[v6,5/5] selftests/mm: add UFFDIO_MOVE ioctl test

Message ID	20231206103702.3873743-6-surenb@google.com (mailing list archive)
State	Accepted
Commit	a2bf6a9ca80532b75f8f8b6a1cd75ef7e5150576
Headers	show Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="J3zB7Ifa" Date: Wed, 6 Dec 2023 02:36:59 -0800 In-Reply-To: <20231206103702.3873743-1-surenb@google.com> Precedence: bulk Mime-Version: 1.0 References: <20231206103702.3873743-1-surenb@google.com> Message-ID: <20231206103702.3873743-6-surenb@google.com> Subject: [PATCH v6 5/5] selftests/mm: add UFFDIO_MOVE ioctl test From: Suren Baghdasaryan <surenb@google.com> To: akpm@linux-foundation.org Cc: viro@zeniv.linux.org.uk, brauner@kernel.org, shuah@kernel.org, aarcange@redhat.com, lokeshgidra@google.com, peterx@redhat.com, david@redhat.com, ryan.roberts@arm.com, hughd@google.com, mhocko@suse.com, axelrasmussen@google.com, rppt@kernel.org, willy@infradead.org, Liam.Howlett@oracle.com, jannh@google.com, zhangpeng362@huawei.com, bgeffon@google.com, kaleshsingh@google.com, ngeoffray@google.com, jdduke@google.com, surenb@google.com, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, kernel-team@android.com Content-Type: text/plain; charset="UTF-8"
Series	userfaultfd move option \| expand [v6,0/5] userfaultfd move option [v6,1/5] mm/rmap: support move to different root anon_vma in folio_move_anon_rmap() [v6,2/5] userfaultfd: UFFDIO_MOVE uABI [v6,3/5] selftests/mm: call uffd_test_ctx_clear at the end of the test [v6,4/5] selftests/mm: add uffd_test_case_ops to allow test case-specific operations [v6,5/5] selftests/mm: add UFFDIO_MOVE ioctl test

diff --git a/tools/testing/selftests/mm/uffd-common.c b/tools/testing/selftests/mm/uffd-common.c index fb3bbc77fd00..b0ac0ec2356d 100644 --- a/tools/testing/selftests/mm/uffd-common.c +++ b/tools/testing/selftests/mm/uffd-common.c @@ -631,6 +631,30 @@ int copy_page(int ufd, unsigned long offset, bool wp) return __copy_page(ufd, offset, false, wp); } +int move_page(int ufd, unsigned long offset, unsigned long len) +{ + struct uffdio_move uffdio_move; + + if (offset + len > nr_pages * page_size) + err("unexpected offset %lu and length %lu\n", offset, len); + uffdio_move.dst = (unsigned long) area_dst + offset; + uffdio_move.src = (unsigned long) area_src + offset; + uffdio_move.len = len; + uffdio_move.mode = UFFDIO_MOVE_MODE_ALLOW_SRC_HOLES; + uffdio_move.move = 0; + if (ioctl(ufd, UFFDIO_MOVE, &uffdio_move)) { + /* real retval in uffdio_move.move */ + if (uffdio_move.move != -EEXIST) + err("UFFDIO_MOVE error: %"PRId64, + (int64_t)uffdio_move.move); + wake_range(ufd, uffdio_move.dst, len); + } else if (uffdio_move.move != len) { + err("UFFDIO_MOVE error: %"PRId64, (int64_t)uffdio_move.move); + } else + return 1; + return 0; +} + int uffd_open_dev(unsigned int flags) { int fd, uffd; diff --git a/tools/testing/selftests/mm/uffd-common.h b/tools/testing/selftests/mm/uffd-common.h index 774595ee629e..cb055282c89c 100644 --- a/tools/testing/selftests/mm/uffd-common.h +++ b/tools/testing/selftests/mm/uffd-common.h @@ -119,6 +119,7 @@ void wp_range(int ufd, __u64 start, __u64 len, bool wp); void uffd_handle_page_fault(struct uffd_msg *msg, struct uffd_args *args); int __copy_page(int ufd, unsigned long offset, bool retry, bool