[2/5] string: Merge strscpy KUnit tests into string_kunit.c

Message ID	20240419140155.3028912-2-keescook@chromium.org (mailing list archive)
State	Mainlined
Commit	bb8d9b742aa7c576d39b354612224b3c6bfd3cbc
Headers	show Received: from mail-pf1-f180.google.com (mail-pf1-f180.google.com [209.85.210.180]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1D80612D77F for <linux-hardening@vger.kernel.org>; Fri, 19 Apr 2024 14:02:01 +0000 (UTC) From: Kees Cook <keescook@chromium.org> To: Andy Shevchenko <andy@kernel.org> Cc: Kees Cook <keescook@chromium.org>, Ivan Orlov <ivan.orlov0322@gmail.com>, linux-hardening@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 2/5] string: Merge strscpy KUnit tests into string_kunit.c Date: Fri, 19 Apr 2024 07:01:51 -0700 Message-Id: <20240419140155.3028912-2-keescook@chromium.org> In-Reply-To: <20240419140017.work.012-kees@kernel.org> References: <20240419140017.work.012-kees@kernel.org> Precedence: bulk MIME-Version: 1.0 Content-Transfer-Encoding: 8bit
Series	string: Merge separate tests into string_kunit.c \| expand [0/5] string: Merge separate tests into string_kunit.c [1/5] string: Prepare to merge strscpy_kunit.c into string_kunit.c [2/5] string: Merge strscpy KUnit tests into string_kunit.c [3/5] string: Prepare to merge strcat KUnit tests into string_kunit.c [4/5] string: Merge strcat KUnit tests into string_kunit.c [5/5] string: Convert KUnit test names to standard convention

diff --git a/MAINTAINERS b/MAINTAINERS index 7c121493f43d..17d079aa15ec 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -8442,7 +8442,6 @@ F: include/linux/fortify-string.h F: lib/fortify_kunit.c F: lib/memcpy_kunit.c F: lib/strcat_kunit.c -F: lib/strscpy_kunit.c F: lib/test_fortify/* F: scripts/test_fortify.sh K: \b__NO_FORTIFY\b diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index c63a5fbf1f1c..7ffb06eabcd1 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -2763,11 +2763,6 @@ config STRCAT_KUNIT_TEST depends on KUNIT default KUNIT_ALL_TESTS -config STRSCPY_KUNIT_TEST - tristate "Test strscpy*() family of functions at runtime" if !KUNIT_ALL_TESTS - depends on KUNIT - default KUNIT_ALL_TESTS - config SIPHASH_KUNIT_TEST tristate "Perform selftest on siphash functions" if !KUNIT_ALL_TESTS depends on KUNIT diff --git a/lib/Makefile b/lib/Makefile index ffc6b2341b45..5f994b963d1a 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -404,7 +404,6 @@ CFLAGS_fortify_kunit.o += $(call cc-disable-warning, stringop-truncation) CFLAGS_fortify_kunit.o += $(DISABLE_STRUCTLEAK_PLUGIN) obj-$(CONFIG_FORTIFY_KUNIT_TEST) += fortify_kunit.o obj-$(CONFIG_STRCAT_KUNIT_TEST) += strcat_kunit.o -obj-$(CONFIG_STRSCPY_KUNIT_TEST) += strscpy_kunit.o obj-$(CONFIG_SIPHASH_KUNIT_TEST) += siphash_kunit.o obj-$(CONFIG_GENERIC_LIB_DEVMEM_IS_ALLOWED) += devmem_is_allowed.o diff --git a/lib/string_kunit.c b/lib/string_kunit.c index dd19bd7748aa..4af04643f4c2 100644 --- a/lib/string_kunit.c +++ b/lib/string_kunit.c @@ -326,6 +326,125 @@ static void test_strncasecmp_long_strings(struct kunit *test) strcmp_buffer2, STRCMP_CHANGE_POINT + 1); } +/** + * strscpy_check() - Run a specific test case. + * @test: KUnit test context pointer + * @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() + * @chars: Number of characters from the src string expected to be + * written to the dst buffer. + * @terminator: 1 if there should be a terminating null byte 0 otherwise. + * @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 void strscpy_check(struct kunit *test, 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'; + + KUNIT_ASSERT_TRUE_MSG(test, src != NULL, + "null source string