lib: Add test module for strscpy_pad (0b0600c8) · Commits · e / devices / android_kernel_fairphone_FP5

lib/Kconfig.debug

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		@@ -1769,6 +1769,9 @@ config TEST_HEXDUMP
		config TEST_STRING_HELPERS
		tristate "Test functions located in the string_helpers module at runtime"

		config TEST_STRSCPY
		tristate "Test strscpy*() family of functions at runtime"

		config TEST_KSTRTOX
		tristate "Test kstrto*() family of functions at runtime"

lib/Makefile

+1 −0

Original line number	Diff line number	Diff line
		@@ -70,6 +70,7 @@ obj-$(CONFIG_TEST_STATIC_KEYS) += test_static_keys.o
		obj-$(CONFIG_TEST_STATIC_KEYS) += test_static_key_base.o
		obj-$(CONFIG_TEST_PRINTF) += test_printf.o
		obj-$(CONFIG_TEST_BITMAP) += test_bitmap.o
		obj-$(CONFIG_TEST_STRSCPY) += test_strscpy.o
		obj-$(CONFIG_TEST_BITFIELD) += test_bitfield.o
		obj-$(CONFIG_TEST_UUID) += test_uuid.o
		obj-$(CONFIG_TEST_XARRAY) += test_xarray.o

lib/test_strscpy.c

0 → 100644

+150 −0

Original line number	Diff line number	Diff line
		// 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");

tools/testing/selftests/lib/Makefile

+1 −1

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		@@ -3,6 +3,6 @@
		# No binaries, but make sure arg-less "make" doesn't trigger "run_tests"
		all:

		TEST_PROGS := printf.sh bitmap.sh prime_numbers.sh
		TEST_PROGS := printf.sh bitmap.sh prime_numbers.sh strscpy.sh

		include ../lib.mk

tools/testing/selftests/lib/config

+1 −0

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		CONFIG_TEST_PRINTF=m
		CONFIG_TEST_BITMAP=m
		CONFIG_PRIME_NUMBERS=m
		CONFIG_TEST_STRSCPY=m