wp); int copy_page(int ufd, unsigned long offset, bool wp); +int move_page(int ufd, unsigned long offset, unsigned long len); void *uffd_poll_thread(void *arg); int uffd_open_dev(unsigned int flags); diff --git a/tools/testing/selftests/mm/uffd-unit-tests.c b/tools/testing/selftests/mm/uffd-unit-tests.c index debc423bdbf4..d8091523c2df 100644 --- a/tools/testing/selftests/mm/uffd-unit-tests.c +++ b/tools/testing/selftests/mm/uffd-unit-tests.c @@ -23,6 +23,9 @@ #define MEM_ALL (MEM_ANON | MEM_SHMEM | MEM_SHMEM_PRIVATE | \ MEM_HUGETLB | MEM_HUGETLB_PRIVATE) +#define ALIGN_UP(x, align_to) \ + ((__typeof__(x))((((unsigned long)(x)) + ((align_to)-1)) & ~((align_to)-1))) + struct mem_type { const char *name; unsigned int mem_flag; @@ -1064,6 +1067,178 @@ static void uffd_poison_test(uffd_test_args_t *targs) uffd_test_pass(); } +static void +uffd_move_handle_fault_common(struct uffd_msg *msg, struct uffd_args *args, + unsigned long len) +{ + unsigned long offset; + + if (msg->event != UFFD_EVENT_PAGEFAULT) + err("unexpected msg event %u", msg->event); + + if (msg->arg.pagefault.flags & + (UFFD_PAGEFAULT_FLAG_WP | UFFD_PAGEFAULT_FLAG_MINOR | UFFD_PAGEFAULT_FLAG_WRITE)) + err("unexpected fault type %llu", msg->arg.pagefault.flags); + + offset = (char *)(unsigned long)msg->arg.pagefault.address - area_dst; + offset &= ~(len-1); + + if (move_page(uffd, offset, len)) + args->missing_faults++; +} + +static void uffd_move_handle_fault(struct uffd_msg *msg, + struct uffd_args *args) +{ + uffd_move_handle_fault_common(msg, args, page_size); +} + +static void uffd_move_pmd_handle_fault(struct uffd_msg *msg, + struct uffd_args *args) +{ + uffd_move_handle_fault_common(msg, args, read_pmd_pagesize()); +} + +static void +uffd_move_test_common(uffd_test_args_t *targs, unsigned long chunk_size, + void (*handle_fault)(struct uffd_msg *msg, struct uffd_args *args)) +{ + unsigned long nr; + pthread_t uffd_mon; + char c; + unsigned long long count; + struct uffd_args args = { 0 }; + char *orig_area_src, *orig_area_dst; + unsigned long step_size, step_count; + unsigned long src_offs = 0; + unsigned long dst_offs = 0; + + /* Prevent source pages from being mapped more than once */ + if (madvise(area_src, nr_pages * page_size, MADV_DONTFORK)) + err("madvise(MADV_DONTFORK) failure"); + + if (uffd_register(uffd, area_dst, nr_pages * page_size, + true, false, false)) + err("register failure"); + + args.handle_fault = handle_fault; + if (pthread_create(&uffd_mon, NULL, uffd_poll_thread, &args)) + err("uffd_poll_thread create"); + + step_size = chunk_size / page_size; + step_count = nr_pages / step_size; + + if (chunk_size > page_size) { + char *aligned_src = ALIGN_UP(area_src, chunk_size); + char *aligned_dst = ALIGN_UP(area_dst, chunk_size); + + if (aligned_src != area_src || aligned_dst != area_dst) { + src_offs = (aligned_src - area_src) / page_size; + dst_offs = (aligned_dst - area_dst) / page_size; + step_count--; + } + orig_area_src = area_src; + orig_area_dst = area_dst; + area_src = aligned_src; + area_dst = aligned_dst; + } + + /* + * Read each of the pages back using the UFFD-registered mapping. We + * expect that the first time we touch a page, it will result in a missing + * fault. uffd_poll_thread will resolve the