probe-event.c

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/*
 * probe-event.c : perf-probe definition to probe_events format converter
 *
 * Written by Masami Hiramatsu <[email protected]>
 *
 * 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 "debugfs.h"
#include "trace-event.h"    /* For __maybe_unused */
#include "probe-event.h"
#include "probe-finder.h"
#include "session.h"

#define MAX_CMDLEN 256
#define MAX_PROBE_ARGS 128
#define PERFPROBE_GROUP "probe"

bool probe_event_dry_run;   /* Dry run flag */

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

/* If there is no space to write, returns -E2BIG. */
static int e_snprintf(char *str, size_t size, const char *format, ...)
    __attribute__((format(printf, 3, 4)));

static 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 char *synthesize_perf_probe_point(struct perf_probe_point *pp);
static int convert_name_to_addr(struct perf_probe_event *pev,
                const char *exec);
static struct machine machine;

/* Initialize symbol maps and path of vmlinux/modules */
static int init_vmlinux(void)
{
    int ret;

    symbol_conf.sort_by_name = true;
    if (symbol_conf.vmlinux_name == NULL)
        symbol_conf.try_vmlinux_path = true;
    else
        pr_debug("Use vmlinux: %s\n", symbol_conf.vmlinux_name);
    ret = symbol__init();
    if (ret < 0) {
        pr_debug("Failed to init symbol map.\n");
        goto out;
    }

    ret = machine__init(&machine, "", HOST_KERNEL_ID);
    if (ret < 0)
        goto out;

    if (machine__create_kernel_maps(&machine) < 0) {
        pr_debug("machine__create_kernel_maps() failed.\n");
        goto out;
    }
out:
    if (ret < 0)
        pr_warning("Failed to init vmlinux path.\n");
    return ret;
}

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

static struct map *kernel_get_module_map(const char *module)
{
    struct rb_node *nd;
    struct map_groups *grp = &machine.kmaps;

    /* A file path -- this is an offline module */
    if (module && strchr(module, '/'))
        return machine__new_module(&machine, 0, module);

    if (!module)
        module = "kernel";

    for (nd = rb_first(&grp->maps[MAP__FUNCTION]); nd; nd = rb_next(nd)) {
        struct map *pos = rb_entry(nd, struct map, rb_node);
        if (strncmp(pos->dso->short_name + 1, module,
                pos->dso->short_name_len - 2) == 0) {
            return pos;
        }
    }
    return NULL;
}

static struct dso *kernel_get_module_dso(const char *module)
{
    struct dso *dso;
    struct map *map;
    const char *vmlinux_name;

    if (module) {
        list_for_each_entry(dso, &machine.kernel_dsos, node) {
            if (strncmp(dso->short_name + 1, module,
                    dso->short_name_len - 2) == 0)
                goto found;
        }
        pr_debug("Failed to find module %s.\n", module);
        return NULL;
    }

    map = machine.vmlinux_maps[MAP__FUNCTION];
    dso = map->dso;

    vmlinux_name = symbol_conf.vmlinux_name;
    if (vmlinux_name) {
        if (dso__load_vmlinux(dso, map, vmlinux_name, NULL) <= 0)
            return NULL;
    } else {
        if (dso__load_vmlinux_path(dso, map, NULL) <= 0) {
            pr_debug("Failed to load kernel map.\n");
            return NULL;
        }
    }
found:
    return dso;
}

const char *kernel_get_module_path(const char *module)
{
    struct dso *dso = kernel_get_module_dso(module);
    return (dso) ? dso->long_name : NULL;
}

static int init_user_exec(void)
{
    int ret = 0;

    symbol_conf.try_vmlinux_path = false;
    symbol_conf.sort_by_name = true;
    ret = symbol__init();

    if (ret < 0)
        pr_debug("Failed to init symbol map.\n");

    return ret;
}

static int convert_to_perf_probe_point(struct probe_trace_point *tp,
                    struct perf_probe_point *pp)
{
    pp->function = strdup(tp->symbol);

    if (pp->function == NULL)
        return -ENOMEM;

    pp->offset = tp->offset;
    pp->retprobe = tp->retprobe;

    return 0;
}

#ifdef DWARF_SUPPORT
/* Open new debuginfo of given module */
static struct debuginfo *open_debuginfo(const char *module)
{
    const char *path;

    /* A file path -- this is an offline module */
    if (module && strchr(module, '/'))
        path = module;
    else {
        path = kernel_get_module_path(module);

        if (!path) {
            pr_err("Failed to find path of %s module.\n",
                   module ?: "kernel");
            return NULL;
        }
    }
    return debuginfo__new(path);
}

