From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752103AbdJ3DSR (ORCPT ); Sun, 29 Oct 2017 23:18:17 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:53814 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751673AbdJ3DSQ (ORCPT ); Sun, 29 Oct 2017 23:18:16 -0400 From: Anshuman Khandual To: linux-mm@kvack.org, linux-kernel@vger.kernel.org Cc: mike.kravetz@oracle.com, mhocko@kernel.org, shuahkh@osg.samsung.com Subject: [PATCH] selftests/vm: Add tests validating mremap mirror functionality Date: Mon, 30 Oct 2017 08:48:08 +0530 X-Mailer: git-send-email 2.9.3 X-TM-AS-GCONF: 00 x-cbid: 17103003-0016-0000-0000-000004FB4258 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 17103003-0017-0000-0000-00002836C3FB Message-Id: <20171030031808.24934-1-khandual@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2017-10-30_01:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 impostorscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1707230000 definitions=main-1710300045 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This adds two tests to validate mirror functionality with mremap() system call on shared and private anon mappings. After the commit dba58d3b8c5 ("mm/mremap: fail map duplication attempts for private mappings"), any attempt to mirror private anon mapping will fail. Suggested-by: Mike Kravetz Signed-off-by: Anshuman Khandual Reviewed-by: Mike Kravetz --- Changes in V4: - Folded these two test files into just one as per Mike - Did some renaming of functions, cleans ups etc Changes in V3: (https://patchwork.kernel.org/patch/10013469/) - Fail any attempts to mirror an existing anon private mapping - Updated run_vmtests to include these new mremap tests - Updated the commit message Changes in V2: (https://patchwork.kernel.org/patch/9861259/) - Added a test for private anon mappings - Used sysconf(_SC_PAGESIZE) instead of hard coding page size - Used MREMAP_MAYMOVE instead of hard coding the flag value 1 Original V1: (https://patchwork.kernel.org/patch/9854415/) tools/testing/selftests/vm/Makefile | 1 + tools/testing/selftests/vm/mremap_mirror.c | 96 ++++++++++++++++++++++++++++++ tools/testing/selftests/vm/run_vmtests | 10 ++++ 3 files changed, 107 insertions(+) create mode 100644 tools/testing/selftests/vm/mremap_mirror.c diff --git a/tools/testing/selftests/vm/Makefile b/tools/testing/selftests/vm/Makefile index cbb29e4..27f1967 100644 --- a/tools/testing/selftests/vm/Makefile +++ b/tools/testing/selftests/vm/Makefile @@ -17,6 +17,7 @@ TEST_GEN_FILES += transhuge-stress TEST_GEN_FILES += userfaultfd TEST_GEN_FILES += mlock-random-test TEST_GEN_FILES += virtual_address_range +TEST_GEN_FILES += mremap_mirror TEST_PROGS := run_vmtests diff --git a/tools/testing/selftests/vm/mremap_mirror.c b/tools/testing/selftests/vm/mremap_mirror.c new file mode 100644 index 0000000..41cdba5 --- /dev/null +++ b/tools/testing/selftests/vm/mremap_mirror.c @@ -0,0 +1,96 @@ +/* + * Test to verify mirror functionality with mremap() system + * call for shared and private anon mappings. In shared anon + * mapping case, the 'mirrored' buffer will match element to + * element with that of the original one. But any attempts + * to create a mirror buffer for an anon private one should + * just fail. + * + * Copyright (C) 2017 Anshuman Khandual, IBM Corporation + * + * Licensed under GPL V2 + */ +#define _GNU_SOURCE +#include +#include +#include +#include +#include +#include + +#define PATTERN 0xbe +#define NR_PAGES 10 + +int test_mirror_shared(char *old, char *new, unsigned long size) +{ + unsigned long i; + + for (i = 0; i < size; i++) { + if (new[i] != old[i]) { + printf("Mismatch at new[%lu] expected \ + %d received %d\n", i, old[i], new[i]); + return 1; + } + } + return 0; +} + +int mirror_anon_shared(unsigned long alloc_size) +{ + char *ptr, *mirror_ptr; + + ptr = mmap(NULL, alloc_size, PROT_READ | PROT_WRITE, + MAP_SHARED | MAP_ANONYMOUS, -1, 0); + if (ptr == MAP_FAILED) { + perror("map() failed"); + return -1; + } + memset(ptr, PATTERN, alloc_size); + + mirror_ptr = (char *) mremap(ptr, 0, alloc_size, MREMAP_MAYMOVE); + if (mirror_ptr == MAP_FAILED) { + perror("mremap() failed"); + return -1; + } + + if (test_mirror_shared(ptr, mirror_ptr, alloc_size)) + return 1; + + return 0; +} + +int mirror_anon_private(unsigned long alloc_size) +{ + char *ptr, *mirror_ptr; + + ptr = mmap(NULL, alloc_size, PROT_READ | PROT_WRITE, + MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); + if (ptr == MAP_FAILED) { + perror("map() failed"); + return -1; + } + memset(ptr, PATTERN, alloc_size); + + mirror_ptr = (char *) mremap(ptr, 0, alloc_size, MREMAP_MAYMOVE); + if (mirror_ptr == MAP_FAILED) + return 0; + + printf("Mirror attempt on private anon mapping should have failed\n"); + return 1; +} + +int main(int argc, char *argv[]) +{ + unsigned long alloc_size; + int ret; + + alloc_size = sysconf(_SC_PAGESIZE) * NR_PAGES; + ret = mirror_anon_private(alloc_size); + if (ret) + return ret; + + ret = mirror_anon_shared(alloc_size); + if (ret) + return ret; + return 0; +} diff --git a/tools/testing/selftests/vm/run_vmtests b/tools/testing/selftests/vm/run_vmtests index 07548a1..7214aa2 100755 --- a/tools/testing/selftests/vm/run_vmtests +++ b/tools/testing/selftests/vm/run_vmtests @@ -176,4 +176,14 @@ else echo "[PASS]" fi +echo "-----------------------------" +echo "mremap_mirror" +echo "-----------------------------" +./mremap_mirror +if [ $? -ne 0 ]; then + echo "[FAIL]" + exitcode=1 +else + echo "[PASS]" +fi exit $exitcode -- 1.8.5.2