// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (C) 2009-2011, Frederic Weisbecker <fweisbec@gmail.com>
 *
 * Handle the callchains from the stream in an ad-hoc radix tree and then
 * sort them in an rbtree.
 *
 * Using a radix for code path provides a fast retrieval and factorizes
 * memory use. Also that lets us use the paths in a hierarchical graph view.
 *
 */

#include <inttypes.h>
#include <stdlib.h>
#include <stdio.h>
#include <stdbool.h>
#include <errno.h>
#include <math.h>
#include <linux/string.h>
#include <linux/zalloc.h>

#include "asm/bug.h"

#include "debug.h"
#include "dso.h"
#include "event.h"
#include "hist.h"
#include "sort.h"
#include "machine.h"
#include "map.h"
#include "callchain.h"
#include "branch.h"
#include "symbol.h"
#include "thread.h"
#include "util.h"
#include "../perf.h"

#define CALLCHAIN_PARAM_DEFAULT                 \
        .mode           = CHAIN_GRAPH_ABS,      \
        .min_percent    = 0.5,                  \
        .order          = ORDER_CALLEE,         \
        .key            = CCKEY_FUNCTION,       \
        .value          = CCVAL_PERCENT,        \

struct callchain_param callchain_param = {
        CALLCHAIN_PARAM_DEFAULT
};

/*
 * Are there any events usind DWARF callchains?
 *
 * I.e.
 *
 * -e cycles/call-graph=dwarf/
 */
bool dwarf_callchain_users;

struct callchain_param callchain_param_default = {
        CALLCHAIN_PARAM_DEFAULT
};

/* Used for thread-local struct callchain_cursor. */
static pthread_key_t callchain_cursor;

int parse_callchain_record_opt(const char *arg, struct callchain_param *param)
{
        return parse_callchain_record(arg, param);
}

static int parse_callchain_mode(const char *value)
{
        if (!strncmp(value, "graph", strlen(value))) {
                callchain_param.mode = CHAIN_GRAPH_ABS;
                return 0;
        }
        if (!strncmp(value, "flat", strlen(value))) {
                callchain_param.mode = CHAIN_FLAT;
                return 0;
        }
        if (!strncmp(value, "fractal", strlen(value))) {
                callchain_param.mode = CHAIN_GRAPH_REL;
                return 0;
        }
        if (!strncmp(value, "folded", strlen(value))) {
                callchain_param.mode = CHAIN_FOLDED;
                return 0;
        }
        return -1;
}

static int parse_callchain_order(const char *value)
{
        if (!strncmp(value, "caller", strlen(value))) {
                callchain_param.order = ORDER_CALLER;
                callchain_param.order_set = true;
                return 0;
        }
        if (!strncmp(value, "callee", strlen(value))) {
                callchain_param.order = ORDER_CALLEE;
                callchain_param.order_set = true;
                return 0;
        }
        return -1;
}

static int parse_callchain_sort_key(const char *value)
{
        if (!strncmp(value, "function", strlen(value))) {
                callchain_param.key = CCKEY_FUNCTION;
                return 0;
        }
        if (!strncmp(value, "address", strlen(value))) {
                callchain_param.key = CCKEY_ADDRESS;
                return 0;
        }
        if (!strncmp(value, "srcline", strlen(value))) {
                callchain_param.key = CCKEY_SRCLINE;
                return 0;
        }
        if (!strncmp(value, "branch", strlen(value))) {
                callchain_param.branch_callstack = 1;
                return 0;
        }
        return -1;
}

static int parse_callchain_value(const char *value)
{
        if (!strncmp(value, "percent", strlen(value))) {
                callchain_param.value = CCVAL_PERCENT;
                return 0;
        }
        if (!strncmp(value, "period", strlen(value))) {
                callchain_param.value = CCVAL_PERIOD;
                return 0;
        }
        if (!strncmp(value, "count", strlen(value))) {
                callchain_param.value = CCVAL_COUNT;
                return 0;
        }
        return -1;
}

static int get_stack_size(const char *str, unsigned long *_size)
{
        char *endptr;
        unsigned long size;
        unsigned long max_size = round_down(USHRT_MAX, sizeof(u64));

        size = strtoul(str, &endptr, 0);

        do {
                if (*endptr)
                        break;

                size = round_up(size, sizeof(u64));
                if (!size || size > max_size)
                        break;

                *_size = size;
                return 0;

        } while (0);

        pr_err("callchain: Incorrect stack dump size (max %ld): %s\n",
               max_size, str);
        return -1;
}

static int
__parse_callchain_report_opt(const char *arg, bool allow_record_opt)
{
        char *tok;
        char *endptr, *saveptr = NULL;
        bool minpcnt_set = false;
        bool record_opt_set = false;
        bool try_stack_size = false;

        callchain_param.enabled = true;
        symbol_conf.use_callchain = true;

        if (!arg)
                return 0;

        while ((tok = strtok_r((char *)arg, ",", &saveptr)) != NULL) {
                if (!strncmp(tok, "none", strlen(tok))) {
                        callchain_param.mode = CHAIN_NONE;
                        callchain_param.enabled = false;
                        symbol_conf.use_callchain = false;
                        return 0;
                }

                if (!parse_callchain_mode(tok) ||
                    !parse_callchain_order(tok) ||
                    !parse_callchain_sort_key(tok) ||
                    !parse_callchain_value(tok)) {
                        /* parsing ok - move on to the next */
                        try_stack_size = false;
                        goto next;
                } else if (allow_record_opt && !record_opt_set) {
                        if (parse_callchain_record(tok, &callchain_param))
                                goto try_numbers;

                        /* assume that number followed by 'dwarf' is stack size */
                        if (callchain_param.record_mode == CALLCHAIN_DWARF)
                                try_stack_size = true;

                        record_opt_set = true;
                        goto next;
                }

try_numbers:
                if (try_stack_size) {
                        unsigned long size = 0;

                        if (get_stack_size(tok, &size) < 0)
                                return -1;
                        callchain_param.dump_size = size;
                        try_stack_size = false;
                } else if (!minpcnt_set) {
                        /* try to get the min percent */
                        callchain_param.min_percent = strtod(tok, &endptr);
                        if (tok == endptr)
                                return -1;
                        minpcnt_set = true;
                } else {
                        /* try print limit at last */
                        callchain_param.print_limit = strtoul(tok, &endptr, 0);
                        if (tok == endptr)
                                return -1;
                }
next:
                arg = NULL;
        }

        if (callchain_register_param(&callchain_param) < 0) {
                pr_err("Can't register callchain params\n");
                return -1;
        }
        return 0;
}

int parse_callchain_report_opt(const char *arg)
{
        return __parse_callchain_report_opt(arg, false);
}

int parse_callchain_top_opt(const char *arg)
{
        return __parse_callchain_report_opt(arg, true);
}

int parse_callchain_record(const char *arg, struct callchain_param *param)
{
        char *tok, *name, *saveptr = NULL;
        char *buf;
        int ret = -1;