/*
 * Convert trace point to probe point with debuginfo
 * Currently only handles kprobes.
 */
static int kprobe_convert_to_perf_probe(struct probe_trace_point *tp,
                    struct perf_probe_point *pp)
{
    struct symbol *sym;
    struct map *map;
    u64 addr;
    int ret = -ENOENT;
    struct debuginfo *dinfo;

    sym = __find_kernel_function_by_name(tp->symbol, &map);
    if (sym) {
        addr = map->unmap_ip(map, sym->start + tp->offset);
        pr_debug("try to find %s+%ld@%" PRIx64 "\n", tp->symbol,
             tp->offset, addr);

        dinfo = debuginfo__new_online_kernel(addr);
        if (dinfo) {
            ret = debuginfo__find_probe_point(dinfo,
                         (unsigned long)addr, pp);
            debuginfo__delete(dinfo);
        } else {
            pr_debug("Failed to open debuginfo at 0x%" PRIx64 "\n",
                 addr);
            ret = -ENOENT;
        }
    }
    if (ret <= 0) {
        pr_debug("Failed to find corresponding probes from "
             "debuginfo. Use kprobe event information.\n");
        return convert_to_perf_probe_point(tp, pp);
    }
    pp->retprobe = tp->retprobe;

    return 0;
}

static int add_module_to_probe_trace_events(struct probe_trace_event *tevs,
                        int ntevs, const char *module)
{
    int i, ret = 0;
    char *tmp;

    if (!module)
        return 0;

    tmp = strrchr(module, '/');
    if (tmp) {
        /* This is a module path -- get the module name */
        module = strdup(tmp + 1);
        if (!module)
            return -ENOMEM;
        tmp = strchr(module, '.');
        if (tmp)
            *tmp = '\0';
        tmp = (char *)module;   /* For free() */
    }

    for (i = 0; i < ntevs; i++) {
        tevs[i].point.module = strdup(module);
        if (!tevs[i].point.module) {
            ret = -ENOMEM;
            break;
        }
    }

    if (tmp)
        free(tmp);

    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,
                      int max_tevs, const char *target)
{
    bool need_dwarf = perf_probe_event_need_dwarf(pev);
    struct debuginfo *dinfo;
    int ntevs, ret = 0;

    if (pev->uprobes) {
        if (need_dwarf) {
            pr_warning("Debuginfo-analysis is not yet supported"
                    " with -x/--exec option.\n");
            return -ENOSYS;
        }
        return convert_name_to_addr(pev, target);
    }

    dinfo = open_debuginfo(target);

    if (!dinfo) {
        if (need_dwarf) {
            pr_warning("Failed to open debuginfo file.\n");
            return -ENOENT;
        }
        pr_debug("Could not open debuginfo. Try to use symbols.\n");
        return 0;
    }

    /* Searching trace events corresponding to a probe event */
    ntevs = debuginfo__find_trace_events(dinfo, pev, tevs, max_tevs);

    debuginfo__delete(dinfo);

    if (ntevs > 0) {    /* Succeeded to find trace events */
        pr_debug("find %d probe_trace_events.\n", ntevs);
        if (target)
            ret = add_module_to_probe_trace_events(*tevs, ntevs,
                                   target);
        return ret < 0 ? ret : ntevs;
    }

    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;
    }
    /* 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;
}

/*
 * Find a src file from a DWARF tag path. Prepend optional source path prefix
 * and chop off leading directories that do not exist. Result is passed back as
 * a newly allocated path on success.
 * Return 0 if file was found and readable, -errno otherwise.
 */
static int get_real_path(const char *raw_path, const char *comp_dir,
             char **new_path)
{
    const char *prefix = symbol_conf.source_prefix;

    if (!prefix) {
        if (raw_path[0] != '/' && comp_dir)
            /* If not an absolute path, try to use comp_dir */
            prefix = comp_dir;
        else {
            if (access(raw_path, R_OK) == 0) {
                *new_path = strdup(raw_path);
                return 0;
            } else
                return -errno;
        }
    }

    *new_path = malloc((strlen(prefix) + strlen(raw_path) + 2));
    if (!*new_path)
        return -ENOMEM;

    for (;;) {
        sprintf(*new_path, "%s/%s", prefix, raw_path);

        if (access(*new_path, R_OK) == 0)
            return 0;

        if (!symbol_conf.source_prefix)
            /* In case of searching comp_dir, don't retry */
            return -errno;

        switch (errno) {
        case ENAMETOOLONG:
        case ENOENT:
        case EROFS:
        case EFAULT:
            raw_path = strchr(++raw_path, '/');
            if (!raw_path) {
                free(*new_path);
                *new_path = NULL;
                return -ENOENT;
            }
            continue;

        default:
            free(*new_path);
            *new_path = NULL;
            return -errno;
        }
    }
}

#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];
    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", strerror(errno));
        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.
 */
int show_line_range(struct line_range *lr, const char *module)
{
    int l = 1;
    struct line_node *ln;
    struct debuginfo *dinfo;
    FILE *fp;
    int ret;
    char *tmp;

    /* Search a line range */
    ret = init_vmlinux();
    if (ret < 0)
        return ret;

    dinfo = open_debuginfo(module);
    if (!dinfo) {
        pr_warning("Failed to open debuginfo file.\n");
        return -ENOENT;
    }

    ret = debuginfo__find_line_range(dinfo, lr);
    debuginfo__delete(dinfo);
    if (ret == 0) {
        pr_warning("Specified source line is not found.\n");
        return -ENOENT;
    } else if (ret < 0) {
        pr_warning("Debuginfo analysis failed. (%d)\n", ret);
        return ret;
    }

