From nobody Sun Feb 8 17:43:25 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 532A8EB64DC for ; Tue, 11 Jul 2023 14:34:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233167AbjGKOeW (ORCPT ); Tue, 11 Jul 2023 10:34:22 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43506 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233560AbjGKOeL (ORCPT ); Tue, 11 Jul 2023 10:34:11 -0400 Received: from mail-ed1-x549.google.com (mail-ed1-x549.google.com [IPv6:2a00:1450:4864:20::549]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id ACB4B10E7 for ; Tue, 11 Jul 2023 07:34:01 -0700 (PDT) Received: by mail-ed1-x549.google.com with SMTP id 4fb4d7f45d1cf-51836731bfbso3126702a12.3 for ; Tue, 11 Jul 2023 07:34:01 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20221208; t=1689086040; x=1691678040; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=6gUN4hkfqv1qmZBEmgq0ujJ8OMQMxN9ipJDwtCO0z/w=; b=ri7p9vV6wORs1YMnbVsQYCOsM+xoAZB3cF7gqHY0/TcF5npm8tbHpwX2wyWrRS5eOe cxnQFf/BJF4hXOinqViiCsfFKctuu14j0AismWmP79AnONqF62avtF9X2j2Kgx0KfPHd y2y23Qez4j3uD5gEqac0wu0yUTUNV2Vdrz6xX3ZoyX3lvrerkh7+JcGftmryZe+yxwHo jzKgxcF3xFaPgSC6kO7SKyBS5TiHWaPfb9+CunLBx5v1eVNxAyiAVBxi9tdKU2HSoUsc SdB3Ld1Ryvz/KmGIMbXAZ7M0qqYwv7XKFe+NCZaKr4WEG80RFBaN264nA/xvtXiyugeL HDJg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1689086040; x=1691678040; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=6gUN4hkfqv1qmZBEmgq0ujJ8OMQMxN9ipJDwtCO0z/w=; b=iGkQ77KsagASh3jIeNACiWuaak6U20qBNCIEwrKJp8LizrKkOSqZNt0W45iw4YYRTs JxxKEI/91N7AM4ji05qGSs8cCS4utyqcDOVoO83bnba/bto/ibRvrWEkF8RjxH3Pmakv s8chgkmBaxf2V7qi5QYhWTb+noHr4O9KLCYXTXUgZf4PrMh9E3aPZwyxZtSkSMv46vop m0MgLs0wd3YwxWs20XVCAJnkL19FGGrOJGLHXYNifFhwlbLghQcK4orYDdIB4UozSA24 N3W4DiIku2UzfFbWXKymtAJvXnEOJv8PdF8O5rW/rcCrecH0yik2uto+SCoZno5tsEN4 Wvlg== X-Gm-Message-State: ABy/qLY1jc57xZKfobbKEYUIjAJ1GLBqIJXvRRUg0UVN0pxFH8WAp7Rb UDPVJ8eF7K+oZT4YvCb+WfAcm7cat/Q= X-Google-Smtp-Source: APBJJlEl5eZizLWdD0LG9EWoFPqQYZtN3FlxalPV8qr6GFGRoc0oBdk244stQXXlvHP/KKaa3FZUvVbs4+c= X-Received: from glider.muc.corp.google.com ([2a00:79e0:9c:201:564d:3aaa:6b5f:4419]) (user=glider job=sendgmr) by 2002:a50:c252:0:b0:51e:1c91:3c7e with SMTP id t18-20020a50c252000000b0051e1c913c7emr82313edf.6.1689086040235; Tue, 11 Jul 2023 07:34:00 -0700 (PDT) Date: Tue, 11 Jul 2023 16:33:32 +0200 In-Reply-To: <20230711143337.3086664-1-glider@google.com> Mime-Version: 1.0 References: <20230711143337.3086664-1-glider@google.com> X-Mailer: git-send-email 2.41.0.255.g8b1d071c50-goog Message-ID: <20230711143337.3086664-6-glider@google.com> Subject: [PATCH 3/5] arm64: mte: add a test for MTE tags compression From: Alexander Potapenko To: glider@google.com, catalin.marinas@arm.com, will@kernel.org, pcc@google.com, andreyknvl@gmail.com Cc: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, eugenis@google.com, yury.norov@gmail.com Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Ensure that tag sequences containing alternating values are compressed to buffers of expected size and correctly decompressed afterwards. Signed-off-by: Alexander Potapenko --- arch/arm64/Kconfig | 10 ++ arch/arm64/mm/Makefile | 1 + arch/arm64/mm/test_mtecomp.c | 175 +++++++++++++++++++++++++++++++++++ 3 files changed, 186 insertions(+) create mode 100644 arch/arm64/mm/test_mtecomp.c diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index b25b584a0a9cb..31fc50208b383 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -2075,6 +2075,16 @@ config ARM64_MTE_COMP 128-byte tag buffers corresponding to 4K pages can be compressed using the EA0 algorithm to save heap memory. =20 +config ARM64_MTE_COMP_KUNIT_TEST + tristate "Test tag compression for ARM64 MTE" if !KUNIT_ALL_TESTS + default KUNIT_ALL_TESTS + depends on KUNIT && ARM64_MTE_COMP + help + Test EA0 compression algorithm enabled by CONFIG_ARM64_MTE_COMP. + + Ensure that tag sequences containing alternating values are compressed + to buffers of expected size and correctly decompressed afterwards. + config ARM64_SVE bool "ARM Scalable Vector Extension support" default y diff --git a/arch/arm64/mm/Makefile b/arch/arm64/mm/Makefile index 46778f6dd83c2..170dc62b010b9 100644 --- a/arch/arm64/mm/Makefile +++ b/arch/arm64/mm/Makefile @@ -11,6 +11,7 @@ obj-$(CONFIG_TRANS_TABLE) +=3D trans_pgd-asm.o obj-$(CONFIG_DEBUG_VIRTUAL) +=3D physaddr.o obj-$(CONFIG_ARM64_MTE) +=3D mteswap.o obj-$(CONFIG_ARM64_MTE_COMP) +=3D mtecomp.o +obj-$(CONFIG_ARM64_MTE_COMP_KUNIT_TEST) +=3D test_mtecomp.o KASAN_SANITIZE_physaddr.o +=3D n =20 obj-$(CONFIG_KASAN) +=3D kasan_init.o diff --git a/arch/arm64/mm/test_mtecomp.c b/arch/arm64/mm/test_mtecomp.c new file mode 100644 index 0000000000000..67bef6f28dac4 --- /dev/null +++ b/arch/arm64/mm/test_mtecomp.c @@ -0,0 +1,175 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Test cases for EA0, the compression algorithm for MTE tags. + */ + +#include +#include +#include +#include + +/* + * Test that ea0_tags_to_ranges() produces a single range for a zero-fille= d tag + * buffer. + */ +static void test_tags_to_ranges_zero(struct kunit *test) +{ + u8 tags[128], dtags[128]; + short r_sizes[256]; + int r_len =3D 256; + u8 r_tags[256]; + + memset(tags, 0, 128); + ea0_tags_to_ranges(tags, r_tags, r_sizes, &r_len); + KUNIT_EXPECT_EQ(test, r_len, 1); + KUNIT_EXPECT_EQ(test, r_tags[0], 0); + KUNIT_EXPECT_EQ(test, r_sizes[0], 256); + ea0_ranges_to_tags(r_tags, r_sizes, r_len, dtags); + KUNIT_EXPECT_EQ(test, memcmp(tags, dtags, 128), 0); +} + +/* + * Test that a small number of different tags is correctly transformed into + * ranges. + */ +static void test_tags_to_ranges_simple(struct kunit *test) +{ + u8 tags[128], dtags[128]; + const u8 ex_tags[] =3D { 0xa, 0x0, 0xa, 0xb, 0x0 }; + const short ex_sizes[] =3D { 1, 2, 2, 1, 250 }; + short r_sizes[256]; + int r_len =3D 256; + u8 r_tags[256]; + + memset(tags, 0, 128); + tags[0] =3D 0xa0; + tags[1] =3D 0x0a; + tags[2] =3D 0xab; + ea0_tags_to_ranges(tags, r_tags, r_sizes, &r_len); + KUNIT_EXPECT_EQ(test, r_len, 5); + KUNIT_EXPECT_EQ(test, memcmp(r_tags, ex_tags, sizeof(ex_tags)), 0); + KUNIT_EXPECT_EQ(test, memcmp(r_sizes, ex_sizes, sizeof(ex_sizes)), 0); + ea0_ranges_to_tags(r_tags, r_sizes, r_len, dtags); + KUNIT_EXPECT_EQ(test, memcmp(tags, dtags, 128), 0); +} + +/* Test that repeated 0xa0 byte produces 256 ranges of length 1. */ +static void