// SPDX-License-Identifier: GPL-2.0
/*
 * User-space helper to sort the output of /sys/kernel/debug/page_owner
 *
 * Example use:
 * cat /sys/kernel/debug/page_owner > page_owner_full.txt
 * ./page_owner_sort page_owner_full.txt sorted_page_owner.txt
 * Or sort by total memory:
 * ./page_owner_sort -m page_owner_full.txt sorted_page_owner.txt
 *
 * See Documentation/mm/page_owner.rst
*/

#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <string.h>
#include <regex.h>
#include <errno.h>
#include <linux/types.h>
#include <getopt.h>

#define TASK_COMM_LEN 16

struct block_list {
        char *txt;
        char *comm; // task command name
        char *stacktrace;
        __u64 ts_nsec;
        int len;
        int num;
        int page_num;
        pid_t pid;
        pid_t tgid;
        int allocator;
};
enum FILTER_BIT {
        FILTER_PID = 1<<1,
        FILTER_TGID = 1<<2,
        FILTER_COMM = 1<<3
};
enum CULL_BIT {
        CULL_PID = 1<<1,
        CULL_TGID = 1<<2,
        CULL_COMM = 1<<3,
        CULL_STACKTRACE = 1<<4,
        CULL_ALLOCATOR = 1<<5
};
enum ALLOCATOR_BIT {
        ALLOCATOR_CMA = 1<<1,
        ALLOCATOR_SLAB = 1<<2,
        ALLOCATOR_VMALLOC = 1<<3,
        ALLOCATOR_OTHERS = 1<<4
};
enum ARG_TYPE {
        ARG_TXT, ARG_COMM, ARG_STACKTRACE, ARG_ALLOC_TS, ARG_CULL_TIME,
        ARG_PAGE_NUM, ARG_PID, ARG_TGID, ARG_UNKNOWN, ARG_ALLOCATOR
};
enum SORT_ORDER {
        SORT_ASC = 1,
        SORT_DESC = -1,
};
enum COMP_FLAG {
        COMP_NO_FLAG = 0,
        COMP_ALLOC = 1<<0,
        COMP_PAGE_NUM = 1<<1,
        COMP_PID = 1<<2,
        COMP_STACK = 1<<3,
        COMP_NUM = 1<<4,
        COMP_TGID = 1<<5,
        COMP_COMM = 1<<6
};
struct filter_condition {
        pid_t *pids;
        pid_t *tgids;
        char **comms;
        int pids_size;
        int tgids_size;
        int comms_size;
};
struct sort_condition {
        int (**cmps)(const void *, const void *);
        int *signs;
        int size;
};
static struct filter_condition fc;
static struct sort_condition sc;
static regex_t order_pattern;
static regex_t pid_pattern;
static regex_t tgid_pattern;
static regex_t comm_pattern;
static regex_t ts_nsec_pattern;
static struct block_list *list;
static int list_size;
static int max_size;
static int cull;
static int filter;
static bool debug_on;

static void set_single_cmp(int (*cmp)(const void *, const void *), int sign);

int read_block(char *buf, char *ext_buf, int buf_size, FILE *fin)
{
        char *curr = buf, *const buf_end = buf + buf_size;

        while (buf_end - curr > 1 && fgets(curr, buf_end - curr, fin)) {
                if (*curr == '\n') { /* empty line */
                        return curr - buf;
                }
                if (!strncmp(curr, "PFN", 3)) {
                        strcpy(ext_buf, curr);
                        continue;
                }
                curr += strlen(curr);
        }

        return -1; /* EOF or no space left in buf. */
}

static int compare_txt(const void *p1, const void *p2)
{
        const struct block_list *l1 = p1, *l2 = p2;

        return strcmp(l1->txt, l2->txt);
}

static int compare_stacktrace(const void *p1, const void *p2)
{
        const struct block_list *l1 = p1, *l2 = p2;

        return strcmp(l1->stacktrace, l2->stacktrace);
}

static int compare_num(const void *p1, const void *p2)
{
        const struct block_list *l1 = p1, *l2 = p2;