    /* Convert source file path */
    tmp = lr->path;
    ret = get_real_path(tmp, lr->comp_dir, &lr->path);
    free(tmp);  /* Free old path */
    if (ret < 0) {
        pr_warning("Failed to find source file. (%d)\n", ret);
        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,
               strerror(errno));
        return -errno;
    }
    /* Skip to starting line number */
    while (l < lr->start) {
        ret = skip_one_line(fp, l++);
        if (ret < 0)
            goto end;
    }

    list_for_each_entry(ln, &lr->line_list, list) {
        for (; ln->line > 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;
}

static int show_available_vars_at(struct debuginfo *dinfo,
                  struct perf_probe_event *pev,
                  int max_vls, struct strfilter *_filter,
                  bool externs)
{
    char *buf;
    int ret, i, nvars;
    struct str_node *node;
    struct variable_list *vls = NULL, *vl;
    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,
                        max_vls, externs);
    if (ret <= 0) {
        pr_err("Failed to find variables at %s (%d)\n", buf, ret);
        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);
        free(vl->point.symbol);
        nvars = 0;
        if (vl->vars) {
            strlist__for_each(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,
            int max_vls, const char *module,
            struct strfilter *_filter, bool externs)
{
    int i, ret = 0;
    struct debuginfo *dinfo;

    ret = init_vmlinux();
    if (ret < 0)
        return ret;

    dinfo = open_debuginfo(module);
    if (!dinfo) {
        pr_warning("Failed to open debuginfo file.\n");
        return -ENOENT;
    }

    setup_pager();

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

    debuginfo__delete(dinfo);
    return ret;
}

#else   /* !DWARF_SUPPORT */

static int kprobe_convert_to_perf_probe(struct probe_trace_point *tp,
                    struct perf_probe_point *pp)
{
    struct symbol *sym;

    sym = __find_kernel_function_by_name(tp->symbol, NULL);
    if (!sym) {
        pr_err("Failed to find symbol %s in kernel.\n", tp->symbol);
        return -ENOENT;
    }

    return convert_to_perf_probe_point(tp, pp);
}

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

    if (pev->uprobes)
        return convert_name_to_addr(pev, target);

    return 0;
}

int show_line_range(struct line_range *lr __maybe_unused,
            const char *module __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, int max_vls __maybe_unused,
            const char *module __maybe_unused,
            struct strfilter *filter __maybe_unused,
            bool externs __maybe_unused)
{
    pr_warning("Debuginfo-analysis is not supported.\n");
    return -ENOSYS;
}
#endif

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;
}

/*
 * 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, '.'))
        lr->file = name;
    else
        lr->function = name;

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

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

/* 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;
    /*
     * <Syntax>
     * perf probe [EVENT=]SRC[:LN|;PTN]
     * perf probe [EVENT=]FUNC[@SRC][+OFFS|%return|:LN|;PAT]
     *
     * TODO:Group name support
     */

    ptr = strpbrk(arg, ";=@+%");
    if (ptr && *ptr == '=') {   /* Event name */
        *ptr = '\0';
        tmp = ptr + 1;
        if (strchr(arg, ':')) {
            semantic_error("Group name is not supported yet.\n");
            return -ENOTSUP;
        }
        if (!check_event_name(arg)) {
            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;
        pev->group = NULL;
        arg = tmp;
    }

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

    tmp = strdup(arg);
    if (tmp == NULL)
        return -ENOMEM;

    /* Check arg is function or file and copy it */
    if (strchr(tmp, '.'))   /* File */
        pp->file = tmp;
    else            /* Function */
        pp->function = tmp;

    /* 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->retprobe && !pp->function) {
        semantic_error("Return probe 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;
}

/* Return true if this perf_probe_event requires debuginfo */
bool perf_probe_event_need_dwarf(struct perf_probe_event *pev)
{
    int i;

    if (pev->point.file || pev->point.line || pev->point.lazy_line)
        return true;

    for (i = 0; i < pev->nargs; i++)
        if (is_c_varname(pev->args[i].var))
            return true;

    return false;
}

/* Parse probe_events event into struct probe_point */
static 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]);
        p++;
    } else
        p = argv[1];
    fmt1_str = strtok_r(p, "+", &fmt);
    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 */
int synthesize_perf_probe_arg(struct perf_probe_arg *pa, char *buf, size_t len)
{
    struct perf_probe_arg_field *field = pa->field;
    int ret;
    char *tmp = buf;

    if (pa->name && pa->var)
        ret = e_snprintf(tmp, len, "%s=%s", pa->name, pa->var);
    else
        ret = e_snprintf(tmp, len, "%s", pa->name ? pa->name : pa->var);
    if (ret <= 0)
        goto error;
    tmp += ret;
    len -= ret;

    while (field) {
        if (field->name[0] == '[')
            ret = e_snprintf(tmp, len, "%s", field->name);
        else
            ret = e_snprintf(tmp, len, "%s%s",
                     field->ref ? "->" : ".", field->name);
        if (ret <= 0)
            goto error;
        tmp += ret;
        len -= ret;
        field = field->next;
    }

    if (pa->type) {
        ret = e_snprintf(tmp, len, ":%s", pa->type);
        if (ret <= 0)
            goto error;
        tmp += ret;
        len -= ret;
    }

    return tmp - buf;
error:
    pr_debug("Failed to synthesize perf probe argument: %s\n",
         strerror(-ret));
    return ret;
}

