root/lib/test_hexdump.c
/*
 * Test cases for lib/hexdump.c module.
 */
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/random.h>
#include <linux/string.h>

static const unsigned char data_b[] = {
        '\xbe', '\x32', '\xdb', '\x7b', '\x0a', '\x18', '\x93', '\xb2', /* 00 - 07 */
        '\x70', '\xba', '\xc4', '\x24', '\x7d', '\x83', '\x34', '\x9b', /* 08 - 0f */
        '\xa6', '\x9c', '\x31', '\xad', '\x9c', '\x0f', '\xac', '\xe9', /* 10 - 17 */
        '\x4c', '\xd1', '\x19', '\x99', '\x43', '\xb1', '\xaf', '\x0c', /* 18 - 1f */
};

static const unsigned char data_a[] = ".2.{....p..$}.4...1.....L...C...";

static const char * const test_data_1[] __initconst = {
        "be", "32", "db", "7b", "0a", "18", "93", "b2",
        "70", "ba", "c4", "24", "7d", "83", "34", "9b",
        "a6", "9c", "31", "ad", "9c", "0f", "ac", "e9",
        "4c", "d1", "19", "99", "43", "b1", "af", "0c",
};

static const char * const test_data_2_le[] __initconst = {
        "32be", "7bdb", "180a", "b293",
        "ba70", "24c4", "837d", "9b34",
        "9ca6", "ad31", "0f9c", "e9ac",
        "d14c", "9919", "b143", "0caf",
};

static const char * const test_data_2_be[] __initconst = {
        "be32", "db7b", "0a18", "93b2",
        "70ba", "c424", "7d83", "349b",
        "a69c", "31ad", "9c0f", "ace9",
        "4cd1", "1999", "43b1", "af0c",
};

static const char * const test_data_4_le[] __initconst = {
        "7bdb32be", "b293180a", "24c4ba70", "9b34837d",
        "ad319ca6", "e9ac0f9c", "9919d14c", "0cafb143",
};

static const char * const test_data_4_be[] __initconst = {
        "be32db7b", "0a1893b2", "70bac424", "7d83349b",
        "a69c31ad", "9c0face9", "4cd11999", "43b1af0c",
};

static const char * const test_data_8_le[] __initconst = {
        "b293180a7bdb32be", "9b34837d24c4ba70",
        "e9ac0f9cad319ca6", "0cafb1439919d14c",
};

static const char * const test_data_8_be[] __initconst = {
        "be32db7b0a1893b2", "70bac4247d83349b",
        "a69c31ad9c0face9", "4cd1199943b1af0c",
};

#define FILL_CHAR       '#'

static unsigned total_tests __initdata;
static unsigned failed_tests __initdata;

static void __init test_hexdump_prepare_test(size_t len, int rowsize,
                                             int groupsize, char *test,
                                             size_t testlen, bool ascii)
{
        char *p;
        const char * const *result;
        size_t l = len;
        int gs = groupsize, rs = rowsize;
        unsigned int i;
        const bool is_be = IS_ENABLED(CONFIG_CPU_BIG_ENDIAN);

        if (rs != 16 && rs != 32)
                rs = 16;

        if (l > rs)
                l = rs;

        if (!is_power_of_2(gs) || gs > 8 || (len % gs != 0))
                gs = 1;

        if (gs == 8)
                result = is_be ? test_data_8_be : test_data_8_le;
        else if (gs == 4)
                result = is_be ? test_data_4_be : test_data_4_le;
        else if (gs == 2)
                result = is_be ? test_data_2_be : test_data_2_le;
        else
                result = test_data_1;

        /* hex dump */
        p = test;
        for (i = 0; i < l / gs; i++) {
                const char *q = *result++;
                size_t amount = strlen(q);

                memcpy(p, q, amount);
                p += amount;

                *p++ = ' ';
        }
        if (i)
                p--;