        return l1->num - l2->num;
}

static int compare_page_num(const void *p1, const void *p2)
{
        const struct block_list *l1 = p1, *l2 = p2;

        return l1->page_num - l2->page_num;
}

static int compare_pid(const void *p1, const void *p2)
{
        const struct block_list *l1 = p1, *l2 = p2;

        return l1->pid - l2->pid;
}

static int compare_tgid(const void *p1, const void *p2)
{
        const struct block_list *l1 = p1, *l2 = p2;

        return l1->tgid - l2->tgid;
}

static int compare_allocator(const void *p1, const void *p2)
{
        const struct block_list *l1 = p1, *l2 = p2;

        return l1->allocator - l2->allocator;
}

static int compare_comm(const void *p1, const void *p2)
{
        const struct block_list *l1 = p1, *l2 = p2;

        return strcmp(l1->comm, l2->comm);
}

static int compare_ts(const void *p1, const void *p2)
{
        const struct block_list *l1 = p1, *l2 = p2;

        if (l1->ts_nsec < l2->ts_nsec)
                return -1;
        if (l1->ts_nsec > l2->ts_nsec)
                return 1;
        return 0;
}

static int compare_cull_condition(const void *p1, const void *p2)
{
        if (cull == 0)
                return compare_txt(p1, p2);
        if ((cull & CULL_STACKTRACE) && compare_stacktrace(p1, p2))
                return compare_stacktrace(p1, p2);
        if ((cull & CULL_PID) && compare_pid(p1, p2))
                return compare_pid(p1, p2);
        if ((cull & CULL_TGID) && compare_tgid(p1, p2))
                return compare_tgid(p1, p2);
        if ((cull & CULL_COMM) && compare_comm(p1, p2))
                return compare_comm(p1, p2);
        if ((cull & CULL_ALLOCATOR) && compare_allocator(p1, p2))
                return compare_allocator(p1, p2);
        return 0;
}

static int compare_sort_condition(const void *p1, const void *p2)
{
        int cmp = 0;

        for (int i = 0; i < sc.size; ++i)
                if (cmp == 0)
                        cmp = sc.signs[i] * sc.cmps[i](p1, p2);
        return cmp;
}

static int remove_pattern(regex_t *pattern, char *buf, int len)
{
        regmatch_t pmatch[2];
        int err;

        err = regexec(pattern, buf, 2, pmatch, REG_NOTBOL);
        if (err != 0 || pmatch[1].rm_so == -1)
                return len;

        memcpy(buf + pmatch[1].rm_so,
                buf + pmatch[1].rm_eo, len - pmatch[1].rm_eo);

        return len - (pmatch[1].rm_eo - pmatch[1].rm_so);
}

static int search_pattern(regex_t *pattern, char *pattern_str, char *buf)
{
        int err, val_len;
        regmatch_t pmatch[2];

        err = regexec(pattern, buf, 2, pmatch, REG_NOTBOL);
        if (err != 0 || pmatch[1].rm_so == -1) {
                if (debug_on)
                        fprintf(stderr, "no matching pattern in %s\n", buf);
                return -1;
        }
        val_len = pmatch[1].rm_eo - pmatch[1].rm_so;

        memcpy(pattern_str, buf + pmatch[1].rm_so, val_len);

        return 0;
}

static bool check_regcomp(regex_t *pattern, const char *regex)
{
        int err;

        err = regcomp(pattern, regex, REG_EXTENDED | REG_NEWLINE);
        if (err != 0 || pattern->re_nsub != 1) {
                fprintf(stderr, "Invalid pattern %s code %d\n", regex, err);
                return false;
        }
        return true;
}

static char **explode(char sep, const char *str, int *size)
{
        int count = 0, len = strlen(str);
        int lastindex = -1, j = 0;

        for (int i = 0; i < len; i++)
                if (str[i] == sep)
                        count++;
        char **ret = calloc(++count, sizeof(char *));