        /* We need buffer that we know we can write to. */
        buf = malloc(strlen(arg) + 1);
        if (!buf)
                return -ENOMEM;

        strcpy(buf, arg);

        tok = strtok_r((char *)buf, ",", &saveptr);
        name = tok ? : (char *)buf;

        do {
                /* Framepointer style */
                if (!strncmp(name, "fp", sizeof("fp"))) {
                        ret = 0;
                        param->record_mode = CALLCHAIN_FP;

                        tok = strtok_r(NULL, ",", &saveptr);
                        if (tok) {
                                unsigned long size;

                                if (!strncmp(tok, "defer", sizeof("defer"))) {
                                        param->defer = true;
                                } else {
                                        size = strtoul(tok, &name, 0);
                                        if (size < (unsigned) sysctl__max_stack())
                                                param->max_stack = size;
                                }
                        }
                        break;

                /* Dwarf style */
                } else if (!strncmp(name, "dwarf", sizeof("dwarf"))) {
                        const unsigned long default_stack_dump_size = 8192;

                        ret = 0;
                        param->record_mode = CALLCHAIN_DWARF;
                        param->dump_size = default_stack_dump_size;
                        dwarf_callchain_users = true;

                        tok = strtok_r(NULL, ",", &saveptr);
                        if (tok) {
                                unsigned long size = 0;

                                ret = get_stack_size(tok, &size);
                                param->dump_size = size;
                        }
                } else if (!strncmp(name, "lbr", sizeof("lbr"))) {
                        if (!strtok_r(NULL, ",", &saveptr)) {
                                param->record_mode = CALLCHAIN_LBR;
                                ret = 0;
                        } else
                                pr_err("callchain: No more arguments "
                                        "needed for --call-graph lbr\n");
                        break;
                } else {
                        pr_err("callchain: Unknown --call-graph option "
                               "value: %s\n", arg);
                        break;
                }

        } while (0);

        free(buf);

        if (param->defer && param->record_mode != CALLCHAIN_FP) {
                pr_err("callchain: deferred callchain only works with FP\n");
                return -EINVAL;
        }

        return ret;
}

int perf_callchain_config(const char *var, const char *value)
{
        char *endptr;

        if (!strstarts(var, "call-graph."))
                return 0;
        var += sizeof("call-graph.") - 1;

        if (!strcmp(var, "record-mode"))
                return parse_callchain_record_opt(value, &callchain_param);
        if (!strcmp(var, "dump-size")) {
                unsigned long size = 0;
                int ret;

                ret = get_stack_size(value, &size);
                callchain_param.dump_size = size;

                return ret;
        }
        if (!strcmp(var, "print-type")){
                int ret;
                ret = parse_callchain_mode(value);
                if (ret == -1)
                        pr_err("Invalid callchain mode: %s\n", value);
                return ret;
        }
        if (!strcmp(var, "order")){
                int ret;
                ret = parse_callchain_order(value);
                if (ret == -1)
                        pr_err("Invalid callchain order: %s\n", value);
                return ret;
        }
        if (!strcmp(var, "sort-key")){
                int ret;
                ret = parse_callchain_sort_key(value);
                if (ret == -1)
                        pr_err("Invalid callchain sort key: %s\n", value);
                return ret;
        }
        if (!strcmp(var, "threshold")) {
                callchain_param.min_percent = strtod(value, &endptr);
                if (value == endptr) {
                        pr_err("Invalid callchain threshold: %s\n", value);
                        return -1;
                }
        }
        if (!strcmp(var, "print-limit")) {
                callchain_param.print_limit = strtod(value, &endptr);
                if (value == endptr) {
                        pr_err("Invalid callchain print limit: %s\n", value);
                        return -1;
                }
        }

        return 0;
}

static void
rb_insert_callchain(struct rb_root *root, struct callchain_node *chain,
                    enum chain_mode mode)
{
        struct rb_node **p = &root->rb_node;
        struct rb_node *parent = NULL;
        struct callchain_node *rnode;
        u64 chain_cumul = callchain_cumul_hits(chain);

        while (*p) {
                u64 rnode_cumul;

                parent = *p;
                rnode = rb_entry(parent, struct callchain_node, rb_node);
                rnode_cumul = callchain_cumul_hits(rnode);

                switch (mode) {
                case CHAIN_FLAT:
                case CHAIN_FOLDED:
                        if (rnode->hit < chain->hit)
                                p = &(*p)->rb_left;
                        else
                                p = &(*p)->rb_right;
                        break;
                case CHAIN_GRAPH_ABS: /* Falldown */
                case CHAIN_GRAPH_REL:
                        if (rnode_cumul < chain_cumul)
                                p = &(*p)->rb_left;
                        else
                                p = &(*p)->rb_right;
                        break;
                case CHAIN_NONE:
                default:
                        break;
                }
        }

        rb_link_node(&chain->rb_node, parent, p);
        rb_insert_color(&chain->rb_node, root);
}

static void
__sort_chain_flat(struct rb_root *rb_root, struct callchain_node *node,
                  u64 min_hit)
{
        struct rb_node *n;
        struct callchain_node *child;

        n = rb_first(&node->rb_root_in);
        while (n) {
                child = rb_entry(n, struct callchain_node, rb_node_in);
                n = rb_next(n);

                __sort_chain_flat(rb_root, child, min_hit);
        }

        if (node->hit && node->hit >= min_hit)
                rb_insert_callchain(rb_root, node, CHAIN_FLAT);
}

/*
 * Once we get every callchains from the stream, we can now
 * sort them by hit
 */
static void
sort_chain_flat(struct rb_root *rb_root, struct callchain_root *root,
                u64 min_hit, struct callchain_param *param __maybe_unused)
{
        *rb_root = RB_ROOT;
        __sort_chain_flat(rb_root, &root->node, min_hit);
}

static void __sort_chain_graph_abs(struct callchain_node *node,
                                   u64 min_hit)
{
        struct rb_node *n;
        struct callchain_node *child;

        node->rb_root = RB_ROOT;
        n = rb_first(&node->rb_root_in);

        while (n) {
                child = rb_entry(n, struct callchain_node, rb_node_in);
                n = rb_next(n);

