// SPDX-License-Identifier: GPL-2.0
#include "perf.h"
#include "util.h"
#include "debug.h"
#include "event.h"
#include <api/fs/fs.h>
#include <sys/stat.h>
#include <sys/utsname.h>
#include <dirent.h>
#include <fcntl.h>
#include <inttypes.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <limits.h>
#include <linux/capability.h>
#include <linux/kernel.h>
#include <linux/log2.h>
#include <linux/time64.h>
#include <linux/overflow.h>
#include <unistd.h>
#include "cap.h"
#include "strlist.h"
#include "string2.h"

/*
 * XXX We need to find a better place for these things...
 */

const char *input_name;

bool perf_singlethreaded = true;

void perf_set_singlethreaded(void)
{
        perf_singlethreaded = true;
}

void perf_set_multithreaded(void)
{
        perf_singlethreaded = false;
}

int sysctl_perf_event_max_stack = PERF_MAX_STACK_DEPTH;
int sysctl_perf_event_max_contexts_per_stack = PERF_MAX_CONTEXTS_PER_STACK;

int sysctl__max_stack(void)
{
        int value;

        if (sysctl__read_int("kernel/perf_event_max_stack", &value) == 0)
                sysctl_perf_event_max_stack = value;

        if (sysctl__read_int("kernel/perf_event_max_contexts_per_stack", &value) == 0)
                sysctl_perf_event_max_contexts_per_stack = value;

        return sysctl_perf_event_max_stack;
}

bool sysctl__nmi_watchdog_enabled(void)
{
        static bool cached;
        static bool nmi_watchdog;
        int value;

        if (cached)
                return nmi_watchdog;

        if (sysctl__read_int("kernel/nmi_watchdog", &value) < 0)
                return false;

        nmi_watchdog = (value > 0) ? true : false;
        cached = true;

        return nmi_watchdog;
}

bool test_attr__enabled;

bool exclude_GH_default;

bool perf_host  = true;
bool perf_guest = false;

void event_attr_init(struct perf_event_attr *attr)
{
        /* to capture ABI version */
        attr->size = sizeof(*attr);

        if (!exclude_GH_default)
                return;

        if (!perf_host)
                attr->exclude_host  = 1;
        if (!perf_guest)
                attr->exclude_guest = 1;
}

int mkdir_p(char *path, mode_t mode)
{
        struct stat st;
        int err;
        char *d = path;

        if (*d != '/')
                return -1;

        if (stat(path, &st) == 0)
                return 0;

        while (*++d == '/');

        while ((d = strchr(d, '/'))) {
                *d = '\0';
                err = stat(path, &st) && mkdir(path, mode);
                *d++ = '/';
                if (err)
                        return -1;
                while (*d == '/')
                        ++d;
        }
        return (stat(path, &st) && mkdir(path, mode)) ? -1 : 0;
}

static bool match_pat(char *file, const char **pat)
{
        int i = 0;

        if (!pat)
                return true;

        while (pat[i]) {
                if (strglobmatch(file, pat[i]))
                        return true;

                i++;
        }

        return false;
}

/*
 * The depth specify how deep the removal will go.
 * 0       - will remove only files under the 'path' directory
 * 1 .. x  - will dive in x-level deep under the 'path' directory
 *
 * If specified the pat is array of string patterns ended with NULL,
 * which are checked upon every file/directory found. Only matching
 * ones are removed.
 *
 * The function returns:
 *    0 on success
 *   -1 on removal failure with errno set
 *   -2 on pattern failure
 */
static int rm_rf_depth_pat(const char *path, int depth, const char **pat)
{
        DIR *dir;
        int ret;
        struct dirent *d;
        char namebuf[PATH_MAX];
        struct stat statbuf;

        /* Do not fail if there's no file. */
        ret = lstat(path, &statbuf);
        if (ret)
                return 0;

        /* Try to remove any file we get. */
        if (!(statbuf.st_mode & S_IFDIR))
                return unlink(path);

        /* We have directory in path. */
        dir = opendir(path);
        if (dir == NULL)
                return -1;

        while ((d = readdir(dir)) != NULL && !ret) {

                if (!strcmp(d->d_name, ".") || !strcmp(d->d_name, ".."))
                        continue;

                if (!match_pat(d->d_name, pat)) {
                        ret =  -2;
                        break;
                }

                scnprintf(namebuf, sizeof(namebuf), "%s/%s",
                          path, d->d_name);

