From mboxrd@z Thu Jan 1 00:00:00 1970 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1EDFCCA0FFB for ; Tue, 5 Sep 2023 16:35:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229460AbjIEQfN (ORCPT ); Tue, 5 Sep 2023 12:35:13 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55106 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242911AbjIEQLD (ORCPT ); Tue, 5 Sep 2023 12:11:03 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 51F8049FA for ; Tue, 5 Sep 2023 09:04:04 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 7969660A50 for ; Tue, 5 Sep 2023 16:02:55 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id CBCBAC433C7; Tue, 5 Sep 2023 16:02:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1693929774; bh=cGsibz7lEjhc5ffsV4wz5X7YCYIQyrpF7tlkxjNqNTI=; h=Date:To:From:Subject:From; b=bZ4SIZ8OlqwuU4mLa7MrRsWgEiCe0RtAc+9zLOYgHJbvyj7ng5emItGex9CFJGmOt SNSXYkslAeOVXiEeclwRKdpjDfqVVlb2HsjuOqFY9fp/ObW8MvurgulKsslMTv0XZX sMu9yKAh9zNs9ttreq5uS1I7+j6AFtWIktDz3uxs= Date: Tue, 05 Sep 2023 09:02:54 -0700 To: mm-commits@vger.kernel.org, vbabka@suse.cz, torvalds@linux-foundation.org, surenb@google.com, shuah@kernel.org, paulmck@kernel.org, mhocko@suse.com, lstoakes@gmail.com, lokeshgidra@google.com, Liam.Howlett@oracle.com, kirill@shutemov.name, kaleshsingh@google.com, joel@joelfernandes.org, akpm@linux-foundation.org From: Andrew Morton Subject: + selftests-mm-add-a-test-for-remapping-within-a-range.patch added to mm-unstable branch Message-Id: <20230905160254.CBCBAC433C7@smtp.kernel.org> Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org The patch titled Subject: selftests: mm: add a test for remapping within a range has been added to the -mm mm-unstable branch. Its filename is selftests-mm-add-a-test-for-remapping-within-a-range.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/selftests-mm-add-a-test-for-remapping-within-a-range.patch This patch will later appear in the mm-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: "Joel Fernandes (Google)" Subject: selftests: mm: add a test for remapping within a range Date: Sun, 3 Sep 2023 15:13:27 +0000 Move a block of memory within a memory range. Any alignment optimization on the source address may cause corruption. Verify using kselftest that it works. I have also verified with tracing that such optimization does not happen due to this check in can_align_down(): if (!for_stack && vma->vm_start != addr_to_align) return false; Link: https://lkml.kernel.org/r/20230903151328.2981432-7-joel@joelfernandes.org Signed-off-by: Joel Fernandes (Google) Reviewed-by: Lorenzo Stoakes Cc: Kalesh Singh Cc: "Kirill A. Shutemov" Cc: Liam R. Howlett Cc: Linus Torvalds Cc: Lokesh Gidra Cc: Michal Hocko Cc: Paul E. McKenney Cc: Shuah Khan Cc: Suren Baghdasaryan Cc: Vlastimil Babka Signed-off-by: Andrew Morton --- tools/testing/selftests/mm/mremap_test.c | 79 ++++++++++++++++++++- 1 file changed, 78 insertions(+), 1 deletion(-) --- a/tools/testing/selftests/mm/mremap_test.c~selftests-mm-add-a-test-for-remapping-within-a-range +++ a/tools/testing/selftests/mm/mremap_test.c @@ -23,6 +23,7 @@ #define VALIDATION_NO_THRESHOLD 0 /* Verify the entire region */ #define MIN(X, Y) ((X) < (Y) ? (X) : (Y)) +#define SIZE_MB(m) ((size_t)m * (1024 * 1024)) struct config { unsigned long long src_alignment; @@ -227,6 +228,79 @@ out: } /* + * Verify that an mremap within a range does not cause corruption + * of unrelated part of