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 <[email protected]> Signed-off-by: Anshuman Khandual <[email protected]> --- 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 <stdio.h> +#include <string.h> +#include <unistd.h> +#include <errno.h> +#include <sys/mman.h> +#include <sys/time.h> + +#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 <stdio.h> +#include <string.h> +#include <unistd.h> +#include <errno.h> +#include <sys/mman.h> +#include <sys/time.h> + +#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 -- 1.8.5.2
