From patchwork Tue Jun 25 12:24:00 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dev Jain X-Patchwork-Id: 13711038 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 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.lore.kernel.org (Postfix) with ESMTPS id 1863BC2BBCA for ; Tue, 25 Jun 2024 12:25:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=WlhQVtZQNbobl4QqQCda7WewsSDOMJMsVEWOPU993bU=; b=iAe1ScluRTY2S/ljT6FKqFGod3 OozqGzZWF7ypTHFan5Z97fwqC9hZ0Z7gXNNDp1aTCl1QMVlAfQGZ66jGc1w7fMj16wfZY9bXA0wIH ONAfucErqsUkwdB7xiiCLTSyl3L8ry+GtWX58qE0+24gBnP5GRkN/8BBx0iOBdMSyHZQ7VQYKq1k/ /l4VWcS5Y3skacrwiyd21kRnv79eGl78151s7uruCuv1SmbE7MRvfRMyU3eremfvKKSimFGJAa0G7 5giMxHx3NmABHMnS9kNcT3o+9Mk0VZLdNBWktCgGata+aEg2WHuq3/YgQti3qoNqitOVGQ+Z/YAGE rh2InDAQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1sM5Ec-00000002jmz-1KF5; Tue, 25 Jun 2024 12:25:18 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1sM5Dy-00000002jQh-128P for linux-arm-kernel@lists.infradead.org; Tue, 25 Jun 2024 12:24:39 +0000 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> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240625_052438_395948_F06CA083 X-CRM114-Status: GOOD ( 15.30 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org 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/selftests/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 = mmap((void *) (1UL << 29), MAP_CHUNK_SIZE, PROT_READ | + PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); + + if (ptr == 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 = 0; i < NR_CHUNKS_4G + 3; ++i) { + ptr[i] = mmap(NULL, MAP_CHUNK_SIZE, PROT_READ | PROT_WRITE, + MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); + + if (ptr[i] == MAP_FAILED) { + if (validate_address_hint()) + ksft_exit_fail_msg("VA exhaustion failed\n"); + break; + } + } + + chunks = i; + + ret = (chunks < NR_CHUNKS_4G); + ksft_test_result(ret, "mmapped chunks under 4GB\n"); + + /* parse /proc/self/maps, confirm 32 bit VA mappings */ + file = fopen("/proc/self/maps", "r"); + if (!file) + ksft_exit_fail_perror("/proc/self/maps"); + + ret = 0; + while (fgets(line, sizeof(line), file)) { + const char *whitespace_loc, *hyphen_loc; + + hyphen_loc = strchr(line, '-'); + whitespace_loc = strchr(line, ' '); + + if (!(hyphen_loc && whitespace_loc)) + ksft_exit_fail_msg("Unexpected format\n"); + + ret |= ((hyphen_loc - line > 8) || + (whitespace_loc - hyphen_loc > 9)); + } + + ksft_test_result(!ret, "Memory map within 32 bits\n"); + + for (i = 0; i < chunks; ++i) + munmap(ptr[i], MAP_CHUNK_SIZE); + + ksft_finished(); +}