From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id F1AF438D009; Wed, 11 Mar 2026 07:10:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.137.202.133 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773213058; cv=none; b=iPTH+vSYZ2/raaFQdTKTBQagmeXRv6suoRvjAl3SbYHQNR8xyCyVZebfWJjlK41fYWcduOU9+nb0I214eXrhK3wMJcO+DTnhRtBNh4KoXeKqmv5uLJyTxOq5p/HSi+c6lj7Ngrf0GpDavZug5rUw+cVTFuCWumhoPeeWS5725mo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773213058; c=relaxed/simple; bh=sGk76CeZpoKPreOT5EWTa4E9C84P+XdmuvM0iQtGhoU=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=dCpTnD+io2hAEBKgytsiI70aF6hB/CGdN2sDy1eFCuInl19RAonNcviBvTreHD24Gx1LEb3CZRA7Va5swNGJ56XiPD36WBgrPvUQJJgZ540nce1u6/tGpOFxnFzikp0uBfOVOqytqaz7NfTUBF1UPR/vUKXo7IKM47MzOQVpugo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=lst.de; spf=none smtp.mailfrom=bombadil.srs.infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=065nLeJ0; arc=none smtp.client-ip=198.137.202.133 Authentication-Results: smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=lst.de Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=bombadil.srs.infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="065nLeJ0" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From:Sender :Reply-To:Content-Type:Content-ID:Content-Description; bh=OxvPKWkX9VjDag7MFdgWgdG+tO7vBe/CAbpQgUGKXQM=; b=065nLeJ0zQCMndvmvoHgyHTI87 pU1WoVrco/zLqAWBX+Or72yeujeZAtEmUmCLbZWVvvZG4m1X9aqEK6YNImN0inkNSNceVr9GRelOd zZ9XPQoBfAJPFYmAGotdO0uASnNGoBRF4Q8mdmEW7DpVbqxCRsp9PB9TIdgy2eIdo9U9pyS161iTD 1GQKOi+Tlw5f5/JCV8iydm2fbcE/fuYA1SLwGx0IM8MVC3pPAOMaYLGOjLv+6oNBHCj8GUnPZUicg BizPJAPh5Z/bZE48qSi9P91/Qx80Ui/5dms5B1zodj4VLUrS8+4OT0XZXeuwu4//PbNj6Doz/8+DL yZ/kIe0A==; Received: from [212.243.42.10] (helo=localhost) by bombadil.infradead.org with esmtpsa (Exim 4.98.2 #2 (Red Hat Linux)) id 1w0DiM-0000000B1m6-3zsl; Wed, 11 Mar 2026 07:10:43 +0000 From: Christoph Hellwig To: Andrew Morton Cc: Richard Henderson , Matt Turner , Magnus Lindholm , Russell King , Catalin Marinas , Will Deacon , Huacai Chen , WANG Xuerui , Madhavan Srinivasan , Michael Ellerman , Nicholas Piggin , "Christophe Leroy (CS GROUP)" , Paul Walmsley , Palmer Dabbelt , Albert Ou , Alexandre Ghiti , Heiko Carstens , Vasily Gorbik , Alexander Gordeev , Christian Borntraeger , Sven Schnelle , "David S. Miller" , Andreas Larsson , Richard Weinberger , Anton Ivanov , Johannes Berg , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , Herbert Xu , Dan Williams , Chris Mason , David Sterba , Arnd Bergmann , Song Liu , Yu Kuai , Li Nan , "Theodore Ts'o" , "Jason A. Donenfeld" , linux-alpha@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, loongarch@lists.linux.dev, linuxppc-dev@lists.ozlabs.org, linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org, sparclinux@vger.kernel.org, linux-um@lists.infradead.org, linux-crypto@vger.kernel.org, linux-btrfs@vger.kernel.org, linux-arch@vger.kernel.org, linux-raid@vger.kernel.org Subject: [PATCH 27/27] xor: add a kunit test case Date: Wed, 11 Mar 2026 08:03:59 +0100 Message-ID: <20260311070416.972667-28-hch@lst.de> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20260311070416.972667-1-hch@lst.de> References: <20260311070416.972667-1-hch@lst.de> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Add a test case for the XOR routines loosely based on the CRC kunit test. Signed-off-by: Christoph Hellwig --- lib/raid/Kconfig | 11 ++ lib/raid/xor/Makefile | 2 +- lib/raid/xor/tests/Makefile | 3 + lib/raid/xor/tests/xor_kunit.c | 180 +++++++++++++++++++++++++++++++++ 4 files changed, 195 insertions(+), 1 deletion(-) create mode 100644 lib/raid/xor/tests/Makefile create mode 100644 lib/raid/xor/tests/xor_kunit.c diff --git a/lib/raid/Kconfig b/lib/raid/Kconfig index 4359971ebd04..97c123806466 100644 --- a/lib/raid/Kconfig +++ b/lib/raid/Kconfig @@ -6,3 +6,14 @@ config XOR_BLOCKS # selected by architectures that provide an optimized XOR implementation config XOR_BLOCKS_ARCH bool + +config XOR_KUNIT_TEST + tristate "KUnit tests for xor_gen" if !KUNIT_ALL_TESTS + depends on KUNIT + default KUNIT_ALL_TESTS + select XOR_BLOCKS + help + Unit tests for the XOR library functions. + + This