                /* We have to check symbolic link itself */
                ret = lstat(namebuf, &statbuf);
                if (ret < 0) {
                        pr_debug("stat failed: %s\n", namebuf);
                        break;
                }

                if (S_ISDIR(statbuf.st_mode))
                        ret = depth ? rm_rf_depth_pat(namebuf, depth - 1, pat) : 0;
                else
                        ret = unlink(namebuf);
        }
        closedir(dir);

        if (ret < 0)
                return ret;

        return rmdir(path);
}

static int rm_rf_a_kcore_dir(const char *path, const char *name)
{
        char kcore_dir_path[PATH_MAX];
        const char *pat[] = {
                "kcore",
                "kallsyms",
                "modules",
                NULL,
        };

        snprintf(kcore_dir_path, sizeof(kcore_dir_path), "%s/%s", path, name);

        return rm_rf_depth_pat(kcore_dir_path, 0, pat);
}

static bool kcore_dir_filter(const char *name __maybe_unused, struct dirent *d)
{
        const char *pat[] = {
                "kcore_dir",
                "kcore_dir__[1-9]*",
                NULL,
        };

        return match_pat(d->d_name, pat);
}

static int rm_rf_kcore_dir(const char *path)
{
        struct strlist *kcore_dirs;
        struct str_node *nd;
        int ret;

        kcore_dirs = lsdir(path, kcore_dir_filter);

        if (!kcore_dirs)
                return 0;

        strlist__for_each_entry(nd, kcore_dirs) {
                ret = rm_rf_a_kcore_dir(path, nd->s);
                if (ret)
                        return ret;
        }

        strlist__delete(kcore_dirs);

        return 0;
}

void cpumask_to_cpulist(char *cpumask, char *cpulist)
{
        int i, j, bm_size, nbits;
        int len = strlen(cpumask);
        unsigned long *bm;
        char cpus[MAX_NR_CPUS];

        for (i = 0; i < len; i++) {
                if (cpumask[i] == ',') {
                        for (j = i; j < len; j++)
                                cpumask[j] = cpumask[j + 1];
                }
        }

        len = strlen(cpumask);
        bm_size = (len + 15) / 16;
        nbits = bm_size * 64;
        if (nbits <= 0)
                return;

        bm = calloc(bm_size, sizeof(unsigned long));
        if (!bm)
                goto free_bm;

        for (i = 0; i < bm_size; i++) {
                char blk[17];
                int blklen = len > 16 ? 16 : len;

                strncpy(blk, cpumask + len - blklen, blklen);
                blk[blklen] = '\0';
                bm[i] = strtoul(blk, NULL, 16);
                cpumask[len - blklen] = '\0';
                len = strlen(cpumask);
        }

        bitmap_scnprintf(bm, nbits, cpus, sizeof(cpus));
        strcpy(cpulist, cpus);

free_bm:
        free(bm);
}

void print_separator2(int pre_dash_cnt, const char *s, int post_dash_cnt)
{
        printf("%.*s%s%.*s\n", pre_dash_cnt, graph_dotted_line, s, post_dash_cnt,
               graph_dotted_line);
}

int rm_rf_perf_data(const char *path)
{
        const char *pat[] = {
                "data",
                "data.*",
                NULL,
        };

        rm_rf_kcore_dir(path);

        return rm_rf_depth_pat(path, 0, pat);
}

int rm_rf(const char *path)
{
        return rm_rf_depth_pat(path, INT_MAX, NULL);
}

/* A filter which removes dot files */
bool lsdir_no_dot_filter(const char *name __maybe_unused, struct dirent *d)
{
        return d->d_name[0] != '.';
}

/* lsdir reads a directory and store it in strlist */
struct strlist *lsdir(const char *name,
                      bool (*filter)(const char *, struct dirent *))
{
        struct strlist *list = NULL;
        DIR *dir;
        struct dirent *d;

        dir = opendir(name);
        if (!dir)
                return NULL;

        list = strlist__new(NULL, NULL);
        if (!list) {
                errno = ENOMEM;
                goto out;
        }

        while ((d = readdir(dir)) != NULL) {
                if (!filter || filter(name, d))
                        strlist__add(list, d->d_name);
        }

out:
        closedir(dir);
        return list;
}

size_t hex_width(u64 v)
{
        size_t n = 1;

        while ((v >>= 4))
                ++n;

        return n;
}

int perf_event_paranoid(void)
{
        int value;

        if (sysctl__read_int("kernel/perf_event_paranoid", &value))
                return INT_MAX;

        return value;
}

bool perf_event_paranoid_check(int max_level)
{
        bool used_root;

        if (perf_cap__capable(CAP_SYS_ADMIN, &used_root))
                return true;

        if (!used_root && perf_cap__capable(CAP_PERFMON, &used_root))
                return true;

        return perf_event_paranoid() <= max_level;
}

int perf_tip(char **strp, const char *dirpath)
{
        struct strlist *tips;
        struct str_node *node;
        struct strlist_config conf = {
                .dirname = dirpath,
                .file_only = true,
        };
        int ret = 0;

