mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-25 10:19:47 +00:00
![Tobin C. Harding](/assets/img/avatar_default.png)
Add a test module for the new strscpy_pad() function. Tie it into the kselftest infrastructure for lib/ tests. Acked-by: Kees Cook <keescook@chromium.org> Signed-off-by: Tobin C. Harding <tobin@kernel.org> Signed-off-by: Shuah Khan <shuah@kernel.org>
150 lines
4 KiB
C
150 lines
4 KiB
C
// SPDX-License-Identifier: GPL-2.0+
|
|
|
|
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
|
|
|
|
#include <linux/string.h>
|
|
|
|
#include "../tools/testing/selftests/kselftest_module.h"
|
|
|
|
/*
|
|
* Kernel module for testing 'strscpy' family of functions.
|
|
*/
|
|
|
|
KSTM_MODULE_GLOBALS();
|
|
|
|
/*
|
|
* tc() - Run a specific test case.
|
|
* @src: Source string, argument to strscpy_pad()
|
|
* @count: Size of destination buffer, argument to strscpy_pad()
|
|
* @expected: Expected return value from call to strscpy_pad()
|
|
* @terminator: 1 if there should be a terminating null byte 0 otherwise.
|
|
* @chars: Number of characters from the src string expected to be
|
|
* written to the dst buffer.
|
|
* @pad: Number of pad characters expected (in the tail of dst buffer).
|
|
* (@pad does not include the null terminator byte.)
|
|
*
|
|
* Calls strscpy_pad() and verifies the return value and state of the
|
|
* destination buffer after the call returns.
|
|
*/
|
|
static int __init tc(char *src, int count, int expected,
|
|
int chars, int terminator, int pad)
|
|
{
|
|
int nr_bytes_poison;
|
|
int max_expected;
|
|
int max_count;
|
|
int written;
|
|
char buf[6];
|
|
int index, i;
|
|
const char POISON = 'z';
|
|
|
|
total_tests++;
|
|
|
|
if (!src) {
|
|
pr_err("null source string not supported\n");
|
|
return -1;
|
|
}
|
|
|
|
memset(buf, POISON, sizeof(buf));
|
|
/* Future proofing test suite, validate args */
|
|
max_count = sizeof(buf) - 2; /* Space for null and to verify overflow */
|
|
max_expected = count - 1; /* Space for the null */
|
|
if (count > max_count) {
|
|
pr_err("count (%d) is too big (%d) ... aborting", count, max_count);
|
|
return -1;
|
|
}
|
|
if (expected > max_expected) {
|
|
pr_warn("expected (%d) is bigger than can possibly be returned (%d)",
|
|
expected, max_expected);
|
|
}
|
|
|
|
written = strscpy_pad(buf, src, count);
|
|
if ((written) != (expected)) {
|
|
pr_err("%d != %d (written, expected)\n", written, expected);
|
|
goto fail;
|
|
}
|
|
|
|
if (count && written == -E2BIG) {
|
|
if (strncmp(buf, src, count - 1) != 0) {
|
|
pr_err("buffer state invalid for -E2BIG\n");
|
|
goto fail;
|
|
}
|
|
if (buf[count - 1] != '\0') {
|
|
pr_err("too big string is not null terminated correctly\n");
|
|
goto fail;
|
|
}
|
|
}
|
|
|
|
for (i = 0; i < chars; i++) {
|
|
if (buf[i] != src[i]) {
|
|
pr_err("buf[i]==%c != src[i]==%c\n", buf[i], src[i]);
|
|
goto fail;
|
|
}
|
|
}
|
|
|
|
if (terminator) {
|
|
if (buf[count - 1] != '\0') {
|
|
pr_err("string is not null terminated correctly\n");
|
|
goto fail;
|
|
}
|
|
}
|
|
|
|
for (i = 0; i < pad; i++) {
|
|
index = chars + terminator + i;
|
|
if (buf[index] != '\0') {
|
|
pr_err("padding missing at index: %d\n", i);
|
|
goto fail;
|
|
}
|
|
}
|
|
|
|
nr_bytes_poison = sizeof(buf) - chars - terminator - pad;
|
|
for (i = 0; i < nr_bytes_poison; i++) {
|
|
index = sizeof(buf) - 1 - i; /* Check from the end back */
|
|
if (buf[index] != POISON) {
|
|
pr_err("poison value missing at index: %d\n", i);
|
|
goto fail;
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
fail:
|
|
failed_tests++;
|
|
return -1;
|
|
}
|
|
|
|
static void __init selftest(void)
|
|
{
|
|
/*
|
|
* tc() uses a destination buffer of size 6 and needs at
|
|
* least 2 characters spare (one for null and one to check for
|
|
* overflow). This means we should only call tc() with
|
|
* strings up to a maximum of 4 characters long and 'count'
|
|
* should not exceed 4. To test with longer strings increase
|
|
* the buffer size in tc().
|
|
*/
|
|
|
|
/* tc(src, count, expected, chars, terminator, pad) */
|
|
KSTM_CHECK_ZERO(tc("a", 0, -E2BIG, 0, 0, 0));
|
|
KSTM_CHECK_ZERO(tc("", 0, -E2BIG, 0, 0, 0));
|
|
|
|
KSTM_CHECK_ZERO(tc("a", 1, -E2BIG, 0, 1, 0));
|
|
KSTM_CHECK_ZERO(tc("", 1, 0, 0, 1, 0));
|
|
|
|
KSTM_CHECK_ZERO(tc("ab", 2, -E2BIG, 1, 1, 0));
|
|
KSTM_CHECK_ZERO(tc("a", 2, 1, 1, 1, 0));
|
|
KSTM_CHECK_ZERO(tc("", 2, 0, 0, 1, 1));
|
|
|
|
KSTM_CHECK_ZERO(tc("abc", 3, -E2BIG, 2, 1, 0));
|
|
KSTM_CHECK_ZERO(tc("ab", 3, 2, 2, 1, 0));
|
|
KSTM_CHECK_ZERO(tc("a", 3, 1, 1, 1, 1));
|
|
KSTM_CHECK_ZERO(tc("", 3, 0, 0, 1, 2));
|
|
|
|
KSTM_CHECK_ZERO(tc("abcd", 4, -E2BIG, 3, 1, 0));
|
|
KSTM_CHECK_ZERO(tc("abc", 4, 3, 3, 1, 0));
|
|
KSTM_CHECK_ZERO(tc("ab", 4, 2, 2, 1, 1));
|
|
KSTM_CHECK_ZERO(tc("a", 4, 1, 1, 1, 2));
|
|
KSTM_CHECK_ZERO(tc("", 4, 0, 0, 1, 3));
|
|
}
|
|
|
|
KSTM_MODULE_LOADERS(test_strscpy);
|
|
MODULE_AUTHOR("Tobin C. Harding <tobin@kernel.org>");
|
|
MODULE_LICENSE("GPL");
|