                __sort_chain_graph_abs(child, min_hit);
                if (callchain_cumul_hits(child) >= min_hit)
                        rb_insert_callchain(&node->rb_root, child,
                                            CHAIN_GRAPH_ABS);
        }
}

static void
sort_chain_graph_abs(struct rb_root *rb_root, struct callchain_root *chain_root,
                     u64 min_hit, struct callchain_param *param __maybe_unused)
{
        __sort_chain_graph_abs(&chain_root->node, min_hit);
        rb_root->rb_node = chain_root->node.rb_root.rb_node;
}

static void __sort_chain_graph_rel(struct callchain_node *node,
                                   double min_percent)
{
        struct rb_node *n;
        struct callchain_node *child;
        u64 min_hit;

        node->rb_root = RB_ROOT;
        min_hit = ceil(node->children_hit * min_percent);

        n = rb_first(&node->rb_root_in);
        while (n) {
                child = rb_entry(n, struct callchain_node, rb_node_in);
                n = rb_next(n);

                __sort_chain_graph_rel(child, min_percent);
                if (callchain_cumul_hits(child) >= min_hit)
                        rb_insert_callchain(&node->rb_root, child,
                                            CHAIN_GRAPH_REL);
        }
}

static void
sort_chain_graph_rel(struct rb_root *rb_root, struct callchain_root *chain_root,
                     u64 min_hit __maybe_unused, struct callchain_param *param)
{
        __sort_chain_graph_rel(&chain_root->node, param->min_percent / 100.0);
        rb_root->rb_node = chain_root->node.rb_root.rb_node;
}

int callchain_register_param(struct callchain_param *param)
{
        switch (param->mode) {
        case CHAIN_GRAPH_ABS:
                param->sort = sort_chain_graph_abs;
                break;
        case CHAIN_GRAPH_REL:
                param->sort = sort_chain_graph_rel;
                break;
        case CHAIN_FLAT:
        case CHAIN_FOLDED:
                param->sort = sort_chain_flat;
                break;
        case CHAIN_NONE:
        default:
                return -1;
        }
        return 0;
}

/*
 * Create a child for a parent. If inherit_children, then the new child
 * will become the new parent of it's parent children
 */
static struct callchain_node *
create_child(struct callchain_node *parent, bool inherit_children)
{
        struct callchain_node *new;

        new = zalloc(sizeof(*new));
        if (!new) {
                perror("not enough memory to create child for code path tree");
                return NULL;
        }
        new->parent = parent;
        INIT_LIST_HEAD(&new->val);
        INIT_LIST_HEAD(&new->parent_val);

        if (inherit_children) {
                struct rb_node *n;
                struct callchain_node *child;

                new->rb_root_in = parent->rb_root_in;
                parent->rb_root_in = RB_ROOT;

                n = rb_first(&new->rb_root_in);
                while (n) {
                        child = rb_entry(n, struct callchain_node, rb_node_in);
                        child->parent = new;
                        n = rb_next(n);
                }

                /* make it the first child */
                rb_link_node(&new->rb_node_in, NULL, &parent->rb_root_in.rb_node);
                rb_insert_color(&new->rb_node_in, &parent->rb_root_in);
        }

        return new;
}


/*
 * Fill the node with callchain values
 */
static int
fill_node(struct callchain_node *node, struct callchain_cursor *cursor)
{
        struct callchain_cursor_node *cursor_node;

        node->val_nr = cursor->nr - cursor->pos;
        if (!node->val_nr)
                pr_warning("Warning: empty node in callchain tree\n");

        cursor_node = callchain_cursor_current(cursor);

        while (cursor_node) {
                struct callchain_list *call;

                call = zalloc(sizeof(*call));
                if (!call) {
                        perror("not enough memory for the code path tree");
                        return -ENOMEM;
                }
                call->ip = cursor_node->ip;
                map_symbol__copy(&call->ms, &cursor_node->ms);
                call->srcline = cursor_node->srcline;

                if (cursor_node->branch) {
                        call->branch_count = 1;

                        if (cursor_node->branch_from) {
                                /*
                                 * branch_from is set with value somewhere else
                                 * to imply it's "to" of a branch.
                                 */
                                if (!call->brtype_stat) {
                                        call->brtype_stat = zalloc(sizeof(*call->brtype_stat));
                                        if (!call->brtype_stat) {
                                                perror("not enough memory for the code path branch statistics");
                                                zfree(&call->brtype_stat);
                                                return -ENOMEM;
                                        }
                                }
                                call->brtype_stat->branch_to = true;

                                if (cursor_node->branch_flags.predicted)
                                        call->predicted_count = 1;

                                if (cursor_node->branch_flags.abort)
                                        call->abort_count = 1;

                                branch_type_count(call->brtype_stat,
                                                  &cursor_node->branch_flags,
                                                  cursor_node->branch_from,
                                                  cursor_node->ip);
                        } else {
                                /*
                                 * It's "from" of a branch
                                 */
                                if (call->brtype_stat && call->brtype_stat->branch_to)
                                        call->brtype_stat->branch_to = false;
                                call->cycles_count =
                                        cursor_node->branch_flags.cycles;
                                call->iter_count = cursor_node->nr_loop_iter;
                                call->iter_cycles = cursor_node->iter_cycles;
                        }
                }

                list_add_tail(&call->list, &node->val);

                callchain_cursor_advance(cursor);
                cursor_node = callchain_cursor_current(cursor);
        }
        return 0;
}

static struct callchain_node *
add_child(struct callchain_node *parent,
          struct callchain_cursor *cursor,
          u64 period)
{
        struct callchain_node *new;

        new = create_child(parent, false);
        if (new == NULL)
                return NULL;

        if (fill_node(new, cursor) < 0) {
                struct callchain_list *call, *tmp;

                list_for_each_entry_safe(call, tmp, &new->val, list) {
                        list_del_init(&call->list);
                        map_symbol__exit(&call->ms);
                        zfree(&call->brtype_stat);
                        free(call);
                }
                free(new);
                return NULL;
        }

        new->children_hit = 0;
        new->hit = period;
        new->children_count = 0;
        new->count = 1;
        return new;
}

enum match_result {
        MATCH_ERROR  = -1,
        MATCH_EQ,
        MATCH_LT,
        MATCH_GT,
};

static enum match_result match_chain_strings(const char *left,
                                             const char *right)
{
        enum match_result ret = MATCH_EQ;
        int cmp;

        if (left && right)
                cmp = strcmp(left, right);
        else if (!left && right)
                cmp = 1;
        else if (left && !right)
                cmp = -1;
        else
                return MATCH_ERROR;

        if (cmp != 0)
                ret = cmp < 0 ? MATCH_LT : MATCH_GT;

        return ret;
}

/*
 * We need to always use relative addresses because we're aggregating
 * callchains from multiple threads, i.e. different address spaces, so
 * comparing absolute addresses make no sense as a symbol in a DSO may end up
 * in a different address when used in a different binary or even the same
 * binary but with some sort of address randomization technique, thus we need
 * to compare just relative addresses. -acme
 */
static enum match_result match_chain_dso_addresses(struct map *left_map, u64 left_ip,
                                                   struct map *right_map, u64 right_ip)
{
        struct dso *left_dso = left_map ? map__dso(left_map) : NULL;
        struct dso *right_dso = right_map ? map__dso(right_map) : NULL;

