From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qk0-f199.google.com (mail-qk0-f199.google.com [209.85.220.199]) by kanga.kvack.org (Postfix) with ESMTP id 8D4086B0260 for ; Thu, 19 Oct 2017 19:24:53 -0400 (EDT) Received: by mail-qk0-f199.google.com with SMTP id w134so9743913qkb.13 for ; Thu, 19 Oct 2017 16:24:53 -0700 (PDT) Received: from userp1040.oracle.com (userp1040.oracle.com. [156.151.31.81]) by mx.google.com with ESMTPS id v24si1897164qtc.170.2017.10.19.16.24.52 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 19 Oct 2017 16:24:52 -0700 (PDT) Subject: Re: [PATCH V3] selftests/vm: Add tests validating mremap mirror functionality References: <20171018055502.31752-1-khandual@linux.vnet.ibm.com> From: Mike Kravetz Message-ID: <472ed67c-7c14-29d3-ac22-e9340a05bc06@oracle.com> Date: Thu, 19 Oct 2017 16:24:46 -0700 MIME-Version: 1.0 In-Reply-To: <20171018055502.31752-1-khandual@linux.vnet.ibm.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Anshuman Khandual , linux-mm@kvack.org, linux-kernel@vger.kernel.org Cc: mhocko@kernel.org, shuahkh@osg.samsung.com On 10/17/2017 10:55 PM, Anshuman Khandual wrote: > 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 The tests themselves look fine. However, they are pretty simple and could very easily be combined into one 'mremap_mirror.c' file. I would prefer that they be combined, but it is not a deal breaker. Reviewed-by: Mike Kravetz > --- > > Changes in V3: > > - 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 | 2 + > .../selftests/vm/mremap_mirror_private_anon.c | 41 +++++++++++++++ > .../selftests/vm/mremap_mirror_shared_anon.c | 58 ++++++++++++++++++++++ > tools/testing/selftests/vm/run_vmtests | 22 ++++++++ > 4 files changed, 123 insertions(+) > create mode 100644 tools/testing/selftests/vm/mremap_mirror_private_anon.c > create mode 100644 tools/testing/selftests/vm/mremap_mirror_shared_anon.c > > diff --git a/tools/testing/selftests/vm/Makefile b/tools/testing/selftests/vm/Makefile > index cbb29e4..6401f91 100644 > --- a/tools/testing/selftests/vm/Makefile > +++ b/tools/testing/selftests/vm/Makefile > @@ -17,6 +17,8 @@ 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_shared_anon > +TEST_GEN_FILES += mremap_mirror_private_anon > > TEST_PROGS := run_vmtests > > diff --git a/tools/testing/selftests/vm/mremap_mirror_private_anon.c b/tools/testing/selftests/vm/mremap_mirror_private_anon.c > new file mode 100644 > index 0000000..e4fa85b > --- /dev/null > +++ b/tools/testing/selftests/vm/mremap_mirror_private_anon.c > @@ -0,0 +1,41 @@ > +/* > + * Test to verify mirror functionality with mremap() system > + * call for private anon mappings. Any attempt to create a > + * mirror mapping for an anon private one should 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 main(int argc, char *argv[]) > +{ > + unsigned long alloc_size; > + char *ptr, *mirror_ptr; > + > + alloc_size = sysconf(_SC_PAGESIZE) * NR_PAGES; > + 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; > +} > diff --git a/tools/testing/selftests/vm/mremap_mirror_shared_anon.c b/tools/testing/selftests/vm/mremap_mirror_shared_anon.c > new file mode 100644 > index 0000000..1d5c838 > --- /dev/null > +++ b/tools/testing/selftests/vm/mremap_mirror_shared_anon.c > @@ -0,0 +1,58 @@ > +/* > + * Test to verify mirror functionality with mremap() system > + * call for shared anon mappings. The 'mirrored' buffer will > + * match element to element with that of the original one. > + * > + * 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(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 main(int argc, char *argv[]) > +{ > + unsigned long alloc_size; > + char *ptr, *mirror_ptr; > + > + alloc_size = sysconf(_SC_PAGESIZE) * NR_PAGES; > + 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(ptr, mirror_ptr, alloc_size)) > + return 1; > + return 0; > +} > diff --git a/tools/testing/selftests/vm/run_vmtests b/tools/testing/selftests/vm/run_vmtests > index 07548a1..4c8d111 100755 > --- a/tools/testing/selftests/vm/run_vmtests > +++ b/tools/testing/selftests/vm/run_vmtests > @@ -176,4 +176,26 @@ else > echo "[PASS]" > fi > > +echo "-----------------------------" > +echo "mremap_mirror_private_anon" > +echo "-----------------------------" > +./mremap_mirror_private_anon > +if [ $? -ne 0 ]; then > + echo "[FAIL]" > + exitcode=1 > +else > + echo "[PASS]" > +fi > + > +echo "-----------------------------" > +echo "mremap_mirror_shared_anon" > +echo "-----------------------------" > +./mremap_mirror_shared_anon > +if [ $? -ne 0 ]; then > + echo "[FAIL]" > + exitcode=1 > +else > + echo "[PASS]" > +fi > + > exit $exitcode > -- Mike Kravetz -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. 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