        for (int i = 0; i < len; i++) {
                if (str[i] == sep) {
                        ret[j] = calloc(i - lastindex, sizeof(char));
                        memcpy(ret[j++], str + lastindex + 1, i - lastindex - 1);
                        lastindex = i;
                }
        }
        if (lastindex <= len - 1) {
                ret[j] = calloc(len - lastindex, sizeof(char));
                memcpy(ret[j++], str + lastindex + 1, strlen(str) - 1 - lastindex);
        }
        *size = j;
        return ret;
}

static void free_explode(char **arr, int size)
{
        for (int i = 0; i < size; i++)
                free(arr[i]);
        free(arr);
}

# define FIELD_BUFF 25

static int get_page_num(char *buf)
{
        int order_val;
        char order_str[FIELD_BUFF] = {0};
        char *endptr;

        search_pattern(&order_pattern, order_str, buf);
        errno = 0;
        order_val = strtol(order_str, &endptr, 10);
        if (order_val > 64 || errno != 0 || endptr == order_str || *endptr != '\0') {
                if (debug_on)
                        fprintf(stderr, "wrong order in follow buf:\n%s\n", buf);
                return 0;
        }

        return 1 << order_val;
}

static pid_t get_pid(char *buf)
{
        pid_t pid;
        char pid_str[FIELD_BUFF] = {0};
        char *endptr;

        search_pattern(&pid_pattern, pid_str, buf);
        errno = 0;
        pid = strtol(pid_str, &endptr, 10);
        if (errno != 0 || endptr == pid_str || *endptr != '\0') {
                if (debug_on)
                        fprintf(stderr, "wrong/invalid pid in follow buf:\n%s\n", buf);
                return -1;
        }

        return pid;

}

static pid_t get_tgid(char *buf)
{
        pid_t tgid;
        char tgid_str[FIELD_BUFF] = {0};
        char *endptr;

        search_pattern(&tgid_pattern, tgid_str, buf);
        errno = 0;
        tgid = strtol(tgid_str, &endptr, 10);
        if (errno != 0 || endptr == tgid_str || *endptr != '\0') {
                if (debug_on)
                        fprintf(stderr, "wrong/invalid tgid in follow buf:\n%s\n", buf);
                return -1;
        }

        return tgid;

}

static __u64 get_ts_nsec(char *buf)
{
        __u64 ts_nsec;
        char ts_nsec_str[FIELD_BUFF] = {0};
        char *endptr;

        search_pattern(&ts_nsec_pattern, ts_nsec_str, buf);
        errno = 0;
        ts_nsec = strtoull(ts_nsec_str, &endptr, 10);
        if (errno != 0 || endptr == ts_nsec_str || *endptr != '\0') {
                if (debug_on)
                        fprintf(stderr, "wrong ts_nsec in follow buf:\n%s\n", buf);
                return -1;
        }

        return ts_nsec;
}

static char *get_comm(char *buf)
{
        char *comm_str = malloc(TASK_COMM_LEN);

        memset(comm_str, 0, TASK_COMM_LEN);

        search_pattern(&comm_pattern, comm_str, buf);
        errno = 0;
        if (errno != 0) {
                if (debug_on)
                        fprintf(stderr, "wrong comm in follow buf:\n%s\n", buf);
                free(comm_str);
                return NULL;
        }

        return comm_str;
}

static int get_arg_type(const char *arg)
{
        if (!strcmp(arg, "pid") || !strcmp(arg, "p"))
                return ARG_PID;
        else if (!strcmp(arg, "tgid") || !strcmp(arg, "tg"))
                return ARG_TGID;
        else if (!strcmp(arg, "name") || !strcmp(arg, "n"))
                return  ARG_COMM;
        else if (!strcmp(arg, "stacktrace") || !strcmp(arg, "st"))
                return ARG_STACKTRACE;
        else if (!strcmp(arg, "txt") || !strcmp(arg, "T"))
                return ARG_TXT;
        else if (!strcmp(arg, "alloc_ts") || !strcmp(arg, "at"))
                return ARG_ALLOC_TS;
        else if (!strcmp(arg, "allocator") || !strcmp(arg, "ator"))
                return ARG_ALLOCATOR;
        else {
                return ARG_UNKNOWN;
        }
}

