret < 0)
                return ret;

        ret = convert_perf_probe_events(pevs, npevs);
        if (ret == 0)
                ret = apply_perf_probe_events(pevs, npevs);

        cleanup_perf_probe_events(pevs, npevs);

        exit_probe_symbol_maps();
        return ret;
}

int del_perf_probe_events(struct strfilter *filter)
{
        int ret, ret2, ufd = -1, kfd = -1;
        char *str = strfilter__string(filter);

        if (!str)
                return -EINVAL;

        /* Get current event names */
        ret = probe_file__open_both(&kfd, &ufd, PF_FL_RW);
        if (ret < 0)
                goto out;

        ret = probe_file__del_events(kfd, filter);
        if (ret < 0 && ret != -ENOENT)
                goto error;

        ret2 = probe_file__del_events(ufd, filter);
        if (ret2 < 0 && ret2 != -ENOENT) {
                ret = ret2;
                goto error;
        }
        ret = 0;

error:
        if (kfd >= 0)
                close(kfd);
        if (ufd >= 0)
                close(ufd);
out:
        free(str);

        return ret;
}

int show_available_funcs(const char *target, struct strfilter *_filter,
                                        bool user)
{
        struct rb_node *nd;
        struct map *map;
        int ret;

        ret = init_probe_symbol_maps(user);
        if (ret < 0)
                return ret;

        /* Get a symbol map */
        map = get_target_map(target, user);
        if (!map) {
                pr_err("Failed to get a map for %s\n", (target) ? : "kernel");
                return -EINVAL;
        }

        ret = map__load(map);
        if (ret) {
                if (ret == -2) {
                        char *str = strfilter__string(_filter);
                        pr_err("Failed to find symbols matched to \"%s\"\n",
                               str);
                        free(str);
                } else
                        pr_err("Failed to load symbols in %s\n",
                               (target) ? : "kernel");
                goto end;
        }
        if (!dso__sorted_by_name(map->dso, map->type))
                dso__sort_by_name(map->dso, map->type);

        /* Show all (filtered) symbols */
        setup_pager();

        for (nd = rb_first(&map->dso->symbol_names[map->type]); nd; nd = rb_next(nd)) {
                struct symbol_name_rb_node *pos = rb_entry(nd, struct symbol_name_rb_node, rb_node);

                if (strfilter__compare(_filter, pos->sym.name))
                        printf("%s\n", pos->sym.name);
        }

end:
        map__put(map);
        exit_probe_symbol_maps();

        return ret;
}

int copy_to_probe_trace_arg(struct probe_trace_arg *tvar,
                            struct perf_probe_arg *pvar)
{
        tvar->value = strdup(pvar->var);
        if (tvar->value == NULL)
                return -ENOMEM;
        if (pvar->type) {
                tvar->type = strdup(pvar->type);
                if (tvar->type == NULL)
                        return -ENOMEM;
        }
        if (pvar->name) {
                tvar->name = strdup(pvar->name);
                if (tvar->name == NULL)
                        return -ENOMEM;
        } else
                tvar->name = NULL;
        return 0;
}