test_tags_to_ranges_repeated(struct kunit *test) +{ + u8 tags[128], dtags[128]; + short r_sizes[256]; + int r_len =3D 256; + u8 r_tags[256]; + + memset(tags, 0xa0, 128); + ea0_tags_to_ranges(tags, r_tags, r_sizes, &r_len); + KUNIT_EXPECT_EQ(test, r_len, 256); + ea0_ranges_to_tags(r_tags, r_sizes, r_len, dtags); + KUNIT_EXPECT_EQ(test, memcmp(tags, dtags, 128), 0); +} + +/* Test that a zero-filled array is compressed into inline storage. */ +static void test_compress_zero(struct kunit *test) +{ + u8 tags[128], dtags[128]; + u64 handle; + + memset(tags, 0, 128); + handle =3D ea0_compress(tags); + KUNIT_EXPECT_EQ(test, handle & BIT_ULL(63), 0); + /* Tags are stored inline. */ + KUNIT_EXPECT_EQ(test, ea0_storage_size(handle), 8); + KUNIT_EXPECT_TRUE(test, ea0_decompress(handle, dtags)); + KUNIT_EXPECT_EQ(test, memcmp(tags, dtags, 128), 0); +} + +/* + * Test that a very small number of tag ranges ends up compressed into 8 b= ytes. + */ +static void test_compress_simple(struct kunit *test) +{ + u8 tags[128], dtags[128]; + u64 handle; + + memset(tags, 0, 128); + tags[0] =3D 0xa0; + tags[1] =3D 0x0a; + tags[2] =3D 0xab; + + handle =3D ea0_compress(tags); + KUNIT_EXPECT_EQ(test, handle & BIT_ULL(63), 0); + /* Tags are stored inline. */ + KUNIT_EXPECT_EQ(test, ea0_storage_size(handle), 8); + KUNIT_EXPECT_TRUE(test, ea0_decompress(handle, dtags)); + KUNIT_EXPECT_EQ(test, memcmp(tags, dtags, 128), 0); +} + +/* + * Generate a buffer that will contain @nranges of tag ranges, test that it + * compresses into @exp_size bytes and decompresses into the original tag + * sequence. + */ +static void compress_range_helper(struct kunit *test, int nranges, int exp= _size) +{ + u8 tags[128], dtags[128]; + u64 handle; + int i; + + memset(tags, 0, 128); + + if (nranges > 1) { + nranges--; + for (i =3D 0; i < nranges / 2; i++) + tags[i] =3D 0xab; + if (nranges % 2) + tags[nranges / 2] =3D 0xa0; + } + + handle =3D ea0_compress(tags); + KUNIT_EXPECT_EQ(test, handle & BIT_ULL(63), 0); + KUNIT_EXPECT_EQ(test, ea0_storage_size(handle), exp_size); + KUNIT_EXPECT_TRUE(test, ea0_decompress(handle, dtags)); + KUNIT_EXPECT_EQ(test, memcmp(tags, dtags, 128), 0); +} + +/* + * Test that every number of tag ranges is correctly compressed and + * decompressed. + */ +static void test_compress_ranges(struct kunit *test) +{ + int i, exp_size; + + for (i =3D 1; i <=3D 256; i++) { + if (i < 7) + exp_size =3D 8; + else if (i < 12) + exp_size =3D 16; + else if (i < 24) + exp_size =3D 32; + else if (i < 47) + exp_size =3D 64; + else + exp_size =3D 128; + compress_range_helper(test, i, exp_size); + } +} + +static struct kunit_case mtecomp_test_cases[] =3D { + KUNIT_CASE(test_tags_to_ranges_zero), + KUNIT_CASE(test_tags_to_ranges_simple), + KUNIT_CASE(test_tags_to_ranges_repeated), + KUNIT_CASE(test_compress_zero), + KUNIT_CASE(test_compress_simple), + KUNIT_CASE(test_compress_ranges), + {} +}; + +static struct kunit_suite mtecomp_test_suite =3D { + .name =3D "mtecomp", + .test_cases =3D mtecomp_test_cases, +}; +kunit_test_suites(&mtecomp_test_suite); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Alexander Potapenko "); --=20 2.41.0.255.g8b1d071c50-goog