        if (left_dso != right_dso)
                return left_dso < right_dso ? MATCH_LT : MATCH_GT;

        if (left_ip != right_ip)
                return left_ip < right_ip ? MATCH_LT : MATCH_GT;

        return MATCH_EQ;
}

static enum match_result match_chain(struct callchain_cursor_node *node,
                                     struct callchain_list *cnode)
{
        enum match_result match = MATCH_ERROR;

        switch (callchain_param.key) {
        case CCKEY_SRCLINE:
                match = match_chain_strings(cnode->srcline, node->srcline);
                if (match != MATCH_ERROR)
                        break;
                /* otherwise fall-back to symbol-based comparison below */
                fallthrough;
        case CCKEY_FUNCTION:
                if (node->ms.sym && cnode->ms.sym) {
                        /*
                         * Compare inlined frames based on their symbol name
                         * because different inlined frames will have the same
                         * symbol start. Otherwise do a faster comparison based
                         * on the symbol start address.
                         */
                        if (cnode->ms.sym->inlined || node->ms.sym->inlined) {
                                match = match_chain_strings(cnode->ms.sym->name,
                                                            node->ms.sym->name);
                                if (match != MATCH_ERROR)
                                        break;
                        } else {
                                match = match_chain_dso_addresses(cnode->ms.map, cnode->ms.sym->start,
                                                                  node->ms.map, node->ms.sym->start);
                                break;
                        }
                }
                /* otherwise fall-back to IP-based comparison below */
                fallthrough;
        case CCKEY_ADDRESS:
        default:
                match = match_chain_dso_addresses(cnode->ms.map, cnode->ip, node->ms.map, node->ip);
                break;
        }

        if (match == MATCH_EQ && node->branch) {
                cnode->branch_count++;

                if (node->branch_from) {
                        /*
                         * It's "to" of a branch
                         */
                        if (!cnode->brtype_stat) {
                                cnode->brtype_stat = zalloc(sizeof(*cnode->brtype_stat));
                                if (!cnode->brtype_stat) {
                                        perror("not enough memory for the code path branch statistics");
                                        return MATCH_ERROR;
                                }
                        }
                        cnode->brtype_stat->branch_to = true;

                        if (node->branch_flags.predicted)
                                cnode->predicted_count++;

                        if (node->branch_flags.abort)
                                cnode->abort_count++;

                        branch_type_count(cnode->brtype_stat,
                                          &node->branch_flags,
                                          node->branch_from,
                                          node->ip);
                } else {
                        /*
                         * It's "from" of a branch
                         */
                        if (cnode->brtype_stat && cnode->brtype_stat->branch_to)
                                cnode->brtype_stat->branch_to = false;
                        cnode->cycles_count += node->branch_flags.cycles;
                        cnode->iter_count += node->nr_loop_iter;
                        cnode->iter_cycles += node->iter_cycles;
                        cnode->from_count++;
                }
        }

        return match;
}

/*
 * Split the parent in two parts (a new child is created) and
 * give a part of its callchain to the created child.
 * Then create another child to host the given callchain of new branch
 */
static int
split_add_child(struct callchain_node *parent,
                struct callchain_cursor *cursor,
                struct callchain_list *to_split,
                u64 idx_parents, u64 idx_local, u64 period)
{
        struct callchain_node *new;
        struct list_head *old_tail;
        unsigned int idx_total = idx_parents + idx_local;

        /* split */
        new = create_child(parent, true);
        if (new == NULL)
                return -1;

        /* split the callchain and move a part to the new child */
        old_tail = parent->val.prev;
        list_del_range(&to_split->list, old_tail);
        new->val.next = &to_split->list;
        new->val.prev = old_tail;
        to_split->list.prev = &new->val;
        old_tail->next = &new->val;

        /* split the hits */
        new->hit = parent->hit;
        new->children_hit = parent->children_hit;
        parent->children_hit = callchain_cumul_hits(new);
        new->val_nr = parent->val_nr - idx_local;
        parent->val_nr = idx_local;
        new->count = parent->count;
        new->children_count = parent->children_count;
        parent->children_count = callchain_cumul_counts(new);

        /* create a new child for the new branch if any */
        if (idx_total < cursor->nr) {
                struct callchain_node *first;
                struct callchain_list *cnode;
                struct callchain_cursor_node *node;
                struct rb_node *p, **pp;

                parent->hit = 0;
                parent->children_hit += period;
                parent->count = 0;
                parent->children_count += 1;

                node = callchain_cursor_current(cursor);
                new = add_child(parent, cursor, period);
                if (new == NULL)
                        return -1;

                /*
                 * This is second child since we moved parent's children
                 * to new (first) child above.
                 */
                p = parent->rb_root_in.rb_node;
                first = rb_entry(p, struct callchain_node, rb_node_in);
                cnode = list_first_entry(&first->val, struct callchain_list,
                                         list);

                if (match_chain(node, cnode) == MATCH_LT)
                        pp = &p->rb_left;
                else
                        pp = &p->rb_right;

                rb_link_node(&new->rb_node_in, p, pp);
                rb_insert_color(&new->rb_node_in, &parent->rb_root_in);
        } else {
                parent->hit = period;
                parent->count = 1;
        }
        return 0;
}

static enum match_result
append_chain(struct callchain_node *root,
             struct callchain_cursor *cursor,
             u64 period);

static int
append_chain_children(struct callchain_node *root,
                      struct callchain_cursor *cursor,
                      u64 period)
{
        struct callchain_node *rnode;
        struct callchain_cursor_node *node;
        struct rb_node **p = &root->rb_root_in.rb_node;
        struct rb_node *parent = NULL;

        node = callchain_cursor_current(cursor);
        if (!node)
                return -1;

        /* lookup in children */
        while (*p) {
                enum match_result ret;

                parent = *p;
                rnode = rb_entry(parent, struct callchain_node, rb_node_in);

                /* If at least first entry matches, rely to children */
                ret = append_chain(rnode, cursor, period);
                if (ret == MATCH_EQ)
                        goto inc_children_hit;
                if (ret == MATCH_ERROR)
                        return -1;

                if (ret == MATCH_LT)
                        p = &parent->rb_left;
                else
                        p = &parent->rb_right;
        }
        /* nothing in children, add to the current node */
        rnode = add_child(root, cursor, period);
        if (rnode == NULL)
                return -1;

        rb_link_node(&rnode->rb_node_in, parent, p);
        rb_insert_color(&rnode->rb_node_in, &root->rb_root_in);

inc_children_hit:
        root->children_hit += period;
        root->children_count++;
        return 0;
}

static enum match_result
append_chain(struct callchain_node *root,
             struct callchain_cursor *cursor,
             u64 period)
{
        struct callchain_list *cnode;
        u64 start = cursor->pos;
        bool found = false;
        u64 matches;
        enum match_result cmp = MATCH_ERROR;

