From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 5EE7CA32 for ; Mon, 2 Sep 2024 03:45:50 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725248750; cv=none; b=hUns33eVY0XISgB4zOOxCfMPN91LwqhLnqk0xuDE2ifeUKMXI8jC8iRmXNdvwTriFXDexZ0wzgv9s8US+WNHVwO90kqfwvPDWvhtGJRFr9yXcTfbAfhxtjVRZvCOHooz0iqoE9S2S727bsJxeudbX7cV6za3NPEXPZSOPSV1IrY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725248750; c=relaxed/simple; bh=XnbBTGQayClBgrGWeWSl8gy9LgZgSwKX0UE70RgLuKs=; h=Date:To:From:Subject:Message-Id; b=ToxSX4PUcmC32WqSpyIwNCNLaMVrJBXAfW5emkzfNAK9h1PWVQODwZlPp44OLk1lXHgRsA0XFWeFu4Z6QM5DiFb8if3x0IdC6EPm3UTxDFWupsUKHQNKjobhnpzCvyBJI/KUHE7ntWtZZ8Dj9n/CXnS1l5dfo+QA6YbmOoej1vA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=y6MjF47U; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="y6MjF47U" Received: by smtp.kernel.org (Postfix) with ESMTPSA id CD3E5C4CEC2; Mon, 2 Sep 2024 03:45:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1725248749; bh=XnbBTGQayClBgrGWeWSl8gy9LgZgSwKX0UE70RgLuKs=; h=Date:To:From:Subject:From; b=y6MjF47UUsC/Ey34fXFdWgdNPcrC59eGEnISgZihA44SARfdI+Wh0Hs0mtVYyNHAr 5nB/M1Lwf7Ikz9SFRsI3A15W3WlGT/7INLlsHVFpxmAUR3eO3ch7xiGBRkyIJ5+BZS AuD4L0VGysriziWQr4f3OXFcorbeZlh/CsFl4fwY= Date: Sun, 01 Sep 2024 20:45:49 -0700 To: mm-commits@vger.kernel.org,u.kleine-koenig@baylibre.com,biju.das.jz@bp.renesas.com,npitre@baylibre.com,akpm@linux-foundation.org From: Andrew Morton Subject: [merged mm-nonmm-stable] mul_u64_u64_div_u64-basic-sanity-test.patch removed from -mm tree Message-Id: <20240902034549.CD3E5C4CEC2@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The quilt patch titled Subject: mul_u64_u64_div_u64: basic sanity test has been removed from the -mm tree. Its filename was mul_u64_u64_div_u64-basic-sanity-test.patch This patch was dropped because it was merged into the mm-nonmm-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: Nicolas Pitre Subject: mul_u64_u64_div_u64: basic sanity test Date: Sun, 7 Jul 2024 15:05:20 -0400 Verify that edge cases produce proper results, and some more. [npitre@baylibre.com: avoid undefined shift value] Link: https://lkml.kernel.org/r/7rrs9pn1-n266-3013-9q6n-1osp8r8s0rrn@syhkavp.arg Link: https://lkml.kernel.org/r/20240707190648.1982714-3-nico@fluxnic.net Signed-off-by: Nicolas Pitre Reviewed-by: Uwe Kleine-König Cc: Biju Das Signed-off-by: Andrew Morton --- lib/Kconfig.debug | 10 ++ lib/math/Makefile | 1 lib/math/div64.c | 9 ++ lib/math/test_mul_u64_u64_div_u64.c | 99 ++++++++++++++++++++++++++ 4 files changed, 118 insertions(+), 1 deletion(-) --- a/lib/Kconfig.debug~mul_u64_u64_div_u64-basic-sanity-test +++ a/lib/Kconfig.debug @@ -2280,6 +2280,16 @@ config TEST_DIV64 If unsure, say N. +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 --- a/lib/math/div64.c~mul_u64_u64_div_u64-basic-sanity-test +++ a/lib/math/div64.c @@ -212,11 +212,18 @@ u64 mul_u64_u64_div_u64(u64 a, u64 b, u6 #endif + /* make sure c is not zero, trigger exception otherwise */ +#pragma GCC diagnostic push +#pragma GCC diagnostic ignored "-Wdiv-by-zero" + if (unlikely(c == 0)) + return 1/0; +#pragma GCC diagnostic pop + int shift = __builtin_ctzll(c); /* try reducing the fraction in case the dividend becomes <= 64 bits */ if ((n_hi >> shift) == 0) { - u64 n = (n_lo >> shift) | (n_hi << (64 - shift)); + u64 n = shift ? (n_lo >> shift) | (n_hi << (64 - shift)) : n_lo; return div64_u64(n, c >> shift); /* --- a/lib/math/Makefile~mul_u64_u64_div_u64-basic-sanity-test +++ a/lib/math/Makefile @@ -6,4 +6,5 @@ obj-$(CONFIG_PRIME_NUMBERS) += prime_num obj-$(CONFIG_RATIONAL) += rational.o obj-$(CONFIG_TEST_DIV64) += test_div64.o +obj-$(CONFIG_TEST_MULDIV64) += test_mul_u64_u64_div_u64.o obj-$(CONFIG_RATIONAL_KUNIT_TEST) += rational-test.o diff --git a/lib/math/test_mul_u64_u64_div_u64.c a/lib/math/test_mul_u64_u64_div_u64.c new file mode 100664 --- /dev/null +++ a/lib/math/test_mul_u64_u64_div_u64.c @@ -0,0 +1,99 @@ +// 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[] = { +/* this contains many edge values followed by a couple random values */ +{ 0xb, 0x7, 0x3, 0x19 }, +{ 0xffff0000, 0xffff0000, 0xf, 0x1110eeef00000000 }, +{ 0xffffffff, 0xffffffff, 0x1, 0xfffffffe00000001 }, +{ 0xffffffff, 0xffffffff, 0x2, 0x7fffffff00000000 }, +{ 0x1ffffffff, 0xffffffff, 0x2, 0xfffffffe80000000 }, +{ 0x1ffffffff, 0xffffffff, 0x3, 0xaaaaaaa9aaaaaaab }, +{ 0x1ffffffff, 0x1ffffffff, 0x4, 0xffffffff00000000 }, +{ 0xffff000000000000, 0xffff000000000000, 0xffff000000000001, 0xfffeffffffffffff }, +{ 0x3333333333333333, 0x3333333333333333, 0x5555555555555555, 0x1eb851eb851eb851 }, +{ 0x7fffffffffffffff, 0x2, 0x3, 0x5555555555555554 }, +{ 0xffffffffffffffff, 0x2, 0x8000000000000000, 0x3 }, +{ 0xffffffffffffffff, 0x2, 0xc000000000000000, 0x2 }, +{ 0xffffffffffffffff, 0x4000000000000004, 0x8000000000000000, 0x8000000000000007 }, +{ 0xffffffffffffffff, 0x4000000000000001, 0x8000000000000000, 0x8000000000000001 }, +{ 0xffffffffffffffff, 0x8000000000000001, 0xffffffffffffffff, 0x8000000000000001 }, +{ 0xfffffffffffffffe, 0x8000000000000001, 0xffffffffffffffff, 0x8000000000000000 }, +{ 0xffffffffffffffff, 0x8000000000000001, 0xfffffffffffffffe, 0x8000000000000001 }, +{ 0xffffffffffffffff, 0x8000000000000001, 0xfffffffffffffffd, 0x8000000000000002 }, +{ 0x7fffffffffffffff, 0xffffffffffffffff, 0xc000000000000000, 0xaaaaaaaaaaaaaaa8 }, +{ 0xffffffffffffffff, 0x7fffffffffffffff, 0xa000000000000000, 0xccccccccccccccca }, +{ 0xffffffffffffffff, 0x7fffffffffffffff, 0x9000000000000000, 0xe38e38e38e38e38b }, +{ 0x7fffffffffffffff, 0x7fffffffffffffff, 0x5000000000000000, 0xccccccccccccccc9 }, +{ 0xffffffffffffffff, 0xfffffffffffffffe, 0xffffffffffffffff, 0xfffffffffffffffe }, +{ 0xe6102d256d7ea3ae, 0x70a77d0be4c31201, 0xd63ec35ab3220357, 0x78f8bf8cc86c6e18 }, +{ 0xf53bae05cb86c6e1, 0x3847b32d2f8d32e0, 0xcfd4f55a647f403c, 0x42687f79d8998d35 }, +{ 0x9951c5498f941092, 0x1f8c8bfdf287a251, 0xa3c8dc5f81ea3fe2, 0x1d887cb25900091f }, +{ 0x374fee9daa1bb2bb, 0x0d0bfbff7b8ae3ef, 0xc169337bd42d5179, 0x03bb2dbaffcbb961 }, +{ 0xeac0d03ac10eeaf0, 0x89be05dfa162ed9b, 0x92bb1679a41f0e4b, 0xdc5f5cc9e270d216 }, +}; + +/* + * The above table can be verified with the following shell script: + * + * #!/bin/sh + * sed -ne 's/^{ \+\(.*\), \+\(.*\), \+\(.*\), \+\(.*\) },$/\1 \2 \3 \4/p' \ + * lib/math/test_mul_u64_u64_div_u64.c | + * while read a b c r; do + * expected=$( printf "obase=16; ibase=16; %X * %X / %X\n" $a $b $c | bc ) + * given=$( printf "%X\n" $r ) + * if [ "$expected" = "$given" ]; then + * echo "$a * $b / $c = $r OK" + * else + * echo "$a * $b / $c = $r is wrong" >&2 + * echo "should be equivalent to 0x$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 = 0; i < ARRAY_SIZE(test_values); i++) { + u64 a = test_values[i].a; + u64 b = test_values[i].b; + u64 c = test_values[i].c; + u64 expected_result = test_values[i].result; + u64 result = mul_u64_u64_div_u64(a, b, c); + + if (result != 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"); _ Patches currently in -mm which might be from npitre@baylibre.com are