static int get_allocator(const char *buf, const char *migrate_info)
{
        char *tmp, *first_line, *second_line;
        int allocator = 0;

        if (strstr(migrate_info, "CMA"))
                allocator |= ALLOCATOR_CMA;
        if (strstr(migrate_info, "slab"))
                allocator |= ALLOCATOR_SLAB;
        tmp = strstr(buf, "__vmalloc_node_range");
        if (tmp) {
                second_line = tmp;
                while (*tmp != '\n')
                        tmp--;
                tmp--;
                while (*tmp != '\n')
                        tmp--;
                first_line = ++tmp;
                tmp = strstr(tmp, "alloc_pages");
                if (tmp && first_line <= tmp && tmp < second_line)
                        allocator |= ALLOCATOR_VMALLOC;
        }
        if (allocator == 0)
                allocator = ALLOCATOR_OTHERS;
        return allocator;
}

static bool match_num_list(int num, int *list, int list_size)
{
        for (int i = 0; i < list_size; ++i)
                if (list[i] == num)
                        return true;
        return false;
}

static bool match_str_list(const char *str, char **list, int list_size)
{
        for (int i = 0; i < list_size; ++i)
                if (!strcmp(list[i], str))
                        return true;
        return false;
}

static bool is_need(char *buf)
{
        if ((filter & FILTER_PID) && !match_num_list(get_pid(buf), fc.pids, fc.pids_size))
                return false;
        if ((filter & FILTER_TGID) &&
                !match_num_list(get_tgid(buf), fc.tgids, fc.tgids_size))
                return false;

        char *comm = get_comm(buf);

        if ((filter & FILTER_COMM) &&
        !match_str_list(comm, fc.comms, fc.comms_size)) {
                free(comm);
                return false;
        }
        free(comm);
        return true;
}

static bool add_list(char *buf, int len, char *ext_buf)
{
        if (list_size == max_size) {
                fprintf(stderr, "max_size too small??\n");
                return false;
        }
        if (!is_need(buf))
                return true;
        list[list_size].pid = get_pid(buf);
        list[list_size].tgid = get_tgid(buf);
        list[list_size].comm = get_comm(buf);
        list[list_size].txt = malloc(len+1);
        if (!list[list_size].txt) {
                fprintf(stderr, "Out of memory\n");
                return false;
        }
        memcpy(list[list_size].txt, buf, len);
        if (sc.cmps[0] != compare_ts) {
                len = remove_pattern(&ts_nsec_pattern, list[list_size].txt, len);
        }
        list[list_size].txt[len] = 0;
        list[list_size].len = len;
        list[list_size].num = 1;
        list[list_size].page_num = get_page_num(buf);

        list[list_size].stacktrace = strchr(list[list_size].txt, '\n') ?: "";
        if (*list[list_size].stacktrace == '\n')
                list[list_size].stacktrace++;
        list[list_size].ts_nsec = get_ts_nsec(buf);
        list[list_size].allocator = get_allocator(buf, ext_buf);
        list_size++;
        if (list_size % 1000 == 0) {
                printf("loaded %d\r", list_size);
                fflush(stdout);
        }
        return true;
}

static bool parse_cull_args(const char *arg_str)
{
        int size = 0;
        char **args = explode(',', arg_str, &size);

        for (int i = 0; i < size; ++i) {
                int arg_type = get_arg_type(args[i]);

                if (arg_type == ARG_PID)
                        cull |= CULL_PID;
                else if (arg_type == ARG_TGID)
                        cull |= CULL_TGID;
                else if (arg_type == ARG_COMM)
                        cull |= CULL_COMM;
                else if (arg_type == ARG_STACKTRACE)
                        cull |= CULL_STACKTRACE;
                else if (arg_type == ARG_ALLOCATOR)
                        cull |= CULL_ALLOCATOR;
                else {
                        free_explode(args, size);
                        return false;
                }
        }
        free_explode(args, size);
        if (sc.size == 0)
                set_single_cmp(compare_num, SORT_DESC);
        return true;
}