/* Compose only probe point (not argument) */
static char *synthesize_perf_probe_point(struct perf_probe_point *pp)
{
    char *buf, *tmp;
    char offs[32] = "", line[32] = "", file[32] = "";
    int ret, len;

    buf = zalloc(MAX_CMDLEN);
    if (buf == NULL) {
        ret = -ENOMEM;
        goto error;
    }
    if (pp->offset) {
        ret = e_snprintf(offs, 32, "+%lu", pp->offset);
        if (ret <= 0)
            goto error;
    }
    if (pp->line) {
        ret = e_snprintf(line, 32, ":%d", pp->line);
        if (ret <= 0)
            goto error;
    }
    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;
        }
        ret = e_snprintf(file, 32, "@%s", tmp);
        if (ret <= 0)
            goto error;
    }

    if (pp->function)
        ret = e_snprintf(buf, MAX_CMDLEN, "%s%s%s%s%s", pp->function,
                 offs, pp->retprobe ? "%return" : "", line,
                 file);
    else
        ret = e_snprintf(buf, MAX_CMDLEN, "%s%s", file, line);
    if (ret <= 0)
        goto error;

    return buf;
error:
    pr_debug("Failed to synthesize perf probe point: %s\n",
         strerror(-ret));
    if (buf)
        free(buf);
    return NULL;
}

#if 0
char *synthesize_perf_probe_command(struct perf_probe_event *pev)
{
    char *buf;
    int i, len, ret;

    buf = synthesize_perf_probe_point(&pev->point);
    if (!buf)
        return NULL;

    len = strlen(buf);
    for (i = 0; i < pev->nargs; i++) {
        ret = e_snprintf(&buf[len], MAX_CMDLEN - len, " %s",
                 pev->args[i].name);
        if (ret <= 0) {
            free(buf);
            return NULL;
        }
        len += ret;
    }

    return buf;
}
#endif

static int __synthesize_probe_trace_arg_ref(struct probe_trace_arg_ref *ref,
                         char **buf, size_t *buflen,
                         int depth)
{
    int ret;
    if (ref->next) {
        depth = __synthesize_probe_trace_arg_ref(ref->next, buf,
                             buflen, depth + 1);
        if (depth < 0)
            goto out;
    }

    ret = e_snprintf(*buf, *buflen, "%+ld(", ref->offset);
    if (ret < 0)
        depth = ret;
    else {
        *buf += ret;
        *buflen -= ret;
    }
out:
    return depth;

}

static int synthesize_probe_trace_arg(struct probe_trace_arg *arg,
                       char *buf, size_t buflen)
{
    struct probe_trace_arg_ref *ref = arg->ref;
    int ret, depth = 0;
    char *tmp = buf;

    /* Argument name or separator */
    if (arg->name)
        ret = e_snprintf(buf, buflen, " %s=", arg->name);
    else
        ret = e_snprintf(buf, buflen, " ");
    if (ret < 0)
        return ret;
    buf += ret;
    buflen -= ret;

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

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

    /* Print argument value */
    if (arg->value[0] == '@' && arg->ref)
        ret = e_snprintf(buf, buflen, "%s%+ld", arg->value,
                 arg->ref->offset);
    else
        ret = e_snprintf(buf, buflen, "%s", arg->value);
    if (ret < 0)
        return ret;
    buf += ret;
    buflen -= ret;

    /* Closing */
    while (depth--) {
        ret = e_snprintf(buf, buflen, ")");
        if (ret < 0)
            return ret;
        buf += ret;
        buflen -= ret;
    }
    /* Print argument type */
    if (arg->type) {
        ret = e_snprintf(buf, buflen, ":%s", arg->type);
        if (ret <= 0)
            return ret;
        buf += ret;
    }

    return buf - tmp;
}

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

    buf = zalloc(MAX_CMDLEN);
    if (buf == NULL)
        return NULL;

    if (tev->uprobes)
        len = e_snprintf(buf, MAX_CMDLEN, "%c:%s/%s %s:%s",
                 tp->retprobe ? 'r' : 'p',
                 tev->group, tev->event,
                 tp->module, tp->symbol);
    else
        len = e_snprintf(buf, MAX_CMDLEN, "%c:%s/%s %s%s%s+%lu",
                 tp->retprobe ? 'r' : 'p',
                 tev->group, tev->event,
                 tp->module ?: "", tp->module ? ":" : "",
                 tp->symbol, tp->offset);

    if (len <= 0)
        goto error;

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

    return buf;
error:
    free(buf);
    return NULL;
}

static int convert_to_perf_probe_event(struct probe_trace_event *tev,
                   struct perf_probe_event *pev, bool is_kprobe)
{
    char buf[64] = "";
    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 */
    if (is_kprobe)
        ret = kprobe_convert_to_perf_probe(&tev->point, &pev->point);
    else
        ret = convert_to_perf_probe_point(&tev->point, &pev->point);

    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 {
            ret = synthesize_probe_trace_arg(&tev->args[i],
                              buf, 64);
            pev->args[i].name = strdup(buf);
        }
        if (pev->args[i].name == NULL && ret >= 0)
            ret = -ENOMEM;
    }

    if (ret < 0)
        clear_perf_probe_event(pev);

    return ret;
}

void clear_perf_probe_event(struct perf_probe_event *pev)
{
    struct perf_probe_point *pp = &pev->point;
    struct perf_probe_arg_field *field, *next;
    int i;

    if (pev->event)
        free(pev->event);
    if (pev->group)
        free(pev->group);
    if (pp->file)
        free(pp->file);
    if (pp->function)
        free(pp->function);
    if (pp->lazy_line)
        free(pp->lazy_line);
    for (i = 0; i < pev->nargs; i++) {
        if (pev->args[i].name)
            free(pev->args[i].name);
        if (pev->args[i].var)
            free(pev->args[i].var);
        if (pev->args[i].type)
            free(pev->args[i].type);
        field = pev->args[i].field;
        while (field) {
            next = field->next;
            if (field->name)
                free(field->name);
            free(field);
            field = next;
        }
    }
    if (pev->args)
        free(pev->args);
    memset(pev, 0, sizeof(*pev));
}