        *strp = NULL;
        tips = strlist__new("tips.txt", &conf);
        if (tips == NULL)
                return -errno;

        if (strlist__nr_entries(tips) == 0)
                goto out;

        node = strlist__entry(tips, random() % strlist__nr_entries(tips));
        if (asprintf(strp, "Tip: %s", node->s) < 0)
                ret = -ENOMEM;

out:
        strlist__delete(tips);

        return ret;
}

char *perf_exe(char *buf, int len)
{
        int n = readlink("/proc/self/exe", buf, len);
        if (n > 0) {
                buf[n] = 0;
                return buf;
        }
        return strcpy(buf, "perf");
}

void perf_debuginfod_setup(struct perf_debuginfod *di)
{
        /*
         * By default '!di->set' we clear DEBUGINFOD_URLS, so debuginfod
         * processing is not triggered, otherwise we set it to 'di->urls'
         * value. If 'di->urls' is "system" we keep DEBUGINFOD_URLS value.
         */
        if (!di->set)
                setenv("DEBUGINFOD_URLS", "", 1);
        else if (di->urls && strcmp(di->urls, "system"))
                setenv("DEBUGINFOD_URLS", di->urls, 1);

        pr_debug("DEBUGINFOD_URLS=%s\n", getenv("DEBUGINFOD_URLS"));

#ifndef HAVE_DEBUGINFOD_SUPPORT
        if (di->set)
                pr_warning("WARNING: debuginfod support requested, but perf is not built with it\n");
#endif
}

/*
 * Return a new filename prepended with task's root directory if it's in
 * a chroot.  Callers should free the returned string.
 */
char *filename_with_chroot(int pid, const char *filename)
{
        char buf[PATH_MAX];
        char proc_root[32];
        char *new_name = NULL;
        int ret;

        scnprintf(proc_root, sizeof(proc_root), "/proc/%d/root", pid);
        ret = readlink(proc_root, buf, sizeof(buf) - 1);
        if (ret <= 0)
                return NULL;

        /* readlink(2) does not append a null byte to buf */
        buf[ret] = '\0';

        if (!strcmp(buf, "/"))
                return NULL;

        if (strstr(buf, "(deleted)"))
                return NULL;

        if (asprintf(&new_name, "%s/%s", buf, filename) < 0)
                return NULL;

        return new_name;
}

/*
 * Reallocate an array *arr of size *arr_sz so that it is big enough to contain
 * x elements of size msz, initializing new entries to *init_val or zero if
 * init_val is NULL
 */
int do_realloc_array_as_needed(void **arr, size_t *arr_sz, size_t x, size_t msz, const void *init_val)
{
        size_t new_sz = *arr_sz;
        void *new_arr;
        size_t i;

        if (!new_sz)
                new_sz = msz >= 64 ? 1 : roundup(64, msz); /* Start with at least 64 bytes */
        while (x >= new_sz) {
                if (check_mul_overflow(new_sz, (size_t)2, &new_sz))
                        return -ENOMEM;
        }
        if (new_sz == *arr_sz)
                return 0;
        new_arr = calloc(new_sz, msz);
        if (!new_arr)
                return -ENOMEM;
        if (*arr_sz)
                memcpy(new_arr, *arr, *arr_sz * msz);
        if (init_val) {
                for (i = *arr_sz; i < new_sz; i++)
                        memcpy(new_arr + (i * msz), init_val, msz);
        }
        *arr = new_arr;
        *arr_sz = new_sz;
        return 0;
}

#ifndef HAVE_SCHED_GETCPU_SUPPORT
int sched_getcpu(void)
{
#ifdef __NR_getcpu
        unsigned int cpu;
        int err = syscall(__NR_getcpu, &cpu, NULL, NULL);

        if (!err)
                return cpu;
#else
        errno = ENOSYS;
#endif
        return -1;
}
#endif

#ifndef HAVE_SCANDIRAT_SUPPORT
int scandirat(int dirfd, const char *dirp,
              struct dirent ***namelist,
              int (*filter)(const struct dirent *),
              int (*compar)(const struct dirent **, const struct dirent **))
{
        char path[PATH_MAX];
        int err, fd = openat(dirfd, dirp, O_PATH);

        if (fd < 0)
                return fd;

        snprintf(path, sizeof(path), "/proc/%d/fd/%d", getpid(), fd);
        err = scandir(path, namelist, filter, compar);
        close(fd);
        return err;
}
#endif