// SPDX-License-Identifier: GPL-2.0
/*
 * This test covers the PR_SET_NAME functionality of prctl calls
 */

#include <errno.h>
#include <sys/prctl.h>
#include <string.h>

#include "kselftest_harness.h"

#define CHANGE_NAME "changename"
#define EMPTY_NAME ""
#define TASK_COMM_LEN 16
#define MAX_PATH_LEN 50

int set_name(char *name)
{
        int res;

        res = prctl(PR_SET_NAME, name, NULL, NULL, NULL);

        if (res < 0)
                return -errno;
        return res;
}

int check_is_name_correct(char *check_name)
{
        char name[TASK_COMM_LEN];
        int res;

        res = prctl(PR_GET_NAME, name, NULL, NULL, NULL);

        if (res < 0)
                return -errno;

        return !strcmp(name, check_name);
}

int check_null_pointer(char *check_name)
{
        char *name = NULL;
        int res;

        res = prctl(PR_GET_NAME, name, NULL, NULL, NULL);

        return res;
}

int check_name(void)
{

        int pid;

        pid = getpid();
        FILE *fptr = NULL;
        char path[MAX_PATH_LEN] = {};
        char name[TASK_COMM_LEN] = {};
        char output[TASK_COMM_LEN] = {};
        int j;

        j = snprintf(path, MAX_PATH_LEN, "/proc/self/task/%d/comm", pid);
        fptr = fopen(path, "r");
        if (!fptr)
                return -EIO;

        fscanf(fptr, "%s", output);
        if (ferror(fptr))
                return -EIO;

        int res = prctl(PR_GET_NAME, name, NULL, NULL, NULL);

        if (res < 0)
                return -errno;

        return !strcmp(output, name);
}

TEST(rename_process) {

        EXPECT_GE(set_name(CHANGE_NAME), 0);
        EXPECT_TRUE(check_is_name_correct(CHANGE_NAME));

        EXPECT_GE(set_name(EMPTY_NAME), 0);
        EXPECT_TRUE(check_is_name_correct(EMPTY_NAME));

        EXPECT_GE(set_name(CHANGE_NAME), 0);
        EXPECT_LT(check_null_pointer(CHANGE_NAME), 0);

        EXPECT_TRUE(check_name());
}

TEST_HARNESS_MAIN