static void set_single_cmp(int (*cmp)(const void *, const void *), int sign)
{
        if (sc.signs == NULL || sc.size < 1)
                sc.signs = calloc(1, sizeof(int));
        sc.signs[0] = sign;
        if (sc.cmps == NULL || sc.size < 1)
                sc.cmps = calloc(1, sizeof(int *));
        sc.cmps[0] = cmp;
        sc.size = 1;
}

static bool parse_sort_args(const char *arg_str)
{
        int size = 0;

        if (sc.size != 0) { /* reset sort_condition */
                free(sc.signs);
                free(sc.cmps);
                size = 0;
        }

        char **args = explode(',', arg_str, &size);

        sc.signs = calloc(size, sizeof(int));
        sc.cmps = calloc(size, sizeof(int *));
        for (int i = 0; i < size; ++i) {
                int offset = 0;

                sc.signs[i] = SORT_ASC;
                if (args[i][0] == '-' || args[i][0] == '+') {
                        if (args[i][0] == '-')
                                sc.signs[i] = SORT_DESC;
                        offset = 1;
                }

                int arg_type = get_arg_type(args[i]+offset);

                if (arg_type == ARG_PID)
                        sc.cmps[i] = compare_pid;
                else if (arg_type == ARG_TGID)
                        sc.cmps[i] = compare_tgid;
                else if (arg_type == ARG_COMM)
                        sc.cmps[i] = compare_comm;
                else if (arg_type == ARG_STACKTRACE)
                        sc.cmps[i] = compare_stacktrace;
                else if (arg_type == ARG_ALLOC_TS)
                        sc.cmps[i] = compare_ts;
                else if (arg_type == ARG_TXT)
                        sc.cmps[i] = compare_txt;
                else if (arg_type == ARG_ALLOCATOR)
                        sc.cmps[i] = compare_allocator;
                else {
                        free_explode(args, size);
                        sc.size = 0;
                        return false;
                }
        }
        sc.size = size;
        free_explode(args, size);
        return true;
}

static int *parse_nums_list(char *arg_str, int *list_size)
{
        int size = 0;
        char **args = explode(',', arg_str, &size);
        int *list = calloc(size, sizeof(int));

        errno = 0;
        for (int i = 0; i < size; ++i) {
                char *endptr = NULL;

                list[i] = strtol(args[i], &endptr, 10);
                if (errno != 0 || endptr == args[i] || *endptr != '\0') {
                        free(list);
                        return NULL;
                }
        }
        *list_size = size;
        free_explode(args, size);
        return list;
}

static void print_allocator(FILE *out, int allocator)
{
        fprintf(out, "allocated by ");
        if (allocator & ALLOCATOR_CMA)
                fprintf(out, "CMA ");
        if (allocator & ALLOCATOR_SLAB)
                fprintf(out, "SLAB ");
        if (allocator & ALLOCATOR_VMALLOC)
                fprintf(out, "VMALLOC ");
        if (allocator & ALLOCATOR_OTHERS)
                fprintf(out, "OTHERS ");
}

#define BUF_SIZE        (128 * 1024)