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

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

static void print_warn_msg(const char *file, bool is_kprobe)
{

    if (errno == ENOENT) {
        const char *config;

        if (!is_kprobe)
            config = "CONFIG_UPROBE_EVENTS";
        else
            config = "CONFIG_KPROBE_EVENTS";

        pr_warning("%s file does not exist - please rebuild kernel"
                " with %s.\n", file, config);
    } else
        pr_warning("Failed to open %s file: %s\n", file,
                strerror(errno));
}

static int open_probe_events(const char *trace_file, bool readwrite,
                bool is_kprobe)
{
    char buf[PATH_MAX];
    const char *__debugfs;
    int ret;

    __debugfs = debugfs_find_mountpoint();
    if (__debugfs == NULL) {
        pr_warning("Debugfs is not mounted.\n");
        return -ENOENT;
    }

    ret = e_snprintf(buf, PATH_MAX, "%s/%s", __debugfs, trace_file);
    if (ret >= 0) {
        pr_debug("Opening %s write=%d\n", buf, readwrite);
        if (readwrite && !probe_event_dry_run)
            ret = open(buf, O_RDWR, O_APPEND);
        else
            ret = open(buf, O_RDONLY, 0);

        if (ret < 0)
            print_warn_msg(buf, is_kprobe);
    }
    return ret;
}

static int open_kprobe_events(bool readwrite)
{
    return open_probe_events("tracing/kprobe_events", readwrite, true);
}

static int open_uprobe_events(bool readwrite)
{
    return open_probe_events("tracing/uprobe_events", readwrite, false);
}

/* Get raw string list of current kprobe_events  or uprobe_events */
static struct strlist *get_probe_trace_command_rawlist(int fd)
{
    int ret, idx;
    FILE *fp;
    char buf[MAX_CMDLEN];
    char *p;
    struct strlist *sl;

    sl = strlist__new(true, NULL);

    fp = fdopen(dup(fd), "r");
    while (!feof(fp)) {
        p = fgets(buf, MAX_CMDLEN, fp);
        if (!p)
            break;

        idx = strlen(p) - 1;
        if (p[idx] == '\n')
            p[idx] = '\0';
        ret = strlist__add(sl, buf);
        if (ret < 0) {
            pr_debug("strlist__add failed: %s\n", strerror(-ret));
            strlist__delete(sl);
            return NULL;
        }
    }
    fclose(fp);

    return sl;
}

/* Show an event */
static int show_perf_probe_event(struct perf_probe_event *pev)
{
    int i, ret;
    char buf[128];
    char *place;

    /* Synthesize only event probe point */
    place = synthesize_perf_probe_point(&pev->point);
    if (!place)
        return -EINVAL;

    ret = e_snprintf(buf, 128, "%s:%s", pev->group, pev->event);
    if (ret < 0)
        return ret;

    printf("  %-20s (on %s", buf, place);

    if (pev->nargs > 0) {
        printf(" with");
        for (i = 0; i < pev->nargs; i++) {
            ret = synthesize_perf_probe_arg(&pev->args[i],
                            buf, 128);
            if (ret < 0)
                break;
            printf(" %s", buf);
        }
    }
    printf(")\n");
    free(place);
    return ret;
}

static int __show_perf_probe_events(int fd, bool is_kprobe)
{
    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 = get_probe_trace_command_rawlist(fd);
    if (!rawlist)
        return -ENOENT;

    strlist__for_each(ent, rawlist) {
        ret = parse_probe_trace_command(ent->s, &tev);
        if (ret >= 0) {
            ret = convert_to_perf_probe_event(&tev, &pev,
                                is_kprobe);
            if (ret >= 0)
                ret = show_perf_probe_event(&pev);
        }
        clear_perf_probe_event(&pev);
        clear_probe_trace_event(&tev);
        if (ret < 0)
            break;
    }
    strlist__delete(rawlist);

    return ret;
}

/* List up current perf-probe events */
int show_perf_probe_events(void)
{
    int fd, ret;

    setup_pager();
    fd = open_kprobe_events(false);

    if (fd < 0)
        return fd;

    ret = init_vmlinux();
    if (ret < 0)
        return ret;

    ret = __show_perf_probe_events(fd, true);
    close(fd);

    fd = open_uprobe_events(false);
    if (fd >= 0) {
        ret = __show_perf_probe_events(fd, false);
        close(fd);
    }

    return ret;
}

/* Get current perf-probe event names */
static struct strlist *get_probe_trace_event_names(int fd, bool include_group)
{
    char buf[128];
    struct strlist *sl, *rawlist;
    struct str_node *ent;
    struct probe_trace_event tev;
    int ret = 0;