range. + * + * Consider the following range which is 2MB aligned and is + * a part of a larger 20MB range which is not shown. Each + * character is 256KB below making the source and destination + * 2MB each. The lower case letters are moved (s to d) and the + * upper case letters are not moved. The below test verifies + * that the upper case S letters are not corrupted by the + * adjacent mremap. + * + * |DDDDddddSSSSssss| + */ +static void mremap_move_within_range(char pattern_seed) +{ + char *test_name = "mremap mremap move within range"; + void *src, *dest; + int i, success = 1; + + size_t size = SIZE_MB(20); + void *ptr = mmap(NULL, size, PROT_READ | PROT_WRITE, + MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); + if (ptr == MAP_FAILED) { + perror("mmap"); + success = 0; + goto out; + } + memset(ptr, 0, size); + + src = ptr + SIZE_MB(6); + src = (void *)((unsigned long)src & ~(SIZE_MB(2) - 1)); + + /* Set byte pattern for source block. */ + srand(pattern_seed); + for (i = 0; i < SIZE_MB(2); i++) { + ((char *)src)[i] = (char) rand(); + } + + dest = src - SIZE_MB(2); + + void *new_ptr = mremap(src + SIZE_MB(1), SIZE_MB(1), SIZE_MB(1), + MREMAP_MAYMOVE | MREMAP_FIXED, dest + SIZE_MB(1)); + if (new_ptr == MAP_FAILED) { + perror("mremap"); + success = 0; + goto out; + } + + /* Verify byte pattern after remapping */ + srand(pattern_seed); + for (i = 0; i < SIZE_MB(1); i++) { + char c = (char) rand(); + + if (((char *)src)[i] != c) { + ksft_print_msg("Data at src at %d got corrupted due to unrelated mremap\n", + i); + ksft_print_msg("Expected: %#x\t Got: %#x\n", c & 0xff, + ((char *) src)[i] & 0xff); + success = 0; + } + } + +out: + if (munmap(ptr, size) == -1) + perror("munmap"); + + if (success) + ksft_test_result_pass("%s\n", test_name); + else + ksft_test_result_fail("%s\n", test_name); +} + +/* * Returns the start address of the mapping on success, else returns * NULL on failure. */ @@ -491,6 +565,7 @@ int main(int argc, char **argv) unsigned int threshold_mb = VALIDATION_DEFAULT_THRESHOLD; unsigned int pattern_seed; int num_expand_tests = 2; + int num_misc_tests = 1; struct test test_cases[MAX_TEST] = {}; struct test perf_test_cases[MAX_PERF_TEST]; int page_size; @@ -572,7 +647,7 @@ int main(int argc, char **argv) (threshold_mb * _1MB >= _1GB); ksft_set_plan(ARRAY_SIZE(test_cases) + (run_perf_tests ? - ARRAY_SIZE(perf_test_cases) : 0) + num_expand_tests); + ARRAY_SIZE(perf_test_cases) : 0) + num_expand_tests + num_misc_tests); for (i = 0; i < ARRAY_SIZE(test_cases); i++) run_mremap_test_case(test_cases[i], &failures, threshold_mb, @@ -590,6 +665,8 @@ int main(int argc, char **argv) fclose(maps_fp); + mremap_move_within_range(pattern_seed); + if (run_perf_tests) { ksft_print_msg("\n%s\n", "mremap HAVE_MOVE_PMD/PUD optimization time comparison for 1GB region:"); _ Patches currently in -mm which might be from joel@joelfernandes.org are mm-vmalloc-add-a-safer-version-of-find_vm_area-for-debug.patch mm-mremap-optimize-the-start-addresses-in-move_page_tables.patch mm-mremap-allow-moves-within-the-same-vma-for-stack-moves.patch selftests-mm-fix-failure-case-when-new-remap-region-was-not-found.patch selftests-mm-add-a-test-for-mutually-aligned-moves-pmd-size.patch selftests-mm-add-a-test-for-remapping-to-area-immediately-after-existing-mapping.patch selftests-mm-add-a-test-for-remapping-within-a-range.patch selftests-mm-add-a-test-for-moving-from-an-offset-from-start-of-mapping.patch