        /* ASCII part */
        if (ascii) {
                do {
                        *p++ = ' ';
                } while (p < test + rs * 2 + rs / gs + 1);

                memcpy(p, data_a, l);
                p += l;
        }

        *p = '\0';
}

#define TEST_HEXDUMP_BUF_SIZE           (32 * 3 + 2 + 32 + 1)

static void __init test_hexdump(size_t len, int rowsize, int groupsize,
                                bool ascii)
{
        char test[TEST_HEXDUMP_BUF_SIZE];
        char real[TEST_HEXDUMP_BUF_SIZE];

        total_tests++;

        memset(real, FILL_CHAR, sizeof(real));
        hex_dump_to_buffer(data_b, len, rowsize, groupsize, real, sizeof(real),
                           ascii);

        memset(test, FILL_CHAR, sizeof(test));
        test_hexdump_prepare_test(len, rowsize, groupsize, test, sizeof(test),
                                  ascii);

        if (memcmp(test, real, TEST_HEXDUMP_BUF_SIZE)) {
                pr_err("Len: %zu row: %d group: %d\n", len, rowsize, groupsize);
                pr_err("Result: '%s'\n", real);
                pr_err("Expect: '%s'\n", test);
                failed_tests++;
        }
}

static void __init test_hexdump_set(int rowsize, bool ascii)
{
        size_t d = min_t(size_t, sizeof(data_b), rowsize);
        size_t len = get_random_u32_inclusive(1, d);

        test_hexdump(len, rowsize, 4, ascii);
        test_hexdump(len, rowsize, 2, ascii);
        test_hexdump(len, rowsize, 8, ascii);
        test_hexdump(len, rowsize, 1, ascii);
}

static void __init test_hexdump_overflow(size_t buflen, size_t len,
                                         int rowsize, int groupsize,
                                         bool ascii)
{
        char test[TEST_HEXDUMP_BUF_SIZE];
        char buf[TEST_HEXDUMP_BUF_SIZE];
        int rs = rowsize, gs = groupsize;
        int ae, he, e, f, r;
        bool a;

        total_tests++;

        memset(buf, FILL_CHAR, sizeof(buf));

        r = hex_dump_to_buffer(data_b, len, rs, gs, buf, buflen, ascii);

        /*
         * Caller must provide the data length multiple of groupsize. The
         * calculations below are made with that assumption in mind.
         */
        ae = rs * 2 /* hex */ + rs / gs /* spaces */ + 1 /* space */ + len /* ascii */;
        he = (gs * 2 /* hex */ + 1 /* space */) * len / gs - 1 /* no trailing space */;

        if (ascii)
                e = ae;
        else
                e = he;

        f = min_t(int, e + 1, buflen);
        if (buflen) {
                test_hexdump_prepare_test(len, rs, gs, test, sizeof(test), ascii);
                test[f - 1] = '\0';
        }
        memset(test + f, FILL_CHAR, sizeof(test) - f);

        a = r == e && !memcmp(test, buf, TEST_HEXDUMP_BUF_SIZE);

        buf[sizeof(buf) - 1] = '\0';

        if (!a) {
                pr_err("Len: %zu buflen: %zu strlen: %zu\n",
                        len, buflen, strnlen(buf, sizeof(buf)));
                pr_err("Result: %d '%s'\n", r, buf);
                pr_err("Expect: %d '%s'\n", e, test);
                failed_tests++;
        }
}

static void __init test_hexdump_overflow_set(size_t buflen, bool ascii)
{
        unsigned int i = 0;
        int rs = get_random_u32_inclusive(1, 2) * 16;

        do {
                int gs = 1 << i;
                size_t len = get_random_u32_below(rs) + gs;

                test_hexdump_overflow(buflen, rounddown(len, gs), rs, gs, ascii);
        } while (i++ < 3);
}

static int __init test_hexdump_init(void)
{
        unsigned int i;
        int rowsize;

        rowsize = get_random_u32_inclusive(1, 2) * 16;
        for (i = 0; i < 16; i++)
                test_hexdump_set(rowsize, false);

        rowsize = get_random_u32_inclusive(1, 2) * 16;
        for (i = 0; i < 16; i++)
                test_hexdump_set(rowsize, true);

        for (i = 0; i <= TEST_HEXDUMP_BUF_SIZE; i++)
                test_hexdump_overflow_set(i, false);

        for (i = 0; i <= TEST_HEXDUMP_BUF_SIZE; i++)
                test_hexdump_overflow_set(i, true);

        if (failed_tests == 0)
                pr_info("all %u tests passed\n", total_tests);
        else
                pr_err("failed %u out of %u tests\n", failed_tests, total_tests);

        return failed_tests ? -EINVAL : 0;
}
module_init(test_hexdump_init);

static void __exit test_hexdump_exit(void)
{
        /* do nothing */
}
module_exit(test_hexdump_exit);

MODULE_AUTHOR("Andy Shevchenko <andriy.shevchenko@linux.intel.com>");
MODULE_DESCRIPTION("Test cases for lib/hexdump.c module");
MODULE_LICENSE("Dual BSD/GPL");