Commit Graph

8 Commits

Author SHA1 Message Date
Jeff Johnson
6a4805b2f5 string: kunit: add missing MODULE_DESCRIPTION() macros
make allmodconfig && make W=1 C=1 reports:
WARNING: modpost: missing MODULE_DESCRIPTION() in lib/string_kunit.o
WARNING: modpost: missing MODULE_DESCRIPTION() in lib/string_helpers_kunit.o

Add the missing invocation of the MODULE_DESCRIPTION() macro.

Signed-off-by: Jeff Johnson <quic_jjohnson@quicinc.com>
Link: https://lore.kernel.org/r/20240531-md-lib-string-v1-1-2738cf057d94@quicinc.com
Signed-off-by: Kees Cook <kees@kernel.org>
2024-06-28 08:54:55 -07:00
Kees Cook
c01c41e500 string_kunit: Move strtomem KUnit test to string_kunit.c
It is more logical to have the strtomem() test in string_kunit.c instead
of the memcpy() suite. Move it to live with memtostr().

Signed-off-by: Kees Cook <keescook@chromium.org>
2024-04-24 09:02:34 -07:00
Kees Cook
0efc5990bc string.h: Introduce memtostr() and memtostr_pad()
Another ambiguous use of strncpy() is to copy from strings that may not
be NUL-terminated. These cases depend on having the destination buffer
be explicitly larger than the source buffer's maximum size, having
the size of the copy exactly match the source buffer's maximum size,
and for the destination buffer to get explicitly NUL terminated.

This usually happens when parsing protocols or hardware character arrays
that are not guaranteed to be NUL-terminated. The code pattern is
effectively this:

	char dest[sizeof(src) + 1];

	strncpy(dest, src, sizeof(src));
	dest[sizeof(dest) - 1] = '\0';

In practice it usually looks like:

struct from_hardware {
	...
	char name[HW_NAME_SIZE] __nonstring;
	...
};

	struct from_hardware *p = ...;
	char name[HW_NAME_SIZE + 1];

	strncpy(name, p->name, HW_NAME_SIZE);
	name[NW_NAME_SIZE] = '\0';

This cannot be replaced with:

	strscpy(name, p->name, sizeof(name));

because p->name is smaller and not NUL-terminated, so FORTIFY will
trigger when strnlen(p->name, sizeof(name)) is used. And it cannot be
replaced with:

	strscpy(name, p->name, sizeof(p->name));

because then "name" may contain a 1 character early truncation of
p->name.

Provide an unambiguous interface for converting a maybe not-NUL-terminated
string to a NUL-terminated string, with compile-time buffer size checking
so that it can never fail at runtime: memtostr() and memtostr_pad(). Also
add KUnit tests for both.

Link: https://lore.kernel.org/r/20240410023155.2100422-1-keescook@chromium.org
Signed-off-by: Kees Cook <keescook@chromium.org>
2024-04-24 08:57:09 -07:00
Kees Cook
dde915c5cb string: Convert KUnit test names to standard convention
The KUnit convention for test names is AREA_test_WHAT. Adjust the string
test names to follow this pattern.

Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Tested-by: Ivan Orlov <ivan.orlov0322@gmail.com>
Link: https://lore.kernel.org/r/20240419140155.3028912-5-keescook@chromium.org
Signed-off-by: Kees Cook <keescook@chromium.org>
2024-04-19 13:12:02 -07:00
Kees Cook
bd678f7d9b string: Merge strcat KUnit tests into string_kunit.c
Move the strcat() tests into string_kunit.c. Remove the separate
Kconfig and Makefile rule.

Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Tested-by: Ivan Orlov <ivan.orlov0322@gmail.com>
Link: https://lore.kernel.org/r/20240419140155.3028912-4-keescook@chromium.org
Signed-off-by: Kees Cook <keescook@chromium.org>
2024-04-19 13:12:01 -07:00
Kees Cook
bb8d9b742a string: Merge strscpy KUnit tests into string_kunit.c
Move the strscpy() tests into string_kunit.c. Remove the separate
Kconfig and Makefile rule.

Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Tested-by: Ivan Orlov <ivan.orlov0322@gmail.com>
Link: https://lore.kernel.org/r/20240419140155.3028912-2-keescook@chromium.org
Signed-off-by: Kees Cook <keescook@chromium.org>
2024-04-19 13:11:57 -07:00
Ivan Orlov
9259a47216 string_kunit: Add test cases for str*cmp functions
Currently, str*cmp functions (strcmp, strncmp, strcasecmp and
strncasecmp) are not covered with tests. Extend the `string_kunit.c`
test by adding the test cases for them.

This patch adds 8 more test cases:

1) strcmp test
2) strcmp test on long strings (2048 chars)
3) strncmp test
4) strncmp test on long strings (2048 chars)
5) strcasecmp test
6) strcasecmp test on long strings
7) strncasecmp test
8) strncasecmp test on long strings

These test cases aim at covering as many edge cases as possible,
including the tests on empty strings, situations when the different
symbol is placed at the end of one of the strings, etc.

Signed-off-by: Ivan Orlov <ivan.orlov0322@gmail.com>
Reviewed-by: Andy Shevchenko <andy@kernel.org>
Link: https://lore.kernel.org/r/20240417233033.717596-1-ivan.orlov0322@gmail.com
Signed-off-by: Kees Cook <keescook@chromium.org>
2024-04-18 10:14:19 -07:00
Kees Cook
29d8568849 string: Convert selftest to KUnit
Convert test_string.c to KUnit so it can be easily run with everything
else.

Additional text context is retained for failure reporting. For example,
when forcing a bad match, we can see the loop counters reported for the
memset() tests:

[09:21:52]     # test_memset64: ASSERTION FAILED at lib/string_kunit.c:93
[09:21:52]     Expected v == 0xa2a1a1a1a1a1a1a1ULL, but
[09:21:52]         v == -6799976246779207263 (0xa1a1a1a1a1a1a1a1)
[09:21:52]         0xa2a1a1a1a1a1a1a1ULL == -6727918652741279327 (0xa2a1a1a1a1a1a1a1)
[09:21:52] i:0 j:0 k:0
[09:21:52] [FAILED] test_memset64

Currently passes without problems:

$ ./tools/testing/kunit/kunit.py run string
...
[09:37:40] Starting KUnit Kernel (1/1)...
[09:37:40] ============================================================
[09:37:40] =================== string (6 subtests) ====================
[09:37:40] [PASSED] test_memset16
[09:37:40] [PASSED] test_memset32
[09:37:40] [PASSED] test_memset64
[09:37:40] [PASSED] test_strchr
[09:37:40] [PASSED] test_strnchr
[09:37:40] [PASSED] test_strspn
[09:37:40] ===================== [PASSED] string ======================
[09:37:40] ============================================================
[09:37:40] Testing complete. Ran 6 tests: passed: 6
[09:37:40] Elapsed time: 6.730s total, 0.001s configuring, 6.562s building, 0.131s running

Link: https://lore.kernel.org/r/20240301202732.2688342-1-keescook@chromium.org
Signed-off-by: Kees Cook <keescook@chromium.org>
2024-03-05 01:55:28 -08:00