static void usage(void)
{
        printf("Usage: ./page_owner_sort [OPTIONS] <input> <output>\n"
                "-a\t\t\tSort by memory allocation time.\n"
                "-m\t\t\tSort by total memory.\n"
                "-n\t\t\tSort by task command name.\n"
                "-p\t\t\tSort by pid.\n"
                "-P\t\t\tSort by tgid.\n"
                "-s\t\t\tSort by the stacktrace.\n"
                "-t\t\t\tSort by number of times record is seen (default).\n\n"
                "--pid <pidlist>\t\tSelect by pid. This selects the information"
                " of\n\t\t\tblocks whose process ID numbers appear in <pidlist>.\n"
                "--tgid <tgidlist>\tSelect by tgid. This selects the information"
                " of\n\t\t\tblocks whose Thread Group ID numbers appear in "
                "<tgidlist>.\n"
                "--name <cmdlist>\tSelect by command name. This selects the"
                " information\n\t\t\tof blocks whose command name appears in"
                " <cmdlist>.\n"
                "--cull <rules>\t\tCull by user-defined rules. <rules> is a "
                "single\n\t\t\targument in the form of a comma-separated list "
                "with some\n\t\t\tcommon fields predefined (pid, tgid, comm, "
                "stacktrace, allocator)\n"
                "--sort <order>\t\tSpecify sort order as: [+|-]key[,[+|-]key[,...]]\n"
        );
}

int main(int argc, char **argv)
{
        FILE *fin, *fout;
        char *buf, *ext_buf;
        int i, count, compare_flag;
        struct stat st;
        int opt;
        struct option longopts[] = {
                { "pid", required_argument, NULL, 1 },
                { "tgid", required_argument, NULL, 2 },
                { "name", required_argument, NULL, 3 },
                { "cull", required_argument, NULL, 4 },
                { "sort", required_argument, NULL, 5 },
                { "help", no_argument, NULL, 'h' },
                { 0, 0, 0, 0},
        };

        compare_flag = COMP_NO_FLAG;

        while ((opt = getopt_long(argc, argv, "admnpstPh", longopts, NULL)) != -1)
                switch (opt) {
                case 'a':
                        compare_flag |= COMP_ALLOC;
                        break;
                case 'd':
                        debug_on = true;
                        break;
                case 'm':
                        compare_flag |= COMP_PAGE_NUM;
                        break;
                case 'p':
                        compare_flag |= COMP_PID;
                        break;
                case 's':
                        compare_flag |= COMP_STACK;
                        break;
                case 't':
                        compare_flag |= COMP_NUM;
                        break;
                case 'P':
                        compare_flag |= COMP_TGID;
                        break;
                case 'n':
                        compare_flag |= COMP_COMM;
                        break;
                case 'h':
                        usage();
                        exit(0);
                case 1:
                        filter = filter | FILTER_PID;
                        fc.pids = parse_nums_list(optarg, &fc.pids_size);
                        if (fc.pids == NULL) {
                                fprintf(stderr, "wrong/invalid pid in from the command line:%s\n",
                                                optarg);
                                exit(1);
                        }
                        break;
                case 2:
                        filter = filter | FILTER_TGID;
                        fc.tgids = parse_nums_list(optarg, &fc.tgids_size);
                        if (fc.tgids == NULL) {
                                fprintf(stderr, "wrong/invalid tgid in from the command line:%s\n",
                                                optarg);
                                exit(1);
                        }
                        break;
                case 3:
                        filter = filter | FILTER_COMM;
                        fc.comms = explode(',', optarg, &fc.comms_size);
                        break;
                case 4:
                        if (!parse_cull_args(optarg)) {
                                fprintf(stderr, "wrong argument after --cull option:%s\n",
                                                optarg);
                                exit(1);
                        }
                        break;
                case 5:
                        if (!parse_sort_args(optarg)) {
                                fprintf(stderr, "wrong argument after --sort option:%s\n",
                                                optarg);
                                exit(1);
                        }
                        break;
                default:
                        usage();
                        exit(1);
                }

        if (optind >= (argc - 1)) {
                usage();
                exit(1);
        }

