lib/raid/xor/tests/xor_kunit.c

Source file repositories/reference/linux-study-clean/lib/raid/xor/tests/xor_kunit.c

File Facts

System
Linux kernel
Corpus path
lib/raid/xor/tests/xor_kunit.c
Extension
.c
Size
4738 bytes
Lines
188
Domain
Kernel Services
Bucket
lib
Inferred role
Kernel Services: implementation source
Status
source implementation candidate

Why This File Exists

Shared kernel service surface used by multiple subsystems, including helpers, cryptography, virtualization support, and async I/O infrastructure.

Dependency Surface

Detected Declarations

Annotated Snippet

if (max_alignment == 0) {
			buffers = test_buffers;
		} else if (rand32() % 2 == 0) {
			/* Use random alignments mod 64 */
			int j;

			for (j = 0; j < nr_buffers; j++)
				aligned_buffers[j] = test_buffers[j] +
					random_alignment(max_alignment);
			buffers = aligned_buffers;
			align = random_alignment(max_alignment);
		} else {
			/* Go up to the guard page, to catch buffer overreads */
			int j;

			align = test_buflen - len;
			for (j = 0; j < nr_buffers; j++)
				aligned_buffers[j] = test_buffers[j] + align;
			buffers = aligned_buffers;
		}

		/*
		 * Compute the XOR, and verify that it equals the XOR computed
		 * by a simple byte-at-a-time reference implementation.
		 */
		xor_ref(test_ref + align, buffers, nr_buffers, len);
		xor_gen(test_dest + align, buffers, nr_buffers, len);
		KUNIT_EXPECT_MEMEQ_MSG(test, test_ref + align,
				test_dest + align, len,
				"Wrong result with buffers=%u, len=%u, unaligned=%s, at_end=%s",
				nr_buffers, len,
				str_yes_no(max_alignment),
				str_yes_no(align + len == test_buflen));
	}
}

static struct kunit_case xor_test_cases[] = {
	KUNIT_CASE(xor_test),
	{},
};

static int xor_suite_init(struct kunit_suite *suite)
{
	int i;

	/*
	 * Allocate the test buffer using vmalloc() with a page-aligned length
	 * so that it is immediately followed by a guard page.  This allows
	 * buffer overreads to be detected, even in assembly code.
	 */
	test_buflen = round_up(XOR_KUNIT_MAX_BYTES, PAGE_SIZE);
	test_ref = vmalloc(test_buflen);
	if (!test_ref)
		return -ENOMEM;
	test_dest = vmalloc(test_buflen);
	if (!test_dest)
		goto out_free_ref;
	for (i = 0; i < XOR_KUNIT_MAX_BUFFERS; i++) {
		test_buffers[i] = vmalloc(test_buflen);
		if (!test_buffers[i])
			goto out_free_buffers;
	}

	prandom_seed_state(&rng, XOR_KUNIT_SEED);
	xor_generate_random_data();
	return 0;

out_free_buffers:
	while (--i >= 0)
		vfree(test_buffers[i]);
	vfree(test_dest);
out_free_ref:
	vfree(test_ref);
	return -ENOMEM;
}

static void xor_suite_exit(struct kunit_suite *suite)
{
	int i;

	vfree(test_ref);
	vfree(test_dest);
	for (i = 0; i < XOR_KUNIT_MAX_BUFFERS; i++)
		vfree(test_buffers[i]);
}

static struct kunit_suite xor_test_suite = {
	.name		= "xor",
	.test_cases	= xor_test_cases,
	.suite_init	= xor_suite_init,

Annotation

Implementation Notes