From nobody Fri Dec 19 12:34:02 2025 Received: from pb-smtp2.pobox.com (pb-smtp2.pobox.com [64.147.108.71]) (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 10B262E85E for ; Sun, 7 Jul 2024 19:07:02 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=64.147.108.71 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720379226; cv=none; b=TXPRGQQ3k4hQIOZzJYnpLAcjP4MBWOawdkrmSJm3goXJiA4OaB93HXodv37iDZ8RF/CQRvIxUV0zsV5GhvkJ0ifkardScPi+k4TKGI+7rVT753llsUPYiPVQ16kvXlxk4BbJ3WN5rwTJRN08gQxkmaZZFYyHhR3WpTdAP/fgCD4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720379226; c=relaxed/simple; bh=y5E7OBngPfDkY3XfbPU8rxbUJdyujoY6VWRWe5uTCEA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=eSfAf4oqBwdH1AUJIF0V8ikSoOgqEwdHQcrYJYKE/x/xRHkRnIiwQEpbB3/H9UIFXXeyro7t4kHMcc7oMW20UEKxsryd0zPdQe/5irbTEQi5kGbNLnjSAzyL8dWc+6VakgjPYecuPhofXbR+OPq7yUl4ytBQWHMrp5NM4Hi4S8o= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=fluxnic.net; spf=pass smtp.mailfrom=fluxnic.net; dkim=pass (1024-bit key) header.d=pobox.com header.i=@pobox.com header.b=BY8BipP5; dkim=fail (1024-bit key) header.d=fluxnic.net header.i=@fluxnic.net header.b=Y3ipbB4V reason="signature verification failed"; arc=none smtp.client-ip=64.147.108.71 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=fluxnic.net Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=fluxnic.net Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=pobox.com header.i=@pobox.com header.b="BY8BipP5"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=fluxnic.net header.i=@fluxnic.net header.b="Y3ipbB4V" Received: from pb-smtp2.pobox.com (unknown [127.0.0.1]) by pb-smtp2.pobox.com (Postfix) with ESMTP id BF8351A0E3; Sun, 7 Jul 2024 15:06:55 -0400 (EDT) (envelope-from nico@fluxnic.net) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed; d=pobox.com; h=from:to:cc :subject:date:message-id:in-reply-to:references:mime-version :content-transfer-encoding; s=sasl; bh=y5E7OBngPfDkY3XfbPU8rxbUJ dyujoY6VWRWe5uTCEA=; b=BY8BipP5TRTQ70GdWG3xVEFfccYi+/8IGOV9Tm4ap 1KcD6fL9h2NuxdGb17eaijUVh9Lf/LO7DMUlpMrGDynD+elKcEW/cpN2bBvJkK7Y RFX51n4WBFA7S1Q5k7KR6DudCPKoUp9gn+vvlFbcMz+lP/3GPnntTVywpfdUCEDT wc= Received: from pb-smtp2.nyi.icgroup.com (unknown [127.0.0.1]) by pb-smtp2.pobox.com (Postfix) with ESMTP id B58091A0E2; Sun, 7 Jul 2024 15:06:55 -0400 (EDT) (envelope-from nico@fluxnic.net) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed; d=fluxnic.net; h=from:to:cc:subject:date:message-id:in-reply-to:references:mime-version:content-transfer-encoding; s=2016-12.pbsmtp; bh=tszzF1rafpYU6uyroSx0MMv1pkglcDvKtgmQW7oeGQ0=; b=Y3ipbB4V/o9XVKgMm7MFIIMn0MwuzClHi8jn8mBQhPvNJkQI6pxnruhuYND+PMPv95dck0/vZIym167cupxNRRRIBJktcLvNfSusNt/qIoAiScyfYcqfuGbjymI/VqL0qDW+iKdKV+e9wXjkDvRARnfm7qs8JZHczVD7oT0IV58= Received: from yoda.fluxnic.net (unknown [184.162.15.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by pb-smtp2.pobox.com (Postfix) with ESMTPSA id 072851A0E1; Sun, 7 Jul 2024 15:06:55 -0400 (EDT) (envelope-from nico@fluxnic.net) Received: from xanadu.lan (OpenWrt.lan [192.168.1.1]) by yoda.fluxnic.net (Postfix) with ESMTPSA id E7006D3B4E3; Sun, 7 Jul 2024 15:06:53 -0400 (EDT) From: Nicolas Pitre To: Andrew Morton , =?UTF-8?q?Uwe=20Kleine-K=C3=B6nig?