    memset(&tev, 0, sizeof(tev));
    rawlist = get_probe_trace_command_rawlist(fd);
    sl = strlist__new(true, NULL);
    strlist__for_each(ent, rawlist) {
        ret = parse_probe_trace_command(ent->s, &tev);
        if (ret < 0)
            break;
        if (include_group) {
            ret = e_snprintf(buf, 128, "%s:%s", tev.group,
                    tev.event);
            if (ret >= 0)
                ret = strlist__add(sl, buf);
        } else
            ret = strlist__add(sl, tev.event);
        clear_probe_trace_event(&tev);
        if (ret < 0)
            break;
    }
    strlist__delete(rawlist);

    if (ret < 0) {
        strlist__delete(sl);
        return NULL;
    }
    return sl;
}

static int write_probe_trace_event(int fd, struct probe_trace_event *tev)
{
    int ret = 0;
    char *buf = synthesize_probe_trace_command(tev);

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

    pr_debug("Writing event: %s\n", buf);
    if (!probe_event_dry_run) {
        ret = write(fd, buf, strlen(buf));
        if (ret <= 0)
            pr_warning("Failed to write event: %s\n",
                   strerror(errno));
    }
    free(buf);
    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;

    /* Try no suffix */
    ret = e_snprintf(buf, len, "%s", base);
    if (ret < 0) {
        pr_debug("snprintf() failed: %s\n", strerror(-ret));
        return ret;
    }
    if (!strlist__has_entry(namelist, buf))
        return 0;

    if (!allow_suffix) {
        pr_warning("Error: event \"%s\" already exists. "
               "(Use -f to force duplicates.)\n", base);
        return -EEXIST;
    }

    /* Try to add suffix */
    for (i = 1; i < MAX_EVENT_INDEX; i++) {
        ret = e_snprintf(buf, len, "%s_%d", base, i);
        if (ret < 0) {
            pr_debug("snprintf() failed: %s\n", strerror(-ret));
            return ret;
        }
        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;
    }

    return ret;
}

static int __add_probe_trace_events(struct perf_probe_event *pev,
                     struct probe_trace_event *tevs,
                     int ntevs, bool allow_suffix)
{
    int i, fd, ret;
    struct probe_trace_event *tev = NULL;
    char buf[64];
    const char *event, *group;
    struct strlist *namelist;

    if (pev->uprobes)
        fd = open_uprobe_events(true);
    else
        fd = open_kprobe_events(true);

    if (fd < 0)
        return fd;
    /* Get current event names */
    namelist = get_probe_trace_event_names(fd, false);
    if (!namelist) {
        pr_debug("Failed to get current event list.\n");
        return -EIO;
    }

    ret = 0;
    printf("Added new event%s\n", (ntevs > 1) ? "s:" : ":");
    for (i = 0; i < ntevs; i++) {
        tev = &tevs[i];
        if (pev->event)
            event = pev->event;
        else
            if (pev->point.function)
                event = pev->point.function;
            else
                event = tev->point.symbol;
        if (pev->group)
            group = pev->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)
            break;
        event = buf;

        tev->event = strdup(event);
        tev->group = strdup(group);
        if (tev->event == NULL || tev->group == NULL) {
            ret = -ENOMEM;
            break;
        }
        ret = write_probe_trace_event(fd, tev);
        if (ret < 0)
            break;
        /* Add added event name to namelist */
        strlist__add(namelist, event);

        /* Trick here - save current event/group */
        event = pev->event;
        group = pev->group;
        pev->event = tev->event;
        pev->group = tev->group;
        show_perf_probe_event(pev);
        /* Trick here - restore current event/group */
        pev->event = (char *)event;
        pev->group = (char *)group;

        /*
         * 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 >= 0) {
        /* Show how to use the event. */
        printf("\nYou can now use it in all perf tools, such as:\n\n");
        printf("\tperf record -e %s:%s -aR sleep 1\n\n", tev->group,
             tev->event);
    }

    strlist__delete(namelist);
    close(fd);
    return ret;
}

static int convert_to_probe_trace_events(struct perf_probe_event *pev,
                      struct probe_trace_event **tevs,
                      int max_tevs, const char *target)
{
    struct symbol *sym;
    int ret = 0, i;
    struct probe_trace_event *tev;

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

    /* Allocate trace event buffer */
    tev = *tevs = zalloc(sizeof(struct probe_trace_event));
    if (tev == NULL)
        return -ENOMEM;

    /* Copy parameters */
    tev->point.symbol = strdup(pev->point.function);
    if (tev->point.symbol == NULL) {
        ret = -ENOMEM;
        goto error;
    }

    if (target) {
        tev->point.module = strdup(target);
        if (tev->point.module == NULL) {
            ret = -ENOMEM;
            goto error;
        }
    }

    tev->point.offset = pev->point.offset;
    tev->point.retprobe = pev->point.retprobe;
    tev->nargs = pev->nargs;
    tev->uprobes = pev->uprobes;

    if (tev->nargs) {
        tev->args = zalloc(sizeof(struct probe_trace_arg)
                   * tev->nargs);
        if (tev->args == NULL) {
            ret = -ENOMEM;
            goto error;
        }
        for (i = 0; i < tev->nargs; i++) {
            if (pev->args[i].name) {
                tev->args[i].name = strdup(pev->args[i].name);
                if (tev->args[i].name == NULL) {
                    ret = -ENOMEM;
                    goto error;
                }
            }
            tev->args[i].value = strdup(pev->args[i].var);
            if (tev->args[i].value == NULL) {
                ret = -ENOMEM;
                goto error;
            }
            if (pev->args[i].type) {
                tev->args[i].type = strdup(pev->args[i].type);
                if (tev->args[i].type == NULL) {
                    ret = -ENOMEM;
                    goto error;
                }
            }
        }
    }

    if (pev->uprobes)
        return 1;