        /* Only one compare option is allowed, yet we also want handle the
         * default case were no option is provided, but we still want to
         * match the behavior of the -t option (compare by number of times
         * a record is seen
         */
        switch (compare_flag) {
        case COMP_ALLOC:
                set_single_cmp(compare_ts, SORT_ASC);
                break;
        case COMP_PAGE_NUM:
                set_single_cmp(compare_page_num, SORT_DESC);
                break;
        case COMP_PID:
                set_single_cmp(compare_pid, SORT_ASC);
                break;
        case COMP_STACK:
                set_single_cmp(compare_stacktrace, SORT_ASC);
                break;
        case COMP_NO_FLAG:
        case COMP_NUM:
                set_single_cmp(compare_num, SORT_DESC);
                break;
        case COMP_TGID:
                set_single_cmp(compare_tgid, SORT_ASC);
                break;
        case COMP_COMM:
                set_single_cmp(compare_comm, SORT_ASC);
                break;
        default:
                usage();
                exit(1);
        }

        fin = fopen(argv[optind], "r");
        fout = fopen(argv[optind + 1], "w");
        if (!fin || !fout) {
                usage();
                perror("open: ");
                exit(1);
        }

        if (!check_regcomp(&order_pattern, "order\\s*([0-9]*),"))
                goto out_order;
        if (!check_regcomp(&pid_pattern, "pid\\s*([0-9]*),"))
                goto out_pid;
        if (!check_regcomp(&tgid_pattern, "tgid\\s*([0-9]*) "))
                goto out_tgid;
        if (!check_regcomp(&comm_pattern, "tgid\\s*[0-9]*\\s*\\((.*)\\),\\s*ts"))
                goto out_comm;
        if (!check_regcomp(&ts_nsec_pattern, "ts\\s*([0-9]*)\\s*ns"))
                goto out_ts;

        fstat(fileno(fin), &st);
        max_size = st.st_size / 100; /* hack ... */

        list = malloc(max_size * sizeof(*list));
        buf = malloc(BUF_SIZE);
        ext_buf = malloc(BUF_SIZE);
        if (!list || !buf || !ext_buf) {
                fprintf(stderr, "Out of memory\n");
                goto out_free;
        }

        for ( ; ; ) {
                int buf_len = read_block(buf, ext_buf, BUF_SIZE, fin);

                if (buf_len < 0)
                        break;
                if (!add_list(buf, buf_len, ext_buf))
                        goto out_free;
        }

        printf("loaded %d\n", list_size);

        printf("sorting ....\n");

        qsort(list, list_size, sizeof(list[0]), compare_cull_condition);

        printf("culling\n");

        for (i = count = 0; i < list_size; i++) {
                if (count == 0 ||
                    compare_cull_condition((void *)(&list[count-1]), (void *)(&list[i])) != 0) {
                        list[count++] = list[i];
                } else {
                        list[count-1].num += list[i].num;
                        list[count-1].page_num += list[i].page_num;
                }
        }

        qsort(list, count, sizeof(list[0]), compare_sort_condition);

        for (i = 0; i < count; i++) {
                if (cull == 0) {
                        fprintf(fout, "%d times, %d pages, ", list[i].num, list[i].page_num);
                        print_allocator(fout, list[i].allocator);
                        fprintf(fout, ":\n%s\n", list[i].txt);
                }
                else {
                        fprintf(fout, "%d times, %d pages",
                                        list[i].num, list[i].page_num);
                        if (cull & CULL_PID || filter & FILTER_PID)
                                fprintf(fout, ", PID %d", list[i].pid);
                        if (cull & CULL_TGID || filter & FILTER_TGID)
                                fprintf(fout, ", TGID %d", list[i].tgid);
                        if (cull & CULL_COMM || filter & FILTER_COMM)
                                fprintf(fout, ", task_comm_name: %s", list[i].comm);
                        if (cull & CULL_ALLOCATOR) {
                                fprintf(fout, ", ");
                                print_allocator(fout, list[i].allocator);
                        }
                        if (cull & CULL_STACKTRACE)
                                fprintf(fout, ":\n%s", list[i].stacktrace);
                        fprintf(fout, "\n");
                }
        }

out_free:
        if (ext_buf)
                free(ext_buf);
        if (buf)
                free(buf);
        if (list)
                free(list);
out_ts:
        regfree(&ts_nsec_pattern);
out_comm:
        regfree(&comm_pattern);
out_tgid:
        regfree(&tgid_pattern);
out_pid:
        regfree(&pid_pattern);
out_order:
        regfree(&order_pattern);

        return 0;
}