fault by moving source + * page to destination. + */ + for (nr = 0; nr < step_count * step_size; nr += step_size) { + unsigned long i; + + /* Check area_src content */ + for (i = 0; i < step_size; i++) { + count = *area_count(area_src, nr + i); + if (count != count_verify[src_offs + nr + i]) + err("nr %lu source memory invalid %llu %llu\n", + nr + i, count, count_verify[src_offs + nr + i]); + } + + /* Faulting into area_dst should move the page or the huge page */ + for (i = 0; i < step_size; i++) { + count = *area_count(area_dst, nr + i); + if (count != count_verify[dst_offs + nr + i]) + err("nr %lu memory corruption %llu %llu\n", + nr, count, count_verify[dst_offs + nr + i]); + } + + /* Re-check area_src content which should be empty */ + for (i = 0; i < step_size; i++) { + count = *area_count(area_src, nr + i); + if (count != 0) + err("nr %lu move failed %llu %llu\n", + nr, count, count_verify[src_offs + nr + i]); + } + } + if (step_size > page_size) { + area_src = orig_area_src; + area_dst = orig_area_dst; + } + + if (write(pipefd[1], &c, sizeof(c)) != sizeof(c)) + err("pipe write"); + if (pthread_join(uffd_mon, NULL)) + err("join() failed"); + + if (args.missing_faults != step_count || args.minor_faults != 0) + uffd_test_fail("stats check error"); + else + uffd_test_pass(); +} + +static void uffd_move_test(uffd_test_args_t *targs) +{ + uffd_move_test_common(targs, page_size, uffd_move_handle_fault); +} + +static void uffd_move_pmd_test(uffd_test_args_t *targs) +{ + uffd_move_test_common(targs, read_pmd_pagesize(), + uffd_move_pmd_handle_fault); +} + +static int prevent_hugepages(const char **errmsg) +{ + /* This should be done before source area is populated */ + if (madvise(area_src, nr_pages * page_size, MADV_NOHUGEPAGE)) { + /* Ignore only if CONFIG_TRANSPARENT_HUGEPAGE=n */ + if (errno != EINVAL) { + if (errmsg) + *errmsg = "madvise(MADV_NOHUGEPAGE) failed"; + return -errno; + } + } + return 0; +} + +static int request_hugepages(const char **errmsg) +{ + /* This should be done before source area is populated */ + if (madvise(area_src, nr_pages * page_size, MADV_HUGEPAGE)) { + if (errmsg) { + *errmsg = (errno == EINVAL) ? + "CONFIG_TRANSPARENT_HUGEPAGE is not set" : + "madvise(MADV_HUGEPAGE) failed"; + } + return -errno; + } + return 0; +} + +struct uffd_test_case_ops uffd_move_test_case_ops = { + .post_alloc = prevent_hugepages, +}; + +struct uffd_test_case_ops uffd_move_test_pmd_case_ops = { + .post_alloc = request_hugepages, +}; + /* * Test the returned uffdio_register.ioctls with different register modes. * Note that _UFFDIO_ZEROPAGE is tested separately in the zeropage test. @@ -1141,6 +1316,20 @@ uffd_test_case_t uffd_tests[] = { .mem_targets = MEM_ALL, .uffd_feature_required = 0, }, + { + .name = "move", + .uffd_fn = uffd_move_test, + .mem_targets = MEM_ANON, + .uffd_feature_required = UFFD_FEATURE_MOVE, + .test_case_ops = &uffd_move_test_case_ops, + }, + { + .name = "move-pmd", + .uffd_fn = uffd_move_pmd_test, + .mem_targets = MEM_ANON, + .uffd_feature_required = UFFD_FEATURE_MOVE, + .test_case_ops = &uffd_move_test_pmd_case_ops, + }, { .name = "wp-fork", .uffd_fn = uffd_wp_fork_test,

[v6,5/5] selftests/mm: add UFFDIO_MOVE ioctl test

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