not supported"); + + 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 */ + + KUNIT_ASSERT_LE_MSG(test, count, max_count, + "count (%d) is too big (%d) ... aborting", count, max_count); + KUNIT_EXPECT_LE_MSG(test, expected, max_expected, + "expected (%d) is bigger than can possibly be returned (%d)", + expected, max_expected); + + written = strscpy_pad(buf, src, count); + KUNIT_ASSERT_EQ(test, written, expected); + + if (count && written == -E2BIG) { + KUNIT_ASSERT_EQ_MSG(test, 0, strncmp(buf, src, count - 1), + "buffer state invalid for -E2BIG"); + KUNIT_ASSERT_EQ_MSG(test, buf[count - 1], '\0', + "too big string is not null terminated correctly"); + } + + for (i = 0; i < chars; i++) + KUNIT_ASSERT_EQ_MSG(test, buf[i], src[i], + "buf[i]==%c != src[i]==%c", buf[i], src[i]); + + if (terminator) + KUNIT_ASSERT_EQ_MSG(test, buf[count - 1], '\0', + "string is not null terminated correctly"); + + for (i = 0; i < pad; i++) { + index = chars + terminator + i; + KUNIT_ASSERT_EQ_MSG(test, buf[index], '\0', + "padding missing at index: %d", i); + } + + 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 */ + KUNIT_ASSERT_EQ_MSG(test, buf[index], POISON, + "poison value missing at index: %d", i); + } +} + +static void test_strscpy(struct kunit *test) +{ + char dest[8]; + + /* + * strscpy_check() 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(). + */ + + /* strscpy_check(test, src, count, expected, chars, terminator, pad) */ + strscpy_check(test, "a", 0, -E2BIG, 0, 0, 0); + strscpy_check(test, "", 0, -E2BIG, 0, 0, 0); + + strscpy_check(test, "a", 1, -E2BIG, 0, 1, 0); + strscpy_check(test, "", 1, 0, 0, 1, 0); + + strscpy_check(test, "ab", 2, -E2BIG, 1, 1, 0); + strscpy_check(test, "a", 2, 1, 1, 1, 0); + strscpy_check(test, "", 2, 0, 0, 1, 1); + + strscpy_check(test, "abc", 3, -E2BIG, 2, 1, 0); + strscpy_check(test, "ab", 3, 2, 2, 1, 0); + strscpy_check(test, "a", 3, 1, 1, 1, 1); + strscpy_check(test, "", 3, 0, 0, 1, 2); + + strscpy_check(test, "abcd", 4, -E2BIG, 3, 1, 0); + strscpy_check(test, "abc", 4, 3, 3, 1, 0); + strscpy_check(test, "ab", 4, 2, 2, 1, 1); + strscpy_check(test, "a", 4, 1, 1, 1, 2); + strscpy_check(test, "", 4, 0, 0, 1, 3); + + /* Compile-time-known source strings. */ + KUNIT_EXPECT_EQ(test, strscpy(dest, "", ARRAY_SIZE(dest)), 0); + KUNIT_EXPECT_EQ(test, strscpy(dest, "", 3), 0); + KUNIT_EXPECT_EQ(test, strscpy(dest, "", 1), 0); + KUNIT_EXPECT_EQ(test, strscpy(dest, "", 0), -E2BIG); + KUNIT_EXPECT_EQ(test, strscpy(dest, "Fixed", ARRAY_SIZE(dest)), 5); + KUNIT_EXPECT_EQ(test, strscpy(dest, "Fixed", 3), -E2BIG); + KUNIT_EXPECT_EQ(test, strscpy(dest, "Fixed", 1), -E2BIG); + KUNIT_EXPECT_EQ(test, strscpy(dest, "Fixed", 0), -E2BIG); + KUNIT_EXPECT_EQ(test, strscpy(dest, "This is too long", ARRAY_SIZE(dest)), -E2BIG); +} + static struct kunit_case string_test_cases[] = { KUNIT_CASE(test_memset16), KUNIT_CASE(test_memset32), @@ -341,6 +460,7 @@ static struct kunit_case string_test_cases[] = { KUNIT_CASE(test_strcasecmp_long_strings), KUNIT_CASE(test_strncasecmp), KUNIT_CASE(test_strncasecmp_long_strings), + KUNIT_CASE(test_strscpy), {} }; diff --git a/lib/strscpy_kunit.c b/lib/strscpy_kunit.c deleted file mode 100644 index b6d1d93a8883..000000000000 --- a/lib/strscpy_kunit.c +++ /dev/null @@ -1,143 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0+ -/* - * Kernel module for testing 'strscpy' family of functions. - */ - -#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt - -#include <kunit/test.h> -#include <linux/string.h> - -/** - * strscpy_check() - Run a specific test case. - * @test: KUnit test context pointer - * @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() - * @chars: Number of characters from the src string expected to be - * written to the dst buffer. - * @terminator: 1 if there should be a terminating null byte 0 otherwise. - * @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 void strscpy_check(struct kunit *test, 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'; - - KUNIT_ASSERT_TRUE_MSG(test, src != NULL, - "null source string not supported"); - - 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 */ - - KUNIT_ASSERT_LE_MSG(test, count, max_count, - "count (%d) is too big (%d) ... aborting", count, max_count); - KUNIT_EXPECT_LE_MSG(test, expected, max_expected, - "expected (%d) is bigger than can possibly be returned (%d)", - expected, max_expected); - - written = strscpy_pad(buf, src, count); - KUNIT_ASSERT_EQ(test, written, expected); - - if (count && written == -E2BIG) { - KUNIT_ASSERT_EQ_MSG(test, 0, strncmp(buf, src, count - 1), - "buffer state invalid for -E2BIG"); - KUNIT_ASSERT_EQ_MSG(test, buf[count - 1], '\0', - "too big string is not null terminated correctly"); - } - - for (i = 0; i < chars; i++) - KUNIT_ASSERT_EQ_MSG(test, buf[i], src[i], - "buf[i]==%c != src[i]==%c", buf[i], src[i]); - - if (terminator) - KUNIT_ASSERT_EQ_MSG(test, buf[count - 1], '\0', - "string is not null terminated correctly"); - - for (i = 0; i < pad; i++) { - index = chars + terminator + i; - KUNIT_ASSERT_EQ_MSG(test, buf[index], '\0', - "padding missing at index: %d", i); - } - - 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 */ - KUNIT_ASSERT_EQ_MSG(test, buf[index], POISON, - "poison value missing at index: %d", i); - } -} - -static void test_strscpy(struct kunit *test) -{ - char dest[8]; - - /* - * strscpy_check() 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(). - */ - - /* strscpy_check(test, src, count, expected, chars, terminator, pad) */ - strscpy_check(test, "a", 0, -E2BIG, 0, 0, 0); - strscpy_check(test, "", 0, -E2BIG, 0, 0, 0); - - strscpy_check(test, "a", 1, -E2BIG, 0, 1, 0); - strscpy_check(test, "", 1, 0, 0, 1, 0); - - strscpy_check(test, "ab", 2, -E2BIG, 1, 1, 0); - strscpy_check(test, "a", 2, 1, 1, 1, 0); - strscpy_check(test, "", 2, 0, 0, 1, 1); - - strscpy_check(test, "abc", 3, -E2BIG, 2, 1, 0); - strscpy_check(test, "ab", 3, 2, 2, 1, 0); - strscpy_check(test, "a", 3, 1, 1, 1, 1); - strscpy_check(test, "", 3, 0, 0, 1, 2); - - strscpy_check(test, "abcd", 4, -E2BIG, 3, 1, 0); - strscpy_check(test, "abc", 4, 3, 3, 1, 0); - strscpy_check(test, "ab", 4, 2, 2, 1, 1); - strscpy_check(test, "a", 4, 1, 1, 1, 2); - strscpy_check(test, "", 4, 0, 0, 1, 3); - - /* Compile-time-known source strings. */ - KUNIT_EXPECT_EQ(test, strscpy(dest, "", ARRAY_SIZE(dest)), 0); - KUNIT_EXPECT_EQ(test, strscpy(dest, "", 3), 0); - KUNIT_EXPECT_EQ(test, strscpy(dest, "", 1), 0); - KUNIT_EXPECT_EQ(test, strscpy(dest, "", 0), -E2BIG); - KUNIT_EXPECT_EQ(test, strscpy(dest, "Fixed", ARRAY_SIZE(dest)), 5); - KUNIT_EXPECT_EQ(test, strscpy(dest, "Fixed", 3), -E2BIG); - KUNIT_EXPECT_EQ(test, strscpy(dest, "Fixed", 1), -E2BIG); - KUNIT_EXPECT_EQ(test, strscpy(dest, "Fixed", 0), -E2BIG); - KUNIT_EXPECT_EQ(test, strscpy(dest, "This is too long", ARRAY_SIZE(dest)), -E2BIG); -} - -static struct kunit_case strscpy_test_cases[] = { - KUNIT_CASE(test_strscpy), - {} -}; - -static struct kunit_suite strscpy_test_suite = { - .name = "strscpy", - .test_cases = strscpy_test_cases, -}; - -kunit_test_suite(strscpy_test_suite); - -MODULE_AUTHOR("Tobin C. Harding <tobin@kernel.org>"); -MODULE_LICENSE("GPL");

[2/5] string: Merge strscpy KUnit tests into string_kunit.c

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