From nobody Wed Dec 17 21:11:29 2025 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id EC77D1553AF; Tue, 25 Jun 2024 12:24:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719318279; cv=none; b=dbIYE5i9EOmT9CxTVjDPcvOMQKx6NlLc4jJsyTawwcsDx9tQWDokmqYDBsHFm5GWz8jDJkIkkdTNCDwGReT00K3jB9EJcJeaOP/VUZs8LEWXSQyctQbP/+XmHRpfz4N8wqWTbc+aZfAvEUNaigEn+Z7kVUeViBDQi29m6DOg46s= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719318279; c=relaxed/simple; bh=MVs5z0/RG/otjMsFB/U3mOThMHQjhs1d7gbRxQCETTM=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=LSHYiNpsu2uiQm4kCgMgasWFdWyxz0qkq1LXV6X/TIm4Elyu/LD1brYY2uW7/1vclERADUbga/mIeAvXdvNOO0J0xtRoIVGlIeSCFDK9LwY5r9tU3QTbHYCleWOIe+mQJzIaQD25sgqIuRu9R430gZMKdBgnopWOKxtUFANJOYw= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 795F5339; Tue, 25 Jun 2024 05:25:02 -0700 (PDT) Received: from e116581.blr.arm.com (e116581.arm.com [10.162.41.12]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id B600F3F766; Tue, 25 Jun 2024 05:24:32 -0700 (PDT) From: Dev Jain To: shuah@kernel.org, linux-arm-kernel@lists.infradead.org, linux-kselftest@vger.kernel.org, Catalin.Marinas@arm.com, will@kernel.org Cc: broonie@kernel.org, ryan.roberts@arm.com, rob.herring@arm.com, mark.rutland@arm.com, linux@armlinux.org.uk, suzuki.poulose@arm.com, Anshuman.Khandual@arm.com, aneesh.kumar@kernel.org, linux-kernel@vger.kernel.org, Dev Jain Subject: [PATCH v3 1/9] selftests/arm: Add mm test Date: Tue, 25 Jun 2024 17:54:00 +0530 Message-Id: <20240625122408.1439097-2-dev.jain@arm.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20240625122408.1439097-1-dev.jain@arm.com> References: <20240625122408.1439097-1-dev.jain@arm.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" This patch tests the 4GB VA restriction for 32-bit processes; it is required to test the compat layer, whether the kernel knows that it is running a 32-bit process or not. Chunks are allocated until the VA gets exhausted; mmap must fail beyond 4GB. This is asserted against the VA mappings found in /proc/self/maps. Signed-off-by: Dev Jain --- v2->v3: - Split into multiple testcases tools/testing/selftests/arm/mm/compat_va.c | 89 ++++++++++++++++++++++ 1 file changed, 89 insertions(+) create mode 100644 tools/testing/selftests/arm/mm/compat_va.c diff --git a/tools/testing/selftests/arm/mm/compat_va.c b/tools/testing/sel= ftests/arm/mm/compat_va.c new file mode 100644 index 000000000000..20aa419eff29 --- /dev/null +++ b/tools/testing/selftests/arm/mm/compat_va.c @@ -0,0 +1,89 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2024 ARM Limited + * + * Author : Dev Jain + * + * Tests 4GB VA restriction for 32 bit process + */ + +#define _GNU_SOURCE +#include +#include +#include +#include + +#include +#include + +#define MAP_CHUNK_SIZE SZ_1M +#define NR_CHUNKS_4G ((SZ_1G / MAP_CHUNK_SIZE) * 4) /* prevent overflow */ + +static int validate_address_hint(void) +{ + char *ptr; + + ptr =3D mmap((void *) (1UL << 29), MAP_CHUNK_SIZE, PROT_READ | + PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); + + if (ptr =3D=3D MAP_FAILED) + return 0; + + return -1; +} + +int main(int argc, char *argv[]) +{ + char *ptr[NR_CHUNKS_4G + 3]; + char line[1000]; + int chunks; + FILE *file; + int ret; + int i; + + ksft_print_header(); + ksft_set_plan(2); + + /* try allocation beyond 4 GB */ + for (i =3D 0; i < NR_CHUNKS_4G + 3; ++i) { + ptr[i] =3D mmap(NULL, MAP_CHUNK_SIZE, PROT_READ | PROT_WRITE, + MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); + + if (ptr[i] =3D=3D MAP_FAILED) { + if (validate_address_hint()) + ksft_exit_fail_msg("VA exhaustion failed\n"); + break; + } + } + + chunks =3D i; + + ret =3D (chunks < NR_CHUNKS_4G); + ksft_test_result(ret, "mmapped chunks under 4GB\n"); + + /* parse /proc/self/maps, confirm 32 bit VA mappings */ + file =3D fopen("/proc/self/maps", "r"); + if (!file) + ksft_exit_fail_perror("/proc/self/maps"); + + ret =3D 0; + while (fgets(line, sizeof(line), file)) { + const char *whitespace_loc, *hyphen_loc; + + hyphen_loc =3D strchr(line, '-'); + whitespace_loc =3D strchr(line, ' '); + + if (!(hyphen_loc && whitespace_loc)) + ksft_exit_fail_msg("Unexpected format\n"); + + ret |=3D ((hyphen_loc - line > 8) || + (whitespace_loc - hyphen_loc > 9)); + } + + ksft_test_result(!ret, "Memory map within 32 bits\n"); + + for (i =3D 0; i < chunks; ++i) + munmap(ptr[i], MAP_CHUNK_SIZE); + + ksft_finished(); +} --=20 2.39.2