    /* Currently just checking function name from symbol map */
    sym = __find_kernel_function_by_name(tev->point.symbol, NULL);
    if (!sym) {
        pr_warning("Kernel symbol \'%s\' not found.\n",
               tev->point.symbol);
        ret = -ENOENT;
        goto error;
    } else if (tev->point.offset > sym->end - sym->start) {
        pr_warning("Offset specified is greater than size of %s\n",
               tev->point.symbol);
        ret = -ENOENT;
        goto error;

    }

    return 1;
error:
    clear_probe_trace_event(tev);
    free(tev);
    *tevs = NULL;
    return ret;
}

struct __event_package {
    struct perf_probe_event     *pev;
    struct probe_trace_event    *tevs;
    int             ntevs;
};

int add_perf_probe_events(struct perf_probe_event *pevs, int npevs,
              int max_tevs, const char *target, bool force_add)
{
    int i, j, ret;
    struct __event_package *pkgs;

    ret = 0;
    pkgs = zalloc(sizeof(struct __event_package) * npevs);

    if (pkgs == NULL)
        return -ENOMEM;

    if (!pevs->uprobes)
        /* Init vmlinux path */
        ret = init_vmlinux();
    else
        ret = init_user_exec();

    if (ret < 0) {
        free(pkgs);
        return ret;
    }

    /* Loop 1: convert all events */
    for (i = 0; i < npevs; i++) {
        pkgs[i].pev = &pevs[i];
        /* Convert with or without debuginfo */
        ret  = convert_to_probe_trace_events(pkgs[i].pev,
                             &pkgs[i].tevs,
                             max_tevs,
                             target);
        if (ret < 0)
            goto end;
        pkgs[i].ntevs = ret;
    }

    /* Loop 2: add all events */
    for (i = 0; i < npevs; i++) {
        ret = __add_probe_trace_events(pkgs[i].pev, pkgs[i].tevs,
                        pkgs[i].ntevs, force_add);
        if (ret < 0)
            break;
    }
end:
    /* Loop 3: cleanup and free trace events  */
    for (i = 0; i < npevs; i++) {
        for (j = 0; j < pkgs[i].ntevs; j++)
            clear_probe_trace_event(&pkgs[i].tevs[j]);
        free(pkgs[i].tevs);
    }
    free(pkgs);

    return ret;
}

static int __del_trace_probe_event(int fd, struct str_node *ent)
{
    char *p;
    char buf[128];
    int ret;

    /* Convert from perf-probe event to trace-probe event */
    ret = e_snprintf(buf, 128, "-:%s", ent->s);
    if (ret < 0)
        goto error;

    p = strchr(buf + 2, ':');
    if (!p) {
        pr_debug("Internal error: %s should have ':' but not.\n",
             ent->s);
        ret = -ENOTSUP;
        goto error;
    }
    *p = '/';

    pr_debug("Writing event: %s\n", buf);
    ret = write(fd, buf, strlen(buf));
    if (ret < 0) {
        ret = -errno;
        goto error;
    }

    printf("Removed event: %s\n", ent->s);
    return 0;
error:
    pr_warning("Failed to delete event: %s\n", strerror(-ret));
    return ret;
}

static int del_trace_probe_event(int fd, const char *buf,
                          struct strlist *namelist)
{
    struct str_node *ent, *n;
    int ret = -1;

    if (strpbrk(buf, "*?")) { /* Glob-exp */
        strlist__for_each_safe(ent, n, namelist)
            if (strglobmatch(ent->s, buf)) {
                ret = __del_trace_probe_event(fd, ent);
                if (ret < 0)
                    break;
                strlist__remove(namelist, ent);
            }
    } else {
        ent = strlist__find(namelist, buf);
        if (ent) {
            ret = __del_trace_probe_event(fd, ent);
            if (ret >= 0)
                strlist__remove(namelist, ent);
        }
    }

    return ret;
}

int del_perf_probe_events(struct strlist *dellist)
{
    int ret = -1, ufd = -1, kfd = -1;
    char buf[128];
    const char *group, *event;
    char *p, *str;
    struct str_node *ent;
    struct strlist *namelist = NULL, *unamelist = NULL;