        /*
         * Lookup in the current node
         * If we have a symbol, then compare the start to match
         * anywhere inside a function, unless function
         * mode is disabled.
         */
        list_for_each_entry(cnode, &root->val, list) {
                struct callchain_cursor_node *node;

                node = callchain_cursor_current(cursor);
                if (!node)
                        break;

                cmp = match_chain(node, cnode);
                if (cmp != MATCH_EQ)
                        break;

                found = true;

                callchain_cursor_advance(cursor);
        }

        /* matches not, relay no the parent */
        if (!found) {
                WARN_ONCE(cmp == MATCH_ERROR, "Chain comparison error\n");
                return cmp;
        }

        matches = cursor->pos - start;

        /* we match only a part of the node. Split it and add the new chain */
        if (matches < root->val_nr) {
                if (split_add_child(root, cursor, cnode, start, matches,
                                    period) < 0)
                        return MATCH_ERROR;

                return MATCH_EQ;
        }

        /* we match 100% of the path, increment the hit */
        if (matches == root->val_nr && cursor->pos == cursor->nr) {
                root->hit += period;
                root->count++;
                return MATCH_EQ;
        }

        /* We match the node and still have a part remaining */
        if (append_chain_children(root, cursor, period) < 0)
                return MATCH_ERROR;

        return MATCH_EQ;
}

int callchain_append(struct callchain_root *root,
                     struct callchain_cursor *cursor,
                     u64 period)
{
        if (cursor == NULL)
                return -1;

        if (!cursor->nr)
                return 0;

        callchain_cursor_commit(cursor);

        if (append_chain_children(&root->node, cursor, period) < 0)
                return -1;

        if (cursor->nr > root->max_depth)
                root->max_depth = cursor->nr;

        return 0;
}

static int
merge_chain_branch(struct callchain_cursor *cursor,
                   struct callchain_node *dst, struct callchain_node *src)
{
        struct callchain_cursor_node **old_last = cursor->last;
        struct callchain_node *child;
        struct callchain_list *list, *next_list;
        struct rb_node *n;
        int old_pos = cursor->nr;
        int err = 0;

        list_for_each_entry_safe(list, next_list, &src->val, list) {
                struct map_symbol ms = {
                        .thread = thread__get(list->ms.thread),
                        .map = map__get(list->ms.map),
                };
                callchain_cursor_append(cursor, list->ip, &ms, false, NULL, 0, 0, 0, list->srcline);
                list_del_init(&list->list);
                map_symbol__exit(&ms);
                map_symbol__exit(&list->ms);
                zfree(&list->brtype_stat);
                free(list);
        }

        if (src->hit) {
                callchain_cursor_commit(cursor);
                if (append_chain_children(dst, cursor, src->hit) < 0)
                        return -1;
        }

        n = rb_first(&src->rb_root_in);
        while (n) {
                child = container_of(n, struct callchain_node, rb_node_in);
                n = rb_next(n);
                rb_erase(&child->rb_node_in, &src->rb_root_in);

                err = merge_chain_branch(cursor, dst, child);
                if (err)
                        break;

                free(child);
        }

        cursor->nr = old_pos;
        cursor->last = old_last;

        return err;
}

int callchain_merge(struct callchain_cursor *cursor,
                    struct callchain_root *dst, struct callchain_root *src)
{
        return merge_chain_branch(cursor, &dst->node, &src->node);
}

int callchain_cursor_append(struct callchain_cursor *cursor,
                            u64 ip, struct map_symbol *ms,
                            bool branch, struct branch_flags *flags,
                            int nr_loop_iter, u64 iter_cycles, u64 branch_from,
                            const char *srcline)
{
        struct callchain_cursor_node *node = *cursor->last;

        if (!node) {
                node = calloc(1, sizeof(*node));
                if (!node)
                        return -ENOMEM;

                *cursor->last = node;
        }

        node->ip = ip;
        map_symbol__exit(&node->ms);
        map_symbol__copy(&node->ms, ms);
        node->branch = branch;
        node->nr_loop_iter = nr_loop_iter;
        node->iter_cycles = iter_cycles;
        node->srcline = srcline;

        if (flags)
                memcpy(&node->branch_flags, flags,
                        sizeof(struct branch_flags));

        node->branch_from = branch_from;
        cursor->nr++;

        cursor->last = &node->next;

        return 0;
}

int sample__resolve_callchain(struct perf_sample *sample,
                              struct callchain_cursor *cursor, struct symbol **parent,
                              struct evsel *evsel, struct addr_location *al,
                              int max_stack)
{
        if (sample->callchain == NULL && !symbol_conf.show_branchflag_count)
                return 0;

        if (symbol_conf.use_callchain || symbol_conf.cumulate_callchain ||
            perf_hpp_list.parent || symbol_conf.show_branchflag_count) {
                return thread__resolve_callchain(al->thread, cursor, evsel, sample,
                                                 parent, al, max_stack);
        }
        return 0;
}

int hist_entry__append_callchain(struct hist_entry *he, struct perf_sample *sample)
{
        if ((!symbol_conf.use_callchain || sample->callchain == NULL) &&
                !symbol_conf.show_branchflag_count)
                return 0;
        return callchain_append(he->callchain, get_tls_callchain_cursor(), sample->period);
}

int fill_callchain_info(struct addr_location *al, struct callchain_cursor_node *node,
                        bool hide_unresolved)
{
        struct machine *machine = NULL;

        if (node->ms.thread)
                machine = maps__machine(thread__maps(node->ms.thread));

        map__put(al->map);
        al->map = map__get(node->ms.map);
        al->sym = node->ms.sym;
        al->srcline = node->srcline;
        al->addr = node->ip;

        if (al->sym == NULL) {
                if (hide_unresolved)
                        return 0;
                if (al->map == NULL)
                        goto out;
        }
        if (maps__equal(thread__maps(al->thread), machine__kernel_maps(machine))) {
                if (machine__is_host(machine)) {
                        al->cpumode = PERF_RECORD_MISC_KERNEL;
                        al->level = 'k';
                } else {
                        al->cpumode = PERF_RECORD_MISC_GUEST_KERNEL;
                        al->level = 'g';
                }
        } else {
                if (machine__is_host(machine)) {
                        al->cpumode = PERF_RECORD_MISC_USER;
                        al->level = '.';
                } else if (perf_guest) {
                        al->cpumode = PERF_RECORD_MISC_GUEST_USER;
                        al->level = 'u';
                } else {
                        al->cpumode = PERF_RECORD_MISC_HYPERVISOR;
                        al->level = 'H';
                }
        }