= Cc: Nicolas Pitre , linux-kernel@vger.kernel.org Subject: [PATCH v3 2/2] mul_u64_u64_div_u64: basic sanity test Date: Sun, 7 Jul 2024 15:05:20 -0400 Message-ID: <20240707190648.1982714-3-nico@fluxnic.net> X-Mailer: git-send-email 2.45.2 In-Reply-To: <20240707190648.1982714-1-nico@fluxnic.net> References: <20240707190648.1982714-1-nico@fluxnic.net> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Pobox-Relay-ID: 136C90EC-3C94-11EF-8CC2-965B910A682E-78420484!pb-smtp2.pobox.com Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: Nicolas Pitre Verify that edge cases produce proper results, and some more. Signed-off-by: Nicolas Pitre --- lib/Kconfig.debug | 10 +++ lib/math/Makefile | 1 + lib/math/test_mul_u64_u64_div_u64.c | 98 +++++++++++++++++++++++++++++ 3 files changed, 109 insertions(+) create mode 100644 lib/math/test_mul_u64_u64_div_u64.c diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 59b6765d86..cc570c6f34 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -2278,6 +2278,16 @@ config TEST_DIV64 =20 If unsure, say N. =20 +config TEST_MULDIV64 + tristate "mul_u64_u64_div_u64() test" + depends on DEBUG_KERNEL || m + help + Enable this to turn on 'mul_u64_u64_div_u64()' function test. + This test is executed only once during system boot (so affects + only boot time), or at module load time. + + If unsure, say N. + config TEST_IOV_ITER tristate "Test iov_iter operation" if !KUNIT_ALL_TESTS depends on KUNIT diff --git a/lib/math/Makefile b/lib/math/Makefile index 91fcdb0c9e..981a26127e 100644 --- a/lib/math/Makefile +++ b/lib/math/Makefile @@ -6,4 +6,5 @@ obj-$(CONFIG_PRIME_NUMBERS) +=3D prime_numbers.o obj-$(CONFIG_RATIONAL) +=3D rational.o =20 obj-$(CONFIG_TEST_DIV64) +=3D test_div64.o +obj-$(CONFIG_TEST_MULDIV64) +=3D test_mul_u64_u64_div_u64.o obj-$(CONFIG_RATIONAL_KUNIT_TEST) +=3D rational-test.o diff --git a/lib/math/test_mul_u64_u64_div_u64.c b/lib/math/test_mul_u64_u6= 4_div_u64.c new file mode 100644 index 0000000000..a25640d349 --- /dev/null +++ b/lib/math/test_mul_u64_u64_div_u64.c @@ -0,0 +1,98 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2024 BayLibre SAS + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include +#include +#include +#include + +typedef struct { u64 a; u64 b; u64 c; u64 result; } test_params; + +static test_params test_values[] =3D { +/* this contains many edge values followed by a couple random values */ +{ 0xb, 0x7, 0x3, = 0x19 }, +{ 0xffff0000, 0xffff0000, 0xf, 0x1110eeef00= 000000 }, +{ 0xffffffff, 0xffffffff, 0x1, 0xfffffffe00= 000001 }, +{ 0xffffffff, 0xffffffff, 0x2, 0x7fffffff00= 000000 }, +{ 0x1ffffffff, 0xffffffff, 0x2, 0xfffffffe80= 000000 }, +{ 0x1ffffffff, 0xffffffff, 0x3, 0xaaaaaaa9aa= aaaaab }, +{ 0x1ffffffff, 0x1ffffffff, 0x4, 0xffffffff00= 000000 }, +{ 0xffff000000000000, 0xffff000000000000, 0xffff000000000001, 0xfffeffffff= ffffff }, +{ 