    /* Get current event names */
    kfd = open_kprobe_events(true);
    if (kfd < 0)
        return kfd;

    namelist = get_probe_trace_event_names(kfd, true);
    ufd = open_uprobe_events(true);

    if (ufd >= 0)
        unamelist = get_probe_trace_event_names(ufd, true);

    if (namelist == NULL && unamelist == NULL)
        goto error;

    strlist__for_each(ent, dellist) {
        str = strdup(ent->s);
        if (str == NULL) {
            ret = -ENOMEM;
            goto error;
        }
        pr_debug("Parsing: %s\n", str);
        p = strchr(str, ':');
        if (p) {
            group = str;
            *p = '\0';
            event = p + 1;
        } else {
            group = "*";
            event = str;
        }

        ret = e_snprintf(buf, 128, "%s:%s", group, event);
        if (ret < 0) {
            pr_err("Failed to copy event.");
            free(str);
            goto error;
        }

        pr_debug("Group: %s, Event: %s\n", group, event);

        if (namelist)
            ret = del_trace_probe_event(kfd, buf, namelist);

        if (unamelist && ret != 0)
            ret = del_trace_probe_event(ufd, buf, unamelist);

        if (ret != 0)
            pr_info("Info: Event \"%s\" does not exist.\n", buf);

        free(str);
    }

error:
    if (kfd >= 0) {
        strlist__delete(namelist);
        close(kfd);
    }

    if (ufd >= 0) {
        strlist__delete(unamelist);
        close(ufd);
    }

    return ret;
}

/* TODO: don't use a global variable for filter ... */
static struct strfilter *available_func_filter;

/*
 * If a symbol corresponds to a function with global binding and
 * matches filter return 0. For all others return 1.
 */
static int filter_available_functions(struct map *map __maybe_unused,
                      struct symbol *sym)
{
    if (sym->binding == STB_GLOBAL &&
        strfilter__compare(available_func_filter, sym->name))
        return 0;
    return 1;
}

static int __show_available_funcs(struct map *map)
{
    if (map__load(map, filter_available_functions)) {
        pr_err("Failed to load map.\n");
        return -EINVAL;
    }
    if (!dso__sorted_by_name(map->dso, map->type))
        dso__sort_by_name(map->dso, map->type);

    dso__fprintf_symbols_by_name(map->dso, map->type, stdout);
    return 0;
}

static int available_kernel_funcs(const char *module)
{
    struct map *map;
    int ret;

    ret = init_vmlinux();
    if (ret < 0)
        return ret;

    map = kernel_get_module_map(module);
    if (!map) {
        pr_err("Failed to find %s map.\n", (module) ? : "kernel");
        return -EINVAL;
    }
    return __show_available_funcs(map);
}

static int available_user_funcs(const char *target)
{
    struct map *map;
    int ret;

    ret = init_user_exec();
    if (ret < 0)
        return ret;

    map = dso__new_map(target);
    ret = __show_available_funcs(map);
    dso__delete(map->dso);
    map__delete(map);
    return ret;
}

int show_available_funcs(const char *target, struct strfilter *_filter,
                    bool user)
{
    setup_pager();
    available_func_filter = _filter;

    if (!user)
        return available_kernel_funcs(target);

    return available_user_funcs(target);
}

/*
 * uprobe_events only accepts address:
 * Convert function and any offset to address
 */
static int convert_name_to_addr(struct perf_probe_event *pev, const char *exec)
{
    struct perf_probe_point *pp = &pev->point;
    struct symbol *sym;
    struct map *map = NULL;
    char *function = NULL, *name = NULL;
    int ret = -EINVAL;
    unsigned long long vaddr = 0;

    if (!pp->function) {
        pr_warning("No function specified for uprobes");
        goto out;
    }

    function = strdup(pp->function);
    if (!function) {
        pr_warning("Failed to allocate memory by strdup.\n");
        ret = -ENOMEM;
        goto out;
    }

    name = realpath(exec, NULL);
    if (!name) {
        pr_warning("Cannot find realpath for %s.\n", exec);
        goto out;
    }
    map = dso__new_map(name);
    if (!map) {
        pr_warning("Cannot find appropriate DSO for %s.\n", exec);
        goto out;
    }
    available_func_filter = strfilter__new(function, NULL);
    if (map__load(map, filter_available_functions)) {
        pr_err("Failed to load map.\n");
        goto out;
    }

    sym = map__find_symbol_by_name(map, function, NULL);
    if (!sym) {
        pr_warning("Cannot find %s in DSO %s\n", function, exec);
        goto out;
    }

    if (map->start > sym->start)
        vaddr = map->start;
    vaddr += sym->start + pp->offset + map->pgoff;
    pp->offset = 0;

    if (!pev->event) {
        pev->event = function;
        function = NULL;
    }
    if (!pev->group) {
        char *ptr1, *ptr2, *exec_copy;

        pev->group = zalloc(sizeof(char *) * 64);
        exec_copy = strdup(exec);
        if (!exec_copy) {
            ret = -ENOMEM;
            pr_warning("Failed to copy exec string.\n");
            goto out;
        }

        ptr1 = strdup(basename(exec_copy));
        if (ptr1) {
            ptr2 = strpbrk(ptr1, "-._");
            if (ptr2)
                *ptr2 = '\0';
            e_snprintf(pev->group, 64, "%s_%s", PERFPROBE_GROUP,
                    ptr1);
            free(ptr1);
        }
        free(exec_copy);
    }
    free(pp->function);
    pp->function = zalloc(sizeof(char *) * MAX_PROBE_ARGS);
    if (!pp->function) {
        ret = -ENOMEM;
        pr_warning("Failed to allocate memory by zalloc.\n");
        goto out;
    }
    e_snprintf(pp->function, MAX_PROBE_ARGS, "0x%llx", vaddr);
    ret = 0;

out:
    if (map) {
        dso__delete(map->dso);
        map__delete(map);
    }
    if (function)
        free(function);
    if (name)
        free(name);
    return ret;
}