out:
        return 1;
}

char *callchain_list__sym_name(struct callchain_list *cl,
                               char *bf, size_t bfsize, bool show_dso)
{
        bool show_addr = callchain_param.key == CCKEY_ADDRESS;
        bool show_srcline = show_addr || callchain_param.key == CCKEY_SRCLINE;
        int printed;

        if (cl->ms.sym) {
                const char *inlined = cl->ms.sym->inlined ? " (inlined)" : "";

                if (show_srcline && cl->srcline)
                        printed = scnprintf(bf, bfsize, "%s %s%s",
                                            cl->ms.sym->name, cl->srcline,
                                            inlined);
                else
                        printed = scnprintf(bf, bfsize, "%s%s",
                                            cl->ms.sym->name, inlined);
        } else
                printed = scnprintf(bf, bfsize, "%#" PRIx64, cl->ip);

        if (show_dso)
                scnprintf(bf + printed, bfsize - printed, " %s",
                          cl->ms.map ?
                          dso__short_name(map__dso(cl->ms.map)) :
                          "unknown");

        return bf;
}

char *callchain_node__scnprintf_value(struct callchain_node *node,
                                      char *bf, size_t bfsize, u64 total)
{
        double percent = 0.0;
        u64 period = callchain_cumul_hits(node);
        unsigned count = callchain_cumul_counts(node);

        if (callchain_param.mode == CHAIN_FOLDED) {
                period = node->hit;
                count = node->count;
        }

        switch (callchain_param.value) {
        case CCVAL_PERIOD:
                scnprintf(bf, bfsize, "%"PRIu64, period);
                break;
        case CCVAL_COUNT:
                scnprintf(bf, bfsize, "%u", count);
                break;
        case CCVAL_PERCENT:
        default:
                if (total)
                        percent = period * 100.0 / total;
                scnprintf(bf, bfsize, "%.2f%%", percent);
                break;
        }
        return bf;
}

int callchain_node__fprintf_value(struct callchain_node *node,
                                 FILE *fp, u64 total)
{
        double percent = 0.0;
        u64 period = callchain_cumul_hits(node);
        unsigned count = callchain_cumul_counts(node);

        if (callchain_param.mode == CHAIN_FOLDED) {
                period = node->hit;
                count = node->count;
        }

        switch (callchain_param.value) {
        case CCVAL_PERIOD:
                return fprintf(fp, "%"PRIu64, period);
        case CCVAL_COUNT:
                return fprintf(fp, "%u", count);
        case CCVAL_PERCENT:
        default:
                if (total)
                        percent = period * 100.0 / total;
                return percent_color_fprintf(fp, "%.2f%%", percent);
        }
        return 0;
}

static void callchain_counts_value(struct callchain_node *node,
                                   u64 *branch_count, u64 *predicted_count,
                                   u64 *abort_count, u64 *cycles_count)
{
        struct callchain_list *clist;

        list_for_each_entry(clist, &node->val, list) {
                if (branch_count)
                        *branch_count += clist->branch_count;

                if (predicted_count)
                        *predicted_count += clist->predicted_count;

                if (abort_count)
                        *abort_count += clist->abort_count;

                if (cycles_count)
                        *cycles_count += clist->cycles_count;
        }
}

static int callchain_node_branch_counts_cumul(struct callchain_node *node,
                                              u64 *branch_count,
                                              u64 *predicted_count,
                                              u64 *abort_count,
                                              u64 *cycles_count)
{
        struct callchain_node *child;
        struct rb_node *n;

        n = rb_first(&node->rb_root_in);
        while (n) {
                child = rb_entry(n, struct callchain_node, rb_node_in);
                n = rb_next(n);

                callchain_node_branch_counts_cumul(child, branch_count,
                                                   predicted_count,
                                                   abort_count,
                                                   cycles_count);

                callchain_counts_value(child, branch_count,
                                       predicted_count, abort_count,
                                       cycles_count);
        }

        return 0;
}

int callchain_branch_counts(struct callchain_root *root,
                            u64 *branch_count, u64 *predicted_count,
                            u64 *abort_count, u64 *cycles_count)
{
        if (branch_count)
                *branch_count = 0;

        if (predicted_count)
                *predicted_count = 0;

        if (abort_count)
                *abort_count = 0;

        if (cycles_count)
                *cycles_count = 0;

        return callchain_node_branch_counts_cumul(&root->node,
                                                  branch_count,
                                                  predicted_count,
                                                  abort_count,
                                                  cycles_count);
}

static int count_pri64_printf(int idx, const char *str, u64 value, char *bf, int bfsize)
{
        return scnprintf(bf, bfsize, "%s%s:%" PRId64 "", (idx) ? " " : " (", str, value);
}

static int count_float_printf(int idx, const char *str, float value,
                              char *bf, int bfsize, float threshold)
{
        if (threshold != 0.0 && value < threshold)
                return 0;

        return scnprintf(bf, bfsize, "%s%s:%.1f%%", (idx) ? " " : " (", str, value);
}

static int branch_to_str(char *bf, int bfsize,
                         u64 branch_count, u64 predicted_count,
                         u64 abort_count,
                         const struct branch_type_stat *brtype_stat)
{
        int printed, i = 0;

        printed = branch_type_str(brtype_stat, bf, bfsize);
        if (printed)
                i++;

        if (predicted_count < branch_count) {
                printed += count_float_printf(i++, "predicted",
                                predicted_count * 100.0 / branch_count,
                                bf + printed, bfsize - printed, 0.0);
        }

        if (abort_count) {
                printed += count_float_printf(i++, "abort",
                                abort_count * 100.0 / branch_count,
                                bf + printed, bfsize - printed, 0.1);
        }

        if (i)
                printed += scnprintf(bf + printed, bfsize - printed, ")");

        return printed;
}

static int branch_from_str(char *bf, int bfsize,
                           u64 branch_count,
                           u64 cycles_count, u64 iter_count,
                           u64 iter_cycles, u64 from_count)
{
        int printed = 0, i = 0;
        u64 cycles, v = 0;

        cycles = cycles_count / branch_count;
        if (cycles) {
                printed += count_pri64_printf(i++, "cycles",
                                cycles,
                                bf + printed, bfsize - printed);
        }

        if (iter_count && from_count) {
                v = iter_count / from_count;
                if (v) {
                        printed += count_pri64_printf(i++, "iter",
                                        v, bf + printed, bfsize - printed);