0x3333333333333333, 0x3333333333333333, 0x5555555555555555, 0x1eb851eb85= 1eb851 }, +{ 0xffffffffffffffff, 0x2, 0x8000000000000000, = 0x3 }, +{ 0xffffffffffffffff, 0x2, 0xc000000000000000, = 0x2 }, +{ 0xffffffffffffffff, 0x4000000000000004, 0x8000000000000000, 0x8000000000= 000007 }, +{ 0xffffffffffffffff, 0x4000000000000001, 0x8000000000000000, 0x8000000000= 000001 }, +{ 0xffffffffffffffff, 0x8000000000000001, 0xffffffffffffffff, 0x8000000000= 000001 }, +{ 0xfffffffffffffffe, 0x8000000000000001, 0xffffffffffffffff, 0x8000000000= 000000 }, +{ 0xffffffffffffffff, 0x8000000000000001, 0xfffffffffffffffe, 0x8000000000= 000001 }, +{ 0xffffffffffffffff, 0x8000000000000001, 0xfffffffffffffffd, 0x8000000000= 000002 }, +{ 0x7fffffffffffffff, 0xffffffffffffffff, 0xc000000000000000, 0xaaaaaaaaaa= aaaaa8 }, +{ 0xffffffffffffffff, 0x7fffffffffffffff, 0xa000000000000000, 0xcccccccccc= ccccca }, +{ 0xffffffffffffffff, 0x7fffffffffffffff, 0x9000000000000000, 0xe38e38e38e= 38e38b }, +{ 0x7fffffffffffffff, 0x7fffffffffffffff, 0x5000000000000000, 0xcccccccccc= ccccc9 }, +{ 0xffffffffffffffff, 0xfffffffffffffffe, 0xffffffffffffffff, 0xffffffffff= fffffe }, +{ 0xe6102d256d7ea3ae, 0x70a77d0be4c31201, 0xd63ec35ab3220357, 0x78f8bf8cc8= 6c6e18 }, +{ 0xf53bae05cb86c6e1, 0x3847b32d2f8d32e0, 0xcfd4f55a647f403c, 0x42687f79d8= 998d35 }, +{ 0x9951c5498f941092, 0x1f8c8bfdf287a251, 0xa3c8dc5f81ea3fe2, 0x1d887cb259= 00091f }, +{ 0x374fee9daa1bb2bb, 0x0d0bfbff7b8ae3ef, 0xc169337bd42d5179, 0x03bb2dbaff= cbb961 }, +{ 0xeac0d03ac10eeaf0, 0x89be05dfa162ed9b, 0x92bb1679a41f0e4b, 0xdc5f5cc9e2= 70d216 }, +}; + +/* + * The above table can be verified with the following shell script: + * + * #!/bin/sh + * sed -ne 's/^{ \+\(.*\), \+\(.*\), \+\(.*\), \+\(.*\) },$/\1 \2 \3 \4/p'= \ + * lib/math/test_mul_u64_u64_div_u64.c | + * while read a b c r; do + * expected=3D$( printf "obase=3D16; ibase=3D16; %X * %X / %X\n" $a $b $= c | bc ) + * given=3D$( printf "%X\n" $r ) + * if [ "$expected" =3D "$given" ]; then + * echo "$a * $b / $c =3D $r OK" + * else + * echo "$a * $b / $c =3D $r is wrong" >&2 + * echo "should be equivalent to 0x$expected" >&2 + * exit 1 + * fi + * done + */ + +static int __init test_init(void) +{ + int i; + + pr_info("Starting mul_u64_u64_div_u64() test\n"); + + for (i =3D 0; i < ARRAY_SIZE(test_values); i++) { + u64 a =3D test_values[i].a; + u64 b =3D test_values[i].b; + u64 c =3D test_values[i].c; + u64 expected_result =3D test_values[i].result; + u64 result =3D mul_u64_u64_div_u64(a, b, c); + + if (result !=3D expected_result) { + pr_err("ERROR: 0x%016llx * 0x%016llx / 0x%016llx\n", a, b, c); + pr_err("ERROR: expected result: %016llx\n", expected_result); + pr_err("ERROR: obtained result: %016llx\n", result); + } + } + + pr_info("Completed mul_u64_u64_div_u64() test\n"); + return 0; +} + +static void __exit test_exit(void) +{ +} + +module_init(test_init); +module_exit(test_exit); + +MODULE_AUTHOR("Nicolas Pitre"); +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("mul_u64_u64_div_u64() test module"); --=20 2.45.2