is intended to help people writing architecture-specific + optimized versions. If unsure, say N. diff --git a/lib/raid/xor/Makefile b/lib/raid/xor/Makefile index 7b748ddda9d4..74185bdc3dd8 100644 --- a/lib/raid/xor/Makefile +++ b/lib/raid/xor/Makefile @@ -30,7 +30,7 @@ xor-$(CONFIG_SPARC64) += sparc/xor-sparc64.o sparc/xor-sparc64-glue.o xor-$(CONFIG_S390) += s390/xor.o xor-$(CONFIG_X86_32) += x86/xor-avx.o x86/xor-sse.o x86/xor-mmx.o xor-$(CONFIG_X86_64) += x86/xor-avx.o x86/xor-sse.o - +obj-y += tests/ CFLAGS_arm/xor-neon.o += $(CC_FLAGS_FPU) CFLAGS_REMOVE_arm/xor-neon.o += $(CC_FLAGS_NO_FPU) diff --git a/lib/raid/xor/tests/Makefile b/lib/raid/xor/tests/Makefile new file mode 100644 index 000000000000..661e8f6ffd1f --- /dev/null +++ b/lib/raid/xor/tests/Makefile @@ -0,0 +1,3 @@ +# SPDX-License-Identifier: GPL-2.0-only + +obj-$(CONFIG_XOR_KUNIT_TEST) += xor_kunit.o diff --git a/lib/raid/xor/tests/xor_kunit.c b/lib/raid/xor/tests/xor_kunit.c new file mode 100644 index 000000000000..23ee415e914c --- /dev/null +++ b/lib/raid/xor/tests/xor_kunit.c @@ -0,0 +1,180 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Unit test the XOR library functions. + * + * Copyright 2024 Google LLC + * Copyright 2026 Christoph Hellwig + * + * Based on the CRC tests by Eric Biggers . + */ +#include +#include +#include +#include +#include + +#define XOR_KUNIT_SEED 42 +#define XOR_KUNIT_MAX_BYTES 16384 +#define XOR_KUNIT_MAX_BUFFERS 64 +#define XOR_KUNIT_NUM_TEST_ITERS 1000 + +static struct rnd_state rng; +static void *test_buffers[XOR_KUNIT_MAX_BUFFERS]; +static void *test_dest; +static void *test_ref; +static size_t test_buflen; + +static u32 rand32(void) +{ + return prandom_u32_state(&rng); +} + +static u32 rand32_below(u32 ceil) +{ + return __limit_random_u32_below(ceil, prandom_u32_state(&rng)); +} + +/* Reference implementation using dumb byte-wise XOR */ +static void xor_ref(void *dest, void **srcs, unsigned int src_cnt, + unsigned int bytes) +{ + unsigned int off, idx; + u8 *d = dest; + + for (off = 0; off < bytes; off++) { + for (idx = 0; idx < src_cnt; idx++) { + u8 *src = srcs[idx]; + + d[off] ^= src[off]; + } + } +} + +/* Generate a random length that is a multiple of 512. */ +static unsigned int generate_random_length(unsigned int max_length) +{ + return (rand32_below(max_length / 512) + 1) * 512; +} + +/* Generate a random alignment that is a multiple of 32. */ +static unsigned int generate_random_alignment(unsigned int max_alignment) +{ + return (rand32_below((max_alignment + 1) / 32)) * 32; +} + +static void xor_generate_random_data(void) +{ + int i; + + prandom_bytes_state(&rng, test_dest, test_buflen); + memcpy(test_ref, test_dest, test_buflen); + for (i = 0; i < XOR_KUNIT_MAX_BUFFERS; i++) + prandom_bytes_state(&rng, test_buffers[i], test_buflen); +} + +/* Test that xor_gen gives the same result as a reference implementation. */ +static void xor_test(struct kunit *test) +{ + void *aligned_buffers[XOR_KUNIT_MAX_BUFFERS]; + size_t i; + + for (i = 0; i < XOR_KUNIT_NUM_TEST_ITERS; i++) { + unsigned int nr_buffers = + rand32_below(XOR_KUNIT_MAX_BUFFERS) + 1; + unsigned int len = generate_random_length(XOR_KUNIT_MAX_BYTES); + unsigned int max_alignment, align = 0; + void *buffers; + + if (rand32() % 8 == 0) + /* Refresh the data occasionally. */ + xor_generate_random_data(); + + /* + * If we're not using the entire buffer size, inject randomize + * alignment into the buffer. + */ + max_alignment = XOR_KUNIT_MAX_BYTES - len; + if (max_alignment) { + int j; + + align = generate_random_alignment(max_alignment); + for (j = 0; j < nr_buffers; j++) + aligned_buffers[j] = test_buffers[j] + + generate_random_alignment(max_alignment); + buffers = aligned_buffers; + } else { + buffers = test_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, test_dest, len, + "Wrong result with buffers=%u, len=%u, align=%s", + nr_buffers, len, str_yes_no(max_alignment)); + } +} + +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, + .suite_exit = xor_suite_exit, +}; +kunit_test_suite(xor_test_suite); + +MODULE_DESCRIPTION("Unit tests and benchmarks for the XOR library functions"); +MODULE_LICENSE("GPL"); -- 2.47.3