                        printed += count_pri64_printf(i++, "avg_cycles",
                                        iter_cycles / iter_count,
                                        bf + printed, bfsize - printed);
                }
        }

        if (i)
                printed += scnprintf(bf + printed, bfsize - printed, ")");

        return printed;
}

static int counts_str_build(char *bf, int bfsize,
                             u64 branch_count, u64 predicted_count,
                             u64 abort_count, u64 cycles_count,
                             u64 iter_count, u64 iter_cycles,
                             u64 from_count,
                             const struct branch_type_stat *brtype_stat)
{
        int printed;

        if (branch_count == 0)
                return scnprintf(bf, bfsize, " (calltrace)");

        if (brtype_stat->branch_to) {
                printed = branch_to_str(bf, bfsize, branch_count,
                                predicted_count, abort_count, brtype_stat);
        } else {
                printed = branch_from_str(bf, bfsize, branch_count,
                                cycles_count, iter_count, iter_cycles,
                                from_count);
        }

        if (!printed)
                bf[0] = 0;

        return printed;
}

static int callchain_counts_printf(FILE *fp, char *bf, int bfsize,
                                   u64 branch_count, u64 predicted_count,
                                   u64 abort_count, u64 cycles_count,
                                   u64 iter_count, u64 iter_cycles,
                                   u64 from_count,
                                   const struct branch_type_stat *brtype_stat)
{
        char str[256];

        counts_str_build(str, sizeof(str), branch_count,
                         predicted_count, abort_count, cycles_count,
                         iter_count, iter_cycles, from_count, brtype_stat);

        if (fp)
                return fprintf(fp, "%s", str);

        return scnprintf(bf, bfsize, "%s", str);
}

int callchain_list_counts__printf_value(struct callchain_list *clist,
                                        FILE *fp, char *bf, int bfsize)
{
        static const struct branch_type_stat empty_brtype_stat = {};
        const struct branch_type_stat *brtype_stat;
        u64 branch_count, predicted_count;
        u64 abort_count, cycles_count;
        u64 iter_count, iter_cycles;
        u64 from_count;

        brtype_stat = clist->brtype_stat ?: &empty_brtype_stat;
        branch_count = clist->branch_count;
        predicted_count = clist->predicted_count;
        abort_count = clist->abort_count;
        cycles_count = clist->cycles_count;
        iter_count = clist->iter_count;
        iter_cycles = clist->iter_cycles;
        from_count = clist->from_count;

        return callchain_counts_printf(fp, bf, bfsize, branch_count,
                                       predicted_count, abort_count,
                                       cycles_count, iter_count, iter_cycles,
                                       from_count, brtype_stat);
}

static void free_callchain_node(struct callchain_node *node)
{
        struct callchain_list *list, *tmp;
        struct callchain_node *child;
        struct rb_node *n;

        list_for_each_entry_safe(list, tmp, &node->parent_val, list) {
                list_del_init(&list->list);
                map_symbol__exit(&list->ms);
                zfree(&list->brtype_stat);
                free(list);
        }

        list_for_each_entry_safe(list, tmp, &node->val, list) {
                list_del_init(&list->list);
                map_symbol__exit(&list->ms);
                zfree(&list->brtype_stat);
                free(list);
        }

        n = rb_first(&node->rb_root_in);
        while (n) {
                child = container_of(n, struct callchain_node, rb_node_in);
                n = rb_next(n);
                rb_erase(&child->rb_node_in, &node->rb_root_in);

                free_callchain_node(child);
                free(child);
        }
}

void free_callchain(struct callchain_root *root)
{
        if (!symbol_conf.use_callchain)
                return;

        free_callchain_node(&root->node);
}

static u64 decay_callchain_node(struct callchain_node *node)
{
        struct callchain_node *child;
        struct rb_node *n;
        u64 child_hits = 0;

        n = rb_first(&node->rb_root_in);
        while (n) {
                child = container_of(n, struct callchain_node, rb_node_in);

                child_hits += decay_callchain_node(child);
                n = rb_next(n);
        }

        node->hit = (node->hit * 7) / 8;
        node->children_hit = child_hits;

        return node->hit;
}

void decay_callchain(struct callchain_root *root)
{
        if (!symbol_conf.use_callchain)
                return;

        decay_callchain_node(&root->node);
}

int callchain_node__make_parent_list(struct callchain_node *node)
{
        struct callchain_node *parent = node->parent;
        struct callchain_list *chain, *new;
        LIST_HEAD(head);

        while (parent) {
                list_for_each_entry_reverse(chain, &parent->val, list) {
                        new = malloc(sizeof(*new));
                        if (new == NULL)
                                goto out;
                        *new = *chain;
                        new->has_children = false;
                        map_symbol__copy(&new->ms, &chain->ms);
                        list_add_tail(&new->list, &head);
                }
                parent = parent->parent;
        }

        list_for_each_entry_safe_reverse(chain, new, &head, list)
                list_move_tail(&chain->list, &node->parent_val);

        if (!list_empty(&node->parent_val)) {
                chain = list_first_entry(&node->parent_val, struct callchain_list, list);
                chain->has_children = rb_prev(&node->rb_node) || rb_next(&node->rb_node);

                chain = list_first_entry(&node->val, struct callchain_list, list);
                chain->has_children = false;
        }
        return 0;

out:
        list_for_each_entry_safe(chain, new, &head, list) {
                list_del_init(&chain->list);
                map_symbol__exit(&chain->ms);
                zfree(&chain->brtype_stat);
                free(chain);
        }
        return -ENOMEM;
}

static void callchain_cursor__delete(void *vcursor)
{
        struct callchain_cursor *cursor = vcursor;
        struct callchain_cursor_node *node, *next;

        callchain_cursor_reset(cursor);
        for (node = cursor->first; node != NULL; node = next) {
                next = node->next;
                free(node);
        }
        free(cursor);
}

static void init_callchain_cursor_key(void)
{
        if (pthread_key_create(&callchain_cursor, callchain_cursor__delete)) {
                pr_err("callchain cursor creation failed");
                abort();
        }
}

struct callchain_cursor *get_tls_callchain_cursor(void)
{
        static pthread_once_t once_control = PTHREAD_ONCE_INIT;
        struct callchain_cursor *cursor;

        pthread_once(&once_control, init_callchain_cursor_key);
        cursor = pthread_getspecific(callchain_cursor);
        if (!cursor) {
                cursor = zalloc(sizeof(*cursor));
                if (!cursor)
                        pr_debug3("%s: not enough memory\n", __func__);
                pthread_setspecific(callchain_cursor, cursor);
        }
        return cursor;
}

int callchain_cursor__copy(struct callchain_cursor *dst,
                           struct callchain_cursor *src)
{
        int rc = 0;

        callchain_cursor_reset(dst);
        callchain_cursor_commit(src);

        while (true) {
                struct callchain_cursor_node *node;

                node = callchain_cursor_current(src);
                if (node == NULL)
                        break;

                rc = callchain_cursor_append(dst, node->ip, &node->ms,
                                             node->branch, &node->branch_flags,
                                             node->nr_loop_iter,
                                             node->iter_cycles,
                                             node->branch_from, node->srcline);
                if (rc)
                        break;

                callchain_cursor_advance(src);
        }

        return rc;
}

/*
 * Initialize a cursor before adding entries inside, but keep
 * the previously allocated entries as a cache.
 */
void callchain_cursor_reset(struct callchain_cursor *cursor)
{
        struct callchain_cursor_node *node;

        cursor->nr = 0;
        cursor->last = &cursor->first;

        for (node = cursor->first; node != NULL; node = node->next)
                map_symbol__exit(&node->ms);
}

void callchain_param_setup(u64 sample_type, uint16_t e_machine)
{
        if (symbol_conf.use_callchain || symbol_conf.cumulate_callchain) {
                if ((sample_type & PERF_SAMPLE_REGS_USER) &&
                    (sample_type & PERF_SAMPLE_STACK_USER)) {
                        callchain_param.record_mode = CALLCHAIN_DWARF;
                        dwarf_callchain_users = true;
                } else if (sample_type & PERF_SAMPLE_BRANCH_STACK)
                        callchain_param.record_mode = CALLCHAIN_LBR;
                else
                        callchain_param.record_mode = CALLCHAIN_FP;
        }

        /*
         * It's necessary to use libunwind to reliably determine the caller of
         * a leaf function on aarch64, as otherwise we cannot know whether to
         * start from the LR or FP.
         *
         * Always starting from the LR can result in duplicate or entirely
         * erroneous entries. Always skipping the LR and starting from the FP
         * can result in missing entries.
         */
        if (callchain_param.record_mode == CALLCHAIN_FP && e_machine == EM_AARCH64)
                dwarf_callchain_users = true;
}

static bool chain_match(struct callchain_list *base_chain,
                        struct callchain_list *pair_chain)
{
        enum match_result match;

        match = match_chain_strings(base_chain->srcline,
                                    pair_chain->srcline);
        if (match != MATCH_ERROR)
                return match == MATCH_EQ;

        match = match_chain_dso_addresses(base_chain->ms.map,
                                          base_chain->ip,
                                          pair_chain->ms.map,
                                          pair_chain->ip);

        return match == MATCH_EQ;
}

bool callchain_cnode_matched(struct callchain_node *base_cnode,
                             struct callchain_node *pair_cnode)
{
        struct callchain_list *base_chain, *pair_chain;
        bool match = false;

        pair_chain = list_first_entry(&pair_cnode->val,
                                      struct callchain_list,
                                      list);

        list_for_each_entry(base_chain, &base_cnode->val, list) {
                if (&pair_chain->list == &pair_cnode->val)
                        return false;

                if (!base_chain->srcline || !pair_chain->srcline) {
                        pair_chain = list_next_entry(pair_chain, list);
                        continue;
                }

                match = chain_match(base_chain, pair_chain);
                if (!match)
                        return false;

                pair_chain = list_next_entry(pair_chain, list);
        }

        /*
         * Say chain1 is ABC, chain2 is ABCD, we consider they are
         * not fully matched.
         */
        if (pair_chain && (&pair_chain->list != &pair_cnode->val))
                return false;

        return match;
}

static u64 count_callchain_hits(struct hist_entry *he)
{
        struct rb_root *root = &he->sorted_chain;
        struct rb_node *rb_node = rb_first(root);
        struct callchain_node *node;
        u64 chain_hits = 0;

        while (rb_node) {
                node = rb_entry(rb_node, struct callchain_node, rb_node);
                chain_hits += node->hit;
                rb_node = rb_next(rb_node);
        }

        return chain_hits;
}

u64 callchain_total_hits(struct hists *hists)
{
        struct rb_node *next = rb_first_cached(&hists->entries);
        u64 chain_hits = 0;

        while (next) {
                struct hist_entry *he = rb_entry(next, struct hist_entry,
                                                 rb_node);

                chain_hits += count_callchain_hits(he);
                next = rb_next(&he->rb_node);
        }

        return chain_hits;
}

s64 callchain_avg_cycles(struct callchain_node *cnode)
{
        struct callchain_list *chain;
        s64 cycles = 0;

        list_for_each_entry(chain, &cnode->val, list) {
                if (chain->srcline && chain->branch_count)
                        cycles += chain->cycles_count / chain->branch_count;
        }

        return cycles;
}

int sample__for_each_callchain_node(struct thread *thread, struct evsel *evsel,
                                    struct perf_sample *sample, int max_stack,
                                    bool symbols, callchain_iter_fn cb, void *data)
{
        struct callchain_cursor *cursor = get_tls_callchain_cursor();
        int ret;

        if (!cursor)
                return -ENOMEM;

        /* Fill in the callchain. */
        ret = __thread__resolve_callchain(thread, cursor, evsel, sample,
                                          /*parent=*/NULL, /*root_al=*/NULL,
                                          max_stack, symbols);
        if (ret)
                return ret;

        /* Switch from writing the callchain to reading it. */
        callchain_cursor_commit(cursor);

        while (1) {
                struct callchain_cursor_node *node = callchain_cursor_current(cursor);

                if (!node)
                        break;

                ret = cb(node, data);
                if (ret)
                        return ret;

                callchain_cursor_advance(cursor);
        }
        return 0;
}

/*
 * This function merges earlier samples (@sample_orig) waiting for deferred
 * user callchains with the matching callchain record (@sample_callchain)
 * which is delivered now.  The @sample_orig->callchain should be released
 * after use if ->deferred_callchain is set.
 */
int sample__merge_deferred_callchain(struct perf_sample *sample_orig,
                                     struct perf_sample *sample_callchain)
{
        u64 nr_orig = sample_orig->callchain->nr - 1;
        u64 nr_deferred = sample_callchain->callchain->nr;
        struct ip_callchain *callchain;

        if (sample_orig->callchain->nr < 2) {
                sample_orig->deferred_callchain = false;
                return -EINVAL;
        }

        callchain = calloc(1 + nr_orig + nr_deferred, sizeof(u64));
        if (callchain == NULL) {
                sample_orig->deferred_callchain = false;
                return -ENOMEM;
        }

        callchain->nr = nr_orig + nr_deferred;
        /* copy original including PERF_CONTEXT_USER_DEFERRED (but the cookie) */
        memcpy(callchain->ips, sample_orig->callchain->ips, nr_orig * sizeof(u64));
        /* copy deferred user callchains */
        memcpy(&callchain->ips[nr_orig], sample_callchain->callchain->ips,
               nr_deferred * sizeof(u64));

        sample_orig->callchain = callchain;
        return 0;
}